tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()

[ Upstream commit 4fab9071950c2021d846e18351e0f46a1cffd67b ]

Make sure we use the correct address-family-specific function for
handling MTU reductions from within tcp_release_cb().

Previously AF_INET6 sockets were incorrectly always using the IPv6
code path when sometimes they were handling IPv4 traffic and thus had
an IPv4 dst.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Diagnosed-by: Willem de Bruijn <willemb@google.com>
Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications")
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index de2c78529afaf81f00abff62bb29708f7f6941a2..0a8f6f961baa749b4b4aaed155ebe999d4c59a0d 100644 (file)
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -62,6 +62,7 @@ struct inet_connection_sock_af_ops {
        void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
        int         (*bind_conflict)(const struct sock *sk,
                                     const struct inet_bind_bucket *tb, bool relax);
+       void        (*mtu_reduced)(struct sock *sk);
 };
 
 /** inet_connection_sock - INET connection oriented sock

diff --git a/include/net/sock.h b/include/net/sock.h
index 26b15c0780bef2e8f07f811d81ec138d9225cf48..c0aad07160ef3e3b03be628634ca6ab70aec339c 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -932,7 +932,6 @@ struct proto {
                                                struct sk_buff *skb);
 
        void            (*release_cb)(struct sock *sk);
-       void            (*mtu_reduced)(struct sock *sk);
 
        /* Keeping track of sk's, looking them up, and port selection methods. */
        void                    (*hash)(struct sock *sk);

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6f87f0873843d3fd65933c7f05e5a51c66103a12..29a1a63cd3033d6967b0b06a003cf26256576156 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -460,6 +460,7 @@ extern const u8 *tcp_parse_md5sig_option(const struct tcphdr *th);
  */
 
 extern void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb);
+void tcp_v4_mtu_reduced(struct sock *sk);
 extern int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 extern struct sock * tcp_create_openreq_child(struct sock *sk,
                                              struct request_sock *req,

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5d87806d3adebedb2f68f94a407627222c387529..e025c1c788a1f2db47b3ed2e36241567dabdf875 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -268,7 +268,7 @@ EXPORT_SYMBOL(tcp_v4_connect);
  * It can be called through tcp_release_cb() if socket was owned by user
  * at the time tcp_v4_err() was called to handle ICMP message.
  */
-static void tcp_v4_mtu_reduced(struct sock *sk)
+void tcp_v4_mtu_reduced(struct sock *sk)
 {
        struct dst_entry *dst;
        struct inet_sock *inet = inet_sk(sk);
@@ -298,6 +298,7 @@ static void tcp_v4_mtu_reduced(struct sock *sk)
                tcp_simple_retransmit(sk);
        } /* else let the usual retransmit timer handle it */
 }
+EXPORT_SYMBOL(tcp_v4_mtu_reduced);
 
 static void do_redirect(struct sk_buff *skb, struct sock *sk)
 {
@@ -2142,6 +2143,7 @@ const struct inet_connection_sock_af_ops ipv4_specific = {
        .compat_setsockopt = compat_ip_setsockopt,
        .compat_getsockopt = compat_ip_getsockopt,
 #endif
+       .mtu_reduced       = tcp_v4_mtu_reduced,
 };
 EXPORT_SYMBOL(ipv4_specific);
 
@@ -2867,7 +2869,6 @@ struct proto tcp_prot = {
        .sendpage               = tcp_sendpage,
        .backlog_rcv            = tcp_v4_do_rcv,
        .release_cb             = tcp_release_cb,
-       .mtu_reduced            = tcp_v4_mtu_reduced,
        .hash                   = inet_hash,
        .unhash                 = inet_unhash,
        .get_port               = inet_csk_get_port,

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 56e29f0e230e4a6c06a24d7a5ee08856a644f697..62aff23d19d1c44078fbf5c660ba93c13270559f 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -775,7 +775,7 @@ void tcp_release_cb(struct sock *sk)
                __sock_put(sk);
        }
        if (flags & (1UL << TCP_MTU_REDUCED_DEFERRED)) {
-               sk->sk_prot->mtu_reduced(sk);
+               inet_csk(sk)->icsk_af_ops->mtu_reduced(sk);
                __sock_put(sk);
        }
 }

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 66c718854e5aa28543fe7352c6546e718b25e7fc..1a87659a61396cf69a1071e34d906b2d5ca4ce51 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1651,6 +1651,7 @@ static const struct inet_connection_sock_af_ops ipv6_specific = {
        .compat_setsockopt = compat_ipv6_setsockopt,
        .compat_getsockopt = compat_ipv6_getsockopt,
 #endif
+       .mtu_reduced       = tcp_v6_mtu_reduced,
 };
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -1682,6 +1683,7 @@ static const struct inet_connection_sock_af_ops ipv6_mapped = {
        .compat_setsockopt = compat_ipv6_setsockopt,
        .compat_getsockopt = compat_ipv6_getsockopt,
 #endif
+       .mtu_reduced       = tcp_v4_mtu_reduced,
 };
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -1919,7 +1921,6 @@ struct proto tcpv6_prot = {
        .sendpage               = tcp_sendpage,
        .backlog_rcv            = tcp_v6_do_rcv,
        .release_cb             = tcp_release_cb,
-       .mtu_reduced            = tcp_v6_mtu_reduced,
        .hash                   = tcp_v6_hash,
        .unhash                 = inet_unhash,
        .get_port               = inet_csk_get_port,