nanoftp.c

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/*
 * nanoftp.c: basic FTP client support
 *
 *  Reference: RFC 959
 */

#ifdef TESTING
#define STANDALONE
#define HAVE_STDLIB_H
#define HAVE_UNISTD_H
#define HAVE_SYS_SOCKET_H
#define HAVE_NETINET_IN_H
#define HAVE_NETDB_H
#define HAVE_SYS_TIME_H
#else /* TESTING */
#define NEED_SOCKETS
#endif /* TESTING */

#define IN_LIBXML
#include "libxml.h"

#ifdef LIBXML_FTP_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_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif

#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <libxml/xmlerror.h>
#include <libxml/uri.h>
#include <libxml/nanoftp.h>
#include <libxml/globals.h>

/* #define DEBUG_FTP 1  */
#ifdef STANDALONE
#ifndef DEBUG_FTP
#define DEBUG_FTP 1
#endif
#endif


#ifdef __MINGW32__
#define _WINSOCKAPI_
#include <wsockcompat.h>
#include <winsock2.h>
#undef XML_SOCKLEN_T
#define XML_SOCKLEN_T unsigned int
#endif

/**
 * A couple portability macros
 */
#ifndef _WINSOCKAPI_
#ifndef __BEOS__
#define closesocket(s) close(s)
#endif
#define SOCKET int
#endif

#ifdef __BEOS__
#ifndef PF_INET
#define PF_INET AF_INET
#endif
#endif

#ifdef _AIX
#define ss_family __ss_family
#endif

#ifndef XML_SOCKLEN_T
#define XML_SOCKLEN_T unsigned int
#endif

#define FTP_COMMAND_OK		200
#define FTP_SYNTAX_ERROR	500
#define FTP_GET_PASSWD		331
#define FTP_BUF_SIZE		1024

#define XML_NANO_MAX_URLBUF	4096

typedef struct xmlNanoFTPCtxt {
    char *protocol;	/* the protocol name */
    char *hostname;	/* the host name */
    int port;		/* the port */
    char *path;		/* the path within the URL */
    char *user;		/* user string */
    char *passwd;	/* passwd string */
#ifdef SUPPORT_IP6
    struct sockaddr_storage ftpAddr; /* this is large enough to hold IPv6 address*/
#else
    struct sockaddr_in ftpAddr; /* the socket address struct */
#endif
    int passive;	/* currently we support only passive !!! */
    SOCKET controlFd;	/* the file descriptor for the control socket */
    SOCKET dataFd;	/* the file descriptor for the data socket */
    int state;		/* WRITE / READ / CLOSED */
    int returnValue;	/* the protocol return value */
    /* buffer for data received from the control connection */
    char controlBuf[FTP_BUF_SIZE + 1];
    int controlBufIndex;
    int controlBufUsed;
    int controlBufAnswer;
} xmlNanoFTPCtxt, *xmlNanoFTPCtxtPtr;

static int initialized = 0;
static char *proxy = NULL;	/* the proxy name if any */
static int proxyPort = 0;	/* the proxy port if any */
static char *proxyUser = NULL;	/* user for proxy authentication */
static char *proxyPasswd = NULL;/* passwd for proxy authentication */
static int proxyType = 0;	/* uses TYPE or a@b ? */

#ifdef SUPPORT_IP6
static
int have_ipv6(void) {
    int s;

    s = socket (AF_INET6, SOCK_STREAM, 0);
    if (s != -1) {
	close (s);
	return (1);
    }
    return (0);
}
#endif

/**
 * xmlFTPErrMemory:
 * @extra:  extra informations
 *
 * Handle an out of memory condition
 */
static void
xmlFTPErrMemory(const char *extra)
{
    __xmlSimpleError(XML_FROM_FTP, XML_ERR_NO_MEMORY, NULL, NULL, extra);
}

/**
 * xmlNanoFTPInit:
 *
 * Initialize the FTP protocol layer.
 * Currently it just checks for proxy informations,
 * and get the hostname
 */

void
xmlNanoFTPInit(void) {
    const char *env;
#ifdef _WINSOCKAPI_
    WSADATA wsaData;    
#endif

    if (initialized)
	return;

