File content as of revision 3:cd9148672e25:

#include "sip.h"
#include "utils.h"

void Sip::__init_sock__( void ){
    sip_server.set_address( this->server_ip , this->server_port );
    sock.set_blocking( false, 1 ); // verificar isso com mais cuidado depois
    sock.bind( this->my_port );
    sock.init();
}

void Sip::__end_sock__(){
    sock.close(); 
}

Sip::Sip( char * server_ip, int server_port, char * my_ip, int my_port, int my_ext, int peer_ext, int id ){
    this->id = id;
    strncpy( this->server_ip, server_ip, 20 );
    this->server_ip[19] = 0;
    this->server_port = server_port;
    strncpy( this->my_ip, my_ip, 20 );
    this->my_ip[19] = 0;
    this->my_port = my_port;
    this->my_rtp_port = fill_random_rtp_port();
    this->my_ext = my_ext;
    itoa( this->my_ext, this->my_display, 10 );
    this->peer_ext = peer_ext;
 
    strcpy( this->fill_random_aux, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789pP" );
    strcpy( this->last_invite_tag, "" );
    strcpy( this->last_invite_callid, "");
    strcpy( this->SVNREV, "COLA" );
    status = sip_idle;
    
    __init_sock__();
}
 
Sip::Sip(){
    this->id = __MY_EXT__;
    strncpy( this->server_ip, __SEVER_IP__, 20 );
    this->server_ip[19] = 0;
    this->server_port = __SERVER_PORT__;
    strncpy( this->my_ip, __MY_IP__, 20 );
    this->my_ip[19] = 0;
    this->my_port = __MY_PORT__;
    this->my_rtp_port = fill_random_rtp_port();
    this->my_ext = __MY_EXT__;
    itoa( this->my_ext, this->my_display, 10 );
    this->peer_ext = __PEER_EXT__;
 
    strcpy( this->fill_random_aux, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789pP" );
    strcpy( this->last_invite_tag, "" );
    strcpy( this->last_invite_callid, "");
    strcpy( this->SVNREV, "COLA" );
    status = sip_idle;
    
    __init_sock__();
}
 
Sip::Sip( int id, uint16_t my_port ){
    this->id = id;
    strncpy( this->server_ip, __SEVER_IP__, 20 );
    this->server_ip[19] = 0;
    this->server_port = __SERVER_PORT__;
    strncpy( this->my_ip, __MY_IP__, 20 );
    this->my_ip[19] = 0;
    this->my_port = my_port;
    this->my_rtp_port = fill_random_rtp_port();
    this->my_ext = id;
    itoa( this->my_ext, this->my_display, 10 );
    this->peer_ext = __PEER_EXT__;
 
    strcpy( this->fill_random_aux, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789pP" );
    strcpy( this->last_invite_tag, "" );
    strcpy( this->last_invite_callid, "");
    strcpy( this->SVNREV, "COLA" );
    status = sip_idle;
    
    __init_sock__();
}
 
Sip::Sip( int id, uint16_t my_port, int dest_ext  ){
    this->id = id;
    strncpy( this->server_ip, __SEVER_IP__, 20 );
    this->server_ip[19] = 0;
    this->server_port = __SERVER_PORT__;
    strncpy( this->my_ip, __MY_IP__, 20 );
    this->my_ip[19] = 0;
    this->my_port = my_port;
    this->my_rtp_port = fill_random_rtp_port();
    this->my_ext = id;
    itoa( this->my_ext, this->my_display, 10 );
    this->peer_ext = dest_ext;
 
    strcpy( this->fill_random_aux, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789pP" );
    strcpy( this->last_invite_tag, "" );
    strcpy( this->last_invite_callid, "");
    strcpy( this->SVNREV, "COLA" );
    status = sip_idle;
    
    __init_sock__();
}
 
Sip::~Sip(){
    __end_sock__();
}
 
void Sip::registry(){
    char out[ 1000 ];
    build_registry_package( buffer );
    sock.sendTo( sip_server, buffer, sizeof( buffer ) );
    sock.receiveFrom( sip_server, buffer, sizeof( buffer ) );
    if( decode_gettag( (unsigned char *)buffer, "cseq: ", out ) ){
        if(strlen( out ) > 7){
            if(strcasecmp("options",out+strlen(out)-7) == 0){
                char ans[ 2000 ];
                build_reply_package( ans, (unsigned char*)buffer );
                sock.sendTo( sip_server, ans, sizeof( ans ) );
            }
        }
    }
}

