src/journal/journal-send.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2011 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <printf.h>
  23 #include <stddef.h>
  24 #include <sys/socket.h>
  25 #include <sys/un.h>
  26 #include <unistd.h>
  27
  28 #define SD_JOURNAL_SUPPRESS_LOCATION
  29
  30 #include "sd-journal.h"
  31
  32 #include "alloc-util.h"
  33 #include "fd-util.h"
  34 #include "fileio.h"
  35 #include "io-util.h"
  36 #include "memfd-util.h"
  37 #include "socket-util.h"
  38 #include "stdio-util.h"
  39 #include "string-util.h"
  40 #include "util.h"
  41
  42 #define SNDBUF_SIZE (8*1024*1024)
  43
  44 #define ALLOCA_CODE_FUNC(f, func)                 \
  45         do {                                      \
  46                 size_t _fl;                       \
  47                 const char *_func = (func);       \
  48                 char **_f = &(f);                 \
  49                 _fl = strlen(_func) + 1;          \
  50                 *_f = alloca(_fl + 10);           \
  51                 memcpy(*_f, "CODE_FUNC=", 10);    \
  52                 memcpy(*_f + 10, _func, _fl);     \
  53         } while (false)
  54
  55 /* We open a single fd, and we'll share it with the current process,
  56  * all its threads, and all its subprocesses. This means we need to
  57  * initialize it atomically, and need to operate on it atomically
  58  * never assuming we are the only user */
  59
  60 static int journal_fd(void) {
  61         int fd;
  62         static int fd_plus_one = 0;
  63
  64 retry:
  65         if (fd_plus_one > 0)
  66                 return fd_plus_one - 1;
  67
  68         fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
  69         if (fd < 0)
  70                 return -errno;
  71
  72         fd_inc_sndbuf(fd, SNDBUF_SIZE);
  73
  74         if (!__sync_bool_compare_and_swap(&fd_plus_one, 0, fd+1)) {
  75                 safe_close(fd);
  76                 goto retry;
  77         }
  78
  79         return fd;
  80 }
  81
  82 _public_ int sd_journal_print(int priority, const char *format, ...) {
  83         int r;
  84         va_list ap;
  85
  86         va_start(ap, format);
  87         r = sd_journal_printv(priority, format, ap);
  88         va_end(ap);
  89
  90         return r;
  91 }
  92
  93 _public_ int sd_journal_printv(int priority, const char *format, va_list ap) {
  94
  95         /* FIXME: Instead of limiting things to LINE_MAX we could do a
  96            C99 variable-length array on the stack here in a loop. */
  97
  98         char buffer[8 + LINE_MAX], p[sizeof("PRIORITY=")-1 + DECIMAL_STR_MAX(int) + 1];
  99         struct iovec iov[2];
 100
 101         assert_return(priority >= 0, -EINVAL);
 102         assert_return(priority <= 7, -EINVAL);
 103         assert_return(format, -EINVAL);
 104
 105         xsprintf(p, "PRIORITY=%i", priority & LOG_PRIMASK);
 106
 107         memcpy(buffer, "MESSAGE=", 8);
 108         vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
 109
 110         /* Strip trailing whitespace, keep prefix whitespace. */
 111         (void) strstrip(buffer);
 112
 113         /* Suppress empty lines */
 114         if (isempty(buffer+8))
 115                 return 0;
 116
 117         zero(iov);
 118         IOVEC_SET_STRING(iov[0], buffer);
 119         IOVEC_SET_STRING(iov[1], p);
 120
 121         return sd_journal_sendv(iov, 2);
 122 }
 123
 124 _printf_(1, 0) static int fill_iovec_sprintf(const char *format, va_list ap, int extra, struct iovec **_iov) {
 125         PROTECT_ERRNO;
 126         int r, n = 0, i = 0, j;
 127         struct iovec *iov = NULL;
 128
 129         assert(_iov);
 130
 131         if (extra > 0) {
 132                 n = MAX(extra * 2, extra + 4);
 133                 iov = malloc0(n * sizeof(struct iovec));
 134                 if (!iov) {
 135                         r = -ENOMEM;
 136                         goto fail;
 137                 }
 138
 139                 i = extra;
 140         }
 141
 142         while (format) {
 143                 struct iovec *c;
 144                 char *buffer;
 145                 va_list aq;
 146
 147                 if (i >= n) {
 148                         n = MAX(i*2, 4);
 149                         c = realloc(iov, n * sizeof(struct iovec));
 150                         if (!c) {
 151                                 r = -ENOMEM;
 152                                 goto fail;
 153                         }
 154
 155                         iov = c;
 156                 }
 157
 158                 va_copy(aq, ap);
 159                 if (vasprintf(&buffer, format, aq) < 0) {
 160                         va_end(aq);
 161                         r = -ENOMEM;
 162                         goto fail;
 163                 }
 164                 va_end(aq);
 165
 166                 VA_FORMAT_ADVANCE(format, ap);
 167
 168                 (void) strstrip(buffer); /* strip trailing whitespace, keep prefixing whitespace */
 169
 170                 IOVEC_SET_STRING(iov[i++], buffer);
 171
 172                 format = va_arg(ap, char *);
 173         }
 174
 175         *_iov = iov;
