diff options
Diffstat (limited to 'pkg/tcpip/stack/iptables.go')
| -rw-r--r-- | pkg/tcpip/stack/iptables.go | 104 |
1 files changed, 85 insertions, 19 deletions
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go index f152c0d83..74c9075b4 100644 --- a/pkg/tcpip/stack/iptables.go +++ b/pkg/tcpip/stack/iptables.go @@ -264,12 +264,62 @@ const ( chainReturn ) -// Check runs pkt through the rules for hook. It returns true when the packet +// CheckPrerouting performs the prerouting hook on the packet. +// +// Returns true iff the packet may continue traversing the stack; the packet +// must be dropped if false is returned. +// +// Precondition: The packet's network and transport header must be set. +func (it *IPTables) CheckPrerouting(pkt *PacketBuffer, addressEP AddressableEndpoint, inNicName string) bool { + return it.check(Prerouting, pkt, nil /* route */, addressEP, inNicName, "" /* outNicName */) +} + +// CheckInput performs the input hook on the packet. +// +// Returns true iff the packet may continue traversing the stack; the packet +// must be dropped if false is returned. +// +// Precondition: The packet's network and transport header must be set. +func (it *IPTables) CheckInput(pkt *PacketBuffer, inNicName string) bool { + return it.check(Input, pkt, nil /* route */, nil /* addressEP */, inNicName, "" /* outNicName */) +} + +// CheckForward performs the forward hook on the packet. +// +// Returns true iff the packet may continue traversing the stack; the packet +// must be dropped if false is returned. +// +// Precondition: The packet's network and transport header must be set. +func (it *IPTables) CheckForward(pkt *PacketBuffer, inNicName, outNicName string) bool { + return it.check(Forward, pkt, nil /* route */, nil /* addressEP */, inNicName, outNicName) +} + +// CheckOutput performs the output hook on the packet. +// +// Returns true iff the packet may continue traversing the stack; the packet +// must be dropped if false is returned. +// +// Precondition: The packet's network and transport header must be set. +func (it *IPTables) CheckOutput(pkt *PacketBuffer, r *Route, outNicName string) bool { + return it.check(Output, pkt, r, nil /* addressEP */, "" /* inNicName */, outNicName) +} + +// CheckPostrouting performs the postrouting hook on the packet. +// +// Returns true iff the packet may continue traversing the stack; the packet +// must be dropped if false is returned. +// +// Precondition: The packet's network and transport header must be set. +func (it *IPTables) CheckPostrouting(pkt *PacketBuffer, r *Route, outNicName string) bool { + return it.check(Postrouting, pkt, r, nil /* addressEP */, "" /* inNicName */, outNicName) +} + +// 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 *PacketBuffer, r *Route, preroutingAddr tcpip.Address, inNicName, outNicName string) bool { +// Precondition: The packet's network and transport header must be set. +func (it *IPTables) check(hook Hook, pkt *PacketBuffer, r *Route, addressEP AddressableEndpoint, inNicName, outNicName string) bool { if pkt.NetworkProtocolNumber != header.IPv4ProtocolNumber && pkt.NetworkProtocolNumber != header.IPv6ProtocolNumber { return true } @@ -300,7 +350,7 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, r *Route, preroutingAddr table = it.v4Tables[tableID] } ruleIdx := table.BuiltinChains[hook] - switch verdict := it.checkChain(hook, pkt, table, ruleIdx, r, preroutingAddr, inNicName, outNicName); verdict { + switch verdict := it.checkChain(hook, pkt, table, ruleIdx, r, addressEP, inNicName, outNicName); verdict { // If the table returns Accept, move on to the next table. case chainAccept: continue @@ -311,7 +361,7 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, r *Route, preroutingAddr // 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, r, preroutingAddr); v { + switch v, _ := underflow.Target.Action(pkt, &it.connections, hook, r, addressEP); v { case RuleAccept: continue case RuleDrop: @@ -375,19 +425,35 @@ func (it *IPTables) startReaper(interval time.Duration) { }() } -// CheckPackets runs pkts through the rules for hook and returns a map of packets that -// should not go