VZ_call * Sip::old_invite(){
    Timer t;
    char buffer[ 1024 ];
    char callbox_string[ 32 ];
    itoa( get_id(), callbox_string, 10 );
    int cseq;
 
    build_invite_package( buffer, callbox_string, &cseq );
    sock.sendTo( sip_server, buffer, sizeof( buffer ) );
 
    t.start();
    while( sock.receiveFrom( sip_server, buffer, sizeof( buffer ) ) < 1 ) {
        if( t.read() > __INVITE_MAX_WAITING_TIME__ ) { /* Trying package */
            change_sip_server();
            t.reset();
            break;
        }
    }
    while( sock.receiveFrom( sip_server, buffer, sizeof( buffer ) ) < 1 ) {
        if( t.read() > __INVITE_MAX_WAITING_TIME__ ) { /* Ringing package */
            change_sip_server();
            t.reset();
            break;
        }
    }
    int call_trying = 1;
    while( call_trying-- ){
        while( sock.receiveFrom( sip_server, buffer, sizeof( buffer ) ) < 1 ) {
            if( t.read() > __INVITE_MAX_WAITING_TIME__ ) { /* ok package */
                change_sip_server();
                t.reset();
                break;
            }
        }
        wait( 3 );
        char * ref = strstr( buffer, "audio" );
        if( ref != NULL ){
            ref += 6; /*audio */
            ref = strtok( ref, " ");
            VZ_call * call = new VZ_call( this->my_ext, this->my_rtp_port, this->peer_ext, atoi( ref ) );
            char ans[ 1024 ];
            build_ack_package( ans, ( unsigned char *)buffer );
            sock.sendTo( sip_server, ans, sizeof( ans ) );
            
            return( call );
        }
    }
    return( NULL );
}

VZ_call * Sip::invite(){
    Timer t;
    char callbox_string[ 32 ];
    itoa( get_id(), callbox_string, 10 );
 
    if( status != sip_on_call ) set_status(status, sip_waiting_trying );
    
    else return( NULL );
    
    int cseq = 0;
 
    build_invite_package( buffer, callbox_string, &cseq );
    sock.sendTo( sip_server, buffer, sizeof( buffer ) );
 
    debug_msg( "Inicio do invite" );
    debug_msg( "Sip::status::%d", status );
    t.start();

    sock.set_blocking( false, 5 );
    
    char buffer_eth_invite[ 1024 ];
    int loop_times = 0;
    int received_loop_times = 0;
    Timer reconnect;
    reconnect.start();
    static int id_ = 0;
    int length = 0;
    bool waiting = false;
    
