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     if (g->entry_group)
 156         avahi_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     g_free(g->filename);
 164     g_free(g->name);
 165     g_free(g->chosen_name);
 166     g_free(g);
 167 }
 168
 169 static void entry_group_callback(AvahiServer *s, AvahiEntryGroup *eg, AvahiEntryGroupState state, gpointer userdata) {
 170     StaticServiceGroup *g = userdata;
 171
 172     g_assert(s);
 173     g_assert(g);
 174
 175     if (state == AVAHI_ENTRY_GROUP_COLLISION) {
 176         gchar *n;
 177
 178         remove_static_service_group_from_server(g);
 179
 180         n = avahi_alternative_service_name(g->chosen_name);
 181         g_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     g_assert(g);
 195
 196     if (g->chosen_name)
 197         g_free(g->chosen_name);
 198
 199     if (g->replace_wildcards)
 200         g->chosen_name = replacestr(g->name, "%h", avahi_server_get_host_name(avahi_server));
 201     else
 202         g->chosen_name = g_strdup(g->name);
 203
 204     if (!g->entry_group)
 205         g->entry_group = avahi_entry_group_new(avahi_server, entry_group_callback, g);
 206
 207     g_assert(avahi_entry_group_is_empty(g->entry_group));
 208
 209     for (s = g->services; s; s = s->services_next) {
 210
 211         if (avahi_server_add_service_strlst(
 212                 avahi_server,
 213                 g->entry_group,
 214                 -1, AF_UNSPEC,
 215                 g->chosen_name, s->type,
 216                 s->domain_name, s->host_name, s->port,
 217                 s->txt_records) < 0) {
 218             avahi_log_error("Failed to add service '%s' of type '%s', ignoring service group (%s): %s",
 219                             g->chosen_name, s->type, g->filename,
 220                             avahi_strerror(avahi_server_errno(avahi_server)));
 221             remove_static_service_group_from_server(g);
 222             return;
 223         }
 224     }
 225
 226     avahi_entry_group_commit(g->entry_group);
 227 }
 228
 229 static void remove_static_service_group_from_server(StaticServiceGroup *g) {
 230     g_assert(g);
 231
 232     if (g->entry_group)
 233         avahi_entry_group_reset(g->entry_group);
 234 }
 235
 236 typedef enum {
 237     XML_TAG_INVALID,
 238     XML_TAG_SERVICE_GROUP,
 239     XML_TAG_NAME,
 240     XML_TAG_SERVICE,
 241     XML_TAG_TYPE,
 242     XML_TAG_DOMAIN_NAME,
 243     XML_TAG_HOST_NAME,
 244     XML_TAG_PORT,
 245     XML_TAG_TXT_RECORD
 246 } xml_tag_name;
 247
 248 struct xml_userdata {
 249     StaticServiceGroup *group;
 250     StaticService *service;
 251     xml_tag_name current_tag;
 252     gboolean failed;
 253     gchar *buf;
 254 };
 255
 256 static void XMLCALL xml_start(void *data, const char *el, const char *attr[]) {
 257     struct xml_userdata *u = data;
 258
 259     g_assert(u);
 260
 261     if (u->failed)
 262         return;
 263
 264     if (u->current_tag == XML_TAG_INVALID && strcmp(el, "service-group") == 0) {
 265
 266         if (attr[0])
 267             goto invalid_attr;
 268
 269         u->current_tag = XML_TAG_SERVICE_GROUP;
 270     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "name") == 0) {
 271         u->current_tag = XML_TAG_NAME;
 272
 273         if (attr[0]) {
 274             if (strcmp(attr[0], "replace-wildcards") == 0)
 275                 u->group->replace_wildcards = strcmp(attr[1], "yes") == 0;
 276             else
 277                 goto invalid_attr;
 278         }
 279
 280         if (attr[2])
 281             goto invalid_attr;
 282
 283
 284
 285     } else if (u->current_tag == XML_TAG_SERVICE_GROUP && strcmp(el, "service") == 0) {
 286         if (attr[0])
 287             goto invalid_attr;
 288
 289         g_assert(!u->service);
 290         u->service = static_service_new(u->group);
 291
 292         u->current_tag = XML_TAG_SERVICE;
 293     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "type") == 0) {
 294         if (attr[0])
 295             goto invalid_attr;
 296
 297         u->current_tag = XML_TAG_TYPE;
 298     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "domain-name") == 0) {
 299         if (attr[0])
 300             goto invalid_attr;
 301
 302         u->current_tag = XML_TAG_DOMAIN_NAME;
 303     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "host-name") == 0) {
 304         if (attr[0])
 305             goto invalid_attr;
 306
 307         u->current_tag = XML_TAG_HOST_NAME;
 308     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "port") == 0) {
 309         if (attr[0])
 310             goto invalid_attr;
 311
