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         char ids[33];
  99         sd_id128_t machine;
 100
 101         assert(s);
 102
 103         /* We split up user logs only on /var, not on /run */
 104         if (!s->system_journal)
 105                 return s->runtime_journal;
 106
 107         if (uid <= 0)
 108                 return s->system_journal;
 109
 110         r = sd_id128_get_machine(&machine);
 111         if (r < 0)
 112                 return s->system_journal;
 113
 114         f = hashmap_get(s->user_journals, UINT32_TO_PTR(uid));
 115         if (f)
 116                 return f;
 117
 118         if (asprintf(&p, "/var/log/journal/%s/user-%lu.journal", sd_id128_to_string(machine, ids), (unsigned long) uid) < 0)
 119                 return s->system_journal;
 120
 121         r = journal_file_open(p, O_RDWR|O_CREAT, 0640, NULL, &f);
 122         free(p);
 123
 124         if (r < 0)
 125                 return s->system_journal;
 126
 127         fix_perms(f, uid);
 128
 129         r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);
 130         if (r < 0) {
 131                 journal_file_close(f);
 132                 return s->system_journal;
 133         }
 134
 135         return f;
 136 }
 137
 138 static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {
 139         char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,
 140                 *source_time = NULL, *boot_id = NULL, *machine_id = NULL,
 141                 *comm = NULL, *cmdline = NULL, *hostname = NULL,
 142                 *audit_session = NULL, *audit_loginuid = NULL,
 143                 *syslog_priority = NULL, *syslog_facility = NULL,
 144                 *exe = NULL, *cgroup = NULL;
 145         struct iovec iovec[16];
 146         unsigned n = 0;
 147         char idbuf[33];
 148         sd_id128_t id;
 149         int r;
 150         char *t;
 151         int priority = LOG_USER | LOG_INFO;
 152         uid_t loginuid = 0;
 153         JournalFile *f;
 154
 155         parse_syslog_priority((char**) &buf, &priority);
 156         skip_syslog_date((char**) &buf);
 157
 158         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
 159                 IOVEC_SET_STRING(iovec[n++], syslog_priority);
 160
 161         if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
 162                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
 163
 164         message = strappend("MESSAGE=", buf);
 165         if (message)
 166                 IOVEC_SET_STRING(iovec[n++], message);
 167
 168         if (ucred) {
 169                 uint32_t session;
 170                 char *path;
 171
 172                 if (asprintf(&pid, "PID=%lu", (unsigned long) ucred->pid) >= 0)
 173                         IOVEC_SET_STRING(iovec[n++], pid);
 174
 175                 if (asprintf(&uid, "UID=%lu", (unsigned long) ucred->uid) >= 0)
 176                         IOVEC_SET_STRING(iovec[n++], uid);
 177
 178                 if (asprintf(&gid, "GID=%lu", (unsigned long) ucred->gid) >= 0)
 179                         IOVEC_SET_STRING(iovec[n++], gid);
 180
 181                 r = get_process_comm(ucred->pid, &t);
 182                 if (r >= 0) {
 183                         comm = strappend("COMM=", t);
 184                         if (comm)
 185                                 IOVEC_SET_STRING(iovec[n++], comm);
 186                         free(t);
 187                 }
 188
 189                 r = get_process_exe(ucred->pid, &t);
 190                 if (r >= 0) {
 191                         exe = strappend("EXE=", t);
 192                         if (comm)
 193                                 IOVEC_SET_STRING(iovec[n++], exe);
 194                         free(t);
 195                 }
 196
 197                 r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);
 198                 if (r >= 0) {
 199                         cmdline = strappend("CMDLINE=", t);
 200                         if (cmdline)
 201                                 IOVEC_SET_STRING(iovec[n++], cmdline);
 202                         free(t);
 203                 }
 204
 205                 r = audit_session_from_pid(ucred->pid, &session);
 206                 if (r >= 0)
 207                         if (asprintf(&audit_session, "AUDIT_SESSION=%lu", (unsigned long) session) >= 0)
 208                                 IOVEC_SET_STRING(iovec[n++], audit_session);
 209
 210                 r = audit_loginuid_from_pid(ucred->pid, &loginuid);
 211                 if (r >= 0)
 212                         if (asprintf(&audit_loginuid, "AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)
 213                                 IOVEC_SET_STRING(iovec[n++], audit_loginuid);
