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Commit | Line | Data |
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b52429d4 LP |
1 | /*-*- Mode: C; c-basic-offset: 8 -*-*/ |
2 | ||
a7334b09 LP |
3 | /*** |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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/>. | |
20 | ***/ | |
21 | ||
b52429d4 LP |
22 | #include <sys/socket.h> |
23 | #include <sys/types.h> | |
24 | #include <assert.h> | |
25 | #include <time.h> | |
26 | #include <string.h> | |
27 | #include <stdio.h> | |
28 | #include <errno.h> | |
29 | #include <unistd.h> | |
30 | #include <sys/poll.h> | |
31 | #include <sys/epoll.h> | |
32 | #include <sys/un.h> | |
4901f972 | 33 | #include <fcntl.h> |
b52429d4 LP |
34 | |
35 | #include "util.h" | |
36 | #include "log.h" | |
37 | #include "list.h" | |
38 | ||
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)) | |
44 | ||
45 | typedef struct Stream Stream; | |
46 | ||
47 | typedef struct Server { | |
4901f972 LP |
48 | int syslog_fd; |
49 | int kmsg_fd; | |
b52429d4 LP |
50 | int epoll_fd; |
51 | ||
52 | unsigned n_server_fd; | |
53 | ||
54 | LIST_HEAD(Stream, streams); | |
55 | unsigned n_streams; | |
56 | } Server; | |
57 | ||
58 | typedef enum StreamState { | |
4901f972 | 59 | STREAM_LOG_TARGET, |
b52429d4 LP |
60 | STREAM_PRIORITY, |
61 | STREAM_PROCESS, | |
62 | STREAM_RUNNING | |
63 | } StreamState; | |
64 | ||
65 | struct Stream { | |
66 | Server *server; | |
67 | ||
68 | StreamState state; | |
69 | ||
70 | int fd; | |
4901f972 LP |
71 | |
72 | LogTarget target; | |
b52429d4 LP |
73 | int priority; |
74 | char *process; | |
4901f972 LP |
75 | pid_t pid; |
76 | uid_t uid; | |
b52429d4 LP |
77 | |
78 | char buffer[STREAM_BUFFER]; | |
79 | size_t length; | |
80 | ||
b52429d4 LP |
81 | LIST_FIELDS(Stream, stream); |
82 | }; | |
83 | ||
b52429d4 LP |
84 | static int stream_log(Stream *s, char *p, usec_t timestamp) { |
85 | ||
86 | char header_priority[16], header_time[64], header_pid[16]; | |
b52429d4 LP |
87 | struct iovec iovec[5]; |
88 | ||
89 | assert(s); | |
90 | assert(p); | |
91 | ||
92 | if (*p == 0) | |
93 | return 0; | |
94 | ||
95 | /* | |
4901f972 LP |
96 | * The format glibc uses to talk to the syslog daemon is: |
97 | * | |
98 | * <priority>time process[pid]: msg | |
b52429d4 | 99 | * |
4901f972 LP |
100 | * The format the kernel uses is: |
101 | * | |
102 | * <priority>msg\n | |
103 | * | |
104 | * We extend the latter to include the process name and pid. | |
b52429d4 LP |
105 | */ |
106 | ||
4901f972 LP |
107 | snprintf(header_priority, sizeof(header_priority), "<%i>", |
108 | s->target == LOG_TARGET_SYSLOG ? s->priority : LOG_PRI(s->priority)); | |
b52429d4 LP |
109 | char_array_0(header_priority); |
110 | ||
4901f972 LP |
111 | if (s->target == LOG_TARGET_SYSLOG) { |
112 | time_t t; | |
113 | struct tm *tm; | |
b52429d4 | 114 | |
4901f972 LP |
115 | t = (time_t) (timestamp / USEC_PER_SEC); |
116 | if (!(tm = localtime(&t))) | |
117 | return -EINVAL; | |
118 | ||
119 | if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0) | |
120 | return -EINVAL; | |
121 | } | |
b52429d4 LP |
122 | |
123 | snprintf(header_pid, sizeof(header_pid), "[%llu]: ", (unsigned long long) s->pid); | |
124 | char_array_0(header_pid); | |
