add ProxyPreserveHost support to mod_proxy. it allows to pass the original

Host header to the backend. default off. henning@ ok.

4 files changed, 83 insertions, 5 deletions

diff --git a/usr.sbin/httpd/htdocs/manual/mod/mod_proxy.html b/usr.sbin/httpd/htdocs/manual/mod/mod_proxy.html
index 6e0b7e19c32..b4e6497d258 100644
--- a/usr.sbin/httpd/htdocs/manual/mod/mod_proxy.html
+++ b/usr.sbin/httpd/htdocs/manual/mod/mod_proxy.html
@@ -61,6 +61,8 @@
 
       <li><a href="#proxypassreverse">ProxyPassReverse</a></li>
 
+      <li><a href="#proxypreservehost">ProxyPreserveHost</a></li>
+
       <li><a href="#proxyblock">ProxyBlock</a></li>
 
       <li><a href="#allowconnect">AllowCONNECT</a></li>
@@ -563,6 +565,33 @@ application/octet-stream        bin dms lha lzh exe class tgz taz
     <samp>ProxyPass</samp> directive.</p>
     <hr />
 
+    <h2><a id="proxypreservehost"
+    name="proxypreservehost">ProxyPreserveHost</a> directive</h2>
+    <a href="directive-dict.html#Syntax"
+    rel="Help"><strong>Syntax:</strong></a> ProxyPreserveHost
+    <em>on|off</em><br />
+     <a href="directive-dict.html#Default"
+    rel="Help"><strong>Default:</strong></a>
+    <em><samp>ProxyPreserveHost</samp> off</em><br />
+     <a href="directive-dict.html#Context"
+    rel="Help"><strong>Context:</strong></a> server config, virtual
+    host<br />
+     <a href="directive-dict.html#Override"
+    rel="Help"><strong>Override:</strong></a> <em>Not
+    applicable</em><br />
+     <a href="directive-dict.html#Status"
+    rel="Help"><strong>Status:</strong></a> Base<br />
+     <a href="directive-dict.html#Module"
+    rel="Help"><strong>Module:</strong></a> mod_proxy<br />
+
+    <p>When enabled, this option will pass the Host: line from the
+    incoming request to the proxied host, instead of the hostname
+    specified in the proxypass line.<br />
+     This option should normally be turned Off. It is mostly useful
+    in special configurations like proxied mass name-based virtual
+    hosting, where the original Host header needs to be evaluated by
+    the backend server.</p>
+
     <h2><a id="allowconnect" name="allowconnect">AllowCONNECT</a>
     directive</h2>
     <a href="directive-dict.html#Syntax"
diff --git a/usr.sbin/httpd/src/modules/proxy/mod_proxy.c b/usr.sbin/httpd/src/modules/proxy/mod_proxy.c
index fb43af97974..5206151041d 100644
--- a/usr.sbin/httpd/src/modules/proxy/mod_proxy.c
+++ b/usr.sbin/httpd/src/modules/proxy/mod_proxy.c
@@ -493,6 +493,8 @@ static void *
     ps->recv_buffer_size_set = 0;
     ps->io_buffer_size = IOBUFSIZE;
     ps->io_buffer_size_set = 0;
+    ps->preserve_host = 0;
+    ps->preserve_host_set = 0;
 
     ps->cache.root = NULL;
     ps->cache.space = DEFAULT_CACHE_SPACE;
@@ -538,6 +540,8 @@ static void *
     ps->recv_buffer_size = (overrides->recv_buffer_size_set == 0) ? base->recv_buffer_size : overrides->recv_buffer_size;
     ps->io_buffer_size = (overrides->io_buffer_size_set == 0) ? base->io_buffer_size : overrides->io_buffer_size;
 
+    ps->preserve_host = (overrides->preserve_host_set == 0) ? base->preserve_host : overrides->preserve_host;
+
     ps->cache.root = (overrides->cache.root == NULL) ? base->cache.root : overrides->cache.root;
     ps->cache.space = (overrides->cache.space_set == 0) ? base->cache.space : overrides->cache.space;
     ps->cache.maxexpire = (overrides->cache.maxexpire_set == 0) ? base->cache.maxexpire : overrides->cache.maxexpire;
@@ -973,6 +977,25 @@ static const char *
     return NULL;
 }
 
