Create mod_rpaf-2.0.c

Author: Prajithp

mod_rpaf-2.0.c

@@ -0,0 +1,252 @@
+
+/* ====================================================================
+ * Copyright (c) 1995 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.
+ *
+ * 5. 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
+ * IT'S 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/>.
+ *
+ */
+
+/*
+ * $Id: mod_rpaf-2.0.c 18 2008-01-01 03:05:40Z thomas $
+ *
+ * Author: Thomas Eibner, <thomas@stderr.net>
+ * URL: http://stderr.net/apache/rpaf/
+ * rpaf is short for reverse proxy add forward 
+ *
+ * This module does the opposite of mod_proxy_add_forward written by
+ * Ask Bj�rn Hansen. http://develooper.com/code/mpaf/ or mod_proxy
+ * in 1.3.25 and above and mod_proxy from Apache 2.0
+ * 
+ */ 
+
+#include "httpd.h"
+#include "http_config.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "http_protocol.h"
+#include "http_vhost.h"
+#include "apr_strings.h"
+
+module AP_MODULE_DECLARE_DATA rpaf_module;
+
+typedef struct {
+    int                enable;
+    int                sethostname;
+    const char         *headername;
+    apr_array_header_t *proxy_ips;
+} rpaf_server_cfg;
+
+typedef struct {
+    const char  *old_ip;
+    request_rec *r;
+} rpaf_cleanup_rec;
+
+static void *rpaf_create_server_cfg(apr_pool_t *p, server_rec *s) {
+    rpaf_server_cfg *cfg = (rpaf_server_cfg *)apr_pcalloc(p, sizeof(rpaf_server_cfg));
+    if (!cfg)
+        return NULL;
+
+    cfg->proxy_ips = apr_array_make(p, 0, sizeof(char *));
+    cfg->enable = 0;
+    cfg->sethostname = 0;
+
+    return (void *)cfg;
+}
+
+static const char *rpaf_set_proxy_ip(cmd_parms *cmd, void *dummy, const char *proxy_ip) {
+    server_rec *s = cmd->server;
+    rpaf_server_cfg *cfg = (rpaf_server_cfg *)ap_get_module_config(s->module_config, 
+                                                                   &rpaf_module);
+
+    /* check for valid syntax of ip */
+    *(char **)apr_array_push(cfg->proxy_ips) = apr_pstrdup(cmd->pool, proxy_ip);
+    return NULL;
+}
+
+static const char *rpaf_set_headername(cmd_parms *cmd, void *dummy, const char *headername) {
+    server_rec *s = cmd->server;
+    rpaf_server_cfg *cfg = (rpaf_server_cfg *)ap_get_module_config(s->module_config, 
+                                                                   &rpaf_module);
+
+    cfg->headername = headername; 
+    return NULL;
+}
+
+static const char *rpaf_enable(cmd_parms *cmd, void *dummy, int flag) {
+    server_rec *s = cmd->server;
+    rpaf_server_cfg *cfg = (rpaf_server_cfg *)ap_get_module_config(s->module_config, 
+                                                                   &rpaf_module);
+
+    cfg->enable = flag;
+    return NULL;
+}
+
+static const char *rpaf_sethostname(cmd_parms *cmd, void *dummy, int flag) {
+    server_rec *s = cmd->server;
+    rpaf_server_cfg *cfg = (rpaf_server_cfg *)ap_get_module_config(s->module_config, 
+                                                                   &rpaf_module);
+
+    cfg->sethostname = flag;
+    return NULL;
+}
+
+static int is_in_array(const char *remote_ip, apr_array_header_t *proxy_ips) {
+    int i;
+    char **list = (char**)proxy_ips->elts;
+    for (i = 0; i < proxy_ips->nelts; i++) {
+        if (strcmp(remote_ip, list[i]) == 0)
+            return 1;
+    }
+    return 0;
+}
+
+static apr_status_t rpaf_cleanup(void *data) {
+    rpaf_cleanup_rec *rcr = (rpaf_cleanup_rec *)data;
+    rcr->r->connection->remote_ip   = apr_pstrdup(rcr->r->connection->pool, rcr->old_ip);
+    rcr->r->connection->remote_addr->sa.sin.sin_addr.s_addr = apr_inet_addr(rcr->r->connection->remote_ip);
+    return APR_SUCCESS;
+}
+
+static int change_remote_ip(request_rec *r) {
+    const char *fwdvalue;
+    char *val;
