* [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure
@ 2012-06-04 12:21 pablo
2012-06-04 12:21 ` [PATCH 1/7] netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names pablo
` (6 more replies)
0 siblings, 7 replies; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
Hi!
This is a new try to provide a full user-space connection tracking helper
infrastructure. Some of you, that check my tree, already know that I've been
working on this since time ago.
Previous approaches had important limitations and the integration with iptables
was not precisely nice.
The initial patches prepare the field for the introduction of the
cthelper infrastructure:
1) allocate fixed area for helper name, as a side effect, the initialization
code of the kernel-space helpers looks better IMO.
2) allow variable length conntrack extensions.
3) add support for variable length helper extensions.
4) improve integration between nfnetlink_queue and ctnetlink. Now, you don't
have to open two handlers listen to packets via nfqueue and receive
events via ctnetlink. Instead, you can enable one flag to get the conntrack
data together with the packet via nfqueue.
5) improve integration of packet mangling and nf_conntrack. This has been
a long standing issue. If you mangle one TCP packet in user-space and
connection tracking is enabled, nf_ct_tcp reports sequence tracking errors.
This patch aims to resolve this issue.
6) Add CTA_HELP_INFO attribute. This is used to store the private helper
data. Thus, we don't need to keep a redundant cache of conntrack entries
in user-space. The private helper information is stored.
7) finally, the netlink cthelper infrastructure.
Of course, this patch makes no sense without the user-space changes, they are:
* updates in the conntrack-tools (see cthelper11 branch):
http://git.netfilter.org/cgi-bin/gitweb.cgi?p=conntrack-tools.git;a=shortlog;h=refs/heads/cthelper11
It includes the FTP user-space helper, one RPC helper (for NFSv3) and one TNS
helper (for Oracle).
* libnetfilter_cthelper
http://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_cthelper.git;a=summary
* libnetfilter_conntrack (new libmnl API)
http://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_conntrack.git;a=summary
* libnetfilter_queue
http://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_queue.git;a=shortlog;h=refs/heads/cthelper2
WARNING: Changes may occur in the user-space side until all those cthelper
branches are merged into master. Mind that this is work-in-progress.
Pablo Neira Ayuso (7):
netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names
netfilter: nf_ct_ext: support variable length extensions
netfilter: nf_ct_helper: implement variable length helper private data
netfilter: add glue code to integrate nfnetlink_queue and ctnetlink
netfilter: nfnl_queue: support NAT TCP sequence adjustment if packet mangled
netfilter: ctnetlink: add CTA_HELP_INFO attribute
netfilter: add user-space connection tracking helper infrastructure
include/linux/netfilter.h | 10 +
include/linux/netfilter/Kbuild | 1 +
include/linux/netfilter/nf_conntrack_sip.h | 1 +
include/linux/netfilter/nfnetlink.h | 3 +-
include/linux/netfilter/nfnetlink_conntrack.h | 1 +
include/linux/netfilter/nfnetlink_cthelper.h | 55 ++
include/linux/netfilter/nfnetlink_queue.h | 7 +
include/linux/netfilter_ipv4.h | 1 +
include/linux/netfilter_ipv6.h | 1 +
include/net/netfilter/nf_conntrack.h | 35 +-
include/net/netfilter/nf_conntrack_expect.h | 4 +-
include/net/netfilter/nf_conntrack_extend.h | 7 +-
include/net/netfilter/nf_conntrack_helper.h | 29 +-
include/net/netfilter/nf_nat_helper.h | 7 +
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 56 +-
net/ipv4/netfilter/nf_nat_amanda.c | 4 +-
net/ipv4/netfilter/nf_nat_h323.c | 8 +-
net/ipv4/netfilter/nf_nat_helper.c | 13 +
net/ipv4/netfilter/nf_nat_pptp.c | 6 +-
net/ipv4/netfilter/nf_nat_sip.c | 14 +-
net/ipv4/netfilter/nf_nat_tftp.c | 4 +-
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 56 +-
net/netfilter/Kconfig | 8 +
net/netfilter/Makefile | 1 +
net/netfilter/core.c | 4 +
net/netfilter/nf_conntrack_core.c | 3 +-
net/netfilter/nf_conntrack_extend.c | 16 +-
net/netfilter/nf_conntrack_ftp.c | 11 +-
net/netfilter/nf_conntrack_h323_main.c | 16 +-
net/netfilter/nf_conntrack_helper.c | 35 +-
net/netfilter/nf_conntrack_irc.c | 8 +-
net/netfilter/nf_conntrack_netlink.c | 190 ++++++-
net/netfilter/nf_conntrack_pptp.c | 17 +-
net/netfilter/nf_conntrack_proto_gre.c | 16 +-
net/netfilter/nf_conntrack_sane.c | 12 +-
net/netfilter/nf_conntrack_sip.c | 36 +-
net/netfilter/nf_conntrack_tftp.c | 8 +-
net/netfilter/nfnetlink_cthelper.c | 668 ++++++++++++++++++++++++
net/netfilter/nfnetlink_queue.c | 84 ++-
net/netfilter/xt_CT.c | 44 +-
40 files changed, 1309 insertions(+), 191 deletions(-)
create mode 100644 include/linux/netfilter/nfnetlink_cthelper.h
create mode 100644 net/netfilter/nfnetlink_cthelper.c
--
1.7.10
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH 1/7] netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 12:21 ` [PATCH 2/7] netfilter: nf_ct_ext: support variable length extensions pablo
` (5 subsequent siblings)
6 siblings, 0 replies; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
This patch modifies the struct nf_conntrack_helper to allocate
the room for the helper name. The maximum length is 16 bytes
(this was already introduced in 2.6.24).
For the maximum length for expectation policy names, I have
also selected 16 bytes.
This patch is required by the follow-up patch to support
user-space connection tracking helpers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_conntrack_expect.h | 4 +++-
include/net/netfilter/nf_conntrack_helper.h | 2 +-
net/netfilter/nf_conntrack_ftp.c | 8 ++------
net/netfilter/nf_conntrack_irc.c | 8 ++------
net/netfilter/nf_conntrack_sane.c | 8 ++------
net/netfilter/nf_conntrack_sip.c | 7 ++-----
net/netfilter/nf_conntrack_tftp.c | 8 ++------
7 files changed, 14 insertions(+), 31 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 4619caa..983f002 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -59,10 +59,12 @@ static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp)
return nf_ct_net(exp->master);
}
+#define NF_CT_EXP_POLICY_NAME_LEN 16
+
struct nf_conntrack_expect_policy {
unsigned int max_expected;
unsigned int timeout;
- const char *name;
+ char name[NF_CT_EXP_POLICY_NAME_LEN];
};
#define NF_CT_EXPECT_CLASS_DEFAULT 0
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 1d18894..5f5a4d9 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -19,7 +19,7 @@ struct module;
struct nf_conntrack_helper {
struct hlist_node hnode; /* Internal use. */
- const char *name; /* name of the module */
+ char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */
struct module *me; /* pointer to self */
const struct nf_conntrack_expect_policy *expect_policy;
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 8c5c95c..44e47c9 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -512,7 +512,6 @@ out_update_nl:
}
static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly;
-static char ftp_names[MAX_PORTS][2][sizeof("ftp-65535")] __read_mostly;
static const struct nf_conntrack_expect_policy ftp_exp_policy = {
.max_expected = 1,
@@ -541,7 +540,6 @@ static void nf_conntrack_ftp_fini(void)
static int __init nf_conntrack_ftp_init(void)
{
int i, j = -1, ret = 0;
- char *tmpname;
ftp_buffer = kmalloc(65536, GFP_KERNEL);
if (!ftp_buffer)
@@ -561,12 +559,10 @@ static int __init nf_conntrack_ftp_init(void)
ftp[i][j].expect_policy = &ftp_exp_policy;
ftp[i][j].me = THIS_MODULE;
ftp[i][j].help = help;
- tmpname = &ftp_names[i][j][0];
if (ports[i] == FTP_PORT)
- sprintf(tmpname, "ftp");
+ sprintf(ftp[i][j].name, "ftp");
else
- sprintf(tmpname, "ftp-%d", ports[i]);
- ftp[i][j].name = tmpname;
+ sprintf(ftp[i][j].name, "ftp-%d", ports[i]);
pr_debug("nf_ct_ftp: registering helper for pf: %d "
"port: %d\n",
diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index 4f9390b..f6342dd 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -223,7 +223,6 @@ static int help(struct sk_buff *skb, unsigned int protoff,
}
static struct nf_conntrack_helper irc[MAX_PORTS] __read_mostly;
-static char irc_names[MAX_PORTS][sizeof("irc-65535")] __read_mostly;
static struct nf_conntrack_expect_policy irc_exp_policy;
static void nf_conntrack_irc_fini(void);
@@ -231,7 +230,6 @@ static void nf_conntrack_irc_fini(void);
static int __init nf_conntrack_irc_init(void)
{
int i, ret;
- char *tmpname;
if (max_dcc_channels < 1) {
printk(KERN_ERR "nf_ct_irc: max_dcc_channels must not be zero\n");
@@ -257,12 +255,10 @@ static int __init nf_conntrack_irc_init(void)
irc[i].me = THIS_MODULE;
irc[i].help = help;
- tmpname = &irc_names[i][0];
if (ports[i] == IRC_PORT)
- sprintf(tmpname, "irc");
+ sprintf(irc[i].name, "irc");
else
- sprintf(tmpname, "irc-%u", i);
- irc[i].name = tmpname;
+ sprintf(irc[i].name, "irc-%u", i);
ret = nf_conntrack_helper_register(&irc[i]);
if (ret) {
diff --git a/net/netfilter/nf_conntrack_sane.c b/net/netfilter/nf_conntrack_sane.c
index 8501823..ec3fc18 100644
--- a/net/netfilter/nf_conntrack_sane.c
+++ b/net/netfilter/nf_conntrack_sane.c
@@ -163,7 +163,6 @@ out:
}
static struct nf_conntrack_helper sane[MAX_PORTS][2] __read_mostly;
-static char sane_names[MAX_PORTS][2][sizeof("sane-65535")] __read_mostly;
static const struct nf_conntrack_expect_policy sane_exp_policy = {
.max_expected = 1,
@@ -190,7 +189,6 @@ static void nf_conntrack_sane_fini(void)
static int __init nf_conntrack_sane_init(void)
{
int i, j = -1, ret = 0;
- char *tmpname;
sane_buffer = kmalloc(65536, GFP_KERNEL);
if (!sane_buffer)
@@ -210,12 +208,10 @@ static int __init nf_conntrack_sane_init(void)
sane[i][j].expect_policy = &sane_exp_policy;
sane[i][j].me = THIS_MODULE;
sane[i][j].help = help;
- tmpname = &sane_names[i][j][0];
if (ports[i] == SANE_PORT)
- sprintf(tmpname, "sane");
+ sprintf(sane[i][j].name, "sane");
else
- sprintf(tmpname, "sane-%d", ports[i]);
- sane[i][j].name = tmpname;
+ sprintf(sane[i][j].name, "sane-%d", ports[i]);
pr_debug("nf_ct_sane: registering helper for pf: %d "
"port: %d\n",
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 6a9c9aa..c2daabe 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1573,7 +1573,6 @@ static void nf_conntrack_sip_fini(void)
static int __init nf_conntrack_sip_init(void)
{
int i, j, ret;
- char *tmpname;
if (ports_c == 0)
ports[ports_c++] = SIP_PORT;
@@ -1601,12 +1600,10 @@ static int __init nf_conntrack_sip_init(void)
sip[i][j].expect_class_max = SIP_EXPECT_MAX;
sip[i][j].me = THIS_MODULE;
- tmpname = &sip_names[i][j][0];
if (ports[i] == SIP_PORT)
- sprintf(tmpname, "sip");
+ sprintf(sip_names[i][j], "sip");
else
- sprintf(tmpname, "sip-%u", i);
- sip[i][j].name = tmpname;
+ sprintf(sip_names[i][j], "sip-%u", i);
pr_debug("port #%u: %u\n", i, ports[i]);
diff --git a/net/netfilter/nf_conntrack_tftp.c b/net/netfilter/nf_conntrack_tftp.c
index 75466fd..81fc61c 100644
--- a/net/netfilter/nf_conntrack_tftp.c
+++ b/net/netfilter/nf_conntrack_tftp.c
@@ -92,7 +92,6 @@ static int tftp_help(struct sk_buff *skb,
}
static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly;
-static char tftp_names[MAX_PORTS][2][sizeof("tftp-65535")] __read_mostly;
static const struct nf_conntrack_expect_policy tftp_exp_policy = {
.max_expected = 1,
@@ -112,7 +111,6 @@ static void nf_conntrack_tftp_fini(void)
static int __init nf_conntrack_tftp_init(void)
{
int i, j, ret;
- char *tmpname;
if (ports_c == 0)
ports[ports_c++] = TFTP_PORT;
@@ -129,12 +127,10 @@ static int __init nf_conntrack_tftp_init(void)
tftp[i][j].me = THIS_MODULE;
tftp[i][j].help = tftp_help;
- tmpname = &tftp_names[i][j][0];
if (ports[i] == TFTP_PORT)
- sprintf(tmpname, "tftp");
+ sprintf(tftp[i][j].name, "tftp");
else
- sprintf(tmpname, "tftp-%u", i);
- tftp[i][j].name = tmpname;
+ sprintf(tftp[i][j].name, "tftp-%u", i);
ret = nf_conntrack_helper_register(&tftp[i][j]);
if (ret) {
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 2/7] netfilter: nf_ct_ext: support variable length extensions
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
2012-06-04 12:21 ` [PATCH 1/7] netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 12:21 ` [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data pablo
` (4 subsequent siblings)
6 siblings, 0 replies; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
We can now define conntrack extensions of variable size. This
patch is useful to get rid of these unions:
union nf_conntrack_help
union nf_conntrack_proto
union nf_conntrack_nat_help
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_conntrack_extend.h | 7 ++++++-
net/netfilter/nf_conntrack_extend.c | 16 +++++++++-------
2 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index 96755c3..ecedd5f 100644
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -79,11 +79,16 @@ static inline void nf_ct_ext_free(struct nf_conn *ct)
kfree(ct->ext);
}
+void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
+ size_t var_alloc_len, gfp_t gfp);
+
/* Add this type, returns pointer to data or NULL. */
void *
__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
#define nf_ct_ext_add(ct, id, gfp) \
- ((id##_TYPE *)__nf_ct_ext_add((ct), (id), (gfp)))
+ ((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), 0, (gfp)))
+#define nf_ct_ext_add_length(ct, id, len, gfp) \
+ ((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), (len), (gfp)))
#define NF_CT_EXT_F_PREALLOC 0x0001
diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index 641ff5f..1a95459 100644
--- a/net/netfilter/nf_conntrack_extend.c
+++ b/net/netfilter/nf_conntrack_extend.c
@@ -44,7 +44,8 @@ void __nf_ct_ext_destroy(struct nf_conn *ct)
EXPORT_SYMBOL(__nf_ct_ext_destroy);
static void *
-nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
+nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id,
+ size_t var_alloc_len, gfp_t gfp)
{
unsigned int off, len;
struct nf_ct_ext_type *t;
@@ -54,8 +55,8 @@ nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
t = rcu_dereference(nf_ct_ext_types[id]);
BUG_ON(t == NULL);
off = ALIGN(sizeof(struct nf_ct_ext), t->align);
- len = off + t->len;
- alloc_size = t->alloc_size;
+ len = off + t->len + var_alloc_len;
+ alloc_size = t->alloc_size + var_alloc_len;
rcu_read_unlock();
*ext = kzalloc(alloc_size, gfp);
@@ -68,7 +69,8 @@ nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
return (void *)(*ext) + off;
}
-void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
+void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
+ size_t var_alloc_len, gfp_t gfp)
{
struct nf_ct_ext *old, *new;
int i, newlen, newoff;
@@ -79,7 +81,7 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
old = ct->ext;
if (!old)
- return nf_ct_ext_create(&ct->ext, id, gfp);
+ return nf_ct_ext_create(&ct->ext, id, var_alloc_len, gfp);
if (__nf_ct_ext_exist(old, id))
return NULL;
@@ -89,7 +91,7 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
BUG_ON(t == NULL);
newoff = ALIGN(old->len, t->align);
- newlen = newoff + t->len;
+ newlen = newoff + t->len + var_alloc_len;
rcu_read_unlock();
new = __krealloc(old, newlen, gfp);
@@ -117,7 +119,7 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
memset((void *)new + newoff, 0, newlen - newoff);
return (void *)new + newoff;
}
-EXPORT_SYMBOL(__nf_ct_ext_add);
+EXPORT_SYMBOL(__nf_ct_ext_add_length);
static void update_alloc_size(struct nf_ct_ext_type *type)
{
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
2012-06-04 12:21 ` [PATCH 1/7] netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names pablo
2012-06-04 12:21 ` [PATCH 2/7] netfilter: nf_ct_ext: support variable length extensions pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 13:06 ` Jan Engelhardt
2012-06-04 12:21 ` [PATCH 4/7] netfilter: add glue code to integrate nfnetlink_queue and ctnetlink pablo
` (3 subsequent siblings)
6 siblings, 1 reply; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
This patch uses the new variable length conntrack extensions.
Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.
