rtsp: connect to an RTSP server, issue a DESCRIBE command and return

the  answer.  It  WON'T  let  you  do  rtsp  as  we  first  need  a  SDP
parser/demuxer, but it is on the way.

 The idea is to have a generic  SDP demuxer that will work with SDP from
file, http or rtsp.

modules/access/rtsp.c

+/*****************************************************************************
+ * rtsp.c: Retreive a description from an RTSP url.
+ *****************************************************************************
+ * Copyright (C) 2003 VideoLAN
+ * $Id: rtsp.c,v 1.1 2003/08/03 02:00:00 fenrir Exp $
+ *
+ * Authors: Laurent Aimar <fenrir@via.ecp.fr>
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <stdlib.h>
+#include <vlc/vlc.h>
+#include <vlc/input.h>
+
+#ifdef HAVE_UNISTD_H
+#   include <unistd.h>
+#endif
+
+#include <errno.h>
+
+#ifdef WIN32
+#   include <winsock2.h>
+#   include <ws2tcpip.h>
+#   ifndef IN_MULTICAST
+#       define IN_MULTICAST(a) IN_CLASSD(a)
+#   endif
+#else
+#   include <sys/socket.h>
+#   include <netinet/in.h>
+#   if HAVE_ARPA_INET_H
+#      include <arpa/inet.h>
+#   elif defined( SYS_BEOS )
+#      include <net/netdb.h>
+#   endif
+#endif
+
+#include "network.h"
+
+/*
+ * TODO:
+ *  - login/password management
+ *  - RTSP over UDP
+ *
+ */
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+static int     Open   ( vlc_object_t * );
+static void    Close  ( vlc_object_t * );
+
+vlc_module_begin();
+    set_description( _("RTSP SDP request") );
+    set_capability( "access", 0 );
+    add_category_hint( "stream", NULL, VLC_FALSE );
+        add_integer( "rtsp-caching", 2 * DEFAULT_PTS_DELAY / 1000, NULL,
+                     "", "", VLC_TRUE );
+    add_shortcut( "rtsp" );
+    add_shortcut( "rtspu" );
+    set_callbacks( Open, Close );
+vlc_module_end();
+
+/*****************************************************************************
+ * Locales prototypes
+ *****************************************************************************/
+static ssize_t Read   ( input_thread_t *, byte_t *, size_t );
+
+typedef struct
+{
+    char           *psz_host;
+    int            i_port;
+    char           *psz_path;
+    char           *psz_login;
+    char           *psz_password;
+} url_t;
+
+static void url_Parse( url_t *, char * );
+static void url_Clean( url_t * );
+
+static int  NetRead ( input_thread_t *, int , uint8_t *, int );
+static void NetClose( input_thread_t *p_input, int i_handle );
+
+struct access_sys_t
+{
+    int i_handle;
+
+    /* description */
+    int     i_data;
+    uint8_t *p_data;
+    uint8_t *p_actu;
+};
+
+#define RTSP_DESCRIBE_REQUEST \
+    "DESCRIBE rtsp://%s:%d/%s RTSP/1.0\r\n" \
+    "CSeq: 1\r\n" \
+    "User-Agent: " COPYRIGHT_MESSAGE "\r\n" \
+    "Accept: application/sdp\r\n" \
+    "\r\n"
+
+/*****************************************************************************
+ * Open: open the file
+ *****************************************************************************/
+static int Open( vlc_object_t *p_this )
+{
+    input_thread_t *p_input = (input_thread_t *)p_this;
+    access_sys_t   *p_sys;
+
+    url_t          url;
+    char           *psz_network = "";
+    vlc_bool_t     b_udp = VLC_FALSE;
+    module_t       *p_network;
+    int            i_handle = -1;
+
+    network_socket_t    socket_desc;
+    int                 i_request;
+    uint8_t             *p_request, *p;
+
+    int                 i_code;
+
+    vlc_value_t    val;
+
+    /* Parse the URL [user:password@]host[:port]/path */
+    url_Parse( &url, p_input->psz_name );
+    if( url.i_port <= 0 )
+    {
+        /* Default RTSP port */
+        url.i_port = 554;
+    }
+
+    /* ipv4 vs ipv6 */
+    var_Create( p_input, "ipv4", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
+    var_Get( p_input, "ipv4", &val );
+    if( val.i_int )
+    {
+        psz_network = "ipv4";
+    }
+
+    var_Create( p_input, "ipv6", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
+    var_Get( p_input, "ipv6", &val );
+    if( val.i_int )
+    {
+        psz_network = "ipv6";
+    }
+
+    /* UDP vs TCP */
+    if( !strcmp( p_input->psz_access, "rtspu" ) )
+    {
+        b_udp = VLC_TRUE;
+    }
+
+    if( b_udp )
+    {
+        msg_Err( p_input, "RTSP over UDP not supported" );
+        goto error;
+    }
+
+    /* Open the TCP connection */
+    socket_desc.i_type          = NETWORK_TCP;
+    socket_desc.psz_server_addr = url.psz_host;