    VZ_call * call = NULL;
    while( t.read() < __INVITE_MAX_WAITING_TIME__ ){    
        loop_times++;        
        length = sock.receiveFrom( sip_server, buffer_eth_invite, sizeof( buffer_eth_invite ) );
        if( length > 0 ){
            reconnect.reset();
            debug_msg("Pacotes recebidos :: %d", id_ );
            buffer_eth_invite[ length ] = 0;
            debug_msg("-- %d :: %s --", id_++, buffer_eth_invite );
            received_loop_times++;
            if( ( status == sip_trying ) || ( status == sip_ringing ) ){            
                if( !( strncasecmp( buffer_eth_invite + 12, "ok", strlen("ok") ) ) ){
                    // tratar depois o esquema do Cseq ::
                    debug_msg( "Cseq == %d", cseq );
                    set_status(status, sip_on_call);
                    char *ref = strstr( buffer_eth_invite, "audio" );
                    debug_msg("ok");
                    if( ref != NULL ){
                        ref += 6; // audio 
                        ref = strtok( ref, " ");
                        if( call == NULL ) call = new VZ_call( this->my_ext, this->my_rtp_port, this->peer_ext, atoi( ref ) );
                        char ans[ 1024 ];
                        build_ack_package( ans, ( unsigned char *)buffer_eth_invite );
                        sock.sendTo( sip_server, ans, sizeof( ans ) );
                        debug_msg("Call alocada -- Sip::status::%d -- loop_times :: %d :: received_loop_times :: %d", status, loop_times, received_loop_times );
                        set_status( status, sip_on_call );
                        return( call );
                    }
                }
            }
            if( ( status == sip_trying ) || ( status == sip_ringing ) ){            
                if( !( strncasecmp( buffer_eth_invite + 12, "Session Progress", strlen("Session Progress") ) ) ){
                    char *ref = strstr( buffer_eth_invite, "audio" );
                    debug_msg( "Trocando dados de audio -- musica de espera com o CBx" );
                    if( ref != NULL ){
                        ref += 6; // audio 
                        ref = strtok( ref, " ");
                        if( call == NULL ) call = new VZ_call( this->my_ext, this->my_rtp_port, this->peer_ext, atoi( ref ) );
                        waiting = true;
                    }
                }
            }
            if( status == sip_trying ){
                if( !( strncasecmp( buffer_eth_invite + 12, "ringing", strlen("ringing") ) ) ){
                    debug_msg("ringing");
                    t.reset();
                    set_status( status, sip_ringing );
                }
            }
            if( status == sip_waiting_trying ){
                if( !( strncasecmp( buffer_eth_invite + 12, "trying", strlen("trying") ) ) ){
                    debug_msg("trying")
                    t.reset();
                    set_status( status, sip_trying );
                }
            }
        }else if( reconnect.read() > 4 ){
            sock.close();
            sock.bind( this->my_port );
            sock.init();
            sock.set_blocking( false, 1 );
            debug_msg("Reconnect");
            reconnect.reset();
            //sock.sendTo( sip_server, buffer, sizeof( buffer ) );
            led4 = !led4;
        }
        if( waiting == true ){
            char * tmp = call->get_eth_message( &length );
            if( tmp != NULL ){
                uint8_t * pkg2cb = __build_cb_package__( this->my_ext, this->my_port, __AUDIO__, 
                    tmp, __AUDIO__, length, (uint8_t *)buffer );
                __send_to_cb__( pkg2cb );
            }
        }
    }
    
    debug_msg("Call nao alocada -- Sip::status::%d -- loop_times :: %d :: received_loop_times :: %d", status, loop_times, received_loop_times );
    if( t.read() > __INVITE_MAX_WAITING_TIME__ ){
        set_status(status, sip_denied);
    }
    delete( call );
    return( NULL );
}
 
char * Sip::build_registry_package( char * buffer ){
    char branch[ SIP_MAXFIELDSIZE ];
    char tag[ SIP_MAXFIELDSIZE ];
    char callid[ SIP_MAXFIELDSIZE ];
    fill_random16h( branch );
    fill_random( tag, 18 );
    fill_random16h( callid );
    char itoa_buffer[ 65 ];
    strcpy( buffer, "REGISTER sip:" );
    strcat( buffer, server_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " SIP/2.0\r\nVia: SIP/2.0/UDP " );
    strcat( buffer, my_ip );
    strcat( buffer, ":" );
    itoa( my_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ";branch=" );
    strcat( buffer, branch );
    strcat( buffer, "\r\nFrom: " );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" ); 
    strcat( buffer, server_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">;tag=" );
    strcat( buffer, tag );
    strcat( buffer, "\r\nTo: " );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, server_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">\r\nCall-ID: " );
    strcat( buffer, callid );
    strcat( buffer, "\r\nCSeq: " );
    itoa( get_cseq(), itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " REGISTER\r\n" );
    strcat( buffer, "Max-Forwards: " );
    itoa( 70, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "Contact: " );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, my_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">;expires=120" );
    //itoa( 1200, itoa_buffer, 10 );
    //strcat( buffer, itoa_buffer );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "User-Agent: VZtech/pabxdriver-" );
    strcat( buffer, SVNREV );
    strcat( buffer, "\r\nContent-Length: 0\r\n" );
    strcat( buffer, SIP_ALLOW );
    strcat( buffer, "\r\n\r\n" );              
    buffer[ SIP_MAXMSGSIZE - 1 ] = 0;
    return buffer;
}
 
