zoneminder/src/zm_remote_camera_http.cpp

//
// ZoneMinder Remote Camera Class Implementation, $Date$, $Revision$
// Copyright (C) 2001-2008 Philip Coombes
// 
// 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  02111-1307, USA.
// 

#include "zm_remote_camera_http.h"

#include "zm_mem_utils.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>

RemoteCameraHttp::RemoteCameraHttp( int p_id, const std::string &p_method, const std::string &p_host, const std::string &p_port, const std::string &p_path, int p_width, int p_height, int p_colours, int p_brightness, int p_contrast, int p_hue, int p_colour, bool p_capture ) :
    RemoteCamera( p_id, "http", p_host, p_port, p_path, p_width, p_height, p_colours, p_brightness, p_contrast, p_hue, p_colour, p_capture )
{
    sd = -1;

    timeout.tv_sec = 0;
    timeout.tv_usec = 0;

    if ( p_method == "simple" )
        method = SIMPLE;
    else if ( p_method == "regexp" )
        method = REGEXP;
    else
        Fatal( "Unrecognised method '%s' when creating HTTP camera %d", p_method.c_str(), id );
    if ( capture )
    {
        Initialise();
    }
}

RemoteCameraHttp::~RemoteCameraHttp()
{
    if ( capture )
    {
        Terminate();
    }
}

void RemoteCameraHttp::Initialise()
{
    RemoteCamera::Initialise();

    if ( request.empty() )
    {
        request = stringtf( "GET %s HTTP/%s\r\n", path.c_str(), config.http_version );
        request += stringtf( "User-Agent: %s/%s\r\n", config.http_ua, ZM_VERSION );
        request += stringtf( "Host: %s\r\n", host .c_str());
        if ( strcmp( config.http_version, "1.0" ) == 0 )
            request += stringtf( "Connection: Keep-Alive\r\n" );
        if ( !auth.empty() )
            request += stringtf( "Authorization: Basic %s\r\n", auth64.c_str() );
        request += "\r\n";
        Debug( 2, "Request: %s", request.c_str() );
    }

    if ( !timeout.tv_sec )
    {
        timeout.tv_sec = config.http_timeout/1000; 
        timeout.tv_usec = (config.http_timeout%1000)*1000;
    }

    int max_size = width*height*colours;

    buffer.size( max_size );

    mode = SINGLE_IMAGE;
    format = UNDEF;
    state = HEADER;
}

int RemoteCameraHttp::Connect()
{
    if ( sd < 0 )
    {
        sd = socket( hp->h_addrtype, SOCK_STREAM, 0 );
        if ( sd < 0 )
        {
            Error( "Can't create socket: %s", strerror(errno) );
            return( -1 );
        }

        if ( connect( sd, (struct sockaddr *)&sa, sizeof(sa) ) < 0 )
        {
            Error( "Can't connect to remote camera: %s", strerror(errno) );
            Disconnect();
            return( -1 );
        }
    }
    Debug( 3, "Connected to host, socket = %d", sd );
    return( sd );
}

int RemoteCameraHttp::Disconnect()
{
    close( sd );
    sd = -1;
    Debug( 3, "Disconnected from host" );
    return( 0 );
}

int RemoteCameraHttp::SendRequest()
{
    if ( write( sd, request.data(), request.length() ) < 0 )
    {
        Error( "Can't write: %s", strerror(errno) );
        Disconnect();
        return( -1 );
    }
    format = UNDEF;
    state = HEADER;
    Debug( 3, "Request sent" );
    return( 0 );
}

int RemoteCameraHttp::ReadData( Buffer &buffer, int bytes_expected )
{
    fd_set rfds;
    FD_ZERO(&rfds);
    FD_SET(sd, &rfds);

    struct timeval temp_timeout = timeout;

    int n_found = select( sd+1, &rfds, NULL, NULL, &temp_timeout );
    if( n_found == 0 )
    {
        Warning( "Select timed out" );
        Disconnect();
        return( 0 );
    }
    else if ( n_found < 0)
    {
        Error( "Select error: %s", strerror(errno) );
        return( -1 );
    }

    int total_bytes_to_read = 0;

    if ( bytes_expected )
    {
        total_bytes_to_read = bytes_expected;
    }
    else
    {
        if ( ioctl( sd, FIONREAD, &total_bytes_to_read ) < 0 )
        {
            Error( "Can't ioctl(): %s", strerror(errno) );
            return( -1 );
        }

