[PATCH net-next 5/8] tcp: Support for TOU

[Tom Herbert]

Need to adjust MSS to account for encapsulation overhead. This is done
by add encpasulation header length into icsk_ext_hdr_len.

Signed-off-by: Tom Herbert <t...@herbertland.com>
---
 net/ipv4/tcp_ipv4.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 3708de2..c344f667 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -74,6 +74,7 @@
 #include <net/xfrm.h>
 #include <net/secure_seq.h>
 #include <net/busy_poll.h>
+#include <net/tou.h>
 
 #include <linux/inet.h>
 #include <linux/ipv6.h>
@@ -205,9 +206,9 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, 
int addr_len)
        inet->inet_dport = usin->sin_port;
        sk_daddr_set(sk, daddr);
 
-       inet_csk(sk)->icsk_ext_hdr_len = 0;
+       inet_csk(sk)->icsk_ext_hdr_len = tou_hdr_len(sk);
        if (inet_opt)
-               inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
+               inet_csk(sk)->icsk_ext_hdr_len += inet_opt->opt.optlen;
 
        tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
 
@@ -1296,9 +1297,9 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, 
struct sk_buff *skb,
        newinet->mc_index     = inet_iif(skb);
        newinet->mc_ttl       = ip_hdr(skb)->ttl;
        newinet->rcv_tos      = ip_hdr(skb)->tos;
-       inet_csk(newsk)->icsk_ext_hdr_len = 0;
+       inet_csk(sk)->icsk_ext_hdr_len = tou_hdr_len(sk);
        if (inet_opt)
-               inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
+               inet_csk(newsk)->icsk_ext_hdr_len += inet_opt->opt.optlen;
        newinet->inet_id = newtp->write_seq ^ jiffies;
 
        if (!dst) {
-- 
2.8.0.rc2