feature: add support for socket reuseport.

src/ngx_stream_lua_socket_udp.c

@@ -80,14 +80,19 @@ static ssize_t ngx_stream_lua_udp_sendmsg(ngx_connection_t *c,
 static ngx_int_t ngx_stream_lua_udp_connect_set_transparent(
      ngx_stream_lua_udp_connection_t *uc, ngx_socket_t s);
 #endif
+#if (NGX_HAVE_REUSEPORT)
+static ngx_int_t ngx_stream_lua_udp_connect_set_reuseport(
+     ngx_stream_lua_udp_connection_t *uc, ngx_socket_t s);
+#endif
 static int ngx_stream_lua_socket_udp_setoption(lua_State *L);
 
 
 enum {
     SOCKET_CTX_INDEX = 1,
     SOCKET_TIMEOUT_INDEX = 2,
     SOCKET_BIND_INDEX = 3,   /* only in upstream cosocket */
-    SOCKET_IP_TRANSPARENT_INDEX = 4
+    SOCKET_IP_TRANSPARENT_INDEX = 4,
+    SOCKET_REUSEPORT_INDEX = 5,
 };
 
 
@@ -454,6 +459,18 @@ ngx_stream_lua_socket_udp_setpeername(lua_State *L)
     lua_pop(L, 1);
 #endif
 
+
+#if (NGX_HAVE_REUSEPORT)
+    lua_rawgeti(L, 1, SOCKET_REUSEPORT_INDEX);
+    if (lua_toboolean(L, -1)) {
+        uc->reuseport = 1;
+        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, r->connection->log, 0,
+                       "stream lua set UDP upstream with REUSEPORT");
+    }
+
+    lua_pop(L, 1);
+#endif
+
     lua_rawgeti(L, 1, SOCKET_TIMEOUT_INDEX);
     timeout = (ngx_int_t) lua_tointeger(L, -1);
     lua_pop(L, 1);
@@ -1640,7 +1657,29 @@ ngx_stream_lua_udp_connect_set_transparent(ngx_stream_lua_udp_connection_t *uc,
 
 #endif /* SO_BINDANY */
 
-return NGX_OK;
+    return NGX_OK;
+}
+#endif
+
+
+#if (NGX_HAVE_REUSEPORT)
+static ngx_int_t
+ngx_stream_lua_udp_connect_set_reuseport(ngx_stream_lua_udp_connection_t *uc,
+    ngx_socket_t s)
+{
+    int  value;
+
+    value = 1;
+
+    if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
+                   (const void *) &value, sizeof(int)) == -1)
+    {
+        ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno,
+                      "setsockopt(SO_REUSEPORT) failed");
+        return NGX_ERROR;
+    }
+
+    return NGX_OK;
 }
 #endif
 
@@ -1741,6 +1780,14 @@ ngx_stream_lua_udp_connect(ngx_stream_lua_socket_udp_upstream_t *u)
         }
 #endif
 
+#if (NGX_HAVE_REUSEPORT)
+        if (uc->reuseport) {
+            if (ngx_stream_lua_udp_connect_set_reuseport(uc, s) != NGX_OK) {
+                return NGX_ERROR;
+            }
+        }
+#endif
+
 #if (NGX_HAVE_IP_BIND_ADDRESS_NO_PORT || NGX_LINUX)
         port = u->resolved->port;
 #endif
@@ -1935,6 +1982,20 @@ ngx_stream_lua_socket_udp_setoption(lua_State *L)
         return 1;
     }
 
+    if (len == sizeof("reuseport") - 1
+        && memcmp(option, "reuseport", len) == 0)
+    {
+#if (NGX_HAVE_REUSEPORT)
+        int  reuseport;
+
+        reuseport = lua_toboolean(L, 3);
+        lua_rawseti(L, 1, SOCKET_REUSEPORT_INDEX);
+        lua_pushboolean(L, reuseport);
+#endif
+        lua_pushnumber(L, 0);
+        return 1;
+    }
+
     lua_pushnil(L);
     lua_pushfstring(L, "unknown option %s", option);
 

