X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/76a2d7bad2f69787569f842d9d154524c4758ce3..8fac7a0b7c8bf8f8f3cde24aeb95ff03756d2633:/src/src/daemon.c diff --git a/src/src/daemon.c b/src/src/daemon.c index 88dd69d21..4a3cb6adb 100644 --- a/src/src/daemon.c +++ b/src/src/daemon.c @@ -1,10 +1,9 @@ -/* $Cambridge: exim/src/src/daemon.c,v 1.6 2005/01/27 15:00:39 ph10 Exp $ */ - /************************************************* * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2005 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ +/* 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 */ @@ -21,9 +20,9 @@ typedef struct smtp_slot { } smtp_slot; /* An empty slot for initializing (Standard C does not allow constructor -expressions in assigments except as initializers in declarations). */ +expressions in assignments except as initializers in declarations). */ -static smtp_slot empty_smtp_slot = { 0, NULL }; +static smtp_slot empty_smtp_slot = { .pid = 0, .host_address = NULL }; @@ -31,16 +30,17 @@ static smtp_slot empty_smtp_slot = { 0, NULL }; * Local static variables * *************************************************/ -static volatile BOOL sigchld_seen; -static volatile BOOL sighup_seen; +static SIGNAL_BOOL sigchld_seen; +static SIGNAL_BOOL sighup_seen; +static SIGNAL_BOOL sigterm_seen; static int accept_retry_count = 0; static int accept_retry_errno; static BOOL accept_retry_select_failed; static int queue_run_count = 0; -static pid_t *queue_pid_slots; -static smtp_slot *smtp_slots; +static pid_t *queue_pid_slots = NULL; +static smtp_slot *smtp_slots = NULL; static BOOL write_pid = TRUE; @@ -59,7 +59,6 @@ Returns: nothing static void sighup_handler(int sig) { -sig = sig; /* Keep picky compilers happy */ sighup_seen = TRUE; signal(SIGHUP, sighup_handler); } @@ -83,12 +82,21 @@ Returns: nothing static void main_sigchld_handler(int sig) { -sig = sig; /* Keep picky compilers happy */ os_non_restarting_signal(SIGCHLD, SIG_DFL); sigchld_seen = TRUE; } +/* SIGTERM handler. Try to get the daemon pid file removed +before exiting. */ + +static void +main_sigterm_handler(int sig) +{ +sigterm_seen = TRUE; +} + + /************************************************* @@ -108,15 +116,46 @@ Returns: nothing static void never_error(uschar *log_msg, uschar *smtp_msg, int was_errno) { -uschar *emsg = (was_errno <= 0)? US"" : - string_sprintf(": %s", strerror(was_errno)); +uschar *emsg = was_errno <= 0 + ? US"" : string_sprintf(": %s", strerror(was_errno)); log_write(0, LOG_MAIN|LOG_PANIC, "%s%s", log_msg, emsg); -if (smtp_out != NULL) smtp_printf("421 %s\r\n", smtp_msg); +if (smtp_out) smtp_printf("421 %s\r\n", FALSE, smtp_msg); } +/************************************************* +*************************************************/ + +#ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS +static void +unlink_notifier_socket(void) +{ +uschar * s = expand_string(notifier_socket); +DEBUG(D_any) debug_printf("unlinking notifier socket %s\n", s); +Uunlink(s); +} +#endif + + +static void +close_daemon_sockets(int daemon_notifier_fd, + struct pollfd * fd_polls, int listen_socket_count) +{ +if (daemon_notifier_fd >= 0) + { + (void) close(daemon_notifier_fd); + daemon_notifier_fd = -1; +#ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS + unlink_notifier_socket(); +#endif + } + +for (int i = 0; i < listen_socket_count; i++) (void) close(fd_polls[i].fd); +} + + /************************************************* * Handle a connected SMTP call * *************************************************/ @@ -128,7 +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 @@ -137,20 +176,18 @@ 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; union sockaddr_46 interface_sockaddr; -SOCKLEN_T ifsize = sizeof(interface_sockaddr); +EXIM_SOCKLEN_T ifsize = sizeof(interface_sockaddr); int dup_accept_socket = -1; int max_for_this_host = 0; -int wfsize = 0; -int wfptr = 0; -int use_log_write_selector = log_write_selector; -uschar *whofrom = NULL; +int save_log_selector = *log_selector; +gstring * whofrom; -void *reset_point = store_get(0); +rmark reset_point = store_mark(); /* Make the address available in ASCII representation, and also fish out the remote port. */ @@ -163,37 +200,35 @@ DEBUG(D_any) debug_printf("Connection request from %s port %d\n", input stream. These operations fail only the exceptional circumstances. Note that never_error() won't use smtp_out if it is NULL. */ -smtp_out = fdopen(accept_socket, "wb"); -if (smtp_out == NULL) +if (!(smtp_out = fdopen(accept_socket, "wb"))) { never_error(US"daemon: fdopen() for smtp_out failed", US"", errno); goto ERROR_RETURN; } -dup_accept_socket = dup(accept_socket); -if (dup_accept_socket < 0) +if ((dup_accept_socket = dup(accept_socket)) < 0) { never_error(US"daemon: couldn't dup socket descriptor", US"Connection setup failed", errno); goto ERROR_RETURN; } -smtp_in = fdopen(dup_accept_socket, "rb"); -if (smtp_in == NULL) +if (!(smtp_in = fdopen(dup_accept_socket, "rb"))) { never_error(US"daemon: fdopen() for smtp_in failed", US"Connection setup failed", errno); goto ERROR_RETURN; } -/* Get the data for the local interface address. */ +/* Get the data for the local interface address. Panic for most errors, but +"connection reset by peer" just means the connection went away. */ if (getsockname(accept_socket, (struct sockaddr *)(&interface_sockaddr), &ifsize) < 0) { - log_write(0, LOG_MAIN|LOG_PANIC, "getsockname() failed: %s", - strerror(errno)); - smtp_printf("421 Local problem: getsockname() failed; please try again later\r\n"); + log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), + "getsockname() failed: %s", strerror(errno)); + smtp_printf("421 Local problem: getsockname() failed; please try again later\r\n", FALSE); goto ERROR_RETURN; } @@ -205,17 +240,16 @@ DEBUG(D_interface) debug_printf("interface address=%s port=%d\n", the local interface data. This is for logging; at the end of this function the memory is reclaimed. */ -whofrom = string_append(whofrom, &wfsize, &wfptr, 3, "[", sender_host_address, "]"); +whofrom = string_append(NULL, 3, "[", sender_host_address, "]"); -if ((log_extra_selector & LX_incoming_port) != 0) - whofrom = string_append(whofrom, &wfsize, &wfptr, 2, ":", string_sprintf("%d", - sender_host_port)); +if (LOGGING(incoming_port)) + whofrom = string_fmt_append(whofrom, ":%d", sender_host_port); -if ((log_extra_selector & LX_incoming_interface) != 0) - whofrom = string_append(whofrom, &wfsize, &wfptr, 4, " I=[", - interface_address, "]:", string_sprintf("%d", interface_port)); +if (LOGGING(incoming_interface)) + whofrom = string_fmt_append(whofrom, " I=[%s]:%d", + interface_address, interface_port); -whofrom[wfptr] = 0; /* Terminate the newly-built string */ +(void) string_from_gstring(whofrom); /* Terminate the newly-built string */ /* Check maximum number of connections. We do not check for reserved connections or unacceptable hosts here. That is done in the subprocess because @@ -226,10 +260,10 @@ if (smtp_accept_max > 0 && smtp_accept_count >= smtp_accept_max) DEBUG(D_any) debug_printf("rejecting SMTP connection: count=%d max=%d\n", smtp_accept_count, smtp_accept_max); smtp_printf("421 Too many concurrent SMTP connections; " - "please try again later.\r\n"); + "please try again later.\r\n", FALSE); log_write(L_connection_reject, LOG_MAIN, "Connection from %s refused: too many connections", - whofrom); + whofrom->s); goto ERROR_RETURN; } @@ -240,15 +274,15 @@ 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) + load_average = OS_GETLOADAVG(); + 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); - smtp_printf("421 Too much load; please try again later.\r\n"); + smtp_printf("421 Too much load; please try again later.\r\n", FALSE); log_write(L_connection_reject, LOG_MAIN, "Connection from %s refused: load average = %.2f", - whofrom, (double)load_average/1000.0); + whofrom->s, (double)load_average/1000.0); goto ERROR_RETURN; } } @@ -261,14 +295,14 @@ to provide host-specific limits according to $sender_host address, but because this is in the daemon mainline, only fast expansions (such as inline address checks) should be used. The documentation is full of warnings. */ -if (smtp_accept_max_per_host != NULL) +if (smtp_accept_max_per_host) { uschar *expanded = expand_string(smtp_accept_max_per_host); - if (expanded == NULL) + if (!expanded) { - if (!expand_string_forcedfail) + if (!f.expand_string_forcedfail) log_write(0, LOG_MAIN|LOG_PANIC, "expansion of smtp_accept_max_per_host " - "failed for %s: %s", whofrom, expand_string_message); + "failed for %s: %s", whofrom->s, expand_string_message); } /* For speed, interpret a decimal number inline here */ else @@ -276,9 +310,9 @@ if (smtp_accept_max_per_host != NULL) uschar *s = expanded; while (isdigit(*s)) max_for_this_host = max_for_this_host * 10 + *s++ - '0'; - if (*s != 0) + if (*s) log_write(0, LOG_MAIN|LOG_PANIC, "expansion of smtp_accept_max_per_host " - "for %s contains non-digit: %s", whofrom, expanded); + "for %s contains non-digit: %s", whofrom->s, expanded); } } @@ -286,16 +320,13 @@ if (smtp_accept_max_per_host != NULL) per host_address checks. Note that at this stage smtp_accept_count contains the count of *other* connections, not including this one. */ -if ((max_for_this_host > 0) && - (smtp_accept_count >= max_for_this_host)) +if (max_for_this_host > 0 && smtp_accept_count >= max_for_this_host) { - int i; int host_accept_count = 0; int other_host_count = 0; /* keep a count of non matches to optimise */ - for (i = 0; i < smtp_accept_max; ++i) - { - if (smtp_slots[i].host_address != NULL) + for (int i = 0; i < smtp_accept_max; ++i) + if (smtp_slots[i].host_address) { if (Ustrcmp(sender_host_address, smtp_slots[i].host_address) == 0) host_accept_count++; @@ -306,11 +337,10 @@ if ((max_for_this_host > 0) && early, either by hitting the target, or finding there are not enough connections left to make the target. */ - if ((host_accept_count >= max_for_this_host) || - ((smtp_accept_count - other_host_count) < max_for_this_host)) + if ( host_accept_count >= max_for_this_host + || smtp_accept_count - other_host_count < max_for_this_host) break; } - } if (host_accept_count >= max_for_this_host) { @@ -318,10 +348,11 @@ if ((max_for_this_host > 0) && "IP address: count=%d max=%d\n", host_accept_count, max_for_this_host); smtp_printf("421 Too many concurrent SMTP connections " - "from this IP address; please try again later.