Commit Graph

511 Commits

Author SHA1 Message Date
Johannes Berg b080db5853 networking: convert many more places to skb_put_zero()
There were many places that my previous spatch didn't find,
as pointed out by yuan linyu in various patches.

The following spatch found many more and also removes the
now unnecessary casts:

    @@
    identifier p, p2;
    expression len;
    expression skb;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, len);
    |
    -memset(p, 0, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, sizeof(*p));
    |
    -memset(p, 0, sizeof(*p));
    )

    @@
    expression skb, len;
    @@
    -memset(skb_put(skb, len), 0, len);
    +skb_put_zero(skb, len);

Apply it to the tree (with one manual fixup to keep the
comment in vxlan.c, which spatch removed.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 11:48:35 -04:00
David Howells 5f2f97656a rxrpc: Fix several cases where a padded len isn't checked in ticket decode
This fixes CVE-2017-7482.

When a kerberos 5 ticket is being decoded so that it can be loaded into an
rxrpc-type key, there are several places in which the length of a
variable-length field is checked to make sure that it's not going to
overrun the available data - but the data is padded to the nearest
four-byte boundary and the code doesn't check for this extra.  This could
lead to the size-remaining variable wrapping and the data pointer going
over the end of the buffer.

Fix this by making the various variable-length data checks use the padded
length.

Reported-by: 石磊 <shilei-c@360.cn>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.c.dionne@auristor.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15 14:23:44 -04:00
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 e754eba685 rxrpc: Provide a cmsg to specify the amount of Tx data for a call
Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.

Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.

By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).

An error will be returned if too little or too much data is presented in
the Tx phase.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-07 17:15:46 +01:00
David Howells 3ab26a6fd0 rxrpc: Consolidate sendmsg parameters
Consolidate the sendmsg control message parameters into a struct rather
than passing them individually through the argument list of
rxrpc_sendmsg_cmsg().  This makes it easier to add more parameters.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-07 17:15:46 +01:00
David Howells 515559ca21 rxrpc: Provide a getsockopt call to query what cmsgs types are supported
Provide a getsockopt() call that can query what cmsg types are supported by
AF_RXRPC.
2017-06-07 17:15:46 +01:00
David Howells 4e255721d1 rxrpc: Add service upgrade support for client connections
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 <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
David Howells 4722974d90 rxrpc: Implement service upgrade
Implement AuriStor's service upgrade facility.  There are three problems
that this is meant to deal with:

 (1) Various of the standard AFS RPC calls have IPv4 addresses in their
     requests and/or replies - but there's no room for including IPv6
     addresses.

 (2) Definition of IPv6-specific RPC operations in the standard operation
     sets has not yet been achieved.

 (3) One could envision the creation a new service on the same port that as
     the original service.  The new service could implement improved
     operations - and the client could try this first, falling back to the
     original service if it's not there.

     Unfortunately, certain servers ignore packets addressed to a service
     they don't implement and don't respond in any way - not even with an
     ABORT.  This means that the client must then wait for the call timeout
     to occur.

What service upgrade does is to see if the connection is marked as being
'upgradeable' and if so, change the service ID in the server and thus the
request and reply formats.  Note that the upgrade isn't mandatory - a
server that supports only the original call set will ignore the upgrade
request.

In the protocol, the procedure is then as follows:

 (1) To request an upgrade, the first DATA packet in a new connection must
     have the userStatus set to 1 (this is normally 0).  The userStatus
     value is normally ignored by the server.

 (2) If the server doesn't support upgrading, the reply packets will
     contain the same service ID as for the first request packet.

 (3) If the server does support upgrading, all future reply packets on that
     connection will contain the new service ID and the new service ID will
     be applied to *all* further calls on that connection as well.

 (4) The RPC op used to probe the upgrade must take the same request data
     as the shadow call in the upgrade set (but may return a different
     reply).  GetCapability RPC ops were added to all standard sets for
     just this purpose.  Ops where the request formats differ cannot be
     used for probing.

 (5) The client must wait for completion of the probe before sending any
     further RPC ops to the same destination.  It should then use the
     service ID that recvmsg() reported back in all future calls.

 (6) The shadow service must have call definitions for all the operation
     IDs defined by the original service.


To support service upgrading, a server should:

 (1) Call bind() twice on its AF_RXRPC socket before calling listen().
     Each bind() should supply a different service ID, but the transport
     addresses must be the same.  This allows the server to receive
     requests with either service ID.

 (2) Enable automatic upgrading by calling setsockopt(), specifying
     RXRPC_UPGRADEABLE_SERVICE and passing in a two-member array of
     unsigned shorts as the argument:

	unsigned short optval[2];

     This specifies a pair of service IDs.  They must be different and must
     match the service IDs bound to the socket.  Member 0 is the service ID
     to upgrade from and member 1 is the service ID to upgrade to.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
David Howells 28036f4485 rxrpc: Permit multiple service binding
Permit bind() to be called on an AF_RXRPC socket more than once (currently
maximum twice) to bind multiple listening services to it.  There are some
restrictions:

 (1) All bind() calls involved must have a non-zero service ID.

 (2) The service IDs must all be different.

 (3) The rest of the address (notably the transport part) must be the same
     in all (a single UDP socket is shared).

 (4) This must be done before listen() or sendmsg() is called.

This allows someone to connect to the service socket with different service
IDs and lays the foundation for service upgrading.

The service ID used by an incoming call can be extracted from the msg_name
returned by recvmsg().

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
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
Jason A. Donenfeld 89a5ea9966 rxrpc: check return value of skb_to_sgvec always
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-04 23:01:47 -04:00
Colin Ian King 1820dd0633 rxrpc: remove redundant proc_remove call
The proc_remove call is dead code as it occurs after a return and
hence can never be called. Remove it.

