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Commit | Line | Data |
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b52429d4 LP |
1 | /*-*- Mode: C; c-basic-offset: 8 -*-*/ |
2 | ||
3 | #include <sys/socket.h> | |
4 | #include <sys/types.h> | |
5 | #include <assert.h> | |
6 | #include <time.h> | |
7 | #include <string.h> | |
8 | #include <stdio.h> | |
9 | #include <errno.h> | |
10 | #include <unistd.h> | |
11 | #include <sys/poll.h> | |
12 | #include <sys/epoll.h> | |
13 | #include <sys/un.h> | |
4901f972 | 14 | #include <fcntl.h> |
b52429d4 LP |
15 | |
16 | #include "util.h" | |
17 | #include "log.h" | |
18 | #include "list.h" | |
19 | ||
20 | #define STREAM_BUFFER 2048 | |
21 | #define STREAMS_MAX 256 | |
22 | #define SERVER_FD_START 3 | |
23 | #define SERVER_FD_MAX 16 | |
24 | #define TIMEOUT ((int) (10*MSEC_PER_SEC)) | |
25 | ||
26 | typedef struct Stream Stream; | |
27 | ||
28 | typedef struct Server { | |
4901f972 LP |
29 | int syslog_fd; |
30 | int kmsg_fd; | |
b52429d4 LP |
31 | int epoll_fd; |
32 | ||
33 | unsigned n_server_fd; | |
34 | ||
35 | LIST_HEAD(Stream, streams); | |
36 | unsigned n_streams; | |
37 | } Server; | |
38 | ||
39 | typedef enum StreamState { | |
4901f972 | 40 | STREAM_LOG_TARGET, |
b52429d4 LP |
41 | STREAM_PRIORITY, |
42 | STREAM_PROCESS, | |
43 | STREAM_RUNNING | |
44 | } StreamState; | |
45 | ||
4901f972 LP |
46 | typedef enum LogTarget { |
47 | LOG_TARGET_SYSLOG, | |
48 | LOG_TARGET_KMSG | |
49 | } LogTarget; | |
50 | ||
b52429d4 LP |
51 | struct Stream { |
52 | Server *server; | |
53 | ||
54 | StreamState state; | |
55 | ||
56 | int fd; | |
4901f972 LP |
57 | |
58 | LogTarget target; | |
b52429d4 LP |
59 | int priority; |
60 | char *process; | |
4901f972 LP |
61 | pid_t pid; |
62 | uid_t uid; | |
b52429d4 LP |
63 | |
64 | char buffer[STREAM_BUFFER]; | |
65 | size_t length; | |
66 | ||
b52429d4 LP |
67 | LIST_FIELDS(Stream, stream); |
68 | }; | |
69 | ||
70 | #define IOVEC_SET_STRING(iovec, s) \ | |
71 | do { \ | |
72 | (iovec).iov_base = s; \ | |
73 | (iovec).iov_len = strlen(s); \ | |
74 | } while(false); | |
75 | ||
76 | static int stream_log(Stream *s, char *p, usec_t timestamp) { | |
77 | ||
78 | char header_priority[16], header_time[64], header_pid[16]; | |
b52429d4 LP |
79 | struct msghdr msghdr; |
80 | struct iovec iovec[5]; | |
81 | ||
82 | assert(s); | |
83 | assert(p); | |
84 | ||
85 | if (*p == 0) | |
86 | return 0; | |
87 | ||
88 | /* | |
4901f972 LP |
89 | * The format glibc uses to talk to the syslog daemon is: |
90 | * | |
91 | * <priority>time process[pid]: msg | |
b52429d4 | 92 | * |
4901f972 LP |
93 | * The format the kernel uses is: |
94 | * | |
95 | * <priority>msg\n | |
96 | * | |
97 | * We extend the latter to include the process name and pid. | |
b52429d4 LP |
98 | */ |
99 | ||
4901f972 LP |
100 | snprintf(header_priority, sizeof(header_priority), "<%i>", |
101 | s->target == LOG_TARGET_SYSLOG ? s->priority : LOG_PRI(s->priority)); | |
b52429d4 LP |
102 | char_array_0(header_priority); |
103 | ||
4901f972 LP |
104 | if (s->target == LOG_TARGET_SYSLOG) { |
105 | time_t t; | |
106 | struct tm *tm; | |
b52429d4 | 107 | |
4901f972 LP |
108 | t = (time_t) (timestamp / USEC_PER_SEC); |
109 | if (!(tm = localtime(&t))) | |
110 | return -EINVAL; | |
