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-rw-r--r--pkg/tcpip/network/ipv4/icmp.go99
-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go351
-rw-r--r--pkg/tcpip/network/ipv4/ipv4_test.go464
3 files changed, 851 insertions, 63 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 1edb6de6b..cf287446e 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -15,6 +15,7 @@
package ipv4
import (
+ "errors"
"fmt"
"gvisor.dev/gvisor/pkg/tcpip"
@@ -23,10 +24,10 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/stack"
)
-// handleControl handles the case when an ICMP packet contains the headers of
-// the original packet that caused the ICMP one to be sent. This information is
-// used to find out which transport endpoint must be notified about the ICMP
-// packet.
+// handleControl handles the case when an ICMP error packet contains the headers
+// of the original packet that caused the ICMP one to be sent. This information
+// is used to find out which transport endpoint must be notified about the ICMP
+// packet. We only expect the payload, not the enclosing ICMP packet.
func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt *stack.PacketBuffer) {
h, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
if !ok {
@@ -73,20 +74,65 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
}
h := header.ICMPv4(v)
+ // Only do in-stack processing if the checksum is correct.
+ if header.ChecksumVV(pkt.Data, 0 /* initial */) != 0xffff {
+ received.Invalid.Increment()
+ // It's possible that a raw socket expects to receive this regardless
+ // of checksum errors. If it's an echo request we know it's safe because
+ // we are the only handler, however other types do not cope well with
+ // packets with checksum errors.
+ switch h.Type() {
+ case header.ICMPv4Echo:
+ e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, pkt)
+ }
+ return
+ }
+
+ iph := header.IPv4(pkt.NetworkHeader().View())
+ var newOptions header.IPv4Options
+ if len(iph) > header.IPv4MinimumSize {
+ // RFC 1122 section 3.2.2.6 (page 43) (and similar for other round trip
+ // type ICMP packets):
+ // If a Record Route and/or Time Stamp option is received in an
+ // ICMP Echo Request, this option (these options) SHOULD be
+ // updated to include the current host and included in the IP
+ // header of the Echo Reply message, without "truncation".
+ // Thus, the recorded route will be for the entire round trip.
+ //
+ // So we need to let the option processor know how it should handle them.
+ var op optionsUsage
+ if h.Type() == header.ICMPv4Echo {
+ op = &optionUsageEcho{}
+ } else {
+ op = &optionUsageReceive{}
+ }
+ aux, tmp, err := processIPOptions(r, iph.Options(), op)
+ if err != nil {
+ switch {
+ case
+ errors.Is(err, header.ErrIPv4OptDuplicate),
+ errors.Is(err, errIPv4RecordRouteOptInvalidLength),
+ errors.Is(err, errIPv4RecordRouteOptInvalidPointer),
+ errors.Is(err, errIPv4TimestampOptInvalidLength),
+ errors.Is(err, errIPv4TimestampOptInvalidPointer),
+ errors.Is(err, errIPv4TimestampOptOverflow):
+ _ = e.protocol.returnError(r, &icmpReasonParamProblem{pointer: aux}, pkt)
+ e.protocol.stack.Stats().MalformedRcvdPackets.Increment()
+ r.Stats().IP.MalformedPacketsReceived.Increment()
+ }
+ return
+ }
+ newOptions = tmp
+ }
+
// TODO(b/112892170): Meaningfully handle all ICMP types.
switch h.Type() {
case header.ICMPv4Echo:
received.Echo.Increment()
- // Only send a reply if the checksum is valid.
- headerChecksum := h.Checksum()
- h.SetChecksum(0)
- calculatedChecksum := ^header.ChecksumVV(pkt.Data, 0 /* initial */)
- h.SetChecksum(headerChecksum)
- if calculatedChecksum != headerChecksum {
- // It's possible that a raw socket still expects to receive this.
- e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, pkt)
- received.Invalid.Increment()
+ sent := stats.ICMP.V4PacketsSent
+ if !r.Stack().AllowICMPMessage() {
+ sent.RateLimited.Increment()
return
}
@@ -98,9 +144,14 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
// waiting endpoints. Consider moving responsibility for doing the copy to
// DeliverTransportPacket so that is is only done when needed.
replyData := pkt.Data.ToOwnedView()
- replyIPHdr := header.IPv4(append(buffer.View(nil), pkt.NetworkHeader().View()...))
+ // It's possible that a raw socket expects to receive this.
e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, pkt)
+ pkt = nil
+ // Take the base of the incoming request IP header but replace the options.
+ replyHeaderLength := uint8(header.IPv4MinimumSize + len(newOptions))
+ replyIPHdr := header.IPv4(append(iph[:header.IPv4MinimumSize:header.IPv4MinimumSize], newOptions...))
+ replyIPHdr.SetHeaderLength(replyHeaderLength)
// As per RFC 1122 section 3.2.1.3, when a host sends any datagram, the IP
// source address MUST be one of its own IP addresses (but not a broadcast
@@ -139,7 +190,8 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
// The fields we need to alter.
//
// We need to produce the entire packet in the data segment in order to
- // use WriteHeaderIncludedPacket().
