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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
ef63833d LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2011 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
ef63833d | 21 | #include <fcntl.h> |
4f5dd394 | 22 | #include <sys/epoll.h> |
ef63833d | 23 | #include <sys/mman.h> |
4871690d | 24 | #include <sys/socket.h> |
4f5dd394 | 25 | #include <unistd.h> |
ef63833d | 26 | |
b4bbcaa9 | 27 | #include "libudev.h" |
4f5dd394 | 28 | #include "sd-messages.h" |
ef63833d | 29 | |
e6a7ec4b | 30 | #include "alloc-util.h" |
4f5dd394 | 31 | #include "escape.h" |
3ffd4af2 | 32 | #include "fd-util.h" |
f97b34a6 | 33 | #include "format-util.h" |
afc5dbf3 | 34 | #include "io-util.h" |
3ffd4af2 | 35 | #include "journald-kmsg.h" |
d025f1e4 | 36 | #include "journald-server.h" |
35e2e347 | 37 | #include "journald-syslog.h" |
6bedfcbb | 38 | #include "parse-util.h" |
0b452006 | 39 | #include "process-util.h" |
15a5e950 | 40 | #include "stdio-util.h" |
07630cea | 41 | #include "string-util.h" |
ef63833d LP |
42 | |
43 | void server_forward_kmsg( | |
44 | Server *s, | |
45 | int priority, | |
46 | const char *identifier, | |
47 | const char *message, | |
3b3154df | 48 | const struct ucred *ucred) { |
ef63833d | 49 | |
e6a7ec4b | 50 | _cleanup_free_ char *ident_buf = NULL; |
ef63833d | 51 | struct iovec iovec[5]; |
3b97fcbd | 52 | char header_priority[DECIMAL_STR_MAX(priority) + 3], |
fbd0b64f | 53 | header_pid[STRLEN("[]: ") + DECIMAL_STR_MAX(pid_t) + 1]; |
ef63833d | 54 | int n = 0; |
ef63833d LP |
55 | |
56 | assert(s); | |
57 | assert(priority >= 0); | |
58 | assert(priority <= 999); | |
59 | assert(message); | |
60 | ||
61 | if (_unlikely_(LOG_PRI(priority) > s->max_level_kmsg)) | |
62 | return; | |
63 | ||
64 | if (_unlikely_(s->dev_kmsg_fd < 0)) | |
65 | return; | |
66 | ||
67 | /* Never allow messages with kernel facility to be written to | |
68 | * kmsg, regardless where the data comes from. */ | |
69 | priority = syslog_fixup_facility(priority); | |
70 | ||
71 | /* First: priority field */ | |
5ffa8c81 | 72 | xsprintf(header_priority, "<%i>", priority); |
e6a7ec4b | 73 | iovec[n++] = IOVEC_MAKE_STRING(header_priority); |
ef63833d LP |
74 | |
75 | /* Second: identifier and PID */ | |
76 | if (ucred) { | |
77 | if (!identifier) { | |
78 | get_process_comm(ucred->pid, &ident_buf); | |
79 | identifier = ident_buf; | |
80 | } | |
81 | ||
5ffa8c81 | 82 | xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid); |
ef63833d LP |
83 | |
84 | if (identifier) | |
e6a7ec4b | 85 | iovec[n++] = IOVEC_MAKE_STRING(identifier); |
ef63833d | 86 | |
e6a7ec4b | 87 | iovec[n++] = IOVEC_MAKE_STRING(header_pid); |
ef63833d | 88 | } else if (identifier) { |
e6a7ec4b LP |
89 | iovec[n++] = IOVEC_MAKE_STRING(identifier); |
90 | iovec[n++] = IOVEC_MAKE_STRING(": "); | |
ef63833d LP |
91 | } |
92 | ||
93 | /* Fourth: message */ | |
e6a7ec4b LP |
94 | iovec[n++] = IOVEC_MAKE_STRING(message); |
95 | iovec[n++] = IOVEC_MAKE_STRING("\n"); | |
ef63833d LP |
96 | |
97 | if (writev(s->dev_kmsg_fd, iovec, n) < 0) | |
56f64d95 | 98 | log_debug_errno(errno, "Failed to write to /dev/kmsg for logging: %m"); |
ef63833d LP |
99 | } |
100 | ||
fe167298 AJ |
101 | static bool is_us(const char *identifier, const char *pid) { |
102 | pid_t pid_num; | |
ef63833d | 103 | |
fe167298 AJ |
104 | if (!identifier || !pid) |
105 | return false; | |
ef63833d | 106 | |
fe167298 | 107 | if (parse_pid(pid, &pid_num) < 0) |
ef63833d LP |
108 | return false; |
109 | ||
fe167298 AJ |
110 | return pid_num == getpid_cached() && |
111 | streq(identifier, program_invocation_short_name); | |
ef63833d LP |
112 | } |
113 | ||
3b3154df | 114 | static void dev_kmsg_record(Server *s, const char *p, size_t l) { |
d3070fbd | 115 | |
e6a7ec4b | 116 | _cleanup_free_ char *message = NULL, *syslog_priority = NULL, *syslog_pid = NULL, *syslog_facility = NULL, *syslog_identifier = NULL, *source_time = NULL, *identifier = NULL, *pid = NULL; |
d3070fbd LP |
117 | struct iovec iovec[N_IOVEC_META_FIELDS + 7 + N_IOVEC_KERNEL_FIELDS + 2 + N_IOVEC_UDEV_FIELDS]; |
118 | char *kernel_device = NULL; | |
e9f600f2 | 119 | unsigned long long usec; |
d3070fbd LP |
120 | size_t n = 0, z = 0, j; |
121 | int priority, r; | |
e6a7ec4b | 122 | char *e, *f, *k; |
ef63833d LP |
123 | uint64_t serial; |
124 | size_t pl; | |
ef63833d LP |
125 | |
126 | assert(s); | |
127 | assert(p); | |
128 | ||
129 | if (l <= 0) | |
130 | return; | |
131 | ||
132 | e = memchr(p, ',', l); | |
133 | if (!e) | |
134 | return; | |
135 | *e = 0; | |
136 | ||
137 | r = safe_atoi(p, &priority); | |
138 | if (r < 0 || priority < 0 || priority > 999) | |
139 | return; | |
140 | ||
b3600346 | 141 | if (s->forward_to_kmsg && LOG_FAC(priority) != LOG_KERN) |
ef63833d LP |
142 | return; |
143 | ||
144 | l -= (e - p) + 1; | |
145 | p = e + 1; | |
146 | e = memchr(p, ',', l); | |
147 | if (!e) | |
148 | return; | |
149 | *e = 0; | |
150 | ||
151 | r = safe_atou64(p, &serial); | |
152 | if (r < 0) | |
153 | return; | |
154 | ||
155 | if (s->kernel_seqnum) { | |
156 | /* We already read this one? */ | |
157 | if (serial < *s->kernel_seqnum) | |
158 | return; | |
159 | ||
160 | /* Did we lose any? */ | |
161 | if (serial > *s->kernel_seqnum) | |
13181942 | 162 | server_driver_message(s, 0, |
2b044526 | 163 | "MESSAGE_ID=" SD_MESSAGE_JOURNAL_MISSED_STR, |
8a03c9ef ZJS |
164 | LOG_MESSAGE("Missed %"PRIu64" kernel messages", |
165 | serial - *s->kernel_seqnum), | |
166 | NULL); | |
ef63833d LP |
167 | |
168 | /* Make sure we never read this one again. Note that | |
169 | * we always store the next message serial we expect | |
170 | * here, simply because this makes handling the first | |
171 | * message with serial 0 easy. */ | |
172 | *s->kernel_seqnum = serial + 1; | |
173 | } | |
174 | ||
175 | l -= (e - p) + 1; | |
176 | p = e + 1; | |
177 | f = memchr(p, ';', l); | |
178 | if (!f) | |
179 | return; | |
180 | /* Kernel 3.6 has the flags field, kernel 3.5 lacks that */ | |
181 | e = memchr(p, ',', l); | |
182 | if (!e || f < e) | |
183 | e = f; | |
184 | *e = 0; | |
185 | ||
e9f600f2 | 186 | r = safe_atollu(p, &usec); |
ef63833d LP |
187 | if (r < 0) |
188 | return; | |
189 | ||
190 | l -= (f - p) + 1; | |
191 | p = f + 1; | |
192 | e = memchr(p, '\n', l); | |
193 | if (!e) | |
