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         iov[0] = IOVEC_MAKE_STRING(buffer);
 118         iov[1] = IOVEC_MAKE_STRING(p);
 119
 120         return sd_journal_sendv(iov, 2);
 121 }
 122
 123 _printf_(1, 0) static int fill_iovec_sprintf(const char *format, va_list ap, int extra, struct iovec **_iov) {
 124         PROTECT_ERRNO;
 125         int r, n = 0, i = 0, j;
 126         struct iovec *iov = NULL;
 127
 128         assert(_iov);
 129
 130         if (extra > 0) {
 131                 n = MAX(extra * 2, extra + 4);
 132                 iov = malloc0(n * sizeof(struct iovec));
 133                 if (!iov) {
 134                         r = -ENOMEM;
 135                         goto fail;
 136                 }
 137
 138                 i = extra;
 139         }
 140
 141         while (format) {
 142                 struct iovec *c;
 143                 char *buffer;
 144                 va_list aq;
 145
 146                 if (i >= n) {
 147                         n = MAX(i*2, 4);
 148                         c = realloc(iov, n * sizeof(struct iovec));
 149                         if (!c) {
 150                                 r = -ENOMEM;
 151                                 goto fail;
 152                         }
 153
 154                         iov = c;
 155                 }
 156
 157                 va_copy(aq, ap);
 158                 if (vasprintf(&buffer, format, aq) < 0) {
 159                         va_end(aq);
 160                         r = -ENOMEM;
 161                         goto fail;
 162                 }
 163                 va_end(aq);
 164
 165                 VA_FORMAT_ADVANCE(format, ap);
 166
 167                 (void) strstrip(buffer); /* strip trailing whitespace, keep prefixing whitespace */
 168
 169                 iov[i++] = IOVEC_MAKE_STRING(buffer);
 170
 171                 format = va_arg(ap, char *);
 172         }
 173
 174         *_iov = iov;
 175
 176         return i;
 177
 178 fail:
 179         for (j = 0; j < i; j++)
 180                 free(iov[j].iov_base);
 181
 182         free(iov);
 183
 184         return r;
 185 }
 186
 187 _public_ int sd_journal_send(const char *format, ...) {
 188         int r, i, j;
 189         va_list ap;
 190         struct iovec *iov = NULL;
 191
 192         va_start(ap, format);
 193         i = fill_iovec_sprintf(format, ap, 0, &iov);
 194         va_end(ap);
 195
 196         if (_unlikely_(i < 0)) {
 197                 r = i;
 198                 goto finish;
 199         }
 200
 201         r = sd_journal_sendv(iov, i);
 202
 203 finish:
 204         for (j = 0; j < i; j++)
 205                 free(iov[j].iov_base);
 206
 207         free(iov);
 208
 209         return r;
 210 }
 211
 212 _public_ int sd_journal_sendv(const struct iovec *iov, int n) {
 213         PROTECT_ERRNO;
 214         int fd, r;
 215         _cleanup_close_ int buffer_fd = -1;
 216         struct iovec *w;
 217         uint64_t *l;
 218         int i, j = 0;
 219         static const union sockaddr_union sa = {
 220                 .un.sun_family = AF_UNIX,
 221                 .un.sun_path = "/run/systemd/journal/socket",
 222         };
 223         struct msghdr mh = {
 224                 .msg_name = (struct sockaddr*) &sa.sa,
 225                 .msg_namelen = SOCKADDR_UN_LEN(sa.un),
 226         };
 227         ssize_t k;
 228         bool have_syslog_identifier = false;
 229         bool seal = true;
 230
 231         assert_return(iov, -EINVAL);
 232         assert_return(n > 0, -EINVAL);
 233
 234         w = newa(struct iovec, n * 5 + 3);
 235         l = newa(uint64_t, n);
 236
 237         for (i = 0; i < n; i++) {
 238                 char *c, *nl;
 239
 240                 if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1))
 241                         return -EINVAL;
 242
 243                 c = memchr(iov[i].iov_base, '=', iov[i].iov_len);
