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-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                 AVAHI_IF_UNSPEC, s->protocol,
 225                 0,
 226                 g->chosen_name, s->type,
 227                 s->domain_name, s->host_name, s->port,
 228                 s->txt_records) < 0) {
 229             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s): %s",
 230                             g->chosen_name, s->type, g->filename,
 231                             avahi_strerror(avahi_server_errno(avahi_server)));
 232             remove_static_service_group_from_server(g);
 233             return;
 234         }
 235     }
 236
 237     avahi_s_entry_group_commit(g->entry_group);
 238 }
 239
 240 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 241     assert(g);
 242
 243     if (g->entry_group)
 244         avahi_s_entry_group_reset(g->entry_group);
 245 }
 246
 247 typedef enum {
 248     XML_TAG_INVALID,
 249     XML_TAG_SERVICE_GROUP,
 250     XML_TAG_NAME,
 251     XML_TAG_SERVICE,
 252     XML_TAG_TYPE,
 253     XML_TAG_DOMAIN_NAME,
 254     XML_TAG_HOST_NAME,
 255     XML_TAG_PORT,
 256     XML_TAG_TXT_RECORD
 257 } xml_tag_name;
 258
 259 struct xml_userdata {
 260     StaticServiceGroup *group;
 261     StaticService *service;
 262     xml_tag_name current_tag;
 263     int failed;
 264     char *buf;
 265 };
 266
 267 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 268     struct xml_userdata *u = data;
 269
 270     assert(u);
 271
 272     if (u->failed)
 273         return;
 274
 275     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 276
 277         if (attr[0])
 278             goto invalid_attr;
 279
 280         u->current_tag = XML_TAG_SERVICE_GROUP;
 281     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 282         u->current_tag = XML_TAG_NAME;
 283
 284         if (attr[0]) {
 285             if (strcmp(attr[0], "replace-wildcards") == 0)
 286                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 287             else
 288                 goto invalid_attr;
 289
 290             if (attr[2])
 291                 goto invalid_attr;
 292         }
 293
 294     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 295         u->current_tag = XML_TAG_SERVICE;
 296
 297         assert(!u->service);
 298         u->service = static_service_new(u->group);
 299
 300         if (attr[0]) {
 301             if (strcmp(attr[0], "protocol") == 0) {
 302                 AvahiProtocol protocol;
 303
 304                 if (strcmp(attr[1], "ipv4") == 0) {
 305                     protocol = AVAHI_PROTO_INET;
 306                 } else if (strcmp(attr[1], "ipv6") == 0) {
 307                     protocol = AVAHI_PROTO_INET6;
 308                 } else if (strcmp(attr[1], "any") == 0) {
 309                     protocol = AVAHI_PROTO_UNSPEC;
 310                 } else {
 311                     avahi_log_error("%s: parse failure: invalid protocol specification \"%s\".", u->group->filename, attr[1]);
 312                     u->failed = 1;
 313                     return;
 314                 }
 315
 316                 u->service->protocol = protocol;
 317             } else
 318                 goto invalid_attr;
 319
 320             if (attr[2])
 321                 goto invalid_attr;
 322         }
 323
 324     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 325         if (attr[0])
 326             goto invalid_attr;
 327
 328         u->current_tag = XML_TAG_TYPE;
 329     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 330         if (attr[0])
 331             goto invalid_attr;
 332
 333         u->current_tag = XML_TAG_DOMAIN_NAME;
 334     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 335         if (attr[0])
 336             goto invalid_attr;
 337
 338         u->current_tag = XML_TAG_HOST_NAME;
 339     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 340         if (attr[0])
 341             goto invalid_attr;
 342
 343         u->current_tag = XML_TAG_PORT;
 344     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 345         if (attr[0])
 346             goto invalid_attr;
 347
 348         u->current_tag = XML_TAG_TXT_RECORD;
 349     } else {
 350         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 351         u->failed = 1;
 352     }
 353
 354     return;
 355
 356 invalid_attr:
 357     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 358     u->failed = 1;
 359     return;
 360 }
 361
 362 static void XMLCALL xml_end(void *data, const char *el) {
 363     struct xml_userdata *u = data;
 364     assert(u);
 365
 366     if (u->failed)
 367         return;
 368
 369     switch (u->current_tag) {
 370         case XML_TAG_SERVICE_GROUP:
 371
 372             if (!u->group->name || !u->group->services) {
 373                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 374                 u->failed = 1;
 375                 return;
 376             }
 377
 378             u->current_tag = XML_TAG_INVALID;
 379             break;
 380
 381         case XML_TAG_SERVICE:
 382
 383             if (!u->service->type) {
 384                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 385                 u->failed = 1;
 386                 return;
 387             }
 388
 389             u->service = NULL;
 390             u->current_tag = XML_TAG_SERVICE_GROUP;
 391             break;
 392
 393         case XML_TAG_NAME:
 394             u->current_tag = XML_TAG_SERVICE_GROUP;
 395             break;
 396
 397         case XML_TAG_PORT: {
 398             int p;
 399             assert(u->service);
 400
 401             p = u->buf ? atoi(u->buf) : 0;
 402
 403             if (p < 0 || p > 0xFFFF) {
 404                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 405                 u->failed = 1;
 406                 return;
 407             }
 408
 409             u->service->port = (uint16_t) p;
 410
 411             u->current_tag = XML_TAG_SERVICE;
 412             break;
 413         }
 414
 415         case XML_TAG_TXT_RECORD: {
 416             assert(u->service);
 417
 418             u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
 419             u->current_tag = XML_TAG_SERVICE;
 420             break;
 421         }
 422
 423         case XML_TAG_TYPE:
 424         case XML_TAG_DOMAIN_NAME:
 425         case XML_TAG_HOST_NAME:
 426             u->current_tag = XML_TAG_SERVICE;
 427             break;
 428
 429         case XML_TAG_INVALID:
 430             ;
 431     }
 432
 433     avahi_free(u->buf);
 434     u->buf = NULL;
 435 }
 436
 437 static char *append_cdata(char *t, const char *n, int length) {
 438     char *r, *k;
 439
 440     if (!length)
 441         return t;
 442
 443
 444     k = avahi_strndup(n, length);
 445
 446     if (t) {
 447         r = avahi_strdup_printf("%s%s", t, k);
 448         avahi_free(k);
 449         avahi_free(t);
 450     } else
 451         r = k;
 452
 453     return r;
 454 }
 455
 456 static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
 457     struct xml_userdata *u = data;
 458     assert(u);
 459
 460     if (u->failed)
 461         return;
 462
 463     switch (u->current_tag) {
 464         case XML_TAG_NAME:
 465             u->group->name = append_cdata(u->group->name, s, len);
 466             break;
 467
 468         case XML_TAG_TYPE:
 469             assert(u->service);
 470             u->service->type = append_cdata(u->service->type, s, len);
 471             break;
 472
 473         case XML_TAG_DOMAIN_NAME:
 474             assert(u->service);
 475             u->service->domain_name = append_cdata(u->service->domain_name, s, len);
 476             break;
 477
 478         case XML_TAG_HOST_NAME:
 479             assert(u->service);
 480             u->service->host_name = append_cdata(u->service->host_name, s, len);
 481             break;
 482
 483         case XML_TAG_PORT:
 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 }