Commit Graph

82 Commits

Author SHA1 Message Date
David Howells
9d35d880e0 rxrpc: Move client call connection to the I/O thread
Move the connection setup of client calls to the I/O thread so that a whole
load of locking and barrierage can be eliminated.  This necessitates the
app thread waiting for connection to complete before it can begin
encrypting data.

This also completes the fix for a race that exists between call connection
and call disconnection whereby the data transmission code adds the call to
the peer error distribution list after the call has been disconnected (say
by the rxrpc socket getting closed).

The fix is to complete the process of moving call connection, data
transmission and call disconnection into the I/O thread and thus forcibly
serialising them.

Note that the issue may predate the overhaul to an I/O thread model that
were included in the merge window for v6.2, but the timing is very much
changed by the change given below.

Fixes: cf37b59875 ("rxrpc: Move DATA transmission into call processor work item")
Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2023-01-06 09:43:33 +00:00
David Howells
0d6bf319bc rxrpc: Move the client conn cache management to the I/O thread
Move the management of the client connection cache to the I/O thread rather
than managing it from the namespace as an aggregate across all the local
endpoints within the namespace.

This will allow a load of locking to be got rid of in a future patch as
only the I/O thread will be looking at the this.

The downside is that the total number of cached connections on the system
can get higher because the limit is now per-local rather than per-netns.
We can, however, keep the number of client conns in use across the entire
netfs and use that to reduce the expiration time of idle connection.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2023-01-06 09:43:33 +00:00
David Howells
1bab27af6b rxrpc: Set up a connection bundle from a call, not rxrpc_conn_parameters
Use the information now stored in struct rxrpc_call to configure the
connection bundle and thence the connection, rather than using the
rxrpc_conn_parameters struct.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2023-01-06 09:43:32 +00:00
David Howells
f06cb29189 rxrpc: Make the set of connection IDs per local endpoint
Make the set of connection IDs per local endpoint so that endpoints don't
cause each other's connections to get dismissed.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2023-01-06 09:43:32 +00:00
David Howells
f2cce89a07 rxrpc: Implement a mechanism to send an event notification to a connection
Provide a means by which an event notification can be sent to a connection
through such that the I/O thread can pick it up and handle it rather than
doing it in a separate workqueue.

This is then used to move the deferred final ACK of a call into the I/O
thread rather than a separate work queue as part of the drive to do all
transmission from the I/O thread.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2023-01-06 09:43:31 +00:00
David Howells
5040011d07 rxrpc: Make the local endpoint hold a ref on a connected call
Make the local endpoint and it's I/O thread hold a reference on a connected
call until that call is disconnected.  Without this, we're reliant on
either the AF_RXRPC socket to hold a ref (which is dropped when the call is
released) or a queued work item to hold a ref (the work item is being
replaced with the I/O thread).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2023-01-06 09:43:31 +00:00
David Howells
5e6ef4f101 rxrpc: Make the I/O thread take over the call and local processor work
Move the functions from the call->processor and local->processor work items
into the domain of the I/O thread.

The call event processor, now called from the I/O thread, then takes over
the job of cranking the call state machine, processing incoming packets and
transmitting DATA, ACK and ABORT packets.  In a future patch,
rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it
for later transmission.

The call event processor becomes purely received-skb driven.  It only
transmits things in response to events.  We use "pokes" to queue a dummy
skb to make it do things like start/resume transmitting data.  Timer expiry
also results in pokes.

The connection event processor, becomes similar, though crypto events, such
as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item
to avoid doing crypto in the I/O thread.

The local event processor is removed and VERSION response packets are
generated directly from the packet parser.  Similarly, ABORTs generated in
response to protocol errors will be transmitted immediately rather than
being pushed onto a queue for later transmission.

Changes:
========
ver #2)
 - Fix a couple of introduced lock context imbalances.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:42 +00:00
David Howells
393a2a2007 rxrpc: Extract the peer address from an incoming packet earlier
Extract the peer address from an incoming packet earlier, at the beginning
of rxrpc_input_packet() and thence pass a pointer to it to various
functions that use it as part of the lookup rather than doing it on several
separate paths.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:42 +00:00
David Howells
29fb4ec385 rxrpc: Remove RCU from peer->error_targets list
Remove the RCU requirements from the peer's list of error targets so that
the error distributor can call sleeping functions.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:41 +00:00
David Howells
3cec055c56 rxrpc: Don't hold a ref for connection workqueue
Currently, rxrpc gives the connection's work item a ref on the connection
when it queues it - and this is called from the timer expiration function.
The problem comes when queue_work() fails (ie. the work item is already
queued): the timer routine must put the ref - but this may cause the
cleanup code to run.