        if ( total_bytes_to_read == 0 )
        {
            Debug( 3, "Socket closed" );
            Disconnect();
            return( 0 );
        }
    }
    Debug( 3, "Expecting %d bytes", total_bytes_to_read );

    int total_bytes_read = 0;
    do
    {
        static unsigned char temp_buffer[ZM_NETWORK_BUFSIZ];
        int bytes_to_read = (unsigned int)total_bytes_to_read>(unsigned int)sizeof(temp_buffer)?sizeof(temp_buffer):total_bytes_to_read;
        int bytes_read = read( sd, temp_buffer, bytes_to_read );

        if ( bytes_read < 0)
        {
            Error( "Read error: %s", strerror(errno) );
            return( -1 );
        }
        else if ( bytes_read == 0)
        {
            Debug( 3, "Socket closed" );
            Disconnect();
            return( 0 );
        }
        else if ( bytes_read < bytes_to_read )
        {
            Error( "Incomplete read, expected %d, got %d", bytes_to_read, bytes_read );
            return( -1 );
        }
        Debug( 3, "Read %d bytes", bytes_read );
        buffer.append( temp_buffer, bytes_read );
        total_bytes_read += bytes_read;
        total_bytes_to_read -= bytes_read;
    }
    while ( total_bytes_to_read );

    return( total_bytes_read );
}

int RemoteCameraHttp::GetResponse()
{
#if HAVE_LIBPCRE
    if ( method == REGEXP )
    {
        const char *header = 0;
        int header_len = 0;
        const char *http_version = 0;
        int status_code = 0;
        const char *status_mesg = 0;
        const char *connection_type = "";
        int content_length = 0;
        const char *content_type = "";
        const char *content_boundary = "";
        const char *subheader = 0;
        int subheader_len = 0;
        //int subcontent_length = 0;
        //const char *subcontent_type = "";

        while ( true )
        {
            switch( state )
            {
                case HEADER :
                {
                    static RegExpr *header_expr = 0;
                    static RegExpr *status_expr = 0;
                    static RegExpr *connection_expr = 0;
                    static RegExpr *content_length_expr = 0;
                    static RegExpr *content_type_expr = 0;

                    int buffer_len = ReadData( buffer );
                    if ( buffer_len == 0 )
                    {
                        Error( "Connection dropped by remote end" );
                        return( 0 );
                    }
                    else if ( buffer_len < 0 )
                    {
                        Error( "Unable to read header data" );
                        return( -1 );
                    }
                    if ( !header_expr )
                        header_expr = new RegExpr( "^(.+?\r?\n\r?\n)", PCRE_DOTALL );
                    if ( header_expr->Match( (char*)buffer, buffer.size() ) == 2 )
                    {
                        header = header_expr->MatchString( 1 );
                        header_len = header_expr->MatchLength( 1 );
                        Debug( 4, "Captured header (%d bytes):\n'%s'", header_len, header );

                        if ( !status_expr )
                            status_expr = new RegExpr( "^HTTP/(1\\.[01]) +([0-9]+) +(.+?)\r?\n", PCRE_CASELESS );
                        if ( status_expr->Match( header, header_len ) < 4 )
                        {
                            Error( "Unable to extract HTTP status from header" );
                            return( -1 );
                        }
                        http_version = status_expr->MatchString( 1 );
                        status_code = atoi( status_expr->MatchString( 2 ) );
                        status_mesg = status_expr->MatchString( 3 );

                        if ( status_code < 200 || status_code > 299 )
                        {
                            Error( "Invalid response status %d: %s", status_code, status_mesg );
                            return( -1 );
                        }
                        Debug( 3, "Got status '%d' (%s), http version %s", status_code, status_mesg, http_version );

                        if ( !connection_expr )
                            connection_expr = new RegExpr( "Connection: ?(.+?)\r?\n", PCRE_CASELESS );
                        if ( connection_expr->Match( header, header_len ) == 2 )
                        {
                            connection_type = connection_expr->MatchString( 1 );
                            Debug( 3, "Got connection '%s'", connection_type );
                        }

                        if ( !content_length_expr )
                            content_length_expr = new RegExpr( "Content-length: ?([0-9]+)\r?\n", PCRE_CASELESS );
                        if ( content_length_expr->Match( header, header_len ) == 2 )
                        {
                            content_length = atoi( content_length_expr->MatchString( 1 ) );
                            Debug( 3, "Got content length '%d'", content_length );
                        }

