Initial commit
This commit is contained in:
Michael Stapelberg
commit
afbe6ed893
|
|
@ -0,0 +1,23 @@
|
|||
# How to Contribute
|
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|
||||
We'd love to accept your patches and contributions to this project. There are
|
||||
just a few small guidelines you need to follow.
|
||||
|
||||
## Contributor License Agreement
|
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|
||||
Contributions to this project must be accompanied by a Contributor License
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Agreement. You (or your employer) retain the copyright to your contribution,
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||||
this simply gives us permission to use and redistribute your contributions as
|
||||
part of the project. Head over to <https://cla.developers.google.com/> to see
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||||
|
||||
You generally only need to submit a CLA once, so if you've already submitted one
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(even if it was for a different project), you probably don't need to do it
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again.
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## Code reviews
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|
||||
All submissions, including submissions by project members, require review. We
|
||||
use GitHub pull requests for this purpose. Consult
|
||||
[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
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information on using pull requests.
|
||||
|
|
@ -0,0 +1,202 @@
|
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|
||||
Apache License
|
||||
Version 2.0, January 2004
|
||||
http://www.apache.org/licenses/
|
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|
||||
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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||||
1. Definitions.
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"License" shall mean the terms and conditions for use, reproduction,
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END OF TERMS AND CONDITIONS
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APPENDIX: How to apply the Apache License to your work.
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To apply the Apache License to your work, attach the following
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Copyright [yyyy] [name of copyright owner]
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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Unless required by applicable law or agreed to in writing, software
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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@ -0,0 +1,141 @@
|
|||
// Copyright 2018 Google LLC. All Rights Reserved.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// Package expr provides nftables rule expressions.
|
||||
package expr
|
||||
|
||||
import (
|
||||
"github.com/google/nftables/internal/binaryutil"
|
||||
"github.com/mdlayher/netlink"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
// Marshal serializes the specified expression into a byte slice.
|
||||
func Marshal(e Any) ([]byte, error) {
|
||||
return e.marshal()
|
||||
}
|
||||
|
||||
// Any is an interface implemented by any expression type.
|
||||
type Any interface {
|
||||
marshal() ([]byte, error)
|
||||
}
|
||||
|
||||
// MetaKey specifies which piece of meta information should be loaded. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Matching_packet_metainformation
|
||||
type MetaKey uint32
|
||||
|
||||
// Possible MetaKey values.
|
||||
const (
|
||||
MetaKeyLEN MetaKey = unix.NFT_META_LEN
|
||||
MetaKeyPROTOCOL MetaKey = unix.NFT_META_PROTOCOL
|
||||
MetaKeyPRIORITY MetaKey = unix.NFT_META_PRIORITY
|
||||
MetaKeyMARK MetaKey = unix.NFT_META_MARK
|
||||
MetaKeyIIF MetaKey = unix.NFT_META_IIF
