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 256
42 #define SERVER_FD_MAX 16
43 #define TIMEOUT ((int) (10*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 {
89 char buffer[LINE_MAX];
92 LIST_FIELDS(Stream, stream);
95 static int stream_log(Stream *s, char *p, usec_t ts) {
97 char header_priority[16], header_time[64], header_pid[16];
98 struct iovec iovec[5];
104 priority = s->priority;
108 p[1] >= '0' && p[1] <= '7' &&
111 /* Detected priority prefix */
112 priority = LOG_MAKEPRI(LOG_FAC(priority), (p[1] - '0'));
121 * The format glibc uses to talk to the syslog daemon is:
123 * <priority>time process[pid]: msg
125 * The format the kernel uses is:
129 * We extend the latter to include the process name and pid.
132 snprintf(header_priority, sizeof(header_priority), "<%i>",
133 s->target == STREAM_SYSLOG ? priority : LOG_PRI(priority));
134 char_array_0(header_priority);
136 if (s->target == STREAM_SYSLOG) {
140 t = (time_t) (ts / USEC_PER_SEC);
141 if (!(tm = localtime(&t)))
144 if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
148 snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) s->pid);
149 char_array_0(header_pid);
152 IOVEC_SET_STRING(iovec[0], header_priority);
154 if (s->target == STREAM_SYSLOG) {
155 struct msghdr msghdr;
157 struct cmsghdr cmsghdr;
158 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
163 control.cmsghdr.cmsg_level = SOL_SOCKET;
164 control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
165 control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
167 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
172 IOVEC_SET_STRING(iovec[1], header_time);
173 IOVEC_SET_STRING(iovec[2], s->process);
174 IOVEC_SET_STRING(iovec[3], header_pid);
175 IOVEC_SET_STRING(iovec[4], p);
177 /* When using syslog via SOCK_STREAM seperate the messages by NUL chars */
178 if (s->server->syslog_is_stream)
182 msghdr.msg_iov = iovec;
183 msghdr.msg_iovlen = ELEMENTSOF(iovec);
184 msghdr.msg_control = &control;
185 msghdr.msg_controllen = control.cmsghdr.cmsg_len;
190 if ((n = sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0)
193 if (!s->server->syslog_is_stream ||
194 (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
197 IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
200 } else if (s->target == STREAM_KMSG) {
201 IOVEC_SET_STRING(iovec[1], s->process);
202 IOVEC_SET_STRING(iovec[2], header_pid);
203 IOVEC_SET_STRING(iovec[3], p);
204 IOVEC_SET_STRING(iovec[4], (char*) "\n");
206 if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
209 assert_not_reached("Unknown log target");
214 static int stream_line(Stream *s, char *p, usec_t ts) {
225 if (streq(p, "syslog"))
226 s->target = STREAM_SYSLOG;
227 else if (streq(p, "kmsg")) {
229 if (s->server->kmsg_fd >= 0 && s->uid == 0)
230 s->target = STREAM_KMSG;
232 log_warning("/dev/kmsg logging not available.");
236 log_warning("Failed to parse log target line.");
239 s->state = STREAM_PRIORITY;
242 case STREAM_PRIORITY:
243 if ((r = safe_atoi(p, &s->priority)) < 0) {
244 log_warning("Failed to parse log priority line: %m");
248 if (s->priority < 0) {
249 log_warning("Log priority negative: %m");
253 s->state = STREAM_PROCESS;
257 if (!(s->process = strdup(p)))
260 s->state = STREAM_PREFIX;
265 if ((r = parse_boolean(p)) < 0)
269 s->state = STREAM_RUNNING;
273 return stream_log(s, p, ts);
276 assert_not_reached("Unknown stream state");
279 static int stream_scan(Stream *s, usec_t ts) {
287 remaining = s->length;
291 if (!(newline = memchr(p, '\n', remaining)))
296 if ((r = stream_line(s, p, ts)) >= 0) {
297 remaining -= newline-p+1;
303 memmove(s->buffer, p, remaining);
304 s->length = remaining;
310 static int stream_process(Stream *s, usec_t ts) {
315 if ((l = read(s->fd, s->buffer+s->length, LINE_MAX-s->length)) < 0) {
320 log_warning("Failed to read from stream: %m");
329 r = stream_scan(s, ts);
337 static void stream_free(Stream *s) {
341 assert(s->server->n_streams > 0);
342 s->server->n_streams--;
343 LIST_REMOVE(Stream, stream, s->server->streams, s);
349 epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL);
351 close_nointr_nofail(s->fd);
358 static int stream_new(Server *s, int server_fd) {
362 socklen_t len = sizeof(ucred);
363 struct epoll_event ev;
368 if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0)
371 if (s->n_streams >= STREAMS_MAX) {
372 log_warning("Too many connections, refusing connection.");
373 close_nointr_nofail(fd);
377 if (!socket_tcpwrap(fd, "systemd-logger")) {
378 close_nointr_nofail(fd);
382 if (!(stream = new0(Stream, 1))) {
383 close_nointr_nofail(fd);
389 if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
394 if (shutdown(fd, SHUT_WR) < 0) {
400 ev.data.ptr = stream;
402 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
407 stream->pid = ucred.pid;
408 stream->uid = ucred.uid;
409 stream->gid = ucred.gid;
412 LIST_PREPEND(Stream, stream, s->streams, stream);
422 static void server_done(Server *s) {
427 stream_free(s->streams);
429 for (i = 0; i < s->n_server_fd; i++)
430 close_nointr_nofail(SD_LISTEN_FDS_START+i);
432 if (s->syslog_fd >= 0)
433 close_nointr_nofail(s->syslog_fd);
435 if (s->epoll_fd >= 0)
436 close_nointr_nofail(s->epoll_fd);
439 close_nointr_nofail(s->kmsg_fd);
442 static int server_init(Server *s, unsigned n_sockets) {
447 struct sockaddr_un un;
451 assert(n_sockets > 0);
455 s->n_server_fd = n_sockets;
459 if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
461 log_error("Failed to create epoll object: %m");
465 for (i = 0; i < n_sockets; i++) {
466 struct epoll_event ev;
469 fd = SD_LISTEN_FDS_START+i;
471 if ((r = sd_is_socket(fd, AF_UNSPEC, SOCK_STREAM, 1)) < 0) {
472 log_error("Failed to determine file descriptor type: %s", strerror(-r));
477 log_error("Wrong file descriptor type.");
482 /* We use ev.data.ptr instead of ev.data.fd here,
483 * since on 64bit archs fd is 32bit while a pointer is
484 * 64bit. To make sure we can easily distuingish fd
485 * values and pointer values we want to make sure to
486 * write the full field unconditionally. */
490 ev.data.ptr = INT_TO_PTR(fd);
491 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
493 log_error("Failed to add server fd to epoll object: %m");
499 sa.un.sun_family = AF_UNIX;
500 strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
502 if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
504 log_error("Failed to create log fd: %m");
508 if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
509 close_nointr_nofail(s->syslog_fd);
511 if ((s->syslog_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0)) < 0) {
513 log_error("Failed to create log fd: %m");
517 if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
519 log_error("Failed to connect log socket to /dev/log: %m");
523 s->syslog_is_stream = true;
525 s->syslog_is_stream = false;
527 /* /dev/kmsg logging is strictly optional */
528 if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0)
529 log_warning("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %m");
538 static int process_event(Server *s, struct epoll_event *ev) {
543 /* Yes, this is a bit ugly, we assume that that valid pointers
544 * are > SD_LISTEN_FDS_START+SERVER_FD_MAX. Which is certainly
545 * true on Linux (and probably most other OSes, too, since the
546 * first 4k usually are part of a separate null pointer
547 * dereference page. */
549 if (PTR_TO_INT(ev->data.ptr) >= SD_LISTEN_FDS_START &&
550 PTR_TO_INT(ev->data.ptr) < SD_LISTEN_FDS_START+(int)s->n_server_fd) {
552 if (ev->events != EPOLLIN) {
553 log_info("Got invalid event from epoll. (1)");
557 if ((r = stream_new(s, PTR_TO_INT(ev->data.ptr))) < 0) {
558 log_info("Failed to accept new connection: %s", strerror(-r));
564 Stream *stream = ev->data.ptr;
566 ts = now(CLOCK_REALTIME);
568 if (!(ev->events & EPOLLIN)) {
569 log_info("Got invalid event from epoll. (2)");
574 if ((r = stream_process(stream, ts)) <= 0) {
577 log_info("Got error on stream: %s", strerror(-r));
587 int main(int argc, char *argv[]) {
589 int r = EXIT_FAILURE, n;
591 if (getppid() != 1) {
592 log_error("This program should be invoked by init only.");
597 log_error("This program does not take arguments.");
601 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
602 log_parse_environment();
605 if ((n = sd_listen_fds(true)) < 0) {
606 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
610 if (n <= 0 || n > SERVER_FD_MAX) {
611 log_error("No or too many file descriptors passed.");
615 if (server_init(&server, (unsigned) n) < 0)
618 log_debug("systemd-logger running as pid %lu", (unsigned long) getpid());
622 "STATUS=Processing requests...");
625 struct epoll_event event;
628 if ((k = epoll_wait(server.epoll_fd,
630 server.n_streams <= 0 ? TIMEOUT : -1)) < 0) {
635 log_error("epoll_wait() failed: %m");
642 if (process_event(&server, &event) < 0)
648 log_debug("systemd-logger stopped as pid %lu", (unsigned long) getpid());
652 "STATUS=Shutting down...");
654 server_done(&server);