418 lines
11 KiB
Go
418 lines
11 KiB
Go
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package netlink
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import (
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"fmt"
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"net"
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"strings"
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"syscall"
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"github.com/vishvananda/netlink/nl"
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"github.com/vishvananda/netns"
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"golang.org/x/sys/unix"
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)
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// IFA_FLAGS is a u32 attribute.
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const IFA_FLAGS = 0x8
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// AddrAdd will add an IP address to a link device.
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//
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// Equivalent to: `ip addr add $addr dev $link`
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//
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// If `addr` is an IPv4 address and the broadcast address is not given, it
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// will be automatically computed based on the IP mask if /30 or larger.
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func AddrAdd(link Link, addr *Addr) error {
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return pkgHandle.AddrAdd(link, addr)
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}
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// AddrAdd will add an IP address to a link device.
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//
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// Equivalent to: `ip addr add $addr dev $link`
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//
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// If `addr` is an IPv4 address and the broadcast address is not given, it
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// will be automatically computed based on the IP mask if /30 or larger.
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func (h *Handle) AddrAdd(link Link, addr *Addr) error {
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req := h.newNetlinkRequest(unix.RTM_NEWADDR, unix.NLM_F_CREATE|unix.NLM_F_EXCL|unix.NLM_F_ACK)
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return h.addrHandle(link, addr, req)
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}
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// AddrReplace will replace (or, if not present, add) an IP address on a link device.
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//
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// Equivalent to: `ip addr replace $addr dev $link`
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//
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// If `addr` is an IPv4 address and the broadcast address is not given, it
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// will be automatically computed based on the IP mask if /30 or larger.
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func AddrReplace(link Link, addr *Addr) error {
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return pkgHandle.AddrReplace(link, addr)
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}
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// AddrReplace will replace (or, if not present, add) an IP address on a link device.
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//
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// Equivalent to: `ip addr replace $addr dev $link`
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//
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// If `addr` is an IPv4 address and the broadcast address is not given, it
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// will be automatically computed based on the IP mask if /30 or larger.
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func (h *Handle) AddrReplace(link Link, addr *Addr) error {
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req := h.newNetlinkRequest(unix.RTM_NEWADDR, unix.NLM_F_CREATE|unix.NLM_F_REPLACE|unix.NLM_F_ACK)
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return h.addrHandle(link, addr, req)
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}
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// AddrDel will delete an IP address from a link device.
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//
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// Equivalent to: `ip addr del $addr dev $link`
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//
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// If `addr` is an IPv4 address and the broadcast address is not given, it
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// will be automatically computed based on the IP mask if /30 or larger.
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func AddrDel(link Link, addr *Addr) error {
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return pkgHandle.AddrDel(link, addr)
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}
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// AddrDel will delete an IP address from a link device.
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// Equivalent to: `ip addr del $addr dev $link`
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//
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// If `addr` is an IPv4 address and the broadcast address is not given, it
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// will be automatically computed based on the IP mask if /30 or larger.
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func (h *Handle) AddrDel(link Link, addr *Addr) error {
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req := h.newNetlinkRequest(unix.RTM_DELADDR, unix.NLM_F_ACK)
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return h.addrHandle(link, addr, req)
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}
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func (h *Handle) addrHandle(link Link, addr *Addr, req *nl.NetlinkRequest) error {
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base := link.Attrs()
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if addr.Label != "" && !strings.HasPrefix(addr.Label, base.Name) {
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return fmt.Errorf("label must begin with interface name")
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}
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h.ensureIndex(base)
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family := nl.GetIPFamily(addr.IP)
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msg := nl.NewIfAddrmsg(family)
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msg.Index = uint32(base.Index)
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msg.Scope = uint8(addr.Scope)
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mask := addr.Mask
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if addr.Peer != nil {
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mask = addr.Peer.Mask
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}
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prefixlen, masklen := mask.Size()
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msg.Prefixlen = uint8(prefixlen)
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req.AddData(msg)
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var localAddrData []byte
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if family == FAMILY_V4 {
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localAddrData = addr.IP.To4()
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} else {
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localAddrData = addr.IP.To16()
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}
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localData := nl.NewRtAttr(unix.IFA_LOCAL, localAddrData)
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req.AddData(localData)
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var peerAddrData []byte
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if addr.Peer != nil {
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if family == FAMILY_V4 {
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peerAddrData = addr.Peer.IP.To4()
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} else {
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peerAddrData = addr.Peer.IP.To16()
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}
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} else {
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peerAddrData = localAddrData
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}
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addressData := nl.NewRtAttr(unix.IFA_ADDRESS, peerAddrData)
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req.AddData(addressData)
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if addr.Flags != 0 {
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if addr.Flags <= 0xff {
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msg.IfAddrmsg.Flags = uint8(addr.Flags)
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} else {
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b := make([]byte, 4)
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native.PutUint32(b, uint32(addr.Flags))
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flagsData := nl.NewRtAttr(IFA_FLAGS, b)
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req.AddData(flagsData)
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}
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}
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if family == FAMILY_V4 {
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// Automatically set the broadcast address if it is unset and the
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// subnet is large enough to sensibly have one (/30 or larger).