 244                 if (_unlikely_(!c || c == iov[i].iov_base))
 245                         return -EINVAL;
 246
 247                 have_syslog_identifier = have_syslog_identifier ||
 248                         (c == (char *) iov[i].iov_base + 17 &&
 249                          startswith(iov[i].iov_base, "SYSLOG_IDENTIFIER"));
 250
 251                 nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len);
 252                 if (nl) {
 253                         if (_unlikely_(nl < c))
 254                                 return -EINVAL;
 255
 256                         /* Already includes a newline? Bummer, then
 257                          * let's write the variable name, then a
 258                          * newline, then the size (64bit LE), followed
 259                          * by the data and a final newline */
 260
 261                         w[j++] = IOVEC_MAKE(iov[i].iov_base, c - (char*) iov[i].iov_base);
 262                         w[j++] = IOVEC_MAKE_STRING("\n");
 263
 264                         l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
 265                         w[j++] = IOVEC_MAKE(&l[i], sizeof(uint64_t));
 266
 267                         w[j++] = IOVEC_MAKE(c + 1, iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
 268                 } else
 269                         /* Nothing special? Then just add the line and
 270                          * append a newline */
 271                         w[j++] = iov[i];
 272
 273                 w[j++] = IOVEC_MAKE_STRING("\n");
 274         }
 275
 276         if (!have_syslog_identifier &&
 277             string_is_safe(program_invocation_short_name)) {
 278
 279                 /* Implicitly add program_invocation_short_name, if it
 280                  * is not set explicitly. We only do this for
 281                  * program_invocation_short_name, and nothing else
 282                  * since everything else is much nicer to retrieve
 283                  * from the outside. */
 284
 285                 w[j++] = IOVEC_MAKE_STRING("SYSLOG_IDENTIFIER=");
 286                 w[j++] = IOVEC_MAKE_STRING(program_invocation_short_name);
 287                 w[j++] = IOVEC_MAKE_STRING("\n");
 288         }
 289
 290         fd = journal_fd();
 291         if (_unlikely_(fd < 0))
 292                 return fd;
 293
 294         mh.msg_iov = w;
 295         mh.msg_iovlen = j;
 296
 297         k = sendmsg(fd, &mh, MSG_NOSIGNAL);
 298         if (k >= 0)
 299                 return 0;
 300
 301         /* Fail silently if the journal is not available */
 302         if (errno == ENOENT)
 303                 return 0;
 304
 305         if (errno != EMSGSIZE && errno != ENOBUFS)
 306                 return -errno;
 307
 308         /* Message doesn't fit... Let's dump the data in a memfd or
 309          * temporary file and just pass a file descriptor of it to the
 310          * other side.
 311          *
 312          * For the temporary files we use /dev/shm instead of /tmp
 313          * here, since we want this to be a tmpfs, and one that is
 314          * available from early boot on and where unprivileged users
 315          * can create files. */
 316         buffer_fd = memfd_new(NULL);
 317         if (buffer_fd < 0) {
 318                 if (buffer_fd == -ENOSYS) {
 319                         buffer_fd = open_tmpfile_unlinkable("/dev/shm", O_RDWR | O_CLOEXEC);
 320                         if (buffer_fd < 0)
 321                                 return buffer_fd;
 322
 323                         seal = false;
 324                 } else
 325                         return buffer_fd;
 326         }
 327
 328         n = writev(buffer_fd, w, j);
 329         if (n < 0)
 330                 return -errno;
 331
 332         if (seal) {
 333                 r = memfd_set_sealed(buffer_fd);
