Previously, when a packet was sent from a raw packet socket, the packet
buffer's link header was left unpopulated and the link header was only
found in the packet buffer's payload. This breaks the expectations of
LinkEndpoints which expect the link layer header to always be populated
when the link requires a header.
PiperOrigin-RevId: 542349445
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
The arguments passed to LinkEndpoint.AddHeader are all available in
the packet buffer so just get the values from the packet buffer.
PiperOrigin-RevId: 424463821
...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
With this change, GSO options no longer needs to be passed around as
a function argument in the write path.
This change is done in preparation for a later change that defers
segmentation, and may change GSO options for a packet as it flows
down the stack.
Updates #170.
PiperOrigin-RevId: 369774872
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
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
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
