src/journal/journal-send.c

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