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 #include <pulse/util.h>
  40
  41 #include <pulsecore/sink.h>
  42 #include <pulsecore/source.h>
  43 #include <pulsecore/native-common.h>
  44 #include <pulsecore/core-util.h>
  45 #include <pulsecore/log.h>
  46 #include <pulsecore/core-subscribe.h>
  47 #include <pulsecore/hashmap.h>
  48 #include <pulsecore/modargs.h>
  49 #include <pulsecore/namereg.h>
  50 #include <pulsecore/avahi-wrap.h>
  51
  52 #include "module-zeroconf-discover-symdef.h"
  53
  54 PA_MODULE_AUTHOR("Lennart Poettering");
  55 PA_MODULE_DESCRIPTION("mDNS/DNS-SD Service Discovery");
  56 PA_MODULE_VERSION(PACKAGE_VERSION);
  57 PA_MODULE_LOAD_ONCE(TRUE);
  58
  59 #define SERVICE_TYPE_SINK "_pulse-sink._tcp"
  60 #define SERVICE_TYPE_SOURCE "_non-monitor._sub._pulse-source._tcp"
  61
  62 static const char* const valid_modargs[] = {
  63     NULL
  64 };
  65
  66 struct tunnel {
  67     AvahiIfIndex interface;
  68     AvahiProtocol protocol;
  69     char *name, *type, *domain;
  70     uint32_t module_index;
  71 };
  72
  73 struct userdata {
  74     pa_core *core;
  75     pa_module *module;
  76     AvahiPoll *avahi_poll;
  77     AvahiClient *client;
  78     AvahiServiceBrowser *source_browser, *sink_browser;
  79
  80     pa_hashmap *tunnels;
  81 };
  82
  83 static unsigned tunnel_hash(const void *p) {
  84     const struct tunnel *t = p;
  85
  86     return
  87         (unsigned) t->interface +
  88         (unsigned) t->protocol +
  89         pa_idxset_string_hash_func(t->name) +
  90         pa_idxset_string_hash_func(t->type) +
  91         pa_idxset_string_hash_func(t->domain);
  92 }
  93
  94 static int tunnel_compare(const void *a, const void *b) {
  95     const struct tunnel *ta = a, *tb = b;
  96     int r;
  97
  98     if (ta->interface != tb->interface)
  99         return 1;
 100     if (ta->protocol != tb->protocol)
 101         return 1;
 102     if ((r = strcmp(ta->name, tb->name)))
 103         return r;
 104     if ((r = strcmp(ta->type, tb->type)))
 105         return r;
 106     if ((r = strcmp(ta->domain, tb->domain)))
 107         return r;
 108
 109     return 0;
 110 }
 111
 112 static struct tunnel *tunnel_new(
 113         AvahiIfIndex interface, AvahiProtocol protocol,
 114         const char *name, const char *type, const char *domain) {
 115
 116     struct tunnel *t;
 117     t = pa_xnew(struct tunnel, 1);
 118     t->interface = interface;
 119     t->protocol = protocol;
 120     t->name = pa_xstrdup(name);
 121     t->type = pa_xstrdup(type);
 122     t->domain = pa_xstrdup(domain);
 123     t->module_index = PA_IDXSET_INVALID;
 124     return t;
 125 }
 126
 127 static void tunnel_free(struct tunnel *t) {
 128     pa_assert(t);
 129     pa_xfree(t->name);
 130     pa_xfree(t->type);
 131     pa_xfree(t->domain);
 132     pa_xfree(t);
 133 }
 134
 135 static void resolver_cb(
 136         AvahiServiceResolver *r,
 137         AvahiIfIndex interface, AvahiProtocol protocol,
 138         AvahiResolverEvent event,
 139         const char *name, const char *type, const char *domain,
 140         const char *host_name, const AvahiAddress *a, uint16_t port,
 141         AvahiStringList *txt,
 142         AvahiLookupResultFlags flags,
 143         void *userdata) {
 144
 145     struct userdata *u = userdata;
 146     struct tunnel *tnl;
 147
 148     pa_assert(u);
 149
 150     tnl = tunnel_new(interface, protocol, name, type, domain);
 151
 152     if (event != AVAHI_RESOLVER_FOUND)
 153         pa_log("Resolving of '%s' failed: %s", name, avahi_strerror(avahi_client_errno(u->client)));
 154     else {
 155         char *device = NULL, *dname, *module_name, *args;
 156         const char *t;
 157         char at[AVAHI_ADDRESS_STR_MAX], cmt[PA_CHANNEL_MAP_SNPRINT_MAX];
 158         pa_sample_spec ss;
 159         pa_channel_map cm;
 160         AvahiStringList *l;
 161         pa_bool_t channel_map_set = FALSE;
 162         pa_module *m;
 163
 164         ss = u->core->default_sample_spec;
 165         cm = u->core->default_channel_map;
 166
 167         for (l = txt; l; l = l->next) {
 168             char *key, *value;
 169             pa_assert_se(avahi_string_list_get_pair(l, &key, &value, NULL) == 0);
 170
 171             if (strcmp(key, "device") == 0) {
 172                 pa_xfree(device);
 173                 device = value;
 174                 value = NULL;
 175             } else if (strcmp(key, "rate") == 0)
 176                 ss.rate = (uint32_t) atoi(value);
