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 } Server;
  47
  48 static void fix_perms(JournalFile *f, uid_t uid) {
  49         acl_t acl;
  50         acl_entry_t entry;
  51         acl_permset_t permset;
  52         int r;
  53
  54         assert(f);
  55
  56         r = fchmod_and_fchown(f->fd, 0640, 0, 0);
  57         if (r < 0)
  58                 log_warning("Failed to fix access mode/rights on %s, ignoring: %s", f->path, strerror(-r));
  59
  60         if (uid <= 0)
  61                 return;
  62
  63         acl = acl_get_fd(f->fd);
  64         if (!acl) {
  65                 log_warning("Failed to read ACL on %s, ignoring: %m", f->path);
  66                 return;
  67         }
  68
  69         r = acl_find_uid(acl, uid, &entry);
  70         if (r <= 0) {
  71
  72                 if (acl_create_entry(&acl, &entry) < 0 ||
  73                     acl_set_tag_type(entry, ACL_USER) < 0 ||
  74                     acl_set_qualifier(entry, &uid) < 0) {
  75                         log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  76                         goto finish;
  77                 }
  78         }
  79
  80         if (acl_get_permset(entry, &permset) < 0 ||
  81             acl_add_perm(permset, ACL_READ) < 0 ||
  82             acl_calc_mask(&acl) < 0) {
  83                 log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);
  84                 goto finish;
  85         }
  86
  87         if (acl_set_fd(f->fd, acl) < 0)
  88                 log_warning("Failed to set ACL on %s, ignoring: %m", f->path);
  89
  90 finish:
  91         acl_free(acl);
  92 }
  93
  94 static JournalFile* find_journal(Server *s, uid_t uid) {
  95         char *p;
  96         int r;
  97         JournalFile *f;
  98
  99         assert(s);
 100
 101         /* We split up user logs only on /var, not on /run */
 102         if (!s->system_journal)
 103                 return s->runtime_journal;
 104
 105         if (uid <= 0)
 106                 return s->system_journal;
 107
 108         f = hashmap_get(s->user_journals, UINT32_TO_PTR(uid));
 109         if (f)
 110                 return f;
 111
 112         if (asprintf(&p, "/var/log/journal/%lu.journal", (unsigned long) uid) < 0)
 113                 return s->system_journal;
 114
 115         r = journal_file_open(p, O_RDWR|O_CREAT, 0640, &f);
 116         free(p);
 117
 118         if (r < 0)
 119                 return s->system_journal;
 120
 121         fix_perms(f, uid);
 122
 123         r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);
 124         if (r < 0) {
 125                 journal_file_close(f);
 126                 return s->system_journal;
 127         }
 128
 129         return f;
 130 }
 131
 132 static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {
 133         char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,
 134                 *source_time = NULL, *boot_id = NULL, *machine_id = NULL,
 135                 *comm = NULL, *cmdline = NULL, *hostname = NULL,
 136                 *audit_session = NULL, *audit_loginuid = NULL,
 137                 *syslog_priority = NULL, *syslog_facility = NULL,
 138                 *exe = NULL, *cgroup = NULL;
 139         struct iovec iovec[16];
 140         unsigned n = 0;
 141         char idbuf[33];
 142         sd_id128_t id;
 143         int r;
 144         char *t;
 145         int priority = LOG_USER | LOG_INFO;
 146         uid_t loginuid = 0;
 147         JournalFile *f;
 148
 149         parse_syslog_priority((char**) &buf, &priority);
 150         skip_syslog_date((char**) &buf);
 151
 152         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
 153                 IOVEC_SET_STRING(iovec[n++], syslog_priority);
 154
 155         if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
 156                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
 157
 158         message = strappend("MESSAGE=", buf);
 159         if (message)
 160                 IOVEC_SET_STRING(iovec[n++], message);
 161
 162         if (ucred) {
 163                 uint32_t session;
 164                 char *path;
 165
 166                 if (asprintf(&pid, "PID=%lu", (unsigned long) ucred->pid) >= 0)
 167                         IOVEC_SET_STRING(iovec[n++], pid);
 168
 169                 if (asprintf(&uid, "UID=%lu", (unsigned long) ucred->uid) >= 0)
 170                         IOVEC_SET_STRING(iovec[n++], uid);
 171
 172                 if (asprintf(&gid, "GID=%lu", (unsigned long) ucred->gid) >= 0)
 173                         IOVEC_SET_STRING(iovec[n++], gid);
 174
 175                 r = get_process_comm(ucred->pid, &t);
 176                 if (r >= 0) {
 177                         comm = strappend("COMM=", t);
 178                         if (comm)
 179                                 IOVEC_SET_STRING(iovec[n++], comm);
 180                         free(t);
 181                 }
 182
 183                 r = get_process_exe(ucred->pid, &t);
 184                 if (r >= 0) {
 185                         exe = strappend("EXE=", t);
 186                         if (comm)