+ // use WriteHeaderIncludedPacket(). WriteHeaderIncludedPacket sets the
+ // total length and the header checksum so we don't need to set those here.
replyIPHdr.SetSourceAddress(r.LocalAddress)
replyIPHdr.SetDestinationAddress(r.RemoteAddress)
replyIPHdr.SetTTL(r.DefaultTTL())
@@ -157,8 +209,6 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
})
replyPkt.TransportProtocolNumber = header.ICMPv4ProtocolNumber
- // The checksum will be calculated so we don't need to do it here.
- sent := stats.ICMP.V4PacketsSent
if err := r.WriteHeaderIncludedPacket(replyPkt); err != nil {
sent.Dropped.Increment()
return
@@ -244,6 +294,14 @@ type icmpReasonReassemblyTimeout struct{}
func (*icmpReasonReassemblyTimeout) isICMPReason() {}
+// icmpReasonParamProblem is an error to use to request a Parameter Problem
+// message to be sent.
+type icmpReasonParamProblem struct {
+ pointer byte
+}
+
+func (*icmpReasonParamProblem) 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
@@ -385,7 +443,7 @@ func (p *protocol) returnError(r *stack.Route, reason icmpReason, pkt *stack.Pac
icmpHdr := header.ICMPv4(icmpPkt.TransportHeader().Push(header.ICMPv4MinimumSize))
var counter *tcpip.StatCounter
- switch reason.(type) {
+ switch reason := reason.(type) {
case *icmpReasonPortUnreachable:
icmpHdr.SetType(header.ICMPv4DstUnreachable)
icmpHdr.SetCode(header.ICMPv4PortUnreachable)
@@ -398,6 +456,11 @@ func (p *protocol) returnError(r *stack.Route, reason icmpReason, pkt *stack.Pac
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))
}
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index e6b842d61..4592984a5 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -16,7 +16,9 @@
package ipv4
import (
+ "errors"
"fmt"
+ "math"
"sync/atomic"
"time"
@@ -31,6 +33,8 @@ import (
)
const (
+ // ReassembleTimeout is the time a packet stays in the reassembly
+ // system before being evicted.
// As per RFC 791 section 3.2:
// The current recommendation for the initial timer setting is 15 seconds.
// This may be changed as experience with this protocol accumulates.
@@ -569,9 +573,14 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
if !ready {
return
}
- }
+ // The reassembler doesn't take care of fixing up the header, so we need
+ // to do it here.
+ h.SetTotalLength(uint16(pkt.Data.Size() + len((h))))
+ h.SetFlagsFragmentOffset(0, 0)
+ }
r.Stats().IP.PacketsDelivered.Increment()
+
p := h.TransportProtocol()
if p == header.ICMPv4ProtocolNumber {
// TODO(gvisor.dev/issues/3810): when we sort out ICMP and transport
@@ -581,6 +590,27 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
e.handleICMP(r, pkt)
return
}
+ if len(h.Options()) != 0 {
+ // TODO(gvisor.dev/issue/4586):
+ // When we add forwarding support we should use the verified options
+ // rather than just throwing them away.
+ aux, _, err := processIPOptions(r, h.Options(), &optionUsageReceive{})
+ if err != nil {
+ switch {
+ case
+ errors.Is(err, header.ErrIPv4OptDuplicate),
+ errors.Is(err, errIPv4RecordRouteOptInvalidPointer),
+ errors.Is(err, errIPv4RecordRouteOptInvalidLength),
+ errors.Is(err, errIPv4TimestampOptInvalidLength),
+ errors.Is(err, errIPv4TimestampOptInvalidPointer),
+ errors.Is(err, errIPv4TimestampOptOverflow):
+ _ = e.protocol.returnError(r, &icmpReasonParamProblem{pointer: aux}, pkt)
+ e.protocol.stack.Stats().MalformedRcvdPackets.Increment()
+ r.Stats().IP.MalformedPacketsReceived.Increment()
+ }
+ return
+ }
+ }
switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res {
case stack.TransportPacketHandled:
@@ -905,3 +935,322 @@ func buildNextFragment(pf *fragmentation.PacketFragmenter, originalIPHeader head
return fragPkt, more
}
+
+// optionAction describes possible actions that may be taken on an option
+// while processing it.
+type optionAction uint8
+
+const (
+ // optionRemove says that the option should not be in the output option set.
+ optionRemove optionAction = iota
+
+ // optionProcess says that the option should be fully processed.
+ optionProcess
+
+ // optionVerify says the option should be checked and passed unchanged.
+ optionVerify
+
+ // optionPass says to pass the output set without checking.
+ optionPass
+)
+
+// optionActions list what to do for each option in a given scenario.
+type optionActions struct {
+ // timestamp controls what to do with a Timestamp option.
+ timestamp optionAction
+
+ // recordroute controls what to do with a Record Route option.
+ recordRoute optionAction
+
+ // unknown controls what to do with an unknown option.
+ unknown optionAction
+}
+
+// optionsUsage specifies the ways options may be operated upon for a given
+// scenario during packet processing.
+type optionsUsage interface {
+ actions() optionActions
+}
+
+// optionUsageReceive implements optionsUsage for received packets.
