1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
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>
39 #define STREAM_BUFFER 2048
40 #define STREAMS_MAX 256
41 #define SERVER_FD_START 3
42 #define SERVER_FD_MAX 16
43 #define TIMEOUT ((int) (10*MSEC_PER_SEC))
45 typedef struct Stream Stream;
47 typedef struct Server {
54 LIST_HEAD(Stream, streams);
58 typedef enum StreamState {
65 typedef enum LogTarget {
83 char buffer[STREAM_BUFFER];
86 LIST_FIELDS(Stream, stream);
89 #define IOVEC_SET_STRING(iovec, s) \
91 (iovec).iov_base = s; \
92 (iovec).iov_len = strlen(s); \
95 static int stream_log(Stream *s, char *p, usec_t timestamp) {
97 char header_priority[16], header_time[64], header_pid[16];
99 struct iovec iovec[5];
108 * The format glibc uses to talk to the syslog daemon is:
110 * <priority>time process[pid]: msg
112 * The format the kernel uses is:
116 * We extend the latter to include the process name and pid.
119 snprintf(header_priority, sizeof(header_priority), "<%i>",
120 s->target == LOG_TARGET_SYSLOG ? s->priority : LOG_PRI(s->priority));
121 char_array_0(header_priority);
123 if (s->target == LOG_TARGET_SYSLOG) {
127 t = (time_t) (timestamp / USEC_PER_SEC);
128 if (!(tm = localtime(&t)))
131 if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
135 snprintf(header_pid, sizeof(header_pid), "[%llu]: ", (unsigned long long) s->pid);
136 char_array_0(header_pid);
139 IOVEC_SET_STRING(iovec[0], header_priority);
141 if (s->target == LOG_TARGET_SYSLOG) {
142 IOVEC_SET_STRING(iovec[1], header_time);
143 IOVEC_SET_STRING(iovec[2], s->process);
144 IOVEC_SET_STRING(iovec[3], header_pid);
145 IOVEC_SET_STRING(iovec[4], p);
148 msghdr.msg_iov = iovec;
149 msghdr.msg_iovlen = ELEMENTSOF(iovec);
151 if (sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL) < 0)
154 } else if (s->target == LOG_TARGET_KMSG) {
155 IOVEC_SET_STRING(iovec[1], s->process);
156 IOVEC_SET_STRING(iovec[2], header_pid);
157 IOVEC_SET_STRING(iovec[3], p);
158 IOVEC_SET_STRING(iovec[4], (char*) "\n");
160 if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
163 assert_not_reached("Unknown log target");
168 static int stream_line(Stream *s, char *p, usec_t timestamp) {
178 case STREAM_LOG_TARGET:
179 if (streq(p, "syslog"))
180 s->target = LOG_TARGET_SYSLOG;
181 else if (streq(p, "kmsg")) {
183 if (s->server->kmsg_fd >= 0 && s->uid == 0)
184 s->target = LOG_TARGET_KMSG;
186 log_warning("/dev/kmsg logging not available.");
190 log_warning("Failed to parse log target line.");
193 s->state = STREAM_PRIORITY;
196 case STREAM_PRIORITY:
197 if ((r = safe_atoi(p, &s->priority)) < 0) {
198 log_warning("Failed to parse log priority line: %s", strerror(errno));
202 if (s->priority < 0) {
203 log_warning("Log priority negative: %s", strerror(errno));
207 s->state = STREAM_PROCESS;
211 if (!(s->process = strdup(p)))
214 s->state = STREAM_RUNNING;
218 return stream_log(s, p, timestamp);
221 assert_not_reached("Unknown stream state");
224 static int stream_scan(Stream *s, usec_t timestamp) {
232 remaining = s->length;
236 if (!(newline = memchr(p, '\n', remaining)))
241 if ((r = stream_line(s, p, timestamp)) >= 0) {
242 remaining -= newline-p+1;
248 memmove(s->buffer, p, remaining);
249 s->length = remaining;
255 static int stream_process(Stream *s, usec_t timestamp) {
260 if ((l = read(s->fd, s->buffer+s->length, STREAM_BUFFER-s->length)) < 0) {
265 log_warning("Failed to read from stream: %s", strerror(errno));
274 r = stream_scan(s, timestamp);
282 static void stream_free(Stream *s) {
286 assert(s->server->n_streams > 0);
287 s->server->n_streams--;
288 LIST_REMOVE(Stream, stream, s->server->streams, s);
294 epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL);
296 assert_se(close_nointr(s->fd) == 0);
303 static int stream_new(Server *s, int server_fd) {
307 socklen_t len = sizeof(ucred);
308 struct epoll_event ev;
313 if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0)
316 if (s->n_streams >= STREAMS_MAX) {
317 log_warning("Too many connections, refusing connection.");
318 assert_se(close_nointr(fd) == 0);
