videolan
/
vlc
mirror of https://code.videolan.org/videolan/vlc
1
Fork 0
Code Releases Activity
vlc/src/stream_output/sap.c

422 lines
12 KiB
C
Raw Blame History

/*****************************************************************************
* sap.c : SAP announce handler
*****************************************************************************
* Copyright (C) 2002-2008 VLC authors and VideoLAN
*
* Authors: Clément Stenac <zorglub@videolan.org>
* Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <vlc_common.h>
#include <stdnoreturn.h>
#include <stdlib.h> /* free() */
#include <stdio.h> /* sprintf() */
#include <string.h>
#include <assert.h>
#include <vlc_sout.h>
#include <vlc_network.h>
#include <vlc_memstream.h>
#include "stream_output.h"
#include "libvlc.h"
/* SAP is always on that port */
#define IPPORT_SAP 9875
/* A SAP session descriptor, enqueued in the SAP handler queue */
struct session_descriptor_t
{
struct session_descriptor_t *next;
size_t length;
char *data;
};
/* A SAP announce address. For each of these, we run the
* control flow algorithm */
typedef struct sap_address_t
{
struct sap_address_t *next;
vlc_thread_t thread;
vlc_mutex_t lock;
vlc_cond_t wait;
char group[NI_MAXNUMERICHOST];
struct sockaddr_storage orig;
socklen_t origlen;
int fd;
unsigned interval;
unsigned session_count;
session_descriptor_t *first;
} sap_address_t;
static sap_address_t *sap_addrs = NULL;
static vlc_mutex_t sap_mutex = VLC_STATIC_MUTEX;
#define SAP_MAX_BUFFER 65534
#define MIN_INTERVAL 2
#define MAX_INTERVAL 300
noreturn static void *RunThread (void *);
static sap_address_t *AddressCreate (vlc_object_t *obj, const char *group)
{
int fd = net_ConnectUDP (obj, group, IPPORT_SAP, 255);
if (fd == -1)
return NULL;
sap_address_t *addr = malloc (sizeof (*addr));
if (addr == NULL)
{
net_Close (fd);
return NULL;
}
strlcpy (addr->group, group, sizeof (addr->group));
addr->fd = fd;
addr->origlen = sizeof (addr->orig);
getsockname (fd, (struct sockaddr *)&addr->orig, &addr->origlen);
addr->interval = var_CreateGetInteger (obj, "sap-interval");
vlc_mutex_init (&addr->lock);
vlc_cond_init (&addr->wait);
addr->session_count = 0;
addr->first = NULL;
if (vlc_clone (&addr->thread, RunThread, addr, VLC_THREAD_PRIORITY_LOW))
{
msg_Err (obj, "unable to spawn SAP announce thread");
net_Close (fd);
free (addr);
return NULL;
}
return addr;
}
static void AddressDestroy (sap_address_t *addr)
{
assert (addr->first == NULL);
vlc_cancel (addr->thread);
vlc_join (addr->thread, NULL);
vlc_cond_destroy (&addr->wait);
vlc_mutex_destroy (&addr->lock);
net_Close (addr->fd);
free (addr);
}
/**
* main SAP handler thread
* \param p_this the SAP Handler object
* \return nothing
*/
noreturn static void *RunThread (void *self)
{
sap_address_t *addr = self;
vlc_mutex_lock (&addr->lock);
mutex_cleanup_push (&addr->lock);
for (;;)
{
session_descriptor_t *p_session;
vlc_tick_t deadline;
while (addr->first == NULL)
vlc_cond_wait (&addr->wait, &addr->lock);
assert (addr->session_count > 0);
deadline = vlc_tick_now ();
for (p_session = addr->first; p_session; p_session = p_session->next)
{
send (addr->fd, p_session->data, p_session->length, 0);
deadline += vlc_tick_from_samples(addr->interval, addr->session_count);
if (vlc_cond_timedwait (&addr->wait, &addr->lock, deadline) == 0)
break; /* list may have changed! */
}
}
vlc_cleanup_pop ();
vlc_assert_unreachable ();
}
#undef sout_AnnounceRegisterSDP
/**
* Registers a new session with the announce handler, using a pregenerated SDP
*
* \param obj a VLC object
* \param sdp the SDP to register
* \param dst session address (needed for SAP address auto detection)
* \return the new session descriptor structure
*/
session_descriptor_t *
sout_AnnounceRegisterSDP (vlc_object_t *obj, const char *sdp,
const char *dst)
{
int i;
char psz_addr[NI_MAXNUMERICHOST];
union
{
struct sockaddr a;
struct sockaddr_in in;
struct sockaddr_in6 in6;
} addr;
socklen_t addrlen = 0;
struct addrinfo *res;
msg_Dbg (obj, "adding SAP session");
if (vlc_getaddrinfo (dst, 0, NULL, &res) == 0)
{
if ((size_t)res->ai_addrlen <= sizeof (addr))
memcpy (&addr, res->ai_addr, res->ai_addrlen);
addrlen = res->ai_addrlen;
freeaddrinfo (res);
}
if (addrlen == 0 || (size_t)addrlen > sizeof (addr))
{
msg_Err (obj, "No/invalid address specified for SAP announce" );
return NULL;
}
/* Determine SAP multicast address automatically */
switch (addr.a.sa_family)
{
#if defined (HAVE_INET_PTON) || defined (_WIN32)
case AF_INET6:
{
/* See RFC3513 for list of valid IPv6 scopes */
struct in6_addr *a6 = &addr.in6.sin6_addr;
memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
if( IN6_IS_ADDR_MULTICAST( a6 ) )
/* force flags to zero, preserve scope */
a6->s6_addr[1] &= 0xf;
else
/* Unicast IPv6 - assume global scope */
memcpy( a6->s6_addr, "\xff\x0e", 2 );
break;
}
#endif
case AF_INET:
{
/* See RFC2365 for IPv4 scopes */
uint32_t ipv4 = addr.in.sin_addr.s_addr;
/* 224.0.0.0/24 => 224.0.0.255 */
if ((ipv4 & htonl (0xffffff00)) == htonl (0xe0000000))
ipv4 = htonl (0xe00000ff);
else
/* 239.255.0.0/16 => 239.255.255.255 */
if ((ipv4 & htonl (0xffff0000)) == htonl (0xefff0000))
ipv4 = htonl (0xefffffff);
else
/* 239.192.0.0/14 => 239.195.255.255 */
if ((ipv4 & htonl (0xfffc0000)) == htonl (0xefc00000))
ipv4 = htonl (0xefc3ffff);
else
if ((ipv4 & htonl (0xff000000)) == htonl (0xef000000))
ipv4 = 0;
else
/* other addresses => 224.2.127.254 */
ipv4 = htonl (0xe0027ffe);
if( ipv4 == 0 )
{
msg_Err (obj, "Out-of-scope multicast address "
"not supported by SAP");
return NULL;
}
addr.in.sin_addr.s_addr = ipv4;
break;
}
default:
msg_Err (obj, "Address family %u not supported by SAP",
(unsigned)addr.a.sa_family);
return NULL;
}
i = vlc_getnameinfo( &addr.a, addrlen,
psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
if( i )
{
msg_Err (obj, "%s", gai_strerror (i));
return NULL;
}
/* Find/create SAP address thread */
sap_address_t *sap_addr;
msg_Dbg (obj, "using SAP address: %s", psz_addr);
vlc_mutex_lock (&sap_mutex);
for (sap_addr = sap_addrs; sap_addr; sap_addr = sap_addr->next)
if (!strcmp (psz_addr, sap_addr->group))
break;
if (sap_addr == NULL)
{
sap_addr = AddressCreate (obj, psz_addr);
if (sap_addr == NULL)
{
vlc_mutex_unlock (&sap_mutex);
return NULL;
}
sap_addr->next = sap_addrs;
sap_addrs = sap_addr;
}
/* Switch locks.
* NEVER take the global SAP lock when holding a SAP thread lock! */
vlc_mutex_lock (&sap_addr->lock);
vlc_mutex_unlock (&sap_mutex);
session_descriptor_t *session = malloc(sizeof (*session));
if (unlikely(session == NULL))
goto out; /* NOTE: we should destroy the thread if left unused */
session->next = sap_addr->first;
/* Build the SAP Headers */
struct vlc_memstream stream;
vlc_memstream_open(&stream);
/* SAPv1, not encrypted, not compressed */
uint8_t flags = 0x20;
#ifdef AF_INET6
if (sap_addr->orig.ss_family == AF_INET6)
flags |= 0x10;
#endif
vlc_memstream_putc(&stream, flags);
vlc_memstream_putc(&stream, 0x00); /* No authentication length */
vlc_memstream_write(&stream, &(uint16_t){ vlc_tick_now() }, 2); /* ID hash */
switch (sap_addr->orig.ss_family)
{
#ifdef AF_INET6
case AF_INET6:
{
const struct in6_addr *a6 =
&((const struct sockaddr_in6 *)&sap_addr->orig)->sin6_addr;
vlc_memstream_write(&stream, &a6, 16);
break;
}
#endif
case AF_INET:
{
const struct in_addr *a4 =
&((const struct sockaddr_in *)&sap_addr->orig)->sin_addr;
vlc_memstream_write(&stream, &a4, 4);
break;
}
default:
vlc_assert_unreachable ();
}
vlc_memstream_puts(&stream, "application/sdp");
vlc_memstream_putc(&stream, '\0');
/* Build the final message */
vlc_memstream_puts(&stream, sdp);
if (vlc_memstream_close(&stream))
{
free(session);
session = NULL;
goto out;
}
session->data = stream.ptr;
session->length = stream.length;
sap_addr->first = session;
sap_addr->session_count++;
vlc_cond_signal (&sap_addr->wait);
out:
vlc_mutex_unlock (&sap_addr->lock);
return session;
}
#undef sout_AnnounceUnRegister
/**
* Unregisters an existing session
*
* \param obj a VLC object
* \param session the session descriptor
*/
void sout_AnnounceUnRegister (vlc_object_t *obj, session_descriptor_t *session)
{
sap_address_t *addr, **paddr;
session_descriptor_t **psession;
msg_Dbg (obj, "removing SAP session");
vlc_mutex_lock (&sap_mutex);
paddr = &sap_addrs;
for (;;)
{
addr = *paddr;
assert (addr != NULL);
psession = &addr->first;
vlc_mutex_lock (&addr->lock);
while (*psession != NULL)
{
if (*psession == session)
goto found;
psession = &(*psession)->next;
}
vlc_mutex_unlock (&addr->lock);
paddr = &addr->next;
}
found:
*psession = session->next;
if (addr->first == NULL)
/* Last session for this address -> unlink the address */
*paddr = addr->next;
vlc_mutex_unlock (&sap_mutex);
if (addr->first == NULL)
{
/* Last session for this address -> unlink the address */
vlc_mutex_unlock (&addr->lock);
AddressDestroy (addr);
}
else
{
addr->session_count--;
vlc_cond_signal (&addr->wait);
vlc_mutex_unlock (&addr->lock);
}
free(session->data);
free(session);
}
View Git Blame Copy Permalink