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 <glib.h>
  35 #include <expat.h>
  36
  37 #include <avahi-core/llist.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     gchar *type;
  50     gchar *domain_name;
  51     gchar *host_name;
  52     guint16 port;
  53
  54     AvahiStringList *txt_records;
  55
  56     AVAHI_LLIST_FIELDS(StaticService, services);
  57 };
  58
  59 struct StaticServiceGroup {
  60     gchar *filename;
  61     time_t mtime;
  62
  63     gchar *name, *chosen_name;
  64     gboolean replace_wildcards;
  65
  66     AvahiEntryGroup *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 gchar *replacestr(const gchar *pattern, const gchar *a, const gchar *b) {
  74     gchar *r = NULL, *e, *n;
  75
  76     while ((e = strstr(pattern, a))) {
  77         gchar *k;
  78
  79         k = g_strndup(pattern, e - pattern);
  80         if (r)
  81             n = g_strconcat(r, k, b, NULL);
  82         else
  83             n = g_strconcat(k, b, NULL);
  84
  85         g_free(k);
  86         g_free(r);
  87         r = n;
  88
  89         pattern = e + strlen(a);
  90     }
  91
  92     if (!r)
  93         return g_strdup(pattern);
  94
  95     n = g_strconcat(r, pattern, NULL);
  96     g_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     g_assert(group);
 108     s = g_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(gchar *filename) {
 122     StaticServiceGroup *g;
 123     g_assert(filename);
 124
 125     g = g_new(StaticServiceGroup, 1);
 126     g->filename = g_strdup(filename);
 127     g->mtime = 0;
 128     g->name = g->chosen_name = NULL;
 129     g->replace_wildcards = FALSE;
 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     g_assert(s);
 140
 141     AVAHI_LLIST_REMOVE(StaticService, services, s->group->services, s);
 142
 143     g_free(s->type);
 144     g_free(s->host_name);
 145     g_free(s->domain_name);
 146
 147     avahi_string_list_free(s->txt_records);
 148
 149     g_free(s);
 150 }
 151
 152 static void static_service_group_free(StaticServiceGroup *g) {
 153     g_assert(g);
 154
 155     remove_static_service_group_from_server(g);
 156
 157     while (g->services)
 158         static_service_free(g->services);
 159
 160     AVAHI_LLIST_REMOVE(StaticServiceGroup, groups, groups, g);
 161
 162     g_free(g->filename);
 163     g_free(g->name);
 164     g_free(g->chosen_name);
 165     g_free(g);
 166 }
 167
 168 static void entry_group_callback(AvahiServer *s, AvahiEntryGroup *eg, AvahiEntryGroupState state, gpointer userdata) {
 169     StaticServiceGroup *g = userdata;
 170
 171     g_assert(s);
 172     g_assert(g);
 173
 174     if (state == AVAHI_ENTRY_GROUP_COLLISION) {
 175         gchar *n;
 176
 177         remove_static_service_group_from_server(g);
 178
 179         n = avahi_alternative_service_name(g->chosen_name);
 180         g_free(g->chosen_name);
 181         g->chosen_name = n;
 182
 183         avahi_log_notice("Service name conflict for \"%s\" (%s), retrying with \"%s\".", g->name, g->filename, g->chosen_name);
 184
 185         add_static_service_group_to_server(g);
 186     } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 187         avahi_log_info("Service \"%s\" (%s) successfully established.", g->chosen_name, g->filename);
 188 }
 189
 190 static void add_static_service_group_to_server(StaticServiceGroup *g) {
 191     StaticService *s;
 192
 193     g_assert(g);
 194
 195     if (g->entry_group)
 196         return;
 197
 198     if (g->chosen_name)
 199         g_free(g->chosen_name);
 200
 201     if (g->replace_wildcards)
 202         g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
 203     else
 204         g->chosen_name = g_strdup(g->name);
 205
 206     g->entry_group = avahi_entry_group_new(avahi_server, entry_group_callback, g);
 207
 208     for (s = g->services; s; s = s->services_next) {
 209
 210         if (avahi_server_add_service_strlst(
 211                 avahi_server,
