| // Copyright 2012 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build darwin dragonfly freebsd linux netbsd openbsd windows |
| |
| package ipv4 |
| |
| import ( |
| "net" |
| "syscall" |
| ) |
| |
| // MulticastTTL returns the time-to-live field value for outgoing |
| // multicast packets. |
| func (c *dgramOpt) MulticastTTL() (int, error) { |
| if !c.ok() { |
| return 0, syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return 0, err |
| } |
| return getInt(fd, &sockOpts[ssoMulticastTTL]) |
| } |
| |
| // SetMulticastTTL sets the time-to-live field value for future |
| // outgoing multicast packets. |
| func (c *dgramOpt) SetMulticastTTL(ttl int) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| return setInt(fd, &sockOpts[ssoMulticastTTL], ttl) |
| } |
| |
| // MulticastInterface returns the default interface for multicast |
| // packet transmissions. |
| func (c *dgramOpt) MulticastInterface() (*net.Interface, error) { |
| if !c.ok() { |
| return nil, syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return nil, err |
| } |
| return getInterface(fd, &sockOpts[ssoMulticastInterface]) |
| } |
| |
| // SetMulticastInterface sets the default interface for future |
| // multicast packet transmissions. |
| func (c *dgramOpt) SetMulticastInterface(ifi *net.Interface) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| return setInterface(fd, &sockOpts[ssoMulticastInterface], ifi) |
| } |
| |
| // MulticastLoopback reports whether transmitted multicast packets |
| // should be copied and send back to the originator. |
| func (c *dgramOpt) MulticastLoopback() (bool, error) { |
| if !c.ok() { |
| return false, syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return false, err |
| } |
| on, err := getInt(fd, &sockOpts[ssoMulticastLoopback]) |
| if err != nil { |
| return false, err |
| } |
| return on == 1, nil |
| } |
| |
| // SetMulticastLoopback sets whether transmitted multicast packets |
| // should be copied and send back to the originator. |
| func (c *dgramOpt) SetMulticastLoopback(on bool) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| return setInt(fd, &sockOpts[ssoMulticastLoopback], boolint(on)) |
| } |
| |
| // JoinGroup joins the group address group on the interface ifi. |
| // By default all sources that can cast data to group are accepted. |
| // It's possible to mute and unmute data transmission from a specific |
| // source by using ExcludeSourceSpecificGroup and |
| // IncludeSourceSpecificGroup. |
| // JoinGroup uses the system assigned multicast interface when ifi is |
| // nil, although this is not recommended because the assignment |
| // depends on platforms and sometimes it might require routing |
| // configuration. |
| func (c *dgramOpt) JoinGroup(ifi *net.Interface, group net.Addr) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| grp := netAddrToIP4(group) |
| if grp == nil { |
| return errMissingAddress |
| } |
| return setGroup(fd, &sockOpts[ssoJoinGroup], ifi, grp) |
| } |
| |
| // LeaveGroup leaves the group address group on the interface ifi |
| // regardless of whether the group is any-source group or |
| // source-specific group. |
| func (c *dgramOpt) LeaveGroup(ifi *net.Interface, group net.Addr) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| grp := netAddrToIP4(group) |
| if grp == nil { |
| return errMissingAddress |
| } |
| return setGroup(fd, &sockOpts[ssoLeaveGroup], ifi, grp) |
| } |
| |
| // JoinSourceSpecificGroup joins the source-specific group comprising |
| // group and source on the interface ifi. |
| // JoinSourceSpecificGroup uses the system assigned multicast |
| // interface when ifi is nil, although this is not recommended because |
| // the assignment depends on platforms and sometimes it might require |
| // routing configuration. |
| func (c *dgramOpt) JoinSourceSpecificGroup(ifi *net.Interface, group, source net.Addr) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| grp := netAddrToIP4(group) |
| if grp == nil { |
| return errMissingAddress |
| } |
| src := netAddrToIP4(source) |
| if src == nil { |
| return errMissingAddress |
| } |
| return setSourceGroup(fd, &sockOpts[ssoJoinSourceGroup], ifi, grp, src) |
| } |
| |
| // LeaveSourceSpecificGroup leaves the source-specific group on the |
| // interface ifi. |
| func (c *dgramOpt) LeaveSourceSpecificGroup(ifi *net.Interface, group, source net.Addr) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| grp := netAddrToIP4(group) |
| if grp == nil { |
| return errMissingAddress |
| } |
| src := netAddrToIP4(source) |
| if src == nil { |
| return errMissingAddress |
| } |
| return setSourceGroup(fd, &sockOpts[ssoLeaveSourceGroup], ifi, grp, src) |
| } |
| |
| // ExcludeSourceSpecificGroup excludes the source-specific group from |
| // the already joined any-source groups by JoinGroup on the interface |
| // ifi. |
| func (c *dgramOpt) ExcludeSourceSpecificGroup(ifi *net.Interface, group, source net.Addr) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| grp := netAddrToIP4(group) |
| if grp == nil { |
| return errMissingAddress |
| } |
| src := netAddrToIP4(source) |
| if src == nil { |
| return errMissingAddress |
| } |
| return setSourceGroup(fd, &sockOpts[ssoBlockSourceGroup], ifi, grp, src) |
| } |
| |
| // IncludeSourceSpecificGroup includes the excluded source-specific |
| // group by ExcludeSourceSpecificGroup again on the interface ifi. |
| func (c *dgramOpt) IncludeSourceSpecificGroup(ifi *net.Interface, group, source net.Addr) error { |
| if !c.ok() { |
| return syscall.EINVAL |
| } |
| fd, err := c.sysfd() |
| if err != nil { |
| return err |
| } |
| grp := netAddrToIP4(group) |
| if grp == nil { |
| return errMissingAddress |
| } |
| src := netAddrToIP4(source) |
| if src == nil { |
| return errMissingAddress |
| } |
| return setSourceGroup(fd, &sockOpts[ssoUnblockSourceGroup], ifi, grp, src) |
| } |