1 /*****************************************************************************
2 * sap.c : SAP announce handler
3 *****************************************************************************
4 * Copyright (C) 2002-2008 the VideoLAN team
7 * Authors: Clément Stenac <zorglub@videolan.org>
8 * Rémi Denis-Courmont <rem # videolan.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
33 #include <vlc_common.h>
35 #include <stdlib.h> /* free() */
36 #include <stdio.h> /* sprintf() */
41 #include <vlc_network.h>
43 #include "stream_output.h"
46 /* SAP is always on that port */
47 #define IPPORT_SAP 9875
49 /* A SAP session descriptor, enqueued in the SAP handler queue */
50 typedef struct sap_session_t
52 struct sap_session_t *next;
53 const session_descriptor_t *p_sd;
58 /* A SAP announce address. For each of these, we run the
59 * control flow algorithm */
60 typedef struct sap_address_t
62 struct sap_address_t *next;
68 char group[NI_MAXNUMERICHOST];
69 struct sockaddr_storage orig;
74 unsigned session_count;
78 /* The SAP handler, running in a separate thread */
87 #define SAP_MAX_BUFFER 65534
88 #define MIN_INTERVAL 2
89 #define MAX_INTERVAL 300
91 /*****************************************************************************
93 *****************************************************************************/
94 static void *RunThread (void *);
97 * Create the SAP handler
99 * \param p_announce a VLC object
100 * \return the newly created SAP handler or NULL on error
102 sap_handler_t *SAP_Create (vlc_object_t *p_announce)
104 sap_handler_t *p_sap;
106 p_sap = vlc_custom_create (p_announce, sizeof (*p_sap),
107 VLC_OBJECT_GENERIC, "sap sender");
111 vlc_object_attach( p_sap, p_announce );
112 vlc_mutex_init (&p_sap->lock);
117 void SAP_Destroy (sap_handler_t *p_sap)
119 assert (p_sap->first == NULL);
120 vlc_mutex_destroy (&p_sap->lock);
121 vlc_object_release (p_sap);
124 static sap_address_t *AddressCreate (vlc_object_t *obj, const char *group)
126 int fd = net_ConnectUDP (obj, group, IPPORT_SAP, 255);
130 sap_address_t *addr = malloc (sizeof (*addr));
137 strlcpy (addr->group, group, sizeof (addr->group));
139 addr->origlen = sizeof (addr->orig);
140 getsockname (fd, (struct sockaddr *)&addr->orig, &addr->origlen);
142 addr->interval = var_CreateGetInteger (obj, "sap-interval");
143 vlc_mutex_init (&addr->lock);
144 vlc_cond_init (&addr->wait);
145 addr->session_count = 0;
148 if (vlc_clone (&addr->thread, RunThread, addr, VLC_THREAD_PRIORITY_LOW))
150 msg_Err (obj, "unable to spawn SAP announce thread");
158 static void AddressDestroy (sap_address_t *addr)
160 assert (addr->first == NULL);
162 vlc_cancel (addr->thread);
163 vlc_join (addr->thread, NULL);
164 vlc_cond_destroy (&addr->wait);
165 vlc_mutex_destroy (&addr->lock);
166 net_Close (addr->fd);
171 * main SAP handler thread
172 * \param p_this the SAP Handler object
175 static void *RunThread (void *self)
177 sap_address_t *addr = self;
179 vlc_mutex_lock (&addr->lock);
180 mutex_cleanup_push (&addr->lock);
184 sap_session_t *p_session;
187 while (addr->first == NULL)
188 vlc_cond_wait (&addr->wait, &addr->lock);
190 assert (addr->session_count > 0);
193 for (p_session = addr->first; p_session; p_session = p_session->next)
195 send (addr->fd, p_session->data, p_session->length, 0);
196 deadline += addr->interval * CLOCK_FREQ / addr->session_count;
198 if (vlc_cond_timedwait (&addr->wait, &addr->lock, deadline) == 0)
199 break; /* list may have changed! */
210 int SAP_Add (sap_handler_t *p_sap, session_descriptor_t *p_session)
213 char psz_addr[NI_MAXNUMERICHOST];
214 bool b_ipv6 = false, b_ssm = false;
215 sap_session_t *p_sap_session;
220 struct sockaddr_in in;
221 struct sockaddr_in6 in6;
225 addrlen = p_session->addrlen;
226 if ((addrlen == 0) || (addrlen > sizeof (addr)))
228 msg_Err( p_sap, "No/invalid address specified for SAP announce" );
232 /* Determine SAP multicast address automatically */
233 memcpy (&addr, &p_session->addr, addrlen);
235 switch (addr.a.sa_family)
237 #if defined (HAVE_INET_PTON) || defined (WIN32)
240 /* See RFC3513 for list of valid IPv6 scopes */
241 struct in6_addr *a6 = &addr.in6.sin6_addr;
243 memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
244 "\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
245 if( IN6_IS_ADDR_MULTICAST( a6 ) )
247 /* SSM <=> ff3x::/32 */
