summaryrefslogtreecommitdiff
path: root/src/journal/journal-send.c
blob: 931c1e73306501714ffe1fc0b8aac3cebce196a2 (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
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
/*-*- 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 <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <printf.h>

#define SD_JOURNAL_SUPPRESS_LOCATION

#include "sd-journal.h"
#include "util.h"
#include "socket-util.h"

#define SNDBUF_SIZE (8*1024*1024)

#define ALLOCA_CODE_FUNC(f, func)                 \
        do {                                      \
                size_t _fl;                       \
                const char *_func = (func);       \
                char **_f = &(f);                 \
                _fl = strlen(_func) + 1;          \
                *_f = alloca(_fl + 10);           \
                memcpy(*_f, "CODE_FUNC=", 10);    \
                memcpy(*_f + 10, _func, _fl);     \
        } while(false)

/* We open a single fd, and we'll share it with the current process,
 * all its threads, and all its subprocesses. This means we need to
 * initialize it atomically, and need to operate on it atomically
 * never assuming we are the only user */

static int journal_fd(void) {
        int fd;
        static int fd_plus_one = 0;

retry:
        if (fd_plus_one > 0)
                return fd_plus_one - 1;

        fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
        if (fd < 0)
                return -errno;

        fd_inc_sndbuf(fd, SNDBUF_SIZE);

        if (!__sync_bool_compare_and_swap(&fd_plus_one, 0, fd+1)) {
                close_nointr_nofail(fd);
                goto retry;
        }

        return fd;
}

_public_ int sd_journal_print(int priority, const char *format, ...) {
        int r;
        va_list ap;

        va_start(ap, format);
        r = sd_journal_printv(priority, format, ap);
        va_end(ap);

        return r;
}

_public_ int sd_journal_printv(int priority, const char *format, va_list ap) {

        /* FIXME: Instead of limiting things to LINE_MAX we could do a
           C99 variable-length array on the stack here in a loop. */

        char buffer[8 + LINE_MAX], p[11]; struct iovec iov[2];

        assert_return(priority >= 0, -EINVAL);
        assert_return(priority <= 7, -EINVAL);
        assert_return(format, -EINVAL);

        snprintf(p, sizeof(p), "PRIORITY=%i", priority & LOG_PRIMASK);
        char_array_0(p);

        memcpy(buffer, "MESSAGE=", 8);
        vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
        char_array_0(buffer);

        zero(iov);
        IOVEC_SET_STRING(iov[0], buffer);
        IOVEC_SET_STRING(iov[1], p);

        return sd_journal_sendv(iov, 2);
}

_printf_(1, 0) static int fill_iovec_sprintf(const char *format, va_list ap, int extra, struct iovec **_iov) {
        PROTECT_ERRNO;
        int r, n = 0, i = 0, j;
        struct iovec *iov = NULL;

        assert(_iov);

        if (extra > 0) {
                n = MAX(extra * 2, extra + 4);
                iov = malloc0(n * sizeof(struct iovec));
                if (!iov) {
                        r = -ENOMEM;
                        goto fail;
                }

                i = extra;
        }

        while (format) {
                struct iovec *c;
                char *buffer;
                va_list aq;

                if (i >= n) {
                        n = MAX(i*2, 4);
                        c = realloc(iov, n * sizeof(struct iovec));
                        if (!c) {
                                r = -ENOMEM;
                                goto fail;
                        }

                        iov = c;
                }

                va_copy(aq, ap);
                if (vasprintf(&buffer, format, aq) < 0) {
                        va_end(aq);
                        r = -ENOMEM;
                        goto fail;
                }
                va_end(aq);

                VA_FORMAT_ADVANCE(format, ap);