 212                 g->entry_group,
 213                 -1, AF_UNSPEC,
 214                 g->chosen_name, s->type,
 215                 s->domain_name, s->host_name, s->port,
 216                 s->txt_records) < 0) {
 217             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s)", g->chosen_name, s->type, g->filename);
 218             remove_static_service_group_from_server(g);
 219             return;
 220         }
 221     }
 222
 223     avahi_entry_group_commit(g->entry_group);
 224 }
 225
 226 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 227     g_assert(g);
 228
 229     if (g->entry_group) {
 230         avahi_entry_group_free(g->entry_group);
 231         g->entry_group = NULL;
 232     }
 233 }
 234
 235 typedef enum {
 236     XML_TAG_INVALID,
 237     XML_TAG_SERVICE_GROUP,
 238     XML_TAG_NAME,
 239     XML_TAG_SERVICE,
 240     XML_TAG_TYPE,
 241     XML_TAG_DOMAIN_NAME,
 242     XML_TAG_HOST_NAME,
 243     XML_TAG_PORT,
 244     XML_TAG_TXT_RECORD
 245 } xml_tag_name;
 246
 247 struct xml_userdata {
 248     StaticServiceGroup *group;
 249     StaticService *service;
 250     xml_tag_name current_tag;
 251     gboolean failed;
 252     gchar *buf;
 253 };
 254
 255 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 256     struct xml_userdata *u = data;
 257
 258     g_assert(u);
 259
 260     if (u->failed)
 261         return;
 262
 263     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 264
 265         if (attr[0])
 266             goto invalid_attr;
 267
 268         u->current_tag = XML_TAG_SERVICE_GROUP;
 269     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 270         u->current_tag = XML_TAG_NAME;
 271
 272         if (attr[0]) {
 273             if (strcmp(attr[0], "replace-wildcards") == 0)
 274                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 275             else
 276                 goto invalid_attr;
 277         }
 278
 279         if (attr[2])
 280             goto invalid_attr;
 281
 282
 283
 284     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 285         if (attr[0])
 286             goto invalid_attr;
 287
 288         g_assert(!u->service);
 289         u->service = static_service_new(u->group);
 290
 291         u->current_tag = XML_TAG_SERVICE;
 292     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 293         if (attr[0])
 294             goto invalid_attr;
 295
 296         u->current_tag = XML_TAG_TYPE;
 297     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 298         if (attr[0])
 299             goto invalid_attr;
 300
 301         u->current_tag = XML_TAG_DOMAIN_NAME;
 302     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 303         if (attr[0])
 304             goto invalid_attr;
 305
 306         u->current_tag = XML_TAG_HOST_NAME;
 307     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 308         if (attr[0])
 309             goto invalid_attr;
 310
 311         u->current_tag = XML_TAG_PORT;
 312     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 313         if (attr[0])
 314             goto invalid_attr;
 315
 316         u->current_tag = XML_TAG_TXT_RECORD;
 317     } else {
 318         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 319         u->failed = TRUE;
 320     }
 321
 322     return;
 323
 324 invalid_attr:
 325     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 326     u->failed = TRUE;
 327     return;
 328 }
 329
 330 static void XMLCALL xml_end(void *data, const char *el) {
 331     struct xml_userdata *u = data;
 332     g_assert(u);
 333
 334     if (u->failed)
 335         return;
 336
 337     switch (u->current_tag) {
 338         case XML_TAG_SERVICE_GROUP:
 339
 340             if (!u->group->name || !u->group->services) {
 341                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 342                 u->failed = TRUE;
 343                 return;
 344             }
 345
 346             u->current_tag = XML_TAG_INVALID;