char * Sip::build_invite_package( char * pkg, char * callbox_string, int * cseq ){
    char header[ SIP_MAXMSGSIZE ], body[ SIP_MAXMSGSIZE ];
    char branch[ SIP_MAXFIELDSIZE ];
    char tag[ SIP_MAXFIELDSIZE ];
    char callid[ SIP_MAXFIELDSIZE ];
    char itoa_buffer[ 65 ];
    *cseq = get_cseq();
    fill_random16h( branch );
    fill_random( tag,18 );
    fill_random16h( callid );
 
    strcpy( last_invite_tag,tag );
    strcpy( last_invite_callid, callid );
    
    strcpy( header, "INVITE sip:" );
    itoa( this->peer_ext, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "@" );
    strcat( header, this->server_ip );
    strcat( header, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, " SIP/" );
    itoa( 2, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "." );
    itoa( 0, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "\r\n" );
    strcat( header, "Via: SIP/" );
    itoa( 2, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "." );
    itoa( 0, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "/UDP"  );
    strcat( header, this->my_ip );
    strcat( header, ":" );
    itoa( this->my_port, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, ";branch="  );
    strcat( header, branch );
    strcat( header, "\r\n" );
    strcat( header, "From: " );
    strcat( header, callbox_string );
    strcat( header, " <sip:" );
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "@" );
    strcat( header, this->server_ip );
    strcat( header, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, ">;tag=" );
    strcat( header, tag );
    strcat( header, "\r\n" );
    strcat( header, "To: <sip:" );
    itoa( this->peer_ext, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "@" );
    strcat( header, this->server_ip );
    strcat( header, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, ">\r\n" );
    strcat( header, "Call-ID: " );
    strcat( header, callid );
    strcat( header, "@" );
    strcat( header, this->my_ip );
    strcat( header, "\r\n" );
    strcat( header, "CSeq: " );
    itoa( *cseq, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, " INVITE\r\n" );
    strcat( header, "Contact: " );
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, " <sip:" );
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "@" );
    strcat( header, this->my_ip );
    strcat( header, ":" );
    itoa( this->my_port, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, ">\r\n" );
    strcat( header, "Max-Forwards: " );
    itoa( 20, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "\r\n" );
    strcat( header, "User-Agent: VZtech/pabxdriver-" );
    strcat( header, SVNREV );
    strcat( header, "\r\n" );
    strcat( header, "Expires: " );
    itoa( 70, itoa_buffer, 10 );
    strcat( header, itoa_buffer );
    strcat( header, "\r\n" );
    strcat( header, SIP_ALLOW );
    strcat( header, "\r\n" );
    strcat( header, "Content-Type: application/sdp\r\n" );
    header[ SIP_MAXMSGSIZE - 1 ] = 0;
    
    strcpy( body, "v=0\r\n" );
    strcat( body, "o=- " );
    itoa( 7377, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " " );
    itoa( 18176, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " IN IP" );
    itoa( 4, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " " );
    strcat( body, this->my_ip );
    strcat( body, "\r\n" );
    strcat( body, "s=-\r\n" );
    strcat( body, "c=IN IP" );
    itoa( 4, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " " );
    strcat( body, this->my_ip );
    strcat( body, "\r\n" );
    strcat( body, "t=" );
    itoa( 0, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " " );
    itoa( 0, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, "\r\n" );
    strcat( body, "m=audio " );
    itoa( this->my_rtp_port, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " RTP/AVP " );
    itoa( 8, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " " );
    itoa( 101, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, "\r\n" );
    strcat( body, "a=rtpmap:" );
    itoa( 8, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " PCMA/" );
    itoa( 8000, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, "/" );
    itoa( 1, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, "\r\n" );
    strcat( body, "a=rtpmap:" );
    itoa( 101, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " telephone-event/" );
    itoa( 8000, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, "\r\n" );
    strcat( body, "a=fmtp: " );
    itoa( 101, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, " " );
    itoa( 0, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    strcat( body, "-" );
    itoa( 11, itoa_buffer, 10 );
    strcat( body, itoa_buffer );
    body[ SIP_MAXMSGSIZE - 1 ] = 0;
 
