Allow disabling TCP timestamp options per route

Implement querying and acting upon the no timestamp bit in the feature
field.

Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 5fb25f977451..6097491aa9fc 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3755,7 +3755,8 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
                         case TCPOPT_TIMESTAMP:
                                 if ((opsize == TCPOLEN_TIMESTAMP) &&
                                     ((estab && opt_rx->tstamp_ok) ||
-                                     (!estab && sysctl_tcp_timestamps))) {
+                                     (!estab && sysctl_tcp_timestamps &&
+                                      !dst_feature(dst, RTAX_FEATURE_NO_TSTAMP)))) {
                                         opt_rx->saw_tstamp = 1;
                                         opt_rx->rcv_tsval = get_unaligned_be32(ptr);
                                         opt_rx->rcv_tsecr = get_unaligned_be32(ptr + 4);