git.meshlink.io Git - catta/blob - avahi-daemon/static-services.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of avahi.
   5
   6   avahi is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   avahi is distributed in the hope that it will be useful, but WITHOUT
  12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  14   Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with avahi; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <sys/stat.h>
  27 #include <glob.h>
  28 #include <limits.h>
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33
  34 #include <glib.h>
  35 #include <expat.h>
  36
  37 #include <avahi-core/llist.h>
  38 #include <avahi-core/log.h>
  39
  40 #include "main.h"
  41 #include "static-services.h"
  42
  43 typedef struct StaticService StaticService;
  44 typedef struct StaticServiceGroup StaticServiceGroup;
  45
  46 struct StaticService {
  47     StaticServiceGroup *group;
  48
  49     gchar *type;
  50     gchar *domain_name;
  51     gchar *host_name;
  52     guint16 port;
  53
  54     AvahiStringList *txt_records;
  55
  56     AVAHI_LLIST_FIELDS(StaticService, services);
  57 };
  58
  59 struct StaticServiceGroup {
  60     gchar *filename;
  61     time_t mtime;
  62
  63     gchar *name, *chosen_name;
  64     gboolean replace_wildcards;
  65
  66     AvahiEntryGroup *entry_group;
  67     AVAHI_LLIST_HEAD(StaticService, services);
  68     AVAHI_LLIST_FIELDS(StaticServiceGroup, groups);
  69 };
  70
  71 static AVAHI_LLIST_HEAD(StaticServiceGroup, groups) = NULL;
  72
  73 static gchar *replacestr(const gchar *pattern, const gchar *a, const gchar *b) {
  74     gchar *r = NULL, *e, *n;
  75
  76     while ((e = strstr(pattern, a))) {
  77         gchar *k;
  78
  79         k = g_strndup(pattern, e - pattern);
  80         if (r)
  81             n = g_strconcat(r, k, b, NULL);
  82         else
  83             n = g_strconcat(k, b, NULL);
  84
  85         g_free(k);
  86         g_free(r);
  87         r = n;
  88
  89         pattern = e + strlen(a);
  90     }
  91
  92     if (!r)
  93         return g_strdup(pattern);
  94
  95     n = g_strconcat(r, pattern, NULL);
  96     g_free(r);
  97
  98     return n;
  99 }
 100
 101 static void add_static_service_group_to_server(StaticServiceGroup *g);
 102 static void remove_static_service_group_from_server(StaticServiceGroup *g);
 103
 104 static StaticService *static_service_new(StaticServiceGroup *group) {
 105     StaticService *s;
 106
 107     g_assert(group);
 108     s = g_new(StaticService, 1);
 109     s->group = group;
 110
 111     s->type = s->host_name = s->domain_name = NULL;
 112     s->port = 0;
 113
 114     s->txt_records = NULL;
 115
 116     AVAHI_LLIST_PREPEND(StaticService, services, group->services, s);
 117
 118     return s;
 119 }
 120
 121 static StaticServiceGroup *static_service_group_new(gchar *filename) {
 122     StaticServiceGroup *g;
 123     g_assert(filename);
 124
 125     g = g_new(StaticServiceGroup, 1);
 126     g->filename = g_strdup(filename);
 127     g->mtime = 0;
 128     g->name = g->chosen_name = NULL;
 129     g->replace_wildcards = FALSE;
 130     g->entry_group = NULL;
 131
 132     AVAHI_LLIST_HEAD_INIT(StaticService, g->services);
 133     AVAHI_LLIST_PREPEND(StaticServiceGroup, groups, groups, g);
 134
 135     return g;
 136 }
 137
 138 static void static_service_free(StaticService *s) {
 139     g_assert(s);
 140
 141     AVAHI_LLIST_REMOVE(StaticService, services, s->group->services, s);
 142
 143     g_free(s->type);
 144     g_free(s->host_name);
 145     g_free(s->domain_name);
 146
 147     avahi_string_list_free(s->txt_records);
 148
 149     g_free(s);
 150 }
 151
 152 static void static_service_group_free(StaticServiceGroup *g) {
 153     g_assert(g);
 154
 155     if (g->entry_group)
 156         avahi_entry_group_free(g->entry_group);
 157
 158     while (g->services)
 159         static_service_free(g->services);
 160
 161     AVAHI_LLIST_REMOVE(StaticServiceGroup, groups, groups, g);
 162
 163     g_free(g->filename);
 164     g_free(g->name);
 165     g_free(g->chosen_name);
 166     g_free(g);
 167 }
 168
 169 static void entry_group_callback(AvahiServer *s, AvahiEntryGroup *eg, AvahiEntryGroupState state, gpointer userdata) {
 170     StaticServiceGroup *g = userdata;
 171
 172     g_assert(s);
 173     g_assert(g);
 174
 175     if (state == AVAHI_ENTRY_GROUP_COLLISION) {
