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   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-common/alternative.h>
  39 #include <avahi-common/error.h>
  40 #include <avahi-core/log.h>
  41 #include <avahi-core/publish.h>
  42
  43 #include "main.h"
  44 #include "static-services.h"
  45
  46 typedef struct StaticService StaticService;
  47 typedef struct StaticServiceGroup StaticServiceGroup;
  48
  49 struct StaticService {
  50     StaticServiceGroup *group;
  51
  52     char *type;
  53     char *domain_name;
  54     char *host_name;
  55     uint16_t port;
  56     int protocol;
  57
  58     AvahiStringList *txt_records;
  59
  60     AVAHI_LLIST_FIELDS(StaticService, services);
  61 };
  62
  63 struct StaticServiceGroup {
  64     char *filename;
  65     time_t mtime;
  66
  67     char *name, *chosen_name;
  68     int replace_wildcards;
  69
  70     AvahiSEntryGroup *entry_group;
  71     AVAHI_LLIST_HEAD(StaticService, services);
  72     AVAHI_LLIST_FIELDS(StaticServiceGroup, groups);
  73 };
  74
  75 static AVAHI_LLIST_HEAD(StaticServiceGroup, groups) = NULL;
  76
  77 static char *replacestr(const char *pattern, const char *a, const char *b) {
  78     char *r = NULL, *e, *n;
  79
  80     while ((e = strstr(pattern, a))) {
  81         char *k;
  82
  83         k = avahi_strndup(pattern, e - pattern);
  84         if (r)
  85             n = avahi_strdup_printf("%s%s%s", r, k, b);
  86         else
  87             n = avahi_strdup_printf("%s%s", k, b);
  88
  89         avahi_free(k);
  90         avahi_free(r);
  91         r = n;
  92
  93         pattern = e + strlen(a);
  94     }
  95
  96     if (!r)
  97         return avahi_strdup(pattern);
  98
  99     n = avahi_strdup_printf("%s%s", r, pattern);
 100     avahi_free(r);
 101
 102     return n;
 103 }
 104
 105 static void add_static_service_group_to_server(StaticServiceGroup *g);
 106 static void remove_static_service_group_from_server(StaticServiceGroup *g);
 107
 108 static StaticService *static_service_new(StaticServiceGroup *group) {
 109     StaticService *s;
 110
 111     assert(group);
 112     s = avahi_new(StaticService, 1);
 113     s->group = group;
 114
 115     s->type = s->host_name = s->domain_name = NULL;
 116     s->port = 0;
 117     s->protocol = AVAHI_PROTO_UNSPEC;
 118
 119     s->txt_records = NULL;
 120
 121     AVAHI_LLIST_PREPEND(StaticService, services, group->services, s);
 122
 123     return s;
 124 }
 125
 126 static StaticServiceGroup *static_service_group_new(char *filename) {
 127     StaticServiceGroup *g;
 128     assert(filename);
 129
 130     g = avahi_new(StaticServiceGroup, 1);
 131     g->filename = avahi_strdup(filename);
 132     g->mtime = 0;
 133     g->name = g->chosen_name = NULL;
 134     g->replace_wildcards = 0;
 135     g->entry_group = NULL;
 136
 137     AVAHI_LLIST_HEAD_INIT(StaticService, g->services);
 138     AVAHI_LLIST_PREPEND(StaticServiceGroup, groups, groups, g);
 139
 140     return g;
 141 }
 142
 143 static void static_service_free(StaticService *s) {
 144     assert(s);
 145
 146     AVAHI_LLIST_REMOVE(StaticService, services, s->group->services, s);
 147
 148     avahi_free(s->type);
 149     avahi_free(s->host_name);
 150     avahi_free(s->domain_name);
 151
 152     avahi_string_list_free(s->txt_records);
 153
 154     avahi_free(s);
 155 }
 156
 157 static void static_service_group_free(StaticServiceGroup *g) {
 158     assert(g);
 159
 160     if (g->entry_group)
 161         avahi_s_entry_group_free(g->entry_group);
 162
 163     while (g->services)
 164         static_service_free(g->services);
 165
 166     AVAHI_LLIST_REMOVE(StaticServiceGroup, groups, groups, g);
 167
 168     avahi_free(g->filename);
 169     avahi_free(g->name);
 170     avahi_free(g->chosen_name);
 171     avahi_free(g);
 172 }
 173
 174 static void entry_group_callback(AvahiServer *s, AvahiSEntryGroup *eg, AvahiEntryGroupState state, void* userdata) {
 175     StaticServiceGroup *g = userdata;
 176
 177     assert(s);
 178     assert(g);
 179
 180     if (state == AVAHI_ENTRY_GROUP_COLLISION) {
 181         char *n;
 182
