tcp: Use defaults when no route options are available

Trying to parse the option of a SYN packet that we have
no route entry for should just use global wide defaults
for route entry options.

Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Tested-by: Valdis.Kletnieks@vt.edu
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 1 insertions, 3 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 39c4a5963e12..387cb3cfde7e 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -113,7 +113,7 @@ dst_metric(const struct dst_entry *dst, int metric)
 static inline u32
 dst_feature(const struct dst_entry *dst, u32 feature)
 {
-        return dst_metric(dst, RTAX_FEATURES) & feature;
+        return (dst ? dst_metric(dst, RTAX_FEATURES) & feature : 0);
 }
 
 static inline u32 dst_mtu(const struct dst_entry *dst)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ba0eab65fe80..be0c5bf7bfca 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3704,8 +3704,6 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
         struct tcphdr *th = tcp_hdr(skb);
         int length = (th->doff * 4) - sizeof(struct tcphdr);
 
-        BUG_ON(!estab && !dst);
-
         ptr = (unsigned char *)(th + 1);
         opt_rx->saw_tstamp = 0;