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-rw-r--r--pkg/tcpip/network/ipv4/icmp.go22
-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go6
-rw-r--r--pkg/tcpip/network/ipv6/icmp.go56
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go115
4 files changed, 159 insertions, 40 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 5c4f715d7..a8985ff5d 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -15,6 +15,8 @@
package ipv4
import (
+ "fmt"
+
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
@@ -211,6 +213,12 @@ type icmpReasonPortUnreachable struct{}
func (*icmpReasonPortUnreachable) isICMPReason() {}
+// icmpReasonProtoUnreachable is an error where the transport protocol is
+// not supported.
+type icmpReasonProtoUnreachable struct{}
+
+func (*icmpReasonProtoUnreachable) isICMPReason() {}
+
// returnError takes an error descriptor and generates the appropriate ICMP
// error packet for IPv4 and sends it back to the remote device that sent
// the problematic packet. It incorporates as much of that packet as
@@ -287,8 +295,6 @@ func returnError(r *stack.Route, reason icmpReason, pkt *stack.PacketBuffer) *tc
// Assume any type we don't know about may be an error type.
return nil
}
- } else if transportHeader.IsEmpty() {
- return nil
}
// Now work out how much of the triggering packet we should return.
@@ -336,13 +342,21 @@ func returnError(r *stack.Route, reason icmpReason, pkt *stack.PacketBuffer) *tc
ReserveHeaderBytes: headerLen,
Data: payload,
})
+
icmpPkt.TransportProtocolNumber = header.ICMPv4ProtocolNumber
icmpHdr := header.ICMPv4(icmpPkt.TransportHeader().Push(header.ICMPv4MinimumSize))
+ switch reason.(type) {
+ case *icmpReasonPortUnreachable:
+ icmpHdr.SetCode(header.ICMPv4PortUnreachable)
+ case *icmpReasonProtoUnreachable:
+ icmpHdr.SetCode(header.ICMPv4ProtoUnreachable)
+ default:
+ panic(fmt.Sprintf("unsupported ICMP type %T", reason))
+ }
icmpHdr.SetType(header.ICMPv4DstUnreachable)
- icmpHdr.SetCode(header.ICMPv4PortUnreachable)
- counter := sent.DstUnreachable
icmpHdr.SetChecksum(header.ICMPv4Checksum(icmpHdr, icmpPkt.Data))
+ counter := sent.DstUnreachable
if err := r.WritePacket(
nil, /* gso */
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index ad7a767a4..34d3f8474 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -567,6 +567,12 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
// (e.g., UDP) is unable to demultiplex the datagram but has no
// protocol mechanism to inform the sender.
_ = returnError(r, &icmpReasonPortUnreachable{}, pkt)
+ case stack.TransportPacketProtocolUnreachable:
+ // As per RFC: 1122 Section 3.2.2.1
+ // A host SHOULD generate Destination Unreachable messages with code:
+ // 2 (Protocol Unreachable), when the designated transport protocol
+ // is not supported
+ _ = returnError(r, &icmpReasonProtoUnreachable{}, pkt)
default:
panic(fmt.Sprintf("unrecognized result from DeliverTransportPacket = %d", res))
}
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 4b4b483cc..8e9def6b8 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -690,6 +690,36 @@ type icmpReason interface {
isICMPReason()
}
+// icmpReasonParameterProblem is an error during processing of extension headers
+// or the fixed header defined in RFC 4443 section 3.4.
+type icmpReasonParameterProblem struct {
+ code header.ICMPv6Code
+
+ // respondToMulticast indicates that we are sending a packet that falls under
+ // the exception outlined by RFC 4443 section 2.4 point e.3 exception 2:
+ //
+ // (e.3) A packet destined to an IPv6 multicast address. (There are
+ // two exceptions to this rule: (1) the Packet Too Big Message
+ // (Section 3.2) to allow Path MTU discovery to work for IPv6
+ // multicast, and (2) the Parameter Problem Message, Code 2
+ // (Section 3.4) reporting an unrecognized IPv6 option (see
+ // Section 4.2 of [IPv6]) that has the Option Type highest-
+ // order two bits set to 10).
+ respondToMulticast bool
+
+ // pointer is defined in the RFC 4443 setion 3.4 which reads:
+ //
+ // Pointer Identifies the octet offset within the invoking packet
+ // where the error was detected.
+ //
+ // The pointer will point beyond the end of the ICMPv6
+ // packet if the field in error is beyond what can fit
+ // in the maximum size of an ICMPv6 error message.
+ pointer uint32
+}
+
+func (*icmpReasonParameterProblem) isICMPReason() {}
+
// icmpReasonPortUnreachable is an error where the transport protocol has no
// listener and no alternative means to inform the sender.
type icmpReasonPortUnreachable struct{}
@@ -709,7 +739,7 @@ func returnError(r *stack.Route, reason icmpReason, pkt *stack.PacketBuffer) *tc
// Only send ICMP error if the address is not a multicast v6
// address and the source is not the unspecified address.
