From 3789c34b22e7a7466149bfbeedf05bf49188130c Mon Sep 17 00:00:00 2001 From: Bhasker Hariharan Date: Tue, 3 Sep 2019 15:59:58 -0700 Subject: Make UDP traceroute work. Adds support to generate Port Unreachable messages for UDP datagrams received on a port for which there is no valid endpoint. Fixes #703 PiperOrigin-RevId: 267034418 --- pkg/tcpip/transport/icmp/endpoint.go | 19 ++++++++----------- pkg/tcpip/transport/icmp/protocol.go | 11 ++++++----- 2 files changed, 14 insertions(+), 16 deletions(-) (limited to 'pkg/tcpip/transport/icmp') diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go index 451d3880e..e1f622af6 100644 --- a/pkg/tcpip/transport/icmp/endpoint.go +++ b/pkg/tcpip/transport/icmp/endpoint.go @@ -15,7 +15,6 @@ package icmp import ( - "encoding/binary" "sync" "gvisor.dev/gvisor/pkg/tcpip" @@ -368,14 +367,13 @@ func send4(r *stack.Route, ident uint16, data buffer.View) *tcpip.Error { return tcpip.ErrInvalidEndpointState } - // Set the ident to the user-specified port. Sequence number should - // already be set by the user. - binary.BigEndian.PutUint16(data[header.ICMPv4PayloadOffset:], ident) - hdr := buffer.NewPrependable(header.ICMPv4MinimumSize + int(r.MaxHeaderLength())) icmpv4 := header.ICMPv4(hdr.Prepend(header.ICMPv4MinimumSize)) copy(icmpv4, data) + // Set the ident to the user-specified port. Sequence number should + // already be set by the user. + icmpv4.SetIdent(ident) data = data[header.ICMPv4MinimumSize:] // Linux performs these basic checks. @@ -394,14 +392,13 @@ func send6(r *stack.Route, ident uint16, data buffer.View) *tcpip.Error { return tcpip.ErrInvalidEndpointState } - // Set the ident. Sequence number is provided by the user. - binary.BigEndian.PutUint16(data[header.ICMPv6MinimumSize:], ident) - - hdr := buffer.NewPrependable(header.ICMPv6EchoMinimumSize + int(r.MaxHeaderLength())) + hdr := buffer.NewPrependable(header.ICMPv6MinimumSize + int(r.MaxHeaderLength())) - icmpv6 := header.ICMPv6(hdr.Prepend(header.ICMPv6EchoMinimumSize)) + icmpv6 := header.ICMPv6(hdr.Prepend(header.ICMPv6MinimumSize)) copy(icmpv6, data) - data = data[header.ICMPv6EchoMinimumSize:] + // Set the ident. Sequence number is provided by the user. + icmpv6.SetIdent(ident) + data = data[header.ICMPv6MinimumSize:] if icmpv6.Type() != header.ICMPv6EchoRequest || icmpv6.Code() != 0 { return tcpip.ErrInvalidEndpointState diff --git a/pkg/tcpip/transport/icmp/protocol.go b/pkg/tcpip/transport/icmp/protocol.go index 7fdba5d56..1eb790932 100644 --- a/pkg/tcpip/transport/icmp/protocol.go +++ b/pkg/tcpip/transport/icmp/protocol.go @@ -23,7 +23,6 @@ package icmp import ( - "encoding/binary" "fmt" "gvisor.dev/gvisor/pkg/tcpip" @@ -92,7 +91,7 @@ func (p *protocol) MinimumPacketSize() int { case ProtocolNumber4: return header.ICMPv4MinimumSize case ProtocolNumber6: - return header.ICMPv6EchoMinimumSize + return header.ICMPv6MinimumSize } panic(fmt.Sprint("unknown protocol number: ", p.number)) } @@ -101,16 +100,18 @@ func (p *protocol) MinimumPacketSize() int { func (p *protocol) ParsePorts(v buffer.View) (src, dst uint16, err *tcpip.Error) { switch p.number { case ProtocolNumber4: - return 0, binary.BigEndian.Uint16(v[header.ICMPv4PayloadOffset:]), nil + hdr := header.ICMPv4(v) + return 0, hdr.Ident(), nil case ProtocolNumber6: - return 0, binary.BigEndian.Uint16(v[header.ICMPv6MinimumSize:]), nil + hdr := header.ICMPv6(v) + return 0, hdr.Ident(), nil } panic(fmt.Sprint("unknown protocol number: ", p.number)) } // HandleUnknownDestinationPacket handles packets targeted at this protocol but // that don't match any existing endpoint. -func (p *protocol) HandleUnknownDestinationPacket(*stack.Route, stack.TransportEndpointID, buffer.VectorisedView) bool { +func (p *protocol) HandleUnknownDestinationPacket(*stack.Route, stack.TransportEndpointID, buffer.View, buffer.VectorisedView) bool { return true } -- cgit v1.2.3