This has the unfortunate effect that the cleanup code may then be run in
softirq context - which means that any spinlocks it might need to touch
have to be guarded to disable softirqs (ie. they need a "_bh" suffix).

 (1) Don't give a ref to the work item.

 (2) Simplify handling of service connections by adding a separate active
     count so that the refcount isn't also used for this.

 (3) Connection destruction for both client and service connections can
     then be cleaned up by putting rxrpc_put_connection() out of line and
     making a tidy progression through the destruction code (offloaded to a
     workqueue if put from softirq or processor function context).  The RCU
     part of the cleanup then only deals with the freeing at the end.

 (4) Make rxrpc_queue_conn() return immediately if it sees the active count
     is -1 rather then queuing the connection.

 (5) Make sure that the cleanup routine waits for the work item to
     complete.

 (6) Stash the rxrpc_net pointer in the conn struct so that the rcu free
     routine can use it, even if the local endpoint has been freed.

Unfortunately, neither the timer nor the work item can simply get around
the problem by just using refcount_inc_not_zero() as the waits would still
have to be done, and there would still be the possibility of having to put
the ref in the expiration function.

Note the connection work item is mostly going to go away with the main
event work being transferred to the I/O thread, so the wait in (6) will
become obsolete.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:40 +00:00
David Howells
fa3492abb6 rxrpc: Trace rxrpc_bundle refcount
Add a tracepoint for the rxrpc_bundle refcounting.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:39 +00:00
David Howells
7fa25105b2 rxrpc: trace: Don't use __builtin_return_address for rxrpc_conn tracing
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_conn tracepoint

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:39 +00:00
David Howells
47c810a798 rxrpc: trace: Don't use __builtin_return_address for rxrpc_peer tracing
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_peer tracepoint

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:38 +00:00
David Howells
0fde882fc9 rxrpc: trace: Don't use __builtin_return_address for rxrpc_local tracing
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_local tracepoint

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:38 +00:00
David Howells
2cc800863c rxrpc: Drop rxrpc_conn_parameters from rxrpc_connection and rxrpc_bundle
Remove the rxrpc_conn_parameters struct from the rxrpc_connection and
rxrpc_bundle structs and emplace the members directly.  These are going to
get filled in from the rxrpc_call struct in future.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:38 +00:00
David Howells
e969c92ce5 rxrpc: Remove the [_k]net() debugging macros
Remove the _net() and knet() debugging macros in favour of tracepoints.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-12-01 13:36:38 +00:00
David Howells
1fc4fa2ac9 rxrpc: Fix congestion management
rxrpc has a problem in its congestion management in that it saves the
congestion window size (cwnd) from one call to another, but if this is 0 at
the time is saved, then the next call may not actually manage to ever
transmit anything.

To this end:

 (1) Don't save cwnd between calls, but rather reset back down to the
     initial cwnd and re-enter slow-start if data transmission is idle for
     more than an RTT.

 (2) Preserve ssthresh instead, as that is a handy estimate of pipe
     capacity.  Knowing roughly when to stop slow start and enter
     congestion avoidance can reduce the tendency to overshoot and drop
     larger amounts of packets when probing.

In future, cwind growth also needs to be constrained when the window isn't
being filled due to being application limited.

Reported-by: Simon Wilkinson <sxw@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-11-08 16:42:28 +00:00
David Howells
5d7edbc923 rxrpc: Get rid of the Rx ring
Get rid of the Rx ring and replace it with a pair of queues instead.  One
queue gets the packets that are in-sequence and are ready for processing by
recvmsg(); the other queue gets the out-of-sequence packets for addition to
the first queue as the holes get filled.

The annotation ring is removed and replaced with a SACK table.  The SACK
table has the bits set that correspond exactly to the sequence number of
the packet being acked.  The SACK ring is copied when an ACK packet is
being assembled and rotated so that the first ACK is in byte 0.

Flow control handling is altered so that packets that are moved to the
in-sequence queue are hard-ACK'd even before they're consumed - and then
the Rx window size in the ACK packet (rsize) is shrunk down to compensate
(even going to 0 if the window is full).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
2022-11-08 16:42:28 +00:00
David Howells
de696c4784 rxrpc, afs: Fix selection of abort codes
The RX_USER_ABORT code should really only be used to indicate that the user
of the rxrpc service (ie. userspace) implicitly caused a call to be aborted
- for instance if the AF_RXRPC socket is closed whilst the call was in
progress.  (The user may also explicitly abort a call and specify the abort
code to use).

