diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4/icmp.go')
| -rw-r--r-- | pkg/tcpip/network/ipv4/icmp.go | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go index 3f2093f00..c8ed1ce79 100644 --- a/pkg/tcpip/network/ipv4/icmp.go +++ b/pkg/tcpip/network/ipv4/icmp.go @@ -446,6 +446,23 @@ func (r *icmpReasonParamProblem) isForwarding() bool { return r.forwarding } +// icmpReasonNetworkUnreachable is an error in which the network specified in +// the internet destination field of the datagram is unreachable. +type icmpReasonNetworkUnreachable struct{} + +func (*icmpReasonNetworkUnreachable) isICMPReason() {} +func (*icmpReasonNetworkUnreachable) isForwarding() bool { + // If we hit a Net Unreachable error, then we know we are operating as + // a router. As per RFC 792 page 5, Destination Unreachable Message, + // + // If, according to the information in the gateway's routing tables, + // the network specified in the internet destination field of a + // datagram is unreachable, e.g., the distance to the network is + // infinity, the gateway may send a destination unreachable message to + // the internet source host of the datagram. + return true +} + // 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 @@ -614,6 +631,10 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip 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 *icmpReasonTTLExceeded: icmpHdr.SetType(header.ICMPv4TimeExceeded) icmpHdr.SetCode(header.ICMPv4TTLExceeded) |