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kc3-lang/libxml2/nanohttp.c

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  • Author : Nick Wellnhofer
    Date : 2023-09-18 14:45:10
    Hash : 4e1c13eb
    Message : debug: Remove debugging code This is barely useful these days and only clutters the code base.

  • nanohttp.c
  • /*
     * nanohttp.c: minimalist HTTP GET implementation to fetch external subsets.
     *             focuses on size, streamability, reentrancy and portability
     *
     * This is clearly not a general purpose HTTP implementation
     * If you look for one, check:
     *         http://www.w3.org/Library/
     *
     * See Copyright for the status of this software.
     *
     * daniel@veillard.com
     */
    
    #define IN_LIBXML
    #include "libxml.h"
    
    #ifdef LIBXML_HTTP_ENABLED
    #include <string.h>
    #include <ctype.h>
    #include <stdlib.h>
    #include <errno.h>
    
    #ifdef HAVE_UNISTD_H
    #include <unistd.h>
    #elif defined (_WIN32)
    #include <io.h>
    #endif
    #ifdef HAVE_SYS_SOCKET_H
    #include <sys/socket.h>
    #endif
    #ifdef HAVE_NETINET_IN_H
    #include <netinet/in.h>
    #endif
    #ifdef HAVE_ARPA_INET_H
    #include <arpa/inet.h>
    #endif
    #ifdef HAVE_NETDB_H
    #include <netdb.h>
    #endif
    #ifdef HAVE_FCNTL_H
    #include <fcntl.h>
    #endif
    #ifdef HAVE_SYS_TIME_H
    #include <sys/time.h>
    #endif
    #ifndef HAVE_POLL_H
    #ifdef HAVE_SYS_SELECT_H
    #include <sys/select.h>
    #endif
    #else
    #include <poll.h>
    #endif
    #ifdef LIBXML_ZLIB_ENABLED
    #include <zlib.h>
    #endif
    
    
    #ifdef VMS
    #include <stropts>
    #define XML_SOCKLEN_T unsigned int
    #endif
    
    #if defined(_WIN32)
    #include <wsockcompat.h>
    #endif
    
    #include <libxml/globals.h>
    #include <libxml/xmlerror.h>
    #include <libxml/xmlmemory.h>
    #include <libxml/parser.h> /* for xmlStr(n)casecmp() */
    #include <libxml/nanohttp.h>
    #include <libxml/globals.h>
    #include <libxml/uri.h>
    
    #include "private/error.h"
    #include "private/io.h"
    
    /**
     * A couple portability macros
     */
    #ifndef _WINSOCKAPI_
    #define closesocket(s) close(s)
    #define SOCKET int
    #define INVALID_SOCKET (-1)
    #endif
    
    #ifndef XML_SOCKLEN_T
    #define XML_SOCKLEN_T unsigned int
    #endif
    
    #define GETHOSTBYNAME_ARG_CAST (char *)
    #define SEND_ARG2_CAST (char *)
    
    #ifdef STANDALONE
    #define xmlStrncasecmp(a, b, n) strncasecmp((char *)a, (char *)b, n)
    #define xmlStrcasecmpi(a, b) strcasecmp((char *)a, (char *)b)
    #endif
    
    #define XML_NANO_HTTP_MAX_REDIR	10
    
    #define XML_NANO_HTTP_CHUNK	4096
    
    #define XML_NANO_HTTP_CLOSED	0
    #define XML_NANO_HTTP_WRITE	1
    #define XML_NANO_HTTP_READ	2
    #define XML_NANO_HTTP_NONE	4
    
    typedef struct xmlNanoHTTPCtxt {
        char *protocol;	/* the protocol name */
        char *hostname;	/* the host name */
        int port;		/* the port */
        char *path;		/* the path within the URL */
        char *query;	/* the query string */
        SOCKET fd;		/* the file descriptor for the socket */
        int state;		/* WRITE / READ / CLOSED */
        char *out;		/* buffer sent (zero terminated) */
        char *outptr;	/* index within the buffer sent */
        char *in;		/* the receiving buffer */
        char *content;	/* the start of the content */
        char *inptr;	/* the next byte to read from network */
        char *inrptr;	/* the next byte to give back to the client */
        int inlen;		/* len of the input buffer */
        int last;		/* return code for last operation */
        int returnValue;	/* the protocol return value */
        int version;        /* the protocol version */
        int ContentLength;  /* specified content length from HTTP header */
        char *contentType;	/* the MIME type for the input */
        char *location;	/* the new URL in case of redirect */
        char *authHeader;	/* contents of {WWW,Proxy}-Authenticate header */
        char *encoding;	/* encoding extracted from the contentType */
        char *mimeType;	/* Mime-Type extracted from the contentType */
    #ifdef LIBXML_ZLIB_ENABLED
        z_stream *strm;	/* Zlib stream object */
        int usesGzip;	/* "Content-Encoding: gzip" was detected */
    #endif
    } xmlNanoHTTPCtxt, *xmlNanoHTTPCtxtPtr;
    
    static int initialized = 0;
    static char *proxy = NULL;	 /* the proxy name if any */
    static int proxyPort;	/* the proxy port if any */
    static unsigned int timeout = 60;/* the select() timeout in seconds */
    
    static int xmlNanoHTTPFetchContent( void * ctx, char ** ptr, int * len );
    
    /**
     * xmlHTTPErrMemory:
     * @extra:  extra information
     *
     * Handle an out of memory condition
     */
    static void
    xmlHTTPErrMemory(const char *extra)
    {
        __xmlSimpleError(XML_FROM_HTTP, XML_ERR_NO_MEMORY, NULL, NULL, extra);
    }
    
    /**
     * A portability function
     */
    static int socket_errno(void) {
    #ifdef _WINSOCKAPI_
        int err = WSAGetLastError();
        switch(err) {
            case WSAECONNRESET:
                return(ECONNRESET);
            case WSAEINPROGRESS:
                return(EINPROGRESS);
            case WSAEINTR:
                return(EINTR);
            case WSAESHUTDOWN:
                return(ESHUTDOWN);
            case WSAEWOULDBLOCK:
                return(EWOULDBLOCK);
            default:
                return(err);
        }
    #else
        return(errno);
    #endif
    }
    
    /**
     * xmlNanoHTTPInit:
     *
     * Initialize the HTTP protocol layer.
     * Currently it just checks for proxy information
     */
    
    void
    xmlNanoHTTPInit(void) {
        const char *env;
    #ifdef _WINSOCKAPI_
        WSADATA wsaData;
    #endif
    
        if (initialized)
    	return;
    
    #ifdef _WINSOCKAPI_
        if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0)
    	return;
    #endif
    
        if (proxy == NULL) {
    	proxyPort = 80;
    	env = getenv("no_proxy");
    	if (env && ((env[0] == '*') && (env[1] == 0)))
    	    goto done;
    	env = getenv("http_proxy");
    	if (env != NULL) {
    	    xmlNanoHTTPScanProxy(env);
    	    goto done;
    	}
    	env = getenv("HTTP_PROXY");
    	if (env != NULL) {
    	    xmlNanoHTTPScanProxy(env);
    	    goto done;
    	}
        }
    done:
        initialized = 1;
    }
    
    /**
     * xmlNanoHTTPCleanup:
     *
     * Cleanup the HTTP protocol layer.
     */
    
    void
    xmlNanoHTTPCleanup(void) {
        if (proxy != NULL) {
    	xmlFree(proxy);
    	proxy = NULL;
        }
    #ifdef _WINSOCKAPI_
        if (initialized)
    	WSACleanup();
    #endif
        initialized = 0;
        return;
    }
    
    /**
     * xmlNanoHTTPScanURL:
     * @ctxt:  an HTTP context
     * @URL:  The URL used to initialize the context
     *
     * (Re)Initialize an HTTP context by parsing the URL and finding
     * the protocol host port and path it indicates.
     */
    
    static void
    xmlNanoHTTPScanURL(xmlNanoHTTPCtxtPtr ctxt, const char *URL) {
        xmlURIPtr uri;
        int len;
    
        /*
         * Clear any existing data from the context
         */
        if (ctxt->protocol != NULL) {
            xmlFree(ctxt->protocol);
    	ctxt->protocol = NULL;
        }
        if (ctxt->hostname != NULL) {
            xmlFree(ctxt->hostname);
    	ctxt->hostname = NULL;
        }
        if (ctxt->path != NULL) {
            xmlFree(ctxt->path);
    	ctxt->path = NULL;
        }
        if (ctxt->query != NULL) {
            xmlFree(ctxt->query);
    	ctxt->query = NULL;
        }
        if (URL == NULL) return;
    
        uri = xmlParseURIRaw(URL, 1);
        if (uri == NULL)
    	return;
    
        if ((uri->scheme == NULL) || (uri->server == NULL)) {
    	xmlFreeURI(uri);
    	return;
        }
    
        ctxt->protocol = xmlMemStrdup(uri->scheme);
        /* special case of IPv6 addresses, the [] need to be removed */
        if ((uri->server != NULL) && (*uri->server == '[')) {
            len = strlen(uri->server);
    	if ((len > 2) && (uri->server[len - 1] == ']')) {
    	    ctxt->hostname = (char *) xmlCharStrndup(uri->server + 1, len -2);
    	} else
    	    ctxt->hostname = xmlMemStrdup(uri->server);
        } else
    	ctxt->hostname = xmlMemStrdup(uri->server);
        if (uri->path != NULL)
    	ctxt->path = xmlMemStrdup(uri->path);
        else
    	ctxt->path = xmlMemStrdup("/");
        if (uri->query != NULL)
    	ctxt->query = xmlMemStrdup(uri->query);
        if (uri->port != 0)
    	ctxt->port = uri->port;
    
        xmlFreeURI(uri);
    }
    
    /**
     * xmlNanoHTTPScanProxy:
     * @URL:  The proxy URL used to initialize the proxy context
     *
     * (Re)Initialize the HTTP Proxy context by parsing the URL and finding
     * the protocol host port it indicates.
     * Should be like http://myproxy/ or http://myproxy:3128/
     * A NULL URL cleans up proxy information.
     */
    
    void
    xmlNanoHTTPScanProxy(const char *URL) {
        xmlURIPtr uri;
    
        if (proxy != NULL) {
            xmlFree(proxy);
    	proxy = NULL;
        }
        proxyPort = 0;
    
        if (URL == NULL) return;
    
        uri = xmlParseURIRaw(URL, 1);
        if ((uri == NULL) || (uri->scheme == NULL) ||
    	(strcmp(uri->scheme, "http")) || (uri->server == NULL)) {
    	__xmlIOErr(XML_FROM_HTTP, XML_HTTP_URL_SYNTAX, "Syntax Error\n");
    	if (uri != NULL)
    	    xmlFreeURI(uri);
    	return;
        }
    
        proxy = xmlMemStrdup(uri->server);
        if (uri->port != 0)
    	proxyPort = uri->port;
    
        xmlFreeURI(uri);
    }
    
    /**
     * xmlNanoHTTPNewCtxt:
     * @URL:  The URL used to initialize the context
     *
     * Allocate and initialize a new HTTP context.
     *
     * Returns an HTTP context or NULL in case of error.
     */
    
    static xmlNanoHTTPCtxtPtr
    xmlNanoHTTPNewCtxt(const char *URL) {
        xmlNanoHTTPCtxtPtr ret;
    
        ret = (xmlNanoHTTPCtxtPtr) xmlMalloc(sizeof(xmlNanoHTTPCtxt));
        if (ret == NULL) {
            xmlHTTPErrMemory("allocating context");
            return(NULL);
        }
    
        memset(ret, 0, sizeof(xmlNanoHTTPCtxt));
        ret->port = 80;
        ret->returnValue = 0;
        ret->fd = INVALID_SOCKET;
        ret->ContentLength = -1;
    
        xmlNanoHTTPScanURL(ret, URL);
    
        return(ret);
    }
    
    /**
     * xmlNanoHTTPFreeCtxt:
     * @ctxt:  an HTTP context
     *
     * Frees the context after closing the connection.
     */
    
    static void
    xmlNanoHTTPFreeCtxt(xmlNanoHTTPCtxtPtr ctxt) {
        if (ctxt == NULL) return;
        if (ctxt->hostname != NULL) xmlFree(ctxt->hostname);
        if (ctxt->protocol != NULL) xmlFree(ctxt->protocol);
        if (ctxt->path != NULL) xmlFree(ctxt->path);
        if (ctxt->query != NULL) xmlFree(ctxt->query);
        if (ctxt->out != NULL) xmlFree(ctxt->out);
        if (ctxt->in != NULL) xmlFree(ctxt->in);
        if (ctxt->contentType != NULL) xmlFree(ctxt->contentType);
        if (ctxt->encoding != NULL) xmlFree(ctxt->encoding);
        if (ctxt->mimeType != NULL) xmlFree(ctxt->mimeType);
        if (ctxt->location != NULL) xmlFree(ctxt->location);
        if (ctxt->authHeader != NULL) xmlFree(ctxt->authHeader);
    #ifdef LIBXML_ZLIB_ENABLED
        if (ctxt->strm != NULL) {
    	inflateEnd(ctxt->strm);
    	xmlFree(ctxt->strm);
        }
    #endif
    
        ctxt->state = XML_NANO_HTTP_NONE;
        if (ctxt->fd != INVALID_SOCKET) closesocket(ctxt->fd);
        ctxt->fd = INVALID_SOCKET;
        xmlFree(ctxt);
    }
    
    /**
     * xmlNanoHTTPSend:
     * @ctxt:  an HTTP context
     *
     * Send the input needed to initiate the processing on the server side
     * Returns number of bytes sent or -1 on error.
     */
    
    static int
    xmlNanoHTTPSend(xmlNanoHTTPCtxtPtr ctxt, const char *xmt_ptr, int outlen)
    {
        int total_sent = 0;
    #ifdef HAVE_POLL_H
        struct pollfd p;
    #else
        struct timeval tv;
        fd_set wfd;
    #endif
    
        if ((ctxt->state & XML_NANO_HTTP_WRITE) && (xmt_ptr != NULL)) {
            while (total_sent < outlen) {
                int nsent = send(ctxt->fd, SEND_ARG2_CAST (xmt_ptr + total_sent),
                                 outlen - total_sent, 0);
    
                if (nsent > 0)
                    total_sent += nsent;
                else if ((nsent == -1) &&
    #if defined(EAGAIN) && EAGAIN != EWOULDBLOCK
                         (socket_errno() != EAGAIN) &&
    #endif
                         (socket_errno() != EWOULDBLOCK)) {
                    __xmlIOErr(XML_FROM_HTTP, 0, "send failed\n");
                    if (total_sent == 0)
                        total_sent = -1;
                    break;
                } else {
                    /*
                     * No data sent
                     * Since non-blocking sockets are used, wait for
                     * socket to be writable or default timeout prior
                     * to retrying.
                     */
    #ifndef HAVE_POLL_H
    #ifndef _WINSOCKAPI_
                    if (ctxt->fd > FD_SETSIZE)
                        return -1;
    #endif
    