+type optionUsageReceive struct{}
+
+// actions implements optionsUsage.
+func (*optionUsageReceive) actions() optionActions {
+ return optionActions{
+ timestamp: optionVerify,
+ recordRoute: optionVerify,
+ unknown: optionPass,
+ }
+}
+
+// TODO(gvisor.dev/issue/4586): Add an entry here for forwarding when it
+// is enabled (Process, Process, Pass) and for fragmenting (Process, Process,
+// Pass for frag1, but Remove,Remove,Remove for all other frags).
+
+// optionUsageEcho implements optionsUsage for echo packet processing.
+type optionUsageEcho struct{}
+
+// actions implements optionsUsage.
+func (*optionUsageEcho) actions() optionActions {
+ return optionActions{
+ timestamp: optionProcess,
+ recordRoute: optionProcess,
+ unknown: optionRemove,
+ }
+}
+
+var (
+ errIPv4TimestampOptInvalidLength = errors.New("invalid Timestamp length")
+ errIPv4TimestampOptInvalidPointer = errors.New("invalid Timestamp pointer")
+ errIPv4TimestampOptOverflow = errors.New("overflow in Timestamp")
+ errIPv4TimestampOptInvalidFlags = errors.New("invalid Timestamp flags")
+)
+
+// handleTimestamp does any required processing on a Timestamp option
+// in place.
+func handleTimestamp(tsOpt header.IPv4OptionTimestamp, localAddress tcpip.Address, clock tcpip.Clock, usage optionsUsage) (uint8, error) {
+ flags := tsOpt.Flags()
+ var entrySize uint8
+ switch flags {
+ case header.IPv4OptionTimestampOnlyFlag:
+ entrySize = header.IPv4OptionTimestampSize
+ case
+ header.IPv4OptionTimestampWithIPFlag,
+ header.IPv4OptionTimestampWithPredefinedIPFlag:
+ entrySize = header.IPv4OptionTimestampWithAddrSize
+ default:
+ return header.IPv4OptTSOFLWAndFLGOffset, errIPv4TimestampOptInvalidFlags
+ }
+
+ pointer := tsOpt.Pointer()
+ // To simplify processing below, base further work on the array of timestamps
+ // beyond the header, rather than on the whole option. Also to aid
+ // calculations set 'nextSlot' to be 0 based as in the packet it is 1 based.
+ nextSlot := pointer - (header.IPv4OptionTimestampHdrLength + 1)
+ optLen := tsOpt.Size()
+ dataLength := optLen - header.IPv4OptionTimestampHdrLength
+
+ // In the section below, we verify the pointer, length and overflow counter
+ // fields of the option. The distinction is in which byte you return as being
+ // in error in the ICMP packet. Offsets 1 (length), 2 pointer)
+ // or 3 (overflowed counter).
+ //
+ // The following RFC sections cover this section:
+ //
+ // RFC 791 (page 22):
+ // If there is some room but not enough room for a full timestamp
+ // to be inserted, or the overflow count itself overflows, the
+ // original datagram is considered to be in error and is discarded.
+ // In either case an ICMP parameter problem message may be sent to
+ // the source host [3].
+ //
+ // You can get this situation in two ways. Firstly if the data area is not
+ // a multiple of the entry size or secondly, if the pointer is not at a
+ // multiple of the entry size. The wording of the RFC suggests that
+ // this is not an error until you actually run out of space.
+ if pointer > optLen {
+ // RFC 791 (page 22) says we should switch to using the overflow count.
+ // If the timestamp data area is already full (the pointer exceeds
+ // the length) the datagram is forwarded without inserting the
+ // timestamp, but the overflow count is incremented by one.
+ if flags == header.IPv4OptionTimestampWithPredefinedIPFlag {
+ // By definition we have nothing to do.
+ return 0, nil
+ }
+
+ if tsOpt.IncOverflow() != 0 {
+ return 0, nil
+ }
+ // The overflow count is also full.
+ return header.IPv4OptTSOFLWAndFLGOffset, errIPv4TimestampOptOverflow
+ }
+ if nextSlot+entrySize > dataLength {
+ // The data area isn't full but there isn't room for a new entry.
+ // Either Length or Pointer could be bad.
+ if false {
+ // We must select Pointer for Linux compatibility, even if
+ // only the length is bad.
+ // The Linux code is at (in October 2020)
+ // https://github.com/torvalds/linux/blob/bbf5c979011a099af5dc76498918ed7df445635b/net/ipv4/ip_options.c#L367-L370
+ // if (optptr[2]+3 > optlen) {
+ // pp_ptr = optptr + 2;
+ // goto error;
+ // }
+ // which doesn't distinguish between which of optptr[2] or optlen
+ // is wrong, but just arbitrarily decides on optptr+2.
+ if dataLength%entrySize != 0 {
+ // The Data section size should be a multiple of the expected
+ // timestamp entry size.
+ return header.IPv4OptionLengthOffset, errIPv4TimestampOptInvalidLength
+ }
+ // If the size is OK, the pointer must be corrupted.