+    socket_desc.i_server_port   = url.i_port;
+    socket_desc.psz_bind_addr   = "";
+    socket_desc.i_bind_port     = 0;
+    socket_desc.i_ttl           = 0;
+
+    p_input->p_private = (void*)&socket_desc;
+    p_network = module_Need( p_input, "network", psz_network );
+    if( p_network == NULL )
+    {
+        goto error;
+    }
+    module_Unneed( p_input, p_network );
+    i_handle = socket_desc.i_handle;
+    p_input->i_mtu    = socket_desc.i_mtu;
+
+    msg_Dbg( p_input, "connected with %s:%d", url.psz_host, url.i_port );
+
+    /* Build request */
+    i_request = strlen( RTSP_DESCRIBE_REQUEST ) +
+                strlen( url.psz_host ) + 5 + strlen( url.psz_path ) + 1;
+    p_request = malloc( i_request );
+    sprintf( p_request, RTSP_DESCRIBE_REQUEST,
+             url.psz_host, url.i_port, url.psz_path );
+
+    msg_Dbg( p_input, "Request=%s", p_request );
+    /* Send the request */
+    for( p = p_request; p < p_request + strlen( p_request ); )
+    {
+        int i_send;
+
+        i_send = send( i_handle, p, strlen( p ), 0 );
+        if( i_send <= 0 )
+        {
+            goto error;
+        }
+
+        p += i_send;
+    }
+    free( p_request );
+
+    /* Read the complete answer*/
+    i_request = 1024;
+    p_request = p = malloc( i_request );
+    p_request[0] = '\0';
+    for( ;; )
+    {
+        int i_recv;
+
+        i_recv = NetRead( p_input, i_handle, p, i_request - ( p - p_request ) - 1);
+        if( i_recv <= 0 )
+        {
+            break;
+        }
+
+        p[i_recv] = '\0';
+
+        p += i_recv;
+
+        if( p >= p_request + i_request - 1 )
+        {
+            int i_size = p - p_request;
+
+            p_request = realloc( p_request, i_request + 1024 );
+
+            p = p_request + i_size;
+        }
+    }
+
+    if( strlen( p_request ) <= 0 ||
+        ( !strstr( p_request, "\n\n" ) && !strstr( p_request, "\r\n\r\n" )  ) )
+    {
+        msg_Dbg( p_input, "failed to retreive description" );
+        goto error;
+    }
+
+    /* Parse the header */
+    msg_Dbg( p_input, "answer header=%s", p_request );
+    if( strncmp( p_request, "RTSP/1.", strlen( "RTSP/1." ) ) )
+    {
+        msg_Err( p_input, "invalid answer" );
+        free( p_request );
+        goto error;
+    }
+    i_code = atoi( &p_request[strlen( "RTSP/1.x" )] );
+
+    if( i_code / 100 != 2 )
+    {
+        msg_Err( p_input, "return code is %d (!=2xx), not yet supported", i_code );
+        free( p_request );
+        goto error;
+    }
+
+    p_input->p_access_data = p_sys = malloc( sizeof( access_sys_t ) );
+    p_sys->i_handle = i_handle;
+    p_sys->p_data   = p_request;
+    p_sys->i_data   = strlen( p_request );
+    if( ( p = strstr( p_request, "\r\n\r\n" ) ) )
+    {
+        p_sys->p_actu = p + 4;
+    }
+    else if( ( p = strstr( p_request, "\n\n" ) ) )
+    {
+        p_sys->p_actu = p + 2;
+    }
+    else
+    {
+        msg_Err( p_input, "mhhh ? cannot happens" );
+        goto error;
+    }
+
+    /* Set exported functions */
+    p_input->pf_read = Read;
+    p_input->pf_seek = NULL;
+    p_input->pf_set_program = input_SetProgram;
+    p_input->pf_set_area = NULL;
+    p_input->p_private = NULL;
+
+    /* Finished to set some variable */
+    vlc_mutex_lock( &p_input->stream.stream_lock );
+    p_input->stream.b_pace_control = VLC_TRUE;
+    p_input->stream.p_selected_area->i_tell = 0;
+    p_input->stream.b_seekable = 0;
+    p_input->stream.p_selected_area->i_size = 0;
+    p_input->stream.i_method = INPUT_METHOD_NETWORK;
+    vlc_mutex_unlock( &p_input->stream.stream_lock );
+
+    /* Update default_pts to a suitable value for RTSP access */
+    p_input->i_pts_delay = config_GetInt( p_input, "rtsp-caching" ) * 1000;
+
+    url_Clean( &url );
+    return VLC_SUCCESS;
+
+error:
+    if( i_handle > 0 )
+    {
+        NetClose( p_input, i_handle );
+    }
+    url_Clean( &url );
+    return VLC_EGENERIC;
+}
+
+/*****************************************************************************
+ * Close: close the target
+ *****************************************************************************/
+static void Close( vlc_object_t * p_this )
+{
+    input_thread_t *p_input = (input_thread_t *)p_this;
+    access_sys_t   *p_sys   = p_input->p_access_data;
+
+    free( p_sys->p_data );
+    free( p_sys );
+}
+
+/*****************************************************************************
+ * Read: standard read on a file descriptor.
+ *****************************************************************************/
+static ssize_t Read( input_thread_t * p_input, byte_t * p_buffer, size_t i_len )
+{
+    access_sys_t   *p_sys   = p_input->p_access_data;
+
+    int            i_copy = __MIN( (int)i_len, &p_sys->p_data[p_sys->i_data] - p_sys->p_actu );
+
+    if( i_copy <= 0 )
+    {
+        return 0;
+    }
+
+    memcpy( p_buffer, p_sys->p_actu, i_copy );
+
+    p_sys->p_actu += i_copy;
+
+    return i_copy;
+}
+
+/*****************************************************************************
+ *
+ *****************************************************************************/
+static void url_Parse( url_t *url, char *psz_url )
+{
+    char *psz_dup = strdup( psz_url );
+    char *psz_tmp, *p;
+
+    p = psz_dup;
+
+    while( *p == '/' )
+    {
+        p++;
+    }
+    if( strchr( p, '@' ) )
+    {
+        /* TODO: There is a login/password */
+    }
+    url->psz_login = strdup( "" );
+    url->psz_password = strdup( "" );
+
+    psz_tmp = p;
+    /* Skip host */
+    while( *p && *p != ':' &&  *p != '/' )
+    {
+        if( *p == '[' )
+        {
+            /* ipv6 address */
+            while( *p && *p != ']' )
+            {
+                *p++;
+            }
+        }
+        p++;
+    }
+
+    /* Get port */
+    if( *p == ':' )
+    {
+        char *psz_port;
+        *p++ = 0;
+        psz_port = p;
+
+        while( *p && *p != '/' )
+        {
+            p++;
+        }
+        url->i_port = atoi( psz_port );
+    }
+    else
+    {
+        url->i_port = 0;
+    }
+    /* Get host */
+    *p++ = '\0';
+    url->psz_host = strdup( psz_tmp );
+
+    /* Get path */
+    url->psz_path = strdup( p );
+
+    free( psz_dup );
+}
+
+static void url_Clean( url_t *url )
+{
+    if( url->psz_host )
+    {
+        free( url->psz_host );
+    }
+    if( url->psz_path )
+    {
+        free( url->psz_path );
+    }
+    if( url->psz_login )
+    {
+        free( url->psz_login );
+    }
+    if( url->psz_password )
+    {
+        free( url->psz_password );
+    }
+}
+
+
+
+static int NetRead( input_thread_t *p_input,
+                    int i_handle,
+                    uint8_t *p_buffer, int i_len )
+{
+    struct timeval  timeout;
+    fd_set          fds;
+    int             i_recv;
+    int             i_ret;
+
+    /* Initialize file descriptor set */
+    FD_ZERO( &fds );
+    FD_SET( i_handle, &fds );
+
+    /* We'll wait 1 second if nothing happens */
+    timeout.tv_sec  = 1;
+    timeout.tv_usec = 0;
+
+    /* Find if some data is available */
+    while( (i_ret = select( i_handle + 1, &fds,
+                            NULL, NULL, &timeout )) == 0
+           || (i_ret < 0 && errno == EINTR) )
+    {
+        FD_ZERO( &fds );
+        FD_SET( i_handle, &fds );
+        timeout.tv_sec  = 1;
+        timeout.tv_usec = 0;
+
+        if( p_input->b_die || p_input->b_error )
+        {
+            return 0;
+        }
+    }
+
+    if( i_ret < 0 )
+    {
+        msg_Err( p_input, "network select error (%s)", strerror(errno) );
+        return -1;
+    }
+
+    i_recv = recv( i_handle, p_buffer, i_len, 0 );
+
+    if( i_recv < 0 )
+    {
+        msg_Err( p_input, "recv failed (%s)", strerror(errno) );
+    }
+
+    return i_recv;
+}
+
+
+
+static void NetClose( input_thread_t *p_input, int i_handle )
+{
+#if defined( UNDER_CE )
+    CloseHandle( (HANDLE)i_handle );
+#elif defined( WIN32 )
+    closesocket( i_handle );
+#else
+    close( i_handle );
+#endif
+}
+
+