    make_content_length( header, body, pkg );
    return( pkg );
}
 
char * Sip::make_content_length( char * header, char * body, char * pkg ){
    int size;
    char itoa_buffer[ 65 ];
    size = strlen( body );
    strcpy( pkg, header );
    strcat( pkg, "Content-Length: " );
    itoa( size, itoa_buffer, 10 );
    strcat( pkg, itoa_buffer );
    strcat( pkg, "\r\n\r\n" );
    strcat( pkg, body );
    pkg[ SIP_MAXMSGSIZE - 1 ] = 0;
    return pkg;
}
 
char * Sip::build_bye_package( char * buffer ){
    char branch[SIP_MAXFIELDSIZE];
    char tag[SIP_MAXFIELDSIZE];
    char itoa_buffer[ 65 ];
    fill_random16h(branch);
    fill_random(tag,18);
    
    strcpy( buffer, "BYE sip:" );
    itoa( this->peer_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, this->server_ip );
    strcat( buffer, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " SIP/2.0\r\n" );
    strcat( buffer, "Via: SIP/2.0/UDP " );
    strcat( buffer, this->my_ip );
    strcat( buffer, ":" );
    itoa( this->my_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ";branch=" );
    strcat( buffer, branch );
    strcat( buffer, "\r\n" );
    strcat( buffer, "From: " );          
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, this->server_ip );
    strcat( buffer, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">;tag=" );
    strcat( buffer, last_invite_tag );
    strcat( buffer, "\r\n" );
    strcat( buffer, "To: <sip:" );
    itoa( this->peer_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, this->server_ip );
    strcat( buffer, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">;tag=" );
    strcat( buffer, tag );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Call-ID: " );
    strcat( buffer, last_invite_callid );
    strcat( buffer, "@" );
    strcat( buffer, this->my_ip );
    strcat( buffer, "\r\n" );
    strcat( buffer, "CSeq: " );
    itoa( get_cseq(), itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " BYE\r\n" );
    strcat( buffer, "Max-Forwards: 70\r\n" );
    strcat( buffer, "User-Agent: VZtech/pabxdriver-" );
    strcat( buffer, SVNREV );
    strcat( buffer, "\r\n" );          
    strcat( buffer, "Content-Length: 0\r\n\r\n" );
    return( buffer );
}
char * Sip::build_ack_package( char * buffer, unsigned char * orig ){
    char to[ SIP_MAXFIELDSIZE ];
    char from[ SIP_MAXFIELDSIZE ];
    char callid[ SIP_MAXFIELDSIZE ];
    char via[ SIP_MAXFIELDSIZE ];
    char branch[ SIP_MAXFIELDSIZE ];
    char cseq[ SIP_MAXFIELDSIZE ];
    char itoa_buffer[ 65 ];
    // FIXME confirmar se nao preciso converter todos os ints com itoa
    if( decode_gettag( orig, "to: ", to ) == 0) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "from: ", from ) == 0) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "call-id: ", callid ) == 0) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    decode_branch( orig, branch );
    decode_cseq( orig, cseq );
 
    if( strlen( via ) > 6 ) {
        if( strcasecmp( ";rport", via+strlen( via )-6) == 0) {
            via[strlen(via)-6] = 0;
        }
    }
    strcpy( buffer, "ACK sip:" );
    itoa( this->peer_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, this->server_ip );
    strcat( buffer, ":" );
    itoa( this->server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " SIP/2.0\r\n" );
    strcat( buffer, "Via: SIP/2.0/UDP " );
    strcat( buffer, this->my_ip );
    strcat( buffer, ":" );
    itoa( this->my_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ";branch=" );
    strcat( buffer, branch );
    strcat( buffer, "\r\n" );
    strcat( buffer, "From: " );
    strcat( buffer, from );
    strcat( buffer, "\r\n" );
    strcat( buffer, "To: " );
    strcat( buffer, to );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Call-ID: " );
    strcat( buffer, callid );
    strcat( buffer, "\r\n" );
    strcat( buffer, "CSeq: " );
    strcat( buffer, cseq );
    strcat( buffer, " ACK\r\n" );
    strcat( buffer, "Max-Forwards: 70\r\n" );
    strcat( buffer, "Contact: " );
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    itoa( this->my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, this->my_ip );
    strcat( buffer, ":" );
    itoa( this->my_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">\r\n" );
    strcat( buffer, "User-Agent: VZtech/pabxdriver-" );
    strcat( buffer, SVNREV );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Content-Length: 0\r\n\r\n" );
    buffer[SIP_MAXMSGSIZE-1] = 0;
    return( buffer );
}
 