125 | ||
126 | zero(iovec); | |
127 | IOVEC_SET_STRING(iovec[0], header_priority); | |
b52429d4 | 128 | |
4901f972 | 129 | if (s->target == LOG_TARGET_SYSLOG) { |
16801e90 LP |
130 | struct msghdr msghdr; |
131 | ||
4901f972 LP |
132 | IOVEC_SET_STRING(iovec[1], header_time); |
133 | IOVEC_SET_STRING(iovec[2], s->process); | |
134 | IOVEC_SET_STRING(iovec[3], header_pid); | |
135 | IOVEC_SET_STRING(iovec[4], p); | |
b52429d4 | 136 | |
4901f972 LP |
137 | zero(msghdr); |
138 | msghdr.msg_iov = iovec; | |
139 | msghdr.msg_iovlen = ELEMENTSOF(iovec); | |
140 | ||
141 | if (sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL) < 0) | |
142 | return -errno; | |
143 | ||
144 | } else if (s->target == LOG_TARGET_KMSG) { | |
145 | IOVEC_SET_STRING(iovec[1], s->process); | |
146 | IOVEC_SET_STRING(iovec[2], header_pid); | |
147 | IOVEC_SET_STRING(iovec[3], p); | |
47be870b | 148 | IOVEC_SET_STRING(iovec[4], (char*) "\n"); |
4901f972 LP |
149 | |
150 | if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0) | |
151 | return -errno; | |
152 | } else | |
153 | assert_not_reached("Unknown log target"); | |
b52429d4 LP |
154 | |
155 | return 0; | |
156 | } | |
157 | ||
158 | static int stream_line(Stream *s, char *p, usec_t timestamp) { | |
159 | int r; | |
160 | ||
161 | assert(s); | |
162 | assert(p); | |
163 | ||
164 | p = strstrip(p); | |
165 | ||
166 | switch (s->state) { | |
167 | ||
4901f972 LP |
168 | case STREAM_LOG_TARGET: |
169 | if (streq(p, "syslog")) | |
170 | s->target = LOG_TARGET_SYSLOG; | |
171 | else if (streq(p, "kmsg")) { | |
172 | ||
173 | if (s->server->kmsg_fd >= 0 && s->uid == 0) | |
174 | s->target = LOG_TARGET_KMSG; | |
175 | else { | |
176 | log_warning("/dev/kmsg logging not available."); | |
177 | return -EPERM; | |
178 | } | |
179 | } else { | |
180 | log_warning("Failed to parse log target line."); | |
181 | return -EBADMSG; | |
182 | } | |
183 | s->state = STREAM_PRIORITY; | |
184 | return 0; | |
185 | ||
b52429d4 | 186 | case STREAM_PRIORITY: |
4901f972 LP |
187 | if ((r = safe_atoi(p, &s->priority)) < 0) { |
188 | log_warning("Failed to parse log priority line: %s", strerror(errno)); | |
b52429d4 | 189 | return r; |
4901f972 | 190 | } |
b52429d4 | 191 | |
4901f972 LP |
192 | if (s->priority < 0) { |
193 | log_warning("Log priority negative: %s", strerror(errno)); | |
b52429d4 | 194 | return -ERANGE; |
4901f972 | 195 | } |
b52429d4 LP |
196 | |
197 | s->state = STREAM_PROCESS; | |
198 | return 0; | |
199 | ||
200 | case STREAM_PROCESS: | |
201 | if (!(s->process = strdup(p))) | |
202 | return -ENOMEM; | |
203 | ||
204 | s->state = STREAM_RUNNING; | |
205 | return 0; | |
206 | ||
207 | case STREAM_RUNNING: | |
208 | return stream_log(s, p, timestamp); | |
209 | } | |
210 | ||
211 | assert_not_reached("Unknown stream state"); | |
212 | } | |
213 | ||
214 | static int stream_scan(Stream *s, usec_t timestamp) { | |
215 | char *p; | |
216 | size_t remaining; | |
217 | int r = 0; | |
218 | ||
219 | assert(s); | |
220 | ||
221 | p = s->buffer; | |
222 | remaining = s->length; | |
223 | for (;;) { | |
224 | char *newline; | |
225 | ||
226 | if (!(newline = memchr(p, '\n', remaining))) | |
227 | break; | |
228 | ||
229 | *newline = 0; | |
230 | ||
