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mirror of https://github.com/cwinfo/yggdrasil-go.git synced 2024-12-23 04:05:39 +00:00

check packet length before checking if it's an ipv6 packet, and add some trace level logging whenever a packet is rejected for being too short to parse

This commit is contained in:
Arceliar 2019-09-26 18:11:58 -05:00
parent a87581b0fa
commit e16d3efb0a
2 changed files with 9 additions and 2 deletions

View File

@ -148,6 +148,11 @@ func (tun *TunAdapter) _handlePacket(recvd []byte, err error) {
// Offset the buffer from now on so that we can ignore ethernet frames if
// they are present
bs := recvd[offset:]
// Check if the packet is long enough to detect if it's an ICMP packet or not
if len(bs) < 7 {
tun.log.Traceln("TUN/TAP iface read undersized unknown packet, length:", len(bs))
return
}
// If we detect an ICMP packet then hand it to the ICMPv6 module
if bs[6] == 58 {
// Found an ICMPv6 packet - we need to make sure to give ICMPv6 the full
@ -175,6 +180,7 @@ func (tun *TunAdapter) _handlePacket(recvd []byte, err error) {
if bs[0]&0xf0 == 0x60 {
// Check if we have a fully-sized IPv6 header
if len(bs) < 40 {
tun.log.Traceln("TUN/TAP iface read undersized ipv6 packet, length:", len(bs))
return
}
// Check the packet size
@ -188,6 +194,7 @@ func (tun *TunAdapter) _handlePacket(recvd []byte, err error) {
} else if bs[0]&0xf0 == 0x40 {
// Check if we have a fully-sized IPv4 header
if len(bs) < 20 {
tun.log.Traceln("TUN/TAP iface read undersized ipv6 packet, length:", len(bs))
return
}
// Check the packet size

View File

@ -11,8 +11,8 @@ import (
// This is and is similar to a context, but with an error to specify the reason for the cancellation.
type Cancellation interface {
Finished() <-chan struct{} // Finished returns a channel which will be closed when Cancellation.Cancel is first called.
Cancel(error) error // Cancel closes the channel returned by Finished and sets the error returned by error, or else returns the existing error if the Cancellation has already run.
Error() error // Error returns the error provided to Cancel, or nil if no error has been provided.
Cancel(error) error // Cancel closes the channel returned by Finished and sets the error returned by error, or else returns the existing error if the Cancellation has already run.
Error() error // Error returns the error provided to Cancel, or nil if no error has been provided.
}
// CancellationFinalized is an error returned if a cancellation object was garbage collected and the finalizer was run.