int Sip::get_return_code( char * buffer ){
    char a[32];
    int i = 0, j;
    if( strncmp( "SIP/", buffer, 4 ) != 0 ) return 0;
    if( strlen( buffer ) < 32) return 0;
    strncpy( a, buffer, 31 );
    a[ 31 ] = 0;
    while ( a[ i ] > ' ') i++;
    j = i+i;
    while( (a[ j ] >= '0') && ( a[ j ] <= '9') ) j++;
    a[ j ] = 0;
    return atoi( a + i + 1 );
}
 
char * Sip::build_generic_reply_package(char * buffer, unsigned char * orig, char * tag){
    char to[ SIP_MAXFIELDSIZE ];
    char from[ SIP_MAXFIELDSIZE ];
    char callid[ SIP_MAXFIELDSIZE ];
    char cseq[ SIP_MAXFIELDSIZE ];
    char via[ SIP_MAXFIELDSIZE ];
 
    if( decode_gettag( orig, "to: ", to ) == 0) {
        buffer[0] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "from: ", from ) == 0) {
        buffer[0] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "call-id: ", callid ) == 0) {
        buffer[0] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "cseq: ", cseq ) == 0) {
        buffer[0] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "via: ", via ) == 0) {
        buffer[0] = 0;
        return NULL;
    }
 
    if (strlen(via) > 6) {
        if (strcasecmp(";rport",via+strlen(via)-6)==0) {
            via[strlen(via)-6] = 0;
        }
    }
 
    strcpy( buffer, "SIP/2.0 " );
    strcat( buffer, tag );
    strcat( buffer, "\r\n" );
    strcat( buffer, "To: " );
    strcat( buffer, to );
    strcat( buffer, "\r\n" );
    strcat( buffer, "From: " );
    strcat( buffer, from );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Call-ID: " );
    strcat( buffer, callid );
    strcat( buffer, "\r\n" );
    strcat( buffer, "CSeq: " );
    strcat( buffer, cseq );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Via: " );
    strcat( buffer, via );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Server: VZtech/pabxdriver-" );
    strcat( buffer, SVNREV );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Content-Length: 0\r\n\r\n" );
    buffer[ SIP_MAXMSGSIZE - 1 ] = 0;
    return( buffer );
}
char * Sip::build_trying_package( char * buffer, unsigned char * orig ){   
    // FIXME trocar 100 para itoa( 100 ... )
    build_generic_reply_package( buffer, orig, "100 Trying" );
    return( buffer );
}
 
char * Sip::build_busy_package( char * buffer, unsigned char * orig ){   
    // FIXME trocar 100 para itoa( 100 ... )
    build_generic_reply_package( buffer, orig, "486 Busy Here");
    return( buffer );
}
char * Sip::build_reply_package( char * buffer, unsigned char * orig ){
    char to[ SIP_MAXFIELDSIZE ];
    char from[ SIP_MAXFIELDSIZE ];
    char callid[ SIP_MAXFIELDSIZE ];
    char cseq[ SIP_MAXFIELDSIZE ];
    char via[ SIP_MAXFIELDSIZE ];
    char tag[ SIP_MAXFIELDSIZE ];
 
    if( decode_gettag( orig, "to: ", to ) == 0) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "from: ", from ) == 0) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "call-id: ", callid ) == 0 ) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "cseq: ", cseq) == 0 ) {
        buffer[ 0 ] = 0;
        return NULL;
    }
    if( decode_gettag( orig, "via: ", via) == 0 ) {
        buffer[ 0 ] = 0;
        return NULL;
    }
 
    if (strlen(via) > 6) {
        if (strcasecmp(";rport",via+strlen(via)-6)==0) {
            via[strlen(via)-6] = 0;
        }
    }
    fill_random(tag,18);
    
