diff options
| author | Claudio Jeker <claudio@cvs.openbsd.org> | 2010-09-29 08:18:24 +0000 |
|---|---|---|
| committer | Claudio Jeker <claudio@cvs.openbsd.org> | 2010-09-29 08:18:24 +0000 |
| commit | e81258ee31422b056e3912ea918fcbacd95cdfd2 (patch) | |
| tree | d6d92392501a9741c526f4d9893887fe19895427 /sys/netinet | |
| parent | 18c92fc2ba01e7464165f7c02fc5f8293a01f3c3 (diff) | |
Do not delay ACKs on connections using loopback interfaces. There is no
reason to reduce the amount of ACKs sent and delayed ACKs have a very bad
interaction with the large MTU of lo(4) and the fairly small socketbuffer
size. In collaboration with andre@freebsd.
OK deraadt@
Diffstat (limited to 'sys/netinet')
| -rw-r--r-- | sys/netinet/tcp_input.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 664687ee821..05c444a9b74 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tcp_input.c,v 1.236 2010/09/24 02:59:45 claudio Exp $ */ +/* $OpenBSD: tcp_input.c,v 1.237 2010/09/29 08:18:23 claudio Exp $ */ /* $NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $ */ /* @@ -175,12 +175,15 @@ do { \ * Macro to compute ACK transmission behavior. Delay the ACK unless * we have already delayed an ACK (must send an ACK every two segments). * We also ACK immediately if we received a PUSH and the ACK-on-PUSH - * option is enabled. + * option is enabled or when the packet is comming from a loopback + * interface. */ -#define TCP_SETUP_ACK(tp, tiflags) \ +#define TCP_SETUP_ACK(tp, tiflags, m) \ do { \ if ((tp)->t_flags & TF_DELACK || \ - (tcp_ack_on_push && (tiflags) & TH_PUSH)) \ + (tcp_ack_on_push && (tiflags) & TH_PUSH) || \ + (m && (m->m_flags & M_PKTHDR) && m->m_pkthdr.rcvif && \ + (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK))) \ tp->t_flags |= TF_ACKNOW; \ else \ TCP_SET_DELACK(tp); \ @@ -1116,6 +1119,8 @@ after_listen: tcpstat.tcps_rcvpack++; tcpstat.tcps_rcvbyte += tlen; ND6_HINT(tp); + + TCP_SETUP_ACK(tp, tiflags, m); /* * Drop TCP, IP headers and TCP options then add data * to socket buffer. @@ -1137,7 +1142,6 @@ after_listen: sbappendstream(&so->so_rcv, m); } sorwakeup(so); - TCP_SETUP_ACK(tp, tiflags); if (tp->t_flags & TF_ACKNOW) (void) tcp_output(tp); return; @@ -2077,7 +2081,7 @@ dodata: /* XXX */ #endif if (th->th_seq == tp->rcv_nxt && TAILQ_EMPTY(&tp->t_segq) && tp->t_state == TCPS_ESTABLISHED) { - TCP_SETUP_ACK(tp, tiflags); + TCP_SETUP_ACK(tp, tiflags, m); tp->rcv_nxt += tlen; tiflags = th->th_flags & TH_FIN; tcpstat.tcps_rcvpack++; |