Line data Source code
1 : /* SPDX-License-Identifier: LGPL-2.1+ */
2 :
3 : #include <stddef.h>
4 : #include <sys/epoll.h>
5 : #include <unistd.h>
6 :
7 : #include "sd-messages.h"
8 :
9 : #include "alloc-util.h"
10 : #include "fd-util.h"
11 : #include "format-util.h"
12 : #include "io-util.h"
13 : #include "journald-console.h"
14 : #include "journald-kmsg.h"
15 : #include "journald-server.h"
16 : #include "journald-syslog.h"
17 : #include "journald-wall.h"
18 : #include "process-util.h"
19 : #include "selinux-util.h"
20 : #include "socket-util.h"
21 : #include "stdio-util.h"
22 : #include "string-util.h"
23 : #include "syslog-util.h"
24 :
25 : /* Warn once every 30s if we missed syslog message */
26 : #define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)
27 :
28 0 : static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned n_iovec, const struct ucred *ucred, const struct timeval *tv) {
29 :
30 : static const union sockaddr_union sa = {
31 : .un.sun_family = AF_UNIX,
32 : .un.sun_path = "/run/systemd/journal/syslog",
33 : };
34 0 : struct msghdr msghdr = {
35 : .msg_iov = (struct iovec *) iovec,
36 : .msg_iovlen = n_iovec,
37 : .msg_name = (struct sockaddr*) &sa.sa,
38 0 : .msg_namelen = SOCKADDR_UN_LEN(sa.un),
39 : };
40 : struct cmsghdr *cmsg;
41 : union {
42 : struct cmsghdr cmsghdr;
43 : uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
44 : } control;
45 :
46 0 : assert(s);
47 0 : assert(iovec);
48 0 : assert(n_iovec > 0);
49 :
50 0 : if (ucred) {
51 0 : zero(control);
52 0 : msghdr.msg_control = &control;
53 0 : msghdr.msg_controllen = sizeof(control);
54 :
55 0 : cmsg = CMSG_FIRSTHDR(&msghdr);
56 0 : cmsg->cmsg_level = SOL_SOCKET;
57 0 : cmsg->cmsg_type = SCM_CREDENTIALS;
58 0 : cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
59 0 : memcpy(CMSG_DATA(cmsg), ucred, sizeof(struct ucred));
60 0 : msghdr.msg_controllen = cmsg->cmsg_len;
61 : }
62 :
63 : /* Forward the syslog message we received via /dev/log to
64 : * /run/systemd/syslog. Unfortunately we currently can't set
65 : * the SO_TIMESTAMP auxiliary data, and hence we don't. */
66 :
67 0 : if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
68 0 : return;
69 :
70 : /* The socket is full? I guess the syslog implementation is
71 : * too slow, and we shouldn't wait for that... */
72 0 : if (errno == EAGAIN) {
73 0 : s->n_forward_syslog_missed++;
74 0 : return;
75 : }
76 :
77 0 : if (ucred && IN_SET(errno, ESRCH, EPERM)) {
78 : struct ucred u;
79 :
80 : /* Hmm, presumably the sender process vanished
81 : * by now, or we don't have CAP_SYS_AMDIN, so
82 : * let's fix it as good as we can, and retry */
83 :
84 0 : u = *ucred;
85 0 : u.pid = getpid_cached();
86 0 : memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred));
87 :
88 0 : if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
89 0 : return;
90 :
91 0 : if (errno == EAGAIN) {
92 0 : s->n_forward_syslog_missed++;
93 0 : return;
94 : }
95 : }
96 :
97 0 : if (errno != ENOENT)
