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 #include "cgroup-util.h"
  37
  38 typedef struct Server {
  39         int syslog_fd;
  40         int epoll_fd;
  41         int signal_fd;
  42
  43         JournalFile *runtime_journal;
  44         JournalFile *system_journal;
  45         Hashmap *user_journals;
  46
  47         uint64_t seqnum;
  48 } Server;
  49
  50 static void fix_perms(JournalFile *f, uid_t uid) {
  51         acl_t acl;
  52         acl_entry_t entry;
  53         acl_permset_t permset;
  54         int r;
  55
  56         assert(f);
  57
  58         r = fchmod_and_fchown(f->fd, 0640, 0, 0);
  59         if (r < 0)
  60                 log_warning("Failed to fix access mode/rights on %s, ignoring: %s", f->path, strerror(-r));
  61
  62         if (uid <= 0)
  63                 return;
  64
  65         acl = acl_get_fd(f->fd);
  66         if (!acl) {
  67                 log_warning("Failed to read ACL on %s, ignoring: %m", f->path);
  68                 return;
  69         }
  70
  71         r = acl_find_uid(acl, uid, &entry);
  72         if (r <= 0) {
  73
  74                 if (acl_create_entry(&acl, &entry) < 0 ||
  75                     acl_set_tag_type(entry, ACL_USER) < 0 ||
  76                     acl_set_qualifier(entry, &uid) < 0) {
  77                         log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  78                         goto finish;
  79                 }
  80         }
  81
  82         if (acl_get_permset(entry, &permset) < 0 ||
  83             acl_add_perm(permset, ACL_READ) < 0 ||
  84             acl_calc_mask(&acl) < 0) {
  85                 log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  86                 goto finish;
  87         }
  88
  89         if (acl_set_fd(f->fd, acl) < 0)
  90                 log_warning("Failed to set ACL on %s, ignoring: %m", f->path);
  91
  92 finish:
  93         acl_free(acl);
  94 }
  95
  96 static JournalFile* find_journal(Server *s, uid_t uid) {
  97         char *p;
  98         int r;
  99         JournalFile *f;
 100         char ids[33];
 101         sd_id128_t machine;
 102
 103         assert(s);
 104
 105         /* We split up user logs only on /var, not on /run */
 106         if (!s->system_journal)
 107                 return s->runtime_journal;
 108
 109         if (uid <= 0)
 110                 return s->system_journal;
 111
 112         r = sd_id128_get_machine(&machine);
 113         if (r < 0)
 114                 return s->system_journal;
 115
 116         f = hashmap_get(s->user_journals, UINT32_TO_PTR(uid));
 117         if (f)
 118                 return f;
 119
 120         if (asprintf(&p, "/var/log/journal/%s/user-%lu.journal", sd_id128_to_string(machine, ids), (unsigned long) uid) < 0)
 121                 return s->system_journal;
 122
 123         r = journal_file_open(p, O_RDWR|O_CREAT, 0640, s->system_journal, &f);
 124         free(p);
 125
 126         if (r < 0)
 127                 return s->system_journal;
 128
 129         fix_perms(f, uid);
 130
 131         r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);
 132         if (r < 0) {
 133                 journal_file_close(f);
 134                 return s->system_journal;
 135         }
 136
 137         return f;
 138 }
 139
 140 static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {
 141         char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,
 142                 *source_time = NULL, *boot_id = NULL, *machine_id = NULL,
 143                 *comm = NULL, *cmdline = NULL, *hostname = NULL,
 144                 *audit_session = NULL, *audit_loginuid = NULL,
 145                 *syslog_priority = NULL, *syslog_facility = NULL,
 146                 *exe = NULL, *cgroup = NULL;
 147         struct iovec iovec[17];
 148         unsigned n = 0;
 149         char idbuf[33];
 150         sd_id128_t id;
 151         int r;
 152         char *t;
 153         int priority = LOG_USER | LOG_INFO;
 154         uid_t loginuid = 0, realuid = 0;
 155         JournalFile *f;
 156
 157         parse_syslog_priority((char**) &buf, &priority);
 158         skip_syslog_date((char**) &buf);
 159
 160         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
 161                 IOVEC_SET_STRING(iovec[n++], syslog_priority);
 162
 163         if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
 164                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
 165
 166         message = strappend("MESSAGE=", buf);
 167         if (message)
 168                 IOVEC_SET_STRING(iovec[n++], message);
 169
 170         if (ucred) {
 171                 uint32_t session;
 172                 char *path;
 173
 174                 realuid = ucred->uid;
 175
 176                 if (asprintf(&pid, "_PID=%lu", (unsigned long) ucred->pid) >= 0)
 177                         IOVEC_SET_STRING(iovec[n++], pid);
 178
 179                 if (asprintf(&uid, "_UID=%lu", (unsigned long) ucred->uid) >= 0)
 180                         IOVEC_SET_STRING(iovec[n++], uid);
 181
 182                 if (asprintf(&gid, "_GID=%lu", (unsigned long) ucred->gid) >= 0)
 183                         IOVEC_SET_STRING(iovec[n++], gid);
 184
 185                 r = get_process_comm(ucred->pid, &t);