 176         gchar *n;
 177
 178         remove_static_service_group_from_server(g);
 179
 180         n = avahi_alternative_service_name(g->chosen_name);
 181         g_free(g->chosen_name);
 182         g->chosen_name = n;
 183
 184         avahi_log_notice("Service name conflict for \"%s\" (%s), retrying with \"%s\".", g->name, g->filename, g->chosen_name);
 185
 186         add_static_service_group_to_server(g);
 187     } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 188         avahi_log_info("Service \"%s\" (%s) successfully established.", g->chosen_name, g->filename);
 189 }
 190
 191 static void add_static_service_group_to_server(StaticServiceGroup *g) {
 192     StaticService *s;
 193
 194     g_assert(g);
 195
 196     if (g->entry_group)
 197         return;
 198
 199     if (g->chosen_name)
 200         g_free(g->chosen_name);
 201
 202     if (g->replace_wildcards)
 203         g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
 204     else
 205         g->chosen_name = g_strdup(g->name);
 206
 207     if (!g->entry_group)
 208         g->entry_group = avahi_entry_group_new(avahi_server, entry_group_callback, g);
 209
 210     g_assert(avahi_entry_group_is_empty(g->entry_group));
 211
 212     for (s = g->services; s; s = s->services_next) {
 213
 214         if (avahi_server_add_service_strlst(
 215                 avahi_server,
 216                 g->entry_group,
 217                 -1, AF_UNSPEC,
 218                 g->chosen_name, s->type,
 219                 s->domain_name, s->host_name, s->port,
 220                 s->txt_records) < 0) {
 221             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s)", g->chosen_name, s->type, g->filename);
 222             remove_static_service_group_from_server(g);
 223             return;
 224         }
 225     }
 226
 227     avahi_entry_group_commit(g->entry_group);
 228 }
 229
 230 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 231     g_assert(g);
 232
 233     if (g->entry_group)
 234         avahi_entry_group_reset(g->entry_group);
 235 }
 236
 237 typedef enum {
 238     XML_TAG_INVALID,
 239     XML_TAG_SERVICE_GROUP,
 240     XML_TAG_NAME,
 241     XML_TAG_SERVICE,
 242     XML_TAG_TYPE,
 243     XML_TAG_DOMAIN_NAME,
 244     XML_TAG_HOST_NAME,
 245     XML_TAG_PORT,
 246     XML_TAG_TXT_RECORD
 247 } xml_tag_name;
 248
 249 struct xml_userdata {
 250     StaticServiceGroup *group;
 251     StaticService *service;
 252     xml_tag_name current_tag;
 253     gboolean failed;
 254     gchar *buf;
 255 };
 256
 257 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 258     struct xml_userdata *u = data;
 259
 260     g_assert(u);
 261
 262     if (u->failed)
 263         return;
 264
 265     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 266
 267         if (attr[0])
 268             goto invalid_attr;
 269
 270         u->current_tag = XML_TAG_SERVICE_GROUP;
 271     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 272         u->current_tag = XML_TAG_NAME;
 273
 274         if (attr[0]) {
 275             if (strcmp(attr[0], "replace-wildcards") == 0)
 276                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 277             else
 278                 goto invalid_attr;
 279         }
 280
 281         if (attr[2])
 282             goto invalid_attr;
 283
 284
 285
 286     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 287         if (attr[0])
 288             goto invalid_attr;
 289
 290         g_assert(!u->service);
 291         u->service = static_service_new(u->group);
 292
 293         u->current_tag = XML_TAG_SERVICE;
 294     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 295         if (attr[0])
 296             goto invalid_attr;
 297
 298         u->current_tag = XML_TAG_TYPE;
 299     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 300         if (attr[0])
 301             goto invalid_attr;
 302
 303         u->current_tag = XML_TAG_DOMAIN_NAME;
 304     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 305         if (attr[0])
 306             goto invalid_attr;
 307
 308         u->current_tag = XML_TAG_HOST_NAME;
 309     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 310         if (attr[0])
 311             goto invalid_attr;
 312
 313         u->current_tag = XML_TAG_PORT;
 314     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 315         if (attr[0])
 316             goto invalid_attr;