\r\n"); + "from this IP address; please try again later.\r\n", FALSE); log_write(L_connection_reject, LOG_MAIN, "Connection from %s refused: too many connections " - "from that IP address", whofrom); + "from that IP address", whofrom->s); + search_tidyup(); goto ERROR_RETURN; } } @@ -339,38 +370,47 @@ the generalized logging code each time when the selector is false. If the selector is set, check whether the host is on the list for logging. If not, arrange to unset the selector in the subprocess. */ -if ((log_write_selector & L_smtp_connection) != 0) +if (LOGGING(smtp_connection)) { uschar *list = hosts_connection_nolog; - if (list != NULL && verify_check_host(&list) == OK) - use_log_write_selector &= ~L_smtp_connection; + memset(sender_host_cache, 0, sizeof(sender_host_cache)); + 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 " - "(TCP/IP connection count = %d)", whofrom, smtp_accept_count + 1); + "(TCP/IP connection count = %d)", whofrom->s, smtp_accept_count + 1); } /* Now we can fork the accepting process; do a lookup tidy, just in case any expansion above did a lookup. */ search_tidyup(); -pid = fork(); +pid = exim_fork(US"daemon-accept"); /* Handle the child process */ if (pid == 0) { - int i; int queue_only_reason = 0; int old_pool = store_pool; - int save_debug_selector = debug_selector; + int save_debug_selector = debug_selector; BOOL local_queue_only; - #ifdef SA_NOCLDWAIT + BOOL session_local_queue_only; +#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_write_selector = use_log_write_selector; + *log_selector = save_log_selector; /* Get the local interface address into permanent store */ @@ -380,37 +420,37 @@ if (pid == 0) /* Check for a tls-on-connect port */ - if (host_is_tls_on_connect_port(interface_port)) tls_on_connect = TRUE; + if (host_is_tls_on_connect_port(interface_port)) tls_in.on_connect = TRUE; /* Expand smtp_active_hostname if required. We do not do this any earlier, because it may depend on the local interface address (indeed, that is most likely what it depends on.) */ smtp_active_hostname = primary_hostname; - if (raw_active_hostname != NULL) + if (raw_active_hostname) { - uschar *nah = expand_string(raw_active_hostname); - if (nah == NULL) + uschar * nah = expand_string(raw_active_hostname); + if (!nah) { - if (!expand_string_forcedfail) + if (!f.expand_string_forcedfail) { log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand \"%s\" " "(smtp_active_hostname): %s", raw_active_hostname, expand_string_message); smtp_printf("421 Local configuration error; " - "please try again later.\r\n"); + "please try again later.\r\n", FALSE); mac_smtp_fflush(); search_tidyup(); - _exit(EXIT_FAILURE); + exim_underbar_exit(EXIT_FAILURE); } } - else if (nah[0] != 0) smtp_active_hostname = nah; + else if (*nah) smtp_active_hostname = nah; } /* Initialize the queueing flags */ queue_check_only(); - local_queue_only = queue_only; + session_local_queue_only = queue_only; /* Close the listening sockets, and set the SIGCHLD handler to SIG_IGN. We also attempt to set things up so that children are automatically reaped, @@ -419,30 +459,39 @@ if (pid == 0) extensive comment before the reception loop in exim.c for a fuller explanation of this logic. */ - for (i = 0; i < listen_socket_count; i++) close(listen_sockets[i]); + close_daemon_sockets(daemon_notifier_fd, fd_polls, listen_socket_count); - #ifdef SA_NOCLDWAIT + /* 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. */ + (void)fcntl(accept_socket, F_SETFD, + fcntl(accept_socket, F_GETFD) | FD_CLOEXEC); + (void)fcntl(dup_accept_socket, F_SETFD, + fcntl(dup_accept_socket, F_GETFD) | FD_CLOEXEC); + +#ifdef SA_NOCLDWAIT act.sa_handler = SIG_IGN; sigemptyset(&(act.sa_mask)); act.sa_flags = SA_NOCLDWAIT; sigaction(SIGCHLD, &act, NULL); - #else +#else signal(SIGCHLD, SIG_IGN); - #endif +#endif + signal(SIGTERM, SIG_DFL); + signal(SIGINT, SIG_DFL); /* Attempt to get an id from the sending machine via the RFC 1413 protocol. We do this in the sub-process in order not to hold up the main process if there is any delay. Then set up the fullhost information - in case there is no HELO/EHLO. - - If debugging is enabled only for the daemon, we must turn if off while - finding the id, but turn it on again afterwards so that information about the + in case there is no HELO/EHLO. + + If debugging is enabled only for the daemon, we must turn if off while + finding the id, but turn it on again afterwards so that information about the incoming connection is output. */ - - if (debug_daemon) debug_selector = 0; + + if (f.debug_daemon) debug_selector = 0; verify_get_ident(IDENT_PORT); host_build_sender_fullhost(); - debug_selector = save_debug_selector; + debug_selector = save_debug_selector; DEBUG(D_any) debug_printf("Process %d is handling incoming connection from %s\n", @@ -451,36 +500,43 @@ if (pid == 0) /* Now disable debugging permanently if it's required only for the daemon process. */ - if (debug_daemon) debug_selector = 0; + if (f.debug_daemon) debug_selector = 0; /* If there are too many child processes for immediate delivery, - set the local_queue_only flag, which is initialized from the + set the session_local_queue_only flag, which is initialized from the configured value and may therefore already be TRUE. Leave logging - till later so it will have a message id attached. */ + till later so it will have a message id attached. Note that there is no + possibility of re-calculating this per-message, because the value of + smtp_accept_count does not change in this subprocess. */ - if (smtp_accept_queue > 0 && smtp_accept_count >= smtp_accept_queue) + if (smtp_accept_queue > 0 && smtp_accept_count > smtp_accept_queue) { - local_queue_only = TRUE; + session_local_queue_only = TRUE; queue_only_reason = 1; } /* Handle the start of the SMTP session, then loop, accepting incoming messages from the SMTP connection. The end will come at the QUIT command, when smtp_setup_msg() returns 0. A break in the connection causes the - process to die (see accept.c). */ + process to die (see accept.c). + + NOTE: We do *not* call smtp_log_no_mail() if smtp_start_session() fails, + because a log line has already been written for all its failure exists + (usually "connection refused: ") and writing another one is + unnecessary clutter. */ if (!smtp_start_session()) { mac_smtp_fflush(); search_tidyup(); - _exit(EXIT_SUCCESS); + exim_underbar_exit(EXIT_SUCCESS); } for (;;) { int rc; message_id[0] = 0; /* Clear out any previous message_id */ - reset_point = store_get(0); /* Save current store high water point */ + reset_point = store_mark(); /* Save current store high water point */ DEBUG(D_any) debug_printf("Process %d is ready for new message\n", (int)getpid()); @@ -498,29 +554,45 @@ if (pid == 0) search_tidyup(); /* Close cached databases */ if (!ok) /* Connection was dropped */ { + cancel_cutthrough_connection(TRUE, US"receive dropped"); mac_smtp_fflush(); - _exit(EXIT_SUCCESS); + smtp_log_no_mail(); /* Log no mail if configured */ + exim_underbar_exit(EXIT_SUCCESS); } if (message_id[0] == 0) continue; /* No message was accepted */ } - else + else /* bad smtp_setup_msg() */ { - mac_smtp_fflush(); + if (smtp_out) + { + int fd = fileno(smtp_in); + uschar buf[128]; + + mac_smtp_fflush(); + /* drain socket, for clean TCP FINs */ + if (fcntl(fd, F_SETFL, O_NONBLOCK) == 0) + for(int i = 16; read(fd, buf, sizeof(buf)) > 0 && i > 0; ) i--; + } + cancel_cutthrough_connection(TRUE, US"message setup dropped"); search_tidyup(); - _exit((rc == 0)? EXIT_SUCCESS : EXIT_FAILURE); + smtp_log_no_mail(); /* Log no mail if configured */ + + /*XXX should we pause briefly, hoping that the client will be the + active TCP closer hence get the TCP_WAIT endpoint? */ + DEBUG(D_receive) debug_printf("SMTP>>(close on process exit)\n"); + exim_underbar_exit(rc ? EXIT_FAILURE : EXIT_SUCCESS); } /* Show the recipients when debugging */ DEBUG(D_receive) { - int i; - if (sender_address != NULL) + if (sender_address) debug_printf("Sender: %s\n", sender_address); - if (recipients_list != NULL) + if (recipients_list) { debug_printf("Recipients:\n"); - for (i = 0; i < recipients_count; i++) + for (int i = 0; i < recipients_count; i++) debug_printf(" %s\n", recipients_list[i].address); } } @@ -537,30 +609,46 @@ if (pid == 0) /* Reclaim up the store used in accepting this message */ - store_reset(reset_point); + { + int r = receive_messagecount; + BOOL q = f.queue_only_policy; + smtp_reset(reset_point); + reset_point = NULL; + f.queue_only_policy = q; + receive_messagecount = r; + } /* If queue_only is set or if there are too many incoming connections in - existence, local_queue_only will be TRUE. If it is not, check whether we - have received too many messages in this session for immediate delivery. If - not, and queue_only_load is set, check that the load average is below it. - Note that, once set, local_queue_only remains set for any subsequent - messages on the same SMTP connection. This is a deliberate choice; even - though the load average may fall, it doesn't seem right to deliver later - messages on the same call when not delivering earlier ones. */ - - if (!local_queue_only) + existence, session_local_queue_only will be TRUE. If it is not, check + whether we have received too many messages in this session for immediate + delivery. */ + + if (!session_local_queue_only && + smtp_accept_queue_per_connection > 0 && + receive_messagecount > smtp_accept_queue_per_connection) { - if (smtp_accept_queue_per_connection > 0 && - receive_messagecount > smtp_accept_queue_per_connection) - { - local_queue_only = TRUE; - queue_only_reason = 2; - } - else if (queue_only_load >= 0) - { - local_queue_only = (load_average = os_getloadavg()) > queue_only_load; - if (local_queue_only) queue_only_reason = 3; - } + session_local_queue_only = TRUE; + queue_only_reason = 2; + } + + /* Initialize local_queue_only from session_local_queue_only. If it is not + true, and queue_only_load is set, check that the load average is below it. + If local_queue_only is set by this means, we also set if for the session if + queue_only_load_latch is true (the default). This means that, once set, + local_queue_only remains set for any subsequent messages on the same SMTP + connection. This is a deliberate choice; even though the load average may + fall, it doesn't seem right to deliver later messages on the same call when + not delivering earlier ones. However, the are special circumstances such as + very long-lived connections from scanning appliances where this is not the + best strategy. In such cases, queue_only_load_latch should be set false. */ + + if ( !(local_queue_only = session_local_queue_only) + && queue_only_load >= 0 + && (local_queue_only = (load_average = OS_GETLOADAVG()) > queue_only_load) + ) + { + queue_only_reason = 3; + if (queue_only_load_latch) session_local_queue_only = TRUE; } /* Log the queueing here, when it will get a message id attached, but @@ -568,80 +656,82 @@ if (pid == 0) if (local_queue_only) switch(queue_only_reason) { - case 1: - log_write(L_delay_delivery, + case 1: log_write(L_delay_delivery, LOG_MAIN, "no immediate delivery: too many connections " "(%d, max %d)", smtp_accept_count, smtp_accept_queue); - break; + break; - case 2: - log_write(L_delay_delivery, + case 2: log_write(L_delay_delivery, LOG_MAIN, "no immediate delivery: more than %d messages " "received in one connection", smtp_accept_queue_per_connection); - break; + break; - case 3: - log_write(L_delay_delivery, + case 3: log_write(L_delay_delivery, LOG_MAIN, "no immediate delivery: load average %.2f", (double)load_average/1000.0); - break; + break; } /* If a delivery attempt is required, spin off a new process to handle it. If we are not root, we have to re-exec exim unless deliveries are being done unprivileged. */ - else if (!queue_only_policy && !deliver_freeze) + else if ( (!f.queue_only_policy || f.queue_smtp) + && !f.deliver_freeze) { pid_t dpid; - /* Before forking, ensure that the C output buffer is flushed. Otherwise - anything that it in it will get duplicated, leading to duplicate copies - of the pending output. */ - - mac_smtp_fflush(); + /* We used to flush smtp_out before forking so that buffered data was not + duplicated, but now we want to pipeline the responses for data and quit. + Instead, hard-close the fd underlying smtp_out right after fork to discard + the data buffer. */ - if ((dpid = fork()) == 0) + if ((dpid = exim_fork(US"daemon-accept-delivery")) == 0) { - fclose(smtp_in); - fclose(smtp_out); + (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. */ - #ifdef SUPPORT_TLS - tls_close(FALSE); - #endif +#ifndef DISABLE_TLS + tls_close(NULL, TLS_NO_SHUTDOWN); +#endif /* Reset SIGHUP and SIGCHLD in the child in both cases. */ signal(SIGHUP, SIG_DFL); signal(SIGCHLD, SIG_DFL); + signal(SIGTERM, SIG_DFL); + signal(SIGINT, SIG_DFL); if (geteuid() != root_uid && !deliver_drop_privilege) { signal(SIGALRM, SIG_DFL); - (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, FALSE, 2, US"-Mc", - message_id); + delivery_re_exec(CEE_EXEC_PANIC); /* Control does not return here. */ } /* No need to re-exec; SIGALRM remains set to the default handler */ - (void)deliver_message(message_id, FALSE, FALSE); + (void) deliver_message(message_id, FALSE, FALSE); search_tidyup(); - _exit(EXIT_SUCCESS); + exim_underbar_exit(EXIT_SUCCESS); } if (dpid > 0) { + release_cutthrough_connection(US"passed for delivery"); DEBUG(D_any) debug_printf("forked delivery process %d\n", (int)dpid); } else - { + { + cancel_cutthrough_connection(TRUE, US"delivery fork failed"); log_write(0, LOG_MAIN|LOG_PANIC, "daemon: delivery process fork " "failed: %s", strerror(errno)); - } + } } } } @@ -652,25 +742,21 @@ failed. Otherwise, keep count of the number of accepting processes and remember the pid for ticking off when the child completes. */ if (pid < 0) - { never_error(US"daemon: accept process fork failed", US"Fork failed", errno); - } else { - int i; - for (i = 0; i < smtp_accept_max; ++i) - { + for (int i = 0; i < smtp_accept_max; ++i) if (smtp_slots[i].pid <= 0) { smtp_slots[i].pid = pid; - if (smtp_accept_max_per_host != NULL) + /* Connection closes come asyncronously, so we cannot stack this store */ + if (smtp_accept_max_per_host) smtp_slots[i].host_address = string_copy_malloc(sender_host_address); smtp_accept_count++; break; } - } DEBUG(D_any) debug_printf("%d SMTP accept process%s running\n", - smtp_accept_count, (smtp_accept_count == 1)? "" : "es"); + smtp_accept_count, smtp_accept_count == 1 ? "" : "es"); } /* Get here via goto in error cases */ @@ -680,33 +766,35 @@ ERROR_RETURN: /* Close the streams associated with the socket which will also close the socket fds in this process. We can't do anything if fclose() fails, but logging brings it to someone's attention. However, "connection reset by peer" -isn't really a problem, so skip that one. If the streams don't exist, something -went wrong while setting things up. Make sure the socket descriptors are -closed, in order to drop the connection. */ +isn't really a problem, so skip that one. On Solaris, a dropped connection can +manifest itself as a broken pipe, so drop that one too. If the streams don't +exist, something went wrong while setting things up. Make sure the socket +descriptors are closed, in order to drop the connection. */ -if (smtp_out != NULL) +if (smtp_out) { - if (fclose(smtp_out) != 0 && errno != ECONNRESET) + if (fclose(smtp_out) != 0 && errno != ECONNRESET && errno != EPIPE) log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fclose(smtp_out) failed: %s", strerror(errno)); smtp_out = NULL; } -else close(accept_socket); +else (void)close(accept_socket); -if (smtp_in != NULL) +if (smtp_in) { - if (fclose(smtp_in) != 0 && errno != ECONNRESET) + if (fclose(smtp_in) != 0 && errno != ECONNRESET && errno != EPIPE) log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fclose(smtp_in) failed: %s", strerror(errno)); smtp_in = NULL; } -else close(dup_accept_socket); +else (void)close(dup_accept_socket); /* Release any store used in this process, including the store used for holding the incoming host address and an expanded active_hostname. */ +log_close_all(); +interface_address = sender_host_name = sender_host_address = NULL; store_reset(reset_point); -sender_host_address = NULL; } @@ -776,6 +864,443 @@ return FALSE; +/************************************************* +* Handle terminating subprocesses * +*************************************************/ + +/* Handle the termination of child processes. Theoretically, this need be done +only when sigchld_seen is TRUE, but rumour has it that some systems lose +SIGCHLD signals at busy times, so to be on the safe side, this function is +called each time round. It shouldn't be too expensive. + +Arguments: none +Returns: nothing +*/ + +static void +handle_ending_processes(void) +{ +int status; +pid_t pid; + +while ((pid = waitpid(-1, &status, WNOHANG)) > 0) + { + DEBUG(D_any) + { + debug_printf("child %d ended: status=0x%x\n", (int)pid, status); +#ifdef WCOREDUMP + if (WIFEXITED(status)) + debug_printf(" normal exit, %d\n", WEXITSTATUS(status)); + else if (WIFSIGNALED(status)) + debug_printf(" signal exit, signal %d%s\n", WTERMSIG(status), + WCOREDUMP(status) ? " (core dumped)" : ""); +#endif + } + + /* If it's a listening daemon for which we are keeping track of individual + subprocesses, deal with an accepting process that has terminated. */ + + if (smtp_slots) + { + int i; + for (i = 0; i < smtp_accept_max; i++) + if (smtp_slots[i].pid == pid) + { + if (smtp_slots[i].host_address) + store_free(smtp_slots[i].host_address); + smtp_slots[i] = empty_smtp_slot; + if (--smtp_accept_count < 0) smtp_accept_count = 0; + DEBUG(D_any) debug_printf("%d SMTP accept process%s now running\n", + smtp_accept_count, (smtp_accept_count == 1)? "" : "es"); + break; + } + if (i < smtp_accept_max) continue; /* Found an accepting process */ + } + + /* If it wasn't an accepting process, see if it was a queue-runner + process that we are tracking. */ + + if (queue_pid_slots) + { + int max = atoi(CS expand_string(queue_run_max)); + for (int i = 0; i < max; i++) + if (queue_pid_slots[i] == pid) + { + queue_pid_slots[i] = 0; + if (--queue_run_count < 0) queue_run_count = 0; + DEBUG(D_any) debug_printf("%d queue-runner process%s now running\n", + queue_run_count, (queue_run_count == 1)? "" : "es"); + break; + } + } + } +} + + +static void +set_pid_file_path(void) +{ +if (override_pid_file_path) + pid_file_path = override_pid_file_path; + +if (!*pid_file_path) + pid_file_path = string_sprintf("%s/exim-daemon.pid", spool_directory); + +if (pid_file_path[0] != '/') + log_write(0, LOG_PANIC_DIE, "pid file path %s must be absolute\n", pid_file_path); +} + + +enum pid_op { PID_WRITE, PID_CHECK, PID_DELETE }; + +/* Do various pid file operations as safe as possible. Ideally we'd just +drop the privileges for creation of the pid file and not care at all about removal of +the file. FIXME. +Returns: true on success, false + errno==EACCES otherwise +*/ + +static BOOL +operate_on_pid_file(const enum pid_op operation, const pid_t pid) +{ +char pid_line[sizeof(int) * 3 + 2]; +const int pid_len = snprintf(pid_line, sizeof(pid_line), "%d\n", (int)pid); +BOOL lines_match = FALSE; +uschar * path, * base, * dir; + +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 = -1, dir_fd = -1, base_fd = -1; +BOOL success = FALSE; +errno = EACCES; + +set_pid_file_path(); +if (!f.running_in_test_harness && real_uid != root_uid && real_uid != exim_uid) goto cleanup; +if (pid_len < 2 || pid_len >= (int)sizeof(pid_line)) goto cleanup; + +path = string_copy(pid_file_path); +if ((base = Ustrrchr(path, '/')) == NULL) /* should not happen, but who knows */ + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "pid file path \"%s\" does not contain a '/'", pid_file_path); + +dir = base != path ? path : US"/"; +*base++ = '\0'; + +if (!dir || !*dir || *dir != '/') goto cleanup; +if (!base || !