+static const char *
+    set_preserve_host(cmd_parms *parms, void *dummy, char *arg)
+{
+    proxy_server_conf *psf =
+    ap_get_module_config(parms->server->module_config, &proxy_module);
+
+    if (strcasecmp(arg, "Off") == 0)
+        psf->preserve_host = 0;
+    else if (strcasecmp(arg, "On") == 0)
+        psf->preserve_host = 1;
+    else {
+        return "ProxyPreserveHost must be one of: "
+            "off | on";
+    }
+
+    psf->preserve_host_set = 1;
+    return NULL;
+}
+
 static const handler_rec proxy_handlers[] =
 {
     {"proxy-server", proxy_handler},
@@ -1001,6 +1024,8 @@ static const command_rec proxy_cmds[] =
     "The default intranet domain name (in absence of a domain in the URL)"},
     {"AllowCONNECT", set_allowed_ports, NULL, RSRC_CONF, ITERATE,
     "A list of ports which CONNECT may connect to"},
+    {"ProxyPreserveHost", set_preserve_host, NULL, RSRC_CONF, TAKE1,
+    "on if the host header should be preserved while proxying"},
     {"CacheRoot", set_cache_root, NULL, RSRC_CONF, TAKE1,
     "The directory to store cache files"},
     {"CacheSize", set_cache_size, NULL, RSRC_CONF, TAKE1,
diff --git a/usr.sbin/httpd/src/modules/proxy/mod_proxy.h b/usr.sbin/httpd/src/modules/proxy/mod_proxy.h
index 998f1ddcbde..2348afa0852 100644
--- a/usr.sbin/httpd/src/modules/proxy/mod_proxy.h
+++ b/usr.sbin/httpd/src/modules/proxy/mod_proxy.h
@@ -203,6 +203,8 @@ typedef struct {
     char recv_buffer_size_set;
     size_t io_buffer_size;
     char io_buffer_size_set;
+    int preserve_host;
+    int preserve_host_set;
 } proxy_server_conf;
 
 struct hdr_entry {
diff --git a/usr.sbin/httpd/src/modules/proxy/proxy_http.c b/usr.sbin/httpd/src/modules/proxy/proxy_http.c
index c750f5f78be..46630aafe32 100644
--- a/usr.sbin/httpd/src/modules/proxy/proxy_http.c
+++ b/usr.sbin/httpd/src/modules/proxy/proxy_http.c
@@ -151,7 +151,7 @@ int ap_proxy_http_handler(request_rec *r, cache_req *c, char *url,
 {
     const char *strp;
     char *strp2;
-    const char *err, *desthost;
+    const char *err, *desthost, *hostname;
     int i, j, sock,/* len,*/ backasswards;
     table *req_hdrs, *resp_hdrs;
     array_header *reqhdrs_arr;
@@ -313,17 +313,39 @@ int ap_proxy_http_handler(request_rec *r, cache_req *c, char *url,
     ap_hard_timeout("proxy send", r);
     ap_bvputs(f, r->method, " ", proxyhost ? url : urlptr, " HTTP/1.1" CRLF,
               NULL);
+
+    if (conf->preserve_host) {
+        hostname = ap_table_get(r->headers_in, "Host");
+        if (!hostname) {
+            hostname = r->server->server_hostname;
+            ap_log_rerror(APLOG_MARK, APLOG_WARNING, r,
+                          "proxy: No host line on incoming request "
+                          "and preserve host set forcing hostname to "
+                          "be %s for uri %s", hostname, r->uri);
+        }
+        strp2 = strchr(hostname, ':');
+        if (strp2 != NULL) {
+            *(strp2++) = '\0';
+            if (ap_isdigit(*strp2)) {
+                destport = atoi(strp2);
+                destportstr = strp2;
+            }
+        }
+    }
+    else
+        hostname = desthost;
+
     {
 	int rc = DECLINED;
 	ap_hook_use("ap::mod_proxy::http::handler::write_host_header", 
 		    AP_HOOK_SIG6(int,ptr,ptr,ptr,int,ptr), 
 		    AP_HOOK_DECLINE(DECLINED),
-		    &rc, r, f, desthost, destport, destportstr);
+		    &rc, r, f, hostname, destport, destportstr);
         if (rc == DECLINED) {
 	    if (destportstr != NULL && destport != DEFAULT_HTTP_PORT)
-		ap_bvputs(f, "Host: ", desthost, ":", destportstr, CRLF, NULL);
+		ap_bvputs(f, "Host: ", hostname, ":", destportstr, CRLF, NULL);
 	    else
-		ap_bvputs(f, "Host: ", desthost, CRLF, NULL);
+		ap_bvputs(f, "Host: ", hostname, CRLF, NULL);
         }
     }
 
@@ -570,7 +592,7 @@ int ap_proxy_http_handler(request_rec *r, cache_req *c, char *url,
     if ((urlstr = ap_table_get(resp_hdrs, "Content-Location")) != NULL)
         ap_table_set(resp_hdrs, "Content-Location", proxy_location_reverse_map(r, urlstr));
 
-/* check if NoCache directive on this host */
+    /* check if NoCache directive on this host */
     if (nocache == 0) {
         for (i = 0; i < conf->nocaches->nelts; i++) {
             if (destaddr.s_addr == ncent[i].addr.s_addr ||