src/journal/journald-stream.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 Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <fcntl.h>
  23 #include <unistd.h>
  24 #include <stddef.h>
  25
  26 #ifdef HAVE_SELINUX
  27 #include <selinux/selinux.h>
  28 #endif
  29
  30 #include "sd-event.h"
  31 #include "socket-util.h"
  32 #include "selinux-util.h"
  33 #include "journald-server.h"
  34 #include "journald-stream.h"
  35 #include "journald-syslog.h"
  36 #include "journald-kmsg.h"
  37 #include "journald-console.h"
  38 #include "journald-wall.h"
  39
  40 #define STDOUT_STREAMS_MAX 4096
  41
  42 typedef enum StdoutStreamState {
  43         STDOUT_STREAM_IDENTIFIER,
  44         STDOUT_STREAM_UNIT_ID,
  45         STDOUT_STREAM_PRIORITY,
  46         STDOUT_STREAM_LEVEL_PREFIX,
  47         STDOUT_STREAM_FORWARD_TO_SYSLOG,
  48         STDOUT_STREAM_FORWARD_TO_KMSG,
  49         STDOUT_STREAM_FORWARD_TO_CONSOLE,
  50         STDOUT_STREAM_RUNNING
  51 } StdoutStreamState;
  52
  53 struct StdoutStream {
  54         Server *server;
  55         StdoutStreamState state;
  56
  57         int fd;
  58
  59         struct ucred ucred;
  60 #ifdef HAVE_SELINUX
  61         security_context_t security_context;
  62 #endif
  63
  64         char *identifier;
  65         char *unit_id;
  66         int priority;
  67         bool level_prefix:1;
  68         bool forward_to_syslog:1;
  69         bool forward_to_kmsg:1;
  70         bool forward_to_console:1;
  71
  72         char buffer[LINE_MAX+1];
  73         size_t length;
  74
  75         sd_event_source *event_source;
  76
  77         LIST_FIELDS(StdoutStream, stdout_stream);
  78 };
  79
  80 static int stdout_stream_log(StdoutStream *s, const char *p) {
  81         struct iovec iovec[N_IOVEC_META_FIELDS + 5];
  82         int priority;
  83         char syslog_priority[] = "PRIORITY=\0";
  84         char syslog_facility[sizeof("SYSLOG_FACILITY=") + DECIMAL_STR_MAX(priority)];
  85         _cleanup_free_ char *message = NULL, *syslog_identifier = NULL;
  86         unsigned n = 0;
  87         char *label = NULL;
  88         size_t label_len = 0;
  89
  90         assert(s);
  91         assert(p);
  92
  93         if (isempty(p))
  94                 return 0;
  95
  96         priority = s->priority;
  97
  98         if (s->level_prefix)
  99                 syslog_parse_priority(&p, &priority, false);
 100
 101         if (s->forward_to_syslog || s->server->forward_to_syslog)
 102                 server_forward_syslog(s->server, syslog_fixup_facility(priority), s->identifier, p, &s->ucred, NULL);
 103
 104         if (s->forward_to_kmsg || s->server->forward_to_kmsg)
 105                 server_forward_kmsg(s->server, priority, s->identifier, p, &s->ucred);
 106
 107         if (s->forward_to_console || s->server->forward_to_console)
 108                 server_forward_console(s->server, priority, s->identifier, p, &s->ucred);
 109
 110         if (s->server->forward_to_wall)
 111                 server_forward_wall(s->server, priority, s->identifier, p, &s->ucred);
 112
 113         IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=stdout");
 114
 115         syslog_priority[strlen("PRIORITY=")] = '0' + LOG_PRI(priority);
 116         IOVEC_SET_STRING(iovec[n++], syslog_priority);
 117
 118         if (priority & LOG_FACMASK) {
 119                 snprintf(syslog_facility, sizeof(syslog_facility), "SYSLOG_FACILITY=%i", LOG_FAC(priority));
 120                 IOVEC_SET_STRING(iovec[n++], syslog_facility);
 121         }
 122
 123         if (s->identifier) {
 124                 syslog_identifier = strappend("SYSLOG_IDENTIFIER=", s->identifier);
 125                 if (syslog_identifier)
 126                         IOVEC_SET_STRING(iovec[n++], syslog_identifier);
 127         }
 128
 129         message = strappend("MESSAGE=", p);
 130         if (message)
 131                 IOVEC_SET_STRING(iovec[n++], message);