This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter/nf_conntrack_sip.h | 1 +
include/net/netfilter/nf_conntrack.h | 35 ++-------------------
include/net/netfilter/nf_conntrack_helper.h | 15 ++++++++-
net/ipv4/netfilter/nf_nat_amanda.c | 4 +--
net/ipv4/netfilter/nf_nat_h323.c | 8 ++---
net/ipv4/netfilter/nf_nat_pptp.c | 6 ++--
net/ipv4/netfilter/nf_nat_sip.c | 14 ++++-----
net/ipv4/netfilter/nf_nat_tftp.c | 4 +--
net/netfilter/nf_conntrack_core.c | 3 +-
net/netfilter/nf_conntrack_ftp.c | 3 +-
net/netfilter/nf_conntrack_h323_main.c | 16 ++++++----
net/netfilter/nf_conntrack_helper.c | 11 ++++---
net/netfilter/nf_conntrack_netlink.c | 4 +--
net/netfilter/nf_conntrack_pptp.c | 17 ++++++-----
net/netfilter/nf_conntrack_proto_gre.c | 16 +++++-----
net/netfilter/nf_conntrack_sane.c | 4 +--
net/netfilter/nf_conntrack_sip.c | 29 +++++++++---------
net/netfilter/xt_CT.c | 44 ++++++++++++++++-----------
18 files changed, 119 insertions(+), 115 deletions(-)
diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index feda699..34e19f8 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -3,6 +3,7 @@
#ifdef __KERNEL__
#include <linux/types.h>
+#include <net/netfilter/nf_conntrack_expect.h>
#define SIP_PORT 5060
#define SIP_TIMEOUT 3600
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index cce7f6a..7449bacd 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -39,36 +39,6 @@ union nf_conntrack_expect_proto {
/* insert expect proto private data here */
};
-/* Add protocol helper include file here */
-#include <linux/netfilter/nf_conntrack_ftp.h>
-#include <linux/netfilter/nf_conntrack_pptp.h>
-#include <linux/netfilter/nf_conntrack_h323.h>
-#include <linux/netfilter/nf_conntrack_sane.h>
-#include <linux/netfilter/nf_conntrack_sip.h>
-
-/* per conntrack: application helper private data */
-union nf_conntrack_help {
- /* insert conntrack helper private data (master) here */
-#if defined(CONFIG_NF_CONNTRACK_FTP) || defined(CONFIG_NF_CONNTRACK_FTP_MODULE)
- struct nf_ct_ftp_master ct_ftp_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_PPTP) || \
- defined(CONFIG_NF_CONNTRACK_PPTP_MODULE)
- struct nf_ct_pptp_master ct_pptp_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_H323) || \
- defined(CONFIG_NF_CONNTRACK_H323_MODULE)
- struct nf_ct_h323_master ct_h323_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_SANE) || \
- defined(CONFIG_NF_CONNTRACK_SANE_MODULE)
- struct nf_ct_sane_master ct_sane_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_SIP) || defined(CONFIG_NF_CONNTRACK_SIP_MODULE)
- struct nf_ct_sip_master ct_sip_info;
-#endif
-};
-
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/timer.h>
@@ -89,12 +59,13 @@ struct nf_conn_help {
/* Helper. if any */
struct nf_conntrack_helper __rcu *helper;
- union nf_conntrack_help help;
-
struct hlist_head expectations;
/* Current number of expected connections */
u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
+
+ /* private helper information. */
+ char data[0];
};
#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 5f5a4d9..5afdcf2 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -11,6 +11,7 @@
#define _NF_CONNTRACK_HELPER_H
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_conntrack_expect.h>
struct module;
@@ -23,6 +24,9 @@ struct nf_conntrack_helper {
struct module *me; /* pointer to self */
const struct nf_conntrack_expect_policy *expect_policy;
+ /* length of internal data, ie. sizeof(struct nf_ct_*_master) */
+ size_t data_len;
+
/* Tuple of things we will help (compared against server response) */
struct nf_conntrack_tuple tuple;
@@ -48,7 +52,7 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum);
extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
-extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
+extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, struct nf_conntrack_helper *helper, gfp_t gfp);
extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
gfp_t flags);
@@ -60,6 +64,15 @@ static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
}
+static inline void *nfct_help_data(const struct nf_conn *ct)
+{
+ struct nf_conn_help *help;
+
+ help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
+
+ return (void *)&help->data;
+}
+
extern int nf_conntrack_helper_init(struct net *net);
extern void nf_conntrack_helper_fini(struct net *net);
diff --git a/net/ipv4/netfilter/nf_nat_amanda.c b/net/ipv4/netfilter/nf_nat_amanda.c
index 7b22382..8973d6a 100644
--- a/net/ipv4/netfilter/nf_nat_amanda.c
+++ b/net/ipv4/netfilter/nf_nat_amanda.c
@@ -13,11 +13,11 @@
#include <linux/skbuff.h>
#include <linux/udp.h>
-#include <net/netfilter/nf_nat_helper.h>
-#include <net/netfilter/nf_nat_rule.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <linux/netfilter/nf_conntrack_amanda.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
MODULE_DESCRIPTION("Amanda NAT helper");
diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c
index 8253670..a83865a 100644
--- a/net/ipv4/netfilter/nf_nat_h323.c
+++ b/net/ipv4/netfilter/nf_nat_h323.c
@@ -99,7 +99,7 @@ static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
unsigned char **data,
TransportAddress *taddr, int count)
{
- const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ const struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
int i;
__be16 port;
@@ -182,7 +182,7 @@ static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
struct nf_conntrack_expect *rtp_exp,
struct nf_conntrack_expect *rtcp_exp)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
int i;
u_int16_t nated_port;
@@ -337,7 +337,7 @@ static int nat_h245(struct sk_buff *skb, struct nf_conn *ct,
TransportAddress *taddr, __be16 port,
struct nf_conntrack_expect *exp)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
u_int16_t nated_port = ntohs(port);
@@ -427,7 +427,7 @@ static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
unsigned char **data, TransportAddress *taddr, int idx,
__be16 port, struct nf_conntrack_expect *exp)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
u_int16_t nated_port = ntohs(port);
union nf_inet_addr addr;
diff --git a/net/ipv4/netfilter/nf_nat_pptp.c b/net/ipv4/netfilter/nf_nat_pptp.c
index c273d58..3881408 100644
--- a/net/ipv4/netfilter/nf_nat_pptp.c
+++ b/net/ipv4/netfilter/nf_nat_pptp.c
@@ -49,7 +49,7 @@ static void pptp_nat_expected(struct nf_conn *ct,
const struct nf_nat_pptp *nat_pptp_info;
struct nf_nat_ipv4_range range;
- ct_pptp_info = &nfct_help(master)->help.ct_pptp_info;
+ ct_pptp_info = nfct_help_data(master);
nat_pptp_info = &nfct_nat(master)->help.nat_pptp_info;
/* And here goes the grand finale of corrosion... */
@@ -123,7 +123,7 @@ pptp_outbound_pkt(struct sk_buff *skb,
__be16 new_callid;
unsigned int cid_off;
- ct_pptp_info = &nfct_help(ct)->help.ct_pptp_info;
+ ct_pptp_info = nfct_help_data(ct);
nat_pptp_info = &nfct_nat(ct)->help.nat_pptp_info;
new_callid = ct_pptp_info->pns_call_id;
@@ -192,7 +192,7 @@ pptp_exp_gre(struct nf_conntrack_expect *expect_orig,
struct nf_ct_pptp_master *ct_pptp_info;
struct nf_nat_pptp *nat_pptp_info;
- ct_pptp_info = &nfct_help(ct)->help.ct_pptp_info;
+ ct_pptp_info = nfct_help_data(ct);
nat_pptp_info = &nfct_nat(ct)->help.nat_pptp_info;
/* save original PAC call ID in nat_info */
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index aafc4b6..f49222e 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -73,7 +73,7 @@ static int map_addr(struct sk_buff *skb, unsigned int dataoff,
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
unsigned int buflen;
__be32 newaddr;
@@ -86,7 +86,7 @@ static int map_addr(struct sk_buff *skb, unsigned int dataoff,
} else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip &&
ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
newaddr = ct->tuplehash[!dir].tuple.src.u3.ip;
- newport = help->help.ct_sip_info.forced_dport ? :
+ newport = ct_sip_info->forced_dport ? :
ct->tuplehash[!dir].tuple.src.u.udp.port;
} else
return 1;
@@ -123,7 +123,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
unsigned int coff, matchoff, matchlen;
enum sip_header_types hdr;
union nf_inet_addr addr;
@@ -233,14 +233,14 @@ next:
return NF_DROP;
/* Mangle destination port for Cisco phones, then fix up checksums */
- if (dir == IP_CT_DIR_REPLY && help->help.ct_sip_info.forced_dport) {
+ if (dir == IP_CT_DIR_REPLY && ct_sip_info->forced_dport) {
struct udphdr *uh;
if (!skb_make_writable(skb, skb->len))
return NF_DROP;
uh = (struct udphdr *)(skb->data + ip_hdrlen(skb));
- uh->dest = help->help.ct_sip_info.forced_dport;
+ uh->dest = ct_sip_info->forced_dport;
if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, 0, 0, NULL, 0))
return NF_DROP;
@@ -297,7 +297,7 @@ static unsigned int ip_nat_sip_expect(struct sk_buff *skb, unsigned int dataoff,
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
__be32 newip;
u_int16_t port;
__be16 srcport;
@@ -313,7 +313,7 @@ static unsigned int ip_nat_sip_expect(struct sk_buff *skb, unsigned int dataoff,
/* If the signalling port matches the connection's source port in the
* original direction, try to use the destination port in the opposite
* direction. */
- srcport = help->help.ct_sip_info.forced_dport ? :
+ srcport = ct_sip_info->forced_dport ? :
ct->tuplehash[dir].tuple.src.u.udp.port;
if (exp->tuple.dst.u.udp.port == srcport)
port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
diff --git a/net/ipv4/netfilter/nf_nat_tftp.c b/net/ipv4/netfilter/nf_nat_tftp.c
index a2901bf..4a1c270 100644
--- a/net/ipv4/netfilter/nf_nat_tftp.c
+++ b/net/ipv4/netfilter/nf_nat_tftp.c
@@ -8,11 +8,11 @@
#include <linux/module.h>
#include <linux/udp.h>
-#include <net/netfilter/nf_nat_helper.h>
-#include <net/netfilter/nf_nat_rule.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <linux/netfilter/nf_conntrack_tftp.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
MODULE_DESCRIPTION("TFTP NAT helper");
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 32c5909..afa6939 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -822,7 +822,8 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
__set_bit(IPS_EXPECTED_BIT, &ct->status);
ct->master = exp->master;
if (exp->helper) {
- help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
+ help = nf_ct_helper_ext_add(ct, exp->helper,
+ GFP_ATOMIC);
if (help)
rcu_assign_pointer(help->helper, exp->helper);
}
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 44e47c9..4bb771d 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -358,7 +358,7 @@ static int help(struct sk_buff *skb,
u32 seq;
int dir = CTINFO2DIR(ctinfo);
unsigned int uninitialized_var(matchlen), uninitialized_var(matchoff);
- struct nf_ct_ftp_master *ct_ftp_info = &nfct_help(ct)->help.ct_ftp_info;
+ struct nf_ct_ftp_master *ct_ftp_info = nfct_help_data(ct);
struct nf_conntrack_expect *exp;
union nf_inet_addr *daddr;
struct nf_conntrack_man cmd = {};
@@ -554,6 +554,7 @@ static int __init nf_conntrack_ftp_init(void)
ftp[i][0].tuple.src.l3num = PF_INET;
ftp[i][1].tuple.src.l3num = PF_INET6;
for (j = 0; j < 2; j++) {
+ ftp[i][j].data_len = sizeof(struct nf_ct_ftp_master);
ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]);
ftp[i][j].tuple.dst.protonum = IPPROTO_TCP;
ftp[i][j].expect_policy = &ftp_exp_policy;
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 471b054..988e9c3 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -114,7 +114,7 @@ static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
struct nf_conn *ct, enum ip_conntrack_info ctinfo,
unsigned char **data, int *datalen, int *dataoff)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
const struct tcphdr *th;
struct tcphdr _tcph;
@@ -619,6 +619,7 @@ static const struct nf_conntrack_expect_policy h245_exp_policy = {
static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
.name = "H.245",
.me = THIS_MODULE,
+ .data_len = sizeof(struct nf_ct_h323_master),
.tuple.src.l3num = AF_UNSPEC,
.tuple.dst.protonum = IPPROTO_UDP,
.help = h245_help,
@@ -1172,6 +1173,7 @@ static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
{
.name = "Q.931",
.me = THIS_MODULE,
+ .data_len = sizeof(struct nf_ct_h323_master),
.tuple.src.l3num = AF_INET,
.tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
.tuple.dst.protonum = IPPROTO_TCP,
@@ -1247,7 +1249,7 @@ static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
unsigned char **data,
TransportAddress *taddr, int count)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
int ret = 0;
int i;
@@ -1362,7 +1364,7 @@ static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
unsigned char **data, RegistrationRequest *rrq)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int ret;
typeof(set_ras_addr_hook) set_ras_addr;
@@ -1397,7 +1399,7 @@ static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
unsigned char **data, RegistrationConfirm *rcf)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
int ret;
struct nf_conntrack_expect *exp;
@@ -1446,7 +1448,7 @@ static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
unsigned char **data, UnregistrationRequest *urq)
{
- struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
int ret;
typeof(set_sig_addr_hook) set_sig_addr;
@@ -1478,7 +1480,7 @@ static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
unsigned char **data, AdmissionRequest *arq)
{
- const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ const struct nf_ct_h323_master *info = nfct_help_data(ct);
int dir = CTINFO2DIR(ctinfo);
__be16 port;
union nf_inet_addr addr;
@@ -1746,6 +1748,7 @@ static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
{
.name = "RAS",
.me = THIS_MODULE,
+ .data_len = sizeof(struct nf_ct_h323_master),
.tuple.src.l3num = AF_INET,
.tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
.tuple.dst.protonum = IPPROTO_UDP,
@@ -1755,6 +1758,7 @@ static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
{
.name = "RAS",
.me = THIS_MODULE,
+ .data_len = sizeof(struct nf_ct_h323_master),
.tuple.src.l3num = AF_INET6,
.tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
.tuple.dst.protonum = IPPROTO_UDP,
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 4fa2ff9..e0d3f4b 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -161,11 +161,14 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum)
}
EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get);
-struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp)
+struct nf_conn_help *
+nf_ct_helper_ext_add(struct nf_conn *ct,
+ struct nf_conntrack_helper *helper, gfp_t gfp)
{
struct nf_conn_help *help;
- help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, gfp);
+ help = nf_ct_ext_add_length(ct, NF_CT_EXT_HELPER,
+ helper->data_len, gfp);
if (help)
INIT_HLIST_HEAD(&help->expectations);
else
@@ -218,13 +221,13 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
}
if (help == NULL) {
- help = nf_ct_helper_ext_add(ct, flags);
+ help = nf_ct_helper_ext_add(ct, helper, flags);
if (help == NULL) {
ret = -ENOMEM;
goto out;
}
} else {
- memset(&help->help, 0, sizeof(help->help));
+ memset(&help->data, 0, sizeof(helper->data_len));
}
rcu_assign_pointer(help->helper, helper);
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 6f4b00a..30f5e12 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1218,7 +1218,7 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[])
if (help->helper)
return -EBUSY;
/* need to zero data of old helper */
- memset(&help->help, 0, sizeof(help->help));
+ memset(&help->data, 0, help->helper->data_len);
} else {
/* we cannot set a helper for an existing conntrack */
return -EOPNOTSUPP;
@@ -1440,7 +1440,7 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
} else {
struct nf_conn_help *help;
- help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
+ help = nf_ct_helper_ext_add(ct, helper, GFP_ATOMIC);
if (help == NULL) {
err = -ENOMEM;
goto err2;
diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c
index 31d56b2..6fed9ec 100644
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -174,7 +174,7 @@ static int destroy_sibling_or_exp(struct net *net, struct nf_conn *ct,
static void pptp_destroy_siblings(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
- const struct nf_conn_help *help = nfct_help(ct);
+ const struct nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
struct nf_conntrack_tuple t;
nf_ct_gre_keymap_destroy(ct);
@@ -182,16 +182,16 @@ static void pptp_destroy_siblings(struct nf_conn *ct)
/* try original (pns->pac) tuple */
memcpy(&t, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, sizeof(t));
t.dst.protonum = IPPROTO_GRE;
- t.src.u.gre.key = help->help.ct_pptp_info.pns_call_id;
- t.dst.u.gre.key = help->help.ct_pptp_info.pac_call_id;
+ t.src.u.gre.key = ct_pptp_info->pns_call_id;
+ t.dst.u.gre.key = ct_pptp_info->pac_call_id;
if (!destroy_sibling_or_exp(net, ct, &t))
pr_debug("failed to timeout original pns->pac ct/exp\n");
/* try reply (pac->pns) tuple */
memcpy(&t, &ct->tuplehash[IP_CT_DIR_REPLY].tuple, sizeof(t));
t.dst.protonum = IPPROTO_GRE;
- t.src.u.gre.key = help->help.ct_pptp_info.pac_call_id;
- t.dst.u.gre.key = help->help.ct_pptp_info.pns_call_id;
+ t.src.u.gre.key = ct_pptp_info->pac_call_id;
+ t.dst.u.gre.key = ct_pptp_info->pns_call_id;
if (!destroy_sibling_or_exp(net, ct, &t))
pr_debug("failed to timeout reply pac->pns ct/exp\n");
}
@@ -269,7 +269,7 @@ pptp_inbound_pkt(struct sk_buff *skb,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
- struct nf_ct_pptp_master *info = &nfct_help(ct)->help.ct_pptp_info;
+ struct nf_ct_pptp_master *info = nfct_help_data(ct);
u_int16_t msg;
__be16 cid = 0, pcid = 0;
typeof(nf_nat_pptp_hook_inbound) nf_nat_pptp_inbound;
@@ -396,7 +396,7 @@ pptp_outbound_pkt(struct sk_buff *skb,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
- struct nf_ct_pptp_master *info = &nfct_help(ct)->help.ct_pptp_info;
+ struct nf_ct_pptp_master *info = nfct_help_data(ct);
u_int16_t msg;
__be16 cid = 0, pcid = 0;
typeof(nf_nat_pptp_hook_outbound) nf_nat_pptp_outbound;
@@ -506,7 +506,7 @@ conntrack_pptp_help(struct sk_buff *skb, unsigned int protoff,
{
int dir = CTINFO2DIR(ctinfo);
- const struct nf_ct_pptp_master *info = &nfct_help(ct)->help.ct_pptp_info;
+ const struct nf_ct_pptp_master *info = nfct_help_data(ct);
const struct tcphdr *tcph;
struct tcphdr _tcph;
const struct pptp_pkt_hdr *pptph;
@@ -592,6 +592,7 @@ static const struct nf_conntrack_expect_policy pptp_exp_policy = {
static struct nf_conntrack_helper pptp __read_mostly = {
.name = "pptp",
.me = THIS_MODULE,
+ .data_len = sizeof(struct nf_ct_pptp_master),
.tuple.src.l3num = AF_INET,
.tuple.src.u.tcp.port = cpu_to_be16(PPTP_CONTROL_PORT),
.tuple.dst.protonum = IPPROTO_TCP,
diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index 4bf6b4e..c04a363 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -110,10 +110,10 @@ int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
{
struct net *net = nf_ct_net(ct);
struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
struct nf_ct_gre_keymap **kmp, *km;
- kmp = &help->help.ct_pptp_info.keymap[dir];
+ kmp = &ct_pptp_info->keymap[dir];
if (*kmp) {
/* check whether it's a retransmission */
read_lock_bh(&net_gre->keymap_lock);
@@ -151,19 +151,19 @@ void nf_ct_gre_keymap_destroy(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
enum ip_conntrack_dir dir;
pr_debug("entering for ct %p\n", ct);
write_lock_bh(&net_gre->keymap_lock);
for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {
- if (help->help.ct_pptp_info.keymap[dir]) {
+ if (ct_pptp_info->keymap[dir]) {
pr_debug("removing %p from list\n",
- help->help.ct_pptp_info.keymap[dir]);
- list_del(&help->help.ct_pptp_info.keymap[dir]->list);
- kfree(help->help.ct_pptp_info.keymap[dir]);
- help->help.ct_pptp_info.keymap[dir] = NULL;
+ ct_pptp_info->keymap[dir]);
+ list_del(&ct_pptp_info->keymap[dir]->list);
+ kfree(ct_pptp_info->keymap[dir]);
+ ct_pptp_info->keymap[dir] = NULL;
}
}
write_unlock_bh(&net_gre->keymap_lock);
diff --git a/net/netfilter/nf_conntrack_sane.c b/net/netfilter/nf_conntrack_sane.c
index ec3fc18..295429f 100644
--- a/net/netfilter/nf_conntrack_sane.c
+++ b/net/netfilter/nf_conntrack_sane.c
@@ -69,13 +69,12 @@ static int help(struct sk_buff *skb,
void *sb_ptr;
int ret = NF_ACCEPT;
int dir = CTINFO2DIR(ctinfo);
- struct nf_ct_sane_master *ct_sane_info;
+ struct nf_ct_sane_master *ct_sane_info = nfct_help_data(ct);
struct nf_conntrack_expect *exp;
struct nf_conntrack_tuple *tuple;
struct sane_request *req;
struct sane_reply_net_start *reply;
- ct_sane_info = &nfct_help(ct)->help.ct_sane_info;
/* Until there's been traffic both ways, don't look in packets. */
if (ctinfo != IP_CT_ESTABLISHED &&
ctinfo != IP_CT_ESTABLISHED_REPLY)
@@ -203,6 +202,7 @@ static int __init nf_conntrack_sane_init(void)
sane[i][0].tuple.src.l3num = PF_INET;
sane[i][1].tuple.src.l3num = PF_INET6;
for (j = 0; j < 2; j++) {
+ sane[i][j].data_len = sizeof(struct nf_ct_sane_master);
sane[i][j].tuple.src.u.tcp.port = htons(ports[i]);
sane[i][j].tuple.dst.protonum = IPPROTO_TCP;
sane[i][j].expect_policy = &sane_exp_policy;
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index c2daabe..a627863 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1075,12 +1075,12 @@ static int process_invite_response(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
if ((code >= 100 && code <= 199) ||
(code >= 200 && code <= 299))
return process_sdp(skb, dataoff, dptr, datalen, cseq);
- else if (help->help.ct_sip_info.invite_cseq == cseq)
+ else if (ct_sip_info->invite_cseq == cseq)
flush_expectations(ct, true);
return NF_ACCEPT;
}
@@ -1091,12 +1091,12 @@ static int process_update_response(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
if ((code >= 100 && code <= 199) ||
(code >= 200 && code <= 299))
return process_sdp(skb, dataoff, dptr, datalen, cseq);
- else if (help->help.ct_sip_info.invite_cseq == cseq)
+ else if (ct_sip_info->invite_cseq == cseq)
flush_expectations(ct, true);
return NF_ACCEPT;
}
@@ -1107,12 +1107,12 @@ static int process_prack_response(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
if ((code >= 100 && code <= 199) ||
(code >= 200 && code <= 299))
return process_sdp(skb, dataoff, dptr, datalen, cseq);
- else if (help->help.ct_sip_info.invite_cseq == cseq)
+ else if (ct_sip_info->invite_cseq == cseq)
flush_expectations(ct, true);
return NF_ACCEPT;
}
@@ -1123,13 +1123,13 @@ static int process_invite_request(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
unsigned int ret;
flush_expectations(ct, true);
ret = process_sdp(skb, dataoff, dptr, datalen, cseq);
if (ret == NF_ACCEPT)
- help->help.ct_sip_info.invite_cseq = cseq;
+ ct_sip_info->invite_cseq = cseq;
return ret;
}
@@ -1154,7 +1154,7 @@ static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
unsigned int matchoff, matchlen;
struct nf_conntrack_expect *exp;
@@ -1235,7 +1235,7 @@ static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
store_cseq:
if (ret == NF_ACCEPT)
- help->help.ct_sip_info.register_cseq = cseq;
+ ct_sip_info->register_cseq = cseq;
return ret;
}
@@ -1245,7 +1245,7 @@ static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
union nf_inet_addr addr;
__be16 port;
@@ -1262,7 +1262,7 @@ static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
* responses, so we store the sequence number of the last valid
* request and compare it here.
