diff options
Diffstat (limited to 'pkg/tcpip/iptables/iptables.go')
| -rw-r--r-- | pkg/tcpip/iptables/iptables.go | 236 |
1 files changed, 0 insertions, 236 deletions
diff --git a/pkg/tcpip/iptables/iptables.go b/pkg/tcpip/iptables/iptables.go deleted file mode 100644 index 75a433a3b..000000000 --- a/pkg/tcpip/iptables/iptables.go +++ /dev/null @@ -1,236 +0,0 @@ -// 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 - -import ( - "fmt" - - "gvisor.dev/gvisor/pkg/tcpip" - "gvisor.dev/gvisor/pkg/tcpip/header" -) - -// Table names. -const ( - TablenameNat = "nat" - TablenameMangle = "mangle" - TablenameFilter = "filter" -) - -// Chain names as defined by net/ipv4/netfilter/ip_tables.c. -const ( - ChainNamePrerouting = "PREROUTING" - ChainNameInput = "INPUT" - ChainNameForward = "FORWARD" - ChainNameOutput = "OUTPUT" - ChainNamePostrouting = "POSTROUTING" -) - -// HookUnset indicates that there is no hook set for an entrypoint or -// underflow. -const HookUnset = -1 - -// DefaultTables returns a default set of tables. Each chain is set to accept -// all packets. -func DefaultTables() IPTables { - // TODO(gvisor.dev/issue/170): We may be able to swap out some strings for - // iotas. - return IPTables{ - Tables: map[string]Table{ - TablenameNat: Table{ - Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, - }, - BuiltinChains: map[Hook]int{ - Prerouting: 0, - Input: 1, - Output: 2, - Postrouting: 3, - }, - Underflows: map[Hook]int{ - Prerouting: 0, - Input: 1, - Output: 2, - Postrouting: 3, - }, - UserChains: map[string]int{}, - }, - TablenameMangle: Table{ - Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, - }, - BuiltinChains: map[Hook]int{ - Prerouting: 0, - Output: 1, - }, - Underflows: map[Hook]int{ - Prerouting: 0, - Output: 1, - }, - UserChains: map[string]int{}, - }, - TablenameFilter: Table{ - Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, - }, - BuiltinChains: map[Hook]int{ - Input: 0, - Forward: 1, - Output: 2, - }, - Underflows: map[Hook]int{ - Input: 0, - Forward: 1, - Output: 2, - }, - UserChains: map[string]int{}, - }, - }, - Priorities: map[Hook][]string{ - Input: []string{TablenameNat, TablenameFilter}, - Prerouting: []string{TablenameMangle, TablenameNat}, - Output: []string{TablenameMangle, TablenameNat, TablenameFilter}, - }, - } -} - -// EmptyFilterTable returns a Table with no rules and the filter table chains -// mapped to HookUnset. -func EmptyFilterTable() Table { - return Table{ - Rules: []Rule{}, - BuiltinChains: map[Hook]int{ - Input: HookUnset, - Forward: HookUnset, - Output: HookUnset, - }, - Underflows: map[Hook]int{ - Input: HookUnset, - Forward: HookUnset, - Output: HookUnset, - }, - UserChains: map[string]int{}, - } -} - -// Check runs pkt through the rules for hook. It returns true when the packet -// should continue traversing the network stack and false when it should be -// dropped. -// -// Precondition: pkt.NetworkHeader is set. -func (it *IPTables) Check(hook Hook, pkt tcpip.PacketBuffer) bool { - // TODO(gvisor.dev/issue/170): A lot of this is uncomplicated because - // we're missing features. Jumps, the call stack, etc. aren't checked - // for yet because we're yet to support them. - - // Go through each table containing the hook. - for _, tablename := range it.Priorities[hook] { - switch verdict := it.checkTable(hook, pkt, tablename); verdict { - // If the table returns Accept, move on to the next table. - case TableAccept: - continue - // The Drop verdict is final. - case TableDrop: - return false - default: - panic(fmt.Sprintf("Unknown verdict %v.", verdict)) - } - } - - // Every table returned Accept. - return true -} - -// Precondition: pkt.NetworkHeader is set. -func (it *IPTables) checkTable(hook Hook, pkt tcpip.PacketBuffer, tablename string) TableVerdict { - // Start from ruleIdx and walk the list of rules until a rule gives us - // a verdict. - table := it.Tables[tablename] - for ruleIdx := table.BuiltinChains[hook]; ruleIdx < len(table.Rules); ruleIdx++ { - switch verdict := it.checkRule(hook, pkt, table, ruleIdx); verdict { - case RuleAccept: - return TableAccept - - case RuleDrop: - return TableDrop - - case RuleContinue: - continue - - case RuleReturn: - // TODO(gvisor.dev/issue/170): We don't implement jump - // yet, so any Return is from a built-in chain. That - // means we have to to call the underflow. - underflow := table.Rules[table.Underflows[hook]] - // Underflow is guaranteed to be an unconditional - // ACCEPT or DROP. - switch v, _ := underflow.Target.Action(pkt); v { - case RuleAccept: - return TableAccept - case RuleDrop: - return TableDrop - case RuleContinue, RuleReturn: - panic("Underflows should only return RuleAccept or RuleDrop.") - default: - panic(fmt.Sprintf("Unknown verdict: %d", v)) - } - - default: - panic(fmt.Sprintf("Unknown verdict: %d", verdict)) - } - - } - - // We got through the entire table without a decision. Default to DROP - // for safety. - return TableDrop -} - -// Precondition: pk.NetworkHeader is set. -func (it *IPTables) checkRule(hook Hook, pkt tcpip.PacketBuffer, table Table, ruleIdx int) RuleVerdict { - rule := table.Rules[ruleIdx] - - // First check whether the packet matches the IP header filter. - // TODO(gvisor.dev/issue/170): Support other fields of the filter. - if rule.Filter.Protocol != 0 && rule.Filter.Protocol != header.IPv4(pkt.NetworkHeader).TransportProtocol() { - return RuleContinue - } - - // Go through each rule matcher. If they all match, run - // the rule target. - for _, matcher := range rule.Matchers { - matches, hotdrop := matcher.Match(hook, pkt, "") - if hotdrop { - return RuleDrop - } - if !matches { - return RuleContinue - } - } - - // All the matchers matched, so run the target. - verdict, _ := rule.Target.Action(pkt) - return verdict -} |