 177             else if (strcmp(key, "channels") == 0)
 178                 ss.channels = (uint8_t) atoi(value);
 179             else if (strcmp(key, "format") == 0)
 180                 ss.format = pa_parse_sample_format(value);
 181             else if (strcmp(key, "channel_map") == 0) {
 182                 pa_channel_map_parse(&cm, value);
 183                 channel_map_set = TRUE;
 184             }
 185
 186             avahi_free(key);
 187             avahi_free(value);
 188         }
 189
 190         if (!channel_map_set && cm.channels != ss.channels)
 191             pa_channel_map_init_extend(&cm, ss.channels, PA_CHANNEL_MAP_DEFAULT);
 192
 193         if (!pa_sample_spec_valid(&ss)) {
 194             pa_log("Service '%s' contains an invalid sample specification.", name);
 195             avahi_free(device);
 196             goto finish;
 197         }
 198
 199         if (!pa_channel_map_valid(&cm) || cm.channels != ss.channels) {
 200             pa_log("Service '%s' contains an invalid channel map.", name);
 201             avahi_free(device);
 202             goto finish;
 203         }
 204
 205         if (device)
 206             dname = pa_sprintf_malloc("tunnel.%s.%s", host_name, device);
 207         else
 208             dname = pa_sprintf_malloc("tunnel.%s", host_name);
 209
 210         if (!pa_namereg_is_valid_name(dname)) {
 211             pa_log("Cannot construct valid device name from credentials of service '%s'.", dname);
 212             avahi_free(device);
 213             pa_xfree(dname);
 214             goto finish;
 215         }
 216
 217         t = strstr(type, "sink") ? "sink" : "source";
 218
 219         module_name = pa_sprintf_malloc("module-tunnel-%s", t);
 220         args = pa_sprintf_malloc("server=[%s]:%u "
 221                                  "%s=%s "
 222                                  "format=%s "
 223                                  "channels=%u "
 224                                  "rate=%u "
 225                                  "%s_name=%s "
 226                                  "channel_map=%s",
 227                                  avahi_address_snprint(at, sizeof(at), a), port,
 228                                  t, device,
 229                                  pa_sample_format_to_string(ss.format),
 230                                  ss.channels,
 231                                  ss.rate,
 232                                  t, dname,
 233                                  pa_channel_map_snprint(cmt, sizeof(cmt), &cm));
 234
 235         pa_log_debug("Loading %s with arguments '%s'", module_name, args);
 236
 237         if ((m = pa_module_load(u->core, module_name, args))) {
 238             tnl->module_index = m->index;
 239             pa_hashmap_put(u->tunnels, tnl, tnl);
 240             tnl = NULL;
 241         }
 242
 243         pa_xfree(module_name);
 244         pa_xfree(dname);
 245         pa_xfree(args);
 246         avahi_free(device);
 247     }
 248
 249 finish:
 250
 251     avahi_service_resolver_free(r);
 252
 253     if (tnl)
 254         tunnel_free(tnl);
 255 }
 256
 257 static void browser_cb(
 258         AvahiServiceBrowser *b,
 259         AvahiIfIndex interface, AvahiProtocol protocol,
 260         AvahiBrowserEvent event,
 261         const char *name, const char *type, const char *domain,
 262         AvahiLookupResultFlags flags,
 263         void *userdata) {
 264
 265     struct userdata *u = userdata;
 266     struct tunnel *t;
 267
 268     pa_assert(u);
 269
 270     if (flags & AVAHI_LOOKUP_RESULT_LOCAL)
 271         return;
 272
 273     t = tunnel_new(interface, protocol, name, type, domain);
 274
 275     if (event == AVAHI_BROWSER_NEW) {
 276
 277         if (!pa_hashmap_get(u->tunnels, t))
 278             if (!(avahi_service_resolver_new(u->client, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, resolver_cb, u)))
 279                 pa_log("avahi_service_resolver_new() failed: %s", avahi_strerror(avahi_client_errno(u->client)));
 280
 281         /* We ignore the returned resolver object here, since the we don't
 282          * need to attach any special data to it, and we can still destroy
 283          * it from the callback */
 284
 285     } else if (event == AVAHI_BROWSER_REMOVE) {
 286         struct tunnel *t2;
 287
 288         if ((t2 = pa_hashmap_get(u->tunnels, t))) {
 289             pa_module_unload_request_by_index(u->core, t2->module_index, TRUE);
 290             pa_hashmap_remove(u->tunnels, t2);
 291             tunnel_free(t2);