Detected by CoverityScan, CID#1437743 ("Logically dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-04 19:59:11 -04:00
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 89ca694806 rxrpc: Trace client call connection
Add a tracepoint (rxrpc_connect_call) to log the combination of rxrpc_call
pointer, afs_call pointer/user data and wire call parameters to make it
easier to match the tracebuffer contents to captured network packets.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 11:10:41 +01:00
David Howells 740586d290 rxrpc: Trace changes in a call's receive window size
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 <dhowells@redhat.com>
2017-04-06 11:10:41 +01:00
David Howells 005ede286f rxrpc: Trace received aborts
Add a tracepoint (rxrpc_rx_abort) to record received aborts.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 11:10:41 +01:00
David Howells fb46f6ee10 rxrpc: Trace protocol errors in received packets
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 <dhowells@redhat.com>
2017-04-06 11:09:39 +01:00
David Howells ef68622da9 rxrpc: Handle temporary errors better in rxkad security
In the rxkad security module, when we encounter a temporary error (such as
ENOMEM) from which we could conceivably recover, don't abort the
connection, but rather permit retransmission of the relevant packets to
induce a retry.

Note that I'm leaving some places that could be merged together to insert
tracing in the next patch.

Signed-off-by; David Howells <dhowells@redhat.com>
2017-04-06 10:11:59 +01:00
David Howells 84a4c09c38 rxrpc: Note a successfully aborted kernel operation
Make rxrpc_kernel_abort_call() return an indication as to whether it
actually aborted the operation or not so that kafs can trace the failure of
the operation.  Note that 'success' in this context means changing the
state of the call, not necessarily successfully transmitting an ABORT
packet.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 10:11:59 +01:00
David Howells 3a92789af0 rxrpc: Use negative error codes in rxrpc_call struct
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 <dhowells@redhat.com>
2017-04-06 10:11:56 +01:00
David Howells 4d4a6ac73e rxrpc: Ignore BUSY packets on old calls
If we receive a BUSY packet for a call we think we've just completed, the
packet is handed off to the connection processor to deal with - but the
connection processor doesn't expect a BUSY packet and so flags a protocol
error.

Fix this by simply ignoring the BUSY packet for the moment.

The symptom of this may appear as a system call failing with EPROTO.  This
may be triggered by pressing ctrl-C under some circumstances.

This comes about we abort calls due to interruption by a signal (which we
shouldn't do, but that's going to be a large fix and mostly in fs/afs/).
What happens is that we abort the call and may also abort follow up calls
too (this needs offloading somehoe).  So we see a transmission of something
like the following sequence of packets:

	DATA for call N
	ABORT call N
	DATA for call N+1
	ABORT call N+1

in very quick succession on the same channel.  However, the peer may have
deferred the processing of the ABORT from the call N to a background thread
and thus sees the DATA message from the call N+1 coming in before it has
cleared the channel.  Thus it sends a BUSY packet[*].

[*] Note that some implementations (OpenAFS, for example) mark the BUSY
    packet with one plus the callNumber of the call prior to call N.
    Ordinarily, this would be call N, but there's no requirement for the
    calls on a channel to be numbered strictly sequentially (the number is
    required to increase).

    This is wrong and means that the callNumber in the BUSY packet should
    be ignored (it really ought to be N+1 since that's what it's in
    response to).

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16 21:27:57 -07:00
David Howells 702f2ac87a rxrpc: Wake up the transmitter if Rx window size increases on the peer
The RxRPC ACK packet may contain an extension that includes the peer's
current Rx window size for this call.  We adjust the local Tx window size
to match.  However, the transmitter can stall if the receive window is
reduced to 0 by the peer and then reopened.

This is because the normal way that the transmitter is re-energised is by
dropping something out of our Tx queue and thus making space.  When a
single gap is made, the transmitter is woken up.  However, because there's
nothing in the Tx queue at this point, this doesn't happen.

To fix this, perform a wake_up() any time we see the peer's Rx window size
increasing.

The observable symptom is that calls start failing on ETIMEDOUT and the
following:

	kAFS: SERVER DEAD state=-62

appears in dmesg.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 09:34:23 -08:00
David Howells 6fc166d62c rxrpc: rxrpc_kernel_send_data() needs to handle failed call better
If rxrpc_kernel_send_data() is asked to send data through a call that has
already failed (due to a remote abort, received protocol error or network
error), then return the associated error code saved in the call rather than
ESHUTDOWN.

This allows the caller to work out whether to ask for the abort code or not
based on this.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:30:10 -08:00
David Howells 146d8fef9d rxrpc: Call state should be read with READ_ONCE() under some circumstances
The call state may be changed at any time by the data-ready routine in
response to received packets, so if the call state is to be read and acted
upon several times in a function, READ_ONCE() must be used unless the call
state lock is held.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-07 13:59:06 -08:00
Linus Torvalds 8d70eeb84a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix double-free in batman-adv, from Sven Eckelmann.

 2) Fix packet stats for fast-RX path, from Joannes Berg.

 3) Netfilter's ip_route_me_harder() doesn't handle request sockets
    properly, fix from Florian Westphal.

 4) Fix sendmsg deadlock in rxrpc, from David Howells.

 5) Add missing RCU locking to transport hashtable scan, from Xin Long.

 6) Fix potential packet loss in mlxsw driver, from Ido Schimmel.

 7) Fix race in NAPI handling between poll handlers and busy polling,
    from Eric Dumazet.

 8) TX path in vxlan and geneve need proper RCU locking, from Jakub
    Kicinski.

 9) SYN processing in DCCP and TCP need to disable BH, from Eric
    Dumazet.

10) Properly handle net_enable_timestamp() being invoked from IRQ
    context, also from Eric Dumazet.

11) Fix crash on device-tree systems in xgene driver, from Alban Bedel.

12) Do not call sk_free() on a locked socket, from Arnaldo Carvalho de
    Melo.

13) Fix use-after-free in netvsc driver, from Dexuan Cui.

14) Fix max MTU setting in bonding driver, from WANG Cong.

15) xen-netback hash table can be allocated from softirq context, so use
    GFP_ATOMIC. From Anoob Soman.

16) Fix MAC address change bug in bgmac driver, from Hari Vyas.

17) strparser needs to destroy strp_wq on module exit, from WANG Cong.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (69 commits)
  strparser: destroy workqueue on module exit
  sfc: fix IPID endianness in TSOv2
  sfc: avoid max() in array size
  rds: remove unnecessary returned value check
  rxrpc: Fix potential NULL-pointer exception
  nfp: correct DMA direction in XDP DMA sync
  nfp: don't tell FW about the reserved buffer space
  net: ethernet: bgmac: mac address change bug
  net: ethernet: bgmac: init sequence bug
  xen-netback: don't vfree() queues under spinlock
  xen-netback: keep a local pointer for vif in backend_disconnect()
  netfilter: nf_tables: don't call nfnetlink_set_err() if nfnetlink_send() fails
  netfilter: nft_set_rbtree: incorrect assumption on lower interval lookups
  netfilter: nf_conntrack_sip: fix wrong memory initialisation
  can: flexcan: fix typo in comment
  can: usb_8dev: Fix memory leak of priv->cmd_msg_buffer
  can: gs_usb: fix coding style
  can: gs_usb: Don't use stack memory for USB transfers
  ixgbe: Limit use of 2K buffers on architectures with 256B or larger cache lines
  ixgbe: update the rss key on h/w, when ethtool ask for it
  ...
2017-03-04 17:31:39 -08:00
David Howells 37411cad63 rxrpc: Fix potential NULL-pointer exception
Fix a potential NULL-pointer exception in rxrpc_do_sendmsg().  The call
state check that I added should have gone into the else-body of the
if-statement where we actually have a call to check.

Found by CoverityScan CID#1414316 ("Dereference after null check").

Fixes: 540b1c48c3 ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03 09:48:00 -08:00
Ingo Molnar 174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
David Howells 540b1c48c3 rxrpc: Fix deadlock between call creation and sendmsg/recvmsg
All the routines by which rxrpc is accessed from the outside are serialised
by means of the socket lock (sendmsg, recvmsg, bind,
rxrpc_kernel_begin_call(), ...) and this presents a problem:

 (1) If a number of calls on the same socket are in the process of
     connection to the same peer, a maximum of four concurrent live calls
     are permitted before further calls need to wait for a slot.

 (2) If a call is waiting for a slot, it is deep inside sendmsg() or
     rxrpc_kernel_begin_call() and the entry function is holding the socket
     lock.

 (3) sendmsg() and recvmsg() or the in-kernel equivalents are prevented
     from servicing the other calls as they need to take the socket lock to
     do so.

 (4) The socket is stuck until a call is aborted and makes its slot
     available to the waiter.

Fix this by:

 (1) Provide each call with a mutex ('user_mutex') that arbitrates access
     by the users of rxrpc separately for each specific call.

 (2) Make rxrpc_sendmsg() and rxrpc_recvmsg() unlock the socket as soon as
     they've got a call and taken its mutex.

     Note that I'm returning EWOULDBLOCK from recvmsg() if MSG_DONTWAIT is
     set but someone else has the lock.  Should I instead only return
     EWOULDBLOCK if there's nothing currently to be done on a socket, and
     sleep in this particular instance because there is something to be
     done, but we appear to be blocked by the interrupt handler doing its
     ping?

 (3) Make rxrpc_new_client_call() unlock the socket after allocating a new
     call, locking its user mutex and adding it to the socket's call tree.
     The call is returned locked so that sendmsg() can add data to it
     immediately.

     From the moment the call is in the socket tree, it is subject to
     access by sendmsg() and recvmsg() - even if it isn't connected yet.

 (4) Lock new service calls in the UDP data_ready handler (in
     rxrpc_new_incoming_call()) because they may already be in the socket's
     tree and the data_ready handler makes them live immediately if a user
     ID has already been preassigned.

     Note that the new call is locked before any notifications are sent
     that it is live, so doing mutex_trylock() *ought* to always succeed.
     Userspace is prevented from doing sendmsg() on calls that are in a
     too-early state in rxrpc_do_sendmsg().

 (5) Make rxrpc_new_incoming_call() return the call with the user mutex
     held so that a ping can be scheduled immediately under it.

     Note that it might be worth moving the ping call into
     rxrpc_new_incoming_call() and then we can drop the mutex there.

 (6) Make rxrpc_accept_call() take the lock on the call it is accepting and
     release the socket after adding the call to the socket's tree.  This
     is slightly tricky as we've dequeued the call by that point and have
     to requeue it.

     Note that requeuing emits a trace event.

 (7) Make rxrpc_kernel_send_data() and rxrpc_kernel_recv_data() take the
     new mutex immediately and don't bother with the socket mutex at all.

This patch has the nice bonus that calls on the same socket are now to some
extent parallelisable.

Note that we might want to move rxrpc_service_prealloc() calls out from the
socket lock and give it its own lock, so that we don't hang progress in
other calls because we're waiting for the allocator.

We probably also want to avoid calling rxrpc_notify_socket() from within
the socket lock (rxrpc_accept_call()).

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.c.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-01 09:50:58 -08:00
David Howells d7e15835ab rxrpc: Kernel calls get stuck in recvmsg
Calls made through the in-kernel interface can end up getting stuck because
of a missed variable update in a loop in rxrpc_recvmsg_data().  The problem
is like this:

 (1) A new packet comes in and doesn't cause a notification to be given to
     the client as there's still another packet in the ring - the
     assumption being that if the client will keep drawing off data until
     the ring is empty.

 (2) The client is in rxrpc_recvmsg_data(), inside the big while loop that
     iterates through the packets.  This copies the window pointers into
     variables rather than using the information in the call struct
     because:

     (a) MSG_PEEK might be in effect;

     (b) we need a barrier after reading call->rx_top to pair with the
     	 barrier in the softirq routine that loads the buffer.

 (3) The reading of call->rx_top is done outside of the loop, and top is
     never updated whilst we're in the loop.  This means that even through
     there's a new packet available, we don't see it and may return -EFAULT
     to the caller - who will happily return to the scheduler and await the
     next notification.

 (4) No further notifications are forthcoming until there's an abort as the
     ring isn't empty.

The fix is to move the read of call->rx_top inside the loop - but it needs
to be done before the condition is checked.

Reported-by: Marc Dionne <marc.dionne@auristor.com>
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>
2017-02-26 21:30:12 -05:00
Marc Dionne 774521f353 rxrpc: Fix an assertion in rxrpc_read()
In the rxrpc_read() function, which allows a user to read the contents of a
key, we miscalculate the expected length of an encoded rxkad token by not
taking into account the key length.  However, the data is stored later
anyway with an ENCODE_DATA() call - and an assertion failure then ensues
when the lengths are checked at the end.