248 b_ssm = (U32_AT (a6->s6_addr) & 0xfff0ffff) == 0xff300000;
250 /* force flags to zero, preserve scope */
251 a6->s6_addr[1] &= 0xf;
254 /* Unicast IPv6 - assume global scope */
255 memcpy( a6->s6_addr, "\xff\x0e", 2 );
264 /* See RFC2365 for IPv4 scopes */
265 uint32_t ipv4 = addr.in.sin_addr.s_addr;
267 /* 224.0.0.0/24 => 224.0.0.255 */
268 if ((ipv4 & htonl (0xffffff00)) == htonl (0xe0000000))
269 ipv4 = htonl (0xe00000ff);
271 /* 239.255.0.0/16 => 239.255.255.255 */
272 if ((ipv4 & htonl (0xffff0000)) == htonl (0xefff0000))
273 ipv4 = htonl (0xefffffff);
275 /* 239.192.0.0/14 => 239.195.255.255 */
276 if ((ipv4 & htonl (0xfffc0000)) == htonl (0xefc00000))
277 ipv4 = htonl (0xefc3ffff);
279 if ((ipv4 & htonl (0xff000000)) == htonl (0xef000000))
282 /* other addresses => 224.2.127.254 */
284 /* SSM: 232.0.0.0/8 */
285 b_ssm = (ipv4 & htonl (255 << 24)) == htonl (232 << 24);
286 ipv4 = htonl (0xe0027ffe);
291 msg_Err( p_sap, "Out-of-scope multicast address "
292 "not supported by SAP" );
296 addr.in.sin_addr.s_addr = ipv4;
301 msg_Err( p_sap, "Address family %d not supported by SAP",
306 i = vlc_getnameinfo( &addr.a, addrlen,
307 psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
311 msg_Err( p_sap, "%s", gai_strerror( i ) );
315 /* Find/create SAP address thread */
316 msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
318 vlc_mutex_lock (&p_sap->lock);
319 sap_address_t *sap_addr;
320 for (sap_addr = p_sap->first; sap_addr; sap_addr = sap_addr->next)
321 if (!strcmp (psz_addr, sap_addr->group))
324 if (sap_addr == NULL)
326 sap_addr = AddressCreate (VLC_OBJECT(p_sap), psz_addr);
327 if (sap_addr == NULL)
329 vlc_mutex_unlock (&p_sap->lock);
332 sap_addr->next = p_sap->first;
333 p_sap->first = sap_addr;
336 * NEVER take the global SAP lock when holding a SAP thread lock! */
337 vlc_mutex_lock (&sap_addr->lock);
338 vlc_mutex_unlock (&p_sap->lock);
340 memcpy (&p_session->orig, &sap_addr->orig, sap_addr->origlen);
341 p_session->origlen = sap_addr->origlen;
343 size_t headsize = 20, length;
344 switch (p_session->orig.ss_family)
358 /* XXX: Check for dupes */
359 length = headsize + strlen (p_session->psz_sdp);
360 p_sap_session = malloc (sizeof (*p_sap_session) + length + 1);
361 if (p_sap_session == NULL)
363 vlc_mutex_unlock (&sap_addr->lock);
364 return VLC_EGENERIC; /* NOTE: we should destroy the thread if left unused */
366 p_sap_session->next = sap_addr->first;
367 sap_addr->first = p_sap_session;
368 p_sap_session->p_sd = p_session;
369 p_sap_session->length = length;
371 /* Build the SAP Headers */
372 uint8_t *psz_head = p_sap_session->data;
374 /* SAPv1, not encrypted, not compressed */
376 psz_head[1] = 0x00; /* No authentication length */
379 psz_head[2] = i_hash >> 8; /* Msg id hash */
380 psz_head[3] = i_hash; /* Msg id hash 2 */
383 switch (p_session->orig.ss_family)
388 struct in6_addr *a6 =
389 &((struct sockaddr_in6 *)&p_session->orig)->sin6_addr;
390 memcpy (psz_head + headsize, a6, 16);
391 psz_head[0] |= 0x10; /* IPv6 flag */
399 (((struct sockaddr_in *)&p_session->orig)->sin_addr.s_addr);
400 memcpy (psz_head + headsize, &ipv4, 4);
407 memcpy (psz_head + headsize, "application/sdp", 16);
410 /* Build the final message */
411 strcpy( (char *)psz_head + headsize, p_session->psz_sdp);
413 sap_addr->session_count++;
414 vlc_cond_signal (&sap_addr->wait);
415 vlc_mutex_unlock (&sap_addr->lock);
420 * Remove a SAP Announce
422 void SAP_Del (sap_handler_t *p_sap, const session_descriptor_t *p_session)
424 vlc_mutex_lock (&p_sap->lock);
426 /* TODO: give a handle back in SAP_Add, and use that... */
427 sap_address_t *addr, **paddr;
428 sap_session_t *session, **psession;
430 paddr = &p_sap->first;
431 for (addr = p_sap->first; addr; addr = addr->next)
433 psession = &addr->first;
434 vlc_mutex_lock (&addr->lock);
435 for (session = addr->first; session; session = session->next)
437 if (session->p_sd == p_session)
439 psession = &session->next;
441 vlc_mutex_unlock (&addr->lock);
447 *psession = session->next;
449 if (addr->first == NULL)
450 /* Last session for this address -> unlink the address */
452 vlc_mutex_unlock (&p_sap->lock);
454 if (addr->first == NULL)
456 /* Last session for this address -> unlink the address */
457 vlc_mutex_unlock (&addr->lock);
458 AddressDestroy (addr);
462 addr->session_count--;
463 vlc_cond_signal (&addr->wait);
464 vlc_mutex_unlock (&addr->lock);