 183         remove_static_service_group_from_server(g);
 184
 185         n = avahi_alternative_service_name(g->chosen_name);
 186         avahi_free(g->chosen_name);
 187         g->chosen_name = n;
 188
 189         avahi_log_notice("Service name conflict for \"%s\" (%s), retrying with \"%s\".", g->name, g->filename, g->chosen_name);
 190
 191         add_static_service_group_to_server(g);
 192     } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 193         avahi_log_info("Service \"%s\" (%s) successfully established.", g->chosen_name, g->filename);
 194 }
 195
 196 static void add_static_service_group_to_server(StaticServiceGroup *g) {
 197     StaticService *s;
 198
 199     assert(g);
 200
 201     if (g->entry_group && !avahi_s_entry_group_is_empty(g->entry_group))
 202         /* This service group is already registered in the server */
 203         return;
 204
 205     if (!g->chosen_name) {
 206
 207         if (g->replace_wildcards)
 208             g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
 209         else
 210             g->chosen_name = avahi_strdup(g->name);
 211
 212     }
 213
 214     if (!g->entry_group)
 215         g->entry_group = avahi_s_entry_group_new(avahi_server, entry_group_callback, g);
 216
 217     assert(avahi_s_entry_group_is_empty(g->entry_group));
 218
 219     for (s = g->services; s; s = s->services_next) {
 220
 221         if (avahi_server_add_service_strlst(
 222                 avahi_server,
 223                 g->entry_group,
 224                 -1, s->protocol,
 225                 g->chosen_name, s->type,
 226                 s->domain_name, s->host_name, s->port,
 227                 s->txt_records) < 0) {
 228             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s): %s",
 229                             g->chosen_name, s->type, g->filename,
 230                             avahi_strerror(avahi_server_errno(avahi_server)));
 231             remove_static_service_group_from_server(g);
 232             return;
 233         }
 234     }
 235
 236     avahi_s_entry_group_commit(g->entry_group);
 237 }
 238
 239 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 240     assert(g);
 241
 242     if (g->entry_group)
 243         avahi_s_entry_group_reset(g->entry_group);
 244 }
 245
 246 typedef enum {
 247     XML_TAG_INVALID,
 248     XML_TAG_SERVICE_GROUP,
 249     XML_TAG_NAME,
 250     XML_TAG_SERVICE,
 251     XML_TAG_TYPE,
 252     XML_TAG_DOMAIN_NAME,
 253     XML_TAG_HOST_NAME,
 254     XML_TAG_PORT,
 255     XML_TAG_TXT_RECORD
 256 } xml_tag_name;
 257
 258 struct xml_userdata {
 259     StaticServiceGroup *group;
 260     StaticService *service;
 261     xml_tag_name current_tag;
 262     int failed;
 263     char *buf;
 264 };
 265
 266 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 267     struct xml_userdata *u = data;
 268
 269     assert(u);
 270
 271     if (u->failed)
 272         return;
 273
 274     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 275
 276         if (attr[0])
 277             goto invalid_attr;
 278
 279         u->current_tag = XML_TAG_SERVICE_GROUP;
 280     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 281         u->current_tag = XML_TAG_NAME;
 282
 283         if (attr[0]) {
 284             if (strcmp(attr[0], "replace-wildcards") == 0)
 285                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 286             else
 287                 goto invalid_attr;
 288
 289             if (attr[2])
 290                 goto invalid_attr;
 291         }
 292
 293     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 294         u->current_tag = XML_TAG_SERVICE;
 295
 296         assert(!u->service);
 297         u->service = static_service_new(u->group);
 298
 299         if (attr[0]) {
 300             if (strcmp(attr[0], "protocol") == 0) {
 301                 AvahiProtocol protocol;
 302
 303                 if (strcmp(attr[1], "ipv4") == 0) {
 304                     protocol = AVAHI_PROTO_INET;
 305                 } else if (strcmp(attr[1], "ipv6") == 0) {
 306                     protocol = AVAHI_PROTO_INET6;
 307                 } else if (strcmp(attr[1], "any") == 0) {
 308                     protocol = AVAHI_PROTO_UNSPEC;
 309                 } else {
 310                     avahi_log_error("%s: parse failure: invalid protocol specification \"%s\".", u->group->filename, attr[1]);
 311                     u->failed = 1;
 312                     return;
 313                 }
 314
 315                 u->service->protocol = protocol;
 316             } else
 317                 goto invalid_attr;
 318
 319             if (attr[2])
 320                 goto invalid_attr;
 321         }
 322
 323     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 324         if (attr[0])
 325             goto invalid_attr;
 326
 327         u->current_tag = XML_TAG_TYPE;
 328     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 329         if (attr[0])
 330             goto invalid_attr;
 331
 332         u->current_tag = XML_TAG_DOMAIN_NAME;
 333     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 334         if (attr[0])
 335             goto invalid_attr;
 336
 337         u->current_tag = XML_TAG_HOST_NAME;
 338     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 339         if (attr[0])
 340             goto invalid_attr;
 341
 342         u->current_tag = XML_TAG_PORT;
 343     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 344         if (attr[0])
 345             goto invalid_attr;
 346
 347         u->current_tag = XML_TAG_TXT_RECORD;
 348     } else {
 349         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 350         u->failed = 1;
 351     }
 352
 353     return;
 354
 355 invalid_attr:
 356     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 357     u->failed = 1;
 358     return;
 359 }
 360
 361 static void XMLCALL xml_end(void *data, const char *el) {
 362     struct xml_userdata *u = data;
 363     assert(u);
 364
 365     if (u->failed)
 366         return;
 367
 368     switch (u->current_tag) {
 369         case XML_TAG_SERVICE_GROUP:
 370
 371             if (!u->group->name || !u->group->services) {
 372                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 373                 u->failed = 1;
 374                 return;
 375             }
 376
 377             u->current_tag = XML_TAG_INVALID;
 378             break;
 379
 380         case XML_TAG_SERVICE:
 381
 382             if (!u->service->type) {
 383                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 384                 u->failed = 1;
 385                 return;
 386             }
 387
 388             u->service = NULL;
 389             u->current_tag = XML_TAG_SERVICE_GROUP;
 390             break;
 391
 392         case XML_TAG_NAME:
 393             u->current_tag = XML_TAG_SERVICE_GROUP;
 394             break;
 395
 396         case XML_TAG_PORT: {
 397             int p;
 398             assert(u->service);
 399
 400             p = u->buf ? atoi(u->buf) : 0;
 401
 402             if (p < 0 || p > 0xFFFF) {
 403                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 404                 u->failed = 1;
 405                 return;
 406             }
 407
 408             u->service->port = (uint16_t) p;
 409
 410             u->current_tag = XML_TAG_SERVICE;
 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_TXT_RECORD:
 484             assert(u->service);
 485             u->buf = append_cdata(u->buf, s, len);
 486             break;
 487
 488         case XML_TAG_SERVICE_GROUP:
 489         case XML_TAG_SERVICE:
 490         case XML_TAG_INVALID:
 491             ;
 492     }
 493 }
 494
 495 static int static_service_group_load(StaticServiceGroup *g) {
 496     XML_Parser parser = NULL;
 497     int fd = -1;
 498     struct xml_userdata u;
 499     int r = -1;
 500     struct stat st;
 501     ssize_t n;
 502
 503     assert(g);
 504
 505     u.buf = NULL;
 506     u.group = g;
 507     u.service = NULL;
 508     u.current_tag = XML_TAG_INVALID;
 509     u.failed = 0;
 510
 511     /* Cleanup old data in this service group, if available */
 512     remove_static_service_group_from_server(g);
 513     while (g->services)
 514         static_service_free(g->services);