forward. +// CheckOutputPackets performs the output hook on the packets. // -// Preconditions: -// * pkt is a IPv4 packet of at least length header.IPv4MinimumSize. -// * pkt.NetworkHeader is not nil. +// Returns a map of packets that must be dropped. +// +// Precondition: The packets' network and transport header must be set. +func (it *IPTables) CheckOutputPackets(pkts PacketBufferList, r *Route, outNicName string) (drop map[*PacketBuffer]struct{}, natPkts map[*PacketBuffer]struct{}) { + return it.checkPackets(Output, pkts, r, outNicName) +} + +// CheckPostroutingPackets performs the postrouting hook on the packets. +// +// Returns a map of packets that must be dropped. +// +// Precondition: The packets' network and transport header must be set. +func (it *IPTables) CheckPostroutingPackets(pkts PacketBufferList, r *Route, outNicName string) (drop map[*PacketBuffer]struct{}, natPkts map[*PacketBuffer]struct{}) { + return it.checkPackets(Postrouting, pkts, r, outNicName) +} + +// checkPackets runs pkts through the rules for hook and returns a map of +// packets that should not go forward. // // NOTE: unlike the Check API the returned map contains packets that should be // dropped. -func (it *IPTables) CheckPackets(hook Hook, pkts PacketBufferList, r *Route, inNicName, outNicName string) (drop map[*PacketBuffer]struct{}, natPkts map[*PacketBuffer]struct{}) { +// +// Precondition: The packets' network and transport header must be set. +func (it *IPTables) checkPackets(hook Hook, pkts PacketBufferList, r *Route, outNicName string) (drop map[*PacketBuffer]struct{}, natPkts map[*PacketBuffer]struct{}) { for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() { if !pkt.NatDone { - if ok := it.Check(hook, pkt, r, "", inNicName, outNicName); !ok { + if ok := it.check(hook, pkt, r, nil /* addressEP */, "" /* inNicName */, outNicName); !ok { if drop == nil { drop = make(map[*PacketBuffer]struct{}) } @@ -407,11 +473,11 @@ func (it *IPTables) CheckPackets(hook Hook, pkts PacketBufferList, r *Route, inN // 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, r *Route, preroutingAddr tcpip.Address, inNicName, outNicName string) chainVerdict { +func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, r *Route, addressEP AddressableEndpoint, inNicName, outNicName 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, r, preroutingAddr, inNicName, outNicName); verdict { + switch verdict, jumpTo := it.checkRule(hook, pkt, table, ruleIdx, r, addressEP, inNicName, outNicName); verdict { case RuleAccept: return chainAccept @@ -428,7 +494,7 @@ func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleId ruleIdx++ continue } - switch verdict := it.checkChain(hook, pkt, table, jumpTo, r, preroutingAddr, inNicName, outNicName); verdict { + switch verdict := it.checkChain(hook, pkt, table, jumpTo, r, addressEP, inNicName, outNicName); verdict { case chainAccept: return chainAccept case chainDrop: @@ -454,7 +520,7 @@ 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, r *Route, preroutingAddr tcpip.Address, inNicName, outNicName string) (RuleVerdict, int) { +func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, r *Route, addressEP AddressableEndpoint, inNicName, outNicName string) (RuleVerdict, int) { rule := table.Rules[ruleIdx] // Check whether the packet matches the IP header filter. @@ -477,16 +543,16 @@ 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, r, preroutingAddr) + return rule.Target.Action(pkt, &it.connections, hook, r, addressEP) } // OriginalDst returns the original destination of redirected connections. It // returns an error if the connection doesn't exist or isn't redirected. -func (it *IPTables) OriginalDst(epID TransportEndpointID, netProto tcpip.NetworkProtocolNumber) (tcpip.Address, uint16, tcpip.Error) { +func (it *IPTables) OriginalDst(epID TransportEndpointID, netProto tcpip.NetworkProtocolNumber, transProto tcpip.TransportProtocolNumber) (tcpip.Address, uint16, tcpip.Error) { it.mu.RLock() defer it.mu.RUnlock() if !it.modified { return "", 0, &tcpip.ErrNotConnected{} } - return it.connections.originalDst(epID, netProto) + return it.connections.originalDst(epID, netProto, transProto) } |