194 | return; | |
195 | *e = 0; | |
196 | ||
197 | pl = e - p; | |
198 | l -= (e - p) + 1; | |
199 | k = e + 1; | |
200 | ||
201 | for (j = 0; l > 0 && j < N_IOVEC_KERNEL_FIELDS; j++) { | |
202 | char *m; | |
dc61b7e4 | 203 | /* Metadata fields attached */ |
ef63833d LP |
204 | |
205 | if (*k != ' ') | |
206 | break; | |
207 | ||
313cefa1 | 208 | k++, l--; |
ef63833d LP |
209 | |
210 | e = memchr(k, '\n', l); | |
211 | if (!e) | |
212 | return; | |
213 | ||
214 | *e = 0; | |
215 | ||
527b7a42 | 216 | if (cunescape_length_with_prefix(k, e - k, "_KERNEL_", UNESCAPE_RELAX, &m) < 0) |
ef63833d LP |
217 | break; |
218 | ||
219 | if (startswith(m, "_KERNEL_DEVICE=")) | |
220 | kernel_device = m + 15; | |
221 | ||
e6a7ec4b | 222 | iovec[n++] = IOVEC_MAKE_STRING(m); |
ef63833d LP |
223 | z++; |
224 | ||
225 | l -= (e - k) + 1; | |
226 | k = e + 1; | |
227 | } | |
228 | ||
229 | if (kernel_device) { | |
230 | struct udev_device *ud; | |
231 | ||
232 | ud = udev_device_new_from_device_id(s->udev, kernel_device); | |
233 | if (ud) { | |
234 | const char *g; | |
235 | struct udev_list_entry *ll; | |
236 | char *b; | |
237 | ||
238 | g = udev_device_get_devnode(ud); | |
239 | if (g) { | |
240 | b = strappend("_UDEV_DEVNODE=", g); | |
241 | if (b) { | |
e6a7ec4b | 242 | iovec[n++] = IOVEC_MAKE_STRING(b); |
ef63833d LP |
243 | z++; |
244 | } | |
245 | } | |
246 | ||
247 | g = udev_device_get_sysname(ud); | |
248 | if (g) { | |
249 | b = strappend("_UDEV_SYSNAME=", g); | |
250 | if (b) { | |
e6a7ec4b | 251 | iovec[n++] = IOVEC_MAKE_STRING(b); |
ef63833d LP |
252 | z++; |
253 | } | |
254 | } | |
255 | ||
256 | j = 0; | |
257 | ll = udev_device_get_devlinks_list_entry(ud); | |
258 | udev_list_entry_foreach(ll, ll) { | |
259 | ||
260 | if (j > N_IOVEC_UDEV_FIELDS) | |
261 | break; | |
262 | ||
263 | g = udev_list_entry_get_name(ll); | |
ef63833d | 264 | if (g) { |
4b94f3b8 ZJS |
265 | b = strappend("_UDEV_DEVLINK=", g); |
266 | if (b) { | |
e6a7ec4b | 267 | iovec[n++] = IOVEC_MAKE_STRING(b); |
4b94f3b8 ZJS |
268 | z++; |
269 | } | |
ef63833d LP |
270 | } |
271 | ||
272 | j++; | |
273 | } | |
274 | ||
275 | udev_device_unref(ud); | |
276 | } | |
277 | } | |
278 | ||
e9f600f2 | 279 | if (asprintf(&source_time, "_SOURCE_MONOTONIC_TIMESTAMP=%llu", usec) >= 0) |
e6a7ec4b | 280 | iovec[n++] = IOVEC_MAKE_STRING(source_time); |
ef63833d | 281 | |
e6a7ec4b | 282 | iovec[n++] = IOVEC_MAKE_STRING("_TRANSPORT=kernel"); |
ef63833d LP |
283 | |
284 | if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0) | |
e6a7ec4b | 285 | iovec[n++] = IOVEC_MAKE_STRING(syslog_priority); |
ef63833d | 286 | |
36dd072c | 287 | if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0) |
e6a7ec4b | 288 | iovec[n++] = IOVEC_MAKE_STRING(syslog_facility); |
36dd072c | 289 | |
b3600346 | 290 | if (LOG_FAC(priority) == LOG_KERN) |
e6a7ec4b | 291 | iovec[n++] = IOVEC_MAKE_STRING("SYSLOG_IDENTIFIER=kernel"); |
ef63833d | 292 | else { |
e88baee8 | 293 | pl -= syslog_parse_identifier((const char**) &p, &identifier, &pid); |
ef63833d LP |
294 | |
295 | /* Avoid any messages we generated ourselves via | |
296 | * log_info() and friends. */ | |