                IOVEC_SET_STRING(iov[i++], buffer);

                format = va_arg(ap, char *);
        }

        *_iov = iov;

        return i;

fail:
        for (j = 0; j < i; j++)
                free(iov[j].iov_base);

        free(iov);

        return r;
}

_public_ int sd_journal_send(const char *format, ...) {
        int r, i, j;
        va_list ap;
        struct iovec *iov = NULL;

        va_start(ap, format);
        i = fill_iovec_sprintf(format, ap, 0, &iov);
        va_end(ap);

        if (_unlikely_(i < 0)) {
                r = i;
                goto finish;
        }

        r = sd_journal_sendv(iov, i);

finish:
        for (j = 0; j < i; j++)
                free(iov[j].iov_base);

        free(iov);

        return r;
}

_public_ int sd_journal_sendv(const struct iovec *iov, int n) {
        PROTECT_ERRNO;
        int fd, buffer_fd;
        struct iovec *w;
        uint64_t *l;
        int i, j = 0;
        struct sockaddr_un sa = {
                .sun_family = AF_UNIX,
                .sun_path = "/run/systemd/journal/socket",
        };
        struct msghdr mh = {
                .msg_name = &sa,
                .msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path),
        };
        ssize_t k;
        union {
                struct cmsghdr cmsghdr;
                uint8_t buf[CMSG_SPACE(sizeof(int))];
        } control;
        struct cmsghdr *cmsg;
        /* We use /dev/shm instead of /tmp here, since we want this to
         * be a tmpfs, and one that is available from early boot on
         * and where unprivileged users can create files. */
        char path[] = "/dev/shm/journal.XXXXXX";
        bool have_syslog_identifier = false;

        assert_return(iov, -EINVAL);
        assert_return(n > 0, -EINVAL);

        w = alloca(sizeof(struct iovec) * n * 5 + 3);
        l = alloca(sizeof(uint64_t) * n);

        for (i = 0; i < n; i++) {
                char *c, *nl;

                if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1))
                        return -EINVAL;

                c = memchr(iov[i].iov_base, '=', iov[i].iov_len);
                if (_unlikely_(!c || c == iov[i].iov_base))
                        return -EINVAL;

                have_syslog_identifier = have_syslog_identifier ||
                        (c == (char *) iov[i].iov_base + 17 &&
                         startswith(iov[i].iov_base, "SYSLOG_IDENTIFIER"));

                nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len);
                if (nl) {
                        if (_unlikely_(nl < c))
                                return -EINVAL;

                        /* Already includes a newline? Bummer, then
                         * let's write the variable name, then a
                         * newline, then the size (64bit LE), followed
                         * by the data and a final newline */

                        w[j].iov_base = iov[i].iov_base;
                        w[j].iov_len = c - (char*) iov[i].iov_base;
                        j++;

                        IOVEC_SET_STRING(w[j++], "\n");

                        l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
                        w[j].iov_base = &l[i];
                        w[j].iov_len = sizeof(uint64_t);
                        j++;

                        w[j].iov_base = c + 1;
                        w[j].iov_len = iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1;
                        j++;

                } else
                        /* Nothing special? Then just add the line and
                         * append a newline */
                        w[j++] = iov[i];

                IOVEC_SET_STRING(w[j++], "\n");
        }

        if (!have_syslog_identifier &&
            string_is_safe(program_invocation_short_name)) {

                /* Implicitly add program_invocation_short_name, if it
                 * is not set explicitly. We only do this for
                 * program_invocation_short_name, and nothing else
                 * since everything else is much nicer to retrieve
                 * from the outside. */

                IOVEC_SET_STRING(w[j++], "SYSLOG_IDENTIFIER=");
                IOVEC_SET_STRING(w[j++], program_invocation_short_name);
                IOVEC_SET_STRING(w[j++], "\n");
        }

        fd = journal_fd();
        if (_unlikely_(fd < 0))
                return fd;

        mh.msg_iov = w;
        mh.msg_iovlen = j;

        k = sendmsg(fd, &mh, MSG_NOSIGNAL);
        if (k >= 0)
                return 0;

        if (errno != EMSGSIZE && errno != ENOBUFS)
                return -errno;

