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kc3-lang/libxml2/nanohttp.c

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  • Author : Daniel Veillard
    Date : 2001-06-09 13:52:58
    Hash : f3afa7dd
    Message : - nanoftp.c nanohttp.c uri.c include/win32config.h: Igor Zlatkovic provided fixes to compile on MSCC again - win32/libxml2/libxml2.def.src win32/libxml2/libxml2*.dsp: he also provided an update for the project files. Daniel

  • 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@w3.org
     */
     
    /* TODO add compression support, Send the Accept- , and decompress on the
            fly with ZLIB if found at compile-time */
    
    #define NEED_SOCKETS
    #include "libxml.h"
    
    #ifdef LIBXML_HTTP_ENABLED
    #include <string.h>
    
    #ifdef HAVE_STDLIB_H
    #include <stdlib.h>
    #endif
    #ifdef HAVE_UNISTD_H
    #include <unistd.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_ERRNO_H
    #include <errno.h>
    #endif
    #ifdef HAVE_SYS_TIME_H
    #include <sys/time.h>
    #endif
    #ifdef HAVE_SYS_SELECT_H
    #include <sys/select.h>
    #endif
    #ifdef HAVE_STRINGS_H
    #include <strings.h>
    #endif
    #ifdef SUPPORT_IP6
    #include <resolv.h>
    #endif
    
    #ifdef VMS
    #include <stropts>
    #define SOCKLEN_T unsigned int
    #define SOCKET int
    #endif
    
    #include <libxml/xmlmemory.h>
    #include <libxml/parser.h> /* for xmlStr(n)casecmp() */
    #include <libxml/nanohttp.h>
    
    /**
     * A couple portability macros
     */
    #ifndef _WINSOCKAPI_
    #define closesocket(s) close(s)
    #define SOCKET int
    #endif
    
    #ifdef STANDALONE
    #define DEBUG_HTTP
    #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 */
        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 */
        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 */
    } 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 */
    
    /**
     * A portability function
     */
    static int socket_errno(void) {
    #ifdef _WINSOCKAPI_
        return(WSAGetLastError());
    #else
        return(errno);
    #endif
    }
    
    /**
     * xmlNanoHTTPInit:
     *
     * Initialize the HTTP protocol layer.
     * Currently it just checks for proxy informations
     */
    
    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 != NULL)
    	    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;
    }
    
    /**
     * xmlNanoHTTPClenup:
     *
     * Cleanup the HTTP protocol layer.
     */
    
    void
    xmlNanoHTTPCleanup(void) {
        if (proxy != NULL)
    	xmlFree(proxy);
    #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) {
        const char *cur = URL;
        char buf[4096];
        int indx = 0;
        int port = 0;
    
        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 (URL == NULL) return;
        buf[indx] = 0;
        while (*cur != 0) {
            if ((cur[0] == ':') && (cur[1] == '/') && (cur[2] == '/')) {
    	    buf[indx] = 0;
    	    ctxt->protocol = xmlMemStrdup(buf);
    	    indx = 0;
                cur += 3;
    	    break;
    	}
    	buf[indx++] = *cur++;
        }
        if (*cur == 0) return;
    
        buf[indx] = 0;
        while (1) {
            if (cur[0] == ':') {
    	    buf[indx] = 0;
    	    ctxt->hostname = xmlMemStrdup(buf);
    	    indx = 0;
    	    cur += 1;
    	    while ((*cur >= '0') && (*cur <= '9')) {
    	        port *= 10;
    		port += *cur - '0';
    		cur++;
    	    }
    	    if (port != 0) ctxt->port = port;
    	    while ((cur[0] != '/') && (*cur != 0)) 
    	        cur++;
    	    break;
    	}
            if ((*cur == '/') || (*cur == 0)) {
    	    buf[indx] = 0;
    	    ctxt->hostname = xmlMemStrdup(buf);
    	    indx = 0;
    	    break;
    	}
    	buf[indx++] = *cur++;
        }
        if (*cur == 0) 
            ctxt->path = xmlMemStrdup("/");
        else {
            indx = 0;
            buf[indx] = 0;
    	while (*cur != 0)
    	    buf[indx++] = *cur++;
    	buf[indx] = 0;
    	ctxt->path = xmlMemStrdup(buf);
        }	
    }
    