 214
 215                 r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, ucred->pid, &path);
 216                 if (r >= 0) {
 217                         cgroup = strappend("SYSTEMD_CGROUP=", path);
 218                         if (cgroup)
 219                                 IOVEC_SET_STRING(iovec[n++], cgroup);
 220                         free(path);
 221                 }
 222         }
 223
 224         if (tv) {
 225                 if (asprintf(&source_time, "SOURCE_REALTIME_TIMESTAMP=%llu",
 226                              (unsigned long long) timeval_load(tv)) >= 0)
 227                         IOVEC_SET_STRING(iovec[n++], source_time);
 228         }
 229
 230         /* Note that strictly speaking storing the boot id here is
 231          * redundant since the entry includes this in-line
 232          * anyway. However, we need this indexed, too. */
 233         r = sd_id128_get_boot(&id);
 234         if (r >= 0)
 235                 if (asprintf(&boot_id, "BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 236                         IOVEC_SET_STRING(iovec[n++], boot_id);
 237
 238         r = sd_id128_get_machine(&id);
 239         if (r >= 0)
 240                 if (asprintf(&machine_id, "MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 241                         IOVEC_SET_STRING(iovec[n++], machine_id);
 242
 243         t = gethostname_malloc();
 244         if (t) {
 245                 hostname = strappend("HOSTNAME=", t);
 246                 if (hostname)
 247                         IOVEC_SET_STRING(iovec[n++], hostname);
 248                 free(t);
 249         }
 250
 251         f = find_journal(s, loginuid);
 252         if (!f)
 253                 log_warning("Dropping message, as we can't find a place to store the data.");
 254         else {
 255                 r = journal_file_append_entry(f, NULL, iovec, n, NULL, NULL);
 256
 257                 if (r < 0)
 258                         log_error("Failed to write entry, ignoring: %s", strerror(-r));
 259         }
 260
 261         free(message);
 262         free(pid);
 263         free(uid);
 264         free(gid);
 265         free(comm);
 266         free(exe);
 267         free(cmdline);
 268         free(source_time);
 269         free(boot_id);
 270         free(machine_id);
 271         free(hostname);
 272         free(audit_session);
 273         free(audit_loginuid);
 274         free(syslog_facility);
 275         free(syslog_priority);
 276         free(cgroup);
 277 }
 278
 279 static int process_event(Server *s, struct epoll_event *ev) {
 280         assert(s);
 281
 282         if (ev->events != EPOLLIN) {
 283                 log_info("Got invalid event from epoll.");
 284                 return -EIO;
 285         }
 286
 287         if (ev->data.fd == s->signal_fd) {
 288                 struct signalfd_siginfo sfsi;
 289                 ssize_t n;
 290
 291                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 292                 if (n != sizeof(sfsi)) {
 293
 294                         if (n >= 0)
 295                                 return -EIO;
 296
 297                         if (errno == EINTR || errno == EAGAIN)
 298                                 return 0;
 299
 300                         return -errno;
 301                 }
 302
 303                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 304                 return 0;
 305
 306         }
 307
 308         if (ev->data.fd == s->syslog_fd) {
 309                 for (;;) {
 310                         char buf[LINE_MAX+1];
 311                         struct msghdr msghdr;
 312                         struct iovec iovec;
 313                         struct ucred *ucred = NULL;
 314                         struct timeval *tv = NULL;
 315                         struct cmsghdr *cmsg;
 316                         union {
 317                                 struct cmsghdr cmsghdr;
 318                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 319                                             CMSG_SPACE(sizeof(struct timeval))];
 320                         } control;
 321                         ssize_t n;
 322                         char *e;
 323
 324                         zero(iovec);
 325                         iovec.iov_base = buf;
 326                         iovec.iov_len = sizeof(buf)-1;
 327
 328                         zero(control);
 329                         zero(msghdr);
 330                         msghdr.msg_iov = &iovec;
 331                         msghdr.msg_iovlen = 1;
 332                         msghdr.msg_control = &control;
 333                         msghdr.msg_controllen = sizeof(control);
 334
