modules/services_discovery/avahi.c

   1 /*****************************************************************************
   2  * avahi.c: Bonjour services discovery module
   3  *****************************************************************************
   4  * Copyright (C) 2005-2009, 2016 VideoLAN and VLC authors
   5  *
   6  * Authors: Jon Lech Johansen <jon@nanocrew.net>
   7  *          Jean-Baptiste Kempf <jb@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Includes
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #define VLC_MODULE_LICENSE VLC_LICENSE_GPL_2_PLUS
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_services_discovery.h>
  36
  37 #include <avahi-client/client.h>
  38 #include <avahi-client/publish.h>
  39 #include <avahi-client/lookup.h>
  40 #include <avahi-common/thread-watch.h>
  41 #include <avahi-common/malloc.h>
  42 #include <avahi-common/error.h>
  43
  44 /*****************************************************************************
  45  * Module descriptor
  46  *****************************************************************************/
  47
  48 /* Callbacks */
  49 static int  Open ( vlc_object_t * );
  50 static void Close( vlc_object_t * );
  51
  52 VLC_SD_PROBE_HELPER("avahi", N_("Zeroconf network services"), SD_CAT_LAN)
  53
  54 vlc_module_begin ()
  55     set_shortname( "Avahi" )
  56     set_description( N_("Zeroconf services") )
  57     set_category( CAT_PLAYLIST )
  58     set_subcategory( SUBCAT_PLAYLIST_SD )
  59     set_capability( "services_discovery", 0 )
  60     set_callbacks( Open, Close )
  61     add_shortcut( "mdns", "avahi" )
  62
  63     VLC_SD_PROBE_SUBMODULE
  64 vlc_module_end ()
  65
  66 /*****************************************************************************
  67  * Local structures
  68  *****************************************************************************/
  69
  70 typedef struct
  71 {
  72     AvahiThreadedPoll   *poll;
  73     AvahiClient         *client;
  74     vlc_dictionary_t    services_name_to_input_item;
  75 } services_discovery_sys_t;
  76
  77 static const struct
  78 {
  79     const char *psz_protocol;
  80     const char *psz_service_name;
  81 } protocols[] = {
  82     { "ftp", "_ftp._tcp" },
  83     { "smb", "_smb._tcp" },
  84     { "nfs", "_nfs._tcp" },
  85     { "sftp", "_sftp-ssh._tcp" },
  86     { "rtsp", "_rtsp._tcp" },
  87 };
  88 #define NB_PROTOCOLS (sizeof(protocols) / sizeof(*protocols))
  89
  90 /*****************************************************************************
  91  * client_callback
  92  *****************************************************************************/
  93 static void client_callback( AvahiClient *c, AvahiClientState state,
  94                              void * userdata )
  95 {
  96     services_discovery_t *p_sd = ( services_discovery_t* )userdata;
  97     services_discovery_sys_t *p_sys = p_sd->p_sys;
  98
  99     if( state == AVAHI_CLIENT_FAILURE &&
 100         (avahi_client_errno(c) == AVAHI_ERR_DISCONNECTED) )
 101     {
 102         msg_Err( p_sd, "avahi client disconnected" );
 103         avahi_threaded_poll_quit( p_sys->poll );
 104     }
 105 }
 106
 107 /*****************************************************************************
 108  * resolve_callback
 109  *****************************************************************************/
 110 static void resolve_callback(
 111     AvahiServiceResolver *r,
 112     AvahiIfIndex interface,
 113     AvahiProtocol protocol,
 114     AvahiResolverEvent event,
 115     const char *name,
 116     const char *type,
 117     const char *domain,
 118     const char *host_name,
 119     const AvahiAddress *address,
 120     uint16_t port,
 121     AvahiStringList *txt,
 122     AvahiLookupResultFlags flags,
 123     void* userdata )
 124 {
 125     services_discovery_t *p_sd = ( services_discovery_t* )userdata;
 126     services_discovery_sys_t *p_sys = p_sd->p_sys;
 127
 128     VLC_UNUSED(interface); VLC_UNUSED(host_name);
 129     VLC_UNUSED(flags);
 130
 131     if( event == AVAHI_RESOLVER_FAILURE )
 132     {
 133         msg_Err( p_sd,
 134                  "failed to resolve service '%s' of type '%s' in domain '%s'",
 135                  name, type, domain );
 136     }
 137     else if( event == AVAHI_RESOLVER_FOUND )
 138     {
 139         char a[128];
 140         char *psz_uri = NULL;
 141         char *psz_addr = NULL;
 142         AvahiStringList *asl = NULL;
 143         input_item_t *p_input = NULL;
 144
 145         msg_Info( p_sd, "service '%s' of type '%s' in domain '%s' port %i",
 146                   name, type, domain, port );
 147
 148         avahi_address_snprint(a, (sizeof(a)/sizeof(a[0]))-1, address);
 149         if( protocol == AVAHI_PROTO_INET6 )
 150             if( asprintf( &psz_addr, "[%s]", a ) == -1 )
 151                 return;
 152
 153         const char *psz_protocol = NULL;
 154         for( unsigned int i = 0; i < NB_PROTOCOLS; i++ )
 155         {
 156             if( !strcmp(type, protocols[i].psz_service_name) )
 157                 psz_protocol = protocols[i].psz_protocol;
 158         }
 159         if( psz_protocol == NULL )
 160             return;
 161
 162         if( txt != NULL )
 163             asl = avahi_string_list_find( txt, "path" );
 164         if( asl != NULL )
 165         {
 166             size_t size;
 167             char *key = NULL;
 168             char *value = NULL;
 169             if( avahi_string_list_get_pair( asl, &key, &value, &size ) == 0 &&
 170                 value != NULL )
 171             {
 172                 if( asprintf( &psz_uri, "%s://%s:%d%s",
 173                           psz_protocol,
 174                           psz_addr != NULL ? psz_addr : a,
 175                           port, value ) == -1 )
 176                 {
 177                     free( psz_addr );
 178                     return;
 179                 }
 180             }
 181             if( key != NULL )
 182                 avahi_free( (void *)key );
 183             if( value != NULL )
 184                 avahi_free( (void *)value );
 185         }
 186         else
 187         {
 188             if( asprintf( &psz_uri, "%s://%s:%d",
 189                       psz_protocol,
 190                       psz_addr != NULL ? psz_addr : a, port ) == -1 )
 191             {
 192                 free( psz_addr );
 193                 return;
 194             }
 195         }
 196
 197         free( psz_addr );
 198
 199         if( psz_uri != NULL )
 200         {
 201             p_input = input_item_New( psz_uri, name );
 202             free( psz_uri );
 203         }
 204         if( p_input != NULL )
 205         {
 206             vlc_dictionary_insert( &p_sys->services_name_to_input_item,
 207                 name, p_input );
 208             services_discovery_AddItem( p_sd, p_input );
 209             input_item_Release( p_input );
 210        }
 211     }
 212
 213     avahi_service_resolver_free( r );
 214 }
 215
 216 /*****************************************************************************
 217  * browser_callback
 218  *****************************************************************************/
 219 static void browse_callback(
 220     AvahiServiceBrowser *b,
 221     AvahiIfIndex interface,
 222     AvahiProtocol protocol,
 223     AvahiBrowserEvent event,
 224     const char *name,
 225     const char *type,
 226     const char *domain,
 227     AvahiLookupResultFlags flags,
 228     void* userdata )
 229 {
 230     VLC_UNUSED(b);
 231     VLC_UNUSED(flags);
 232     services_discovery_t *p_sd = ( services_discovery_t* )userdata;
 233     services_discovery_sys_t *p_sys = p_sd->p_sys;
 234     if( event == AVAHI_BROWSER_NEW )
 235     {
 236         if( avahi_service_resolver_new( p_sys->client, interface, protocol,
 237                                         name, type, domain, AVAHI_PROTO_UNSPEC,