    /**
     * 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 informations.
     */
    
    void
    xmlNanoHTTPScanProxy(const char *URL) {
        const char *cur = URL;
        char buf[4096];
        int indx = 0;
        int port = 0;
    
        if (proxy != NULL) { 
            xmlFree(proxy);
    	proxy = NULL;
        }
        if (proxyPort != 0) { 
    	proxyPort = 0;
        }
    #ifdef DEBUG_HTTP
        if (URL == NULL)
    	xmlGenericError(xmlGenericErrorContext,
    		"Removing HTTP proxy info\n");
        else
    	xmlGenericError(xmlGenericErrorContext,
    		"Using HTTP proxy %s\n", URL);
    #endif
        if (URL == NULL) return;
        buf[indx] = 0;
        while (*cur != 0) {
            if ((cur[0] == ':') && (cur[1] == '/') && (cur[2] == '/')) {
    	    buf[indx] = 0;
    	    indx = 0;
                cur += 3;
    	    break;
    	}
    	buf[indx++] = *cur++;
        }
        if (*cur == 0) return;
    
        buf[indx] = 0;
        while (1) {
            if (cur[0] == ':') {
    	    buf[indx] = 0;
    	    proxy = xmlMemStrdup(buf);
    	    indx = 0;
    	    cur += 1;
    	    while ((*cur >= '0') && (*cur <= '9')) {
    	        port *= 10;
    		port += *cur - '0';
    		cur++;
    	    }
    	    if (port != 0) proxyPort = port;
    	    while ((cur[0] != '/') && (*cur != 0)) 
    	        cur++;
    	    break;
    	}
            if ((*cur == '/') || (*cur == 0)) {
    	    buf[indx] = 0;
    	    proxy = xmlMemStrdup(buf);
    	    indx = 0;
    	    break;
    	}
    	buf[indx++] = *cur++;
        }
    }
    
    /**
     * 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) return(NULL);
    
        memset(ret, 0, sizeof(xmlNanoHTTPCtxt));
        ret->port = 80;
        ret->returnValue = 0;
        ret->fd = -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->out != NULL) xmlFree(ctxt->out);
        if (ctxt->in != NULL) xmlFree(ctxt->in);
        if (ctxt->contentType != NULL) xmlFree(ctxt->contentType);
        if (ctxt->location != NULL) xmlFree(ctxt->location);
        if (ctxt->authHeader != NULL) xmlFree(ctxt->authHeader);
        ctxt->state = XML_NANO_HTTP_NONE;
        if (ctxt->fd >= 0) closesocket(ctxt->fd);
        ctxt->fd = -1;
        xmlFree(ctxt);
    }
    
    /**
     * xmlNanoHTTPSend:
     * @ctxt:  an HTTP context
     *
     * Send the input needed to initiate the processing on the server side
     */
    
    static void
    xmlNanoHTTPSend(xmlNanoHTTPCtxtPtr ctxt) {
        if (ctxt->state & XML_NANO_HTTP_WRITE) {
            unsigned int total_sent = 0;
            while (total_sent <strlen(ctxt->outptr)) {
                unsigned int nsent = send(ctxt->fd, ctxt->outptr+total_sent,
                                          strlen(ctxt->outptr)-total_sent, 0);
                if (nsent>0)
                    total_sent += nsent;
    	}
            ctxt->last = 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) {
        fd_set rfd;
        struct timeval tv;
    
    
        while (ctxt->state & XML_NANO_HTTP_READ) {
    	if (ctxt->in == NULL) {
    	    ctxt->in = (char *) xmlMalloc(65000 * sizeof(char));
    	    if (ctxt->in == NULL) {
    	        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;
    
    	    ctxt->inlen *= 2;
                ctxt->in = (char *) xmlRealloc(ctxt->in, ctxt->inlen);
    	    if (ctxt->in == NULL) {
    	        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;
    		default:
    		    return(0);
    	    }
    	}
    
    	tv.tv_sec = timeout;
    	tv.tv_usec = 0;
    	FD_ZERO(&rfd);
    	FD_SET(ctxt->fd, &rfd);
    	
    	if (select(ctxt->fd+1, &rfd, NULL, NULL, &tv)<1)
    		return(0);
        }
        return(0);
    }
    
