net: join and leave a IPv6 group address, on a specific interface
This CL changes both JoinGroup and LeaveGroup methods
to take an interface as an argument for enabling IPv6
group address join/leave, join a group address on a
specific interface.
R=rsc, dave
CC=golang-dev
https://golang.org/cl/4815074
diff --git a/src/pkg/net/udpsock_posix.go b/src/pkg/net/udpsock_posix.go
index d4ea056..dfda997 100644
--- a/src/pkg/net/udpsock_posix.go
+++ b/src/pkg/net/udpsock_posix.go
@@ -7,6 +7,7 @@
package net
import (
+ "bytes"
"os"
"syscall"
)
@@ -252,43 +253,94 @@
// Closing c does not affect f, and closing f does not affect c.
func (c *UDPConn) File() (f *os.File, err os.Error) { return c.fd.dup() }
-var errInvalidMulticast = os.NewError("invalid IPv4 multicast address")
-
-// JoinGroup joins the IPv4 multicast group named by addr.
-// The UDPConn must use the "udp4" network.
-func (c *UDPConn) JoinGroup(addr IP) os.Error {
+// JoinGroup joins the IP multicast group named by addr on ifi,
+// which specifies the interface to join. JoinGroup uses the
+// default multicast interface if ifi is nil.
+func (c *UDPConn) JoinGroup(ifi *Interface, addr IP) os.Error {
if !c.ok() {
return os.EINVAL
}
ip := addr.To4()
- if ip == nil {
- return &OpError{"joingroup", "udp", &IPAddr{ip}, errInvalidMulticast}
+ if ip != nil {
+ return joinIPv4GroupUDP(c, ifi, ip)
}
- mreq := &syscall.IPMreq{
- Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]},
+ return joinIPv6GroupUDP(c, ifi, addr)
+}
+
+// LeaveGroup exits the IP multicast group named by addr on ifi.
+func (c *UDPConn) LeaveGroup(ifi *Interface, addr IP) os.Error {
+ if !c.ok() {
+ return os.EINVAL
}
- err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(c.fd.sysfd, syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq))
- if err != nil {
- return &OpError{"joingroup", "udp", &IPAddr{ip}, err}
+ ip := addr.To4()
+ if ip != nil {
+ return leaveIPv4GroupUDP(c, ifi, ip)
+ }
+ return leaveIPv6GroupUDP(c, ifi, addr)
+}
+
+func joinIPv4GroupUDP(c *UDPConn, ifi *Interface, ip IP) os.Error {
+ mreq := &syscall.IPMreq{Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]}}
+ if err := setIPv4InterfaceToJoin(mreq, ifi); err != nil {
+ return &OpError{"joinipv4group", "udp", &IPAddr{ip}, err}
+ }
+ if err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(c.fd.sysfd, syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq)); err != nil {
+ return &OpError{"joinipv4group", "udp", &IPAddr{ip}, err}
}
return nil
}
-// LeaveGroup exits the IPv4 multicast group named by addr.
-func (c *UDPConn) LeaveGroup(addr IP) os.Error {
- if !c.ok() {
+func leaveIPv4GroupUDP(c *UDPConn, ifi *Interface, ip IP) os.Error {
+ mreq := &syscall.IPMreq{Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]}}
+ if err := setIPv4InterfaceToJoin(mreq, ifi); err != nil {
+ return &OpError{"leaveipv4group", "udp", &IPAddr{ip}, err}
+ }
+ if err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(c.fd.sysfd, syscall.IPPROTO_IP, syscall.IP_DROP_MEMBERSHIP, mreq)); err != nil {
+ return &OpError{"leaveipv4group", "udp", &IPAddr{ip}, err}
+ }
+ return nil
+}
+
+func setIPv4InterfaceToJoin(mreq *syscall.IPMreq, ifi *Interface) os.Error {
+ if ifi == nil {
+ return nil
+ }
+ ifat, err := ifi.Addrs()
+ if err != nil {
+ return err
+ }
+ for _, ifa := range ifat {
+ if x := ifa.(*IPAddr).IP.To4(); x != nil {
+ copy(mreq.Interface[:], x)
+ break
+ }
+ }
+ if bytes.Equal(mreq.Multiaddr[:], IPv4zero) {
return os.EINVAL
}
- ip := addr.To4()
- if ip == nil {
- return &OpError{"leavegroup", "udp", &IPAddr{ip}, errInvalidMulticast}
+ return nil
+}
+
+func joinIPv6GroupUDP(c *UDPConn, ifi *Interface, ip IP) os.Error {
+ mreq := &syscall.IPv6Mreq{}
+ copy(mreq.Multiaddr[:], ip)
+ if ifi != nil {
+ mreq.Interface = uint32(ifi.Index)
}
- mreq := &syscall.IPMreq{
- Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]},
+ if err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPv6Mreq(c.fd.sysfd, syscall.IPPROTO_IPV6, syscall.IPV6_JOIN_GROUP, mreq)); err != nil {
+ return &OpError{"joinipv6group", "udp", &IPAddr{ip}, err}
}
- err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPMreq(c.fd.sysfd, syscall.IPPROTO_IP, syscall.IP_DROP_MEMBERSHIP, mreq))
- if err != nil {
- return &OpError{"leavegroup", "udp", &IPAddr{ip}, err}
+ return nil
+}
+
+func leaveIPv6GroupUDP(c *UDPConn, ifi *Interface, ip IP) os.Error {
+ mreq := &syscall.IPv6Mreq{}
+ copy(mreq.Multiaddr[:], ip)
+ if ifi != nil {
+ mreq.Interface = uint32(ifi.Index)
+ }
+ if err := os.NewSyscallError("setsockopt", syscall.SetsockoptIPv6Mreq(c.fd.sysfd, syscall.IPPROTO_IPV6, syscall.IPV6_LEAVE_GROUP, mreq)); err != nil {
+ return &OpError{"leaveipv6group", "udp", &IPAddr{ip}, err}
}
return nil
}