*/
- if (help->help.ct_sip_info.register_cseq != cseq)
+ if (ct_sip_info->register_cseq != cseq)
return NF_ACCEPT;
if (code >= 100 && code <= 199)
@@ -1363,7 +1363,7 @@ static int process_sip_request(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct nf_conn_help *help = nfct_help(ct);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
unsigned int matchoff, matchlen;
unsigned int cseq, i;
@@ -1381,7 +1381,7 @@ static int process_sip_request(struct sk_buff *skb, unsigned int dataoff,
&matchlen, &addr, &port) > 0 &&
port != ct->tuplehash[dir].tuple.src.u.udp.port &&
nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3))
- help->help.ct_sip_info.forced_dport = port;
+ ct_sip_info->forced_dport = port;
for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
const struct sip_handler *handler;
@@ -1595,6 +1595,7 @@ static int __init nf_conntrack_sip_init(void)
sip[i][3].help = sip_help_tcp;
for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
+ sip[i][j].data_len = sizeof(struct nf_ct_sip_master);
sip[i][j].tuple.src.u.udp.port = htons(ports[i]);
sip[i][j].expect_policy = sip_exp_policy;
sip[i][j].expect_class_max = SIP_EXPECT_MAX;
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index 3746d8b..3641e1b 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -113,6 +113,8 @@ static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
goto err3;
if (info->helper[0]) {
+ struct nf_conntrack_helper *helper;
+
ret = -ENOENT;
proto = xt_ct_find_proto(par);
if (!proto) {
@@ -121,19 +123,21 @@ static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
goto err3;
}
- ret = -ENOMEM;
- help = nf_ct_helper_ext_add(ct, GFP_KERNEL);
- if (help == NULL)
- goto err3;
-
ret = -ENOENT;
- help->helper = nf_conntrack_helper_try_module_get(info->helper,
- par->family,
- proto);
- if (help->helper == NULL) {
+ helper = nf_conntrack_helper_try_module_get(info->helper,
+ par->family,
+ proto);
+ if (helper == NULL) {
pr_info("No such helper \"%s\"\n", info->helper);
goto err3;
}
+
+ ret = -ENOMEM;
+ help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
+ if (help == NULL)
+ goto err3;
+
+ help->helper = helper;
}
__set_bit(IPS_TEMPLATE_BIT, &ct->status);
@@ -203,6 +207,8 @@ static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
goto err3;
if (info->helper[0]) {
+ struct nf_conntrack_helper *helper;
+
ret = -ENOENT;
proto = xt_ct_find_proto(par);
if (!proto) {
@@ -211,19 +217,21 @@ static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
goto err3;
}
- ret = -ENOMEM;
- help = nf_ct_helper_ext_add(ct, GFP_KERNEL);
- if (help == NULL)
- goto err3;
-
ret = -ENOENT;
- help->helper = nf_conntrack_helper_try_module_get(info->helper,
- par->family,
- proto);
- if (help->helper == NULL) {
+ helper = nf_conntrack_helper_try_module_get(info->helper,
+ par->family,
+ proto);
+ if (helper == NULL) {
pr_info("No such helper \"%s\"\n", info->helper);
goto err3;
}
+
+ ret = -ENOMEM;
+ help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
+ if (help == NULL)
+ goto err3;
+
+ help->helper = helper;
}
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 4/7] netfilter: add glue code to integrate nfnetlink_queue and ctnetlink
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
` (2 preceding siblings ...)
2012-06-04 12:21 ` [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 13:38 ` Jan Engelhardt
2012-06-04 12:21 ` [PATCH 5/7] netfilter: nfnl_queue: support NAT TCP sequence adjustment if packet mangled pablo
` (2 subsequent siblings)
6 siblings, 1 reply; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
This patch allows you to include the conntrack information together
with the packet that is sent to user-space via NFQUEUE.
Previously, there was no integration between ctnetlink and
nfnetlink_queue. If you wanted to access conntrack information
from your libnetfilter_queue program, you required to query
ctnetlink from user-space to obtain it. Thus, delaying the packet
processing even more.
Including the conntrack information is optional, you can set it
via NFQNL_F_CONNTRACK flag with the new NFQ_CFG_FLAGS attribute.
This change provides the required features to use nfnetlink_queue
as the user-space queueing infrastructure for the follow-up patch
that introduces user-space conntrack helpers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter.h | 10 ++
include/linux/netfilter/nfnetlink_queue.h | 7 ++
net/netfilter/core.c | 4 +
net/netfilter/nf_conntrack_netlink.c | 158 ++++++++++++++++++++++++++++-
net/netfilter/nfnetlink_queue.c | 62 +++++++++++
5 files changed, 240 insertions(+), 1 deletion(-)
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index ff9c84c..a08dcb6 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -383,6 +383,16 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu;
extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
+
+struct nf_conn;
+struct nlattr;
+
+struct nfq_ct_hook {
+ size_t (*build_size)(const struct nf_conn *ct);
+ int (*build)(struct sk_buff *skb, struct nf_conn *ct);
+ int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
+};
+extern struct nfq_ct_hook *nfq_ct_hook;
#else
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
#endif
diff --git a/include/linux/netfilter/nfnetlink_queue.h b/include/linux/netfilter/nfnetlink_queue.h
index 24b32e6..da44b33 100644
--- a/include/linux/netfilter/nfnetlink_queue.h
+++ b/include/linux/netfilter/nfnetlink_queue.h
@@ -42,6 +42,8 @@ enum nfqnl_attr_type {
NFQA_IFINDEX_PHYSOUTDEV, /* __u32 ifindex */
NFQA_HWADDR, /* nfqnl_msg_packet_hw */
NFQA_PAYLOAD, /* opaque data payload */
+ NFQA_CT, /* nf_conntrack_netlink.h */
+ NFQA_CT_INFO, /* enum ip_conntrack_info */
__NFQA_MAX
};
@@ -78,12 +80,17 @@ struct nfqnl_msg_config_params {
__u8 copy_mode; /* enum nfqnl_config_mode */
} __attribute__ ((packed));
+enum nfqnl_flags {
+ NFQNL_F_NONE = 0,
+ NFQNL_F_CONNTRACK = (1 << 0),
+};
enum nfqnl_attr_config {
NFQA_CFG_UNSPEC,
NFQA_CFG_CMD, /* nfqnl_msg_config_cmd */
NFQA_CFG_PARAMS, /* nfqnl_msg_config_params */
NFQA_CFG_QUEUE_MAXLEN, /* __u32 */
+ NFQA_CFG_FLAGS, /* __u32 */
__NFQA_CFG_MAX
};
#define NFQA_CFG_MAX (__NFQA_CFG_MAX-1)
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index e19f365..7eef845 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -264,6 +264,10 @@ void nf_conntrack_destroy(struct nf_conntrack *nfct)
rcu_read_unlock();
}
EXPORT_SYMBOL(nf_conntrack_destroy);
+
+struct nfq_ct_hook *nfq_ct_hook;
+EXPORT_SYMBOL_GPL(nfq_ct_hook);
+
#endif /* CONFIG_NF_CONNTRACK */
#ifdef CONFIG_PROC_FS
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 30f5e12..28ac04c 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1620,6 +1620,152 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
return err;
}
+#if defined(CONFIG_NETFILTER_NETLINK_QUEUE) || \
+ defined(CONFIG_NETFILTER_NETLINK_QUEUE_MODULE)
+static size_t
+ctnetlink_nfqueue_build_size(const struct nf_conn *ct)
+{
+ return 3 * nla_total_size(0) /* CTA_TUPLE_ORIG|REPL|MASTER */
+ + 3 * nla_total_size(0) /* CTA_TUPLE_IP */
+ + 3 * nla_total_size(0) /* CTA_TUPLE_PROTO */
+ + 3 * nla_total_size(sizeof(u_int8_t)) /* CTA_PROTO_NUM */
+ + nla_total_size(sizeof(u_int32_t)) /* CTA_ID */
+ + nla_total_size(sizeof(u_int32_t)) /* CTA_STATUS */
+ + nla_total_size(sizeof(u_int32_t)) /* CTA_TIMEOUT */
+ + nla_total_size(0) /* CTA_PROTOINFO */
+ + nla_total_size(0) /* CTA_HELP */
+ + nla_total_size(NF_CT_HELPER_NAME_LEN) /* CTA_HELP_NAME */
+ + ctnetlink_secctx_size(ct)
+#ifdef CONFIG_NF_NAT_NEEDED
+ + 2 * nla_total_size(0) /* CTA_NAT_SEQ_ADJ_ORIG|REPL */
+ + 6 * nla_total_size(sizeof(u_int32_t)) /* CTA_NAT_SEQ_OFFSET */
+#endif
+#ifdef CONFIG_NF_CONNTRACK_MARK
+ + nla_total_size(sizeof(u_int32_t)) /* CTA_MARK */
+#endif
+ + ctnetlink_proto_size(ct)
+ ;
+}
+
+static int
+ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)
+{
+ struct nlattr *nest_parms;
+
+ rcu_read_lock();
+ nest_parms = nla_nest_start(skb, CTA_TUPLE_ORIG | NLA_F_NESTED);
+ if (!nest_parms)
+ goto nla_put_failure;
+ if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
+ goto nla_put_failure;
+ nla_nest_end(skb, nest_parms);
+
+ nest_parms = nla_nest_start(skb, CTA_TUPLE_REPLY | NLA_F_NESTED);
+ if (!nest_parms)
+ goto nla_put_failure;
+ if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_REPLY)) < 0)
+ goto nla_put_failure;
+ nla_nest_end(skb, nest_parms);
+
+ if (nf_ct_zone(ct)) {
+ if (nla_put_be16(skb, CTA_ZONE, htons(nf_ct_zone(ct))))
+ goto nla_put_failure;
+ }
+
+ if (ctnetlink_dump_id(skb, ct) < 0)
+ goto nla_put_failure;
+
+ if (ctnetlink_dump_status(skb, ct) < 0)
+ goto nla_put_failure;
+
+ if (ctnetlink_dump_timeout(skb, ct) < 0)
+ goto nla_put_failure;
+
+ if (ctnetlink_dump_protoinfo(skb, ct) < 0)
+ goto nla_put_failure;
+
+ if (ctnetlink_dump_helpinfo(skb, ct) < 0)
+ goto nla_put_failure;
+
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+ if (ct->secmark && ctnetlink_dump_secctx(skb, ct) < 0)
+ goto nla_put_failure;
+#endif
+ if (ct->master && ctnetlink_dump_master(skb, ct) < 0)
+ goto nla_put_failure;
+
+ if ((ct->status & IPS_SEQ_ADJUST) &&
+ ctnetlink_dump_nat_seq_adj(skb, ct) < 0)
+ goto nla_put_failure;
+
+#ifdef CONFIG_NF_CONNTRACK_MARK
+ if (ct->mark && ctnetlink_dump_mark(skb, ct) < 0)
+ goto nla_put_failure;
+#endif
+ rcu_read_unlock();
+ return 0;
+
+nla_put_failure:
+ rcu_read_unlock();
+ return -ENOSPC;
+}
+
+static int
+ctnetlink_nfqueue_parse(const struct nlattr *attr, struct nf_conn *ct)
+{
+ const struct nlattr * const cda[CTA_MAX+1];
+ struct nf_conntrack_tuple otuple, rtuple;
+ u16 u3 = nf_ct_l3num(ct);
+ int err;
+
+ nla_parse_nested((struct nlattr **)cda, CTA_MAX, attr, ct_nla_policy);
+
+ if (cda[CTA_TUPLE_ORIG]) {
+ err = ctnetlink_parse_tuple(cda, &otuple, CTA_TUPLE_ORIG, u3);
+ if (err < 0)
+ return err;
+ }
+ if (cda[CTA_TUPLE_REPLY]) {
+ err = ctnetlink_parse_tuple(cda, &rtuple, CTA_TUPLE_REPLY, u3);
+ if (err < 0)
+ return err;
+ }
+ if (cda[CTA_TIMEOUT]) {
+ err = ctnetlink_change_timeout(ct, cda);
+ if (err < 0)
+ return err;
+ }
+ if (cda[CTA_STATUS]) {
+ err = ctnetlink_change_status(ct, cda);
+ if (err < 0)
+ return err;
+ }
+ if (cda[CTA_PROTOINFO]) {
+ err = ctnetlink_change_protoinfo(ct, cda);
+ if (err < 0)
+ return err;
+ }
+#if defined(CONFIG_NF_CONNTRACK_MARK)
+ if (cda[CTA_MARK])
+ ct->mark = ntohl(nla_get_be32(cda[CTA_MARK]));
+#endif
+#ifdef CONFIG_NF_NAT_NEEDED
+ if (cda[CTA_NAT_SEQ_ADJ_ORIG] || cda[CTA_NAT_SEQ_ADJ_REPLY]) {
+ err = ctnetlink_change_nat_seq_adj(ct, cda);
+ if (err < 0)
+ return err;
+ }
+#endif
+ return 0;
+}
+
+static struct nfq_ct_hook ctnetlink_nfqueue_hook = {
+ .build_size = ctnetlink_nfqueue_build_size,
+ .build = ctnetlink_nfqueue_build,
+ .parse = ctnetlink_nfqueue_parse,
+};
+#endif /* CONFIG_NETFILTER_NETLINK_QUEUE */
+
/***********************************************************************
* EXPECT
***********************************************************************/
@@ -2424,7 +2570,12 @@ static int __init ctnetlink_init(void)
pr_err("ctnetlink_init: cannot register pernet operations\n");
goto err_unreg_exp_subsys;
}
-
+#if defined(CONFIG_NETFILTER_NETLINK_QUEUE) || \
+ defined(CONFIG_NETFILTER_NETLINK_QUEUE_MODULE)
+ /* setup interaction between nf_queue and nf_conntrack_netlink. */
+ RCU_INIT_POINTER(nfq_ct_hook, &ctnetlink_nfqueue_hook);
+ printk("registering nf_queue and ctnetlink interaction\n");
+#endif
return 0;
err_unreg_exp_subsys:
@@ -2442,6 +2593,11 @@ static void __exit ctnetlink_exit(void)
unregister_pernet_subsys(&ctnetlink_net_ops);
nfnetlink_subsys_unregister(&ctnl_exp_subsys);
nfnetlink_subsys_unregister(&ctnl_subsys);
+#if defined(CONFIG_NETFILTER_NETLINK_QUEUE) || \
+ defined(CONFIG_NETFILTER_NETLINK_QUEUE_MODULE)
+ RCU_INIT_POINTER(nfq_ct_hook, NULL);
+ printk("unregistering nf_queue and ctnetlink interaction\n");
+#endif
}
module_init(ctnetlink_init);
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 8d6bcf3..b007779 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -30,6 +30,7 @@
#include <linux/list.h>
#include <net/sock.h>
#include <net/netfilter/nf_queue.h>
+#include <net/netfilter/nf_conntrack.h>
#include <linux/atomic.h>
@@ -44,6 +45,7 @@ struct nfqnl_instance {
struct rcu_head rcu;
int peer_pid;
+ unsigned int flags;
unsigned int queue_maxlen;
unsigned int copy_range;
unsigned int queue_dropped;
@@ -232,6 +234,9 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
struct sk_buff *entskb = entry->skb;
struct net_device *indev;
struct net_device *outdev;
+ struct nfq_ct_hook *nfq_ct;
+ struct nf_conn *ct = NULL;
+ enum ip_conntrack_info ctinfo = 0; /* make gcc happy. */
size = NLMSG_SPACE(sizeof(struct nfgenmsg))
+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
@@ -265,6 +270,17 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
break;
}
+ /* rcu_read_lock()ed by __nf_queue already. */
+ nfq_ct = rcu_dereference(nfq_ct_hook);
+ if (nfq_ct != NULL && (queue->flags & NFQNL_F_CONNTRACK)) {
+ ct = nf_ct_get(entskb, &ctinfo);
+ if (ct) {
+ if (!nf_ct_is_untracked(ct))
+ size += nfq_ct->build_size(ct);
+ else
+ ct = NULL;
+ }
+ }
skb = alloc_skb(size, GFP_ATOMIC);
if (!skb)
@@ -388,6 +404,24 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
BUG();
}
+ if (nfq_ct != NULL && (queue->flags & NFQNL_F_CONNTRACK) && ct) {
+ struct nlattr *nest_parms;
+ u_int32_t tmp;
+
+ nest_parms = nla_nest_start(skb, NFQA_CT | NLA_F_NESTED);
+ if (!nest_parms)
+ goto nla_put_failure;
+
+ if (nfq_ct->build(skb, ct) < 0)
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms);
+
+ tmp = ctinfo;
+ if (nla_put_u32(skb, NFQA_CT_INFO, htonl(ctinfo)))
+ goto nla_put_failure;
+ }
+
nlh->nlmsg_len = skb->tail - old_tail;
return skb;
@@ -726,6 +760,7 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
struct nfqnl_instance *queue;
unsigned int verdict;
struct nf_queue_entry *entry;
+ struct nfq_ct_hook *nfq_ct;
queue = instance_lookup(queue_num);
if (!queue)
@@ -753,6 +788,19 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
if (nfqa[NFQA_MARK])
entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
+ rcu_read_lock();
+ nfq_ct = rcu_dereference(nfq_ct_hook);
+ if (nfq_ct != NULL &&
+ (queue->flags & NFQNL_F_CONNTRACK) && nfqa[NFQA_CT]) {
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+
+ ct = nf_ct_get(entry->skb, &ctinfo);
+ if (ct && !nf_ct_is_untracked(ct))
+ nfq_ct->parse(nfqa[NFQA_CT], ct);
+ }
+ rcu_read_unlock();
+
nf_reinject(entry, verdict);
return 0;
}
@@ -768,6 +816,7 @@ nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
[NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
[NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
+ [NFQA_CFG_FLAGS] = { .type = NLA_U32 }
};
static const struct nf_queue_handler nfqh = {
@@ -861,6 +910,19 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
spin_unlock_bh(&queue->lock);
}
+ if (nfqa[NFQA_CFG_FLAGS]) {
+ __be32 *flags;
+
+ if (!queue) {
+ ret = -ENODEV;
+ goto err_out_unlock;
+ }
+ flags = nla_data(nfqa[NFQA_CFG_FLAGS]);
+ spin_lock_bh(&queue->lock);
+ queue->flags = ntohl(*flags);
+ spin_unlock_bh(&queue->lock);
+ }
+
err_out_unlock:
rcu_read_unlock();
return ret;
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 5/7] netfilter: nfnl_queue: support NAT TCP sequence adjustment if packet mangled
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
` (3 preceding siblings ...)