|
||||
MetaKeyOIF MetaKey = unix.NFT_META_OIF
|
||||
MetaKeyIIFNAME MetaKey = unix.NFT_META_IIFNAME
|
||||
MetaKeyOIFNAME MetaKey = unix.NFT_META_OIFNAME
|
||||
MetaKeyIIFTYPE MetaKey = unix.NFT_META_IIFTYPE
|
||||
MetaKeyOIFTYPE MetaKey = unix.NFT_META_OIFTYPE
|
||||
MetaKeySKUID MetaKey = unix.NFT_META_SKUID
|
||||
MetaKeySKGID MetaKey = unix.NFT_META_SKGID
|
||||
MetaKeyNFTRACE MetaKey = unix.NFT_META_NFTRACE
|
||||
MetaKeyRTCLASSID MetaKey = unix.NFT_META_RTCLASSID
|
||||
MetaKeySECMARK MetaKey = unix.NFT_META_SECMARK
|
||||
MetaKeyNFPROTO MetaKey = unix.NFT_META_NFPROTO
|
||||
MetaKeyL4PROTO MetaKey = unix.NFT_META_L4PROTO
|
||||
MetaKeyBRIIIFNAME MetaKey = unix.NFT_META_BRI_IIFNAME
|
||||
MetaKeyBRIOIFNAME MetaKey = unix.NFT_META_BRI_OIFNAME
|
||||
MetaKeyPKTTYPE MetaKey = unix.NFT_META_PKTTYPE
|
||||
MetaKeyCPU MetaKey = unix.NFT_META_CPU
|
||||
MetaKeyIIFGROUP MetaKey = unix.NFT_META_IIFGROUP
|
||||
MetaKeyOIFGROUP MetaKey = unix.NFT_META_OIFGROUP
|
||||
MetaKeyCGROUP MetaKey = unix.NFT_META_CGROUP
|
||||
MetaKeyPRANDOM MetaKey = unix.NFT_META_PRANDOM
|
||||
)
|
||||
|
||||
// Meta loads packet meta information for later comparisons. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Matching_packet_metainformation
|
||||
type Meta struct {
|
||||
Key MetaKey
|
||||
Register uint32
|
||||
}
|
||||
|
||||
func (e *Meta) marshal() ([]byte, error) {
|
||||
exprData, err := netlink.MarshalAttributes(
|
||||
[]netlink.Attribute{
|
||||
{Type: unix.NFTA_META_KEY, Data: binaryutil.BigEndian.PutUint32(uint32(e.Key))},
|
||||
{Type: unix.NFTA_META_DREG, Data: binaryutil.BigEndian.PutUint32(e.Register)},
|
||||
},
|
||||
)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_EXPR_NAME, Data: []byte("meta\x00")},
|
||||
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: exprData},
|
||||
})
|
||||
}
|
||||
|
||||
// Masq (Masquerade) is a special case of SNAT, where the source address is
|
||||
// automagically set to the address of the output interface. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Performing_Network_Address_Translation_(NAT)#Masquerading
|
||||
type Masq struct{}
|
||||
|
||||
func (e *Masq) marshal() ([]byte, error) {
|
||||
return netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_EXPR_NAME, Data: []byte("masq\x00")},
|
||||
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: nil},
|
||||
})
|
||||
}
|
||||
|
||||
// CmpOp specifies which type of comparison should be performed.
|
||||
type CmpOp uint32
|
||||
|
||||
// Possible CmpOp values.
|
||||
const (
|
||||
CmpOpEq CmpOp = unix.NFT_CMP_EQ
|
||||
CmpOpNeq CmpOp = unix.NFT_CMP_NEQ
|
||||
CmpOpLt CmpOp = unix.NFT_CMP_LT
|
||||
CmpOpLte CmpOp = unix.NFT_CMP_LTE
|
||||
CmpOpGt CmpOp = unix.NFT_CMP_GT
|
||||
CmpOpGte CmpOp = unix.NFT_CMP_GTE
|
||||
)
|
||||
|
||||
// Cmp compares a register with the specified data.
|
||||
type Cmp struct {
|
||||
Op CmpOp
|
||||
Register uint32
|
||||
Data uint32
|
||||
}
|
||||
|
||||
func (e *Cmp) marshal() ([]byte, error) {
|
||||
cmpData, err := netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_DATA_VALUE, Data: binaryutil.NativeEndian.PutUint32(e.Data)},
|
||||
})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
exprData, err := netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_CMP_SREG, Data: binaryutil.BigEndian.PutUint32(e.Register)},
|
||||
{Type: unix.NFTA_CMP_OP, Data: binaryutil.BigEndian.PutUint32(unix.NFT_CMP_EQ)},
|
||||
{Type: unix.NLA_F_NESTED | unix.NFTA_CMP_DATA, Data: cmpData},
|
||||
})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_EXPR_NAME, Data: []byte("cmp\x00")},
|
||||
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: exprData},
|
||||
})
|
||||
}
|
||||
|
|
@ -0,0 +1,65 @@
|
|||
// Copyright 2018 Google LLC. All Rights Reserved.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// Package binaryutil contains convenience wrappers around encoding/binary.
