tcp: add mss_clamp to tcp_request_sock_ops

Add mss_clamp member to tcp_request_sock_ops so that we can later
unify tcp_v4_conn_request and tcp_v6_conn_request.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 6 insertions, 2 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 8e9c28dccb80..30fe98bc8957 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1592,6 +1592,7 @@ struct tcp_sock_af_ops {
 };
 
 struct tcp_request_sock_ops {
+        u16 mss_clamp;
 #ifdef CONFIG_TCP_MD5SIG
         struct tcp_md5sig_key   *(*md5_lookup) (struct sock *sk,
                                                 struct request_sock *req);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 597dd9d75210..499d440539ad 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1265,6 +1265,7 @@ struct request_sock_ops tcp_request_sock_ops __read_mostly = {
 };
 
 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
+        .mss_clamp      =       TCP_MSS_DEFAULT,
 #ifdef CONFIG_TCP_MD5SIG
         .md5_lookup     =       tcp_v4_reqsk_md5_lookup,
         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
@@ -1324,7 +1325,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         af_ops = tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
 
         tcp_clear_options(&tmp_opt);
-        tmp_opt.mss_clamp = TCP_MSS_DEFAULT;
+        tmp_opt.mss_clamp = af_ops->mss_clamp;
         tmp_opt.user_mss  = tp->rx_opt.user_mss;
         tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc);
 
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 41389bbb08c0..ad658332cf7d 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -754,6 +754,8 @@ struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 };
 
 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
+        .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
+                                sizeof(struct ipv6hdr),
 #ifdef CONFIG_TCP_MD5SIG
         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
@@ -1047,7 +1049,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
         af_ops = tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
 
         tcp_clear_options(&tmp_opt);
-        tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
+        tmp_opt.mss_clamp = af_ops->mss_clamp;
         tmp_opt.user_mss = tp->rx_opt.user_mss;
         tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc);