src/modules/module-zeroconf-discover.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it 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   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; 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 <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include <avahi-client/client.h>
  32 #include <avahi-client/lookup.h>
  33 #include <avahi-common/alternative.h>
  34 #include <avahi-common/error.h>
  35 #include <avahi-common/domain.h>
  36 #include <avahi-common/malloc.h>
  37
  38 #include <pulse/xmalloc.h>
  39
  40 #include <pulsecore/core-util.h>
  41 #include <pulsecore/log.h>
  42 #include <pulsecore/hashmap.h>
  43 #include <pulsecore/modargs.h>
  44 #include <pulsecore/namereg.h>
  45 #include <pulsecore/avahi-wrap.h>
  46
  47 #include "module-zeroconf-discover-symdef.h"
  48
  49 PA_MODULE_AUTHOR("Lennart Poettering");
  50 PA_MODULE_DESCRIPTION("mDNS/DNS-SD Service Discovery");
  51 PA_MODULE_VERSION(PACKAGE_VERSION);
  52 PA_MODULE_LOAD_ONCE(TRUE);
  53
  54 #define SERVICE_TYPE_SINK "_pulse-sink._tcp"
  55 #define SERVICE_TYPE_SOURCE "_non-monitor._sub._pulse-source._tcp"
  56
  57 static const char* const valid_modargs[] = {
  58     NULL
  59 };
  60
  61 struct tunnel {
  62     AvahiIfIndex interface;
  63     AvahiProtocol protocol;
  64     char *name, *type, *domain;
  65     uint32_t module_index;
  66 };
  67
  68 struct userdata {
  69     pa_core *core;
  70     pa_module *module;
  71     AvahiPoll *avahi_poll;
  72     AvahiClient *client;
  73     AvahiServiceBrowser *source_browser, *sink_browser;
  74
  75     pa_hashmap *tunnels;
  76 };
  77
  78 static unsigned tunnel_hash(const void *p) {
  79     const struct tunnel *t = p;
  80
  81     return
  82         (unsigned) t->interface +
  83         (unsigned) t->protocol +
  84         pa_idxset_string_hash_func(t->name) +
  85         pa_idxset_string_hash_func(t->type) +
  86         pa_idxset_string_hash_func(t->domain);
  87 }
  88
  89 static int tunnel_compare(const void *a, const void *b) {
  90     const struct tunnel *ta = a, *tb = b;
  91     int r;
  92
  93     if (ta->interface != tb->interface)
  94         return 1;
  95     if (ta->protocol != tb->protocol)
  96         return 1;
  97     if ((r = strcmp(ta->name, tb->name)))
  98         return r;
  99     if ((r = strcmp(ta->type, tb->type)))
 100         return r;
 101     if ((r = strcmp(ta->domain, tb->domain)))
 102         return r;
 103
 104     return 0;
 105 }
 106
 107 static struct tunnel *tunnel_new(
 108         AvahiIfIndex interface, AvahiProtocol protocol,
 109         const char *name, const char *type, const char *domain) {
 110
 111     struct tunnel *t;
 112     t = pa_xnew(struct tunnel, 1);
 113     t->interface = interface;
 114     t->protocol = protocol;
 115     t->name = pa_xstrdup(name);
 116     t->type = pa_xstrdup(type);
 117     t->domain = pa_xstrdup(domain);
 118     t->module_index = PA_IDXSET_INVALID;
 119     return t;
 120 }
 121
 122 static void tunnel_free(struct tunnel *t) {
 123     pa_assert(t);
 124     pa_xfree(t->name);
 125     pa_xfree(t->type);
 126     pa_xfree(t->domain);
 127     pa_xfree(t);
 128 }
 129
 130 static void resolver_cb(
 131         AvahiServiceResolver *r,
 132         AvahiIfIndex interface, AvahiProtocol protocol,
 133         AvahiResolverEvent event,
 134         const char *name, const char *type, const char *domain,
 135         const char *host_name, const AvahiAddress *a, uint16_t port,
 136         AvahiStringList *txt,
 137         AvahiLookupResultFlags flags,
 138         void *userdata) {
 139
 140     struct userdata *u = userdata;
 141     struct tunnel *tnl;
 142
 143     pa_assert(u);
 144
 145     tnl = tunnel_new(interface, protocol, name, type, domain);
 146
 147     if (event != AVAHI_RESOLVER_FOUND)
 148         pa_log("Resolving of '%s' failed: %s", name, avahi_strerror(avahi_client_errno(u->client)));
 149     else {
 150         char *device = NULL, *dname, *module_name, *args;
 151         const char *t;
 152         char at[AVAHI_ADDRESS_STR_MAX], cmt[PA_CHANNEL_MAP_SNPRINT_MAX];
 153         pa_sample_spec ss;
 154         pa_channel_map cm;
 155         AvahiStringList *l;
 156         pa_bool_t channel_map_set = FALSE;
 157         pa_module *m;
 158
 159         ss = u->core->default_sample_spec;
 160         cm = u->core->default_channel_map;
 161
 162         for (l = txt; l; l = l->next) {
 163             char *key, *value;
 164             pa_assert_se(avahi_string_list_get_pair(l, &key, &value, NULL) == 0);
 165
 166             if (strcmp(key, "device") == 0) {