 334                 if (r < 0)
 335                         return r;
 336         }
 337
 338         r = send_one_fd_sa(fd, buffer_fd, mh.msg_name, mh.msg_namelen, 0);
 339         if (r == -ENOENT)
 340                 /* Fail silently if the journal is not available */
 341                 return 0;
 342         return r;
 343 }
 344
 345 static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) {
 346         PROTECT_ERRNO;
 347         size_t n, k;
 348
 349         k = isempty(message) ? 0 : strlen(message) + 2;
 350         n = 8 + k + 256 + 1;
 351
 352         for (;;) {
 353                 char buffer[n];
 354                 char* j;
 355
 356                 errno = 0;
 357                 j = strerror_r(_saved_errno_, buffer + 8 + k, n - 8 - k);
 358                 if (errno == 0) {
 359                         char error[sizeof("ERRNO=")-1 + DECIMAL_STR_MAX(int) + 1];
 360
 361                         if (j != buffer + 8 + k)
 362                                 memmove(buffer + 8 + k, j, strlen(j)+1);
 363
 364                         memcpy(buffer, "MESSAGE=", 8);
 365
 366                         if (k > 0) {
 367                                 memcpy(buffer + 8, message, k - 2);
 368                                 memcpy(buffer + 8 + k - 2, ": ", 2);
 369                         }
 370
 371                         xsprintf(error, "ERRNO=%i", _saved_errno_);
 372
 373                         assert_cc(3 == LOG_ERR);
 374                         iov[skip+0] = IOVEC_MAKE_STRING("PRIORITY=3");
 375                         iov[skip+1] = IOVEC_MAKE_STRING(buffer);
 376                         iov[skip+2] = IOVEC_MAKE_STRING(error);
 377
 378                         return sd_journal_sendv(iov, skip + 3);
 379                 }
 380
 381                 if (errno != ERANGE)
 382                         return -errno;
 383
 384                 n *= 2;
 385         }
 386 }
 387
 388 _public_ int sd_journal_perror(const char *message) {
 389         struct iovec iovec[3];
 390
 391         return fill_iovec_perror_and_send(message, 0, iovec);
 392 }
 393
 394 _public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) {
 395         static const union sockaddr_union sa = {
 396                 .un.sun_family = AF_UNIX,
 397                 .un.sun_path = "/run/systemd/journal/stdout",
 398         };
 399         _cleanup_close_ int fd = -1;
 400         char *header;
 401         size_t l;
 402         int r;
 403
 404         assert_return(priority >= 0, -EINVAL);
 405         assert_return(priority <= 7, -EINVAL);
 406
 407         fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
 408         if (fd < 0)
 409                 return -errno;
 410
 411         r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
 412         if (r < 0)
 413                 return -errno;
 414
 415         if (shutdown(fd, SHUT_RD) < 0)
 416                 return -errno;
 417
 418         fd_inc_sndbuf(fd, SNDBUF_SIZE);
 419
 420         if (!identifier)
 421                 identifier = "";
 422
 423         l = strlen(identifier);
 424         header = alloca(l + 1 + 1 + 2 + 2 + 2 + 2 + 2);
 425
 426         memcpy(header, identifier, l);
 427         header[l++] = '\n';
 428         header[l++] = '\n'; /* unit id */
 429         header[l++] = '0' + priority;
 430         header[l++] = '\n';
 431         header[l++] = '0' + !!level_prefix;
 432         header[l++] = '\n';
 433         header[l++] = '0';
 434         header[l++] = '\n';
 435         header[l++] = '0';
 436         header[l++] = '\n';
 437         header[l++] = '0';
 438         header[l++] = '\n';
 439
 440         r = loop_write(fd, header, l, false);
 441         if (r < 0)
 442                 return r;
 443
 444         r = fd;
 445         fd = -1;
 446         return r;
 447 }
 448