 132
 133 #ifdef HAVE_SELINUX
 134         if (s->security_context) {
 135                 label = (char*) s->security_context;
 136                 label_len = strlen((char*) s->security_context);
 137         }
 138 #endif
 139
 140         server_dispatch_message(s->server, iovec, n, ELEMENTSOF(iovec), &s->ucred, NULL, label, label_len, s->unit_id, priority, 0);
 141         return 0;
 142 }
 143
 144 static int stdout_stream_line(StdoutStream *s, char *p) {
 145         int r;
 146
 147         assert(s);
 148         assert(p);
 149
 150         p = strstrip(p);
 151
 152         switch (s->state) {
 153
 154         case STDOUT_STREAM_IDENTIFIER:
 155                 if (isempty(p))
 156                         s->identifier = NULL;
 157                 else  {
 158                         s->identifier = strdup(p);
 159                         if (!s->identifier)
 160                                 return log_oom();
 161                 }
 162
 163                 s->state = STDOUT_STREAM_UNIT_ID;
 164                 return 0;
 165
 166         case STDOUT_STREAM_UNIT_ID:
 167                 if (s->ucred.uid == 0) {
 168                         if (isempty(p))
 169                                 s->unit_id = NULL;
 170                         else  {
 171                                 s->unit_id = strdup(p);
 172                                 if (!s->unit_id)
 173                                         return log_oom();
 174                         }
 175                 }
 176
 177                 s->state = STDOUT_STREAM_PRIORITY;
 178                 return 0;
 179
 180         case STDOUT_STREAM_PRIORITY:
 181                 r = safe_atoi(p, &s->priority);
 182                 if (r < 0 || s->priority < 0 || s->priority > 999) {
 183                         log_warning("Failed to parse log priority line.");
 184                         return -EINVAL;
 185                 }
 186
 187                 s->state = STDOUT_STREAM_LEVEL_PREFIX;
 188                 return 0;
 189
 190         case STDOUT_STREAM_LEVEL_PREFIX:
 191                 r = parse_boolean(p);
 192                 if (r < 0) {
 193                         log_warning("Failed to parse level prefix line.");
 194                         return -EINVAL;
 195                 }
 196
 197                 s->level_prefix = !!r;
 198                 s->state = STDOUT_STREAM_FORWARD_TO_SYSLOG;
 199                 return 0;
 200
 201         case STDOUT_STREAM_FORWARD_TO_SYSLOG:
 202                 r = parse_boolean(p);
 203                 if (r < 0) {
 204                         log_warning("Failed to parse forward to syslog line.");
 205                         return -EINVAL;
 206                 }
 207
 208                 s->forward_to_syslog = !!r;
 209                 s->state = STDOUT_STREAM_FORWARD_TO_KMSG;
 210                 return 0;
 211
 212         case STDOUT_STREAM_FORWARD_TO_KMSG:
 213                 r = parse_boolean(p);
 214                 if (r < 0) {
 215                         log_warning("Failed to parse copy to kmsg line.");
 216                         return -EINVAL;
 217                 }
 218
 219                 s->forward_to_kmsg = !!r;
 220                 s->state = STDOUT_STREAM_FORWARD_TO_CONSOLE;
 221                 return 0;
 222
 223         case STDOUT_STREAM_FORWARD_TO_CONSOLE:
 224                 r = parse_boolean(p);
 225                 if (r < 0) {
 226                         log_warning("Failed to parse copy to console line.");
 227                         return -EINVAL;
 228                 }
 229
 230                 s->forward_to_console = !!r;
 231                 s->state = STDOUT_STREAM_RUNNING;
 232                 return 0;
 233
 234         case STDOUT_STREAM_RUNNING:
 235                 return stdout_stream_log(s, p);
 236         }
 237
 238         assert_not_reached("Unknown stream state");
 239 }
 240
 241 static int stdout_stream_scan(StdoutStream *s, bool force_flush) {
 242         char *p;
 243         size_t remaining;
 244         int r;
 245
 246         assert(s);
 247
 248         p = s->buffer;
 249         remaining = s->length;
 250         for (;;) {
 251                 char *end;
 252                 size_t skip;
 253
 254                 end = memchr(p, '\n', remaining);
 255                 if (end)
 256                         skip = end - p + 1;
 257                 else if (remaining >= sizeof(s->buffer) - 1) {
 258                         end = p + sizeof(s->buffer) - 1;
 259                         skip = remaining;
 260                 } else
 261                         break;
 262
 263                 *end = 0;
 264
 265                 r = stdout_stream_line(s, p);
 266                 if (r < 0)
 267                         return r;
 268
 269                 remaining -= skip;
 270                 p += skip;
 271         }
 272
 273         if (force_flush && remaining > 0) {
 274                 p[remaining] = 0;
 275                 r = stdout_stream_line(s, p);
 276                 if (r < 0)
 277                         return r;
 278
 279                 p += remaining;
 280                 remaining = 0;
 281         }
 282
 283         if (p > s->buffer) {
 284                 memmove(s->buffer, p, remaining);
 285                 s->length = remaining;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 292         StdoutStream *s = userdata;
 293         ssize_t l;
 294         int r;
 295
 296         assert(s);
 297
 298         if ((revents|EPOLLIN|EPOLLHUP) != (EPOLLIN|EPOLLHUP)) {
 299                 log_error("Got invalid event from epoll for stdout stream: %"PRIx32, revents);
 300                 goto terminate;
 301         }
 302
 303         l = read(s->fd, s->buffer+s->length, sizeof(s->buffer)-1-s->length);
 304         if (l < 0) {
 305
 306                 if (errno == EAGAIN)
 307                         return 0;
 308
 309                 log_warning("Failed to read from stream: %m");
 310                 goto terminate;
 311         }
 312
 313         if (l == 0) {
 314                 stdout_stream_scan(s, true);
 315                 goto terminate;
 316         }
 317
 318         s->length += l;
 319         r = stdout_stream_scan(s, false);
 320         if (r < 0)
 321                 goto terminate;
 322
 323         return 1;
 324
 325 terminate:
 326         stdout_stream_free(s);
 327         return 0;
 328 }
 329
 330 void stdout_stream_free(StdoutStream *s) {
 331         assert(s);
 332
 333         if (s->server) {
 334                 assert(s->server->n_stdout_streams > 0);
 335                 s->server->n_stdout_streams --;
 336                 LIST_REMOVE(stdout_stream, s->server->stdout_streams, s);
 337         }
 338
 339         if (s->event_source) {
 340                 sd_event_source_set_enabled(s->event_source, SD_EVENT_OFF);
 341                 s->event_source = sd_event_source_unref(s->event_source);
 342         }
 343
 344         if (s->fd >= 0)
 345                 close_nointr_nofail(s->fd);
 346
 347 #ifdef HAVE_SELINUX
 348         if (s->security_context)
 349                 freecon(s->security_context);
 350 #endif
 351
 352         free(s->identifier);
 353         free(s->unit_id);
 354         free(s);
 355 }
 356
 357 static int stdout_stream_new(sd_event_source *es, int listen_fd, uint32_t revents, void *userdata) {
 358         Server *s = userdata;
 359         StdoutStream *stream;
 360         int fd, r;
 361
 362         assert(s);
 363
 364         if (revents != EPOLLIN) {
 365                 log_error("Got invalid event from epoll for stdout server fd: %"PRIx32, revents);
 366                 return -EIO;
 367         }
 368
 369         fd = accept4(s->stdout_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
 370         if (fd < 0) {
 371                 if (errno == EAGAIN)
