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|
package netlink
import (
"fmt"
"syscall"
"github.com/vishvananda/netlink/nl"
)
func writeStateAlgo(a *XfrmStateAlgo) []byte {
algo := nl.XfrmAlgo{
AlgKeyLen: uint32(len(a.Key) * 8),
AlgKey: a.Key,
}
end := len(a.Name)
if end > 64 {
end = 64
}
copy(algo.AlgName[:end], a.Name)
return algo.Serialize()
}
func writeStateAlgoAuth(a *XfrmStateAlgo) []byte {
algo := nl.XfrmAlgoAuth{
AlgKeyLen: uint32(len(a.Key) * 8),
AlgTruncLen: uint32(a.TruncateLen),
AlgKey: a.Key,
}
end := len(a.Name)
if end > 64 {
end = 64
}
copy(algo.AlgName[:end], a.Name)
return algo.Serialize()
}
// XfrmStateAdd will add an xfrm state to the system.
// Equivalent to: `ip xfrm state add $state`
func XfrmStateAdd(state *XfrmState) error {
// A state with spi 0 can't be deleted so don't allow it to be set
if state.Spi == 0 {
return fmt.Errorf("Spi must be set when adding xfrm state.")
}
req := nl.NewNetlinkRequest(nl.XFRM_MSG_NEWSA, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
msg := &nl.XfrmUsersaInfo{}
msg.Family = uint16(nl.GetIPFamily(state.Dst))
msg.Id.Daddr.FromIP(state.Dst)
msg.Saddr.FromIP(state.Src)
msg.Id.Proto = uint8(state.Proto)
msg.Mode = uint8(state.Mode)
msg.Id.Spi = nl.Swap32(uint32(state.Spi))
msg.Reqid = uint32(state.Reqid)
msg.ReplayWindow = uint8(state.ReplayWindow)
msg.Lft.SoftByteLimit = nl.XFRM_INF
msg.Lft.HardByteLimit = nl.XFRM_INF
msg.Lft.SoftPacketLimit = nl.XFRM_INF
msg.Lft.HardPacketLimit = nl.XFRM_INF
req.AddData(msg)
if state.Auth != nil {
out := nl.NewRtAttr(nl.XFRMA_ALG_AUTH_TRUNC, writeStateAlgoAuth(state.Auth))
req.AddData(out)
}
if state.Crypt != nil {
out := nl.NewRtAttr(nl.XFRMA_ALG_CRYPT, writeStateAlgo(state.Crypt))
req.AddData(out)
}
if state.Encap != nil {
encapData := make([]byte, nl.SizeofXfrmEncapTmpl)
encap := nl.DeserializeXfrmEncapTmpl(encapData)
encap.EncapType = uint16(state.Encap.Type)
encap.EncapSport = nl.Swap16(uint16(state.Encap.SrcPort))
encap.EncapDport = nl.Swap16(uint16(state.Encap.DstPort))
encap.EncapOa.FromIP(state.Encap.OriginalAddress)
out := nl.NewRtAttr(nl.XFRMA_ENCAP, encapData)
req.AddData(out)
}
_, err := req.Execute(syscall.NETLINK_XFRM, 0)
return err
}
// XfrmStateDel will delete an xfrm state from the system. Note that
// the Algos are ignored when matching the state to delete.
// Equivalent to: `ip xfrm state del $state`
func XfrmStateDel(state *XfrmState) error {
req := nl.NewNetlinkRequest(nl.XFRM_MSG_DELSA, syscall.NLM_F_ACK)
msg := &nl.XfrmUsersaId{}
msg.Daddr.FromIP(state.Dst)
msg.Family = uint16(nl.GetIPFamily(state.Dst))
msg.Proto = uint8(state.Proto)
msg.Spi = nl.Swap32(uint32(state.Spi))
req.AddData(msg)
saddr := nl.XfrmAddress{}
saddr.FromIP(state.Src)
srcdata := nl.NewRtAttr(nl.XFRMA_SRCADDR, saddr.Serialize())
req.AddData(srcdata)
_, err := req.Execute(syscall.NETLINK_XFRM, 0)
return err
}
// XfrmStateList gets a list of xfrm states in the system.
// Equivalent to: `ip xfrm state show`.
// The list can be filtered by ip family.
func XfrmStateList(family int) ([]XfrmState, error) {
req := nl.NewNetlinkRequest(nl.XFRM_MSG_GETSA, syscall.NLM_F_DUMP)
msgs, err := req.Execute(syscall.NETLINK_XFRM, nl.XFRM_MSG_NEWSA)
if err != nil {
return nil, err
}
var res []XfrmState
for _, m := range msgs {
msg := nl.DeserializeXfrmUsersaInfo(m)
if family != FAMILY_ALL && family != int(msg.Family) {
continue
}
var state XfrmState
state.Dst = msg.Id.Daddr.ToIP()
state.Src = msg.Saddr.ToIP()
state.Proto = Proto(msg.Id.Proto)
state.Mode = Mode(msg.Mode)
state.Spi = int(nl.Swap32(msg.Id.Spi))
state.Reqid = int(msg.Reqid)
state.ReplayWindow = int(msg.ReplayWindow)
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return nil, err
}
for _, attr := range attrs {
switch attr.Attr.Type {
case nl.XFRMA_ALG_AUTH, nl.XFRMA_ALG_CRYPT:
var resAlgo *XfrmStateAlgo
if attr.Attr.Type == nl.XFRMA_ALG_AUTH {
if state.Auth == nil {
state.Auth = new(XfrmStateAlgo)
}
resAlgo = state.Auth
} else {
state.Crypt = new(XfrmStateAlgo)
resAlgo = state.Crypt
}
algo := nl.DeserializeXfrmAlgo(attr.Value[:])
(*resAlgo).Name = nl.BytesToString(algo.AlgName[:])
(*resAlgo).Key = algo.AlgKey
case nl.XFRMA_ALG_AUTH_TRUNC:
if state.Auth == nil {
state.Auth = new(XfrmStateAlgo)
}
algo := nl.DeserializeXfrmAlgoAuth(attr.Value[:])
state.Auth.Name = nl.BytesToString(algo.AlgName[:])
state.Auth.Key = algo.AlgKey
state.Auth.TruncateLen = int(algo.AlgTruncLen)
case nl.XFRMA_ENCAP:
encap := nl.DeserializeXfrmEncapTmpl(attr.Value[:])
state.Encap = new(XfrmStateEncap)
state.Encap.Type = EncapType(encap.EncapType)
state.Encap.SrcPort = int(nl.Swap16(encap.EncapSport))
state.Encap.DstPort = int(nl.Swap16(encap.EncapDport))
state.Encap.OriginalAddress = encap.EncapOa.ToIP()
}
}
res = append(res, state)
}
return res, nil
}
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