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// See: RFC 3021
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if addr.Broadcast == nil && prefixlen < 31 {
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calcBroadcast := make(net.IP, masklen/8)
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for i := range localAddrData {
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calcBroadcast[i] = localAddrData[i] | ^mask[i]
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}
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addr.Broadcast = calcBroadcast
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}
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if addr.Broadcast != nil {
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req.AddData(nl.NewRtAttr(unix.IFA_BROADCAST, addr.Broadcast))
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}
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if addr.Label != "" {
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labelData := nl.NewRtAttr(unix.IFA_LABEL, nl.ZeroTerminated(addr.Label))
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req.AddData(labelData)
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}
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}
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// 0 is the default value for these attributes. However, 0 means "expired", while the least-surprising default
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// value should be "forever". To compensate for that, only add the attributes if at least one of the values is
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// non-zero, which means the caller has explicitly set them
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if addr.ValidLft > 0 || addr.PreferedLft > 0 {
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cachedata := nl.IfaCacheInfo{
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IfaValid: uint32(addr.ValidLft),
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IfaPrefered: uint32(addr.PreferedLft),
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}
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req.AddData(nl.NewRtAttr(unix.IFA_CACHEINFO, cachedata.Serialize()))
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}
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_, err := req.Execute(unix.NETLINK_ROUTE, 0)
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return err
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}
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// AddrList gets a list of IP addresses in the system.
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// Equivalent to: `ip addr show`.
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// The list can be filtered by link and ip family.
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func AddrList(link Link, family int) ([]Addr, error) {
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return pkgHandle.AddrList(link, family)
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}
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// AddrList gets a list of IP addresses in the system.
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// Equivalent to: `ip addr show`.
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// The list can be filtered by link and ip family.
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func (h *Handle) AddrList(link Link, family int) ([]Addr, error) {
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req := h.newNetlinkRequest(unix.RTM_GETADDR, unix.NLM_F_DUMP)
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msg := nl.NewIfInfomsg(family)
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req.AddData(msg)
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msgs, err := req.Execute(unix.NETLINK_ROUTE, unix.RTM_NEWADDR)
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if err != nil {
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return nil, err
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}
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indexFilter := 0
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if link != nil {
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base := link.Attrs()
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h.ensureIndex(base)
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indexFilter = base.Index
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}
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var res []Addr
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for _, m := range msgs {
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addr, msgFamily, ifindex, err := parseAddr(m)
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if err != nil {
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return res, err
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}
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if link != nil && ifindex != indexFilter {
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// Ignore messages from other interfaces
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continue
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}
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if family != FAMILY_ALL && msgFamily != family {
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continue
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}
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res = append(res, addr)
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}
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return res, nil
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}
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func parseAddr(m []byte) (addr Addr, family, index int, err error) {
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msg := nl.DeserializeIfAddrmsg(m)
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family = -1
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index = -1
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attrs, err1 := nl.ParseRouteAttr(m[msg.Len():])
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if err1 != nil {
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err = err1
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return
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}
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family = int(msg.Family)
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index = int(msg.Index)
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var local, dst *net.IPNet
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for _, attr := range attrs {
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switch attr.Attr.Type {
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case unix.IFA_ADDRESS:
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dst = &net.IPNet{
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IP: attr.Value,
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Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)),
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}
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case unix.IFA_LOCAL:
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// iproute2 manual:
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// If a peer address is specified, the local address
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// cannot have a prefix length. The network prefix is
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// associated with the peer rather than with the local
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// address.
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n := 8 * len(attr.Value)
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local = &net.IPNet{
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IP: attr.Value,
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Mask: net.CIDRMask(n, n),
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}
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case unix.IFA_BROADCAST:
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addr.Broadcast = attr.Value
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case unix.IFA_LABEL:
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addr.Label = string(attr.Value[:len(attr.Value)-1])
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case IFA_FLAGS:
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addr.Flags = int(native.Uint32(attr.Value[0:4]))
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case nl.IFA_CACHEINFO:
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ci := nl.DeserializeIfaCacheInfo(attr.Value)
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addr.PreferedLft = int(ci.IfaPrefered)
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addr.ValidLft = int(ci.IfaValid)
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}
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}
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// libnl addr.c comment:
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// IPv6 sends the local address as IFA_ADDRESS with no
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// IFA_LOCAL, IPv4 sends both IFA_LOCAL and IFA_ADDRESS
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// with IFA_ADDRESS being the peer address if they differ
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//
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// But obviously, as there are IPv6 PtP addresses, too,
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// IFA_LOCAL should also be handled for IPv6.
