nghttpx: Deprecate --backend-ipv4 and --backend-ipv6 in favor of --backend-address-family

gennghttpxfun.py

@@ -123,6 +123,7 @@ OPTIONS = [
     "tls-ticket-key-memcached-cert-file",
     "tls-ticket-key-memcached-private-key-file",
     "tls-ticket-key-memcached-address-family",
+    "backend-address-family"
 ]
 
 LOGVARS = [

src/shrpx.cc

@@ -1166,6 +1166,7 @@ void fill_default_config() {
     downstreamconf.connections_per_host = 8;
     downstreamconf.request_buffer_size = 16_k;
     downstreamconf.response_buffer_size = 128_k;
+    downstreamconf.family = AF_UNSPEC;
   }
 }
 
@@ -1270,10 +1271,12 @@ Connections:
   --backlog=<N>
               Set listen backlog size.
               Default: )" << get_config()->conn.listener.backlog << R"(
-  --backend-ipv4
-              Resolve backend hostname to IPv4 address only.
-  --backend-ipv6
-              Resolve backend hostname to IPv6 address only.
+  --backend-address-family=(auto|IPv4|IPv6)
+              Specify  address  family  of  backend  connections.   If
+              "auto" is given, both IPv4  and IPv6 are considered.  If
+              "IPv4" is  given, only  IPv4 address is  considered.  If
+              "IPv6" is given, only IPv6 address is considered.
+              Default: auto
   --backend-http-proxy-uri=<URI>
               Specify      proxy       URI      in       the      form
               http://[<USER>:<PASS>@]<PROXY>:<PORT>.    If   a   proxy
@@ -2055,12 +2058,6 @@ void process_options(
     listenerconf.addrs.push_back(std::move(addr));
   }
 
-  if (downstreamconf.ipv4 && downstreamconf.ipv6) {
-    LOG(FATAL) << "--backend-ipv4 and --backend-ipv6 cannot be used at the "
-               << "same time.";
-    exit(EXIT_FAILURE);
-  }
-
   if (upstreamconf.worker_connections == 0) {
     upstreamconf.worker_connections = std::numeric_limits<size_t>::max();
   }
@@ -2195,11 +2192,8 @@ void process_options(
       addr.hostport =
           ImmutableString(util::make_hostport(addr.host.c_str(), addr.port));
 
-      if (resolve_hostname(
-              &addr.addr, addr.host.c_str(), addr.port,
-              downstreamconf.ipv4
-                  ? AF_INET
-                  : (downstreamconf.ipv6 ? AF_INET6 : AF_UNSPEC)) == -1) {
+      if (resolve_hostname(&addr.addr, addr.host.c_str(), addr.port,
+                           downstreamconf.family) == -1) {
         exit(EXIT_FAILURE);
       }
     }
@@ -2453,6 +2447,7 @@ int main(int argc, char **argv) {
          &flag, 114},
         {SHRPX_OPT_TLS_SESSION_CACHE_MEMCACHED_ADDRESS_FAMILY,
          required_argument, &flag, 115},
+        {SHRPX_OPT_BACKEND_ADDRESS_FAMILY, required_argument, &flag, 116},
         {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
@@ -2949,6 +2944,10 @@ int main(int argc, char **argv) {
         cmdcfgs.emplace_back(
             SHRPX_OPT_TLS_SESSION_CACHE_MEMCACHED_ADDRESS_FAMILY, optarg);
         break;
+      case 116:
+        // --backend-address-family
+        cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_ADDRESS_FAMILY, optarg);
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -693,6 +693,7 @@ enum {
   SHRPX_OPTID_ADD_X_FORWARDED_FOR,
   SHRPX_OPTID_ALTSVC,
   SHRPX_OPTID_BACKEND,
+  SHRPX_OPTID_BACKEND_ADDRESS_FAMILY,
   SHRPX_OPTID_BACKEND_HTTP_PROXY_URI,
   SHRPX_OPTID_BACKEND_HTTP1_CONNECTIONS_PER_FRONTEND,
   SHRPX_OPTID_BACKEND_HTTP1_CONNECTIONS_PER_HOST,
@@ -1232,6 +1233,11 @@ int option_lookup_token(const char *name, size_t namelen) {
         return SHRPX_OPTID_FRONTEND_WRITE_TIMEOUT;
       }
       break;
+    case 'y':
+      if (util::strieq_l("backend-address-famil", name, 21)) {
+        return SHRPX_OPTID_BACKEND_ADDRESS_FAMILY;
+      }
+      break;
     }
     break;
   case 23:
@@ -1854,11 +1860,17 @@ int parse_config(const char *opt, const char *optarg,
 
     return 0;
   case SHRPX_OPTID_BACKEND_IPV4:
-    mod_config()->conn.downstream.ipv4 = util::strieq(optarg, "yes");
+    LOG(WARN) << opt
+              << ": deprecated.  Use backend-address-family=IPv4 instead.";
+
+    mod_config()->conn.downstream.family = AF_INET;
 
     return 0;
   case SHRPX_OPTID_BACKEND_IPV6:
-    mod_config()->conn.downstream.ipv6 = util::strieq(optarg, "yes");
+    LOG(WARN) << opt
+              << ": deprecated.  Use backend-address-family=IPv6 instead.";
+
+    mod_config()->conn.downstream.family = AF_INET6;
 
     return 0;
   case SHRPX_OPTID_BACKEND_HTTP_PROXY_URI: {
@@ -2348,6 +2360,9 @@ int parse_config(const char *opt, const char *optarg,
   case SHRPX_OPTID_TLS_SESSION_CACHE_MEMCACHED_ADDRESS_FAMILY:
     return parse_address_family(
         &mod_config()->tls.session_cache.memcached.family, opt, optarg);
+  case SHRPX_OPTID_BACKEND_ADDRESS_FAMILY:
+    return parse_address_family(&mod_config()->conn.downstream.family, opt,
+                                optarg);
   case SHRPX_OPTID_CONF:
     LOG(WARN) << "conf: ignored";
 

src/shrpx_config.h

@@ -225,6 +225,7 @@ constexpr char SHRPX_OPT_TLS_TICKET_KEY_MEMCACHED_PRIVATE_KEY_FILE[] =
     "tls-ticket-key-memcached-private-key-file";
 constexpr char SHRPX_OPT_TLS_TICKET_KEY_MEMCACHED_ADDRESS_FAMILY[] =
     "tls-ticket-key-memcached-address-family";
+constexpr char SHRPX_OPT_BACKEND_ADDRESS_FAMILY[] = "backend-address-family";
 
 constexpr size_t SHRPX_OBFUSCATED_NODE_LENGTH = 8;
 
@@ -567,13 +568,12 @@ struct ConnectionConfig {
     size_t response_buffer_size;
     // downstream protocol; this will be determined by given options.
     shrpx_proto proto;
+    // Address family of backend connection.  One of either AF_INET,
+    // AF_INET6 or AF_UNSPEC.  This is ignored if backend connection
+    // is made via Unix domain socket.
+    int family;
     bool no_tls;
     bool http1_tls;
-    // true if IPv4 only; ipv4 and ipv6 are mutually exclusive; and
-    // (ipv4 && ipv6) must be false.
-    bool ipv4;
-    // true if IPv6 only
-    bool ipv6;
   } downstream;
 };