Restructure code base into smaller files (#15)
* Restrcture code base into smaller files * Package level doc string * Move ExprsFromMsg back from expr sub-module * gofmt
This commit is contained in:
Ryan Whelan
Michael Stapelberg
parent
07c974e364
commit
7bac3e3135
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@ -0,0 +1,108 @@
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// Copyright 2018 Google LLC. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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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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// limitations under the License.
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package nftables
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import (
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"math"
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"github.com/google/nftables/binaryutil"
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"github.com/mdlayher/netlink"
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"golang.org/x/sys/unix"
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)
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// ChainHook specifies at which step in packet processing the Chain should be
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// executed. See also
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// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Base_chain_hooks
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type ChainHook uint32
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// Possible ChainHook values.
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const (
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ChainHookPrerouting ChainHook = unix.NF_INET_PRE_ROUTING
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ChainHookInput ChainHook = unix.NF_INET_LOCAL_IN
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ChainHookForward ChainHook = unix.NF_INET_FORWARD
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ChainHookOutput ChainHook = unix.NF_INET_LOCAL_OUT
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ChainHookPostrouting ChainHook = unix.NF_INET_POST_ROUTING
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ChainHookIngress ChainHook = unix.NF_NETDEV_INGRESS
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)
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// ChainPriority orders the chain relative to Netfilter internal operations. See
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// also
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// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Base_chain_priority
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type ChainPriority int32
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// Possible ChainPriority values.
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const ( // from /usr/include/linux/netfilter_ipv4.h
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ChainPriorityFirst ChainPriority = math.MinInt32
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ChainPriorityConntrackDefrag ChainPriority = -400
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ChainPriorityRaw ChainPriority = -300
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ChainPrioritySELinuxFirst ChainPriority = -225
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ChainPriorityConntrack ChainPriority = -200
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ChainPriorityMangle ChainPriority = -150
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ChainPriorityNATDest ChainPriority = -100
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ChainPriorityFilter ChainPriority = 0
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ChainPrioritySecurity ChainPriority = 50
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ChainPriorityNATSource ChainPriority = 100
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ChainPrioritySELinuxLast ChainPriority = 225
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ChainPriorityConntrackHelper ChainPriority = 300
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ChainPriorityConntrackConfirm ChainPriority = math.MaxInt32
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ChainPriorityLast ChainPriority = math.MaxInt32
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)
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// ChainType defines what this chain will be used for. See also
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// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Base_chain_types
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type ChainType string
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// Possible ChainType values.
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const (
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ChainTypeFilter ChainType = "filter"
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ChainTypeRoute ChainType = "route"
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ChainTypeNAT ChainType = "nat"
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)
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// A Chain contains Rules. See also
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// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains
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type Chain struct {
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Name string
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Table *Table
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Hooknum ChainHook
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Priority ChainPriority
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Type ChainType
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}
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// AddChain adds the specified Chain. See also
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// https://wiki.nftables.org/wiki-nftables/index.php/Configuring_chains#Adding_base_chains
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func (cc *Conn) AddChain(c *Chain) *Chain {
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chainHook := cc.marshalAttr([]netlink.Attribute{
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{Type: unix.NFTA_HOOK_HOOKNUM, Data: binaryutil.BigEndian.PutUint32(uint32(c.Hooknum))},
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{Type: unix.NFTA_HOOK_PRIORITY, Data: binaryutil.BigEndian.PutUint32(uint32(c.Priority))},
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})
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data := cc.marshalAttr([]netlink.Attribute{
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{Type: unix.NFTA_CHAIN_TABLE, Data: []byte(c.Table.Name + "\x00")},
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{Type: unix.NFTA_CHAIN_NAME, Data: []byte(c.Name + "\x00")},
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{Type: unix.NLA_F_NESTED | unix.NFTA_CHAIN_HOOK, Data: chainHook},
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{Type: unix.NFTA_CHAIN_TYPE, Data: []byte(c.Type + "\x00")},
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})
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cc.messages = append(cc.messages, netlink.Message{
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Header: netlink.Header{
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Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWCHAIN),
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Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
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},
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Data: append(extraHeader(uint8(c.Table.Family), 0), data...),
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})
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return c
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}
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@ -0,0 +1,130 @@
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// Copyright 2018 Google LLC. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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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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// limitations under the License.
