src/basic/log.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 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 <inttypes.h>
  23 #include <limits.h>
  24 #include <stdarg.h>
  25 #include <stddef.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <sys/signalfd.h>
  29 #include <sys/socket.h>
  30 #include <sys/time.h>
  31 #include <sys/uio.h>
  32 #include <sys/un.h>
  33 #include <time.h>
  34 #include <unistd.h>
  35
  36 #include "sd-messages.h"
  37
  38 #include "alloc-util.h"
  39 #include "fd-util.h"
  40 #include "format-util.h"
  41 #include "io-util.h"
  42 #include "log.h"
  43 #include "macro.h"
  44 #include "missing.h"
  45 #include "parse-util.h"
  46 #include "proc-cmdline.h"
  47 #include "process-util.h"
  48 #include "signal-util.h"
  49 #include "socket-util.h"
  50 #include "stdio-util.h"
  51 #include "string-table.h"
  52 #include "string-util.h"
  53 #include "syslog-util.h"
  54 #include "terminal-util.h"
  55 #include "time-util.h"
  56 #include "util.h"
  57
  58 #define SNDBUF_SIZE (8*1024*1024)
  59
  60 static LogTarget log_target = LOG_TARGET_CONSOLE;
  61 static int log_max_level[] = {LOG_INFO, LOG_INFO};
  62 assert_cc(ELEMENTSOF(log_max_level) == _LOG_REALM_MAX);
  63 static int log_facility = LOG_DAEMON;
  64
  65 static int console_fd = STDERR_FILENO;
  66 static int syslog_fd = -1;
  67 static int kmsg_fd = -1;
  68 static int journal_fd = -1;
  69
  70 static bool syslog_is_stream = false;
  71
  72 static bool show_color = false;
  73 static bool show_location = false;
  74
  75 static bool upgrade_syslog_to_journal = false;
  76 static bool always_reopen_console = false;
  77
  78 /* Akin to glibc's __abort_msg; which is private and we hence cannot
  79  * use here. */
  80 static char *log_abort_msg = NULL;
  81
  82 void log_close_console(void) {
  83
  84         if (console_fd < 0)
  85                 return;
  86
  87         if (getpid() == 1) {
  88                 if (console_fd >= 3)
  89                         safe_close(console_fd);
  90
  91                 console_fd = -1;
  92         }
  93 }
  94
  95 static int log_open_console(void) {
  96
  97         if (console_fd >= 0)
  98                 return 0;
  99
 100         if (always_reopen_console) {
 101                 console_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
 102                 if (console_fd < 0)
 103                         return console_fd;
 104         } else
 105                 console_fd = STDERR_FILENO;
 106
 107         return 0;
 108 }
 109
 110 void log_close_kmsg(void) {
 111         kmsg_fd = safe_close(kmsg_fd);
 112 }
 113
 114 static int log_open_kmsg(void) {
 115
 116         if (kmsg_fd >= 0)
 117                 return 0;
 118
 119         kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC);
 120         if (kmsg_fd < 0)
 121                 return -errno;
 122
 123         return 0;
 124 }
 125
 126 void log_close_syslog(void) {
 127         syslog_fd = safe_close(syslog_fd);
 128 }
 129
 130 static int create_log_socket(int type) {
 131         struct timeval tv;
 132         int fd;
 133
 134         fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0);
 135         if (fd < 0)
 136                 return -errno;
 137
 138         (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
 139
 140         /* We need a blocking fd here since we'd otherwise lose
 141         messages way too early. However, let's not hang forever in the
 142         unlikely case of a deadlock. */
 143         if (getpid() == 1)
 144                 timeval_store(&tv, 10 * USEC_PER_MSEC);
 145         else
 146                 timeval_store(&tv, 10 * USEC_PER_SEC);
 147         (void) setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
 148
 149         return fd;
 150 }
 151
 152 static int log_open_syslog(void) {
 153
 154         static const union sockaddr_union sa = {
 155                 .un.sun_family = AF_UNIX,
 156                 .un.sun_path = "/dev/log",
 157         };
 158
 159         int r;
 160
 161         if (syslog_fd >= 0)
 162                 return 0;
 163
 164         syslog_fd = create_log_socket(SOCK_DGRAM);
 165         if (syslog_fd < 0) {
 166                 r = syslog_fd;
 167                 goto fail;
 168         }
 169
 170         if (connect(syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
 171                 safe_close(syslog_fd);
 172
 173                 /* Some legacy syslog systems still use stream
 174                  * sockets. They really shouldn't. But what can we
 175                  * do... */
 176                 syslog_fd = create_log_socket(SOCK_STREAM);
 177                 if (syslog_fd < 0) {
 178                         r = syslog_fd;
 179                         goto fail;
 180                 }
 181
 182                 if (connect(syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
 183                         r = -errno;
 184                         goto fail;
 185                 }
 186
 187                 syslog_is_stream = true;
 188         } else
 189                 syslog_is_stream = false;
 190
 191         return 0;
 192
 193 fail:
 194         log_close_syslog();
 195         return r;
 196 }
 197
 198 void log_close_journal(void) {
 199         journal_fd = safe_close(journal_fd);
 200 }
 201
 202 static int log_open_journal(void) {
 203
 204         static const union sockaddr_union sa = {
 205                 .un.sun_family = AF_UNIX,
 206                 .un.sun_path = "/run/systemd/journal/socket",
 207         };
 208
 209         int r;
 210
 211         if (journal_fd >= 0)
 212                 return 0;
 213
 214         journal_fd = create_log_socket(SOCK_DGRAM);
 215         if (journal_fd < 0) {
 216                 r = journal_fd;
 217                 goto fail;
 218         }
 219
 220         if (connect(journal_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
 221                 r = -errno;
 222                 goto fail;
 223         }
 224
 225         return 0;
 226
 227 fail:
 228         log_close_journal();
 229         return r;
 230 }
 231
 232 int log_open(void) {
 233         int r;
 234
 235         /* Do not call from library code. */
 236
 237         /* If we don't use the console we close it here, to not get
 238          * killed by SAK. If we don't use syslog we close it here so
 239          * that we are not confused by somebody deleting the socket in
 240          * the fs. If we don't use /dev/kmsg we still keep it open,
 241          * because there is no reason to close it. */
 242
 243         if (log_target == LOG_TARGET_NULL) {
 244                 log_close_journal();
 245                 log_close_syslog();
 246                 log_close_console();
 247                 return 0;
 248         }
 249
 250         if (!IN_SET(log_target, LOG_TARGET_AUTO, LOG_TARGET_SAFE) ||
 251             getpid() == 1 ||
 252             isatty(STDERR_FILENO) <= 0) {
 253
 254                 if (IN_SET(log_target, LOG_TARGET_AUTO,
 255                                        LOG_TARGET_JOURNAL_OR_KMSG,
 256                                        LOG_TARGET_JOURNAL)) {
 257                         r = log_open_journal();
 258                         if (r >= 0) {
 259                                 log_close_syslog();
 260                                 log_close_console();
 261                                 return r;
 262                         }
 263                 }
 264
 265                 if (IN_SET(log_target, LOG_TARGET_SYSLOG_OR_KMSG,
 266                                        LOG_TARGET_SYSLOG)) {
 267                         r = log_open_syslog();
 268                         if (r >= 0) {
 269                                 log_close_journal();
 270                                 log_close_console();
 271                                 return r;
 272                         }
 273                 }
 274
 275                 if (IN_SET(log_target, LOG_TARGET_AUTO,
 276                                        LOG_TARGET_SAFE,
 277                                        LOG_TARGET_JOURNAL_OR_KMSG,
 278                                        LOG_TARGET_SYSLOG_OR_KMSG,
 279                                        LOG_TARGET_KMSG)) {
 280                         r = log_open_kmsg();
 281                         if (r >= 0) {
 282                                 log_close_journal();
 283                                 log_close_syslog();
 284                                 log_close_console();
 285                                 return r;
 286                         }
 287                 }
 288         }
 289
 290         log_close_journal();
 291         log_close_syslog();
 292
 293         return log_open_console();
 294 }
 295
 296 void log_set_target(LogTarget target) {
 297         assert(target >= 0);
 298         assert(target < _LOG_TARGET_MAX);
 299
 300         if (upgrade_syslog_to_journal) {
 301                 if (target == LOG_TARGET_SYSLOG)
 302                         target = LOG_TARGET_JOURNAL;
 303                 else if (target == LOG_TARGET_SYSLOG_OR_KMSG)
 304                         target = LOG_TARGET_JOURNAL_OR_KMSG;
 305         }
 306
 307         log_target = target;
 308 }
 309
 310 void log_close(void) {
 311         /* Do not call from library code. */
 312
 313         log_close_journal();
 314         log_close_syslog();
 315         log_close_kmsg();
 316         log_close_console();
 317 }
 318
 319 void log_forget_fds(void) {
 320         /* Do not call from library code. */
 321
 322         console_fd = kmsg_fd = syslog_fd = journal_fd = -1;
 323 }
 324
 325 void log_set_max_level_realm(LogRealm realm, int level) {
 326         assert((level & LOG_PRIMASK) == level);
 327         assert(realm < ELEMENTSOF(log_max_level));
 328
 329         log_max_level[realm] = level;
 330 }
 331
 332 void log_set_facility(int facility) {
 333         log_facility = facility;
 334 }
 335
 336 static int write_to_console(
 337                 int level,
 338                 int error,
 339                 const char *file,
 340                 int line,
