git » go-net » commit cfe3c2a

diff --git a/icmp/listen_posix.go b/icmp/listen_posix.go
index b9f2607..7fac4f9 100644
--- a/icmp/listen_posix.go
+++ b/icmp/listen_posix.go
@@ -65,22 +65,24 @@ func ListenPacket(network, address string) (*PacketConn, error) {
 		if err != nil {
 			return nil, os.NewSyscallError("socket", err)
 		}
-		defer syscall.Close(s)
 		if runtime.GOOS == "darwin" && family == syscall.AF_INET {
 			if err := syscall.SetsockoptInt(s, iana.ProtocolIP, sysIP_STRIPHDR, 1); err != nil {
+				syscall.Close(s)
 				return nil, os.NewSyscallError("setsockopt", err)
 			}
 		}
 		sa, err := sockaddr(family, address)
 		if err != nil {
+			syscall.Close(s)
 			return nil, err
 		}
 		if err := syscall.Bind(s, sa); err != nil {
+			syscall.Close(s)
 			return nil, os.NewSyscallError("bind", err)
 		}
 		f := os.NewFile(uintptr(s), "datagram-oriented icmp")
-		defer f.Close()
 		c, cerr = net.FilePacketConn(f)
+		f.Close()
 	default:
 		c, cerr = net.ListenPacket(network, address)
 	}
diff --git a/icmp/ping_test.go b/icmp/ping_test.go
index 4ec2692..3171dad 100644
--- a/icmp/ping_test.go
+++ b/icmp/ping_test.go
@@ -10,6 +10,7 @@ import (
 	"net"
 	"os"
 	"runtime"
+	"sync"
 	"testing"
 	"time"
 
@@ -164,3 +165,36 @@ func doPing(tt pingTest, seq int) error {
 		return fmt.Errorf("got %+v from %v; want echo reply", rm, peer)
 	}
 }
+
+func TestConcurrentNonPrivilegedListenPacket(t *testing.T) {
+	if testing.Short() {
+		t.Skip("avoid external network")
+	}
+	switch runtime.GOOS {
+	case "darwin":
+	case "linux":
+		t.Log("you may need to adjust the net.ipv4.ping_group_range kernel state")
+	default:
+		t.Skipf("not supported on %s", runtime.GOOS)
+	}
+
+	network, address := "udp4", "127.0.0.1"
+	if !nettest.SupportsIPv4() {
+		network, address = "udp6", "::1"
+	}
+	const N = 1000
+	var wg sync.WaitGroup
+	wg.Add(N)
+	for i := 0; i < N; i++ {
+		go func() {
+			defer wg.Done()
+			c, err := icmp.ListenPacket(network, address)
+			if err != nil {
+				t.Error(err)
+				return
+			}
+			c.Close()
+		}()
+	}
+	wg.Wait()
+}