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-rw-r--r--pkg/tcpip/stack/iptables.go120
-rw-r--r--pkg/tcpip/stack/iptables_types.go65
-rw-r--r--pkg/tcpip/stack/nic.go3
-rw-r--r--pkg/tcpip/stack/packet_buffer.go2
4 files changed, 147 insertions, 43 deletions
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go
index 0e33cbe92..b6ef04d32 100644
--- a/pkg/tcpip/stack/iptables.go
+++ b/pkg/tcpip/stack/iptables.go
@@ -57,7 +57,72 @@ const reaperDelay = 5 * time.Second
// all packets.
func DefaultTables() *IPTables {
return &IPTables{
- tables: [numTables]Table{
+ v4Tables: [numTables]Table{
+ natID: Table{
+ Rules: []Rule{
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: ErrorTarget{}},
+ },
+ BuiltinChains: [NumHooks]int{
+ Prerouting: 0,
+ Input: 1,
+ Forward: HookUnset,
+ Output: 2,
+ Postrouting: 3,
+ },
+ Underflows: [NumHooks]int{
+ Prerouting: 0,
+ Input: 1,
+ Forward: HookUnset,
+ Output: 2,
+ Postrouting: 3,
+ },
+ },
+ mangleID: Table{
+ Rules: []Rule{
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: ErrorTarget{}},
+ },
+ BuiltinChains: [NumHooks]int{
+ Prerouting: 0,
+ Output: 1,
+ },
+ Underflows: [NumHooks]int{
+ Prerouting: 0,
+ Input: HookUnset,
+ Forward: HookUnset,
+ Output: 1,
+ Postrouting: HookUnset,
+ },
+ },
+ filterID: Table{
+ Rules: []Rule{
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: AcceptTarget{}},
+ Rule{Target: ErrorTarget{}},
+ },
+ BuiltinChains: [NumHooks]int{
+ Prerouting: HookUnset,
+ Input: 0,
+ Forward: 1,
+ Output: 2,
+ Postrouting: HookUnset,
+ },
+ Underflows: [NumHooks]int{
+ Prerouting: HookUnset,
+ Input: 0,
+ Forward: 1,
+ Output: 2,
+ Postrouting: HookUnset,
+ },
+ },
+ },
+ v6Tables: [numTables]Table{
natID: Table{
Rules: []Rule{
Rule{Target: AcceptTarget{}},
@@ -166,25 +231,20 @@ func EmptyNATTable() Table {
// GetTable returns a table by name.
func (it *IPTables) GetTable(name string, ipv6 bool) (Table, bool) {
- // TODO(gvisor.dev/issue/3549): Enable IPv6.
- if ipv6 {
- return Table{}, false
- }
id, ok := nameToID[name]
if !ok {
return Table{}, false
}
it.mu.RLock()
defer it.mu.RUnlock()
- return it.tables[id], true
+ if ipv6 {
+ return it.v6Tables[id], true
+ }
+ return it.v4Tables[id], true
}
// ReplaceTable replaces or inserts table by name.
func (it *IPTables) ReplaceTable(name string, table Table, ipv6 bool) *tcpip.Error {
- // TODO(gvisor.dev/issue/3549): Enable IPv6.
- if ipv6 {
- return tcpip.ErrInvalidOptionValue
- }
id, ok := nameToID[name]
if !ok {
return tcpip.ErrInvalidOptionValue
@@ -198,7 +258,11 @@ func (it *IPTables) ReplaceTable(name string, table Table, ipv6 bool) *tcpip.Err
it.startReaper(reaperDelay)
}
it.modified = true
- it.tables[id] = table
+ if ipv6 {
+ it.v6Tables[id] = table
+ } else {
+ it.v4Tables[id] = table
+ }
return nil
}
@@ -221,8 +285,17 @@ const (
// should continue traversing the network stack and false when it should be
// dropped.
//
+// TODO(gvisor.dev/issue/170): PacketBuffer should hold the GSO and route, from
+// which address and nicName can be gathered. Currently, address is only
+// needed for prerouting and nicName is only needed for output.
+//
+// TODO(gvisor.dev/issue/170): Dropped packets should be counted.
+//
// Precondition: pkt.NetworkHeader is set.