                    tv.tv_sec = timeout;
                    tv.tv_usec = 0;
                    FD_ZERO(&wfd);
    #ifdef _MSC_VER
    #pragma warning(push)
    #pragma warning(disable: 4018)
    #endif
                    FD_SET(ctxt->fd, &wfd);
    #ifdef _MSC_VER
    #pragma warning(pop)
    #endif
                    (void) select(ctxt->fd + 1, NULL, &wfd, NULL, &tv);
    #else
                    p.fd = ctxt->fd;
                    p.events = POLLOUT;
                    (void) poll(&p, 1, timeout * 1000);
    #endif /* !HAVE_POLL_H */
                }
            }
        }
    
        return total_sent;
    }
    
    /**
     * xmlNanoHTTPRecv:
     * @ctxt:  an HTTP context
     *
     * Read information coming from the HTTP connection.
     * This is a blocking call (but it blocks in select(), not read()).
     *
     * Returns the number of byte read or -1 in case of error.
     */
    
    static int
    xmlNanoHTTPRecv(xmlNanoHTTPCtxtPtr ctxt)
    {
    #ifdef HAVE_POLL_H
        struct pollfd p;
    #else
        fd_set rfd;
        struct timeval tv;
    #endif
    
    
        while (ctxt->state & XML_NANO_HTTP_READ) {
            if (ctxt->in == NULL) {
                ctxt->in = (char *) xmlMallocAtomic(65000);
                if (ctxt->in == NULL) {
                    xmlHTTPErrMemory("allocating input");
                    ctxt->last = -1;
                    return (-1);
                }
                ctxt->inlen = 65000;
                ctxt->inptr = ctxt->content = ctxt->inrptr = ctxt->in;
            }
            if (ctxt->inrptr > ctxt->in + XML_NANO_HTTP_CHUNK) {
                int delta = ctxt->inrptr - ctxt->in;
                int len = ctxt->inptr - ctxt->inrptr;
    
                memmove(ctxt->in, ctxt->inrptr, len);
                ctxt->inrptr -= delta;
                ctxt->content -= delta;
                ctxt->inptr -= delta;
            }
            if ((ctxt->in + ctxt->inlen) < (ctxt->inptr + XML_NANO_HTTP_CHUNK)) {
                int d_inptr = ctxt->inptr - ctxt->in;
                int d_content = ctxt->content - ctxt->in;
                int d_inrptr = ctxt->inrptr - ctxt->in;
                char *tmp_ptr = ctxt->in;
    
                ctxt->inlen *= 2;
                ctxt->in = (char *) xmlRealloc(tmp_ptr, ctxt->inlen);
                if (ctxt->in == NULL) {
                    xmlHTTPErrMemory("allocating input buffer");
                    xmlFree(tmp_ptr);
                    ctxt->last = -1;
                    return (-1);
                }
                ctxt->inptr = ctxt->in + d_inptr;
                ctxt->content = ctxt->in + d_content;
                ctxt->inrptr = ctxt->in + d_inrptr;
            }
            ctxt->last = recv(ctxt->fd, ctxt->inptr, XML_NANO_HTTP_CHUNK, 0);
            if (ctxt->last > 0) {
                ctxt->inptr += ctxt->last;
                return (ctxt->last);
            }
            if (ctxt->last == 0) {
                return (0);
            }
            if (ctxt->last == -1) {
                switch (socket_errno()) {
                    case EINPROGRESS:
                    case EWOULDBLOCK:
    #if defined(EAGAIN) && EAGAIN != EWOULDBLOCK
                    case EAGAIN:
    #endif
                        break;
    
                    case ECONNRESET:
                    case ESHUTDOWN:
                        return (0);
    
                    default:
                        __xmlIOErr(XML_FROM_HTTP, 0, "recv failed\n");
                        return (-1);
                }
            }
    #ifdef HAVE_POLL_H
            p.fd = ctxt->fd;
            p.events = POLLIN;
            if ((poll(&p, 1, timeout * 1000) < 1)
    #if defined(EINTR)
                && (errno != EINTR)
    #endif
                )
                return (0);
    #else /* !HAVE_POLL_H */
    #ifndef _WINSOCKAPI_
            if (ctxt->fd > FD_SETSIZE)
                return 0;
    #endif
    
            tv.tv_sec = timeout;
            tv.tv_usec = 0;
            FD_ZERO(&rfd);
    
    #ifdef _MSC_VER
    #pragma warning(push)
    #pragma warning(disable: 4018)
    #endif
    
            FD_SET(ctxt->fd, &rfd);
    
    #ifdef _MSC_VER
    #pragma warning(pop)
    #endif
    
            if ((select(ctxt->fd + 1, &rfd, NULL, NULL, &tv) < 1)
    #if defined(EINTR)
                && (socket_errno() != EINTR)
    #endif
                )
                return (0);
    #endif /* !HAVE_POLL_H */
        }
        return (0);
    }
    
    /**
     * xmlNanoHTTPReadLine:
     * @ctxt:  an HTTP context
     *
     * Read one line in the HTTP server output, usually for extracting
     * the HTTP protocol information from the answer header.
     *
     * Returns a newly allocated string with a copy of the line, or NULL
     *         which indicate the end of the input.
     */
    
    static char *
    xmlNanoHTTPReadLine(xmlNanoHTTPCtxtPtr ctxt) {
        char buf[4096];
        char *bp = buf;
        int	rc;
    
        while (bp - buf < 4095) {
    	if (ctxt->inrptr == ctxt->inptr) {
    	    if ( (rc = xmlNanoHTTPRecv(ctxt)) == 0) {
    		if (bp == buf)
    		    return(NULL);
    		else
    		    *bp = 0;
    		return(xmlMemStrdup(buf));
    	    }
    	    else if ( rc == -1 ) {
    	        return ( NULL );
    	    }
    	}
    	*bp = *ctxt->inrptr++;
    	if (*bp == '\n') {
    	    *bp = 0;
    	    return(xmlMemStrdup(buf));
    	}
    	if (*bp != '\r')
    	    bp++;
        }
        buf[4095] = 0;
        return(xmlMemStrdup(buf));
    }
    
    
    /**
     * xmlNanoHTTPScanAnswer:
     * @ctxt:  an HTTP context
     * @line:  an HTTP header line
     *
     * Try to extract useful information from the server answer.
     * We currently parse and process:
     *  - The HTTP revision/ return code
     *  - The Content-Type, Mime-Type and charset used
     *  - The Location for redirect processing.
     *
     * Returns -1 in case of failure, the file descriptor number otherwise
     */
    
    static void
    xmlNanoHTTPScanAnswer(xmlNanoHTTPCtxtPtr ctxt, const char *line) {
        const char *cur = line;
    
        if (line == NULL) return;
    
        if (!strncmp(line, "HTTP/", 5)) {
            int version = 0;
    	int ret = 0;
    