fe167298 | 297 | if (is_us(identifier, pid)) |
ef63833d LP |
298 | goto finish; |
299 | ||
300 | if (identifier) { | |
301 | syslog_identifier = strappend("SYSLOG_IDENTIFIER=", identifier); | |
302 | if (syslog_identifier) | |
e6a7ec4b | 303 | iovec[n++] = IOVEC_MAKE_STRING(syslog_identifier); |
ef63833d LP |
304 | } |
305 | ||
306 | if (pid) { | |
307 | syslog_pid = strappend("SYSLOG_PID=", pid); | |
308 | if (syslog_pid) | |
e6a7ec4b | 309 | iovec[n++] = IOVEC_MAKE_STRING(syslog_pid); |
ef63833d | 310 | } |
ef63833d LP |
311 | } |
312 | ||
527b7a42 | 313 | if (cunescape_length_with_prefix(p, pl, "MESSAGE=", UNESCAPE_RELAX, &message) >= 0) |
e6a7ec4b | 314 | iovec[n++] = IOVEC_MAKE_STRING(message); |
ef63833d | 315 | |
22e3a02b | 316 | server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), NULL, NULL, priority, 0); |
ef63833d LP |
317 | |
318 | finish: | |
319 | for (j = 0; j < z; j++) | |
320 | free(iovec[j].iov_base); | |
ef63833d LP |
321 | } |
322 | ||
f9a810be | 323 | static int server_read_dev_kmsg(Server *s) { |
ef63833d LP |
324 | char buffer[8192+1]; /* the kernel-side limit per record is 8K currently */ |
325 | ssize_t l; | |
326 | ||
327 | assert(s); | |
328 | assert(s->dev_kmsg_fd >= 0); | |
329 | ||
330 | l = read(s->dev_kmsg_fd, buffer, sizeof(buffer) - 1); | |
331 | if (l == 0) | |
332 | return 0; | |
333 | if (l < 0) { | |
334 | /* Old kernels who don't allow reading from /dev/kmsg | |
335 | * return EINVAL when we try. So handle this cleanly, | |
336 | * but don' try to ever read from it again. */ | |
337 | if (errno == EINVAL) { | |
f9a810be | 338 | s->dev_kmsg_event_source = sd_event_source_unref(s->dev_kmsg_event_source); |
ef63833d LP |
339 | return 0; |
340 | } | |
341 | ||
3742095b | 342 | if (IN_SET(errno, EAGAIN, EINTR, EPIPE)) |
ef63833d LP |
343 | return 0; |
344 | ||
e1427b13 | 345 | return log_error_errno(errno, "Failed to read from kernel: %m"); |
ef63833d LP |
346 | } |
347 | ||
348 | dev_kmsg_record(s, buffer, l); | |
349 | return 1; | |
350 | } | |
351 | ||
352 | int server_flush_dev_kmsg(Server *s) { | |
353 | int r; | |
354 | ||
355 | assert(s); | |
356 | ||
357 | if (s->dev_kmsg_fd < 0) | |
358 | return 0; | |
359 | ||
360 | if (!s->dev_kmsg_readable) | |
361 | return 0; | |
362 | ||
2b43f939 | 363 | log_debug("Flushing /dev/kmsg..."); |
ef63833d LP |
364 | |
365 | for (;;) { | |
366 | r = server_read_dev_kmsg(s); | |
367 | if (r < 0) | |
368 | return r; | |
369 | ||
370 | if (r == 0) | |
371 | break; | |
372 | } | |
373 | ||
374 | return 0; | |
375 | } | |
376 | ||
f9a810be LP |
377 | static int dispatch_dev_kmsg(sd_event_source *es, int fd, uint32_t revents, void *userdata) { |
378 | Server *s = userdata; | |
379 | ||
380 | assert(es); | |
381 | assert(fd == s->dev_kmsg_fd); | |
382 | assert(s); | |
383 | ||
384 | if (revents & EPOLLERR) | |
385 | log_warning("/dev/kmsg buffer overrun, some messages lost."); | |
386 | ||
387 | if (!(revents & EPOLLIN)) | |
388 | log_error("Got invalid event from epoll for /dev/kmsg: %"PRIx32, revents); | |
389 | ||
390 | return server_read_dev_kmsg(s); | |
391 | } | |
392 | ||
ef63833d | 393 | int server_open_dev_kmsg(Server *s) { |