Fix this by including the key length in the token size estimation.

The following assertion is produced:

Assertion failed - 384(0x180) == 380(0x17c) is false
------------[ cut here ]------------
kernel BUG at ../net/rxrpc/key.c:1221!
invalid opcode: 0000 [#1] SMP
Modules linked in:
CPU: 2 PID: 2957 Comm: keyctl Not tainted 4.10.0-fscache+ #483
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804013a8500 task.stack: ffff8804013ac000
RIP: 0010:rxrpc_read+0x10de/0x11b6
RSP: 0018:ffff8804013afe48 EFLAGS: 00010296
RAX: 000000000000003b RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000040001 RSI: 00000000000000f6 RDI: 0000000000000300
RBP: ffff8804013afed8 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8804013afd90 R11: 0000000000000002 R12: 00005575f7c911b4
R13: 00005575f7c911b3 R14: 0000000000000157 R15: ffff880408a5d640
FS:  00007f8dfbc73700(0000) GS:ffff88041fb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005575f7c91008 CR3: 000000040120a000 CR4: 00000000001406e0
Call Trace:
 keyctl_read_key+0xb6/0xd7
 SyS_keyctl+0x83/0xe7
 do_syscall_64+0x80/0x191
 entry_SYSCALL64_slow_path+0x25/0x25

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-24 11:42:55 -05:00
David Howells 88c4845d7d rxrpc: Change module filename to rxrpc.ko
Change module filename from af-rxrpc.ko to rxrpc.ko so as to be consistent
with the other protocol drivers.

Also adjust the documentation to reflect this.

Further, there is no longer a standalone rxkad module, as it has been
merged into the rxrpc core, so get rid of references to that.

Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-17 15:09:19 -05:00
David Howells 210f035316 rxrpc: Allow listen(sock, 0) to be used to disable listening
Allow listen() with a backlog of 0 to be used to disable listening on an
AF_RXRPC socket.  This also releases any preallocation, thereby making it
easier for a kernel service to account for all allocated call structures
when shutting down the service.

The socket cannot thereafter have listening reenabled, but must rather be
closed and reopened.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-09 11:10:02 +00:00
David Howells 3e018daf04 rxrpc: Show a call's hard-ACK cursors in /proc/net/rxrpc_calls
Show a call's hard-ACK cursors in /proc/net/rxrpc_calls so that a call's
progress can be more easily monitored.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 11:39:44 +00:00
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 b54a134a7d rxrpc: Fix handling of enums-to-string translation in tracing
Fix the way enum values are translated into strings in AF_RXRPC
tracepoints.  The problem with just doing a lookup in a normal flat array
of strings or chars is that external tracing infrastructure can't find it.
Rather, TRACE_DEFINE_ENUM must be used.

Also sort the enums and string tables to make it easier to keep them in
order so that a future patch to __print_symbolic() can be optimised to try
a direct lookup into the table first before iterating over it.

A couple of _proto() macro calls are removed because they refered to tables
that got moved to the tracing infrastructure.  The relevant data can be
found by way of tracing.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 10:38:33 +00:00
yuan linyu 1ff8cebf49 scm: remove use CMSG{_COMPAT}_ALIGN(sizeof(struct {compat_}cmsghdr))
sizeof(struct cmsghdr) and sizeof(struct compat_cmsghdr) already aligned.
remove use CMSG_ALIGN(sizeof(struct cmsghdr)) and
CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)) keep code consistent.

Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-04 13:04:37 -05:00
Matthew Wilcox 444306129a rxrpc: abstract away knowledge of IDR internals
Add idr_get_cursor() / idr_set_cursor() APIs, and remove the reference
to IDR_SIZE.

Link: http://lkml.kernel.org/r/1480369871-5271-65-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14 16:04:10 -08:00
Paolo Abeni 7c13f97ffd udp: do fwd memory scheduling on dequeue
A new argument is added to __skb_recv_datagram to provide
an explicit skb destructor, invoked under the receive queue
lock.
The UDP protocol uses such argument to perform memory
reclaiming on dequeue, so that the UDP protocol does not
set anymore skb->desctructor.
Instead explicit memory reclaiming is performed at close() time and
when skbs are removed from the receive queue.
The in kernel UDP protocol users now need to call a
skb_recv_udp() variant instead of skb_recv_datagram() to
properly perform memory accounting on dequeue.

Overall, this allows acquiring only once the receive queue
lock on dequeue.

Tested using pktgen with random src port, 64 bytes packet,
wire-speed on a 10G link as sender and udp_sink as the receiver,
using an l4 tuple rxhash to stress the contention, and one or more
udp_sink instances with reuseport.

nr sinks	vanilla		patched
1		440		560
3		2150		2300
6		3650		3800
9		4450		4600
12		6250		6450

v1 -> v2:
 - do rmem and allocated memory scheduling under the receive lock
 - do bulk scheduling in first_packet_length() and in udp_destruct_sock()
 - avoid the typdef for the dequeue callback

Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-07 13:24:41 -05:00
David Howells 07096f612f rxrpc: Fix checking of error from ip6_route_output()
ip6_route_output() doesn't return a negative error when it fails, rather
the ->error field of the returned dst_entry struct needs to be checked.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 75b54cb57c ("rxrpc: Add IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-13 08:43:17 +01:00
David Howells 54fde42345 rxrpc: Fix checker warning by not passing always-zero value to ERR_PTR()
Fix the following checker warning:

	net/rxrpc/call_object.c:279 rxrpc_new_client_call()
	warn: passing zero to 'ERR_PTR'

where a value that's always zero is passed to ERR_PTR() so that it can be
passed to a tracepoint in an auxiliary pointer field.

Just pass NULL instead to the tracepoint.

Fixes: a84a46d730 ("rxrpc: Add some additional call tracing")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-13 08:39:52 +01:00
David Howells bf7d620abf rxrpc: Don't request an ACK on the last DATA packet of a call's Tx phase
Don't request an ACK on the last DATA packet of a call's Tx phase as for a
client there will be a reply packet or some sort of ACK to shift phase.  If
the ACK is requested, OpenAFS sends a REQUESTED-ACK ACK with soft-ACKs in
it and doesn't follow up with a hard-ACK.