                        if ( !content_type_expr )
                            content_type_expr = new RegExpr( "Content-type: ?(.+?)(?:; ?boundary=(.+?))?\r?\n", PCRE_CASELESS );
                        if ( content_type_expr->Match( header, header_len ) >= 2 )
                        {
                            content_type = content_type_expr->MatchString( 1 );
                            Debug( 3, "Got content type '%s'\n", content_type );
                            if ( content_type_expr->MatchCount() > 2 )
                            {
                                content_boundary = content_type_expr->MatchString( 2 );
                                Debug( 3, "Got content boundary '%s'", content_boundary );
                            }
                        }

                        if ( !strcasecmp( content_type, "image/jpeg" ) || !strcasecmp( content_type, "image/jpg" ) )
                        {
                            // Single image
                            mode = SINGLE_IMAGE;
                            format = JPEG;
                            state = CONTENT;
                        }
                        else if ( !strcasecmp( content_type, "image/x-rgb" ) )
                        {
                            // Single image
                            mode = SINGLE_IMAGE;
                            format = X_RGB;
                            state = CONTENT;
                        }
                        else if ( !strcasecmp( content_type, "image/x-rgbz" ) )
                        {
                            // Single image
                            mode = SINGLE_IMAGE;
                            format = X_RGBZ;
                            state = CONTENT;
                        }
                        else if ( !strcasecmp( content_type, "multipart/x-mixed-replace" ) )
                        {
                            // Image stream, so start processing
                            if ( !content_boundary[0] )
                            {
                                Error( "No content boundary found in header '%s'", header );
                                return( -1 );
                            }
                            mode = MULTI_IMAGE;
                            state = SUBHEADER;
                        }
                        //else if ( !strcasecmp( content_type, "video/mpeg" ) || !strcasecmp( content_type, "video/mpg" ) )
                        //{
                            //// MPEG stream, coming soon!
                        //}
                        else
                        {
                            Error( "Unrecognised content type '%s'", content_type );
                            return( -1 );
                        }
                        buffer.consume( header_len );
                    }
                    else
                    {
                        Debug( 3, "Unable to extract header from stream, retrying" );
                        //return( -1 );
                    }
                    break;
                }
                case SUBHEADER :
                {
                    static RegExpr *subheader_expr = 0;
                    static RegExpr *subcontent_length_expr = 0;
                    static RegExpr *subcontent_type_expr = 0;

                    if ( !subheader_expr )
                    {
                        char subheader_pattern[256] = "";
                        snprintf( subheader_pattern, sizeof(subheader_pattern), "^((?:\r?\n){0,2}?(?:--)?%s\r?\n.+?\r?\n\r?\n)", content_boundary );
                        subheader_expr = new RegExpr( subheader_pattern, PCRE_DOTALL );
                    }
                    if ( subheader_expr->Match( (char *)buffer, (int)buffer ) == 2 )
                    {
                        subheader = subheader_expr->MatchString( 1 );
                        subheader_len = subheader_expr->MatchLength( 1 );
                        Debug( 4, "Captured subheader (%d bytes):'%s'", subheader_len, subheader );

                        if ( !subcontent_length_expr )
                            subcontent_length_expr = new RegExpr( "Content-length: ?([0-9]+)\r?\n", PCRE_CASELESS );
                        if ( subcontent_length_expr->Match( subheader, subheader_len ) == 2 )
                        {
                            content_length = atoi( subcontent_length_expr->MatchString( 1 ) );
                            Debug( 3, "Got subcontent length '%d'", content_length );
                        }

                        if ( !subcontent_type_expr )
                            subcontent_type_expr = new RegExpr( "Content-type: ?(.+?)\r?\n", PCRE_CASELESS );
                        if ( subcontent_type_expr->Match( subheader, subheader_len ) == 2 )
                        {
                            content_type = subcontent_type_expr->MatchString( 1 );
                            Debug( 3, "Got subcontent type '%s'", content_type );
                        }

                        buffer.consume( subheader_len );
                        state = CONTENT;
                    }
                    else
                    {
                        Debug( 3, "Unable to extract subheader from stream, retrying" );
                        int buffer_len = ReadData( buffer );
                        if ( buffer_len == 0 )
                        {
                            Error( "Connection dropped by remote end" );
                            return( 0 );
                        }
                        else if ( buffer_len < 0 )
                        {
                            return( -1 );
                        }
                    }
                    break;
                }
                case CONTENT :
                {
                    if ( !strcasecmp( content_type, "image/jpeg" ) || !strcasecmp( content_type, "image/jpg" ) )
                    {
                        format = JPEG;
                    }
                    else if ( !strcasecmp( content_type, "image/x-rgb" ) )
                    {
                        format = X_RGB;
                    }
                    else if ( !strcasecmp( content_type, "image/x-rgbz" ) )
                    {
                        format = X_RGBZ;
                    }
                    else
                    {
                        Error( "Found unsupported content type '%s'", content_type );
                        return( -1 );
                    }