+ }
+ return header.IPv4OptTSPointerOffset, errIPv4TimestampOptInvalidPointer
+ }
+
+ if usage.actions().timestamp == optionProcess {
+ tsOpt.UpdateTimestamp(localAddress, clock)
+ }
+ return 0, nil
+}
+
+var (
+ errIPv4RecordRouteOptInvalidLength = errors.New("invalid length in Record Route")
+ errIPv4RecordRouteOptInvalidPointer = errors.New("invalid pointer in Record Route")
+)
+
+// handleRecordRoute checks and processes a Record route option. It is much
+// like the timestamp type 1 option, but without timestamps. The passed in
+// address is stored in the option in the correct spot if possible.
+func handleRecordRoute(rrOpt header.IPv4OptionRecordRoute, localAddress tcpip.Address, usage optionsUsage) (uint8, error) {
+ optlen := rrOpt.Size()
+
+ if optlen < header.IPv4AddressSize+header.IPv4OptionRecordRouteHdrLength {
+ return header.IPv4OptionLengthOffset, errIPv4RecordRouteOptInvalidLength
+ }
+
+ nextSlot := rrOpt.Pointer() - 1 // Pointer is 1 based.
+
+ // RFC 791 page 21 says
+ // If the route data area is already full (the pointer exceeds the
+ // length) the datagram is forwarded without inserting the address
+ // into the recorded route. If there is some room but not enough
+ // room for a full address to be inserted, the original datagram is
+ // considered to be in error and is discarded. In either case an
+ // ICMP parameter problem message may be sent to the source
+ // host.
+ // The use of the words "In either case" suggests that a 'full' RR option
+ // could generate an ICMP at every hop after it fills up. We chose to not
+ // do this (as do most implementations). It is probable that the inclusion
+ // of these words is a copy/paste error from the timestamp option where
+ // there are two failure reasons given.
+ if nextSlot >= optlen {
+ return 0, nil
+ }
+
+ // The data area isn't full but there isn't room for a new entry.
+ // Either Length or Pointer could be bad. We must select Pointer for Linux
+ // compatibility, even if only the length is bad.
+ if nextSlot+header.IPv4AddressSize > optlen {
+ if false {
+ // This is what we would do if we were not being Linux compatible.
+ // Check for bad pointer or length value. Must be a multiple of 4 after
+ // accounting for the 3 byte header and not within that header.
+ // RFC 791, page 20 says:
+ // The pointer is relative to this option, and the
+ // smallest legal value for the pointer is 4.
+ //
+ // A recorded route is composed of a series of internet addresses.
+ // Each internet address is 32 bits or 4 octets.
+ // Linux skips this test so we must too. See Linux code at:
+ // https://github.com/torvalds/linux/blob/bbf5c979011a099af5dc76498918ed7df445635b/net/ipv4/ip_options.c#L338-L341
+ // if (optptr[2]+3 > optlen) {
+ // pp_ptr = optptr + 2;
+ // goto error;
+ // }
+ if (optlen-header.IPv4OptionRecordRouteHdrLength)%header.IPv4AddressSize != 0 {
+ // Length is bad, not on integral number of slots.
+ return header.IPv4OptionLengthOffset, errIPv4RecordRouteOptInvalidLength
+ }
+ // If not length, the fault must be with the pointer.
+ }
+ return header.IPv4OptRRPointerOffset, errIPv4RecordRouteOptInvalidPointer
+ }
+ if usage.actions().recordRoute == optionVerify {
+ return 0, nil
+ }
+ rrOpt.StoreAddress(localAddress)
+ return 0, nil
+}
+
+// processIPOptions parses the IPv4 options and produces a new set of options
+// suitable for use in the next step of packet processing as informed by usage.
+// The original will not be touched.
+//
+// Returns
+// - The location of an error if there was one (or 0 if no error)
+// - If there is an error, information as to what it was was.
+// - The replacement option set.
+func processIPOptions(r *stack.Route, orig header.IPv4Options, usage optionsUsage) (uint8, header.IPv4Options, error) {
+
+ opts := header.IPv4Options(orig)
+ optIter := opts.MakeIterator()
+
+ // Each option other than NOP must only appear (RFC 791 section 3.1, at the
+ // definition of every type). Keep track of each of the possible types in
+ // the 8 bit 'type' field.
+ var seenOptions [math.MaxUint8 + 1]bool
+
+ // TODO(gvisor.dev/issue/4586):
+ // This will need tweaking when we start really forwarding packets
+ // as we may need to get two addresses, for rx and tx interfaces.
+ // We will also have to take usage into account.