If we don't set the flag, OpenAFS will send a DELAY ACK that hard-ACKs the
reply data, thereby allowing the call to terminate cleanly.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:51 +01:00
David Howells 9749fd2bea rxrpc: Need to produce an ACK for service op if op takes a long time
We need to generate a DELAY ACK from the service end of an operation if we
start doing the actual operation work and it takes longer than expected.
This will hard-ACK the request data and allow the client to release its
resources.

To make this work:

 (1) We have to set the ack timer and propose an ACK when the call moves to
     the RXRPC_CALL_SERVER_ACK_REQUEST and clear the pending ACK and cancel
     the timer when we start transmitting the reply (the first DATA packet
     of the reply implicitly ACKs the request phase).

 (2) It must be possible to set the timer when the caller is holding
     call->state_lock, so split the lock-getting part of the timer function
     out.

 (3) Add trace notes for the ACK we're requesting and the timer we clear.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells cf69207afa rxrpc: Return negative error code to kernel service
In rxrpc_kernel_recv_data(), when we return the error number incurred by a
failed call, we must negate it before returning it as it's stored as
positive (that's what we have to pass back to userspace).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells 94bc669efa rxrpc: Add missing notification
The call's background processor work item needs to notify the socket when
it completes a call so that recvmsg() or the AFS fs can deal with it.
Without this, call expiry isn't handled.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells d7833d0091 rxrpc: Queue the call on expiry
When a call expires, it must be queued for the background processor to deal
with otherwise a service call that is improperly terminated will just sit
there awaiting an ACK and won't expire.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells b3156274ca rxrpc: Partially handle OpenAFS's improper termination of calls
OpenAFS doesn't always correctly terminate client calls that it makes -
this includes calls the OpenAFS servers make to the cache manager service.
It should end the client call with either:

 (1) An ACK that has firstPacket set to one greater than the seq number of
     the reply DATA packet with the LAST_PACKET flag set (thereby
     hard-ACK'ing all packets).  nAcks should be 0 and acks[] should be
     empty (ie. no soft-ACKs).

 (2) An ACKALL packet.

OpenAFS, though, may send an ACK packet with firstPacket set to the last
seq number or less and soft-ACKs listed for all packets up to and including
the last DATA packet.

The transmitter, however, is obliged to keep the call live and the
soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is
permitted to drop any merely soft-ACK'd packet and request retransmission
by sending an ACK packet with a NACK in it.

Further, OpenAFS will also terminate a client call by beginning the next
client call on the same connection channel.  This implicitly completes the
previous call.

This patch handles implicit ACK of a call on a channel by the reception of
the first packet of the next call on that channel.

If another call doesn't come along to implicitly ACK a call, then we have
to time the call out.  There are some bugs there that will be addressed in
subsequent patches.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells a5af7e1fc6 rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKs
Separate the output of PING ACKs from the output of other sorts of ACK so
that if we receive a PING ACK and schedule transmission of a PING RESPONSE
ACK, the response doesn't get cancelled by a PING ACK we happen to be
scheduling transmission of at the same time.

If a PING RESPONSE gets lost, the other side might just sit there waiting
for it and refuse to proceed otherwise.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells 26cb02aa6d rxrpc: Fix warning by splitting rxrpc_send_call_packet()
Split rxrpc_send_data_packet() to separate ACK generation (which is more
complicated) from ABORT generation.  This simplifies the code a bit and
fixes the following warning:

In file included from ../net/rxrpc/output.c:20:0:
net/rxrpc/output.c: In function 'rxrpc_send_call_packet':
net/rxrpc/ar-internal.h:1187:27: error: 'top' may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/rxrpc/output.c:103:24: note: 'top' was declared here
net/rxrpc/output.c:225:25: error: 'hard_ack' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells a9f312d98a rxrpc: Only ping for lost reply in client call
When a reply is deemed lost, we send a ping to find out the other end
received all the request data packets we sent.  This should be limited to
client calls and we shouldn't do this on service calls.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells 7212a57e8e rxrpc: Fix oops on incoming call to serviceless endpoint
If an call comes in to a local endpoint that isn't listening for any
incoming calls at the moment, an oops will happen.  We need to check that
the local endpoint's service pointer isn't NULL before we dereference it.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells 19c0dbd540 rxrpc: Fix duplicate const
Remove a duplicate const keyword.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:48 +01:00
David Howells b63452c11e rxrpc: Accesses of rxrpc_local::service need to be RCU managed
struct rxrpc_local->service is marked __rcu - this means that accesses of
it need to be managed using RCU wrappers.  There are two such places in
rxrpc_release_sock() where the value is checked and cleared.  Fix this by
using the appropriate wrappers.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:48 +01:00
David Howells 405dea1deb rxrpc: Fix the call timer handling
The call timer's concept of a call timeout (of which there are three) that
is inactive is that it is the timeout has the same expiration time as the
call expiration timeout (the expiration timer is never inactive).  However,
I'm not resetting the timeouts when they expire, leading to repeated
processing of expired timeouts when other timeout events occur.

Fix this by:

 (1) Move the timer expiry detection into rxrpc_set_timer() inside the
     locked section.  This means that if a timeout is set that will expire
     immediately, we deal with it immediately.

 (2) If a timeout is at or before now then it has expired.  When an expiry
     is detected, an event is raised, the timeout is automatically
     inactivated and the event processor is queued.

 (3) If a timeout is at or after the expiry timeout then it is inactive.
     Inactive timeouts do not contribute to the timer setting.

 (4) The call timer callback can now just call rxrpc_set_timer() to handle
     things.