Change some of the points of generation to use other abort codes instead:

 (1) Abort the call with RXGEN_SS_UNMARSHAL or RXGEN_CC_UNMARSHAL if we see
     ENOMEM and EFAULT during received data delivery and abort with
     RX_CALL_DEAD in the default case.

 (2) Abort with RXGEN_SS_MARSHAL if we get ENOMEM whilst trying to send a
     reply.

 (3) Abort with RX_CALL_DEAD if we stop hearing from the peer if we had
     heard from the peer and abort with RX_CALL_TIMEOUT if we hadn't.

 (4) Abort with RX_CALL_DEAD if we try to disconnect a call that's not
     completed successfully or been aborted.

Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-22 21:03:02 +01:00
David Howells
a05754295e rxrpc: Use refcount_t rather than atomic_t
Move to using refcount_t rather than atomic_t for refcounts in rxrpc.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-22 21:03:01 +01:00
David Howells
d7d775b1ff rxrpc: Ask the security class how much space to allow in a packet
Ask the security class how much header and trailer space to allow for when
allocating a packet, given how much data is remaining.

This will allow the rxgk security class to stick both a trailer in as well
as a header as appropriate in the future.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-11-23 19:53:11 +00:00
David Howells
ec832bd06d rxrpc: Don't retain the server key in the connection
Don't retain a pointer to the server key in the connection, but rather get
it on demand when the server has to deal with a response packet.

This is necessary to implement RxGK (GSSAPI-mediated transport class),
where we can't know which key we'll need until we've challenged the client
and got back the response.

This also means that we don't need to do a key search in the accept path in
softirq mode.

Also, whilst we're at it, allow the security class to ask for a kvno and
encoding-type variant of a server key as RxGK needs different keys for
different encoding types.  Keys of this type have an extra bit in the
description:

	"<service-id>:<security-index>:<kvno>:<enctype>"

Signed-off-by: David Howells <dhowells@redhat.com>
2020-11-23 18:09:29 +00:00
David Howells
245500d853 rxrpc: Rewrite the client connection manager
Rewrite the rxrpc client connection manager so that it can support multiple
connections for a given security key to a peer.  The following changes are
made:

 (1) For each open socket, the code currently maintains an rbtree with the
     connections placed into it, keyed by communications parameters.  This
     is tricky to maintain as connections can be culled from the tree or
     replaced within it.  Connections can require replacement for a number
     of reasons, e.g. their IDs span too great a range for the IDR data
     type to represent efficiently, the call ID numbers on that conn would
     overflow or the conn got aborted.

     This is changed so that there's now a connection bundle object placed
     in the tree, keyed on the same parameters.  The bundle, however, does
     not need to be replaced.

 (2) An rxrpc_bundle object can now manage the available channels for a set
     of parallel connections.  The lock that manages this is moved there
     from the rxrpc_connection struct (channel_lock).

 (3) There'a a dummy bundle for all incoming connections to share so that
     they have a channel_lock too.  It might be better to give each
     incoming connection its own bundle.  This bundle is not needed to
     manage which channels incoming calls are made on because that's the
     solely at whim of the client.

 (4) The restrictions on how many client connections are around are
     removed.  Instead, a previous patch limits the number of client calls
     that can be allocated.  Ordinarily, client connections are reaped
     after 2 minutes on the idle queue, but when more than a certain number
     of connections are in existence, the reaper starts reaping them after
     2s of idleness instead to get the numbers back down.

     It could also be made such that new call allocations are forced to
     wait until the number of outstanding connections subsides.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-09-08 21:11:43 +01:00
David Howells
65550098c1 rxrpc: Fix race between recvmsg and sendmsg on immediate call failure
There's a race between rxrpc_sendmsg setting up a call, but then failing to
send anything on it due to an error, and recvmsg() seeing the call
completion occur and trying to return the state to the user.

An assertion fails in rxrpc_recvmsg() because the call has already been
released from the socket and is about to be released again as recvmsg deals
with it.  (The recvmsg_q queue on the socket holds a ref, so there's no
problem with use-after-free.)

We also have to be careful not to end up reporting an error twice, in such
a way that both returns indicate to userspace that the user ID supplied
with the call is no longer in use - which could cause the client to
malfunction if it recycles the user ID fast enough.

Fix this by the following means:

 (1) When sendmsg() creates a call after the point that the call has been
     successfully added to the socket, don't return any errors through
     sendmsg(), but rather complete the call and let recvmsg() retrieve
     them.  Make sendmsg() return 0 at this point.  Further calls to
     sendmsg() for that call will fail with ESHUTDOWN.

     Note that at this point, we haven't send any packets yet, so the
     server doesn't yet know about the call.