                    if ( content_length )
                    {
                        while ( buffer.size() < (unsigned int)content_length )
                        {
                            int buffer_len = ReadData( buffer );
                            if ( buffer_len == 0 )
                            {
                                Error( "Connection dropped by remote end" );
                                return( 0 );
                            }
                            else if ( buffer_len < 0 )
                            {
                                Error( "Unable to read content" );
                                return( -1 );
                            }
                        }
                        Debug( 3, "Got end of image by length, content-length = %d", content_length );
                    }
                    else
                    {
                        while ( !content_length )
                        {
                            int buffer_len = ReadData( buffer );
                            if ( buffer_len == 0 )
                            {
                                if ( mode == MULTI_IMAGE )
                                {
                                    Error( "Connection dropped by remote end" );
                                    return( 0 );
                                }
                            }
                            else if ( buffer_len < 0 )
                            {
                                Error( "Unable to read content" );
                                return( -1 );
                            }
                            static RegExpr *content_expr = 0;
                            if ( buffer_len )
                            {
                                if ( mode == MULTI_IMAGE )
                                {
                                    if ( !content_expr )
                                    {
                                        char content_pattern[256] = "";
                                        snprintf( content_pattern, sizeof(content_pattern), "^(.+?)(?:\r?\n)*(?:--)?%s\r?\n", content_boundary );
                                        content_expr = new RegExpr( content_pattern, PCRE_DOTALL );
                                    }
                                    if ( content_expr->Match( buffer, buffer.size() ) == 2 )
                                    {
                                        content_length = content_expr->MatchLength( 1 );
                                        Debug( 3, "Got end of image by pattern, content-length = %d", content_length );
                                    }
                                }
                            }
                            else
                            {
                                content_length = buffer.size();
                                Debug( 3, "Got end of image by closure, content-length = %d", content_length );
                                if ( mode == SINGLE_IMAGE )
                                {
                                    if ( !content_expr )
                                    {
                                        content_expr = new RegExpr( "^(.+?)(?:\r?\n){1,2}?$", PCRE_DOTALL );
                                    }
                                    if ( content_expr->Match( buffer, buffer.size() ) == 2 )
                                    {
                                        content_length = content_expr->MatchLength( 1 );
                                        Debug( 3, "Trimmed end of image, new content-length = %d", content_length );
                                    }
                                }
                            }
                        }
                    }
                    if ( mode == SINGLE_IMAGE )
                    {
                        state = HEADER;
                        Disconnect();
                    }
                    else
                    {
                        state = SUBHEADER;
                    }
                    Debug( 3, "Returning %d (%d) bytes of captured content", content_length, buffer.size() );
                    return( content_length );
                }
                case HEADERCONT :
                case SUBHEADERCONT :
                {
                    // Ignore
                    break;
                }
            }
        }
    }
    else
#endif // HAVE_LIBPCRE
    {
        if ( method == REGEXP )
        {
            Warning( "Unable to use netcam regexps as not compiled with libpcre" );
        }
        static const char *http_match = "HTTP/";
        static const char *connection_match = "Connection:";
        static const char *content_length_match = "Content-length:";
        static const char *content_type_match = "Content-type:";
        static const char *boundary_match = "boundary=";
        static int http_match_len = 0;
        static int connection_match_len = 0;
        static int content_length_match_len = 0;
        static int content_type_match_len = 0;
        static int boundary_match_len = 0;

        if ( !http_match_len )
            http_match_len = strlen( http_match );
        if ( !connection_match_len )
            connection_match_len = strlen( connection_match );
        if ( !content_length_match_len )
            content_length_match_len = strlen( content_length_match );
        if ( !content_type_match_len )
            content_type_match_len = strlen( content_type_match );
        if ( !boundary_match_len )
            boundary_match_len = strlen( boundary_match );

        static int n_headers;
        //static char *headers[32];

        static int n_subheaders;
        //static char *subheaders[32];

        static char *http_header;
        static char *connection_header;
        static char *content_length_header;
        static char *content_type_header;
        static char *boundary_header;
        static char subcontent_length_header[32];
        static char subcontent_type_header[64];
    
