X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/5fd673807d3cbe09b68c7e2631184d929905949b..dd19ce4f24eec64177cdcfcf294b8efbb631a24b:/src/src/daemon.c diff --git a/src/src/daemon.c b/src/src/daemon.c index 7decc7223..a248a4f40 100644 --- a/src/src/daemon.c +++ b/src/src/daemon.c @@ -3,7 +3,7 @@ *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2018 */ -/* Copyright (c) The Exim Maintainers 2020 */ +/* Copyright (c) The Exim Maintainers 2020 - 2021 */ /* See the file NOTICE for conditions of use and distribution. */ /* Functions concerned with running Exim as a daemon */ @@ -87,7 +87,7 @@ sigchld_seen = TRUE; } -/* SIGTERM handler. Try to get the damon pif file removed +/* SIGTERM handler. Try to get the damon pid file removed before exiting. */ static void @@ -141,7 +141,7 @@ Uunlink(s); static void close_daemon_sockets(int daemon_notifier_fd, - int * listen_sockets, int listen_socket_count) + struct pollfd * fd_polls, int listen_socket_count) { if (daemon_notifier_fd >= 0) { @@ -152,7 +152,7 @@ if (daemon_notifier_fd >= 0) #endif } -for (int i = 0; i < listen_socket_count; i++) (void) close(listen_sockets[i]); +for (int i = 0; i < listen_socket_count; i++) (void) close(fd_polls[i].fd); } @@ -167,7 +167,7 @@ is required so that they can be closed in the sub-process. Take care not to leak store in this process - reset the stacking pool at the end. Arguments: - listen_sockets sockets which are listening for incoming calls + fd_polls sockets which are listening for incoming calls listen_socket_count count of listening sockets accept_socket socket of the current accepted call accepted socket information about the current call @@ -176,7 +176,7 @@ Returns: nothing */ static void -handle_smtp_call(int *listen_sockets, int listen_socket_count, +handle_smtp_call(struct pollfd *fd_polls, int listen_socket_count, int accept_socket, struct sockaddr *accepted) { pid_t pid; @@ -275,7 +275,7 @@ subprocess because it might take time. */ if (smtp_load_reserve >= 0) { load_average = OS_GETLOADAVG(); - if (smtp_reserve_hosts == NULL && load_average > smtp_load_reserve) + if (!smtp_reserve_hosts && load_average > smtp_load_reserve) { DEBUG(D_any) debug_printf("rejecting SMTP connection: load average = %.2f\n", (double)load_average/1000.0); @@ -374,7 +374,7 @@ if (LOGGING(smtp_connection)) { uschar *list = hosts_connection_nolog; memset(sender_host_cache, 0, sizeof(sender_host_cache)); - if (list != NULL && verify_check_host(&list) == OK) + if (list && verify_check_host(&list) == OK) save_log_selector &= ~L_smtp_connection; else log_write(L_smtp_connection, LOG_MAIN, "SMTP connection from %s " @@ -396,12 +396,18 @@ if (pid == 0) int save_debug_selector = debug_selector; BOOL local_queue_only; BOOL session_local_queue_only; - #ifdef SA_NOCLDWAIT +#ifdef SA_NOCLDWAIT struct sigaction act; - #endif +#endif smtp_accept_count++; /* So that it includes this process */ + /* If the listen backlog was over the monitoring level, log it. */ + + if (smtp_listen_backlog > smtp_backlog_monitor) + log_write(0, LOG_MAIN, "listen backlog %d I=[%s]:%d", + smtp_listen_backlog, interface_address, interface_port); + /* May have been modified for the subprocess */ *log_selector = save_log_selector; @@ -453,7 +459,7 @@ if (pid == 0) extensive comment before the reception loop in exim.c for a fuller explanation of this logic. */ - close_daemon_sockets(daemon_notifier_fd, listen_sockets, listen_socket_count); + close_daemon_sockets(daemon_notifier_fd, fd_polls, listen_socket_count); /* Set FD_CLOEXEC on the SMTP socket. We don't want any rogue child processes to be able to communicate with them, under any circumstances. */ @@ -685,6 +691,7 @@ if (pid == 0) (void)fclose(smtp_in); (void)close(fileno(smtp_out)); (void)fclose(smtp_out); + smtp_in = smtp_out = NULL; /* Don't ever molest the parent's SSL connection, but do clean up the data structures if necessary. */ @@ -966,7 +973,7 @@ const int dir_flags = O_RDONLY | O_NONBLOCK; const int base_flags = O_NOFOLLOW | O_NONBLOCK; const mode_t base_mode = 0644; struct stat sb; -int cwd_fd, dir_fd, base_fd; +int cwd_fd = -1, dir_fd = -1, base_fd = -1; BOOL success = FALSE; errno = EACCES; @@ -1298,13 +1305,6 @@ return FALSE; -static void -add_listener_socket(int fd, fd_set * fds, int * fd_max) -{ -FD_SET(fd, fds); -if (fd > *fd_max) *fd_max = fd; -} - /************************************************* * Exim Daemon Mainline * *************************************************/ @@ -1332,9 +1332,8 @@ void daemon_go(void) { struct passwd * pw; -int * listen_sockets = NULL; -int listen_socket_count = 0, listen_fd_max = 0; -fd_set select_listen; +struct pollfd * fd_polls, * tls_watch_poll = NULL, * dnotify_poll = NULL; +int listen_socket_count = 0, poll_fd_count; ip_address_item * addresses = NULL; time_t last_connection_time = (time_t)0; int local_queue_run_max = atoi(CS expand_string(queue_run_max)); @@ -1346,17 +1345,21 @@ debugging lines get the pid added. */ DEBUG(D_any|D_v) debug_selector |= D_pid; -FD_ZERO(&select_listen); +/* Allocate enough pollstructs for inetd mode plus the ancillary sockets; +also used when there are no listen sockets. */ + +fd_polls = store_get(sizeof(struct pollfd) * 3, FALSE); + if (f.inetd_wait_mode) { listen_socket_count = 1; - listen_sockets = store_get(sizeof(int), FALSE); (void) close(3); if (dup2(0, 3) == -1) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to dup inetd socket safely away: %s", strerror(errno)); - listen_sockets[0] = 3; + fd_polls[0].fd = 3; + fd_polls[0].events = POLLIN; (void) close(0); (void) close(1); (void) close(2); @@ -1383,9 +1386,6 @@ if (f.inetd_wait_mode) if (setsockopt(3, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to set socket NODELAY: %s", strerror(errno)); - - FD_SET(3, &select_listen); - listen_fd_max = 3; } @@ -1679,11 +1679,16 @@ if (f.daemon_listen && !f.inetd_wait_mode) } } - /* Get a vector to remember all the sockets in */ + /* Get a vector to remember all the sockets in. + Two extra elements for the ancillary sockets */ for (ipa = addresses; ipa; ipa = ipa->next) listen_socket_count++; - listen_sockets = store_get(sizeof(int) * listen_socket_count, FALSE); + fd_polls = store_get(sizeof(struct pollfd) * (listen_socket_count + 2), + FALSE); + for (struct pollfd * p = fd_polls; p < fd_polls + listen_socket_count + 2; + p++) + { p->fd = -1; p->events = POLLIN; } } /* daemon_listen but not inetd_wait_mode */ @@ -1788,7 +1793,7 @@ if (f.daemon_listen && !f.inetd_wait_mode) wildcard = ipa->address[0] == 0; } - if ((listen_sockets[sk] = fd = ip_socket(SOCK_STREAM, af)) < 0) + if ((fd_polls[sk].fd = fd = ip_socket(SOCK_STREAM, af)) < 0) { if (check_special_case(0, addresses, ipa, FALSE)) { @@ -1797,7 +1802,7 @@ if (f.daemon_listen && !f.inetd_wait_mode) goto SKIP_SOCKET; } log_write(0, LOG_PANIC_DIE, "IPv%c socket creation failed: %s", - (af == AF_INET6)? '6' : '4', strerror(errno)); + af == AF_INET6 ? '6' : '4', strerror(errno)); } /* If this is an IPv6 wildcard socket, set IPV6_V6ONLY if that option is @@ -1806,8 +1811,7 @@ if (f.daemon_listen && !f.inetd_wait_mode) #ifdef IPV6_V6ONLY if (af == AF_INET6 && wildcard && - setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, CS (&on), - sizeof(on)) < 0) + setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) log_write(0, LOG_MAIN, "Setting IPV6_V6ONLY on daemon's IPv6 wildcard " "socket failed (%s): carrying on without it", strerror(errno)); #endif /* IPV6_V6ONLY */ @@ -1816,16 +1820,14 @@ if (f.daemon_listen && !f.inetd_wait_mode) is being handled. Without this, a connection will prevent reuse of the smtp port for listening. */ - if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, - US (&on), sizeof(on)) < 0) + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "setting SO_REUSEADDR on socket " "failed when starting daemon: %s", strerror(errno)); /* Set TCP_NODELAY; Exim does its own buffering. There is a switch to disable this because it breaks some broken clients. */ - if (tcp_nodelay) setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, - US (&on), sizeof(on)); + if (tcp_nodelay) setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)); /* Now bind the socket to the required port; if Exim is being restarted it may not always be possible to bind immediately, even with SO_REUSEADDR @@ -1899,8 +1901,7 @@ if (f.daemon_listen && !f.inetd_wait_mode) f.tcp_fastopen_ok = FALSE; } #endif - - add_listener_socket(fd, &select_listen, &listen_fd_max); + fd_polls[sk].fd = fd; continue; } @@ -1966,17 +1967,6 @@ if (f.running_in_test_harness || write_pid) DEBUG(D_any) debug_printf("%s pid file %s: %s\n", (operation == PID_WRITE) ? "write" : "check", pid_file_path, strerror(errno)); } -/* Add ancillary sockets to the set for select */ - -#ifndef DISABLE_TLS -if (tls_watch_fd >= 0) - add_listener_socket(tls_watch_fd, &select_listen, &listen_fd_max); -#endif -if (daemon_notifier_fd >= 0) - add_listener_socket(daemon_notifier_fd, &select_listen, &listen_fd_max); - -listen_fd_max++; - /* Set up the handler for SIGHUP, which causes a restart of the daemon. */ sighup_seen = FALSE; @@ -2192,6 +2182,24 @@ spf_init(); tls_daemon_init(); #endif +/* Add ancillary sockets to the set for select */ + +poll_fd_count = listen_socket_count; +#ifndef DISABLE_TLS +if (tls_watch_fd >= 0) + { + tls_watch_poll = &fd_polls[poll_fd_count++]; + tls_watch_poll->fd = tls_watch_fd; + tls_watch_poll->events = POLLIN; + } +#endif +if (daemon_notifier_fd >= 0) + { + dnotify_poll = &fd_polls[poll_fd_count++]; + dnotify_poll->fd = daemon_notifier_fd; + dnotify_poll->events = POLLIN; + } + /* Close the log so it can be renamed and moved. In the few cases below where this long-running process writes to the log (always exceptional conditions), it closes the log afterwards, for the same reason. */ @@ -2212,13 +2220,6 @@ report_time_since(×tamp_startup, US"daemon loop start"); /* testcase 0022 * for (;;) { - #if HAVE_IPV6 - struct sockaddr_in6 accepted; - #else - struct sockaddr_in accepted; - #endif - - EXIM_SOCKLEN_T len; pid_t pid; if (sigterm_seen) @@ -2296,7 +2297,7 @@ for (;;) /* Close any open listening sockets in the child */ close_daemon_sockets(daemon_notifier_fd, - listen_sockets, listen_socket_count); + fd_polls, listen_socket_count); /* Reset SIGHUP and SIGCHLD in the child in both cases. */ @@ -2426,7 +2427,6 @@ for (;;) { int lcount; BOOL select_failed = FALSE; - fd_set fds = select_listen; DEBUG(D_any) debug_printf("Listening...\n"); @@ -2443,8 +2443,7 @@ for (;;) errno = EINTR; } else - lcount = select(listen_fd_max, (SELECT_ARG2_TYPE *)&fds, - NULL, NULL, NULL); + lcount = poll(fd_polls, poll_fd_count, -1); if (lcount < 0) { @@ -2464,8 +2463,15 @@ for (;;) handle_ending_processes(); #ifndef DISABLE_TLS + { + int old_tfd; /* Create or rotate any required keys; handle (delayed) filewatch event */ - tls_daemon_tick(); + + if ((old_tfd = tls_daemon_tick()) >= 0) + for (struct pollfd * p = &fd_polls[listen_socket_count]; + p < fd_polls + poll_fd_count; p++) + if (p->fd == old_tfd) { p->fd = tls_watch_fd ; break; } + } #endif errno = select_errno; } @@ -2477,31 +2483,57 @@ for (;;) while (lcount-- > 0) { int accept_socket = -1; +#if HAVE_IPV6 + struct sockaddr_in6 accepted; +#else + struct sockaddr_in accepted; +#endif if (!select_failed) { #if !defined(DISABLE_TLS) && (defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)) - if (tls_watch_fd >= 0 && FD_ISSET(tls_watch_fd, &fds)) + if (tls_watch_poll && tls_watch_poll->revents & POLLIN) { - FD_CLR(tls_watch_fd, &fds); + tls_watch_poll->revents = 0; tls_watch_trigger_time = time(NULL); /* Set up delayed event */ tls_watch_discard_event(tls_watch_fd); break; /* to top of daemon loop */ } #endif - if (daemon_notifier_fd >= 0 && FD_ISSET(daemon_notifier_fd, &fds)) + if (dnotify_poll && dnotify_poll->revents & POLLIN) { - FD_CLR(daemon_notifier_fd, &fds); + dnotify_poll->revents = 0; sigalrm_seen = daemon_notification(); break; /* to top of daemon loop */ } - for (int sk = 0; sk < listen_socket_count; sk++) - if (FD_ISSET(listen_sockets[sk], &fds)) + for (struct pollfd * p = fd_polls; p < fd_polls + listen_socket_count; + p++) + if (p->revents & POLLIN) { - len = sizeof(accepted); - accept_socket = accept(listen_sockets[sk], - (struct sockaddr *)&accepted, &len); - FD_CLR(listen_sockets[sk], &fds); + EXIM_SOCKLEN_T alen = sizeof(accepted); +#ifdef TCP_INFO + struct tcp_info ti; + socklen_t tlen = sizeof(ti); + + /* If monitoring the backlog is wanted, grab for later logging */ + + smtp_listen_backlog = 0; + if ( smtp_backlog_monitor > 0 + && getsockopt(p->fd, IPPROTO_TCP, TCP_INFO, &ti, &tlen) == 0) + { +# ifdef EXIM_HAVE_TCPI_UNACKED + DEBUG(D_interface) debug_printf("listen fd %d queue max %u curr %u\n", + p->fd, ti.tcpi_sacked, ti.tcpi_unacked); + smtp_listen_backlog = ti.tcpi_unacked; +# elif defined(__FreeBSD__) /* This does not work. Investigate kernel sourcecode. */ + DEBUG(D_interface) debug_printf("listen fd %d queue max %u curr %u\n", + p->fd, ti.__tcpi_sacked, ti.__tcpi_unacked); + smtp_listen_backlog = ti.__tcpi_unacked; +# endif + } +#endif + p->revents = 0; + accept_socket = accept(p->fd, (struct sockaddr *)&accepted, &alen); break; } } @@ -2526,18 +2558,18 @@ for (;;) else if ( errno != accept_retry_errno || select_failed != accept_retry_select_failed || accept_retry_count >= 50) - { - log_write(0, LOG_MAIN | (accept_retry_count >= 50 ? LOG_PANIC : 0), - "%d %s() failure%s: %s", - accept_retry_count, - accept_retry_select_failed ? "select" : "accept", - accept_retry_count == 1 ? "" : "s", - strerror(accept_retry_errno)); - log_close_all(); - accept_retry_count = 0; - accept_retry_errno = errno; - accept_retry_select_failed = select_failed; - } + { + log_write(0, LOG_MAIN | (accept_retry_count >= 50 ? LOG_PANIC : 0), + "%d %s() failure%s: %s", + accept_retry_count, + accept_retry_select_failed ? "select" : "accept", + accept_retry_count == 1 ? "" : "s", + strerror(accept_retry_errno)); + log_close_all(); + accept_retry_count = 0; + accept_retry_errno = errno; + accept_retry_select_failed = select_failed; + } accept_retry_count++; } else if (accept_retry_count > 0) @@ -2562,7 +2594,7 @@ for (;;) #endif if (inetd_wait_timeout) last_connection_time = time(NULL); - handle_smtp_call(listen_sockets, listen_socket_count, accept_socket, + handle_smtp_call(fd_polls, listen_socket_count, accept_socket, (struct sockaddr *)&accepted); } } @@ -2577,10 +2609,8 @@ for (;;) else { - struct timeval tv; - tv.tv_sec = queue_interval; - tv.tv_usec = 0; - select(0, NULL, NULL, NULL, &tv); + struct pollfd p; + poll(&p, 0, queue_interval * 1000); handle_ending_processes(); } @@ -2605,8 +2635,7 @@ for (;;) { log_write(0, LOG_MAIN, "pid %d: SIGHUP received: re-exec daemon", getpid()); - close_daemon_sockets(daemon_notifier_fd, - listen_sockets, listen_socket_count); + close_daemon_sockets(daemon_notifier_fd, fd_polls, listen_socket_count); ALARM_CLR(0); signal(SIGHUP, SIG_IGN); sighup_argv[0] = exim_path;