In preparation for improving ARP handling of gratuitous ARPs, set PktType in
regular inbound flow instead of only when handling packet sockets.
PiperOrigin-RevId: 501562322
The packetsocket link endpoint is used to enable a packet endpoint to
receive packets right before they are sent to the driver for outgoing
packets or right after they are recieved from the driver for incoming
packets.
Before this change, only packets that are sent/received by the
`stack.nic` were delivered to packet endpoints. However, the packet
endpoint should also receive packets that don't reach `stack.nic`.
Such an example can be when the interface is bridged and an incoming
packet is sent out through a sibling bridge port instead of being
delivered to a `stack.nic`.
The packetsocket link endpoint must wrap a link endpoint that
populates the link headers for ingress packets. It should ideally
be placed as low in the link endpoint heirarchy as possible so that
packets are probed as close to device drivers as possible.
https://github.com/google/gvisor/commit/2d9b33c0fd7d812a7296cd71f14c03925f815f28
removed the original packetsocket link endpoint which only allowed
low-level capturing of outbound packets but not inbound packets.
The CL mentioned above is cl/395761629.
PiperOrigin-RevId: 424947620
...as they are not used in all cases expect in the packet endpoint
which can get the link address directly from the link header.
PiperOrigin-RevId: 424427195
Formerly, when a packet is constructed or parsed, all headers are set by the
client code. This almost always involved prepending to pk.Header buffer or
trimming pk.Data portion. This is known to prone to bugs, due to the complexity
and number of the invariants assumed across netstack to maintain.
In the new PacketHeader API, client will call Push()/Consume() method to
construct/parse an outgoing/incoming packet. All invariants, such as slicing
and trimming, are maintained by the API itself.
NewPacketBuffer() is introduced to create new PacketBuffer. Zero value is no
longer valid.
PacketBuffer now assumes the packet is a concatenation of following portions:
* LinkHeader
* NetworkHeader
* TransportHeader
* Data
Any of them could be empty, or zero-length.
PiperOrigin-RevId: 326507688
... and unify logic for detached netsted endpoints.
sniffer.go caused crashes if a packet delivery is attempted when the dispatcher
is nil.
Extracted the endpoint nesting logic into a common composable type so it can be
used by the Fuchsia Netstack (the pattern is widespread there).
PiperOrigin-RevId: 317682842