 176
 177         return i;
 178
 179 fail:
 180         for (j = 0; j < i; j++)
 181                 free(iov[j].iov_base);
 182
 183         free(iov);
 184
 185         return r;
 186 }
 187
 188 _public_ int sd_journal_send(const char *format, ...) {
 189         int r, i, j;
 190         va_list ap;
 191         struct iovec *iov = NULL;
 192
 193         va_start(ap, format);
 194         i = fill_iovec_sprintf(format, ap, 0, &iov);
 195         va_end(ap);
 196
 197         if (_unlikely_(i < 0)) {
 198                 r = i;
 199                 goto finish;
 200         }
 201
 202         r = sd_journal_sendv(iov, i);
 203
 204 finish:
 205         for (j = 0; j < i; j++)
 206                 free(iov[j].iov_base);
 207
 208         free(iov);
 209
 210         return r;
 211 }
 212
 213 _public_ int sd_journal_sendv(const struct iovec *iov, int n) {
 214         PROTECT_ERRNO;
 215         int fd, r;
 216         _cleanup_close_ int buffer_fd = -1;
 217         struct iovec *w;
 218         uint64_t *l;
 219         int i, j = 0;
 220         static const union sockaddr_union sa = {
 221                 .un.sun_family = AF_UNIX,
 222                 .un.sun_path = "/run/systemd/journal/socket",
 223         };
 224         struct msghdr mh = {
 225                 .msg_name = (struct sockaddr*) &sa.sa,
 226                 .msg_namelen = SOCKADDR_UN_LEN(sa.un),
 227         };
 228         ssize_t k;
 229         bool have_syslog_identifier = false;
 230         bool seal = true;
 231
 232         assert_return(iov, -EINVAL);
 233         assert_return(n > 0, -EINVAL);
 234
 235         w = newa(struct iovec, n * 5 + 3);
 236         l = newa(uint64_t, n);
 237
 238         for (i = 0; i < n; i++) {
 239                 char *c, *nl;
 240
 241                 if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1))
 242                         return -EINVAL;
 243
 244                 c = memchr(iov[i].iov_base, '=', iov[i].iov_len);
 245                 if (_unlikely_(!c || c == iov[i].iov_base))
 246                         return -EINVAL;
 247
 248                 have_syslog_identifier = have_syslog_identifier ||
 249                         (c == (char *) iov[i].iov_base + 17 &&
 250                          startswith(iov[i].iov_base, "SYSLOG_IDENTIFIER"));
 251
 252                 nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len);
 253                 if (nl) {
 254                         if (_unlikely_(nl < c))
 255                                 return -EINVAL;
 256
 257                         /* Already includes a newline? Bummer, then
 258                          * let's write the variable name, then a
 259                          * newline, then the size (64bit LE), followed
 260                          * by the data and a final newline */
 261
 262                         w[j].iov_base = iov[i].iov_base;
 263                         w[j].iov_len = c - (char*) iov[i].iov_base;
 264                         j++;
 265
 266                         IOVEC_SET_STRING(w[j++], "\n");
 267
 268                         l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
 269                         w[j].iov_base = &l[i];
 270                         w[j].iov_len = sizeof(uint64_t);
 271                         j++;
 272
 273                         w[j].iov_base = c + 1;
 274                         w[j].iov_len = iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1;
 275                         j++;
 276
 277                 } else
 278                         /* Nothing special? Then just add the line and
 279                          * append a newline */
 280                         w[j++] = iov[i];
 281
 282                 IOVEC_SET_STRING(w[j++], "\n");
 283         }
 284
 285         if (!have_syslog_identifier &&
 286             string_is_safe(program_invocation_short_name)) {
 287
 288                 /* Implicitly add program_invocation_short_name, if it
 289                  * is not set explicitly. We only do this for
 290                  * program_invocation_short_name, and nothing else
 291                  * since everything else is much nicer to retrieve
 292                  * from the outside. */
 293
 294                 IOVEC_SET_STRING(w[j++], "SYSLOG_IDENTIFIER=");
 295                 IOVEC_SET_STRING(w[j++], program_invocation_short_name);
 296                 IOVEC_SET_STRING(w[j++], "\n");
 297         }
 298
 299         fd = journal_fd();
 300         if (_unlikely_(fd < 0))
 301                 return fd;
 302
 303         mh.msg_iov = w;
 304         mh.msg_iovlen = j;
 305
 306         k = sendmsg(fd, &mh, MSG_NOSIGNAL);
 307         if (k >= 0)
 308                 return 0;
 309
 310         /* Fail silently if the journal is not available */
 311         if (errno == ENOENT)
 312                 return 0;
 313
 314         if (errno != EMSGSIZE && errno != ENOBUFS)
 315                 return -errno;
 316
 317         /* Message doesn't fit... Let's dump the data in a memfd or
 318          * temporary file and just pass a file descriptor of it to the
 319          * other side.