 341                 const char *func,
 342                 const char *buffer) {
 343
 344         char location[256], prefix[1 + DECIMAL_STR_MAX(int) + 2];
 345         struct iovec iovec[6] = {};
 346         unsigned n = 0;
 347         bool highlight;
 348
 349         if (console_fd < 0)
 350                 return 0;
 351
 352         if (log_target == LOG_TARGET_CONSOLE_PREFIXED) {
 353                 xsprintf(prefix, "<%i>", level);
 354                 IOVEC_SET_STRING(iovec[n++], prefix);
 355         }
 356
 357         highlight = LOG_PRI(level) <= LOG_ERR && show_color;
 358
 359         if (show_location) {
 360                 snprintf(location, sizeof(location), "(%s:%i) ", file, line);
 361                 IOVEC_SET_STRING(iovec[n++], location);
 362         }
 363
 364         if (highlight)
 365                 IOVEC_SET_STRING(iovec[n++], ANSI_HIGHLIGHT_RED);
 366         IOVEC_SET_STRING(iovec[n++], buffer);
 367         if (highlight)
 368                 IOVEC_SET_STRING(iovec[n++], ANSI_NORMAL);
 369         IOVEC_SET_STRING(iovec[n++], "\n");
 370
 371         if (writev(console_fd, iovec, n) < 0) {
 372
 373                 if (errno == EIO && getpid() == 1) {
 374
 375                         /* If somebody tried to kick us from our
 376                          * console tty (via vhangup() or suchlike),
 377                          * try to reconnect */
 378
 379                         log_close_console();
 380                         log_open_console();
 381
 382                         if (console_fd < 0)
 383                                 return 0;
 384
 385                         if (writev(console_fd, iovec, n) < 0)
 386                                 return -errno;
 387                 } else
 388                         return -errno;
 389         }
 390
 391         return 1;
 392 }
 393
 394 static int write_to_syslog(
 395                 int level,
 396                 int error,
 397                 const char *file,
 398                 int line,
 399                 const char *func,
 400                 const char *buffer) {
 401
 402         char header_priority[2 + DECIMAL_STR_MAX(int) + 1],
 403              header_time[64],
 404              header_pid[4 + DECIMAL_STR_MAX(pid_t) + 1];
 405         struct iovec iovec[5] = {};
 406         struct msghdr msghdr = {
 407                 .msg_iov = iovec,
 408                 .msg_iovlen = ELEMENTSOF(iovec),
 409         };
 410         time_t t;
 411         struct tm *tm;
 412
 413         if (syslog_fd < 0)
 414                 return 0;
 415
 416         xsprintf(header_priority, "<%i>", level);
 417
 418         t = (time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC);
 419         tm = localtime(&t);
 420         if (!tm)
 421                 return -EINVAL;
 422
 423         if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
 424                 return -EINVAL;
 425
 426         xsprintf(header_pid, "["PID_FMT"]: ", getpid());
 427
 428         IOVEC_SET_STRING(iovec[0], header_priority);
 429         IOVEC_SET_STRING(iovec[1], header_time);
 430         IOVEC_SET_STRING(iovec[2], program_invocation_short_name);
 431         IOVEC_SET_STRING(iovec[3], header_pid);
 432         IOVEC_SET_STRING(iovec[4], buffer);
 433
 434         /* When using syslog via SOCK_STREAM separate the messages by NUL chars */
 435         if (syslog_is_stream)
 436                 iovec[4].iov_len++;
 437
 438         for (;;) {
 439                 ssize_t n;
 440
 441                 n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL);
 442                 if (n < 0)
 443                         return -errno;
 444
 445                 if (!syslog_is_stream ||
 446                     (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
 447                         break;
 448
 449                 IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
 450         }
 451
 452         return 1;
 453 }
 454
 455 static int write_to_kmsg(
 456                 int level,
 457                 int error,
 458                 const char *file,
 459                 int line,
 460                 const char *func,
 461                 const char *buffer) {
 462
 463         char header_priority[2 + DECIMAL_STR_MAX(int) + 1],
 464              header_pid[4 + DECIMAL_STR_MAX(pid_t) + 1];
 465         struct iovec iovec[5] = {};
 466
 467         if (kmsg_fd < 0)
 468                 return 0;
 469
 470         xsprintf(header_priority, "<%i>", level);
 471         xsprintf(header_pid, "["PID_FMT"]: ", getpid());
 472
 473         IOVEC_SET_STRING(iovec[0], header_priority);
 474         IOVEC_SET_STRING(iovec[1], program_invocation_short_name);
 475         IOVEC_SET_STRING(iovec[2], header_pid);
 476         IOVEC_SET_STRING(iovec[3], buffer);
 477         IOVEC_SET_STRING(iovec[4], "\n");
 478
 479         if (writev(kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
 480                 return -errno;
 481
 482         return 1;
 483 }
 484
 485 static int log_do_header(