 187                                 IOVEC_SET_STRING(iovec[n++], exe);
 188                         free(t);
 189                 }
 190
 191                 r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);
 192                 if (r >= 0) {
 193                         cmdline = strappend("CMDLINE=", t);
 194                         if (cmdline)
 195                                 IOVEC_SET_STRING(iovec[n++], cmdline);
 196                         free(t);
 197                 }
 198
 199                 r = audit_session_from_pid(ucred->pid, &session);
 200                 if (r >= 0)
 201                         if (asprintf(&audit_session, "AUDIT_SESSION=%lu", (unsigned long) session) >= 0)
 202                                 IOVEC_SET_STRING(iovec[n++], audit_session);
 203
 204                 r = audit_loginuid_from_pid(ucred->pid, &loginuid);
 205                 if (r >= 0)
 206                         if (asprintf(&audit_loginuid, "AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)
 207                                 IOVEC_SET_STRING(iovec[n++], audit_loginuid);
 208
 209                 r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, ucred->pid, &path);
 210                 if (r >= 0) {
 211                         cgroup = strappend("SYSTEMD_CGROUP=", path);
 212                         if (cgroup)
 213                                 IOVEC_SET_STRING(iovec[n++], cgroup);
 214                         free(path);
 215                 }
 216         }
 217
 218         if (tv) {
 219                 if (asprintf(&source_time, "SOURCE_REALTIME_TIMESTAMP=%llu",
 220                              (unsigned long long) timeval_load(tv)) >= 0)
 221                         IOVEC_SET_STRING(iovec[n++], source_time);
 222         }
 223
 224         /* Note that strictly speaking storing the boot id here is
 225          * redundant since the entry includes this in-line
 226          * anyway. However, we need this indexed, too. */
 227         r = sd_id128_get_boot(&id);
 228         if (r >= 0)
 229                 if (asprintf(&boot_id, "BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 230                         IOVEC_SET_STRING(iovec[n++], boot_id);
 231
 232         r = sd_id128_get_machine(&id);
 233         if (r >= 0)
 234                 if (asprintf(&machine_id, "MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 235                         IOVEC_SET_STRING(iovec[n++], machine_id);
 236
 237         t = gethostname_malloc();
 238         if (t) {
 239                 hostname = strappend("HOSTNAME=", t);
 240                 if (hostname)
 241                         IOVEC_SET_STRING(iovec[n++], hostname);
 242                 free(t);
 243         }
 244
 245         f = find_journal(s, loginuid);
 246         if (!f)
 247                 log_warning("Dropping message, as we can't find a place to store the data.");
 248         else {
 249                 r = journal_file_append_entry(f, NULL, iovec, n, NULL, NULL);
 250
 251                 if (r < 0)
 252                         log_error("Failed to write entry, ignoring: %s", strerror(-r));
 253         }
 254
 255         free(message);
 256         free(pid);
 257         free(uid);
 258         free(gid);
 259         free(comm);
 260         free(exe);
 261         free(cmdline);
 262         free(source_time);
 263         free(boot_id);
 264         free(machine_id);
 265         free(hostname);
 266         free(audit_session);
 267         free(audit_loginuid);
 268         free(syslog_facility);
 269         free(syslog_priority);
 270         free(cgroup);
 271 }
 272
 273 static int process_event(Server *s, struct epoll_event *ev) {
 274         assert(s);
 275
 276         if (ev->events != EPOLLIN) {
 277                 log_info("Got invalid event from epoll.");
 278                 return -EIO;
 279         }
 280
 281         if (ev->data.fd == s->signal_fd) {
 282                 struct signalfd_siginfo sfsi;
 283                 ssize_t n;
 284
 285                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 286                 if (n != sizeof(sfsi)) {
 287
 288                         if (n >= 0)
 289                                 return -EIO;
 290
 291                         if (errno == EINTR || errno == EAGAIN)
 292                                 return 0;
 293
 294                         return -errno;
 295                 }
 296
 297                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 298                 return 0;
 299
 300         }
 301
 302         if (ev->data.fd == s->syslog_fd) {
 303                 for (;;) {
 304                         char buf[LINE_MAX+1];
 305                         struct msghdr msghdr;
 306                         struct iovec iovec;
 307                         struct ucred *ucred = NULL;
 308                         struct timeval *tv = NULL;
 309                         struct cmsghdr *cmsg;
 310                         union {
 311                                 struct cmsghdr cmsghdr;
 312                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 313                                             CMSG_SPACE(sizeof(struct timeval))];
 314                         } control;
 315                         ssize_t n;
 316                         char *e;
 317
 318                         zero(iovec);
 319                         iovec.iov_base = buf;
 320                         iovec.iov_len = sizeof(buf)-1;
 321
 322                         zero(control);
 323                         zero(msghdr);
 324                         msghdr.msg_iov = &iovec;
 325                         msghdr.msg_iovlen = 1;
 326                         msghdr.msg_control = &control;
 327                         msghdr.msg_controllen = sizeof(control);
 328
 329                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 330                         if (n < 0) {
 331
 332                                 if (errno == EINTR || errno == EAGAIN)
 333                                         return 1;
 334
 335                                 log_error("recvmsg() failed: %m");
 336                                 return -errno;
 337                         }
 338
 339                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 340
 341                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 342                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 343                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 344                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 345                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 346                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 347                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 348                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 349                         }
 350
 351                         e = memchr(buf, '\n', n);
 352                         if (e)
 353                                 *e = 0;
 354                         else
 355                                 buf[n] = 0;
 356
 357                         process_message(s, strstrip(buf), ucred, tv);
 358                 }
 359
 360                 return 1;
 361         }
 362
 363         log_error("Unknown event.");
 364         return 0;
 365 }
 366
 367 static int system_journal_open(Server *s) {
 368         int r;
 369         char *fn;
 370         sd_id128_t machine;
 371         char ids[33];
 372
 373         r = sd_id128_get_machine(&machine);
 374         if (r < 0)
 375                 return r;
 376
 377         /* First try to create the machine path, but not the prefix */
 378         fn = join("/var/log/journal/", sd_id128_to_string(machine, ids), NULL);
 379         if (!fn)
 380                 return -ENOMEM;
 381         (void) mkdir(fn, 0755);
 382         free(fn);
 383
 384         /* The create the system journal file */
 385         fn = join("/var/log/journal/", ids, "/system.journal", NULL);
 386         if (!fn)
 387                 return -ENOMEM;
 388
 389         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, &s->system_journal);
 390         free(fn);
 391
 392         if (r >= 0)
 393                 fix_perms(s->system_journal, 0);
 394         else if (r == -ENOENT) {
 395
 396                 /* /var didn't work, so try /run, but this time we
 397                  * create the prefix too */
 398                 fn = join("/run/log/journal/", ids, NULL);
 399                 if (!fn)
 400                         return -ENOMEM;
 401                 (void) mkdir_p(fn, 0755);
 402                 free(fn);
 403
 404                 /* Then create the runtime journal file */
 405                 fn = join("/run/log/journal/", ids, "/system.journal", NULL);
 406                 if (!fn)
 407                         return -ENOMEM;
 408                 r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, &s->runtime_journal);
 409                 free(fn);
 410
 411                 if (r >= 0)
 412                         fix_perms(s->runtime_journal, 0);
 413         }
 414
 415         if (r < 0 && r != -ENOENT) {
 416                 log_error("Failed to open journal: %s", strerror(-r));
 417                 return r;
 418         }
 419
 420         return 0;
 421 }
 422
 423 static int server_init(Server *s) {
 424         int n, one, r;
 425         struct epoll_event ev;
 426         sigset_t mask;
 427
 428         assert(s);
 429
 430         zero(*s);
 431         s->syslog_fd = s->signal_fd = -1;
 432
 433         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 434         if (s->epoll_fd < 0) {
 435                 log_error("Failed to create epoll object: %m");
 436                 return -errno;
 437         }
 438
 439         n = sd_listen_fds(true);
 440         if (n < 0) {
 441                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 442                 return n;
 443         }
 444
 445         if (n > 1) {
 446                 log_error("Too many file descriptors passed.");
 447                 return -EINVAL;
 448         }
 449
 450         if (n == 1)
 451                 s->syslog_fd = SD_LISTEN_FDS_START;
 452         else {
 453                 union sockaddr_union sa;