*base || Ustrchr(base, '/') != NULL) goto cleanup; + +cwd_fd = open(".", dir_flags); +if (cwd_fd < 0 || fstat(cwd_fd, &sb) != 0 || !S_ISDIR(sb.st_mode)) goto cleanup; +dir_fd = open(CS dir, dir_flags); +if (dir_fd < 0 || fstat(dir_fd, &sb) != 0 || !S_ISDIR(sb.st_mode)) goto cleanup; + +/* emulate openat */ +if (fchdir(dir_fd) != 0) goto cleanup; +base_fd = open(CS base, O_RDONLY | base_flags); +if (fchdir(cwd_fd) != 0) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "can't return to previous working dir: %s", strerror(errno)); + +if (base_fd >= 0) + { + char line[sizeof(pid_line)]; + ssize_t len = -1; + + if (fstat(base_fd, &sb) != 0 || !S_ISREG(sb.st_mode)) goto cleanup; + if ((sb.st_mode & 07777) != base_mode || sb.st_nlink != 1) goto cleanup; + if (sb.st_size < 2 || sb.st_size >= (off_t)sizeof(line)) goto cleanup; + + len = read(base_fd, line, sizeof(line)); + if (len != (ssize_t)sb.st_size) goto cleanup; + line[len] = '\0'; + + if (strspn(line, "0123456789") != (size_t)len-1) goto cleanup; + if (line[len-1] != '\n') goto cleanup; + lines_match = len == pid_len && strcmp(line, pid_line) == 0; + } + +if (operation == PID_WRITE) + { + if (!lines_match) + { + if (base_fd >= 0) + { + int error = -1; + /* emulate unlinkat */ + if (fchdir(dir_fd) != 0) goto cleanup; + error = unlink(CS base); + if (fchdir(cwd_fd) != 0) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "can't return to previous working dir: %s", strerror(errno)); + if (error) goto cleanup; + (void)close(base_fd); + base_fd = -1; + } + /* emulate openat */ + if (fchdir(dir_fd) != 0) goto cleanup; + base_fd = open(CS base, O_WRONLY | O_CREAT | O_EXCL | base_flags, base_mode); + if (fchdir(cwd_fd) != 0) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "can't return to previous working dir: %s", strerror(errno)); + if (base_fd < 0) goto cleanup; + if (fchmod(base_fd, base_mode) != 0) goto cleanup; + if (write(base_fd, pid_line, pid_len) != pid_len) goto cleanup; + DEBUG(D_any) debug_printf("pid written to %s\n", pid_file_path); + } + } +else + { + if (!lines_match) goto cleanup; + if (operation == PID_DELETE) + { + int error = -1; + /* emulate unlinkat */ + if (fchdir(dir_fd) != 0) goto cleanup; + error = unlink(CS base); + if (fchdir(cwd_fd) != 0) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "can't return to previous working dir: %s", strerror(errno)); + if (error) goto cleanup; + } + } + +success = TRUE; +errno = 0; + +cleanup: +if (cwd_fd >= 0) (void)close(cwd_fd); +if (dir_fd >= 0) (void)close(dir_fd); +if (base_fd >= 0) (void)close(base_fd); +return success; +} + + +/* Remove the daemon's pidfile. Note: runs with root privilege, +as a direct child of the daemon. Does not return. */ + +void +delete_pid_file(void) +{ +const BOOL success = operate_on_pid_file(PID_DELETE, getppid()); + +DEBUG(D_any) + debug_printf("delete pid file %s %s: %s\n", pid_file_path, + success ? "success" : "failure", strerror(errno)); + +exim_exit(EXIT_SUCCESS); +} + + +/* Called by the daemon; exec a child to get the pid file deleted +since we may require privs for the containing directory */ + +static void +daemon_die(void) +{ +int pid; + +DEBUG(D_any) debug_printf("SIGTERM/SIGINT seen\n"); +#if !defined(DISABLE_TLS) && (defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)) +tls_watch_invalidate(); +#endif + +if (daemon_notifier_fd >= 0) + { + close(daemon_notifier_fd); + daemon_notifier_fd = -1; +#ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS + unlink_notifier_socket(); +#endif + } + +if (f.running_in_test_harness || write_pid) + { + if ((pid = exim_fork(US"daemon-del-pidfile")) == 0) + { + if (override_pid_file_path) + (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, FALSE, 3, + "-oP", override_pid_file_path, "-oPX"); + else + (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, FALSE, 1, "-oPX"); + + /* Control never returns here. */ + } + if (pid > 0) + child_close(pid, 1); + } +exim_exit(EXIT_SUCCESS); +} + + +/************************************************* +* Listener socket for local work prompts * +*************************************************/ + +static void +daemon_notifier_socket(void) +{ +int fd; +const uschar * where; +struct sockaddr_un sa_un = {.sun_family = AF_UNIX}; +int len; + +if (!notifier_socket || !*notifier_socket) + { + DEBUG(D_any) debug_printf("-oY used so not creating notifier socket\n"); + return; + } +if (override_local_interfaces && !override_pid_file_path) + { + DEBUG(D_any) + debug_printf("-oX used without -oP so not creating notifier socket\n"); + return; + } + +DEBUG(D_any) debug_printf("creating notifier socket\n"); + +#ifdef SOCK_CLOEXEC +if ((fd = socket(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) + { where = US"socket"; goto bad; } +#else +if ((fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) + { where = US"socket"; goto bad; } +(void)fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC); +#endif + +#ifdef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS +sa_un.sun_path[0] = 0; /* Abstract local socket addr - Linux-specific? */ +len = offsetof(struct sockaddr_un, sun_path) + 1 + + snprintf(sa_un.sun_path+1, sizeof(sa_un.sun_path)-1, "%s", + expand_string(notifier_socket)); +DEBUG(D_any) debug_printf(" @%s\n", sa_un.sun_path+1); +#else /* filesystem-visible and persistent; will neeed removal */ +len = offsetof(struct sockaddr_un, sun_path) + + snprintf(sa_un.sun_path, sizeof(sa_un.sun_path), "%s", + expand_string(notifier_socket)); +DEBUG(D_any) debug_printf(" %s\n", sa_un.sun_path); +#endif + +if (bind(fd, (const struct sockaddr *)&sa_un, len) < 0) + { where = US"bind"; goto bad; } + +#ifdef SO_PASSCRED /* Linux */ +if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) + { where = US"SO_PASSCRED"; goto bad2; } +#elif defined(LOCAL_CREDS) /* FreeBSD-ish */ +if (setsockopt(fd, 0, LOCAL_CREDS, &on, sizeof(on)) < 0) + { where = US"LOCAL_CREDS"; goto bad2; } +#endif + +/* debug_printf("%s: fd %d\n", __FUNCTION__, fd); */ +daemon_notifier_fd = fd; +return; + +bad2: +#ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS + Uunlink(sa_un.sun_path); +#endif +bad: + log_write(0, LOG_MAIN|LOG_PANIC, "%s %s: %s", + __FUNCTION__, where, strerror(errno)); + close(fd); + return; +} + + +static uschar queuerun_msgid[MESSAGE_ID_LENGTH+1]; + +/* Return TRUE if a sigalrm should be emulated */ +static BOOL +daemon_notification(void) +{ +uschar buf[256], cbuf[256]; +struct sockaddr_un sa_un; +struct iovec iov = {.iov_base = buf, .iov_len = sizeof(buf)-1}; +struct msghdr msg = { .msg_name = &sa_un, + .msg_namelen = sizeof(sa_un), + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = cbuf, + .msg_controllen = sizeof(cbuf) + }; +ssize_t sz; + +buf[sizeof(buf)-1] = 0; +if ((sz = recvmsg(daemon_notifier_fd, &msg, 0)) <= 0) return FALSE; +if (sz >= sizeof(buf)) return FALSE; + +#ifdef notdef +debug_printf("addrlen %d\n", msg.msg_namelen); +#endif +DEBUG(D_queue_run) debug_printf("%s from addr '%s%.*s'\n", __FUNCTION__, + *sa_un.sun_path ? "" : "@", + (int)msg.msg_namelen - (*sa_un.sun_path ? 0 : 1), + sa_un.sun_path + (*sa_un.sun_path ? 0 : 1)); + +/* Refuse to handle the item unless the peer has good credentials */ +#ifdef SCM_CREDENTIALS +# define EXIM_SCM_CR_TYPE SCM_CREDENTIALS +#elif defined(LOCAL_CREDS) && defined(SCM_CREDS) +# define EXIM_SCM_CR_TYPE SCM_CREDS +#else + /* The OS has no way to get the creds of the caller (for a unix/datagram socket. + Punt; don't try to check. */ +#endif + +#ifdef EXIM_SCM_CR_TYPE +for (struct cmsghdr * cp = CMSG_FIRSTHDR(&msg); + cp; + cp = CMSG_NXTHDR(&msg, cp)) + if (cp->cmsg_level == SOL_SOCKET && cp->cmsg_type == EXIM_SCM_CR_TYPE) + { +# ifdef SCM_CREDENTIALS /* Linux */ + struct ucred * cr = (struct ucred *) CMSG_DATA(cp); + if (cr->uid && cr->uid != exim_uid) + { + DEBUG(D_queue_run) debug_printf("%s: sender creds pid %d uid %d gid %d\n", + __FUNCTION__, (int)cr->pid, (int)cr->uid, (int)cr->gid); + return FALSE; + } +# elif defined(LOCAL_CREDS) /* BSD-ish */ + struct sockcred * cr = (struct sockcred *) CMSG_DATA(cp); + if (cr->sc_uid && cr->sc_uid != exim_uid) + { + DEBUG(D_queue_run) debug_printf("%s: sender creds pid ??? uid %d gid %d\n", + __FUNCTION__, (int)cr->sc_uid, (int)cr->sc_gid); + return FALSE; + } +# endif + break; + } +#endif + +buf[sz] = 0; +switch (buf[0]) + { +#ifndef DISABLE_QUEUE_RAMP + case NOTIFY_MSG_QRUN: + /* this should be a message_id */ + DEBUG(D_queue_run) + debug_printf("%s: qrunner trigger: %s\n", __FUNCTION__, buf+1); + memcpy(queuerun_msgid, buf+1, MESSAGE_ID_LENGTH+1); + return TRUE; +#endif + + case NOTIFY_QUEUE_SIZE_REQ: + { + uschar buf[16]; + int len = snprintf(CS buf, sizeof(buf), "%u", queue_count_cached()); + + DEBUG(D_queue_run) + debug_printf("%s: queue size request: %s\n", __FUNCTION__, buf); + + if (sendto(daemon_notifier_fd, buf, len, 0, + (const struct sockaddr *)&sa_un, msg.msg_namelen) < 0) + log_write(0, LOG_MAIN|LOG_PANIC, + "%s: sendto: %s\n", __FUNCTION__, strerror(errno)); + return FALSE; + } + } +return FALSE; +} + + /************************************************* @@ -804,15 +1329,78 @@ There are no arguments to this function, and it never returns. */ void daemon_go(void) { -int *listen_sockets = NULL; -int listen_socket_count = 0; -ip_address_item *addresses = NULL; +struct passwd * pw; +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)); + +process_purpose = US"daemon"; /* If any debugging options are set, turn on the D_pid bit so that all debugging lines get the pid added. */ DEBUG(D_any|D_v) debug_selector |= D_pid; +/* 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; + (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)); + + fd_polls[0].fd = 3; + fd_polls[0].events = POLLIN; + (void) close(0); + (void) close(1); + (void) close(2); + exim_nullstd(); + + if (debug_file == stderr) + { + /* need a call to log_write before call to open debug_file, so that + log.c:file_path has been initialised. This is unfortunate. */ + log_write(0, LOG_MAIN, "debugging Exim in inetd wait mode starting"); + + fclose(debug_file); + debug_file = NULL; + exim_nullstd(); /* re-open fd2 after we just closed it again */ + debug_logging_activate(US"-wait", NULL); + } + + DEBUG(D_any) debug_printf("running