src/journal/journald.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <sys/epoll.h>
  23 #include <sys/socket.h>
  24 #include <errno.h>
  25 #include <sys/signalfd.h>
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <sys/acl.h>
  29 #include <acl/libacl.h>
  30
  31 #include "hashmap.h"
  32 #include "journal-file.h"
  33 #include "sd-daemon.h"
  34 #include "socket-util.h"
  35 #include "acl-util.h"
  36
  37 typedef struct Server {
  38         int syslog_fd;
  39         int epoll_fd;
  40         int signal_fd;
  41
  42         JournalFile *runtime_journal;
  43         JournalFile *system_journal;
  44         Hashmap *user_journals;
  45 } Server;
  46
  47 static void fix_perms(JournalFile *f, uid_t uid) {
  48         acl_t acl;
  49         acl_entry_t entry;
  50         acl_permset_t permset;
  51         int r;
  52
  53         assert(f);
  54
  55         r = fchmod_and_fchown(f->fd, 0640, 0, 0);
  56         if (r < 0)
  57                 log_warning("Failed to fix access mode/rights on %s, ignoring: %s", f->path, strerror(-r));
  58
  59         if (uid <= 0)
  60                 return;
  61
  62         acl = acl_get_fd(f->fd);
  63         if (!acl) {
  64                 log_warning("Failed to read ACL on %s, ignoring: %m", f->path);
  65                 return;
  66         }
  67
  68         r = acl_find_uid(acl, uid, &entry);
  69         if (r <= 0) {
  70
  71                 if (acl_create_entry(&acl, &entry) < 0 ||
  72                     acl_set_tag_type(entry, ACL_USER) < 0 ||
  73                     acl_set_qualifier(entry, &uid) < 0) {
  74                         log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  75                         goto finish;
  76                 }
  77         }
  78
  79         if (acl_get_permset(entry, &permset) < 0 ||
  80             acl_add_perm(permset, ACL_READ) < 0 ||
  81             acl_calc_mask(&acl) < 0) {
  82                 log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  83                 goto finish;
  84         }
  85
  86         if (acl_set_fd(f->fd, acl) < 0)
  87                 log_warning("Failed to set ACL on %s, ignoring: %m", f->path);
  88
  89 finish:
  90         acl_free(acl);
  91 }
  92
  93 static JournalFile* find_journal(Server *s, uid_t uid) {
  94         char *p;
  95         int r;
  96         JournalFile *f;
  97
  98         assert(s);
  99
 100         /* We split up user logs only on /var, not on /run */
 101         if (!s->system_journal)
 102                 return s->runtime_journal;
 103
 104         if (uid <= 0)
 105                 return s->system_journal;
 106
 107         f = hashmap_get(s->user_journals, UINT32_TO_PTR(uid));
 108         if (f)
 109                 return f;
 110
 111         if (asprintf(&p, "/var/log/journal/%lu.journal", (unsigned long) uid) < 0)
 112                 return s->system_journal;
 113
 114         r = journal_file_open(p, O_RDWR|O_CREAT, 0640, &f);
 115         free(p);
 116
 117         if (r < 0)
 118                 return s->system_journal;
 119
 120         fix_perms(f, uid);
 121
 122         r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);
 123         if (r < 0) {
 124                 journal_file_close(f);
 125                 return s->system_journal;
 126         }
 127
 128         return f;
 129 }
 130
 131 static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {
 132         char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,
 133                 *source_time = NULL, *boot_id = NULL, *machine_id = NULL,
 134                 *comm = NULL, *cmdline = NULL, *hostname = NULL,
 135                 *audit_session = NULL, *audit_loginuid = NULL,
 136                 *syslog_priority = NULL, *syslog_facility = NULL,
 137                 *exe = NULL;
 138         struct iovec iovec[15];
 139         unsigned n = 0;
 140         char idbuf[33];
 141         sd_id128_t id;
 142         int r;
 143         char *t;
 144         int priority = LOG_USER | LOG_INFO;
 145         uid_t loginuid = 0;
 146         JournalFile *f;
 147
 148         parse_syslog_priority((char**) &buf, &priority);
 149         skip_syslog_date((char**) &buf);
 150
 151         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
 152                 IOVEC_SET_STRING(iovec[n++], syslog_priority);
 153
 154         if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
 155                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
 156
 157         message = strappend("MESSAGE=", buf);
 158         if (message)
 159                 IOVEC_SET_STRING(iovec[n++], message);
 160
 161         if (ucred) {
 162                 uint32_t session;
 163
 164                 if (asprintf(&pid, "PID=%lu", (unsigned long) ucred->pid) >= 0)
 165                         IOVEC_SET_STRING(iovec[n++], pid);
 166
 167                 if (asprintf(&uid, "UID=%lu", (unsigned long) ucred->uid) >= 0)
 168                         IOVEC_SET_STRING(iovec[n++], uid);
 169
 170                 if (asprintf(&gid, "GID=%lu", (unsigned long) ucred->gid) >= 0)
 171                         IOVEC_SET_STRING(iovec[n++], gid);
 172
 173                 r = get_process_comm(ucred->pid, &t);
 174                 if (r >= 0) {
 175                         comm = strappend("COMM=", t);
 176                         if (comm)
 177                                 IOVEC_SET_STRING(iovec[n++], comm);
 178                         free(t);
 179                 }
 180
 181                 r = get_process_exe(ucred->pid, &t);
 182                 if (r >= 0) {
 183                         exe = strappend("EXE=", t);
 184                         if (comm)
 185                                 IOVEC_SET_STRING(iovec[n++], exe);
 186                         free(t);
 187                 }
 188
 189                 r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);
 190                 if (r >= 0) {
 191                         cmdline = strappend("CMDLINE=", t);
 192                         if (cmdline)
 193                                 IOVEC_SET_STRING(iovec[n++], cmdline);
 194                         free(t);
 195                 }
 196
 197                 r = audit_session_from_pid(ucred->pid, &session);
 198                 if (r >= 0)
 199                         if (asprintf(&audit_session, "AUDIT_SESSION=%lu", (unsigned long) session) >= 0)
 200                                 IOVEC_SET_STRING(iovec[n++], audit_session);
 201
 202                 r = audit_loginuid_from_pid(ucred->pid, &loginuid);
 203                 if (r >= 0)
 204                         if (asprintf(&audit_loginuid, "AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)
 205                                 IOVEC_SET_STRING(iovec[n++], audit_loginuid);
 206         }
 207
 208         if (tv) {
 209                 if (asprintf(&source_time, "SOURCE_REALTIME_TIMESTAMP=%llu",
 210                              (unsigned long long) timeval_load(tv)) >= 0)
 211                         IOVEC_SET_STRING(iovec[n++], source_time);
 212         }
 213
 214         /* Note that strictly speaking storing the boot id here is
 215          * redundant since the entry includes this in-line
 216          * anyway. However, we need this indexed, too. */
 217         r = sd_id128_get_boot(&id);
 218         if (r >= 0)
 219                 if (asprintf(&boot_id, "BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 220                         IOVEC_SET_STRING(iovec[n++], boot_id);
 221
 222         r = sd_id128_get_machine(&id);
 223         if (r >= 0)
 224                 if (asprintf(&machine_id, "MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 225                         IOVEC_SET_STRING(iovec[n++], machine_id);
 226
 227         t = gethostname_malloc();
 228         if (t) {
 229                 hostname = strappend("HOSTNAME=", t);
 230                 if (hostname)
 231                         IOVEC_SET_STRING(iovec[n++], hostname);
 232                 free(t);
 233         }
 234
 235         f = find_journal(s, loginuid);
 236         if (!f)
 237                 log_warning("Dropping message, as we can't find a place to store the data.");
 238         else {
 239                 r = journal_file_append_entry(f, NULL, iovec, n, NULL, NULL);
 240
 241                 if (r < 0)
 242                         log_error("Failed to write entry, ignoring: %s", strerror(-r));
 243         }
 244
 245         free(message);
 246         free(pid);
 247         free(uid);
 248         free(gid);
 249         free(comm);
 250         free(cmdline);
 251         free(source_time);
 252         free(boot_id);
 253         free(machine_id);
 254         free(hostname);
 255         free(audit_session);
 256         free(audit_loginuid);
 257         free(syslog_facility);
 258         free(syslog_priority);
 259 }
 260
 261 static int process_event(Server *s, struct epoll_event *ev) {
 262         assert(s);
 263
 264         if (ev->events != EPOLLIN) {
 265                 log_info("Got invalid event from epoll.");
 266                 return -EIO;
 267         }
 268
 269         if (ev->data.fd == s->signal_fd) {
 270                 struct signalfd_siginfo sfsi;
 271                 ssize_t n;
 272
 273                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 274                 if (n != sizeof(sfsi)) {
 275
 276                         if (n >= 0)
 277                                 return -EIO;
 278
 279                         if (errno == EINTR || errno == EAGAIN)
 280                                 return 0;
 281
 282                         return -errno;
 283                 }
 284
 285                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 286                 return 0;
 287
 288         }
 289
 290         if (ev->data.fd == s->syslog_fd) {
 291                 for (;;) {
 292                         char buf[LINE_MAX+1];
 293                         struct msghdr msghdr;
 294                         struct iovec iovec;
 295                         struct ucred *ucred = NULL;
 296                         struct timeval *tv = NULL;
 297                         struct cmsghdr *cmsg;
 298                         union {
 299                                 struct cmsghdr cmsghdr;
