Supporting UNIX sockets in address matching.

This closes #645 issue on GitHub.

(Also moved a changelog line that was misplaced in a previous commit.)

src/nxt_conf_validation.c

@@ -2157,6 +2157,11 @@ nxt_conf_vldt_match_addr(nxt_conf_validation_t *vldt,
         return nxt_conf_vldt_error(vldt, "The \"address\" does not support "
                                          "IPv6 with your configuration.");
 
+    case NXT_ADDR_PATTERN_NO_UNIX_ERROR:
+        return nxt_conf_vldt_error(vldt, "The \"address\" does not support "
+                                         "UNIX domain sockets with your "
+                                         "configuration.");
+
     default:
         return nxt_conf_vldt_error(vldt, "The \"address\" has an unknown "
                                          "format.");

src/nxt_http_route.c

@@ -1818,6 +1818,13 @@ nxt_http_route_addr_pattern_match(nxt_http_route_addr_pattern_t *p,
         break;
 #endif
 
+#if (NXT_HAVE_UNIX_DOMAIN)
+    case AF_UNIX:
+
+        match = (base->addr_family == AF_UNIX);
+        break;
+#endif
+
     default:
         match = 0;
         break;

src/nxt_http_route_addr.c

@@ -41,6 +41,16 @@ nxt_http_route_addr_pattern_parse(nxt_mp_t *mp,
         base->negative = 0;
     }
 
+    if (nxt_str_eq(&addr, "unix", 4)) {
+#if (NXT_HAVE_UNIX_DOMAIN)
+        base->addr_family = AF_UNIX;
+
+        return NXT_OK;
+#else
+        return NXT_ADDR_PATTERN_NO_UNIX_ERROR;
+#endif
+    }
+
     if (nxt_slow_path(addr.length < 2)) {
         return NXT_ADDR_PATTERN_LENGTH_ERROR;
     }

src/nxt_http_route_addr.h

@@ -26,6 +26,7 @@ enum {
     NXT_ADDR_PATTERN_RANGE_OVERLAP_ERROR,
     NXT_ADDR_PATTERN_CIDR_ERROR,
     NXT_ADDR_PATTERN_NO_IPv6_ERROR,
+    NXT_ADDR_PATTERN_NO_UNIX_ERROR,
 };