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package nftables
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import (
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"fmt"
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"github.com/google/nftables/expr"
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"github.com/mdlayher/netlink"
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"github.com/mdlayher/netlink/nltest"
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"golang.org/x/sys/unix"
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)
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// A Conn represents a netlink connection of the nftables family.
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//
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// All methods return their input, so that variables can be defined from string
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// literals when desired.
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//
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// Commands are buffered. Flush sends all buffered commands in a single batch.
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type Conn struct {
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TestDial nltest.Func // for testing only; passed to nltest.Dial
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NetNS int // Network namespace netlink will interact with.
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messages []netlink.Message
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err error
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}
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// Flush sends all buffered commands in a single batch to nftables.
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func (cc *Conn) Flush() error {
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if cc.err != nil {
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return cc.err // serialization error
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}
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conn, err := cc.dialNetlink()
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if err != nil {
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return err
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}
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defer conn.Close()
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if _, err := conn.SendMessages(batch(cc.messages)); err != nil {
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return fmt.Errorf("SendMessages: %v", err)
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}
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if _, err := conn.Receive(); err != nil {
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return fmt.Errorf("Receive: %v", err)
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}
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cc.messages = nil
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return nil
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}
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// FlushRuleset flushes the entire ruleset. See also
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// https://wiki.nftables.org/wiki-nftables/index.php/Operations_at_ruleset_level
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func (cc *Conn) FlushRuleset() {
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cc.messages = append(cc.messages, netlink.Message{
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Header: netlink.Header{
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Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_DELTABLE),
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Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
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},
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Data: extraHeader(0, 0),
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})
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}
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func (cc *Conn) dialNetlink() (*netlink.Conn, error) {
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if cc.TestDial != nil {
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return nltest.Dial(cc.TestDial), nil
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}
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return netlink.Dial(unix.NETLINK_NETFILTER, &netlink.Config{NetNS: cc.NetNS})
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}
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func (cc *Conn) setErr(err error) {
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if cc.err != nil {
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return
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}
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cc.err = err
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}
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func (cc *Conn) marshalAttr(attrs []netlink.Attribute) []byte {
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b, err := netlink.MarshalAttributes(attrs)
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if err != nil {
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cc.setErr(err)
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return nil
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}
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return b
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}
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func (cc *Conn) marshalExpr(e expr.Any) []byte {
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b, err := expr.Marshal(e)
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if err != nil {
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cc.setErr(err)
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return nil
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}
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return b
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}
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func batch(messages []netlink.Message) []netlink.Message {
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batch := []netlink.Message{
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{
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Header: netlink.Header{
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Type: netlink.HeaderType(unix.NFNL_MSG_BATCH_BEGIN),
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Flags: netlink.Request,
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},
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Data: extraHeader(0, unix.NFNL_SUBSYS_NFTABLES),
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},
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}
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batch = append(batch, messages...)
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batch = append(batch, netlink.Message{
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Header: netlink.Header{
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Type: netlink.HeaderType(unix.NFNL_MSG_BATCH_END),
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Flags: netlink.Request,
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},
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Data: extraHeader(0, unix.NFNL_SUBSYS_NFTABLES),
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})
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return batch
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}
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@ -0,0 +1,66 @@
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// Copyright 2018 Google LLC. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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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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// limitations under the License.
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package nftables
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import (
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"github.com/google/nftables/binaryutil"
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"github.com/mdlayher/netlink"
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"golang.org/x/sys/unix"
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)
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// CounterObj implements Obj.
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type CounterObj struct {
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Table *Table
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Name string // e.g. “fwded”
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Bytes uint64
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Packets uint64
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}
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func (c *CounterObj) unmarshal(ad *netlink.AttributeDecoder) error {
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for ad.Next() {
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switch ad.Type() {
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case unix.NFTA_COUNTER_BYTES:
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c.Bytes = ad.Uint64()
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case unix.NFTA_COUNTER_PACKETS:
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c.Packets = ad.Uint64()
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}
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}
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return ad.Err()
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}
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func (c *CounterObj) family() TableFamily {
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return c.Table.Family
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}
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func (c *CounterObj) marshal(data bool) ([]byte, error) {
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obj, err := netlink.MarshalAttributes([]netlink.Attribute{
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{Type: unix.NFTA_COUNTER_BYTES, Data: binaryutil.BigEndian.PutUint64(c.Bytes)},
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{Type: unix.NFTA_COUNTER_PACKETS, Data: binaryutil.BigEndian.PutUint64(c.Packets)},
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})
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if err != nil {
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return nil, err
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}
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const NFT_OBJECT_COUNTER = 1 // TODO: get into x/sys/unix
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attrs := []netlink.Attribute{
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{Type: unix.NFTA_OBJ_TABLE, Data: []byte(c.Table.Name + "\x00")},
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{Type: unix.NFTA_OBJ_NAME, Data: []byte(c.Name + "\x00")},
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{Type: unix.NFTA_OBJ_TYPE, Data: binaryutil.BigEndian.PutUint32(NFT_OBJECT_COUNTER)},
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}
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if data {
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attrs = append(attrs, netlink.Attribute{Type: unix.NLA_F_NESTED | unix.NFTA_OBJ_DATA, Data: obj})
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}
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return netlink.MarshalAttributes(attrs)
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}
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@ -0,0 +1,16 @@
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// Copyright 2018 Google LLC. All Rights Reserved.
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//
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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.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
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// 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.
|
||||
|
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// Package nftables manipulates Linux nftables (the iptables successor).
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package nftables
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625
nftables.go
625
nftables.go
|
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@ -1,625 +0,0 @@
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// Copyright 2018 Google LLC. All Rights Reserved.
|
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//
|
||||
// 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).
|
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package nftables
|
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|
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import (
|
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"encoding/binary"
|
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"fmt"
|
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"math"
|
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"strings"
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|
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"github.com/google/nftables/binaryutil"
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"github.com/google/nftables/expr"
|
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"github.com/mdlayher/netlink"
|
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"github.com/mdlayher/netlink/nltest"
|
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"golang.org/x/sys/unix"
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)
|
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|
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func extraHeader(family uint8, resID uint16) []byte {
|
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return append([]byte{
|
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family,
|
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unix.NFNETLINK_V0,
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}, binaryutil.BigEndian.PutUint16(resID)...)
|
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}
|
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|
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func batch(messages []netlink.Message) []netlink.Message {
|
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batch := []netlink.Message{
|
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{
|
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Header: netlink.Header{
|
||||
Type: netlink.HeaderType(unix.NFNL_MSG_BATCH_BEGIN),
|
||||
Flags: netlink.Request,
|
||||
},
|
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Data: extraHeader(0, unix.NFNL_SUBSYS_NFTABLES),
|
||||
},
|
||||
}
|
||||
|
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batch = append(batch, messages...)
|
||||
|
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batch = append(batch, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType(unix.NFNL_MSG_BATCH_END),
|
||||
Flags: netlink.Request,
|
||||
},
|
||||
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.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: append(extraHeader(uint8(c.Table.Family), 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
|
||||
}
|
||||
|
||||
var ruleHeaderType = netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWRULE)
|
||||
|
||||
func stringFrom0(b []byte) string {
|
||||
return strings.TrimSuffix(string(b), "\x00")
|
||||
}
|
||||
|
||||
func exprsFromMsg(b []byte) ([]expr.Any, error) {
|
||||
ad, err := netlink.NewAttributeDecoder(b)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var exprs []expr.Any
|
||||
for ad.Next() {
|
||||
ad.Do(func(b []byte) error {
|
||||
ad, err := netlink.NewAttributeDecoder(b)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var name string
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_EXPR_NAME:
|
||||
name = ad.String()
|
||||
case unix.NFTA_EXPR_DATA:
|
||||
var e expr.Any
|
||||
switch name {
|
||||
case "meta":
|
||||
e = &expr.Meta{}
|
||||
case "cmp":
|
||||
e = &expr.Cmp{}
|
||||
case "counter":
|
||||
e = &expr.Counter{}
|
||||
case "payload":
|
||||
e = &expr.Payload{}
|
||||
case "lookup":
|
||||
e = &expr.Lookup{}
|
||||
case "immediate":
|
||||
e = &expr.Immediate{}
|
||||
}
|
||||
if e == nil {
|
||||
// TODO: introduce an opaque expression type so that users know
|
||||
// something is here.
|
||||
continue // unsupported expression type
|
||||
}
|
||||
|
||||
ad.Do(func(b []byte) error {
|
||||
if err := expr.Unmarshal(b, e); err != nil {
|
||||
return err
|
||||
}
|
||||
// Verdict expressions are a special-case of immediate expressions, so
|
||||
// if the expression is an immediate writing nothing into the verdict
|
||||
// register (invalid), re-parse it as a verdict expression.
|
||||
if imm, isImmediate := e.(*expr.Immediate); isImmediate && imm.Register == unix.NFT_REG_VERDICT && len(imm.Data) == 0 {
|
||||
e = &expr.Verdict{}
|
||||
if err := expr.Unmarshal(b, e); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
exprs = append(exprs, e)
|
||||
return nil
|
||||
})
|
||||
}
|
||||
}
|
||||
return ad.Err()
|
||||
})
|
||||
}
|
||||
return exprs, ad.Err()
|
||||
}
|
||||
|
||||
func ruleFromMsg(msg netlink.Message) (*Rule, error) {
|
||||
if got, want := msg.Header.Type, ruleHeaderType; got != want {
|
||||
return nil, fmt.Errorf("unexpected header type: got %v, want %v", got, want)
|
||||
}
|
||||
ad, err := netlink.NewAttributeDecoder(msg.Data[4:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var r Rule
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_RULE_TABLE:
|
||||
r.Table = &Table{Name: ad.String()}
|
||||
case unix.NFTA_RULE_CHAIN:
|
||||
r.Chain = &Chain{Name: ad.String()}
|
||||
case unix.NFTA_RULE_EXPRESSIONS:
|
||||
ad.Do(func(b []byte) error {
|
||||
r.Exprs, err = exprsFromMsg(b)
|
||||
return err
|
||||
})
|
||||
}
|
||||
}
|
||||
return &r, ad.Err()
|
||||
}
|
||||
|
||||
// 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: ruleHeaderType,
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: append(extraHeader(uint8(r.Table.Family), 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
|
||||
NetNS int // Network namespace netlink will interact with.
|
||||
messages []netlink.Message
|
||||
err error
|
||||
}
|
||||
|
||||
// FlushRuleset flushes the entire ruleset. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Operations_at_ruleset_level
|
||||
func (cc *Conn) FlushRuleset() {
|
||||
cc.messages = append(cc.messages, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_DELTABLE),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: extraHeader(0, 0),
|
||||
})
|
||||
}
|
||||
|
||||
// DelTable deletes a specific table, along with all chains/rules it contains.
|
||||
func (cc *Conn) DelTable(t *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_DELTABLE),
|
||||
Flags: netlink.Request | netlink.Acknowledge,
|
||||
},
|
||||
Data: append(extraHeader(uint8(t.Family), 0), data...),
|
||||
})
|
||||
}
|
||||
|
||||
// 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.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
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
|
||||
}
|
||||
conn, err := cc.dialNetlink()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
defer conn.Close()
|
||||
|
||||
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
|
||||
}
|
||||
|
||||
// GetRule returns the rules in the specified table and chain.
|
||||
func (cc *Conn) GetRule(t *Table, c *Chain) ([]*Rule, error) {
|
||||
conn, err := cc.dialNetlink()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer conn.Close()
|
||||
|
||||
data, err := netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_RULE_TABLE, Data: []byte(t.Name + "\x00")},
|
||||
{Type: unix.NFTA_RULE_CHAIN, Data: []byte(c.Name + "\x00")},
|
||||
})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
message := netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_GETRULE),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Dump,
|
||||
},
|
||||
Data: append(extraHeader(uint8(t.Family), 0), data...),
|
||||
}
|
||||
|
||||
if _, err := conn.SendMessages([]netlink.Message{message}); err != nil {
|
||||
return nil, fmt.Errorf("SendMessages: %v", err)
|
||||
}
|
||||
|
||||
reply, err := conn.Receive()
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("Receive: %v", err)
|
||||
}
|
||||
var rules []*Rule
|
||||
for _, msg := range reply {
|
||||
r, err := ruleFromMsg(msg)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
rules = append(rules, r)
|
||||
}
|
||||
|
||||
return rules, nil
|
||||
}
|
||||
|
||||
// CounterObj implements Obj.