 300                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 301                                             CMSG_SPACE(sizeof(struct timeval))];
 302                         } control;
 303                         ssize_t n;
 304                         char *e;
 305
 306                         zero(iovec);
 307                         iovec.iov_base = buf;
 308                         iovec.iov_len = sizeof(buf)-1;
 309
 310                         zero(control);
 311                         zero(msghdr);
 312                         msghdr.msg_iov = &iovec;
 313                         msghdr.msg_iovlen = 1;
 314                         msghdr.msg_control = &control;
 315                         msghdr.msg_controllen = sizeof(control);
 316
 317                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 318                         if (n < 0) {
 319
 320                                 if (errno == EINTR || errno == EAGAIN)
 321                                         return 1;
 322
 323                                 log_error("recvmsg() failed: %m");
 324                                 return -errno;
 325                         }
 326
 327                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 328
 329                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 330                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 331                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 332                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 333                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 334                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 335                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 336                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 337                         }
 338
 339                         e = memchr(buf, '\n', n);
 340                         if (e)
 341                                 *e = 0;
 342                         else
 343                                 buf[n] = 0;
 344
 345                         process_message(s, strstrip(buf), ucred, tv);
 346                 }
 347
 348                 return 1;
 349         }
 350
 351         log_error("Unknown event.");
 352         return 0;
 353 }
 354
 355 static int system_journal_open(Server *s) {
 356         int r;
 357         char *fn;
 358         sd_id128_t machine;
 359         char ids[33];
 360
 361         r = sd_id128_get_machine(&machine);
 362         if (r < 0)
 363                 return r;
 364
 365         /* First try to create the machine path, but not the prefix */
 366         fn = join("/var/log/journal/", sd_id128_to_string(machine, ids), NULL);
 367         if (!fn)
 368                 return -ENOMEM;
 369         (void) mkdir(fn, 0755);
 370         free(fn);
 371
 372         /* The create the system journal file */
 373         fn = join("/var/log/journal/", ids, "/system.journal", NULL);
 374         if (!fn)
 375                 return -ENOMEM;
 376
 377         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, &s->system_journal);
 378         free(fn);
 379
 380         if (r >= 0)
 381                 fix_perms(s->system_journal, 0);
 382         else if (r == -ENOENT) {
 383
 384                 /* /var didn't work, so try /run, but this time we
 385                  * create the prefix too */
 386                 fn = join("/run/log/journal/", ids, NULL);
 387                 if (!fn)
 388                         return -ENOMEM;
 389                 (void) mkdir_p(fn, 0755);
 390                 free(fn);
 391
 392                 /* Then create the runtime journal file */
 393                 fn = join("/run/log/journal/", ids, "/system.journal", NULL);
 394                 if (!fn)
 395                         return -ENOMEM;
 396                 r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, &s->runtime_journal);
 397                 free(fn);
 398
 399                 if (r >= 0)
 400                         fix_perms(s->runtime_journal, 0);
 401         }
 402
 403         if (r < 0 && r != -ENOENT) {
 404                 log_error("Failed to open journal: %s", strerror(-r));
 405                 return r;
 406         }
 407
 408         return 0;
 409 }
 410
 411 static int server_init(Server *s) {
 412         int n, one, r;
 413         struct epoll_event ev;
 414         sigset_t mask;
 415
 416         assert(s);
 417
 418         zero(*s);
 419         s->syslog_fd = s->signal_fd = -1;
 420
 421         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 422         if (s->epoll_fd < 0) {
 423                 log_error("Failed to create epoll object: %m");
 424                 return -errno;
 425         }
 426
 427         n = sd_listen_fds(true);
 428         if (n < 0) {
 429                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 430                 return n;
 431         }
 432
 433         if (n > 1) {
 434                 log_error("Too many file descriptors passed.");
 435                 return -EINVAL;
 436         }
 437
 438         if (n == 1)
 439                 s->syslog_fd = SD_LISTEN_FDS_START;
 440         else {
