diff options
Diffstat (limited to 'pkg/tcpip/stack')
-rw-r--r-- | pkg/tcpip/stack/iptables.go | 24 | ||||
-rw-r--r-- | pkg/tcpip/stack/iptables_types.go | 64 | ||||
-rw-r--r-- | pkg/tcpip/stack/stack_state_autogen.go | 21 |
3 files changed, 69 insertions, 40 deletions
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go index 09c7811fa..04af933a6 100644 --- a/pkg/tcpip/stack/iptables.go +++ b/pkg/tcpip/stack/iptables.go @@ -267,11 +267,11 @@ const ( // 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. +// which address can be gathered. Currently, address is only needed for +// prerouting. // // Precondition: pkt.NetworkHeader is set. -func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, preroutingAddr tcpip.Address, nicName string) bool { +func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, preroutingAddr tcpip.Address, inNicName, outNicName string) bool { if pkt.NetworkProtocolNumber != header.IPv4ProtocolNumber && pkt.NetworkProtocolNumber != header.IPv6ProtocolNumber { return true } @@ -302,7 +302,7 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, prer table = it.v4Tables[tableID] } ruleIdx := table.BuiltinChains[hook] - switch verdict := it.checkChain(hook, pkt, table, ruleIdx, gso, r, preroutingAddr, nicName); verdict { + switch verdict := it.checkChain(hook, pkt, table, ruleIdx, gso, r, preroutingAddr, inNicName, outNicName); verdict { // If the table returns Accept, move on to the next table. case chainAccept: continue @@ -385,10 +385,10 @@ func (it *IPTables) startReaper(interval time.Duration) { // // NOTE: unlike the Check API the returned map contains packets that should be // dropped. -func (it *IPTables) CheckPackets(hook Hook, pkts PacketBufferList, gso *GSO, r *Route, nicName string) (drop map[*PacketBuffer]struct{}, natPkts map[*PacketBuffer]struct{}) { +func (it *IPTables) CheckPackets(hook Hook, pkts PacketBufferList, gso *GSO, r *Route, inNicName, 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, gso, r, "", nicName); !ok { + if ok := it.Check(hook, pkt, gso, r, "", inNicName, outNicName); !ok { if drop == nil { drop = make(map[*PacketBuffer]struct{}) } @@ -408,11 +408,11 @@ 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, preroutingAddr tcpip.Address, nicName string) chainVerdict { +func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleIdx int, gso *GSO, r *Route, preroutingAddr tcpip.Address, 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, gso, r, preroutingAddr, nicName); verdict { + switch verdict, jumpTo := it.checkRule(hook, pkt, table, ruleIdx, gso, r, preroutingAddr, inNicName, outNicName); verdict { case RuleAccept: return chainAccept @@ -429,7 +429,7 @@ func (it *IPTables) checkChain(hook Hook, pkt *PacketBuffer, table Table, ruleId ruleIdx++ continue } - switch verdict := it.checkChain(hook, pkt, table, jumpTo, gso, r, preroutingAddr, nicName); verdict { + switch verdict := it.checkChain(hook, pkt, table, jumpTo, gso, r, preroutingAddr, inNicName, outNicName); verdict { case chainAccept: return chainAccept case chainDrop: @@ -455,11 +455,11 @@ 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, preroutingAddr 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, inNicName, outNicName string) (RuleVerdict, int) { rule := table.Rules[ruleIdx] // Check whether the packet matches the IP header filter. - if !rule.Filter.match(pkt, hook, nicName) { + if !rule.Filter.match(pkt, hook, inNicName, outNicName) { // Continue on to the next rule. return RuleJump, ruleIdx + 1 } @@ -467,7 +467,7 @@ func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx // Go through each rule matcher. If they all match, run // the rule target. for _, matcher := range rule.Matchers { - matches, hotdrop := matcher.Match(hook, pkt, "") + matches, hotdrop := matcher.Match(hook, pkt, inNicName, outNicName) if hotdrop { return RuleDrop, 0 } diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go index 56a3e7861..fd9d61e39 100644 --- a/pkg/tcpip/stack/iptables_types.go +++ b/pkg/tcpip/stack/iptables_types.go @@ -210,8 +210,19 @@ type IPHeaderFilter struct { // filter will match packets that fail the source comparison. SrcInvert bool - // OutputInterface matches the name of the outgoing interface for the - // packet. + // InputInterface matches the name of the incoming interface for the packet. + InputInterface string + + // InputInterfaceMask masks the characters of the interface name when + // comparing with InputInterface. + InputInterfaceMask string + + // InputInterfaceInvert inverts the meaning of incoming interface