 312         u->current_tag = XML_TAG_PORT;
 313     } else if (u->current_tag == XML_TAG_SERVICE && strcmp(el, "txt-record") == 0) {
 314         if (attr[0])
 315             goto invalid_attr;
 316
 317         u->current_tag = XML_TAG_TXT_RECORD;
 318     } else {
 319         avahi_log_error("%s: parse failure: didn't expect element <%s>.", u->group->filename, el);
 320         u->failed = TRUE;
 321     }
 322
 323     return;
 324
 325 invalid_attr:
 326     avahi_log_error("%s: parse failure: invalid attribute for element <%s>.", u->group->filename, el);
 327     u->failed = TRUE;
 328     return;
 329 }
 330
 331 static void XMLCALL xml_end(void *data, const char *el) {
 332     struct xml_userdata *u = data;
 333     g_assert(u);
 334
 335     if (u->failed)
 336         return;
 337
 338     switch (u->current_tag) {
 339         case XML_TAG_SERVICE_GROUP:
 340
 341             if (!u->group->name || !u->group->services) {
 342                 avahi_log_error("%s: parse failure: service group incomplete.", u->group->filename);
 343                 u->failed = TRUE;
 344                 return;
 345             }
 346
 347             u->current_tag = XML_TAG_INVALID;
 348             break;
 349
 350         case XML_TAG_SERVICE:
 351
 352             if (u->service->port == 0 || !u->service->type) {
 353                 avahi_log_error("%s: parse failure: service incomplete.", u->group->filename);
 354                 u->failed = TRUE;
 355                 return;
 356             }
 357
 358             u->service = NULL;
 359             u->current_tag = XML_TAG_SERVICE_GROUP;
 360             break;
 361
 362         case XML_TAG_NAME:
 363             u->current_tag = XML_TAG_SERVICE_GROUP;
 364             break;
 365
 366         case XML_TAG_PORT: {
 367             int p;
 368             g_assert(u->service);
 369
 370             p = u->buf ? atoi(u->buf) : 0;
 371
 372             if (p <= 0 || p > 0xFFFF) {
 373                 avahi_log_error("%s: parse failure: invalid port specification \"%s\".", u->group->filename, u->buf);
 374                 u->failed = TRUE;
 375                 return;
 376             }
 377
 378             u->service->port = (guint16) p;
 379
 380             u->current_tag = XML_TAG_SERVICE;
 381             break;
 382         }
 383
 384         case XML_TAG_TXT_RECORD: {
 385             g_assert(u->service);
 386
 387             u->service->txt_records = avahi_string_list_add(u->service->txt_records, u->buf ? u->buf : "");
 388             u->current_tag = XML_TAG_SERVICE;
 389             break;
 390         }
 391
 392         case XML_TAG_TYPE:
 393         case XML_TAG_DOMAIN_NAME:
 394         case XML_TAG_HOST_NAME:
 395             u->current_tag = XML_TAG_SERVICE;
 396             break;
 397
 398         case XML_TAG_INVALID:
 399             ;
 400     }
 401
 402     g_free(u->buf);
 403     u->buf = NULL;
 404 }
 405
 406 static gchar *append_cdata(gchar *t, const gchar *n, int length) {
 407     gchar *r, *k;
 408
 409     if (!length)
 410         return t;
 411
 412     k = g_strndup(n, length);
 413
 414     if (t) {
 415         r = g_strconcat(t, k, NULL);
 416         g_free(k);
 417         g_free(t);
 418     } else
 419         r = k;
 420
 421     return r;
 422 }
 423
 424 static void XMLCALL xml_cdata(void *data, const XML_Char *s, int len) {
 425     struct xml_userdata *u = data;
 426     g_assert(u);
 427
 428     if (u->failed)
 429         return;
 430
 431     switch (u->current_tag) {
 432         case XML_TAG_NAME:
 433             u->group->name = append_cdata(u->group->name, s, len);
 434             break;
 435
 436         case XML_TAG_TYPE:
 437             g_assert(u->service);
 438             u->service->type = append_cdata(u->service->type, s, len);
 439             break;
 440
 441         case XML_TAG_DOMAIN_NAME:
 442             g_assert(u->service);
 443             u->service->domain_name = append_cdata(u->service->domain_name, s, len);
 444             break;
 445
 446         case XML_TAG_HOST_NAME:
 447             g_assert(u->service);
 448             u->service->host_name = append_cdata(u->service->host_name, s, len);
 449             break;
 450
 451         case XML_TAG_PORT:
 452         case XML_TAG_TXT_RECORD:
 453             u->buf = append_cdata(u->buf, s, len);
 454             break;
 455
 456         case XML_TAG_SERVICE_GROUP:
 457         case XML_TAG_SERVICE:
 458         case XML_TAG_INVALID:
 459             ;
 460     }
 461 }
 462
 463 static gint static_service_group_load(StaticServiceGroup *g) {
 464     XML_Parser parser = NULL;
 465     gint fd = -1;
 466     struct xml_userdata u;
