[PATCH v6] net: ip, diag -- Add diag interface for raw sockets

* [PATCH v6] net: ip, diag -- Add diag interface for raw sockets
@ 2016-10-06 10:00 Cyrill Gorcunov
  2016-10-12  5:50 ` David Miller
  0 siblings, 1 reply; 7+ messages in thread
From: Cyrill Gorcunov @ 2016-10-06 10:00 UTC (permalink / raw)
  To: netdev
  Cc: Eric Dumazet, Jamal Hadi Salim, David Ahern, linux-kernel,
	David Miller, kuznet, jmorris, yoshfuji, kaber, avagin, stephen

In criu we are actively using diag interface to collect sockets
present in the system when dumping applications. And while for
unix, tcp, udp[lite], packet, netlink it works as expected,
the raw sockets do not have. Thus add it.

v2:
 - add missing sock_put calls in raw_diag_dump_one (by eric.dumazet@)
 - implement @destroy for diag requests (by dsa@)

v3:
 - add export of raw_abort for IPv6 (by dsa@)
 - pass net-admin flag into inet_sk_diag_fill due to
   changes in net-next branch (by dsa@)

v4:
 - use @pad in struct inet_diag_req_v2 for raw socket
   protocol specification: raw module carries sockets
   which may have custom protocol passed from socket()
   syscall and sole @sdiag_protocol is not enough to
   match underlied ones
 - start reporting protocol specifed in socket() call
   when sockets are raw ones for the same reason: user
   space tools like ss may parse this attribute and use
   it for socket matching

v5 (by eric.dumazet@):
 - use sock_hold in raw_sock_get instead of atomic_inc,
   we're holding (raw_v4_hashinfo|raw_v6_hashinfo)->lock
   when looking up so counter won't be zero here.

v6:
 - use sdiag_raw_protocol() helper which will access @pad
   structure used for raw sockets protocol specification:
   we can't simply rename this member without breaking uapi.

CC: David S. Miller <davem@davemloft.net>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: David Ahern <dsa@cumulusnetworks.com>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
CC: James Morris <jmorris@namei.org>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Patrick McHardy <kaber@trash.net>
CC: Andrey Vagin <avagin@openvz.org>
CC: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---
Really sorry for delay. Take a look please once time permit,
I think the most safe solution is to use macro which wraps
@pad access so the userspace progs won't fail on compilation
if they keep the reference on this field.

 include/net/raw.h              |    6 +
 include/net/rawv6.h            |    7 +
 include/uapi/linux/inet_diag.h |    9 +
 net/ipv4/Kconfig               |    8 +
 net/ipv4/Makefile              |    1 
 net/ipv4/inet_diag.c           |    9 +
 net/ipv4/raw.c                 |   21 +++
 net/ipv4/raw_diag.c            |  239 +++++++++++++++++++++++++++++++++++++++++
 net/ipv6/raw.c                 |    7 -
 9 files changed, 303 insertions(+), 4 deletions(-)

Index: linux-ml.git/include/net/raw.h
===================================================================

--- linux-ml.git.orig/include/net/raw.h
+++ linux-ml.git/include/net/raw.h
@@ -23,6 +23,12 @@
 
 extern struct proto raw_prot;
 
+extern struct raw_hashinfo raw_v4_hashinfo;
+struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
+			     unsigned short num, __be32 raddr,
+			     __be32 laddr, int dif);
+
+int raw_abort(struct sock *sk, int err);
 void raw_icmp_error(struct sk_buff *, int, u32);
 int raw_local_deliver(struct sk_buff *, int);
 
Index: linux-ml.git/include/net/rawv6.h
===================================================================
--- linux-ml.git.orig/include/net/rawv6.h
+++ linux-ml.git/include/net/rawv6.h
@@ -3,6 +3,13 @@
 
 #include <net/protocol.h>
 
+extern struct raw_hashinfo raw_v6_hashinfo;
+struct sock *__raw_v6_lookup(struct net *net, struct sock *sk,
+			     unsigned short num, const struct in6_addr *loc_addr,
+			     const struct in6_addr *rmt_addr, int dif);
+
+int raw_abort(struct sock *sk, int err);
+
 void raw6_icmp_error(struct sk_buff *, int nexthdr,
 		u8 type, u8 code, int inner_offset, __be32);
 bool raw6_local_deliver(struct sk_buff *, int);
Index: linux-ml.git/include/uapi/linux/inet_diag.h
===================================================================
--- linux-ml.git.orig/include/uapi/linux/inet_diag.h
+++ linux-ml.git/include/uapi/linux/inet_diag.h
@@ -43,6 +43,15 @@ struct inet_diag_req_v2 {
 	struct inet_diag_sockid id;
 };
 