 (2) If sendmsg() returns an error when it was expected to create a new
     call, it means that the user ID wasn't used.

 (3) Mark the call disconnected before marking it completed to prevent an
     oops in rxrpc_release_call().

 (4) recvmsg() will then retrieve the error and set MSG_EOR to indicate
     that the user ID is no longer known by the kernel.

An oops like the following is produced:

	kernel BUG at net/rxrpc/recvmsg.c:605!
	...
	RIP: 0010:rxrpc_recvmsg+0x256/0x5ae
	...
	Call Trace:
	 ? __init_waitqueue_head+0x2f/0x2f
	 ____sys_recvmsg+0x8a/0x148
	 ? import_iovec+0x69/0x9c
	 ? copy_msghdr_from_user+0x5c/0x86
	 ___sys_recvmsg+0x72/0xaa
	 ? __fget_files+0x22/0x57
	 ? __fget_light+0x46/0x51
	 ? fdget+0x9/0x1b
	 do_recvmmsg+0x15e/0x232
	 ? _raw_spin_unlock+0xa/0xb
	 ? vtime_delta+0xf/0x25
	 __x64_sys_recvmmsg+0x2c/0x2f
	 do_syscall_64+0x4c/0x78
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 357f5ef646 ("rxrpc: Call rxrpc_release_call() on error in rxrpc_new_client_call()")
Reported-by: syzbot+b54969381df354936d96@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:50:20 -07:00
David Howells
b39a934ec7 rxrpc: Fix service call disconnection
The recent patch that substituted a flag on an rxrpc_call for the
connection pointer being NULL as an indication that a call was disconnected
puts the set_bit in the wrong place for service calls.  This is only a
problem if a call is implicitly terminated by a new call coming in on the
same connection channel instead of a terminating ACK packet.

In such a case, rxrpc_input_implicit_end_call() calls
__rxrpc_disconnect_call(), which is now (incorrectly) setting the
disconnection bit, meaning that when rxrpc_release_call() is later called,
it doesn't call rxrpc_disconnect_call() and so the call isn't removed from
the peer's error distribution list and the list gets corrupted.

KASAN finds the issue as an access after release on a call, but the
position at which it occurs is confusing as it appears to be related to a
different call (the call site is where the latter call is being removed
from the error distribution list and either the next or pprev pointer
points to a previously released call).

Fix this by moving the setting of the flag from __rxrpc_disconnect_call()
to rxrpc_disconnect_call() in the same place that the connection pointer
was being cleared.

Fixes: 5273a191dc ("rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnect")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-07 11:19:38 +01:00
David Howells
5273a191dc rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnect
When a call is disconnected, the connection pointer from the call is
cleared to make sure it isn't used again and to prevent further attempted
transmission for the call.  Unfortunately, there might be a daemon trying
to use it at the same time to transmit a packet.

Fix this by keeping call->conn set, but setting a flag on the call to
indicate disconnection instead.

Remove also the bits in the transmission functions where the conn pointer is
checked and a ref taken under spinlock as this is now redundant.

Fixes: 8d94aa381d ("rxrpc: Calls shouldn't hold socket refs")
Signed-off-by: David Howells <dhowells@redhat.com>
2020-02-03 10:25:30 +00:00
David Howells
4c1295dccc rxrpc: Fix trace-after-put looking at the put connection record
rxrpc_put_*conn() calls trace_rxrpc_conn() after they have done the
decrement of the refcount - which looks at the debug_id in the connection
record.  But unless the refcount was reduced to zero, we no longer have the
right to look in the record and, indeed, it may be deleted by some other
thread.

Fix this by getting the debug_id out before decrementing the refcount and
then passing that into the tracepoint.

Fixes: 363deeab6d ("rxrpc: Add connection tracepoint and client conn state tracepoint")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-10-07 11:05:05 +01:00
David Howells
d12040b693 rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2]
When a local endpoint is ceases to be in use, such as when the kafs module
is unloaded, the kernel will emit an assertion failure if there are any
outstanding client connections:

	rxrpc: Assertion failed
	------------[ cut here ]------------
	kernel BUG at net/rxrpc/local_object.c:433!

and even beyond that, will evince other oopses if there are service
connections still present.

Fix this by:

 (1) Removing the triggering of connection reaping when an rxrpc socket is
     released.  These don't actually clean up the connections anyway - and
     further, the local endpoint may still be in use through another
     socket.

 (2) Mark the local endpoint as dead when we start the process of tearing
     it down.

 (3) When destroying a local endpoint, strip all of its client connections
     from the idle list and discard the ref on each that the list was
     holding.

