proxy_http.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/>.
 *
 */

/* HTTP routines for Apache proxy */

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

/*
 * Canonicalise http-like URLs.
 *  scheme is the scheme for the URL
 *  url    is the URL starting with the first '/'
 *  def_port is the default port for this scheme.
 */
int ap_proxy_http_canon(request_rec *r, char *url, const char *scheme, int def_port)
{
    char *host, *path, *search, sport[7];
    const char *err;
    int port;

/* do syntatic check.
 * We break the URL into host, port, path, search
 */
    port = def_port;
    err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port);
    if (err)
	return HTTP_BAD_REQUEST;

/* now parse path/search args, according to rfc1738 */
/* N.B. if this isn't a true proxy request, then the URL _path_
 * has already been decoded.  True proxy requests have r->uri
 * == r->unparsed_uri, and no others have that property.
 */
    if (r->uri == r->unparsed_uri) {
	search = strchr(url, '?');
	if (search != NULL)
	    *(search++) = '\0';
    }
    else
	search = r->args;

/* process path */
    path = ap_proxy_canonenc(r->pool, url, strlen(url), enc_path, r->proxyreq);
    if (path == NULL)
	return HTTP_BAD_REQUEST;

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

    r->filename = ap_pstrcat(r->pool, "proxy:", scheme, "://", host, sport, "/",
		   path, (search) ? "?" : "", (search) ? search : "", NULL);
    return OK;
}
 
static const char *proxy_location_reverse_map(request_rec *r, const char *url)
{
    void *sconf;
    proxy_server_conf *conf;
    struct proxy_alias *ent;
    int i, l1, l2;
    char *u;

    sconf = r->server->module_config;
    conf = (proxy_server_conf *)ap_get_module_config(sconf, &proxy_module);
    l1 = strlen(url);
    ent = (struct proxy_alias *)conf->raliases->elts;
    for (i = 0; i < conf->raliases->nelts; i++) {
        l2 = strlen(ent[i].real);
        if (l1 >= l2 && strncmp(ent[i].real, url, l2) == 0) {
            u = ap_pstrcat(r->pool, ent[i].fake, &url[l2], NULL);
            return ap_construct_url(r->pool, u, r);
        }
    }
    return url;
}

/* Clear all connection-based headers from the incoming headers table */
static void clear_connection(pool *p, table *headers)
{
    const char *name;
    char *next = ap_pstrdup(p, ap_table_get(headers, "Connection"));

    ap_table_unset(headers, "Proxy-Connection");
    if (!next)
	return;

    while (*next) {
	name = next;
	while (*next && !ap_isspace(*next) && (*next != ','))
	    ++next;
	while (*next && (ap_isspace(*next) || (*next == ','))) {
	    *next = '\0';
	    ++next;
	}
	ap_table_unset(headers, name);
    }
    ap_table_unset(headers, "Connection");
}

/*
 * This handles http:// URLs, and other URLs using a remote proxy over http
 * If proxyhost is NULL, then contact the server directly, otherwise
 * go via the proxy.
 * Note that if a proxy is used, then URLs other than http: can be accessed,
 * also, if we have trouble which is clearly specific to the proxy, then
 * we return DECLINED so that we can try another proxy. (Or the direct
 * route.)
 */
int ap_proxy_http_handler(request_rec *r, cache_req *c, char *url,
		       const char *proxyhost, int proxyport)
{
    const char *strp;
    char *strp2;
    const char *err, *desthost;
    int i, j, sock, len, backasswards;
    array_header *reqhdrs_arr;
    table *resp_hdrs;
    table_entry *reqhdrs;
    struct sockaddr_in server;
    struct in_addr destaddr;
    struct hostent server_hp;
    BUFF *f;
    char buffer[HUGE_STRING_LEN];
    char portstr[32];
    pool *p = r->pool;
    const long int zero = 0L;
    int destport = 0;
    char *destportstr = NULL;
    const char *urlptr = NULL;
    const char *datestr;
    struct tbl_do_args tdo;

    void *sconf = r->server->module_config;
    proxy_server_conf *conf =
    (proxy_server_conf *) ap_get_module_config(sconf, &proxy_module);
    struct noproxy_entry *npent = (struct noproxy_entry *) conf->noproxies->elts;
    struct nocache_entry *ncent = (struct nocache_entry *) conf->nocaches->elts;
    int nocache = 0;

    memset(&server, '\0', sizeof(server));
    server.sin_family = AF_INET;

/* We break the URL into host, port, path-search */

    urlptr = strstr(url, "://");
    if (urlptr == NULL)
	return HTTP_BAD_REQUEST;
    urlptr += 3;
    destport = DEFAULT_HTTP_PORT;
    strp = strchr(urlptr, '/');
    if (strp == NULL) {
	desthost = ap_pstrdup(p, urlptr);
	urlptr = "/";
    }
    else {
	char *q = ap_palloc(p, strp - urlptr + 1);
	memcpy(q, urlptr, strp - urlptr);
	q[strp - urlptr] = '\0';
	urlptr = strp;
	desthost = q;
    }

    strp2 = strchr(desthost, ':');
    if (strp2 != NULL) {
	*(strp2++) = '\0';
	if (ap_isdigit(*strp2)) {
	    destport = atoi(strp2);
	    destportstr = strp2;
	}
    }

/* check if ProxyBlock directive on this host */
    destaddr.s_addr = ap_inet_addr(desthost);
    for (i = 0; i < conf->noproxies->nelts; i++) {
	if ((npent[i].name != NULL && strstr(desthost, npent[i].name) != NULL)
	    || destaddr.s_addr == npent[i].addr.s_addr || npent[i].name[0] == '*')
	    return ap_proxyerror(r, "Connect to remote machine blocked");
    }

    if (proxyhost != NULL) {
	server.sin_port = htons(proxyport);
	err = ap_proxy_host2addr(proxyhost, &server_hp);
	if (err != NULL)
	    return DECLINED;	/* try another */
    }
    else {
	server.sin_port = htons(destport);
	err = ap_proxy_host2addr(desthost, &server_hp);
	if (err != NULL)
	    return ap_proxyerror(r, err);	/* give up */
    }

    sock = ap_psocket(p, PF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sock == -1) {
	ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
		    "proxy: error creating socket");
	return HTTP_INTERNAL_SERVER_ERROR;
    }

    if (conf->recv_buffer_size) {
	if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
		       (const char *) &conf->recv_buffer_size, sizeof(int))
	    == -1) {
	    ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
			 "setsockopt(SO_RCVBUF): Failed to set ProxyReceiveBufferSize, using default");