        /* Message doesn't fit... Let's dump the data in a temporary
         * file and just pass a file descriptor of it to the other
         * side */

        buffer_fd = mkostemp(path, O_CLOEXEC|O_RDWR);
        if (buffer_fd < 0)
                return -errno;

        if (unlink(path) < 0) {
                close_nointr_nofail(buffer_fd);
                return -errno;
        }

        n = writev(buffer_fd, w, j);
        if (n < 0) {
                close_nointr_nofail(buffer_fd);
                return -errno;
        }

        mh.msg_iov = NULL;
        mh.msg_iovlen = 0;

        zero(control);
        mh.msg_control = &control;
        mh.msg_controllen = sizeof(control);

        cmsg = CMSG_FIRSTHDR(&mh);
        cmsg->cmsg_level = SOL_SOCKET;
        cmsg->cmsg_type = SCM_RIGHTS;
        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
        memcpy(CMSG_DATA(cmsg), &buffer_fd, sizeof(int));

        mh.msg_controllen = cmsg->cmsg_len;

        k = sendmsg(fd, &mh, MSG_NOSIGNAL);
        close_nointr_nofail(buffer_fd);

        if (k < 0)
                return -errno;

        return 0;
}

static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) {
        PROTECT_ERRNO;
        size_t n, k;

        k = isempty(message) ? 0 : strlen(message) + 2;
        n = 8 + k + 256 + 1;

        for (;;) {
                char buffer[n];
                char* j;

                errno = 0;
                j = strerror_r(_saved_errno_, buffer + 8 + k, n - 8 - k);
                if (errno == 0) {
                        char error[6 + 10 + 1]; /* for a 32bit value */

                        if (j != buffer + 8 + k)
                                memmove(buffer + 8 + k, j, strlen(j)+1);

                        memcpy(buffer, "MESSAGE=", 8);

                        if (k > 0) {
                                memcpy(buffer + 8, message, k - 2);
                                memcpy(buffer + 8 + k - 2, ": ", 2);
                        }

                        snprintf(error, sizeof(error), "ERRNO=%u", _saved_errno_);
                        char_array_0(error);

                        IOVEC_SET_STRING(iov[skip+0], "PRIORITY=3");
                        IOVEC_SET_STRING(iov[skip+1], buffer);
                        IOVEC_SET_STRING(iov[skip+2], error);

                        return sd_journal_sendv(iov, skip + 3);
                }

                if (errno != ERANGE)
                        return -errno;

                n *= 2;
        }
}

_public_ int sd_journal_perror(const char *message) {
        struct iovec iovec[3];

        return fill_iovec_perror_and_send(message, 0, iovec);
}

_public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) {
        union sockaddr_union sa = {
                .un.sun_family = AF_UNIX,
                .un.sun_path = "/run/systemd/journal/stdout",
        };
        int fd;
        char *header;
        size_t l;
        ssize_t r;

        assert_return(priority >= 0, -EINVAL);
        assert_return(priority <= 7, -EINVAL);

        fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
        if (fd < 0)
                return -errno;

        r = connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
        if (r < 0) {
                close_nointr_nofail(fd);
                return -errno;
        }

        if (shutdown(fd, SHUT_RD) < 0) {
                close_nointr_nofail(fd);
                return -errno;
        }

        fd_inc_sndbuf(fd, SNDBUF_SIZE);

        if (!identifier)
                identifier = "";

        l = strlen(identifier);
        header = alloca(l + 1 + 1 + 2 + 2 + 2 + 2 + 2);

        memcpy(header, identifier, l);
        header[l++] = '\n';
        header[l++] = '\n'; /* unit id */
        header[l++] = '0' + priority;
        header[l++] = '\n';
        header[l++] = '0' + !!level_prefix;
        header[l++] = '\n';
        header[l++] = '0';
        header[l++] = '\n';
        header[l++] = '0';
        header[l++] = '\n';
        header[l++] = '0';
        header[l++] = '\n';