|
||||
package binaryutil
|
||||
|
||||
import (
|
||||
"encoding/binary"
|
||||
|
||||
"github.com/koneu/natend"
|
||||
)
|
||||
|
||||
// ByteOrder is like binary.ByteOrder, but allocates memory and returns byte
|
||||
// slices, for convenience.
|
||||
type ByteOrder interface {
|
||||
PutUint16(v uint16) []byte
|
||||
PutUint32(v uint32) []byte
|
||||
}
|
||||
|
||||
// NativeEndian is either little endian or big endian, depending on the native
|
||||
// endian-ness, and allocates memory and returns byte slices, for convenience.
|
||||
var NativeEndian ByteOrder = &nativeEndian{}
|
||||
|
||||
type nativeEndian struct{}
|
||||
|
||||
func (nativeEndian) PutUint16(v uint16) []byte {
|
||||
buf := make([]byte, 2)
|
||||
natend.NativeEndian.PutUint16(buf, v)
|
||||
return buf
|
||||
}
|
||||
|
||||
func (nativeEndian) PutUint32(v uint32) []byte {
|
||||
buf := make([]byte, 4)
|
||||
natend.NativeEndian.PutUint32(buf, v)
|
||||
return buf
|
||||
}
|
||||
|
||||
// BigEndian is like binary.BigEndian, but allocates memory and returns byte
|
||||
// slices, for convenience.
|
||||
var BigEndian ByteOrder = &bigEndian{}
|
||||
|
||||
type bigEndian struct{}
|
||||
|
||||
func (bigEndian) PutUint16(v uint16) []byte {
|
||||
buf := make([]byte, 2)
|
||||
binary.BigEndian.PutUint16(buf, v)
|
||||
return buf
|
||||
}
|
||||
|
||||
func (bigEndian) PutUint32(v uint32) []byte {
|
||||
buf := make([]byte, 4)
|
||||
binary.BigEndian.PutUint32(buf, v)
|
||||
return buf
|
||||
}
|
||||
|
|
@ -0,0 +1,21 @@
|
|||
// Copyright 2018 Google LLC. All Rights Reserved.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
package nftables
|
||||
|
||||
import "github.com/google/nftables/internal/binaryutil"
|
||||
|
||||
// NativeEndian is either little endian or big endian, depending on the
|
||||
// native endian-ness.
|
||||
var NativeEndian binaryutil.ByteOrder = binaryutil.NativeEndian
|
||||
|
|
@ -0,0 +1,278 @@
|
|||
// Copyright 2018 Google LLC. All Rights Reserved.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// Package nftables manipulates Linux nftables (the iptables successor).
|
||||
package nftables
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"math"
|
||||
|
||||
"github.com/google/nftables/expr"
|
||||
"github.com/google/nftables/internal/binaryutil"
|
||||
"github.com/mdlayher/netlink"
|
||||
"github.com/mdlayher/netlink/nltest"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
func extraHeader(family uint8, resID uint16) []byte {
|
||||
return append([]byte{
|
||||
family,
|
||||
unix.NFNETLINK_V0,
|
||||
}, binaryutil.NativeEndian.PutUint16(resID)...)
|
||||
}
|
||||
|
||||
func batch(messages []netlink.Message) []netlink.Message {
|
||||
batch := []netlink.Message{
|
||||
{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType(unix.NFNL_MSG_BATCH_BEGIN),
|
||||
Flags: netlink.HeaderFlagsRequest,
|
||||
},
|
||||
Data: extraHeader(0, unix.NFNL_SUBSYS_NFTABLES),
|
||||
},
|
||||
}
|
||||
|
||||
batch = append(batch, messages...)