//
- // TODO(b/164522993) There are exceptions to this rule.
+ // There are exceptions to this rule.
// See: point e.3) RFC 4443 section-2.4
//
// (e) An ICMPv6 error message MUST NOT be originated as a result of
@@ -727,7 +757,12 @@ func returnError(r *stack.Route, reason icmpReason, pkt *stack.PacketBuffer) *tc
// Section 4.2 of [IPv6]) that has the Option Type highest-
// order two bits set to 10).
//
- if header.IsV6MulticastAddress(r.LocalAddress) || r.RemoteAddress == header.IPv6Any {
+ var allowResponseToMulticast bool
+ if reason, ok := reason.(*icmpReasonParameterProblem); ok {
+ allowResponseToMulticast = reason.respondToMulticast
+ }
+
+ if (!allowResponseToMulticast && header.IsV6MulticastAddress(r.LocalAddress)) || r.RemoteAddress == header.IPv6Any {
return nil
}
@@ -780,10 +815,21 @@ func returnError(r *stack.Route, reason icmpReason, pkt *stack.PacketBuffer) *tc
newPkt.TransportProtocolNumber = header.ICMPv6ProtocolNumber
icmpHdr := header.ICMPv6(newPkt.TransportHeader().Push(header.ICMPv6DstUnreachableMinimumSize))
- icmpHdr.SetCode(header.ICMPv6PortUnreachable)
- icmpHdr.SetType(header.ICMPv6DstUnreachable)
+ var counter *tcpip.StatCounter
+ switch reason := reason.(type) {
+ case *icmpReasonParameterProblem:
+ icmpHdr.SetType(header.ICMPv6ParamProblem)
+ icmpHdr.SetCode(reason.code)
+ icmpHdr.SetTypeSpecific(reason.pointer)
+ counter = sent.ParamProblem
+ case *icmpReasonPortUnreachable:
+ icmpHdr.SetType(header.ICMPv6DstUnreachable)
+ icmpHdr.SetCode(header.ICMPv6PortUnreachable)
+ counter = sent.DstUnreachable
+ default:
+ panic(fmt.Sprintf("unsupported ICMP type %T", reason))
+ }
icmpHdr.SetChecksum(header.ICMPv6Checksum(icmpHdr, r.LocalAddress, r.RemoteAddress, newPkt.Data))
- counter := sent.DstUnreachable
err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: r.DefaultTTL(), TOS: stack.DefaultTOS}, newPkt)
if err != nil {
sent.Dropped.Increment()
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index aff4e1425..7458c3795 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The gVisor Authors.
+// Copyright 2020 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.
@@ -536,7 +536,10 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
return
}
- for firstHeader := true; ; firstHeader = false {
+ for {
+ // Keep track of the start of the previous header so we can report the
+ // special case of a Hop by Hop at a location other than at the start.
+ previousHeaderStart := it.HeaderOffset()
extHdr, done, err := it.Next()
if err != nil {
r.Stats().IP.MalformedPacketsReceived.Increment()
@@ -550,11 +553,11 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
case header.IPv6HopByHopOptionsExtHdr:
// As per RFC 8200 section 4.1, the Hop By Hop extension header is
// restricted to appear immediately after an IPv6 fixed header.
- //
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1
- // (unrecognized next header) error in response to an extension header's
- // Next Header field with the Hop By Hop extension header identifier.
- if !firstHeader {
+ if previousHeaderStart != 0 {
+ _ = returnError(r, &icmpReasonParameterProblem{
+ code: header.ICMPv6UnknownHeader,
+ pointer: previousHeaderStart,
+ }, pkt)
return
}
@@ -576,13 +579,25 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
case header.IPv6OptionUnknownActionSkip:
case header.IPv6OptionUnknownActionDiscard:
return
- case header.IPv6OptionUnknownActionDiscardSendICMP:
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for
- // unrecognized IPv6 extension header options.
- return
case header.IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest:
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for
- // unrecognized IPv6 extension header options.
+ if header.IsV6MulticastAddress(r.LocalAddress) {
+ return
+ }
+ fallthrough
+ case header.IPv6OptionUnknownActionDiscardSendICMP:
+ // This case satisfies a requirement of RFC 8200 section 4.2
+ // which states that an unknown option starting with bits [10] should:
+ //
+ // discard the packet and, regardless of whether or not the
+ // packet's Destination Address was a multicast address, send an
+ // ICMP Parameter Problem, Code 2, message to the packet's
+ // Source Address, pointing to the unrecognized Option Type.
