* [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump
@ 2020-03-30 20:46 Romain Bellan
2020-04-26 21:43 ` Pablo Neira Ayuso
0 siblings, 1 reply; 6+ messages in thread
From: Romain Bellan @ 2020-03-30 20:46 UTC (permalink / raw)
To: netfilter-devel; +Cc: Romain Bellan, Florent Fourcot
Conntrack dump does not support kernel side filtering (only get exists,
but it returns only one entry. And user has to give a full valid tuple)
It means that userspace has to implement filtering after receiving many
irrelevant entries, consuming resources (conntrack table is sometimes
very huge, much more than a routing table for example).
This patch adds filtering in kernel side. To achieve this goal, we:
* Add a new CTA_FILTER netlink attributes, actually a flag list to
parametize filtering
* Convert some *nlattr_to_tuple() functions, to allow a partial parsing
of CTA_TUPLE_ORIG and CTA_TUPLE_REPLY (so nf_conntrack_tuple it not
fully set)
Filtering is now possible on:
* IP SRC/DST values
* Ports for TCP and UDP flows
* IMCP(v6) codes types and IDs
Filtering is done as an "AND" operator. For example, when flags
PROTO_SRC_PORT, PROTO_NUM and IP_SRC are sets, only entries matching all
values are dumped.
Changes since v1:
Set NLM_F_DUMP_FILTERED in nlm flags if entries are filtered
Changes since v2:
Move several constants to nf_internals.h
Move a fix on netlink values check in a separate patch
Add a check on not-supported flags
Return EOPNOTSUPP if CDA_FILTER is set in ctnetlink_flush_conntrack
(not yet implemented)
Code style issues
Changes since v3:
Fix compilation warning reported by kbuild test robot
Changes since v4:
Fix a regression introduced in v3 (returned EINVAL for valid netlink
messages without CTA_MARK)
Signed-off-by: Romain Bellan <romain.bellan@wifirst.fr>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
---
include/net/netfilter/nf_conntrack_l4proto.h | 6 +-
.../linux/netfilter/nfnetlink_conntrack.h | 9 +
net/netfilter/nf_conntrack_core.c | 19 +-
net/netfilter/nf_conntrack_netlink.c | 341 ++++++++++++++++--
net/netfilter/nf_conntrack_proto_icmp.c | 43 ++-
net/netfilter/nf_conntrack_proto_icmpv6.c | 45 ++-
net/netfilter/nf_internals.h | 16 +
7 files changed, 406 insertions(+), 73 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index 4cad1f0a327a..88186b95b3c2 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -42,7 +42,8 @@ struct nf_conntrack_l4proto {
/* Calculate tuple nlattr size */
unsigned int (*nlattr_tuple_size)(void);
int (*nlattr_to_tuple)(struct nlattr *tb[],
- struct nf_conntrack_tuple *t);
+ struct nf_conntrack_tuple *t,
+ u_int32_t flags);
const struct nla_policy *nla_policy;
struct {
@@ -152,7 +153,8 @@ const struct nf_conntrack_l4proto *nf_ct_l4proto_find(u8 l4proto);
int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple);
int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
- struct nf_conntrack_tuple *t);
+ struct nf_conntrack_tuple *t,
+ u_int32_t flags);
unsigned int nf_ct_port_nlattr_tuple_size(void);
extern const struct nla_policy nf_ct_port_nla_policy[];
diff --git a/include/uapi/linux/netfilter/nfnetlink_conntrack.h b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
index 1d41810d17e2..262881792671 100644
--- a/include/uapi/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
@@ -55,6 +55,7 @@ enum ctattr_type {
CTA_LABELS,
CTA_LABELS_MASK,
CTA_SYNPROXY,
+ CTA_FILTER,
__CTA_MAX
};
#define CTA_MAX (__CTA_MAX - 1)
@@ -276,4 +277,12 @@ enum ctattr_expect_stats {
};
#define CTA_STATS_EXP_MAX (__CTA_STATS_EXP_MAX - 1)
+enum ctattr_filter {
+ CTA_FILTER_UNSPEC,
+ CTA_FILTER_ORIG_FLAGS,
+ CTA_FILTER_REPLY_FLAGS,
+ __CTA_FILTER_MAX
+};
+#define CTA_FILTER_MAX (__CTA_FILTER_MAX - 1)
+
#endif /* _IPCONNTRACK_NETLINK_H */