2012-06-04 12:21 ` [PATCH 4/7] netfilter: add glue code to integrate nfnetlink_queue and ctnetlink pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 12:21 ` [PATCH 6/7] netfilter: ctnetlink: add CTA_HELP_INFO attribute pablo
2012-06-04 12:21 ` [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure pablo
6 siblings, 0 replies; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
User-space programs that receive traffic via NFQUEUE may mangle packets.
If NAT is enabled, this usually puzzles sequence tracking, leading to
traffic disruptions.
With this patch, nfnl_queue will make the corresponding NAT TCP sequence
adjustment if:
1) The packet has been mangled,
2) the NFQNL_F_CONNTRACK flag has been set, and
3) NAT is detected.
This is required by the new user-space cthelper infrastructure.
By now, we only support TCP since we have no helpers for DCCP
or SCTP. Better to add this if we do ever need it.
You can still use this without the cthelper infrastructure. There
are several post on the Internet complaning about this (mostly
people using NFQUEUE for IDS).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_nat_helper.h | 7 ++++++
net/ipv4/netfilter/nf_nat_helper.c | 13 ++++++++++
net/netfilter/nfnetlink_queue.c | 42 ++++++++++++++++++++++-----------
3 files changed, 48 insertions(+), 14 deletions(-)
diff --git a/include/net/netfilter/nf_nat_helper.h b/include/net/netfilter/nf_nat_helper.h
index 02bb6c2..ee92a0c 100644
--- a/include/net/netfilter/nf_nat_helper.h
+++ b/include/net/netfilter/nf_nat_helper.h
@@ -46,6 +46,13 @@ extern int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo);
+extern void nf_nat_tcp_seq_adjust(struct sk_buff *skb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ int off);
+
+struct nf_conntrack_expect;
+
/* Setup NAT on this expected conntrack so it follows master, but goes
* to port ct->master->saved_proto. */
extern void nf_nat_follow_master(struct nf_conn *ct,
diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
index af65958..7c7b5b8 100644
--- a/net/ipv4/netfilter/nf_nat_helper.c
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -153,6 +153,19 @@ void nf_nat_set_seq_adjust(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
}
EXPORT_SYMBOL_GPL(nf_nat_set_seq_adjust);
+void nf_nat_tcp_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo, int off)
+{
+ const struct tcphdr *th;
+
+ if (nf_ct_protonum(ct) != IPPROTO_TCP)
+ return;
+
+ th = (struct tcphdr *)(skb_network_header(skb)+ ip_hdrlen(skb));
+ nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
+}
+EXPORT_SYMBOL_GPL(nf_nat_tcp_seq_adjust);
+
static void nf_nat_csum(struct sk_buff *skb, const struct iphdr *iph, void *data,
int datalen, __sum16 *check, int oldlen)
{
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index b007779..b18a367 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -38,6 +38,10 @@
#include "../bridge/br_private.h"
#endif
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat_helper.h>
+#endif
+
#define NFQNL_QMAX_DEFAULT 1024
struct nfqnl_instance {
@@ -497,12 +501,10 @@ err_out:
}
static int
-nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e)
+nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
{
struct sk_buff *nskb;
- int diff;
- diff = data_len - e->skb->len;
if (diff < 0) {
if (pskb_trim(e->skb, data_len))
return -ENOMEM;
@@ -761,6 +763,8 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
unsigned int verdict;
struct nf_queue_entry *entry;
struct nfq_ct_hook *nfq_ct;
+ enum ip_conntrack_info uninitialized_var(ctinfo);
+ struct nf_conn *ct = NULL;
queue = instance_lookup(queue_num);
if (!queue)
@@ -779,26 +783,36 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
if (entry == NULL)
return -ENOENT;
+ rcu_read_lock();
+ nfq_ct = rcu_dereference(nfq_ct_hook);
+ if (nfq_ct != NULL && (queue->flags & NFQNL_F_CONNTRACK) &&
+ nfqa[NFQA_CT]) {
+ ct = nf_ct_get(entry->skb, &ctinfo);
+ if (ct && nf_ct_is_untracked(ct))
+ ct = NULL;
+ }
+
if (nfqa[NFQA_PAYLOAD]) {
+ u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
+ int diff = payload_len - entry->skb->len;
+
if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
- nla_len(nfqa[NFQA_PAYLOAD]), entry) < 0)
+ payload_len, entry, diff) < 0)
verdict = NF_DROP;
+
+#ifdef CONFIG_NF_NAT_NEEDED
+ /* Adjust sequence numbers to avoid puzzling conntrack */
+ if (ct && (ct->status & IPS_NAT_MASK) && diff)
+ nf_nat_tcp_seq_adjust(skb, ct, ctinfo, diff);
+#endif
}
if (nfqa[NFQA_MARK])
entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
- rcu_read_lock();
- nfq_ct = rcu_dereference(nfq_ct_hook);
- if (nfq_ct != NULL &&
- (queue->flags & NFQNL_F_CONNTRACK) && nfqa[NFQA_CT]) {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct;
+ if (ct)
+ nfq_ct->parse(nfqa[NFQA_CT], ct);
- ct = nf_ct_get(entry->skb, &ctinfo);
- if (ct && !nf_ct_is_untracked(ct))
- nfq_ct->parse(nfqa[NFQA_CT], ct);
- }
rcu_read_unlock();
nf_reinject(entry, verdict);
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 6/7] netfilter: ctnetlink: add CTA_HELP_INFO attribute
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
` (4 preceding siblings ...)
2012-06-04 12:21 ` [PATCH 5/7] netfilter: nfnl_queue: support NAT TCP sequence adjustment if packet mangled pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 12:21 ` [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure pablo
6 siblings, 0 replies; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
This attribute can be used to modify and to dump the internal
protocol information. This is required by the follow-up patch
that adds the user-space cthelper infrastructure.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter/nfnetlink_conntrack.h | 1 +
include/net/netfilter/nf_conntrack_helper.h | 1 +
net/netfilter/nf_conntrack_netlink.c | 28 ++++++++++++++++++++-----
3 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/include/linux/netfilter/nfnetlink_conntrack.h b/include/linux/netfilter/nfnetlink_conntrack.h
index e58e4b9..7688833 100644
--- a/include/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/linux/netfilter/nfnetlink_conntrack.h
@@ -191,6 +191,7 @@ enum ctattr_expect_nat {
enum ctattr_help {
CTA_HELP_UNSPEC,
CTA_HELP_NAME,
+ CTA_HELP_INFO,
__CTA_HELP_MAX
};
#define CTA_HELP_MAX (__CTA_HELP_MAX - 1)
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 5afdcf2..e5091a9 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -39,6 +39,7 @@ struct nf_conntrack_helper {
void (*destroy)(struct nf_conn *ct);
+ int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
unsigned int expect_class_max;
};
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 28ac04c..27b6a75 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -901,7 +901,8 @@ static const struct nla_policy help_nla_policy[CTA_HELP_MAX+1] = {
};
static inline int
-ctnetlink_parse_help(const struct nlattr *attr, char **helper_name)
+ctnetlink_parse_help(const struct nlattr *attr, char **helper_name,
+ struct nlattr **helpinfo)
{
struct nlattr *tb[CTA_HELP_MAX+1];
@@ -912,6 +913,9 @@ ctnetlink_parse_help(const struct nlattr *attr, char **helper_name)
*helper_name = nla_data(tb[CTA_HELP_NAME]);
+ if (tb[CTA_HELP_INFO])
+ *helpinfo = tb[CTA_HELP_INFO];
+
return 0;
}
@@ -1172,13 +1176,14 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[])
struct nf_conntrack_helper *helper;
struct nf_conn_help *help = nfct_help(ct);
char *helpname = NULL;
+ struct nlattr *helpinfo = NULL;
int err;
/* don't change helper of sibling connections */
if (ct->master)
return -EBUSY;
- err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);
+ err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
if (err < 0)
return err;
@@ -1213,8 +1218,12 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[])
}
if (help) {
- if (help->helper == helper)
+ if (help->helper == helper) {
+ /* update private helper data if allowed. */
+ if (helper->from_nlattr && helpinfo)
+ helper->from_nlattr(helpinfo, ct);
return 0;
+ }
if (help->helper)
return -EBUSY;
/* need to zero data of old helper */
@@ -1410,8 +1419,9 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
rcu_read_lock();
if (cda[CTA_HELP]) {
char *helpname = NULL;
-
- err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);
+ struct nlattr *helpinfo = NULL;
+
+ err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
if (err < 0)
goto err2;
@@ -1445,6 +1455,9 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
err = -ENOMEM;
goto err2;
}
+ /* set private helper data if allowed. */
+ if (helper->from_nlattr && helpinfo)
+ helper->from_nlattr(helpinfo, ct);
/* not in hash table yet so not strictly necessary */
RCU_INIT_POINTER(help->helper, helper);
@@ -1745,6 +1758,11 @@ ctnetlink_nfqueue_parse(const struct nlattr *attr, struct nf_conn *ct)
if (err < 0)
return err;
}
+ if (cda[CTA_HELP]) {
+ err = ctnetlink_change_helper(ct, cda);
+ if (err < 0)
+ return err;
+ }
#if defined(CONFIG_NF_CONNTRACK_MARK)
if (cda[CTA_MARK])
ct->mark = ntohl(nla_get_be32(cda[CTA_MARK]));
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
` (5 preceding siblings ...)
2012-06-04 12:21 ` [PATCH 6/7] netfilter: ctnetlink: add CTA_HELP_INFO attribute pablo
@ 2012-06-04 12:21 ` pablo
2012-06-04 14:04 ` Jan Engelhardt
2012-06-06 9:39 ` Ferenc Wagner
6 siblings, 2 replies; 17+ messages in thread
From: pablo @ 2012-06-04 12:21 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
There are good reasons to supports helpers in user-space instead:
* Rapid connection tracking helper development, as developing code
in user-space is usually faster.
* Reliability: A buggy helper does not crash the kernel. Moreover,
we can monitor the helper process and restart it in case of problems.
* Security: Avoid complex string matching and mangling in kernel-space
running in unprivileged mode. Going further, we can even think about
running user-space helpers as a non-root process.
* It allows the development of very specific helpers (most likely
non-standard proprietary protocols) that are very likely to be rejected
for mainline inclusion in the form of kernel-space connection tracking
helpers.
This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).
I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.
Basic operation, in a few steps:
1) Register user-space helper by means of `nfct':
nfct helper add ftp inet
[ It must be a valid existing helper supported by conntrack-tools.
2) Add rules to enable the FTP user-space helper which is
used to track traffic going to TCP port 10000.
For locally generated packets:
iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp
For non-locally generated packets:
iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp
3) Run the test conntrackd in helper mode (see example files under
doc/helper/conntrackd.conf
conntrackd
4) Generate FTP traffic going, if everything is OK, then conntrackd
should create expectations (you can check that with `conntrack':
conntrack -E expect
[NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.
The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter/Kbuild | 1 +
include/linux/netfilter/nfnetlink.h | 3 +-
include/linux/netfilter/nfnetlink_cthelper.h | 55 ++
include/linux/netfilter_ipv4.h | 1 +
include/linux/netfilter_ipv6.h | 1 +
include/net/netfilter/nf_conntrack_helper.h | 11 +
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 56 +-
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 56 +-
net/netfilter/Kconfig | 8 +
net/netfilter/Makefile | 1 +
net/netfilter/nf_conntrack_helper.c | 24 +-
net/netfilter/nfnetlink_cthelper.c | 668 ++++++++++++++++++++++++
12 files changed, 858 insertions(+), 27 deletions(-)
create mode 100644 include/linux/netfilter/nfnetlink_cthelper.h
create mode 100644 net/netfilter/nfnetlink_cthelper.c
diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild
index 1697036..874ae8f 100644
--- a/include/linux/netfilter/Kbuild
+++ b/include/linux/netfilter/Kbuild
@@ -10,6 +10,7 @@ header-y += nfnetlink.h
header-y += nfnetlink_acct.h
header-y += nfnetlink_compat.h
header-y += nfnetlink_conntrack.h
+header-y += nfnetlink_cthelper.h
header-y += nfnetlink_cttimeout.h
header-y += nfnetlink_log.h
header-y += nfnetlink_queue.h
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index a1048c1..18341cd 100644
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -50,7 +50,8 @@ struct nfgenmsg {
#define NFNL_SUBSYS_IPSET 6
#define NFNL_SUBSYS_ACCT 7
#define NFNL_SUBSYS_CTNETLINK_TIMEOUT 8
-#define NFNL_SUBSYS_COUNT 9
+#define NFNL_SUBSYS_CTHELPER 9
+#define NFNL_SUBSYS_COUNT 10
#ifdef __KERNEL__
diff --git a/include/linux/netfilter/nfnetlink_cthelper.h b/include/linux/netfilter/nfnetlink_cthelper.h
new file mode 100644
index 0000000..33659f6
--- /dev/null
+++ b/include/linux/netfilter/nfnetlink_cthelper.h
@@ -0,0 +1,55 @@
+#ifndef _NFNL_CTHELPER_H_
+#define _NFNL_CTHELPER_H_
+
+#define NFCT_HELPER_STATUS_DISABLED 0
+#define NFCT_HELPER_STATUS_ENABLED 1
+
+enum nfnl_acct_msg_types {
+ NFNL_MSG_CTHELPER_NEW,
+ NFNL_MSG_CTHELPER_GET,
+ NFNL_MSG_CTHELPER_DEL,
+ NFNL_MSG_CTHELPER_MAX
+};
+
+enum nfnl_cthelper_type {
+ NFCTH_UNSPEC,
+ NFCTH_NAME,
+ NFCTH_TUPLE,
+ NFCTH_QUEUE_NUM,
+ NFCTH_POLICY,
+ NFCTH_PRIV_DATA_LEN,
+ NFCTH_STATUS,
+ __NFCTH_MAX
+};
+#define NFCTH_MAX (__NFCTH_MAX - 1)
+
+enum nfnl_cthelper_policy_type {
+ NFCTH_POLICY_SET_UNSPEC,
+ NFCTH_POLICY_SET_NUM,
+ NFCTH_POLICY_SET,
+ NFCTH_POLICY_SET1 = NFCTH_POLICY_SET,
+ NFCTH_POLICY_SET2,
+ NFCTH_POLICY_SET3,
+ NFCTH_POLICY_SET4,
+ __NFCTH_POLICY_SET_MAX
+};
+#define NFCTH_POLICY_SET_MAX (__NFCTH_POLICY_SET_MAX - 1)
+
+enum nfnl_cthelper_pol_type {
+ NFCTH_POLICY_UNSPEC,
+ NFCTH_POLICY_NAME,
+ NFCTH_POLICY_EXPECT_MAX,
+ NFCTH_POLICY_EXPECT_TIMEOUT,
+ __NFCTH_POLICY_MAX
+};
+#define NFCTH_POLICY_MAX (__NFCTH_POLICY_MAX - 1)
+
+enum nfnl_cthelper_tuple_type {
+ NFCTH_TUPLE_UNSPEC,
+ NFCTH_TUPLE_L3PROTONUM,
+ NFCTH_TUPLE_L4PROTONUM,
+ __NFCTH_TUPLE_MAX,
+};
+#define NFCTH_TUPLE_MAX (__NFCTH_TUPLE_MAX - 1)
+
+#endif /* _NFNL_CTHELPER_H */
diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h
index fa0946c..e2b1280 100644
--- a/include/linux/netfilter_ipv4.h
+++ b/include/linux/netfilter_ipv4.h
@@ -66,6 +66,7 @@ enum nf_ip_hook_priorities {
NF_IP_PRI_SECURITY = 50,
NF_IP_PRI_NAT_SRC = 100,
NF_IP_PRI_SELINUX_LAST = 225,
+ NF_IP_PRI_CONNTRACK_HELPER = 300,
NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX,
NF_IP_PRI_LAST = INT_MAX,
};
diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h
index 57c0251..7c8a513 100644
--- a/include/linux/netfilter_ipv6.h
+++ b/include/linux/netfilter_ipv6.h
@@ -71,6 +71,7 @@ enum nf_ip6_hook_priorities {
NF_IP6_PRI_SECURITY = 50,
NF_IP6_PRI_NAT_SRC = 100,
NF_IP6_PRI_SELINUX_LAST = 225,
+ NF_IP6_PRI_CONNTRACK_HELPER = 300,
NF_IP6_PRI_LAST = INT_MAX,
};
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index e5091a9..f499aa5 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -15,6 +15,11 @@
struct module;
+enum nf_ct_helper_flags {
+ NF_CT_HELPER_F_USERSPACE = (1 << 0),
+ NF_CT_HELPER_F_CONFIGURED = (1 << 1),
+};
+
#define NF_CT_HELPER_NAME_LEN 16
struct nf_conntrack_helper {
@@ -42,6 +47,9 @@ struct nf_conntrack_helper {
int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
unsigned int expect_class_max;
+
+ unsigned int flags;
+ unsigned int queue_num; /* For user-space helpers. */
};
extern struct nf_conntrack_helper *
@@ -96,4 +104,7 @@ nf_ct_helper_expectfn_find_by_name(const char *name);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
+extern struct hlist_head *nf_ct_helper_hash;
+extern unsigned int nf_ct_helper_hsize;
+
#endif /*_NF_CONNTRACK_HELPER_H*/
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 91747d4..d3cb34d 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -95,11 +95,11 @@ static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
return NF_ACCEPT;
}
-static unsigned int ipv4_confirm(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+static unsigned int ipv4_helper(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
@@ -110,24 +110,45 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- goto out;
+ return NF_ACCEPT;
help = nfct_help(ct);
if (!help)
- goto out;
+ return NF_ACCEPT;
/* rcu_read_lock()ed by nf_hook_slow */
helper = rcu_dereference(help->helper);
if (!helper)
- goto out;
+ return NF_ACCEPT;
+
+ /* This is an user-space helper not yet configured, skip. */
+ if ((helper->flags &
+ (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
+ NF_CT_HELPER_F_USERSPACE) {
+ return NF_ACCEPT;
+ }
ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
ct, ctinfo);
- if (ret != NF_ACCEPT) {
+ if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
"nf_ct_%s: dropping packet", helper->name);
- return ret;
}
+ return ret;
+}
+
+static unsigned int ipv4_confirm(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ return NF_ACCEPT;
/* adjust seqs for loopback traffic only in outgoing direction */
if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
@@ -140,7 +161,6 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
return NF_DROP;
}
}
-out:
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(skb);
}
@@ -185,6 +205,13 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
.priority = NF_IP_PRI_CONNTRACK,
},
{
+ .hook = ipv4_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV4,
@@ -192,6 +219,13 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
.priority = NF_IP_PRI_CONNTRACK_CONFIRM,
},
{
+ .hook = ipv4_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV4,
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index fe925e4..f9b3693 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -143,11 +143,11 @@ static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
return NF_ACCEPT;
}
-static unsigned int ipv6_confirm(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+static unsigned int ipv6_helper(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
const struct nf_conn_help *help;
@@ -161,15 +161,15 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- goto out;
+ return NF_ACCEPT;
help = nfct_help(ct);
if (!help)
- goto out;
+ return NF_ACCEPT;
/* rcu_read_lock()ed by nf_hook_slow */
helper = rcu_dereference(help->helper);
if (!helper)
- goto out;
+ return NF_ACCEPT;
protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum,
skb->len - extoff);
@@ -178,13 +178,35 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
return NF_ACCEPT;
}
+ /* This is an user-space helper not yet configured, skip. */
+ if ((helper->flags &
+ (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
+ NF_CT_HELPER_F_USERSPACE) {
+ return NF_ACCEPT;
+ }
+
ret = helper->help(skb, protoff, ct, ctinfo);
- if (ret != NF_ACCEPT) {
+ if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
nf_log_packet(NFPROTO_IPV6, hooknum, skb, in, out, NULL,
"nf_ct_%s: dropping packet", helper->name);
return ret;
}
-out:
+ return ret;
+}
+
+static unsigned int ipv6_confirm(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ return NF_ACCEPT;
+
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(skb);
}
@@ -255,6 +277,13 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_CONNTRACK,
},
{
+ .hook = ipv6_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP6_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV6,
@@ -262,6 +291,13 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_LAST,
},
{
+ .hook = ipv6_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP6_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV6,
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 209c1ed..cd5668e 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -12,6 +12,14 @@ tristate "Netfilter NFACCT over NFNETLINK interface"
If this option is enabled, the kernel will include support
for extended accounting via NFNETLINK.