|
||||
type CounterObj struct {
|
||||
Table *Table
|
||||
Name string // e.g. “fwded”
|
||||
|
||||
Bytes uint64
|
||||
Packets uint64
|
||||
}
|
||||
|
||||
func (c *CounterObj) unmarshal(ad *netlink.AttributeDecoder) error {
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_COUNTER_BYTES:
|
||||
c.Bytes = ad.Uint64()
|
||||
case unix.NFTA_COUNTER_PACKETS:
|
||||
c.Packets = ad.Uint64()
|
||||
}
|
||||
}
|
||||
return ad.Err()
|
||||
}
|
||||
|
||||
func (c *CounterObj) family() TableFamily {
|
||||
return c.Table.Family
|
||||
}
|
||||
|
||||
func (c *CounterObj) marshal(data bool) ([]byte, error) {
|
||||
obj, err := netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_COUNTER_BYTES, Data: binaryutil.BigEndian.PutUint64(c.Bytes)},
|
||||
{Type: unix.NFTA_COUNTER_PACKETS, Data: binaryutil.BigEndian.PutUint64(c.Packets)},
|
||||
})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
const NFT_OBJECT_COUNTER = 1 // TODO: get into x/sys/unix
|
||||
attrs := []netlink.Attribute{
|
||||
{Type: unix.NFTA_OBJ_TABLE, Data: []byte(c.Table.Name + "\x00")},
|
||||
{Type: unix.NFTA_OBJ_NAME, Data: []byte(c.Name + "\x00")},
|
||||
{Type: unix.NFTA_OBJ_TYPE, Data: binaryutil.BigEndian.PutUint32(NFT_OBJECT_COUNTER)},
|
||||
}
|
||||
if data {
|
||||
attrs = append(attrs, netlink.Attribute{Type: unix.NLA_F_NESTED | unix.NFTA_OBJ_DATA, Data: obj})
|
||||
}
|
||||
return netlink.MarshalAttributes(attrs)
|
||||
}
|
||||
|
||||
// Obj represents a netfilter stateful object. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Stateful_objects
|
||||
type Obj interface {
|
||||
family() TableFamily
|
||||
unmarshal(*netlink.AttributeDecoder) error
|
||||
marshal(data bool) ([]byte, error)
|
||||
}
|
||||
|
||||
// AddObj adds the specified Obj. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Stateful_objects
|
||||
func (cc *Conn) AddObj(o Obj) Obj {
|
||||
data, err := o.marshal(true)
|
||||
if err != nil {
|
||||
cc.setErr(err)
|
||||
return nil
|
||||
}
|
||||
|
||||
cc.messages = append(cc.messages, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWOBJ),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: append(extraHeader(uint8(o.family()), 0), data...),
|
||||
})
|
||||
return o
|
||||
}
|
||||
|
||||
var objHeaderType = netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWOBJ)
|
||||
|
||||
func objFromMsg(msg netlink.Message) (Obj, error) {
|
||||
if got, want := msg.Header.Type, objHeaderType; got != want {
|
||||
return nil, fmt.Errorf("unexpected header type: got %v, want %v", got, want)
|
||||
}
|
||||
ad, err := netlink.NewAttributeDecoder(msg.Data[4:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var (
|
||||
table *Table
|
||||
name string
|
||||
objectType uint32
|
||||
)
|
||||
const NFT_OBJECT_COUNTER = 1 // TODO: get into x/sys/unix
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_OBJ_TABLE:
|
||||
table = &Table{Name: ad.String(), Family: TableFamily(msg.Data[0])}
|
||||
case unix.NFTA_OBJ_NAME:
|
||||
name = ad.String()
|
||||
case unix.NFTA_OBJ_TYPE:
|
||||
objectType = ad.Uint32()
|
||||
case unix.NFTA_OBJ_DATA:
|
||||
switch objectType {
|
||||
case NFT_OBJECT_COUNTER:
|
||||
o := CounterObj{
|
||||
Table: table,
|
||||
Name: name,
|
||||
}
|
||||
|
||||
ad.Do(func(b []byte) error {
|
||||