231 | if ((r = stream_line(s, p, timestamp)) >= 0) { | |
232 | remaining -= newline-p+1; | |
233 | p = newline+1; | |
234 | } | |
235 | } | |
236 | ||
237 | if (p > s->buffer) { | |
238 | memmove(s->buffer, p, remaining); | |
239 | s->length = remaining; | |
240 | } | |
241 | ||
242 | return r; | |
243 | } | |
244 | ||
245 | static int stream_process(Stream *s, usec_t timestamp) { | |
246 | ssize_t l; | |
247 | int r; | |
248 | assert(s); | |
249 | ||
250 | if ((l = read(s->fd, s->buffer+s->length, STREAM_BUFFER-s->length)) < 0) { | |
251 | ||
252 | if (errno == EAGAIN) | |
253 | return 0; | |
254 | ||
255 | log_warning("Failed to read from stream: %s", strerror(errno)); | |
256 | return -1; | |
257 | } | |
258 | ||
259 | ||
260 | if (l == 0) | |
261 | return 0; | |
262 | ||
263 | s->length += l; | |
264 | r = stream_scan(s, timestamp); | |
265 | ||
266 | if (r < 0) | |
267 | return r; | |
268 | ||
269 | return 1; | |
270 | } | |
271 | ||
272 | static void stream_free(Stream *s) { | |
273 | assert(s); | |
274 | ||
275 | if (s->server) { | |
276 | assert(s->server->n_streams > 0); | |
277 | s->server->n_streams--; | |
278 | LIST_REMOVE(Stream, stream, s->server->streams, s); | |
279 | ||
280 | } | |
281 | ||
282 | if (s->fd >= 0) { | |
283 | if (s->server) | |
284 | epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL); | |
285 | ||
a16e1123 | 286 | close_nointr_nofail(s->fd); |
b52429d4 LP |
287 | } |
288 | ||
289 | free(s->process); | |
290 | free(s); | |
291 | } | |
292 | ||
293 | static int stream_new(Server *s, int server_fd) { | |
294 | Stream *stream; | |
295 | int fd; | |
296 | struct ucred ucred; | |
297 | socklen_t len = sizeof(ucred); | |
298 | struct epoll_event ev; | |
299 | int r; | |
300 | ||
301 | assert(s); | |
302 | ||
303 | if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0) | |
304 | return -errno; | |
305 | ||
306 | if (s->n_streams >= STREAMS_MAX) { | |
307 | log_warning("Too many connections, refusing connection."); | |
a16e1123 | 308 | close_nointr_nofail(fd); |
b52429d4 LP |
309 | return 0; |
310 | } | |
311 | ||
312 | if (!(stream = new0(Stream, 1))) { | |
a16e1123 | 313 | close_nointr_nofail(fd); |
b52429d4 LP |
314 | return -ENOMEM; |
315 | } | |
316 | ||
317 | stream->fd = fd; | |
318 | ||
319 | if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) { | |
320 | r = -errno; | |
321 | goto fail; | |
322 | } | |
323 | ||
324 | if (shutdown(fd, SHUT_WR) < 0) { | |
325 | r = -errno; | |
326 | goto fail; | |
327 | } | |
328 | ||
329 | zero(ev); | |
330 | ev.data.ptr = stream; | |
f94ea366 | 331 | ev.events = EPOLLIN; |
b52429d4 LP |
332 | if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) { |
333 | r = -errno; | |
334 | goto fail; | |
335 | } | |
336 | ||
337 | stream->pid = ucred.pid; | |
4901f972 | 338 | stream->uid = ucred.uid; |
b52429d4 LP |
339 | |
340 | stream->server = s; | |
341 | LIST_PREPEND(Stream, stream, s->streams, stream); | |
342 | s->n_streams ++; | |
343 | ||
344 | return 0; | |
345 | ||
346 | fail: | |
347 | stream_free(stream); | |
348 | return r; | |
349 | } | |
350 | ||
351 | static int verify_environment(unsigned *n_sockets) { | |
352 | unsigned long long pid; | |
353 | const char *e; | |
354 | int r; | |
355 | unsigned ns; | |
356 | ||
357 | assert_se(n_sockets); | |