 (4) When destroying a local endpoint, call the service connection reaper
     directly (rather than through a workqueue) to immediately kill off all
     outstanding service connections.

 (5) Make the service connection reaper reap connections for which the
     local endpoint is marked dead.

Only after destroying the connections can we close the socket lest we get
an oops in a workqueue that's looking at a connection or a peer.

Fixes: 3d18cbb7fd ("rxrpc: Fix conn expiry timers")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-30 15:06:52 -07:00
Thomas Gleixner
2874c5fd28 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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
David Howells
5a790b7375 rxrpc: Drop the local endpoint arg from rxrpc_extract_addr_from_skb()
rxrpc_extract_addr_from_skb() doesn't use the argument that points to the
local endpoint, so remove the argument.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-04 09:32:28 +01:00
David Howells
46894a1359 rxrpc: Use IPv4 addresses throught the IPv6
AF_RXRPC opens an IPv6 socket through which to send and receive network
packets, both IPv6 and IPv4.  It currently turns AF_INET addresses into
AF_INET-as-AF_INET6 addresses based on an assumption that this was
necessary; on further inspection of the code, however, it turns out that
the IPv6 code just farms packets aimed at AF_INET addresses out to the IPv4
code.

Fix AF_RXRPC to use AF_INET addresses directly when given them.

Fixes: 7b674e390e ("rxrpc: Fix IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-04 09:32:28 +01:00
David Howells
f334430316 rxrpc: Fix error distribution
Fix error distribution by immediately delivering the errors to all the
affected calls rather than deferring them to a worker thread.  The problem
with the latter is that retries and things can happen in the meantime when we
want to stop that sooner.

To this end:

 (1) Stop the error distributor from removing calls from the error_targets
     list so that peer->lock isn't needed to synchronise against other adds
     and removals.

 (2) Require the peer's error_targets list to be accessed with RCU, thereby
     avoiding the need to take peer->lock over distribution.

 (3) Don't attempt to affect a call's state if it is already marked complete.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-09-28 10:33:17 +01:00
David Howells
0099dc589b rxrpc: Make service call handling more robust
Make the following changes to improve the robustness of the code that sets
up a new service call:

 (1) Cache the rxrpc_sock struct obtained in rxrpc_data_ready() to do a
     service ID check and pass that along to rxrpc_new_incoming_call().
     This means that I can remove the check from rxrpc_new_incoming_call()
     without the need to worry about the socket attached to the local
     endpoint getting replaced - which would invalidate the check.

 (2) Cache the rxrpc_peer struct, thereby allowing the peer search to be
     done once.  The peer is passed to rxrpc_new_incoming_call(), thereby
     saving the need to repeat the search.

     This also reduces the possibility of rxrpc_publish_service_conn()
     BUG()'ing due to the detection of a duplicate connection, despite the
     initial search done by rxrpc_find_connection_rcu() having turned up
     nothing.

     This BUG() shouldn't ever get hit since rxrpc_data_ready() *should* be
     non-reentrant and the result of the initial search should still hold
     true, but it has proven possible to hit.

     I *think* this may be due to __rxrpc_lookup_peer_rcu() cutting short
     the iteration over the hash table if it finds a matching peer with a
     zero usage count, but I don't know for sure since it's only ever been
     hit once that I know of.

     Another possibility is that a bug in rxrpc_data_ready() that checked
     the wrong byte in the header for the RXRPC_CLIENT_INITIATED flag
     might've let through a packet that caused a spurious and invalid call
     to be set up.  That is addressed in another patch.

 (3) Fix __rxrpc_lookup_peer_rcu() to skip peer records that have a zero
     usage count rather than stopping and returning not found, just in case
     there's another peer record behind it in the bucket.

 (4) Don't search the peer records in rxrpc_alloc_incoming_call(), but
     rather either use the peer cached in (2) or, if one wasn't found,
     preemptively install a new one.

Fixes: 8496af50eb ("rxrpc: Use RCU to access a peer's service connection tree")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-09-28 10:32:49 +01:00
David Howells
dc71db34e4 rxrpc: Fix checks as to whether we should set up a new call
There's a check in rxrpc_data_ready() that's checking the CLIENT_INITIATED
flag in the packet type field rather than in the packet flags field.

Fix this by creating a pair of helper functions to check whether the packet
is going to the client or to the server and use them generally.

Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-09-28 10:31:20 +01:00
David Howells
092ffc51fb rxrpc: Remove dup code from rxrpc_find_connection_rcu()
rxrpc_find_connection_rcu() initialises variable k twice with the same
information.  Remove one of the initialisations.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-09-27 15:13:07 +01:00
Mark Rutland
bfc18e389c atomics/treewide: Rename __atomic_add_unless() => atomic_fetch_add_unless()
While __atomic_add_unless() was originally intended as a building-block
for atomic_add_unless(), it's now used in a number of places around the
kernel. It's the only common atomic operation named __atomic*(), rather
than atomic_*(), and for consistency it would be better named
atomic_fetch_add_unless().

This lack of consistency is slightly confusing, and gets in the way of
scripting atomics. Given that, let's clean things up and promote it to
an official part of the atomics API, in the form of
atomic_fetch_add_unless().

This patch converts definitions and invocations over to the new name,
including the instrumented version, using the following script:

  ----
  git grep -w __atomic_add_unless | while read line; do
  sed -i '{s/\<__atomic_add_unless\>/atomic_fetch_add_unless/}' "${line%%:*}";
  done
  git grep -w __arch_atomic_add_unless | while read line; do
  sed -i '{s/\<__arch_atomic_add_unless\>/arch_atomic_fetch_add_unless/}' "${line%%:*}";
  done
  ----

Note that we do not have atomic{64,_long}_fetch_add_unless(), which will
be introduced by later patches.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-2-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 14:22:32 +02:00
Linus Torvalds
5bb053bef8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Support offloading wireless authentication to userspace via
    NL80211_CMD_EXTERNAL_AUTH, from Srinivas Dasari.

 2) A lot of work on network namespace setup/teardown from Kirill Tkhai.
    Setup and cleanup of namespaces now all run asynchronously and thus
    performance is significantly increased.

 3) Add rx/tx timestamping support to mv88e6xxx driver, from Brandon
    Streiff.

 4) Support zerocopy on RDS sockets, from Sowmini Varadhan.

 5) Use denser instruction encoding in x86 eBPF JIT, from Daniel
    Borkmann.

 6) Support hw offload of vlan filtering in mvpp2 dreiver, from Maxime
    Chevallier.

 7) Support grafting of child qdiscs in mlxsw driver, from Nogah
    Frankel.

 8) Add packet forwarding tests to selftests, from Ido Schimmel.

 9) Deal with sub-optimal GSO packets better in BBR congestion control,
    from Eric Dumazet.

10) Support 5-tuple hashing in ipv6 multipath routing, from David Ahern.

11) Add path MTU tests to selftests, from Stefano Brivio.

12) Various bits of IPSEC offloading support for mlx5, from Aviad
    Yehezkel, Yossi Kuperman, and Saeed Mahameed.

13) Support RSS spreading on ntuple filters in SFC driver, from Edward
    Cree.

14) Lots of sockmap work from John Fastabend. Applications can use eBPF
    to filter sendmsg and sendpage operations.

15) In-kernel receive TLS support, from Dave Watson.

16) Add XDP support to ixgbevf, this is significant because it should
    allow optimized XDP usage in various cloud environments. From Tony
    Nguyen.

17) Add new Intel E800 series "ice" ethernet driver, from Anirudh
    Venkataramanan et al.

18) IP fragmentation match offload support in nfp driver, from Pieter
    Jansen van Vuuren.

19) Support XDP redirect in i40e driver, from Björn Töpel.

20) Add BPF_RAW_TRACEPOINT program type for accessing the arguments of
    tracepoints in their raw form, from Alexei Starovoitov.

21) Lots of striding RQ improvements to mlx5 driver with many
    performance improvements, from Tariq Toukan.

22) Use rhashtable for inet frag reassembly, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1678 commits)
  net: mvneta: improve suspend/resume
  net: mvneta: split rxq/txq init and txq deinit into SW and HW parts
  ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh
  net: bgmac: Fix endian access in bgmac_dma_tx_ring_free()
  net: bgmac: Correctly annotate register space
  route: check sysctl_fib_multipath_use_neigh earlier than hash
  fix typo in command value in drivers/net/phy/mdio-bitbang.
  sky2: Increase D3 delay to sky2 stops working after suspend
  net/mlx5e: Set EQE based as default TX interrupt moderation mode
  ibmvnic: Disable irqs before exiting reset from closed state
  net: sched: do not emit messages while holding spinlock
  vlan: also check phy_driver ts_info for vlan's real device
  Bluetooth: Mark expected switch fall-throughs
  Bluetooth: Set HCI_QUIRK_SIMULTANEOUS_DISCOVERY for BTUSB_QCA_ROME
  Bluetooth: btrsi: remove unused including <linux/version.h>
  Bluetooth: hci_bcm: Remove DMI quirk for the MINIX Z83-4
  sh_eth: kill useless check in __sh_eth_get_regs()
  sh_eth: add sh_eth_cpu_data::no_xdfar flag
  ipv6: factorize sk_wmem_alloc updates done by __ip6_append_data()
  ipv4: factorize sk_wmem_alloc updates done by __ip_append_data()
  ...
2018-04-03 14:04:18 -07:00
David Howells
31f5f9a169 rxrpc: Fix apparent leak of rxrpc_local objects
rxrpc_local objects cannot be disposed of until all the connections that
point to them have been RCU'd as a connection object holds refcount on the
local endpoint it is communicating through.  Currently, this can cause an
assertion failure to occur when a network namespace is destroyed as there's
no check that the RCU destructors for the connections have been run before
we start trying to destroy local endpoints.