#ifdef _WINSOCKAPI_
    if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0)
	return;
#endif

    proxyPort = 21;
    env = getenv("no_proxy");
    if (env && ((env[0] == '*' ) && (env[1] == 0)))
	return;
    env = getenv("ftp_proxy");
    if (env != NULL) {
	xmlNanoFTPScanProxy(env);
    } else {
	env = getenv("FTP_PROXY");
	if (env != NULL) {
	    xmlNanoFTPScanProxy(env);
	}
    }
    env = getenv("ftp_proxy_user");
    if (env != NULL) {
	proxyUser = xmlMemStrdup(env);
    }
    env = getenv("ftp_proxy_password");
    if (env != NULL) {
	proxyPasswd = xmlMemStrdup(env);
    }
    initialized = 1;
}

/**
 * xmlNanoFTPCleanup:
 *
 * Cleanup the FTP protocol layer. This cleanup proxy informations.
 */

void
xmlNanoFTPCleanup(void) {
    if (proxy != NULL) {
	xmlFree(proxy);
	proxy = NULL;
    }
    if (proxyUser != NULL) {
	xmlFree(proxyUser);
	proxyUser = NULL;
    }
    if (proxyPasswd != NULL) {
	xmlFree(proxyPasswd);
	proxyPasswd = NULL;
    }
#ifdef _WINSOCKAPI_
    if (initialized)
	WSACleanup();
#endif
    initialized = 0;
}

/**
 * xmlNanoFTPProxy:
 * @host:  the proxy host name
 * @port:  the proxy port
 * @user:  the proxy user name
 * @passwd:  the proxy password
 * @type:  the type of proxy 1 for using SITE, 2 for USER a@b
 *
 * Setup the FTP proxy informations.
 * This can also be done by using ftp_proxy ftp_proxy_user and
 * ftp_proxy_password environment variables.
 */

void
xmlNanoFTPProxy(const char *host, int port, const char *user,
	        const char *passwd, int type) {
    if (proxy != NULL) {
	xmlFree(proxy);
	proxy = NULL;
    }
    if (proxyUser != NULL) {
	xmlFree(proxyUser);
	proxyUser = NULL;
    }
    if (proxyPasswd != NULL) {
	xmlFree(proxyPasswd);
	proxyPasswd = NULL;
    }
    if (host)
	proxy = xmlMemStrdup(host);
    if (user)
	proxyUser = xmlMemStrdup(user);
    if (passwd)
	proxyPasswd = xmlMemStrdup(passwd);
    proxyPort = port;
    proxyType = type;
}

/**
 * xmlNanoFTPScanURL:
 * @ctx:  an FTP context
 * @URL:  The URL used to initialize the context
 *
 * (Re)Initialize an FTP context by parsing the URL and finding
 * the protocol host port and path it indicates.
 */

static void
xmlNanoFTPScanURL(void *ctx, const char *URL) {
    xmlNanoFTPCtxtPtr ctxt = (xmlNanoFTPCtxtPtr) ctx;
    xmlURIPtr uri;

    /*
     * 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 (URL == NULL) return;

    uri = xmlParseURI(URL);
    if (uri == NULL)
	return;

    if ((uri->scheme == NULL) || (uri->server == NULL)) {
	xmlFreeURI(uri);
	return;
    }
    
    ctxt->protocol = xmlMemStrdup(uri->scheme);
    ctxt->hostname = xmlMemStrdup(uri->server);
    if (uri->path != NULL)
	ctxt->path = xmlMemStrdup(uri->path);
    else
	ctxt->path = xmlMemStrdup("/");
    if (uri->port != 0)
	ctxt->port = uri->port;

    if (uri->user != NULL) {
	char *cptr;
	if ((cptr=strchr(uri->user, ':')) == NULL)
	    ctxt->user = xmlMemStrdup(uri->user);
	else {
	    ctxt->user = (char *)xmlStrndup((xmlChar *)uri->user,
			    (cptr - uri->user));
	    ctxt->passwd = xmlMemStrdup(cptr+1);
	}
    }

    xmlFreeURI(uri);

}

/**
 * xmlNanoFTPUpdateURL:
 * @ctx:  an FTP context
 * @URL:  The URL used to update the context
 *
 * Update an FTP context by parsing the URL and finding
 * new path it indicates. If there is an error in the 
 * protocol, hostname, port or other information, the
 * error is raised. It indicates a new connection has to
 * be established.
 *
 * Returns 0 if Ok, -1 in case of error (other host).
 */

int
xmlNanoFTPUpdateURL(void *ctx, const char *URL) {
    xmlNanoFTPCtxtPtr ctxt = (xmlNanoFTPCtxtPtr) ctx;
    xmlURIPtr uri;

    if (URL == NULL)
	return(-1);
    if (ctxt == NULL)
	return(-1);
    if (ctxt->protocol == NULL)
	return(-1);
    if (ctxt->hostname == NULL)
	return(-1);

