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-private.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         r = sd_id128_get_boot(&id);
 215         if (r >= 0)
 216                 if (asprintf(&boot_id, "BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 217                         IOVEC_SET_STRING(iovec[n++], boot_id);
 218
 219         r = sd_id128_get_machine(&id);
 220         if (r >= 0)
 221                 if (asprintf(&machine_id, "MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 222                         IOVEC_SET_STRING(iovec[n++], machine_id);
 223
 224         t = gethostname_malloc();
 225         if (t) {
 226                 hostname = strappend("HOSTNAME=", t);
 227                 if (hostname)
 228                         IOVEC_SET_STRING(iovec[n++], hostname);
 229                 free(t);
 230         }
 231
 232         f = find_journal(s, loginuid);
 233         if (!f)
 234                 log_warning("Dropping message, as we can't find a place to store the data.");
 235         else {
 236                 r = journal_file_append_entry(f, NULL, iovec, n, NULL, NULL);
 237
 238                 if (r < 0)
 239                         log_error("Failed to write entry, ignoring: %s", strerror(-r));
 240         }
 241
 242         free(message);
 243         free(pid);
 244         free(uid);
 245         free(gid);
 246         free(comm);
 247         free(cmdline);
 248         free(source_time);
 249         free(boot_id);
 250         free(machine_id);
 251         free(hostname);
 252         free(audit_session);
 253         free(audit_loginuid);
 254         free(syslog_facility);
 255         free(syslog_priority);
 256 }
 257
 258 static int process_event(Server *s, struct epoll_event *ev) {
 259         assert(s);
 260
 261         if (ev->events != EPOLLIN) {
 262                 log_info("Got invalid event from epoll.");
 263                 return -EIO;
 264         }
 265
 266         if (ev->data.fd == s->signal_fd) {
 267                 struct signalfd_siginfo sfsi;
 268                 ssize_t n;
 269
 270                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 271                 if (n != sizeof(sfsi)) {
 272
 273                         if (n >= 0)
 274                                 return -EIO;
 275
 276                         if (errno == EINTR || errno == EAGAIN)
 277                                 return 0;
 278
 279                         return -errno;
 280                 }
 281
 282                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 283                 return 0;
 284
 285         } else {
 286                 for (;;) {
 287                         char buf[LINE_MAX+1];
 288                         struct msghdr msghdr;
 289                         struct iovec iovec;
 290                         struct ucred *ucred = NULL;
 291                         struct timeval *tv = NULL;
 292                         struct cmsghdr *cmsg;
 293                         union {
 294                                 struct cmsghdr cmsghdr;
 295                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 296                                             CMSG_SPACE(sizeof(struct timeval))];
 297                         } control;
 298                         ssize_t n;
 299                         char *e;
 300
 301                         zero(iovec);
 302                         iovec.iov_base = buf;
 303                         iovec.iov_len = sizeof(buf)-1;
 304
 305                         zero(control);
 306                         zero(msghdr);
 307                         msghdr.msg_iov = &iovec;
 308                         msghdr.msg_iovlen = 1;
 309                         msghdr.msg_control = &control;
 310                         msghdr.msg_controllen = sizeof(control);
 311
 312                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 313                         if (n < 0) {
 314
 315                                 if (errno == EINTR || errno == EAGAIN)
 316                                         return 1;
 317
 318                                 log_error("recvmsg() failed: %m");
 319                                 return -errno;
 320                         }
 321
 322                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 323
 324                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 325                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 326                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 327                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 328                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 329                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 330                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 331                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 332                         }
 333
 334                         e = memchr(buf, '\n', n);
 335                         if (e)
 336                                 *e = 0;
 337                         else
 338                                 buf[n] = 0;
 339
 340                         process_message(s, strstrip(buf), ucred, tv);
 341                 }
 342         }
 343
 344         return 1;
 345 }
 346
 347 static int server_init(Server *s) {
 348         int n, one, r;
 349         struct epoll_event ev;
 350         sigset_t mask;
 351
 352         assert(s);
 353
 354         zero(*s);
 355         s->syslog_fd = s->signal_fd = -1;
 356
 357         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 358         if (s->epoll_fd < 0) {
 359                 log_error("Failed to create epoll object: %m");
 360                 return -errno;
 361         }
 362
 363         n = sd_listen_fds(true);
 364         if (n < 0) {
 365                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 366                 return n;
 367         }
 368
 369         if (n > 1) {
