diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4')
| -rw-r--r-- | pkg/tcpip/network/ipv4/icmp.go | 89 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 28 |
2 files changed, 66 insertions, 51 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go index 2aa38eb98..d51c36f19 100644 --- a/pkg/tcpip/network/ipv4/icmp.go +++ b/pkg/tcpip/network/ipv4/icmp.go @@ -240,12 +240,6 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { case header.ICMPv4Echo: received.echoRequest.Increment() - sent := e.stats.icmp.packetsSent - if !e.protocol.stack.AllowICMPMessage() { - sent.rateLimited.Increment() - return - } - // DeliverTransportPacket will take ownership of pkt so don't use it beyond // this point. Make a deep copy of the data before pkt gets sent as we will // be modifying fields. @@ -281,6 +275,12 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { } defer r.Release() + sent := e.stats.icmp.packetsSent + if !e.protocol.allowICMPReply(header.ICMPv4EchoReply, header.ICMPv4UnusedCode) { + sent.rateLimited.Increment() + return + } + // TODO(gvisor.dev/issue/3810:) When adding protocol numbers into the // header information, we may have to change this code to handle the // ICMP header no longer being in the data buffer. @@ -562,13 +562,6 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip return &tcpip.ErrNotConnected{} } - sent := netEP.stats.icmp.packetsSent - - if !p.stack.AllowICMPMessage() { - sent.rateLimited.Increment() - return nil - } - transportHeader := pkt.TransportHeader().View() // Don't respond to icmp error packets. @@ -606,6 +599,35 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip } } + sent := netEP.stats.icmp.packetsSent + icmpType, icmpCode, counter, pointer := func() (header.ICMPv4Type, header.ICMPv4Code, tcpip.MultiCounterStat, byte) { + switch reason := reason.(type) { + case *icmpReasonPortUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4PortUnreachable, sent.dstUnreachable, 0 + case *icmpReasonProtoUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4ProtoUnreachable, sent.dstUnreachable, 0 + case *icmpReasonNetworkUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4NetUnreachable, sent.dstUnreachable, 0 + case *icmpReasonHostUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4HostUnreachable, sent.dstUnreachable, 0 + case *icmpReasonFragmentationNeeded: + return header.ICMPv4DstUnreachable, header.ICMPv4FragmentationNeeded, sent.dstUnreachable, 0 + case *icmpReasonTTLExceeded: + return header.ICMPv4TimeExceeded, header.ICMPv4TTLExceeded, sent.timeExceeded, 0 + case *icmpReasonReassemblyTimeout: + return header.ICMPv4TimeExceeded, header.ICMPv4ReassemblyTimeout, sent.timeExceeded, 0 + case *icmpReasonParamProblem: + return header.ICMPv4ParamProblem, header.ICMPv4UnusedCode, sent.paramProblem, reason.pointer + default: + panic(fmt.Sprintf("unsupported ICMP type %T", reason)) + } + }() + + if !p.allowICMPReply(icmpType, icmpCode) { + sent.rateLimited.Increment() + return nil + } + // Now work out how much of the triggering packet we should return. // As per RFC 1812 Section 4.3.2.3 // @@ -658,44 +680,9 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip icmpPkt.TransportProtocolNumber = header.ICMPv4ProtocolNumber icmpHdr := header.ICMPv4(icmpPkt.TransportHeader().Push(header.ICMPv4MinimumSize)) - var counter tcpip.MultiCounterStat - switch reason := reason.(type) { - case *icmpReasonPortUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4PortUnreachable) - counter = sent.dstUnreachable - case *icmpReasonProtoUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4ProtoUnreachable) - counter = sent.dstUnreachable - case *icmpReasonNetworkUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4NetUnreachable) - counter = sent.dstUnreachable - case *icmpReasonHostUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4HostUnreachable) - counter = sent.dstUnreachable - case *icmpReasonFragmentationNeeded: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4FragmentationNeeded) - counter = sent.dstUnreachable - case *icmpReasonTTLExceeded: - icmpHdr.SetType(header.ICMPv4TimeExceeded) - icmpHdr.SetCode(header.ICMPv4TTLExceeded) - counter = sent.timeExceeded - case *icmpReasonReassemblyTimeout: - icmpHdr.SetType(header.ICMPv4TimeExceeded) - icmpHdr.SetCode(header.ICMPv4ReassemblyTimeout) - counter = sent.timeExceeded - case *icmpReasonParamProblem: - icmpHdr.SetType(header.ICMPv4ParamProblem) - icmpHdr.SetCode(header.ICMPv4UnusedCode) - icmpHdr.SetPointer(reason.pointer) - counter = sent.paramProblem - default: - panic(fmt.Sprintf("unsupported ICMP type %T", reason)) - } + icmpHdr.SetCode(icmpCode) + icmpHdr.SetType(icmpType) + icmpHdr.SetPointer(pointer) icmpHdr.SetChecksum(header.ICMPv4Checksum(icmpHdr, icmpPkt.Data().AsRange().Checksum())) if err := route.WritePacket( diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 63223bc92..25f5a52e3 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -1215,6 +1215,9 @@ type protocol struct { // eps is keyed by NICID to allow protocol methods to retrieve an endpoint // when handling a packet, by looking at which NIC handled the packet. eps map[tcpip.NICID]*endpoint + + // ICMP types for which the stack's global rate limiting must apply. + icmpRateLimitedTypes map[header.ICMPv4Type]struct{} } // defaultTTL is the current default TTL for the protocol. Only the @@ -1330,6 +1333,23 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu return ipHdr.TransportProtocol(), !ipHdr.More() && ipHdr.FragmentOffset() == 0, true } +// allowICMPReply reports whether an ICMP reply with provided type and code may +// be sent following the rate mask options and global ICMP rate limiter. +func (p *protocol) allowICMPReply(icmpType header.ICMPv4Type, code header.ICMPv4Code) bool { + // Mimic linux and never rate limit for PMTU discovery. + // https://github.com/torvalds/linux/blob/9e9fb7655ed585da8f468e29221f0ba194a5f613/net/ipv4/icmp.c#L288 + if icmpType == header.ICMPv4DstUnreachable && code == header.ICMPv4FragmentationNeeded { + return true + } + p.mu.RLock() + defer p.mu.RUnlock() + + if _, ok := p.mu.icmpRateLimitedTypes[icmpType]; ok { + return p.stack.AllowICMPMessage() + } + return true +} + // calculateNetworkMTU calculates the network-layer payload MTU based on the // link-layer payload mtu. func calculateNetworkMTU(linkMTU, networkHeaderSize uint32) (uint32, tcpip.Error) { @@ -1409,6 +1429,14 @@ func NewProtocolWithOptions(opts Options) stack.NetworkProtocolFactory { } p.fragmentation = fragmentation.NewFragmentation(fragmentblockSize, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, ReassembleTimeout, s.Clock(), p) p.mu.eps = make(map[tcpip.NICID]*endpoint) + // Set ICMP rate limiting to Linux defaults. + // See https://man7.org/linux/man-pages/man7/icmp.7.html. + p.mu.icmpRateLimitedTypes = map[header.ICMPv4Type]struct{}{ + header.ICMPv4DstUnreachable: struct{}{}, + header.ICMPv4SrcQuench: struct{}{}, + header.ICMPv4TimeExceeded: struct{}{}, + header.ICMPv4ParamProblem: struct{}{}, + } return p } } |