    /**
     * xmlNanoHTTPReadLine:
     * @ctxt:  an HTTP context
     *
     * Read one line in the HTTP server output, usually for extracting
     * the HTTP protocol informations 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;
        
        while (bp - buf < 4095) {
    	if (ctxt->inrptr == ctxt->inptr) {
    	    if (xmlNanoHTTPRecv(ctxt) == 0) {
    		if (bp == buf)
    		    return(NULL);
    		else
    		    *bp = 0;
    		return(xmlMemStrdup(buf));
    	    }
    	}
    	*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 informations from the server answer.
     * We currently parse and process:
     *  - The HTTP revision/ return code
     *  - The Content-Type
     *  - The Location for redirrect 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;
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"Content-Type:", 13)) {
            cur += 13;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if (ctxt->contentType != NULL)
    	    xmlFree(ctxt->contentType);
    	ctxt->contentType = xmlMemStrdup(cur);
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"ContentType:", 12)) {
            cur += 12;
    	if (ctxt->contentType != NULL) return;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	ctxt->contentType = xmlMemStrdup(cur);
        } else if (!xmlStrncasecmp(BAD_CAST line, BAD_CAST"Location:", 9)) {
            cur += 9;
    	while ((*cur == ' ') || (*cur == '\t')) cur++;
    	if (ctxt->location != NULL)
    	    xmlFree(ctxt->location);
    	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);
        }
    }
    
    /**
     * xmlNanoHTTPConnectAttempt:
     * @addr:  a socket adress 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 int
    xmlNanoHTTPConnectAttempt(struct sockaddr *addr)
    {
        SOCKET s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
        fd_set wfd;
        struct timeval tv;
        int status;
        
        if (s==-1) {
    #ifdef DEBUG_HTTP
    	perror("socket");
    #endif
    	return(-1);
        }
        
    #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) {
    #ifdef DEBUG_HTTP
    	perror("nonblocking");
    #endif
    	closesocket(s);
    	return(-1);
        }
    #endif /* !VMS */
    #endif /* !_WINSOCKAPI_ */
    
    
        if ((connect(s, addr, sizeof(*addr))==-1)) {
    	switch (socket_errno()) {
    	    case EINPROGRESS:
    	    case EWOULDBLOCK:
    		break;
    	    default:
    		perror("connect");
    		closesocket(s);
    		return(-1);
    	}
        }	
        
        tv.tv_sec = timeout;
        tv.tv_usec = 0;
        
        FD_ZERO(&wfd);
        FD_SET(s, &wfd);
        
        switch(select(s+1, NULL, &wfd, NULL, &tv))
        {
    	case 0:
    	    /* Time out */
    	    closesocket(s);
    	    return(-1);
    	case -1:
    	    /* Ermm.. ?? */
    #ifdef DEBUG_HTTP
    	    perror("select");
    #endif
    	    closesocket(s);
    	    return(-1);
        }
    
        if ( FD_ISSET(s, &wfd) ) {
    	SOCKLEN_T len;
    	len = sizeof(status);
    	if (getsockopt(s, SOL_SOCKET, SO_ERROR, (char*)&status, &len) < 0 ) {
    	    /* Solaris error code */
    	    return (-1);
    	}
    	if ( status ) {
    	    closesocket(s);
    	    errno = status;
    	    return (-1);
    	}
        } else {
    	/* pbm */
    	return (-1);
        }
        
        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 int
    xmlNanoHTTPConnectHost(const char *host, int port)
    {
        struct hostent *h;
        struct sockaddr *addr;
        struct in_addr ia;
        struct sockaddr_in sockin;
    #ifdef SUPPORT_IP6
        struct in6_addr ia6;
        struct sockaddr_in6 sockin6;
    #endif
        int i;
        int s;
        
