From: Eric Covener <covener@apache.org>
Date: Sun, 17 Jan 2016 23:40:09 +0000 (+0000)
Subject: allow expressions to be used in SetHandler. Opt-in with expr= prefix.
X-Git-Tag: 2.5.0-alpha~2404
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e89938830a456da686fdb035918e087cf8344b5a;p=apache

allow expressions to be used in SetHandler. Opt-in with expr= prefix.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1725149 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/CHANGES b/CHANGES
index 33666a4be5..b13c091ebc 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,9 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.5.0
 
+  *) core: Add expression support to SetHandler.
+     [Eric Covener]
+
   *) mod_proxy_fcgi: Suppress HTTP error 503 and message 01075, 
      "Error dispatching request", when the cause appears to be 
      due to the client closing the connection. 
diff --git a/docs/manual/mod/core.xml b/docs/manual/mod/core.xml
index 682792083c..1035178ce2 100644
--- a/docs/manual/mod/core.xml
+++ b/docs/manual/mod/core.xml
@@ -4318,11 +4318,12 @@ header</description>
 <name>SetHandler</name>
 <description>Forces all matching files to be processed by a
 handler</description>
-<syntax>SetHandler <var>handler-name</var>|None</syntax>
+<syntax>SetHandler <var>handler-name</var>|None|expr=<var>expression</var></syntax>
 <contextlist><context>server config</context><context>virtual host</context>
 <context>directory</context><context>.htaccess</context>
 </contextlist>
 <override>FileInfo</override>
+<compatibility>2.5 and later</compatibility>
 
 <usage>
     <p>When placed into an <code>.htaccess</code> file or a
@@ -4359,6 +4360,15 @@ SetHandler imap-file
 &lt;/FilesMatch&gt;
     </highlight>
 
+    <p>String-valued expressions can be used to reference per-request 
+    variables, including backreferences to named regular expressions:</p>
+
+    <highlight language="config">
+&lt;LocationMatch ^/app/(?&lt;sub&gt;[^/]+)/&gt;
+     SetHandler "expr=proxy:unix:/var/run/app_%{env:MATCH_sub}.sock|fcgi://localhost:8080"
+&lt;/FilesMatch&gt;
+    </highlight>
+
     <p>You can override an earlier defined <directive>SetHandler</directive>
     directive by using the value <code>None</code>.</p>
 
diff --git a/include/ap_mmn.h b/include/ap_mmn.h
index 53e2f1e1b2..6930e26926 100644
--- a/include/ap_mmn.h
+++ b/include/ap_mmn.h
@@ -497,6 +497,7 @@
  * 20150222.6 (2.5.0-dev)  Add async_filter to conn_rec.
  * 20150222.7 (2.5.0-dev)  Add ap_casecmpstr[n]();
  * 20150222.8 (2.5.0-dev)  Add ap_getword_conf2[_nc]();
+ * 20150222.9 (2.5.0-dev)  Add epxr_hander to core_dir_config.
  */
 
 #define MODULE_MAGIC_COOKIE 0x41503235UL /* "AP25" */
diff --git a/include/http_core.h b/include/http_core.h
index 3ecd5f119f..eaff248575 100644
--- a/include/http_core.h
+++ b/include/http_core.h
@@ -646,7 +646,7 @@ typedef struct {
     apr_hash_t *response_code_exprs;
 
     unsigned int qualify_redirect_url :2;
-
+    ap_expr_info_t  *expr_handler;         /* forced with SetHandler expr= */
 } core_dir_config;
 
 /* macro to implement off by default behaviour */
diff --git a/server/core.c b/server/core.c
index c9150b443d..1a464c1322 100644
--- a/server/core.c
+++ b/server/core.c
@@ -356,6 +356,9 @@ static void *merge_core_dir_configs(apr_pool_t *a, void *basev, void *newv)
     if (new->handler) {
         conf->handler = new->handler;
     }
+    if (new->expr_handler) {
+        conf->expr_handler = new->expr_handler;
+    }
 
     if (new->output_filters) {
         conf->output_filters = new->output_filters;
@@ -1967,7 +1970,18 @@ static const char *set_sethandler(cmd_parms *cmd,
 {
     core_dir_config *dirconf = d_;
 
-    if (arg_ == ap_strstr_c(arg_, "proxy:unix")) { 
+    if (!strncmp(arg_, "expr=", 5)) {
+        const char *err;
+        dirconf->expr_handler = ap_expr_parse_cmd(cmd, arg_+5,
+                                          AP_EXPR_FLAG_STRING_RESULT,
+                                          &err, NULL);
+        if (err) {
+            return apr_pstrcat(cmd->pool,
+                    "Can't parse expression : ", err, NULL);
+        }
+        return NULL;
+    }
+    else if (arg_ == ap_strstr_c(arg_, "proxy:unix")) { 
         dirconf->handler = arg_;
     }
     else { 
@@ -4644,8 +4658,22 @@ static int core_override_type(request_rec *r)
     if (conf->mime_type && strcmp(conf->mime_type, "none"))
         ap_set_content_type(r, (char*) conf->mime_type);
 
-    if (conf->handler && strcmp(conf->handler, "none"))
+    if (conf->expr_handler) { 
+        const char *err;
+        const char *val;
+        val = ap_expr_str_exec(r, conf->expr_handler, &err);
+        if (err) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO()
+                          "Can't evaluate handler expression: %s", err);
+            return HTTP_INTERNAL_SERVER_ERROR;
+        }
+        if (strcmp(val, "none")) { 
+            r->handler = apr_pstrdup(r->pool, val);
+        }
+    }
+    else if (conf->handler && strcmp(conf->handler, "none")) { 
         r->handler = conf->handler;
+    }
 
     /* Deal with the poor soul who is trying to force path_info to be
      * accepted within the core_handler, where they will let the subreq