 347             break;
 348
 349         case XML_TAG_SERVICE:
 350
 351             if (u->service->port == 0 || !u->service->type) {
 352                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 353                 u->failed = TRUE;
 354                 return;
 355             }
 356
 357             u->service = NULL;
 358             u->current_tag = XML_TAG_SERVICE_GROUP;
 359             break;
 360
 361         case XML_TAG_NAME:
 362             u->current_tag = XML_TAG_SERVICE_GROUP;
 363             break;
 364
 365         case XML_TAG_PORT: {
 366             int p;
 367             g_assert(u->service);
 368
 369             p = u->buf ? atoi(u->buf) : 0;
 370
 371             if (p <= 0 || p > 0xFFFF) {
 372                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 373                 u->failed = TRUE;
 374                 return;
 375             }
 376
 377             u->service->port = (guint16) p;
 378
 379             u->current_tag = XML_TAG_SERVICE;
 380             break;
 381         }
 382
 383         case XML_TAG_TXT_RECORD: {
 384             g_assert(u->service);
 385
 386             u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
 387             u->current_tag = XML_TAG_SERVICE;
 388             break;
 389         }
 390
 391         case XML_TAG_TYPE:
 392         case XML_TAG_DOMAIN_NAME:
 393         case XML_TAG_HOST_NAME:
 394             u->current_tag = XML_TAG_SERVICE;
 395             break;
 396
 397         case XML_TAG_INVALID:
 398             ;
 399     }
 400
 401     g_free(u->buf);
 402     u->buf = NULL;
 403 }
 404
 405 static gchar *append_cdata(gchar *t, const gchar *n, int length) {
 406     gchar *r, *k;
 407
 408     if (!length)
 409         return t;
 410
 411     k = g_strndup(n, length);
 412
 413     if (t) {
 414         r = g_strconcat(t, k, NULL);
 415         g_free(k);
 416         g_free(t);
 417     } else
 418         r = k;
 419
 420     return r;
 421 }
 422
 423 static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
 424     struct xml_userdata *u = data;
 425     g_assert(u);
 426
 427     if (u->failed)
 428         return;
 429
 430     switch (u->current_tag) {
 431         case XML_TAG_NAME:
 432             u->group->name = append_cdata(u->group->name, s, len);
 433             break;
 434
 435         case XML_TAG_TYPE:
 436             g_assert(u->service);
 437             u->service->type = append_cdata(u->service->type, s, len);
 438             break;
 439
 440         case XML_TAG_DOMAIN_NAME:
 441             g_assert(u->service);
 442             u->service->domain_name = append_cdata(u->service->domain_name, s, len);
 443             break;
 444
 445         case XML_TAG_HOST_NAME:
 446             g_assert(u->service);
 447             u->service->host_name = append_cdata(u->service->host_name, s, len);
 448             break;
 449
 450         case XML_TAG_PORT:
 451         case XML_TAG_TXT_RECORD:
 452             u->buf = append_cdata(u->buf, s, len);
 453             break;
 454
 455         case XML_TAG_SERVICE_GROUP:
 456         case XML_TAG_SERVICE:
 457         case XML_TAG_INVALID:
 458             ;
 459     }
 460 }
 461
 462 static gint static_service_group_load(StaticServiceGroup *g) {
 463     XML_Parser parser = NULL;
 464     gint fd = -1;
 465     struct xml_userdata u;
 466     gint r = -1;
 467     struct stat st;
 468     ssize_t n;
 469
 470     g_assert(g);
 471
 472     u.buf = NULL;
 473     u.group = g;
 474     u.service = NULL;
 475     u.current_tag = XML_TAG_INVALID;
 476     u.failed = FALSE;
 477
 478     /* Cleanup old data in this service group, if available */
 479     remove_static_service_group_from_server(g);
 480     while (g->services)
 481         static_service_free(g->services);
 482
 483     g_free(g->name);
 484     g_free(g->chosen_name);
 485     g->name = g->chosen_name = NULL;
 486     g->replace_wildcards = FALSE;
 487