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if local != nil {
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if family == FAMILY_V4 && local.IP.Equal(dst.IP) {
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addr.IPNet = dst
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} else {
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addr.IPNet = local
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addr.Peer = dst
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}
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} else {
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addr.IPNet = dst
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}
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addr.Scope = int(msg.Scope)
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return
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}
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type AddrUpdate struct {
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LinkAddress net.IPNet
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LinkIndex int
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Flags int
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Scope int
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PreferedLft int
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ValidLft int
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NewAddr bool // true=added false=deleted
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}
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// AddrSubscribe takes a chan down which notifications will be sent
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// when addresses change. Close the 'done' chan to stop subscription.
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func AddrSubscribe(ch chan<- AddrUpdate, done <-chan struct{}) error {
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return addrSubscribeAt(netns.None(), netns.None(), ch, done, nil, false, 0)
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}
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// AddrSubscribeAt works like AddrSubscribe plus it allows the caller
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// to choose the network namespace in which to subscribe (ns).
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func AddrSubscribeAt(ns netns.NsHandle, ch chan<- AddrUpdate, done <-chan struct{}) error {
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return addrSubscribeAt(ns, netns.None(), ch, done, nil, false, 0)
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}
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// AddrSubscribeOptions contains a set of options to use with
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// AddrSubscribeWithOptions.
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type AddrSubscribeOptions struct {
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Namespace *netns.NsHandle
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ErrorCallback func(error)
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ListExisting bool
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ReceiveBufferSize int
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}
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// AddrSubscribeWithOptions work like AddrSubscribe but enable to
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// provide additional options to modify the behavior. Currently, the
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// namespace can be provided as well as an error callback.
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func AddrSubscribeWithOptions(ch chan<- AddrUpdate, done <-chan struct{}, options AddrSubscribeOptions) error {
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if options.Namespace == nil {
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none := netns.None()
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options.Namespace = &none
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}
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return addrSubscribeAt(*options.Namespace, netns.None(), ch, done, options.ErrorCallback, options.ListExisting, options.ReceiveBufferSize)
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}
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func addrSubscribeAt(newNs, curNs netns.NsHandle, ch chan<- AddrUpdate, done <-chan struct{}, cberr func(error), listExisting bool, rcvbuf int) error {
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s, err := nl.SubscribeAt(newNs, curNs, unix.NETLINK_ROUTE, unix.RTNLGRP_IPV4_IFADDR, unix.RTNLGRP_IPV6_IFADDR)
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if err != nil {
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return err
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}
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if done != nil {
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go func() {
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<-done
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s.Close()
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}()
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}
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if rcvbuf != 0 {
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err = pkgHandle.SetSocketReceiveBufferSize(rcvbuf, false)
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if err != nil {
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return err
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}
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}
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if listExisting {
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req := pkgHandle.newNetlinkRequest(unix.RTM_GETADDR,
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unix.NLM_F_DUMP)
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infmsg := nl.NewIfInfomsg(unix.AF_UNSPEC)
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req.AddData(infmsg)
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if err := s.Send(req); err != nil {
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return err
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}
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}
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go func() {
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defer close(ch)
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for {
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msgs, from, err := s.Receive()
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if err != nil {
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if cberr != nil {
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cberr(err)
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}
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return
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}
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if from.Pid != nl.PidKernel {
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if cberr != nil {
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||
|
|
cberr(fmt.Errorf("Wrong sender portid %d, expected %d", from.Pid, nl.PidKernel))
|
||
|
|
}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
for _, m := range msgs {
|
||
|
|
if m.Header.Type == unix.NLMSG_DONE {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
if m.Header.Type == unix.NLMSG_ERROR {
|
||
|
|
native := nl.NativeEndian()
|
||
|
|
error := int32(native.Uint32(m.Data[0:4]))
|
||
|
|
if error == 0 {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
if cberr != nil {
|
||
|
|
cberr(fmt.Errorf("error message: %v",
|
||
|
|
syscall.Errno(-error)))
|
||
|
|
}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
msgType := m.Header.Type
|
||
|
|
if msgType != unix.RTM_NEWADDR && msgType != unix.RTM_DELADDR {
|
||
|
|
if cberr != nil {
|
||
|
|
cberr(fmt.Errorf("bad message type: %d", msgType))
|
||
|
|
}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
addr, _, ifindex, err := parseAddr(m.Data)
|
||
|
|
if err != nil {
|
||
|
|
if cberr != nil {
|
||
|
|
cberr(fmt.Errorf("could not parse address: %v", err))
|
||
|
|
}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
ch <- AddrUpdate{LinkAddress: *addr.IPNet,
|
||
|
|
LinkIndex: ifindex,
|
||
|
|
NewAddr: msgType == unix.RTM_NEWADDR,
|
||
|
|
Flags: addr.Flags,
|
||
|
|
Scope: addr.Scope,
|
||
|
|
PreferedLft: addr.PreferedLft,
|
||
|
|
ValidLft: addr.ValidLft}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}()
|
||
|
|
|
||
|
|
return nil
|
||
|
|
}
|