 186                 if (r >= 0) {
 187                         comm = strappend("_COMM=", t);
 188                         if (comm)
 189                                 IOVEC_SET_STRING(iovec[n++], comm);
 190                         free(t);
 191                 }
 192
 193                 r = get_process_exe(ucred->pid, &t);
 194                 if (r >= 0) {
 195                         exe = strappend("_EXE=", t);
 196                         if (comm)
 197                                 IOVEC_SET_STRING(iovec[n++], exe);
 198                         free(t);
 199                 }
 200
 201                 r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);
 202                 if (r >= 0) {
 203                         cmdline = strappend("_CMDLINE=", t);
 204                         if (cmdline)
 205                                 IOVEC_SET_STRING(iovec[n++], cmdline);
 206                         free(t);
 207                 }
 208
 209                 r = audit_session_from_pid(ucred->pid, &session);
 210                 if (r >= 0)
 211                         if (asprintf(&audit_session, "_AUDIT_SESSION=%lu", (unsigned long) session) >= 0)
 212                                 IOVEC_SET_STRING(iovec[n++], audit_session);
 213
 214                 r = audit_loginuid_from_pid(ucred->pid, &loginuid);
 215                 if (r >= 0)
 216                         if (asprintf(&audit_loginuid, "_AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)
 217                                 IOVEC_SET_STRING(iovec[n++], audit_loginuid);
 218
 219                 r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, ucred->pid, &path);
 220                 if (r >= 0) {
 221                         cgroup = strappend("_SYSTEMD_CGROUP=", path);
 222                         if (cgroup)
 223                                 IOVEC_SET_STRING(iovec[n++], cgroup);
 224                         free(path);
 225                 }
 226         }
 227
 228         if (tv) {
 229                 if (asprintf(&source_time, "_SOURCE_REALTIME_TIMESTAMP=%llu",
 230                              (unsigned long long) timeval_load(tv)) >= 0)
 231                         IOVEC_SET_STRING(iovec[n++], source_time);
 232         }
 233
 234         /* Note that strictly speaking storing the boot id here is
 235          * redundant since the entry includes this in-line
 236          * anyway. However, we need this indexed, too. */
 237         r = sd_id128_get_boot(&id);
 238         if (r >= 0)
 239                 if (asprintf(&boot_id, "_BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 240                         IOVEC_SET_STRING(iovec[n++], boot_id);
 241
 242         r = sd_id128_get_machine(&id);
 243         if (r >= 0)
 244                 if (asprintf(&machine_id, "_MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 245                         IOVEC_SET_STRING(iovec[n++], machine_id);
 246
 247         t = gethostname_malloc();
 248         if (t) {
 249                 hostname = strappend("_HOSTNAME=", t);
 250                 if (hostname)
 251                         IOVEC_SET_STRING(iovec[n++], hostname);
 252                 free(t);
 253         }
 254
 255         f = find_journal(s, realuid == 0 ? 0 : loginuid);
 256         if (!f)
 257                 log_warning("Dropping message, as we can't find a place to store the data.");
 258         else {
 259                 r = journal_file_append_entry(f, NULL, iovec, n, &s->seqnum, NULL, NULL);
 260
 261                 if (r < 0)
 262                         log_error("Failed to write entry, ignoring: %s", strerror(-r));
 263         }
 264
 265         free(message);
 266         free(pid);
 267         free(uid);
 268         free(gid);
 269         free(comm);
 270         free(exe);
 271         free(cmdline);
 272         free(source_time);
 273         free(boot_id);
 274         free(machine_id);
 275         free(hostname);
 276         free(audit_session);
 277         free(audit_loginuid);
 278         free(syslog_facility);
 279         free(syslog_priority);
 280         free(cgroup);
 281 }
 282
 283 static int process_event(Server *s, struct epoll_event *ev) {
 284         assert(s);
 285
 286         if (ev->events != EPOLLIN) {
 287                 log_info("Got invalid event from epoll.");
 288                 return -EIO;
 289         }
 290
 291         if (ev->data.fd == s->signal_fd) {
 292                 struct signalfd_siginfo sfsi;
 293                 ssize_t n;
 294
 295                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 296                 if (n != sizeof(sfsi)) {
 297
 298                         if (n >= 0)
 299                                 return -EIO;
 300
 301                         if (errno == EINTR || errno == EAGAIN)
 302                                 return 0;
 303
 304                         return -errno;
 305                 }
 306
 307                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 308                 return 0;
 309
 310         }
 311
 312         if (ev->data.fd == s->syslog_fd) {
 313                 for (;;) {
 314                         char buf[LINE_MAX+1];
 315                         struct msghdr msghdr;