        static char http_version[16];
        static char status_code[16];
        static char status_mesg[256];
        static char connection_type[32];
        static int content_length;
        static char content_type[32];
        static char content_boundary[64];
        static int content_boundary_len;

        while ( true )
        {
            switch( state )
            {
                case HEADER :
                {
                    n_headers = 0;
                    http_header = 0;
                    connection_header = 0;
                    content_length_header = 0;
                    content_type_header = 0;

                    http_version[0] = '\0';
                    status_code [0]= '\0';
                    status_mesg [0]= '\0';
                    connection_type [0]= '\0';
                    content_length = 0;
                    content_type[0] = '\0';
                    content_boundary[0] = '\0';
                    content_boundary_len = 0;
                }
                case HEADERCONT :
                {
                    int buffer_len = ReadData( buffer );
                    if ( buffer_len == 0 )
                    {
                        Error( "Connection dropped by remote end" );
                        return( 0 );
                    }
                    else if ( buffer_len < 0 )
                    {
                        Error( "Unable to read header" );
                        return( -1 );
                    }

                    char *crlf = 0;
                    char *header_ptr = (char *)buffer;
                    int header_len = buffer.size();
                    bool all_headers = false;

                    while( true )
                    {
                        int crlf_len = memspn( header_ptr, "\r\n", header_len );
                        if ( n_headers )
                        {
                            if ( (crlf_len == 2 && !strncmp( header_ptr, "\n\n", crlf_len )) || (crlf_len == 4 && !strncmp( header_ptr, "\r\n\r\n", crlf_len )) )
                            {
                                *header_ptr = '\0';
                                header_ptr += crlf_len;
                                header_len -= buffer.consume( header_ptr-(char *)buffer );
                                all_headers = true;
                                break;
                            }
                        }
                        if ( crlf_len )
                        {
                            if ( header_len == crlf_len )
                            {
                                break;
                            }
                            else
                            {
                                *header_ptr = '\0';
                                header_ptr += crlf_len;
                                header_len -= buffer.consume( header_ptr-(char *)buffer );
                            }
                        }

                        Debug( 6, "%s", header_ptr );
                        if ( (crlf = mempbrk( header_ptr, "\r\n", header_len )) )
                        {
                            //headers[n_headers++] = header_ptr;
                            n_headers++;

                            if ( !http_header && (strncasecmp( header_ptr, http_match, http_match_len ) == 0) )
                            {
                                http_header = header_ptr+http_match_len;
                                Debug( 6, "Got http header '%s'", header_ptr );
                            }
                            else if ( !connection_header && (strncasecmp( header_ptr, connection_match, connection_match_len) == 0) )
                            {
                                connection_header = header_ptr+connection_match_len;
                                Debug( 6, "Got connection header '%s'", header_ptr );
                            }
                            else if ( !content_length_header && (strncasecmp( header_ptr, content_length_match, content_length_match_len) == 0) )
                            {
                                content_length_header = header_ptr+content_length_match_len;
                                Debug( 6, "Got content length header '%s'", header_ptr );
                            }
                            else if ( !content_type_header && (strncasecmp( header_ptr, content_type_match, content_type_match_len) == 0) )
                            {
                                content_type_header = header_ptr+content_type_match_len;
                                Debug( 6, "Got content type header '%s'", header_ptr );
                            }
                            else
                            {
                                Debug( 6, "Got ignored header '%s'", header_ptr );
                            }
                            header_ptr = crlf;
                            header_len -= buffer.consume( header_ptr-(char *)buffer );
                        }
                        else
                        {
                            // No end of line found
                            break;
                        }
                    }

                    if ( all_headers )
                    {
                        char *start_ptr, *end_ptr;

                        if ( !http_header )
                        {
                            Error( "Unable to extract HTTP status from header" );
                            return( -1 );
                        }

                        start_ptr = http_header;
                        end_ptr = start_ptr+strspn( start_ptr, "10." );

                        memset( http_version, 0, sizeof(http_version) );
                        strncpy( http_version, start_ptr, end_ptr-start_ptr );

                        start_ptr = end_ptr;
                        start_ptr += strspn( start_ptr, " " );
                        end_ptr = start_ptr+strspn( start_ptr, "0123456789" );

                        memset( status_code, 0, sizeof(status_code) );
                        strncpy( status_code, start_ptr, end_ptr-start_ptr );
                        int status = atoi( status_code );

                        start_ptr = end_ptr;
                        start_ptr += strspn( start_ptr, " " );
                        strcpy( status_mesg, start_ptr );