98 0 : log_debug_errno(errno, "Failed to forward syslog message: %m");
99 : }
100 :
101 0 : static void forward_syslog_raw(Server *s, int priority, const char *buffer, size_t buffer_len, const struct ucred *ucred, const struct timeval *tv) {
102 : struct iovec iovec;
103 :
104 0 : assert(s);
105 0 : assert(buffer);
106 :
107 0 : if (LOG_PRI(priority) > s->max_level_syslog)
108 0 : return;
109 :
110 0 : iovec = IOVEC_MAKE((char *) buffer, buffer_len);
111 0 : forward_syslog_iovec(s, &iovec, 1, ucred, tv);
112 : }
113 :
114 0 : void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv) {
115 : struct iovec iovec[5];
116 : char header_priority[DECIMAL_STR_MAX(priority) + 3], header_time[64],
117 : header_pid[STRLEN("[]: ") + DECIMAL_STR_MAX(pid_t) + 1];
118 0 : int n = 0;
119 : time_t t;
120 : struct tm tm;
121 0 : _cleanup_free_ char *ident_buf = NULL;
122 :
123 0 : assert(s);
124 0 : assert(priority >= 0);
125 0 : assert(priority <= 999);
126 0 : assert(message);
127 :
128 0 : if (LOG_PRI(priority) > s->max_level_syslog)
129 0 : return;
130 :
131 : /* First: priority field */
132 0 : xsprintf(header_priority, "<%i>", priority);
133 0 : iovec[n++] = IOVEC_MAKE_STRING(header_priority);
134 :
135 : /* Second: timestamp */
136 0 : t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));
137 0 : if (!localtime_r(&t, &tm))
138 0 : return;
139 0 : if (strftime(header_time, sizeof(header_time), "%h %e %T ", &tm) <= 0)
140 0 : return;
141 0 : iovec[n++] = IOVEC_MAKE_STRING(header_time);
142 :
143 : /* Third: identifier and PID */
144 0 : if (ucred) {
145 0 : if (!identifier) {
146 0 : get_process_comm(ucred->pid, &ident_buf);
147 0 : identifier = ident_buf;
148 : }
149 :
150 0 : xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid);
151 :
152 0 : if (identifier)
153 0 : iovec[n++] = IOVEC_MAKE_STRING(identifier);
154 :
155 0 : iovec[n++] = IOVEC_MAKE_STRING(header_pid);
156 0 : } else if (identifier) {
157 0 : iovec[n++] = IOVEC_MAKE_STRING(identifier);
158 0 : iovec[n++] = IOVEC_MAKE_STRING(": ");
159 : }
160 :
161 : /* Fourth: message */
162 0 : iovec[n++] = IOVEC_MAKE_STRING(message);
163 :
164 0 : forward_syslog_iovec(s, iovec, n, ucred, tv);
165 : }
166 :
167 0 : int syslog_fixup_facility(int priority) {
168 :
169 0 : if ((priority & LOG_FACMASK) == 0)
170 0 : return (priority & LOG_PRIMASK) | LOG_USER;
171 :
172 0 : return priority;
173 : }
174 :
175 14 : size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid) {
176 : const char *p;
177 : char *t;
178 : size_t l, e;
179 :
180 14 : assert(buf);
181 14 : assert(identifier);
182 14 : assert(pid);
183 :
184 14 : p = *buf;
185 :
186 14 : p += strspn(p, WHITESPACE);
187 14 : l = strcspn(p, WHITESPACE);
188 :
189 14 : if (l <= 0 ||
190 12 : p[l-1] != ':')
191 5 : return 0;
192 :
193 9 : e = l;
194 9 : l--;
195 :
196 9 : if (l > 0 && p[l-1] == ']') {
197 1 : size_t k = l-1;
198 :
199 : for (;;) {
200 :
201 5 : if (p[k] == '[') {
202 1 : t = strndup(p+k+1, l-k-2);
203 1 : if (t)
204 1 : *pid = t;
205 :
