summaryrefslogtreecommitdiff
path: root/src/journal/journald-syslog.c
blob: 0be73088e29bc09ef80476516bbdbc50bed2d1ad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2011 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <stddef.h>
#include <sys/epoll.h>
#include <unistd.h>

#include "sd-messages.h"

#include "alloc-util.h"
#include "fd-util.h"
#include "formats-util.h"
#include "io-util.h"
#include "journald-console.h"
#include "journald-kmsg.h"
#include "journald-server.h"
#include "journald-syslog.h"
#include "journald-wall.h"
#include "process-util.h"
#include "selinux-util.h"
#include "socket-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "syslog-util.h"

/* Warn once every 30s if we missed syslog message */
#define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)

static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned n_iovec, const struct ucred *ucred, const struct timeval *tv) {

        static const union sockaddr_union sa = {
                .un.sun_family = AF_UNIX,
                .un.sun_path = "/run/systemd/journal/syslog",
        };
        struct msghdr msghdr = {
                .msg_iov = (struct iovec *) iovec,
                .msg_iovlen = n_iovec,
                .msg_name = (struct sockaddr*) &sa.sa,
                .msg_namelen = offsetof(union sockaddr_union, un.sun_path)
                               + strlen("/run/systemd/journal/syslog"),
        };
        struct cmsghdr *cmsg;
        union {
                struct cmsghdr cmsghdr;
                uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
        } control;

        assert(s);
        assert(iovec);
        assert(n_iovec > 0);

        if (ucred) {
                zero(control);
                msghdr.msg_control = &control;
                msghdr.msg_controllen = sizeof(control);

                cmsg = CMSG_FIRSTHDR(&msghdr);
                cmsg->cmsg_level = SOL_SOCKET;
                cmsg->cmsg_type = SCM_CREDENTIALS;
                cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
                memcpy(CMSG_DATA(cmsg), ucred, sizeof(struct ucred));
                msghdr.msg_controllen = cmsg->cmsg_len;
        }

        /* Forward the syslog message we received via /dev/log to
         * /run/systemd/syslog. Unfortunately we currently can't set
         * the SO_TIMESTAMP auxiliary data, and hence we don't. */

        if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
                return;

        /* The socket is full? I guess the syslog implementation is
         * too slow, and we shouldn't wait for that... */
        if (errno == EAGAIN) {
                s->n_forward_syslog_missed++;
                return;
        }

        if (ucred && (errno == ESRCH || errno == EPERM)) {
                struct ucred u;

                /* Hmm, presumably the sender process vanished
                 * by now, or we don't have CAP_SYS_AMDIN, so
                 * let's fix it as good as we can, and retry */

                u = *ucred;
                u.pid = getpid();
                memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred));

                if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
                        return;

                if (errno == EAGAIN) {
                        s->n_forward_syslog_missed++;
                        return;
                }
        }

        if (errno != ENOENT)
                log_debug_errno(errno, "Failed to forward syslog message: %m");
}

static void forward_syslog_raw(Server *s, int priority, const char *buffer, const struct ucred *ucred, const struct timeval *tv) {
        struct iovec iovec;

        assert(s);
        assert(buffer);

        if (LOG_PRI(priority) > s->max_level_syslog)
                return;

        IOVEC_SET_STRING(iovec, buffer);
        forward_syslog_iovec(s, &iovec, 1, ucred, tv);
}

void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv) {
        struct iovec iovec[5];
        char header_priority[DECIMAL_STR_MAX(priority) + 3], header_time[64],
             header_pid[sizeof("[]: ")-1 + DECIMAL_STR_MAX(pid_t) + 1];
        int n = 0;
        time_t t;
        struct tm *tm;
        char *ident_buf = NULL;

        assert(s);
        assert(priority >= 0);
        assert(priority <= 999);
        assert(message);

        if (LOG_PRI(priority) > s->max_level_syslog)
                return;

