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
  29 #include "hashmap.h"
  30 #include "journal-private.h"
  31 #include "sd-daemon.h"
  32 #include "socket-util.h"
  33
  34 typedef struct Server {
  35         int syslog_fd;
  36         int epoll_fd;
  37         int signal_fd;
  38
  39         JournalFile *system_journal;
  40         Hashmap *user_journals;
  41 } Server;
  42
  43 static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {
  44         char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,
  45                 *source_time = NULL, *boot_id = NULL, *machine_id = NULL,
  46                 *comm = NULL, *cmdline = NULL, *hostname = NULL,
  47                 *audit_session = NULL, *audit_loginuid = NULL,
  48                 *syslog_priority = NULL, *syslog_facility = NULL,
  49                 *exe = NULL;
  50         dual_timestamp ts;
  51         struct iovec iovec[15];
  52         unsigned n = 0;
  53         char idbuf[33];
  54         sd_id128_t id;
  55         int r;
  56         char *t;
  57         int priority = LOG_USER | LOG_INFO;
  58
  59         dual_timestamp_get(&ts);
  60
  61         parse_syslog_priority((char**) &buf, &priority);
  62         skip_syslog_date((char**) &buf);
  63
  64         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
  65                 IOVEC_SET_STRING(iovec[n++], syslog_priority);
  66
  67         if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
  68                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
  69
  70         message = strappend("MESSAGE=", buf);
  71         if (message)
  72                 IOVEC_SET_STRING(iovec[n++], message);
  73
  74         if (ucred) {
  75                 uint32_t session;
  76                 uid_t loginuid;
  77
  78                 if (asprintf(&pid, "PID=%lu", (unsigned long) ucred->pid) >= 0)
  79                         IOVEC_SET_STRING(iovec[n++], pid);
  80
  81                 if (asprintf(&uid, "UID=%lu", (unsigned long) ucred->uid) >= 0)
  82                         IOVEC_SET_STRING(iovec[n++], uid);
  83
  84                 if (asprintf(&gid, "GID=%lu", (unsigned long) ucred->gid) >= 0)
  85                         IOVEC_SET_STRING(iovec[n++], gid);
  86
  87                 r = get_process_comm(ucred->pid, &t);
  88                 if (r >= 0) {
  89                         comm = strappend("COMM=", t);
  90                         if (comm)
  91                                 IOVEC_SET_STRING(iovec[n++], comm);
  92                         free(t);
  93                 }
  94
  95                 r = get_process_exe(ucred->pid, &t);
  96                 if (r >= 0) {
  97                         exe = strappend("EXE=", t);
  98                         if (comm)
  99                                 IOVEC_SET_STRING(iovec[n++], exe);
 100                         free(t);
 101                 }
 102
 103                 r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);
 104                 if (r >= 0) {
 105                         cmdline = strappend("CMDLINE=", t);
 106                         if (cmdline)
 107                                 IOVEC_SET_STRING(iovec[n++], cmdline);
 108                         free(t);
 109                 }
 110
 111                 r = audit_session_from_pid(ucred->pid, &session);
 112                 if (r >= 0)
 113                         if (asprintf(&audit_session, "AUDIT_SESSION=%lu", (unsigned long) session) >= 0)
 114                                 IOVEC_SET_STRING(iovec[n++], audit_session);
 115
 116                 r = audit_loginuid_from_pid(ucred->pid, &loginuid);
 117                 if (r >= 0)
 118                         if (asprintf(&audit_loginuid, "AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)
 119                                 IOVEC_SET_STRING(iovec[n++], audit_loginuid);
 120         }
 121
 122         if (tv) {
 123                 if (asprintf(&source_time, "SOURCE_REALTIME_TIMESTAMP=%llu",
 124                              (unsigned long long) timeval_load(tv)) >= 0)
 125                         IOVEC_SET_STRING(iovec[n++], source_time);
 126         }
 127
 128         r = sd_id128_get_boot(&id);
 129         if (r >= 0)
 130                 if (asprintf(&boot_id, "BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 131                         IOVEC_SET_STRING(iovec[n++], boot_id);
 132
 133         r = sd_id128_get_machine(&id);
 134         if (r >= 0)
 135                 if (asprintf(&machine_id, "MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)
 136                         IOVEC_SET_STRING(iovec[n++], machine_id);
 137
 138         t = gethostname_malloc();
 139         if (t) {
 140                 hostname = strappend("HOSTNAME=", t);
 141                 if (hostname)
 142                         IOVEC_SET_STRING(iovec[n++], hostname);
 143                 free(t);
 144         }
 145
 146         r = journal_file_append_entry(s->system_journal, &ts, iovec, n, NULL, NULL);
 147         if (r < 0)
 148                 log_error("Failed to write entry: %s", strerror(-r));
 149
 150
 151         free(message);
 152         free(pid);
 153         free(uid);
 154         free(gid);
 155         free(comm);
 156         free(cmdline);
 157         free(source_time);
 158         free(boot_id);
 159         free(machine_id);
 160         free(hostname);
 161         free(audit_session);
 162         free(audit_loginuid);
 163         free(syslog_facility);
 164         free(syslog_priority);
 165 }
 166
 167 static int process_event(Server *s, struct epoll_event *ev) {
 168         assert(s);
 169
 170         if (ev->events != EPOLLIN) {
 171                 log_info("Got invalid event from epoll.");
 172                 return -EIO;
 173         }
 174
 175         if (ev->data.fd == s->signal_fd) {
 176                 struct signalfd_siginfo sfsi;
 177                 ssize_t n;
 178
 179                 n = read(s->signal_fd, &sfsi, sizeof(sfsi));
 180                 if (n != sizeof(sfsi)) {
 181
 182                         if (n >= 0)
 183                                 return -EIO;
 184
 185                         if (errno == EINTR || errno == EAGAIN)
 186                                 return 0;
 187
 188                         return -errno;
 189                 }
 190
 191                 log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));
 192                 return 0;
 193
 194         } else {
 195                 for (;;) {
 196                         char buf[LINE_MAX+1];
 197                         struct msghdr msghdr;
 198                         struct iovec iovec;
 199                         struct ucred *ucred = NULL;
 200                         struct timeval *tv = NULL;
 201                         struct cmsghdr *cmsg;
 202                         union {
 203                                 struct cmsghdr cmsghdr;
 204                                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
 205                                             CMSG_SPACE(sizeof(struct timeval))];
 206                         } control;
 207                         ssize_t n;
 208                         char *e;
 209
 210                         zero(iovec);
 211                         iovec.iov_base = buf;
 212                         iovec.iov_len = sizeof(buf)-1;
 213
 214                         zero(control);
 215                         zero(msghdr);
 216                         msghdr.msg_iov = &iovec;
 217                         msghdr.msg_iovlen = 1;
 218                         msghdr.msg_control = &control;
 219                         msghdr.msg_controllen = sizeof(control);
 220
 221                         n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);
 222                         if (n < 0) {
 223
 224                                 if (errno == EINTR || errno == EAGAIN)
 225                                         return 1;
 226
 227                                 log_error("recvmsg() failed: %m");
 228                                 return -errno;
 229                         }
 230
 231                         for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
 232
 233                                 if (cmsg->cmsg_level == SOL_SOCKET &&
 234                                     cmsg->cmsg_type == SCM_CREDENTIALS &&
 235                                     cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
 236                                         ucred = (struct ucred*) CMSG_DATA(cmsg);
 237                                 else if (cmsg->cmsg_level == SOL_SOCKET &&
 238                                          cmsg->cmsg_type == SO_TIMESTAMP &&
 239                                          cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
 240                                         tv = (struct timeval*) CMSG_DATA(cmsg);
 241                         }
 242
 243                         e = memchr(buf, '\n', n);
 244                         if (e)
 245                                 *e = 0;
 246                         else
 247                                 buf[n] = 0;
 248
 249                         process_message(s, strstrip(buf), ucred, tv);
 250                 }
 251         }
 252
 253         return 1;
 254 }
 255
 256
 257 static int open_system_journal(JournalFile **f) {
 258         int r;
 259
 260         r = journal_file_open("/var/log/journal/system.journal", O_RDWR|O_CREAT, 0644, f);
 261         if (r == -ENOENT) {
 262                 mkdir_p("/run/log/journal", 0755);
 263
 264                 r = journal_file_open("/run/log/journal/system.journal", O_RDWR|O_CREAT, 0644, f);
 265         }
 266
 267         return r;
 268 }
 269
 270 static int server_init(Server *s) {
 271         int n, one, r;
 272         struct epoll_event ev;
 273         sigset_t mask;
 274
 275         assert(s);
 276
 277         zero(*s);
 278         s->syslog_fd = s->signal_fd = -1;
 279
 280         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 281         if (s->epoll_fd < 0) {
 282                 log_error("Failed to create epoll object: %m");
 283                 return -errno;
 284         }
 285
 286         n = sd_listen_fds(true);
 287         if (n < 0) {
 288                 log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));
 289                 return n;
 290         }
 291
 292         if (n > 1) {
 293                 log_error("Too many file descriptors passed.");
 294                 return -EINVAL;
 295         }
 296
 297         if (n == 1)
 298                 s->syslog_fd = SD_LISTEN_FDS_START;
 299         else {
 300                 union sockaddr_union sa;
 301
 302                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
 303                 if (s->syslog_fd < 0) {
 304                         log_error("socket() failed: %m");
 305                         return -errno;
 306                 }
 307
 308                 zero(sa);
 309                 sa.un.sun_family = AF_UNIX;
 310                 strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
 311
 312                 unlink(sa.un.sun_path);
 313
 314                 r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));
 315                 if (r < 0) {
 316                         log_error("bind() failed: %m");
 317                         return -errno;
 318                 }
 319
 320                 chmod(sa.un.sun_path, 0666);
 321         }
 322
 323         one = 1;
 324         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
 325         if (r < 0) {
 326                 log_error("SO_PASSCRED failed: %m");
 327                 return -errno;
 328         }
 329
 330         one = 1;
 331         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
 332         if (r < 0) {
 333                 log_error("SO_TIMESTAMP failed: %m");
 334                 return -errno;
 335         }
 336
 337         zero(ev);
 338         ev.events = EPOLLIN;
 339         ev.data.fd = s->syslog_fd;
 340         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
 341                 log_error("Failed to add server fd to epoll object: %m");
 342                 return -errno;
 343         }
 344
 345         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
 346         if (!s->user_journals) {
 347                 log_error("Out of memory.");
 348                 return -ENOMEM;
 349         }
 350
 351         r = open_system_journal(&s->system_journal);
 352         if (r < 0) {
 353                 log_error("Failed to open journal: %s", strerror(-r));
 354                 return r;
 355         }
 356
 357         assert_se(sigemptyset(&mask) == 0);
 358         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
 359         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 360
 361         s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 362         if (s->signal_fd < 0) {
 363                 log_error("signalfd(): %m");
 364                 return -errno;
 365         }
 366
 367         zero(ev);
 368         ev.events = EPOLLIN;
 369         ev.data.fd = s->signal_fd;
 370
 371         if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
 372                 log_error("epoll_ctl(): %m");
 373                 return -errno;
 374         }
 375
 376         return 0;
 377 }
 378
 379 static void server_done(Server *s) {
 380         JournalFile *f;
 381         assert(s);
 382
 383         if (s->system_journal)
 384                 journal_file_close(s->system_journal);
 385
 386         while ((f = hashmap_steal_first(s->user_journals)))
 387                 journal_file_close(f);
 388
 389         hashmap_free(s->user_journals);
 390
 391         if (s->epoll_fd >= 0)
 392                 close_nointr_nofail(s->epoll_fd);
 393
 394         if (s->signal_fd >= 0)
 395                 close_nointr_nofail(s->signal_fd);
 396
 397         if (s->syslog_fd >= 0)
 398                 close_nointr_nofail(s->syslog_fd);
 399 }
 400
 401 int main(int argc, char *argv[]) {
 402         Server server;
 403         int r;
 404
 405         /* if (getppid() != 1) { */
 406         /*         log_error("This program should be invoked by init only."); */
 407         /*         return EXIT_FAILURE; */
 408         /* } */
 409
 410         if (argc > 1) {
 411                 log_error("This program does not take arguments.");
 412                 return EXIT_FAILURE;
 413         }
 414
 415         log_set_target(LOG_TARGET_AUTO);
 416         log_parse_environment();
 417         log_open();
 418
 419         umask(0022);
 420
 421         r = server_init(&server);
 422         if (r < 0)
 423                 goto finish;
 424
 425         log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());
 426
 427         sd_notify(false,
 428                   "READY=1\n"
 429                   "STATUS=Processing messages...");
 430
 431         for (;;) {
 432                 struct epoll_event event;
 433
 434                 r = epoll_wait(server.epoll_fd, &event, 1, -1);
 435                 if (r < 0) {
 436
 437                         if (errno == EINTR)
 438                                 continue;
 439
 440                         log_error("epoll_wait() failed: %m");
 441                         r = -errno;
 442                         goto finish;
 443                 } else if (r == 0)
 444                         break;
 445
 446                 r = process_event(&server, &event);
 447                 if (r < 0)
 448                         goto finish;
 449                 else if (r == 0)
 450                         break;
 451         }
 452
 453 finish:
 454         sd_notify(false,
 455                   "STATUS=Shutting down...");
 456
 457         server_done(&server);
 458
 459         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 460 }