+/*
+ * SOCK_RAW sockets require the underlied protocol to be
+ * additionally specified so we can use @pad member for
+ * this, but we can't rename it because userspace programs
+ * still may depend on this name. Instead lets use an explicit
+ * helper.
+ */
+#define sdiag_raw_protocol(__req)	(__req)->pad
+
 enum {
 	INET_DIAG_REQ_NONE,
 	INET_DIAG_REQ_BYTECODE,
Index: linux-ml.git/net/ipv4/Kconfig
===================================================================
--- linux-ml.git.orig/net/ipv4/Kconfig
+++ linux-ml.git/net/ipv4/Kconfig
@@ -430,6 +430,14 @@ config INET_UDP_DIAG
 	  Support for UDP socket monitoring interface used by the ss tool.
 	  If unsure, say Y.
 
+config INET_RAW_DIAG
+	tristate "RAW: socket monitoring interface"
+	depends on INET_DIAG && (IPV6 || IPV6=n)
+	default n
+	---help---
+	  Support for RAW socket monitoring interface used by the ss tool.
+	  If unsure, say Y.
+
 config INET_DIAG_DESTROY
 	bool "INET: allow privileged process to administratively close sockets"
 	depends on INET_DIAG
Index: linux-ml.git/net/ipv4/Makefile
===================================================================
--- linux-ml.git.orig/net/ipv4/Makefile
+++ linux-ml.git/net/ipv4/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_NETFILTER)	+= netfilter.o n
 obj-$(CONFIG_INET_DIAG) += inet_diag.o 
 obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o
 obj-$(CONFIG_INET_UDP_DIAG) += udp_diag.o
+obj-$(CONFIG_INET_RAW_DIAG) += raw_diag.o
 obj-$(CONFIG_NET_TCPPROBE) += tcp_probe.o
 obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o
 obj-$(CONFIG_TCP_CONG_CDG) += tcp_cdg.o
Index: linux-ml.git/net/ipv4/inet_diag.c
===================================================================
--- linux-ml.git.orig/net/ipv4/inet_diag.c
+++ linux-ml.git/net/ipv4/inet_diag.c
@@ -200,6 +200,15 @@ int inet_sk_diag_fill(struct sock *sk, s
 		if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
 			goto errout;
 
+	/*
+	 * RAW sockets might have user-defined protocols assigned,
+	 * so report the one supplied on socket creation.
+	 */
+	if (sk->sk_type == SOCK_RAW) {
+		if (nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))
+			goto errout;
+	}
+
 	if (!icsk) {
 		handler->idiag_get_info(sk, r, NULL);
 		goto out;
Index: linux-ml.git/net/ipv4/raw.c
===================================================================
--- linux-ml.git.orig/net/ipv4/raw.c
+++ linux-ml.git/net/ipv4/raw.c
@@ -89,9 +89,10 @@ struct raw_frag_vec {
 	int hlen;
 };
 
-static struct raw_hashinfo raw_v4_hashinfo = {
+struct raw_hashinfo raw_v4_hashinfo = {
 	.lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock),
 };
+EXPORT_SYMBOL_GPL(raw_v4_hashinfo);
 
 int raw_hash_sk(struct sock *sk)
 {
@@ -120,7 +121,7 @@ void raw_unhash_sk(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(raw_unhash_sk);
 
-static struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
+struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
 		unsigned short num, __be32 raddr, __be32 laddr, int dif)
 {
 	sk_for_each_from(sk) {
@@ -136,6 +137,7 @@ static struct sock *__raw_v4_lookup(stru
 found:
 	return sk;
 }
+EXPORT_SYMBOL_GPL(__raw_v4_lookup);
 
 /*
  *	0 - deliver
@@ -918,6 +920,20 @@ static int compat_raw_ioctl(struct sock
 }
 #endif
 
+int raw_abort(struct sock *sk, int err)
+{
+	lock_sock(sk);
+
+	sk->sk_err = err;
+	sk->sk_error_report(sk);
+	udp_disconnect(sk, 0);
+
+	release_sock(sk);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(raw_abort);
+
 struct proto raw_prot = {
 	.name		   = "RAW",
 	.owner		   = THIS_MODULE,
@@ -943,6 +959,7 @@ struct proto raw_prot = {
 	.compat_getsockopt = compat_raw_getsockopt,
 	.compat_ioctl	   = compat_raw_ioctl,
 #endif
+	.diag_destroy	   = raw_abort,
 };
 