 292         }
 293     }
 294
 295     tunnel_free(t);
 296 }
 297
 298 static void client_callback(AvahiClient *c, AvahiClientState state, void *userdata) {
 299     struct userdata *u = userdata;
 300
 301     pa_assert(c);
 302     pa_assert(u);
 303
 304     u->client = c;
 305
 306     switch (state) {
 307         case AVAHI_CLIENT_S_REGISTERING:
 308         case AVAHI_CLIENT_S_RUNNING:
 309         case AVAHI_CLIENT_S_COLLISION:
 310
 311             if (!u->sink_browser) {
 312
 313                 if (!(u->sink_browser = avahi_service_browser_new(
 314                               c,
 315                               AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
 316                               SERVICE_TYPE_SINK,
 317                               NULL,
 318                               0,
 319                               browser_cb, u))) {
 320
 321                     pa_log("avahi_service_browser_new() failed: %s", avahi_strerror(avahi_client_errno(c)));
 322                     pa_module_unload_request(u->module, TRUE);
 323                 }
 324             }
 325
 326             if (!u->source_browser) {
 327
 328                 if (!(u->source_browser = avahi_service_browser_new(
 329                               c,
 330                               AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
 331                               SERVICE_TYPE_SOURCE,
 332                               NULL,
 333                               0,
 334                               browser_cb, u))) {
 335
 336                     pa_log("avahi_service_browser_new() failed: %s", avahi_strerror(avahi_client_errno(c)));
 337                     pa_module_unload_request(u->module, TRUE);
 338                 }
 339             }
 340
 341             break;
 342
 343         case AVAHI_CLIENT_FAILURE:
 344             if (avahi_client_errno(c) == AVAHI_ERR_DISCONNECTED) {
 345                 int error;
 346
 347                 pa_log_debug("Avahi daemon disconnected.");
 348
 349                 if (!(u->client = avahi_client_new(u->avahi_poll, AVAHI_CLIENT_NO_FAIL, client_callback, u, &error))) {
 350                     pa_log("avahi_client_new() failed: %s", avahi_strerror(error));
 351                     pa_module_unload_request(u->module, TRUE);
 352                 }
 353             }
 354
 355             /* Fall through */
 356
 357         case AVAHI_CLIENT_CONNECTING:
 358
 359             if (u->sink_browser) {
 360                 avahi_service_browser_free(u->sink_browser);
 361                 u->sink_browser = NULL;
 362             }
 363
 364             if (u->source_browser) {
 365                 avahi_service_browser_free(u->source_browser);
 366                 u->source_browser = NULL;
 367             }
 368
 369             break;
 370
 371         default: ;
 372     }
 373 }
 374
 375 int pa__init(pa_module*m) {
 376
 377     struct userdata *u;
 378     pa_modargs *ma = NULL;
 379     int error;
 380
 381     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 382         pa_log("Failed to parse module arguments.");
 383         goto fail;
 384     }
 385
 386     m->userdata = u = pa_xnew(struct userdata, 1);
 387     u->core = m->core;
 388     u->module = m;
 389     u->sink_browser = u->source_browser = NULL;
 390
 391     u->tunnels = pa_hashmap_new(tunnel_hash, tunnel_compare);
 392
 393     u->avahi_poll = pa_avahi_poll_new(m->core->mainloop);
 394
 395     if (!(u->client = avahi_client_new(u->avahi_poll, AVAHI_CLIENT_NO_FAIL, client_callback, u, &error))) {
 396         pa_log("pa_avahi_client_new() failed: %s", avahi_strerror(error));
 397         goto fail;
 398     }
 399
 400     pa_modargs_free(ma);
 401
 402     return 0;
 403
 404 fail:
 405     pa__done(m);
 406
 407     if (ma)
 408         pa_modargs_free(ma);
 409
 410     return -1;
 411 }
 412
 413 void pa__done(pa_module*m) {
 414     struct userdata*u;
 415     pa_assert(m);
 416
 417     if (!(u = m->userdata))
 418         return;
 419
 420     if (u->client)
 421         avahi_client_free(u->client);
 422
 423     if (u->avahi_poll)
 424         pa_avahi_poll_free(u->avahi_poll);
 425
 426     if (u->tunnels) {
 427         struct tunnel *t;
 428
 429         while ((t = pa_hashmap_steal_first(u->tunnels))) {
 430             pa_module_unload_request_by_index(u->core, t->module_index, TRUE);
 431             tunnel_free(t);
 432         }
 433
 434         pa_hashmap_free(u->tunnels, NULL, NULL);
 435     }
 436
 437     pa_xfree(u);
 438 }