+ prefixedAddress, err := r.Stack().GetMainNICAddress(r.NICID(), ProtocolNumber)
+ localAddress := prefixedAddress.Address
+ if err != nil {
+ if r.IsInboundBroadcast() || header.IsV4MulticastAddress(r.LocalAddress) {
+ return 0 /* errCursor */, nil, header.ErrIPv4OptionAddress
+ }
+ localAddress = r.LocalAddress
+ }
+
+ for {
+ option, done, err := optIter.Next()
+ if done || err != nil {
+ return optIter.ErrCursor, optIter.Finalize(), err
+ }
+ optType := option.Type()
+ if optType == header.IPv4OptionNOPType {
+ optIter.PushNOPOrEnd(optType)
+ continue
+ }
+ if optType == header.IPv4OptionListEndType {
+ optIter.PushNOPOrEnd(optType)
+ return 0 /* errCursor */, optIter.Finalize(), nil /* err */
+ }
+
+ // check for repeating options (multiple NOPs are OK)
+ if seenOptions[optType] {
+ return optIter.ErrCursor, nil, header.ErrIPv4OptDuplicate
+ }
+ seenOptions[optType] = true
+
+ optLen := int(option.Size())
+ switch option := option.(type) {
+ case *header.IPv4OptionTimestamp:
+ r.Stats().IP.OptionTSReceived.Increment()
+ if usage.actions().timestamp != optionRemove {
+ clock := r.Stack().Clock()
+ newBuffer := optIter.RemainingBuffer()[:len(*option)]
+ _ = copy(newBuffer, option.Contents())
+ offset, err := handleTimestamp(header.IPv4OptionTimestamp(newBuffer), localAddress, clock, usage)
+ if err != nil {
+ return optIter.ErrCursor + offset, nil, err
+ }
+ optIter.ConsumeBuffer(optLen)
+ }
+
+ case *header.IPv4OptionRecordRoute:
+ r.Stats().IP.OptionRRReceived.Increment()
+ if usage.actions().recordRoute != optionRemove {
+ newBuffer := optIter.RemainingBuffer()[:len(*option)]
+ _ = copy(newBuffer, option.Contents())
+ offset, err := handleRecordRoute(header.IPv4OptionRecordRoute(newBuffer), localAddress, usage)
+ if err != nil {
+ return optIter.ErrCursor + offset, nil, err
+ }
+ optIter.ConsumeBuffer(optLen)
+ }
+
+ default:
+ r.Stats().IP.OptionUnknownReceived.Increment()
+ if usage.actions().unknown == optionPass {
+ newBuffer := optIter.RemainingBuffer()[:optLen]
+ // Arguments already heavily checked.. ignore result.
+ _ = copy(newBuffer, option.Contents())
+ optIter.ConsumeBuffer(optLen)
+ }
+ }
+ }
+}
diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go
index dbe0935be..61672a5ff 100644
--- a/pkg/tcpip/network/ipv4/ipv4_test.go
+++ b/pkg/tcpip/network/ipv4/ipv4_test.go
@@ -21,6 +21,7 @@ import (
"math"
"net"
"testing"
+ "time"
"github.com/google/go-cmp/cmp"
"gvisor.dev/gvisor/pkg/tcpip"
@@ -120,20 +121,22 @@ func TestIPv4Sanity(t *testing.T) {
)
tests := []struct {
- name string
- headerLength uint8 // value of 0 means "use correct size"
- badHeaderChecksum bool
- maxTotalLength uint16
- transportProtocol uint8
- TTL uint8
- shouldFail bool
- expectICMP bool
- ICMPType header.ICMPv4Type
- ICMPCode header.ICMPv4Code
- options []byte
+ name string
+ headerLength uint8 // value of 0 means "use correct size"
+ badHeaderChecksum bool
+ maxTotalLength uint16
+ transportProtocol uint8
+ TTL uint8
+ options []byte
+ replyOptions []byte // if succeeds, reply should look like this
+ shouldFail bool
+ expectErrorICMP bool
+ ICMPType header.ICMPv4Type
+ ICMPCode header.ICMPv4Code
+ paramProblemPointer uint8
}{
{
- name: "valid",
+ name: "valid no options",
maxTotalLength: ipv4.MaxTotalSize,
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
@@ -162,14 +165,12 @@ func TestIPv4Sanity(t *testing.T) {
maxTotalLength: ipv4.MaxTotalSize,
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: 0,
- shouldFail: false,
},
{
name: "one TTL",
maxTotalLength: ipv4.MaxTotalSize,
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: 1,
- shouldFail: false,
},
{
name: "End options",
@@ -177,6 +178,7 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
options: []byte{0, 0, 0, 0},
+ replyOptions: []byte{0, 0, 0, 0},
},
{
name: "NOP options",
@@ -184,6 +186,7 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
options: []byte{1, 1, 1, 1},
+ replyOptions: []byte{1, 1, 1, 1},
},
{
name: "NOP and End options",
@@ -191,6 +194,7 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
options: []byte{1, 1, 0, 0},
+ replyOptions: []byte{1, 1, 0, 0},
},
{
name: "bad header length",
@@ -199,7 +203,6 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
shouldFail: true,
- expectICMP: false,
},
{
name: "bad total length (0)",
@@ -207,7 +210,6 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
shouldFail: true,
- expectICMP: false,
},
{
name: "bad total length (ip - 1)",
@@ -215,7 +217,6 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
shouldFail: true,
- expectICMP: false,
},
{
name: "bad total length (ip + icmp - 1)",
@@ -223,7 +224,6 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: uint8(header.ICMPv4ProtocolNumber),
TTL: ttl,
shouldFail: true,
- expectICMP: false,
},
{
name: "bad protocol",
@@ -231,20 +231,354 @@ func TestIPv4Sanity(t *testing.T) {
transportProtocol: 99,
TTL: ttl,
shouldFail: true,
- expectICMP: true,
+ expectErrorICMP: true,
ICMPType: header.ICMPv4DstUnreachable,
ICMPCode: header.ICMPv4ProtoUnreachable,
},
+ {
+ name: "timestamp option overflow",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 12, 13, 0x11,
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ },
+ replyOptions: []byte{
+ 68, 12, 13, 0x21,
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ },
+ },
+ {
+ name: "timestamp option overflow full",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 12, 13, 0xF1,
+ // ^ Counter full (15/0xF)
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ },
+ shouldFail: true,
+ expectErrorICMP: true,
+ ICMPType: header.ICMPv4ParamProblem,
+ ICMPCode: header.ICMPv4UnusedCode,
+ paramProblemPointer: header.IPv4MinimumSize + 3,
+ replyOptions: []byte{},
+ },
+ {
+ name: "unknown option",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{10, 4, 9, 0},
+ // ^^
+ // The unknown option should be stripped out of the reply.
