proxy_ftp.c

apache简化版

/* ====================================================================
 * Copyright (c) 1996-1998 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

/* FTP routines for Apache proxy */

#include "mod_proxy.h"
#include "http_main.h"
#include "http_log.h"

#define AUTODETECT_PWD

DEF_Explain

/*
 * Decodes a '%' escaped string, and returns the number of characters
 */
static int decodeenc(char *x)
{
    int i, j, ch;

    if (x[0] == '\0')
	return 0;		/* special case for no characters */
    for (i = 0, j = 0; x[i] != '\0'; i++, j++) {
/* decode it if not already done */
	ch = x[i];
	if (ch == '%' && isxdigit(x[i + 1]) && isxdigit(x[i + 2])) {
	    ch = ap_proxy_hex2c(&x[i + 1]);
	    i += 2;
	}
	x[j] = ch;
    }
    x[j] = '\0';
    return j;
}

/*
 * checks an encoded ftp string for bad characters, namely, CR, LF or
 * non-ascii character
 */
static int ftp_check_string(const char *x)
{
    int i, ch;

    for (i = 0; x[i] != '\0'; i++) {
	ch = x[i];
	if (ch == '%' && isxdigit(x[i + 1]) && isxdigit(x[i + 2])) {
	    ch = ap_proxy_hex2c(&x[i + 1]);
	    i += 2;
	}
#ifndef CHARSET_EBCDIC
	if (ch == '\015' || ch == '\012' || (ch & 0x80))
#else /*CHARSET_EBCDIC*/
	if (ch == '\r' || ch == '\n' || (os_toascii[ch] & 0x80))
#endif /*CHARSET_EBCDIC*/
	    return 0;
    }
    return 1;
}

/*
 * Canonicalise ftp URLs.
 */
int ap_proxy_ftp_canon(request_rec *r, char *url)
{
    char *user, *password, *host, *path, *parms, *strp, sport[7];
    pool *p = r->pool;
    const char *err;
    int port;

    port = DEFAULT_FTP_PORT;
    err = ap_proxy_canon_netloc(p, &url, &user, &password, &host, &port);
    if (err)
	return HTTP_BAD_REQUEST;
    if (user != NULL && !ftp_check_string(user))
	return HTTP_BAD_REQUEST;
    if (password != NULL && !ftp_check_string(password))
	return HTTP_BAD_REQUEST;

/* now parse path/parameters args, according to rfc1738 */
/* N.B. if this isn't a true proxy request, then the URL path
 * (but not query args) has already been decoded.
 * This gives rise to the problem of a ; being decoded into the
 * path.
 */
    strp = strchr(url, ';');
    if (strp != NULL) {
	*(strp++) = '\0';
	parms = ap_proxy_canonenc(p, strp, strlen(strp), enc_parm, r->proxyreq);
	if (parms == NULL)
	    return HTTP_BAD_REQUEST;
    }
    else
	parms = "";

    path = ap_proxy_canonenc(p, url, strlen(url), enc_path, r->proxyreq);
    if (path == NULL)
	return HTTP_BAD_REQUEST;
    if (!ftp_check_string(path))
	return HTTP_BAD_REQUEST;

    if (!r->proxyreq && r->args != NULL) {
	if (strp != NULL) {
	    strp = ap_proxy_canonenc(p, r->args, strlen(r->args), enc_parm, 1);
	    if (strp == NULL)
		return HTTP_BAD_REQUEST;
	    parms = ap_pstrcat(p, parms, "?", strp, NULL);
	}
	else {
	    strp = ap_proxy_canonenc(p, r->args, strlen(r->args), enc_fpath, 1);
	    if (strp == NULL)
		return HTTP_BAD_REQUEST;
	    path = ap_pstrcat(p, path, "?", strp, NULL);
	}
	r->args = NULL;
    }

/* now, rebuild URL */

    if (port != DEFAULT_FTP_PORT)
	ap_snprintf(sport, sizeof(sport), ":%d", port);
    else
	sport[0] = '\0';

    r->filename = ap_pstrcat(p, "proxy:ftp://", (user != NULL) ? user : "",
			       (password != NULL) ? ":" : "",
			       (password != NULL) ? password : "",
		          (user != NULL) ? "@" : "", host, sport, "/", path,
			       (parms[0] != '\0') ? ";" : "", parms, NULL);

    return OK;
}

/*
 * Returns the ftp status code;
 *  or -1 on I/O error, 0 on data error
 */
static int ftp_getrc(BUFF *f)
{
    int len, status;
    char linebuff[100], buff[5];