    uri = xmlParseURI(URL);
    if (uri == NULL)
	return(-1);

    if ((uri->scheme == NULL) || (uri->server == NULL)) {
	xmlFreeURI(uri);
	return(-1);
    }
    if ((strcmp(ctxt->protocol, uri->scheme)) ||
	(strcmp(ctxt->hostname, uri->server)) ||
	((uri->port != 0) && (ctxt->port != uri->port))) {
	xmlFreeURI(uri);
	return(-1);
    }

    if (uri->port != 0)
	ctxt->port = uri->port;

    if (ctxt->path != NULL) {
	xmlFree(ctxt->path);
	ctxt->path = NULL;
    }

    if (uri->path == NULL) 
        ctxt->path = xmlMemStrdup("/");
    else
	ctxt->path = xmlMemStrdup(uri->path);

    xmlFreeURI(uri);

    return(0);
}

/**
 * xmlNanoFTPScanProxy:
 * @URL:  The proxy URL used to initialize the proxy context
 *
 * (Re)Initialize the FTP Proxy context by parsing the URL and finding
 * the protocol host port it indicates.
 * Should be like ftp://myproxy/ or ftp://myproxy:3128/
 * A NULL URL cleans up proxy informations.
 */

void
xmlNanoFTPScanProxy(const char *URL) {
    xmlURIPtr uri;

    if (proxy != NULL) { 
        xmlFree(proxy);
	proxy = NULL;
    }
    proxyPort = 0;

#ifdef DEBUG_FTP
    if (URL == NULL)
	xmlGenericError(xmlGenericErrorContext,
		"Removing FTP proxy info\n");
    else
	xmlGenericError(xmlGenericErrorContext,
		"Using FTP proxy %s\n", URL);
#endif
    if (URL == NULL) return;

    uri = xmlParseURI(URL);
    if ((uri == NULL) || (uri->scheme == NULL) ||
	(strcmp(uri->scheme, "ftp")) || (uri->server == NULL)) {
	__xmlIOErr(XML_FROM_FTP, XML_FTP_URL_SYNTAX, "Syntax Error\n");
	if (uri != NULL)
	    xmlFreeURI(uri);
	return;
    }
    
    proxy = xmlMemStrdup(uri->server);
    if (uri->port != 0)
	proxyPort = uri->port;

    xmlFreeURI(uri);
}

/**
 * xmlNanoFTPNewCtxt:
 * @URL:  The URL used to initialize the context
 *
 * Allocate and initialize a new FTP context.
 *
 * Returns an FTP context or NULL in case of error.
 */

void*
xmlNanoFTPNewCtxt(const char *URL) {
    xmlNanoFTPCtxtPtr ret;
    char *unescaped;

    ret = (xmlNanoFTPCtxtPtr) xmlMalloc(sizeof(xmlNanoFTPCtxt));
    if (ret == NULL) {
        xmlFTPErrMemory("allocating FTP context");
        return(NULL);
    }

    memset(ret, 0, sizeof(xmlNanoFTPCtxt));
    ret->port = 21;
    ret->passive = 1;
    ret->returnValue = 0;
    ret->controlBufIndex = 0;
    ret->controlBufUsed = 0;
    ret->controlFd = -1;

    unescaped = xmlURIUnescapeString(URL, 0, NULL);
    if (unescaped != NULL) {
	xmlNanoFTPScanURL(ret, unescaped);
	xmlFree(unescaped);
    } else if (URL != NULL)
	xmlNanoFTPScanURL(ret, URL);

    return(ret);
}

/**
 * xmlNanoFTPFreeCtxt:
 * @ctx:  an FTP context
 *
 * Frees the context after closing the connection.
 */

void
xmlNanoFTPFreeCtxt(void * ctx) {
    xmlNanoFTPCtxtPtr ctxt = (xmlNanoFTPCtxtPtr) ctx;
    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);
    ctxt->passive = 1;
    if (ctxt->controlFd >= 0) closesocket(ctxt->controlFd);
    ctxt->controlFd = -1;
    ctxt->controlBufIndex = -1;
    ctxt->controlBufUsed = -1;
    xmlFree(ctxt);
}

/**
 * xmlNanoFTPParseResponse:
 * @buf:  the buffer containing the response
 * @len:  the buffer length
 * 
 * Parsing of the server answer, we just extract the code.
 *
 * returns 0 for errors
 *     +XXX for last line of response
 *     -XXX for response to be continued