|
||||
|
||||
batch = append(batch, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType(unix.NFNL_MSG_BATCH_END),
|
||||
Flags: netlink.HeaderFlagsRequest,
|
||||
},
|
||||
Data: extraHeader(0, unix.NFNL_SUBSYS_NFTABLES),
|
||||
})
|
||||
|
||||
return batch
|
||||
}
|
||||
|
||||
// ChainHook specifies at which step in packet processing the Chain should be
|
||||
// executed. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Base_chain_hooks
|
||||
type ChainHook uint32
|
||||
|
||||
// Possible ChainHook values.
|
||||
const (
|
||||
ChainHookPrerouting ChainHook = unix.NF_INET_PRE_ROUTING
|
||||
ChainHookInput ChainHook = unix.NF_INET_LOCAL_IN
|
||||
ChainHookForward ChainHook = unix.NF_INET_FORWARD
|
||||
ChainHookOutput ChainHook = unix.NF_INET_LOCAL_OUT
|
||||
ChainHookPostrouting ChainHook = unix.NF_INET_POST_ROUTING
|
||||
ChainHookIngress ChainHook = unix.NF_NETDEV_INGRESS
|
||||
)
|
||||
|
||||
// ChainPriority orders the chain relative to Netfilter internal operations. See
|
||||
// also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Base_chain_priority
|
||||
type ChainPriority int32
|
||||
|
||||
// Possible ChainPriority values.
|
||||
const ( // from /usr/include/linux/netfilter_ipv4.h
|
||||
ChainPriorityFirst ChainPriority = math.MinInt32
|
||||
ChainPriorityConntrackDefrag ChainPriority = -400
|
||||
ChainPriorityRaw ChainPriority = -300
|
||||
ChainPrioritySELinuxFirst ChainPriority = -225
|
||||
ChainPriorityConntrack ChainPriority = -200
|
||||
ChainPriorityMangle ChainPriority = -150
|
||||
ChainPriorityNATDest ChainPriority = -100
|
||||
ChainPriorityFilter ChainPriority = 0
|
||||
ChainPrioritySecurity ChainPriority = 50
|
||||
ChainPriorityNATSource ChainPriority = 100
|
||||
ChainPrioritySELinuxLast ChainPriority = 225
|
||||
ChainPriorityConntrackHelper ChainPriority = 300
|
||||
ChainPriorityConntrackConfirm ChainPriority = math.MaxInt32
|
||||
ChainPriorityLast ChainPriority = math.MaxInt32
|
||||
)
|
||||
|
||||
// ChainType defines what this chain will be used for. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Base_chain_types
|
||||
type ChainType string
|
||||
|
||||
// Possible ChainType values.
|
||||
const (
|
||||
ChainTypeFilter ChainType = "filter"
|
||||
ChainTypeRoute ChainType = "route"
|
||||
ChainTypeNAT ChainType = "nat"
|
||||
)
|
||||
|
||||
// A Chain contains Rules. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains
|
||||
type Chain struct {
|
||||
Name string
|
||||
Table *Table
|
||||
Hooknum ChainHook
|
||||
Priority ChainPriority
|
||||
Type ChainType
|
||||
}
|
||||
|
||||
// AddChain adds the specified Chain. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Adding_base_chains
|
||||
func (cc *Conn) AddChain(c *Chain) *Chain {
|
||||
chainHook := cc.marshalAttr([]netlink.Attribute{
|
||||
{Type: unix.NFTA_HOOK_HOOKNUM, Data: binaryutil.BigEndian.PutUint32(uint32(c.Hooknum))},
|
||||
{Type: unix.NFTA_HOOK_PRIORITY, Data: binaryutil.BigEndian.PutUint32(uint32(c.Priority))},
|
||||
})
|
||||
|
||||
data := cc.marshalAttr([]netlink.Attribute{
|
||||
