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/doc/go1.html b/doc/go1.html
index 0f53efa..4c118e0 100644
--- a/doc/go1.html
+++ b/doc/go1.html
@@ -1215,8 +1215,13 @@
</p>
<p>
-There is also a new <a href="/pkg/net/#DialTimeout"><code>net.DialTimeout</code></a> method to simplify
-timing out dialing a network address.
+There are also new functions
+<a href="/pkg/net/#DialTimeout"><code>net.DialTimeout</code></a>
+to simplify timing out dialing a network address and
+<a href="/pkg/net/#ListenMulticastUDP"><code>net.ListenMulticastUDP</code></a>
+to allow multicast UDP to listen concurrently across multiple listeners.
+The <code>net.ListenMulticastUDP</code> function replaces the old
+<code>JoinGroup</code> and <code>LeaveGroup</code> methods.
</p>
<p>
diff --git a/doc/go1.tmpl b/doc/go1.tmpl
index 0e5b1ed..940f2d7 100644
--- a/doc/go1.tmpl
+++ b/doc/go1.tmpl
@@ -1118,8 +1118,13 @@
</p>
<p>
-There is also a new <a href="/pkg/net/#DialTimeout"><code>net.DialTimeout</code></a> method to simplify
-timing out dialing a network address.
+There are also new functions
+<a href="/pkg/net/#DialTimeout"><code>net.DialTimeout</code></a>
+to simplify timing out dialing a network address and
+<a href="/pkg/net/#ListenMulticastUDP"><code>net.ListenMulticastUDP</code></a>
+to allow multicast UDP to listen concurrently across multiple listeners.
+The <code>net.ListenMulticastUDP</code> function replaces the old
+<code>JoinGroup</code> and <code>LeaveGroup</code> methods.
</p>
<p>
diff --git a/src/pkg/net/multicast_test.go b/src/pkg/net/multicast_test.go
index b6a2fa6..0daca19 100644
--- a/src/pkg/net/multicast_test.go
+++ b/src/pkg/net/multicast_test.go
@@ -5,43 +5,36 @@
package net
import (
- "flag"
"os"
"runtime"
"testing"
)
-var multicast = flag.Bool("multicast", false, "enable multicast tests")
-
-var multicastUDPTests = []struct {
+var listenMulticastUDPTests = []struct {
net string
- laddr IP
- gaddr IP
+ gaddr *UDPAddr
flags Flags
ipv6 bool
}{
// cf. RFC 4727: Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Headers
- {"udp", IPv4zero, IPv4(224, 0, 0, 254), (FlagUp | FlagLoopback), false},
- {"udp4", IPv4zero, IPv4(224, 0, 0, 254), (FlagUp | FlagLoopback), false},
- {"udp", IPv6unspecified, ParseIP("ff0e::114"), (FlagUp | FlagLoopback), true},
- {"udp6", IPv6unspecified, ParseIP("ff01::114"), (FlagUp | FlagLoopback), true},
- {"udp6", IPv6unspecified, ParseIP("ff02::114"), (FlagUp | FlagLoopback), true},
- {"udp6", IPv6unspecified, ParseIP("ff04::114"), (FlagUp | FlagLoopback), true},
- {"udp6", IPv6unspecified, ParseIP("ff05::114"), (FlagUp | FlagLoopback), true},
- {"udp6", IPv6unspecified, ParseIP("ff08::114"), (FlagUp | FlagLoopback), true},
- {"udp6", IPv6unspecified, ParseIP("ff0e::114"), (FlagUp | FlagLoopback), true},
+ {"udp", &UDPAddr{IPv4(224, 0, 0, 254), 12345}, FlagUp | FlagLoopback, false},
+ {"udp4", &UDPAddr{IPv4(224, 0, 0, 254), 12345}, FlagUp | FlagLoopback, false},
+ {"udp", &UDPAddr{ParseIP("ff0e::114"), 12345}, FlagUp | FlagLoopback, true},
+ {"udp6", &UDPAddr{ParseIP("ff01::114"), 12345}, FlagUp | FlagLoopback, true},
+ {"udp6", &UDPAddr{ParseIP("ff02::114"), 12345}, FlagUp | FlagLoopback, true},
+ {"udp6", &UDPAddr{ParseIP("ff04::114"), 12345}, FlagUp | FlagLoopback, true},
+ {"udp6", &UDPAddr{ParseIP("ff05::114"), 12345}, FlagUp | FlagLoopback, true},
+ {"udp6", &UDPAddr{ParseIP("ff08::114"), 12345}, FlagUp | FlagLoopback, true},
+ {"udp6", &UDPAddr{ParseIP("ff0e::114"), 12345}, FlagUp | FlagLoopback, true},
}
-func TestMulticastUDP(t *testing.T) {
- if runtime.GOOS == "plan9" || runtime.GOOS == "windows" {