ad, err := netlink.NewAttributeDecoder(b)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
return o.unmarshal(ad)
|
||||
})
|
||||
return &o, ad.Err()
|
||||
}
|
||||
}
|
||||
}
|
||||
if err := ad.Err(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return nil, fmt.Errorf("malformed stateful object")
|
||||
}
|
||||
|
||||
func (cc *Conn) dialNetlink() (*netlink.Conn, error) {
|
||||
if cc.TestDial != nil {
|
||||
return nltest.Dial(cc.TestDial), nil
|
||||
}
|
||||
return netlink.Dial(unix.NETLINK_NETFILTER, &netlink.Config{NetNS: cc.NetNS})
|
||||
}
|
||||
|
||||
func (cc *Conn) getObj(o Obj, msgType uint16) ([]Obj, error) {
|
||||
conn, err := cc.dialNetlink()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer conn.Close()
|
||||
|
||||
data, err := o.marshal(false)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
message := netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | msgType),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Dump,
|
||||
},
|
||||
Data: append(extraHeader(uint8(o.family()), 0), data...),
|
||||
}
|
||||
|
||||
if _, err := conn.SendMessages([]netlink.Message{message}); err != nil {
|
||||
return nil, fmt.Errorf("SendMessages: %v", err)
|
||||
}
|
||||
|
||||
reply, err := conn.Receive()
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("Receive: %v", err)
|
||||
}
|
||||
var objs []Obj
|
||||
for _, msg := range reply {
|
||||
o, err := objFromMsg(msg)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
objs = append(objs, o)
|
||||
}
|
||||
|
||||
return objs, nil
|
||||
}
|
||||
|
||||
// GetObj gets the specified Obj without resetting it.
|
||||
func (cc *Conn) GetObj(o Obj) ([]Obj, error) {
|
||||
return cc.getObj(o, unix.NFT_MSG_GETOBJ)
|
||||
}
|
||||
|
||||
// GetObjReset gets the specified Obj and resets it.
|
||||
func (cc *Conn) GetObjReset(o Obj) ([]Obj, error) {
|
||||
return cc.getObj(o, unix.NFT_MSG_GETOBJ_RESET)
|
||||
}
|
||||
|
|
@ -0,0 +1,151 @@
|
|||
// 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 (
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
|
||||
"github.com/mdlayher/netlink"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
var objHeaderType = netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWOBJ)
|
||||
|
||||
// Obj represents a netfilter stateful object. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Stateful_objects
|
||||
type Obj interface {
|
||||
family() TableFamily
|
||||
unmarshal(*netlink.AttributeDecoder) error
|
||||
marshal(data bool) ([]byte, error)
|
||||
}
|
||||
|
||||
// AddObj adds the specified Obj. See also
|
||||
// https://wiki.nftables.org/wiki-nftables/index.php/Stateful_objects
|
||||
func (cc *Conn) AddObj(o Obj) Obj {
|
||||
data, err := o.marshal(true)
|
||||
if err != nil {
|
||||
cc.setErr(err)
|
||||
return nil
|
||||
}
|
||||
|
||||
cc.messages = append(cc.messages, netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWOBJ),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: append(extraHeader(uint8(o.family()), 0), data...),
|
||||
})
|
||||
return o
|
||||
}
|
||||
|
||||
// GetObj gets the specified Obj without resetting it.
|
||||
func (cc *Conn) GetObj(o Obj) ([]Obj, error) {
|
||||
return cc.getObj(o, unix.NFT_MSG_GETOBJ)
|
||||
}
|
||||
|
||||
// GetObjReset gets the specified Obj and resets it.
