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 <expat.h>
  35
  36 #include <avahi-common/llist.h>
  37 #include <avahi-common/malloc.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     char *type;
  50     char *domain_name;
  51     char *host_name;
  52     uint16_t port;
  53     int protocol;
  54
  55     AvahiStringList *txt_records;
  56
  57     AVAHI_LLIST_FIELDS(StaticService, services);
  58 };
  59
  60 struct StaticServiceGroup {
  61     char *filename;
  62     time_t mtime;
  63
  64     char *name, *chosen_name;
  65     int replace_wildcards;
  66
  67     AvahiSEntryGroup *entry_group;
  68     AVAHI_LLIST_HEAD(StaticService, services);
  69     AVAHI_LLIST_FIELDS(StaticServiceGroup, groups);
  70 };
  71
  72 static AVAHI_LLIST_HEAD(StaticServiceGroup, groups) = NULL;
  73
  74 static char *replacestr(const char *pattern, const char *a, const char *b) {
  75     char *r = NULL, *e, *n;
  76
  77     while ((e = strstr(pattern, a))) {
  78         char *k;
  79
  80         k = avahi_strndup(pattern, e - pattern);
  81         if (r)
  82             n = avahi_strdup_printf("%s%s%s", r, k, b);
  83         else
  84             n = avahi_strdup_printf("%s%s", k, b);
  85
  86         avahi_free(k);
  87         avahi_free(r);
  88         r = n;
  89
  90         pattern = e + strlen(a);
  91     }
  92
  93     if (!r)
  94         return avahi_strdup(pattern);
  95
  96     n = avahi_strdup_printf("%s%s", r, pattern);
  97     avahi_free(r);
  98
  99     return n;
 100 }
 101
 102 static void add_static_service_group_to_server(StaticServiceGroup *g);
 103 static void remove_static_service_group_from_server(StaticServiceGroup *g);
 104
 105 static StaticService *static_service_new(StaticServiceGroup *group) {
 106     StaticService *s;
 107
 108     assert(group);
 109     s = avahi_new(StaticService, 1);
 110     s->group = group;
 111
 112     s->type = s->host_name = s->domain_name = NULL;
 113     s->port = 0;
 114     s->protocol = AF_UNSPEC;
 115
 116     s->txt_records = NULL;
 117
 118     AVAHI_LLIST_PREPEND(StaticService, services, group->services, s);
 119
 120     return s;
 121 }
 122
 123 static StaticServiceGroup *static_service_group_new(char *filename) {
 124     StaticServiceGroup *g;
 125     assert(filename);
 126
 127     g = avahi_new(StaticServiceGroup, 1);
 128     g->filename = avahi_strdup(filename);
 129     g->mtime = 0;
 130     g->name = g->chosen_name = NULL;
 131     g->replace_wildcards = 0;
 132     g->entry_group = NULL;
 133
 134     AVAHI_LLIST_HEAD_INIT(StaticService, g->services);
 135     AVAHI_LLIST_PREPEND(StaticServiceGroup, groups, groups, g);
 136
 137     return g;
 138 }
 139
 140 static void static_service_free(StaticService *s) {
 141     assert(s);
 142
 143     AVAHI_LLIST_REMOVE(StaticService, services, s->group->services, s);
 144
 145     avahi_free(s->type);
 146     avahi_free(s->host_name);
 147     avahi_free(s->domain_name);
 148
 149     avahi_string_list_free(s->txt_records);
 150
 151     avahi_free(s);
 152 }
 153
 154 static void static_service_group_free(StaticServiceGroup *g) {
 155     assert(g);
 156
 157     if (g->entry_group)
 158         avahi_s_entry_group_free(g->entry_group);
 159
 160     while (g->services)
 161         static_service_free(g->services);
 162
 163     AVAHI_LLIST_REMOVE(StaticServiceGroup, groups, groups, g);
 164
 165     avahi_free(g->filename);
 166     avahi_free(g->name);
 167     avahi_free(g->chosen_name);
 168     avahi_free(g);
 169 }
 170
 171 static void entry_group_callback(AvahiServer *s, AvahiSEntryGroup *eg, AvahiEntryGroupState state, void* userdata) {
 172     StaticServiceGroup *g = userdata;
 173
 174     assert(s);
 175     assert(g);
 176
 177     if (state == AVAHI_ENTRY_GROUP_COLLISION) {
 178         char *n;
 179
 180         remove_static_service_group_from_server(g);
 181
 182         n = avahi_alternative_service_name(g->chosen_name);
 183         avahi_free(g->chosen_name);
 184         g->chosen_name = n;
 185
 186         avahi_log_notice("Service name conflict for \"%s\" (%s), retrying with \"%s\".", g->name, g->filename, g->chosen_name);
 187
 188         add_static_service_group_to_server(g);
 189     } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 190         avahi_log_info("Service \"%s\" (%s) successfully established.", g->chosen_name, g->filename);
 191 }
 192
 193 static void add_static_service_group_to_server(StaticServiceGroup *g) {
 194     StaticService *s;
 195
 196     assert(g);
 197
 198     if (g->entry_group && !avahi_s_entry_group_is_empty(g->entry_group))
 199         /* This service group is already registered in the server */
 200         return;
 201
 202     if (g->chosen_name)
 203         avahi_free(g->chosen_name);
 204
 205     if (g->replace_wildcards)
 206         g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
 207     else
 208         g->chosen_name = avahi_strdup(g->name);
 209
 210     if (!g->entry_group)
 211         g->entry_group = avahi_s_entry_group_new(avahi_server, entry_group_callback, g);
 212
 213     assert(avahi_s_entry_group_is_empty(g->entry_group));
 214
 215     for (s = g->services; s; s = s->services_next) {
 216
 217         if (avahi_server_add_service_strlst(
 218                 avahi_server,
 219                 g->entry_group,
 220                 -1, s->protocol,
 221                 g->chosen_name, s->type,
 222                 s->domain_name, s->host_name, s->port,
 223                 s->txt_records) < 0) {
 224             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s): %s",
 225                             g->chosen_name, s->type, g->filename,
 226                             avahi_strerror(avahi_server_errno(avahi_server)));
 227             remove_static_service_group_from_server(g);
 228             return;
 229         }
 230     }
 231
 232     avahi_s_entry_group_commit(g->entry_group);
 233 }
 234
 235 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 236     assert(g);
 237
 238     if (g->entry_group)
 239         avahi_s_entry_group_reset(g->entry_group);
 240 }
 241
 242 typedef enum {
 243     XML_TAG_INVALID,
 244     XML_TAG_SERVICE_GROUP,
 245     XML_TAG_NAME,
 246     XML_TAG_SERVICE,
 247     XML_TAG_TYPE,
 248     XML_TAG_DOMAIN_NAME,
 249     XML_TAG_HOST_NAME,
 250     XML_TAG_PORT,
 251     XML_TAG_PROTOCOL,
 252     XML_TAG_TXT_RECORD
 253 } xml_tag_name;
 254
 255 struct xml_userdata {
 256     StaticServiceGroup *group;
 257     StaticService *service;
 258     xml_tag_name current_tag;
 259     int failed;
 260     char *buf;
 261 };
 262
 263 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 264     struct xml_userdata *u = data;
 265
 266     assert(u);
 267
 268     if (u->failed)
 269         return;
 270
 271     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 272
 273         if (attr[0])
 274             goto invalid_attr;
 275
 276         u->current_tag = XML_TAG_SERVICE_GROUP;
 277     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 278         u->current_tag = XML_TAG_NAME;
 279
 280         if (attr[0]) {
 281             if (strcmp(attr[0], "replace-wildcards") == 0)
 282                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 283             else
 284                 goto invalid_attr;
 285         }
 286
 287         if (attr[2])
 288             goto invalid_attr;
 289
 290     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 291         if (attr[0])
 292             goto invalid_attr;
 293
 294         assert(!u->service);
 295         u->service = static_service_new(u->group);
 296
 297         u->current_tag = XML_TAG_SERVICE;
 298     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 299         if (attr[0])
 300             goto invalid_attr;
 301
 302         u->current_tag = XML_TAG_TYPE;
 303     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 304         if (attr[0])
 305             goto invalid_attr;
 306
 307         u->current_tag = XML_TAG_DOMAIN_NAME;
 308     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 309         if (attr[0])
 310             goto invalid_attr;
 311
 312         u->current_tag = XML_TAG_HOST_NAME;
 313     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 314         if (attr[0])
 315             goto invalid_attr;
 316
 317         u->current_tag = XML_TAG_PORT;
 318     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "protocol") == 0) {
 319         if (attr[0])
 320             goto invalid_attr;
 321
 322         u->current_tag = XML_TAG_PROTOCOL;
 323     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 324         if (attr[0])
 325             goto invalid_attr;
 326
 327         u->current_tag = XML_TAG_TXT_RECORD;
 328     } else {
 329         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 330         u->failed = 1;
 331     }
 332
 333     return;
 334
 335 invalid_attr:
 336     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 337     u->failed = 1;
 338     return;
 339 }
 340
 341 static void XMLCALL xml_end(void *data, const char *el) {
 342     struct xml_userdata *u = data;
 343     assert(u);
 344
