net: ListenMulticastUDP to listen concurrently across multiple listeners
This CL introduces new function ListenMulticastUDP to fix
multicast UDP listening across multiple listeners issue,
to replace old multicast methods JoinGroup and LeaveGroup
on UDPConn.
This CL also enables multicast testing by default.
Fixes #2730.
R=rsc, paul.a.lalonde, fullung, devon.odell
CC=golang-dev
https://golang.org/cl/5562048
diff --git a/src/pkg/net/sockopt_linux.go b/src/pkg/net/sockopt_linux.go
index 9dbb4e5..67c1dc8 100644
--- a/src/pkg/net/sockopt_linux.go
+++ b/src/pkg/net/sockopt_linux.go
@@ -7,31 +7,43 @@
package net
import (
+ "os"
"syscall"
)
-func setDefaultSockopts(s, f, t int) {
+func setDefaultSockopts(s, f, t int) error {
switch f {
case syscall.AF_INET6:
// Allow both IP versions even if the OS default is otherwise.
+ // Note that some operating systems never admit this option.
syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
}
if f == syscall.AF_UNIX ||
(f == syscall.AF_INET || f == syscall.AF_INET6) && t == syscall.SOCK_STREAM {
// Allow reuse of recently-used addresses.
- syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+ err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+ if err != nil {
+ return os.NewSyscallError("setsockopt", err)
+ }
+
}
// Allow broadcast.
- syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)
+ err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)
+ if err != nil {
+ return os.NewSyscallError("setsockopt", err)
+ }
+ return nil
}
-func setDefaultMulticastSockopts(fd *netFD) {
- fd.incref()
- defer fd.decref()
+func setDefaultMulticastSockopts(s int) error {
// Allow multicast UDP and raw IP datagram sockets to listen
// concurrently across multiple listeners.
- syscall.SetsockoptInt(fd.sysfd, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+ err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+ if err != nil {
+ return os.NewSyscallError("setsockopt", err)
+ }
+ return nil
}