+ replyOptions: []byte{},
+ },
+ {
+ name: "bad option - length 0",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 0, 9, 0,
+ // ^
+ 1, 2, 3, 4,
+ },
+ shouldFail: true,
+ },
+ {
+ name: "bad option - length big",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 9, 9, 0,
+ // ^
+ // There are only 8 bytes allocated to options so 9 bytes of timestamp
+ // space is not possible. (Second byte)
+ 1, 2, 3, 4,
+ },
+ shouldFail: true,
+ },
+ {
+ // This tests for some linux compatible behaviour.
+ // The ICMP pointer returned is 22 for Linux but the
+ // error is actually in spot 21.
+ name: "bad option - length bad",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ // Timestamps are in multiples of 4 or 8 but never 7.
+ // The option space should be padded out.
+ options: []byte{
+ 68, 7, 5, 0,
+ // ^ ^ Linux points here which is wrong.
+ // | Not a multiple of 4
+ 1, 2, 3,
+ },
+ shouldFail: true,
+ expectErrorICMP: true,
+ ICMPType: header.ICMPv4ParamProblem,
+ ICMPCode: header.ICMPv4UnusedCode,
+ paramProblemPointer: header.IPv4MinimumSize + 2,
+ },
+ {
+ name: "multiple type 0 with room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 24, 21, 0x00,
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 0, 0, 0, 0,
+ },
+ replyOptions: []byte{
+ 68, 24, 25, 0x00,
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 0x00, 0xad, 0x1c, 0x40, // time we expect from fakeclock
+ },
+ },
+ {
+ // The timestamp area is full so add to the overflow count.
+ name: "multiple type 1 timestamps",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 20, 21, 0x11,
+ // ^
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 192, 168, 1, 13,
+ 5, 6, 7, 8,
+ },
+ // Overflow count is the top nibble of the 4th byte.
+ replyOptions: []byte{
+ 68, 20, 21, 0x21,
+ // ^
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 192, 168, 1, 13,
+ 5, 6, 7, 8,
+ },
+ },
+ {
+ name: "multiple type 1 timestamps with room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 28, 21, 0x01,
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 192, 168, 1, 13,
+ 5, 6, 7, 8,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ },
+ replyOptions: []byte{
+ 68, 28, 29, 0x01,
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 192, 168, 1, 13,
+ 5, 6, 7, 8,
+ 192, 168, 1, 58, // New IP Address.
+ 0x00, 0xad, 0x1c, 0x40, // time we expect from fakeclock
+ },
+ },
+ {
+ // Needs 8 bytes for a type 1 timestamp but there are only 4 free.
+ name: "bad timer element alignment",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 20, 17, 0x01,
+ // ^^ ^^ 20 byte area, next free spot at 17.
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ },
+ shouldFail: true,
+ expectErrorICMP: true,
+ ICMPType: header.ICMPv4ParamProblem,
+ ICMPCode: header.ICMPv4UnusedCode,
+ paramProblemPointer: header.IPv4MinimumSize + 2,
+ },
+ // End of option list with illegal option after it, which should be ignored.
+ {
+ name: "end of options list",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 68, 12, 13, 0x11,
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 0, 10, 3, 99,
+ },
+ replyOptions: []byte{
+ 68, 12, 13, 0x21,
+ 192, 168, 1, 12,
+ 1, 2, 3, 4,
+ 0, 0, 0, 0, // 3 bytes unknown option
+ }, // ^ End of options hides following bytes.
+ },
+ {
+ // Timestamp with a size too small.
+ name: "timestamp truncated",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{68, 1, 0, 0},
+ // ^ Smallest possible is 8.
+ shouldFail: true,
+ },
+ {
+ name: "single record route with room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 7, 7, 4, // 3 byte header
+ 0, 0, 0, 0,
+ 0,
+ },
+ replyOptions: []byte{
+ 7, 7, 8, // 3 byte header
+ 192, 168, 1, 58, // New IP Address.