in inetd wait mode\n"); + + /* As per below, when creating sockets ourselves, we handle tcp_nodelay for + our own buffering; we assume though that inetd set the socket REUSEADDR. */ + + if (tcp_nodelay) + 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)); + } + + +if (f.inetd_wait_mode || f.daemon_listen) + { + /* If any option requiring a load average to be available during the + reception of a message is set, call os_getloadavg() while we are root + for those OS for which this is necessary the first time it is called (in + order to perform an "open" on the kernel memory file). */ + +#ifdef LOAD_AVG_NEEDS_ROOT + if (queue_only_load >= 0 || smtp_load_reserve >= 0 || + (deliver_queue_load_max >= 0 && deliver_drop_privilege)) + (void)os_getloadavg(); +#endif + } + /* Do the preparation for setting up a listener on one or more interfaces, and possible on various ports. This is controlled by the combination of @@ -881,90 +1469,57 @@ The preparation code decodes options and sets up the relevant data. We do this first, so that we can return non-zero if there are any syntax errors, and also write to stderr. */ -if (daemon_listen) +if (f.daemon_listen && !f.inetd_wait_mode) { int *default_smtp_port; int sep; int pct = 0; uschar *s; - uschar *list; + const uschar * list; uschar *local_iface_source = US"local_interfaces"; ip_address_item *ipa; ip_address_item **pipa; - /* If any option requiring a load average to be available during the - reception of a message is set, call os_getloadavg() while we are root - for those OS for which this is necessary the first time it is called (in - order to perform an "open" on the kernel memory file). */ - - #ifdef LOAD_AVG_NEEDS_ROOT - if (queue_only_load >= 0 || smtp_load_reserve >= 0 || - (deliver_queue_load_max >= 0 && deliver_drop_privilege)) - (void)os_getloadavg(); - #endif - /* If -oX was used, disable the writing of a pid file unless -oP was explicitly used to force it. Then scan the string given to -oX. Any items that contain neither a dot nor a colon are used to override daemon_smtp_port. Any other items are used to override local_interfaces. */ - if (override_local_interfaces != NULL) + if (override_local_interfaces) { - uschar *new_smtp_port = NULL; - uschar *new_local_interfaces = NULL; - int portsize = 0; - int portptr = 0; - int ifacesize = 0; - int ifaceptr = 0; + gstring * new_smtp_port = NULL; + gstring * new_local_interfaces = NULL; - if (override_pid_file_path == NULL) write_pid = FALSE; + if (!override_pid_file_path) write_pid = FALSE; list = override_local_interfaces; sep = 0; - while ((s = string_nextinlist(&list,&sep,big_buffer,big_buffer_size)) - != NULL) + while ((s = string_nextinlist(&list, &sep, NULL, 0))) { uschar joinstr[4]; - uschar **ptr; - int *sizeptr; - int *ptrptr; - - if (Ustrpbrk(s, ".:") == NULL) - { - ptr = &new_smtp_port; - sizeptr = &portsize; - ptrptr = &portptr; - } - else - { - ptr = &new_local_interfaces; - sizeptr = &ifacesize; - ptrptr = &ifaceptr; - } + gstring ** gp = Ustrpbrk(s, ".:") ? &new_local_interfaces : &new_smtp_port; - if (*ptr == NULL) + if (!*gp) { joinstr[0] = sep; joinstr[1] = ' '; - *ptr = string_cat(*ptr, sizeptr, ptrptr, US"<", 1); + *gp = string_catn(*gp, US"<", 1); } - *ptr = string_cat(*ptr, sizeptr, ptrptr, joinstr, 2); - *ptr = string_cat(*ptr, sizeptr, ptrptr, s, Ustrlen(s)); + *gp = string_catn(*gp, joinstr, 2); + *gp = string_cat (*gp, s); } - if (new_smtp_port != NULL) + if (new_smtp_port) { - new_smtp_port[portptr] = 0; - daemon_smtp_port = new_smtp_port; + daemon_smtp_port = string_from_gstring(new_smtp_port); DEBUG(D_any) debug_printf("daemon_smtp_port overridden by -oX:\n %s\n", daemon_smtp_port); } - if (new_local_interfaces != NULL) + if (new_local_interfaces) { - new_local_interfaces[ifaceptr] = 0; - local_interfaces = new_local_interfaces; + local_interfaces = string_from_gstring(new_local_interfaces); local_iface_source = US"-oX data"; DEBUG(D_any) debug_printf("local_interfaces overridden by -oX:\n %s\n", local_interfaces); @@ -972,18 +1527,18 @@ if (daemon_listen) } /* Create a list of default SMTP ports, to be used if local_interfaces - contains entries without explict ports. First count the number of ports, then + contains entries without explicit ports. First count the number of ports, then build a translated list in a vector. */ list = daemon_smtp_port; sep = 0; - while ((s = string_nextinlist(&list,&sep,big_buffer,big_buffer_size)) != NULL) + while ((s = string_nextinlist(&list, &sep, NULL, 0))) pct++; - default_smtp_port = store_get((pct+1) * sizeof(int)); + default_smtp_port = store_get((pct+1) * sizeof(int), FALSE); list = daemon_smtp_port; sep = 0; for (pct = 0; - (s = string_nextinlist(&list,&sep,big_buffer,big_buffer_size)) != NULL; + (s = string_nextinlist(&list, &sep, NULL, 0)); pct++) { if (isdigit(*s)) @@ -996,13 +1551,42 @@ if (daemon_listen) else { struct servent *smtp_service = getservbyname(CS s, "tcp"); - if (smtp_service == NULL) + if (!smtp_service) log_write(0, LOG_PANIC_DIE|LOG_CONFIG, "TCP port \"%s\" not found", s); default_smtp_port[pct] = ntohs(smtp_service->s_port); } } default_smtp_port[pct] = 0; + /* Check the list of TLS-on-connect ports and do name lookups if needed */ + + list = tls_in.on_connect_ports; + sep = 0; + /* the list isn't expanded so cannot be tainted. If it ever is we will trap here */ + while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))) + if (!isdigit(*s)) + { + gstring * g = NULL; + + list = tls_in.on_connect_ports; + tls_in.on_connect_ports = NULL; + sep = 0; + while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))) + { + if (!isdigit(*s)) + { + struct servent * smtp_service = getservbyname(CS s, "tcp"); + if (!smtp_service) + log_write(0, LOG_PANIC_DIE|LOG_CONFIG, "TCP port \"%s\" not found", s); + s = string_sprintf("%d", (int)ntohs(smtp_service->s_port)); + } + g = string_append_listele(g, ':', s); + } + if (g) + tls_in.on_connect_ports = g->s; + break; + } + /* Create the list of local interfaces, possibly with ports included. This list may contain references to 0.0.0.0 and ::0 as wildcards. These special values are converted below. */ @@ -1018,11 +1602,10 @@ if (daemon_listen) In the same scan, fill in missing port numbers from the default list. When there is more than one item in the list, extra items are created. */ - for (ipa = addresses; ipa != NULL; ipa = ipa->next) + for (ipa = addresses; ipa; ipa = ipa->next) { - int i; - - if (Ustrcmp(ipa->address, "0.0.0.0") == 0) ipa->address[0] = 0; + if (Ustrcmp(ipa->address, "0.0.0.0") == 0) + ipa->address[0] = 0; else if (Ustrcmp(ipa->address, "::0") == 0) { ipa->address[0] = ':'; @@ -1034,12 +1617,14 @@ if (daemon_listen) if (daemon_smtp_port[0] <= 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "no port specified for interface " "%s and daemon_smtp_port is unset; cannot start daemon", - (ipa->address[0] == 0)? US"\"all IPv4\"" : - (ipa->address[1] == 0)? US"\"all IPv6\"" : ipa->address); + ipa->address[0] == 0 ? US"\"all IPv4\"" : + ipa->address[1] == 0 ? US"\"all IPv6\"" : ipa->address); + ipa->port = default_smtp_port[0]; - for (i = 1; default_smtp_port[i] > 0; i++) + for (int i = 1; default_smtp_port[i] > 0; i++) { - ip_address_item *new = store_get(sizeof(ip_address_item)); + ip_address_item *new = store_get(sizeof(ip_address_item), FALSE); + memcpy(new->address, ipa->address, Ustrlen(ipa->address) + 1); new->port = default_smtp_port[i]; new->next = ipa->next; @@ -1054,15 +1639,14 @@ if (daemon_listen) also simplifies the construction of the "daemon started" log line. */ pipa = &addresses; - for (ipa = addresses; ipa != NULL; pipa = &(ipa->next), ipa = ipa->next) + for (ipa = addresses; ipa; pipa = &ipa->next, ipa = ipa->next) { ip_address_item *ipa2; /* Handle an IPv4 wildcard */ if (ipa->address[0] == 0) - { - for (ipa2 = ipa; ipa2->next != NULL; ipa2 = ipa2->next) + for (ipa2 = ipa; ipa2->next; ipa2 = ipa2->next) { ip_address_item *ipa3 = ipa2->next; if (ipa3->address[0] == ':' && @@ -1075,13 +1659,11 @@ if (daemon_listen) break; } } - } /* Handle an IPv6 wildcard. */ else if (ipa->address[0] == ':' && ipa->address[1] == 0) - { - for (ipa2 = ipa; ipa2->next != NULL; ipa2 = ipa2->next) + for (ipa2 = ipa; ipa2->next; ipa2 = ipa2->next) { ip_address_item *ipa3 = ipa2->next; if (ipa3->address[0] == 0 && ipa3->port == ipa->port) @@ -1093,14 +1675,23 @@ if (daemon_listen) break; } } - } } - /* 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 != NULL; ipa = ipa->next) + for (ipa = addresses; ipa; ipa = ipa->next) listen_socket_count++; - listen_sockets = store_get(sizeof(int *) * listen_socket_count); + 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 */ + +if (f.daemon_listen) + { /* Do a sanity check on the max connects value just to save us from getting a huge amount of store. */ @@ -1118,16 +1709,16 @@ if (daemon_listen) if (smtp_accept_max > 0) { - int i; - smtp_slots = store_get(smtp_accept_max * sizeof(smtp_slot)); - for (i = 0; i < smtp_accept_max; i++) smtp_slots[i] = empty_smtp_slot; + smtp_slots = store_get(smtp_accept_max * sizeof(smtp_slot), FALSE); + for (int i = 0; i < smtp_accept_max; i++) smtp_slots[i] = empty_smtp_slot; } } /* The variable background_daemon is always false when debugging, but can also be forced false in order to keep a non-debugging daemon in the foreground. If background_daemon is true, close all open file descriptors that -we know about, but then re-open stdin, stdout, and stderr to /dev/null. +we know about, but then re-open stdin, stdout, and stderr to /dev/null. Also +do this for inetd_wait mode. This is protection against any called functions (in libraries, or in Perl, or whatever) that think they can write to stderr (or stdout). Before this @@ -1138,25 +1729,28 @@ Then disconnect from the controlling terminal, Most modern Unixes seem to have setsid() for getting rid of the controlling terminal. For any OS that doesn't, setsid() can be #defined as a no-op, or as something else. */ -if (background_daemon) +if (f.background_daemon || f.inetd_wait_mode) { log_close_all(); /* Just in case anything was logged earlier */ search_tidyup(); /* Just in case any were used in reading the config. */ - close(0); /* Get rid of stdin/stdout/stderr */ - close(1); - close(2); - exim_nullstd(); /* Connect stdin/stdout/stderr to /dev/null */ + (void)close(0); /* Get rid of stdin/stdout/stderr */ + (void)close(1); + (void)close(2); + exim_nullstd(); /* Connect stdin/stdout/stderr to /dev/null */ log_stderr = NULL; /* So no attempt to copy paniclog output */ + } +if (f.background_daemon) + { /* If the parent process of this one has pid == 1, we are re-initializing the - daemon as the result of a SIGHUP. In this case, there is no need to do + daemon as the result of a SIGHUP. In this case, there is no need to do anything, because the controlling terminal has long gone. Otherwise, fork, in case current process is a process group leader (see 'man setsid' for an explanation) before calling setsid(). */ if (getppid() != 1) { - pid_t pid = fork(); + pid_t pid = exim_fork(US"daemon"); if (pid < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "fork() failed when starting daemon: %s", strerror(errno)); if (pid > 0) exit(EXIT_SUCCESS); /* in parent process, just exit */ @@ -1167,10 +1761,11 @@ if (background_daemon) /* We are now in the disconnected, daemon process (unless debugging). Set up the listening sockets if required. */ -if (daemon_listen) +daemon_notifier_socket(); + +if (f.daemon_listen && !f.inetd_wait_mode) { int sk; - int on = 1; ip_address_item *ipa; /* For each IP address, create a socket, bind it to the appropriate port, and @@ -1182,9 +1777,8 @@ if (daemon_listen) for (ipa = addresses, sk = 0; sk < listen_socket_count; ipa = ipa->next, sk++) { BOOL wildcard; - ip_address_item *ipa2; - int retries = 9; - int af; + ip_address_item * ipa2; + int fd, af; if (Ustrchr(ipa->address, ':') != NULL) { @@ -1197,8 +1791,7 @@ if (daemon_listen) wildcard = ipa->address[0] == 0; } - listen_sockets[sk] = ip_socket(SOCK_STREAM, af); - if (listen_sockets[sk] < 0) + if ((fd_polls[sk].fd = fd = ip_socket(SOCK_STREAM, af)) < 0) { if (check_special_case(0, addresses, ipa, FALSE)) { @@ -1207,35 +1800,32 @@ if (daemon_listen) 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 available. Just log failure (can get protocol not available, just like socket creation can). */ - #ifdef IPV6_V6ONLY +#ifdef IPV6_V6ONLY if (af == AF_INET6 && wildcard && - setsockopt(listen_sockets[sk], IPPROTO_IPV6, IPV6_V6ONLY, (char *)(&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 */ +#endif /* IPV6_V6ONLY */ /* Set SO_REUSEADDR so that the daemon can be restarted while a connection is being handled. Without this, a connection will prevent reuse of the smtp port for listening. */ - if (setsockopt(listen_sockets[sk], SOL_SOCKET, SO_REUSEADDR, - (uschar *)(&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(listen_sockets[sk], IPPROTO_TCP, TCP_NODELAY, - (uschar *)(&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 @@ -1247,42 +1837,71 @@ if (daemon_listen) necessary for (some release of) USAGI Linux; other IP stacks fail at the listen() stage instead. */ +#ifdef TCP_FASTOPEN + f.tcp_fastopen_ok = TRUE; +#endif for(;;) { uschar *msg, *addr; - if (ip_bind(listen_sockets[sk], af, ipa->address, ipa->port) >= 0) break; + if (ip_bind(fd, af, ipa->address, ipa->port) >= 0) break; if (check_special_case(errno, addresses, ipa, TRUE)) { DEBUG(D_any) debug_printf("wildcard IPv4 bind() failed after IPv6 " "listen() success; EADDRINUSE ignored\n"); - close(listen_sockets[sk]); + (void)close(fd); goto SKIP_SOCKET; } msg = US strerror(errno); - addr = wildcard? ((af == AF_INET6)? US"(any IPv6)" : US"(any IPv4)") : - ipa->address; - if (retries-- <= 0) + addr = wildcard + ? af == AF_INET6 + ? US"(any IPv6)" + : US"(any IPv4)" + : ipa->address; + if (daemon_startup_retries <= 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "socket bind() to port %d for address %s failed: %s: " "daemon abandoned", ipa->port, addr, msg); log_write(0, LOG_MAIN, "socket bind() to port %d for address %s " - "failed: %s: waiting before trying again", ipa->port, addr, msg); - sleep(30); + "failed: %s: waiting %s before trying again (%d more %s)", + ipa->port, addr, msg, readconf_printtime(daemon_startup_sleep), + daemon_startup_retries, (daemon_startup_retries > 1)? "tries" : "try"); + daemon_startup_retries--; + sleep(daemon_startup_sleep); } DEBUG(D_any) - { if (wildcard) debug_printf("listening on all interfaces (IPv%c) port %d\n", - (af == AF_INET6)? '6' : '4', ipa->port); + af == AF_INET6 ? '6' : '4', ipa->port); else debug_printf("listening on %s port %d\n", ipa->address, ipa->port); - } /* Start listening on the bound socket, establishing the maximum backlog of - connections that is allowed. On success, continue to the next address. */ + connections that is allowed. On success, add to the set of sockets for select + and continue to the next address. */ - if (listen(listen_sockets[sk], smtp_connect_backlog) >= 0) continue; +#if defined(TCP_FASTOPEN) && !defined(__APPLE__) + if ( f.tcp_fastopen_ok + && setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, + &smtp_connect_backlog, sizeof(smtp_connect_backlog))) + { + DEBUG(D_any) debug_printf("setsockopt FASTOPEN: %s\n", strerror(errno)); + f.tcp_fastopen_ok = FALSE; + } +#endif + if (listen(fd, smtp_connect_backlog) >= 0) + { +#if defined(TCP_FASTOPEN) && defined(__APPLE__) + if ( f.tcp_fastopen_ok + && setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &on, sizeof(on))) + { + DEBUG(D_any) debug_printf("setsockopt FASTOPEN: %s\n", strerror(errno)); + f.tcp_fastopen_ok = FALSE; + } +#endif + fd_polls[sk].fd = fd; + continue; + } /* Listening has failed. In an IPv6 environment, as for bind(), if listen() fails with the error EADDRINUSE and we are doing IPv4 wildcard listening @@ -1292,19 +1911,19 @@ if (daemon_listen) if (!check_special_case(errno, addresses, ipa, TRUE)) log_write(0, LOG_PANIC_DIE, "listen() failed on interface %s: %s", - wildcard? ((af == AF_INET6)? US"(any IPv6)" : US"(any IPv4)") : - ipa->address, + wildcard + ? af == AF_INET6 ? US"(any IPv6)" : US"(any IPv4)" : ipa->address, strerror(errno)); DEBUG(D_any) debug_printf("wildcard IPv4 listen() failed after IPv6 " "listen() success; EADDRINUSE ignored\n"); - close(listen_sockets[sk]); + (void)close(fd); /* Come here if there has been a problem with the socket which we are going to ignore. We remove the address from the chain, and back up the counts. */ - SKIP_SOCKET: + SKIP_SOCKET: sk--; /* Back up the count */ listen_socket_count--; /* Reduce the total */ if (ipa == addresses) addresses = ipa->next; else @@ -1320,7 +1939,8 @@ if (daemon_listen) /* If we are not listening, we want to write a pid file only if -oP was explicitly given. */ -else if (override_pid_file_path == NULL) write_pid = FALSE; +else if (!override_pid_file_path) + write_pid = FALSE; /* Write the pid to a known file for assistance in identification, if required. We do this before giving up root privilege, because on some systems it is @@ -1336,30 +1956,13 @@ automatically. Consequently, Exim 4 writes a pid file only The variable daemon_write_pid is used to control this. */ -if (running_in_test_harness || write_pid) +if (f.running_in_test_harness || write_pid) { - FILE *f; - - if (override_pid_file_path != NULL) - pid_file_path = override_pid_file_path; - - if (pid_file_path[0] == 0) - pid_file_path = string_sprintf("%s/exim-daemon.pid", spool_directory); - - f = Ufopen(pid_file_path, "wb"); - if (f != NULL) - { - fprintf(f, "%d\n", (int)getpid()); - fchmod(fileno(f), 0644); - fclose(f); - DEBUG(D_any) debug_printf("pid written to %s\n", pid_file_path); - } - else - { - DEBUG(D_any) - debug_printf("%s\n", string_open_failed(errno, "pid file %s", - pid_file_path)); - } + const enum pid_op operation = (f.running_in_test_harness + || real_uid == root_uid + || (real_uid == exim_uid && !override_pid_file_path)) ? PID_WRITE : PID_CHECK; + if (!operate_on_pid_file(operation, getpid())) + DEBUG(D_any) debug_printf("%s pid file %s: %s\n", (operation == PID_WRITE) ? "write" : "check", pid_file_path, strerror(errno)); } /* Set up the handler for SIGHUP, which causes a restart of the daemon. */ @@ -1375,21 +1978,33 @@ cannot do this. */ exim_setugid(exim_uid, exim_gid, geteuid()==root_uid, US"running as a daemon"); +/* Update the originator_xxx fields so that received messages as listed as +coming from Exim, not whoever started the daemon. */ + +originator_uid = exim_uid; +originator_gid = exim_gid; +originator_login = (pw = getpwuid(exim_uid)) + ? string_copy_perm(US pw->pw_name, FALSE) : US"exim"; + /* Get somewhere to keep the list of queue-runner pids if we are keeping track of them (and also if we are doing queue runs). */ -if (queue_interval > 0 && queue_run_max > 0) +if (queue_interval > 0 && local_queue_run_max > 0) { - int i; - queue_pid_slots = store_get(queue_run_max * sizeof(pid_t)); - for (i = 0; i < queue_run_max; i++) queue_pid_slots[i] = 0; + queue_pid_slots = store_get(local_queue_run_max * sizeof(pid_t), FALSE); + for (int i = 0; i < local_queue_run_max; i++) queue_pid_slots[i] = 0; } -/* Set up the handler for termination of child processes. */ +/* Set up the handler for termination of child processes, and the one +telling us to die. */ sigchld_seen = FALSE; os_non_restarting_signal(SIGCHLD, main_sigchld_handler); +sigterm_seen = FALSE; +os_non_restarting_signal(SIGTERM, main_sigterm_handler); +os_non_restarting_signal(SIGINT, main_sigterm_handler); + /* If we are to run the queue periodically, pretend the alarm has just gone off. This will cause the first queue-runner to get kicked off straight away. */ @@ -1398,17 +2013,34 @@ sigalrm_seen = (queue_interval > 0); /* Log the start up of a daemon - at least one of listening or queue running must be set up. */ -if (daemon_listen) +if (f.inetd_wait_mode) + { + uschar *p = big_buffer; + + if (inetd_wait_timeout >= 0) + sprintf(CS p, "terminating after %d seconds", inetd_wait_timeout); + else + sprintf(CS p, "with no wait timeout"); + + log_write(0, LOG_MAIN, + "exim %s daemon started: pid=%d, launched with listening socket, %s", + version_string, getpid(), big_buffer); + set_process_info("daemon(%s): pre-listening