-func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, address tcpip.Address, nicName string) bool {
+func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, preroutingAddr tcpip.Address, nicName string) bool {
+ if pkt.NetworkProtocolNumber != header.IPv4ProtocolNumber && pkt.NetworkProtocolNumber != header.IPv6ProtocolNumber {
+ return true
+ }
// Many users never configure iptables. Spare them the cost of rule
// traversal if rules have never been set.
it.mu.RLock()
@@ -243,9 +316,14 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, addr
if tableID == natID && pkt.NatDone {
continue
}
- table := it.tables[tableID]
+ var table Table
+ if pkt.NetworkProtocolNumber == header.IPv6ProtocolNumber {
+ table = it.v6Tables[tableID]
+ } else {
+ table = it.v4Tables[tableID]
+ }
ruleIdx := table.BuiltinChains[hook]
- switch verdict := it.checkChain(hook, pkt, table, ruleIdx, gso, r, address, nicName); verdict {
+ switch verdict := it.checkChain(hook, pkt, table, ruleIdx, gso, r, preroutingAddr, nicName); verdict {
// If the table returns Accept, move on to the next table.
case chainAccept:
continue
@@ -256,7 +334,7 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, addr
// Any Return from a built-in chain means we have to
// call the underflow.
underflow := table.Rules[table.Underflows[hook]]
- switch v, _ := underflow.Target.Action(pkt, &it.connections, hook, gso, r, address); v {
+ switch v, _ := underflow.Target.Action(pkt, &it.connections, hook, gso, r, preroutingAddr); v {
case RuleAccept:
continue
case RuleDrop:
@@ -351,11 +429,11 @@ func (it *IPTables) CheckPackets(hook Hook, pkts PacketBufferList, gso *GSO, r *
// Preconditions:
// * pkt is a IPv4 packet of at least length header.IPv4MinimumSize.
// * pkt.NetworkHeader is not nil.
-func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, gso *GSO, r *Route, address tcpip.Address, nicName string) chainVerdict {
+func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, gso *GSO, r *Route, preroutingAddr tcpip.Address, nicName string) chainVerdict {
// Start from ruleIdx and walk the list of rules until a rule gives us
// a verdict.
for ruleIdx < len(table.Rules) {
- switch verdict, jumpTo := it.checkRule(hook, pkt, table, ruleIdx, gso, r, address, nicName); verdict {
+ switch verdict, jumpTo := it.checkRule(hook, pkt, table, ruleIdx, gso, r, preroutingAddr, nicName); verdict {
case RuleAccept:
return chainAccept
@@ -372,7 +450,7 @@ func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleId
ruleIdx++
continue
}
- switch verdict := it.checkChain(hook, pkt, table, jumpTo, gso, r, address, nicName); verdict {
+ switch verdict := it.checkChain(hook, pkt, table, jumpTo, gso, r, preroutingAddr, nicName); verdict {
case chainAccept:
return chainAccept
case chainDrop:
@@ -398,11 +476,11 @@ func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleId
// Preconditions:
// * pkt is a IPv4 packet of at least length header.IPv4MinimumSize.
// * pkt.NetworkHeader is not nil.
-func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, gso *GSO, r *Route, address tcpip.Address, nicName string) (RuleVerdict, int) {
+func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, gso *GSO, r *Route, preroutingAddr tcpip.Address, nicName string) (RuleVerdict, int) {
rule := table.Rules[ruleIdx]
// Check whether the packet matches the IP header filter.
- if !rule.Filter.match(header.IPv4(pkt.NetworkHeader().View()), hook, nicName) {
+ if !rule.Filter.match(pkt, hook, nicName) {
// Continue on to the next rule.
return RuleJump, ruleIdx + 1
}
@@ -421,7 +499,7 @@ func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx
}
// All the matchers matched, so run the target.
- return rule.Target.Action(pkt, &it.connections, hook, gso, r, address)
+ return rule.Target.Action(pkt, &it.connections, hook, gso, r, preroutingAddr)
}
// OriginalDst returns the original destination of redirected connections. It
diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go
index fbbd2f50f..093ee6881 100644
--- a/pkg/tcpip/stack/iptables_types.go
+++ b/pkg/tcpip/stack/iptables_types.go
@@ -15,6 +15,7 @@
package stack
import (
+ "fmt"
"strings"
"sync"
@@ -81,26 +82,25 @@ const (
//
// +stateify savable
type IPTables struct {
- // mu protects tables, priorities, and modified.
+ // mu protects v4Tables, v6Tables, and modified.
mu sync.RWMutex
-
- // tables maps tableIDs to tables. Holds builtin tables only, not user
- // tables. mu must be locked for accessing.
- tables [numTables]Table
-
- // priorities maps each hook to a list of table names. The order of the
- // list is the order in which each table should be visited for that
- // hook. mu needs to be locked for accessing.
