rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)

Implement path-MTU probing (along the lines of RFC8899) by padding some of
the PING ACKs we send. PING ACKs get their own individu

rxrpc: Implement path-MTU probing using padded PING ACKs (RFC8899)

Implement path-MTU probing (along the lines of RFC8899) by padding some of
the PING ACKs we send. PING ACKs get their own individual responses quite
apart from the acking of data (though, as ACKs, they fulfil that role
also).

The probing concentrates on packet sizes that correspond how many
subpackets can be stuffed inside a jumbo packet as jumbo DATA packets are
just aggregations of individual DATA packets and can be split easily for
retransmission purposes.

If we want to perform probing, we advertise this by setting the maximum
number of jumbo subpackets to 0 in the ack trailer when we send an ACK and
see if the peer is also advertising the service. This is interpreted by
non-supporting Rx stacks as an indication that jumbo packets aren't
supported.

The MTU sizes advertised in the ACK trailer AF_RXRPC transmits are pegged
at a maximum of 1444 unless pmtud is supported by both sides.

Signed-off-by: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

rxrpc: Fix the names of the fields in the ACK trailer struct

From AFS-3.3 a trailer containing extra info was added to the ACK packet
format - but AF_RXRPC has the names of some of the fields mixed

rxrpc: Fix the names of the fields in the ACK trailer struct

From AFS-3.3 a trailer containing extra info was added to the ACK packet
format - but AF_RXRPC has the names of some of the fields mixed up compared
to other AFS implementations.

Rename the struct and the fields to make them match.

Signed-off-by: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: "David S. Miller" <[email protected]>
cc: Eric Dumazet <[email protected]>
cc: Jakub Kicinski <[email protected]>
cc: Paolo Abeni <[email protected]>
cc: [email protected]
cc: [email protected]

show more ...

rxrpc: Replace fake flex-array with flexible-array member

Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.

Transform

rxrpc: Replace fake flex-array with flexible-array member

Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.

Transform zero-length array into flexible-array member in struct
rxrpc_ackpacket.

Address the following warnings found with GCC-13 and
-fstrict-flex-arrays=3 enabled:
net/rxrpc/call_event.c:149:38: warning: array subscript i is outside array bounds of ‘uint8_t[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/263
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeffrey Altman <[email protected]>
cc: Marc Dionne <[email protected]>
cc: "David S. Miller" <[email protected]>
cc: Eric Dumazet <[email protected]>
cc: Jakub Kicinski <[email protected]>
cc: Paolo Abeni <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/ZAZT11n4q5bBttW0@work/
Signed-off-by: David S. Miller <[email protected]>

show more ...

rxrpc: Clone received jumbo subpackets and queue separately

Split up received jumbo packets into separate skbuffs by cloning the
original skbuff for each subpacket and setting the offset and length

rxrpc: Clone received jumbo subpackets and queue separately

Split up received jumbo packets into separate skbuffs by cloning the
original skbuff for each subpacket and setting the offset and length of the
data in that subpacket in the skbuff's private data. The subpackets are
then placed on the recvmsg queue separately. The security class then gets
to revise the offset and length to remove its metadata.

If we fail to clone a packet, we just drop it and let the peer resend it.
The original packet gets used for the final subpacket.

This should make it easier to handle parallel decryption of the subpackets.
It also simplifies the handling of lost or misordered packets in the
queuing/buffering loop as the possibility of overlapping jumbo packets no
longer needs to be considered.

Signed-off-by: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]

show more ...

rxrpc: Clean up ACK handling

Clean up the rxrpc_propose_ACK() function. If deferred PING ACK proposal
is split out, it's only really needed for deferred DELAY ACKs. All other
ACKs, bar terminal ID

rxrpc: Clean up ACK handling

Clean up the rxrpc_propose_ACK() function. If deferred PING ACK proposal
is split out, it's only really needed for deferred DELAY ACKs. All other
ACKs, bar terminal IDLE ACK are sent immediately. The deferred IDLE ACK
submission can be handled by conversion of a DELAY ACK into an IDLE ACK if
there's nothing to be SACK'd.

Also, because there's a delay between an ACK being generated and being
transmitted, it's possible that other ACKs of the same type will be
generated during that interval. Apart from the ACK time and the serial
number responded to, most of the ACK body, including window and SACK
parameters, are not filled out till the point of transmission - so we can
avoid generating a new ACK if there's one pending that will cover the SACK
data we need to convey.

Therefore, don't propose a new DELAY or IDLE ACK for a call if there's one
already pending.

Signed-off-by: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]

show more ...

net: delete extra space and tab in blank line

delete extra space and tab in blank line, there is no functional change.

Reported-by: Hacash Robot <[email protected]>
Signed-off-by: William Dea

net: delete extra space and tab in blank line

delete extra space and tab in blank line, there is no functional change.

Reported-by: Hacash Robot <[email protected]>
Signed-off-by: William Dean <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

rxrpc: Improve jumbo packet counting

Improve the information stored about jumbo packets so that we don't need to
reparse them so much later.

Signed-off-by: David Howells <[email protected]>
Revie

rxrpc: Improve jumbo packet counting

Improve the information stored about jumbo packets so that we don't need to
reparse them so much later.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeffrey Altman <[email protected]>

show more ...

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

rxrpc: Improve up-front incoming packet checking

Do more up-front checking on incoming packets to weed out invalid ones and
also ones aimed at services that we don't support.

Whilst we're at it, re

rxrpc: Improve up-front incoming packet checking

Do more up-front checking on incoming packets to weed out invalid ones and
also ones aimed at services that we don't support.

Whilst we're at it, replace the clearing of call and skew if we don't find
a connection with just initialising the variables to zero at the top of the
function.

Signed-off-by: David Howells <[email protected]>

show more ...

rxrpc: Fix undefined packet handling

By analogy with other Rx implementations, RxRPC packet types 9, 10 and 11
should just be discarded rather than being aborted like other undefined
packet types.

rxrpc: Fix undefined packet handling

By analogy with other Rx implementations, RxRPC packet types 9, 10 and 11
should just be discarded rather than being aborted like other undefined
packet types.

Reported-by: Jeffrey Altman <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

rxrpc: Move the packet.h include file into net/rxrpc/

Move the protocol description header file into net/rxrpc/ and rename it to
protocol.h. It's no longer necessary to expose it as packets are no

rxrpc: Move the packet.h include file into net/rxrpc/

Move the protocol description header file into net/rxrpc/ and rename it to
protocol.h. It's no longer necessary to expose it as packets are no longer
exposed to kernel services (such as AFS) that use the facility.

The abort codes are transferred to the UAPI header instead as we pass these
back to userspace and also to kernel services.

Signed-off-by: David Howells <[email protected]>

show more ...