        r = loop_write(fd, header, l, false);
        if (r < 0) {
                close_nointr_nofail(fd);
                return (int) r;
        }

        if ((size_t) r != l) {
                close_nointr_nofail(fd);
                return -errno;
        }

        return fd;
}

_public_ int sd_journal_print_with_location(int priority, const char *file, const char *line, const char *func, const char *format, ...) {
        int r;
        va_list ap;

        va_start(ap, format);
        r = sd_journal_printv_with_location(priority, file, line, func, format, ap);
        va_end(ap);

        return r;
}

_public_ int sd_journal_printv_with_location(int priority, const char *file, const char *line, const char *func, const char *format, va_list ap) {
        char buffer[8 + LINE_MAX], p[11];
        struct iovec iov[5];
        char *f;

        assert_return(priority >= 0, -EINVAL);
        assert_return(priority <= 7, -EINVAL);
        assert_return(format, -EINVAL);

        snprintf(p, sizeof(p), "PRIORITY=%i", priority & LOG_PRIMASK);
        char_array_0(p);

        memcpy(buffer, "MESSAGE=", 8);
        vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
        char_array_0(buffer);

        /* func is initialized from __func__ which is not a macro, but
         * a static const char[], hence cannot easily be prefixed with
         * CODE_FUNC=, hence let's do it manually here. */
        ALLOCA_CODE_FUNC(f, func);

        zero(iov);
        IOVEC_SET_STRING(iov[0], buffer);
        IOVEC_SET_STRING(iov[1], p);
        IOVEC_SET_STRING(iov[2], file);
        IOVEC_SET_STRING(iov[3], line);
        IOVEC_SET_STRING(iov[4], f);

        return sd_journal_sendv(iov, ELEMENTSOF(iov));
}

_public_ int sd_journal_send_with_location(const char *file, const char *line, const char *func, const char *format, ...) {
        int r, i, j;
        va_list ap;
        struct iovec *iov = NULL;
        char *f;

        va_start(ap, format);
        i = fill_iovec_sprintf(format, ap, 3, &iov);
        va_end(ap);

        if (_unlikely_(i < 0)) {
                r = i;
                goto finish;
        }

        ALLOCA_CODE_FUNC(f, func);

        IOVEC_SET_STRING(iov[0], file);
        IOVEC_SET_STRING(iov[1], line);
        IOVEC_SET_STRING(iov[2], f);

        r = sd_journal_sendv(iov, i);

finish:
        for (j = 3; j < i; j++)
                free(iov[j].iov_base);

        free(iov);

        return r;
}

_public_ int sd_journal_sendv_with_location(
                const char *file, const char *line,
                const char *func,
                const struct iovec *iov, int n) {

        struct iovec *niov;
        char *f;

        assert_return(iov, -EINVAL);
        assert_return(n > 0, -EINVAL);

        niov = alloca(sizeof(struct iovec) * (n + 3));
        memcpy(niov, iov, sizeof(struct iovec) * n);

        ALLOCA_CODE_FUNC(f, func);

        IOVEC_SET_STRING(niov[n++], file);
        IOVEC_SET_STRING(niov[n++], line);
        IOVEC_SET_STRING(niov[n++], f);

        return sd_journal_sendv(niov, n);
}

_public_ int sd_journal_perror_with_location(
                const char *file, const char *line,
                const char *func,
                const char *message) {

        struct iovec iov[6];
        char *f;

        ALLOCA_CODE_FUNC(f, func);

        IOVEC_SET_STRING(iov[0], file);
        IOVEC_SET_STRING(iov[1], line);
        IOVEC_SET_STRING(iov[2], f);

        return fill_iovec_perror_and_send(message, 3, iov);
}