 320          *
 321          * For the temporary files we use /dev/shm instead of /tmp
 322          * here, since we want this to be a tmpfs, and one that is
 323          * available from early boot on and where unprivileged users
 324          * can create files. */
 325         buffer_fd = memfd_new(NULL);
 326         if (buffer_fd < 0) {
 327                 if (buffer_fd == -ENOSYS) {
 328                         buffer_fd = open_tmpfile_unlinkable("/dev/shm", O_RDWR | O_CLOEXEC);
 329                         if (buffer_fd < 0)
 330                                 return buffer_fd;
 331
 332                         seal = false;
 333                 } else
 334                         return buffer_fd;
 335         }
 336
 337         n = writev(buffer_fd, w, j);
 338         if (n < 0)
 339                 return -errno;
 340
 341         if (seal) {
 342                 r = memfd_set_sealed(buffer_fd);
 343                 if (r < 0)
 344                         return r;
 345         }
 346
 347         r = send_one_fd_sa(fd, buffer_fd, mh.msg_name, mh.msg_namelen, 0);
 348         if (r == -ENOENT)
 349                 /* Fail silently if the journal is not available */
 350                 return 0;
 351         return r;
 352 }
 353
 354 static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) {
 355         PROTECT_ERRNO;
 356         size_t n, k;
 357
 358         k = isempty(message) ? 0 : strlen(message) + 2;
 359         n = 8 + k + 256 + 1;
 360
 361         for (;;) {
 362                 char buffer[n];
 363                 char* j;
 364
 365                 errno = 0;
 366                 j = strerror_r(_saved_errno_, buffer + 8 + k, n - 8 - k);
 367                 if (errno == 0) {
 368                         char error[sizeof("ERRNO=")-1 + DECIMAL_STR_MAX(int) + 1];
 369
 370                         if (j != buffer + 8 + k)
 371                                 memmove(buffer + 8 + k, j, strlen(j)+1);
 372
 373                         memcpy(buffer, "MESSAGE=", 8);
 374
 375                         if (k > 0) {
 376                                 memcpy(buffer + 8, message, k - 2);
 377                                 memcpy(buffer + 8 + k - 2, ": ", 2);
 378                         }
 379
 380                         xsprintf(error, "ERRNO=%i", _saved_errno_);
 381
 382                         assert_cc(3 == LOG_ERR);
 383                         IOVEC_SET_STRING(iov[skip+0], "PRIORITY=3");
 384                         IOVEC_SET_STRING(iov[skip+1], buffer);
 385                         IOVEC_SET_STRING(iov[skip+2], error);
 386
 387                         return sd_journal_sendv(iov, skip + 3);
 388                 }
 389
 390                 if (errno != ERANGE)
 391                         return -errno;
 392
 393                 n *= 2;
 394         }
 395 }
 396
 397 _public_ int sd_journal_perror(const char *message) {
 398         struct iovec iovec[3];
 399
 400         return fill_iovec_perror_and_send(message, 0, iovec);
 401 }
 402
 403 _public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) {
 404         static const union sockaddr_union sa = {
 405                 .un.sun_family = AF_UNIX,
 406                 .un.sun_path = "/run/systemd/journal/stdout",
 407         };
 408         _cleanup_close_ int fd = -1;
 409         char *header;
 410         size_t l;
 411         int r;
 412
 413         assert_return(priority >= 0, -EINVAL);
 414         assert_return(priority <= 7, -EINVAL);
 415
 416         fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
 417         if (fd < 0)
 418                 return -errno;
 419
 420         r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
 421         if (r < 0)
 422                 return -errno;
 423
 424         if (shutdown(fd, SHUT_RD) < 0)
 425                 return -errno;
 426
 427         fd_inc_sndbuf(fd, SNDBUF_SIZE);
 428
 429         if (!identifier)
 430                 identifier = "";
 431
 432         l = strlen(identifier);
 433         header = alloca(l + 1 + 1 + 2 + 2 + 2 + 2 + 2);
 434
 435         memcpy(header, identifier, l);
 436         header[l++] = '\n';
 437         header[l++] = '\n'; /* unit id */
 438         header[l++] = '0' + priority;
 439         header[l++] = '\n';
 440         header[l++] = '0' + !!level_prefix;
 441         header[l++] = '\n';