{Type: unix.NFTA_CHAIN_TABLE, Data: []byte(c.Table.Name + "\x00")},
|
||||
{Type: unix.NFTA_CHAIN_NAME, Data: []byte(c.Name + "\x00")},
|
||||
{Type: unix.NLA_F_NESTED | unix.NFTA_CHAIN_HOOK, Data: chainHook},
|
||||
{Type: unix.NFTA_CHAIN_TYPE, Data: []byte(c.Type + "\x00")},
|
||||
})
|
||||
|
||||
cc.messages = append(cc.messages, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWCHAIN),
|
||||
Flags: netlink.HeaderFlagsRequest | netlink.HeaderFlagsAcknowledge | netlink.HeaderFlagsCreate,
|
||||
},
|
||||
Data: append(extraHeader(unix.AF_INET, 0), data...),
|
||||
})
|
||||
|
||||
return c
|
||||
}
|
||||
|
||||
func (cc *Conn) setErr(err error) {
|
||||
if cc.err != nil {
|
||||
return
|
||||
}
|
||||
cc.err = err
|
||||
}
|
||||
|
||||
func (cc *Conn) marshalAttr(attrs []netlink.Attribute) []byte {
|
||||
b, err := netlink.MarshalAttributes(attrs)
|
||||
if err != nil {
|
||||
cc.setErr(err)
|
||||
return nil
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
||||
func (cc *Conn) marshalExpr(e expr.Any) []byte {
|
||||
b, err := expr.Marshal(e)
|
||||
if err != nil {
|
||||
cc.setErr(err)
|
||||
return nil
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
||||
// A Rule does something with a packet. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Simple_rule_management
|
||||
type Rule struct {
|
||||
Table *Table
|
||||
Chain *Chain
|
||||
Exprs []expr.Any
|
||||
}
|
||||
|
||||
// AddRule adds the specified Rule. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Simple_rule_management
|
||||
func (cc *Conn) AddRule(r *Rule) *Rule {
|
||||
exprAttrs := make([]netlink.Attribute, len(r.Exprs))
|
||||
for idx, expr := range r.Exprs {
|
||||
exprAttrs[idx] = netlink.Attribute{
|
||||
Type: unix.NLA_F_NESTED | unix.NFTA_LIST_ELEM,
|
||||
Data: cc.marshalExpr(expr),
|
||||
}
|
||||
}
|
||||
|
||||
data := cc.marshalAttr([]netlink.Attribute{
|
||||
{Type: unix.NFTA_RULE_TABLE, Data: []byte(r.Table.Name + "\x00")},
|
||||
{Type: unix.NFTA_RULE_CHAIN, Data: []byte(r.Chain.Name + "\x00")},
|
||||
{Type: unix.NLA_F_NESTED | unix.NFTA_RULE_EXPRESSIONS, Data: cc.marshalAttr(exprAttrs)},
|
||||
})
|
||||
|
||||
cc.messages = append(cc.messages, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWRULE),
|
||||
Flags: netlink.HeaderFlagsRequest | netlink.HeaderFlagsAcknowledge | netlink.HeaderFlagsCreate,
|
||||
},
|
||||
Data: append(extraHeader(unix.AF_INET, 0), data...),
|
||||
})
|
||||
|
||||
return r
|
||||
}
|
||||
|
||||
// TableFamily specifies the address family for this table.
|
||||
type TableFamily byte
|
||||
|
||||
// Possible TableFamily values.
|
||||
const (
|
||||
TableFamilyIPv4 TableFamily = unix.AF_INET
|
||||
TableFamilyIPv6 TableFamily = unix.AF_INET6
|
||||
)
|
||||
|
||||
// A Table contains Chains. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_tables
|
||||
type Table struct {
|
||||
Name string
|
||||
Family TableFamily
|
||||
}
|
||||
|
||||
// A Conn represents a netlink connection of the nftables family.
|
||||
//
|
||||
// All methods return their input, so that variables can be defined from string
|
||||
// literals when desired.
|
||||
//
|
||||
// Commands are buffered. Flush sends all buffered commands in a single batch.
|
||||
type Conn struct {
|
||||
TestDial nltest.Func // for testing only; passed to nltest.Dial
|
||||
messages []netlink.Message
|
||||
err error
|
||||
}
|
||||
|
||||
// AddTable adds the specified Table. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_tables
|
||||
func (cc *Conn) AddTable(t *Table) *Table {
|
||||
data := cc.marshalAttr([]netlink.Attribute{
|
||||
{Type: unix.NFTA_TABLE_NAME, Data: []byte(t.Name + "\x00")},
|
||||
{Type: unix.NFTA_TABLE_FLAGS, Data: []byte{0, 0, 0, 0}},
|
||||
})
|
||||
cc.messages = append(cc.messages, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWTABLE),
|
||||
Flags: netlink.HeaderFlagsRequest | netlink.HeaderFlagsAcknowledge | netlink.HeaderFlagsCreate,
|
||||
},
|
||||
Data: append(extraHeader(uint8(t.Family), 0), data...),
|
||||
})
|
||||
return t
|
||||
}
|
||||
|
||||
// Flush sends all buffered commands in a single batch to nftables.
|
||||
func (cc *Conn) Flush() error {
|
||||
if cc.err != nil {
|
||||
return cc.err // serialization error
|
||||
}
|
||||
var conn *netlink.Conn
|
||||
var err error
|
||||
if cc.TestDial == nil {
|
||||
conn, err = netlink.Dial(unix.NETLINK_NETFILTER, nil)
|
||||
} else {
|
||||
conn = nltest.Dial(cc.TestDial)
|
||||
}
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if _, err := conn.SendMessages(batch(cc.messages)); err != nil {
|
||||
return fmt.Errorf("SendMessages: %v", err)
|
||||
}
|
||||
|
||||
if _, err := conn.Receive(); err != nil {
|
||||
return fmt.Errorf("Receive: %v", err)
|
||||
}
|
||||
|
||||
cc.messages = nil
|
||||
|
||||
return nil
|
||||
}
|
||||
|
|
@ -0,0 +1,115 @@
|
|||
// Copyright 2018 Google LLC. All Rights Reserved.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
package nftables_test
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"testing"
|
||||
|
||||
"github.com/google/nftables"
|
||||
"github.com/google/nftables/expr"
|
||||
"github.com/mdlayher/netlink"
|
||||
)
|
||||
|
||||
func TestConfigureNAT(t *testing.T) {
|
||||
// TODO: skip this test as non-root
|
||||
// TODO: run this in its own network namespace to not mess with the host
|
||||
|
||||
// The want byte sequences come from stracing nft(8), e.g.:
|
||||
// strace -f -v -x -s 2048 -eraw=sendto nft add table ip nat
|
||||
//
|
||||
// The nft(8) command sequence was taken from:
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Performing_Network_Address_Translation_(NAT)
|
||||
want := [][]byte{
|
||||
// batch begin
|
||||
[]byte("\x00\x00\x0a\x00"),
|
||||
// nft add table ip nat
|
||||
[]byte("\x02\x00\x00\x00\x08\x00\x01\x00\x6e\x61\x74\x00\x08\x00\x02\x00\x00\x00\x00\x00"),
|
||||
// nft add chain nat prerouting '{' type nat hook prerouting priority 0 \; '}'
|
||||