 167                 pa_xfree(device);
 168                 device = value;
 169                 value = NULL;
 170             } else if (strcmp(key, "rate") == 0)
 171                 ss.rate = (uint32_t) atoi(value);
 172             else if (strcmp(key, "channels") == 0)
 173                 ss.channels = (uint8_t) atoi(value);
 174             else if (strcmp(key, "format") == 0)
 175                 ss.format = pa_parse_sample_format(value);
 176             else if (strcmp(key, "channel_map") == 0) {
 177                 pa_channel_map_parse(&cm, value);
 178                 channel_map_set = TRUE;
 179             }
 180
 181             avahi_free(key);
 182             avahi_free(value);
 183         }
 184
 185         if (!channel_map_set && cm.channels != ss.channels)
 186             pa_channel_map_init_extend(&cm, ss.channels, PA_CHANNEL_MAP_DEFAULT);
 187
 188         if (!pa_sample_spec_valid(&ss)) {
 189             pa_log("Service '%s' contains an invalid sample specification.", name);
 190             avahi_free(device);
 191             goto finish;
 192         }
 193
 194         if (!pa_channel_map_valid(&cm) || cm.channels != ss.channels) {
 195             pa_log("Service '%s' contains an invalid channel map.", name);
 196             avahi_free(device);
 197             goto finish;
 198         }
 199
 200         if (device)
 201             dname = pa_sprintf_malloc("tunnel.%s.%s", host_name, device);
 202         else
 203             dname = pa_sprintf_malloc("tunnel.%s", host_name);
 204
 205         if (!pa_namereg_is_valid_name(dname)) {
 206             pa_log("Cannot construct valid device name from credentials of service '%s'.", dname);
 207             avahi_free(device);
 208             pa_xfree(dname);
 209             goto finish;
 210         }
 211
 212         t = strstr(type, "sink") ? "sink" : "source";
 213
 214         module_name = pa_sprintf_malloc("module-tunnel-%s", t);
 215         args = pa_sprintf_malloc("server=[%s]:%u "
 216                                  "%s=%s "
 217                                  "format=%s "
 218                                  "channels=%u "
 219                                  "rate=%u "
 220                                  "%s_name=%s "
 221                                  "channel_map=%s",
 222                                  avahi_address_snprint(at, sizeof(at), a), port,
 223                                  t, device,
 224                                  pa_sample_format_to_string(ss.format),
 225                                  ss.channels,
 226                                  ss.rate,
 227                                  t, dname,
 228                                  pa_channel_map_snprint(cmt, sizeof(cmt), &cm));
 229
 230         pa_log_debug("Loading %s with arguments '%s'", module_name, args);
 231
 232         if ((m = pa_module_load(u->core, module_name, args))) {
 233             tnl->module_index = m->index;
 234             pa_hashmap_put(u->tunnels, tnl, tnl);
 235             tnl = NULL;
 236         }
 237
 238         pa_xfree(module_name);
 239         pa_xfree(dname);
 240         pa_xfree(args);
 241         avahi_free(device);
 242     }
 243
 244 finish:
 245
 246     avahi_service_resolver_free(r);
 247
 248     if (tnl)
 249         tunnel_free(tnl);
 250 }
 251
 252 static void browser_cb(
 253         AvahiServiceBrowser *b,
 254         AvahiIfIndex interface, AvahiProtocol protocol,
 255         AvahiBrowserEvent event,
 256         const char *name, const char *type, const char *domain,
 257         AvahiLookupResultFlags flags,
 258         void *userdata) {
 259
 260     struct userdata *u = userdata;
 261     struct tunnel *t;
 262
 263     pa_assert(u);
 264
 265     if (flags & AVAHI_LOOKUP_RESULT_LOCAL)
 266         return;
 267
 268     t = tunnel_new(interface, protocol, name, type, domain);
 269
 270     if (event == AVAHI_BROWSER_NEW) {
 271
 272         if (!pa_hashmap_get(u->tunnels, t))
 273             if (!(avahi_service_resolver_new(u->client, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, resolver_cb, u)))
 274                 pa_log("avahi_service_resolver_new() failed: %s", avahi_strerror(avahi_client_errno(u->client)));
 275
 276         /* We ignore the returned resolver object here, since the we don't
 277          * need to attach any special data to it, and we can still destroy
 278          * it from the callback */
 279
 280     } else if (event == AVAHI_BROWSER_REMOVE) {
 281         struct tunnel *t2;
 282
 283         if ((t2 = pa_hashmap_get(u->tunnels, t))) {
 284             pa_module_unload_request_by_index(u->core, t2->module_index, TRUE);