 486                 char *header,
 487                 size_t size,
 488                 int level,
 489                 int error,
 490                 const char *file, int line, const char *func,
 491                 const char *object_field, const char *object,
 492                 const char *extra_field, const char *extra) {
 493
 494         snprintf(header, size,
 495                  "PRIORITY=%i\n"
 496                  "SYSLOG_FACILITY=%i\n"
 497                  "%s%s%s"
 498                  "%s%.*i%s"
 499                  "%s%s%s"
 500                  "%s%.*i%s"
 501                  "%s%s%s"
 502                  "%s%s%s"
 503                  "SYSLOG_IDENTIFIER=%s\n",
 504                  LOG_PRI(level),
 505                  LOG_FAC(level),
 506                  isempty(file) ? "" : "CODE_FILE=",
 507                  isempty(file) ? "" : file,
 508                  isempty(file) ? "" : "\n",
 509                  line ? "CODE_LINE=" : "",
 510                  line ? 1 : 0, line, /* %.0d means no output too, special case for 0 */
 511                  line ? "\n" : "",
 512                  isempty(func) ? "" : "CODE_FUNC=",
 513                  isempty(func) ? "" : func,
 514                  isempty(func) ? "" : "\n",
 515                  error ? "ERRNO=" : "",
 516                  error ? 1 : 0, error,
 517                  error ? "\n" : "",
 518                  isempty(object) ? "" : object_field,
 519                  isempty(object) ? "" : object,
 520                  isempty(object) ? "" : "\n",
 521                  isempty(extra) ? "" : extra_field,
 522                  isempty(extra) ? "" : extra,
 523                  isempty(extra) ? "" : "\n",
 524                  program_invocation_short_name);
 525
 526         return 0;
 527 }
 528
 529 static int write_to_journal(
 530                 int level,
 531                 int error,
 532                 const char *file,
 533                 int line,
 534                 const char *func,
 535                 const char *object_field,
 536                 const char *object,
 537                 const char *extra_field,
 538                 const char *extra,
 539                 const char *buffer) {
 540
 541         char header[LINE_MAX];
 542         struct iovec iovec[4] = {};
 543         struct msghdr mh = {};
 544
 545         if (journal_fd < 0)
 546                 return 0;
 547
 548         log_do_header(header, sizeof(header), level, error, file, line, func, object_field, object, extra_field, extra);
 549
 550         IOVEC_SET_STRING(iovec[0], header);
 551         IOVEC_SET_STRING(iovec[1], "MESSAGE=");
 552         IOVEC_SET_STRING(iovec[2], buffer);
 553         IOVEC_SET_STRING(iovec[3], "\n");
 554
 555         mh.msg_iov = iovec;
 556         mh.msg_iovlen = ELEMENTSOF(iovec);
 557
 558         if (sendmsg(journal_fd, &mh, MSG_NOSIGNAL) < 0)
 559                 return -errno;
 560
 561         return 1;
 562 }
 563
 564 int log_dispatch_internal(
 565                 int level,
 566                 int error,
 567                 const char *file,
 568                 int line,
 569                 const char *func,
 570                 const char *object_field,
 571                 const char *object,
 572                 const char *extra,
 573                 const char *extra_field,
 574                 char *buffer) {
 575
 576         assert(buffer);
 577
 578         if (error < 0)
 579                 error = -error;
 580
 581         if (log_target == LOG_TARGET_NULL)
 582                 return -error;
 583
 584         /* Patch in LOG_DAEMON facility if necessary */
 585         if ((level & LOG_FACMASK) == 0)
 586                 level = log_facility | LOG_PRI(level);
 587
 588         do {
 589                 char *e;
 590                 int k = 0;
 591
 592                 buffer += strspn(buffer, NEWLINE);
 593
 594                 if (buffer[0] == 0)
 595                         break;
 596
 597                 if ((e = strpbrk(buffer, NEWLINE)))
 598                         *(e++) = 0;
 599
 600                 if (IN_SET(log_target, LOG_TARGET_AUTO,
 601                                        LOG_TARGET_JOURNAL_OR_KMSG,
 602                                        LOG_TARGET_JOURNAL)) {
 603
 604                         k = write_to_journal(level, error, file, line, func, object_field, object, extra_field, extra, buffer);
 605                         if (k < 0) {
 606                                 if (k != -EAGAIN)
 607                                         log_close_journal();
 608                                 log_open_kmsg();
 609                         }
 610                 }
 611
 612                 if (IN_SET(log_target, LOG_TARGET_SYSLOG_OR_KMSG,
 613                                        LOG_TARGET_SYSLOG)) {
 614
 615                         k = write_to_syslog(level, error, file, line, func, buffer);
 616                         if (k < 0) {
 617                                 if (k != -EAGAIN)
 618                                         log_close_syslog();
