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
  42 #include "main.h"
  43 #include "static-services.h"
  44
  45 typedef struct StaticService StaticService;
  46 typedef struct StaticServiceGroup StaticServiceGroup;
  47
  48 struct StaticService {
  49     StaticServiceGroup *group;
  50
  51     char *type;
  52     char *domain_name;
  53     char *host_name;
  54     uint16_t port;
  55     int protocol;
  56
  57     AvahiStringList *txt_records;
  58
  59     AVAHI_LLIST_FIELDS(StaticService, services);
  60 };
  61
  62 struct StaticServiceGroup {
  63     char *filename;
  64     time_t mtime;
  65
  66     char *name, *chosen_name;
  67     int replace_wildcards;
  68
  69     AvahiSEntryGroup *entry_group;
  70     AVAHI_LLIST_HEAD(StaticService, services);
  71     AVAHI_LLIST_FIELDS(StaticServiceGroup, groups);
  72 };
  73
  74 static AVAHI_LLIST_HEAD(StaticServiceGroup, groups) = NULL;
  75
  76 static char *replacestr(const char *pattern, const char *a, const char *b) {
  77     char *r = NULL, *e, *n;
  78
  79     while ((e = strstr(pattern, a))) {
  80         char *k;
  81
  82         k = avahi_strndup(pattern, e - pattern);
  83         if (r)
  84             n = avahi_strdup_printf("%s%s%s", r, k, b);
  85         else
  86             n = avahi_strdup_printf("%s%s", k, b);
  87
  88         avahi_free(k);
  89         avahi_free(r);
  90         r = n;
  91
  92         pattern = e + strlen(a);
  93     }
  94
  95     if (!r)
  96         return avahi_strdup(pattern);
  97
  98     n = avahi_strdup_printf("%s%s", r, pattern);
  99     avahi_free(r);
 100
 101     return n;
 102 }
 103
 104 static void add_static_service_group_to_server(StaticServiceGroup *g);
 105 static void remove_static_service_group_from_server(StaticServiceGroup *g);
 106
 107 static StaticService *static_service_new(StaticServiceGroup *group) {
 108     StaticService *s;
 109
 110     assert(group);
 111     s = avahi_new(StaticService, 1);
 112     s->group = group;
 113
 114     s->type = s->host_name = s->domain_name = NULL;
 115     s->port = 0;
 116     s->protocol = AVAHI_PROTO_UNSPEC;
 117
 118     s->txt_records = NULL;
 119
 120     AVAHI_LLIST_PREPEND(StaticService, services, group->services, s);
 121
 122     return s;
 123 }
 124
 125 static StaticServiceGroup *static_service_group_new(char *filename) {
 126     StaticServiceGroup *g;
 127     assert(filename);
 128
 129     g = avahi_new(StaticServiceGroup, 1);
 130     g->filename = avahi_strdup(filename);
 131     g->mtime = 0;
 132     g->name = g->chosen_name = NULL;
 133     g->replace_wildcards = 0;
 134     g->entry_group = NULL;
 135
 136     AVAHI_LLIST_HEAD_INIT(StaticService, g->services);
 137     AVAHI_LLIST_PREPEND(StaticServiceGroup, groups, groups, g);
 138
 139     return g;
 140 }
 141
 142 static void static_service_free(StaticService *s) {
 143     assert(s);
 144
 145     AVAHI_LLIST_REMOVE(StaticService, services, s->group->services, s);
 146
 147     avahi_free(s->type);
 148     avahi_free(s->host_name);
 149     avahi_free(s->domain_name);
 150
 151     avahi_string_list_free(s->txt_records);
 152
 153     avahi_free(s);
 154 }
 155
 156 static void static_service_group_free(StaticServiceGroup *g) {
 157     assert(g);
 158
 159     if (g->entry_group)
 160         avahi_s_entry_group_free(g->entry_group);
 161
 162     while (g->services)
 163         static_service_free(g->services);
 164
 165     AVAHI_LLIST_REMOVE(StaticServiceGroup, groups, groups, g);
 166
 167     avahi_free(g->filename);
 168     avahi_free(g->name);
 169     avahi_free(g->chosen_name);
 170     avahi_free(g);
 171 }
 172
 173 static void entry_group_callback(AvahiServer *s, AvahiSEntryGroup *eg, AvahiEntryGroupState state, void* userdata) {
 174     StaticServiceGroup *g = userdata;
 175
 176     assert(s);
 177     assert(g);
 178
 179     if (state == AVAHI_ENTRY_GROUP_COLLISION) {
 180         char *n;
 181
 182         remove_static_service_group_from_server(g);
 183
 184         n = avahi_alternative_service_name(g->chosen_name);
 185         avahi_free(g->chosen_name);
 186         g->chosen_name = n;
 187
 188         avahi_log_notice("Service name conflict for \"%s\" (%s), retrying with \"%s\".", g->name, g->filename, g->chosen_name);
 189
 190         add_static_service_group_to_server(g);
 191     } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 192         avahi_log_info("Service \"%s\" (%s) successfully established.", g->chosen_name, g->filename);
 193 }
 194
 195 static void add_static_service_group_to_server(StaticServiceGroup *g) {