 335                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 336                         if (n < 0) {
 337
 338                                 if (errno == EINTR || errno == EAGAIN)
 339                                         return 1;
 340
 341                                 log_error("recvmsg() failed: %m");
 342                                 return -errno;
 343                         }
 344
 345                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 346
 347                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 348                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 349                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 350                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 351                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 352                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 353                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 354                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 355                         }
 356
 357                         e = memchr(buf, '\n', n);
 358                         if (e)
 359                                 *e = 0;
 360                         else
 361                                 buf[n] = 0;
 362
 363                         process_message(s, strstrip(buf), ucred, tv);
 364                 }
 365
 366                 return 1;
 367         }
 368
 369         log_error("Unknown event.");
 370         return 0;
 371 }
 372
 373 static int system_journal_open(Server *s) {
 374         int r;
 375         char *fn;
 376         sd_id128_t machine;
 377         char ids[33];
 378
 379         r = sd_id128_get_machine(&machine);
 380         if (r < 0)
 381                 return r;
 382
 383         /* First try to create the machine path, but not the prefix */
 384         fn = strappend("/var/log/journal/", sd_id128_to_string(machine, ids));
 385         if (!fn)
 386                 return -ENOMEM;
 387         (void) mkdir(fn, 0755);
 388         free(fn);
 389
 390         /* The create the system journal file */
 391         fn = join("/var/log/journal/", ids, "/system.journal", NULL);
 392         if (!fn)
 393                 return -ENOMEM;
 394
 395         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->system_journal);
 396         free(fn);
 397
 398         if (r >= 0) {
 399                 fix_perms(s->system_journal, 0);
 400                 return r;
 401         }
 402
 403         if (r < 0 && r != -ENOENT) {
 404                 log_error("Failed to open system journal: %s", strerror(-r));
 405                 return r;
 406         }
 407
 408         /* /var didn't work, so try /run, but this time we
 409          * create the prefix too */
 410         fn = join("/run/log/journal/", ids, "/system.journal", NULL);
 411         if (!fn)
 412                 return -ENOMEM;
 413
 414         (void) mkdir_parents(fn, 0755);
 415         r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->runtime_journal);
 416         free(fn);
 417
 418         if (r < 0) {
 419                 log_error("Failed to open runtime journal: %s", strerror(-r));
 420                 return r;
 421         }
 422
 423         fix_perms(s->runtime_journal, 0);
 424         return r;
 425 }
 426
 427 static int server_init(Server *s) {
 428         int n, one, r;
 429         struct epoll_event ev;
 430         sigset_t mask;
 431
 432         assert(s);
 433
 434         zero(*s);
 435         s->syslog_fd = s->signal_fd = -1;
 436
 437         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 438         if (s->epoll_fd < 0) {
 439                 log_error("Failed to create epoll object: %m");
 440                 return -errno;
 441         }
 442
 443         n = sd_listen_fds(true);
 444         if (n < 0) {
 445                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 446                 return n;
 447         }
 448
 449         if (n > 1) {
 450                 log_error("Too many file descriptors passed.");
 451                 return -EINVAL;
 452         }
 453
 454         if (n == 1)
 455                 s->syslog_fd = SD_LISTEN_FDS_START;
 456         else {
 457                 union sockaddr_union sa;
 458
 459                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 460                 if (s->syslog_fd < 0) {
 461                         log_error("socket() failed: %m");
 462                         return -errno;
 463                 }
 464
 465                 zero(sa);
 466                 sa.un.sun_family = AF_UNIX;
 467                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 468