 488     if (!(parser = XML_ParserCreate(NULL))) {
 489         avahi_log_error("XML_ParserCreate() failed.");
 490         goto finish;
 491     }
 492
 493     if ((fd = open(g->filename, O_RDONLY)) < 0) {
 494         avahi_log_error("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
 495         goto finish;
 496     }
 497
 498     if (fstat(fd, &st) < 0) {
 499         avahi_log_error("fstat(): %s", strerror(errno));
 500         goto finish;
 501     }
 502
 503     g->mtime = st.st_mtime;
 504
 505     XML_SetUserData(parser, &u);
 506
 507     XML_SetElementHandler(parser, xml_start, xml_end);
 508     XML_SetCharacterDataHandler(parser, xml_cdata);
 509
 510     do {
 511         void *buffer;
 512
 513 #define BUFSIZE (10*1024)
 514
 515         if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
 516             avahi_log_error("XML_GetBuffer() failed.");
 517             goto finish;
 518         }
 519
 520         if ((n = read(fd, buffer, BUFSIZE)) < 0) {
 521             avahi_log_error("read(): %s\n", strerror(errno));
 522             goto finish;
 523         }
 524
 525         if (!XML_ParseBuffer(parser, n, n == 0)) {
 526             avahi_log_error("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
 527             goto finish;
 528         }
 529
 530     } while (n != 0);
 531
 532     if (!u.failed)
 533         r = 0;
 534
 535 finish:
 536
 537     if (fd >= 0)
 538         close(fd);
 539
 540     if (parser)
 541         XML_ParserFree(parser);
 542
 543     g_free(u.buf);
 544
 545     return r;
 546 }
 547
 548 static void load_file(gchar *n) {
 549     StaticServiceGroup *g;
 550     g_assert(n);
 551
 552     for (g = groups; g; g = g->groups_next)
 553         if (strcmp(g->filename, n) == 0)
 554             return;
 555
 556     avahi_log_info("Loading service file %s", n);
 557
 558     g = static_service_group_new(n);
 559     if (static_service_group_load(g) < 0) {
 560         avahi_log_error("Failed to load service group file %s, ignoring.", g->filename);
 561         static_service_group_free(g);
 562     }
 563 }
 564
 565 void static_service_load(void) {
 566     StaticServiceGroup *g, *n;
 567     glob_t globbuf;
 568     gchar **p;
 569
 570     for (g = groups; g; g = n) {
 571         struct stat st;
 572
 573         n = g->groups_next;
 574
 575         if (stat(g->filename, &st) < 0) {
 576
 577             if (errno == ENOENT)
 578                 avahi_log_info("Service group file %s vanished, removing services.", g->filename);
 579             else
 580                 avahi_log_warn("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
 581
 582             static_service_group_free(g);
 583         } else if (st.st_mtime != g->mtime) {
 584             avahi_log_info("Service group file %s changed, reloading.", g->filename);
 585
 586             if (static_service_group_load(g) < 0) {
 587                 avahi_log_warn("Failed to load service group file %s, removing service.", g->filename);
 588                 static_service_group_free(g);
 589             }
 590         }
 591     }
 592
 593     memset(&globbuf, 0, sizeof(globbuf));
 594     if (glob(AVAHI_SERVICE_DIR "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
 595         avahi_log_error("Failed to read service directory.");
 596     else {
 597         for (p = globbuf.gl_pathv; *p; p++)
 598             load_file(*p);
 599
 600         globfree(&globbuf);
 601     }
 602 }
 603
 604 void static_service_free_all(void) {
 605
 606     while (groups)
 607         static_service_group_free(groups);
 608 }
 609
 610 void static_service_add_to_server(void) {
 611     StaticServiceGroup *g;
 612
 613     for (g = groups; g; g = g->groups_next)
 614         add_static_service_group_to_server(g);
 615 }
 616
 617 void static_service_remove_from_server(void) {
 618     StaticServiceGroup *g;
 619
 620     for (g = groups; g; g = g->groups_next)
 621         remove_static_service_group_from_server(g);
 622 }