                        if ( status < 200 || status > 299 )
                        {
                            Error( "Invalid response status %s: %s", status_code, status_mesg );
                            return( -1 );
                        }
                        Debug( 3, "Got status '%d' (%s), http version %s", status, status_mesg, http_version );

                        if ( connection_header )
                        {
                            memset( connection_type, 0, sizeof(connection_type) );
                            start_ptr = connection_header + strspn( connection_header, " " );
                            strcpy( connection_type, start_ptr );
                            Debug( 3, "Got connection '%s'", connection_type );
                        }
                        if ( content_length_header )
                        {
                            start_ptr = content_length_header + strspn( content_length_header, " " );
                            content_length = atoi( start_ptr );
                            Debug( 3, "Got content length '%d'", content_length );
                        }
                        if ( content_type_header )
                        {
                            memset( content_type, 0, sizeof(content_type) );
                            start_ptr = content_type_header + strspn( content_type_header, " " );
                            if ( (end_ptr = strchr( start_ptr, ';' )) )
                            {
                                strncpy( content_type, start_ptr, end_ptr-start_ptr );
                                Debug( 3, "Got content type '%s'", content_type );

                                start_ptr = end_ptr + strspn( end_ptr, "; " );

                                if ( strncasecmp( start_ptr, boundary_match, boundary_match_len ) == 0 )
                                {
                                    start_ptr += boundary_match_len;
                                    start_ptr += strspn( start_ptr, "-" );
                                    content_boundary_len = sprintf( content_boundary, "--%s", start_ptr );
                                    Debug( 3, "Got content boundary '%s'", content_boundary );
                                }
                                else
                                {
                                    Error( "No content boundary found in header '%s'", content_type_header );
                                }
                            }
                            else
                            {
                                strcpy( content_type, start_ptr );
                                Debug( 3, "Got content type '%s'", content_type );
                            }
                        }

                        if ( !strcasecmp( content_type, "image/jpeg" ) || !strcasecmp( content_type, "image/jpg" ) )
                        {
                            // Single image
                            mode = SINGLE_IMAGE;
                            format = JPEG;
                            state = CONTENT;
                        }
                        else if ( !strcasecmp( content_type, "image/x-rgb" ) )
                        {
                            // Single image
                            mode = SINGLE_IMAGE;
                            format = X_RGB;
                            state = CONTENT;
                        }
                        else if ( !strcasecmp( content_type, "image/x-rgbz" ) )
                        {
                            // Single image
                            mode = SINGLE_IMAGE;
                            format = X_RGBZ;
                            state = CONTENT;
                        }
                        else if ( !strcasecmp( content_type, "multipart/x-mixed-replace" ) )
                        {
                            // Image stream, so start processing
                            if ( !content_boundary[0] )
                            {
                                Error( "No content boundary found in header '%s'", content_type_header );
                                return( -1 );
                            }
                            mode = MULTI_IMAGE;
                            state = SUBHEADER;
                        }
                        //else if ( !strcasecmp( content_type, "video/mpeg" ) || !strcasecmp( content_type, "video/mpg" ) )
                        //{
                            //// MPEG stream, coming soon!
                        //}
                        else
                        {
                            Error( "Unrecognised content type '%s'", content_type );
                            return( -1 );
                        }
                    }
                    else
                    {
                        Debug( 3, "Unable to extract entire header from stream, continuing" );
                        state = HEADERCONT;
                        //return( -1 );
                    }
                    break;
                }
                case SUBHEADER :
                {
                    n_subheaders = 0;
                    boundary_header = 0;
                    subcontent_length_header[0] = '\0';
                    subcontent_type_header[0] = '\0';
                    content_length = 0;
                    content_type[0] = '\0';
                }
                case SUBHEADERCONT :
                {
                    char *crlf = 0;
                    char *subheader_ptr = (char *)buffer;
                    int subheader_len = buffer.size();
                    bool all_headers = false;

                    while( true )
                    {
                        int crlf_len = memspn( subheader_ptr, "\r\n", subheader_len );
                        if ( n_subheaders )
                        {
                            if ( (crlf_len == 2 && !strncmp( subheader_ptr, "\n\n", crlf_len )) || (crlf_len == 4 && !strncmp( subheader_ptr, "\r\n\r\n", crlf_len )) )
                            {
                                *subheader_ptr = '\0';
                                subheader_ptr += crlf_len;
                                subheader_len -= buffer.consume( subheader_ptr-(char *)buffer );
                                all_headers = true;
                                break;
                            }
                        }
                        if ( crlf_len )
                        {
                            if ( subheader_len == crlf_len )
                            {
                                break;
                            }
                            else
                            {
                                *subheader_ptr = '\0';
                                subheader_ptr += crlf_len;
                                subheader_len -= buffer.consume( subheader_ptr-(char *)buffer );
                            }
                        }