 372                         return 0;
 373
 374                 log_error("Failed to accept stdout connection: %m");
 375                 return -errno;
 376         }
 377
 378         if (s->n_stdout_streams >= STDOUT_STREAMS_MAX) {
 379                 log_warning("Too many stdout streams, refusing connection.");
 380                 close_nointr_nofail(fd);
 381                 return 0;
 382         }
 383
 384         stream = new0(StdoutStream, 1);
 385         if (!stream) {
 386                 close_nointr_nofail(fd);
 387                 return log_oom();
 388         }
 389
 390         stream->fd = fd;
 391
 392         r = getpeercred(fd, &stream->ucred);
 393         if (r < 0) {
 394                 log_error("Failed to determine peer credentials: %m");
 395                 goto fail;
 396         }
 397
 398 #ifdef HAVE_SELINUX
 399         if (use_selinux()) {
 400                 if (getpeercon(fd, &stream->security_context) < 0 && errno != ENOPROTOOPT)
 401                         log_error("Failed to determine peer security context: %m");
 402         }
 403 #endif
 404
 405         if (shutdown(fd, SHUT_WR) < 0) {
 406                 log_error("Failed to shutdown writing side of socket: %m");
 407                 goto fail;
 408         }
 409
 410         r = sd_event_add_io(s->event, &stream->event_source, fd, EPOLLIN, stdout_stream_process, stream);
 411         if (r < 0) {
 412                 log_error("Failed to add stream to event loop: %s", strerror(-r));
 413                 goto fail;
 414         }
 415
 416         r = sd_event_source_set_priority(stream->event_source, SD_EVENT_PRIORITY_NORMAL+5);
 417         if (r < 0) {
 418                 log_error("Failed to adjust stdout event source priority: %s", strerror(-r));
 419                 goto fail;
 420         }
 421
 422         stream->server = s;
 423         LIST_PREPEND(stdout_stream, s->stdout_streams, stream);
 424         s->n_stdout_streams ++;
 425
 426         return 0;
 427
 428 fail:
 429         stdout_stream_free(stream);
 430         return 0;
 431 }
 432
 433 int server_open_stdout_socket(Server *s) {
 434         int r;
 435
 436         assert(s);
 437
 438         if (s->stdout_fd < 0) {
 439                 union sockaddr_union sa = {
 440                         .un.sun_family = AF_UNIX,
 441                         .un.sun_path = "/run/systemd/journal/stdout",
 442                 };
 443
 444                 s->stdout_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
 445                 if (s->stdout_fd < 0) {
 446                         log_error("socket() failed: %m");
 447                         return -errno;
 448                 }
 449
 450                 unlink(sa.un.sun_path);
 451
 452                 r = bind(s->stdout_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
 453                 if (r < 0) {
 454                         log_error("bind() failed: %m");
 455                         return -errno;
 456                 }
 457
 458                 chmod(sa.un.sun_path, 0666);
 459
 460                 if (listen(s->stdout_fd, SOMAXCONN) < 0) {
 461                         log_error("listen() failed: %m");
 462                         return -errno;
 463                 }
 464         } else
 465                 fd_nonblock(s->stdout_fd, 1);
 466
 467         r = sd_event_add_io(s->event, &s->stdout_event_source, s->stdout_fd, EPOLLIN, stdout_stream_new, s);
 468         if (r < 0) {
 469                 log_error("Failed to add stdout server fd to event source: %s", strerror(-r));
 470                 return r;
 471         }
 472
 473         r = sd_event_source_set_priority(s->stdout_event_source, SD_EVENT_PRIORITY_NORMAL+10);
 474         if (r < 0) {
 475                 log_error("Failed to adjust priority of stdout server event source: %s", strerror(-r));
 476                 return r;
 477         }
 478
 479         return 0;
 480 }