    len = ap_bgets(linebuff, sizeof linebuff, f);
    if (len == -1)
	return -1;
/* check format */
    if (len < 5 || !ap_isdigit(linebuff[0]) || !ap_isdigit(linebuff[1]) ||
	!ap_isdigit(linebuff[2]) || (linebuff[3] != ' ' && linebuff[3] != '-'))
	status = 0;
    else
	status = 100 * linebuff[0] + 10 * linebuff[1] + linebuff[2] - 111 * '0';

    if (linebuff[len - 1] != '\n') {
	(void)ap_bskiplf(f);
    }

/* skip continuation lines */
    if (linebuff[3] == '-') {
	memcpy(buff, linebuff, 3);
	buff[3] = ' ';
	do {
	    len = ap_bgets(linebuff, sizeof linebuff, f);
	    if (len == -1)
		return -1;
	    if (linebuff[len - 1] != '\n') {
		(void)ap_bskiplf(f);
	    }
	} while (memcmp(linebuff, buff, 4) != 0);
    }

    return status;
}

/*
 * Like ftp_getrc but returns both the ftp status code and 
 * remembers the response message in the supplied buffer
 */
static int ftp_getrc_msg(BUFF *f, char *msgbuf, int msglen)
{
    int len, status;
    char linebuff[100], buff[5];
    char *mb = msgbuf,
	 *me = &msgbuf[msglen];

    len = ap_bgets(linebuff, sizeof linebuff, f);
    if (len == -1)
	return -1;
    if (len < 5 || !ap_isdigit(linebuff[0]) || !ap_isdigit(linebuff[1]) ||
	!ap_isdigit(linebuff[2]) || (linebuff[3] != ' ' && linebuff[3] != '-'))
	status = 0;
    else
	status = 100 * linebuff[0] + 10 * linebuff[1] + linebuff[2] - 111 * '0';

    mb = ap_cpystrn(mb, linebuff+4, me - mb);

    if (linebuff[len - 1] != '\n')
	(void)ap_bskiplf(f);

    if (linebuff[3] == '-') {
	memcpy(buff, linebuff, 3);
	buff[3] = ' ';
	do {
	    len = ap_bgets(linebuff, sizeof linebuff, f);
	    if (len == -1)
		return -1;
	    if (linebuff[len - 1] != '\n') {
		(void)ap_bskiplf(f);
	    }
	    mb = ap_cpystrn(mb, linebuff+4, me - mb);
	} while (memcmp(linebuff, buff, 4) != 0);
    }
    return status;
}

static long int send_dir(BUFF *f, request_rec *r, cache_req *c, char *cwd)
{
    char buf[IOBUFSIZE];
    char buf2[IOBUFSIZE];
    char *filename;
    int searchidx = 0;
    char *searchptr = NULL;
    int firstfile = 1;
    unsigned long total_bytes_sent = 0;
    register int n, o, w;
    conn_rec *con = r->connection;
    char *dir, *path, *reldir, *site;

    /* Save "scheme://site" prefix without password */
    site = ap_unparse_uri_components(r->pool, &r->parsed_uri, UNP_OMITPASSWORD|UNP_OMITPATHINFO);
    /* ... and path without query args */
    path = ap_unparse_uri_components(r->pool, &r->parsed_uri, UNP_OMITSITEPART|UNP_OMITQUERY);
    (void)decodeenc(path);

    /* Copy path, strip (all except the last) trailing slashes */
    path = dir = ap_pstrcat(r->pool, path, "/", NULL);
    while ((n = strlen(path)) > 1 && path[n-1] == '/' && path[n-2] == '/')
	path[n-1] = '\0';

    /* print "ftp://host/" */
    n = ap_snprintf(buf, sizeof(buf), "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2 Final//EN\">\n"
		"<HTML><HEAD><TITLE>%s%s</TITLE>\n"
		"<BASE HREF=\"%s%s\"></HEAD>\n"
		"<BODY><H2>Directory of "
		"<A HREF=\"/\">%s</A>/",
		site, path, site, path, site);
    total_bytes_sent += ap_proxy_bputs2(buf, con->client, c);