- return
- }
- if !*multicast {
- t.Logf("test disabled; use --multicast to enable")
+func TestListenMulticastUDP(t *testing.T) {
+ switch runtime.GOOS {
+ case "netbsd", "openbsd", "plan9", "windows":
return
}
- for _, tt := range multicastUDPTests {
+ for _, tt := range listenMulticastUDPTests {
if tt.ipv6 && (!supportsIPv6 || os.Getuid() != 0) {
continue
}
@@ -60,14 +53,11 @@
t.Logf("an appropriate multicast interface not found")
return
}
- c, err := ListenUDP(tt.net, &UDPAddr{IP: tt.laddr})
+ c, err := ListenMulticastUDP(tt.net, ifi, tt.gaddr)
if err != nil {
- t.Fatalf("ListenUDP failed: %v", err)
+ t.Fatalf("ListenMulticastUDP failed: %v", err)
}
- defer c.Close()
- if err := c.JoinGroup(ifi, tt.gaddr); err != nil {
- t.Fatalf("JoinGroup failed: %v", err)
- }
+ defer c.Close() // test to listen concurrently across multiple listeners
if !tt.ipv6 {
testIPv4MulticastSocketOptions(t, c.fd, ifi)
} else {
@@ -79,7 +69,7 @@
}
var found bool
for _, ifma := range ifmat {
- if ifma.(*IPAddr).IP.Equal(tt.gaddr) {
+ if ifma.(*IPAddr).IP.Equal(tt.gaddr.IP) {
found = true
break
}
@@ -87,23 +77,16 @@
if !found {
t.Fatalf("%q not found in RIB", tt.gaddr.String())
}
- if err := c.LeaveGroup(ifi, tt.gaddr); err != nil {
- t.Fatalf("LeaveGroup failed: %v", err)
- }
}
}
-func TestSimpleMulticastUDP(t *testing.T) {
- if runtime.GOOS == "plan9" {
- return
- }
- if !*multicast {
- t.Logf("test disabled; use --multicast to enable")
+func TestSimpleListenMulticastUDP(t *testing.T) {
+ switch runtime.GOOS {
+ case "plan9":
return
}
- for _, tt := range multicastUDPTests {
- var ifi *Interface
+ for _, tt := range listenMulticastUDPTests {
if tt.ipv6 {
continue
}
@@ -112,6 +95,7 @@
if err != nil {
t.Fatalf("Interfaces failed: %v", err)
}
+ var ifi *Interface
for _, x := range ift {
if x.Flags&tt.flags == tt.flags {
ifi = &x
@@ -122,17 +106,11 @@
t.Logf("an appropriate multicast interface not found")
return
}
- c, err := ListenUDP(tt.net, &UDPAddr{IP: tt.laddr})
+ c, err := ListenMulticastUDP(tt.net, ifi, tt.gaddr)
if err != nil {
- t.Fatalf("ListenUDP failed: %v", err)
+ t.Fatalf("ListenMulticastUDP failed: %v", err)
}
- defer c.Close()
- if err := c.JoinGroup(ifi, tt.gaddr); err != nil {
- t.Fatalf("JoinGroup failed: %v", err)
- }
- if err := c.LeaveGroup(ifi, tt.gaddr); err != nil {
- t.Fatalf("LeaveGroup failed: %v", err)
- }
+ c.Close()
}
}
diff --git a/src/pkg/net/sock.go b/src/pkg/net/sock.go
index 867e328..2dbe108 100644
--- a/src/pkg/net/sock.go
+++ b/src/pkg/net/sock.go
@@ -28,9 +28,18 @@
syscall.CloseOnExec(s)
syscall.ForkLock.RUnlock()
- setDefaultSockopts(s, f, t)
+ err = setDefaultSockopts(s, f, t)
+ if err != nil {
+ closesocket(s)
+ return nil, err
+ }
if la != nil {
+ la, err = listenerSockaddr(s, f, la, toAddr)
+ if err != nil {
+ closesocket(s)
+ return nil, err
+ }
err = syscall.Bind(s, la)
if err != nil {
closesocket(s)
diff --git a/src/pkg/net/sock_bsd.go b/src/pkg/net/sock_bsd.go
index 630a91ed..7c693a2 100644
--- a/src/pkg/net/sock_bsd.go
+++ b/src/pkg/net/sock_bsd.go
@@ -31,3 +31,27 @@
}
return int(n)
}
+
+func listenerSockaddr(s, f int, la syscall.Sockaddr, toAddr func(syscall.Sockaddr) Addr) (syscall.Sockaddr, error) {
+ a := toAddr(la)
+ if a == nil {
+ return la, nil
+ }
+ switch v := a.(type) {
+ case *UDPAddr:
+ if v.IP.IsMulticast() {
+ err := setDefaultMulticastSockopts(s)
+ if err != nil {
+ return nil, err
+ }
+ switch f {
+ case syscall.AF_INET:
+ v.IP = IPv4zero
+ case syscall.AF_INET6:
+ v.IP = IPv6unspecified
+ }
+ return v.sockaddr(f)
+ }
+ }
+ return la, nil
+}