 196     StaticService *s;
 197
 198     assert(g);
 199
 200     if (g->entry_group && !avahi_s_entry_group_is_empty(g->entry_group))
 201         /* This service group is already registered in the server */
 202         return;
 203
 204     if (!g->chosen_name) {
 205
 206         if (g->replace_wildcards)
 207             g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
 208         else
 209             g->chosen_name = avahi_strdup(g->name);
 210
 211     }
 212
 213     if (!g->entry_group)
 214         g->entry_group = avahi_s_entry_group_new(avahi_server, entry_group_callback, g);
 215
 216     assert(avahi_s_entry_group_is_empty(g->entry_group));
 217
 218     for (s = g->services; s; s = s->services_next) {
 219
 220         if (avahi_server_add_service_strlst(
 221                 avahi_server,
 222                 g->entry_group,
 223                 -1, s->protocol,
 224                 g->chosen_name, s->type,
 225                 s->domain_name, s->host_name, s->port,
 226                 s->txt_records) < 0) {
 227             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s): %s",
 228                             g->chosen_name, s->type, g->filename,
 229                             avahi_strerror(avahi_server_errno(avahi_server)));
 230             remove_static_service_group_from_server(g);
 231             return;
 232         }
 233     }
 234
 235     avahi_s_entry_group_commit(g->entry_group);
 236 }
 237
 238 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 239     assert(g);
 240
 241     if (g->entry_group)
 242         avahi_s_entry_group_reset(g->entry_group);
 243 }
 244
 245 typedef enum {
 246     XML_TAG_INVALID,
 247     XML_TAG_SERVICE_GROUP,
 248     XML_TAG_NAME,
 249     XML_TAG_SERVICE,
 250     XML_TAG_TYPE,
 251     XML_TAG_DOMAIN_NAME,
 252     XML_TAG_HOST_NAME,
 253     XML_TAG_PORT,
 254     XML_TAG_TXT_RECORD
 255 } xml_tag_name;
 256
 257 struct xml_userdata {
 258     StaticServiceGroup *group;
 259     StaticService *service;
 260     xml_tag_name current_tag;
 261     int failed;
 262     char *buf;
 263 };
 264
 265 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 266     struct xml_userdata *u = data;
 267
 268     assert(u);
 269
 270     if (u->failed)
 271         return;
 272
 273     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 274
 275         if (attr[0])
 276             goto invalid_attr;
 277
 278         u->current_tag = XML_TAG_SERVICE_GROUP;
 279     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 280         u->current_tag = XML_TAG_NAME;
 281
 282         if (attr[0]) {
 283             if (strcmp(attr[0], "replace-wildcards") == 0)
 284                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 285             else
 286                 goto invalid_attr;
 287
 288             if (attr[2])
 289                 goto invalid_attr;
 290         }
 291
 292     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 293         u->current_tag = XML_TAG_SERVICE;
 294
 295         assert(!u->service);
 296         u->service = static_service_new(u->group);
 297
 298         if (attr[0]) {
 299             if (strcmp(attr[0], "protocol") == 0) {
 300                 AvahiProtocol protocol;
 301
 302                 if (strcmp(attr[1], "ipv4") == 0) {
 303                     protocol = AVAHI_PROTO_INET;
 304                 } else if (strcmp(attr[1], "ipv6") == 0) {
 305                     protocol = AVAHI_PROTO_INET6;
 306                 } else if (strcmp(attr[1], "any") == 0) {
 307                     protocol = AVAHI_PROTO_UNSPEC;
 308                 } else {
 309                     avahi_log_error("%s: parse failure: invalid protocol specification \"%s\".", u->group->filename, attr[1]);
 310                     u->failed = 1;
 311                     return;
 312                 }
 313
 314                 u->service->protocol = protocol;
 315             } else
 316                 goto invalid_attr;
 317
 318             if (attr[2])
 319                 goto invalid_attr;
 320         }
 321
 322     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 323         if (attr[0])
 324             goto invalid_attr;
 325
 326         u->current_tag = XML_TAG_TYPE;
 327     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 328         if (attr[0])
 329             goto invalid_attr;
 330
 331         u->current_tag = XML_TAG_DOMAIN_NAME;
 332     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 333         if (attr[0])
 334             goto invalid_attr;
 335
