5 files changed, 30 insertions, 0 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index 0707fb9551aa..a68f838a132c 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -143,6 +143,8 @@ static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 extern int              ip4_datagram_connect(struct sock *sk, 
                                              struct sockaddr *uaddr, int addr_len);
 
+extern void ip4_datagram_release_cb(struct sock *sk);
+
 struct ip_reply_arg {
         struct kvec iov[1];   
         int         flags;
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 424fafbc8cb0..b28e863fe0a7 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -85,3 +85,28 @@ out:
         return err;
 }
 EXPORT_SYMBOL(ip4_datagram_connect);
+
+void ip4_datagram_release_cb(struct sock *sk)
+{
+        const struct inet_sock *inet = inet_sk(sk);
+        const struct ip_options_rcu *inet_opt;
+        __be32 daddr = inet->inet_daddr;
+        struct flowi4 fl4;
+        struct rtable *rt;
+
+        if (! __sk_dst_get(sk) || __sk_dst_check(sk, 0))
+                return;
+
+        rcu_read_lock();
+        inet_opt = rcu_dereference(inet->inet_opt);
+        if (inet_opt && inet_opt->opt.srr)
+                daddr = inet_opt->opt.faddr;
+        rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr,
+                                   inet->inet_saddr, inet->inet_dport,
+                                   inet->inet_sport, sk->sk_protocol,
+                                   RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
+        if (!IS_ERR(rt))
+                __sk_dst_set(sk, &rt->dst);
+        rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(ip4_datagram_release_cb);
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 8f3d05424a3e..6f9c07268cf6 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -738,6 +738,7 @@ struct proto ping_prot = {
         .recvmsg =      ping_recvmsg,
         .bind =         ping_bind,
         .backlog_rcv =  ping_queue_rcv_skb,
+        .release_cb =   ip4_datagram_release_cb,
         .hash =         ping_v4_hash,
         .unhash =       ping_v4_unhash,
         .get_port =     ping_v4_get_port,
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 73d1e4df4bf6..6f08991409c3 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -894,6 +894,7 @@ struct proto raw_prot = {
         .recvmsg           = raw_recvmsg,
         .bind              = raw_bind,
         .backlog_rcv       = raw_rcv_skb,
+        .release_cb        = ip4_datagram_release_cb,
         .hash              = raw_hash_sk,
         .unhash            = raw_unhash_sk,
         .obj_size          = sizeof(struct raw_sock),
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 79c8dbe59b54..1f4d405eafba 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1952,6 +1952,7 @@ struct proto udp_prot = {
         .recvmsg           = udp_recvmsg,
         .sendpage          = udp_sendpage,
         .backlog_rcv       = __udp_queue_rcv_skb,
+        .release_cb        = ip4_datagram_release_cb,
         .hash              = udp_lib_hash,
         .unhash            = udp_lib_unhash,
         .rehash            = udp_v4_rehash,