    	cur += 5;
    	while ((*cur >= '0') && (*cur <= '9')) {
    	    version *= 10;
    	    version += *cur - '0';
    	    cur++;
    	}
    	if (*cur == '.') {
    	    cur++;
    	    if ((*cur >= '0') && (*cur <= '9')) {
    		version *= 10;
    		version += *cur - '0';
    		cur++;
    	    }
    	    while ((*cur >= '0') && (*cur <= '9'))
    		cur++;
    	} else
    	    version *= 10;
    	if ((*cur != ' ') && (*cur != '\t')) return;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if ((*cur < '0') || (*cur > '9')) return;
    	while ((*cur >= '0') && (*cur <= '9')) {
    	    ret *= 10;
    	    ret += *cur - '0';
    	    cur++;
    	}
    	if ((*cur != 0) && (*cur != ' ') && (*cur != '\t')) return;
    	ctxt->returnValue = ret;
            ctxt->version = version;
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"Content-Type:", 13)) {
            const xmlChar *charset, *last, *mime;
            cur += 13;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if (ctxt->contentType != NULL)
    	    xmlFree(ctxt->contentType);
    	ctxt->contentType = xmlMemStrdup(cur);
    	mime = (const xmlChar *) cur;
    	last = mime;
    	while ((*last != 0) && (*last != ' ') && (*last != '\t') &&
    	       (*last != ';') && (*last != ','))
    	    last++;
    	if (ctxt->mimeType != NULL)
    	    xmlFree(ctxt->mimeType);
    	ctxt->mimeType = (char *) xmlStrndup(mime, last - mime);
    	charset = xmlStrstr(BAD_CAST ctxt->contentType, BAD_CAST "charset=");
    	if (charset != NULL) {
    	    charset += 8;
    	    last = charset;
    	    while ((*last != 0) && (*last != ' ') && (*last != '\t') &&
    	           (*last != ';') && (*last != ','))
    		last++;
    	    if (ctxt->encoding != NULL)
    	        xmlFree(ctxt->encoding);
    	    ctxt->encoding = (char *) xmlStrndup(charset, last - charset);
    	}
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"ContentType:", 12)) {
            const xmlChar *charset, *last, *mime;
            cur += 12;
    	if (ctxt->contentType != NULL) return;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	ctxt->contentType = xmlMemStrdup(cur);
    	mime = (const xmlChar *) cur;
    	last = mime;
    	while ((*last != 0) && (*last != ' ') && (*last != '\t') &&
    	       (*last != ';') && (*last != ','))
    	    last++;
    	if (ctxt->mimeType != NULL)
    	    xmlFree(ctxt->mimeType);
    	ctxt->mimeType = (char *) xmlStrndup(mime, last - mime);
    	charset = xmlStrstr(BAD_CAST ctxt->contentType, BAD_CAST "charset=");
    	if (charset != NULL) {
    	    charset += 8;
    	    last = charset;
    	    while ((*last != 0) && (*last != ' ') && (*last != '\t') &&
    	           (*last != ';') && (*last != ','))
    		last++;
    	    if (ctxt->encoding != NULL)
    	        xmlFree(ctxt->encoding);
    	    ctxt->encoding = (char *) xmlStrndup(charset, last - charset);
    	}
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"Location:", 9)) {
            cur += 9;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if (ctxt->location != NULL)
    	    xmlFree(ctxt->location);
    	if (*cur == '/') {
    	    xmlChar *tmp_http = xmlStrdup(BAD_CAST "http://");
    	    xmlChar *tmp_loc =
    	        xmlStrcat(tmp_http, (const xmlChar *) ctxt->hostname);
    	    ctxt->location =
    	        (char *) xmlStrcat (tmp_loc, (const xmlChar *) cur);
    	} else {
    	    ctxt->location = xmlMemStrdup(cur);
    	}
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"WWW-Authenticate:", 17)) {
            cur += 17;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if (ctxt->authHeader != NULL)
    	    xmlFree(ctxt->authHeader);
    	ctxt->authHeader = xmlMemStrdup(cur);
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"Proxy-Authenticate:", 19)) {
            cur += 19;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if (ctxt->authHeader != NULL)
    	    xmlFree(ctxt->authHeader);
    	ctxt->authHeader = xmlMemStrdup(cur);
    #ifdef LIBXML_ZLIB_ENABLED
        } else if ( !xmlStrncasecmp( BAD_CAST line, BAD_CAST"Content-Encoding:", 17) ) {
    	cur += 17;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if ( !xmlStrncasecmp( BAD_CAST cur, BAD_CAST"gzip", 4) ) {
    	    ctxt->usesGzip = 1;
    
    	    ctxt->strm = xmlMalloc(sizeof(z_stream));
    
    	    if (ctxt->strm != NULL) {
    		ctxt->strm->zalloc = Z_NULL;
    		ctxt->strm->zfree = Z_NULL;
    		ctxt->strm->opaque = Z_NULL;
    		ctxt->strm->avail_in = 0;
    		ctxt->strm->next_in = Z_NULL;
    
    		inflateInit2( ctxt->strm, 31 );
    	    }
    	}
    #endif
        } else if ( !xmlStrncasecmp( BAD_CAST line, BAD_CAST"Content-Length:", 15) ) {
    	cur += 15;
    	ctxt->ContentLength = strtol( cur, NULL, 10 );
        }
    }
    
    /**
     * xmlNanoHTTPConnectAttempt:
     * @addr:  a socket address structure
     *
     * Attempt a connection to the given IP:port endpoint. It forces
     * non-blocking semantic on the socket, and allow 60 seconds for
     * the host to answer.
     *
     * Returns -1 in case of failure, the file descriptor number otherwise
     */
    
    static SOCKET
    xmlNanoHTTPConnectAttempt(struct sockaddr *addr)
    {
    #ifndef HAVE_POLL_H
        fd_set wfd;
    #ifdef _WINSOCKAPI_
        fd_set xfd;
    #endif
        struct timeval tv;
    #else /* !HAVE_POLL_H */
        struct pollfd p;
    #endif /* !HAVE_POLL_H */
        int status;
    
        int addrlen;
    
        SOCKET s;
    
    #ifdef SUPPORT_IP6
        if (addr->sa_family == AF_INET6) {
            s = socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP);
            addrlen = sizeof(struct sockaddr_in6);
        } else
    #endif
        {
            s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
            addrlen = sizeof(struct sockaddr_in);
        }
        if (s == INVALID_SOCKET) {
            __xmlIOErr(XML_FROM_HTTP, 0, "socket failed\n");
            return INVALID_SOCKET;
        }
    #ifdef _WINSOCKAPI_
        {
            u_long one = 1;
    
            status = ioctlsocket(s, FIONBIO, &one) == SOCKET_ERROR ? -1 : 0;
        }
    #else /* _WINSOCKAPI_ */
    #if defined(VMS)
        {
            int enable = 1;
    
            status = ioctl(s, FIONBIO, &enable);
        }
    #else /* VMS */
        if ((status = fcntl(s, F_GETFL, 0)) != -1) {
    #ifdef O_NONBLOCK
            status |= O_NONBLOCK;
    #else /* O_NONBLOCK */
    #ifdef F_NDELAY
            status |= F_NDELAY;
    #endif /* F_NDELAY */
    #endif /* !O_NONBLOCK */
            status = fcntl(s, F_SETFL, status);
        }
        if (status < 0) {
            __xmlIOErr(XML_FROM_HTTP, 0, "error setting non-blocking IO\n");
            closesocket(s);
            return INVALID_SOCKET;
        }
    #endif /* !VMS */
    #endif /* !_WINSOCKAPI_ */
    
        if (connect(s, addr, addrlen) == -1) {
            switch (socket_errno()) {
                case EINPROGRESS:
                case EWOULDBLOCK:
                    break;
                default:
                    __xmlIOErr(XML_FROM_HTTP, 0,
                               "error connecting to HTTP server");
                    closesocket(s);
                    return INVALID_SOCKET;
            }
        }
    #ifndef HAVE_POLL_H
        tv.tv_sec = timeout;
        tv.tv_usec = 0;
    
