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 STREAM_BUFFER 2048
42 #define STREAMS_MAX 256
43 #define SERVER_FD_MAX 16
44 #define TIMEOUT ((int) (10*MSEC_PER_SEC))
46 typedef struct Stream Stream;
48 typedef struct Server {
55 LIST_HEAD(Stream, streams);
59 typedef enum StreamTarget {
64 typedef enum StreamState {
87 char buffer[STREAM_BUFFER];
90 LIST_FIELDS(Stream, stream);
93 static int stream_log(Stream *s, char *p, usec_t ts) {
95 char header_priority[16], header_time[64], header_pid[16];
96 struct iovec iovec[5];
102 priority = s->priority;
106 p[1] >= '0' && p[1] <= '7' &&
109 /* Detected priority prefix */
110 priority = LOG_MAKEPRI(LOG_FAC(priority), (p[1] - '0'));
119 * The format glibc uses to talk to the syslog daemon is:
121 * <priority>time process[pid]: msg
123 * The format the kernel uses is:
127 * We extend the latter to include the process name and pid.
130 snprintf(header_priority, sizeof(header_priority), "<%i>",
131 s->target == STREAM_SYSLOG ? priority : LOG_PRI(priority));
132 char_array_0(header_priority);
134 if (s->target == STREAM_SYSLOG) {
138 t = (time_t) (ts / USEC_PER_SEC);
139 if (!(tm = localtime(&t)))
142 if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
146 snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) s->pid);
147 char_array_0(header_pid);
150 IOVEC_SET_STRING(iovec[0], header_priority);
152 if (s->target == STREAM_SYSLOG) {
153 struct msghdr msghdr;
155 IOVEC_SET_STRING(iovec[1], header_time);
156 IOVEC_SET_STRING(iovec[2], s->process);
157 IOVEC_SET_STRING(iovec[3], header_pid);
158 IOVEC_SET_STRING(iovec[4], p);
161 msghdr.msg_iov = iovec;
162 msghdr.msg_iovlen = ELEMENTSOF(iovec);
164 if (sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL) < 0)
167 } else if (s->target == STREAM_KMSG) {
168 IOVEC_SET_STRING(iovec[1], s->process);
169 IOVEC_SET_STRING(iovec[2], header_pid);
170 IOVEC_SET_STRING(iovec[3], p);
171 IOVEC_SET_STRING(iovec[4], (char*) "\n");
173 if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
176 assert_not_reached("Unknown log target");
181 static int stream_line(Stream *s, char *p, usec_t ts) {
192 if (streq(p, "syslog"))
193 s->target = STREAM_SYSLOG;
194 else if (streq(p, "kmsg")) {
196 if (s->server->kmsg_fd >= 0 && s->uid == 0)
197 s->target = STREAM_KMSG;
199 log_warning("/dev/kmsg logging not available.");
203 log_warning("Failed to parse log target line.");
206 s->state = STREAM_PRIORITY;
209 case STREAM_PRIORITY:
210 if ((r = safe_atoi(p, &s->priority)) < 0) {
211 log_warning("Failed to parse log priority line: %s", strerror(errno));
215 if (s->priority < 0) {
216 log_warning("Log priority negative: %s", strerror(errno));
220 s->state = STREAM_PROCESS;
224 if (!(s->process = strdup(p)))
227 s->state = STREAM_PREFIX;
232 if ((r = parse_boolean(p)) < 0)
236 s->state = STREAM_RUNNING;
240 return stream_log(s, p, ts);
243 assert_not_reached("Unknown stream state");
246 static int stream_scan(Stream *s, usec_t ts) {
254 remaining = s->length;
258 if (!(newline = memchr(p, '\n', remaining)))
263 if ((r = stream_line(s, p, ts)) >= 0) {
264 remaining -= newline-p+1;
270 memmove(s->buffer, p, remaining);
271 s->length = remaining;
277 static int stream_process(Stream *s, usec_t ts) {
282 if ((l = read(s->fd, s->buffer+s->length, STREAM_BUFFER-s->length)) < 0) {
287 log_warning("Failed to read from stream: %s", strerror(errno));
296 r = stream_scan(s, ts);
304 static void stream_free(Stream *s) {
308 assert(s->server->n_streams > 0);
309 s->server->n_streams--;
310 LIST_REMOVE(Stream, stream, s->server->streams, s);
316 epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL);
318 close_nointr_nofail(s->fd);
325 static int stream_new(Server *s, int server_fd) {
329 socklen_t len = sizeof(ucred);
330 struct epoll_event ev;
335 if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0)
338 if (s->n_streams >= STREAMS_MAX) {
339 log_warning("Too many connections, refusing connection.");
340 close_nointr_nofail(fd);
