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