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@ --- ChangeLog | 4 ++++ channels.c | 52 ++++++++++++++++++++++++++++++++++++++++++++-------- channels.h | 6 ++++-- clientloop.c | 8 ++++++-- serverloop.c | 14 ++++++++++---- 5 files changed, 68 insertions(+), 16 deletions(-) diff --git a/ChangeLog b/ChangeLog index 1b5e78a4..d19da34a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -17,6 +17,10 @@ [channels.c channels.h servconf.c] Add PermitOpen none option based on patch from Loganaden Velvindron (bz #1949). ok djm@ + - 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@ 20120420 - (djm) [contrib/caldera/openssh.spec contrib/redhat/openssh.spec] 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); } diff --git a/channels.h b/channels.h index 6ed1ce00..d75b800f 100644 --- a/channels.h +++ b/channels.h @@ -1,4 +1,4 @@ -/* $OpenBSD: channels.h,v 1.110 2012/03/29 23:54:36 dtucker Exp $ */ +/* $OpenBSD: channels.h,v 1.111 2012/04/11 13:16:19 djm Exp $ */ /* * Author: Tatu Ylonen @@ -105,6 +105,7 @@ struct Channel { int wfd_isatty; /* wfd is a tty */ int client_tty; /* (client) TTY has been requested */ int force_drain; /* force close on iEOF */ + time_t notbefore; /* Pause IO until deadline (time_t) */ int delayed; /* post-select handlers for newly created * channels are delayed until the first call * to a matching pre-select handler. @@ -238,7 +239,8 @@ void channel_input_status_confirm(int, u_int32_t, void *); /* file descriptor handling (read/write) */ -void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); +void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, + time_t*, int); void channel_after_select(fd_set *, fd_set *); void channel_output_poll(void); diff --git a/clientloop.c b/clientloop.c index f69a9b02..58357cf3 100644 --- a/clientloop.c +++ b/clientloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: clientloop.c,v 1.238 2012/01/18 21:46:43 dtucker Exp $ */ +/* $OpenBSD: clientloop.c,v 1.239 2012/04/11 13:16:19 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -583,10 +583,12 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, { struct timeval tv, *tvp; int timeout_secs; + time_t minwait_secs; int ret; /* Add any selections by the channel mechanism. */ - channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); + channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, + &minwait_secs, rekeying); if (!compat20) { /* Read from the connection, unless our buffers are full. */ @@ -639,6 +641,8 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, if (timeout_secs < 0) timeout_secs = 0; } + if (minwait_secs != 0) + timeout_secs = MIN(timeout_secs, (int)minwait_secs); if (timeout_secs == INT_MAX) tvp = NULL; else { diff --git a/serverloop.c b/serverloop.c index 19b84ff2..50be16b7 100644 --- a/serverloop.c +++ b/serverloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: serverloop.c,v 1.160 2011/05/15 08:09:01 djm Exp $ */ +/* $OpenBSD: serverloop.c,v 1.161 2012/04/11 13:16:19 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -281,9 +281,18 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, { struct timeval tv, *tvp; int ret; + time_t minwait_secs; int client_alive_scheduled = 0; int program_alive_scheduled = 0; + /* Allocate and update select() masks for channel descriptors. */ + channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, + &minwait_secs, 0); + + if (minwait_secs != 0) + max_time_milliseconds = MIN(max_time_milliseconds, + (u_int)minwait_secs * 1000); + /* * if using client_alive, set the max timeout accordingly, * and indicate that this particular timeout was for client @@ -298,9 +307,6 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, max_time_milliseconds = options.client_alive_interval * 1000; } - /* Allocate and update select() masks for channel descriptors. */ - channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); - if (compat20) { #if 0 /* wrong: bad condition XXX */ -- cgit v1.2.3