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c4582eb71766..dbcabe12bb58 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1974,13 +1974,22 @@ const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
- struct nf_conntrack_tuple *t)
+ struct nf_conntrack_tuple *t,
+ u_int32_t flags)
{
- if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
- return -EINVAL;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_SRC_PORT)) {
+ if (!tb[CTA_PROTO_SRC_PORT])
+ return -EINVAL;
+
+ t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
+ }
- t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
- t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_DST_PORT)) {
+ if (!tb[CTA_PROTO_DST_PORT])
+ return -EINVAL;
+
+ t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
+ }
return 0;
}
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9ddfcd002d3b..9c0364b49fc0 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -54,6 +54,8 @@
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
+#include "nf_internals.h"
+
MODULE_LICENSE("GPL");
static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
@@ -544,14 +546,16 @@ static int ctnetlink_dump_info(struct sk_buff *skb, struct nf_conn *ct)
static int
ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
- struct nf_conn *ct, bool extinfo)
+ struct nf_conn *ct, bool extinfo, unsigned int flags)
{
const struct nf_conntrack_zone *zone;
struct nlmsghdr *nlh;
struct nfgenmsg *nfmsg;
struct nlattr *nest_parms;
- unsigned int flags = portid ? NLM_F_MULTI : 0, event;
+ unsigned int event;
+ if (portid)
+ flags |= NLM_F_MULTI;
event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK, IPCTNL_MSG_CT_NEW);
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
if (nlh == NULL)
@@ -847,17 +851,72 @@ static int ctnetlink_done(struct netlink_callback *cb)
}
struct ctnetlink_filter {
+ u_int32_t cta_flags;
u8 family;
+
+ u_int32_t orig_flags;
+ u_int32_t reply_flags;
+
+ struct nf_conntrack_tuple orig;
+ struct nf_conntrack_tuple reply;
+ struct nf_conntrack_zone zone;
+
struct {
u_int32_t val;
u_int32_t mask;
} mark;
};
+
+static const struct nla_policy cta_filter_nla_policy[CTA_FILTER_MAX + 1] = {
+ [CTA_FILTER_ORIG_FLAGS] = { .type = NLA_U32 },
+ [CTA_FILTER_REPLY_FLAGS] = { .type = NLA_U32 },
+};
+
+static int ctnetlink_parse_filter(const struct nlattr *attr,
+ struct ctnetlink_filter *filter)
+{
+ struct nlattr *tb[CTA_FILTER_MAX+1];
+ int ret = 0;
+
+ ret = nla_parse_nested(tb, CTA_FILTER_MAX, attr, cta_filter_nla_policy, NULL);
+ if (ret)
+ return ret;
+
+ if (tb[CTA_FILTER_ORIG_FLAGS])
+ {
+ filter->orig_flags = nla_get_u32(tb[CTA_FILTER_ORIG_FLAGS]);
+ if (filter->orig_flags & ~(CTA_FILTER_F_ALL - 1))
+ return -EOPNOTSUPP;
+ }
+
+ if (tb[CTA_FILTER_REPLY_FLAGS])
+ {
+ filter->reply_flags = nla_get_u32(tb[CTA_FILTER_REPLY_FLAGS]);
+ if (filter->reply_flags & ~(CTA_FILTER_F_ALL - 1))
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int ctnetlink_parse_zone(const struct nlattr *attr,
+ struct nf_conntrack_zone *zone);
+static int ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],
+ struct nf_conntrack_tuple *tuple,
+ u32 type, u_int8_t l3num,
+ struct nf_conntrack_zone *zone,
+ u_int32_t flags);
+
+/* applied on filters */
+#define CTA_FILTER_F_CTA_MARK (1 << 0)
+#define CTA_FILTER_F_CTA_MARK_MASK (1 << 1)
+
static struct ctnetlink_filter *
ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
{
struct ctnetlink_filter *filter;
+ int err;
#ifndef CONFIG_NF_CONNTRACK_MARK
if (cda[CTA_MARK] || cda[CTA_MARK_MASK])
@@ -871,14 +930,67 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
filter->family = family;
#ifdef CONFIG_NF_CONNTRACK_MARK
- if (cda[CTA_MARK] && cda[CTA_MARK_MASK]) {
+ if (cda[CTA_MARK]) {
filter->mark.val = ntohl(nla_get_be32(cda[CTA_MARK]));
- filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
+ filter->cta_flags |= CTA_FILTER_FLAG(CTA_MARK);
+
+ if (cda[CTA_MARK_MASK]) {
+ filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
+ filter->cta_flags |= CTA_FILTER_FLAG(CTA_MARK_MASK);
+ }
+ else {
+ filter->mark.mask = 0xffffffff;
+ }
+ }
+ else if (cda[CTA_MARK_MASK]) {
+ return ERR_PTR(-EINVAL);
}
#endif
+ if (!cda[CTA_FILTER])
+ return filter;
+
+ err = ctnetlink_parse_zone(cda[CTA_ZONE], &filter->zone);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ err = ctnetlink_parse_filter(cda[CTA_FILTER], filter);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ if (filter->orig_flags) {
+ if (!cda[CTA_TUPLE_ORIG])
+ return ERR_PTR(-EINVAL);
+
+ err = ctnetlink_parse_tuple_filter(cda, &filter->orig,
+ CTA_TUPLE_ORIG,
+ filter->family,
+ &filter->zone,
+ filter->orig_flags);
+ if (err < 0)
+ return ERR_PTR(err);
+ }
+
+ if (filter->reply_flags) {
+ if (!cda[CTA_TUPLE_REPLY])
+ return ERR_PTR(-EINVAL);
+
+ err = ctnetlink_parse_tuple_filter(cda, &filter->reply,
+ CTA_TUPLE_REPLY,
+ filter->family,
+ &filter->zone,
+ filter->orig_flags);
+ if (err < 0)
+ return ERR_PTR(err);
+ }
+
return filter;
}
+static bool ctnetlink_needs_filter(u8 family, const struct nlattr * const *cda)
+{
+ return (family || cda[CTA_MARK] || cda[CTA_FILTER]);
+}
+
static int ctnetlink_start(struct netlink_callback *cb)
{
const struct nlattr * const *cda = cb->data;
@@ -886,7 +998,7 @@ static int ctnetlink_start(struct netlink_callback *cb)
struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
u8 family = nfmsg->nfgen_family;
- if (family || (cda[CTA_MARK] && cda[CTA_MARK_MASK])) {
+ if (ctnetlink_needs_filter(family, cda)) {
filter = ctnetlink_alloc_filter(cda, family);
if (IS_ERR(filter))
return PTR_ERR(filter);
@@ -896,9 +1008,82 @@ static int ctnetlink_start(struct netlink_callback *cb)
return 0;
}
+static int ctnetlink_filter_match_tuple(struct nf_conntrack_tuple *filter_tuple,
+ struct nf_conntrack_tuple *ct_tuple,
+ u_int32_t flags, int family)
+{
+ switch (family) {
+ case NFPROTO_IPV4:
+ if (flags & CTA_FILTER_FLAG(CTA_IP_SRC) &&
+ filter_tuple->src.u3.ip != ct_tuple->src.u3.ip)
+ return 0;
+
+ if (flags & CTA_FILTER_FLAG(CTA_IP_DST) &&
+ filter_tuple->dst.u3.ip != ct_tuple->dst.u3.ip)
+ return 0;
+ break;
+
+ case NFPROTO_IPV6:
+ if (flags & CTA_FILTER_FLAG(CTA_IP_SRC) &&
+ !ipv6_addr_cmp(&filter_tuple->src.u3.in6,
+ &ct_tuple->src.u3.in6))
+ return 0;
+
+ if (flags & CTA_FILTER_FLAG(CTA_IP_DST) &&
+ !ipv6_addr_cmp(&filter_tuple->dst.u3.in6,
+ &ct_tuple->dst.u3.in6))
+ return 0;
+ break;
+ }
+
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_NUM) &&
+ filter_tuple->dst.protonum != ct_tuple->dst.protonum)
+ return 0;
+
+ switch (ct_tuple->dst.protonum) {
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_SRC_PORT) &&
+ filter_tuple->src.u.tcp.port != ct_tuple->src.u.tcp.port)
+ return 0;
+
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_DST_PORT) &&
+ filter_tuple->dst.u.tcp.port != ct_tuple->dst.u.tcp.port)
+ return 0;
+ break;
+
+ case IPPROTO_ICMP:
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_TYPE) &&
+ filter_tuple->dst.u.icmp.type != ct_tuple->dst.u.icmp.type)
+ return 0;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_CODE) &&
+ filter_tuple->dst.u.icmp.code != ct_tuple->dst.u.icmp.code)
+ return 0;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_ID) &&
+ filter_tuple->src.u.icmp.id != ct_tuple->src.u.icmp.id)
+ return 0;
+ break;
+
+ case IPPROTO_ICMPV6:
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_TYPE) &&
+ filter_tuple->dst.u.icmp.type != ct_tuple->dst.u.icmp.type)
+ return 0;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_CODE) &&
+ filter_tuple->dst.u.icmp.code != ct_tuple->dst.u.icmp.code)
