package netlink
import (
"fmt"
"net"
"github.com/vishvananda/netlink/nl"
"golang.org/x/sys/unix"
)
// Dir is an enum representing an ipsec template direction.
type Dir uint8
const (
XFRM_DIR_IN Dir = iota
XFRM_DIR_OUT
XFRM_DIR_FWD
XFRM_SOCKET_IN
XFRM_SOCKET_OUT
XFRM_SOCKET_FWD
)
func (d Dir) String() string {
switch d {
case XFRM_DIR_IN:
return "dir in"
case XFRM_DIR_OUT:
return "dir out"
case XFRM_DIR_FWD:
return "dir fwd"
case XFRM_SOCKET_IN:
return "socket in"
case XFRM_SOCKET_OUT:
return "socket out"
case XFRM_SOCKET_FWD:
return "socket fwd"
}
return fmt.Sprintf("socket %d", d-XFRM_SOCKET_IN)
}
// PolicyAction is an enum representing an ipsec policy action.
type PolicyAction uint8
const (
XFRM_POLICY_ALLOW PolicyAction = 0
XFRM_POLICY_BLOCK PolicyAction = 1
)
func (a PolicyAction) String() string {
switch a {
case XFRM_POLICY_ALLOW:
return "allow"
case XFRM_POLICY_BLOCK:
return "block"
default:
return fmt.Sprintf("action %d", a)
}
}
// XfrmPolicyTmpl encapsulates a rule for the base addresses of an ipsec
// policy. These rules are matched with XfrmState to determine encryption
// and authentication algorithms.
type XfrmPolicyTmpl struct {
Dst net.IP
Src net.IP
Proto Proto
Mode Mode
Spi int
Reqid int
Optional int
}
func (t XfrmPolicyTmpl) String() string {
return fmt.Sprintf("{Dst: %v, Src: %v, Proto: %s, Mode: %s, Spi: 0x%x, Reqid: 0x%x}",
t.Dst, t.Src, t.Proto, t.Mode, t.Spi, t.Reqid)
}
// XfrmPolicy represents an ipsec policy. It represents the overlay network
// and has a list of XfrmPolicyTmpls representing the base addresses of
// the policy.
type XfrmPolicy struct {
Dst *net.IPNet
Src *net.IPNet
Proto Proto
DstPort int
SrcPort int
Dir Dir
Priority int
Index int
Action PolicyAction
Ifindex int
Ifid int
Mark *XfrmMark
Tmpls []XfrmPolicyTmpl
}
func (p XfrmPolicy) String() string {
return fmt.Sprintf("{Dst: %v, Src: %v, Proto: %s, DstPort: %d, SrcPort: %d, Dir: %s, Priority: %d, Index: %d, Action: %s, Ifindex: %d, Ifid: %d, Mark: %s, Tmpls: %s}",
p.Dst, p.Src, p.Proto, p.DstPort, p.SrcPort, p.Dir, p.Priority, p.Index, p.Action, p.Ifindex, p.Ifid, p.Mark, p.Tmpls)
}
func selFromPolicy(sel *nl.XfrmSelector, policy *XfrmPolicy) {
sel.Family = uint16(nl.FAMILY_V4)
if policy.Dst != nil {
sel.Family = uint16(nl.GetIPFamily(policy.Dst.IP))
sel.Daddr.FromIP(policy.Dst.IP)
prefixlenD, _ := policy.Dst.Mask.Size()
sel.PrefixlenD = uint8(prefixlenD)
}
if policy.Src != nil {
sel.Saddr.FromIP(policy.Src.IP)
prefixlenS, _ := policy.Src.Mask.Size()
sel.PrefixlenS = uint8(prefixlenS)
}
sel.Proto = uint8(policy.Proto)
sel.Dport = nl.Swap16(uint16(policy.DstPort))
sel.Sport = nl.Swap16(uint16(policy.SrcPort))
if sel.Dport != 0 {
sel.DportMask = ^uint16(0)
}
if sel.Sport != 0 {
sel.SportMask = ^uint16(0)
}
sel.Ifindex = int32(policy.Ifindex)
}
// XfrmPolicyAdd will add an xfrm policy to the system.
// Equivalent to: `ip xfrm policy add $policy`
func XfrmPolicyAdd(policy *XfrmPolicy) error {
return pkgHandle.XfrmPolicyAdd(policy)
}
// XfrmPolicyAdd will add an xfrm policy to the system.
// Equivalent to: `ip xfrm policy add $policy`
func (h *Handle) XfrmPolicyAdd(policy *XfrmPolicy) error {
return h.xfrmPolicyAddOrUpdate(policy, nl.XFRM_MSG_NEWPOLICY)
}
// XfrmPolicyUpdate will update an xfrm policy to the system.
// Equivalent to: `ip xfrm policy update $policy`
func XfrmPolicyUpdate(policy *XfrmPolicy) error {
return pkgHandle.XfrmPolicyUpdate(policy)
}
// XfrmPolicyUpdate will update an xfrm policy to the system.
// Equivalent to: `ip xfrm policy update $policy`
func (h *Handle) XfrmPolicyUpdate(policy *XfrmPolicy) error {
return h.xfrmPolicyAddOrUpdate(policy, nl.XFRM_MSG_UPDPOLICY)
}
func (h *Handle) xfrmPolicyAddOrUpdate(policy *XfrmPolicy, nlProto int) error {
req := h.newNetlinkRequest(nlProto, unix.NLM_F_CREATE|unix.NLM_F_EXCL|unix.NLM_F_ACK)
msg := &nl.XfrmUserpolicyInfo{}
selFromPolicy(&msg.Sel, policy)
msg.Priority = uint32(policy.Priority)
msg.Index = uint32(policy.Index)
msg.Dir = uint8(policy.Dir)
msg.Action = uint8(policy.Action)
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)
tmplData := make([]byte, nl.SizeofXfrmUserTmpl*len(policy.Tmpls))
for i, tmpl := range policy.Tmpls {
start := i * nl.SizeofXfrmUserTmpl
userTmpl := nl.DeserializeXfrmUserTmpl(tmplData[start : start+nl.SizeofXfrmUserTmpl])
userTmpl.XfrmId.Daddr.FromIP(tmpl.Dst)
userTmpl.Saddr.FromIP(tmpl.Src)
userTmpl.Family = uint16(nl.GetIPFamily(tmpl.Dst))
userTmpl.XfrmId.Proto = uint8(tmpl.Proto)
userTmpl.XfrmId.Spi = nl.Swap32(uint32(tmpl.Spi))
userTmpl.Mode = uint8(tmpl.Mode)
userTmpl.Reqid = uint32(tmpl.Reqid)
userTmpl.Optional = uint8(tmpl.Optional)
userTmpl.Aalgos = ^uint32(0)
userTmpl.Ealgos = ^uint32(0)
userTmpl.Calgos = ^uint32(0)
}
if len(tmplData) > 0 {
tmpls := nl.NewRtAttr(nl.XFRMA_TMPL, tmplData)
req.AddData(tmpls)
}
if policy.Mark != nil {
out := nl.NewRtAttr(nl.XFRMA_MARK, writeMark(policy.Mark))
req.AddData(out)
}
if policy.Ifid != 0 {
ifId := nl.NewRtAttr(nl.XFRMA_IF_ID, nl.Uint32Attr(uint32(policy.Ifid)))
req.AddData(ifId)
}
_, err := req.Execute(unix.NETLINK_XFRM, 0)
return err
}
// XfrmPolicyDel will delete an xfrm policy from the system. Note that
// the Tmpls are ignored when matching the policy to delete.
// Equivalent to: `ip xfrm policy del $policy`
func XfrmPolicyDel(policy *XfrmPolicy) error {
return pkgHandle.XfrmPolicyDel(policy)
}
// XfrmPolicyDel will delete an xfrm policy from the system. Note that
// the Tmpls are ignored when matching the policy to delete.
// Equivalent to: `ip xfrm policy del $policy`
func (h *Handle) XfrmPolicyDel(policy *XfrmPolicy) error {
_, err := h.xfrmPolicyGetOrDelete(policy, nl.XFRM_MSG_DELPOLICY)
return err
}
// XfrmPolicyList gets a list of xfrm policies in the system.
// Equivalent to: `ip xfrm policy show`.
// The list can be filtered by ip family.
func XfrmPolicyList(family int) ([]XfrmPolicy, error) {
return pkgHandle.XfrmPolicyList(family)
}
// XfrmPolicyList gets a list of xfrm policies in the system.
// Equivalent to: `ip xfrm policy show`.
// The list can be filtered by ip family.
func (h *Handle) XfrmPolicyList(family int) ([]XfrmPolicy, error) {
req := h.newNetlinkRequest(nl.XFRM_MSG_GETPOLICY, unix.NLM_F_DUMP)
msg := nl.NewIfInfomsg(family)
req.AddData(msg)
msgs, err := req.Execute(unix.NETLINK_XFRM, nl.XFRM_MSG_NEWPOLICY)
if err != nil {
return nil, err
}
var res []XfrmPolicy
for _, m := range msgs {
if policy, err := parseXfrmPolicy(m, family); err == nil {
res = append(res, *policy)
} else if err == familyError {
continue
} else {
return nil, err
}
}
return res, nil
}
// XfrmPolicyGet gets a the policy described by the index or selector, if found.