322 if (!(stream = new0(Stream, 1))) {
323 assert_se(close_nointr(fd) == 0);
329 if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
334 if (shutdown(fd, SHUT_WR) < 0) {
340 ev.data.ptr = stream;
342 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
347 stream->pid = ucred.pid;
348 stream->uid = ucred.uid;
351 LIST_PREPEND(Stream, stream, s->streams, stream);
361 static int verify_environment(unsigned *n_sockets) {
362 unsigned long long pid;
367 assert_se(n_sockets);
369 if (!(e = getenv("LISTEN_PID"))) {
370 log_error("Missing $LISTEN_PID environment variable.");
374 if ((r = safe_atollu(e, &pid)) < 0) {
375 log_error("Failed to parse $LISTEN_PID: %s", strerror(-r));
379 if (pid != (unsigned long long) getpid()) {
380 log_error("Socket nor for me.");
384 if (!(e = getenv("LISTEN_FDS"))) {
385 log_error("Missing $LISTEN_FDS environment variable.");
389 if ((r = safe_atou(e, &ns)) < 0) {
390 log_error("Failed to parse $LISTEN_FDS: %s", strerror(-r));
394 if (ns <= 0 || ns > SERVER_FD_MAX) {
395 log_error("Wrong number of file descriptors passed: %s", e);
404 static void server_done(Server *s) {
409 stream_free(s->streams);
411 for (i = 0; i < s->n_server_fd; i++)
412 assert_se(close_nointr(SERVER_FD_START+i) == 0);
414 if (s->syslog_fd >= 0)
415 assert_se(close_nointr(s->syslog_fd) == 0);
417 if (s->epoll_fd >= 0)
418 assert_se(close_nointr(s->epoll_fd) == 0);
421 assert_se(close_nointr(s->kmsg_fd) == 0);
424 static int server_init(Server *s, unsigned n_sockets) {
429 struct sockaddr_un un;
433 assert(n_sockets > 0);
437 s->n_server_fd = n_sockets;
441 if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
443 log_error("Failed to create epoll object: %s", strerror(errno));
447 for (i = 0; i < n_sockets; i++) {
448 struct epoll_event ev;
452 ev.data.ptr = UINT_TO_PTR(SERVER_FD_START+i);
453 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, SERVER_FD_START+i, &ev) < 0) {
455 log_error("Failed to add server fd to epoll object: %s", strerror(errno));
460 if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
462 log_error("Failed to create log fd: %s", strerror(errno));
467 sa.un.sun_family = AF_UNIX;
468 strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
470 if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
472 log_error("Failed to connect log socket to /dev/log: %s", strerror(errno));
476 /* /dev/kmsg logging is strictly optional */
477 if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0)
478 log_debug("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %s", strerror(errno));
487 static int process_event(Server *s, struct epoll_event *ev) {
492 /* Yes, this is a bit ugly, we assume that that valid pointers
493 * are > SERVER_FD_START+SERVER_FD_MAX. Which is certainly
494 * true on Linux (and probably most other OSes, too, since the
495 * first 4k usually are part of a seperate null pointer
496 * dereference page. */
498 if (PTR_TO_UINT(ev->data.ptr) >= SERVER_FD_START &&
499 PTR_TO_UINT(ev->data.ptr) < SERVER_FD_START+s->n_server_fd) {
501 if (ev->events != EPOLLIN) {
502 log_info("Got invalid event from epoll. (1)");
506 if ((r = stream_new(s, PTR_TO_UINT(ev->data.ptr))) < 0) {
507 log_info("Failed to accept new connection: %s", strerror(-r));
513 Stream *stream = ev->data.ptr;
515 timestamp = now(CLOCK_REALTIME);
517 if (!(ev->events & EPOLLIN)) {
518 log_info("Got invalid event from epoll. (3)");
523 if ((r = stream_process(stream, timestamp)) <= 0) {
526 log_info("Got error on stream: %s", strerror(-r));
536 int main(int argc, char *argv[]) {
541 log_info("systemd-logger running as pid %llu", (unsigned long long) getpid());
543 if (verify_environment(&n) < 0)
546 if (server_init(&server, n) < 0)
550 struct epoll_event event;
553 if ((k = epoll_wait(server.epoll_fd,
555 server.n_streams <= 0 ? TIMEOUT : -1)) < 0) {
560 log_error("epoll_wait() failed: %s", strerror(errno));
567 if ((r = process_event(&server, &event)) < 0)
573 server_done(&server);
575 log_info("systemd-logger stopped as pid %llu", (unsigned long long) getpid());