+ return 0;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_ID) &&
+ filter_tuple->src.u.icmp.id != ct_tuple->src.u.icmp.id)
+ return 0;
+ break;
+ }
+
+ return 1;
+}
+
static int ctnetlink_filter_match(struct nf_conn *ct, void *data)
{
struct ctnetlink_filter *filter = data;
+ struct nf_conntrack_tuple *tuple;
if (filter == NULL)
goto out;
@@ -910,8 +1095,29 @@ static int ctnetlink_filter_match(struct nf_conn *ct, void *data)
if (filter->family && nf_ct_l3num(ct) != filter->family)
goto ignore_entry;
+ if (filter->orig_flags) {
+ tuple = nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL);
+ if (!ctnetlink_filter_match_tuple(&filter->orig, tuple,
+ filter->orig_flags,
+ filter->family))
+ goto ignore_entry;
+ }
+
+ if (filter->reply_flags) {
+ tuple = nf_ct_tuple(ct, IP_CT_DIR_REPLY);
+ if (!ctnetlink_filter_match_tuple(&filter->reply, tuple,
+ filter->reply_flags,
+ filter->family))
+ goto ignore_entry;
+ }
+
+
#ifdef CONFIG_NF_CONNTRACK_MARK
- if ((ct->mark & filter->mark.mask) != filter->mark.val)
+ if ((filter->cta_flags & CTA_FILTER_FLAG(CTA_MARK_MASK)) &&
+ (ct->mark & filter->mark.mask) != filter->mark.val)
+ goto ignore_entry;
+ else if ((filter->cta_flags & CTA_FILTER_FLAG(CTA_MARK)) &&
+ ct->mark != filter->mark.val)
goto ignore_entry;
#endif
@@ -930,6 +1136,7 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
struct nf_conn *nf_ct_evict[8];
+ unsigned int flags = cb->data ? NLM_F_DUMP_FILTERED : 0;
int res, i;
spinlock_t *lockp;
@@ -979,7 +1186,7 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
- ct, true);
+ ct, true, flags);
if (res < 0) {
nf_conntrack_get(&ct->ct_general);
cb->args[1] = (unsigned long)ct;
@@ -1014,31 +1221,50 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
}
static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
- struct nf_conntrack_tuple *t)
+ struct nf_conntrack_tuple *t,
+ u_int32_t flags)
{
- if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
- return -EINVAL;
+ if (flags & CTA_FILTER_FLAG(CTA_IP_SRC)) {
+ if (!tb[CTA_IP_V4_SRC])
+ return -EINVAL;
+
+ t->src.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_SRC]);
+ }
- t->src.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_SRC]);
- t->dst.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_DST]);
+ if (flags & CTA_FILTER_FLAG(CTA_IP_DST)) {
+ if (!tb[CTA_IP_V4_DST])
+ return -EINVAL;
+
+ t->dst.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_DST]);
+ }
return 0;
}
static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
- struct nf_conntrack_tuple *t)
+ struct nf_conntrack_tuple *t,
+ u_int32_t flags)
{
- if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
- return -EINVAL;
+ if (flags & CTA_FILTER_FLAG(CTA_IP_SRC)) {
+ if (!tb[CTA_IP_V6_SRC])
+ return -EINVAL;
+
+ t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
+ }
- t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
- t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
+ if (flags & CTA_FILTER_FLAG(CTA_IP_DST)) {
+ if (!tb[CTA_IP_V6_DST])
+ return -EINVAL;
+
+ t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
+ }
return 0;
}
static int ctnetlink_parse_tuple_ip(struct nlattr *attr,
- struct nf_conntrack_tuple *tuple)
+ struct nf_conntrack_tuple *tuple,
+ u_int32_t flags)
{
struct nlattr *tb[CTA_IP_MAX+1];
int ret = 0;
@@ -1054,10 +1280,10 @@ static int ctnetlink_parse_tuple_ip(struct nlattr *attr,
switch (tuple->src.l3num) {
case NFPROTO_IPV4:
- ret = ipv4_nlattr_to_tuple(tb, tuple);
+ ret = ipv4_nlattr_to_tuple(tb, tuple, flags);
break;
case NFPROTO_IPV6:
- ret = ipv6_nlattr_to_tuple(tb, tuple);
+ ret = ipv6_nlattr_to_tuple(tb, tuple, flags);
break;
}
@@ -1069,7 +1295,8 @@ static const struct nla_policy proto_nla_policy[CTA_PROTO_MAX+1] = {
};