 467     gint r = -1;
 468     struct stat st;
 469     ssize_t n;
 470
 471     g_assert(g);
 472
 473     u.buf = NULL;
 474     u.group = g;
 475     u.service = NULL;
 476     u.current_tag = XML_TAG_INVALID;
 477     u.failed = FALSE;
 478
 479     /* Cleanup old data in this service group, if available */
 480     remove_static_service_group_from_server(g);
 481     while (g->services)
 482         static_service_free(g->services);
 483
 484     g_free(g->name);
 485     g_free(g->chosen_name);
 486     g->name = g->chosen_name = NULL;
 487     g->replace_wildcards = FALSE;
 488
 489     if (!(parser = XML_ParserCreate(NULL))) {
 490         avahi_log_error("XML_ParserCreate() failed.");
 491         goto finish;
 492     }
 493
 494     if ((fd = open(g->filename, O_RDONLY)) < 0) {
 495         avahi_log_error("open(\"%s\", O_RDONLY): %s", g->filename, strerror(errno));
 496         goto finish;
 497     }
 498
 499     if (fstat(fd, &st) < 0) {
 500         avahi_log_error("fstat(): %s", strerror(errno));
 501         goto finish;
 502     }
 503
 504     g->mtime = st.st_mtime;
 505
 506     XML_SetUserData(parser, &u);
 507
 508     XML_SetElementHandler(parser, xml_start, xml_end);
 509     XML_SetCharacterDataHandler(parser, xml_cdata);
 510
 511     do {
 512         void *buffer;
 513
 514 #define BUFSIZE (10*1024)
 515
 516         if (!(buffer = XML_GetBuffer(parser, BUFSIZE))) {
 517             avahi_log_error("XML_GetBuffer() failed.");
 518             goto finish;
 519         }
 520
 521         if ((n = read(fd, buffer, BUFSIZE)) < 0) {
 522             avahi_log_error("read(): %s\n", strerror(errno));
 523             goto finish;
 524         }
 525
 526         if (!XML_ParseBuffer(parser, n, n == 0)) {
 527             avahi_log_error("XML_ParseBuffer() failed at line %d: %s.\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(XML_GetErrorCode(parser)));
 528             goto finish;
 529         }
 530
 531     } while (n != 0);
 532
 533     if (!u.failed)
 534         r = 0;
 535
 536 finish:
 537
 538     if (fd >= 0)
 539         close(fd);
 540
 541     if (parser)
 542         XML_ParserFree(parser);
 543
 544     g_free(u.buf);
 545
 546     return r;
 547 }
 548
 549 static void load_file(gchar *n) {
 550     StaticServiceGroup *g;
 551     g_assert(n);
 552
 553     for (g = groups; g; g = g->groups_next)
 554         if (strcmp(g->filename, n) == 0)
 555             return;
 556
 557     avahi_log_info("Loading service file %s", n);
 558
 559     g = static_service_group_new(n);
 560     if (static_service_group_load(g) < 0) {
 561         avahi_log_error("Failed to load service group file %s, ignoring.", g->filename);
 562         static_service_group_free(g);
 563     }
 564 }
 565
 566 void static_service_load(void) {
 567     StaticServiceGroup *g, *n;
 568     glob_t globbuf;
 569     gchar **p;
 570
 571     for (g = groups; g; g = n) {
 572         struct stat st;
 573
 574         n = g->groups_next;
 575
 576         if (stat(g->filename, &st) < 0) {
 577
 578             if (errno == ENOENT)
 579                 avahi_log_info("Service group file %s vanished, removing services.", g->filename);
 580             else
 581                 avahi_log_warn("Failed to stat() file %s, ignoring: %s", g->filename, strerror(errno));
 582
 583             static_service_group_free(g);
 584         } else if (st.st_mtime != g->mtime) {
 585             avahi_log_info("Service group file %s changed, reloading.", g->filename);
 586
 587             if (static_service_group_load(g) < 0) {
 588                 avahi_log_warn("Failed to load service group file %s, removing service.", g->filename);
 589                 static_service_group_free(g);
 590             }
 591         }
 592     }
 593
 594     memset(&globbuf, 0, sizeof(globbuf));
 595     if (glob(AVAHI_SERVICE_DIR "/*.service", GLOB_ERR, NULL, &globbuf) != 0)
 596         avahi_log_error("Failed to read service directory.");
 597     else {
 598         for (p = globbuf.gl_pathv; *p; p++)
 599             load_file(*p);
 600
 601         globfree(&globbuf);
 602     }
 603 }
 604
 605 void static_service_free_all(void) {
 606
 607     while (groups)
 608         static_service_group_free(groups);
 609 }
 610
 611 void static_service_add_to_server(void) {
 612     StaticServiceGroup *g;
 613
 614     for (g = groups; g; g = g->groups_next)
 615         add_static_service_group_to_server(g);
 616 }
 617
 618 void static_service_remove_from_server(void) {
 619     StaticServiceGroup *g;
 620
 621     for (g = groups; g; g = g->groups_next)
 622         remove_static_service_group_from_server(g);
 623 }