 345     if (u->failed)
 346         return;
 347
 348     switch (u->current_tag) {
 349         case XML_TAG_SERVICE_GROUP:
 350
 351             if (!u->group->name || !u->group->services) {
 352                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 353                 u->failed = 1;
 354                 return;
 355             }
 356
 357             u->current_tag = XML_TAG_INVALID;
 358             break;
 359
 360         case XML_TAG_SERVICE:
 361
 362             if (!u->service->type) {
 363                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 364                 u->failed = 1;
 365                 return;
 366             }
 367
 368             u->service = NULL;
 369             u->current_tag = XML_TAG_SERVICE_GROUP;
 370             break;
 371
 372         case XML_TAG_NAME:
 373             u->current_tag = XML_TAG_SERVICE_GROUP;
 374             break;
 375
 376         case XML_TAG_PORT: {
 377             int p;
 378             assert(u->service);
 379
 380             p = u->buf ? atoi(u->buf) : 0;
 381
 382             if (p < 0 || p > 0xFFFF) {
 383                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 384                 u->failed = 1;
 385                 return;
 386             }
 387
 388             u->service->port = (uint16_t) p;
 389
 390             u->current_tag = XML_TAG_SERVICE;
 391             break;
 392         }
 393
 394         case XML_TAG_PROTOCOL: {
 395             int protocol;
 396             assert(u->service);
 397
 398             if (strcasecmp (u->buf, "ipv4") == 0) {
 399                 protocol = AF_INET;
 400             } else if (strcasecmp (u->buf, "ipv6") == 0) {
 401                 protocol = AF_INET6;
 402             } else if (strcasecmp (u->buf, "any") == 0) {
 403                 protocol = AF_UNSPEC;
 404             } else {
 405                 avahi_log_error("%s: parse failure: invalid protocol specification \"%s\".", u->group->filename, u->buf);
 406                 u->failed = 1;
 407                 return;
 408             }
 409
 410             u->service->protocol = protocol;
 411             break;
 412         }
 413
 414         case XML_TAG_TXT_RECORD: {
 415             assert(u->service);
 416
 417             u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
 418             u->current_tag = XML_TAG_SERVICE;
 419             break;
 420         }
 421
 422         case XML_TAG_TYPE:
 423         case XML_TAG_DOMAIN_NAME:
 424         case XML_TAG_HOST_NAME:
 425             u->current_tag = XML_TAG_SERVICE;
 426             break;
 427
 428         case XML_TAG_INVALID:
 429             ;
 430     }
 431
 432     avahi_free(u->buf);
 433     u->buf = NULL;
 434 }
 435
 436 static char *append_cdata(char *t, const char *n, int length) {
 437     char *r, *k;
 438
 439     if (!length)
 440         return t;
 441
 442
 443     k = avahi_strndup(n, length);
 444
 445     if (t) {
 446         r = avahi_strdup_printf("%s%s", t, k);
 447         avahi_free(k);
 448         avahi_free(t);
 449     } else
 450         r = k;
 451
 452     return r;
 453 }
 454
 455 static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
 456     struct xml_userdata *u = data;
 457     assert(u);
 458
 459     if (u->failed)
 460         return;
 461
 462     switch (u->current_tag) {
 463         case XML_TAG_NAME:
 464             u->group->name = append_cdata(u->group->name, s, len);
 465             break;
 466
 467         case XML_TAG_TYPE:
 468             assert(u->service);
 469             u->service->type = append_cdata(u->service->type, s, len);
 470             break;
 471
 472         case XML_TAG_DOMAIN_NAME:
 473             assert(u->service);
 474             u->service->domain_name = append_cdata(u->service->domain_name, s, len);
 475             break;
 476
 477         case XML_TAG_HOST_NAME:
 478             assert(u->service);
 479             u->service->host_name = append_cdata(u->service->host_name, s, len);
 480             break;
 481
 482         case XML_TAG_PORT:
 483         case XML_TAG_PROTOCOL:
 484         case XML_TAG_TXT_RECORD:
 485             assert(u->service);
 486             u->buf = append_cdata(u->buf, s, len);
 487             break;
 488
 489         case XML_TAG_SERVICE_GROUP:
 490         case XML_TAG_SERVICE:
 491         case XML_TAG_INVALID:
 492             ;
 493     }
 494 }
 495
 496 static int static_service_group_load(StaticServiceGroup *g) {
 497     XML_Parser parser = NULL;
 498     int fd = -1;
 499     struct xml_userdata u;