 317
 318         u->current_tag = XML_TAG_TXT_RECORD;
 319     } else {
 320         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 321         u->failed = TRUE;
 322     }
 323
 324     return;
 325
 326 invalid_attr:
 327     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 328     u->failed = TRUE;
 329     return;
 330 }
 331
 332 static void XMLCALL xml_end(void *data, const char *el) {
 333     struct xml_userdata *u = data;
 334     g_assert(u);
 335
 336     if (u->failed)
 337         return;
 338
 339     switch (u->current_tag) {
 340         case XML_TAG_SERVICE_GROUP:
 341
 342             if (!u->group->name || !u->group->services) {
 343                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 344                 u->failed = TRUE;
 345                 return;
 346             }
 347
 348             u->current_tag = XML_TAG_INVALID;
 349             break;
 350
 351         case XML_TAG_SERVICE:
 352
 353             if (u->service->port == 0 || !u->service->type) {
 354                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 355                 u->failed = TRUE;
 356                 return;
 357             }
 358
 359             u->service = NULL;
 360             u->current_tag = XML_TAG_SERVICE_GROUP;
 361             break;
 362
 363         case XML_TAG_NAME:
 364             u->current_tag = XML_TAG_SERVICE_GROUP;
 365             break;
 366
 367         case XML_TAG_PORT: {
 368             int p;
 369             g_assert(u->service);
 370
 371             p = u->buf ? atoi(u->buf) : 0;
 372
 373             if (p <= 0 || p > 0xFFFF) {
 374                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 375                 u->failed = TRUE;
 376                 return;
 377             }
 378
 379             u->service->port = (guint16) p;
 380
 381             u->current_tag = XML_TAG_SERVICE;
 382             break;
 383         }
 384
 385         case XML_TAG_TXT_RECORD: {
 386             g_assert(u->service);
 387
 388             u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
 389             u->current_tag = XML_TAG_SERVICE;
 390             break;
 391         }
 392
 393         case XML_TAG_TYPE:
 394         case XML_TAG_DOMAIN_NAME:
 395         case XML_TAG_HOST_NAME:
 396             u->current_tag = XML_TAG_SERVICE;
 397             break;
 398
 399         case XML_TAG_INVALID:
 400             ;
 401     }
 402
 403     g_free(u->buf);
 404     u->buf = NULL;
 405 }
 406
 407 static gchar *append_cdata(gchar *t, const gchar *n, int length) {
 408     gchar *r, *k;
 409
 410     if (!length)
 411         return t;
 412
 413     k = g_strndup(n, length);
 414
 415     if (t) {
 416         r = g_strconcat(t, k, NULL);
 417         g_free(k);
 418         g_free(t);
 419     } else
 420         r = k;
 421
 422     return r;
 423 }
 424
 425 static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
 426     struct xml_userdata *u = data;
 427     g_assert(u);
 428
 429     if (u->failed)
 430         return;
 431
 432     switch (u->current_tag) {
 433         case XML_TAG_NAME:
 434             u->group->name = append_cdata(u->group->name, s, len);
 435             break;
 436
 437         case XML_TAG_TYPE:
 438             g_assert(u->service);
 439             u->service->type = append_cdata(u->service->type, s, len);
 440             break;
 441
 442         case XML_TAG_DOMAIN_NAME:
 443             g_assert(u->service);
 444             u->service->domain_name = append_cdata(u->service->domain_name, s, len);
 445             break;
 446
 447         case XML_TAG_HOST_NAME:
 448             g_assert(u->service);
 449             u->service->host_name = append_cdata(u->service->host_name, s, len);
 450             break;
 451
 452         case XML_TAG_PORT:
 453         case XML_TAG_TXT_RECORD:
 454             u->buf = append_cdata(u->buf, s, len);
 455             break;
 456
 457         case XML_TAG_SERVICE_GROUP:
 458         case XML_TAG_SERVICE:
 459         case XML_TAG_INVALID:
 460             ;
 461     }
 462 }
 463
 464 static gint static_service_group_load(StaticServiceGroup *g) {
 465     XML_Parser parser = NULL;
 466     gint fd = -1;
 467     struct xml_userdata u;
 468     gint r = -1;
 469     struct stat st;
 470     ssize_t n;
 471
 472     g_assert(g);
 473
 474     u.buf = NULL;
 475     u.group = g;
 476     u.service = NULL;
