From 153e5b57af486fe5b341605806781a0253916809 Mon Sep 17 00:00:00 2001 From: Andre Oppermann Date: Sat, 14 Aug 2010 21:41:33 +0000 Subject: [PATCH] When using TSO and sending more than TCP_MAXWIN sendalot is set and we loop back to 'again'. If the remainder is less or equal to one full segment, the TSO flag was not cleared even though it isn't necessary anymore. Enabling the TSO flag on a segment that doesn't require any offloaded segmentation by the NIC may cause confusion in the driver or hardware. Reset the internal tso flag in tcp_output() on every iteration of sendalot. PR: kern/132832 Submitted by: Renaud Lienhart MFC after: 1 week --- sys/netinet/tcp_output.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c index 50973c4d455c..4327c7e6da54 100644 --- a/sys/netinet/tcp_output.c +++ b/sys/netinet/tcp_output.c @@ -153,7 +153,7 @@ tcp_output(struct tcpcb *tp) int idle, sendalot; int sack_rxmit, sack_bytes_rxmt; struct sackhole *p; - int tso = 0; + int tso; struct tcpopt to; #if 0 int maxburst = TCP_MAXBURST; @@ -211,6 +211,7 @@ tcp_output(struct tcpcb *tp) SEQ_LT(tp->snd_nxt, tp->snd_max)) tcp_sack_adjust(tp); sendalot = 0; + tso = 0; off = tp->snd_nxt - tp->snd_una; sendwin = min(tp->snd_wnd, tp->snd_cwnd); sendwin = min(sendwin, tp->snd_bwnd); @@ -490,9 +491,9 @@ tcp_output(struct tcpcb *tp) } else { len = tp->t_maxseg; sendalot = 1; - tso = 0; } } + if (sack_rxmit) { if (SEQ_LT(p->rxmit + len, tp->snd_una + so->so_snd.sb_cc)) flags &= ~TH_FIN; @@ -1051,6 +1052,8 @@ tcp_output(struct tcpcb *tp) * XXX: Fixme: This is currently not the case for IPv6. */ if (tso) { + KASSERT(len > tp->t_maxopd - optlen, + ("%s: len <= tso_segsz", __func__)); m->m_pkthdr.csum_flags |= CSUM_TSO; m->m_pkthdr.tso_segsz = tp->t_maxopd - optlen; }