+config NETFILTER_NETLINK_CTHELPER
+tristate "Netfilter NFCT_HELPER over NFNETLINK interface"
+ depends on NETFILTER_ADVANCED
+ select NETFILTER_NETLINK
+ help
+ If this option is enabled, the kernel will include support
+ for user-space connection tracking helpers via NFNETLINK.
+
config NETFILTER_NETLINK_QUEUE
tristate "Netfilter NFQUEUE over NFNETLINK interface"
depends on NETFILTER_ADVANCED
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 4e7960c..2f3bc0f 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_NETFILTER) = netfilter.o
obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
obj-$(CONFIG_NETFILTER_NETLINK_ACCT) += nfnetlink_acct.o
+obj-$(CONFIG_NETFILTER_NETLINK_CTHELPER) += nfnetlink_cthelper.o
obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index e0d3f4b..3d91d11 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -30,8 +30,10 @@
#include <net/netfilter/nf_conntrack_extend.h>
static DEFINE_MUTEX(nf_ct_helper_mutex);
-static struct hlist_head *nf_ct_helper_hash __read_mostly;
-static unsigned int nf_ct_helper_hsize __read_mostly;
+struct hlist_head *nf_ct_helper_hash __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_helper_hash);
+unsigned int nf_ct_helper_hsize __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_helper_hsize);
static unsigned int nf_ct_helper_count __read_mostly;
static bool nf_ct_auto_assign_helper __read_mostly = true;
@@ -322,18 +324,30 @@ EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
+ int ret = 0;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n;
unsigned int h = helper_hash(&me->tuple);
- BUG_ON(me->expect_policy == NULL);
+ BUG_ON(me->expect_policy == NULL &&
+ !(me->flags & NF_CT_HELPER_F_USERSPACE));
BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES);
BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1);
mutex_lock(&nf_ct_helper_mutex);
+ hlist_for_each_entry(cur, n, &nf_ct_helper_hash[h], hnode) {
+ if (strncmp(cur->name, me->name, NF_CT_HELPER_NAME_LEN) == 0 &&
+ cur->tuple.src.l3num == me->tuple.src.l3num &&
+ cur->tuple.dst.protonum == me->tuple.dst.protonum) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]);
nf_ct_helper_count++;
+out:
mutex_unlock(&nf_ct_helper_mutex);
-
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_helper_register);
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
new file mode 100644
index 0000000..8c80a34
--- /dev/null
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -0,0 +1,668 @@
+/*
+ * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation (or any later at your option).
+ *
+ * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <net/netlink.h>
+#include <net/sock.h>
+
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+#include <linux/netfilter/nfnetlink_cthelper.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
+
+static int
+nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+ const struct nf_conn_help *help;
+ struct nf_conntrack_helper *helper;
+
+ help = nfct_help(ct);
+ if (help == NULL)
+ return NF_DROP;
+
+ /* rcu_read_lock()ed by nf_hook_slow */
+ helper = rcu_dereference(help->helper);
+ if (helper == NULL)
+ return NF_DROP;
+
+ /* If the user-space helper is not available, don't block traffic. */
+ return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
+}
+
+static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
+ [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
+ [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
+};
+
+static int
+nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nlattr *attr)
+{
+ struct nlattr *tb[NFCTH_TUPLE_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
+
+ if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
+ return -EINVAL;
+
+ tuple->src.l3num = ntohs(nla_get_u16(tb[NFCTH_TUPLE_L3PROTONUM]));
+ tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
+
+ return 0;
+}
+
+static int
+nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
+{
+ const struct nf_conn_help *help = nfct_help(ct);
+
+ if (help->helper->data_len == 0)
+ return -EINVAL;
+
+ memcpy(&help->data, nla_data(attr), help->helper->data_len);
+ return 0;
+}
+
+static int
+nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
+{
+ const struct nf_conn_help *help = nfct_help(ct);
+
+ if (help->helper->data_len &&
+ nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -ENOSPC;
+}
+
+static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
+ [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
+ .len = NF_CT_HELPER_NAME_LEN-1 },
+ [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
+ [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
+};
+
+static int
+nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
+ const struct nlattr *attr)
+{
+ struct nlattr *tb[NFCTH_POLICY_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
+
+ if (!tb[NFCTH_POLICY_NAME] ||
+ !tb[NFCTH_POLICY_EXPECT_MAX] ||
+ !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
+ return -EINVAL;
+
+ strncpy(expect_policy->name,
+ nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
+ expect_policy->max_expected =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
+ expect_policy->timeout =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
+
+ return 0;
+}
+
+static const struct nla_policy
+nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
+ [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
+};
+
+static int
+nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
+ const struct nlattr *attr)
+{
+ int i, ret;
+ struct nf_conntrack_expect_policy *expect_policy;
+ struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
+ nfnl_cthelper_expect_policy_set);
+
+ if (!tb[NFCTH_POLICY_SET_NUM])
+ return -EINVAL;
+
+ helper->expect_class_max =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
+
+ if (helper->expect_class_max != 0 &&
+ helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
+ return -EOVERFLOW;
+
+ expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
+ helper->expect_class_max, GFP_KERNEL);
+ if (expect_policy == NULL)
+ return -ENOMEM;
+
+ for (i=0; i<helper->expect_class_max; i++) {
+ if (!tb[NFCTH_POLICY_SET+i])
+ goto err;
+
+ ret = nfnl_cthelper_expect_policy(&expect_policy[i],
+ tb[NFCTH_POLICY_SET+i]);
+ if (ret < 0)
+ goto err;
+ }
+ helper->expect_policy = expect_policy;
+ return 0;
+err:
+ kfree(expect_policy);
+ return -EINVAL;
+}
+
+static int
+nfnl_cthelper_create(const struct nlattr * const tb[],
+ struct nf_conntrack_tuple *tuple)
+{
+ struct nf_conntrack_helper *helper;
+ int ret;
+
+ if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
+ return -EINVAL;
+
+ helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
+ if (helper == NULL)
+ return -ENOMEM;
+
+ ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
+ if (ret < 0)
+ goto err;
+
+ strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
+ helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
+ helper->flags |= NF_CT_HELPER_F_USERSPACE;
+ memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
+
+ helper->me = THIS_MODULE;
+ helper->help = nfnl_userspace_cthelper;
+ helper->from_nlattr = nfnl_cthelper_from_nlattr;
+ helper->to_nlattr = nfnl_cthelper_to_nlattr;
+
+ /* Default to queue number zero, this can be updated at any time. */
+ if (tb[NFCTH_QUEUE_NUM])
+ helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
+
+ if (tb[NFCTH_STATUS]) {
+ int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
+
+ switch(status) {
+ case NFCT_HELPER_STATUS_ENABLED:
+ helper->flags |= NF_CT_HELPER_F_CONFIGURED;
+ break;
+ case NFCT_HELPER_STATUS_DISABLED:
+ helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
+ break;
+ }
+ }
+
+ ret = nf_conntrack_helper_register(helper);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+err:
+ kfree(helper);
+ return ret;
+}
+
+static int
+nfnl_cthelper_update(const struct nlattr * const tb[],
+ struct nf_conntrack_helper *helper)
+{
+ int ret;
+
+ if (tb[NFCTH_PRIV_DATA_LEN])
+ return -EBUSY;
+
+ if (tb[NFCTH_POLICY]) {
+ ret = nfnl_cthelper_parse_expect_policy(helper,
+ tb[NFCTH_POLICY]);
+ if (ret < 0)
+ return ret;
+ }
+ if (tb[NFCTH_QUEUE_NUM])
+ helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
+
+ if (tb[NFCTH_STATUS]) {
+ int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
+
+ switch(status) {
+ case NFCT_HELPER_STATUS_ENABLED:
+ helper->flags |= NF_CT_HELPER_F_CONFIGURED;
+ break;
+ case NFCT_HELPER_STATUS_DISABLED:
+ helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
+ break;
+ }
+ }
+ return 0;
+}
+
+static int
+nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ const char *helper_name;
+ struct nf_conntrack_helper *cur, *helper = NULL;
+ struct nf_conntrack_tuple tuple;
+ struct hlist_node *n;
+ int ret = 0, i;
+
+ if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
+ return -EINVAL;
+
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ rcu_read_lock();
+ for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
+ hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0)
+ continue;
+
+ if ((tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ if (nlh->nlmsg_flags & NLM_F_EXCL) {
+ ret = -EEXIST;
+ goto err;
+ }
+ helper = cur;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ if (helper == NULL)
+ ret = nfnl_cthelper_create(tb, &tuple);
+ else
+ ret = nfnl_cthelper_update(tb, helper);
+
+ return ret;
+err:
+ rcu_read_unlock();
+ return ret;
+}
+
+static int
+nfnl_cthelper_dump_tuple(struct sk_buff *skb,
+ struct nf_conntrack_helper *helper)
+{
+ struct nlattr *nest_parms;
+
+ nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED);
+ if (nest_parms == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_u16(skb, NFCTH_TUPLE_L3PROTONUM,
+ htons(helper->tuple.src.l3num)))
+ goto nla_put_failure;
+
+ if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static int
+nfnl_cthelper_dump_policy(struct sk_buff *skb,
+ struct nf_conntrack_helper *helper)
+{
+ int i;
+ struct nlattr *nest_parms1, *nest_parms2;
+
+ nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED);
+ if (nest_parms1 == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, NFCTH_POLICY_SET_NUM,
+ htonl(helper->expect_class_max)))
+ goto nla_put_failure;
+
+ for (i=0; i<helper->expect_class_max; i++) {
+ nest_parms2 = nla_nest_start(skb,
+ (NFCTH_POLICY_SET+i) | NLA_F_NESTED);
+ if (nest_parms2 == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_string(skb, NFCTH_POLICY_NAME,
+ helper->expect_policy[i].name))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, NFCTH_POLICY_EXPECT_MAX,
+ htonl(helper->expect_policy[i].max_expected)))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
+ htonl(helper->expect_policy[i].timeout)))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms2);
+ }
+ nla_nest_end(skb, nest_parms1);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static int
+nfnl_cthelper_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type,
+ int event, struct nf_conntrack_helper *helper)
+{
+ struct nlmsghdr *nlh;
+ struct nfgenmsg *nfmsg;
+ unsigned int flags = pid ? NLM_F_MULTI : 0;
+ int status;
+
+ event |= NFNL_SUBSYS_CTHELPER << 8;
+ nlh = nlmsg_put(skb, pid, seq, event, sizeof(*nfmsg), flags);
+ if (nlh == NULL)
+ goto nlmsg_failure;
+
+ nfmsg = nlmsg_data(nlh);
+ nfmsg->nfgen_family = AF_UNSPEC;
+ nfmsg->version = NFNETLINK_V0;
+ nfmsg->res_id = 0;
+
+ if (nla_put_string(skb, NFCTH_NAME, helper->name))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
+ goto nla_put_failure;
+
+ if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
+ goto nla_put_failure;
+
+ if (nfnl_cthelper_dump_policy(skb, helper) < 0)
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
+ goto nla_put_failure;
+
+ if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
+ status = NFCT_HELPER_STATUS_ENABLED;
+ else
+ status = NFCT_HELPER_STATUS_DISABLED;
+
+ if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ return skb->len;
+
+nlmsg_failure:
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -1;
+}
+
+static int
+nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct nf_conntrack_helper *cur, *last;
+ struct hlist_node *n;
+
+ rcu_read_lock();
+ last = (struct nf_conntrack_helper *)cb->args[1];
+ for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
+restart:
+ hlist_for_each_entry_rcu(cur, n,
+ &nf_ct_helper_hash[cb->args[0]], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (cb->args[1]) {
+ if (cur != last)
+ continue;
+ cb->args[1] = 0;
+ }
+ if (nfnl_cthelper_fill_info(skb,
+ NETLINK_CB(cb->skb).pid,
+ cb->nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur) < 0) {
+ cb->args[1] = (unsigned long)cur;
+ goto out;
+ }
+ }
+ }
+ if (cb->args[1]) {
+ cb->args[1] = 0;
+ goto restart;
+ }
+out:
+ rcu_read_unlock();
+ return skb->len;
+}
+
+static int
+nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ int ret = -ENOENT, i;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n;
+ struct sk_buff *skb2;
+ char *helper_name = NULL;
+ struct nf_conntrack_tuple tuple;
+ bool tuple_set = false;
+
+ if (nlh->nlmsg_flags & NLM_F_DUMP) {
+ struct netlink_dump_control c = {
+ .dump = nfnl_cthelper_dump_table,
+ };
+ return netlink_dump_start(nfnl, skb, nlh, &c);
+ }
+
+ if (tb[NFCTH_NAME])
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ if (tb[NFCTH_TUPLE]) {
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ tuple_set = true;
+ }
+
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (helper_name && strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0) {
+ continue;
+ }
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (skb2 == NULL) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).pid,
+ nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur);
+ if (ret <= 0) {
+ kfree_skb(skb2);
+ break;
+ }
+
+ ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).pid,
+ MSG_DONTWAIT);
+ if (ret > 0)
+ ret = 0;
+
+ /* this avoids a loop in nfnetlink. */
+ return ret == -EAGAIN ? -ENOBUFS : ret;
+ }
+ }
+ return ret;
+}
+
+static int
+nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ char *helper_name = NULL;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n, *tmp;
+ struct nf_conntrack_tuple tuple;
+ bool tuple_set = false, found = false;
+ int i, j = 0, ret;
+
+ if (tb[NFCTH_NAME])
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ if (tb[NFCTH_TUPLE]) {
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ tuple_set = true;
+ }
+
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
+ hnode) {
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ j++;
+
+ if (helper_name && strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0) {
+ continue;
+ }
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ found = true;
+ nf_conntrack_helper_unregister(cur);
+ }
+ }
+ /* Make sure we return success if we flush and there is no helpers */
+ return (found || j == 0) ? 0 : -ENOENT;
+}
+
+static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
+ [NFCTH_NAME] = { .type = NLA_NUL_STRING,
+ .len = NF_CT_HELPER_NAME_LEN-1 },
+ [NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
+};
+
+static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
+ [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+ [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+ [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+};
+
+static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
+ .name = "cthelper",
+ .subsys_id = NFNL_SUBSYS_CTHELPER,
+ .cb_count = NFNL_MSG_CTHELPER_MAX,
+ .cb = nfnl_cthelper_cb,
+};
+
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
+
+static int __init nfnl_cthelper_init(void)
+{
+ int ret;
+
+ pr_info("nfnl_cthelper: registering with nfnetlink.\n");
+ ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
+ if (ret < 0) {
+ pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
+ goto err_out;
+ }
+ return 0;
+err_out:
+ return ret;
+}
+
+static void __exit nfnl_cthelper_exit(void)
+{
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n, *tmp;
+ int i;
+
+ pr_info("nfnl_cthelper: unregistering from nfnetlink.\n");
+ nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
+
+ for (i=0; i<nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
+ hnode) {
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ nf_conntrack_helper_unregister(cur);
+ }
+ }
+}
+
+module_init(nfnl_cthelper_init);
+module_exit(nfnl_cthelper_exit);
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* Re: [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data
2012-06-04 12:21 ` [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data pablo
@ 2012-06-04 13:06 ` Jan Engelhardt
2012-06-04 13:09 ` Joe Perches
0 siblings, 1 reply; 17+ messages in thread
From: Jan Engelhardt @ 2012-06-04 13:06 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
On Monday 2012-06-04 14:21, pablo@netfilter.org wrote:
>+static inline void *nfct_help_data(const struct nf_conn *ct)
>+{
>+ struct nf_conn_help *help;
>+
>+ help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
>+
>+ return (void *)&help->data;
>+}
I think you wanted
return help->data;
here. Remember that help->data is of type char[0] which is
convertible to char* - which is what you want,
while adding an extra & would turn that into the undesired (char[0])*.
>@@ -89,12 +59,13 @@ struct nf_conn_help {
> /* Helper. if any */
> struct nf_conntrack_helper __rcu *helper;
>
>- union nf_conntrack_help help;
>-
> struct hlist_head expectations;
>
> /* Current number of expected connections */
> u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
>+
>+ /* private helper information. */
>+ char data[0];
There is a now-standardized notation:
char data[];
>@@ -218,13 +221,13 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
> }
>
> if (help == NULL) {
>- help = nf_ct_helper_ext_add(ct, flags);
>+ help = nf_ct_helper_ext_add(ct, helper, flags);
> if (help == NULL) {
> ret = -ENOMEM;
> goto out;
> }
> } else {
>- memset(&help->help, 0, sizeof(help->help));
>+ memset(&help->data, 0, sizeof(helper->data_len));
> }
memset(help->data, 0, sizeof(helper->data_len));
>index 6f4b00a..30f5e12 100644
>--- a/net/netfilter/nf_conntrack_netlink.c
>+++ b/net/netfilter/nf_conntrack_netlink.c
>@@ -1218,7 +1218,7 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[])
> if (help->helper)
> return -EBUSY;
> /* need to zero data of old helper */
>- memset(&help->help, 0, sizeof(help->help));
>+ memset(&help->data, 0, help->helper->data_len);
Here too.. memset(help->data,...