 449 _public_ int sd_journal_print_with_location(int priority, const char *file, const char *line, const char *func, const char *format, ...) {
 450         int r;
 451         va_list ap;
 452
 453         va_start(ap, format);
 454         r = sd_journal_printv_with_location(priority, file, line, func, format, ap);
 455         va_end(ap);
 456
 457         return r;
 458 }
 459
 460 _public_ int sd_journal_printv_with_location(int priority, const char *file, const char *line, const char *func, const char *format, va_list ap) {
 461         char buffer[8 + LINE_MAX], p[sizeof("PRIORITY=")-1 + DECIMAL_STR_MAX(int) + 1];
 462         struct iovec iov[5];
 463         char *f;
 464
 465         assert_return(priority >= 0, -EINVAL);
 466         assert_return(priority <= 7, -EINVAL);
 467         assert_return(format, -EINVAL);
 468
 469         xsprintf(p, "PRIORITY=%i", priority & LOG_PRIMASK);
 470
 471         memcpy(buffer, "MESSAGE=", 8);
 472         vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
 473
 474         /* Strip trailing whitespace, keep prefixing whitespace */
 475         (void) strstrip(buffer);
 476
 477         /* Suppress empty lines */
 478         if (isempty(buffer+8))
 479                 return 0;
 480
 481         /* func is initialized from __func__ which is not a macro, but
 482          * a static const char[], hence cannot easily be prefixed with
 483          * CODE_FUNC=, hence let's do it manually here. */
 484         ALLOCA_CODE_FUNC(f, func);
 485
 486         iov[0] = IOVEC_MAKE_STRING(buffer);
 487         iov[1] = IOVEC_MAKE_STRING(p);
 488         iov[2] = IOVEC_MAKE_STRING(file);
 489         iov[3] = IOVEC_MAKE_STRING(line);
 490         iov[4] = IOVEC_MAKE_STRING(f);
 491
 492         return sd_journal_sendv(iov, ELEMENTSOF(iov));
 493 }
 494
 495 _public_ int sd_journal_send_with_location(const char *file, const char *line, const char *func, const char *format, ...) {
 496         _cleanup_free_ struct iovec *iov = NULL;
 497         int r, i, j;
 498         va_list ap;
 499         char *f;
 500
 501         va_start(ap, format);
 502         i = fill_iovec_sprintf(format, ap, 3, &iov);
 503         va_end(ap);
 504
 505         if (_unlikely_(i < 0)) {
 506                 r = i;
 507                 goto finish;
 508         }
 509
 510         ALLOCA_CODE_FUNC(f, func);
 511
 512         iov[0] = IOVEC_MAKE_STRING(file);
 513         iov[1] = IOVEC_MAKE_STRING(line);
 514         iov[2] = IOVEC_MAKE_STRING(f);
 515
 516         r = sd_journal_sendv(iov, i);
 517
 518 finish:
 519         for (j = 3; j < i; j++)
 520                 free(iov[j].iov_base);
 521
 522         return r;
 523 }
 524
 525 _public_ int sd_journal_sendv_with_location(
 526                 const char *file, const char *line,
 527                 const char *func,
 528                 const struct iovec *iov, int n) {
 529
 530         struct iovec *niov;
 531         char *f;
 532
 533         assert_return(iov, -EINVAL);
 534         assert_return(n > 0, -EINVAL);
 535
 536         niov = alloca(sizeof(struct iovec) * (n + 3));
 537         memcpy(niov, iov, sizeof(struct iovec) * n);
 538
 539         ALLOCA_CODE_FUNC(f, func);
 540
 541         niov[n++] = IOVEC_MAKE_STRING(file);
 542         niov[n++] = IOVEC_MAKE_STRING(line);
 543         niov[n++] = IOVEC_MAKE_STRING(f);
 544
 545         return sd_journal_sendv(niov, n);
 546 }
 547
 548 _public_ int sd_journal_perror_with_location(
 549                 const char *file, const char *line,
 550                 const char *func,
 551                 const char *message) {
 552
 553         struct iovec iov[6];
 554         char *f;
 555
 556         ALLOCA_CODE_FUNC(f, func);
 557
 558         iov[0] = IOVEC_MAKE_STRING(file);
 559         iov[1] = IOVEC_MAKE_STRING(line);
 560         iov[2] = IOVEC_MAKE_STRING(f);
 561
 562         return fill_iovec_perror_and_send(message, 3, iov);
 563 }