Previously, if address resolution for UDP or Ping sockets required sending
packets using Write in Transport layer, Resolve would return ErrWouldBlock
and Write would return ErrNoLinkAddress. Meanwhile startAddressResolution
would run in background. Further calls to Write using same address would also
return ErrNoLinkAddress until resolution has been completed successfully.
Since Write is not allowed to block and System Calls need to be
interruptible in System Call layer, the caller to Write is responsible for
blocking upon return of ErrWouldBlock.
Now, when startAddressResolution is called a notification channel for
the completion of the address resolution is returned.
The channel will traverse up to the calling function of Write as well as
ErrNoLinkAddress. Once address resolution is complete (success or not) the
channel is closed. The caller would call Write again to send packets and
check if address resolution was compeleted successfully or not.
Fixesgoogle/gvisor#5
Change-Id: Idafaf31982bee1915ca084da39ae7bd468cebd93
PiperOrigin-RevId: 214962200
There is a subtle bug that is the result of two changes made when upstreaming
ICMPv6 support from Fuchsia:
1) ipv6.endpoint.WritePacket writes the local address it was initialized with,
rather than the provided route's local address
2) ipv6.endpoint.handleICMP doesn't set its route's local address to the ICMP
target address before writing the response
The result is that the ICMP response erroneously uses the target ipv6 address
(rather than icmp) as its source address in the response. When trying to debug
this by fixing (2), we ran into problems with bad ipv6 checksums because (1)
didn't respect the local address of the route being passed to it.
This fixes both problems.
PiperOrigin-RevId: 214650822
Change-Id: Ib6148bf432e6428d760ef9da35faef8e4b610d69
Makes it possible to avoid copying or allocating in cases where DeliverNetworkPacket (rx)
needs to turn around and call WritePacket (tx) with its VectorisedView.
Also removes the restriction on having VectorisedViews with multiple views in the write path.
PiperOrigin-RevId: 211728717
Change-Id: Ie03a65ecb4e28bd15ebdb9c69f05eced18fdfcff
This CL does NDP link-address discovery for IPv6.
It includes several small changes necessary to get linux to talk to
this implementation. In particular, a hop limit of 255 is necessary
for ICMPv6.
PiperOrigin-RevId: 211103930
Change-Id: If25370ab84c6b1decfb15de917f3b0020f2c4e0e