 500     int r = -1;
 501     struct stat st;
 502     ssize_t n;
 503
 504     assert(g);
 505
 506     u.buf = NULL;
 507     u.group = g;
 508     u.service = NULL;
 509     u.current_tag = XML_TAG_INVALID;
 510     u.failed = 0;
 511
 512     /* Cleanup old data in this service group, if available */
 513     remove_static_service_group_from_server(g);
 514     while (g->services)
 515         static_service_free(g->services);
 516
 517     avahi_free(g->name);
 518     avahi_free(g->chosen_name);
 519     g->name = g->chosen_name = NULL;
 520     g->replace_wildcards = 0;
 521
 522     if (!(parser = XML_ParserCreate(NULL))) {
 523         avahi_log_error("XML_ParserCreate() failed.");
 524         goto finish;
 525     }
 526
 527     if ((fd = open(g->filename, O_RDONLY)) < 0) {
 528         avahi_log_error("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
 529         goto finish;
 530     }
 531
 532     if (fstat(fd, &st) < 0) {
 533         avahi_log_error("fstat(): %s", strerror(errno));
 534         goto finish;
 535     }
 536
 537     g->mtime = st.st_mtime;
 538
 539     XML_SetUserData(parser, &u);
 540
 541     XML_SetElementHandler(parser, xml_start, xml_end);
 542     XML_SetCharacterDataHandler(parser, xml_cdata);
 543
 544     do {
 545         void *buffer;
 546
 547 #define BUFSIZE (10*1024)
 548
 549         if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
 550             avahi_log_error("XML_GetBuffer() failed.");
 551             goto finish;
 552         }
 553
 554         if ((n = read(fd, buffer, BUFSIZE)) < 0) {
 555             avahi_log_error("read(): %s\n", strerror(errno));
 556             goto finish;
 557         }
 558
 559         if (!XML_ParseBuffer(parser, n, n == 0)) {
 560             avahi_log_error("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
 561             goto finish;
 562         }
 563
 564     } while (n != 0);
 565
 566     if (!u.failed)
 567         r = 0;
 568
 569 finish:
 570
 571     if (fd >= 0)
 572         close(fd);
 573
 574     if (parser)
 575         XML_ParserFree(parser);
 576
 577     avahi_free(u.buf);
 578
 579     return r;
 580 }
 581
 582 static void load_file(char *n) {
 583     StaticServiceGroup *g;
 584     assert(n);
 585
 586     for (g = groups; g; g = g->groups_next)
 587         if (strcmp(g->filename, n) == 0)
 588             return;
 589
 590     avahi_log_info("Loading service file %s", n);
 591
 592     g = static_service_group_new(n);
 593     if (static_service_group_load(g) < 0) {
 594         avahi_log_error("Failed to load service group file %s, ignoring.", g->filename);
 595         static_service_group_free(g);
 596     }
 597 }
 598
 599 void static_service_load(void) {
 600     StaticServiceGroup *g, *n;
 601     glob_t globbuf;
 602     char **p;
 603
 604     for (g = groups; g; g = n) {
 605         struct stat st;
 606
 607         n = g->groups_next;
 608
 609         if (stat(g->filename, &st) < 0) {
 610
 611             if (errno == ENOENT)
 612                 avahi_log_info("Service group file %s vanished, removing services.", g->filename);
 613             else
 614                 avahi_log_warn("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
 615
 616             static_service_group_free(g);
 617         } else if (st.st_mtime != g->mtime) {
 618             avahi_log_info("Service group file %s changed, reloading.", g->filename);
 619
 620             if (static_service_group_load(g) < 0) {
 621                 avahi_log_warn("Failed to load service group file %s, removing service.", g->filename);
 622                 static_service_group_free(g);
 623             }
 624         }
 625     }
 626
 627     memset(&globbuf, 0, sizeof(globbuf));
 628     if (glob(AVAHI_SERVICE_DIR "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
 629         avahi_log_error("Failed to read service directory.");
 630     else {
 631         for (p = globbuf.gl_pathv; *p; p++)
 632             load_file(*p);
 633
 634         globfree(&globbuf);
 635     }
 636 }
 637
 638 void static_service_free_all(void) {
 639
 640     while (groups)
 641         static_service_group_free(groups);
 642 }
 643
 644 void static_service_add_to_server(void) {
 645     StaticServiceGroup *g;
 646
 647     for (g = groups; g; g = g->groups_next)
 648         add_static_service_group_to_server(g);
 649 }
 650
 651 void static_service_remove_from_server(void) {
 652     StaticServiceGroup *g;
 653
 654     for (g = groups; g; g = g->groups_next)
 655         remove_static_service_group_from_server(g);
 656 }