                        Debug( 6, "%d: %s", subheader_len, subheader_ptr );

                        if ( (crlf = mempbrk( subheader_ptr, "\r\n", subheader_len )) )
                        {
                            //subheaders[n_subheaders++] = subheader_ptr;
                            n_subheaders++;

                            if ( !boundary_header && (strncasecmp( subheader_ptr, content_boundary, content_boundary_len ) == 0) )
                            {
                                boundary_header = subheader_ptr;
                                Debug( 4, "Got boundary subheader '%s'", subheader_ptr );
                            }
                            else if ( !subcontent_length_header[0] && (strncasecmp( subheader_ptr, content_length_match, content_length_match_len) == 0) )
                            {
                                strncpy( subcontent_length_header, subheader_ptr+content_length_match_len, sizeof(subcontent_length_header) );
                                *(subcontent_length_header+strcspn( subcontent_length_header, "\r\n" )) = '\0';
                                Debug( 4, "Got content length subheader '%s'", subcontent_length_header );
                            }
                            else if ( !subcontent_type_header[0] && (strncasecmp( subheader_ptr, content_type_match, content_type_match_len) == 0) )
                            {
                                strncpy( subcontent_type_header, subheader_ptr+content_type_match_len, sizeof(subcontent_type_header) );
                                *(subcontent_type_header+strcspn( subcontent_type_header, "\r\n" )) = '\0';
                                Debug( 4, "Got content type subheader '%s'", subcontent_type_header );
                            }
                            else
                            {
                                Debug( 6, "Got ignored subheader '%s' found", subheader_ptr );
                            }
                            subheader_ptr = crlf;
                            subheader_len -= buffer.consume( subheader_ptr-(char *)buffer );
                        }
                        else
                        {
                            // No line end found
                            break;
                        }
                    }
                    
                    if ( all_headers && boundary_header )
                    {
                        char *start_ptr/*, *end_ptr*/;

                        Debug( 3, "Got boundary '%s'", boundary_header );

                        if ( subcontent_length_header[0] )
                        {
                            start_ptr = subcontent_length_header + strspn( subcontent_length_header, " " );
                            content_length = atoi( start_ptr );
                            Debug( 3, "Got subcontent length '%d'", content_length );
                        }
                        if ( subcontent_type_header[0] )
                        {
                            memset( content_type, 0, sizeof(content_type) );
                            start_ptr = subcontent_type_header + strspn( subcontent_type_header, " " );
                            strcpy( content_type, start_ptr );
                            Debug( 3, "Got subcontent type '%s'", content_type );
                        }
                        state = CONTENT;
                    }
                    else
                    {
                        Debug( 3, "Unable to extract subheader from stream, retrying" );
                        int buffer_len = ReadData( buffer );
                        if ( buffer_len == 0 )
                        {
                            Error( "Connection dropped by remote end" );
                            return( 0 );
                        }
                        else if ( buffer_len < 0 )
                        {
                            Error( "Unable to read subheader" );
                            return( -1 );
                        }
                        state = SUBHEADERCONT;
                    }
                    break;
                }
                case CONTENT :
                {
                    if ( !strcasecmp( content_type, "image/jpeg" ) || !strcasecmp( content_type, "image/jpg" ) )
                    {
                        format = JPEG;
                    }
                    else if ( !strcasecmp( content_type, "image/x-rgb" ) )
                    {
                        format = X_RGB;
                    }
                    else if ( !strcasecmp( content_type, "image/x-rgbz" ) )
                    {
                        format = X_RGBZ;
                    }
                    else
                    {
                        Error( "Found unsupported content type '%s'", content_type );
                        return( -1 );
                    }

                    if ( format == JPEG && buffer.size() >= 2 )
                    {
                        if ( buffer[0] != 0xff || buffer[1] != 0xd8 )
                        {
                            Error( "Found bogus jpeg header '%02x%02x'", buffer[0], buffer[1] );
                            return( -1 );
                        }
                    }