src/ngx_stream_lua_socket_udp.h

@@ -44,7 +44,10 @@ typedef struct {
     struct sockaddr          *sockaddr;
     socklen_t                 socklen;
 #if (NGX_HAVE_TRANSPARENT_PROXY)
-    unsigned                   transparent:1;
+    unsigned                  transparent:1;
+#endif
+#if (NGX_HAVE_REUSEPORT)
+    unsigned                  reuseport:1;
 #endif
     ngx_str_t                 server;
     ngx_log_t                 log;

t/144-udp-socket-reuseport.t

@@ -0,0 +1,141 @@
+# vim:set ft= ts=4 sw=4 et fdm=marker:
+
+our $SkipReason;
+
+BEGIN {
+    if ($^O ne 'linux') {
+        $SkipReason = "SO_REUSEPORT is only supported on Linux";
+    }
+}
+
+use Test::Nginx::Socket::Lua::Stream $SkipReason ? (skip_all => $SkipReason) : ();
+
+repeat_each(2);
+
+plan tests => blocks() * (repeat_each() * 3);
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: udp socket setoption reuseport sanity
+--- stream_config
+server {
+   listen 127.0.0.1:2986 udp;
+   content_by_lua_block {
+     ngx.log(ngx.INFO, "udp reuseport test remote: " .. ngx.var.remote_addr)
+    }
+}
+--- stream_server_config
+  content_by_lua_block {
+      local ip = "127.0.0.1"
+      local port = 2986
+      local sock = ngx.socket.udp()
+
+      local ok, err = sock:setoption("reuseport", true)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to set reuseport: ", err)
+          return
+      end
+
+      local ok, err = sock:setpeername(ip, port)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to setpeername: ", err)
+          return
+      end
+
+      local ok, err = sock:send("trigger")
+      if not ok then
+          ngx.log(ngx.ERR, "failed to send: ", err)
+      end
+  }
+
+--- no_error_log
+[error]
+--- error_log eval
+["stream lua set UDP upstream with REUSEPORT"]
+
+
+
+=== TEST 2: udp socket setoption reuseport false
+--- stream_config
+server {
+   listen 127.0.0.1:2986 udp;
+   content_by_lua_block {
+     ngx.log(ngx.INFO, "udp reuseport test remote: " .. ngx.var.remote_addr)
+    }
+}
+--- stream_server_config
+  content_by_lua_block {
+      local ip = "127.0.0.1"
+      local port = 2986
+      local sock = ngx.socket.udp()
+
+      local ok, err = sock:setoption("reuseport", false)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to set reuseport: ", err)
+          return
+      end
+
+      local ok, err = sock:setpeername(ip, port)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to setpeername: ", err)
+          return
+      end
+
+      local ok, err = sock:send("trigger")
+      if not ok then
+          ngx.log(ngx.ERR, "failed to send: ", err)
+      end
+  }
+
+--- no_error_log
+[error]
+--- no_error_log eval
+["stream lua set UDP upstream with REUSEPORT"]
+
+
+
+=== TEST 3: udp socket setoption reuseport with bind
+--- stream_config
+server {
+   listen 127.0.0.1:2986 udp;
+   content_by_lua_block {
+     ngx.log(ngx.INFO, "udp reuseport test remote: " .. ngx.var.remote_addr)
+    }
+}
+--- stream_server_config
+  content_by_lua_block {
+      local ip = "127.0.0.1"
+      local port = 2986
+      local sock = ngx.socket.udp()
+
+      local ok, err = sock:bind(ip)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to bind: ", err)
+          return
+      end
+
+      local ok, err = sock:setoption("reuseport", true)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to set reuseport: ", err)
+          return
+      end
+
+      local ok, err = sock:setpeername("127.0.0.1", port)
+      if not ok then
+          ngx.log(ngx.ERR, "failed to setpeername: ", err)
+          return
+      end
+
+      local ok, err = sock:send("trigger")
+      if not ok then
+          ngx.log(ngx.ERR, "failed to send: ", err)
+      end
+  }
+
+--- no_error_log
+[error]
+--- error_log eval
+["lua udp socket bind ip: 127.0.0.1",
+"stream lua set UDP upstream with REUSEPORT"]