check, + // i.e. when true the filter will match packets that fail the incoming + // interface comparison. + InputInterfaceInvert bool + + // OutputInterface matches the name of the outgoing interface for the packet. OutputInterface string // OutputInterfaceMask masks the characters of the interface name when @@ -228,7 +239,7 @@ type IPHeaderFilter struct { // // 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 { +func (fl IPHeaderFilter) match(pkt *PacketBuffer, hook Hook, inNicName, outNicName string) bool { // Extract header fields. var ( // TODO(gvisor.dev/issue/170): Support other filter fields. @@ -264,26 +275,35 @@ func (fl IPHeaderFilter) match(pkt *PacketBuffer, hook Hook, nicName string) boo return false } - // Check the output interface. - // TODO(gvisor.dev/issue/170): Add the check for FORWARD and POSTROUTING - // hooks after supported. - if hook == Output { - n := len(fl.OutputInterface) - if n == 0 { - return true - } - - // If the interface name ends with '+', any interface which - // begins with the name should be matched. - ifName := fl.OutputInterface - matches := nicName == ifName - if strings.HasSuffix(ifName, "+") { - matches = strings.HasPrefix(nicName, ifName[:n-1]) - } - return fl.OutputInterfaceInvert != matches + switch hook { + case Prerouting, Input: + return matchIfName(inNicName, fl.InputInterface, fl.InputInterfaceInvert) + case Output: + return matchIfName(outNicName, fl.OutputInterface, fl.OutputInterfaceInvert) + case Forward, Postrouting: + // TODO(gvisor.dev/issue/170): Add the check for FORWARD and POSTROUTING + // hooks after supported. + return true + default: + panic(fmt.Sprintf("unknown hook: %d", hook)) } +} - return true +func matchIfName(nicName string, ifName string, invert bool) bool { + n := len(ifName) + if n == 0 { + // If the interface name is omitted in the filter, any interface will match. + return true + } + // If the interface name ends with '+', any interface which begins with the + // name should be matched. + var matches bool + if strings.HasSuffix(ifName, "+") { + matches = strings.HasPrefix(nicName, ifName[:n-1]) + } else { + matches = nicName == ifName + } + return matches != invert } // NetworkProtocol returns the protocol (IPv4 or IPv6) on to which the header @@ -320,7 +340,7 @@ type Matcher interface { // used for suspicious packets. // // Precondition: packet.NetworkHeader is set. - Match(hook Hook, packet *PacketBuffer, interfaceName string) (matches bool, hotdrop bool) + Match(hook Hook, packet *PacketBuffer, inputInterfaceName, outputInterfaceName string) (matches bool, hotdrop bool) } // A Target is the interface for taking an action for a packet. diff --git a/pkg/tcpip/stack/stack_state_autogen.go b/pkg/tcpip/stack/stack_state_autogen.go index e22bf506d..271e0f1f4 100644 --- a/pkg/tcpip/stack/stack_state_autogen.go +++ b/pkg/tcpip/stack/stack_state_autogen.go @@ -298,6 +298,9 @@ func (fl *IPHeaderFilter) StateFields() []string { "Src", "SrcMask", "SrcInvert", + "InputInterface", + "InputInterfaceMask", + "InputInterfaceInvert", "OutputInterface", "OutputInterfaceMask", "OutputInterfaceInvert", @@ -316,9 +319,12 @@ func (fl *IPHeaderFilter) StateSave(stateSinkObject state.Sink) { stateSinkObject.Save(5, &fl.Src) stateSinkObject.Save(6, &fl.SrcMask) stateSinkObject.Save(7, &fl.SrcInvert) - stateSinkObject.Save(8, &fl.OutputInterface) - stateSinkObject.Save(9, &fl.OutputInterfaceMask) - stateSinkObject.Save(10, &fl.OutputInterfaceInvert) + stateSinkObject.Save(8, &fl.InputInterface) + stateSinkObject.Save(9, &fl.InputInterfaceMask) + stateSinkObject.Save(10, &fl.InputInterfaceInvert) + stateSinkObject.Save(11, &fl.OutputInterface) + stateSinkObject.Save(12, &fl.OutputInterfaceMask) + stateSinkObject.Save(13, &fl.OutputInterfaceInvert) } func (fl *IPHeaderFilter) afterLoad() {} @@ -332,9 +338,12 @@ func (fl *IPHeaderFilter) StateLoad(stateSourceObject state.Source) { stateSourceObject.Load(5, &fl.Src) stateSourceObject.Load(6, &fl.SrcMask) stateSourceObject.Load(7, &fl.SrcInvert) - stateSourceObject.Load(8, &fl.OutputInterface) - stateSourceObject.Load(9, &fl.OutputInterfaceMask) - stateSourceObject.Load(10, &fl.OutputInterfaceInvert) + stateSourceObject.Load(8, &fl.InputInterface) + stateSourceObject.Load(9, &fl.InputInterfaceMask) + stateSourceObject.Load(10, &fl.InputInterfaceInvert) + stateSourceObject.Load(11, &fl.OutputInterface) + stateSourceObject.Load(12, &fl.OutputInterfaceMask) + stateSourceObject.Load(13, &fl.OutputInterfaceInvert) } func (l *linkAddrEntryList) StateTypeName() string { |