 336         u->current_tag = XML_TAG_HOST_NAME;
 337     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 338         if (attr[0])
 339             goto invalid_attr;
 340
 341         u->current_tag = XML_TAG_PORT;
 342     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 343         if (attr[0])
 344             goto invalid_attr;
 345
 346         u->current_tag = XML_TAG_TXT_RECORD;
 347     } else {
 348         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 349         u->failed = 1;
 350     }
 351
 352     return;
 353
 354 invalid_attr:
 355     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 356     u->failed = 1;
 357     return;
 358 }
 359
 360 static void XMLCALL xml_end(void *data, const char *el) {
 361     struct xml_userdata *u = data;
 362     assert(u);
 363
 364     if (u->failed)
 365         return;
 366
 367     switch (u->current_tag) {
 368         case XML_TAG_SERVICE_GROUP:
 369
 370             if (!u->group->name || !u->group->services) {
 371                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 372                 u->failed = 1;
 373                 return;
 374             }
 375
 376             u->current_tag = XML_TAG_INVALID;
 377             break;
 378
 379         case XML_TAG_SERVICE:
 380
 381             if (!u->service->type) {
 382                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 383                 u->failed = 1;
 384                 return;
 385             }
 386
 387             u->service = NULL;
 388             u->current_tag = XML_TAG_SERVICE_GROUP;
 389             break;
 390
 391         case XML_TAG_NAME:
 392             u->current_tag = XML_TAG_SERVICE_GROUP;
 393             break;
 394
 395         case XML_TAG_PORT: {
 396             int p;
 397             assert(u->service);
 398
 399             p = u->buf ? atoi(u->buf) : 0;
 400
 401             if (p < 0 || p > 0xFFFF) {
 402                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 403                 u->failed = 1;
 404                 return;
 405             }
 406
 407             u->service->port = (uint16_t) p;
 408
 409             u->current_tag = XML_TAG_SERVICE;
 410             break;
 411         }
 412
 413         case XML_TAG_TXT_RECORD: {
 414             assert(u->service);
 415
 416             u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
 417             u->current_tag = XML_TAG_SERVICE;
 418             break;
 419         }
 420
 421         case XML_TAG_TYPE:
 422         case XML_TAG_DOMAIN_NAME:
 423         case XML_TAG_HOST_NAME:
 424             u->current_tag = XML_TAG_SERVICE;
 425             break;
 426
 427         case XML_TAG_INVALID:
 428             ;
 429     }
 430
 431     avahi_free(u->buf);
 432     u->buf = NULL;
 433 }
 434
 435 static char *append_cdata(char *t, const char *n, int length) {
 436     char *r, *k;
 437
 438     if (!length)
 439         return t;
 440
 441
 442     k = avahi_strndup(n, length);
 443
 444     if (t) {
 445         r = avahi_strdup_printf("%s%s", t, k);
 446         avahi_free(k);
 447         avahi_free(t);
 448     } else
 449         r = k;
 450
 451     return r;
 452 }
 453
 454 static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
 455     struct xml_userdata *u = data;
 456     assert(u);
 457
 458     if (u->failed)
 459         return;
 460
 461     switch (u->current_tag) {
 462         case XML_TAG_NAME:
 463             u->group->name = append_cdata(u->group->name, s, len);
 464             break;
 465
 466         case XML_TAG_TYPE:
 467             assert(u->service);
 468             u->service->type = append_cdata(u->service->type, s, len);
 469             break;
 470
 471         case XML_TAG_DOMAIN_NAME:
 472             assert(u->service);
 473             u->service->domain_name = append_cdata(u->service->domain_name, s, len);
 474             break;
 475
 476         case XML_TAG_HOST_NAME:
 477             assert(u->service);
 478             u->service->host_name = append_cdata(u->service->host_name, s, len);
 479             break;
 480
 481         case XML_TAG_PORT:
 482         case XML_TAG_TXT_RECORD:
 483             assert(u->service);
 484             u->buf = append_cdata(u->buf, s, len);
 485             break;
 486
 487         case XML_TAG_SERVICE_GROUP:
 488         case XML_TAG_SERVICE:
 489         case XML_TAG_INVALID:
 490             ;
 491     }
 492 }
 493
 494 static int static_service_group_load(StaticServiceGroup *g) {
 495     XML_Parser parser = NULL;
 496     int fd = -1;
 497     struct xml_userdata u;