 #ifdef CONFIG_PROC_FS
Index: linux-ml.git/net/ipv4/raw_diag.c
===================================================================
--- /dev/null
+++ linux-ml.git/net/ipv4/raw_diag.c
@@ -0,0 +1,239 @@
+#include <linux/module.h>
+
+#include <linux/inet_diag.h>
+#include <linux/sock_diag.h>
+
+#include <net/raw.h>
+#include <net/rawv6.h>
+
+#ifdef pr_fmt
+# undef pr_fmt
+#endif
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+static struct raw_hashinfo *
+raw_get_hashinfo(const struct inet_diag_req_v2 *r)
+{
+	if (r->sdiag_family == AF_INET) {
+		return &raw_v4_hashinfo;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (r->sdiag_family == AF_INET6) {
+		return &raw_v6_hashinfo;
+#endif
+	} else {
+		pr_warn_once("Unexpected inet family %d\n",
+			     r->sdiag_family);
+		WARN_ON_ONCE(1);
+		return ERR_PTR(-EINVAL);
+	}
+}
+
+/*
+ * Due to requirement of not breaking user API we can't simply
+ * rename @pad field in inet_diag_req_v2 structure, instead
+ * use helper to figure it out.
+ */
+
+static struct sock *raw_lookup(struct net *net, struct sock *from,
+			       const struct inet_diag_req_v2 *r)
+{
+	struct sock *sk = NULL;
+
+	if (r->sdiag_family == AF_INET)
+		sk = __raw_v4_lookup(net, from, sdiag_raw_protocol(r),
+				     r->id.idiag_dst[0],
+				     r->id.idiag_src[0],
+				     r->id.idiag_if);
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		sk = __raw_v6_lookup(net, from, sdiag_raw_protocol(r),
+				     (const struct in6_addr *)r->id.idiag_src,
+				     (const struct in6_addr *)r->id.idiag_dst,
+				     r->id.idiag_if);
+#endif
+	return sk;
+}
+
+static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
+{
+	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
+	struct sock *sk = NULL, *s;
+	int slot;
+
+	if (IS_ERR(hashinfo))
+		return ERR_CAST(hashinfo);
+
+	read_lock(&hashinfo->lock);
+	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
+		sk_for_each(s, &hashinfo->ht[slot]) {
+			sk = raw_lookup(net, s, r);
+			if (sk) {
+				/*
+				 * Grab it and keep until we fill
+				 * diag meaage to be reported, so
+				 * caller should call sock_put then.
+				 * We can do that because we're keeping
+				 * hashinfo->lock here.
+				 */
+				sock_hold(sk);
+				break;
+			}
+		}
+	}
+	read_unlock(&hashinfo->lock);
+
+	return sk ? sk : ERR_PTR(-ENOENT);
+}
+
+static int raw_diag_dump_one(struct sk_buff *in_skb,
+			     const struct nlmsghdr *nlh,
+			     const struct inet_diag_req_v2 *r)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct sk_buff *rep;
+	struct sock *sk;
+	int err;
+
+	sk = raw_sock_get(net, r);
+	if (IS_ERR(sk))
+		return PTR_ERR(sk);
+
+	rep = nlmsg_new(sizeof(struct inet_diag_msg) +
+			sizeof(struct inet_diag_meminfo) + 64,
+			GFP_KERNEL);
+	if (!rep) {
+		sock_put(sk);
+		return -ENOMEM;
+	}
+
+	err = inet_sk_diag_fill(sk, NULL, rep, r,
+				sk_user_ns(NETLINK_CB(in_skb).sk),
+				NETLINK_CB(in_skb).portid,
+				nlh->nlmsg_seq, 0, nlh,
+				netlink_net_capable(in_skb, CAP_NET_ADMIN));
+	sock_put(sk);
+
+	if (err < 0) {
+		kfree_skb(rep);
+		return err;
+	}
+
+	err = netlink_unicast(net->diag_nlsk, rep,
+			      NETLINK_CB(in_skb).portid,
+			      MSG_DONTWAIT);
+	if (err > 0)
+		err = 0;
+	return err;
+}
+
+static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
+			struct netlink_callback *cb,
+			const struct inet_diag_req_v2 *r,
+			struct nlattr *bc, bool net_admin)
+{
+	if (!inet_diag_bc_sk(bc, sk))
+		return 0;
+
+	return inet_sk_diag_fill(sk, NULL, skb, r,
+			sk_user_ns(NETLINK_CB(cb->skb).sk),
+			NETLINK_CB(cb->skb).portid,
+			cb->nlh->nlmsg_seq, NLM_F_MULTI,
+			cb->nlh, net_admin);
+}
+
+static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
+			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
+{
+	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
+	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
+	struct net *net = sock_net(skb->sk);
+	int num, s_num, slot, s_slot;
+	struct sock *sk = NULL;
+
+	if (IS_ERR(hashinfo))
+		return;
+
+	s_slot = cb->args[0];
+	num = s_num = cb->args[1];
+
+	read_lock(&hashinfo->lock);
+	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
+		num = 0;
+
+		sk_for_each(sk, &hashinfo->ht[slot]) {
+			struct inet_sock *inet = inet_sk(sk);
+
+			if (!net_eq(sock_net(sk), net))
+				continue;
+			if (num < s_num)
+				goto next;
+			if (sk->sk_family != r->sdiag_family)
+				goto next;
+			if (r->id.idiag_sport != inet->inet_sport &&
+			    r->id.idiag_sport)
+				goto next;
+			if (r->id.idiag_dport != inet->inet_dport &&
+			    r->id.idiag_dport)
+				goto next;
+			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
+				goto out_unlock;
+next:
+			num++;
+		}
+	}
+
+out_unlock:
+	read_unlock(&hashinfo->lock);
+
+	cb->args[0] = slot;
+	cb->args[1] = num;
+}
+
+static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
+			      void *info)
+{
+	r->idiag_rqueue = sk_rmem_alloc_get(sk);
+	r->idiag_wqueue = sk_wmem_alloc_get(sk);
+}
+
+#ifdef CONFIG_INET_DIAG_DESTROY
+static int raw_diag_destroy(struct sk_buff *in_skb,
+			    const struct inet_diag_req_v2 *r)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct sock *sk;
+
+	sk = raw_sock_get(net, r);
+	if (IS_ERR(sk))
+		return PTR_ERR(sk);
+	return sock_diag_destroy(sk, ECONNABORTED);
+}
+#endif
+
+static const struct inet_diag_handler raw_diag_handler = {
+	.dump			= raw_diag_dump,
+	.dump_one		= raw_diag_dump_one,
+	.idiag_get_info		= raw_diag_get_info,
+	.idiag_type		= IPPROTO_RAW,
+	.idiag_info_size	= 0,
+#ifdef CONFIG_INET_DIAG_DESTROY
+	.destroy		= raw_diag_destroy,
+#endif
+};
+
+static int __init raw_diag_init(void)
+{
+	return inet_diag_register(&raw_diag_handler);
+}
+
+static void __exit raw_diag_exit(void)
+{
+	inet_diag_unregister(&raw_diag_handler);
+}
+
+module_init(raw_diag_init);
+module_exit(raw_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
Index: linux-ml.git/net/ipv6/raw.c
===================================================================
--- linux-ml.git.orig/net/ipv6/raw.c
+++ linux-ml.git/net/ipv6/raw.c
@@ -65,11 +65,12 @@
 
