sap.c
资源名称:vlc-1.0.5.zip [点击查看]
上传用户:kjfoods
上传日期:2020-07-06
资源大小:29949k
文件大小:13k
源码类别:
midi
开发平台:
Unix_Linux
- /*****************************************************************************
- * sap.c : SAP announce handler
- *****************************************************************************
- * Copyright (C) 2002-2008 the VideoLAN team
- * $Id: e71906114db4bb0aeca777063a9414205f0317a6 $
- *
- * Authors: Clément Stenac <zorglub@videolan.org>
- * Rémi Denis-Courmont <rem # videolan.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 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 General Public License for more details.
- *
- * You should have received a copy of the GNU 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.
- *****************************************************************************/
- /*****************************************************************************
- * Preamble
- *****************************************************************************/
- #ifdef HAVE_CONFIG_H
- # include "config.h"
- #endif
- #include <vlc_common.h>
- #include <stdlib.h> /* free() */
- #include <stdio.h> /* sprintf() */
- #include <string.h>
- #include <ctype.h> /* tolower(), isxdigit() */
- #include <assert.h>
- #include <vlc_sout.h>
- #include <vlc_network.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 */
- typedef struct sap_session_t
- {
- struct sap_session_t *next;
- const session_descriptor_t *p_sd;
- size_t length;
- uint8_t data[];
- } sap_session_t;
- /* 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;
- sap_session_t *first;
- } sap_address_t;
- /* The SAP handler, running in a separate thread */
- struct sap_handler_t
- {
- VLC_COMMON_MEMBERS
- vlc_mutex_t lock;
- sap_address_t *first;
- };
- #define SAP_MAX_BUFFER 65534
- #define MIN_INTERVAL 2
- #define MAX_INTERVAL 300
- /*****************************************************************************
- * Local prototypes
- *****************************************************************************/
- static void *RunThread (void *);
- /**
- * Create the SAP handler
- *
- * param p_announce a VLC object
- * return the newly created SAP handler or NULL on error
- */
- sap_handler_t *SAP_Create (vlc_object_t *p_announce)
- {
- sap_handler_t *p_sap;
- p_sap = vlc_custom_create (p_announce, sizeof (*p_sap),
- VLC_OBJECT_GENERIC, "sap sender");
- if (p_sap == NULL)
- return NULL;
- vlc_mutex_init (&p_sap->lock);
- p_sap->first = NULL;
- return p_sap;
- }
- void SAP_Destroy (sap_handler_t *p_sap)
- {
- assert (p_sap->first == NULL);
- vlc_mutex_destroy (&p_sap->lock);
- vlc_object_release (p_sap);
- }
- 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
- */
- static void *RunThread (void *self)
- {
- sap_address_t *addr = self;
- vlc_mutex_lock (&addr->lock);
- mutex_cleanup_push (&addr->lock);
- for (;;)
- {
- sap_session_t *p_session;
- mtime_t deadline;
- while (addr->first == NULL)
- vlc_cond_wait (&addr->wait, &addr->lock);
- assert (addr->session_count > 0);
- deadline = mdate ();
- for (p_session = addr->first; p_session; p_session = p_session->next)
- {
- send (addr->fd, p_session->data, p_session->length, 0);
- deadline += addr->interval * CLOCK_FREQ / addr->session_count;
- if (vlc_cond_timedwait (&addr->wait, &addr->lock, deadline) == 0)
- break; /* list may have changed! */
- }
- }
- vlc_cleanup_pop ();
- assert (0);
- }
- /**
- * Add a SAP announce
- */
- int SAP_Add (sap_handler_t *p_sap, session_descriptor_t *p_session)
- {
- int i;
- char psz_addr[NI_MAXNUMERICHOST];
- bool b_ipv6 = false, b_ssm = false;
- sap_session_t *p_sap_session;
- mtime_t i_hash;
- struct sockaddr_storage addr;
- socklen_t addrlen;
- addrlen = p_session->addrlen;
- if ((addrlen == 0) || (addrlen > sizeof (addr)))
- {
- msg_Err( p_sap, "No/invalid address specified for SAP announce" );
- return VLC_EGENERIC;
- }
- /* Determine SAP multicast address automatically */
- memcpy (&addr, &p_session->addr, addrlen);
- switch( p_session->addr.ss_family )
- {
- #if defined (HAVE_INET_PTON) || defined (WIN32)
- case AF_INET6:
- {
- /* See RFC3513 for list of valid IPv6 scopes */
- struct in6_addr *a6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
- memcpy( a6->s6_addr + 2, "x00x00x00x00x00x00"
- "x00x00x00x00x00x02x7fxfe", 14 );
- if( IN6_IS_ADDR_MULTICAST( a6 ) )
- {
- /* SSM <=> ff3x::/32 */
- b_ssm = (U32_AT (a6->s6_addr) & 0xfff0ffff) == 0xff300000;
- /* force flags to zero, preserve scope */
- a6->s6_addr[1] &= 0xf;
- }
- else
- /* Unicast IPv6 - assume global scope */
- memcpy( a6->s6_addr, "xffx0e", 2 );
- b_ipv6 = true;
- break;
- }
- #endif
- case AF_INET:
- {
- /* See RFC2365 for IPv4 scopes */
- uint32_t ipv4;
- ipv4 = ntohl( ((struct sockaddr_in *)&addr)->sin_addr.s_addr );
- /* 224.0.0.0/24 => 224.0.0.255 */
- if ((ipv4 & 0xffffff00) == 0xe0000000)
- ipv4 = 0xe00000ff;
- else
- /* 239.255.0.0/16 => 239.255.255.255 */
- if ((ipv4 & 0xffff0000) == 0xefff0000)
- ipv4 = 0xefffffff;
- else
- /* 239.192.0.0/14 => 239.195.255.255 */
- if ((ipv4 & 0xfffc0000) == 0xefc00000)
- ipv4 = 0xefc3ffff;
- else
- if ((ipv4 & 0xff000000) == 0xef000000)
- ipv4 = 0;
- else
- /* other addresses => 224.2.127.254 */
- {
- /* SSM: 232.0.0.0/8 */
- b_ssm = (ipv4 >> 24) == 232;
- ipv4 = 0xe0027ffe;
- }
- if( ipv4 == 0 )
- {
- msg_Err( p_sap, "Out-of-scope multicast address "
- "not supported by SAP" );
- return VLC_EGENERIC;
- }
- ((struct sockaddr_in *)&addr)->sin_addr.s_addr = htonl( ipv4 );
- break;
- }
- default:
- msg_Err( p_sap, "Address family %d not supported by SAP",
- addr.ss_family );
- return VLC_EGENERIC;
- }
- i = vlc_getnameinfo( (struct sockaddr *)&addr, addrlen,
- psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
- if( i )
- {
- msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
- return VLC_EGENERIC;
- }
- /* Find/create SAP address thread */
- msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
- vlc_mutex_lock (&p_sap->lock);
- sap_address_t *sap_addr;
- for (sap_addr = p_sap->first; sap_addr; sap_addr = sap_addr->next)
- if (!strcmp (psz_addr, sap_addr->group))
- break;
- if (sap_addr == NULL)
- {
- sap_addr = AddressCreate (VLC_OBJECT(p_sap), psz_addr);
- if (sap_addr == NULL)
- {
- vlc_mutex_unlock (&p_sap->lock);
- return VLC_EGENERIC;
- }
- sap_addr->next = p_sap->first;
- p_sap->first = 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 (&p_sap->lock);
- memcpy (&p_session->orig, &sap_addr->orig, sap_addr->origlen);
- p_session->origlen = sap_addr->origlen;
- size_t headsize = 20, length;
- switch (p_session->orig.ss_family)
- {
- #ifdef AF_INET6
- case AF_INET6:
- headsize += 16;
- break;
- #endif
- case AF_INET:
- headsize += 4;
- break;
- default:
- assert (0);
- }
- /* XXX: Check for dupes */
- length = headsize + strlen (p_session->psz_sdp);
- p_sap_session = malloc (sizeof (*p_sap_session) + length + 1);
- if (p_sap_session == NULL)
- {
- vlc_mutex_unlock (&sap_addr->lock);
- return VLC_EGENERIC; /* NOTE: we should destroy the thread if left unused */
- }
- p_sap_session->next = sap_addr->first;
- sap_addr->first = p_sap_session;
- p_sap_session->p_sd = p_session;
- p_sap_session->length = length;
- /* Build the SAP Headers */
- uint8_t *psz_head = p_sap_session->data;
- /* SAPv1, not encrypted, not compressed */
- psz_head[0] = 0x20;
- psz_head[1] = 0x00; /* No authentification length */
- i_hash = mdate();
- psz_head[2] = i_hash >> 8; /* Msg id hash */
- psz_head[3] = i_hash; /* Msg id hash 2 */
- headsize = 4;
- switch (p_session->orig.ss_family)
- {
- #ifdef AF_INET6
- case AF_INET6:
- {
- struct in6_addr *a6 =
- &((struct sockaddr_in6 *)&p_session->orig)->sin6_addr;
- memcpy (psz_head + headsize, a6, 16);
- psz_head[0] |= 0x10; /* IPv6 flag */
- headsize += 16;
- break;
- }
- #endif
- case AF_INET:
- {
- uint32_t ipv4 =
- (((struct sockaddr_in *)&p_session->orig)->sin_addr.s_addr);
- memcpy (psz_head + headsize, &ipv4, 4);
- headsize += 4;
- break;
- }
- }
- memcpy (psz_head + headsize, "application/sdp", 16);
- headsize += 16;
- /* Build the final message */
- strcpy( (char *)psz_head + headsize, p_session->psz_sdp);
- sap_addr->session_count++;
- vlc_cond_signal (&sap_addr->wait);
- vlc_mutex_unlock (&sap_addr->lock);
- return VLC_SUCCESS;
- }
- /**
- * Remove a SAP Announce
- */
- void SAP_Del (sap_handler_t *p_sap, const session_descriptor_t *p_session)
- {
- vlc_mutex_lock (&p_sap->lock);
- /* TODO: give a handle back in SAP_Add, and use that... */
- sap_address_t *addr, **paddr;
- sap_session_t *session, **psession;
- paddr = &p_sap->first;
- for (addr = p_sap->first; addr; addr = addr->next)
- {
- psession = &addr->first;
- vlc_mutex_lock (&addr->lock);
- for (session = addr->first; session; session = session->next)
- {
- if (session->p_sd == p_session)
- goto found;
- psession = &session->next;
- }
- vlc_mutex_unlock (&addr->lock);
- paddr = &addr->next;
- }
- assert (0);
- found:
- *psession = session->next;
- if (addr->first == NULL)
- /* Last session for this address -> unlink the address */
- *paddr = addr->next;
- vlc_mutex_unlock (&p_sap->lock);
- 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);
- }