Add the no SACK route option feature

Implement querying and acting upon the no sack bit in the features
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>
This commit is contained in:
Gilad Ben-Yossef 2009-10-28 04:15:24 +00:00 committed by David S. Miller
parent 0c3adfb8ec
commit 1aba721eba
3 changed files with 6 additions and 3 deletions

View file

@ -377,7 +377,7 @@ enum
#define RTAX_MAX (__RTAX_MAX - 1)
#define RTAX_FEATURE_ECN 0x00000001
#define RTAX_FEATURE_SACK 0x00000002
#define RTAX_FEATURE_NO_SACK 0x00000002
#define RTAX_FEATURE_TIMESTAMP 0x00000004
#define RTAX_FEATURE_ALLFRAG 0x00000008

View file

@ -3763,7 +3763,8 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
break;
case TCPOPT_SACK_PERM:
if (opsize == TCPOLEN_SACK_PERM && th->syn &&
!estab && sysctl_tcp_sack) {
!estab && sysctl_tcp_sack &&
!dst_feature(dst, RTAX_FEATURE_NO_SACK)) {
opt_rx->sack_ok = 1;
tcp_sack_reset(opt_rx);
}

View file

@ -464,6 +464,7 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
struct tcp_md5sig_key **md5) {
struct tcp_sock *tp = tcp_sk(sk);
unsigned size = 0;
struct dst_entry *dst = __sk_dst_get(sk);
#ifdef CONFIG_TCP_MD5SIG
*md5 = tp->af_specific->md5_lookup(sk, sk);
@ -498,7 +499,8 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
opts->options |= OPTION_WSCALE;
size += TCPOLEN_WSCALE_ALIGNED;
}
if (likely(sysctl_tcp_sack)) {
if (likely(sysctl_tcp_sack &&
!dst_feature(dst, RTAX_FEATURE_NO_SACK))) {
opts->options |= OPTION_SACK_ADVERTISE;
if (unlikely(!(OPTION_TS & opts->options)))
size += TCPOLEN_SACKPERM_ALIGNED;