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data
2012-06-04 13:06 ` Jan Engelhardt
@ 2012-06-04 13:09 ` Joe Perches
2012-06-04 13:16 ` Jan Engelhardt
0 siblings, 1 reply; 17+ messages in thread
From: Joe Perches @ 2012-06-04 13:09 UTC (permalink / raw)
To: Jan Engelhardt; +Cc: pablo, netfilter-devel, netdev
On Mon, 2012-06-04 at 15:06 +0200, Jan Engelhardt wrote:
> On Monday 2012-06-04 14:21, pablo@netfilter.org wrote:
> >@@ -218,13 +221,13 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
> > }
> >
> > if (help == NULL) {
> >- help = nf_ct_helper_ext_add(ct, flags);
> >+ help = nf_ct_helper_ext_add(ct, helper, flags);
> > if (help == NULL) {
> > ret = -ENOMEM;
> > goto out;
> > }
> > } else {
> >- memset(&help->help, 0, sizeof(help->help));
> >+ memset(&help->data, 0, sizeof(helper->data_len));
> > }
>
> memset(help->data, 0, sizeof(helper->data_len));
memset(help->data, 0, helper->data_len);
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data
2012-06-04 13:09 ` Joe Perches
@ 2012-06-04 13:16 ` Jan Engelhardt
0 siblings, 0 replies; 17+ messages in thread
From: Jan Engelhardt @ 2012-06-04 13:16 UTC (permalink / raw)
To: Joe Perches; +Cc: pablo, netfilter-devel, netdev
On Monday 2012-06-04 15:09, Joe Perches wrote:
>On Mon, 2012-06-04 at 15:06 +0200, Jan Engelhardt wrote:
>> On Monday 2012-06-04 14:21, pablo@netfilter.org wrote:
>
>> >@@ -218,13 +221,13 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
>> > }
>> >
>> > if (help == NULL) {
>> >- help = nf_ct_helper_ext_add(ct, flags);
>> >+ help = nf_ct_helper_ext_add(ct, helper, flags);
>> > if (help == NULL) {
>> > ret = -ENOMEM;
>> > goto out;
>> > }
>> > } else {
>> >- memset(&help->help, 0, sizeof(help->help));
>> >+ memset(&help->data, 0, sizeof(helper->data_len));
>> > }
>>
>> memset(help->data, 0, sizeof(helper->data_len));
>
> memset(help->data, 0, helper->data_len);
I knew this looked suspect. With so many "sizeof"s, this spot was
starting to look like a "mine is bigger" competition.
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH 4/7] netfilter: add glue code to integrate nfnetlink_queue and ctnetlink
2012-06-04 12:21 ` [PATCH 4/7] netfilter: add glue code to integrate nfnetlink_queue and ctnetlink pablo
@ 2012-06-04 13:38 ` Jan Engelhardt
0 siblings, 0 replies; 17+ messages in thread
From: Jan Engelhardt @ 2012-06-04 13:38 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
On Monday 2012-06-04 14:21, pablo@netfilter.org wrote:
>+static int
>+ctnetlink_nfqueue_parse(const struct nlattr *attr, struct nf_conn *ct)
>+{
>+ const struct nlattr * const cda[CTA_MAX+1];
I suppose you wrote that because the same appears in function
headers/signatures
void foo(const struct nlattr *const tb[]) { ... }
But there, it is actually equal to
void foo(const struct nlattr *const *tb) { ... }
In either case, tb is writable. IMHO, [] should be avoided in
signatures to avoid self-confusion, as it seemed to occur in your
case, where cda is - unlike tb - really marked const.
You likely wanted
const struct nlattr *cda[CTA_MAX+1];
>+ nla_parse_nested((struct nlattr **)cda, CTA_MAX, attr, ct_nla_policy);
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure
2012-06-04 12:21 ` [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure pablo
@ 2012-06-04 14:04 ` Jan Engelhardt
2012-06-06 9:39 ` Ferenc Wagner
1 sibling, 0 replies; 17+ messages in thread
From: Jan Engelhardt @ 2012-06-04 14:04 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
On Monday 2012-06-04 14:21, pablo@netfilter.org wrote:
>+static int
>+nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
>+{
>+ const struct nf_conn_help *help = nfct_help(ct);
>+
>+ if (help->helper->data_len == 0)
>+ return -EINVAL;
>+
>+ memcpy(&help->data, nla_data(attr), help->helper->data_len);
memcpy(help->data, ...)
>+static int
>+nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
>+{
>+ const struct nf_conn_help *help = nfct_help(ct);
>+
>+ if (help->helper->data_len &&
>+ nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
>+ goto nla_put_failure;
help->data
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure
2012-06-04 12:21 ` [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure pablo
2012-06-04 14:04 ` Jan Engelhardt
@ 2012-06-06 9:39 ` Ferenc Wagner
1 sibling, 0 replies; 17+ messages in thread
From: Ferenc Wagner @ 2012-06-06 9:39 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev, wferi
pablo@netfilter.org writes:
> * Security: Avoid complex string matching and mangling in kernel-space
> running in unprivileged mode.
Or rather in privileged mode?
> 2) Add rules to enable the FTP user-space helper which is
> used to track traffic going to TCP port 10000.
The examples use port 21 in the iptables commands and the expectations:
> iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp
> iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp
>
> [NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
> [DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
--
Regards,
Feri.
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure
2012-06-16 15:49 [PATCH 0/7] netfilter updates for net-next (upcoming 3.6), batch 2 pablo
@ 2012-06-16 15:49 ` pablo
0 siblings, 0 replies; 17+ messages in thread
From: pablo @ 2012-06-16 15:49 UTC (permalink / raw)
To: netfilter-devel; +Cc: davem, netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
There are good reasons to supports helpers in user-space instead:
* Rapid connection tracking helper development, as developing code
in user-space is usually faster.
* Reliability: A buggy helper does not crash the kernel. Moreover,
we can monitor the helper process and restart it in case of problems.
* Security: Avoid complex string matching and mangling in kernel-space
running in privileged mode. Going further, we can even think about
running user-space helpers as a non-root process.
* Extensibility: It allows the development of very specific helpers (most
likely non-standard proprietary protocols) that are very likely not to be
accepted for mainline inclusion in the form of kernel-space connection
tracking helpers.
This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).
I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.
Basic operation, in a few steps:
1) Register user-space helper by means of `nfct':
nfct helper add ftp inet tcp
[ It must be a valid existing helper supported by conntrack-tools ]
2) Add rules to enable the FTP user-space helper which is
used to track traffic going to TCP port 21.
For locally generated packets:
iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp
For non-locally generated packets:
iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp
3) Run the test conntrackd in helper mode (see example files under
doc/helper/conntrackd.conf
conntrackd
4) Generate FTP traffic going, if everything is OK, then conntrackd
should create expectations (you can check that with `conntrack':
conntrack -E expect
[NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.
The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter/Kbuild | 1 +
include/linux/netfilter/nfnetlink.h | 3 +-
include/linux/netfilter/nfnetlink_cthelper.h | 55 ++
include/linux/netfilter_ipv4.h | 1 +
include/linux/netfilter_ipv6.h | 1 +
include/net/netfilter/nf_conntrack_helper.h | 11 +
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 48 +-
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 43 +-
net/netfilter/Kconfig | 8 +
net/netfilter/Makefile | 1 +
net/netfilter/nf_conntrack_helper.c | 21 +-
net/netfilter/nfnetlink_cthelper.c | 672 ++++++++++++++++++++++++
12 files changed, 839 insertions(+), 26 deletions(-)
create mode 100644 include/linux/netfilter/nfnetlink_cthelper.h
create mode 100644 net/netfilter/nfnetlink_cthelper.c
diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild
index 1697036..874ae8f 100644
--- a/include/linux/netfilter/Kbuild
+++ b/include/linux/netfilter/Kbuild
@@ -10,6 +10,7 @@ header-y += nfnetlink.h
header-y += nfnetlink_acct.h
header-y += nfnetlink_compat.h
header-y += nfnetlink_conntrack.h
+header-y += nfnetlink_cthelper.h
header-y += nfnetlink_cttimeout.h
header-y += nfnetlink_log.h
header-y += nfnetlink_queue.h
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index a1048c1..18341cd 100644
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -50,7 +50,8 @@ struct nfgenmsg {
#define NFNL_SUBSYS_IPSET 6
#define NFNL_SUBSYS_ACCT 7
#define NFNL_SUBSYS_CTNETLINK_TIMEOUT 8
-#define NFNL_SUBSYS_COUNT 9
+#define NFNL_SUBSYS_CTHELPER 9
+#define NFNL_SUBSYS_COUNT 10
#ifdef __KERNEL__
diff --git a/include/linux/netfilter/nfnetlink_cthelper.h b/include/linux/netfilter/nfnetlink_cthelper.h
new file mode 100644
index 0000000..33659f6
--- /dev/null
+++ b/include/linux/netfilter/nfnetlink_cthelper.h
@@ -0,0 +1,55 @@
+#ifndef _NFNL_CTHELPER_H_
+#define _NFNL_CTHELPER_H_
+
+#define NFCT_HELPER_STATUS_DISABLED 0
+#define NFCT_HELPER_STATUS_ENABLED 1
+
+enum nfnl_acct_msg_types {
+ NFNL_MSG_CTHELPER_NEW,
+ NFNL_MSG_CTHELPER_GET,
+ NFNL_MSG_CTHELPER_DEL,
+ NFNL_MSG_CTHELPER_MAX
+};
+
+enum nfnl_cthelper_type {
+ NFCTH_UNSPEC,
+ NFCTH_NAME,
+ NFCTH_TUPLE,
+ NFCTH_QUEUE_NUM,
+ NFCTH_POLICY,
+ NFCTH_PRIV_DATA_LEN,
+ NFCTH_STATUS,
+ __NFCTH_MAX
+};
+#define NFCTH_MAX (__NFCTH_MAX - 1)
+
+enum nfnl_cthelper_policy_type {
+ NFCTH_POLICY_SET_UNSPEC,
+ NFCTH_POLICY_SET_NUM,
+ NFCTH_POLICY_SET,
+ NFCTH_POLICY_SET1 = NFCTH_POLICY_SET,
+ NFCTH_POLICY_SET2,
+ NFCTH_POLICY_SET3,
+ NFCTH_POLICY_SET4,
+ __NFCTH_POLICY_SET_MAX
+};
+#define NFCTH_POLICY_SET_MAX (__NFCTH_POLICY_SET_MAX - 1)
+
+enum nfnl_cthelper_pol_type {
+ NFCTH_POLICY_UNSPEC,
+ NFCTH_POLICY_NAME,
+ NFCTH_POLICY_EXPECT_MAX,
+ NFCTH_POLICY_EXPECT_TIMEOUT,
+ __NFCTH_POLICY_MAX
+};
+#define NFCTH_POLICY_MAX (__NFCTH_POLICY_MAX - 1)
+
+enum nfnl_cthelper_tuple_type {
+ NFCTH_TUPLE_UNSPEC,
+ NFCTH_TUPLE_L3PROTONUM,
+ NFCTH_TUPLE_L4PROTONUM,
+ __NFCTH_TUPLE_MAX,
+};
+#define NFCTH_TUPLE_MAX (__NFCTH_TUPLE_MAX - 1)
+
+#endif /* _NFNL_CTHELPER_H */
diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h
index fa0946c..e2b1280 100644
--- a/include/linux/netfilter_ipv4.h
+++ b/include/linux/netfilter_ipv4.h
@@ -66,6 +66,7 @@ enum nf_ip_hook_priorities {
NF_IP_PRI_SECURITY = 50,
NF_IP_PRI_NAT_SRC = 100,
NF_IP_PRI_SELINUX_LAST = 225,
+ NF_IP_PRI_CONNTRACK_HELPER = 300,
NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX,
NF_IP_PRI_LAST = INT_MAX,
};
diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h
index 57c0251..7c8a513 100644
--- a/include/linux/netfilter_ipv6.h
+++ b/include/linux/netfilter_ipv6.h
@@ -71,6 +71,7 @@ enum nf_ip6_hook_priorities {
NF_IP6_PRI_SECURITY = 50,
NF_IP6_PRI_NAT_SRC = 100,
NF_IP6_PRI_SELINUX_LAST = 225,
+ NF_IP6_PRI_CONNTRACK_HELPER = 300,
NF_IP6_PRI_LAST = INT_MAX,
};
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 84b24c3..9aad956 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -15,6 +15,11 @@
struct module;
+enum nf_ct_helper_flags {
+ NF_CT_HELPER_F_USERSPACE = (1 << 0),
+ NF_CT_HELPER_F_CONFIGURED = (1 << 1),
+};
+
#define NF_CT_HELPER_NAME_LEN 16
struct nf_conntrack_helper {
@@ -42,6 +47,9 @@ struct nf_conntrack_helper {
int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
unsigned int expect_class_max;
+
+ unsigned int flags;
+ unsigned int queue_num; /* For user-space helpers. */
};
extern struct nf_conntrack_helper *
@@ -96,4 +104,7 @@ nf_ct_helper_expectfn_find_by_name(const char *name);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
+extern struct hlist_head *nf_ct_helper_hash;
+extern unsigned int nf_ct_helper_hsize;
+
#endif /*_NF_CONNTRACK_HELPER_H*/
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index d79b961..e7ff2dc 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -95,11 +95,11 @@ static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
return NF_ACCEPT;
}
-static unsigned int ipv4_confirm(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+static unsigned int ipv4_helper(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
@@ -110,24 +110,38 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- goto out;
+ return NF_ACCEPT;
help = nfct_help(ct);
if (!help)
- goto out;
+ return NF_ACCEPT;
/* rcu_read_lock()ed by nf_hook_slow */
helper = rcu_dereference(help->helper);
if (!helper)
- goto out;
+ return NF_ACCEPT;
ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
ct, ctinfo);
- if (ret != NF_ACCEPT) {
+ if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
"nf_ct_%s: dropping packet", helper->name);
- return ret;
}
+ return ret;
+}
+
+static unsigned int ipv4_confirm(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ goto out;
/* adjust seqs for loopback traffic only in outgoing direction */
if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
@@ -185,6 +199,13 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
.priority = NF_IP_PRI_CONNTRACK,
},
{
+ .hook = ipv4_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV4,
@@ -192,6 +213,13 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
.priority = NF_IP_PRI_CONNTRACK_CONFIRM,
},
{
+ .hook = ipv4_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV4,
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index fca10da..4794f96 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -143,11 +143,11 @@ static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
return NF_ACCEPT;
}
-static unsigned int ipv6_confirm(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+static unsigned int ipv6_helper(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
const struct nf_conn_help *help;
@@ -161,15 +161,15 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- goto out;
+ return NF_ACCEPT;
help = nfct_help(ct);
if (!help)
- goto out;
+ return NF_ACCEPT;
/* rcu_read_lock()ed by nf_hook_slow */
helper = rcu_dereference(help->helper);
if (!helper)
- goto out;
+ return NF_ACCEPT;
protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum,
skb->len - extoff);
@@ -179,12 +179,19 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
}
ret = helper->help(skb, protoff, ct, ctinfo);
- if (ret != NF_ACCEPT) {
+ if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
nf_log_packet(NFPROTO_IPV6, hooknum, skb, in, out, NULL,
"nf_ct_%s: dropping packet", helper->name);
- return ret;
}
-out:
+ return ret;
+}
+
+static unsigned int ipv6_confirm(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(skb);
}
@@ -254,6 +261,13 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_CONNTRACK,
},
{
+ .hook = ipv6_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP6_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV6,
@@ -261,6 +275,13 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_LAST,
},
{
+ .hook = ipv6_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP6_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV6,
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 209c1ed..aae6c62 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -12,6 +12,14 @@ tristate "Netfilter NFACCT over NFNETLINK interface"
If this option is enabled, the kernel will include support
for extended accounting via NFNETLINK.
+config NETFILTER_NETLINK_CTHELPER
+tristate "Netfilter CTHELPER over NFNETLINK interface"
+ depends on NETFILTER_ADVANCED
+ select NETFILTER_NETLINK
+ help
+ If this option is enabled, the kernel will include support
+ for user-space connection tracking helpers via NFNETLINK.
+
config NETFILTER_NETLINK_QUEUE
tristate "Netfilter NFQUEUE over NFNETLINK interface"
depends on NETFILTER_ADVANCED
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 4e7960c..2f3bc0f 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_NETFILTER) = netfilter.o
obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
obj-$(CONFIG_NETFILTER_NETLINK_ACCT) += nfnetlink_acct.o
+obj-$(CONFIG_NETFILTER_NETLINK_CTHELPER) += nfnetlink_cthelper.o
obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 9c18ecb..2918ec2 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -30,8 +30,10 @@
#include <net/netfilter/nf_conntrack_extend.h>
static DEFINE_MUTEX(nf_ct_helper_mutex);
-static struct hlist_head *nf_ct_helper_hash __read_mostly;
-static unsigned int nf_ct_helper_hsize __read_mostly;
+struct hlist_head *nf_ct_helper_hash __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_helper_hash);
+unsigned int nf_ct_helper_hsize __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_helper_hsize);
static unsigned int nf_ct_helper_count __read_mostly;
static bool nf_ct_auto_assign_helper __read_mostly = true;
@@ -322,6 +324,9 @@ EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
+ int ret = 0;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n;
unsigned int h = helper_hash(&me->tuple);
BUG_ON(me->expect_policy == NULL);
@@ -329,11 +334,19 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1);
mutex_lock(&nf_ct_helper_mutex);
+ hlist_for_each_entry(cur, n, &nf_ct_helper_hash[h], hnode) {
+ if (strncmp(cur->name, me->name, NF_CT_HELPER_NAME_LEN) == 0 &&
+ cur->tuple.src.l3num == me->tuple.src.l3num &&
+ cur->tuple.dst.protonum == me->tuple.dst.protonum) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]);
nf_ct_helper_count++;
+out:
mutex_unlock(&nf_ct_helper_mutex);
-
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_helper_register);
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
new file mode 100644
index 0000000..d683619
--- /dev/null
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -0,0 +1,672 @@
+/*
+ * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation (or any later at your option).