    #if defined(SUPPORT_IP6) && defined(RES_USE_INET6)
        if (!(_res.options & RES_INIT))
    	res_init();
        _res.options |= RES_USE_INET6;
    #endif
        h=gethostbyname(host);
        if (h==NULL)
        {
    #ifdef DEBUG_HTTP
    	xmlGenericError(xmlGenericErrorContext,"unable to resolve '%s'.\n", host);
    #endif
    	return(-1);
        }
        
        for(i=0; h->h_addr_list[i]; i++)
        {
    	if (h->h_addrtype == AF_INET) {
    	    /* A records (IPv4) */
    	    memcpy(&ia, h->h_addr_list[i], h->h_length);
    	    sockin.sin_family = h->h_addrtype;
    	    sockin.sin_addr   = ia;
    	    sockin.sin_port   = htons(port);
    	    addr = (struct sockaddr *)&sockin;
    #ifdef SUPPORT_IP6
    	} else if (h->h_addrtype == AF_INET6) {
    	    /* AAAA records (IPv6) */
    	    memcpy(&ia6, h->h_addr_list[i], h->h_length);
    	    sockin6.sin_family = h->h_addrtype;
    	    sockin6.sin_addr   = ia6;
    	    sockin6.sin_port   = htons(port);
    	    addr = (struct sockaddr *)&sockin6;
    #endif
    	} else
    	    break; /* for */
    	
    	s = xmlNanoHTTPConnectAttempt(addr);
    	if (s != -1)
    	    return(s);
        }
    
    #ifdef DEBUG_HTTP
        xmlGenericError(xmlGenericErrorContext,
    	    "unable to connect to '%s'.\n", host);
    #endif
        return(-1);
    }
    
    
    /**
     * 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));
    }
    
    /**
     * xmlNanoHTTPOpenRedir:
     * @URL:  The URL to load
     * @contentType:  if available the Content-Type information will be
     *                returned at that location
     * @redir: if availble 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));
    }
    
    /**
     * 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;
    
        if (ctx == NULL) return(-1);
        if (dest == NULL) return(-1);
        if (len <= 0) return(0);
    
        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);
    }
    
    /**
     * 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
     *
     * 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) {
        xmlNanoHTTPCtxtPtr ctxt;
        char *bp, *p;
        int blen, ilen, ret;
        int head;
        int nbRedirects = 0;
        char *redirURL = NULL;
        
        if (URL == NULL) return(NULL);
        if (method == NULL) method = "GET";
        xmlNanoHTTPInit();
    
    retry:
        if (redirURL == NULL)
    	ctxt = xmlNanoHTTPNewCtxt(URL);
        else {
    	ctxt = xmlNanoHTTPNewCtxt(redirURL);
        }
    
        if ((ctxt->protocol == NULL) || (strcmp(ctxt->protocol, "http"))) {
            xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
            return(NULL);
        }
        if (ctxt->hostname == NULL) {
            xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
            return(NULL);
        }
        if (proxy) {
    	blen = strlen(ctxt->hostname) * 2 + 16;
    	ret = xmlNanoHTTPConnectHost(proxy, proxyPort);
        }
        else {
    	blen = strlen(ctxt->hostname);
    	ret = xmlNanoHTTPConnectHost(ctxt->hostname, ctxt->port);
        }
        if (ret < 0) {
            xmlNanoHTTPFreeCtxt(ctxt);
    	if (redirURL != NULL) xmlFree(redirURL);
            return(NULL);
        }
        ctxt->fd = ret;
    