diff --git a/src/pkg/net/sock_linux.go b/src/pkg/net/sock_linux.go
index 2cbc34f..0743843 100644
--- a/src/pkg/net/sock_linux.go
+++ b/src/pkg/net/sock_linux.go
@@ -25,3 +25,27 @@
}
return n
}
+
+func listenerSockaddr(s, f int, la syscall.Sockaddr, toAddr func(syscall.Sockaddr) Addr) (syscall.Sockaddr, error) {
+ a := toAddr(la)
+ if a == nil {
+ return la, nil
+ }
+ switch v := a.(type) {
+ case *UDPAddr:
+ if v.IP.IsMulticast() {
+ err := setDefaultMulticastSockopts(s)
+ if err != nil {
+ return nil, err
+ }
+ switch f {
+ case syscall.AF_INET:
+ v.IP = IPv4zero
+ case syscall.AF_INET6:
+ v.IP = IPv6unspecified
+ }
+ return v.sockaddr(f)
+ }
+ }
+ return la, nil
+}
diff --git a/src/pkg/net/sock_windows.go b/src/pkg/net/sock_windows.go
index 2d803de..434122c 100644
--- a/src/pkg/net/sock_windows.go
+++ b/src/pkg/net/sock_windows.go
@@ -12,3 +12,27 @@
// TODO: Implement this
return syscall.SOMAXCONN
}
+
+func listenerSockaddr(s syscall.Handle, f int, la syscall.Sockaddr, toAddr func(syscall.Sockaddr) Addr) (syscall.Sockaddr, error) {
+ a := toAddr(la)
+ if a == nil {
+ return la, nil
+ }
+ switch v := a.(type) {
+ case *UDPAddr:
+ if v.IP.IsMulticast() {
+ err := setDefaultMulticastSockopts(s)
+ if err != nil {
+ return nil, err
+ }
+ switch f {
+ case syscall.AF_INET:
+ v.IP = IPv4zero
+ case syscall.AF_INET6:
+ v.IP = IPv6unspecified
+ }
+ return v.sockaddr(f)
+ }
+ }
+ return la, nil
+}
diff --git a/src/pkg/net/sockopt_bsd.go b/src/pkg/net/sockopt_bsd.go
index 2093e08..bc76465 100644
--- a/src/pkg/net/sockopt_bsd.go
+++ b/src/pkg/net/sockopt_bsd.go
@@ -9,37 +9,55 @@
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 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)
+ err = syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 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)
- syscall.SetsockoptInt(fd.sysfd, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
+ err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+ if err != nil {
+ return os.NewSyscallError("setsockopt", err)
+ }
+ err = syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
+ if err != nil {
+ return os.NewSyscallError("setsockopt", err)
+ }
+ return nil
}
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
}
diff --git a/src/pkg/net/sockopt_windows.go b/src/pkg/net/sockopt_windows.go
index a7b5606..2b861de 100644
--- a/src/pkg/net/sockopt_windows.go
+++ b/src/pkg/net/sockopt_windows.go
@@ -7,13 +7,15 @@
package net
import (
+ "os"
"syscall"
)
-func setDefaultSockopts(s syscall.Handle, f, t int) {
+func setDefaultSockopts(s syscall.Handle, 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)
}
@@ -25,14 +27,20 @@
// to be handled by the correct socket.
// 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 syscall.Handle) 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
}
diff --git a/src/pkg/net/udpsock_plan9.go b/src/pkg/net/udpsock_plan9.go
index cf50753..f90a5fe 100644
--- a/src/pkg/net/udpsock_plan9.go
+++ b/src/pkg/net/udpsock_plan9.go
@@ -186,20 +186,10 @@
return &UDPConn{*l.plan9Conn()}, nil
}
-// 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) error {
- if !c.ok() {
- return os.EINVAL
- }
- return os.EPLAN9
-}
-
-// LeaveGroup exits the IP multicast group named by addr on ifi.
-func (c *UDPConn) LeaveGroup(ifi *Interface, addr IP) error {
- if !c.ok() {
- return os.EINVAL
- }
- return os.EPLAN9
+// ListenMulticastUDP listens for incoming multicast UDP packets
+// addressed to the group address gaddr on ifi, which specifies
+// the interface to join. ListenMulticastUDP uses default
+// multicast interface if ifi is nil.
