linux-toradex.git/include/net/mptcp.h, branch v5.12

mptcp: add port support for ADD_ADDR suboption writing

2020-12-10T03:02:15+00:00

In rfc8684, the length of ADD_ADDR suboption with IPv4 address and port
is 18 octets, but mptcp_write_options is 32-bit aligned, so we need to
pad it to 20 octets. All the other port related option lengths need to
be added up 2 octets similarly.

This patch added a new field 'port' in mptcp_out_options. When this
field is set with a port number, we need to add up 4 octets for the
ADD_ADDR suboption, and put the port number into the suboption.

Signed-off-by: Geliang Tang 
Signed-off-by: Mat Martineau 
Signed-off-by: David S. Miller

mptcp: track window announced to peer

2020-11-20T23:33:25+00:00

OoO handling attempts to detect when packet is out-of-window by testing
current ack sequence and remaining space vs. sequence number.

This doesn't work reliably. Store the highest allowed sequence number
that we've announced and use it to detect oow packets.

Do this when mptcp options get written to the packet (wire format).
For this to work we need to move the write_options call until after
stack selected a new tcp window.

Acked-by: Paolo Abeni 
Signed-off-by: Florian Westphal 
Signed-off-by: Mat Martineau 
Signed-off-by: Jakub Kicinski

tcp: propagate MPTCP skb extensions on xmit splits

2020-11-05T01:45:53+00:00

When the TCP stack splits a packet on the write queue, the tail
half currently lose the associated skb extensions, and will not
carry the DSM on the wire.

The above does not cause functional problems and is allowed by
the RFC, but interact badly with GRO and RX coalescing, as possible
candidates for aggregation will carry different TCP options.

This change tries to improve the MPTCP behavior, propagating the
skb extensions on split.

Additionally, we must prevent the MPTCP stack from updating the
mapping after the split occur: that will both violate the RFC and
fool the reader.

Signed-off-by: Paolo Abeni 
Signed-off-by: Mat Martineau 
Signed-off-by: Jakub Kicinski

net: tcp: drop unused function argument from mptcp_incoming_options

2020-09-25T03:17:01+00:00

Since commit cfde141ea3faa30e ("mptcp: move option parsing into
mptcp_incoming_options()"), the 3rd function argument is no longer used.

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

mptcp: subflow: add mptcp_subflow_init_cookie_req helper

2020-07-31T23:55:32+00:00

Will be used to initialize the mptcp request socket when a MP_CAPABLE
request was handled in syncookie mode, i.e. when a TCP ACK containing a
MP_CAPABLE option is a valid syncookie value.

Normally (non-cookie case), MPTCP will generate a unique 32 bit connection
ID and stores it in the MPTCP token storage to be able to retrieve the
mptcp socket for subflow joining.

In syncookie case, we do not want to store any state, so just generate the
unique ID and use it in the reply.

This means there is a small window where another connection could generate
the same token.

When Cookie ACK comes back, we check that the token has not been registered
in the mean time.  If it was, the connection needs to fall back to TCP.

Changes in v2:
 - use req->syncookie instead of passing 'want_cookie' arg to ->init_req()
   (Eric Dumazet)

Signed-off-by: Florian Westphal 
Reviewed-by: Mat Martineau 
Signed-off-by: David S. Miller

mptcp: rename and export mptcp_subflow_request_sock_ops

2020-07-31T23:55:32+00:00

syncookie code path needs to create an mptcp request sock.

Prepare for this and add mptcp prefix plus needed export of ops struct.

Signed-off-by: Florian Westphal 
Reviewed-by: Mat Martineau 
Signed-off-by: David S. Miller

mptcp: Remove unused inline function mptcp_rcv_synsent()

2020-07-15T14:45:24+00:00

commit 263e1201a2c3 ("mptcp: consolidate synack processing.")
left behind this, remove it.

Signed-off-by: YueHaibing 
Acked-by: Paolo Abeni 
Signed-off-by: David S. Miller

mptcp: Use 32-bit DATA_ACK when possible

2020-05-16T20:51:10+00:00

RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not
sending 64-bit data-sequence numbers. The 64-bit DSN is only there for
extreme scenarios when a very high throughput subflow is combined with a
long-RTT subflow such that the high-throughput subflow wraps around the
32-bit sequence number space within an RTT of the high-RTT subflow.

It is thus a rare scenario and we should try to use the 32-bit DATA_ACK
instead as long as possible. It allows to reduce the TCP-option overhead
by 4 bytes, thus makes space for an additional SACK-block. It also makes
tcpdumps much easier to read when the DSN and DATA_ACK are both either
32 or 64-bit.

Signed-off-by: Christoph Paasch 
Reviewed-by: Matthieu Baerts 
Signed-off-by: David S. Miller

mptcp: add new sock flag to deal with join subflows

2020-05-15T19:30:13+00:00

MP_JOIN subflows must not land into the accept queue.
Currently tcp_check_req() calls an mptcp specific helper
to detect such scenario.

Such helper leverages the subflow context to check for
MP_JOIN subflows. We need to deal also with MP JOIN
failures, even when the subflow context is not available
due allocation failure.

A possible solution would be changing the syn_recv_sock()
signature to allow returning a more descriptive action/
error code and deal with that in tcp_check_req().

Since the above need is MPTCP specific, this patch instead
uses a TCP request socket hole to add a MPTCP specific flag.
Such flag is used by the MPTCP syn_recv_sock() to tell
tcp_check_req() how to deal with the request socket.

This change is a no-op for !MPTCP build, and makes the
MPTCP code simpler. It allows also the next patch to deal
correctly with MP JOIN failure.

v1 -> v2:
 - be more conservative on drop_req initialization (Mat)

RFC -> v1:
 - move the drop_req bit inside tcp_request_sock (Eric)

Signed-off-by: Paolo Abeni 
Reviewed-by: Mat Martineau 
Reviewed-by: Christoph Paasch 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-05-07T05:10:13+00:00

Conflicts were all overlapping changes.

Signed-off-by: David S. Miller