+ 0, // padding to multiple of 4 bytes.
+ },
+ },
+ {
+ name: "multiple record route with room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 7, 23, 20, // 3 byte header
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 0, 0, 0, 0,
+ 0,
+ },
+ replyOptions: []byte{
+ 7, 23, 24,
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 192, 168, 1, 58, // New IP Address.
+ 0, // padding to multiple of 4 bytes.
+ },
+ },
+ {
+ name: "single record route with no room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 7, 7, 8, // 3 byte header
+ 1, 2, 3, 4,
+ 0,
+ },
+ replyOptions: []byte{
+ 7, 7, 8, // 3 byte header
+ 1, 2, 3, 4,
+ 0, // padding to multiple of 4 bytes.
+ },
+ },
+ {
+ // Unlike timestamp, this should just succeed.
+ name: "multiple record route with no room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 7, 23, 24, // 3 byte header
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 17, 18, 19, 20,
+ 0,
+ },
+ replyOptions: []byte{
+ 7, 23, 24,
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 17, 18, 19, 20,
+ 0, // padding to multiple of 4 bytes.
+ },
+ },
+ {
+ // Confirm linux bug for bug compatibility.
+ // Linux returns slot 22 but the error is in slot 21.
+ name: "multiple record route with not enough room",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 7, 8, 8, // 3 byte header
+ // ^ ^ Linux points here. We must too.
+ // | Not enough room. 1 byte free, need 4.
+ 1, 2, 3, 4,
+ 0,
+ },
+ shouldFail: true,
+ expectErrorICMP: true,
+ ICMPType: header.ICMPv4ParamProblem,
+ ICMPCode: header.ICMPv4UnusedCode,
+ paramProblemPointer: header.IPv4MinimumSize + 2,
+ replyOptions: []byte{},
+ },
+ {
+ name: "duplicate record route",
+ maxTotalLength: ipv4.MaxTotalSize,
+ transportProtocol: uint8(header.ICMPv4ProtocolNumber),
+ TTL: ttl,
+ options: []byte{
+ 7, 7, 8, // 3 byte header
+ 1, 2, 3, 4,
+ 7, 7, 8, // 3 byte header
+ 1, 2, 3, 4,
+ 0, 0, // pad
+ },
+ shouldFail: true,
+ expectErrorICMP: true,
+ ICMPType: header.ICMPv4ParamProblem,
+ ICMPCode: header.ICMPv4UnusedCode,
+ paramProblemPointer: header.IPv4MinimumSize + 7,
+ replyOptions: []byte{},
+ },
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
+ clock := faketime.NewManualClock()
s := stack.New(stack.Options{
NetworkProtocols: []stack.NetworkProtocolFactory{ipv4.NewProtocol},
TransportProtocols: []stack.TransportProtocolFactory{icmp.NewProtocol4},
+ Clock: clock,
})
// We expect at most a single packet in response to our ICMP Echo Request.
- e := channel.New(1, defaultMTU, "")
+ e := channel.New(1, ipv4.MaxTotalSize, "")
if err := s.CreateNIC(nicID, e); err != nil {
t.Fatalf("CreateNIC(%d, _): %s", nicID, err)
}
@@ -252,6 +586,9 @@ func TestIPv4Sanity(t *testing.T) {
if err := s.AddProtocolAddress(nicID, ipv4ProtoAddr); err != nil {
t.Fatalf("AddProtocolAddress(%d, %#v): %s", nicID, ipv4ProtoAddr, err)
}
+ // Advance the clock by some unimportant amount to make
+ // sure it's all set up.
+ clock.Advance(time.Millisecond * 0x10203040)
// Default routes for IPv4 so ICMP can find a route to the remote
// node when attempting to send the ICMP Echo Reply.
@@ -314,14 +651,20 @@ func TestIPv4Sanity(t *testing.T) {
reply, ok := e.Read()
if !ok {
if test.shouldFail {
- if test.expectICMP {
- t.Fatal("expected ICMP error response missing")
+ if test.expectErrorICMP {
+ t.Fatalf("ICMP error response (type %d, code %d) missing", test.ICMPType, test.ICMPCode)
}
return // Expected silent failure.
}
t.Fatal("expected ICMP echo reply missing")
}
+ // We didn't expect a packet. Register our surprise but carry on to
+ // provide more information about what we got.
+ if test.shouldFail && !test.expectErrorICMP {
+ t.Error("unexpected packet response")
+ }
+
// Check the route that brought the packet to us.
if reply.Route.LocalAddress != ipv4Addr.Address {
t.Errorf("got pkt.Route.LocalAddress = %s, want = %s", reply.Route.LocalAddress, ipv4Addr.Address)
@@ -330,57 +673,90 @@ func TestIPv4Sanity(t *testing.T) {
t.Errorf("got pkt.Route.RemoteAddress = %s, want = %s", reply.Route.RemoteAddress, remoteIPv4Addr)
}
- // Make sure it's all in one buffer.
- vv := buffer.NewVectorisedView(reply.Pkt.Size(), reply.Pkt.Views())
- replyIPHeader := header.IPv4(vv.ToView())
+ // Make sure it's all in one buffer for checker.