 316                         struct iovec iovec;
 317                         struct ucred *ucred = NULL;
 318                         struct timeval *tv = NULL;
 319                         struct cmsghdr *cmsg;
 320                         union {
 321                                 struct cmsghdr cmsghdr;
 322                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 323                                             CMSG_SPACE(sizeof(struct timeval))];
 324                         } control;
 325                         ssize_t n;
 326                         char *e;
 327
 328                         zero(iovec);
 329                         iovec.iov_base = buf;
 330                         iovec.iov_len = sizeof(buf)-1;
 331
 332                         zero(control);
 333                         zero(msghdr);
 334                         msghdr.msg_iov = &iovec;
 335                         msghdr.msg_iovlen = 1;
 336                         msghdr.msg_control = &control;
 337                         msghdr.msg_controllen = sizeof(control);
 338
 339                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 340                         if (n < 0) {
 341
 342                                 if (errno == EINTR || errno == EAGAIN)
 343                                         return 1;
 344
 345                                 log_error("recvmsg() failed: %m");
 346                                 return -errno;
 347                         }
 348
 349                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 350
 351                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 352                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 353                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 354                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 355                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 356                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 357                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 358                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 359                         }
 360
 361                         e = memchr(buf, '\n', n);
 362                         if (e)
 363                                 *e = 0;
 364                         else
 365                                 buf[n] = 0;
 366
 367                         process_message(s, strstrip(buf), ucred, tv);
 368                 }
 369
 370                 return 1;
 371         }
 372
 373         log_error("Unknown event.");
 374         return 0;
 375 }
 376
 377 static int system_journal_open(Server *s) {
 378         int r;
 379         char *fn;
 380         sd_id128_t machine;
 381         char ids[33];
 382
 383         r = sd_id128_get_machine(&machine);
 384         if (r < 0)
 385                 return r;
 386
 387         /* First try to create the machine path, but not the prefix */
 388         fn = strappend("/var/log/journal/", sd_id128_to_string(machine, ids));
 389         if (!fn)
 390                 return -ENOMEM;
 391         (void) mkdir(fn, 0755);
 392         free(fn);
 393
 394         /* The create the system journal file */
 395         fn = join("/var/log/journal/", ids, "/system.journal", NULL);
 396         if (!fn)
 397                 return -ENOMEM;
 398
 399         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->system_journal);
 400         free(fn);
 401
 402         if (r >= 0) {
 403                 fix_perms(s->system_journal, 0);
 404                 return r;
 405         }
 406
 407         if (r < 0 && r != -ENOENT) {
 408                 log_error("Failed to open system journal: %s", strerror(-r));
 409                 return r;
 410         }
 411
 412         /* /var didn't work, so try /run, but this time we
 413          * create the prefix too */
 414         fn = join("/run/log/journal/", ids, "/system.journal", NULL);
 415         if (!fn)
 416                 return -ENOMEM;
 417
 418         (void) mkdir_parents(fn, 0755);
 419         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->runtime_journal);
 420         free(fn);
 421
 422         if (r < 0) {
 423                 log_error("Failed to open runtime journal: %s", strerror(-r));
 424                 return r;
 425         }
 426
 427         fix_perms(s->runtime_journal, 0);
 428         return r;
 429 }
 430
 431 static int server_init(Server *s) {
 432         int n, one, r;
 433         struct epoll_event ev;
 434         sigset_t mask;
 435
 436         assert(s);
 437
 438         zero(*s);
 439         s->syslog_fd = s->signal_fd = -1;
 440
 441         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 442         if (s->epoll_fd < 0) {
 443                 log_error("Failed to create epoll object: %m");
 444                 return -errno;
 445         }
 446
 447         n = sd_listen_fds(true);
 448         if (n < 0) {
 449                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 450                 return n;
 451         }
 452
 453         if (n > 1) {
 454                 log_error("Too many file descriptors passed.");
 455                 return -EINVAL;
 456         }
 457
 458         if (n == 1)