- priorities [NumHooks][]tableID
-
+ // v4Tables and v6tables map tableIDs to tables. They hold builtin
+ // tables only, not user tables. mu must be locked for accessing.
+ v4Tables [numTables]Table
+ v6Tables [numTables]Table
// modified is whether tables have been modified at least once. It is
// used to elide the iptables performance overhead for workloads that
// don't utilize iptables.
modified bool
+ // priorities maps each hook to a list of table names. The order of the
+ // list is the order in which each table should be visited for that
+ // hook. It is immutable.
+ priorities [NumHooks][]tableID
+
connections ConnTrack
- // reaperDone can be signalled to stop the reaper goroutine.
+ // reaperDone can be signaled to stop the reaper goroutine.
reaperDone chan struct{}
}
@@ -148,7 +148,7 @@ type Rule struct {
Target Target
}
-// IPHeaderFilter holds basic IP filtering data common to every rule.
+// IPHeaderFilter performs basic IP header matching common to every rule.
//
// +stateify savable
type IPHeaderFilter struct {
@@ -196,16 +196,43 @@ type IPHeaderFilter struct {
OutputInterfaceInvert bool
}
-// match returns whether hdr matches the filter.
-func (fl IPHeaderFilter) match(hdr header.IPv4, hook Hook, nicName string) bool {
- // TODO(gvisor.dev/issue/170): Support other fields of the filter.
+// match returns whether pkt matches the filter.
+//
+// Preconditions: pkt.NetworkHeader is set and is at least of the minimal IPv4
+// or IPv6 header length.
+func (fl IPHeaderFilter) match(pkt *PacketBuffer, hook Hook, nicName string) bool {
+ // Extract header fields.
+ var (
+ // TODO(gvisor.dev/issue/170): Support other filter fields.
+ transProto tcpip.TransportProtocolNumber
+ dstAddr tcpip.Address
+ srcAddr tcpip.Address
+ )
+ switch proto := pkt.NetworkProtocolNumber; proto {
+ case header.IPv4ProtocolNumber:
+ hdr := header.IPv4(pkt.NetworkHeader().View())
+ transProto = hdr.TransportProtocol()
+ dstAddr = hdr.DestinationAddress()
+ srcAddr = hdr.SourceAddress()
+
+ case header.IPv6ProtocolNumber:
+ hdr := header.IPv6(pkt.NetworkHeader().View())
+ transProto = hdr.TransportProtocol()
+ dstAddr = hdr.DestinationAddress()
+ srcAddr = hdr.SourceAddress()
+
+ default:
+ panic(fmt.Sprintf("unknown network protocol with EtherType: %d", proto))
+ }
+
// Check the transport protocol.
- if fl.Protocol != 0 && fl.Protocol != hdr.TransportProtocol() {
+ if fl.CheckProtocol && fl.Protocol != transProto {
return false
}
- // Check the source and destination IPs.
- if !filterAddress(hdr.DestinationAddress(), fl.DstMask, fl.Dst, fl.DstInvert) || !filterAddress(hdr.SourceAddress(), fl.SrcMask, fl.Src, fl.SrcInvert) {
+ // Check the addresses.
+ if !filterAddress(dstAddr, fl.DstMask, fl.Dst, fl.DstInvert) ||
+ !filterAddress(srcAddr, fl.SrcMask, fl.Src, fl.SrcInvert) {
return false
}
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 1f1a1426b..821d3feb9 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -1282,9 +1282,8 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
return
}
- // TODO(gvisor.dev/issue/170): Not supporting iptables for IPv6 yet.
// Loopback traffic skips the prerouting chain.
- if protocol == header.IPv4ProtocolNumber && !n.isLoopback() {
+ if !n.isLoopback() {
// iptables filtering.
ipt := n.stack.IPTables()
address := n.primaryAddress(protocol)
diff --git a/pkg/tcpip/stack/packet_buffer.go b/pkg/tcpip/stack/packet_buffer.go
index 17b8beebb..1932aaeb7 100644
--- a/pkg/tcpip/stack/packet_buffer.go
+++ b/pkg/tcpip/stack/packet_buffer.go
@@ -80,7 +80,7 @@ type PacketBuffer struct {
// data are held in the same underlying buffer storage.
header buffer.Prependable
- // NetworkProtocol is only valid when NetworkHeader is set.
+ // NetworkProtocolNumber is only valid when NetworkHeader is set.
// TODO(gvisor.dev/issue/3574): Remove the separately passed protocol
// numbers in registration APIs that take a PacketBuffer.
NetworkProtocolNumber tcpip.NetworkProtocolNumber
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 12:43:15 +0000