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