206 1 : l = k;
207 1 : break;
208 : }
209 :
210 4 : if (k == 0)
211 0 : break;
212 :
213 4 : k--;
214 : }
215 : }
216 :
217 9 : t = strndup(p, l);
218 9 : if (t)
219 9 : *identifier = t;
220 :
221 : /* Single space is used as separator */
222 9 : if (p[e] != '\0' && strchr(WHITESPACE, p[e]))
223 5 : e++;
224 :
225 9 : l = (p - *buf) + e;
226 9 : *buf = p + e;
227 9 : return l;
228 : }
229 :
230 0 : static int syslog_skip_timestamp(const char **buf) {
231 : enum {
232 : LETTER,
233 : SPACE,
234 : NUMBER,
235 : SPACE_OR_NUMBER,
236 : COLON
237 0 : } sequence[] = {
238 : LETTER, LETTER, LETTER,
239 : SPACE,
240 : SPACE_OR_NUMBER, NUMBER,
241 : SPACE,
242 : SPACE_OR_NUMBER, NUMBER,
243 : COLON,
244 : SPACE_OR_NUMBER, NUMBER,
245 : COLON,
246 : SPACE_OR_NUMBER, NUMBER,
247 : SPACE
248 : };
249 :
250 : const char *p, *t;
251 : unsigned i;
252 :
253 0 : assert(buf);
254 0 : assert(*buf);
255 :
256 0 : for (i = 0, p = *buf; i < ELEMENTSOF(sequence); i++, p++) {
257 0 : if (!*p)
258 0 : return 0;
259 :
260 0 : switch (sequence[i]) {
261 :
262 0 : case SPACE:
263 0 : if (*p != ' ')
264 0 : return 0;
265 0 : break;
266 :
267 0 : case SPACE_OR_NUMBER:
268 0 : if (*p == ' ')
269 0 : break;
270 :
271 : _fallthrough_;
272 : case NUMBER:
273 0 : if (*p < '0' || *p > '9')
274 0 : return 0;
275 :
276 0 : break;
277 :
278 0 : case LETTER:
279 0 : if (!(*p >= 'A' && *p <= 'Z') &&
280 0 : !(*p >= 'a' && *p <= 'z'))
281 0 : return 0;
282 :
283 0 : break;
284 :
285 0 : case COLON:
286 0 : if (*p != ':')
287 0 : return 0;
288 0 : break;
289 :
290 : }
291 0 : }
292 :
293 0 : t = *buf;
294 0 : *buf = p;
295 0 : return p - t;
296 : }
297 :
298 0 : void server_process_syslog_message(
299 : Server *s,
300 : const char *buf,
301 : size_t raw_len,
302 : const struct ucred *ucred,
303 : const struct timeval *tv,
304 : const char *label,
305 : size_t label_len) {
306 :
307 : char *t, syslog_priority[sizeof("PRIORITY=") + DECIMAL_STR_MAX(int)],
308 : syslog_facility[sizeof("SYSLOG_FACILITY=") + DECIMAL_STR_MAX(int)];
309 : const char *msg, *syslog_ts, *a;
310 0 : _cleanup_free_ char *identifier = NULL, *pid = NULL,
311 0 : *dummy = NULL, *msg_msg = NULL, *msg_raw = NULL;
312 0 : int priority = LOG_USER | LOG_INFO, r;
313 0 : ClientContext *context = NULL;
314 : struct iovec *iovec;
315 0 : size_t n = 0, m, i, leading_ws, syslog_ts_len;
316 : bool store_raw;
317 :
318 0 : assert(s);
319 0 : assert(buf);
320 : /* The message cannot be empty. */
321 0 : assert(raw_len > 0);
322 : /* The buffer NUL-terminated and can be used a string. raw_len is the length
323 : * without the terminating NUL byte, the buffer is actually one bigger. */
324 0 : assert(buf[raw_len] == '\0');
325 :
326 0 : if (ucred && pid_is_valid(ucred->pid)) {
327 0 : r = client_context_get(s, ucred->pid, ucred, label, label_len, NULL, &context);
328 0 : if (r < 0)
329 0 : log_warning_errno(r, "Failed to retrieve credentials for PID " PID_FMT ", ignoring: %m", ucred->pid);
330 : }
331 :
332 : /* We are creating a copy of the message because we want to forward the original message
333 : verbatim to the legacy syslog implementation */
334 0 : for (i = raw_len; i > 0; i--)
335 0 : if (!strchr(WHITESPACE, buf[i-1]))
336 0 : break;
337 :
338 0 : leading_ws = strspn(buf, WHITESPACE);
339 :
340 0 : if (i == 0)
341 : /* The message contains only whitespaces */
342 0 : msg = buf + raw_len;
343 0 : else if (i == raw_len)
344 : /* Nice! No need to strip anything on the end, let's optimize this a bit */
345 0 : msg = buf + leading_ws;
346 : else {
347 0 : msg = dummy = new(char, i - leading_ws + 1);
348 0 : if (!dummy) {
349 0 : log_oom();
350 0 : return;
351 : }
352 :
353 0 : memcpy(dummy, buf + leading_ws, i - leading_ws);
354 0 : dummy[i - leading_ws] = 0;
355 : }
356 :
357 : /* We will add the SYSLOG_RAW= field when we stripped anything
358 : * _or_ if the input message contained NUL bytes. */
359 0 : store_raw = msg != buf || strlen(msg) != raw_len;
360 :
361 0 : syslog_parse_priority(&msg, &priority, true);
362 :
363 0 : if (!client_context_test_priority(context, priority))
364 0 : return;
365 :
366 0 : syslog_ts = msg;
367 0 : syslog_ts_len = syslog_skip_timestamp(&msg);
368 0 : if (syslog_ts_len == 0)
369 : /* We failed to parse the full timestamp, store the raw message too */
370 0 : store_raw = true;
371 :
372 0 : syslog_parse_identifier(&msg, &identifier, &pid);
373 :
374 0 : if (s->forward_to_syslog)
375 0 : forward_syslog_raw(s, priority, buf, raw_len, ucred, tv);
376 :
377 0 : if (s->forward_to_kmsg)
378 0 : server_forward_kmsg(s, priority, identifier, msg, ucred);
379 :
380 0 : if (s->forward_to_console)
381 0 : server_forward_console(s, priority, identifier, msg, ucred);
382 :
383 0 : if (s->forward_to_wall)
384 0 : server_forward_wall(s, priority, identifier, msg, ucred);
385 :
386 0 : m = N_IOVEC_META_FIELDS + 8 + client_context_extra_fields_n_iovec(context);
387 0 : iovec = newa(struct iovec, m);
388 :
389 0 : iovec[n++] = IOVEC_MAKE_STRING("_TRANSPORT=syslog");
390 :
391 0 : xsprintf(syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK);
392 0 : iovec[n++] = IOVEC_MAKE_STRING(syslog_priority);
393 :
394 0 : if (priority & LOG_FACMASK) {
395 0 : xsprintf(syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority));
396 0 : iovec[n++] = IOVEC_MAKE_STRING(syslog_facility);
397 : }
398 :
399 0 : if (identifier) {
400 0 : a = strjoina("SYSLOG_IDENTIFIER=", identifier);
401 0 : iovec[n++] = IOVEC_MAKE_STRING(a);
402 : }
403 :
404 0 : if (pid) {
405 0 : a = strjoina("SYSLOG_PID=", pid);
406 0 : iovec[n++] = IOVEC_MAKE_STRING(a);
407 : }
408 :
409 0 : if (syslog_ts_len > 0) {
410 0 : const size_t hlen = STRLEN("SYSLOG_TIMESTAMP=");
411 :
412 0 : t = newa(char, hlen + syslog_ts_len);
413 0 : memcpy(t, "SYSLOG_TIMESTAMP=", hlen);
414 0 : memcpy(t + hlen, syslog_ts, syslog_ts_len);
415 :
416 0 : iovec[n++] = IOVEC_MAKE(t, hlen + syslog_ts_len);
417 : }
418 :
419 0 : msg_msg = strjoin("MESSAGE=", msg);
420 0 : if (!msg_msg) {