344 if (!socket_tcpwrap(fd, "systemd-logger")) {
345 close_nointr_nofail(fd);
349 if (!(stream = new0(Stream, 1))) {
350 close_nointr_nofail(fd);
356 if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
361 if (shutdown(fd, SHUT_WR) < 0) {
367 ev.data.ptr = stream;
369 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
374 stream->pid = ucred.pid;
375 stream->uid = ucred.uid;
378 LIST_PREPEND(Stream, stream, s->streams, stream);
388 static void server_done(Server *s) {
393 stream_free(s->streams);
395 for (i = 0; i < s->n_server_fd; i++)
396 close_nointr_nofail(SD_LISTEN_FDS_START+i);
398 if (s->syslog_fd >= 0)
399 close_nointr_nofail(s->syslog_fd);
401 if (s->epoll_fd >= 0)
402 close_nointr_nofail(s->epoll_fd);
405 close_nointr_nofail(s->kmsg_fd);
408 static int server_init(Server *s, unsigned n_sockets) {
413 struct sockaddr_un un;
417 assert(n_sockets > 0);
421 s->n_server_fd = n_sockets;
425 if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
427 log_error("Failed to create epoll object: %s", strerror(errno));
431 for (i = 0; i < n_sockets; i++) {
432 struct epoll_event ev;
435 fd = SD_LISTEN_FDS_START+i;
437 if ((r = sd_is_socket(fd, AF_UNSPEC, SOCK_STREAM, 1)) < 0) {
438 log_error("Failed to determine file descriptor type: %s", strerror(-r));
443 log_error("Wrong file descriptor type.");
450 ev.data.ptr = UINT_TO_PTR(fd);
451 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
453 log_error("Failed to add server fd to epoll object: %s", strerror(errno));
458 if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
460 log_error("Failed to create log fd: %s", strerror(errno));
465 sa.un.sun_family = AF_UNIX;
466 strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
468 if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
470 log_error("Failed to connect log socket to /dev/log: %s", strerror(errno));
474 /* /dev/kmsg logging is strictly optional */
475 if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0)
476 log_warning("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %s", strerror(errno));
485 static int process_event(Server *s, struct epoll_event *ev) {
490 /* Yes, this is a bit ugly, we assume that that valid pointers
491 * are > SD_LISTEN_FDS_START+SERVER_FD_MAX. Which is certainly
492 * true on Linux (and probably most other OSes, too, since the
493 * first 4k usually are part of a seperate null pointer
494 * dereference page. */
496 if (PTR_TO_UINT(ev->data.ptr) >= SD_LISTEN_FDS_START &&
497 PTR_TO_UINT(ev->data.ptr) < SD_LISTEN_FDS_START+s->n_server_fd) {
499 if (ev->events != EPOLLIN) {
500 log_info("Got invalid event from epoll. (1)");
504 if ((r = stream_new(s, PTR_TO_UINT(ev->data.ptr))) < 0) {
505 log_info("Failed to accept new connection: %s", strerror(-r));
511 Stream *stream = ev->data.ptr;
513 ts = now(CLOCK_REALTIME);
515 if (!(ev->events & EPOLLIN)) {
516 log_info("Got invalid event from epoll. (2)");
521 if ((r = stream_process(stream, ts)) <= 0) {
524 log_info("Got error on stream: %s", strerror(-r));
534 int main(int argc, char *argv[]) {
538 if (getppid() != 1) {
539 log_error("This program should be invoked by init only.");
544 log_error("This program does not take arguments.");
548 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
549 log_parse_environment();
552 if ((n = sd_listen_fds(true)) < 0) {
553 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
557 if (n <= 0 || n > SERVER_FD_MAX) {
558 log_error("No or too many file descriptors passed.");
562 if (server_init(&server, (unsigned) n) < 0)
565 log_debug("systemd-logger running as pid %lu", (unsigned long) getpid());
569 "STATUS=Processing requests...");
572 struct epoll_event event;
575 if ((k = epoll_wait(server.epoll_fd,
577 server.n_streams <= 0 ? TIMEOUT : -1)) < 0) {
582 log_error("epoll_wait() failed: %s", strerror(errno));
589 if (process_event(&server, &event) < 0)
595 log_info("systemd-logger stopped as pid %lu", (unsigned long) getpid());
599 "STATUS=Shutting down...");
601 server_done(&server);