src/journal/journal-send.c

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