1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/socket.h>
23 #include <sys/types.h>
31 #include <sys/epoll.h>
38 #include "sd-daemon.h"
41 #define STREAMS_MAX 4096
42 #define SERVER_FD_MAX 16
43 #define TIMEOUT ((int) (5*60*MSEC_PER_SEC))
45 typedef struct Stream Stream;
47 typedef struct Server {
54 bool syslog_is_stream;
56 LIST_HEAD(Stream, streams);
60 typedef enum StreamTarget {
65 typedef enum StreamState {
90 char buffer[LINE_MAX];
93 LIST_FIELDS(Stream, stream);
96 static int stream_log(Stream *s, char *p, usec_t ts) {
98 char header_priority[16], header_time[64], header_pid[16];
99 struct iovec iovec[5];
105 priority = s->priority;
108 parse_syslog_priority(&p, &priority);
113 /* Patch in LOG_USER facility if necessary */
114 if ((priority & LOG_FACMASK) == 0)
115 priority = LOG_USER | LOG_PRI(priority);
118 * The format glibc uses to talk to the syslog daemon is:
120 * <priority>time process[pid]: msg
122 * The format the kernel uses is:
126 * We extend the latter to include the process name and pid.
129 snprintf(header_priority, sizeof(header_priority), "<%i>", priority);
130 char_array_0(header_priority);
132 if (s->target == STREAM_SYSLOG) {
136 t = (time_t) (ts / USEC_PER_SEC);
137 if (!(tm = localtime(&t)))
140 if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
144 snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) s->pid);
145 char_array_0(header_pid);
148 IOVEC_SET_STRING(iovec[0], header_priority);
150 if (s->target == STREAM_SYSLOG) {
151 struct msghdr msghdr;
153 struct cmsghdr cmsghdr;
154 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
159 control.cmsghdr.cmsg_level = SOL_SOCKET;
160 control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
161 control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
163 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
168 IOVEC_SET_STRING(iovec[1], header_time);
169 IOVEC_SET_STRING(iovec[2], s->process);
170 IOVEC_SET_STRING(iovec[3], header_pid);
171 IOVEC_SET_STRING(iovec[4], p);
173 /* When using syslog via SOCK_STREAM separate the messages by NUL chars */
174 if (s->server->syslog_is_stream)
178 msghdr.msg_iov = iovec;
179 msghdr.msg_iovlen = ELEMENTSOF(iovec);
180 msghdr.msg_control = &control;
181 msghdr.msg_controllen = control.cmsghdr.cmsg_len;
186 if ((n = sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0) {
188 if (errno == ESRCH) {
191 /* Hmm, maybe the process this
192 * line originates from is
193 * dead? Then let's patch in
194 * our own pid and retry,
195 * since we have nothing
200 if (ucred->pid != our_pid) {
201 ucred->pid = our_pid;
209 if (!s->server->syslog_is_stream ||
210 (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
213 IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
216 } else if (s->target == STREAM_KMSG) {
217 IOVEC_SET_STRING(iovec[1], s->process);
218 IOVEC_SET_STRING(iovec[2], header_pid);
219 IOVEC_SET_STRING(iovec[3], p);
220 IOVEC_SET_STRING(iovec[4], (char*) "\n");
222 if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
225 assert_not_reached("Unknown log target");
227 if (s->tee_console) {
230 if ((console = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) >= 0) {
231 IOVEC_SET_STRING(iovec[0], s->process);
232 IOVEC_SET_STRING(iovec[1], header_pid);
233 IOVEC_SET_STRING(iovec[2], p);
234 IOVEC_SET_STRING(iovec[3], (char*) "\n");
236 writev(console, iovec, 4);
244 static int stream_line(Stream *s, char *p, usec_t ts) {
255 if (streq(p, "syslog") || streq(p, "syslog+console"))
256 s->target = STREAM_SYSLOG;
257 else if (streq(p, "kmsg") || streq(p, "kmsg+console")) {
259 if (s->server->kmsg_fd >= 0 && s->uid == 0)
260 s->target = STREAM_KMSG;
262 log_warning("/dev/kmsg logging not available.");
266 log_warning("Failed to parse log target line.");
270 if (endswith(p, "+console"))
271 s->tee_console = true;
273 s->state = STREAM_PRIORITY;
276 case STREAM_PRIORITY:
277 if ((r = safe_atoi(p, &s->priority)) < 0) {
278 log_warning("Failed to parse log priority line: %m");
282 if (s->priority < 0) {
283 log_warning("Log priority negative: %m");
287 s->state = STREAM_PROCESS;
291 if (!(s->process = strdup(p)))
294 s->state = STREAM_PREFIX;
299 if ((r = parse_boolean(p)) < 0)
303 s->state = STREAM_RUNNING;
307 return stream_log(s, p, ts);
310 assert_not_reached("Unknown stream state");
313 static int stream_scan(Stream *s, usec_t ts) {
321 remaining = s->length;
325 if (!(newline = memchr(p, '\n', remaining)))
330 if ((r = stream_line(s, p, ts)) >= 0) {
331 remaining -= newline-p+1;
337 memmove(s->buffer, p, remaining);
338 s->length = remaining;
344 static int stream_process(Stream *s, usec_t ts) {
349 if ((l = read(s->fd, s->buffer+s->length, LINE_MAX-s->length)) < 0) {
354 log_warning("Failed to read from stream: %m");
363 r = stream_scan(s, ts);
371 static void stream_free(Stream *s) {
375 assert(s->server->n_streams > 0);
376 s->server->n_streams--;
377 LIST_REMOVE(Stream, stream, s->server->streams, s);
