| // Copyright 2019 The gVisor authors. |
| // |
| // 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 iptables supports packet filtering and manipulation via the iptables |
| // tool. |
| package iptables |
| |
| const ( |
| tablenameNat = "nat" |
| tablenameMangle = "mangle" |
| ) |
| |
| // Chain names as defined by net/ipv4/netfilter/ip_tables.c. |
| const ( |
| chainNamePrerouting = "PREROUTING" |
| chainNameInput = "INPUT" |
| chainNameForward = "FORWARD" |
| chainNameOutput = "OUTPUT" |
| chainNamePostrouting = "POSTROUTING" |
| ) |
| |
| // DefaultTables returns a default set of tables. Each chain is set to accept |
| // all packets. |
| func DefaultTables() IPTables { |
| return IPTables{ |
| Tables: map[string]Table{ |
| tablenameNat: Table{ |
| BuiltinChains: map[Hook]Chain{ |
| Prerouting: unconditionalAcceptChain(chainNamePrerouting), |
| Input: unconditionalAcceptChain(chainNameInput), |
| Output: unconditionalAcceptChain(chainNameOutput), |
| Postrouting: unconditionalAcceptChain(chainNamePostrouting), |
| }, |
| DefaultTargets: map[Hook]Target{ |
| Prerouting: UnconditionalAcceptTarget{}, |
| Input: UnconditionalAcceptTarget{}, |
| Output: UnconditionalAcceptTarget{}, |
| Postrouting: UnconditionalAcceptTarget{}, |
| }, |
| UserChains: map[string]Chain{}, |
| }, |
| tablenameMangle: Table{ |
| BuiltinChains: map[Hook]Chain{ |
| Prerouting: unconditionalAcceptChain(chainNamePrerouting), |
| Output: unconditionalAcceptChain(chainNameOutput), |
| }, |
| DefaultTargets: map[Hook]Target{ |
| Prerouting: UnconditionalAcceptTarget{}, |
| Output: UnconditionalAcceptTarget{}, |
| }, |
| UserChains: map[string]Chain{}, |
| }, |
| }, |
| Priorities: map[Hook][]string{ |
| Prerouting: []string{tablenameMangle, tablenameNat}, |
| Output: []string{tablenameMangle, tablenameNat}, |
| }, |
| } |
| } |
| |
| func unconditionalAcceptChain(name string) Chain { |
| return Chain{ |
| Name: name, |
| Rules: []Rule{ |
| Rule{ |
| Target: UnconditionalAcceptTarget{}, |
| }, |
| }, |
| } |
| } |