+ replyIPHeader := header.IPv4(stack.PayloadSince(reply.Pkt.NetworkHeader()))
- // At this stage we only know it's an IP header so verify that much.
+ // At this stage we only know it's probably an IP+ICMP header so verify
+ // that much.
checker.IPv4(t, replyIPHeader,
checker.SrcAddr(ipv4Addr.Address),
checker.DstAddr(remoteIPv4Addr),
+ checker.ICMPv4(
+ checker.ICMPv4Checksum(),
+ ),
)
- // All expected responses are ICMP packets.
- if got, want := replyIPHeader.Protocol(), uint8(header.ICMPv4ProtocolNumber); got != want {
- t.Fatalf("not ICMP response, got protocol %d, want = %d", got, want)
+ // Don't proceed any further if the checker found problems.
+ if t.Failed() {
+ t.FailNow()
}
- replyICMPHeader := header.ICMPv4(replyIPHeader.Payload())
- // Sanity check the response.
+ // OK it's ICMP. We can safely look at the type now.
+ replyICMPHeader := header.ICMPv4(replyIPHeader.Payload())
switch replyICMPHeader.Type() {
- case header.ICMPv4DstUnreachable:
+ case header.ICMPv4ParamProblem:
+ if !test.shouldFail {
+ t.Fatalf("got Parameter Problem with pointer %d, wanted Echo Reply", replyICMPHeader.Pointer())
+ }
+ if !test.expectErrorICMP {
+ t.Fatalf("got Parameter Problem with pointer %d, wanted no response", replyICMPHeader.Pointer())
+ }
checker.IPv4(t, replyIPHeader,
checker.IPFullLength(uint16(header.IPv4MinimumSize+header.ICMPv4MinimumSize+requestPkt.Size())),
checker.IPv4HeaderLength(header.IPv4MinimumSize),
checker.ICMPv4(
+ checker.ICMPv4Type(test.ICMPType),
checker.ICMPv4Code(test.ICMPCode),
- checker.ICMPv4Checksum(),
+ checker.ICMPv4Pointer(test.paramProblemPointer),
checker.ICMPv4Payload([]byte(hdr.View())),
),
)
- if !test.shouldFail || !test.expectICMP {
- t.Fatalf("unexpected packet rejection, got ICMP error packet type %d, code %d",
+ return
+ case header.ICMPv4DstUnreachable:
+ if !test.shouldFail {
+ t.Fatalf("got ICMP error packet type %d, code %d, wanted Echo Reply",
header.ICMPv4DstUnreachable, replyICMPHeader.Code())
}
+ if !test.expectErrorICMP {
+ t.Fatalf("got ICMP error packet type %d, code %d, wanted no response",
+ header.ICMPv4DstUnreachable, replyICMPHeader.Code())
+ }
+ checker.IPv4(t, replyIPHeader,
+ checker.IPFullLength(uint16(header.IPv4MinimumSize+header.ICMPv4MinimumSize+requestPkt.Size())),
+ checker.IPv4HeaderLength(header.IPv4MinimumSize),
+ checker.ICMPv4(
+ checker.ICMPv4Type(test.ICMPType),
+ checker.ICMPv4Code(test.ICMPCode),
+ checker.ICMPv4Payload([]byte(hdr.View())),
+ ),
+ )
return
case header.ICMPv4EchoReply:
+ if test.shouldFail {
+ if !test.expectErrorICMP {
+ t.Error("got Echo Reply packet, want no response")
+ } else {
+ t.Errorf("got Echo Reply, want ICMP error type %d, code %d", test.ICMPType, test.ICMPCode)
+ }
+ }
+ // If the IP options change size then the packet will change size, so
+ // some IP header fields will need to be adjusted for the checks.
+ sizeChange := len(test.replyOptions) - len(test.options)
+
checker.IPv4(t, replyIPHeader,
- checker.IPv4HeaderLength(ipHeaderLength),
- checker.IPv4Options(test.options),
- checker.IPFullLength(uint16(requestPkt.Size())),
+ checker.IPv4HeaderLength(ipHeaderLength+sizeChange),
+ checker.IPv4Options(test.replyOptions),
+ checker.IPFullLength(uint16(requestPkt.Size()+sizeChange)),
checker.ICMPv4(
+ checker.ICMPv4Checksum(),
checker.ICMPv4Code(header.ICMPv4UnusedCode),
checker.ICMPv4Seq(randomSequence),
checker.ICMPv4Ident(randomIdent),
- checker.ICMPv4Checksum(),
),
)
- if test.shouldFail {
- t.Fatalf("unexpected Echo Reply packet\n")
- }
default:
- t.Fatalf("unexpected ICMP response, got type %d, want = %d or %d",
- replyICMPHeader.Type(), header.ICMPv4EchoReply, header.ICMPv4DstUnreachable)
+ t.Fatalf("unexpected ICMP response, got type %d, want = %d, %d or %d",
+ replyICMPHeader.Type(), header.ICMPv4EchoReply, header.ICMPv4DstUnreachable, header.ICMPv4ParamProblem)
}
})
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-21 13:16:53 +0000