 477     u.current_tag = XML_TAG_INVALID;
 478     u.failed = FALSE;
 479
 480     /* Cleanup old data in this service group, if available */
 481     remove_static_service_group_from_server(g);
 482     while (g->services)
 483         static_service_free(g->services);
 484
 485     g_free(g->name);
 486     g_free(g->chosen_name);
 487     g->name = g->chosen_name = NULL;
 488     g->replace_wildcards = FALSE;
 489
 490     if (!(parser = XML_ParserCreate(NULL))) {
 491         avahi_log_error("XML_ParserCreate() failed.");
 492         goto finish;
 493     }
 494
 495     if ((fd = open(g->filename, O_RDONLY)) < 0) {
 496         avahi_log_error("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
 497         goto finish;
 498     }
 499
 500     if (fstat(fd, &st) < 0) {
 501         avahi_log_error("fstat(): %s", strerror(errno));
 502         goto finish;
 503     }
 504
 505     g->mtime = st.st_mtime;
 506
 507     XML_SetUserData(parser, &u);
 508
 509     XML_SetElementHandler(parser, xml_start, xml_end);
 510     XML_SetCharacterDataHandler(parser, xml_cdata);
 511
 512     do {
 513         void *buffer;
 514
 515 #define BUFSIZE (10*1024)
 516
 517         if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
 518             avahi_log_error("XML_GetBuffer() failed.");
 519             goto finish;
 520         }
 521
 522         if ((n = read(fd, buffer, BUFSIZE)) < 0) {
 523             avahi_log_error("read(): %s\n", strerror(errno));
 524             goto finish;
 525         }
 526
 527         if (!XML_ParseBuffer(parser, n, n == 0)) {
 528             avahi_log_error("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
 529             goto finish;
 530         }
 531
 532     } while (n != 0);
 533
 534     if (!u.failed)
 535         r = 0;
 536
 537 finish:
 538
 539     if (fd >= 0)
 540         close(fd);
 541
 542     if (parser)
 543         XML_ParserFree(parser);
 544
 545     g_free(u.buf);
 546
 547     return r;
 548 }
 549
 550 static void load_file(gchar *n) {
 551     StaticServiceGroup *g;
 552     g_assert(n);
 553
 554     for (g = groups; g; g = g->groups_next)
 555         if (strcmp(g->filename, n) == 0)
 556             return;
 557
 558     avahi_log_info("Loading service file %s", n);
 559
 560     g = static_service_group_new(n);
 561     if (static_service_group_load(g) < 0) {
 562         avahi_log_error("Failed to load service group file %s, ignoring.", g->filename);
 563         static_service_group_free(g);
 564     }
 565 }
 566
 567 void static_service_load(void) {
 568     StaticServiceGroup *g, *n;
 569     glob_t globbuf;
 570     gchar **p;
 571
 572     for (g = groups; g; g = n) {
 573         struct stat st;
 574
 575         n = g->groups_next;
 576
 577         if (stat(g->filename, &st) < 0) {
 578
 579             if (errno == ENOENT)
 580                 avahi_log_info("Service group file %s vanished, removing services.", g->filename);
 581             else
 582                 avahi_log_warn("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
 583
 584             static_service_group_free(g);
 585         } else if (st.st_mtime != g->mtime) {
 586             avahi_log_info("Service group file %s changed, reloading.", g->filename);
 587
 588             if (static_service_group_load(g) < 0) {
 589                 avahi_log_warn("Failed to load service group file %s, removing service.", g->filename);
 590                 static_service_group_free(g);
 591             }
 592         }
 593     }
 594
 595     memset(&globbuf, 0, sizeof(globbuf));
 596     if (glob(AVAHI_SERVICE_DIR "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
 597         avahi_log_error("Failed to read service directory.");
 598     else {
 599         for (p = globbuf.gl_pathv; *p; p++)
 600             load_file(*p);
 601
 602         globfree(&globbuf);
 603     }
 604 }
 605
 606 void static_service_free_all(void) {
 607
 608     while (groups)
 609         static_service_group_free(groups);
 610 }
 611
 612 void static_service_add_to_server(void) {
 613     StaticServiceGroup *g;
 614
 615     for (g = groups; g; g = g->groups_next)
 616         add_static_service_group_to_server(g);
 617 }
 618
 619 void static_service_remove_from_server(void) {
 620     StaticServiceGroup *g;
 621
 622     for (g = groups; g; g = g->groups_next)
 623         remove_static_service_group_from_server(g);
 624 }