 454
 455                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 456                 if (s->syslog_fd < 0) {
 457                         log_error("socket() failed: %m");
 458                         return -errno;
 459                 }
 460
 461                 zero(sa);
 462                 sa.un.sun_family = AF_UNIX;
 463                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 464
 465                 unlink(sa.un.sun_path);
 466
 467                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 468                 if (r < 0) {
 469                         log_error("bind() failed: %m");
 470                         return -errno;
 471                 }
 472
 473                 chmod(sa.un.sun_path, 0666);
 474         }
 475
 476         one = 1;
 477         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 478         if (r < 0) {
 479                 log_error("SO_PASSCRED failed: %m");
 480                 return -errno;
 481         }
 482
 483         one = 1;
 484         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 485         if (r < 0) {
 486                 log_error("SO_TIMESTAMP failed: %m");
 487                 return -errno;
 488         }
 489
 490         zero(ev);
 491         ev.events = EPOLLIN;
 492         ev.data.fd = s->syslog_fd;
 493         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 494                 log_error("Failed to add server fd to epoll object: %m");
 495                 return -errno;
 496         }
 497
 498         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 499         if (!s->user_journals) {
 500                 log_error("Out of memory.");
 501                 return -ENOMEM;
 502         }
 503
 504         r = system_journal_open(s);
 505         if (r < 0)
 506                 return r;
 507
 508         assert_se(sigemptyset(&mask) == 0);
 509         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 510         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 511
 512         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 513         if (s->signal_fd < 0) {
 514                 log_error("signalfd(): %m");
 515                 return -errno;
 516         }
 517
 518         zero(ev);
 519         ev.events = EPOLLIN;
 520         ev.data.fd = s->signal_fd;
 521
 522         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 523                 log_error("epoll_ctl(): %m");
 524                 return -errno;
 525         }
 526
 527         return 0;
 528 }
 529
 530 static void server_done(Server *s) {
 531         JournalFile *f;
 532         assert(s);
 533
 534         if (s->system_journal)
 535                 journal_file_close(s->system_journal);
 536
 537         if (s->runtime_journal)
 538                 journal_file_close(s->runtime_journal);
 539
 540         while ((f = hashmap_steal_first(s->user_journals)))
 541                 journal_file_close(f);
 542
 543         hashmap_free(s->user_journals);
 544
 545         if (s->epoll_fd >= 0)
 546                 close_nointr_nofail(s->epoll_fd);
 547
 548         if (s->signal_fd >= 0)
 549                 close_nointr_nofail(s->signal_fd);
 550
 551         if (s->syslog_fd >= 0)
 552                 close_nointr_nofail(s->syslog_fd);
 553 }
 554
 555 int main(int argc, char *argv[]) {
 556         Server server;
 557         int r;
 558
 559         /* if (getppid() != 1) { */
 560         /*         log_error("This program should be invoked by init only."); */
 561         /*         return EXIT_FAILURE; */
 562         /* } */
 563
 564         if (argc > 1) {
 565                 log_error("This program does not take arguments.");
 566                 return EXIT_FAILURE;
 567         }
 568
 569         log_set_target(LOG_TARGET_CONSOLE);
 570         log_parse_environment();
 571         log_open();
 572
 573         umask(0022);
 574
 575         r = server_init(&server);
 576         if (r < 0)
 577                 goto finish;
 578
 579         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 580
 581         sd_notify(false,
 582                   "READY=1\n"
 583                   "STATUS=Processing messages...");
 584
 585         for (;;) {
 586                 struct epoll_event event;
 587
 588                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 589                 if (r < 0) {
 590
 591                         if (errno == EINTR)
 592                                 continue;
 593
 594                         log_error("epoll_wait() failed: %m");
 595                         r = -errno;
 596                         goto finish;
 597                 } else if (r == 0)
 598                         break;
 599
 600                 r = process_event(&server, &event);
 601                 if (r < 0)
 602                         goto finish;
 603                 else if (r == 0)
 604                         break;
 605         }
 606
 607 finish:
 608         sd_notify(false,
 609                   "STATUS=Shutting down...");
 610
 611         server_done(&server);
 612
 613         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 614 }