        if (input != NULL) {
    	ilen = strlen(input);
    	blen += ilen + 32;
        }
        else
    	ilen = 0;
        if (headers != NULL)
    	blen += strlen(headers);
        if (contentType && *contentType)
    	blen += strlen(*contentType) + 16;
        blen += strlen(method) + strlen(ctxt->path) + 23;
        bp = xmlMalloc(blen);
        if (proxy) {
    	if (ctxt->port != 80) {
    	    sprintf(bp, "%s http://%s:%d%s", method, ctxt->hostname,
    		 ctxt->port, ctxt->path);
    	}
    	else
    	    sprintf(bp, "%s http://%s%s", method, ctxt->hostname, ctxt->path);
        }
        else
    	sprintf(bp, "%s %s", method, ctxt->path);
        p = bp + strlen(bp);
        sprintf(p, " HTTP/1.0\r\nHost: %s\r\n", ctxt->hostname);
        p += strlen(p);
        if (contentType != NULL && *contentType) {
    	sprintf(p, "Content-Type: %s\r\n", *contentType);
    	p += strlen(p);
        }
        if (headers != NULL) {
    	strcpy(p, headers);
    	p += strlen(p);
        }
        if (input != NULL)
    	sprintf(p, "Content-Length: %d\r\n\r\n%s", ilen, input);
        else
    	strcpy(p, "\r\n");
    #ifdef DEBUG_HTTP
        xmlGenericError(xmlGenericErrorContext,
    	    "-> %s%s", proxy? "(Proxy) " : "", bp);
        if ((blen -= strlen(bp)+1) < 0)
    	xmlGenericError(xmlGenericErrorContext,
    		"ERROR: overflowed buffer by %d bytes\n", -blen);
    #endif
        ctxt->outptr = ctxt->out = bp;
        ctxt->state = XML_NANO_HTTP_WRITE;
        xmlNanoHTTPSend(ctxt);
        ctxt->state = XML_NANO_HTTP_READ;
        head = 1;
    
        while ((p = xmlNanoHTTPReadLine(ctxt)) != NULL) {
            if (head && (*p == 0)) {
    	    head = 0;
    	    ctxt->content = ctxt->inrptr;
    	    xmlFree(p);
    	    break;
    	}
    	xmlNanoHTTPScanAnswer(ctxt, p);
    
    #ifdef DEBUG_HTTP
    	xmlGenericError(xmlGenericErrorContext, "<- %s\n", p);
    #endif
            xmlFree(p);
        }
    
        if ((ctxt->location != NULL) && (ctxt->returnValue >= 300) &&
            (ctxt->returnValue < 400)) {
    #ifdef DEBUG_HTTP
    	xmlGenericError(xmlGenericErrorContext,
    		"\nRedirect to: %s\n", ctxt->location);
    #endif
    	while (xmlNanoHTTPRecv(ctxt)) ;
            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);
    #ifdef DEBUG_HTTP
    	xmlGenericError(xmlGenericErrorContext,
    		"Too many redirects, aborting ...\n");
    #endif
    	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;
        }
    
    #ifdef DEBUG_HTTP
        if (ctxt->contentType != NULL)
    	xmlGenericError(xmlGenericErrorContext,
    		"\nCode %d, content-type '%s'\n\n",
    	       ctxt->returnValue, ctxt->contentType);
        else
    	xmlGenericError(xmlGenericErrorContext,
    		"\nCode %d, no content-type\n\n",
    	       ctxt->returnValue);
    #endif
    
        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
     *
     * 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) {
        return(xmlNanoHTTPMethodRedir(URL, method, input, contentType,
    		                  NULL, headers));
    }
    
    /**
     * 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 incase of success. The contentType,
     *     if provided must be freed by the caller
     */
    int
    xmlNanoHTTPFetch(const char *URL, const char *filename, char **contentType) {
        void *ctxt;
        char buf[4096];
        int fd;
        int len;
        
        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);
    	}
        }
    
        while ((len = xmlNanoHTTPRead(ctxt, buf, sizeof(buf))) > 0) {
    	write(fd, buf, len);
        }
    
        xmlNanoHTTPClose(ctxt);
        close(fd);
        return(0);
    }
    
    /**
     * 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 incase of success.
     */
    int
    xmlNanoHTTPSave(void *ctxt, const char *filename) {
        char buf[4096];
        int fd;
        int len;
        
        if (ctxt == NULL) return(-1);
    
        if (!strcmp(filename, "-")) 
            fd = 0;
        else {
            fd = open(filename, O_CREAT | O_WRONLY);
    	if (fd < 0) {
    	    xmlNanoHTTPClose(ctxt);
    	    return(-1);
    	}
        }
    
        while ((len = xmlNanoHTTPRead(ctxt, buf, sizeof(buf))) > 0) {
    	write(fd, buf, len);
        }
    
        xmlNanoHTTPClose(ctxt);
        return(0);
    }
    
    /**
     * xmlNanoHTTPReturnCode:
     * @ctx:  the HTTP context
     *
     * 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
     *
     * 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);
    }
    
    #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();
        xmlMemoryDump();
        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 */