358 | ||
359 | if (!(e = getenv("LISTEN_PID"))) { | |
360 | log_error("Missing $LISTEN_PID environment variable."); | |
361 | return -ENOENT; | |
362 | } | |
363 | ||
364 | if ((r = safe_atollu(e, &pid)) < 0) { | |
365 | log_error("Failed to parse $LISTEN_PID: %s", strerror(-r)); | |
366 | return r; | |
367 | } | |
368 | ||
369 | if (pid != (unsigned long long) getpid()) { | |
370 | log_error("Socket nor for me."); | |
371 | return -ENOENT; | |
372 | } | |
373 | ||
374 | if (!(e = getenv("LISTEN_FDS"))) { | |
375 | log_error("Missing $LISTEN_FDS environment variable."); | |
376 | return -ENOENT; | |
377 | } | |
378 | ||
379 | if ((r = safe_atou(e, &ns)) < 0) { | |
380 | log_error("Failed to parse $LISTEN_FDS: %s", strerror(-r)); | |
381 | return -E2BIG; | |
382 | } | |
383 | ||
384 | if (ns <= 0 || ns > SERVER_FD_MAX) { | |
385 | log_error("Wrong number of file descriptors passed: %s", e); | |
386 | return -E2BIG; | |
387 | } | |
388 | ||
389 | *n_sockets = ns; | |
390 | ||
391 | return 0; | |
392 | } | |
393 | ||
394 | static void server_done(Server *s) { | |
395 | unsigned i; | |
396 | assert(s); | |
397 | ||
398 | while (s->streams) | |
399 | stream_free(s->streams); | |
400 | ||
401 | for (i = 0; i < s->n_server_fd; i++) | |
a16e1123 | 402 | close_nointr_nofail(SERVER_FD_START+i); |
b52429d4 | 403 | |
4901f972 | 404 | if (s->syslog_fd >= 0) |
a16e1123 | 405 | close_nointr_nofail(s->syslog_fd); |
b52429d4 LP |
406 | |
407 | if (s->epoll_fd >= 0) | |
a16e1123 | 408 | close_nointr_nofail(s->epoll_fd); |
4901f972 LP |
409 | |
410 | if (s->kmsg_fd >= 0) | |
a16e1123 | 411 | close_nointr_nofail(s->kmsg_fd); |
b52429d4 LP |
412 | } |
413 | ||
414 | static int server_init(Server *s, unsigned n_sockets) { | |
415 | int r; | |
416 | unsigned i; | |
417 | union { | |
418 | struct sockaddr sa; | |
419 | struct sockaddr_un un; | |
420 | } sa; | |
421 | ||
422 | assert(s); | |
423 | assert(n_sockets > 0); | |
424 | ||
425 | zero(*s); | |
426 | ||
427 | s->n_server_fd = n_sockets; | |
4901f972 LP |
428 | s->syslog_fd = -1; |
429 | s->kmsg_fd = -1; | |
b52429d4 LP |
430 | |
431 | if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) { | |
432 | r = -errno; | |
433 | log_error("Failed to create epoll object: %s", strerror(errno)); | |
434 | goto fail; | |
435 | } | |
436 | ||
437 | for (i = 0; i < n_sockets; i++) { | |
438 | struct epoll_event ev; | |
439 | ||
440 | zero(ev); | |
f94ea366 | 441 | ev.events = EPOLLIN; |
b52429d4 LP |
442 | ev.data.ptr = UINT_TO_PTR(SERVER_FD_START+i); |
443 | if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, SERVER_FD_START+i, &ev) < 0) { | |
444 | r = -errno; | |
445 | log_error("Failed to add server fd to epoll object: %s", strerror(errno)); | |
446 | goto fail; | |
447 | } | |
448 | } | |
449 | ||
4901f972 | 450 | if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) { |
b52429d4 LP |
451 | r = -errno; |
452 | log_error("Failed to create log fd: %s", strerror(errno)); | |
453 | goto fail; | |
454 | } | |
455 | ||
456 | zero(sa); | |
457 | sa.un.sun_family = AF_UNIX; | |
458 | strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path)); | |
459 | ||
4901f972 | 460 | if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) { |
b52429d4 LP |
461 | r = -errno; |
462 | log_error("Failed to connect log socket to /dev/log: %s", strerror(errno)); | |
463 | goto fail; | |
464 | } | |
465 | ||
4901f972 LP |
466 | /* /dev/kmsg logging is strictly optional */ |
467 | if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) | |
468 | log_debug("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %s", strerror(errno)); | |
469 | ||
b52429d4 LP |
470 | return 0; |
471 | ||
472 | fail: | |
473 | server_done(s); | |
474 | return r; | |
475 | } | |
476 | ||
477 | static int process_event(Server *s, struct epoll_event *ev) { | |
478 | int r; | |
479 | ||
480 | assert(s); | |
481 | ||
482 | /* Yes, this is a bit ugly, we assume that that valid pointers | |
483 | * are > SERVER_FD_START+SERVER_FD_MAX. Which is certainly | |
484 | * true on Linux (and probably most other OSes, too, since the | |
485 | * first 4k usually are part of a seperate null pointer | |
486 | * dereference page. */ | |
487 | ||
488 | if (PTR_TO_UINT(ev->data.ptr) >= SERVER_FD_START && | |
489 | PTR_TO_UINT(ev->data.ptr) < SERVER_FD_START+s->n_server_fd) { | |
490 | ||
f94ea366 | 491 | if (ev->events != EPOLLIN) { |
b52429d4 LP |
492 | log_info("Got invalid event from epoll. (1)"); |
493 | return -EIO; | |
494 | } | |
495 | ||
496 | if ((r = stream_new(s, PTR_TO_UINT(ev->data.ptr))) < 0) { | |
497 | log_info("Failed to accept new connection: %s", strerror(-r)); | |
498 | return r; | |
499 | } | |
500 | ||
501 | } else { | |
502 | usec_t timestamp; | |
503 | Stream *stream = ev->data.ptr; | |
504 | ||
505 | timestamp = now(CLOCK_REALTIME); | |
506 | ||
f94ea366 | 507 | if (!(ev->events & EPOLLIN)) { |
b52429d4 LP |
508 | log_info("Got invalid event from epoll. (3)"); |
509 | stream_free(stream); | |
510 | return 0; | |
511 | } | |
512 | ||
513 | if ((r = stream_process(stream, timestamp)) <= 0) { | |
514 | ||
515 | if (r < 0) | |
516 | log_info("Got error on stream: %s", strerror(-r)); | |
517 | ||
518 | stream_free(stream); | |
519 | return 0; | |
520 | } | |
521 | } | |
522 | ||
523 | return 0; | |
524 | } | |
525 | ||
526 | int main(int argc, char *argv[]) { | |
527 | Server server; | |
528 | int r = 3; | |
529 | unsigned n; | |
530 | ||
531 | log_info("systemd-logger running as pid %llu", (unsigned long long) getpid()); | |
532 | ||
533 | if (verify_environment(&n) < 0) | |
534 | return 1; | |
535 | ||
536 | if (server_init(&server, n) < 0) | |
537 | return 2; | |
538 | ||
b52429d4 LP |
539 | for (;;) { |
540 | struct epoll_event event; | |
47be870b | 541 | int k; |
b52429d4 | 542 | |
47be870b | 543 | if ((k = epoll_wait(server.epoll_fd, |
b52429d4 LP |
544 | &event, 1, |
545 | server.n_streams <= 0 ? TIMEOUT : -1)) < 0) { | |
546 | ||
547 | if (errno == EINTR) | |
548 | continue; | |
549 | ||
550 | log_error("epoll_wait() failed: %s", strerror(errno)); | |
551 | goto fail; | |
552 | } | |
553 | ||
47be870b | 554 | if (k <= 0) |
b52429d4 LP |
555 | break; |
556 | ||
6ab3c207 | 557 | if ((k = process_event(&server, &event)) < 0) |
b52429d4 LP |
558 | goto fail; |
559 | } | |
560 | r = 0; | |
561 | ||
562 | fail: | |
563 | server_done(&server); | |
564 | ||
565 | log_info("systemd-logger stopped as pid %llu", (unsigned long long) getpid()); | |
566 | ||
567 | return r; | |
568 | } |