 441                 union sockaddr_union sa;
 442
 443                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 444                 if (s->syslog_fd < 0) {
 445                         log_error("socket() failed: %m");
 446                         return -errno;
 447                 }
 448
 449                 zero(sa);
 450                 sa.un.sun_family = AF_UNIX;
 451                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 452
 453                 unlink(sa.un.sun_path);
 454
 455                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 456                 if (r < 0) {
 457                         log_error("bind() failed: %m");
 458                         return -errno;
 459                 }
 460
 461                 chmod(sa.un.sun_path, 0666);
 462         }
 463
 464         one = 1;
 465         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 466         if (r < 0) {
 467                 log_error("SO_PASSCRED failed: %m");
 468                 return -errno;
 469         }
 470
 471         one = 1;
 472         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 473         if (r < 0) {
 474                 log_error("SO_TIMESTAMP failed: %m");
 475                 return -errno;
 476         }
 477
 478         zero(ev);
 479         ev.events = EPOLLIN;
 480         ev.data.fd = s->syslog_fd;
 481         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 482                 log_error("Failed to add server fd to epoll object: %m");
 483                 return -errno;
 484         }
 485
 486         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 487         if (!s->user_journals) {
 488                 log_error("Out of memory.");
 489                 return -ENOMEM;
 490         }
 491
 492         r = system_journal_open(s);
 493         if (r < 0)
 494                 return r;
 495
 496         assert_se(sigemptyset(&mask) == 0);
 497         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 498         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 499
 500         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 501         if (s->signal_fd < 0) {
 502                 log_error("signalfd(): %m");
 503                 return -errno;
 504         }
 505
 506         zero(ev);
 507         ev.events = EPOLLIN;
 508         ev.data.fd = s->signal_fd;
 509
 510         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 511                 log_error("epoll_ctl(): %m");
 512                 return -errno;
 513         }
 514
 515         return 0;
 516 }
 517
 518 static void server_done(Server *s) {
 519         JournalFile *f;
 520         assert(s);
 521
 522         if (s->system_journal)
 523                 journal_file_close(s->system_journal);
 524
 525         if (s->runtime_journal)
 526                 journal_file_close(s->runtime_journal);
 527
 528         while ((f = hashmap_steal_first(s->user_journals)))
 529                 journal_file_close(f);
 530
 531         hashmap_free(s->user_journals);
 532
 533         if (s->epoll_fd >= 0)
 534                 close_nointr_nofail(s->epoll_fd);
 535
 536         if (s->signal_fd >= 0)
 537                 close_nointr_nofail(s->signal_fd);
 538
 539         if (s->syslog_fd >= 0)
 540                 close_nointr_nofail(s->syslog_fd);
 541 }
 542
 543 int main(int argc, char *argv[]) {
 544         Server server;
 545         int r;
 546
 547         /* if (getppid() != 1) { */
 548         /*         log_error("This program should be invoked by init only."); */
 549         /*         return EXIT_FAILURE; */
 550         /* } */
 551
 552         if (argc > 1) {
 553                 log_error("This program does not take arguments.");
 554                 return EXIT_FAILURE;
 555         }
 556
 557         log_set_target(LOG_TARGET_CONSOLE);
 558         log_parse_environment();
 559         log_open();
 560
 561         umask(0022);
 562
 563         r = server_init(&server);
 564         if (r < 0)
 565                 goto finish;
 566
 567         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 568
 569         sd_notify(false,
 570                   "READY=1\n"
 571                   "STATUS=Processing messages...");
 572
 573         for (;;) {
 574                 struct epoll_event event;
 575
 576                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 577                 if (r < 0) {
 578
 579                         if (errno == EINTR)
 580                                 continue;
 581
 582                         log_error("epoll_wait() failed: %m");
 583                         r = -errno;
 584                         goto finish;
 585                 } else if (r == 0)
 586                         break;
 587
 588                 r = process_event(&server, &event);
 589                 if (r < 0)
 590                         goto finish;
 591                 else if (r == 0)
 592                         break;
 593         }
 594
 595 finish:
 596         sd_notify(false,
 597                   "STATUS=Shutting down...");
 598
 599         server_done(&server);
 600
 601         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 602 }