 238                                         0,
 239                                         resolve_callback, userdata ) == NULL )
 240         {
 241             msg_Err( p_sd, "failed to resolve service '%s': %s", name,
 242                      avahi_strerror( avahi_client_errno( p_sys->client ) ) );
 243         }
 244     }
 245     else if( event == AVAHI_BROWSER_REMOVE && name )
 246     {
 247         /** \todo Store the input id and search it, rather than searching the items */
 248         input_item_t *p_item;
 249         p_item = vlc_dictionary_value_for_key(
 250                         &p_sys->services_name_to_input_item,
 251                         name );
 252         if( !p_item )
 253             msg_Err( p_sd, "failed to find service '%s' in playlist", name );
 254         else
 255         {
 256             services_discovery_RemoveItem( p_sd, p_item );
 257             vlc_dictionary_remove_value_for_key(
 258                         &p_sys->services_name_to_input_item,
 259                         name, NULL, NULL );
 260         }
 261     }
 262 }
 263
 264 /*****************************************************************************
 265  * Open: initialize and create stuff
 266  *****************************************************************************/
 267 static int Open( vlc_object_t *p_this )
 268 {
 269     services_discovery_t *p_sd = ( services_discovery_t* )p_this;
 270     services_discovery_sys_t *p_sys;
 271     int err;
 272
 273     p_sd->p_sys = p_sys = calloc( 1, sizeof( services_discovery_sys_t ) );
 274     if( !p_sys )
 275         return VLC_ENOMEM;
 276
 277     p_sd->description = _("Zeroconf network services");
 278
 279     vlc_dictionary_init( &p_sys->services_name_to_input_item, 1 );
 280
 281     p_sys->poll = avahi_threaded_poll_new();
 282     if( p_sys->poll == NULL )
 283     {
 284         msg_Err( p_sd, "failed to create Avahi threaded poll" );
 285         goto error;
 286     }
 287
 288     p_sys->client = avahi_client_new( avahi_threaded_poll_get(p_sys->poll),
 289                                       0, client_callback, p_sd, &err );
 290     if( p_sys->client == NULL )
 291     {
 292         msg_Err( p_sd, "failed to create avahi client: %s",
 293                  avahi_strerror( err ) );
 294         goto error;
 295     }
 296
 297     for( unsigned i = 0; i < NB_PROTOCOLS; i++ )
 298     {
 299         AvahiServiceBrowser *sb;
 300         sb = avahi_service_browser_new( p_sys->client, AVAHI_IF_UNSPEC,
 301                 AVAHI_PROTO_UNSPEC,
 302                 protocols[i].psz_service_name, NULL,
 303                 0, browse_callback, p_sd );
 304         if( sb == NULL )
 305         {
 306             msg_Err( p_sd, "failed to create avahi service browser %s", avahi_strerror( avahi_client_errno(p_sys->client) ) );
 307             goto error;
 308         }
 309     }
 310
 311     avahi_threaded_poll_start( p_sys->poll );
 312
 313     return VLC_SUCCESS;
 314
 315 error:
 316     if( p_sys->client != NULL )
 317         avahi_client_free( p_sys->client );
 318     if( p_sys->poll != NULL )
 319         avahi_threaded_poll_free( p_sys->poll );
 320
 321     vlc_dictionary_clear( &p_sys->services_name_to_input_item, NULL, NULL );
 322     free( p_sys );
 323
 324     return VLC_EGENERIC;
 325 }
 326
 327 /*****************************************************************************
 328  * Close: cleanup
 329  *****************************************************************************/
 330 static void Close( vlc_object_t *p_this )
 331 {
 332     services_discovery_t *p_sd = ( services_discovery_t* )p_this;
 333     services_discovery_sys_t *p_sys = p_sd->p_sys;
 334     avahi_threaded_poll_stop( p_sys->poll );
 335
 336     avahi_client_free( p_sys->client );
 337     avahi_threaded_poll_free( p_sys->poll );
 338
 339     vlc_dictionary_clear( &p_sys->services_name_to_input_item, NULL, NULL );
 340     free( p_sys );
 341 }