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