X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/d85cdeb5e554b59bf4c43c54461409c15c6ee9c5..137ae145e066dda8f9d81cf6d2c9f76c15929605:/src/src/daemon.c diff --git a/src/src/daemon.c b/src/src/daemon.c index 3fc73babe..3b21d272b 100644 --- a/src/src/daemon.c +++ b/src/src/daemon.c @@ -31,6 +31,7 @@ static smtp_slot empty_smtp_slot = { .pid = 0, .host_address = NULL }; 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; @@ -87,6 +88,16 @@ sigchld_seen = TRUE; } +/* SIGTERM handler. Try to get the damon pif file removed +before exiting. */ + +static void +main_sigterm_handler(int sig) +{ +sigterm_seen = TRUE; +} + + /************************************************* @@ -115,6 +126,18 @@ if (smtp_out) smtp_printf("421 %s\r\n", FALSE, smtp_msg); +/************************************************* +*************************************************/ + +static void +close_daemon_sockets(int daemon_notifier_fd, + int * listen_sockets, int listen_socket_count) +{ +if (daemon_notifier_fd >= 0) (void) close(daemon_notifier_fd); +for (int i = 0; i < listen_socket_count; i++) (void) close(listen_sockets[i]); +} + + /************************************************* * Handle a connected SMTP call * *************************************************/ @@ -344,7 +367,7 @@ if (LOGGING(smtp_connection)) expansion above did a lookup. */ search_tidyup(); -pid = fork(); +pid = exim_fork(US"daemon-accept"); /* Handle the child process */ @@ -413,7 +436,7 @@ 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++) (void)close(listen_sockets[i]); + close_daemon_sockets(daemon_notifier_fd, listen_sockets, 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. */ @@ -430,6 +453,7 @@ if (pid == 0) #else signal(SIGCHLD, SIG_IGN); #endif + signal(SIGTERM, 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 @@ -628,7 +652,8 @@ if (pid == 0) If we are not root, we have to re-exec exim unless deliveries are being done unprivileged. */ - else if (!f.queue_only_policy && !f.deliver_freeze) + else if ( (!f.queue_only_policy || f.queue_smtp) + && !f.deliver_freeze) { pid_t dpid; @@ -638,7 +663,7 @@ if (pid == 0) mac_smtp_fflush(); - if ((dpid = fork()) == 0) + if ((dpid = exim_fork(US"daemon-accept-delivery")) == 0) { (void)fclose(smtp_in); (void)fclose(smtp_out); @@ -654,6 +679,7 @@ if (pid == 0) signal(SIGHUP, SIG_DFL); signal(SIGCHLD, SIG_DFL); + signal(SIGTERM, SIG_DFL); if (geteuid() != root_uid && !deliver_drop_privilege) { @@ -888,6 +914,259 @@ while ((pid = waitpid(-1, &status, WNOHANG)) > 0) +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); +} + + +/* 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) +{ +uschar * daemon_pid = string_sprintf("%d\n", (int)getppid()); +FILE * f; + +set_pid_file_path(); +if ((f = Ufopen(pid_file_path, "rb"))) + { + if ( fgets(CS big_buffer, big_buffer_size, f) + && Ustrcmp(daemon_pid, big_buffer) == 0 + ) + if (Uunlink(pid_file_path) == 0) + { + DEBUG(D_any) + debug_printf("%s unlink: %s\n", pid_file_path, strerror(errno)); + } + else + DEBUG(D_any) + debug_printf("unlinked %s\n", pid_file_path); + fclose(f); + } +else + DEBUG(D_any) + debug_printf("%s\n", string_open_failed(errno, "pid file %s", + pid_file_path)); +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; + +if (daemon_notifier_fd >= 0) + { + close(daemon_notifier_fd); + daemon_notifier_fd = -1; +#ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS + { + uschar * s = expand_string(notifier_socket); + DEBUG(D_any) debug_printf("unlinking notifier socket %s\n", s); + Uunlink(s); + } +#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 (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; +struct cmsghdr * cp; + +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]) + { +#ifdef EXPERIMENTAL_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 /*EXPERIMENTAL_QUEUE_RAMP*/ + + 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; +} + + /************************************************* * Exim Daemon Mainline * *************************************************/ @@ -921,6 +1200,8 @@ 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. */ @@ -1068,19 +1349,14 @@ if (f.daemon_listen && !f.inetd_wait_mode) 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))) { uschar joinstr[4]; - gstring ** gp; - - if (Ustrpbrk(s, ".:") == NULL) - gp = &new_smtp_port; - else - gp = &new_local_interfaces; + gstring ** gp = Ustrpbrk(s, ".:") ? &new_local_interfaces : &new_smtp_port; if (!*gp) { @@ -1327,7 +1603,7 @@ if (f.background_daemon) 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 */ @@ -1338,6 +1614,8 @@ if (f.background_daemon) /* We are now in the disconnected, daemon process (unless debugging). Set up the listening sockets if required. */ +daemon_notifier_socket(); + if (f.daemon_listen && !f.inetd_wait_mode) { int sk; @@ -1538,12 +1816,7 @@ if (f.running_in_test_harness || write_pid) { FILE *f; - if (override_pid_file_path) - pid_file_path = override_pid_file_path; - - if (pid_file_path[0] == 0) - pid_file_path = string_sprintf("%s/exim-daemon.pid", spool_directory); - + set_pid_file_path(); if ((f = modefopen(pid_file_path, "wb", 0644))) { (void)fprintf(f, "%d\n", (int)getpid()); @@ -1586,11 +1859,15 @@ if (queue_interval > 0 && local_queue_run_max > 0) 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); + /* 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. */ @@ -1614,7 +1891,7 @@ if (f.inetd_wait_mode) set_process_info("daemon(%s): pre-listening socket", version_string); /* set up the timeout logic */ - sigalrm_seen = 1; + sigalrm_seen = TRUE; } else if (f.daemon_listen) @@ -1791,6 +2068,9 @@ for (;;) EXIM_SOCKLEN_T len; 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, for the queue-runner case, so that the first one can be started immediately. @@ -1839,20 +2119,21 @@ for (;;) else { - DEBUG(D_any) debug_printf("SIGALRM received\n"); + DEBUG(D_any) debug_printf("%s received\n", +#ifdef EXPERIMENTAL_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)) + if ( queue_interval > 0 + && (local_queue_run_max <= 0 || queue_run_count < local_queue_run_max)) { - if ((pid = fork()) == 0) + if ((pid = exim_fork(US"queue-runner")) == 0) { - DEBUG(D_any) debug_printf("Starting queue-runner: pid %d\n", - (int)getpid()); - /* 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. */ @@ -1861,13 +2142,14 @@ for (;;) /* Close any open listening sockets in the child */ - for (int sk = 0; sk < listen_socket_count; sk++) - (void)close(listen_sockets[sk]); + close_daemon_sockets(daemon_notifier_fd, + listen_sockets, listen_socket_count); /* Reset SIGHUP and SIGCHLD in the child in both cases. */ signal(SIGHUP, SIG_DFL); signal(SIGCHLD, SIG_DFL); + signal(SIGTERM, SIG_DFL); /* Re-exec if privilege has been given up, unless deliver_drop_ privilege is set. Reset SIGALRM before exec(). */ @@ -1876,21 +2158,34 @@ for (;;) { uschar opt[8]; uschar *p = opt; - uschar *extra[5]; + uschar *extra[7]; int extracount = 1; signal(SIGALRM, SIG_DFL); *p++ = '-'; *p++ = 'q'; - if (f.queue_2stage) *p++ = 'q'; + if ( f.queue_2stage +#ifdef EXPERIMENTAL_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 + extra[0] = *queue_name ? string_sprintf("%sG%s", opt, queue_name) : opt; +#ifdef EXPERIMENTAL_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. */ @@ -1909,15 +2204,24 @@ for (;;) /* Overlay this process with a new execution. */ - (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, TRUE, extracount, - extra[0], extra[1], extra[2], extra[3], extra[4]); + (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. */ } /* No need to re-exec; SIGALRM remains set to the default handler */ - queue_run(NULL, NULL, FALSE); +#ifdef EXPERIMENTAL_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); } @@ -1944,7 +2248,12 @@ for (;;) /* Reset the alarm clock */ sigalrm_seen = FALSE; - ALARM(queue_interval); +#ifdef EXPERIMENTAL_QUEUE_RAMP + if (*queuerun_msgid) + *queuerun_msgid = 0; + else +#endif + ALARM(queue_interval); } } /* sigalrm_seen */ @@ -1967,6 +2276,8 @@ for (;;) fd_set select_listen; FD_ZERO(&select_listen); + if (daemon_notifier_fd >= 0) + FD_SET(daemon_notifier_fd, &select_listen); for (int sk = 0; sk < listen_socket_count; sk++) { FD_SET(listen_sockets[sk], &select_listen); @@ -2022,6 +2333,14 @@ for (;;) int accept_socket = -1; if (!select_failed) + { + if ( daemon_notifier_fd >= 0 + && FD_ISSET(daemon_notifier_fd, &select_listen)) + { + FD_CLR(daemon_notifier_fd, &select_listen); + 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], &select_listen)) { @@ -2031,6 +2350,7 @@ for (;;) FD_CLR(listen_sockets[sk], &select_listen); 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 @@ -2133,8 +2453,8 @@ for (;;) { log_write(0, LOG_MAIN, "pid %d: SIGHUP received: re-exec daemon", getpid()); - for (int sk = 0; sk < listen_socket_count; sk++) - (void)close(listen_sockets[sk]); + close_daemon_sockets(daemon_notifier_fd, + listen_sockets, listen_socket_count); ALARM_CLR(0); signal(SIGHUP, SIG_IGN); sighup_argv[0] = exim_path;