    #ifdef _MSC_VER
    #pragma warning(push)
    #pragma warning(disable: 4018)
    #endif
    #ifndef _WINSOCKAPI_
        if (s > FD_SETSIZE)
            return INVALID_SOCKET;
    #endif
        FD_ZERO(&wfd);
        FD_SET(s, &wfd);
    
    #ifdef _WINSOCKAPI_
        FD_ZERO(&xfd);
        FD_SET(s, &xfd);
    
        switch (select(s + 1, NULL, &wfd, &xfd, &tv))
    #else
        switch (select(s + 1, NULL, &wfd, NULL, &tv))
    #endif
    #ifdef _MSC_VER
    #pragma warning(pop)
    #endif
    
    #else /* !HAVE_POLL_H */
        p.fd = s;
        p.events = POLLOUT;
        switch (poll(&p, 1, timeout * 1000))
    #endif /* !HAVE_POLL_H */
    
        {
            case 0:
                /* Time out */
                __xmlIOErr(XML_FROM_HTTP, 0, "Connect attempt timed out");
                closesocket(s);
                return INVALID_SOCKET;
            case -1:
                /* Ermm.. ?? */
                __xmlIOErr(XML_FROM_HTTP, 0, "Connect failed");
                closesocket(s);
                return INVALID_SOCKET;
        }
    
    #ifndef HAVE_POLL_H
        if (FD_ISSET(s, &wfd)
    #ifdef _WINSOCKAPI_
            || FD_ISSET(s, &xfd)
    #endif
            )
    #else /* !HAVE_POLL_H */
        if (p.revents == POLLOUT)
    #endif /* !HAVE_POLL_H */
        {
            XML_SOCKLEN_T len;
    
            len = sizeof(status);
    #ifdef SO_ERROR
            if (getsockopt(s, SOL_SOCKET, SO_ERROR, (char *) &status, &len) <
                0) {
                /* Solaris error code */
                __xmlIOErr(XML_FROM_HTTP, 0, "getsockopt failed\n");
                closesocket(s);
                return INVALID_SOCKET;
            }
    #endif
            if (status) {
                __xmlIOErr(XML_FROM_HTTP, 0,
                           "Error connecting to remote host");
                closesocket(s);
                errno = status;
                return INVALID_SOCKET;
            }
        } else {
            /* pbm */
            __xmlIOErr(XML_FROM_HTTP, 0, "select failed\n");
            closesocket(s);
            return INVALID_SOCKET;
        }
    
        return (s);
    }
    
    /**
     * xmlNanoHTTPConnectHost:
     * @host:  the host name
     * @port:  the port number
     *
     * Attempt a connection to the given host:port endpoint. It tries
     * the multiple IP provided by the DNS if available.
     *
     * Returns -1 in case of failure, the file descriptor number otherwise
     */
    
    static SOCKET
    xmlNanoHTTPConnectHost(const char *host, int port)
    {
        struct sockaddr *addr = NULL;
        struct sockaddr_in sockin;
    
    #ifdef SUPPORT_IP6
        struct sockaddr_in6 sockin6;
    #endif
        SOCKET s;
    
        memset (&sockin, 0, sizeof(sockin));
    
    #if defined(SUPPORT_IP6)
        {
    	int status;
    	struct addrinfo hints, *res, *result;
    
            memset (&sockin6, 0, sizeof(sockin6));
    
    	result = NULL;
    	memset (&hints, 0,sizeof(hints));
    	hints.ai_socktype = SOCK_STREAM;
    
    	status = getaddrinfo (host, NULL, &hints, &result);
    	if (status) {
    	    __xmlIOErr(XML_FROM_HTTP, 0, "getaddrinfo failed\n");
    	    return INVALID_SOCKET;
    	}
    
    	for (res = result; res; res = res->ai_next) {
    	    if (res->ai_family == AF_INET) {
    		if ((size_t)res->ai_addrlen > sizeof(sockin)) {
    		    __xmlIOErr(XML_FROM_HTTP, 0, "address size mismatch\n");
    		    freeaddrinfo (result);
    		    return INVALID_SOCKET;
    		}
    		memcpy (&sockin, res->ai_addr, res->ai_addrlen);
    		sockin.sin_port = htons (port);
    		addr = (struct sockaddr *)&sockin;
    	    } else if (res->ai_family == AF_INET6) {
    		if ((size_t)res->ai_addrlen > sizeof(sockin6)) {
    		    __xmlIOErr(XML_FROM_HTTP, 0, "address size mismatch\n");
    		    freeaddrinfo (result);
    		    return INVALID_SOCKET;
    		}
    		memcpy (&sockin6, res->ai_addr, res->ai_addrlen);
    		sockin6.sin6_port = htons (port);
    		addr = (struct sockaddr *)&sockin6;
    	    } else
    		continue;              /* for */
    
    	    s = xmlNanoHTTPConnectAttempt (addr);
    	    if (s != INVALID_SOCKET) {
    		freeaddrinfo (result);
    		return (s);
    	    }
    	}
    
    	if (result)
    	    freeaddrinfo (result);
        }
    #else
        {
            struct hostent *h;
            struct in_addr ia;
            int i;
    
    	h = gethostbyname (GETHOSTBYNAME_ARG_CAST host);
    	if (h == NULL) {
    
    /*
     * Okay, I got fed up by the non-portability of this error message
     * extraction code. it work on Linux, if it work on your platform
     * and one want to enable it, send me the defined(foobar) needed
     */
    #if defined(HAVE_NETDB_H) && defined(HOST_NOT_FOUND) && defined(__linux__)
    	    const char *h_err_txt = "";
    
    	    switch (h_errno) {
    		case HOST_NOT_FOUND:
    		    h_err_txt = "Authoritative host not found";
    		    break;
    
    		case TRY_AGAIN:
    		    h_err_txt =
    			"Non-authoritative host not found or server failure.";
    		    break;
    
    		case NO_RECOVERY:
    		    h_err_txt =
    			"Non-recoverable errors:  FORMERR, REFUSED, or NOTIMP.";
    		    break;
    
    #ifdef NO_ADDRESS
    		case NO_ADDRESS:
    		    h_err_txt =
    			"Valid name, no data record of requested type.";
    		    break;
    #endif
    
    		default:
    		    h_err_txt = "No error text defined.";
    		    break;
    	    }
    	    __xmlIOErr(XML_FROM_HTTP, 0, h_err_txt);
    #else
    	    __xmlIOErr(XML_FROM_HTTP, 0, "Failed to resolve host");
    #endif
    	    return INVALID_SOCKET;
    	}
    
    	for (i = 0; h->h_addr_list[i]; i++) {
    	    if (h->h_addrtype == AF_INET) {
    		/* A records (IPv4) */
    		if ((unsigned int) h->h_length > sizeof(ia)) {
    		    __xmlIOErr(XML_FROM_HTTP, 0, "address size mismatch\n");
    		    return INVALID_SOCKET;
    		}
    		memcpy (&ia, h->h_addr_list[i], h->h_length);
    		sockin.sin_family = h->h_addrtype;
    		sockin.sin_addr = ia;
    		sockin.sin_port = (unsigned short)htons ((unsigned short)port);
    		addr = (struct sockaddr *) &sockin;
    	    } else
    		break;              /* for */
    
    	    s = xmlNanoHTTPConnectAttempt (addr);
    	    if (s != INVALID_SOCKET)
    		return (s);
    	}
        }
    #endif
    
        return INVALID_SOCKET;
    }
    
    
    /**
     * xmlNanoHTTPOpen:
     * @URL:  The URL to load
     * @contentType:  if available the Content-Type information will be
     *                returned at that location
     *
     * This function try to open a connection to the indicated resource
     * via HTTP GET.
     *
     * Returns NULL in case of failure, otherwise a request handler.
     *     The contentType, if provided must be freed by the caller
     */
    
    void*
    xmlNanoHTTPOpen(const char *URL, char **contentType) {
        if (contentType != NULL) *contentType = NULL;
        return(xmlNanoHTTPMethod(URL, NULL, NULL, contentType, NULL, 0));
    }
    