421 0 : log_oom();
422 0 : return;
423 : }
424 0 : iovec[n++] = IOVEC_MAKE_STRING(msg_msg);
425 :
426 0 : if (store_raw) {
427 0 : const size_t hlen = STRLEN("SYSLOG_RAW=");
428 :
429 0 : msg_raw = new(char, hlen + raw_len);
430 0 : if (!msg_raw) {
431 0 : log_oom();
432 0 : return;
433 : }
434 :
435 0 : memcpy(msg_raw, "SYSLOG_RAW=", hlen);
436 0 : memcpy(msg_raw + hlen, buf, raw_len);
437 :
438 0 : iovec[n++] = IOVEC_MAKE(msg_raw, hlen + raw_len);
439 : }
440 :
441 0 : server_dispatch_message(s, iovec, n, m, context, tv, priority, 0);
442 : }
443 :
444 0 : int server_open_syslog_socket(Server *s) {
445 :
446 : static const union sockaddr_union sa = {
447 : .un.sun_family = AF_UNIX,
448 : .un.sun_path = "/run/systemd/journal/dev-log",
449 : };
450 : int r;
451 :
452 0 : assert(s);
453 :
454 0 : if (s->syslog_fd < 0) {
455 0 : s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
456 0 : if (s->syslog_fd < 0)
457 0 : return log_error_errno(errno, "socket() failed: %m");
458 :
459 0 : (void) sockaddr_un_unlink(&sa.un);
460 :
461 0 : r = bind(s->syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
462 0 : if (r < 0)
463 0 : return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
464 :
465 0 : (void) chmod(sa.un.sun_path, 0666);
466 : } else
467 0 : (void) fd_nonblock(s->syslog_fd, true);
468 :
469 0 : r = setsockopt_int(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, true);
470 0 : if (r < 0)
471 0 : return log_error_errno(r, "SO_PASSCRED failed: %m");
472 :
473 : #if HAVE_SELINUX
474 0 : if (mac_selinux_use()) {
475 0 : r = setsockopt_int(s->syslog_fd, SOL_SOCKET, SO_PASSSEC, true);
476 0 : if (r < 0)
477 0 : log_warning_errno(r, "SO_PASSSEC failed: %m");
478 : }
479 : #endif
480 :
481 0 : r = setsockopt_int(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, true);
482 0 : if (r < 0)
483 0 : return log_error_errno(r, "SO_TIMESTAMP failed: %m");
484 :
485 0 : r = sd_event_add_io(s->event, &s->syslog_event_source, s->syslog_fd, EPOLLIN, server_process_datagram, s);
486 0 : if (r < 0)
487 0 : return log_error_errno(r, "Failed to add syslog server fd to event loop: %m");
488 :
489 0 : r = sd_event_source_set_priority(s->syslog_event_source, SD_EVENT_PRIORITY_NORMAL+5);
490 0 : if (r < 0)
491 0 : return log_error_errno(r, "Failed to adjust syslog event source priority: %m");
492 :
493 0 : return 0;
494 : }
495 :
496 0 : void server_maybe_warn_forward_syslog_missed(Server *s) {
497 : usec_t n;
498 :
499 0 : assert(s);
500 :
501 0 : if (s->n_forward_syslog_missed <= 0)
502 0 : return;
503 :
504 0 : n = now(CLOCK_MONOTONIC);
505 0 : if (s->last_warn_forward_syslog_missed + WARN_FORWARD_SYSLOG_MISSED_USEC > n)
506 0 : return;
507 :
508 0 : server_driver_message(s, 0,
509 : "MESSAGE_ID=" SD_MESSAGE_FORWARD_SYSLOG_MISSED_STR,
510 : LOG_MESSAGE("Forwarding to syslog missed %u messages.",
511 : s->n_forward_syslog_missed),
512 : NULL);
513 :
514 0 : s->n_forward_syslog_missed = 0;
515 0 : s->last_warn_forward_syslog_missed = n;
516 : }
|