The kernel reports:

	rxrpc: AF_RXRPC: Leaked local 0000000036a41bc1 {5}
	------------[ cut here ]------------
	kernel BUG at ../net/rxrpc/local_object.c:439!

Fix this by keeping a count of the live connections and waiting for it to
go to zero at the end of rxrpc_destroy_all_connections().

Fixes: dee46364ce ("rxrpc: Add RCU destruction for connections and calls")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-03-30 21:05:33 +01:00
David Howells
88f2a8257c rxrpc: Fix checker warnings and errors
Fix various issues detected by checker.

Errors:

 (*) rxrpc_discard_prealloc() should be using rcu_assign_pointer to set
     call->socket.

Warnings:

 (*) rxrpc_service_connection_reaper() should be passing NULL rather than 0 to
     trace_rxrpc_conn() as the where argument.

 (*) rxrpc_disconnect_client_call() should get its net pointer via the
     call->conn rather than call->sock to avoid a warning about accessing
     an RCU pointer without protection.

 (*) Proc seq start/stop functions need annotation as they pass locks
     between the functions.

False positives:

 (*) Checker doesn't correctly handle of seq-retry lock context balance in
     rxrpc_find_service_conn_rcu().

 (*) Checker thinks execution may proceed past the BUG() in
     rxrpc_publish_service_conn().

 (*) Variable length array warnings from SKCIPHER_REQUEST_ON_STACK() in
     rxkad.c.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-03-30 21:05:17 +01:00
David Howells
17e9e23b13 rxrpc: Fix received abort handling
AF_RXRPC is incorrectly sending back to the server any abort it receives
for a client connection.  This is due to the final-ACK offload to the
connection event processor patch.  The abort code is copied into the
last-call information on the connection channel and then the event
processor is set.

Instead, the following should be done:

 (1) In the case of a final-ACK for a successful call, the ACK should be
     scheduled as before.

 (2) In the case of a locally generated ABORT, the ABORT details should be
     cached for sending in response to further packets related to that
     call and no further action scheduled at call disconnect time.

 (3) In the case of an ACK received from the peer, the call should be
     considered dead, no ABORT should be transmitted at this time.  In
     response to further non-ABORT packets from the peer relating to this
     call, an RX_USER_ABORT ABORT should be transmitted.

 (4) In the case of a call killed due to network error, an RX_USER_ABORT
     ABORT should be cached for transmission in response to further
     packets, but no ABORT should be sent at this time.

Fixes: 3136ef49a1 ("rxrpc: Delay terminal ACK transmission on a client call")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-07 21:47:10 -05:00
David Howells
3d7682af22 rxrpc: Clean up whitespace
Clean up some whitespace from rxrpc.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-29 14:40:41 +00:00
David Howells
3d18cbb7fd rxrpc: Fix conn expiry timers
Fix the rxrpc connection expiry timers so that connections for closed
AF_RXRPC sockets get deleted in a more timely fashion, freeing up the
transport UDP port much more quickly.

 (1) Replace the delayed work items with work items plus timers so that
     timer_reduce() can be used to shorten them and so that the timer
     doesn't requeue the work item if the net namespace is dead.

 (2) Don't use queue_delayed_work() as that won't alter the timeout if the
     timer is already running.

 (3) Don't rearm the timers if the network namespace is dead.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:42 +00:00
David Howells
f859ab6187 rxrpc: Fix service endpoint expiry
RxRPC service endpoints expire like they're supposed to by the following
means:

 (1) Mark dead rxrpc_net structs (with ->live) rather than twiddling the
     global service conn timeout, otherwise the first rxrpc_net struct to
     die will cause connections on all others to expire immediately from
     then on.

 (2) Mark local service endpoints for which the socket has been closed
     (->service_closed) so that the expiration timeout can be much
     shortened for service and client connections going through that
     endpoint.

