header_rewrite rm-destination support

doc/admin-guide/plugins/header_rewrite.en.rst

@@ -689,6 +689,18 @@ used as its replacement. You must supply a non-zero length value, otherwise
 this operator will be an effective no-op (though a warning will be emitted to
 the logs if debugging is enabled).
 
+rm-destination
+~~~~~~~~~~~~~~
+::
+
+  rm-destination <part>
+
+Removes individual components of the remapped destination's address. When
+changing the remapped destination, ``<part>`` should be used to indicate the
+component that is being modified (see `URL Parts`_). Currently the only valid
+parts for rm-destination are QUERY, PATH, and PORT.
+
+
 set-header
 ~~~~~~~~~~
 ::
@@ -1204,3 +1216,11 @@ could each be tagged with a consistent name to make finding logs easier.::
    set-header @PropertyName "someproperty"
 
 (Then in :file:`logging.yaml`, log ``%<{@PropertyName}cqh>``)
+
+Remove Client Query Parameters
+------------------------------------
+
+The following ruleset removes any query parameters set by the client.::
+
+   cond %{REMAP_PSEUDO_HOOK}
+   rm-destination QUERY

plugins/header_rewrite/factory.cc

@@ -47,6 +47,8 @@ operator_factory(const std::string &op)
     o = new OperatorSetStatusReason();
   } else if (op == "set-destination") {
     o = new OperatorSetDestination();
+  } else if (op == "rm-destination") {
+    o = new OperatorRMDestination();
   } else if (op == "set-redirect") {
     o = new OperatorSetRedirect();
   } else if (op == "timeout-out") {

plugins/header_rewrite/operators.cc

@@ -164,6 +164,17 @@ OperatorSetDestination::initialize(Parser &p)
   require_resources(RSRC_SERVER_REQUEST_HEADERS);
 }
 
+// OperatorRMDestination
+void
+OperatorRMDestination::initialize(Parser &p)
+{
+  Operator::initialize(p);
+
+  _url_qual = parse_url_qualifier(p.get_arg());
+  require_resources(RSRC_CLIENT_REQUEST_HEADERS);
+  require_resources(RSRC_SERVER_REQUEST_HEADERS);
+}
+
 void
 OperatorSetDestination::exec(const Resources &res) const
 {
@@ -273,6 +284,54 @@ OperatorSetDestination::exec(const Resources &res) const
   }
 }
 
+void
+OperatorRMDestination::exec(const Resources &res) const
+{
+  if (res._rri || (res.bufp && res.hdr_loc)) {
+    // Default empty string to delete components
+    static std::string value = "";
+
+    // Determine which TSMBuffer and TSMLoc to use
+    TSMBuffer bufp;
+    TSMLoc url_m_loc;
+    if (res._rri) {
+      bufp      = res._rri->requestBufp;
+      url_m_loc = res._rri->requestUrl;
+    } else {
+      bufp = res.bufp;
+      if (TSHttpHdrUrlGet(res.bufp, res.hdr_loc, &url_m_loc) != TS_SUCCESS) {
+        TSDebug(PLUGIN_NAME, "TSHttpHdrUrlGet was unable to return the url m_loc");
+        return;
+      }
+    }
+
+    // Never set an empty destination value (I don't think that ever makes sense?)
+    switch (_url_qual) {
+    case URL_QUAL_PATH:
+      const_cast<Resources &>(res).changed_url = true;
+      TSUrlPathSet(bufp, url_m_loc, value.c_str(), value.size());
+      TSDebug(PLUGIN_NAME, "OperatorRMDestination::exec() deleting PATH");
+      break;
+    case URL_QUAL_QUERY:
+      const_cast<Resources &>(res).changed_url = true;
+      TSUrlHttpQuerySet(bufp, url_m_loc, value.c_str(), value.size());
+      TSDebug(PLUGIN_NAME, "OperatorRMDestination::exec() deleting QUERY");
+      break;
+    case URL_QUAL_PORT:
+      const_cast<Resources &>(res).changed_url = true;
+      TSUrlPortSet(bufp, url_m_loc, 0);
+      TSDebug(PLUGIN_NAME, "OperatorRMDestination::exec() deleting PORT");
+      break;
+    default:
+      TSDebug(PLUGIN_NAME, "RM Destination %i has no handler", _url_qual);
+      break;
+    }
+  } else {
+    TSDebug(PLUGIN_NAME, "OperatorRMDestination::exec() unable to continue due to missing bufp=%p or hdr_loc=%p, rri=%p!", res.bufp,
+            res.hdr_loc, res._rri);
+  }
+}
+
 // OperatorSetRedirect
 void
 OperatorSetRedirect::initialize(Parser &p)

plugins/header_rewrite/operators.h

@@ -113,6 +113,25 @@ class OperatorSetDestination : public Operator
   Value _value;
 };
 
+// All the header operators share a base class
+class OperatorRMDestination : public Operator
+{
+public:
+  OperatorRMDestination() { TSDebug(PLUGIN_NAME_DBG, "Calling CTOR for OperatorRMDestination"); }
+
+  // noncopyable
+  OperatorRMDestination(const OperatorRMDestination &) = delete;
+  void operator=(const OperatorRMDestination &) = delete;
+
+  void initialize(Parser &p) override;
+
+protected:
+  void exec(const Resources &res) const override;
+
+private:
+  UrlQualifiers _url_qual = URL_QUAL_NONE;
+};
+
 class OperatorSetRedirect : public Operator
 {
 public: