[mod_magnet] reset config cache for remote addr

reset config cache for changes to
  lighty.r.req_attr["request.remote-addr"]

Changes might affect subsequent modules when those modules patch config,
but does not affect the core config options which have already been
processed.

If lighttpd config needs to be reprocessed after making changes, then
return lighty.RESTART_REQUEST from lua script to tell lighttpd to
restart the request, including reprocessing the core config options.

src/mod_magnet.c

@@ -1362,7 +1362,7 @@ typedef struct {
 		MAGNET_ENV_REQUEST_URI,
 		MAGNET_ENV_REQUEST_ORIG_URI,
 		MAGNET_ENV_REQUEST_PATH_INFO,
-		MAGNET_ENV_REQUEST_REMOTE_IP,
+		MAGNET_ENV_REQUEST_REMOTE_ADDR,
 		MAGNET_ENV_REQUEST_SERVER_ADDR,
 		MAGNET_ENV_REQUEST_PROTOCOL,
 
@@ -1388,8 +1388,8 @@ static const magnet_env_t magnet_env[] = {
     { CONST_STR_LEN("request.uri"),          MAGNET_ENV_REQUEST_URI },
     { CONST_STR_LEN("request.orig-uri"),     MAGNET_ENV_REQUEST_ORIG_URI },
     { CONST_STR_LEN("request.path-info"),    MAGNET_ENV_REQUEST_PATH_INFO },
-    { CONST_STR_LEN("request.remote-ip"),    MAGNET_ENV_REQUEST_REMOTE_IP },
-    { CONST_STR_LEN("request.remote-addr"),  MAGNET_ENV_REQUEST_REMOTE_IP },
+    { CONST_STR_LEN("request.remote-ip"),    MAGNET_ENV_REQUEST_REMOTE_ADDR },
+    { CONST_STR_LEN("request.remote-addr"),  MAGNET_ENV_REQUEST_REMOTE_ADDR },
     { CONST_STR_LEN("request.server-addr"),  MAGNET_ENV_REQUEST_SERVER_ADDR },
     { CONST_STR_LEN("request.protocol"),     MAGNET_ENV_REQUEST_PROTOCOL },
 
@@ -1436,7 +1436,7 @@ static buffer *magnet_env_get_buffer_by_id(request_st * const r, int id) {
 	case MAGNET_ENV_REQUEST_URI:      dest = &r->target; break;
 	case MAGNET_ENV_REQUEST_ORIG_URI: dest = &r->target_orig; break;
 	case MAGNET_ENV_REQUEST_PATH_INFO: dest = &r->pathinfo; break;
-	case MAGNET_ENV_REQUEST_REMOTE_IP: dest = &r->con->dst_addr_buf; break;
+	case MAGNET_ENV_REQUEST_REMOTE_ADDR: dest = &r->con->dst_addr_buf; break;
 	case MAGNET_ENV_REQUEST_SERVER_ADDR: /* local IP without port */
 	    {
 		const server_socket * const srv_socket = r->con->srv_socket;
@@ -1533,7 +1533,7 @@ static int magnet_env_set(lua_State *L) {
     /* __newindex: param 1 is the (empty) table the value is supposed to be set in */
     size_t klen;
     const char * const key = luaL_checklstring(L, 2, &klen);
-    luaL_checkany(L, 3); /* nil or a string */
+    const_buffer val = magnet_checkconstbuffer(L, 3);
 
     request_st * const r = magnet_get_request(L);
     const int env_id = magnet_env_get_id(key, klen);
@@ -1547,9 +1547,6 @@ static int magnet_env_set(lua_State *L) {
         /* XXX: should we require that resulting path begin with '/' or %2F ? */
         const uint32_t len = buffer_clen(&r->target);
         const char * const qmark = memchr(r->target.ptr, '?', len);
-        const_buffer val = { NULL, 0 };
-        if (!lua_isnil(L, 3))
-            val = magnet_checkconstbuffer(L, 3);
         if (NULL != qmark)
             buffer_copy_string_len(r->tmp_buf, qmark,
                                    len - (uint32_t)(qmark - r->target.ptr));
@@ -1558,6 +1555,36 @@ static int magnet_env_set(lua_State *L) {
             buffer_append_string_buffer(&r->target, r->tmp_buf);
         return 0;
       }
+      case MAGNET_ENV_REQUEST_REMOTE_ADDR:
+       #ifdef HAVE_SYS_UN_H
+        if (val.len && *val.ptr == '/'
+            && 0 == sock_addr_assign(&r->con->dst_addr, AF_UNIX, 0, val.ptr)) {
+        }
+        else
+       #endif
+        {
+            sock_addr saddr;
+            saddr.plain.sa_family = AF_UNSPEC;
+            if (1 == sock_addr_from_str_numeric(&saddr, val.ptr, r->conf.errh)
+                && saddr.plain.sa_family != AF_UNSPEC) {
+                /*(set port 0 instead of memset(&saddr, 0, sizeof(saddr)) above
+                 * and instead of sock_addr_assign() as in mod_extforward.c)
+                 *(future: might provide MAGNET_ENV_REQUEST_REMOTE_PORT
+                 * and create sock_addr_set_port()) */
+                if (saddr.plain.sa_family == AF_INET)
+                    saddr.ipv4.sin_port = 0;
+                else if (saddr.plain.sa_family == AF_INET6)
+                    saddr.ipv6.sin6_port = 0;
+                memcpy(&r->con->dst_addr, &saddr, sizeof(sock_addr));
+            }
+            else {
+                return luaL_error(L, "lighty.r.req_attr['%s'] invalid addr: %s",
+                                  key, val.ptr);
+            }
+        }
+        buffer_copy_string_len(&r->con->dst_addr_buf, val.ptr, val.len);
+        config_cond_cache_reset_item(r, COMP_HTTP_REMOTE_IP);
+        return 0;
       case MAGNET_ENV_RESPONSE_HTTP_STATUS:
       case MAGNET_ENV_RESPONSE_BODY_LENGTH:
       case MAGNET_ENV_RESPONSE_BODY: