// AddrList gets a list of IP addresses in the system. // Equivalent to: `ip addr show`. // The list can be filtered by link and ip family. func AddrList(link Link, family int) ([]Addr, error) { req := nl.NewNetlinkRequest(syscall.RTM_GETADDR, syscall.NLM_F_DUMP) msg := nl.NewIfInfomsg(family) req.AddData(msg) msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWADDR) if err != nil { return nil, err } index := 0 if link != nil { base := link.Attrs() ensureIndex(base) index = base.Index } var res []Addr for _, m := range msgs { msg := nl.DeserializeIfAddrmsg(m) if link != nil && msg.Index != uint32(index) { // Ignore messages from other interfaces continue } attrs, err := nl.ParseRouteAttr(m[msg.Len():]) if err != nil { return nil, err } var local, dst *net.IPNet var addr Addr for _, attr := range attrs { switch attr.Attr.Type { case syscall.IFA_ADDRESS: dst = &net.IPNet{ IP: attr.Value, Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)), } case syscall.IFA_LOCAL: local = &net.IPNet{ IP: attr.Value, Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)), } case syscall.IFA_LABEL: addr.Label = string(attr.Value[:len(attr.Value)-1]) case IFA_FLAGS: addr.Flags = int(native.Uint32(attr.Value[0:4])) } } // IFA_LOCAL should be there but if not, fall back to IFA_ADDRESS if local != nil { addr.IPNet = local } else { addr.IPNet = dst } addr.Scope = int(msg.Scope) res = append(res, addr) } return res, nil }
// AddrSubscribe takes a chan down which notifications will be sent // when addresses change. Close the 'done' chan to stop subscription. func AddrSubscribe(ch chan<- AddrUpdate, done <-chan struct{}) error { s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_IPV4_IFADDR, syscall.RTNLGRP_IPV6_IFADDR) if err != nil { return err } if done != nil { go func() { <-done s.Close() }() } go func() { defer close(ch) for { msgs, err := s.Receive() if err != nil { log.Printf("netlink.AddrSubscribe: Receive() error: %v", err) return } for _, m := range msgs { msgType := m.Header.Type if msgType != syscall.RTM_NEWADDR && msgType != syscall.RTM_DELADDR { log.Printf("netlink.AddrSubscribe: bad message type: %d", msgType) continue } msg := nl.DeserializeIfAddrmsg(m.Data) attrs, err := nl.ParseRouteAttr(m.Data[msg.Len():]) if err != nil { log.Printf("netlink.AddrSubscribe: nl.ParseRouteAttr() error: %v", err) return } var local, dst *net.IPNet var addr Addr for _, attr := range attrs { switch attr.Attr.Type { case syscall.IFA_ADDRESS: dst = &net.IPNet{ IP: attr.Value, Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)), } case syscall.IFA_LOCAL: local = &net.IPNet{ IP: attr.Value, Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)), } case syscall.IFA_LABEL: addr.Label = string(attr.Value[:len(attr.Value)-1]) case IFA_FLAGS: addr.Flags = int(native.Uint32(attr.Value[0:4])) } } // IFA_LOCAL should be there but if not, fall back to IFA_ADDRESS if local != nil { addr.IPNet = local } else { addr.IPNet = dst } ch <- AddrUpdate{LinkAddress: *addr.IPNet, LinkIndex: int(msg.Index), NewAddr: msgType == syscall.RTM_NEWADDR} } } }() return nil }