static int ctnetlink_parse_tuple_proto(struct nlattr *attr,
- struct nf_conntrack_tuple *tuple)
+ struct nf_conntrack_tuple *tuple,
+ u_int32_t flags)
{
const struct nf_conntrack_l4proto *l4proto;
struct nlattr *tb[CTA_PROTO_MAX+1];
@@ -1080,8 +1307,12 @@ static int ctnetlink_parse_tuple_proto(struct nlattr *attr,
if (ret < 0)
return ret;
+ if (!(flags & CTA_FILTER_FLAG(CTA_PROTO_NUM)))
+ return 0;
+
if (!tb[CTA_PROTO_NUM])
return -EINVAL;
+
tuple->dst.protonum = nla_get_u8(tb[CTA_PROTO_NUM]);
rcu_read_lock();
@@ -1092,7 +1323,7 @@ static int ctnetlink_parse_tuple_proto(struct nlattr *attr,
l4proto->nla_policy,
NULL);
if (ret == 0)
- ret = l4proto->nlattr_to_tuple(tb, tuple);
+ ret = l4proto->nlattr_to_tuple(tb, tuple, flags);
}
rcu_read_unlock();
@@ -1143,10 +1374,21 @@ static const struct nla_policy tuple_nla_policy[CTA_TUPLE_MAX+1] = {
[CTA_TUPLE_ZONE] = { .type = NLA_U16 },
};
+#define CTA_FILTER_F_ALL_CTA_PROTO \
+ (CTA_FILTER_F_CTA_PROTO_SRC_PORT | \
+ CTA_FILTER_F_CTA_PROTO_DST_PORT | \
+ CTA_FILTER_F_CTA_PROTO_ICMP_TYPE | \
+ CTA_FILTER_F_CTA_PROTO_ICMP_CODE | \
+ CTA_FILTER_F_CTA_PROTO_ICMP_ID | \
+ CTA_FILTER_F_CTA_PROTO_ICMPV6_TYPE | \
+ CTA_FILTER_F_CTA_PROTO_ICMPV6_CODE | \
+ CTA_FILTER_F_CTA_PROTO_ICMPV6_ID)
+
static int
-ctnetlink_parse_tuple(const struct nlattr * const cda[],
- struct nf_conntrack_tuple *tuple, u32 type,
- u_int8_t l3num, struct nf_conntrack_zone *zone)
+ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],
+ struct nf_conntrack_tuple *tuple, u32 type,
+ u_int8_t l3num, struct nf_conntrack_zone *zone,
+ u_int32_t flags)
{
struct nlattr *tb[CTA_TUPLE_MAX+1];
int err;
@@ -1158,23 +1400,31 @@ ctnetlink_parse_tuple(const struct nlattr * const cda[],
if (err < 0)
return err;
- if (!tb[CTA_TUPLE_IP])
- return -EINVAL;
tuple->src.l3num = l3num;
- err = ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP], tuple);
- if (err < 0)
- return err;
+ if (flags & CTA_FILTER_FLAG(CTA_IP_DST) ||
+ flags & CTA_FILTER_FLAG(CTA_IP_SRC)) {
+ if (!tb[CTA_TUPLE_IP])
+ return -EINVAL;
- if (!tb[CTA_TUPLE_PROTO])
- return -EINVAL;
+ err = ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP], tuple, flags);
+ if (err < 0)
+ return err;
+ }
- err = ctnetlink_parse_tuple_proto(tb[CTA_TUPLE_PROTO], tuple);
- if (err < 0)
- return err;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_NUM)) {
+ if (!tb[CTA_TUPLE_PROTO])
+ return -EINVAL;
+ err = ctnetlink_parse_tuple_proto(tb[CTA_TUPLE_PROTO], tuple, flags);
+ if (err < 0)
+ return err;
+ } else if (flags & CTA_FILTER_FLAG(ALL_CTA_PROTO)) {
+ /* Can't manage proto flags without a protonum */
+ return -EINVAL;
+ }
- if (tb[CTA_TUPLE_ZONE]) {
+ if (flags & CTA_FILTER_FLAG(CTA_TUPLE_ZONE)) {
if (!zone)
return -EINVAL;
@@ -1193,6 +1443,15 @@ ctnetlink_parse_tuple(const struct nlattr * const cda[],
return 0;
}
+static int
+ctnetlink_parse_tuple(const struct nlattr * const cda[],
+ struct nf_conntrack_tuple *tuple, u32 type,
+ u_int8_t l3num, struct nf_conntrack_zone *zone)
+{
+ return ctnetlink_parse_tuple_filter(cda, tuple, type, l3num, zone,
+ CTA_FILTER_FLAG(ALL));
+}
+
static const struct nla_policy help_nla_policy[CTA_HELP_MAX+1] = {
[CTA_HELP_NAME] = { .type = NLA_NUL_STRING,
.len = NF_CT_HELPER_NAME_LEN - 1 },
@@ -1240,6 +1499,7 @@ static const struct nla_policy ct_nla_policy[CTA_MAX+1] = {
.len = NF_CT_LABELS_MAX_SIZE },
[CTA_LABELS_MASK] = { .type = NLA_BINARY,
.len = NF_CT_LABELS_MAX_SIZE },
+ [CTA_FILTER] = { .type = NLA_NESTED },
};
static int ctnetlink_flush_iterate(struct nf_conn *ct, void *data)
@@ -1256,7 +1516,10 @@ static int ctnetlink_flush_conntrack(struct net *net,
{
struct ctnetlink_filter *filter = NULL;
- if (family || (cda[CTA_MARK] && cda[CTA_MARK_MASK])) {
+ if (ctnetlink_needs_filter(family, cda)) {
+ if (cda[CTA_FILTER])
+ return -EOPNOTSUPP;
+
filter = ctnetlink_alloc_filter(cda, family);
if (IS_ERR(filter))
return PTR_ERR(filter);
@@ -1385,7 +1648,7 @@ static int ctnetlink_get_conntrack(struct net *net, struct sock *ctnl,
}
err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
- NFNL_MSG_TYPE(nlh->nlmsg_type), ct, true);
+ NFNL_MSG_TYPE(nlh->nlmsg_type), ct, true, 0);
nf_ct_put(ct);
if (err <= 0)
goto free;
@@ -1458,7 +1721,7 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
res = ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
- ct, dying ? true : false);
+ ct, dying ? true : false, 0);
if (res < 0) {
if (!atomic_inc_not_zero(&ct->ct_general.use))
continue;
diff --git a/net/netfilter/nf_conntrack_proto_icmp.c b/net/netfilter/nf_conntrack_proto_icmp.c
index c2e3dff773bc..2efd9f50481e 100644
--- a/net/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/netfilter/nf_conntrack_proto_icmp.c
@@ -20,6 +20,8 @@
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_log.h>
+#include "nf_internals.h"
+
static const unsigned int nf_ct_icmp_timeout = 30*HZ;
bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
@@ -271,20 +273,35 @@ static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
};
static int icmp_nlattr_to_tuple(struct nlattr *tb[],
- struct nf_conntrack_tuple *tuple)
+ struct nf_conntrack_tuple *tuple,
+ u_int32_t flags)
{
- if (!tb[CTA_PROTO_ICMP_TYPE] ||
- !tb[CTA_PROTO_ICMP_CODE] ||
- !tb[CTA_PROTO_ICMP_ID])
- return -EINVAL;
-
- tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
- tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
- tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
-
- if (tuple->dst.u.icmp.type >= sizeof(invmap) ||
- !invmap[tuple->dst.u.icmp.type])
- return -EINVAL;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_TYPE)) {
+
+ if (!tb[CTA_PROTO_ICMP_TYPE])
+ return -EINVAL;
+
+ tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
+ if (tuple->dst.u.icmp.type >= sizeof(invmap) ||
+ !invmap[tuple->dst.u.icmp.type])
+ return -EINVAL;
+ }
+
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_CODE)) {
+
+ if (!tb[CTA_PROTO_ICMP_CODE])
+ return -EINVAL;
+
+ tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
+ }
+
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_ID)) {
+
+ if (!tb[CTA_PROTO_ICMP_ID])
+ return -EINVAL;
+
+ tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
+ }
return 0;
}
diff --git a/net/netfilter/nf_conntrack_proto_icmpv6.c b/net/netfilter/nf_conntrack_proto_icmpv6.c
index 6f9144e1f1c1..4a374b619421 100644
--- a/net/netfilter/nf_conntrack_proto_icmpv6.c
+++ b/net/netfilter/nf_conntrack_proto_icmpv6.c
@@ -24,6 +24,8 @@
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_log.h>
+#include "nf_internals.h"
+
static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
@@ -193,21 +195,36 @@ static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
};
static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
- struct nf_conntrack_tuple *tuple)
+ struct nf_conntrack_tuple *tuple,
+ u_int32_t flags)
{
- if (!tb[CTA_PROTO_ICMPV6_TYPE] ||
- !tb[CTA_PROTO_ICMPV6_CODE] ||
- !tb[CTA_PROTO_ICMPV6_ID])
- return -EINVAL;
-
- tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
- tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
- tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
-
- if (tuple->dst.u.icmp.type < 128 ||
- tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
- !invmap[tuple->dst.u.icmp.type - 128])
- return -EINVAL;
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_TYPE)) {
+
+ if (!tb[CTA_PROTO_ICMPV6_TYPE])
+ return -EINVAL;
+
+ tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
+ if (tuple->dst.u.icmp.type < 128 ||
+ tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
+ !invmap[tuple->dst.u.icmp.type - 128])