    strcpy( buffer, "SIP/2.0 200 OK\r\n" );
    strcat( buffer, "To: " );
    strcat( buffer, to );
    strcat( buffer, ";tag=" );
    strcat( buffer, tag );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "From: " );
    strcat( buffer, from );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "Call-ID: " );
    strcat( buffer, callid );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "CSeq: " );
    strcat( buffer, cseq );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "Via: " );
    strcat( buffer, via );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "Server: VZtech/pabxdriver-" );
    strcat( buffer, SVNREV );
    strcat( buffer, "\r\n" );
    strcat( buffer, "Content-Length: 0\r\n" );
    strcat( buffer, SIP_ALLOW );
    strcat( buffer, "\r\n\r\n" );
    
    buffer[ SIP_MAXMSGSIZE - 1 ] = 0;
    return( buffer );
}
char * Sip::fill_random16h(char * buffer ){
    fill_random( buffer, 16 );
    buffer[ 7 ] = '-';
    return( buffer );
}
 
char * Sip::fill_random( char * buffer, int size ){
    static uint16_t seed = time( NULL );
    seed += 1;
    srand( seed );
 
    int i;
    for (i=0; i<size; i++) {
        buffer[ i ] = fill_random_aux[ rand() & 0x3f ];
    }
    buffer[ size ] = 0;
    return( buffer );
}
 
int Sip::get_cseq( void ){
    static unsigned int cseq = 0;
    if( cseq == 0 ) {
        /* initial value, random number */
        cseq = rand();
        cseq &= 0x7fff;
    }
    cseq++;
    cseq &= 0x7fff;
    if( cseq == 0 ) cseq++;
    return cseq;
}
 
char * Sip::decode_cseq( unsigned char * package, char * cseq ){
    char pkg[ 2048 ], cs[ 2048 ];
    if( decode_gettag( package, "cseq: ", pkg ) != 0) {
        int i = 0;
        strcpy( cs, pkg );
        while( ( cs[ i ] != 0 ) && ( cs[ i ] != ' ' ) ) i++;
        cs[ i ] = 0;
        strcpy( cseq, cs );
    } else {
        cseq[ 0 ] = 0;
    }
    return( cseq );
}
 
char * Sip::decode_branch( unsigned char * package, char * branch ){
    char pkg[ 2048 ];
    if( decode_gettag( package, "branch=", pkg ) != 0 ) {
        int i = 0;
        strcpy( branch, pkg );
        while( ( branch[ i ] != 0 ) && ( branch[ i ] != ';' ) ) i++;
        branch[ i ] = 0;
    } else {
        branch[ 0 ] = 0;
    }
    return( branch );
}
int Sip::decode_gettag( unsigned char * package, char * tag, char * out ){
    int size, i, cmpsize;
    cmpsize = strlen( tag );
    size = strlen( ( char * )package )-cmpsize;
    for ( i=0; i<size; i++) {
        if( strncasecmp( tag, (char*)package+i, cmpsize ) == 0) {
            char * s;
            s = (char*)package+i+cmpsize;
            register int j = 0;
            while ((s[ j ] != '\r') && (s[ j ] != '\n')) j++;
            strncpy( out, s, j ); // copy string to output
            out[ j ] = 0; // terminate string
            return 1; // found
        }
    }
    return 0; // not found
}
 
int Sip::get_id( void ){
    return this->id;
}
int Sip::get_my_rtp_port( void ){
    return this->my_rtp_port;
}
inline int Sip::fill_random_rtp_port(){  
    // o range [ 16384 - 32767 ] eh configuravel no server
    return ( ( this->my_ext + 16384 ) > 32767 ) ? ( ( this->my_ext + 16384 ) % ( 32767 - 16384 ) + 16384 ) : this->my_ext + 16384;
}
 
void Sip::change_sip_server(){
    // just in case sip server don't answer, invite another server
    // mudar para os sets
    set_server_ip( get_next_server_ip( this->buffer) );
    set_server_ext( get_next_server_ext() );
    set_server_port( get_next_server_port() );
    registry();
}
 
char * Sip::get_next_server_ip( char * server_ip ){
    strcpy( server_ip, this->server_ip );
    return server_ip;
}
int Sip::get_next_server_port(){
    return this->server_port;
}
int Sip::get_next_server_ext(){
    return this->peer_ext;
}
void Sip::set_server_port( int new_server_port ){
    this->server_port = new_server_port;
}
void Sip::set_server_ext( int new_server_ext ){
    this->peer_ext = new_server_ext;
}
void Sip::set_server_ip( char * new_server_ip ){
    strcpy( this->server_ip, new_server_ip );
    this->server_ip[19] = 0;
}