+func ListenMulticastUDP(net string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
+ return nil, os.EPLAN9
}
diff --git a/src/pkg/net/udpsock_posix.go b/src/pkg/net/udpsock_posix.go
index 0f63e95..6108373 100644
--- a/src/pkg/net/udpsock_posix.go
+++ b/src/pkg/net/udpsock_posix.go
@@ -61,7 +61,7 @@
// Implementation of the Conn interface - see Conn for documentation.
// Read implements the Conn Read method.
-func (c *UDPConn) Read(b []byte) (n int, err error) {
+func (c *UDPConn) Read(b []byte) (int, error) {
if !c.ok() {
return 0, os.EINVAL
}
@@ -69,7 +69,7 @@
}
// Write implements the Conn Write method.
-func (c *UDPConn) Write(b []byte) (n int, err error) {
+func (c *UDPConn) Write(b []byte) (int, error) {
if !c.ok() {
return 0, os.EINVAL
}
@@ -167,7 +167,7 @@
}
// ReadFrom implements the PacketConn ReadFrom method.
-func (c *UDPConn) ReadFrom(b []byte) (n int, addr Addr, err error) {
+func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error) {
if !c.ok() {
return 0, nil, os.EINVAL
}
@@ -207,6 +207,11 @@
return c.WriteToUDP(b, a)
}
+// File returns a copy of the underlying os.File, set to blocking mode.
+// It is the caller's responsibility to close f when finished.
+// Closing c does not affect f, and closing f does not affect c.
+func (c *UDPConn) File() (f *os.File, err error) { return c.fd.dup() }
+
// DialUDP connects to the remote address raddr on the network net,
// which must be "udp", "udp4", or "udp6". If laddr is not nil, it is used
// as the local address for the connection.
@@ -246,36 +251,75 @@
return newUDPConn(fd), nil
}
-// File returns a copy of the underlying os.File, set to blocking mode.
-// It is the caller's responsibility to close f when finished.
-// Closing c does not affect f, and closing f does not affect c.
-func (c *UDPConn) File() (f *os.File, err error) { return c.fd.dup() }
-
-// 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) error {
- if !c.ok() {
- return os.EINVAL
+// ListenMulticastUDP listens for incoming multicast UDP packets
+// addressed to the group address gaddr on ifi, which specifies
+// the interface to join. ListenMulticastUDP uses default
+// multicast interface if ifi is nil.
+func ListenMulticastUDP(net string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
+ switch net {
+ case "udp", "udp4", "udp6":
+ default:
+ return nil, UnknownNetworkError(net)
}
- setDefaultMulticastSockopts(c.fd)
- ip := addr.To4()
- if ip != nil {
- return joinIPv4GroupUDP(c, ifi, ip)
+ if gaddr == nil || gaddr.IP == nil {
+ return nil, &OpError{"listenmulticastudp", "udp", nil, errMissingAddress}
}
- return joinIPv6GroupUDP(c, ifi, addr)
+ fd, err := internetSocket(net, gaddr.toAddr(), nil, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
+ if err != nil {
+ return nil, err
+ }
+ c := newUDPConn(fd)
+ ip4 := gaddr.IP.To4()
+ if ip4 != nil {
+ err := listenIPv4MulticastUDP(c, ifi, ip4)
+ if err != nil {
+ c.Close()
+ return nil, err
+ }
+ } else {
+ err := listenIPv6MulticastUDP(c, ifi, gaddr.IP)
+ if err != nil {
+ c.Close()
+ return nil, err
+ }
+ }
+ return c, nil
}
-// LeaveGroup exits the IP multicast group named by addr on ifi.
-func (c *UDPConn) LeaveGroup(ifi *Interface, addr IP) error {
- if !c.ok() {
- return os.EINVAL
+func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
+ if ifi != nil {
+ err := setIPv4MulticastInterface(c.fd, ifi)
+ if err != nil {
+ return err
+ }
}
- ip := addr.To4()
- if ip != nil {
- return leaveIPv4GroupUDP(c, ifi, ip)
+ err := setIPv4MulticastLoopback(c.fd, false)
+ if err != nil {
+ return err
}
- return leaveIPv6GroupUDP(c, ifi, addr)
+ err = joinIPv4GroupUDP(c, ifi, ip)
+ if err != nil {
+ return err
+ }
+ return nil
+}
+
+func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
+ if ifi != nil {
+ err := setIPv6MulticastInterface(c.fd, ifi)
+ if err != nil {
+ return err
+ }
+ }
+ err := setIPv6MulticastLoopback(c.fd, false)
+ if err != nil {
+ return err
+ }
+ err = joinIPv6GroupUDP(c, ifi, ip)
+ if err != nil {
+ return err
+ }
+ return nil
}
func joinIPv4GroupUDP(c *UDPConn, ifi *Interface, ip IP) error {