 469                 unlink(sa.un.sun_path);
 470
 471                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 472                 if (r < 0) {
 473                         log_error("bind() failed: %m");
 474                         return -errno;
 475                 }
 476
 477                 chmod(sa.un.sun_path, 0666);
 478         }
 479
 480         one = 1;
 481         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 482         if (r < 0) {
 483                 log_error("SO_PASSCRED failed: %m");
 484                 return -errno;
 485         }
 486
 487         one = 1;
 488         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 489         if (r < 0) {
 490                 log_error("SO_TIMESTAMP failed: %m");
 491                 return -errno;
 492         }
 493
 494         zero(ev);
 495         ev.events = EPOLLIN;
 496         ev.data.fd = s->syslog_fd;
 497         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 498                 log_error("Failed to add server fd to epoll object: %m");
 499                 return -errno;
 500         }
 501
 502         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 503         if (!s->user_journals) {
 504                 log_error("Out of memory.");
 505                 return -ENOMEM;
 506         }
 507
 508         r = system_journal_open(s);
 509         if (r < 0)
 510                 return r;
 511
 512         assert_se(sigemptyset(&mask) == 0);
 513         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 514         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 515
 516         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 517         if (s->signal_fd < 0) {
 518                 log_error("signalfd(): %m");
 519                 return -errno;
 520         }
 521
 522         zero(ev);
 523         ev.events = EPOLLIN;
 524         ev.data.fd = s->signal_fd;
 525
 526         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 527                 log_error("epoll_ctl(): %m");
 528                 return -errno;
 529         }
 530
 531         return 0;
 532 }
 533
 534 static void server_done(Server *s) {
 535         JournalFile *f;
 536         assert(s);
 537
 538         if (s->system_journal)
 539                 journal_file_close(s->system_journal);
 540
 541         if (s->runtime_journal)
 542                 journal_file_close(s->runtime_journal);
 543
 544         while ((f = hashmap_steal_first(s->user_journals)))
 545                 journal_file_close(f);
 546
 547         hashmap_free(s->user_journals);
 548
 549         if (s->epoll_fd >= 0)
 550                 close_nointr_nofail(s->epoll_fd);
 551
 552         if (s->signal_fd >= 0)
 553                 close_nointr_nofail(s->signal_fd);
 554
 555         if (s->syslog_fd >= 0)
 556                 close_nointr_nofail(s->syslog_fd);
 557 }
 558
 559 int main(int argc, char *argv[]) {
 560         Server server;
 561         int r;
 562
 563         /* if (getppid() != 1) { */
 564         /*         log_error("This program should be invoked by init only."); */
 565         /*         return EXIT_FAILURE; */
 566         /* } */
 567
 568         if (argc > 1) {
 569                 log_error("This program does not take arguments.");
 570                 return EXIT_FAILURE;
 571         }
 572
 573         log_set_target(LOG_TARGET_CONSOLE);
 574         log_parse_environment();
 575         log_open();
 576
 577         umask(0022);
 578
 579         r = server_init(&server);
 580         if (r < 0)
 581                 goto finish;
 582
 583         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 584
 585         sd_notify(false,
 586                   "READY=1\n"
 587                   "STATUS=Processing messages...");
 588 #
 589         for (;;) {
 590                 struct epoll_event event;
 591
 592                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 593                 if (r < 0) {
 594
 595                         if (errno == EINTR)
 596                                 continue;
 597
 598                         log_error("epoll_wait() failed: %m");
 599                         r = -errno;
 600                         goto finish;
 601                 } else if (r == 0)
 602                         break;
 603
 604                 r = process_event(&server, &event);
 605                 if (r < 0)
 606                         goto finish;
 607                 else if (r == 0)
 608                         break;
 609         }
 610
 611 finish:
 612         sd_notify(false,
 613                   "STATUS=Shutting down...");
 614
 615         server_done(&server);
 616
 617         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 618 }