socket", version_string); + + /* set up the timeout logic */ + sigalrm_seen = TRUE; + } + +else if (f.daemon_listen) { - int i, j; int smtp_ports = 0; int smtps_ports = 0; - ip_address_item *ipa; - uschar *p = big_buffer; - uschar *qinfo = (queue_interval > 0)? - string_sprintf("-q%s", readconf_printtime(queue_interval)) - : - US"no queue runs"; + ip_address_item * ipa; + uschar * p; + uschar * qinfo = queue_interval > 0 + ? string_sprintf("-q%s%s", + f.queue_2stage ? "q" : "", readconf_printtime(queue_interval)) + : US"no queue runs"; /* Build a list of listening addresses in big_buffer, but limit it to 10 items. The style is for backwards compatibility. @@ -1417,78 +2049,154 @@ if (daemon_listen) deprecated protocol that starts TLS without using STARTTLS), and others listening for standard SMTP. Keep their listings separate. */ - for (j = 0; j < 2; j++) + for (int j = 0, i; j < 2; j++) { - for (i = 0, ipa = addresses; i < 10 && ipa != NULL; i++, ipa = ipa->next) - { - /* First time round, look for SMTP ports; second time round, look for - SMTPS ports. For the first one of each, insert leading text. */ - - if (host_is_tls_on_connect_port(ipa->port) == (j > 0)) - { - if (j == 0) - { - if (smtp_ports++ == 0) - { - memcpy(p, "SMTP on", 8); - p += 7; - } - } - else - { - if (smtps_ports++ == 0) - { - (void)sprintf(CS p, "%sSMTPS on", - (smtp_ports == 0)? "":" and for "); - while (*p != 0) p++; - } - } - - /* Now the information about the port (and sometimes interface) */ - - if (ipa->address[0] == ':' && ipa->address[1] == 0) - { - if (ipa->next != NULL && ipa->next->address[0] == 0 && - ipa->next->port == ipa->port) - { - (void)sprintf(CS p, " port %d (IPv6 and IPv4)", ipa->port); - ipa = ipa->next; - } - else if (ipa->v6_include_v4) - (void)sprintf(CS p, " port %d (IPv6 with IPv4)", ipa->port); - else - (void)sprintf(CS p, " port %d (IPv6)", ipa->port); - } - else if (ipa->address[0] == 0) - (void)sprintf(CS p, " port %d (IPv4)", ipa->port); - else - (void)sprintf(CS p, " [%s]:%d", ipa->address, ipa->port); - while (*p != 0) p++; - } - } - - if (ipa != NULL) + for (i = 0, ipa = addresses; i < 10 && ipa; i++, ipa = ipa->next) { - memcpy(p, " ...", 5); - p += 4; + /* First time round, look for SMTP ports; second time round, look for + SMTPS ports. Build IP+port strings. */ + + if (host_is_tls_on_connect_port(ipa->port) == (j > 0)) + { + if (j == 0) + smtp_ports++; + else + smtps_ports++; + + /* Now the information about the port (and sometimes interface) */ + + if (ipa->address[0] == ':' && ipa->address[1] == 0) + { /* v6 wildcard */ + if (ipa->next && ipa->next->address[0] == 0 && + ipa->next->port == ipa->port) + { + ipa->log = string_sprintf(" port %d (IPv6 and IPv4)", ipa->port); + (ipa = ipa->next)->log = NULL; + } + else if (ipa->v6_include_v4) + ipa->log = string_sprintf(" port %d (IPv6 with IPv4)", ipa->port); + else + ipa->log = string_sprintf(" port %d (IPv6)", ipa->port); + } + else if (ipa->address[0] == 0) /* v4 wildcard */ + ipa->log = string_sprintf(" port %d (IPv4)", ipa->port); + else /* check for previously-seen IP */ + { + ip_address_item * i2; + for (i2 = addresses; i2 != ipa; i2 = i2->next) + if ( host_is_tls_on_connect_port(i2->port) == (j > 0) + && Ustrcmp(ipa->address, i2->address) == 0 + ) + { /* found; append port to list */ + for (p = i2->log; *p; ) p++; /* end of existing string */ + if (*--p == '}') *p = '\0'; /* drop EOL */ + while (isdigit(*--p)) ; /* char before port */ + + i2->log = *p == ':' /* no list yet? */ + ? string_sprintf("%.*s{%s,%d}", + (int)(p - i2->log + 1), i2->log, p+1, ipa->port) + : string_sprintf("%s,%d}", i2->log, ipa->port); + ipa->log = NULL; + break; + } + if (i2 == ipa) /* first-time IP */ + ipa->log = string_sprintf(" [%s]:%d", ipa->address, ipa->port); + } + } } } + p = big_buffer; + for (int j = 0, i; j < 2; j++) + { + /* First time round, look for SMTP ports; second time round, look for + SMTPS ports. For the first one of each, insert leading text. */ + + if (j == 0) + { + if (smtp_ports > 0) + p += sprintf(CS p, "SMTP on"); + } + else + if (smtps_ports > 0) + p += sprintf(CS p, "%sSMTPS on", + smtp_ports == 0 ? "" : " and for "); + + /* Now the information about the port (and sometimes interface) */ + + for (i = 0, ipa = addresses; i < 10 && ipa; i++, ipa = ipa->next) + if (host_is_tls_on_connect_port(ipa->port) == (j > 0)) + if (ipa->log) + p += sprintf(CS p, "%s", ipa->log); + + if (ipa) + p += sprintf(CS p, " ..."); + } + log_write(0, LOG_MAIN, "exim %s daemon started: pid=%d, %s, listening for %s", version_string, getpid(), qinfo, big_buffer); - set_process_info("daemon: %s, listening for %s", qinfo, big_buffer); + set_process_info("daemon(%s): %s, listening for %s", + version_string, qinfo, big_buffer); } else { + uschar * s = *queue_name + ? string_sprintf("-qG%s/%s", queue_name, readconf_printtime(queue_interval)) + : string_sprintf("-q%s", readconf_printtime(queue_interval)); log_write(0, LOG_MAIN, - "exim %s daemon started: pid=%d, -q%s, not listening for SMTP", - version_string, getpid(), readconf_printtime(queue_interval)); - set_process_info("daemon: -q%s, not listening", - readconf_printtime(queue_interval)); + "exim %s daemon started: pid=%d, %s, not listening for SMTP", + version_string, getpid(), s); + set_process_info("daemon(%s): %s, not listening", version_string, s); } +/* Do any work it might be useful to amortize over our children +(eg: compile regex) */ + +dns_pattern_init(); +smtp_deliver_init(); /* Used for callouts */ + +#ifndef DISABLE_DKIM + { +# ifdef MEASURE_TIMING + struct timeval t0; + gettimeofday(&t0, NULL); +# endif + dkim_exim_init(); +# ifdef MEASURE_TIMING + report_time_since(&t0, US"dkim_exim_init (delta)"); +# endif + } +#endif + +#ifdef WITH_CONTENT_SCAN +malware_init(); +#endif +#ifdef SUPPORT_SPF +spf_init(); +#endif +#ifndef DISABLE_TLS +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 @@ -1502,113 +2210,206 @@ DEBUG(D_any) debug_print_ids(US"daemon running with"); smtp_input = TRUE; +#ifdef MEASURE_TIMING +report_time_since(×tamp_startup, US"daemon loop start"); /* testcase 0022 */ +#endif + /* Enter the never-ending loop... */ for (;;) { - #if HAVE_IPV6 - struct sockaddr_in6 accepted; - #else - struct sockaddr_in accepted; - #endif - - SOCKLEN_T len = sizeof(accepted); - int status; pid_t pid; + if (sigterm_seen) + daemon_die(); /* Does not return */ + /* This code is placed first in the loop, so that it gets obeyed at the - start, before the first wait. This causes the first queue-runner to be - started immediately. */ + start, before the first wait, for the queue-runner case, so that the first + one can be started immediately. + + The other option is that we have an inetd wait timeout specified to -bw. */ if (sigalrm_seen) { - DEBUG(D_any) debug_printf("SIGALRM received\n"); + if (inetd_wait_timeout > 0) + { + time_t resignal_interval = inetd_wait_timeout; + + if (last_connection_time == (time_t)0) + { + DEBUG(D_any) + debug_printf("inetd wait timeout expired, but still not seen first message, ignoring\n"); + } + else + { + time_t now = time(NULL); + if (now == (time_t)-1) + { + DEBUG(D_any) debug_printf("failed to get time: %s\n", strerror(errno)); + } + else + { + if ((now - last_connection_time) >= inetd_wait_timeout) + { + DEBUG(D_any) + debug_printf("inetd wait timeout %d expired, ending daemon\n", + inetd_wait_timeout); + log_write(0, LOG_MAIN, "exim %s daemon terminating, inetd wait timeout reached.\n", + version_string); + exit(EXIT_SUCCESS); + } + else + { + resignal_interval -= (now - last_connection_time); + } + } + } - /* Do a full queue run in a child process, if required, unless we already - have enough queue runners on the go. If we are not running as root, a - re-exec is required. */ + sigalrm_seen = FALSE; + ALARM(resignal_interval); + } - if (queue_interval > 0 && - (queue_run_max <= 0 || queue_run_count < queue_run_max)) + else { - if ((pid = fork()) == 0) + DEBUG(D_any) debug_printf("%s received\n", +#ifndef DISABLE_QUEUE_RAMP + *queuerun_msgid ? "qrun notification" : +#endif + "SIGALRM"); + + /* Do a full queue run in a child process, if required, unless we already + have enough queue runners on the go. If we are not running as root, a + re-exec is required. */ + + if ( queue_interval > 0 + && (local_queue_run_max <= 0 || queue_run_count < local_queue_run_max)) { - int sk; - - DEBUG(D_any) debug_printf("Starting queue-runner: pid %d\n", - (int)getpid()); + if ((pid = exim_fork(US"queue-runner")) == 0) + { + /* Disable debugging if it's required only for the daemon process. We + leave the above message, because it ties up with the "child ended" + debugging messages. */ - /* Disable debugging if it's required only for the daemon process. We - leave the above message, because it ties up with the "child ended" - debugging messages. */ + if (f.debug_daemon) debug_selector = 0; - if (debug_daemon) debug_selector = 0; - - /* Close any open listening sockets in the child */ + /* Close any open listening sockets in the child */ - for (sk = 0; sk < listen_socket_count; sk++) close(listen_sockets[sk]); + close_daemon_sockets(daemon_notifier_fd, + fd_polls, listen_socket_count); - /* Reset SIGHUP and SIGCHLD in the child in both cases. */ + /* Reset SIGHUP and SIGCHLD in the child in both cases. */ - signal(SIGHUP, SIG_DFL); - signal(SIGCHLD, SIG_DFL); + signal(SIGHUP, SIG_DFL); + signal(SIGCHLD, SIG_DFL); + signal(SIGTERM, SIG_DFL); + signal(SIGINT, SIG_DFL); - /* Re-exec if privilege has been given up, unless deliver_drop_ - privilege is set. Reset SIGALRM before exec(). */ + /* Re-exec if privilege has been given up, unless deliver_drop_ + privilege is set. Reset SIGALRM before exec(). */ - if (geteuid() != root_uid && !deliver_drop_privilege) - { - uschar opt[8]; - uschar *p = opt; + if (geteuid() != root_uid && !deliver_drop_privilege) + { + uschar opt[8]; + uschar *p = opt; + uschar *extra[7]; + int extracount = 1; + + signal(SIGALRM, SIG_DFL); + *p++ = '-'; + *p++ = 'q'; + if ( f.queue_2stage +#ifndef DISABLE_QUEUE_RAMP + && !