+ return -EINVAL;
+ }
+
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_CODE)) {
+
+ if (!tb[CTA_PROTO_ICMPV6_CODE])
+ return -EINVAL;
+
+ tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
+ }
+
+ if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_ID)) {
+
+ if (!tb[CTA_PROTO_ICMPV6_ID])
+ return -EINVAL;
+
+ tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
+ }
return 0;
}
diff --git a/net/netfilter/nf_internals.h b/net/netfilter/nf_internals.h
index d6c43902ebd7..92a406e06e13 100644
--- a/net/netfilter/nf_internals.h
+++ b/net/netfilter/nf_internals.h
@@ -6,6 +6,22 @@
#include <linux/skbuff.h>
#include <linux/netdevice.h>
+/* applied on tuple filters */
+#define CTA_FILTER_F_CTA_IP_SRC (1 << 0)
+#define CTA_FILTER_F_CTA_IP_DST (1 << 1)
+#define CTA_FILTER_F_CTA_TUPLE_ZONE (1 << 2)
+#define CTA_FILTER_F_CTA_PROTO_NUM (1 << 3)
+#define CTA_FILTER_F_CTA_PROTO_SRC_PORT (1 << 4)
+#define CTA_FILTER_F_CTA_PROTO_DST_PORT (1 << 5)
+#define CTA_FILTER_F_CTA_PROTO_ICMP_TYPE (1 << 6)
+#define CTA_FILTER_F_CTA_PROTO_ICMP_CODE (1 << 7)
+#define CTA_FILTER_F_CTA_PROTO_ICMP_ID (1 << 8)
+#define CTA_FILTER_F_CTA_PROTO_ICMPV6_TYPE (1 << 9)
+#define CTA_FILTER_F_CTA_PROTO_ICMPV6_CODE (1 << 10)
+#define CTA_FILTER_F_CTA_PROTO_ICMPV6_ID (1 << 11)
+#define CTA_FILTER_F_ALL (1 << 12)
+#define CTA_FILTER_FLAG(ctattr) CTA_FILTER_F_ ## ctattr
+
/* nf_queue.c */
void nf_queue_nf_hook_drop(struct net *net);
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump
2020-03-30 20:46 [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump Romain Bellan
@ 2020-04-26 21:43 ` Pablo Neira Ayuso
2020-05-04 19:37 ` Florent Fourcot
0 siblings, 1 reply; 6+ messages in thread
From: Pablo Neira Ayuso @ 2020-04-26 21:43 UTC (permalink / raw)
To: Romain Bellan; +Cc: netfilter-devel, Florent Fourcot
Hi Florent, Romain,
On Mon, Mar 30, 2020 at 10:46:37PM +0200, Romain Bellan wrote:
> Conntrack dump does not support kernel side filtering (only get exists,
> but it returns only one entry. And user has to give a full valid tuple)
>
> It means that userspace has to implement filtering after receiving many
> irrelevant entries, consuming resources (conntrack table is sometimes
> very huge, much more than a routing table for example).
>
> This patch adds filtering in kernel side. To achieve this goal, we:
>
> * Add a new CTA_FILTER netlink attributes, actually a flag list to
> parametize filtering
> * Convert some *nlattr_to_tuple() functions, to allow a partial parsing
> of CTA_TUPLE_ORIG and CTA_TUPLE_REPLY (so nf_conntrack_tuple it not
> fully set)
Still some issues here running conntrack-tools/tests/conntrack/test-conntrack.c
with your patch v5 on top of nf-next, it reports:
OK: 84 BAD: 38
it should say:
OK: 122 BAD: 0
The test this needs to be compiled via:
gcc -lnetfilter_conntrack test-conntrack.c -o test
I'm attaching the log for the run of your patch v5.
Have a look at the "BAD" pattern which provides tells what conntrack
command stopped working.
Thanks for working on this.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump
2020-04-26 21:43 ` Pablo Neira Ayuso
@ 2020-05-04 19:37 ` Florent Fourcot
2020-05-05 19:14 ` Pablo Neira Ayuso
2020-05-29 18:04 ` Pablo Neira Ayuso
0 siblings, 2 replies; 6+ messages in thread
From: Florent Fourcot @ 2020-05-04 19:37 UTC (permalink / raw)
To: Pablo Neira Ayuso, Romain Bellan; +Cc: netfilter-devel
Hello Pablo,
We just posted a v6. We hope that this one will be the good one.
>
> The test this needs to be compiled via:
>
> gcc -lnetfilter_conntrack test-conntrack.c -o test
>
Thanks for the pointer, it helped us a lot, it was not clear before for
us how to test it.
We applied patch on top of current net-next HEAD and it looks good for
this one (OK: 122 BAD: 0).
