*************************************************/
/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions concerned with running Exim as a daemon */
+/*************************************************
+*************************************************/
+
+#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,
+ int * listen_sockets, 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(listen_sockets[i]);
+}
+
+
/*************************************************
* Handle a connected SMTP call *
*************************************************/
log_write(L_connection_reject,
LOG_MAIN, "Connection from %s refused: too many connections "
"from that IP address", whofrom->s);
+ search_tidyup();
goto ERROR_RETURN;
}
}
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;
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. */
signal(SIGCHLD, SIG_IGN);
#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
mac_smtp_fflush();
- if ((dpid = fork()) == 0)
+ if ((dpid = exim_fork(US"daemon-accept-delivery")) == 0)
{
(void)fclose(smtp_in);
(void)fclose(smtp_out);
signal(SIGHUP, SIG_DFL);
signal(SIGCHLD, SIG_DFL);
signal(SIGTERM, SIG_DFL);
+ signal(SIGINT, SIG_DFL);
if (geteuid() != root_uid && !deliver_drop_privilege)
{
}
-
static void
set_pid_file_path(void)
{
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);
}
-/* Remove the daemon's pidfile. Note: runs with root privilege,
-as a direct child of the daemon. Does not return. */
+enum pid_op { PID_WRITE, PID_CHECK, PID_DELETE };
-void
-delete_pid_file(void)
+/* 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)
{
-uschar * daemon_pid = string_sprintf("%d\n", (int)getppid());
-FILE * f;
+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;
+
+char * path = NULL;
+char * base = NULL;
+char * dir = NULL;
+
+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;
+int dir_fd = -1;
+int base_fd = -1;
+
+BOOL success = FALSE;
+errno = EACCES;
set_pid_file_path();
-if ((f = Ufopen(pid_file_path, "rb")))
+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 = CS 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 : "/";
+*base++ = '\0';
+
+if (!dir || !*dir || *dir != '/') goto cleanup;
+if (!base || !*base || strchr(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(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(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 ( fgets(CS big_buffer, big_buffer_size, f)
- && Ustrcmp(daemon_pid, big_buffer) == 0
- )
- if (Uunlink(pid_file_path) == 0)
+ if (!lines_match)
+ {
+ if (base_fd >= 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);
+ int error = -1;
+ /* emulate unlinkat */
+ if (fchdir(dir_fd) != 0) goto cleanup;
+ error = unlink(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(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
- DEBUG(D_any)
- debug_printf("%s\n", string_open_failed(errno, "pid file %s",
- pid_file_path));
-exim_exit(EXIT_SUCCESS, US"pid file remover");
+ {
+ if (!lines_match) goto cleanup;
+ if (operation == PID_DELETE)
+ {
+ int error = -1;
+ /* emulate unlinkat */
+ if (fchdir(dir_fd) != 0) goto cleanup;
+ error = unlink(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);
}
{
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
- {
- uschar * s = string_sprintf("%s/%s", spool_directory, NOTIFIER_SOCKET_NAME);
- DEBUG(D_any) debug_printf("unlinking notifier socket %s\n", s);
- Uunlink(s);
- }
+ unlink_notifier_socket();
#endif
}
if (f.running_in_test_harness || write_pid)
{
- if ((pid = fork()) == 0)
+ 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,
if (pid > 0)
child_close(pid, 1);
}
-exim_exit(EXIT_SUCCESS, US"daemon");
+exim_exit(EXIT_SUCCESS);
}
struct sockaddr_un sa_un = {.sun_family = AF_UNIX};
int len;
-DEBUG(D_any) debug_printf("creating notifier socket ");
+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)
#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", NOTIFIER_SOCKET_NAME);
-DEBUG(D_any) debug_printf("@%s\n", sa_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/%s",
- spool_directory, NOTIFIER_SOCKET_NAME);
-DEBUG(D_any) debug_printf("%s\n", sa_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)
.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;
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. */
list = override_local_interfaces;
sep = 0;
- while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
+ while ((s = string_nextinlist(&list, &sep, NULL, 0)))
{
uschar joinstr[4];
gstring ** gp = Ustrpbrk(s, ".:") ? &new_local_interfaces : &new_smtp_port;
list = daemon_smtp_port;
sep = 0;
- while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
+ while ((s = string_nextinlist(&list, &sep, NULL, 0)))
pct++;
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));
+ (s = string_nextinlist(&list, &sep, NULL, 0));
pct++)
{
if (isdigit(*s))
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 */
if (f.running_in_test_harness || write_pid)
{
- FILE *f;
-
- set_pid_file_path();
- if ((f = modefopen(pid_file_path, "wb", 0644)))
- {
- (void)fprintf(f, "%d\n", (int)getpid());
- (void)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. */
-
sighup_seen = FALSE;
signal(SIGHUP, sighup_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. */
ip_address_item * ipa;
uschar * p;
uschar * qinfo = queue_interval > 0
- ? string_sprintf("-q%s", readconf_printtime(queue_interval))
+ ? 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
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. */
/* Close any open listening sockets in the child */
- if (daemon_notifier_fd >= 0)
- (void) close(daemon_notifier_fd);
- 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);
+ signal(SIGINT, SIG_DFL);
/* Re-exec if privilege has been given up, unless deliver_drop_
privilege is set. Reset SIGALRM before exec(). */
#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 */
}
#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);
}
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)
+ 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),
+ 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",
+ 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, "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;