 498     int r = -1;
 499     struct stat st;
 500     ssize_t n;
 501
 502     assert(g);
 503
 504     u.buf = NULL;
 505     u.group = g;
 506     u.service = NULL;
 507     u.current_tag = XML_TAG_INVALID;
 508     u.failed = 0;
 509
 510     /* Cleanup old data in this service group, if available */
 511     remove_static_service_group_from_server(g);
 512     while (g->services)
 513         static_service_free(g->services);
 514
 515     avahi_free(g->name);
 516     avahi_free(g->chosen_name);
 517     g->name = g->chosen_name = NULL;
 518     g->replace_wildcards = 0;
 519
 520     if (!(parser = XML_ParserCreate(NULL))) {
 521         avahi_log_error("XML_ParserCreate() failed.");
 522         goto finish;
 523     }
 524
 525     if ((fd = open(g->filename, O_RDONLY)) < 0) {
 526         avahi_log_error("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
 527         goto finish;
 528     }
 529
 530     if (fstat(fd, &st) < 0) {
 531         avahi_log_error("fstat(): %s", strerror(errno));
 532         goto finish;
 533     }
 534
 535     g->mtime = st.st_mtime;
 536
 537     XML_SetUserData(parser, &u);
 538
 539     XML_SetElementHandler(parser, xml_start, xml_end);
 540     XML_SetCharacterDataHandler(parser, xml_cdata);
 541
 542     do {
 543         void *buffer;
 544
 545 #define BUFSIZE (10*1024)
 546
 547         if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
 548             avahi_log_error("XML_GetBuffer() failed.");
 549             goto finish;
 550         }
 551
 552         if ((n = read(fd, buffer, BUFSIZE)) < 0) {
 553             avahi_log_error("read(): %s\n", strerror(errno));
 554             goto finish;
 555         }
 556
 557         if (!XML_ParseBuffer(parser, n, n == 0)) {
 558             avahi_log_error("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
 559             goto finish;
 560         }
 561
 562     } while (n != 0);
 563
 564     if (!u.failed)
 565         r = 0;
 566
 567 finish:
 568
 569     if (fd >= 0)
 570         close(fd);
 571
 572     if (parser)
 573         XML_ParserFree(parser);
 574
 575     avahi_free(u.buf);
 576
 577     return r;
 578 }
 579
 580 static void load_file(char *n) {
 581     StaticServiceGroup *g;
 582     assert(n);
 583
 584     for (g = groups; g; g = g->groups_next)
 585         if (strcmp(g->filename, n) == 0)
 586             return;
 587
 588     avahi_log_info("Loading service file %s", n);
 589
 590     g = static_service_group_new(n);
 591     if (static_service_group_load(g) < 0) {
 592         avahi_log_error("Failed to load service group file %s, ignoring.", g->filename);
 593         static_service_group_free(g);
 594     }
 595 }
 596
 597 void static_service_load(void) {
 598     StaticServiceGroup *g, *n;
 599     glob_t globbuf;
 600     char **p;
 601
 602     for (g = groups; g; g = n) {
 603         struct stat st;
 604
 605         n = g->groups_next;
 606
 607         if (stat(g->filename, &st) < 0) {
 608
 609             if (errno == ENOENT)
 610                 avahi_log_info("Service group file %s vanished, removing services.", g->filename);
 611             else
 612                 avahi_log_warn("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
 613
 614             static_service_group_free(g);
 615         } else if (st.st_mtime != g->mtime) {
 616             avahi_log_info("Service group file %s changed, reloading.", g->filename);
 617
 618             if (static_service_group_load(g) < 0) {
 619                 avahi_log_warn("Failed to load service group file %s, removing service.", g->filename);
 620                 static_service_group_free(g);
 621             }
 622         }
 623     }
 624
 625     memset(&globbuf, 0, sizeof(globbuf));
 626     if (glob(AVAHI_SERVICE_DIR "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
 627         avahi_log_error("Failed to read service directory.");
 628     else {
 629         for (p = globbuf.gl_pathv; *p; p++)
 630             load_file(*p);
 631
 632         globfree(&globbuf);
 633     }
 634 }
 635
 636 void static_service_free_all(void) {
 637
 638     while (groups)
 639         static_service_group_free(groups);
 640 }
 641
 642 void static_service_add_to_server(void) {
 643     StaticServiceGroup *g;
 644
 645     for (g = groups; g; g = g->groups_next)
 646         add_static_service_group_to_server(g);
 647 }
 648
 649 void static_service_remove_from_server(void) {
 650     StaticServiceGroup *g;
 651
 652     for (g = groups; g; g = g->groups_next)
 653         remove_static_service_group_from_server(g);
 654 }