 619                                 log_open_kmsg();
 620                         }
 621                 }
 622
 623                 if (k <= 0 &&
 624                     IN_SET(log_target, LOG_TARGET_AUTO,
 625                                        LOG_TARGET_SAFE,
 626                                        LOG_TARGET_SYSLOG_OR_KMSG,
 627                                        LOG_TARGET_JOURNAL_OR_KMSG,
 628                                        LOG_TARGET_KMSG)) {
 629
 630                         k = write_to_kmsg(level, error, file, line, func, buffer);
 631                         if (k < 0) {
 632                                 log_close_kmsg();
 633                                 log_open_console();
 634                         }
 635                 }
 636
 637                 if (k <= 0)
 638                         (void) write_to_console(level, error, file, line, func, buffer);
 639
 640                 buffer = e;
 641         } while (buffer);
 642
 643         return -error;
 644 }
 645
 646 int log_dump_internal(
 647                 int level,
 648                 int error,
 649                 const char *file,
 650                 int line,
 651                 const char *func,
 652                 char *buffer) {
 653
 654         LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
 655         PROTECT_ERRNO;
 656
 657         /* This modifies the buffer... */
 658
 659         if (error < 0)
 660                 error = -error;
 661
 662         if (_likely_(LOG_PRI(level) > log_max_level[realm]))
 663                 return -error;
 664
 665         return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, buffer);
 666 }
 667
 668 int log_internalv_realm(
 669                 int level,
 670                 int error,
 671                 const char *file,
 672                 int line,
 673                 const char *func,
 674                 const char *format,
 675                 va_list ap) {
 676
 677         LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
 678         char buffer[LINE_MAX];
 679         PROTECT_ERRNO;
 680
 681         if (error < 0)
 682                 error = -error;
 683
 684         if (_likely_(LOG_PRI(level) > log_max_level[realm]))
 685                 return -error;
 686
 687         /* Make sure that %m maps to the specified error */
 688         if (error != 0)
 689                 errno = error;
 690
 691         vsnprintf(buffer, sizeof(buffer), format, ap);
 692
 693         return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, buffer);
 694 }
 695
 696 int log_internal_realm(
 697                 int level,
 698                 int error,
 699                 const char *file,
 700                 int line,
 701                 const char *func,
 702                 const char *format, ...) {
 703
 704         va_list ap;
 705         int r;
 706
 707         va_start(ap, format);
 708         r = log_internalv_realm(level, error, file, line, func, format, ap);
 709         va_end(ap);
 710
 711         return r;
 712 }
 713
 714 int log_object_internalv(
 715                 int level,
 716                 int error,
 717                 const char *file,
 718                 int line,
 719                 const char *func,
 720                 const char *object_field,
 721                 const char *object,
 722                 const char *extra_field,
 723                 const char *extra,
 724                 const char *format,
 725                 va_list ap) {
 726
 727         PROTECT_ERRNO;
 728         char *buffer, *b;
 729
 730         if (error < 0)
 731                 error = -error;
 732
 733         if (_likely_(LOG_PRI(level) > log_max_level[LOG_REALM_SYSTEMD]))
 734                 return -error;
 735
 736         /* Make sure that %m maps to the specified error */
 737         if (error != 0)
 738                 errno = error;
 739
 740         /* Prepend the object name before the message */
 741         if (object) {
 742                 size_t n;
 743
 744                 n = strlen(object);
 745                 buffer = newa(char, n + 2 + LINE_MAX);
 746                 b = stpcpy(stpcpy(buffer, object), ": ");
 747         } else
 748                 b = buffer = newa(char, LINE_MAX);
 749
 750         vsnprintf(b, LINE_MAX, format, ap);
 751
 752         return log_dispatch_internal(level, error, file, line, func,
 753                                      object_field, object, extra_field, extra, buffer);
 754 }
 755
 756 int log_object_internal(
 757                 int level,
 758                 int error,
 759                 const char *file,
 760                 int line,
 761                 const char *func,
 762                 const char *object_field,
 763                 const char *object,
 764                 const char *extra_field,
 765                 const char *extra,
 766                 const char *format, ...) {
 767
 768         va_list ap;
 769         int r;
 770
 771         va_start(ap, format);
