src/journal/journal-send.c

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