b2392ff3 | 394 | mode_t mode; |
f9a810be | 395 | int r; |
ef63833d LP |
396 | |
397 | assert(s); | |
398 | ||
b2392ff3 SS |
399 | if (s->read_kmsg) |
400 | mode = O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY; | |
401 | else | |
402 | mode = O_WRONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY; | |
403 | ||
404 | s->dev_kmsg_fd = open("/dev/kmsg", mode); | |
ef63833d | 405 | if (s->dev_kmsg_fd < 0) { |
445ea9be LP |
406 | log_full(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, |
407 | "Failed to open /dev/kmsg, ignoring: %m"); | |
ef63833d LP |
408 | return 0; |
409 | } | |
410 | ||
b2392ff3 SS |
411 | if (!s->read_kmsg) |
412 | return 0; | |
413 | ||
151b9b96 | 414 | r = sd_event_add_io(s->event, &s->dev_kmsg_event_source, s->dev_kmsg_fd, EPOLLIN, dispatch_dev_kmsg, s); |
f9a810be | 415 | if (r < 0) { |
ef63833d LP |
416 | |
417 | /* This will fail with EPERM on older kernels where | |
418 | * /dev/kmsg is not readable. */ | |
c0f71f46 LP |
419 | if (r == -EPERM) { |
420 | r = 0; | |
421 | goto fail; | |
422 | } | |
ef63833d | 423 | |
da927ba9 | 424 | log_error_errno(r, "Failed to add /dev/kmsg fd to event loop: %m"); |
c0f71f46 | 425 | goto fail; |
f9a810be LP |
426 | } |
427 | ||
428 | r = sd_event_source_set_priority(s->dev_kmsg_event_source, SD_EVENT_PRIORITY_IMPORTANT+10); | |
429 | if (r < 0) { | |
da927ba9 | 430 | log_error_errno(r, "Failed to adjust priority of kmsg event source: %m"); |
c0f71f46 | 431 | goto fail; |
ef63833d LP |
432 | } |
433 | ||
434 | s->dev_kmsg_readable = true; | |
435 | ||
436 | return 0; | |
c0f71f46 LP |
437 | |
438 | fail: | |
03e334a1 LP |
439 | s->dev_kmsg_event_source = sd_event_source_unref(s->dev_kmsg_event_source); |
440 | s->dev_kmsg_fd = safe_close(s->dev_kmsg_fd); | |
c0f71f46 LP |
441 | |
442 | return r; | |
ef63833d LP |
443 | } |
444 | ||
445 | int server_open_kernel_seqnum(Server *s) { | |
03e334a1 | 446 | _cleanup_close_ int fd; |
ef63833d | 447 | uint64_t *p; |
7bb87460 | 448 | int r; |
ef63833d LP |
449 | |
450 | assert(s); | |
451 | ||
452 | /* We store the seqnum we last read in an mmaped file. That | |
453 | * way we can just use it like a variable, but it is | |
b2e6df73 | 454 | * persistent and automatically flushed at reboot. */ |
ef63833d LP |
455 | |
456 | fd = open("/run/systemd/journal/kernel-seqnum", O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644); | |
457 | if (fd < 0) { | |
56f64d95 | 458 | log_error_errno(errno, "Failed to open /run/systemd/journal/kernel-seqnum, ignoring: %m"); |
ef63833d LP |
459 | return 0; |
460 | } | |
461 | ||
7bb87460 MS |
462 | r = posix_fallocate(fd, 0, sizeof(uint64_t)); |
463 | if (r != 0) { | |
464 | log_error_errno(r, "Failed to allocate sequential number file, ignoring: %m"); | |
ef63833d LP |
465 | return 0; |
466 | } | |
467 | ||
468 | p = mmap(NULL, sizeof(uint64_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); | |
469 | if (p == MAP_FAILED) { | |
56f64d95 | 470 | log_error_errno(errno, "Failed to map sequential number file, ignoring: %m"); |
ef63833d LP |
471 | return 0; |
472 | } | |
473 | ||
ef63833d LP |
474 | s->kernel_seqnum = p; |
475 | ||
476 | return 0; | |
477 | } |