 772         r = log_object_internalv(level, error, file, line, func, object_field, object, extra_field, extra, format, ap);
 773         va_end(ap);
 774
 775         return r;
 776 }
 777
 778 static void log_assert(
 779                 int level,
 780                 const char *text,
 781                 const char *file,
 782                 int line,
 783                 const char *func,
 784                 const char *format) {
 785
 786         static char buffer[LINE_MAX];
 787         LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
 788
 789         if (_likely_(LOG_PRI(level) > log_max_level[realm]))
 790                 return;
 791
 792         DISABLE_WARNING_FORMAT_NONLITERAL;
 793         snprintf(buffer, sizeof buffer, format, text, file, line, func);
 794         REENABLE_WARNING;
 795
 796         log_abort_msg = buffer;
 797
 798         log_dispatch_internal(level, 0, file, line, func, NULL, NULL, NULL, NULL, buffer);
 799 }
 800
 801 noreturn void log_assert_failed_realm(
 802                 LogRealm realm,
 803                 const char *text,
 804                 const char *file,
 805                 int line,
 806                 const char *func) {
 807         log_assert(LOG_REALM_PLUS_LEVEL(realm, LOG_CRIT), text, file, line, func,
 808                    "Assertion '%s' failed at %s:%u, function %s(). Aborting.");
 809         abort();
 810 }
 811
 812 noreturn void log_assert_failed_unreachable_realm(
 813                 LogRealm realm,
 814                 const char *text,
 815                 const char *file,
 816                 int line,
 817                 const char *func) {
 818         log_assert(LOG_REALM_PLUS_LEVEL(realm, LOG_CRIT), text, file, line, func,
 819                    "Code should not be reached '%s' at %s:%u, function %s(). Aborting.");
 820         abort();
 821 }
 822
 823 void log_assert_failed_return_realm(
 824                 LogRealm realm,
 825                 const char *text,
 826                 const char *file,
 827                 int line,
 828                 const char *func) {
 829         PROTECT_ERRNO;
 830         log_assert(LOG_REALM_PLUS_LEVEL(realm, LOG_DEBUG), text, file, line, func,
 831                    "Assertion '%s' failed at %s:%u, function %s(). Ignoring.");
 832 }
 833
 834 int log_oom_internal(LogRealm realm, const char *file, int line, const char *func) {
 835         log_internal_realm(LOG_REALM_PLUS_LEVEL(realm, LOG_ERR),
 836                            ENOMEM, file, line, func, "Out of memory.");
 837         return -ENOMEM;
 838 }
 839
 840 int log_format_iovec(
 841                 struct iovec *iovec,
 842                 unsigned iovec_len,
 843                 unsigned *n,
 844                 bool newline_separator,
 845                 int error,
 846                 const char *format,
 847                 va_list ap) {
 848
 849         static const char nl = '\n';
 850
 851         while (format && *n + 1 < iovec_len) {
 852                 va_list aq;
 853                 char *m;
 854                 int r;
 855
 856                 /* We need to copy the va_list structure,
 857                  * since vasprintf() leaves it afterwards at
 858                  * an undefined location */
 859
 860                 if (error != 0)
 861                         errno = error;
 862
 863                 va_copy(aq, ap);
 864                 r = vasprintf(&m, format, aq);
 865                 va_end(aq);
 866                 if (r < 0)
 867                         return -EINVAL;
 868
 869                 /* Now, jump enough ahead, so that we point to
 870                  * the next format string */
 871                 VA_FORMAT_ADVANCE(format, ap);
 872
 873                 IOVEC_SET_STRING(iovec[(*n)++], m);
 874
 875                 if (newline_separator) {
 876                         iovec[*n].iov_base = (char*) &nl;
 877                         iovec[*n].iov_len = 1;
 878                         (*n)++;
 879                 }
 880
 881                 format = va_arg(ap, char *);
 882         }
 883         return 0;
 884 }
 885
 886 int log_struct_internal(
 887                 int level,
 888                 int error,
 889                 const char *file,
 890                 int line,
 891                 const char *func,
 892                 const char *format, ...) {
 893
 894         char buf[LINE_MAX];
 895         bool found = false;
 896         LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
 897         PROTECT_ERRNO;
 898         va_list ap;
 899
 900         if (error < 0)
 901                 error = -error;
 902
 903         if (_likely_(LOG_PRI(level) > log_max_level[realm]))
 904                 return -error;
 905
 906         if (log_target == LOG_TARGET_NULL)
 907                 return -error;
 908
 909         if ((level & LOG_FACMASK) == 0)
 910                 level = log_facility | LOG_PRI(level);
 911
 912         if (IN_SET(log_target, LOG_TARGET_AUTO,
 913                                LOG_TARGET_JOURNAL_OR_KMSG,
 914                                LOG_TARGET_JOURNAL) &&