 442         header[l++] = '0';
 443         header[l++] = '\n';
 444         header[l++] = '0';
 445         header[l++] = '\n';
 446         header[l++] = '0';
 447         header[l++] = '\n';
 448
 449         r = loop_write(fd, header, l, false);
 450         if (r < 0)
 451                 return r;
 452
 453         r = fd;
 454         fd = -1;
 455         return r;
 456 }
 457
 458 _public_ int sd_journal_print_with_location(int priority, const char *file, const char *line, const char *func, const char *format, ...) {
 459         int r;
 460         va_list ap;
 461
 462         va_start(ap, format);
 463         r = sd_journal_printv_with_location(priority, file, line, func, format, ap);
 464         va_end(ap);
 465
 466         return r;
 467 }
 468
 469 _public_ int sd_journal_printv_with_location(int priority, const char *file, const char *line, const char *func, const char *format, va_list ap) {
 470         char buffer[8 + LINE_MAX], p[sizeof("PRIORITY=")-1 + DECIMAL_STR_MAX(int) + 1];
 471         struct iovec iov[5];
 472         char *f;
 473
 474         assert_return(priority >= 0, -EINVAL);
 475         assert_return(priority <= 7, -EINVAL);
 476         assert_return(format, -EINVAL);
 477
 478         xsprintf(p, "PRIORITY=%i", priority & LOG_PRIMASK);
 479
 480         memcpy(buffer, "MESSAGE=", 8);
 481         vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
 482
 483         /* Strip trailing whitespace, keep prefixing whitespace */
 484         (void) strstrip(buffer);
 485
 486         /* Suppress empty lines */
 487         if (isempty(buffer+8))
 488                 return 0;
 489
 490         /* func is initialized from __func__ which is not a macro, but
 491          * a static const char[], hence cannot easily be prefixed with
 492          * CODE_FUNC=, hence let's do it manually here. */
 493         ALLOCA_CODE_FUNC(f, func);
 494
 495         zero(iov);
 496         IOVEC_SET_STRING(iov[0], buffer);
 497         IOVEC_SET_STRING(iov[1], p);
 498         IOVEC_SET_STRING(iov[2], file);
 499         IOVEC_SET_STRING(iov[3], line);
 500         IOVEC_SET_STRING(iov[4], f);
 501
 502         return sd_journal_sendv(iov, ELEMENTSOF(iov));
 503 }
 504
 505 _public_ int sd_journal_send_with_location(const char *file, const char *line, const char *func, const char *format, ...) {
 506         int r, i, j;
 507         va_list ap;
 508         struct iovec *iov = NULL;
 509         char *f;
 510
 511         va_start(ap, format);
 512         i = fill_iovec_sprintf(format, ap, 3, &iov);
 513         va_end(ap);
 514
 515         if (_unlikely_(i < 0)) {
 516                 r = i;
 517                 goto finish;
 518         }
 519
 520         ALLOCA_CODE_FUNC(f, func);
 521
 522         IOVEC_SET_STRING(iov[0], file);
 523         IOVEC_SET_STRING(iov[1], line);
 524         IOVEC_SET_STRING(iov[2], f);
 525
 526         r = sd_journal_sendv(iov, i);
 527
 528 finish:
 529         for (j = 3; j < i; j++)
 530                 free(iov[j].iov_base);
 531
 532         free(iov);
 533
 534         return r;
 535 }
 536
 537 _public_ int sd_journal_sendv_with_location(
 538                 const char *file, const char *line,
 539                 const char *func,
 540                 const struct iovec *iov, int n) {
 541
 542         struct iovec *niov;
 543         char *f;
 544
 545         assert_return(iov, -EINVAL);
 546         assert_return(n > 0, -EINVAL);
 547
 548         niov = alloca(sizeof(struct iovec) * (n + 3));
 549         memcpy(niov, iov, sizeof(struct iovec) * n);
 550
 551         ALLOCA_CODE_FUNC(f, func);
 552
 553         IOVEC_SET_STRING(niov[n++], file);
 554         IOVEC_SET_STRING(niov[n++], line);
 555         IOVEC_SET_STRING(niov[n++], f);
 556
 557         return sd_journal_sendv(niov, n);
 558 }
 559
 560 _public_ int sd_journal_perror_with_location(
 561                 const char *file, const char *line,
 562                 const char *func,
 563                 const char *message) {
 564
 565         struct iovec iov[6];
 566         char *f;
 567
 568         ALLOCA_CODE_FUNC(f, func);
 569
 570         IOVEC_SET_STRING(iov[0], file);
 571         IOVEC_SET_STRING(iov[1], line);
 572         IOVEC_SET_STRING(iov[2], f);
 573
 574         return fill_iovec_perror_and_send(message, 3, iov);
 575 }