+ *
+ * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <net/netlink.h>
+#include <net/sock.h>
+
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+#include <linux/netfilter/nfnetlink_cthelper.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
+
+static int
+nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+ const struct nf_conn_help *help;
+ struct nf_conntrack_helper *helper;
+
+ help = nfct_help(ct);
+ if (help == NULL)
+ return NF_DROP;
+
+ /* rcu_read_lock()ed by nf_hook_slow */
+ helper = rcu_dereference(help->helper);
+ if (helper == NULL)
+ return NF_DROP;
+
+ /* This is an user-space helper not yet configured, skip. */
+ if ((helper->flags &
+ (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
+ NF_CT_HELPER_F_USERSPACE)
+ return NF_ACCEPT;
+
+ /* If the user-space helper is not available, don't block traffic. */
+ return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
+}
+
+static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
+ [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
+ [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
+};
+
+static int
+nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nlattr *attr)
+{
+ struct nlattr *tb[NFCTH_TUPLE_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
+
+ if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
+ return -EINVAL;
+
+ tuple->src.l3num = ntohs(nla_get_u16(tb[NFCTH_TUPLE_L3PROTONUM]));
+ tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
+
+ return 0;
+}
+
+static int
+nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
+{
+ const struct nf_conn_help *help = nfct_help(ct);
+
+ if (help->helper->data_len == 0)
+ return -EINVAL;
+
+ memcpy(&help->data, nla_data(attr), help->helper->data_len);
+ return 0;
+}
+
+static int
+nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
+{
+ const struct nf_conn_help *help = nfct_help(ct);
+
+ if (help->helper->data_len &&
+ nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -ENOSPC;
+}
+
+static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
+ [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
+ .len = NF_CT_HELPER_NAME_LEN-1 },
+ [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
+ [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
+};
+
+static int
+nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
+ const struct nlattr *attr)
+{
+ struct nlattr *tb[NFCTH_POLICY_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
+
+ if (!tb[NFCTH_POLICY_NAME] ||
+ !tb[NFCTH_POLICY_EXPECT_MAX] ||
+ !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
+ return -EINVAL;
+
+ strncpy(expect_policy->name,
+ nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
+ expect_policy->max_expected =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
+ expect_policy->timeout =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
+
+ return 0;
+}
+
+static const struct nla_policy
+nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
+ [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
+};
+
+static int
+nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
+ const struct nlattr *attr)
+{
+ int i, ret;
+ struct nf_conntrack_expect_policy *expect_policy;
+ struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
+ nfnl_cthelper_expect_policy_set);
+
+ if (!tb[NFCTH_POLICY_SET_NUM])
+ return -EINVAL;
+
+ helper->expect_class_max =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
+
+ if (helper->expect_class_max != 0 &&
+ helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
+ return -EOVERFLOW;
+
+ expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
+ helper->expect_class_max, GFP_KERNEL);
+ if (expect_policy == NULL)
+ return -ENOMEM;
+
+ for (i=0; i<helper->expect_class_max; i++) {
+ if (!tb[NFCTH_POLICY_SET+i])
+ goto err;
+
+ ret = nfnl_cthelper_expect_policy(&expect_policy[i],
+ tb[NFCTH_POLICY_SET+i]);
+ if (ret < 0)
+ goto err;
+ }
+ helper->expect_policy = expect_policy;
+ return 0;
+err:
+ kfree(expect_policy);
+ return -EINVAL;
+}
+
+static int
+nfnl_cthelper_create(const struct nlattr * const tb[],
+ struct nf_conntrack_tuple *tuple)
+{
+ struct nf_conntrack_helper *helper;
+ int ret;
+
+ if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
+ return -EINVAL;
+
+ helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
+ if (helper == NULL)
+ return -ENOMEM;
+
+ ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
+ if (ret < 0)
+ goto err;
+
+ strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
+ helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
+ helper->flags |= NF_CT_HELPER_F_USERSPACE;
+ memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
+
+ helper->me = THIS_MODULE;
+ helper->help = nfnl_userspace_cthelper;
+ helper->from_nlattr = nfnl_cthelper_from_nlattr;
+ helper->to_nlattr = nfnl_cthelper_to_nlattr;
+
+ /* Default to queue number zero, this can be updated at any time. */
+ if (tb[NFCTH_QUEUE_NUM])
+ helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
+
+ if (tb[NFCTH_STATUS]) {
+ int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
+
+ switch(status) {
+ case NFCT_HELPER_STATUS_ENABLED:
+ helper->flags |= NF_CT_HELPER_F_CONFIGURED;
+ break;
+ case NFCT_HELPER_STATUS_DISABLED:
+ helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
+ break;
+ }
+ }
+
+ ret = nf_conntrack_helper_register(helper);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+err:
+ kfree(helper);
+ return ret;
+}
+
+static int
+nfnl_cthelper_update(const struct nlattr * const tb[],
+ struct nf_conntrack_helper *helper)
+{
+ int ret;
+
+ if (tb[NFCTH_PRIV_DATA_LEN])
+ return -EBUSY;
+
+ if (tb[NFCTH_POLICY]) {
+ ret = nfnl_cthelper_parse_expect_policy(helper,
+ tb[NFCTH_POLICY]);
+ if (ret < 0)
+ return ret;
+ }
+ if (tb[NFCTH_QUEUE_NUM])
+ helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
+
+ if (tb[NFCTH_STATUS]) {
+ int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
+
+ switch(status) {
+ case NFCT_HELPER_STATUS_ENABLED:
+ helper->flags |= NF_CT_HELPER_F_CONFIGURED;
+ break;
+ case NFCT_HELPER_STATUS_DISABLED:
+ helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
+ break;
+ }
+ }
+ return 0;
+}
+
+static int
+nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ const char *helper_name;
+ struct nf_conntrack_helper *cur, *helper = NULL;
+ struct nf_conntrack_tuple tuple;
+ struct hlist_node *n;
+ int ret = 0, i;
+
+ if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
+ return -EINVAL;
+
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ rcu_read_lock();
+ for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
+ hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0)
+ continue;
+
+ if ((tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ if (nlh->nlmsg_flags & NLM_F_EXCL) {
+ ret = -EEXIST;
+ goto err;
+ }
+ helper = cur;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ if (helper == NULL)
+ ret = nfnl_cthelper_create(tb, &tuple);
+ else
+ ret = nfnl_cthelper_update(tb, helper);
+
+ return ret;
+err:
+ rcu_read_unlock();
+ return ret;
+}
+
+static int
+nfnl_cthelper_dump_tuple(struct sk_buff *skb,
+ struct nf_conntrack_helper *helper)
+{
+ struct nlattr *nest_parms;
+
+ nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED);
+ if (nest_parms == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
+ htons(helper->tuple.src.l3num)))
+ goto nla_put_failure;
+
+ if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static int
+nfnl_cthelper_dump_policy(struct sk_buff *skb,
+ struct nf_conntrack_helper *helper)
+{
+ int i;
+ struct nlattr *nest_parms1, *nest_parms2;
+
+ nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED);
+ if (nest_parms1 == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
+ htonl(helper->expect_class_max)))
+ goto nla_put_failure;
+
+ for (i=0; i<helper->expect_class_max; i++) {
+ nest_parms2 = nla_nest_start(skb,
+ (NFCTH_POLICY_SET+i) | NLA_F_NESTED);
+ if (nest_parms2 == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_string(skb, NFCTH_POLICY_NAME,
+ helper->expect_policy[i].name))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
+ htonl(helper->expect_policy[i].max_expected)))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
+ htonl(helper->expect_policy[i].timeout)))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms2);
+ }
+ nla_nest_end(skb, nest_parms1);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static int
+nfnl_cthelper_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type,
+ int event, struct nf_conntrack_helper *helper)
+{
+ struct nlmsghdr *nlh;
+ struct nfgenmsg *nfmsg;
+ unsigned int flags = pid ? NLM_F_MULTI : 0;
+ int status;
+
+ event |= NFNL_SUBSYS_CTHELPER << 8;
+ nlh = nlmsg_put(skb, pid, seq, event, sizeof(*nfmsg), flags);
+ if (nlh == NULL)
+ goto nlmsg_failure;
+
+ nfmsg = nlmsg_data(nlh);
+ nfmsg->nfgen_family = AF_UNSPEC;
+ nfmsg->version = NFNETLINK_V0;
+ nfmsg->res_id = 0;
+
+ if (nla_put_string(skb, NFCTH_NAME, helper->name))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
+ goto nla_put_failure;
+
+ if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
+ goto nla_put_failure;
+
+ if (nfnl_cthelper_dump_policy(skb, helper) < 0)
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
+ goto nla_put_failure;
+
+ if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
+ status = NFCT_HELPER_STATUS_ENABLED;
+ else
+ status = NFCT_HELPER_STATUS_DISABLED;
+
+ if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ return skb->len;
+
+nlmsg_failure:
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -1;
+}
+
+static int
+nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct nf_conntrack_helper *cur, *last;
+ struct hlist_node *n;
+
+ rcu_read_lock();
+ last = (struct nf_conntrack_helper *)cb->args[1];
+ for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
+restart:
+ hlist_for_each_entry_rcu(cur, n,
+ &nf_ct_helper_hash[cb->args[0]], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (cb->args[1]) {
+ if (cur != last)
+ continue;
+ cb->args[1] = 0;
+ }
+ if (nfnl_cthelper_fill_info(skb,
+ NETLINK_CB(cb->skb).pid,
+ cb->nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur) < 0) {
+ cb->args[1] = (unsigned long)cur;
+ goto out;
+ }
+ }
+ }
+ if (cb->args[1]) {
+ cb->args[1] = 0;
+ goto restart;
+ }
+out:
+ rcu_read_unlock();
+ return skb->len;
+}
+
+static int
+nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ int ret = -ENOENT, i;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n;
+ struct sk_buff *skb2;
+ char *helper_name = NULL;
+ struct nf_conntrack_tuple tuple;
+ bool tuple_set = false;
+
+ if (nlh->nlmsg_flags & NLM_F_DUMP) {
+ struct netlink_dump_control c = {
+ .dump = nfnl_cthelper_dump_table,
+ };
+ return netlink_dump_start(nfnl, skb, nlh, &c);
+ }
+
+ if (tb[NFCTH_NAME])
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ if (tb[NFCTH_TUPLE]) {
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ tuple_set = true;
+ }
+
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (helper_name && strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0) {
+ continue;
+ }
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (skb2 == NULL) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).pid,
+ nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur);
+ if (ret <= 0) {
+ kfree_skb(skb2);
+ break;
+ }
+
+ ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).pid,
+ MSG_DONTWAIT);
+ if (ret > 0)
+ ret = 0;
+
+ /* this avoids a loop in nfnetlink. */
+ return ret == -EAGAIN ? -ENOBUFS : ret;
+ }
+ }
+ return ret;
+}
+
+static int
+nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ char *helper_name = NULL;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n, *tmp;
+ struct nf_conntrack_tuple tuple;
+ bool tuple_set = false, found = false;
+ int i, j = 0, ret;
+
+ if (tb[NFCTH_NAME])
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ if (tb[NFCTH_TUPLE]) {
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ tuple_set = true;
+ }
+
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
+ hnode) {
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ j++;
+
+ if (helper_name && strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0) {
+ continue;
+ }
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ found = true;
+ nf_conntrack_helper_unregister(cur);
+ }
+ }
+ /* Make sure we return success if we flush and there is no helpers */
+ return (found || j == 0) ? 0 : -ENOENT;
+}
+
+static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
+ [NFCTH_NAME] = { .type = NLA_NUL_STRING,
+ .len = NF_CT_HELPER_NAME_LEN-1 },
+ [NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
+};
+
+static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
+ [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+ [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+ [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+};
+
+static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
+ .name = "cthelper",
+ .subsys_id = NFNL_SUBSYS_CTHELPER,
+ .cb_count = NFNL_MSG_CTHELPER_MAX,
+ .cb = nfnl_cthelper_cb,
+};
+
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
+
+static int __init nfnl_cthelper_init(void)
+{
+ int ret;
+
+ ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
+ if (ret < 0) {
+ pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
+ goto err_out;
+ }
+ return 0;
+err_out:
+ return ret;
+}
+
+static void __exit nfnl_cthelper_exit(void)
+{
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n, *tmp;
+ int i;
+
+ nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
+
+ for (i=0; i<nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
+ hnode) {
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ nf_conntrack_helper_unregister(cur);
+ }
+ }
+}
+
+module_init(nfnl_cthelper_init);
+module_exit(nfnl_cthelper_exit);
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
* Re: [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure
2012-06-12 18:06 ` [PATCH 7/7] netfilter: add " pablo
@ 2012-06-12 22:46 ` David Miller
0 siblings, 0 replies; 17+ messages in thread
From: David Miller @ 2012-06-12 22:46 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
From: pablo@netfilter.org
Date: Tue, 12 Jun 2012 20:06:20 +0200
> + pr_info("nfnl_cthelper: registering with nfnetlink.\n");
...
> + pr_info("nfnl_cthelper: unregistering from nfnetlink.\n");
These messages are fine during development, but not for the copy you
actually finally commit into your tree :-)
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure
2012-06-12 18:06 [PATCH 0/7] [RFCv2] new " pablo
@ 2012-06-12 18:06 ` pablo
2012-06-12 22:46 ` David Miller
0 siblings, 1 reply; 17+ messages in thread
From: pablo @ 2012-06-12 18:06 UTC (permalink / raw)
To: netfilter-devel; +Cc: netdev
From: Pablo Neira Ayuso <pablo@netfilter.org>
There are good reasons to supports helpers in user-space instead:
* Rapid connection tracking helper development, as developing code
in user-space is usually faster.
* Reliability: A buggy helper does not crash the kernel. Moreover,
we can monitor the helper process and restart it in case of problems.
* Security: Avoid complex string matching and mangling in kernel-space
running in privileged mode. Going further, we can even think about
running user-space helpers as a non-root process.
* Extensibility: It allows the development of very specific helpers (most
likely non-standard proprietary protocols) that are very likely not to be
accepted for mainline inclusion in the form of kernel-space connection
tracking helpers.
This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).
I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.
Basic operation, in a few steps:
1) Register user-space helper by means of `nfct':
nfct helper add ftp inet
[ It must be a valid existing helper supported by conntrack-tools.
2) Add rules to enable the FTP user-space helper which is
used to track traffic going to TCP port 21.
For locally generated packets:
iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp
For non-locally generated packets:
iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp
3) Run the test conntrackd in helper mode (see example files under
doc/helper/conntrackd.conf
conntrackd
4) Generate FTP traffic going, if everything is OK, then conntrackd
should create expectations (you can check that with `conntrack':
conntrack -E expect
[NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.
The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter/Kbuild | 1 +
include/linux/netfilter/nfnetlink.h | 3 +-
include/linux/netfilter/nfnetlink_cthelper.h | 55 ++
include/linux/netfilter_ipv4.h | 1 +
include/linux/netfilter_ipv6.h | 1 +
include/net/netfilter/nf_conntrack_helper.h | 11 +
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 49 +-
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 49 +-
net/netfilter/Kconfig | 8 +
net/netfilter/Makefile | 1 +
net/netfilter/nf_conntrack_helper.c | 21 +-
net/netfilter/nfnetlink_cthelper.c | 674 ++++++++++++++++++++++++
12 files changed, 848 insertions(+), 26 deletions(-)
create mode 100644 include/linux/netfilter/nfnetlink_cthelper.h
create mode 100644 net/netfilter/nfnetlink_cthelper.c
diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild
index 1697036..874ae8f 100644
--- a/include/linux/netfilter/Kbuild
+++ b/include/linux/netfilter/Kbuild
@@ -10,6 +10,7 @@ header-y += nfnetlink.h
header-y += nfnetlink_acct.h
header-y += nfnetlink_compat.h
header-y += nfnetlink_conntrack.h
+header-y += nfnetlink_cthelper.h
header-y += nfnetlink_cttimeout.h
header-y += nfnetlink_log.h
header-y += nfnetlink_queue.h
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index a1048c1..18341cd 100644
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -50,7 +50,8 @@ struct nfgenmsg {
#define NFNL_SUBSYS_IPSET 6
#define NFNL_SUBSYS_ACCT 7
#define NFNL_SUBSYS_CTNETLINK_TIMEOUT 8
-#define NFNL_SUBSYS_COUNT 9
+#define NFNL_SUBSYS_CTHELPER 9
+#define NFNL_SUBSYS_COUNT 10
#ifdef __KERNEL__
diff --git a/include/linux/netfilter/nfnetlink_cthelper.h b/include/linux/netfilter/nfnetlink_cthelper.h
new file mode 100644
index 0000000..33659f6
--- /dev/null
+++ b/include/linux/netfilter/nfnetlink_cthelper.h
@@ -0,0 +1,55 @@
+#ifndef _NFNL_CTHELPER_H_
+#define _NFNL_CTHELPER_H_
+
+#define NFCT_HELPER_STATUS_DISABLED 0
+#define NFCT_HELPER_STATUS_ENABLED 1
+
+enum nfnl_acct_msg_types {
+ NFNL_MSG_CTHELPER_NEW,
+ NFNL_MSG_CTHELPER_GET,
+ NFNL_MSG_CTHELPER_DEL,
+ NFNL_MSG_CTHELPER_MAX
+};
+
+enum nfnl_cthelper_type {
+ NFCTH_UNSPEC,
+ NFCTH_NAME,
+ NFCTH_TUPLE,
+ NFCTH_QUEUE_NUM,
+ NFCTH_POLICY,
+ NFCTH_PRIV_DATA_LEN,
+ NFCTH_STATUS,
+ __NFCTH_MAX
+};
+#define NFCTH_MAX (__NFCTH_MAX - 1)
+
+enum nfnl_cthelper_policy_type {
+ NFCTH_POLICY_SET_UNSPEC,
+ NFCTH_POLICY_SET_NUM,
+ NFCTH_POLICY_SET,
+ NFCTH_POLICY_SET1 = NFCTH_POLICY_SET,
+ NFCTH_POLICY_SET2,
+ NFCTH_POLICY_SET3,
+ NFCTH_POLICY_SET4,
+ __NFCTH_POLICY_SET_MAX
+};
+#define NFCTH_POLICY_SET_MAX (__NFCTH_POLICY_SET_MAX - 1)
+
+enum nfnl_cthelper_pol_type {
+ NFCTH_POLICY_UNSPEC,
+ NFCTH_POLICY_NAME,
+ NFCTH_POLICY_EXPECT_MAX,
+ NFCTH_POLICY_EXPECT_TIMEOUT,
+ __NFCTH_POLICY_MAX
+};
+#define NFCTH_POLICY_MAX (__NFCTH_POLICY_MAX - 1)
+
+enum nfnl_cthelper_tuple_type {
+ NFCTH_TUPLE_UNSPEC,
+ NFCTH_TUPLE_L3PROTONUM,
+ NFCTH_TUPLE_L4PROTONUM,
+ __NFCTH_TUPLE_MAX,
+};
+#define NFCTH_TUPLE_MAX (__NFCTH_TUPLE_MAX - 1)
+
+#endif /* _NFNL_CTHELPER_H */
diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h
index fa0946c..e2b1280 100644
--- a/include/linux/netfilter_ipv4.h
+++ b/include/linux/netfilter_ipv4.h
@@ -66,6 +66,7 @@ enum nf_ip_hook_priorities {
NF_IP_PRI_SECURITY = 50,
NF_IP_PRI_NAT_SRC = 100,
NF_IP_PRI_SELINUX_LAST = 225,
+ NF_IP_PRI_CONNTRACK_HELPER = 300,
NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX,
NF_IP_PRI_LAST = INT_MAX,
};
diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h
index 57c0251..7c8a513 100644
--- a/include/linux/netfilter_ipv6.h
+++ b/include/linux/netfilter_ipv6.h
@@ -71,6 +71,7 @@ enum nf_ip6_hook_priorities {
NF_IP6_PRI_SECURITY = 50,
NF_IP6_PRI_NAT_SRC = 100,
NF_IP6_PRI_SELINUX_LAST = 225,
+ NF_IP6_PRI_CONNTRACK_HELPER = 300,
NF_IP6_PRI_LAST = INT_MAX,
};
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 84b24c3..9aad956 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -15,6 +15,11 @@
struct module;
+enum nf_ct_helper_flags {
+ NF_CT_HELPER_F_USERSPACE = (1 << 0),
+ NF_CT_HELPER_F_CONFIGURED = (1 << 1),
+};
+
#define NF_CT_HELPER_NAME_LEN 16
struct nf_conntrack_helper {
@@ -42,6 +47,9 @@ struct nf_conntrack_helper {
int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
unsigned int expect_class_max;
+
+ unsigned int flags;
+ unsigned int queue_num; /* For user-space helpers. */
};
extern struct nf_conntrack_helper *
@@ -96,4 +104,7 @@ nf_ct_helper_expectfn_find_by_name(const char *name);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
+extern struct hlist_head *nf_ct_helper_hash;
+extern unsigned int nf_ct_helper_hsize;
+
#endif /*_NF_CONNTRACK_HELPER_H*/
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index d79b961..8227edc 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -95,11 +95,11 @@ static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
return NF_ACCEPT;
}
-static unsigned int ipv4_confirm(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+static unsigned int ipv4_helper(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
@@ -110,24 +110,38 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- goto out;
+ return NF_ACCEPT;
help = nfct_help(ct);
if (!help)
- goto out;
+ return NF_ACCEPT;
/* rcu_read_lock()ed by nf_hook_slow */
helper = rcu_dereference(help->helper);
if (!helper)
- goto out;
+ return NF_ACCEPT;
ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
ct, ctinfo);
- if (ret != NF_ACCEPT) {
+ if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
"nf_ct_%s: dropping packet", helper->name);
- return ret;
}
+ return ret;
+}
+
+static unsigned int ipv4_confirm(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ return NF_ACCEPT;
/* adjust seqs for loopback traffic only in outgoing direction */
if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
@@ -140,7 +154,6 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
return NF_DROP;
}
}
-out:
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(skb);
}
@@ -185,6 +198,13 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
.priority = NF_IP_PRI_CONNTRACK,
},
{
+ .hook = ipv4_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV4,
@@ -192,6 +212,13 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
.priority = NF_IP_PRI_CONNTRACK_CONFIRM,
},
{
+ .hook = ipv4_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV4,
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index fca10da..b656d06 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -143,11 +143,11 @@ static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
return NF_ACCEPT;
}
-static unsigned int ipv6_confirm(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+static unsigned int ipv6_helper(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
const struct nf_conn_help *help;
@@ -161,15 +161,15 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- goto out;
+ return NF_ACCEPT;
help = nfct_help(ct);
if (!help)
- goto out;
+ return NF_ACCEPT;
/* rcu_read_lock()ed by nf_hook_slow */
helper = rcu_dereference(help->helper);
if (!helper)
- goto out;
+ return NF_ACCEPT;
protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum,
skb->len - extoff);
@@ -179,12 +179,27 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
}
ret = helper->help(skb, protoff, ct, ctinfo);
- if (ret != NF_ACCEPT) {
+ if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
nf_log_packet(NFPROTO_IPV6, hooknum, skb, in, out, NULL,
"nf_ct_%s: dropping packet", helper->name);
return ret;
}
-out:
+ return ret;
+}
+
+static unsigned int ipv6_confirm(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ return NF_ACCEPT;
+
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(skb);
}
@@ -254,6 +269,13 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_CONNTRACK,
},
{
+ .hook = ipv6_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP6_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV6,
@@ -261,6 +283,13 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_LAST,
},
{
+ .hook = ipv6_helper,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP6_PRI_CONNTRACK_HELPER,
+ },
+ {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = NFPROTO_IPV6,
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 209c1ed..aae6c62 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -12,6 +12,14 @@ tristate "Netfilter NFACCT over NFNETLINK interface"
If this option is enabled, the kernel will include support
for extended accounting via NFNETLINK.