/*  Retorna 
    = 0 :: ok
    < 0 :: tive problemas
    > 0 :: devo remover essa call do vetor de calls 
*/
int Sip::listen_SIP_server( void ){
    sock.set_blocking( false, 3 ); // verificar isso com mais cuidado depois
    uint8_t read = sock.receiveFrom( sip_server, this->buffer, sizeof( this->buffer ) );
    if( read > 0 ){
        debug_msg( "-- SIP recebeu algo --" );
        if( !( strncasecmp( buffer, "bye", strlen("bye") ) ) ){
            char ans[ 2000 ];
            build_reply_package( ans, (unsigned char*)buffer );
            sock.sendTo( sip_server, ans, sizeof( ans ) );
            
            debug_msg(" Server request BYE to %d ext", my_ext );
            return( this->my_ext );
        }else if( !( strncasecmp( buffer, "options", strlen("options") ) ) ){
            char ans[ 2000 ];
            debug_msg(" Options received ");
            build_reply_package( ans, (unsigned char*)buffer );
            sock.sendTo( sip_server, ans, sizeof( ans ) );
        }
    }
    return( 0 ); 
}

void Sip::set_ext( int ext ){
    my_ext = ext;
}

void Sip::set_port( int port ){
    my_port = port;
}

void Sip::send_bye( void ){
    build_bye_package( this->buffer );
    sock.sendTo( sip_server, build_bye_package( this->buffer ), sizeof( this->buffer ) );
}

void Sip::send_unregistry_pkg(){
    build_unregistry_package( this->buffer );
    for( register int i = 0; i < 7; i++ )
        sock.sendTo( sip_server, build_bye_package( this->buffer ), sizeof( this->buffer ) );
}

char * Sip::build_unregistry_package( char * buffer ){
    char branch[ SIP_MAXFIELDSIZE ];
    char tag[ SIP_MAXFIELDSIZE ];
    char callid[ SIP_MAXFIELDSIZE ];
    fill_random16h( branch );
    fill_random( tag, 18 );
    fill_random16h( callid );
    char itoa_buffer[ 65 ];
    strcpy( buffer, "REGISTER sip:" );
    strcat( buffer, server_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " SIP/2.0\r\nVia: SIP/2.0/UDP " );
    strcat( buffer, my_ip );
    strcat( buffer, ":" );
    itoa( my_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ";branch=" );
    strcat( buffer, branch );
    strcat( buffer, "\r\nFrom: " );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" ); 
    strcat( buffer, server_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">;tag=" );
    strcat( buffer, tag );
    strcat( buffer, "\r\nTo: " );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, server_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">\r\nCall-ID: " );
    strcat( buffer, callid );
    strcat( buffer, "\r\nCSeq: " );
    itoa( get_cseq(), itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " REGISTER\r\n" );
    strcat( buffer, "Max-Forwards: " );
    itoa( 70, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "\r\n" );
    
    strcat( buffer, "Contact: " );
    itoa( my_ext, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, " <sip:" );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "@" );
    strcat( buffer, my_ip );
    strcat( buffer, ":" );
    itoa( server_port, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, ">;expires=0\r\n" );
    /*
    strcat( buffer, ">;expires=" );
    itoa( 0, itoa_buffer, 10 );
    strcat( buffer, itoa_buffer );
    strcat( buffer, "\r\n" );
    */
    
    strcat( buffer, "User-Agent: VZtech/pabxdriver-" );
    strcat( buffer, SVNREV );
    strcat( buffer, "\r\nContent-Length: 0\r\n" );
    strcat( buffer, SIP_ALLOW );
    strcat( buffer, "\r\n\r\n" );              
    buffer[ SIP_MAXMSGSIZE - 1 ] = 0;
    return buffer;
}