                    if ( content_length )
                    {
                        while ( buffer.size() < (unsigned int)content_length )
                        {
                            //int buffer_len = ReadData( buffer, content_length-buffer.size() );
                            int buffer_len = ReadData( buffer );
                            if ( buffer_len == 0 )
                            {
                                Error( "Connection dropped by remote end" );
                                return( 0 );
                            }
                            else if ( buffer_len < 0 )
                            {
                                Error( "Unable to read content" );
                                return( -1 );
                            }
                        }
                        Debug( 3, "Got end of image by length, content-length = %d", content_length );
                    }
                    else
                    {
                        int content_pos = 0;
                        while ( !content_length )
                        {
                            int buffer_len = ReadData( buffer );
                            if ( buffer_len == 0 )
                            {
                                if ( mode == MULTI_IMAGE )
                                {
                                    Error( "Connection dropped by remote end" );
                                    return( 0 );
                                }
                            }
                            else if ( buffer_len < 0 )
                            {
                                Error( "Unable to read content" );
                                return( -1 );
                            }
                            int buffer_size = buffer.size();
                            if ( buffer_len )
                            {
                                if ( mode == MULTI_IMAGE )
                                {
                                    while ( char *start_ptr = (char *)memstr( (char *)buffer+content_pos, "\r\n--", buffer_size-content_pos ) )
                                    {
                                        content_length = start_ptr - (char *)buffer;
                                        Debug( 3, "Got end of image by pattern (crlf--), content-length = %d", content_length );
                                        break;
                                    }
                                }
                            }
                            else
                            {
                                content_length = buffer_size;
                                Debug( 3, "Got end of image by closure, content-length = %d", content_length );
                                if ( mode == SINGLE_IMAGE )
                                {
                                    char *end_ptr = (char *)buffer+buffer_size;

                                    while( *end_ptr == '\r' || *end_ptr == '\n' )
                                    {
                                        content_length--;
                                        end_ptr--;
                                    }

                                    if ( end_ptr != ((char *)buffer+buffer_size) )
                                    {
                                        Debug( 3, "Trimmed end of image, new content-length = %d", content_length );
                                    }
                                }
                            }
                        }
                    }
                    if ( mode == SINGLE_IMAGE )
                    {
                        state = HEADER;
                        Disconnect();
                    }
                    else
                    {
                        state = SUBHEADER;
                    }

                    if ( format == JPEG && buffer.size() >= 2 )
                    {
                        if ( buffer[0] != 0xff || buffer[1] != 0xd8 )
                        {
                            Error( "Found bogus jpeg header '%02x%02x'", buffer[0], buffer[1] );
                            return( -1 );
                        }
                    }

                    Debug( 3, "Returning %d (%d) bytes of captured content", content_length, buffer.size() );
                    return( content_length );
                }
            }
        }
    }
    return( 0 );
}

int RemoteCameraHttp::PreCapture()
{
    if ( sd < 0 )
    {
        Connect();
        if ( sd < 0 )
        {
            Error( "Unable to connect to camera" );
            return( -1 );
        }
        mode = SINGLE_IMAGE;
        buffer.clear();
    }
    if ( mode == SINGLE_IMAGE )
    {
        if ( SendRequest() < 0 )
        {
            Error( "Unable to send request" );
            Disconnect();
            return( -1 );
        }
    }
    return( 0 );
}

int RemoteCameraHttp::Capture( Image &image )
{
    int content_length = GetResponse();
    if ( content_length == 0 )
    {
        Warning( "Unable to capture image, retrying" );
        return( 1 );
    }
    if ( content_length < 0 )
    {
        Error( "Unable to get response" );
        Disconnect();
        return( -1 );
    }
    switch( format )
    {
        case JPEG :
        {
            if ( !image.DecodeJpeg( buffer.extract( content_length ), content_length, colours, subpixelorder ) )
            {
                Error( "Unable to decode jpeg" );
                Disconnect();
                return( -1 );
            }
            break;
        }
        case X_RGB :
        {
            if ( content_length != image.Size() )
            {
                Error( "Image length mismatch, expected %d bytes, content length was %d", image.Size(), content_length );
                Disconnect();
                return( -1 );
            }
            image.Assign( width, height, colours, subpixelorder, buffer, imagesize );
            break;
        }
        case X_RGBZ :
        {
            if ( !image.Unzip( buffer.extract( content_length ), content_length ) )
            {
                Error( "Unable to unzip RGB image" );
                Disconnect();
                return( -1 );
            }
            image.Assign( width, height, colours, subpixelorder, buffer, imagesize );
            break;
        }
        default :
        {
            Error( "Unexpected image format encountered" );
            Disconnect();
            return( -1 );
        }
    }
    return( 0 );
}

int RemoteCameraHttp::PostCapture()
{
    return( 0 );
}