 515
 516     avahi_free(g->name);
 517     avahi_free(g->chosen_name);
 518     g->name = g->chosen_name = NULL;
 519     g->replace_wildcards = 0;
 520
 521     if (!(parser = XML_ParserCreate(NULL))) {
 522         avahi_log_error("XML_ParserCreate() failed.");
 523         goto finish;
 524     }
 525
 526     if ((fd = open(g->filename, O_RDONLY)) < 0) {
 527         avahi_log_error("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
 528         goto finish;
 529     }
 530
 531     if (fstat(fd, &st) < 0) {
 532         avahi_log_error("fstat(): %s", strerror(errno));
 533         goto finish;
 534     }
 535
 536     g->mtime = st.st_mtime;
 537
 538     XML_SetUserData(parser, &u);
 539
 540     XML_SetElementHandler(parser, xml_start, xml_end);
 541     XML_SetCharacterDataHandler(parser, xml_cdata);
 542
 543     do {
 544         void *buffer;
 545
 546 #define BUFSIZE (10*1024)
 547
 548         if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
 549             avahi_log_error("XML_GetBuffer() failed.");
 550             goto finish;
 551         }
 552
 553         if ((n = read(fd, buffer, BUFSIZE)) < 0) {
 554             avahi_log_error("read(): %s\n", strerror(errno));
 555             goto finish;
 556         }
 557
 558         if (!XML_ParseBuffer(parser, n, n == 0)) {
 559             avahi_log_error("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
 560             goto finish;
 561         }
 562
 563     } while (n != 0);
 564
 565     if (!u.failed)
 566         r = 0;
 567
 568 finish:
 569
 570     if (fd >= 0)
 571         close(fd);
 572
 573     if (parser)
 574         XML_ParserFree(parser);
 575
 576     avahi_free(u.buf);
 577
 578     return r;
 579 }
 580
 581 static void load_file(char *n) {
 582     StaticServiceGroup *g;
 583     assert(n);
 584
 585     for (g = groups; g; g = g->groups_next)
 586         if (strcmp(g->filename, n) == 0)
 587             return;
 588
 589     avahi_log_info("Loading service file %s.", n);
 590
 591     g = static_service_group_new(n);
 592     if (static_service_group_load(g) < 0) {
 593         avahi_log_error("Failed to load service group file %s, ignoring.", g->filename);
 594         static_service_group_free(g);
 595     }
 596 }
 597
 598 void static_service_load(void) {
 599     StaticServiceGroup *g, *n;
 600     glob_t globbuf;
 601     char **p;
 602
 603     for (g = groups; g; g = n) {
 604         struct stat st;
 605
 606         n = g->groups_next;
 607
 608         if (stat(g->filename, &st) < 0) {
 609
 610             if (errno == ENOENT)
 611                 avahi_log_info("Service group file %s vanished, removing services.", g->filename);
 612             else
 613                 avahi_log_warn("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
 614
 615             static_service_group_free(g);
 616         } else if (st.st_mtime != g->mtime) {
 617             avahi_log_info("Service group file %s changed, reloading.", g->filename);
 618
 619             if (static_service_group_load(g) < 0) {
 620                 avahi_log_warn("Failed to load service group file %s, removing service.", g->filename);
 621                 static_service_group_free(g);
 622             }
 623         }
 624     }
 625
 626     memset(&globbuf, 0, sizeof(globbuf));
 627     if (glob(AVAHI_SERVICE_DIR "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
 628         avahi_log_error("Failed to read service directory.");
 629     else {
 630         for (p = globbuf.gl_pathv; *p; p++)
 631             load_file(*p);
 632
 633         globfree(&globbuf);
 634     }
 635 }
 636
 637 void static_service_free_all(void) {
 638
 639     while (groups)
 640         static_service_group_free(groups);
 641 }
 642
 643 void static_service_add_to_server(void) {
 644     StaticServiceGroup *g;
 645
 646     for (g = groups; g; g = g->groups_next)
 647         add_static_service_group_to_server(g);
 648 }
 649
 650 void static_service_remove_from_server(void) {
 651     StaticServiceGroup *g;
 652
 653     for (g = groups; g; g = g->groups_next)
 654         remove_static_service_group_from_server(g);
 655 }