 915             journal_fd >= 0) {
 916                 char header[LINE_MAX];
 917                 struct iovec iovec[17] = {};
 918                 unsigned n = 0, i;
 919                 int r;
 920                 struct msghdr mh = {
 921                         .msg_iov = iovec,
 922                 };
 923                 bool fallback = false;
 924
 925                 /* If the journal is available do structured logging */
 926                 log_do_header(header, sizeof(header), level, error, file, line, func, NULL, NULL, NULL, NULL);
 927                 IOVEC_SET_STRING(iovec[n++], header);
 928
 929                 va_start(ap, format);
 930                 r = log_format_iovec(iovec, ELEMENTSOF(iovec), &n, true, error, format, ap);
 931                 if (r < 0)
 932                         fallback = true;
 933                 else {
 934                         mh.msg_iovlen = n;
 935                         (void) sendmsg(journal_fd, &mh, MSG_NOSIGNAL);
 936                 }
 937
 938                 va_end(ap);
 939                 for (i = 1; i < n; i += 2)
 940                         free(iovec[i].iov_base);
 941
 942                 if (!fallback)
 943                         return -error;
 944         }
 945
 946         /* Fallback if journal logging is not available or didn't work. */
 947
 948         va_start(ap, format);
 949         while (format) {
 950                 va_list aq;
 951
 952                 if (error != 0)
 953                         errno = error;
 954
 955                 va_copy(aq, ap);
 956                 vsnprintf(buf, sizeof(buf), format, aq);
 957                 va_end(aq);
 958
 959                 if (startswith(buf, "MESSAGE=")) {
 960                         found = true;
 961                         break;
 962                 }
 963
 964                 VA_FORMAT_ADVANCE(format, ap);
 965
 966                 format = va_arg(ap, char *);
 967         }
 968         va_end(ap);
 969
 970         if (!found)
 971                 return -error;
 972
 973         return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, buf + 8);
 974 }
 975
 976 int log_set_target_from_string(const char *e) {
 977         LogTarget t;
 978
 979         t = log_target_from_string(e);
 980         if (t < 0)
 981                 return -EINVAL;
 982
 983         log_set_target(t);
 984         return 0;
 985 }
 986
 987 int log_set_max_level_from_string_realm(LogRealm realm, const char *e) {
 988         int t;
 989
 990         t = log_level_from_string(e);
 991         if (t < 0)
 992                 return -EINVAL;
 993
 994         log_set_max_level_realm(realm, t);
 995         return 0;
 996 }
 997
 998 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 999
1000         /*
1001          * The systemd.log_xyz= settings are parsed by all tools, and
1002          * so is "debug".
1003          *
1004          * However, "quiet" is only parsed by PID 1, and only turns of
1005          * status output to /dev/console, but does not alter the log
1006          * level.
1007          */
1008
1009         if (streq(key, "debug") && !value)
1010                 log_set_max_level(LOG_DEBUG);
1011
1012         else if (proc_cmdline_key_streq(key, "systemd.log_target")) {
1013
1014                 if (proc_cmdline_value_missing(key, value))
1015                         return 0;
1016
1017                 if (log_set_target_from_string(value) < 0)
1018                         log_warning("Failed to parse log target '%s'. Ignoring.", value);
1019
1020         } else if (proc_cmdline_key_streq(key, "systemd.log_level")) {
1021
1022                 if (proc_cmdline_value_missing(key, value))
1023                         return 0;
1024
1025                 if (log_set_max_level_from_string(value) < 0)
1026                         log_warning("Failed to parse log level '%s'. Ignoring.", value);
1027
1028         } else if (proc_cmdline_key_streq(key, "systemd.log_color")) {
1029
1030                 if (log_show_color_from_string(value ?: "1") < 0)
1031                         log_warning("Failed to parse log color setting '%s'. Ignoring.", value);
1032
1033         } else if (proc_cmdline_key_streq(key, "systemd.log_location")) {
1034
1035                 if (log_show_location_from_string(value ?: "1") < 0)
1036                         log_warning("Failed to parse log location setting '%s'. Ignoring.", value);
1037         }
1038
1039         return 0;
1040 }
1041
1042 void log_parse_environment_realm(LogRealm realm) {
1043         /* Do not call from library code. */
1044
1045         const char *e;
1046
1047         if (get_ctty_devnr(0, NULL) < 0)
1048                 /* Only try to read the command line in daemons.  We assume that anything that has a controlling tty is
1049                    user stuff. */
1050                 (void) proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
1051
1052         e = getenv("SYSTEMD_LOG_TARGET");
1053         if (e && log_set_target_from_string(e) < 0)
