stack.Route is used to send network packets and resolve link addresses.
A LinkEndpoint does not need to do either of these and only needs the
route's fields at the time of the packet write request.
Since LinkEndpoints only need the route's fields when writing packets,
pass a stack.RouteInfo instead.
PiperOrigin-RevId: 352108405
We loop over the list of packets anyways so setting these aren't
expensive.
Now that they are populated only by the link endpoint that uses them,
TCP does not need to.
PiperOrigin-RevId: 352090853
Removes the period of time in which subseqeuent traffic to a Failed neighbor
immediately fails with ErrNoLinkAddress. A Failed neighbor is one in which
address resolution fails; or in other words, the neighbor's IP address cannot
be translated to a MAC address.
This means removing the Failed state for linkAddrCache and allowing transitiong
out of Failed into Incomplete for neighborCache. Previously, both caches would
transition entries to Failed after address resolution fails. In this state, any
subsequent traffic requested within an unreachable time would immediately fail
with ErrNoLinkAddress. This does not follow RFC 4861 section 7.3.3:
If address resolution fails, the entry SHOULD be deleted, so that subsequent
traffic to that neighbor invokes the next-hop determination procedure again.
Invoking next-hop determination at this point ensures that alternate default
routers are tried.
The API for getting a link address for a given address, whether through the link
address cache or the neighbor table, is updated to optionally take a callback
which will be called when address resolution completes. This allows `Route` to
handle completing link resolution internally, so callers of (*Route).Resolve
(e.g. endpoints) don’t have to keep track of when it completes and update the
Route accordingly.
This change also removes the wakers from LinkAddressCache, NeighborCache, and
Route in favor of the callbacks, and callers that previously used a waker can
now just pass a callback to (*Route).Resolve that will notify the waker on
resolution completion.
Fixes#4796
Startblock:
has LGTM from sbalana
and then
add reviewer ghanan
PiperOrigin-RevId: 348597478
Multiple goroutines may use the same stack.Route concurrently so
the stack.Route should make sure that any functions called on it
are thread-safe.
Fixes#4073
PiperOrigin-RevId: 344320491
gVisor incorrectly returns the wrong ARP type for SIOGIFHWADDR. This breaks
tcpdump as it tries to interpret the packets incorrectly.
Similarly, SIOCETHTOOL is used by tcpdump to query interface properties which
fails with an EINVAL since we don't implement it. For now change it to return
EOPNOTSUPP to indicate that we don't support the query rather than return
EINVAL.
NOTE: ARPHRD types for link endpoints are distinct from NIC capabilities
and NIC flags. In Linux all 3 exist eg. ARPHRD types are stored in dev->type
field while NIC capabilities are more like the device features which can be
queried using SIOCETHTOOL but not modified and NIC Flags are fields that can
be modified from user space. eg. NIC status (UP/DOWN/MULTICAST/BROADCAST) etc.
Updates #2746
PiperOrigin-RevId: 321436525
Historically we've been passing PacketBuffer by shallow copying through out
the stack. Right now, this is only correct as the caller would not use
PacketBuffer after passing into the next layer in netstack.
With new buffer management effort in gVisor/netstack, PacketBuffer will
own a Buffer (to be added). Internally, both PacketBuffer and Buffer may
have pointers and shallow copying shouldn't be used.
Updates #2404.
PiperOrigin-RevId: 314610879
The specified LinkEndpoint is not being used in a significant way.
No behavior change, existing tests pass.
This change is a breaking change.
PiperOrigin-RevId: 313496602
Tamir Duberstein
Ghanan Gowripalan
Peter Johnston
Bruno Dal Bo
Adin Scannell
Bhasker Hariharan
Ting-Yu Wang
Sam Balana