+ //
+ _ = returnError(r, &icmpReasonParameterProblem{
+ code: header.ICMPv6UnknownOption,
+ pointer: it.ParseOffset() + optsIt.OptionOffset(),
+ respondToMulticast: true,
+ }, pkt)
return
default:
panic(fmt.Sprintf("unrecognized action for an unrecognized Hop By Hop extension header option = %d", opt))
@@ -593,16 +608,20 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
// As per RFC 8200 section 4.4, if a node encounters a routing header with
// an unrecognized routing type value, with a non-zero Segments Left
// value, the node must discard the packet and send an ICMP Parameter
- // Problem, Code 0. If the Segments Left is 0, the node must ignore the
- // Routing extension header and process the next header in the packet.
+ // Problem, Code 0 to the packet's Source Address, pointing to the
+ // unrecognized Routing Type.
+ //
+ // If the Segments Left is 0, the node must ignore the Routing extension
+ // header and process the next header in the packet.
//
// Note, the stack does not yet handle any type of routing extension
// header, so we just make sure Segments Left is zero before processing
// the next extension header.
- //
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 0 for
- // unrecognized routing types with a non-zero Segments Left value.
if extHdr.SegmentsLeft() != 0 {
+ _ = returnError(r, &icmpReasonParameterProblem{
+ code: header.ICMPv6ErroneousHeader,
+ pointer: it.ParseOffset(),
+ }, pkt)
return
}
@@ -737,13 +756,25 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
case header.IPv6OptionUnknownActionSkip:
case header.IPv6OptionUnknownActionDiscard:
return
- case header.IPv6OptionUnknownActionDiscardSendICMP:
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for
- // unrecognized IPv6 extension header options.
- return
case header.IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest:
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for
- // unrecognized IPv6 extension header options.
+ if header.IsV6MulticastAddress(r.LocalAddress) {
+ return
+ }
+ fallthrough
+ case header.IPv6OptionUnknownActionDiscardSendICMP:
+ // This case satisfies a requirement of RFC 8200 section 4.2
+ // which states that an unknown option starting with bits [10] should:
+ //
+ // discard the packet and, regardless of whether or not the
+ // packet's Destination Address was a multicast address, send an
+ // ICMP Parameter Problem, Code 2, message to the packet's
+ // Source Address, pointing to the unrecognized Option Type.
+ //
+ _ = returnError(r, &icmpReasonParameterProblem{
+ code: header.ICMPv6UnknownOption,
+ pointer: it.ParseOffset() + optsIt.OptionOffset(),
+ respondToMulticast: true,
+ }, pkt)
return
default:
panic(fmt.Sprintf("unrecognized action for an unrecognized Destination extension header option = %d", opt))
@@ -767,8 +798,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
pkt.TransportProtocolNumber = p
e.handleICMP(r, pkt, hasFragmentHeader)
} else {
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1 error
- // in response to unrecognized next header values.
+ r.Stats().IP.PacketsDelivered.Increment()
switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res {
case stack.TransportPacketHandled:
case stack.TransportPacketDestinationPortUnreachable:
@@ -778,17 +808,40 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
// transport protocol (e.g., UDP) has no listener, if that transport
// protocol has no alternative means to inform the sender.
_ = returnError(r, &icmpReasonPortUnreachable{}, pkt)
+ case stack.TransportPacketProtocolUnreachable:
+ // As per RFC 8200 section 4. (page 7):
+ // Extension headers are numbered from IANA IP Protocol Numbers
+ // [IANA-PN], the same values used for IPv4 and IPv6. When
+ // processing a sequence of Next Header values in a packet, the
+ // first one that is not an extension header [IANA-EH] indicates
+ // that the next item in the packet is the corresponding upper-layer
+ // header.
+ // With more related information on page 8:
+ // If, as a result of processing a header, the destination node is
+ // required to proceed to the next header but the Next Header value
+ // in the current header is unrecognized by the node, it should
+ // discard the packet and send an ICMP Parameter Problem message to
+ // the source of the packet, with an ICMP Code value of 1
+ // ("unrecognized Next Header type encountered") and the ICMP
+ // Pointer field containing the offset of the unrecognized value
+ // within the original packet.
+ //
+ // Which when taken together indicate that an unknown protocol should
+ // be treated as an unrecognized next header value.
+ _ = returnError(r, &icmpReasonParameterProblem{
+ code: header.ICMPv6UnknownHeader,
+ pointer: it.ParseOffset(),
+ }, pkt)
default:
panic(fmt.Sprintf("unrecognized result from DeliverTransportPacket = %d", res))
}
}
default:
- // If we receive a packet for an extension header we do not yet handle,
- // drop the packet for now.
- //
- // TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1 error
- // in response to unrecognized next header values.
+ _ = returnError(r, &icmpReasonParameterProblem{
+ code: header.ICMPv6UnknownHeader,
+ pointer: it.ParseOffset(),
+ }, pkt)
r.Stats().UnknownProtocolRcvdPackets.Increment()
return
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-14 16:05:54 +0000