1054                 log_warning("Failed to parse log target '%s'. Ignoring.", e);
1055
1056         e = getenv("SYSTEMD_LOG_LEVEL");
1057         if (e && log_set_max_level_from_string_realm(realm, e) < 0)
1058                 log_warning("Failed to parse log level '%s'. Ignoring.", e);
1059
1060         e = getenv("SYSTEMD_LOG_COLOR");
1061         if (e && log_show_color_from_string(e) < 0)
1062                 log_warning("Failed to parse bool '%s'. Ignoring.", e);
1063
1064         e = getenv("SYSTEMD_LOG_LOCATION");
1065         if (e && log_show_location_from_string(e) < 0)
1066                 log_warning("Failed to parse bool '%s'. Ignoring.", e);
1067 }
1068
1069 LogTarget log_get_target(void) {
1070         return log_target;
1071 }
1072
1073 int log_get_max_level_realm(LogRealm realm) {
1074         return log_max_level[realm];
1075 }
1076
1077 void log_show_color(bool b) {
1078         show_color = b;
1079 }
1080
1081 bool log_get_show_color(void) {
1082         return show_color;
1083 }
1084
1085 void log_show_location(bool b) {
1086         show_location = b;
1087 }
1088
1089 bool log_get_show_location(void) {
1090         return show_location;
1091 }
1092
1093 int log_show_color_from_string(const char *e) {
1094         int t;
1095
1096         t = parse_boolean(e);
1097         if (t < 0)
1098                 return t;
1099
1100         log_show_color(t);
1101         return 0;
1102 }
1103
1104 int log_show_location_from_string(const char *e) {
1105         int t;
1106
1107         t = parse_boolean(e);
1108         if (t < 0)
1109                 return t;
1110
1111         log_show_location(t);
1112         return 0;
1113 }
1114
1115 bool log_on_console(void) {
1116         if (IN_SET(log_target, LOG_TARGET_CONSOLE,
1117                                LOG_TARGET_CONSOLE_PREFIXED))
1118                 return true;
1119
1120         return syslog_fd < 0 && kmsg_fd < 0 && journal_fd < 0;
1121 }
1122
1123 static const char *const log_target_table[_LOG_TARGET_MAX] = {
1124         [LOG_TARGET_CONSOLE] = "console",
1125         [LOG_TARGET_CONSOLE_PREFIXED] = "console-prefixed",
1126         [LOG_TARGET_KMSG] = "kmsg",
1127         [LOG_TARGET_JOURNAL] = "journal",
1128         [LOG_TARGET_JOURNAL_OR_KMSG] = "journal-or-kmsg",
1129         [LOG_TARGET_SYSLOG] = "syslog",
1130         [LOG_TARGET_SYSLOG_OR_KMSG] = "syslog-or-kmsg",
1131         [LOG_TARGET_AUTO] = "auto",
1132         [LOG_TARGET_SAFE] = "safe",
1133         [LOG_TARGET_NULL] = "null"
1134 };
1135
1136 DEFINE_STRING_TABLE_LOOKUP(log_target, LogTarget);
1137
1138 void log_received_signal(int level, const struct signalfd_siginfo *si) {
1139         if (si->ssi_pid > 0) {
1140                 _cleanup_free_ char *p = NULL;
1141
1142                 get_process_comm(si->ssi_pid, &p);
1143
1144                 log_full(level,
1145                          "Received SIG%s from PID %"PRIu32" (%s).",
1146                          signal_to_string(si->ssi_signo),
1147                          si->ssi_pid, strna(p));
1148         } else
1149                 log_full(level,
1150                          "Received SIG%s.",
1151                          signal_to_string(si->ssi_signo));
1152
1153 }
1154
1155 void log_set_upgrade_syslog_to_journal(bool b) {
1156         upgrade_syslog_to_journal = b;
1157 }
1158
1159 int log_syntax_internal(
1160                 const char *unit,
1161                 int level,
1162                 const char *config_file,
1163                 unsigned config_line,
1164                 int error,
1165                 const char *file,
1166                 int line,
1167                 const char *func,
1168                 const char *format, ...) {
1169
1170         PROTECT_ERRNO;
1171         char buffer[LINE_MAX];
1172         va_list ap;
1173         const char *unit_fmt = NULL;
1174
1175         if (error < 0)
1176                 error = -error;
1177
1178         if (_likely_(LOG_PRI(level) > log_max_level[LOG_REALM_SYSTEMD]))
1179                 return -error;
1180
1181         if (log_target == LOG_TARGET_NULL)
1182                 return -error;
1183
1184         if (error != 0)
1185                 errno = error;
1186
1187         va_start(ap, format);
1188         vsnprintf(buffer, sizeof(buffer), format, ap);
1189         va_end(ap);
1190
1191         if (unit)
1192                 unit_fmt = getpid() == 1 ? "UNIT=%s" : "USER_UNIT=%s";
1193
1194         return log_struct_internal(
1195                         LOG_REALM_PLUS_LEVEL(LOG_REALM_SYSTEMD, level),
1196                         error,
1197                         file, line, func,
1198                         "MESSAGE_ID=" SD_MESSAGE_INVALID_CONFIGURATION_STR,
1199                         "CONFIG_FILE=%s", config_file,
1200                         "CONFIG_LINE=%u", config_line,
1201                         LOG_MESSAGE("%s:%u: %s", config_file, config_line, buffer),
1202                         unit_fmt, unit,
1203                         NULL);
1204 }
1205
1206 void log_set_always_reopen_console(bool b) {
1207         always_reopen_console = b;
1208 }