    /**
     * xmlNanoHTTPOpenRedir:
     * @URL:  The URL to load
     * @contentType:  if available the Content-Type information will be
     *                returned at that location
     * @redir: if available the redirected URL will be returned
     *
     * This function try to open a connection to the indicated resource
     * via HTTP GET.
     *
     * Returns NULL in case of failure, otherwise a request handler.
     *     The contentType, if provided must be freed by the caller
     */
    
    void*
    xmlNanoHTTPOpenRedir(const char *URL, char **contentType, char **redir) {
        if (contentType != NULL) *contentType = NULL;
        if (redir != NULL) *redir = NULL;
        return(xmlNanoHTTPMethodRedir(URL, NULL, NULL, contentType, redir, NULL,0));
    }
    
    /**
     * xmlNanoHTTPRead:
     * @ctx:  the HTTP context
     * @dest:  a buffer
     * @len:  the buffer length
     *
     * This function tries to read @len bytes from the existing HTTP connection
     * and saves them in @dest. This is a blocking call.
     *
     * Returns the number of byte read. 0 is an indication of an end of connection.
     *         -1 indicates a parameter error.
     */
    int
    xmlNanoHTTPRead(void *ctx, void *dest, int len) {
        xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;
    #ifdef LIBXML_ZLIB_ENABLED
        int bytes_read = 0;
        int orig_avail_in;
        int z_ret;
    #endif
    
        if (ctx == NULL) return(-1);
        if (dest == NULL) return(-1);
        if (len <= 0) return(0);
    
    #ifdef LIBXML_ZLIB_ENABLED
        if (ctxt->usesGzip == 1) {
            if (ctxt->strm == NULL) return(0);
    
            ctxt->strm->next_out = dest;
            ctxt->strm->avail_out = len;
    	ctxt->strm->avail_in = ctxt->inptr - ctxt->inrptr;
    
            while (ctxt->strm->avail_out > 0 &&
    	       (ctxt->strm->avail_in > 0 || xmlNanoHTTPRecv(ctxt) > 0)) {
                orig_avail_in = ctxt->strm->avail_in =
    			    ctxt->inptr - ctxt->inrptr - bytes_read;
                ctxt->strm->next_in = BAD_CAST (ctxt->inrptr + bytes_read);
    
                z_ret = inflate(ctxt->strm, Z_NO_FLUSH);
                bytes_read += orig_avail_in - ctxt->strm->avail_in;
    
                if (z_ret != Z_OK) break;
    	}
    
            ctxt->inrptr += bytes_read;
            return(len - ctxt->strm->avail_out);
        }
    #endif
    
        while (ctxt->inptr - ctxt->inrptr < len) {
            if (xmlNanoHTTPRecv(ctxt) <= 0) break;
        }
        if (ctxt->inptr - ctxt->inrptr < len)
            len = ctxt->inptr - ctxt->inrptr;
        memcpy(dest, ctxt->inrptr, len);
        ctxt->inrptr += len;
        return(len);
    }
    
    /**
     * xmlNanoHTTPClose:
     * @ctx:  the HTTP context
     *
     * This function closes an HTTP context, it ends up the connection and
     * free all data related to it.
     */
    void
    xmlNanoHTTPClose(void *ctx) {
        xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;
    
        if (ctx == NULL) return;
    
        xmlNanoHTTPFreeCtxt(ctxt);
    }
    
    
    /**
     * xmlNanoHTTPHostnameMatch:
     * @pattern: The pattern as it appears in no_proxy environment variable
     * @hostname: The hostname to test as it appears in the URL
     *
     * This function tests whether a given hostname matches a pattern. The pattern
     * usually is a token from the no_proxy environment variable. Wildcards in the
     * pattern are not supported.
     *
     * Returns true, iff hostname matches the pattern.
     */
    
    static int 
    xmlNanoHTTPHostnameMatch(const char *pattern, const char *hostname) {
        int idx_pattern, idx_hostname;
        const char * pattern_start;
    
        if (!pattern || *pattern == '\0' || !hostname)
    	return 0;
    
        /* Ignore trailing '.' */
        if (*pattern == '.') {
            idx_pattern = strlen(pattern) -1;
            pattern_start = pattern + 1;
        }
        else {
            idx_pattern = strlen(pattern);
            pattern_start = pattern;
        }
        idx_hostname = strlen(hostname);
    
        for (; idx_pattern >= 0 && idx_hostname >= 0; 
               --idx_pattern, --idx_hostname) {
    	if (tolower(pattern_start[idx_pattern]) != tolower(hostname[idx_hostname]))
    	    break;
        }
    
        return idx_pattern == -1 && (idx_hostname == -1|| hostname[idx_hostname] == '.');
    }
    
    
    /**
     * xmlNanoHTTPBypassProxy:
     * @hostname: The hostname as it appears in the URL
     *
     * This function evaluates the no_proxy environment variable and returns
     * whether the proxy server should be bypassed for a given host.
     *
     * Returns true, iff a proxy server should be bypassed for the given hostname.
     */
    
    static int
    xmlNanoHTTPBypassProxy(const char *hostname) {
        size_t envlen;
        char *env = getenv("no_proxy"), *cpy=NULL, *p=NULL;
        if (!env)
    	return 0;
    
        /* (Avoid strdup because it's not portable.) */
        envlen = strlen(env) + 1;
        cpy = xmlMalloc(envlen);
        memcpy(cpy, env, envlen);
        env = cpy;
    
        /* The remainder of the function is basically a tokenizing: */
        while (isspace(*env))
        	++env;
        if (*env == '\0') {
        	xmlFree(cpy);
    	return 0;
        }
    
        p = env;
        while (*env) {
    
        	if (*env != ',') {
    	    ++env;
    	    continue;
    	}
    
    	*(env++) = '\0';
    	if (xmlNanoHTTPHostnameMatch(p, hostname)) {
    	    xmlFree(cpy);
    	    return 1;
    	}
    
    	while (isspace(*env))
    	    ++env;
    	p = env;
        }
        if (xmlNanoHTTPHostnameMatch(p, hostname)) {
        	xmlFree(cpy);
        	return 1;
        }
    
        xmlFree(cpy);
        return 0;
    }
    
    
    /**
     * xmlNanoHTTPMethodRedir:
     * @URL:  The URL to load
     * @method:  the HTTP method to use
     * @input:  the input string if any
     * @contentType:  the Content-Type information IN and OUT
     * @redir:  the redirected URL OUT
     * @headers:  the extra headers
     * @ilen:  input length
     *
     * This function try to open a connection to the indicated resource
     * via HTTP using the given @method, adding the given extra headers
     * and the input buffer for the request content.
     *
     * Returns NULL in case of failure, otherwise a request handler.
     *     The contentType, or redir, if provided must be freed by the caller
     */
    
    void*
    xmlNanoHTTPMethodRedir(const char *URL, const char *method, const char *input,
                      char **contentType, char **redir,
    		  const char *headers, int ilen ) {
        xmlNanoHTTPCtxtPtr ctxt;
        char *bp, *p;
        int blen;
        SOCKET ret;
        int nbRedirects = 0;
        int use_proxy;
        char *redirURL = NULL;
    
