ipv4: Add a socket release callback for datagram sockets
This implements a socket release callback function to check
if the socket cached route got invalid during the time
we owned the socket. The function is used from udp, raw
and ping sockets.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 424fafb..b28e863 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -85,3 +85,28 @@
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 8f3d054..6f9c072 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -738,6 +738,7 @@
.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 73d1e4d..6f08991 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -894,6 +894,7 @@
.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 79c8dbe..1f4d405 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1952,6 +1952,7 @@
.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,