 #define	ICMPV6_HDRLEN	4	/* ICMPv6 header, RFC 4443 Section 2.1 */
 
-static struct raw_hashinfo raw_v6_hashinfo = {
+struct raw_hashinfo raw_v6_hashinfo = {
 	.lock = __RW_LOCK_UNLOCKED(raw_v6_hashinfo.lock),
 };
+EXPORT_SYMBOL_GPL(raw_v6_hashinfo);
 
-static struct sock *__raw_v6_lookup(struct net *net, struct sock *sk,
+struct sock *__raw_v6_lookup(struct net *net, struct sock *sk,
 		unsigned short num, const struct in6_addr *loc_addr,
 		const struct in6_addr *rmt_addr, int dif)
 {
@@ -102,6 +103,7 @@ static struct sock *__raw_v6_lookup(stru
 found:
 	return sk;
 }
+EXPORT_SYMBOL_GPL(__raw_v6_lookup);
 
 /*
  *	0 - deliver
@@ -1252,6 +1254,7 @@ struct proto rawv6_prot = {
 	.compat_getsockopt = compat_rawv6_getsockopt,
 	.compat_ioctl	   = compat_rawv6_ioctl,
 #endif
+	.diag_destroy	   = raw_abort,
 };
 
 #ifdef CONFIG_PROC_FS

^ permalink raw reply	[flat|nested] 7+ messages in thread