383 epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL);
385 close_nointr_nofail(s->fd);
392 static int stream_new(Server *s, int server_fd) {
396 socklen_t len = sizeof(ucred);
397 struct epoll_event ev;
402 if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0)
405 if (s->n_streams >= STREAMS_MAX) {
406 log_warning("Too many connections, refusing connection.");
407 close_nointr_nofail(fd);
411 if (!socket_tcpwrap(fd, "systemd-logger")) {
412 close_nointr_nofail(fd);
416 if (!(stream = new0(Stream, 1))) {
417 close_nointr_nofail(fd);
423 if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
428 if (shutdown(fd, SHUT_WR) < 0) {
434 ev.data.ptr = stream;
436 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
441 stream->pid = ucred.pid;
442 stream->uid = ucred.uid;
443 stream->gid = ucred.gid;
446 LIST_PREPEND(Stream, stream, s->streams, stream);
456 static void server_done(Server *s) {
461 stream_free(s->streams);
463 for (i = 0; i < s->n_server_fd; i++)
464 close_nointr_nofail(SD_LISTEN_FDS_START+i);
466 if (s->syslog_fd >= 0)
467 close_nointr_nofail(s->syslog_fd);
469 if (s->epoll_fd >= 0)
470 close_nointr_nofail(s->epoll_fd);
473 close_nointr_nofail(s->kmsg_fd);
476 static int server_init(Server *s, unsigned n_sockets) {
481 struct sockaddr_un un;
485 assert(n_sockets > 0);
489 s->n_server_fd = n_sockets;
493 if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
495 log_error("Failed to create epoll object: %m");
499 for (i = 0; i < n_sockets; i++) {
500 struct epoll_event ev;
503 fd = SD_LISTEN_FDS_START+i;
505 if ((r = sd_is_socket(fd, AF_UNSPEC, SOCK_STREAM, 1)) < 0) {
506 log_error("Failed to determine file descriptor type: %s", strerror(-r));
511 log_error("Wrong file descriptor type.");
516 /* We use ev.data.ptr instead of ev.data.fd here,
517 * since on 64bit archs fd is 32bit while a pointer is
518 * 64bit. To make sure we can easily distinguish fd
519 * values and pointer values we want to make sure to
520 * write the full field unconditionally. */
524 ev.data.ptr = INT_TO_PTR(fd);
525 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
527 log_error("Failed to add server fd to epoll object: %m");
533 sa.un.sun_family = AF_UNIX;
534 strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
536 if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
538 log_error("Failed to create log fd: %m");
542 if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
543 close_nointr_nofail(s->syslog_fd);
545 if ((s->syslog_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0)) < 0) {
547 log_error("Failed to create log fd: %m");
551 if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
553 log_error("Failed to connect log socket to /dev/log: %m");
557 s->syslog_is_stream = true;
559 s->syslog_is_stream = false;
561 /* /dev/kmsg logging is strictly optional */
562 if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0)
563 log_warning("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %m");
572 static int process_event(Server *s, struct epoll_event *ev) {
577 /* Yes, this is a bit ugly, we assume that that valid pointers
578 * are > SD_LISTEN_FDS_START+SERVER_FD_MAX. Which is certainly
579 * true on Linux (and probably most other OSes, too, since the
580 * first 4k usually are part of a separate null pointer
581 * dereference page. */
583 if (PTR_TO_INT(ev->data.ptr) >= SD_LISTEN_FDS_START &&
584 PTR_TO_INT(ev->data.ptr) < SD_LISTEN_FDS_START+(int)s->n_server_fd) {
586 if (ev->events != EPOLLIN) {
587 log_info("Got invalid event from epoll. (1)");
591 if ((r = stream_new(s, PTR_TO_INT(ev->data.ptr))) < 0) {
592 log_info("Failed to accept new connection: %s", strerror(-r));
598 Stream *stream = ev->data.ptr;
600 ts = now(CLOCK_REALTIME);
602 if (!(ev->events & EPOLLIN)) {
603 log_info("Got invalid event from epoll. (2)");
608 if ((r = stream_process(stream, ts)) <= 0) {
611 log_info("Got error on stream: %s", strerror(-r));
621 int main(int argc, char *argv[]) {
623 int r = EXIT_FAILURE, n;
625 if (getppid() != 1) {
626 log_error("This program should be invoked by init only.");
631 log_error("This program does not take arguments.");
635 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
636 log_parse_environment();
639 if ((n = sd_listen_fds(true)) < 0) {
640 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
644 if (n <= 0 || n > SERVER_FD_MAX) {
645 log_error("No or too many file descriptors passed.");
649 if (server_init(&server, (unsigned) n) < 0)
652 log_debug("systemd-logger running as pid %lu", (unsigned long) getpid());
656 "STATUS=Processing requests...");
659 struct epoll_event event;
662 if ((k = epoll_wait(server.epoll_fd,
664 server.n_streams <= 0 ? TIMEOUT : -1)) < 0) {
669 log_error("epoll_wait() failed: %m");
676 if (process_event(&server, &event) < 0)
682 log_debug("systemd-logger stopped as pid %lu", (unsigned long) getpid());
686 "STATUS=Shutting down...");
688 server_done(&server);