 (5) The call processor work function now checks the event flags rather
     than checking the timeouts directly.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:40:11 +01:00
David Howells df0adc788a rxrpc: Keep the call timeouts as ktimes rather than jiffies
Keep that call timeouts as ktimes rather than jiffies so that they can be
expressed as functions of RTT.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:40:11 +01:00
David Howells c31410ea00 rxrpc: Remove error from struct rxrpc_skb_priv as it is unused
Remove error from struct rxrpc_skb_priv as it is no longer used.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:39:32 +01:00
David Howells 775e5b71db rxrpc: The offset field in struct rxrpc_skb_priv is unnecessary
The offset field in struct rxrpc_skb_priv is unnecessary as the value can
always be calculated.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:39:28 +01:00
David Howells 0851115090 rxrpc: Reduce ssthresh to peer's receive window
When we receive an ACK from the peer that tells us what the peer's receive
window (rwind) is, we should reduce ssthresh to rwind if rwind is smaller
than ssthresh.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:38:59 +01:00
David Howells 8782def204 rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthresh
Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying
on cwnd getting incremented beyond ssthresh and the window size, the mode
being shifted and then cwnd being corrected.

We need to make sure we switch into CA mode so that we stop marking every
packet for ACK.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:38:56 +01:00
David Howells ed1e8679d8 rxrpc: Note serial number being ACK'd in the congestion management trace
Note the serial number of the packet being ACK'd in the congestion
management trace rather than the serial number of the ACK packet.  Whilst
the serial number of the ACK packet is useful for matching ACK packet in
the output of wireshark, the serial number that the ACK is in response to
is of more use in working out how different trace lines relate.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells b112a67081 rxrpc: Request more ACKs in slow-start mode
Set the request-ACK on more DATA packets whilst we're in slow start mode so
that we get sufficient ACKs back to supply information to configure the
window.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells 1e9e5c9521 rxrpc: Reduce the rxrpc_local::services list to a pointer
Reduce the rxrpc_local::services list to just a pointer as we don't permit
multiple service endpoints to bind to a single transport endpoints (this is
excluded by rxrpc_lookup_local()).

The reason we don't allow this is that if you send a request to an AFS
filesystem service, it will try to talk back to your cache manager on the
port you sent from (this is how file change notifications are handled).  To
prevent someone from stealing your CM callbacks, we don't let AF_RXRPC
sockets share a UDP socket if at least one of them has a service bound.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells 2629c7fa7c rxrpc: When activating client conn channels, do state check inside lock
In rxrpc_activate_channels(), the connection cache state is checked outside
of the lock, which means it can change whilst we're waking calls up,
thereby changing whether or not we're allowed to wake calls up.

Fix this by moving the check inside the locked region.  The check to see if
all the channels are currently busy can stay outside of the locked region.

Whilst we're at it:

 (1) Split the locked section out into its own function so that we can call
     it from other places in a later patch.

 (2) Determine the mask of channels dependent on the state as we're going
     to add another state in a later patch that will restrict the number of
     simultaneous calls to 1 on a connection.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells a1767077b0 rxrpc: Make Tx loss-injection go through normal return and adjust tracing
In rxrpc_send_data_packet() make the loss-injection path return through the
same code as the transmission path so that the RTT determination is
initiated and any future timer shuffling will be done, despite the packet
having been binned.

Whilst we're at it:

 (1) Add to the tx_data tracepoint an indication of whether or not we're
     retransmitting a data packet.

 (2) When we're deciding whether or not to request an ACK, rather than
     checking if we're in fast-retransmit mode check instead if we're
     retransmitting.

 (3) Don't invoke the lose_skb tracepoint when losing a Tx packet as we're
     not altering the sk_buff refcount nor are we just seeing it after
     getting it off the Tx list.

 (4) The rxrpc_skb_tx_lost note is then no longer used so remove it.

 (5) rxrpc_lose_skb() no longer needs to deal with rxrpc_skb_tx_lost.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:37:15 +01:00
David Howells 8732db67c6 rxrpc: Fix exclusive client connections
Exclusive connections are currently reusable (which they shouldn't be)
because rxrpc_alloc_client_connection() checks the exclusive flag in the
rxrpc_connection struct before it's initialised from the function
parameters.  This means that the DONT_REUSE flag doesn't get set.

Fix this by checking the function parameters for the exclusive flag.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:37:15 +01:00
David Howells 57494343cb rxrpc: Implement slow-start
Implement RxRPC slow-start, which is similar to RFC 5681 for TCP.  A
tracepoint is added to log the state of the congestion management algorithm
and the decisions it makes.

Notes:

 (1) Since we send fixed-size DATA packets (apart from the final packet in
     each phase), counters and calculations are in terms of packets rather
     than bytes.

 (2) The ACK packet carries the equivalent of TCP SACK.

 (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly
     suited to SACK of a small number of packets.  It seems that, almost
     inevitably, by the time three 'duplicate' ACKs have been seen, we have
     narrowed the loss down to one or two missing packets, and the
     FLIGHT_SIZE calculation ends up as 2.

 (4) In rxrpc_resend(), if there was no data that apparently needed
     retransmission, we transmit a PING ACK to ask the peer to tell us what
     its Rx window state is.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells 0d967960d3 rxrpc: Schedule an ACK if the reply to a client call appears overdue
If we've sent all the request data in a client call but haven't seen any
sign of the reply data yet, schedule an ACK to be sent to the server to
find out if the reply data got lost.

If the server hasn't yet hard-ACK'd the request data, we send a PING ACK to
demand a response to find out whether we need to retransmit.

If the server says it has received all of the data, we send an IDLE ACK to
tell the server that we haven't received anything in the receive phase as
yet.

To make this work, a non-immediate PING ACK must carry a delay.  I've chosen
the same as the IDLE ACK for the moment.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells 31a1b98950 rxrpc: Generate a summary of the ACK state for later use
Generate a summary of the Tx buffer packet state when an ACK is received
for use in a later patch that does congestion management.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells df0562a72d rxrpc: Delay the resend timer to allow for nsec->jiffies conv error
When determining the resend timer value, we have a value in nsec but the
timer is in jiffies which may be a million or more times more coarse.
nsecs_to_jiffies() rounds down - which means that the resend timeout
expressed as jiffies is very likely earlier than the one expressed as
nanoseconds from which it was derived.

The problem is that rxrpc_resend() gets triggered by the timer, but can't
then find anything to resend yet.  It sets the timer again - but gets
kicked off immediately again and again until the nanosecond-based expiry
time is reached and we actually retransmit.