 459                 s->syslog_fd = SD_LISTEN_FDS_START;
 460         else {
 461                 union sockaddr_union sa;
 462
 463                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 464                 if (s->syslog_fd < 0) {
 465                         log_error("socket() failed: %m");
 466                         return -errno;
 467                 }
 468
 469                 zero(sa);
 470                 sa.un.sun_family = AF_UNIX;
 471                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 472
 473                 unlink(sa.un.sun_path);
 474
 475                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 476                 if (r < 0) {
 477                         log_error("bind() failed: %m");
 478                         return -errno;
 479                 }
 480
 481                 chmod(sa.un.sun_path, 0666);
 482         }
 483
 484         one = 1;
 485         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 486         if (r < 0) {
 487                 log_error("SO_PASSCRED failed: %m");
 488                 return -errno;
 489         }
 490
 491         one = 1;
 492         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 493         if (r < 0) {
 494                 log_error("SO_TIMESTAMP failed: %m");
 495                 return -errno;
 496         }
 497
 498         zero(ev);
 499         ev.events = EPOLLIN;
 500         ev.data.fd = s->syslog_fd;
 501         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 502                 log_error("Failed to add server fd to epoll object: %m");
 503                 return -errno;
 504         }
 505
 506         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 507         if (!s->user_journals) {
 508                 log_error("Out of memory.");
 509                 return -ENOMEM;
 510         }
 511
 512         r = system_journal_open(s);
 513         if (r < 0)
 514                 return r;
 515
 516         assert_se(sigemptyset(&mask) == 0);
 517         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 518         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 519
 520         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 521         if (s->signal_fd < 0) {
 522                 log_error("signalfd(): %m");
 523                 return -errno;
 524         }
 525
 526         zero(ev);
 527         ev.events = EPOLLIN;
 528         ev.data.fd = s->signal_fd;
 529
 530         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 531                 log_error("epoll_ctl(): %m");
 532                 return -errno;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static void server_done(Server *s) {
 539         JournalFile *f;
 540         assert(s);
 541
 542         if (s->system_journal)
 543                 journal_file_close(s->system_journal);
 544
 545         if (s->runtime_journal)
 546                 journal_file_close(s->runtime_journal);
 547
 548         while ((f = hashmap_steal_first(s->user_journals)))
 549                 journal_file_close(f);
 550
 551         hashmap_free(s->user_journals);
 552
 553         if (s->epoll_fd >= 0)
 554                 close_nointr_nofail(s->epoll_fd);
 555
 556         if (s->signal_fd >= 0)
 557                 close_nointr_nofail(s->signal_fd);
 558
 559         if (s->syslog_fd >= 0)
 560                 close_nointr_nofail(s->syslog_fd);
 561 }
 562
 563 int main(int argc, char *argv[]) {
 564         Server server;
 565         int r;
 566
 567         /* if (getppid() != 1) { */
 568         /*         log_error("This program should be invoked by init only."); */
 569         /*         return EXIT_FAILURE; */
 570         /* } */
 571
 572         if (argc > 1) {
 573                 log_error("This program does not take arguments.");
 574                 return EXIT_FAILURE;
 575         }
 576
 577         log_set_target(LOG_TARGET_CONSOLE);
 578         log_parse_environment();
 579         log_open();
 580
 581         umask(0022);
 582
 583         r = server_init(&server);
 584         if (r < 0)
 585                 goto finish;
 586
 587         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 588
 589         sd_notify(false,
 590                   "READY=1\n"
 591                   "STATUS=Processing messages...");
 592 #
 593         for (;;) {
 594                 struct epoll_event event;
 595
 596                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 597                 if (r < 0) {
 598
 599                         if (errno == EINTR)
 600                                 continue;
 601
 602                         log_error("epoll_wait() failed: %m");
 603                         r = -errno;
 604                         goto finish;
 605                 } else if (r == 0)
 606                         break;
 607
 608                 r = process_event(&server, &event);
 609                 if (r < 0)
 610                         goto finish;
 611                 else if (r == 0)
 612                         break;
 613         }
 614
 615 finish:
 616         sd_notify(false,
 617                   "STATUS=Shutting down...");
 618
 619         server_done(&server);
 620
 621         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 622 }