 (3) rxrpc_put_service_conn() needs to schedule the reaper when the usage
     count reaches 1, not 0, as idle conns have a 1 count.

 (4) The accumulator for the earliest time we might want to schedule for
     should be initialised to jiffies + MAX_JIFFY_OFFSET, not ULONG_MAX as
     the comparison functions use signed arithmetic.

 (5) Simplify the expiration handling, adding the expiration value to the
     idle timestamp each time rather than keeping track of the time in the
     past before which the idle timestamp must go to be expired.  This is
     much easier to read.

 (6) Ignore the timeouts if the net namespace is dead.

 (7) Restart the service reaper work item rather the client reaper.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:42 +00:00
David Howells
3136ef49a1 rxrpc: Delay terminal ACK transmission on a client call
Delay terminal ACK transmission on a client call by deferring it to the
connection processor.  This allows it to be skipped if we can send the next
call instead, the first DATA packet of which will implicitly ack this call.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
David Howells
7b674e390e rxrpc: Fix IPv6 support
Fix IPv6 support in AF_RXRPC in the following ways:

 (1) When extracting the address from a received IPv4 packet, if the local
     transport socket is open for IPv6 then fill out the sockaddr_rxrpc
     struct for an IPv4-mapped-to-IPv6 AF_INET6 transport address instead
     of an AF_INET one.

 (2) When sending CHALLENGE or RESPONSE packets, the transport length needs
     to be set from the sockaddr_rxrpc::transport_len field rather than
     sizeof() on the IPv4 transport address.

 (3) When processing an IPv4 ICMP packet received by an IPv6 socket, set up
     the address correctly before searching for the affected peer.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-08-29 10:55:20 +01:00
David Howells
f7aec129a3 rxrpc: Cache the congestion window setting
Cache the congestion window setting that was determined during a call's
transmission phase when it finishes so that it can be used by the next call
to the same peer, thereby shortcutting the slow-start algorithm.

The value is stored in the rxrpc_peer struct and is accessed without
locking.  Each call takes the value that happens to be there when it starts
and just overwrites the value when it finishes.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 15:42:45 -04:00
David Howells
68d6d1ae5c rxrpc: Separate the connection's protocol service ID from the lookup ID
Keep the rxrpc_connection struct's idea of the service ID that is exposed
in the protocol separate from the service ID that's used as a lookup key.

This allows the protocol service ID on a client connection to get upgraded
without making the connection unfindable for other client calls that also
would like to use the upgraded connection.

The connection's actual service ID is then returned through recvmsg() by
way of msg_name.

Whilst we're at it, we get rid of the last_service_id field from each
channel.  The service ID is per-connection, not per-call and an entire
connection is upgraded in one go.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
David Howells
2baec2c3f8 rxrpc: Support network namespacing
Support network namespacing in AF_RXRPC with the following changes:

 (1) All the local endpoint, peer and call lists, locks, counters, etc. are
     moved into the per-namespace record.

 (2) All the connection tracking is moved into the per-namespace record
     with the exception of the client connection ID tree, which is kept
     global so that connection IDs are kept unique per-machine.

 (3) Each namespace gets its own epoch.  This allows each network namespace
     to pretend to be a separate client machine.

 (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and
     the contents reflect the namespace.

fs/afs/ should be okay with this patch as it explicitly requires the current
net namespace to be init_net to permit a mount to proceed at the moment.  It
will, however, need updating so that cells, IP addresses and DNS records are
per-namespace also.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25 13:15:11 -04:00
David Howells
b1d9f7fde0 rxrpc: Add some more tracing
Add the following extra tracing information:

 (1) Modify the rxrpc_transmit tracepoint to record the Tx window size as
     this is varied by the slow-start algorithm.

 (2) Modify the rxrpc_rx_ack tracepoint to record more information from
     received ACK packets.

 (3) Add an rxrpc_rx_data tracepoint to record the information in DATA
     packets.

 (4) Add an rxrpc_disconnect_call tracepoint to record call disconnection,
     including the reason the call was disconnected.

 (5) Add an rxrpc_improper_term tracepoint to record implicit termination
     of a call by a client either by starting a new call on a particular
     connection channel without first transmitting the final ACK for the
     previous call.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 11:39:12 +00:00
David Howells
5a924b8951 rxrpc: Don't store the rxrpc header in the Tx queue sk_buffs
Don't store the rxrpc protocol header in sk_buffs on the transmit queue,
but rather generate it on the fly and pass it to kernel_sendmsg() as a
separate iov.  This reduces the amount of storage required.

Note that the security header is still stored in the sk_buff as it may get
encrypted along with the data (and doesn't change with each transmission).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 01:23:50 +01:00