Best regards,
--
Florent.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump
2020-05-04 19:37 ` Florent Fourcot
@ 2020-05-05 19:14 ` Pablo Neira Ayuso
2020-05-29 18:04 ` Pablo Neira Ayuso
1 sibling, 0 replies; 6+ messages in thread
From: Pablo Neira Ayuso @ 2020-05-05 19:14 UTC (permalink / raw)
To: Florent Fourcot; +Cc: Romain Bellan, netfilter-devel
Hello Florent,
On Mon, May 04, 2020 at 09:37:37PM +0200, Florent Fourcot wrote:
> Hello Pablo,
>
> We just posted a v6. We hope that this one will be the good one.
Thanks, I'll review asap.
> > The test this needs to be compiled via:
> >
> > gcc -lnetfilter_conntrack test-conntrack.c -o test
> >
>
> Thanks for the pointer, it helped us a lot, it was not clear before for us
> how to test it.
I should have said since the beginning, I forgot about these tests
when reviewing.
> We applied patch on top of current net-next HEAD and it looks good for this
> one (OK: 122 BAD: 0).
Great.
I'll review asap.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump
2020-05-04 19:37 ` Florent Fourcot
2020-05-05 19:14 ` Pablo Neira Ayuso
@ 2020-05-29 18:04 ` Pablo Neira Ayuso
2020-06-04 16:08 ` Florent Fourcot
1 sibling, 1 reply; 6+ messages in thread
From: Pablo Neira Ayuso @ 2020-05-29 18:04 UTC (permalink / raw)
To: Florent Fourcot; +Cc: Romain Bellan, netfilter-devel
Hi,
Just a followed up after including your ctnetlink update in the last
upstream pull request for net-next.
I think you already mentioned, but it should be possible to extend
the conntrack utility to support for kernel side filtering seamlessly.
The idea is to keep the userspace filtering as a fallback, regardless
the kernel supports for CTA_FILTER or not.
I'm missing one feature in the CTA_FILTER, that is the netmask
filtering for IP addresses. It would be also good to make this fit
into libnetfilter_conntrack.
Probably this patch can be extended to include two objects, the
conntrack object that represents the exact matching (values) and
another one that represent the mask:
https://patchwork.ozlabs.org/project/netfilter-devel/patch/20200129094719.670-1-romain.bellan@wifirst.fr/
The mask object would only work for the IP address and mark.
Probably rename NFCT_FILTER_DUMP_TUPLE to NFCT_FILTER_DUMP, which
would provide the most generic version to request kernel side
filtering.
Thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump
2020-05-29 18:04 ` Pablo Neira Ayuso
@ 2020-06-04 16:08 ` Florent Fourcot
0 siblings, 0 replies; 6+ messages in thread
From: Florent Fourcot @ 2020-06-04 16:08 UTC (permalink / raw)
To: Pablo Neira Ayuso; +Cc: Romain Bellan, netfilter-devel
Dear Pablo,
>
> I think you already mentioned, but it should be possible to extend
> the conntrack utility to support for kernel side filtering seamlessly.
>
> The idea is to keep the userspace filtering as a fallback, regardless
> the kernel supports for CTA_FILTER or not.
>
We agree, and we are currently working on a transparent implementation
for another netlink userspace library (pyroute2).
About our patches on libnetfilter_conntrack, first step is probably one
small refresh, since kernel part change a little bit. And we saw a first
issue. Definitions of CTA_FILTER_* are now in nf_internals.h in kernel,
so synchronization of linux_nfnetlink_conntrack.h will not be enough to
export FILTER_FLAGS values. What do you think about the best way to
synchronize flags values between userspace and kernel?
After this refresh, we can extend code of the submitted example for a
full support.
> I'm missing one feature in the CTA_FILTER, that is the netmask
> filtering for IP addresses. It would be also good to make this fit
> into libnetfilter_conntrack.
>
Yes, but it needs some extensions in kernel before. It's in our
planning, but not done yet.
>
> Probably rename NFCT_FILTER_DUMP_TUPLE to NFCT_FILTER_DUMP, which
> would provide the most generic version to request kernel side
> filtering.
>
Ok, we will do that.
Thanks for the follow-up,
--
Florent.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-06-04 16:08 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-30 20:46 [PATCH nf-next v5 1/1] netfilter: ctnetlink: add kernel side filtering for dump Romain Bellan
2020-04-26 21:43 ` Pablo Neira Ayuso
2020-05-04 19:37 ` Florent Fourcot
2020-05-05 19:14 ` Pablo Neira Ayuso
2020-05-29 18:04 ` Pablo Neira Ayuso
2020-06-04 16:08 ` Florent Fourcot
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