diff options
Diffstat (limited to 'sys/netinet/tcp_usrreq.c')
| -rw-r--r-- | sys/netinet/tcp_usrreq.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c index e2464dc5717..8dc00e67f38 100644 --- a/sys/netinet/tcp_usrreq.c +++ b/sys/netinet/tcp_usrreq.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tcp_usrreq.c,v 1.126 2015/07/15 22:16:42 deraadt Exp $ */ +/* $OpenBSD: tcp_usrreq.c,v 1.127 2015/08/27 17:10:45 bluhm Exp $ */ /* $NetBSD: tcp_usrreq.c,v 1.20 1996/02/13 23:44:16 christos Exp $ */ /* @@ -980,6 +980,14 @@ tcp_update_sndspace(struct tcpcb *tp) nmax = MIN(sb_max, so->so_snd.sb_wat + tp->snd_max - tp->snd_una); + /* a writable socket must be preserved because of poll(2) semantics */ + if (sbspace(&so->so_snd) >= so->so_snd.sb_lowat) { + if (nmax < so->so_snd.sb_cc + so->so_snd.sb_lowat) + nmax = so->so_snd.sb_cc + so->so_snd.sb_lowat; + if (nmax * 2 < so->so_snd.sb_mbcnt + so->so_snd.sb_lowat) + nmax = (so->so_snd.sb_mbcnt+so->so_snd.sb_lowat+1) / 2; + } + /* round to MSS boundary */ nmax = roundup(nmax, tp->t_maxseg); @@ -1012,6 +1020,11 @@ tcp_update_rcvspace(struct tcpcb *tp) tcp_autorcvbuf_inc); } + /* a readable socket must be preserved because of poll(2) semantics */ + if (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat && + nmax < so->so_snd.sb_lowat) + nmax = so->so_snd.sb_lowat; + if (nmax == so->so_rcv.sb_hiwat) return; |