linux.git/net/rxrpc/input.c, branch v4.15

rxrpc: Clean up whitespace

2017-11-29T14:40:41+00:00

Clean up some whitespace from rxrpc.

Signed-off-by: David Howells

rxrpc: Add a timeout for detecting lost ACKs/lost DATA

2017-11-24T10:18:42+00:00

Add an extra timeout that is set/updated when we send a DATA packet that
has the request-ack flag set.  This allows us to detect if we don't get an
ACK in response to the latest flagged packet.

The ACK packet is adjudged to have been lost if it doesn't turn up within
2*RTT of the transmission.

If the timeout occurs, we schedule the sending of a PING ACK to find out
the state of the other side.  If a new DATA packet is ready to go sooner,
we cancel the sending of the ping and set the request-ack flag on that
instead.

If we get back a PING-RESPONSE ACK that indicates a lower tx_top than what
we had at the time of the ping transmission, we adjudge all the DATA
packets sent between the response tx_top and the ping-time tx_top to have
been lost and retransmit immediately.

Rather than sending a PING ACK, we could just pick a DATA packet and
speculatively retransmit that with request-ack set.  It should result in
either a REQUESTED ACK or a DUPLICATE ACK which we can then use in lieu the
a PING-RESPONSE ACK mentioned above.

Signed-off-by: David Howells

rxrpc: Fix call timeouts

2017-11-24T10:18:41+00:00

Fix the rxrpc call expiration timeouts and make them settable from
userspace.  By analogy with other rx implementations, there should be three
timeouts:

 (1) "Normal timeout"

     This is set for all calls and is triggered if we haven't received any
     packets from the peer in a while.  It is measured from the last time
     we received any packet on that call.  This is not reset by any
     connection packets (such as CHALLENGE/RESPONSE packets).

     If a service operation takes a long time, the server should generate
     PING ACKs at a duration that's substantially less than the normal
     timeout so is to keep both sides alive.  This is set at 1/6 of normal
     timeout.

 (2) "Idle timeout"

     This is set only for a service call and is triggered if we stop
     receiving the DATA packets that comprise the request data.  It is
     measured from the last time we received a DATA packet.

 (3) "Hard timeout"

     This can be set for a call and specified the maximum lifetime of that
     call.  It should not be specified by default.  Some operations (such
     as volume transfer) take a long time.

Allow userspace to set/change the timeouts on a call with sendmsg, using a
control message:

	RXRPC_SET_CALL_TIMEOUTS

The data to the message is a number of 32-bit words, not all of which need
be given:

	u32 hard_timeout;	/* sec from first packet */
	u32 idle_timeout;	/* msec from packet Rx */
	u32 normal_timeout;	/* msec from data Rx */

This can be set in combination with any other sendmsg() that affects a
call.

Signed-off-by: David Howells

rxrpc: Fix call expiry handling

2017-11-02T15:20:43+00:00

Fix call expiry handling in the following ways

 (1) If all the request data from a client call is acked, don't send a
     follow up IDLE ACK with firstPacket == 1 and previousPacket == 0 as
     this appears to fool some servers into thinking everything has been
     accepted.

 (2) Never send an abort back to the server once it has ACK'd all the
     request packets; rather just try to reuse the channel for the next
     call.  The first request DATA packet of the next call on the same
     channel will implicitly ACK the entire reply of the dead call - even
     if we haven't transmitted it yet.

 (3) Don't send RX_CALL_TIMEOUT in an ABORT packet, librx uses abort codes
     to pass local errors to the caller in addition to remote errors, and
     this is meant to be local only.

The following also need to be addressed in future patches:

 (4) Service calls should send PING ACKs as 'keep alives' if the server is
     still processing the call.

 (5) VERSION REPLY packets should be sent to the peers of service
     connections to act as keep-alives.  This is used to keep firewall
     routes in place.  The AFS CM should enable this.

Signed-off-by: David Howells

net: rxrpc: mark expected switch fall-throughs

2017-10-24T09:27:06+00:00

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: David S. Miller

rxrpc: Add service upgrade support for client connections

2017-06-05T13:30:49+00:00

Make it possible for a client to use AuriStor's service upgrade facility.

The client does this by adding an RXRPC_UPGRADE_SERVICE control message to
the first sendmsg() of a call.  This takes no parameters.

When recvmsg() starts returning data from the call, the service ID field in
the returned msg_name will reflect the result of the upgrade attempt.  If
the upgrade was ignored, srx_service will match what was set in the
sendmsg(); if the upgrade happened the srx_service will be altered to
indicate the service the server upgraded to.

Note that:

 (1) The choice of upgrade service is up to the server

 (2) Further client calls to the same server that would share a connection
     are blocked if an upgrade probe is in progress.

 (3) This should only be used to probe the service.  Clients should then
     use the returned service ID in all subsequent communications with that
     server (and not set the upgrade).  Note that the kernel will not
     retain this information should the connection expire from its cache.

 (4) If a server that supports upgrading is replaced by one that doesn't,
     whilst a connection is live, and if the replacement is running, say,
     OpenAFS 1.6.4 or older or an older IBM AFS, then the replacement
     server will not respond to packets sent to the upgraded connection.

     At this point, calls will time out and the server must be reprobed.

Signed-off-by: David Howells

rxrpc: Trace changes in a call's receive window size

2017-04-06T10:10:41+00:00

Add a tracepoint (rxrpc_rx_rwind_change) to log changes in a call's receive
window size as imposed by the peer through an ACK packet.

Signed-off-by: David Howells

rxrpc: Trace received aborts

2017-04-06T10:10:41+00:00

Add a tracepoint (rxrpc_rx_abort) to record received aborts.

Signed-off-by: David Howells

rxrpc: Trace protocol errors in received packets

2017-04-06T10:09:39+00:00

Add a tracepoint (rxrpc_rx_proto) to record protocol errors in received
packets.  The following changes are made:

 (1) Add a function, __rxrpc_abort_eproto(), to note a protocol error on a
     call and mark the call aborted.  This is wrapped by
     rxrpc_abort_eproto() that makes the why string usable in trace.

 (2) Add trace_rxrpc_rx_proto() or rxrpc_abort_eproto() to protocol error
     generation points, replacing rxrpc_abort_call() with the latter.

 (3) Only send an abort packet in rxkad_verify_packet*() if we actually
     managed to abort the call.

Note that a trace event is also emitted if a kernel user (e.g. afs) tries
to send data through a call when it's not in the transmission phase, though
it's not technically a receive event.

Signed-off-by: David Howells

rxrpc: Use negative error codes in rxrpc_call struct

2017-04-06T09:11:56+00:00

Use negative error codes in struct rxrpc_call::error because that's what
the kernel normally deals with and to make the code consistent.  We only
turn them positive when transcribing into a cmsg for userspace recvmsg.

Signed-off-by: David Howells