        /* First: priority field */
        xsprintf(header_priority, "<%i>", priority);
        IOVEC_SET_STRING(iovec[n++], header_priority);

        /* Second: timestamp */
        t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));
        tm = localtime(&t);
        if (!tm)
                return;
        if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
                return;
        IOVEC_SET_STRING(iovec[n++], header_time);

        /* Third: identifier and PID */
        if (ucred) {
                if (!identifier) {
                        get_process_comm(ucred->pid, &ident_buf);
                        identifier = ident_buf;
                }

                xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid);

                if (identifier)
                        IOVEC_SET_STRING(iovec[n++], identifier);

                IOVEC_SET_STRING(iovec[n++], header_pid);
        } else if (identifier) {
                IOVEC_SET_STRING(iovec[n++], identifier);
                IOVEC_SET_STRING(iovec[n++], ": ");
        }

        /* Fourth: message */
        IOVEC_SET_STRING(iovec[n++], message);

        forward_syslog_iovec(s, iovec, n, ucred, tv);

        free(ident_buf);
}

int syslog_fixup_facility(int priority) {

        if ((priority & LOG_FACMASK) == 0)
                return (priority & LOG_PRIMASK) | LOG_USER;

        return priority;
}

size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid) {
        const char *p;
        char *t;
        size_t l, e;

        assert(buf);
        assert(identifier);
        assert(pid);

        p = *buf;

        p += strspn(p, WHITESPACE);
        l = strcspn(p, WHITESPACE);

        if (l <= 0 ||
            p[l-1] != ':')
                return 0;

        e = l;
        l--;

        if (p[l-1] == ']') {
                size_t k = l-1;

                for (;;) {

                        if (p[k] == '[') {
                                t = strndup(p+k+1, l-k-2);
                                if (t)
                                        *pid = t;

                                l = k;
                                break;
                        }

                        if (k == 0)
                                break;

                        k--;
                }
        }

        t = strndup(p, l);
        if (t)
                *identifier = t;

        if (strchr(WHITESPACE, p[e]))
                e++;
        *buf = p + e;
        return e;
}

static void syslog_skip_date(char **buf) {
        enum {
                LETTER,
                SPACE,
                NUMBER,
                SPACE_OR_NUMBER,
                COLON
        } sequence[] = {
                LETTER, LETTER, LETTER,
                SPACE,
                SPACE_OR_NUMBER, NUMBER,
                SPACE,
                SPACE_OR_NUMBER, NUMBER,
                COLON,
                SPACE_OR_NUMBER, NUMBER,
                COLON,
                SPACE_OR_NUMBER, NUMBER,
                SPACE
        };

        char *p;
        unsigned i;

        assert(buf);
        assert(*buf);

        p = *buf;

        for (i = 0; i < ELEMENTSOF(sequence); i++, p++) {

                if (!*p)
                        return;

                switch (sequence[i]) {

                case SPACE:
                        if (*p != ' ')
                                return;
                        break;

                case SPACE_OR_NUMBER:
                        if (*p == ' ')
                                break;

                        /* fall through */

                case NUMBER:
                        if (*p < '0' || *p > '9')
                                return;

                        break;

                case LETTER:
                        if (!(*p >= 'A' && *p <= 'Z') &&
                            !(*p >= 'a' && *p <= 'z'))
                                return;

                        break;

                case COLON:
                        if (*p != ':')
                                return;
                        break;

                }
        }

        *buf = p;
}

void server_process_syslog_message(
        Server *s,
        const char *buf,
        const struct ucred *ucred,
        const struct timeval *tv,
        const char *label,
        size_t label_len) {

        char syslog_priority[sizeof("PRIORITY=") + DECIMAL_STR_MAX(int)],
             syslog_facility[sizeof("SYSLOG_FACILITY=") + DECIMAL_STR_MAX(int)];
        const char *message = NULL, *syslog_identifier = NULL, *syslog_pid = NULL;
        struct iovec iovec[N_IOVEC_META_FIELDS + 6];
        unsigned n = 0;
        int priority = LOG_USER | LOG_INFO;
        _cleanup_free_ char *identifier = NULL, *pid = NULL;
        const char *orig;

        assert(s);
        assert(buf);

        orig = buf;
        syslog_parse_priority(&buf, &priority, true);

        if (s->forward_to_syslog)
                forward_syslog_raw(s, priority, orig, ucred, tv);

        syslog_skip_date((char**) &buf);
        syslog_parse_identifier(&buf, &identifier, &pid);

        if (s->forward_to_kmsg)
                server_forward_kmsg(s, priority, identifier, buf, ucred);

        if (s->forward_to_console)
                server_forward_console(s, priority, identifier, buf, ucred);

        if (s->forward_to_wall)
                server_forward_wall(s, priority, identifier, buf, ucred);

        IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=syslog");

        xsprintf(syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK);
        IOVEC_SET_STRING(iovec[n++], syslog_priority);

        if (priority & LOG_FACMASK) {
                xsprintf(syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority));
                IOVEC_SET_STRING(iovec[n++], syslog_facility);
        }

        if (identifier) {
                syslog_identifier = strjoina("SYSLOG_IDENTIFIER=", identifier);
                if (syslog_identifier)
                        IOVEC_SET_STRING(iovec[n++], syslog_identifier);
        }

        if (pid) {
                syslog_pid = strjoina("SYSLOG_PID=", pid);
                if (syslog_pid)
                        IOVEC_SET_STRING(iovec[n++], syslog_pid);
        }

        message = strjoina("MESSAGE=", buf);
        if (message)
                IOVEC_SET_STRING(iovec[n++], message);

        server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), ucred, tv, label, label_len, NULL, priority, 0);
}

int server_open_syslog_socket(Server *s) {
        static const int one = 1;
        int r;

        assert(s);

        if (s->syslog_fd < 0) {
                static const union sockaddr_union sa = {
                        .un.sun_family = AF_UNIX,
                        .un.sun_path = "/run/systemd/journal/dev-log",
                };

                s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                if (s->syslog_fd < 0)
                        return log_error_errno(errno, "socket() failed: %m");

                unlink(sa.un.sun_path);

                r = bind(s->syslog_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
                if (r < 0)
                        return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);

                (void) chmod(sa.un.sun_path, 0666);
        } else
                fd_nonblock(s->syslog_fd, 1);

        r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
        if (r < 0)
                return log_error_errno(errno, "SO_PASSCRED failed: %m");

#ifdef HAVE_SELINUX
        if (mac_selinux_have()) {
                r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one));
                if (r < 0)
                        log_warning_errno(errno, "SO_PASSSEC failed: %m");
        }
#endif

        r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
        if (r < 0)
                return log_error_errno(errno, "SO_TIMESTAMP failed: %m");

        r = sd_event_add_io(s->event, &s->syslog_event_source, s->syslog_fd, EPOLLIN, server_process_datagram, s);
        if (r < 0)
                return log_error_errno(r, "Failed to add syslog server fd to event loop: %m");

        r = sd_event_source_set_priority(s->syslog_event_source, SD_EVENT_PRIORITY_NORMAL+5);
        if (r < 0)
                return log_error_errno(r, "Failed to adjust syslog event source priority: %m");

        return 0;
}

void server_maybe_warn_forward_syslog_missed(Server *s) {
        usec_t n;
        assert(s);

        if (s->n_forward_syslog_missed <= 0)
                return;

        n = now(CLOCK_MONOTONIC);
        if (s->last_warn_forward_syslog_missed + WARN_FORWARD_SYSLOG_MISSED_USEC > n)
                return;

        server_driver_message(s, SD_MESSAGE_FORWARD_SYSLOG_MISSED, "Forwarding to syslog missed %u messages.", s->n_forward_syslog_missed);

        s->n_forward_syslog_missed = 0;
        s->last_warn_forward_syslog_missed = n;
}