111 | ||
112 | if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0) | |
113 | return -EINVAL; | |
114 | } | |
b52429d4 LP |
115 | |
116 | snprintf(header_pid, sizeof(header_pid), "[%llu]: ", (unsigned long long) s->pid); | |
117 | char_array_0(header_pid); | |
118 | ||
119 | zero(iovec); | |
120 | IOVEC_SET_STRING(iovec[0], header_priority); | |
b52429d4 | 121 | |
4901f972 LP |
122 | if (s->target == LOG_TARGET_SYSLOG) { |
123 | IOVEC_SET_STRING(iovec[1], header_time); | |
124 | IOVEC_SET_STRING(iovec[2], s->process); | |
125 | IOVEC_SET_STRING(iovec[3], header_pid); | |
126 | IOVEC_SET_STRING(iovec[4], p); | |
b52429d4 | 127 | |
4901f972 LP |
128 | zero(msghdr); |
129 | msghdr.msg_iov = iovec; | |
130 | msghdr.msg_iovlen = ELEMENTSOF(iovec); | |
131 | ||
132 | if (sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL) < 0) | |
133 | return -errno; | |
134 | ||
135 | } else if (s->target == LOG_TARGET_KMSG) { | |
136 | IOVEC_SET_STRING(iovec[1], s->process); | |
137 | IOVEC_SET_STRING(iovec[2], header_pid); | |
138 | IOVEC_SET_STRING(iovec[3], p); | |
139 | IOVEC_SET_STRING(iovec[4], "\n"); | |
140 | ||
141 | if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0) | |
142 | return -errno; | |
143 | } else | |
144 | assert_not_reached("Unknown log target"); | |
b52429d4 LP |
145 | |
146 | return 0; | |
147 | } | |
148 | ||
149 | static int stream_line(Stream *s, char *p, usec_t timestamp) { | |
150 | int r; | |
151 | ||
152 | assert(s); | |
153 | assert(p); | |
154 | ||
155 | p = strstrip(p); | |
156 | ||
157 | switch (s->state) { | |
158 | ||
4901f972 LP |
159 | case STREAM_LOG_TARGET: |
160 | if (streq(p, "syslog")) | |
161 | s->target = LOG_TARGET_SYSLOG; | |
162 | else if (streq(p, "kmsg")) { | |
163 | ||
164 | if (s->server->kmsg_fd >= 0 && s->uid == 0) | |
165 | s->target = LOG_TARGET_KMSG; | |
166 | else { | |
167 | log_warning("/dev/kmsg logging not available."); | |
168 | return -EPERM; | |
169 | } | |
170 | } else { | |
171 | log_warning("Failed to parse log target line."); | |
172 | return -EBADMSG; | |
173 | } | |
174 | s->state = STREAM_PRIORITY; | |
175 | return 0; | |
176 | ||
b52429d4 | 177 | case STREAM_PRIORITY: |
4901f972 LP |
178 | if ((r = safe_atoi(p, &s->priority)) < 0) { |
179 | log_warning("Failed to parse log priority line: %s", strerror(errno)); | |
b52429d4 | 180 | return r; |
4901f972 | 181 | } |
b52429d4 | 182 | |
4901f972 LP |
183 | if (s->priority < 0) { |
184 | log_warning("Log priority negative: %s", strerror(errno)); | |
b52429d4 | 185 | return -ERANGE; |
4901f972 | 186 | } |
b52429d4 LP |
187 | |
188 | s->state = STREAM_PROCESS; | |
189 | return 0; | |
190 | ||
191 | case STREAM_PROCESS: | |
192 | if (!(s->process = strdup(p))) | |
193 | return -ENOMEM; | |
194 | ||
195 | s->state = STREAM_RUNNING; | |
196 | return 0; | |
197 | ||
198 | case STREAM_RUNNING: | |
199 | return stream_log(s, p, timestamp); | |
200 | } | |
201 | ||
202 | assert_not_reached("Unknown stream state"); | |
203 | } | |
204 | ||
205 | static int stream_scan(Stream *s, usec_t timestamp) { | |
206 | char *p; | |
207 | size_t remaining; | |
208 | int r = 0; | |
209 | ||
210 | assert(s); | |
211 | ||
212 | p = s->buffer; | |
213 | remaining = s->length; | |
214 | for (;;) { | |
215 | char *newline; | |
216 | ||
217 | if (!(newline = memchr(p, '\n', remaining))) | |
218 | break; | |
219 | ||
220 | *newline = 0; | |
221 | ||
222 | if ((r = stream_line(s, p, timestamp)) >= 0) { | |
223 | remaining -= newline-p+1; | |
224 | p = newline+1; | |
225 | } | |
226 | } | |
227 | ||
228 | if (p > s->buffer) { | |
229 | memmove(s->buffer, p, remaining); | |
230 | s->length = remaining; | |
231 | } | |
232 | ||
233 | return r; | |
234 | } | |
235 | ||
236 | static int stream_process(Stream *s, usec_t timestamp) { | |
237 | ssize_t l; | |
238 | int r; | |
239 | assert(s); | |
240 | ||
241 | if ((l = read(s->fd, s->buffer+s->length, STREAM_BUFFER-s->length)) < 0) { | |
242 | ||
243 | if (errno == EAGAIN) | |
244 | return 0; | |
245 | ||
246 | log_warning("Failed to read from stream: %s", strerror(errno)); | |
247 | return -1; | |
248 | } | |
249 | ||
250 | ||
251 | if (l == 0) | |
252 | return 0; | |
253 | ||
254 | s->length += l; | |
255 | r = stream_scan(s, timestamp); | |
256 | ||
257 | if (r < 0) | |
258 | return r; | |
259 | ||
260 | return 1; | |
261 | } | |
262 | ||
263 | static void stream_free(Stream *s) { | |
264 | assert(s); | |
265 | ||
266 | if (s->server) { | |
267 | assert(s->server->n_streams > 0); | |
268 | s->server->n_streams--; | |
269 | LIST_REMOVE(Stream, stream, s->server->streams, s); | |
270 | ||
271 | } | |
272 | ||
273 | if (s->fd >= 0) { | |
274 | if (s->server) | |
275 | epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL); | |
276 | ||
277 | assert_se(close_nointr(s->fd) == 0); | |
278 | } | |
279 | ||
280 | free(s->process); | |
281 | free(s); | |
282 | } | |
283 | ||
284 | static int stream_new(Server *s, int server_fd) { | |
285 | Stream *stream; | |
286 | int fd; | |
287 | struct ucred ucred; | |
288 | socklen_t len = sizeof(ucred); | |
289 | struct epoll_event ev; | |
290 | int r; | |
291 | ||
292 | assert(s); | |
293 | ||
294 | if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0) | |
295 | return -errno; | |
296 | ||
297 | if (s->n_streams >= STREAMS_MAX) { | |
298 | log_warning("Too many connections, refusing connection."); | |
299 | assert_se(close_nointr(fd) == 0); | |
300 | return 0; | |
301 | } | |
302 | ||
303 | if (!(stream = new0(Stream, 1))) { | |
304 | assert_se(close_nointr(fd) == 0); | |
305 | return -ENOMEM; | |
306 | } | |
307 | ||
308 | stream->fd = fd; | |
309 | ||
310 | if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) { | |
311 | r = -errno; | |
312 | goto fail; | |
313 | } | |
314 | ||
315 | if (shutdown(fd, SHUT_WR) < 0) { | |
316 | r = -errno; | |
317 | goto fail; | |
318 | } | |
319 | ||
320 | zero(ev); | |
321 | ev.data.ptr = stream; | |
f94ea366 | 322 | ev.events = EPOLLIN; |
b52429d4 LP |
323 | if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) { |
324 | r = -errno; | |
325 | goto fail; | |
326 | } | |
327 | ||
328 | stream->pid = ucred.pid; | |
4901f972 | 329 | stream->uid = ucred.uid; |
b52429d4 LP |
330 | |
331 | stream->server = s; | |
332 | LIST_PREPEND(Stream, stream, s->streams, stream); | |
333 | s->n_streams ++; | |
334 | ||
335 | return 0; | |
336 | ||
337 | fail: | |
338 | stream_free(stream); | |
339 | return r; | |
340 | } | |
341 | ||
342 | static int verify_environment(unsigned *n_sockets) { | |
343 | unsigned long long pid; | |
344 | const char *e; | |
345 | int r; | |
346 | unsigned ns; | |
347 | ||
348 | assert_se(n_sockets); | |
349 | ||
350 | if (!(e = getenv("LISTEN_PID"))) { | |
351 | log_error("Missing $LISTEN_PID environment variable."); | |
352 | return -ENOENT; | |
353 | } | |
354 | ||
355 | if ((r = safe_atollu(e, &pid)) < 0) { | |
356 | log_error("Failed to parse $LISTEN_PID: %s", strerror(-r)); | |
357 | return r; | |
358 | } | |
359 | ||
360 | if (pid != (unsigned long long) getpid()) { | |
361 | log_error("Socket nor for me."); | |
362 | return -ENOENT; | |
363 | } | |
364 | ||
365 | if (!(e = getenv("LISTEN_FDS"))) { | |
366 | log_error("Missing $LISTEN_FDS environment variable."); | |
367 | return -ENOENT; | |
368 | } | |
369 | ||
370 | if ((r = safe_atou(e, &ns)) < 0) { | |
371 | log_error("Failed to parse $LISTEN_FDS: %s", strerror(-r)); | |
372 | return -E2BIG; | |
373 | } | |
374 | ||
375 | if (ns <= 0 || ns > SERVER_FD_MAX) { | |
376 | log_error("Wrong number of file descriptors passed: %s", e); | |
377 | return -E2BIG; | |
378 | } | |
379 | ||
380 | *n_sockets = ns; | |
381 | ||
382 | return 0; | |
383 | } | |
384 | ||
385 | static void server_done(Server *s) { | |
386 | unsigned i; | |
387 | assert(s); | |
388 | ||
389 | while (s->streams) | |
390 | stream_free(s->streams); | |
391 | ||
392 | for (i = 0; i < s->n_server_fd; i++) | |
393 | assert_se(close_nointr(SERVER_FD_START+i) == 0); | |
394 | ||
4901f972 LP |
395 | if (s->syslog_fd >= 0) |
396 | assert_se(close_nointr(s->syslog_fd) == 0); | |
b52429d4 LP |
397 | |
398 | if (s->epoll_fd >= 0) | |
399 | assert_se(close_nointr(s->epoll_fd) == 0); | |
4901f972 LP |
400 | |
401 | if (s->kmsg_fd >= 0) | |
402 | assert_se(close_nointr(s->kmsg_fd) == 0); | |
b52429d4 LP |
403 | } |
404 | ||
405 | static int server_init(Server *s, unsigned n_sockets) { | |
406 | int r; | |
407 | unsigned i; | |
408 | union { | |
409 | struct sockaddr sa; | |
410 | struct sockaddr_un un; | |
411 | } sa; | |
412 | ||
413 | assert(s); | |
414 | assert(n_sockets > 0); | |
415 | ||
416 | zero(*s); | |
417 | ||
418 | s->n_server_fd = n_sockets; | |
4901f972 LP |
419 | s->syslog_fd = -1; |
420 | s->kmsg_fd = -1; | |
b52429d4 LP |
421 | |
422 | if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) { | |
423 | r = -errno; | |
424 | log_error("Failed to create epoll object: %s", strerror(errno)); | |
425 | goto fail; | |
426 | } | |
427 | ||
428 | for (i = 0; i < n_sockets; i++) { | |
429 | struct epoll_event ev; | |
430 | ||
431 | zero(ev); | |
f94ea366 | 432 | ev.events = EPOLLIN; |
b52429d4 LP |
433 | ev.data.ptr = UINT_TO_PTR(SERVER_FD_START+i); |
434 | if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, SERVER_FD_START+i, &ev) < 0) { | |
435 | r = -errno; | |
436 | log_error("Failed to add server fd to epoll object: %s", strerror(errno)); | |
437 | goto fail; | |
438 | } | |
439 | } | |
440 | ||
4901f972 | 441 | if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) { |
b52429d4 LP |
442 | r = -errno; |
443 | log_error("Failed to create log fd: %s", strerror(errno)); | |
444 | goto fail; | |
445 | } | |
446 | ||
447 | zero(sa); | |
448 | sa.un.sun_family = AF_UNIX; | |
449 | strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path)); | |
450 | ||
4901f972 | 451 | if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) { |
b52429d4 LP |
452 | r = -errno; |
453 | log_error("Failed to connect log socket to /dev/log: %s", strerror(errno)); | |
454 | goto fail; | |
455 | } | |
456 | ||
4901f972 LP |
457 | /* /dev/kmsg logging is strictly optional */ |
458 | if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) | |
459 | log_debug("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %s", strerror(errno)); | |
460 | ||
b52429d4 LP |
461 | return 0; |
462 | ||
463 | fail: | |
464 | server_done(s); | |
465 | return r; | |
466 | } | |
467 | ||
468 | static int process_event(Server *s, struct epoll_event *ev) { | |
469 | int r; | |
470 | ||
471 | assert(s); | |
472 | ||
473 | /* Yes, this is a bit ugly, we assume that that valid pointers | |
474 | * are > SERVER_FD_START+SERVER_FD_MAX. Which is certainly | |
475 | * true on Linux (and probably most other OSes, too, since the | |
476 | * first 4k usually are part of a seperate null pointer | |
477 | * dereference page. */ | |
478 | ||
479 | if (PTR_TO_UINT(ev->data.ptr) >= SERVER_FD_START && | |
480 | PTR_TO_UINT(ev->data.ptr) < SERVER_FD_START+s->n_server_fd) { | |
481 | ||
f94ea366 | 482 | if (ev->events != EPOLLIN) { |
b52429d4 LP |
483 | log_info("Got invalid event from epoll. (1)"); |
484 | return -EIO; | |
485 | } | |
486 | ||
487 | if ((r = stream_new(s, PTR_TO_UINT(ev->data.ptr))) < 0) { | |
488 | log_info("Failed to accept new connection: %s", strerror(-r)); | |
489 | return r; | |
490 | } | |
491 | ||
492 | } else { | |
493 | usec_t timestamp; | |
494 | Stream *stream = ev->data.ptr; | |
495 | ||
496 | timestamp = now(CLOCK_REALTIME); | |
497 | ||
f94ea366 | 498 | if (!(ev->events & EPOLLIN)) { |
b52429d4 LP |
499 | log_info("Got invalid event from epoll. (3)"); |
500 | stream_free(stream); | |
501 | return 0; | |
502 | } | |
503 | ||
504 | if ((r = stream_process(stream, timestamp)) <= 0) { | |
505 | ||
506 | if (r < 0) | |
507 | log_info("Got error on stream: %s", strerror(-r)); | |
508 | ||
509 | stream_free(stream); | |
510 | return 0; | |
511 | } | |
512 | } | |
513 | ||
514 | return 0; | |
515 | } | |
516 | ||
517 | int main(int argc, char *argv[]) { | |
518 | Server server; | |
519 | int r = 3; | |
520 | unsigned n; | |
521 | ||
522 | log_info("systemd-logger running as pid %llu", (unsigned long long) getpid()); | |
523 | ||
524 | if (verify_environment(&n) < 0) | |
525 | return 1; | |
526 | ||
527 | if (server_init(&server, n) < 0) | |
528 | return 2; | |
529 | ||
b52429d4 LP |
530 | for (;;) { |
531 | struct epoll_event event; | |
532 | int n; | |
533 | ||
534 | if ((n = epoll_wait(server.epoll_fd, | |
535 | &event, 1, | |
536 | server.n_streams <= 0 ? TIMEOUT : -1)) < 0) { | |
537 | ||
538 | if (errno == EINTR) | |
539 | continue; | |
540 | ||
541 | log_error("epoll_wait() failed: %s", strerror(errno)); | |
542 | goto fail; | |
543 | } | |
544 | ||
545 | if (n <= 0) | |
546 | break; | |
547 | ||
548 | if ((r = process_event(&server, &event)) < 0) | |
549 | goto fail; | |
550 | } | |
551 | r = 0; | |
552 | ||
553 | fail: | |
554 | server_done(&server); | |
555 | ||
556 | log_info("systemd-logger stopped as pid %llu", (unsigned long long) getpid()); | |
557 | ||
558 | return r; | |
559 | } |