|
||||
func (cc *Conn) GetObjReset(o Obj) ([]Obj, error) {
|
||||
return cc.getObj(o, unix.NFT_MSG_GETOBJ_RESET)
|
||||
}
|
||||
|
||||
func objFromMsg(msg netlink.Message) (Obj, error) {
|
||||
if got, want := msg.Header.Type, objHeaderType; got != want {
|
||||
return nil, fmt.Errorf("unexpected header type: got %v, want %v", got, want)
|
||||
}
|
||||
ad, err := netlink.NewAttributeDecoder(msg.Data[4:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var (
|
||||
table *Table
|
||||
name string
|
||||
objectType uint32
|
||||
)
|
||||
const NFT_OBJECT_COUNTER = 1 // TODO: get into x/sys/unix
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_OBJ_TABLE:
|
||||
table = &Table{Name: ad.String(), Family: TableFamily(msg.Data[0])}
|
||||
case unix.NFTA_OBJ_NAME:
|
||||
name = ad.String()
|
||||
case unix.NFTA_OBJ_TYPE:
|
||||
objectType = ad.Uint32()
|
||||
case unix.NFTA_OBJ_DATA:
|
||||
switch objectType {
|
||||
case NFT_OBJECT_COUNTER:
|
||||
o := CounterObj{
|
||||
Table: table,
|
||||
Name: name,
|
||||
}
|
||||
|
||||
ad.Do(func(b []byte) error {
|
||||
ad, err := netlink.NewAttributeDecoder(b)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
return o.unmarshal(ad)
|
||||
})
|
||||
return &o, ad.Err()
|
||||
}
|
||||
}
|
||||
}
|
||||
if err := ad.Err(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return nil, fmt.Errorf("malformed stateful object")
|
||||
}
|
||||
|
||||
func (cc *Conn) getObj(o Obj, msgType uint16) ([]Obj, error) {
|
||||
conn, err := cc.dialNetlink()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer conn.Close()
|
||||
|
||||
data, err := o.marshal(false)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
message := netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | msgType),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Dump,
|
||||
},
|
||||
Data: append(extraHeader(uint8(o.family()), 0), data...),
|
||||
}
|
||||
|
||||
if _, err := conn.SendMessages([]netlink.Message{message}); err != nil {
|
||||
return nil, fmt.Errorf("SendMessages: %v", err)
|
||||
}
|
||||
|
||||
reply, err := conn.Receive()
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("Receive: %v", err)
|
||||
}
|
||||
var objs []Obj
|
||||
for _, msg := range reply {
|
||||
o, err := objFromMsg(msg)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
objs = append(objs, o)
|
||||
}
|
||||
|
||||
return objs, nil
|
||||
}
|
||||
|
|
@ -0,0 +1,197 @@
|
|||
// 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 (
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
|
||||
"github.com/google/nftables/expr"
|
||||
"github.com/mdlayher/netlink"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
var ruleHeaderType = netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_NEWRULE)
|
||||
|
||||
// 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
|
||||
}
|
||||
|
||||
// GetRule returns the rules in the specified table and chain.
|
||||
func (cc *Conn) GetRule(t *Table, c *Chain) ([]*Rule, error) {
|
||||
conn, err := cc.dialNetlink()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer conn.Close()
|
||||
|
||||
data, err := netlink.MarshalAttributes([]netlink.Attribute{
|
||||
{Type: unix.NFTA_RULE_TABLE, Data: []byte(t.Name + "\x00")},
|
||||
{Type: unix.NFTA_RULE_CHAIN, Data: []byte(c.Name + "\x00")},
|
||||
})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
message := netlink.Message{
|
||||
Header: netlink.Header{
|
||||
Type: netlink.HeaderType((unix.NFNL_SUBSYS_NFTABLES << 8) | unix.NFT_MSG_GETRULE),
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Dump,
|
||||
},
|
||||
Data: append(extraHeader(uint8(t.Family), 0), data...),
|
||||
}
|
||||
|
||||
if _, err := conn.SendMessages([]netlink.Message{message}); err != nil {
|
||||
return nil, fmt.Errorf("SendMessages: %v", err)
|
||||
}
|
||||
|
||||
reply, err := conn.Receive()
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("Receive: %v", err)
|
||||
}
|
||||
var rules []*Rule
|
||||
for _, msg := range reply {
|
||||
r, err := ruleFromMsg(msg)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
rules = append(rules, r)
|
||||
}
|
||||
|
||||
return rules, nil
|
||||
}
|
||||
|
||||
// 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: ruleHeaderType,
|
||||
Flags: netlink.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: append(extraHeader(uint8(r.Table.Family), 0), data...),
|
||||
})
|
||||
|
||||
return r
|
||||
}
|
||||
|
||||
func exprsFromMsg(b []byte) ([]expr.Any, error) {
|
||||
ad, err := netlink.NewAttributeDecoder(b)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var exprs []expr.Any
|
||||
for ad.Next() {
|
||||
ad.Do(func(b []byte) error {
|
||||
ad, err := netlink.NewAttributeDecoder(b)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var name string
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_EXPR_NAME:
|
||||
name = ad.String()
|
||||
case unix.NFTA_EXPR_DATA:
|
||||
var e expr.Any
|
||||
switch name {
|
||||
case "meta":
|
||||
e = &expr.Meta{}
|
||||
case "cmp":
|
||||
e = &expr.Cmp{}
|
||||
case "counter":
|
||||
e = &expr.Counter{}
|
||||
case "payload":
|
||||
e = &expr.Payload{}
|
||||
case "lookup":
|
||||
e = &expr.Lookup{}
|
||||
case "immediate":
|
||||
e = &expr.Immediate{}
|
||||
}
|
||||
if e == nil {
|
||||
// TODO: introduce an opaque expression type so that users know
|
||||
// something is here.