        if (URL == NULL) return(NULL);
        if (method == NULL) method = "GET";
        xmlNanoHTTPInit();
    
    retry:
        if (redirURL == NULL) {
    	ctxt = xmlNanoHTTPNewCtxt(URL);
    	if (ctxt == NULL)
    	    return(NULL);
        } else {
    	ctxt = xmlNanoHTTPNewCtxt(redirURL);
    	if (ctxt == NULL)
    	    return(NULL);
    	ctxt->location = xmlMemStrdup(redirURL);
        }
    
        if ((ctxt->protocol == NULL) || (strcmp(ctxt->protocol, "http"))) {
    	__xmlIOErr(XML_FROM_HTTP, XML_HTTP_URL_SYNTAX, "Not a valid HTTP URI");
            xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
            return(NULL);
        }
        if (ctxt->hostname == NULL) {
    	__xmlIOErr(XML_FROM_HTTP, XML_HTTP_UNKNOWN_HOST,
    	           "Failed to identify host in URI");
            xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
            return(NULL);
        }
        use_proxy = proxy && !xmlNanoHTTPBypassProxy(ctxt->hostname);
        if (use_proxy) {
    	blen = strlen(ctxt->hostname) * 2 + 16;
    	ret = xmlNanoHTTPConnectHost(proxy, proxyPort);
        }
        else {
    	blen = strlen(ctxt->hostname);
    	ret = xmlNanoHTTPConnectHost(ctxt->hostname, ctxt->port);
        }
        if (ret == INVALID_SOCKET) {
            xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
            return(NULL);
        }
        ctxt->fd = ret;
    
        if (input == NULL)
    	ilen = 0;
        else
    	blen += 36;
    
        if (headers != NULL)
    	blen += strlen(headers) + 2;
        if (contentType && *contentType)
    	/* reserve for string plus 'Content-Type: \r\n" */
    	blen += strlen(*contentType) + 16;
        if (ctxt->query != NULL)
    	/* 1 for '?' */
    	blen += strlen(ctxt->query) + 1;
        blen += strlen(method) + strlen(ctxt->path) + 24;
    #ifdef LIBXML_ZLIB_ENABLED
        /* reserve for possible 'Accept-Encoding: gzip' string */
        blen += 23;
    #endif
        if (ctxt->port != 80) {
    	/* reserve space for ':xxxxx', incl. potential proxy */
    	if (use_proxy)
    	    blen += 17;
    	else
    	    blen += 11;
        }
        bp = (char*)xmlMallocAtomic(blen);
        if ( bp == NULL ) {
            xmlNanoHTTPFreeCtxt( ctxt );
    	xmlHTTPErrMemory("allocating header buffer");
    	return ( NULL );
        }
    
        p = bp;
    
        if (use_proxy) {
    	if (ctxt->port != 80) {
    	    p += snprintf( p, blen - (p - bp), "%s http://%s:%d%s",
    			method, ctxt->hostname,
    			ctxt->port, ctxt->path );
    	}
    	else
    	    p += snprintf( p, blen - (p - bp), "%s http://%s%s", method,
    			ctxt->hostname, ctxt->path);
        }
        else
    	p += snprintf( p, blen - (p - bp), "%s %s", method, ctxt->path);
    
        if (ctxt->query != NULL)
    	p += snprintf( p, blen - (p - bp), "?%s", ctxt->query);
    
        if (ctxt->port == 80) {
            p += snprintf( p, blen - (p - bp), " HTTP/1.0\r\nHost: %s\r\n",
    		    ctxt->hostname);
        } else {
            p += snprintf( p, blen - (p - bp), " HTTP/1.0\r\nHost: %s:%d\r\n",
    		    ctxt->hostname, ctxt->port);
        }
    
    #ifdef LIBXML_ZLIB_ENABLED
        p += snprintf(p, blen - (p - bp), "Accept-Encoding: gzip\r\n");
    #endif
    
        if (contentType != NULL && *contentType)
    	p += snprintf(p, blen - (p - bp), "Content-Type: %s\r\n", *contentType);
    
        if (headers != NULL)
    	p += snprintf( p, blen - (p - bp), "%s", headers );
    
        if (input != NULL)
    	snprintf(p, blen - (p - bp), "Content-Length: %d\r\n\r\n", ilen );
        else
    	snprintf(p, blen - (p - bp), "\r\n");
    
        ctxt->outptr = ctxt->out = bp;
        ctxt->state = XML_NANO_HTTP_WRITE;
        blen = strlen( ctxt->out );
        xmlNanoHTTPSend(ctxt, ctxt->out, blen );
    
        if ( input != NULL ) {
    	xmlNanoHTTPSend( ctxt, input, ilen );
        }
    
        ctxt->state = XML_NANO_HTTP_READ;
    
        while ((p = xmlNanoHTTPReadLine(ctxt)) != NULL) {
            if (*p == 0) {
    	    ctxt->content = ctxt->inrptr;
    	    xmlFree(p);
    	    break;
    	}
    	xmlNanoHTTPScanAnswer(ctxt, p);
    
            xmlFree(p);
        }
    
        if ((ctxt->location != NULL) && (ctxt->returnValue >= 300) &&
            (ctxt->returnValue < 400)) {
    	while ( xmlNanoHTTPRecv(ctxt) > 0 )
                ;
            if (nbRedirects < XML_NANO_HTTP_MAX_REDIR) {
    	    nbRedirects++;
    	    if (redirURL != NULL)
    		xmlFree(redirURL);
    	    redirURL = xmlMemStrdup(ctxt->location);
    	    xmlNanoHTTPFreeCtxt(ctxt);
    	    goto retry;
    	}
    	xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
    	return(NULL);
        }
    
        if (contentType != NULL) {
    	if (ctxt->contentType != NULL)
    	    *contentType = xmlMemStrdup(ctxt->contentType);
    	else
    	    *contentType = NULL;
        }
    
        if ((redir != NULL) && (redirURL != NULL)) {
    	*redir = redirURL;
        } else {
    	if (redirURL != NULL)
    	    xmlFree(redirURL);
    	if (redir != NULL)
    	    *redir = NULL;
        }
    
        return((void *) ctxt);
    }
    
    /**
     * xmlNanoHTTPMethod:
     * @URL:  The URL to load
     * @method:  the HTTP method to use
     * @input:  the input string if any
     * @contentType:  the Content-Type information IN and OUT
     * @headers:  the extra headers
     * @ilen:  input length
     *
     * This function try to open a connection to the indicated resource
     * via HTTP using the given @method, adding the given extra headers
     * and the input buffer for the request content.
     *
     * Returns NULL in case of failure, otherwise a request handler.
     *     The contentType, if provided must be freed by the caller
     */
    
    void*
    xmlNanoHTTPMethod(const char *URL, const char *method, const char *input,
                      char **contentType, const char *headers, int ilen) {
        return(xmlNanoHTTPMethodRedir(URL, method, input, contentType,
    		                  NULL, headers, ilen));
    }
    