*queuerun_msgid +#endif + ) *p++ = 'q'; + if (f.queue_run_first_delivery) *p++ = 'i'; + if (f.queue_run_force) *p++ = 'f'; + if (f.deliver_force_thaw) *p++ = 'f'; + if (f.queue_run_local) *p++ = 'l'; + *p = 0; + extra[0] = *queue_name + ? string_sprintf("%sG%s", opt, queue_name) : opt; + +#ifndef DISABLE_QUEUE_RAMP + if (*queuerun_msgid) + { + log_write(0, LOG_MAIN, "notify triggered queue run"); + extra[extracount++] = queuerun_msgid; /* Trigger only the */ + extra[extracount++] = queuerun_msgid; /* one message */ + } +#endif + + /* If -R or -S were on the original command line, ensure they get + passed on. */ + + if (deliver_selectstring) + { + extra[extracount++] = f.deliver_selectstring_regex ? US"-Rr" : US"-R"; + extra[extracount++] = deliver_selectstring; + } + + if (deliver_selectstring_sender) + { + extra[extracount++] = f.deliver_selectstring_sender_regex + ? US"-Sr" : US"-S"; + extra[extracount++] = deliver_selectstring_sender; + } + + /* Overlay this process with a new execution. */ + + (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, FALSE, extracount, + extra[0], extra[1], extra[2], extra[3], extra[4], extra[5], extra[6]); + + /* Control never returns here. */ + } - signal(SIGALRM, SIG_DFL); - *p++ = '-'; - *p++ = 'q'; - if (queue_2stage) *p++ = 'q'; - if (queue_run_first_delivery) *p++ = 'i'; - if (queue_run_force) *p++ = 'f'; - if (deliver_force_thaw) *p++ = 'f'; - if (queue_run_local) *p++ = 'l'; - *p = 0; - - (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, TRUE, 1, opt); - /* Control never returns here. */ + /* No need to re-exec; SIGALRM remains set to the default handler */ + +#ifndef DISABLE_QUEUE_RAMP + if (*queuerun_msgid) + { + log_write(0, LOG_MAIN, "notify triggered queue run"); + f.queue_2stage = FALSE; + queue_run(queuerun_msgid, queuerun_msgid, FALSE); + } + else +#endif + queue_run(NULL, NULL, FALSE); + exim_underbar_exit(EXIT_SUCCESS); } - /* No need to re-exec; SIGALRM remains set to the default handler */ - - queue_run(NULL, NULL, FALSE); - _exit(EXIT_SUCCESS); - } - - if (pid < 0) - { - log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fork of queue-runner " - "process failed: %s", strerror(errno)); - log_close_all(); - } - else - { - int i; - for (i = 0; i < queue_run_max; ++i) + if (pid < 0) { - if (queue_pid_slots[i] <= 0) - { - queue_pid_slots[i] = pid; - queue_run_count++; - break; - } + log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fork of queue-runner " + "process failed: %s", strerror(errno)); + log_close_all(); + } + else + { + for (int i = 0; i < local_queue_run_max; ++i) + if (queue_pid_slots[i] <= 0) + { + queue_pid_slots[i] = pid; + queue_run_count++; + break; + } + DEBUG(D_any) debug_printf("%d queue-runner process%s running\n", + queue_run_count, queue_run_count == 1 ? "" : "es"); } - DEBUG(D_any) debug_printf("%d queue-runner process%s running\n", - queue_run_count, (queue_run_count == 1)? "" : "es"); } - } - /* Reset the alarm clock */ + /* Reset the alarm clock */ - sigalrm_seen = FALSE; - alarm(queue_interval); - } + sigalrm_seen = FALSE; +#ifndef DISABLE_QUEUE_RAMP + if (*queuerun_msgid) + *queuerun_msgid = 0; + else +#endif + ALARM(queue_interval); + } + + } /* sigalrm_seen */ /* Sleep till a connection happens if listening, and handle the connection if @@ -1620,46 +2421,59 @@ for (;;) new OS. In fact, the later addition of listening on specific interfaces only requires this way of working anyway. */ - if (daemon_listen) + if (f.daemon_listen) { - int sk, lcount; - int max_socket = 0; + int lcount; BOOL select_failed = FALSE; - fd_set select_listen; - - FD_ZERO(&select_listen); - for (sk = 0; sk < listen_socket_count; sk++) - { - FD_SET(listen_sockets[sk], &select_listen); - if (listen_sockets[sk] > max_socket) max_socket = listen_sockets[sk]; - } DEBUG(D_any) debug_printf("Listening...\n"); - - /* In rare cases we may have had a SIGCHLD signal in the time between - setting the handler (below) and getting back here. If so, pretend that the + + /* In rare cases we may have had a SIGCHLD signal in the time between + setting the handler (below) and getting back here. If so, pretend that the select() was interrupted so that we reap the child. This might still leave - a small window when a SIGCHLD could get lost. However, since we use SIGCHLD + a small window when a SIGCHLD could get lost. However, since we use SIGCHLD only to do the reaping more quickly, it shouldn't result in anything other than a delay until something else causes a wake-up. */ if (sigchld_seen) { lcount = -1; - errno = EINTR; + errno = EINTR; } else - { - lcount = select(max_socket + 1, (SELECT_ARG2_TYPE *)&select_listen, - NULL, NULL, NULL); - } + lcount = poll(fd_polls, poll_fd_count, -1); if (lcount < 0) { select_failed = TRUE; lcount = 1; } - + + /* Clean up any subprocesses that may have terminated. We need to do this + here so that smtp_accept_max_per_host works when a connection to that host + has completed, and we are about to accept a new one. When this code was + later in the sequence, a new connection could be rejected, even though an + old one had just finished. Preserve the errno from any select() failure for + the use of the common select/accept error processing below. */ + + { + int select_errno = errno; + handle_ending_processes(); + +#ifndef DISABLE_TLS + { + int old_tfd; + /* Create or rotate any required keys; handle (delayed) filewatch event */ + + 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; + } + /* Loop for all the sockets that are currently ready to go. If select actually failed, we have set the count to 1 and select_failed=TRUE, so as to use the common error code for select/accept below. */ @@ -1667,19 +2481,60 @@ for (;;) while (lcount-- > 0) { int accept_socket = -1; +#if HAVE_IPV6 + struct sockaddr_in6 accepted; +#else + struct sockaddr_in accepted; +#endif + if (!select_failed) - { - for (sk = 0; sk < listen_socket_count; sk++) - { - if (FD_ISSET(listen_sockets[sk], &select_listen)) + { +#if !defined(DISABLE_TLS) && (defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)) + if (tls_watch_poll && tls_watch_poll->revents & POLLIN) + { + 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 (dnotify_poll && dnotify_poll->revents & POLLIN) + { + dnotify_poll->revents = 0; + sigalrm_seen = daemon_notification(); + break; /* to top of daemon loop */ + } + for (struct pollfd * p = fd_polls; p < fd_polls + listen_socket_count; + p++) + if (p->revents & POLLIN) { - accept_socket = accept(listen_sockets[sk], - (struct sockaddr *)&accepted, &len); - FD_CLR(listen_sockets[sk], &select_listen); + 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; } - } - } + } /* If select or accept has failed and this was not caused by an interruption, log the incident and try again. With asymmetric TCP/IP @@ -1698,46 +2553,48 @@ for (;;) accept_retry_errno = errno; accept_retry_select_failed = select_failed; } - 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; - } - } + 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; + } accept_retry_count++; } - - else - { - if (accept_retry_count > 0) - { - log_write(0, LOG_MAIN, "%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; - } - } + else if (accept_retry_count > 0) + { + log_write(0, LOG_MAIN, "%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; + } /* If select/accept succeeded, deal with the connection. */ if (accept_socket >= 0) - handle_smtp_call(listen_sockets, listen_socket_count, accept_socket, + { +#ifdef TCP_QUICKACK /* Avoid pure-ACKs while in tls protocol pingpong phase */ + /* Unfortunately we cannot be certain to do this before a TLS-on-connect + Client Hello arrives and is acked. We do it as early as possible. */ + (void) setsockopt(accept_socket, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); +#endif + if (inetd_wait_timeout) + last_connection_time = time(NULL); + handle_smtp_call(fd_polls, listen_socket_count, accept_socket, (struct sockaddr *)&accepted); + } } } @@ -1750,61 +2607,9 @@ for (;;) else { - struct timeval tv; - tv.tv_sec = queue_interval; - tv.tv_usec = 0; - select(0, NULL, NULL, NULL, &tv); - } - - /* Handle the termination of a child process. Theoretically, this need - be done only when sigchld_seen is TRUE, but rumour has it that some systems - lose SIGCHLD signals at busy times, so to be on the safe side, just - do it each time round. It shouldn't be too expensive. */ - - while ((pid = waitpid(-1, &status, WNOHANG)) > 0) - { - int i; - DEBUG(D_any) debug_printf("child %d ended: status=0x%x\n", (int)pid, - status); - - /* If it's a listening daemon, deal with an accepting process that has - terminated. */ - - if (daemon_listen) - { - for (i = 0; i < smtp_accept_max; i++) - { - if (smtp_slots[i].pid == pid) - { - if (smtp_slots[i].host_address != NULL) - store_free(smtp_slots[i].host_address); - smtp_slots[i] = empty_smtp_slot; - if (--smtp_accept_count < 0) smtp_accept_count = 0; - DEBUG(D_any) debug_printf("%d SMTP accept process%s now running\n", - smtp_accept_count, (smtp_accept_count == 1)? "" : "es"); - break; - } - } - if (i < smtp_accept_max) continue; /* Found an accepting process */ - } - - /* If it wasn't an accepting process, see if it was a queue-runner - process, if we are keeping track of them. */ - - if (queue_interval > 0) - { - for (i = 0; i < queue_run_max; i++) - { - if (queue_pid_slots[i] == pid) - { - queue_pid_slots[i] = 0; - if (--queue_run_count < 0) queue_run_count = 0; - DEBUG(D_any) debug_printf("%d queue-runner process%s now running\n", - queue_run_count, (queue_run_count == 1)? "" : "es"); - break; - } - } - } + struct pollfd p; + poll(&p, 0, queue_interval * 1000); + handle_ending_processes(); } /* Re-enable the SIGCHLD handler if it has been run. It can't do it @@ -1826,11 +2631,10 @@ for (;;) if (sighup_seen) { - int sk; log_write(0, LOG_MAIN, "pid %d: SIGHUP received: re-exec daemon", getpid()); - for (sk = 0; sk < listen_socket_count; sk++) close(listen_sockets[sk]); - alarm(0); + close_daemon_sockets(daemon_notifier_fd, fd_polls, listen_socket_count); + ALARM_CLR(0); signal(SIGHUP, SIG_IGN); sighup_argv[0] = exim_path; exim_nullstd(); @@ -1845,5 +2649,6 @@ for (;;) /* Control never reaches here */ } +/* vi: aw ai sw=2 +*/ /* End of exim_daemon.c */ -