net: platform-dependent default socket options
This CL revises existing platform-dependent default socket
options to make it possible to accomodate multiple multicast
datagram listeners on a single service port.
Also removes unnecessary SO_REUSEADDR, SO_REUSEPORT socket
options from unicast datagram sockets by default.
Fixes #1692.
R=devon.odell, alex.brainman, rsc
CC=golang-dev
https://golang.org/cl/5538052
diff --git a/src/pkg/net/sockopt_bsd.go b/src/pkg/net/sockopt_bsd.go
index 370831f..e99fb41 100644
--- a/src/pkg/net/sockopt_bsd.go
+++ b/src/pkg/net/sockopt_bsd.go
@@ -12,22 +12,33 @@
"syscall"
)
-func setKernelSpecificSockopt(s, f int) {
- // Allow reuse of recently-used addresses.
- syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+func setDefaultSockopts(s, f, p int) {
+ switch f {
+ case syscall.AF_INET6:
+ // Allow both IP versions even if the OS default is otherwise.
+ syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
+ }
- // Allow reuse of recently-used ports.
- // This option is supported only in descendants of 4.4BSD,
- // to make an effective multicast application and an application
- // that requires quick draw possible.
- syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
+ if f == syscall.AF_UNIX || p == syscall.IPPROTO_TCP {
+ // Allow reuse of recently-used addresses.
+ syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+
+ // Allow reuse of recently-used ports.
+ // This option is supported only in descendants of 4.4BSD,
+ // to make an effective multicast application and an application
+ // that requires quick draw possible.
+ syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
+ }
// Allow broadcast.
syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)
+}
- if f == syscall.AF_INET6 {
- // using ip, tcp, udp, etc.
- // allow both protocols even if the OS default is otherwise.
- syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
- }
+func setDefaultMulticastSockopts(fd *netFD) {
+ fd.incref()
+ defer fd.decref()
+ // 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)
+ syscall.SetsockoptInt(fd.sysfd, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
}