[]byte("\x02\x00\x00\x00\x08\x00\x01\x00\x6e\x61\x74\x00\x0f\x00\x03\x00\x70\x72\x65\x72\x6f\x75\x74\x69\x6e\x67\x00\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x00\x08\x00\x02\x00\x00\x00\x00\x00\x08\x00\x07\x00\x6e\x61\x74\x00"),
|
||||
// nft add chain nat postrouting { type nat hook postrouting priority 100 \; }
|
||||
[]byte("\x02\x00\x00\x00\x08\x00\x01\x00\x6e\x61\x74\x00\x10\x00\x03\x00\x70\x6f\x73\x74\x72\x6f\x75\x74\x69\x6e\x67\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x04\x08\x00\x02\x00\x00\x00\x00\x64\x08\x00\x07\x00\x6e\x61\x74\x00"),
|
||||
// nft add rule nat postrouting oif wlp4s0 masquerade
|
||||
[]byte("\x02\x00\x00\x00\x08\x00\x01\x00\x6e\x61\x74\x00\x10\x00\x02\x00\x70\x6f\x73\x74\x72\x6f\x75\x74\x69\x6e\x67\x00\x68\x00\x04\x80\x24\x00\x01\x80\x09\x00\x01\x00\x6d\x65\x74\x61\x00\x00\x00\x00\x14\x00\x02\x80\x08\x00\x02\x00\x00\x00\x00\x05\x08\x00\x01\x00\x00\x00\x00\x01\x2c\x00\x01\x80\x08\x00\x01\x00\x63\x6d\x70\x00\x20\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x00\x0c\x00\x03\x80\x08\x00\x01\x00\x03\x00\x00\x00\x14\x00\x01\x80\x09\x00\x01\x00\x6d\x61\x73\x71\x00\x00\x00\x00\x04\x00\x02\x80"),
|
||||
// batch end
|
||||
[]byte("\x00\x00\x0a\x00"),
|
||||
}
|
||||
|
||||
c := &nftables.Conn{
|
||||
TestDial: func(req []netlink.Message) ([]netlink.Message, error) {
|
||||
for idx, msg := range req {
|
||||
b, err := msg.MarshalBinary()
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
if len(b) < 16 {
|
||||
continue
|
||||
}
|
||||
b = b[16:]
|
||||
if len(want) == 0 {
|
||||
t.Errorf("no want entry for message %d: %x", idx, b)
|
||||
continue
|
||||
}
|
||||
if got, want := b, want[0]; !bytes.Equal(got, want) {
|
||||
t.Errorf("message %d: got %x, want %x", idx, got, want)
|
||||
}
|
||||
want = want[1:]
|
||||
}
|
||||
return req, nil
|
||||
},
|
||||
}
|
||||
|
||||
nat := c.AddTable(&nftables.Table{
|
||||
Family: nftables.TableFamilyIPv4,
|
||||
Name: "nat",
|
||||
})
|
||||
|
||||
c.AddChain(&nftables.Chain{
|
||||
Name: "prerouting",
|
||||
Hooknum: nftables.ChainHookPrerouting,
|
||||
Priority: nftables.ChainPriorityFilter,
|
||||
Table: nat,
|
||||
Type: nftables.ChainTypeNAT,
|
||||
})
|
||||
|
||||
postrouting := c.AddChain(&nftables.Chain{
|
||||
Name: "postrouting",
|
||||
Hooknum: nftables.ChainHookPostrouting,
|
||||
Priority: nftables.ChainPriorityNATSource,
|
||||
Table: nat,
|
||||
Type: nftables.ChainTypeNAT,
|
||||
})
|
||||
|
||||
c.AddRule(&nftables.Rule{
|
||||
Table: nat,
|
||||
Chain: postrouting,
|
||||
Exprs: []expr.Any{
|
||||
// meta load oif => reg 1
|
||||
&expr.Meta{Key: expr.MetaKeyOIF, Register: 1},
|
||||
// cmp eq reg 1 0x00000003
|
||||
&expr.Cmp{
|
||||
Op: expr.CmpOpEq,
|
||||
Register: 1,
|
||||
Data: 3, /* wlp4s0 */
|
||||
},
|
||||
// masq
|
||||
&expr.Masq{},
|
||||
},
|
||||
})
|
||||
|
||||
if err := c.Flush(); err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue