From a6508753db3c49910068d8fc324bd284d72ff153 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Sun, 22 Apr 2012 11:21:10 +1000 Subject: - djm@cvs.openbsd.org 2012/04/11 13:16:19 [channels.c channels.h clientloop.c serverloop.c] don't spin in accept() when out of fds (ENFILE/ENFILE) - back off for a while; ok deraadt@ markus@ --- channels.c | 52 ++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 44 insertions(+), 8 deletions(-) (limited to 'channels.c') diff --git a/channels.c b/channels.c index e5783b19..cacd2fe5 100644 --- a/channels.c +++ b/channels.c @@ -1,4 +1,4 @@ -/* $OpenBSD: channels.c,v 1.316 2012/03/29 23:54:36 dtucker Exp $ */ +/* $OpenBSD: channels.c,v 1.317 2012/04/11 13:16:19 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -311,6 +311,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, c->istate = CHAN_INPUT_OPEN; c->flags = 0; channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0); + c->notbefore = 0; c->self = found; c->type = type; c->ctype = ctype; @@ -1339,6 +1340,8 @@ channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset) } if (newsock < 0) { error("accept: %.100s", strerror(errno)); + if (errno == EMFILE || errno == ENFILE) + c->notbefore = time(NULL) + 1; return; } set_nodelay(newsock); @@ -1482,6 +1485,8 @@ channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset) newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen); if (newsock < 0) { error("accept: %.100s", strerror(errno)); + if (errno == EMFILE || errno == ENFILE) + c->notbefore = time(NULL) + 1; return; } set_nodelay(newsock); @@ -1514,7 +1519,10 @@ channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset) addrlen = sizeof(addr); newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen); if (newsock < 0) { - error("accept from auth socket: %.100s", strerror(errno)); + error("accept from auth socket: %.100s", + strerror(errno)); + if (errno == EMFILE || errno == ENFILE) + c->notbefore = time(NULL) + 1; return; } nc = channel_new("accepted auth socket", @@ -1917,6 +1925,8 @@ channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset) if ((newsock = accept(c->sock, (struct sockaddr*)&addr, &addrlen)) == -1) { error("%s accept: %s", __func__, strerror(errno)); + if (errno == EMFILE || errno == ENFILE) + c->notbefore = time(NULL) + 1; return; } @@ -2067,16 +2077,21 @@ channel_garbage_collect(Channel *c) } static void -channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset) +channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset, + time_t *unpause_secs) { static int did_init = 0; u_int i, oalloc; Channel *c; + time_t now; if (!did_init) { channel_handler_init(); did_init = 1; } + now = time(NULL); + if (unpause_secs != NULL) + *unpause_secs = 0; for (i = 0, oalloc = channels_alloc; i < oalloc; i++) { c = channels[i]; if (c == NULL) @@ -2087,10 +2102,30 @@ channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset) else continue; } - if (ftab[c->type] != NULL) - (*ftab[c->type])(c, readset, writeset); + if (ftab[c->type] != NULL) { + /* + * Run handlers that are not paused. + */ + if (c->notbefore <= now) + (*ftab[c->type])(c, readset, writeset); + else if (unpause_secs != NULL) { + /* + * Collect the time that the earliest + * channel comes off pause. + */ + debug3("%s: chan %d: skip for %d more seconds", + __func__, c->self, + (int)(c->notbefore - now)); + if (*unpause_secs == 0 || + (c->notbefore - now) < *unpause_secs) + *unpause_secs = c->notbefore - now; + } + } channel_garbage_collect(c); } + if (unpause_secs != NULL && *unpause_secs != 0) + debug3("%s: first channel unpauses in %d seconds", + __func__, (int)*unpause_secs); } /* @@ -2099,7 +2134,7 @@ channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset) */ void channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, - u_int *nallocp, int rekeying) + u_int *nallocp, int *minwait_secs, int rekeying) { u_int n, sz, nfdset; @@ -2122,7 +2157,8 @@ channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, memset(*writesetp, 0, sz); if (!rekeying) - channel_handler(channel_pre, *readsetp, *writesetp); + channel_handler(channel_pre, *readsetp, *writesetp, + minwait_secs); } /* @@ -2132,7 +2168,7 @@ channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, void channel_after_select(fd_set *readset, fd_set *writeset) { - channel_handler(channel_post, readset, writeset); + channel_handler(channel_post, readset, writeset, NULL); } -- cgit v1.2.3