|
||||
continue // unsupported expression type
|
||||
}
|
||||
|
||||
ad.Do(func(b []byte) error {
|
||||
if err := expr.Unmarshal(b, e); err != nil {
|
||||
return err
|
||||
}
|
||||
// Verdict expressions are a special-case of immediate expressions, so
|
||||
// if the expression is an immediate writing nothing into the verdict
|
||||
// register (invalid), re-parse it as a verdict expression.
|
||||
if imm, isImmediate := e.(*expr.Immediate); isImmediate && imm.Register == unix.NFT_REG_VERDICT && len(imm.Data) == 0 {
|
||||
e = &expr.Verdict{}
|
||||
if err := expr.Unmarshal(b, e); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
exprs = append(exprs, e)
|
||||
return nil
|
||||
})
|
||||
}
|
||||
}
|
||||
return ad.Err()
|
||||
})
|
||||
}
|
||||
return exprs, ad.Err()
|
||||
}
|
||||
|
||||
func ruleFromMsg(msg netlink.Message) (*Rule, error) {
|
||||
if got, want := msg.Header.Type, ruleHeaderType; got != want {
|
||||
return nil, fmt.Errorf("unexpected header type: got %v, want %v", got, want)
|
||||
}
|
||||
ad, err := netlink.NewAttributeDecoder(msg.Data[4:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ad.ByteOrder = binary.BigEndian
|
||||
var r Rule
|
||||
for ad.Next() {
|
||||
switch ad.Type() {
|
||||
case unix.NFTA_RULE_TABLE:
|
||||
r.Table = &Table{Name: ad.String()}
|
||||
case unix.NFTA_RULE_CHAIN:
|
||||
r.Chain = &Chain{Name: ad.String()}
|
||||
case unix.NFTA_RULE_EXPRESSIONS:
|
||||
ad.Do(func(b []byte) error {
|
||||
r.Exprs, err = exprsFromMsg(b)
|
||||
return err
|
||||
})
|
||||
}
|
||||
}
|
||||
return &r, ad.Err()
|
||||
}
|
||||
|
|
@ -0,0 +1,68 @@
|
|||
// 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/mdlayher/netlink"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
// 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
|
||||
}
|
||||
|
||||
// DelTable deletes a specific table, along with all chains/rules it contains.
|
||||
func (cc *Conn) DelTable(t *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_DELTABLE),
|
||||
Flags: netlink.Request | netlink.Acknowledge,
|
||||
},
|
||||
Data: append(extraHeader(uint8(t.Family), 0), data...),
|
||||
})
|
||||
}
|
||||
|
||||
// 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.Request | netlink.Acknowledge | netlink.Create,
|
||||
},
|
||||
Data: append(extraHeader(uint8(t.Family), 0), data...),
|
||||
})
|
||||
return t
|
||||
}
|
||||
|
|
@ -0,0 +1,27 @@
|
|||
// 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/binaryutil"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
func extraHeader(family uint8, resID uint16) []byte {
|
||||
return append([]byte{
|
||||
family,
|
||||
unix.NFNETLINK_V0,
|
||||
}, binaryutil.BigEndian.PutUint16(resID)...)
|
||||
}
|
||||
Loading…
Reference in New Issue