Fix this by adding 1 to the jiffies-based resend_at value to counteract the
rounding and make sure that the timer happens after the nanosecond-based
expiry is passed.

Alternatives would be to adjust the timestamp on the packets to align
with the jiffie scale or to switch back to using jiffie-timestamps.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells dd7c1ee59a rxrpc: Reinitialise the call ACK and timer state for client reply phase
Clear the ACK reason, ACK timer and resend timer when entering the client
reply phase when the first DATA packet is received.  New ACKs will be
proposed once the data is queued.

The resend timer is no longer relevant and we need to cancel ACKs scheduled
to probe for a lost reply.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells b69d94d799 rxrpc: Include the last reply DATA serial number in the final ACK
In a client call, include the serial number of the last DATA packet of the
reply in the final ACK.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells a7056c5ba6 rxrpc: Send an immediate ACK if we fill in a hole
Send an immediate ACK if we fill in a hole in the buffer left by an
out-of-sequence packet.  This may allow the congestion management in the peer
to avoid a retransmission if packets got reordered on the wire.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells 805b21b929 rxrpc: Send an ACK after every few DATA packets we receive
Send an ACK if we haven't sent one for the last two packets we've received.
This keeps the other end apprised of where we've got to - which is
important if they're doing slow-start.

We do this in recvmsg so that we can dispatch a packet directly without the
need to wake up the background thread.

This should possibly be made configurable in future.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 18:05:26 +01:00
David Howells c6672e3fe4 rxrpc: Add a tracepoint to log which packets will be retransmitted
Add a tracepoint to log in rxrpc_resend() which packets will be
retransmitted.  Note that if a positive ACK comes in whilst we have dropped
the lock to retransmit another packet, the actual retransmission may not
happen, though some of the effects will (such as altering the congestion
management).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 9c7ad43444 rxrpc: Add tracepoint for ACK proposal
Add a tracepoint to log proposed ACKs, including whether the proposal is
used to update a pending ACK or is discarded in favour of an easlier,
higher priority ACK.

Whilst we're at it, get rid of the rxrpc_acks() function and access the
name array directly.  We do, however, need to validate the ACK reason
number given to trace_rxrpc_rx_ack() to make sure we don't overrun the
array.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 89b475abdb rxrpc: Add a tracepoint to log injected Rx packet loss
Add a tracepoint to log received packets that get discarded due to Rx
packet loss.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells be832aecc5 rxrpc: Add data Tx tracepoint and adjust Tx ACK tracepoint
Add a tracepoint to log transmission of DATA packets (including loss
injection).

Adjust the ACK transmission tracepoint to include the packet serial number
and to line this up with the DATA transmission display.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells fc7ab6d29a rxrpc: Add a tracepoint for the call timer
Add a tracepoint to log call timer initiation, setting and expiry.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells b86e218e0d rxrpc: Don't call the tx_ack tracepoint if don't generate an ACK
rxrpc_send_call_packet() is invoking the tx_ack tracepoint before it checks
whether there's an ACK to transmit (another thread may jump in and transmit
it).

Fix this by only invoking the tracepoint if we get a valid ACK to transmit.

Further, only allocate a serial number if we're going to actually transmit
something.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 70790dbe3f rxrpc: Pass the last Tx packet marker in the annotation buffer
When the last packet of data to be transmitted on a call is queued, tx_top
is set and then the RXRPC_CALL_TX_LAST flag is set.  Unfortunately, this
leaves a race in the ACK processing side of things because the flag affects
the interpretation of tx_top and also allows us to start receiving reply
data before we've finished transmitting.

To fix this, make the following changes:

 (1) rxrpc_queue_packet() now sets a marker in the annotation buffer
     instead of setting the RXRPC_CALL_TX_LAST flag.

 (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the
     same context as the routines that use it.

 (3) rxrpc_end_tx_phase() is simplified to just shift the call state.
     The Tx window must have been rotated before calling to discard the
     last packet.

 (4) rxrpc_receiving_reply() is added to handle the arrival of the first
     DATA packet of a reply to a client call (which is an implicit ACK of
     the Tx phase).

 (5) The last part of rxrpc_input_ack() is reordered to perform Tx
     rotation, then soft-ACK application and then to end the phase if we've
     rotated the last packet.  In the event of a terminal ACK, the soft-ACK
     application will be skipped as nAcks should be 0.

 (6) rxrpc_input_ackall() now has to rotate as well as ending the phase.

In addition:

 (7) Alter the transmit tracepoint to log the rotation of the last packet.

 (8) Remove the no-longer relevant queue_reqack tracepoint note.  The
     ACK-REQUESTED packet header flag is now set as needed when we actually
     transmit the packet and may vary by retransmission.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 01a88f7f6b rxrpc: Fix call timer
Fix the call timer in the following ways:

 (1) If call->resend_at or call->ack_at are before or equal to the current
     time, then ignore that timeout.

 (2) If call->expire_at is before or equal to the current time, then don't
     set the timer at all (possibly we should queue the call).

 (3) Don't skip modifying the timer if timer_pending() is true.  This
     indicates that the timer is working, not that it has expired and is
     running/waiting to run its expiry handler.

Also call rxrpc_set_timer() to start the call timer going rather than
calling add_timer().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells be8aa33806 rxrpc: Fix accidental cancellation of scheduled resend by ACK parser
When rxrpc_input_soft_acks() is parsing the soft-ACKs from an ACK packet,
it updates the Tx packet annotations in the annotation buffer.  If a
soft-ACK is an ACK, then we overwrite unack'd, nak'd or to-be-retransmitted
states and that is fine; but if the soft-ACK is an NACK, we overwrite the
to-be-retransmitted with a nak - which isn't.

Instead, we need to let any scheduled retransmission stand if the packet
was NAK'd.

Note that we don't reissue a resend if the annotation is in the
to-be-retransmitted state because someone else must've scheduled the
resend already.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:35:45 +01:00
David Howells dfc3da4404 rxrpc: Need to start the resend timer on initial transmission
When a DATA packet has its initial transmission, we may need to start or
adjust the resend timer.  Without this we end up relying on being sent a
NACK to initiate the resend.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 14:05:12 +01:00
David Howells 98dafac569 rxrpc: Use before_eq() and friends to compare serial numbers
before_eq() and friends should be used to compare serial numbers (when not
checking for (non)equality) rather than casting to int, subtracting and
checking the result.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 14:05:08 +01:00
David Howells 90bd684ded rxrpc: Should be using ktime_add_ms() not ktime_add_ns()
ktime_add_ms() should be used to add the resend time (in ms) rather than
ktime_add_ns().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:23:09 +01:00
David Howells c0d058c21c rxrpc: Make sure sendmsg() is woken on call completion
Make sure that sendmsg() gets woken up if the call it is waiting for
completes abnormally.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:23:09 +01:00
David Howells 9aff212bd6 rxrpc: Don't send an ACK at the end of service call response transmission
Don't send an IDLE ACK at the end of the transmission of the response to a
service call.  The service end resends DATA packets until the client sends an
ACK that hard-acks all the send data.  At that point, the call is complete.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:23:09 +01:00
David Howells b24d2891cf rxrpc: Preset timestamp on Tx sk_buffs
Set the timestamp on sk_buffs holding packets to be transmitted before
queueing them because the moment the packet is on the queue it can be seen
by the retransmission algorithm - which may see a completely random
timestamp.

If the retransmission algorithm sees such a timestamp, it may retransmit
the packet and, in future, tell the congestion management algorithm that
the retransmit timer expired.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:17:52 +01:00
David Howells fc943f6777 rxrpc: Reduce the number of PING ACKs sent
We don't want to send a PING ACK for every new incoming call as that just
adds to the network traffic.  Instead, we send a PING ACK to the first
three that we receive and then once per second thereafter.

This could probably be made adjustable in future.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:49:22 +01:00
David Howells 0d4b103c00 rxrpc: Reduce the number of ACK-Requests sent
Reduce the number of ACK-Requests we set on DATA packets that we're sending
to reduce network traffic.  We set the flag on odd-numbered DATA packets to
start off the RTT cache until we have at least three entries in it and then
probe once per second thereafter to keep it topped up.

This could be made tunable in future.

Note that from this point, the RXRPC_REQUEST_ACK flag is set on DATA
packets as we transmit them and not stored statically in the sk_buff.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:49:20 +01:00
David Howells 50235c4b5a rxrpc: Obtain RTT data by requesting ACKs on DATA packets
In addition to sending a PING ACK to gain RTT data, we can set the
RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK.  The
ACK packet contains the serial number of the packet it is in response to,
so we can look through the Tx buffer for a matching DATA packet.

This requires that the data packets be stamped with the time of
transmission as a ktime rather than having the resend_at time in jiffies.

This further requires the resend code to do the resend determination in
ktimes and convert to jiffies to set the timer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:21:24 +01:00
David Howells 7aa51da7c8 rxrpc: Expedite ping response transmission
Expedite the transmission of a response to a PING ACK by sending it from
sendmsg if one is pending.  We're most likely to see a PING ACK during the
client call Tx phase as the other side may use it to determine a number of
parameters, such as the client's receive window size, the RTT and whether
the client is doing slow start (similar to RFC5681).

If we don't expedite it, it's left to the background processing thread to
transmit.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:21:24 +01:00
David Howells 8e83134db4 rxrpc: Send pings to get RTT data
Send a PING ACK packet to the peer when we get a new incoming call from a
peer we don't have a record for.  The PING RESPONSE ACK packet will tell us
the following about the peer:

 (1) its receive window size

 (2) its MTU sizes

 (3) its support for jumbo DATA packets

 (4) if it supports slow start (similar to RFC 5681)

 (5) an estimate of the RTT

This is necessary because the peer won't normally send us an ACK until it
gets to the Rx phase and we send it a packet, but we would like to know
some of this information before we start sending packets.

A pair of tracepoints are added so that RTT determination can be observed.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:21:24 +01:00
David Howells cf1a6474f8 rxrpc: Add per-peer RTT tracker
Add a function to track the average RTT for a peer.  Sources of RTT data
will be added in subsequent patches.

The RTT data will be useful in the future for determining resend timeouts
and for handling the slow-start part of the Rx protocol.

Also add a pair of tracepoints, one to log transmissions to elicit a
response for RTT purposes and one to log responses that contribute RTT
data.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 01:26:25 +01:00
David Howells f07373ead4 rxrpc: Add re-sent Tx annotation
Add a Tx-phase annotation for packet buffers to indicate that a buffer has
already been retransmitted.  This will be used by future congestion
management.  Re-retransmissions of a packet don't affect the congestion
window managment in the same way as initial retransmissions.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 01:23:50 +01:00
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
David Howells 8a681c3605 rxrpc: Add config to inject packet loss
Add a configuration option to inject packet loss by discarding
approximately every 8th packet received and approximately every 8th DATA
packet transmitted.

Note that no locking is used, but it shouldn't really matter.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:04 +01:00
David Howells 71f3ca408f rxrpc: Improve skb tracing
Improve sk_buff tracing within AF_RXRPC by the following means:

 (1) Use an enum to note the event type rather than plain integers and use
     an array of event names rather than a big multi ?: list.

 (2) Distinguish Rx from Tx packets and account them separately.  This
     requires the call phase to be tracked so that we know what we might
     find in rxtx_buffer[].

 (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the
     event type.

 (4) A pair of 'rotate' events are added to indicate packets that are about
     to be rotated out of the Rx and Tx windows.

 (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for
     packet loss injection recording.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:04 +01:00
David Howells ba39f3a0ed rxrpc: Remove printks from rxrpc_recvmsg_data() to fix uninit var
Remove _enter/_debug/_leave calls from rxrpc_recvmsg_data() of which one
uses an uninitialised variable.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:04 +01:00
David Howells 849979051c rxrpc: Add a tracepoint to follow what recvmsg does
Add a tracepoint to follow what recvmsg does within AF_RXRPC.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells 58dc63c998 rxrpc: Add a tracepoint to follow packets in the Rx buffer
Add a tracepoint to follow the life of packets that get added to a call's
receive buffer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00