 285             pa_hashmap_remove(u->tunnels, t2);
 286             tunnel_free(t2);
 287         }
 288     }
 289
 290     tunnel_free(t);
 291 }
 292
 293 static void client_callback(AvahiClient *c, AvahiClientState state, void *userdata) {
 294     struct userdata *u = userdata;
 295
 296     pa_assert(c);
 297     pa_assert(u);
 298
 299     u->client = c;
 300
 301     switch (state) {
 302         case AVAHI_CLIENT_S_REGISTERING:
 303         case AVAHI_CLIENT_S_RUNNING:
 304         case AVAHI_CLIENT_S_COLLISION:
 305
 306             if (!u->sink_browser) {
 307
 308                 if (!(u->sink_browser = avahi_service_browser_new(
 309                               c,
 310                               AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
 311                               SERVICE_TYPE_SINK,
 312                               NULL,
 313                               0,
 314                               browser_cb, u))) {
 315
 316                     pa_log("avahi_service_browser_new() failed: %s", avahi_strerror(avahi_client_errno(c)));
 317                     pa_module_unload_request(u->module, TRUE);
 318                 }
 319             }
 320
 321             if (!u->source_browser) {
 322
 323                 if (!(u->source_browser = avahi_service_browser_new(
 324                               c,
 325                               AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
 326                               SERVICE_TYPE_SOURCE,
 327                               NULL,
 328                               0,
 329                               browser_cb, u))) {
 330
 331                     pa_log("avahi_service_browser_new() failed: %s", avahi_strerror(avahi_client_errno(c)));
 332                     pa_module_unload_request(u->module, TRUE);
 333                 }
 334             }
 335
 336             break;
 337
 338         case AVAHI_CLIENT_FAILURE:
 339             if (avahi_client_errno(c) == AVAHI_ERR_DISCONNECTED) {
 340                 int error;
 341
 342                 pa_log_debug("Avahi daemon disconnected.");
 343
 344                 if (!(u->client = avahi_client_new(u->avahi_poll, AVAHI_CLIENT_NO_FAIL, client_callback, u, &error))) {
 345                     pa_log("avahi_client_new() failed: %s", avahi_strerror(error));
 346                     pa_module_unload_request(u->module, TRUE);
 347                 }
 348             }
 349
 350             /* Fall through */
 351
 352         case AVAHI_CLIENT_CONNECTING:
 353
 354             if (u->sink_browser) {
 355                 avahi_service_browser_free(u->sink_browser);
 356                 u->sink_browser = NULL;
 357             }
 358
 359             if (u->source_browser) {
 360                 avahi_service_browser_free(u->source_browser);
 361                 u->source_browser = NULL;
 362             }
 363
 364             break;
 365
 366         default: ;
 367     }
 368 }
 369
 370 int pa__init(pa_module*m) {
 371
 372     struct userdata *u;
 373     pa_modargs *ma = NULL;
 374     int error;
 375
 376     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 377         pa_log("Failed to parse module arguments.");
 378         goto fail;
 379     }
 380
 381     m->userdata = u = pa_xnew(struct userdata, 1);
 382     u->core = m->core;
 383     u->module = m;
 384     u->sink_browser = u->source_browser = NULL;
 385
 386     u->tunnels = pa_hashmap_new(tunnel_hash, tunnel_compare);
 387
 388     u->avahi_poll = pa_avahi_poll_new(m->core->mainloop);
 389
 390     if (!(u->client = avahi_client_new(u->avahi_poll, AVAHI_CLIENT_NO_FAIL, client_callback, u, &error))) {
 391         pa_log("pa_avahi_client_new() failed: %s", avahi_strerror(error));
 392         goto fail;
 393     }
 394
 395     pa_modargs_free(ma);
 396
 397     return 0;
 398
 399 fail:
 400     pa__done(m);
 401
 402     if (ma)
 403         pa_modargs_free(ma);
 404
 405     return -1;
 406 }
 407
 408 void pa__done(pa_module*m) {
 409     struct userdata*u;
 410     pa_assert(m);
 411
 412     if (!(u = m->userdata))
 413         return;
 414
 415     if (u->client)
 416         avahi_client_free(u->client);
 417
 418     if (u->avahi_poll)
 419         pa_avahi_poll_free(u->avahi_poll);
 420
 421     if (u->tunnels) {
 422         struct tunnel *t;
 423
 424         while ((t = pa_hashmap_steal_first(u->tunnels))) {
 425             pa_module_unload_request_by_index(u->core, t->module_index, TRUE);
 426             tunnel_free(t);
 427         }
 428
 429         pa_hashmap_free(u->tunnels, NULL, NULL);
 430     }
 431
 432     pa_xfree(u);
 433 }