// Equivalent to: `ip xfrm policy get { SELECTOR | index INDEX } dir DIR [ctx CTX ] [ mark MARK [ mask MASK ] ] [ ptype PTYPE ]`.
func XfrmPolicyGet(policy *XfrmPolicy) (*XfrmPolicy, error) {
return pkgHandle.XfrmPolicyGet(policy)
}
// XfrmPolicyGet gets a the policy described by the index or selector, if found.
// Equivalent to: `ip xfrm policy get { SELECTOR | index INDEX } dir DIR [ctx CTX ] [ mark MARK [ mask MASK ] ] [ ptype PTYPE ]`.
func (h *Handle) XfrmPolicyGet(policy *XfrmPolicy) (*XfrmPolicy, error) {
return h.xfrmPolicyGetOrDelete(policy, nl.XFRM_MSG_GETPOLICY)
}
// XfrmPolicyFlush will flush the policies on the system.
// Equivalent to: `ip xfrm policy flush`
func XfrmPolicyFlush() error {
return pkgHandle.XfrmPolicyFlush()
}
// XfrmPolicyFlush will flush the policies on the system.
// Equivalent to: `ip xfrm policy flush`
func (h *Handle) XfrmPolicyFlush() error {
req := h.newNetlinkRequest(nl.XFRM_MSG_FLUSHPOLICY, unix.NLM_F_ACK)
_, err := req.Execute(unix.NETLINK_XFRM, 0)
return err
}
func (h *Handle) xfrmPolicyGetOrDelete(policy *XfrmPolicy, nlProto int) (*XfrmPolicy, error) {
req := h.newNetlinkRequest(nlProto, unix.NLM_F_ACK)
msg := &nl.XfrmUserpolicyId{}
selFromPolicy(&msg.Sel, policy)
msg.Index = uint32(policy.Index)
msg.Dir = uint8(policy.Dir)
req.AddData(msg)
if policy.Mark != nil {
out := nl.NewRtAttr(nl.XFRMA_MARK, writeMark(policy.Mark))
req.AddData(out)
}
if policy.Ifid != 0 {
ifId := nl.NewRtAttr(nl.XFRMA_IF_ID, nl.Uint32Attr(uint32(policy.Ifid)))
req.AddData(ifId)
}
resType := nl.XFRM_MSG_NEWPOLICY
if nlProto == nl.XFRM_MSG_DELPOLICY {
resType = 0
}
msgs, err := req.Execute(unix.NETLINK_XFRM, uint16(resType))
if err != nil {
return nil, err
}
if nlProto == nl.XFRM_MSG_DELPOLICY {
return nil, err
}
return parseXfrmPolicy(msgs[0], FAMILY_ALL)
}
func parseXfrmPolicy(m []byte, family int) (*XfrmPolicy, error) {
msg := nl.DeserializeXfrmUserpolicyInfo(m)
// This is mainly for the policy dump
if family != FAMILY_ALL && family != int(msg.Sel.Family) {
return nil, familyError
}
var policy XfrmPolicy
policy.Dst = msg.Sel.Daddr.ToIPNet(msg.Sel.PrefixlenD, uint16(family))
policy.Src = msg.Sel.Saddr.ToIPNet(msg.Sel.PrefixlenS, uint16(family))
policy.Proto = Proto(msg.Sel.Proto)
policy.DstPort = int(nl.Swap16(msg.Sel.Dport))
policy.SrcPort = int(nl.Swap16(msg.Sel.Sport))
policy.Ifindex = int(msg.Sel.Ifindex)
policy.Priority = int(msg.Priority)
policy.Index = int(msg.Index)
policy.Dir = Dir(msg.Dir)
policy.Action = PolicyAction(msg.Action)
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return nil, err
}
for _, attr := range attrs {
switch attr.Attr.Type {
case nl.XFRMA_TMPL:
max := len(attr.Value)
for i := 0; i < max; i += nl.SizeofXfrmUserTmpl {
var resTmpl XfrmPolicyTmpl
tmpl := nl.DeserializeXfrmUserTmpl(attr.Value[i : i+nl.SizeofXfrmUserTmpl])
resTmpl.Dst = tmpl.XfrmId.Daddr.ToIP()
resTmpl.Src = tmpl.Saddr.ToIP()
resTmpl.Proto = Proto(tmpl.XfrmId.Proto)
resTmpl.Mode = Mode(tmpl.Mode)
resTmpl.Spi = int(nl.Swap32(tmpl.XfrmId.Spi))
resTmpl.Reqid = int(tmpl.Reqid)
resTmpl.Optional = int(tmpl.Optional)
policy.Tmpls = append(policy.Tmpls, resTmpl)
}
case nl.XFRMA_MARK:
mark := nl.DeserializeXfrmMark(attr.Value[:])
policy.Mark = new(XfrmMark)
policy.Mark.Value = mark.Value
policy.Mark.Mask = mark.Mask
case nl.XFRMA_IF_ID:
policy.Ifid = int(native.Uint32(attr.Value))
}
}
return &policy, nil
}
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