 370                 log_error("Too many file descriptors passed.");
 371                 return -EINVAL;
 372         }
 373
 374         if (n == 1)
 375                 s->syslog_fd = SD_LISTEN_FDS_START;
 376         else {
 377                 union sockaddr_union sa;
 378
 379                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 380                 if (s->syslog_fd < 0) {
 381                         log_error("socket() failed: %m");
 382                         return -errno;
 383                 }
 384
 385                 zero(sa);
 386                 sa.un.sun_family = AF_UNIX;
 387                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 388
 389                 unlink(sa.un.sun_path);
 390
 391                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 392                 if (r < 0) {
 393                         log_error("bind() failed: %m");
 394                         return -errno;
 395                 }
 396
 397                 chmod(sa.un.sun_path, 0666);
 398         }
 399
 400         one = 1;
 401         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 402         if (r < 0) {
 403                 log_error("SO_PASSCRED failed: %m");
 404                 return -errno;
 405         }
 406
 407         one = 1;
 408         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 409         if (r < 0) {
 410                 log_error("SO_TIMESTAMP failed: %m");
 411                 return -errno;
 412         }
 413
 414         zero(ev);
 415         ev.events = EPOLLIN;
 416         ev.data.fd = s->syslog_fd;
 417         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 418                 log_error("Failed to add server fd to epoll object: %m");
 419                 return -errno;
 420         }
 421
 422         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 423         if (!s->user_journals) {
 424                 log_error("Out of memory.");
 425                 return -ENOMEM;
 426         }
 427
 428         r = journal_file_open("/var/log/journal/system.journal", O_RDWR|O_CREAT, 0640, &s->system_journal);
 429         if (r >= 0)
 430                 fix_perms(s->system_journal, 0);
 431         else if (r == -ENOENT) {
 432                 mkdir_p("/run/log/journal", 0755);
 433
 434                 r = journal_file_open("/run/log/journal/system.journal", O_RDWR|O_CREAT, 0640, &s->runtime_journal);
 435                 if (r >= 0)
 436                         fix_perms(s->runtime_journal, 0);
 437         }
 438
 439         if (r < 0 && r != -ENOENT) {
 440                 log_error("Failed to open journal: %s", strerror(-r));
 441                 return r;
 442         }
 443
 444         assert_se(sigemptyset(&mask) == 0);
 445         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 446         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 447
 448         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 449         if (s->signal_fd < 0) {
 450                 log_error("signalfd(): %m");
 451                 return -errno;
 452         }
 453
 454         zero(ev);
 455         ev.events = EPOLLIN;
 456         ev.data.fd = s->signal_fd;
 457
 458         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 459                 log_error("epoll_ctl(): %m");
 460                 return -errno;
 461         }
 462
 463         return 0;
 464 }
 465
 466 static void server_done(Server *s) {
 467         JournalFile *f;
 468         assert(s);
 469
 470         if (s->system_journal)
 471                 journal_file_close(s->system_journal);
 472
 473         if (s->runtime_journal)
 474                 journal_file_close(s->runtime_journal);
 475
 476         while ((f = hashmap_steal_first(s->user_journals)))
 477                 journal_file_close(f);
 478
 479         hashmap_free(s->user_journals);
 480
 481         if (s->epoll_fd >= 0)
 482                 close_nointr_nofail(s->epoll_fd);
 483
 484         if (s->signal_fd >= 0)
 485                 close_nointr_nofail(s->signal_fd);
 486
 487         if (s->syslog_fd >= 0)
 488                 close_nointr_nofail(s->syslog_fd);
 489 }
 490
 491 int main(int argc, char *argv[]) {
 492         Server server;
 493         int r;
 494
 495         /* if (getppid() != 1) { */
 496         /*         log_error("This program should be invoked by init only."); */
 497         /*         return EXIT_FAILURE; */
 498         /* } */
 499
 500         if (argc > 1) {
 501                 log_error("This program does not take arguments.");
 502                 return EXIT_FAILURE;
 503         }
 504
 505         log_set_target(LOG_TARGET_CONSOLE);
 506         log_parse_environment();
 507         log_open();
 508
 509         umask(0022);
 510
 511         r = server_init(&server);
 512         if (r < 0)
 513                 goto finish;
 514
 515         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 516
 517         sd_notify(false,
 518                   "READY=1\n"
 519                   "STATUS=Processing messages...");
 520
 521         for (;;) {
 522                 struct epoll_event event;
 523
 524                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 525                 if (r < 0) {
 526
 527                         if (errno == EINTR)
 528                                 continue;
 529
 530                         log_error("epoll_wait() failed: %m");
 531                         r = -errno;
 532                         goto finish;
 533                 } else if (r == 0)
 534                         break;
 535
 536                 r = process_event(&server, &event);
 537                 if (r < 0)
 538                         goto finish;
 539                 else if (r == 0)
 540                         break;
 541         }
 542
 543 finish:
 544         sd_notify(false,
 545                   "STATUS=Shutting down...");
 546
 547         server_done(&server);
 548
 549         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 550 }