    while ((dir = strchr(dir+1, '/')) != NULL)
    {
	*dir = '\0';
	if ((reldir = strrchr(path+1, '/'))==NULL)
	    reldir = path+1;
	else
	    ++reldir;
	/* print "path/" component */
	ap_snprintf(buf, sizeof(buf), "<A HREF=\"/%s/\">%s</A>/", path+1, reldir);
	total_bytes_sent += ap_proxy_bputs2(buf, con->client, c);
	*dir = '/';
    }
    /* If the caller has determined the current directory, and it differs */
    /* from what the client requested, then show the real name */
    if (cwd == NULL || strncmp (cwd, path, strlen(cwd)) == 0) {
	ap_snprintf(buf, sizeof(buf), "</H2>\n<HR><PRE>");
    } else {
	ap_snprintf(buf, sizeof(buf), "</H2>\n(%s)\n<HR><PRE>", cwd);
    }
    total_bytes_sent += ap_proxy_bputs2(buf, con->client, c);

    while (!con->aborted) {
	n = ap_bgets(buf, sizeof buf, f);
	if (n == -1) {		/* input error */
	    if (c != NULL)
		c = ap_proxy_cache_error(c);
	    break;
	}
	if (n == 0)
	    break;		/* EOF */
	if (buf[0] == 'l' && (filename=strstr(buf, " -> ")) != NULL) {
	    char *link_ptr = filename;

	    do {
		filename--;
	    } while (filename[0] != ' ');
	    *(filename++) = '\0';
	    *(link_ptr++) = '\0';
	    if ((n = strlen(link_ptr)) > 1 && link_ptr[n - 1] == '\n')
	      link_ptr[n - 1] = '\0';
	    ap_snprintf(buf2, sizeof(buf2), "%s <A HREF=\"%s\">%s %s</A>\n", buf, filename, filename, link_ptr);
	    ap_cpystrn(buf, buf2, sizeof(buf));
	    n = strlen(buf);
	}
	else if (buf[0] == 'd' || buf[0] == '-' || buf[0] == 'l' || ap_isdigit(buf[0])) {
	    if (ap_isdigit(buf[0])) {	/* handle DOS dir */
		searchptr = strchr(buf, '<');
		if (searchptr != NULL)
		    *searchptr = '[';
		searchptr = strchr(buf, '>');
		if (searchptr != NULL)
		    *searchptr = ']';
	    }

	    filename = strrchr(buf, ' ');
	    *(filename++) = 0;
	    filename[strlen(filename) - 1] = 0;

	    /* handle filenames with spaces in 'em */
	    if (!strcmp(filename, ".") || !strcmp(filename, "..") || firstfile) {
		firstfile = 0;
		searchidx = filename - buf;
	    }
	    else if (searchidx != 0 && buf[searchidx] != 0) {
		*(--filename) = ' ';
		buf[searchidx - 1] = 0;
		filename = &buf[searchidx];
	    }

	    /* Special handling for '.' and '..' */
	    if (!strcmp(filename, ".") || !strcmp(filename, "..") || buf[0] == 'd') {
		ap_snprintf(buf2, sizeof(buf2), "%s <A HREF=\"%s/\">%s</A>\n",
		    buf, filename, filename);
	    }
	    else {
		ap_snprintf(buf2, sizeof(buf2), "%s <A HREF=\"%s\">%s</A>\n", buf, filename, filename);
	    }
	    ap_cpystrn(buf, buf2, sizeof(buf));
	    n = strlen(buf);
	}

	o = 0;
	total_bytes_sent += n;

	if (c != NULL && c->fp && ap_bwrite(c->fp, buf, n) != n)
	    c = ap_proxy_cache_error(c);

	while (n && !r->connection->aborted) {
	    w = ap_bwrite(con->client, &buf[o], n);
	    if (w <= 0)
		break;
	    ap_reset_timeout(r);	/* reset timeout after successfule write */
	    n -= w;
	    o += w;
	}
    }

    total_bytes_sent += ap_proxy_bputs2("</PRE><HR>\n", con->client, c);
    total_bytes_sent += ap_proxy_bputs2(ap_psignature("", r), con->client, c);
    total_bytes_sent += ap_proxy_bputs2("</BODY></HTML>\n", con->client, c);

    ap_bflush(con->client);

    return total_bytes_sent;
}

/* Common routine for failed authorization (i.e., missing or wrong password)
 * to an ftp service. This causes most browsers to retry the request
 * with username and password (which was presumably queried from the user)
 * supplied in the Authorization: header.
 * Note that we "invent" a realm name which consists of the
 * ftp://user@host part of the reqest (sans password -if supplied but invalid-)
 */
static int ftp_unauthorized (request_rec *r, int log_it)
{
    r->proxyreq = 0;
    /* Log failed requests if they supplied a password
     * (log username/password guessing attempts)