    /**
     * xmlNanoHTTPFetch:
     * @URL:  The URL to load
     * @filename:  the filename where the content should be saved
     * @contentType:  if available the Content-Type information will be
     *                returned at that location
     *
     * This function try to fetch the indicated resource via HTTP GET
     * and save it's content in the file.
     *
     * Returns -1 in case of failure, 0 in case of success. The contentType,
     *     if provided must be freed by the caller
     */
    int
    xmlNanoHTTPFetch(const char *URL, const char *filename, char **contentType) {
        void *ctxt = NULL;
        char *buf = NULL;
        int fd;
        int len;
        int ret = 0;
    
        if (filename == NULL) return(-1);
        ctxt = xmlNanoHTTPOpen(URL, contentType);
        if (ctxt == NULL) return(-1);
    
        if (!strcmp(filename, "-"))
            fd = 0;
        else {
            fd = open(filename, O_CREAT | O_WRONLY, 00644);
    	if (fd < 0) {
    	    xmlNanoHTTPClose(ctxt);
    	    if ((contentType != NULL) && (*contentType != NULL)) {
    	        xmlFree(*contentType);
    		*contentType = NULL;
    	    }
    	    return(-1);
    	}
        }
    
        xmlNanoHTTPFetchContent( ctxt, &buf, &len );
        if ( len > 0 ) {
    	if (write(fd, buf, len) == -1) {
    	    ret = -1;
    	}
        }
    
        xmlNanoHTTPClose(ctxt);
        close(fd);
        return(ret);
    }
    
    #ifdef LIBXML_OUTPUT_ENABLED
    /**
     * xmlNanoHTTPSave:
     * @ctxt:  the HTTP context
     * @filename:  the filename where the content should be saved
     *
     * This function saves the output of the HTTP transaction to a file
     * It closes and free the context at the end
     *
     * Returns -1 in case of failure, 0 in case of success.
     */
    int
    xmlNanoHTTPSave(void *ctxt, const char *filename) {
        char *buf = NULL;
        int fd;
        int len;
        int ret = 0;
    
        if ((ctxt == NULL) || (filename == NULL)) return(-1);
    
        if (!strcmp(filename, "-"))
            fd = 0;
        else {
            fd = open(filename, O_CREAT | O_WRONLY, 0666);
    	if (fd < 0) {
    	    xmlNanoHTTPClose(ctxt);
    	    return(-1);
    	}
        }
    
        xmlNanoHTTPFetchContent( ctxt, &buf, &len );
        if ( len > 0 ) {
    	if (write(fd, buf, len) == -1) {
    	    ret = -1;
    	}
        }
    
        xmlNanoHTTPClose(ctxt);
        close(fd);
        return(ret);
    }
    #endif /* LIBXML_OUTPUT_ENABLED */
    
    /**
     * xmlNanoHTTPReturnCode:
     * @ctx:  the HTTP context
     *
     * Get the latest HTTP return code received
     *
     * Returns the HTTP return code for the request.
     */
    int
    xmlNanoHTTPReturnCode(void *ctx) {
        xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;
    
        if (ctxt == NULL) return(-1);
    
        return(ctxt->returnValue);
    }
    
    /**
     * xmlNanoHTTPAuthHeader:
     * @ctx:  the HTTP context
     *
     * Get the authentication header of an HTTP context
     *
     * Returns the stashed value of the WWW-Authenticate or Proxy-Authenticate
     * header.
     */
    const char *
    xmlNanoHTTPAuthHeader(void *ctx) {
        xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;
    
        if (ctxt == NULL) return(NULL);
    
        return(ctxt->authHeader);
    }
    
    /**
     * xmlNanoHTTPContentLength:
     * @ctx:  the HTTP context
     *
     * Provides the specified content length from the HTTP header.
     *
     * Return the specified content length from the HTTP header.  Note that
     * a value of -1 indicates that the content length element was not included in
     * the response header.
     */
    int
    xmlNanoHTTPContentLength( void * ctx ) {
        xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;
    
        return ( ( ctxt == NULL ) ? -1 : ctxt->ContentLength );
    }
    
    /**
     * xmlNanoHTTPRedir:
     * @ctx:  the HTTP context
     *
     * Provides the specified redirection URL if available from the HTTP header.
     *
     * Return the specified redirection URL or NULL if not redirected.
     */
    const char *
    xmlNanoHTTPRedir( void * ctx ) {
        xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;
    
        return ( ( ctxt == NULL ) ? NULL : ctxt->location );
    }
    
    /**
     * xmlNanoHTTPEncoding:
     * @ctx:  the HTTP context
     *
     * Provides the specified encoding if specified in the HTTP headers.
     *
     * Return the specified encoding or NULL if not available
     */
    const char *
    xmlNanoHTTPEncoding( void * ctx ) {
        xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;
    
        return ( ( ctxt == NULL ) ? NULL : ctxt->encoding );
    }
    
    /**
     * xmlNanoHTTPMimeType:
     * @ctx:  the HTTP context
     *
     * Provides the specified Mime-Type if specified in the HTTP headers.
     *
     * Return the specified Mime-Type or NULL if not available
     */
    const char *
    xmlNanoHTTPMimeType( void * ctx ) {
        xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;
    
        return ( ( ctxt == NULL ) ? NULL : ctxt->mimeType );
    }
    
    /**
     * xmlNanoHTTPFetchContent:
     * @ctx:  the HTTP context
     * @ptr:  pointer to set to the content buffer.
     * @len:  integer pointer to hold the length of the content
     *
     * Check if all the content was read
     *
     * Returns 0 if all the content was read and available, returns
     * -1 if received content length was less than specified or an error
     * occurred.
     */
    static int
    xmlNanoHTTPFetchContent( void * ctx, char ** ptr, int * len ) {
        xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;
    
        int			rc = 0;
        int			cur_lgth;
        int			rcvd_lgth;
        int			dummy_int;
        char *		dummy_ptr = NULL;
    
        /*  Dummy up return input parameters if not provided  */
    
        if ( len == NULL )
            len = &dummy_int;
    
        if ( ptr == NULL )
            ptr = &dummy_ptr;
    
        /*  But can't work without the context pointer  */
    
        if ( ( ctxt == NULL ) || ( ctxt->content == NULL ) ) {
            *len = 0;
    	*ptr = NULL;
    	return ( -1 );
        }
    
        rcvd_lgth = ctxt->inptr - ctxt->content;
    
        while ( (cur_lgth = xmlNanoHTTPRecv( ctxt )) > 0 ) {
    
    	rcvd_lgth += cur_lgth;
    	if ( (ctxt->ContentLength > 0) && (rcvd_lgth >= ctxt->ContentLength) )
    	    break;
        }
    
        *ptr = ctxt->content;
        *len = rcvd_lgth;
    
        if ( ( ctxt->ContentLength > 0 ) && ( rcvd_lgth < ctxt->ContentLength ) )
            rc = -1;
        else if ( rcvd_lgth == 0 )
    	rc = -1;
    
        return ( rc );
    }
    
    #ifdef STANDALONE
    int main(int argc, char **argv) {
        char *contentType = NULL;
    
        if (argv[1] != NULL) {
    	if (argv[2] != NULL)
    	    xmlNanoHTTPFetch(argv[1], argv[2], &contentType);
            else
    	    xmlNanoHTTPFetch(argv[1], "-", &contentType);
    	if (contentType != NULL) xmlFree(contentType);
        } else {
            xmlGenericError(xmlGenericErrorContext,
    		"%s: minimal HTTP GET implementation\n", argv[0]);
            xmlGenericError(xmlGenericErrorContext,
    		"\tusage %s [ URL [ filename ] ]\n", argv[0]);
        }
        xmlNanoHTTPCleanup();
        return(0);
    }
    #endif /* STANDALONE */
    #else /* !LIBXML_HTTP_ENABLED */
    #ifdef STANDALONE
    #include <stdio.h>
    int main(int argc, char **argv) {
        xmlGenericError(xmlGenericErrorContext,
    	    "%s : HTTP support not compiled in\n", argv[0]);
        return(0);
    }
    #endif /* STANDALONE */
    #endif /* LIBXML_HTTP_ENABLED */