+    rpaf_server_cfg *cfg = (rpaf_server_cfg *)ap_get_module_config(r->server->module_config,
+                                                                   &rpaf_module);
+
+    if (!cfg->enable)
+        return DECLINED;
+
+    if (is_in_array(r->connection->remote_ip, cfg->proxy_ips) == 1) {
+        /* check if cfg->headername is set and if it is use
+           that instead of X-Forwarded-For by default */
+        if (cfg->headername && (fwdvalue = apr_table_get(r->headers_in, cfg->headername))) {
+            //
+        } else if (fwdvalue = apr_table_get(r->headers_in, "X-Forwarded-For")) {
+            //
+        } else {
+            return DECLINED;
+        }
+
+        if (fwdvalue) {
+            rpaf_cleanup_rec *rcr = (rpaf_cleanup_rec *)apr_pcalloc(r->pool, sizeof(rpaf_cleanup_rec));
+            apr_array_header_t *arr = apr_array_make(r->pool, 0, sizeof(char*));
+            while (*fwdvalue && (val = ap_get_token(r->pool, &fwdvalue, 1))) {
+                *(char **)apr_array_push(arr) = apr_pstrdup(r->pool, val);
+                if (*fwdvalue != '\0')
+                    ++fwdvalue;
+            }
+            rcr->old_ip = apr_pstrdup(r->connection->pool, r->connection->remote_ip);
+            rcr->r = r;
+            apr_pool_cleanup_register(r->pool, (void *)rcr, rpaf_cleanup, apr_pool_cleanup_null);
+            r->connection->remote_ip = apr_pstrdup(r->connection->pool, ((char **)arr->elts)[((arr->nelts)-1)]);
+            r->connection->remote_addr->sa.sin.sin_addr.s_addr = apr_inet_addr(r->connection->remote_ip);
+            if (cfg->sethostname) {
+                const char *hostvalue;
+                if (hostvalue = apr_table_get(r->headers_in, "X-Forwarded-Host")) {
+                    /* 2.0 proxy frontend or 1.3 => 1.3.25 proxy frontend */
+                    apr_table_set(r->headers_in, "Host", apr_pstrdup(r->pool, hostvalue));
+                    r->hostname = apr_pstrdup(r->pool, hostvalue);
+                    ap_update_vhost_from_headers(r);
+                } else if (hostvalue = apr_table_get(r->headers_in, "X-Host")) {
+                    /* 1.3 proxy frontend with mod_proxy_add_forward */
+                    apr_table_set(r->headers_in, "Host", apr_pstrdup(r->pool, hostvalue));
+                    r->hostname = apr_pstrdup(r->pool, hostvalue);
+                    ap_update_vhost_from_headers(r);
+                }
+            }
+
+        }
+    }
+    return DECLINED;
+}
+
+static const command_rec rpaf_cmds[] = {
+    AP_INIT_FLAG(
+                 "RPAFenable",
+                 rpaf_enable,
+                 NULL,
+                 RSRC_CONF,
+                 "Enable mod_rpaf"
+                 ),
+    AP_INIT_FLAG(
+                 "RPAFsethostname",
+                 rpaf_sethostname,
+                 NULL,
+                 RSRC_CONF,
+                 "Let mod_rpaf set the hostname from X-Host header and update vhosts"
+                 ),
+    AP_INIT_ITERATE(
+                    "RPAFproxy_ips",
+                    rpaf_set_proxy_ip,
+                    NULL,
+                    RSRC_CONF,
+                    "IP(s) of Proxy server setting X-Forwarded-For header"
+                    ),
+    AP_INIT_TAKE1(
+                    "RPAFheader",
+                    rpaf_set_headername,
+                    NULL,
+                    RSRC_CONF,
+                    "Which header to look for when trying to find the real ip of the client in a proxy setup"
+                    ),
+    { NULL }
+};
+
+static void register_hooks(apr_pool_t *p) {
+    ap_hook_post_read_request(change_remote_ip, NULL, NULL, APR_HOOK_FIRST);
+}
+
+module AP_MODULE_DECLARE_DATA rpaf_module = {
+    STANDARD20_MODULE_STUFF,
+    NULL,
+    NULL,
+    rpaf_create_server_cfg,
+    NULL,
+    rpaf_cmds,
+    register_hooks,
+};