+config NETFILTER_NETLINK_CTHELPER
+tristate "Netfilter CTHELPER over NFNETLINK interface"
+ depends on NETFILTER_ADVANCED
+ select NETFILTER_NETLINK
+ help
+ If this option is enabled, the kernel will include support
+ for user-space connection tracking helpers via NFNETLINK.
+
config NETFILTER_NETLINK_QUEUE
tristate "Netfilter NFQUEUE over NFNETLINK interface"
depends on NETFILTER_ADVANCED
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 4e7960c..2f3bc0f 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_NETFILTER) = netfilter.o
obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
obj-$(CONFIG_NETFILTER_NETLINK_ACCT) += nfnetlink_acct.o
+obj-$(CONFIG_NETFILTER_NETLINK_CTHELPER) += nfnetlink_cthelper.o
obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 9c18ecb..2918ec2 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -30,8 +30,10 @@
#include <net/netfilter/nf_conntrack_extend.h>
static DEFINE_MUTEX(nf_ct_helper_mutex);
-static struct hlist_head *nf_ct_helper_hash __read_mostly;
-static unsigned int nf_ct_helper_hsize __read_mostly;
+struct hlist_head *nf_ct_helper_hash __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_helper_hash);
+unsigned int nf_ct_helper_hsize __read_mostly;
+EXPORT_SYMBOL_GPL(nf_ct_helper_hsize);
static unsigned int nf_ct_helper_count __read_mostly;
static bool nf_ct_auto_assign_helper __read_mostly = true;
@@ -322,6 +324,9 @@ EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
+ int ret = 0;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n;
unsigned int h = helper_hash(&me->tuple);
BUG_ON(me->expect_policy == NULL);
@@ -329,11 +334,19 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1);
mutex_lock(&nf_ct_helper_mutex);
+ hlist_for_each_entry(cur, n, &nf_ct_helper_hash[h], hnode) {
+ if (strncmp(cur->name, me->name, NF_CT_HELPER_NAME_LEN) == 0 &&
+ cur->tuple.src.l3num == me->tuple.src.l3num &&
+ cur->tuple.dst.protonum == me->tuple.dst.protonum) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]);
nf_ct_helper_count++;
+out:
mutex_unlock(&nf_ct_helper_mutex);
-
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_helper_register);
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
new file mode 100644
index 0000000..f399b46
--- /dev/null
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -0,0 +1,674 @@
+/*
+ * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation (or any later at your option).
+ *
+ * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <net/netlink.h>
+#include <net/sock.h>
+
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+#include <linux/netfilter/nfnetlink_cthelper.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
+
+static int
+nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+ const struct nf_conn_help *help;
+ struct nf_conntrack_helper *helper;
+
+ help = nfct_help(ct);
+ if (help == NULL)
+ return NF_DROP;
+
+ /* rcu_read_lock()ed by nf_hook_slow */
+ helper = rcu_dereference(help->helper);
+ if (helper == NULL)
+ return NF_DROP;
+
+ /* This is an user-space helper not yet configured, skip. */
+ if ((helper->flags &
+ (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
+ NF_CT_HELPER_F_USERSPACE)
+ return NF_ACCEPT;
+
+ /* If the user-space helper is not available, don't block traffic. */
+ return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
+}
+
+static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
+ [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
+ [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
+};
+
+static int
+nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nlattr *attr)
+{
+ struct nlattr *tb[NFCTH_TUPLE_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
+
+ if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
+ return -EINVAL;
+
+ tuple->src.l3num = ntohs(nla_get_u16(tb[NFCTH_TUPLE_L3PROTONUM]));
+ tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
+
+ return 0;
+}
+
+static int
+nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
+{
+ const struct nf_conn_help *help = nfct_help(ct);
+
+ if (help->helper->data_len == 0)
+ return -EINVAL;
+
+ memcpy(&help->data, nla_data(attr), help->helper->data_len);
+ return 0;
+}
+
+static int
+nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
+{
+ const struct nf_conn_help *help = nfct_help(ct);
+
+ if (help->helper->data_len &&
+ nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -ENOSPC;
+}
+
+static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
+ [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
+ .len = NF_CT_HELPER_NAME_LEN-1 },
+ [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
+ [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
+};
+
+static int
+nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
+ const struct nlattr *attr)
+{
+ struct nlattr *tb[NFCTH_POLICY_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
+
+ if (!tb[NFCTH_POLICY_NAME] ||
+ !tb[NFCTH_POLICY_EXPECT_MAX] ||
+ !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
+ return -EINVAL;
+
+ strncpy(expect_policy->name,
+ nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
+ expect_policy->max_expected =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
+ expect_policy->timeout =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
+
+ return 0;
+}
+
+static const struct nla_policy
+nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
+ [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
+};
+
+static int
+nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
+ const struct nlattr *attr)
+{
+ int i, ret;
+ struct nf_conntrack_expect_policy *expect_policy;
+ struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
+
+ nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
+ nfnl_cthelper_expect_policy_set);
+
+ if (!tb[NFCTH_POLICY_SET_NUM])
+ return -EINVAL;
+
+ helper->expect_class_max =
+ ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
+
+ if (helper->expect_class_max != 0 &&
+ helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
+ return -EOVERFLOW;
+
+ expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
+ helper->expect_class_max, GFP_KERNEL);
+ if (expect_policy == NULL)
+ return -ENOMEM;
+
+ for (i=0; i<helper->expect_class_max; i++) {
+ if (!tb[NFCTH_POLICY_SET+i])
+ goto err;
+
+ ret = nfnl_cthelper_expect_policy(&expect_policy[i],
+ tb[NFCTH_POLICY_SET+i]);
+ if (ret < 0)
+ goto err;
+ }
+ helper->expect_policy = expect_policy;
+ return 0;
+err:
+ kfree(expect_policy);
+ return -EINVAL;
+}
+
+static int
+nfnl_cthelper_create(const struct nlattr * const tb[],
+ struct nf_conntrack_tuple *tuple)
+{
+ struct nf_conntrack_helper *helper;
+ int ret;
+
+ if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
+ return -EINVAL;
+
+ helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
+ if (helper == NULL)
+ return -ENOMEM;
+
+ ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
+ if (ret < 0)
+ goto err;
+
+ strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
+ helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
+ helper->flags |= NF_CT_HELPER_F_USERSPACE;
+ memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
+
+ helper->me = THIS_MODULE;
+ helper->help = nfnl_userspace_cthelper;
+ helper->from_nlattr = nfnl_cthelper_from_nlattr;
+ helper->to_nlattr = nfnl_cthelper_to_nlattr;
+
+ /* Default to queue number zero, this can be updated at any time. */
+ if (tb[NFCTH_QUEUE_NUM])
+ helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
+
+ if (tb[NFCTH_STATUS]) {
+ int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
+
+ switch(status) {
+ case NFCT_HELPER_STATUS_ENABLED:
+ helper->flags |= NF_CT_HELPER_F_CONFIGURED;
+ break;
+ case NFCT_HELPER_STATUS_DISABLED:
+ helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
+ break;
+ }
+ }
+
+ ret = nf_conntrack_helper_register(helper);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+err:
+ kfree(helper);
+ return ret;
+}
+
+static int
+nfnl_cthelper_update(const struct nlattr * const tb[],
+ struct nf_conntrack_helper *helper)
+{
+ int ret;
+
+ if (tb[NFCTH_PRIV_DATA_LEN])
+ return -EBUSY;
+
+ if (tb[NFCTH_POLICY]) {
+ ret = nfnl_cthelper_parse_expect_policy(helper,
+ tb[NFCTH_POLICY]);
+ if (ret < 0)
+ return ret;
+ }
+ if (tb[NFCTH_QUEUE_NUM])
+ helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
+
+ if (tb[NFCTH_STATUS]) {
+ int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
+
+ switch(status) {
+ case NFCT_HELPER_STATUS_ENABLED:
+ helper->flags |= NF_CT_HELPER_F_CONFIGURED;
+ break;
+ case NFCT_HELPER_STATUS_DISABLED:
+ helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
+ break;
+ }
+ }
+ return 0;
+}
+
+static int
+nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ const char *helper_name;
+ struct nf_conntrack_helper *cur, *helper = NULL;
+ struct nf_conntrack_tuple tuple;
+ struct hlist_node *n;
+ int ret = 0, i;
+
+ if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
+ return -EINVAL;
+
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ rcu_read_lock();
+ for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
+ hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0)
+ continue;
+
+ if ((tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ if (nlh->nlmsg_flags & NLM_F_EXCL) {
+ ret = -EEXIST;
+ goto err;
+ }
+ helper = cur;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ if (helper == NULL)
+ ret = nfnl_cthelper_create(tb, &tuple);
+ else
+ ret = nfnl_cthelper_update(tb, helper);
+
+ return ret;
+err:
+ rcu_read_unlock();
+ return ret;
+}
+
+static int
+nfnl_cthelper_dump_tuple(struct sk_buff *skb,
+ struct nf_conntrack_helper *helper)
+{
+ struct nlattr *nest_parms;
+
+ nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED);
+ if (nest_parms == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
+ htons(helper->tuple.src.l3num)))
+ goto nla_put_failure;
+
+ if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static int
+nfnl_cthelper_dump_policy(struct sk_buff *skb,
+ struct nf_conntrack_helper *helper)
+{
+ int i;
+ struct nlattr *nest_parms1, *nest_parms2;
+
+ nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED);
+ if (nest_parms1 == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
+ htonl(helper->expect_class_max)))
+ goto nla_put_failure;
+
+ for (i=0; i<helper->expect_class_max; i++) {
+ nest_parms2 = nla_nest_start(skb,
+ (NFCTH_POLICY_SET+i) | NLA_F_NESTED);
+ if (nest_parms2 == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_string(skb, NFCTH_POLICY_NAME,
+ helper->expect_policy[i].name))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
+ htonl(helper->expect_policy[i].max_expected)))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
+ htonl(helper->expect_policy[i].timeout)))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest_parms2);
+ }
+ nla_nest_end(skb, nest_parms1);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static int
+nfnl_cthelper_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type,
+ int event, struct nf_conntrack_helper *helper)
+{
+ struct nlmsghdr *nlh;
+ struct nfgenmsg *nfmsg;
+ unsigned int flags = pid ? NLM_F_MULTI : 0;
+ int status;
+
+ event |= NFNL_SUBSYS_CTHELPER << 8;
+ nlh = nlmsg_put(skb, pid, seq, event, sizeof(*nfmsg), flags);
+ if (nlh == NULL)
+ goto nlmsg_failure;
+
+ nfmsg = nlmsg_data(nlh);
+ nfmsg->nfgen_family = AF_UNSPEC;
+ nfmsg->version = NFNETLINK_V0;
+ nfmsg->res_id = 0;
+
+ if (nla_put_string(skb, NFCTH_NAME, helper->name))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
+ goto nla_put_failure;
+
+ if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
+ goto nla_put_failure;
+
+ if (nfnl_cthelper_dump_policy(skb, helper) < 0)
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
+ goto nla_put_failure;
+
+ if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
+ status = NFCT_HELPER_STATUS_ENABLED;
+ else
+ status = NFCT_HELPER_STATUS_DISABLED;
+
+ if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ return skb->len;
+
+nlmsg_failure:
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -1;
+}
+
+static int
+nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct nf_conntrack_helper *cur, *last;
+ struct hlist_node *n;
+
+ rcu_read_lock();
+ last = (struct nf_conntrack_helper *)cb->args[1];
+ for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
+restart:
+ hlist_for_each_entry_rcu(cur, n,
+ &nf_ct_helper_hash[cb->args[0]], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (cb->args[1]) {
+ if (cur != last)
+ continue;
+ cb->args[1] = 0;
+ }
+ if (nfnl_cthelper_fill_info(skb,
+ NETLINK_CB(cb->skb).pid,
+ cb->nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur) < 0) {
+ cb->args[1] = (unsigned long)cur;
+ goto out;
+ }
+ }
+ }
+ if (cb->args[1]) {
+ cb->args[1] = 0;
+ goto restart;
+ }
+out:
+ rcu_read_unlock();
+ return skb->len;
+}
+
+static int
+nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ int ret = -ENOENT, i;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n;
+ struct sk_buff *skb2;
+ char *helper_name = NULL;
+ struct nf_conntrack_tuple tuple;
+ bool tuple_set = false;
+
+ if (nlh->nlmsg_flags & NLM_F_DUMP) {
+ struct netlink_dump_control c = {
+ .dump = nfnl_cthelper_dump_table,
+ };
+ return netlink_dump_start(nfnl, skb, nlh, &c);
+ }
+
+ if (tb[NFCTH_NAME])
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ if (tb[NFCTH_TUPLE]) {
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ tuple_set = true;
+ }
+
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
+
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ if (helper_name && strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0) {
+ continue;
+ }
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (skb2 == NULL) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).pid,
+ nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur);
+ if (ret <= 0) {
+ kfree_skb(skb2);
+ break;
+ }
+
+ ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).pid,
+ MSG_DONTWAIT);
+ if (ret > 0)
+ ret = 0;
+
+ /* this avoids a loop in nfnetlink. */
+ return ret == -EAGAIN ? -ENOBUFS : ret;
+ }
+ }
+ return ret;
+}
+
+static int
+nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+ char *helper_name = NULL;
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n, *tmp;
+ struct nf_conntrack_tuple tuple;
+ bool tuple_set = false, found = false;
+ int i, j = 0, ret;
+
+ if (tb[NFCTH_NAME])
+ helper_name = nla_data(tb[NFCTH_NAME]);
+
+ if (tb[NFCTH_TUPLE]) {
+ ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
+ if (ret < 0)
+ return ret;
+
+ tuple_set = true;
+ }
+
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
+ hnode) {
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ j++;
+
+ if (helper_name && strncmp(cur->name, helper_name,
+ NF_CT_HELPER_NAME_LEN) != 0) {
+ continue;
+ }
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
+
+ found = true;
+ nf_conntrack_helper_unregister(cur);
+ }
+ }
+ /* Make sure we return success if we flush and there is no helpers */
+ return (found || j == 0) ? 0 : -ENOENT;
+}
+
+static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
+ [NFCTH_NAME] = { .type = NLA_NUL_STRING,
+ .len = NF_CT_HELPER_NAME_LEN-1 },
+ [NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
+};
+
+static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
+ [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+ [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+ [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy },
+};
+
+static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
+ .name = "cthelper",
+ .subsys_id = NFNL_SUBSYS_CTHELPER,
+ .cb_count = NFNL_MSG_CTHELPER_MAX,
+ .cb = nfnl_cthelper_cb,
+};
+
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
+
+static int __init nfnl_cthelper_init(void)
+{
+ int ret;
+
+ pr_info("nfnl_cthelper: registering with nfnetlink.\n");
+ ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
+ if (ret < 0) {
+ pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
+ goto err_out;
+ }
+ return 0;
+err_out:
+ return ret;
+}
+
+static void __exit nfnl_cthelper_exit(void)
+{
+ struct nf_conntrack_helper *cur;
+ struct hlist_node *n, *tmp;
+ int i;
+
+ pr_info("nfnl_cthelper: unregistering from nfnetlink.\n");
+ nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
+
+ for (i=0; i<nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
+ hnode) {
+ /* skip non-userspace conntrack helpers. */
+ if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
+ continue;
+
+ nf_conntrack_helper_unregister(cur);
+ }
+ }
+}
+
+module_init(nfnl_cthelper_init);
+module_exit(nfnl_cthelper_exit);
--
1.7.10
^ permalink raw reply related [flat|nested] 17+ messages in thread
end of thread, other threads:[~2012-06-16 15:51 UTC | newest]
Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-06-04 12:21 [PATCH 0/7] [RFC] new user-space connection tracking helper infrastructure pablo
2012-06-04 12:21 ` [PATCH 1/7] netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names pablo
2012-06-04 12:21 ` [PATCH 2/7] netfilter: nf_ct_ext: support variable length extensions pablo
2012-06-04 12:21 ` [PATCH 3/7] netfilter: nf_ct_helper: implement variable length helper private data pablo
2012-06-04 13:06 ` Jan Engelhardt
2012-06-04 13:09 ` Joe Perches
2012-06-04 13:16 ` Jan Engelhardt
2012-06-04 12:21 ` [PATCH 4/7] netfilter: add glue code to integrate nfnetlink_queue and ctnetlink pablo
2012-06-04 13:38 ` Jan Engelhardt
2012-06-04 12:21 ` [PATCH 5/7] netfilter: nfnl_queue: support NAT TCP sequence adjustment if packet mangled pablo
2012-06-04 12:21 ` [PATCH 6/7] netfilter: ctnetlink: add CTA_HELP_INFO attribute pablo
2012-06-04 12:21 ` [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure pablo
2012-06-04 14:04 ` Jan Engelhardt
2012-06-06 9:39 ` Ferenc Wagner
2012-06-12 18:06 [PATCH 0/7] [RFCv2] new " pablo
2012-06-12 18:06 ` [PATCH 7/7] netfilter: add " pablo
2012-06-12 22:46 ` David Miller
2012-06-16 15:49 [PATCH 0/7] netfilter updates for net-next (upcoming 3.6), batch 2 pablo
2012-06-16 15:49 ` [PATCH 7/7] netfilter: add user-space connection tracking helper infrastructure pablo
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