rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags

Switch from keeping the transmission buffers in the rxrpc_txbuf struct and
allocated from the slab, to allocating them using page fragment allocators
(which uses raw pages), thereby allowing them to be passed to
MSG_SPLICE_PAGES and avoid copying into the UDP buffers.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Don't pick values out of the wire header when setting up security

Don't pick values out of the wire header in rxkad when setting up DATA
packet security, but rather use other sources. This makes it easier to get
rid of txb->wire.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Do lazy DF flag resetting

Don't reset the DF flag after transmission, but rather set it when needed
since it should be a fast op now that we call IP directly.

This includes turning it off for RESPONSE packets and, for the moment, ACK
packets. In future, we will need to turn it on for ACK packets used to do
path MTU discovery.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Note cksum in txbuf

Add a field to rxrpc_txbuf in which to store the checksum to go in the
header as this may get overwritten in the wire header struct when
transmitting as part of a jumbo packet.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

rxrpc: Fix generation of serial numbers to skip zero

In the Rx protocol, every packet generated is marked with a per-connection
monotonically increasing serial number. This number can be referenced in
an ACK packet generated in response to an incoming packet - thereby
allowing the sender to use this for RTT determination, amongst other
things.

However, if the reference field in the ACK is zero, it doesn't refer to any
incoming packet (it could be a ping to find out if a packet got lost, for
example) - so we shouldn't generate zero serial numbers.

Fix the generation of serial numbers to retry if it comes up with a zero.

Furthermore, since the serial numbers are only ever allocated within the
I/O thread this connection is bound to, there's no need for atomics so
remove that too.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Fix use of Don't Fragment flag

rxrpc normally has the Don't Fragment flag set on the UDP packets it
transmits, except when it has decided that DATA packets aren't getting
through - in which case it turns it off just for the DATA transmissions.
This can be a problem, however, for RESPONSE packets that convey
authentication and crypto data from the client to the server as ticket may
be larger than can fit in the MTU.

In such a case, rxrpc gets itself into an infinite loop as the sendmsg
returns an error (EMSGSIZE), which causes rxkad_send_response() to return
-EAGAIN - and the CHALLENGE packet is put back on the Rx queue to retry,
leading to the I/O thread endlessly attempting to perform the transmission.

Fix this by disabling DF on RESPONSE packets for now. The use of DF and
best data MTU determination needs reconsidering at some point in the
future.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/1581852.1704813048@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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: cf37b5987508 ("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

rxrpc: Remove call->state_lock

All the setters of call->state are now in the I/O thread and thus the state
lock is now unnecessary.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

rxrpc: Tidy up abort generation infrastructure

Tidy up the abort generation infrastructure in the following ways:

(1) Create an enum and string mapping table to list the reasons an abort
might be generated in tracing.

(2) Replace the 3-char string with the values from (1) in the places that
use that to log the abort source. This gets rid of a memcpy() in the
tracepoint.

(3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint
and use values from (1) to indicate the trace reason.

(4) Always make a call to an abort function at the point of the abort
rather than stashing the values into variables and using goto to get
to a place where it reported. The C optimiser will collapse the calls
together as appropriate. The abort functions return a value that can
be returned directly if appropriate.

Note that this extends into afs also at the points where that generates an
abort. To aid with this, the afs sources need to #define
RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header
because they don't have access to the rxrpc internal structures that some
of the tracepoints make use of.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

rxrpc: Clean up connection abort

Clean up connection abort, using the connection state_lock to gate access
to change that state, and use an rxrpc_call_completion value to indicate
the difference between local and remote aborts as these can be pasted
directly into the call state.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

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

rxrpc: Remove the [k_]proto() debugging macros

Remove the kproto() and _proto() debugging macros in preference to using
tracepoints for this.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

rxrpc: fix rxkad_verify_response()

The error handling for if skb_copy_bits() fails was accidentally deleted
so the rxkad_decrypt_ticket() function is not called.

Fixes: 5d7edbc9231e ("rxrpc: Get rid of the Rx ring")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Allocate an skcipher each time needed rather than reusing

In the rxkad security class, allocate the skcipher used to do packet
encryption and decription rather than allocating one up front and reusing
it for each packet. Reusing the skcipher precludes doing crypto in
parallel.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

rxrpc: Don't use a ring buffer for call Tx queue

Change the way the Tx queueing works to make the following ends easier to
achieve:

(1) The filling of packets, the encryption of packets and the transmission
of packets can be handled in parallel by separate threads, rather than
rxrpc_sendmsg() allocating, filling, encrypting and transmitting each
packet before moving onto the next one.

(2) Get rid of the fixed-size ring which sets a hard limit on the number
of packets that can be retained in the ring. This allows the number
of packets to increase without having to allocate a very large ring or
having variable-sized rings.

[Note: the downside of this is that it's then less efficient to locate
a packet for retransmission as we then have to step through a list and
examine each buffer in the list.]

(3) Allow the filler/encrypter to run ahead of the transmission window.

(4) Make it easier to do zero copy UDP from the packet buffers.

(5) Make it easier to do zero copy from userspace to the packet buffers -
and thence to UDP (only if for unauthenticated connections).

To that end, the following changes are made:

(1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets
to be transmitted in. This allows them to be placed on multiple
queues simultaneously. An sk_buff isn't really necessary as it's
never passed on to lower-level networking code.

(2) Keep the transmissable packets in a linked list on the call struct
rather than in a ring. As a consequence, the annotation buffer isn't
used either; rather a flag is set on the packet to indicate ackedness.

(3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be
transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate
that all packets up to and including the last got hard acked.

(4) Wire headers are now stored in the txbuf rather than being concocted
on the stack and they're stored immediately before the data, thereby
allowing zerocopy of a single span.

(5) Don't bother with instant-resend on transmission failure; rather,
leave it for a timer or an ACK packet to trigger.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

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

rxrpc: Clone received jumbo subpackets and queue separately

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

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

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

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

rxrpc: Fix an insufficiently large sglist in rxkad_verify_packet_2()

rxkad_verify_packet_2() has a small stack-allocated sglist of 4 elements,
but if that isn't sufficient for the number of fragments in the socket
buffer, we try to allocate an sglist large enough to hold all the
fragments.

However, for large packets with a lot of fragments, this isn't sufficient
and we need at least one additional fragment.

The problem manifests as skb_to_sgvec() returning -EMSGSIZE and this then
getting returned by userspace. Most of the time, this isn't a problem as
rxrpc sets a limit of 5692, big enough for 4 jumbo subpackets to be glued
together; occasionally, however, the server will ignore the reported limit
and give a packet that's a lot bigger - say 19852 bytes with ->nr_frags
being 7. skb_to_sgvec() then tries to return a "zeroth" fragment that
seems to occur before the fragments counted by ->nr_frags and we hit the
end of the sglist too early.

Note that __skb_to_sgvec() also has an skb_walk_frags() loop that is
recursive up to 24 deep. I'm not sure if I need to take account of that
too - or if there's an easy way of counting those frags too.

Fix this by counting an extra frag and allocating a larger sglist based on
that.

Fixes: d0d5c0cd1e71 ("rxrpc: Use skb_unshare() rather than skb_cow_data()")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org

net: rxrpc: fix clang -Wformat warning

When building with Clang we encounter this warning:
| net/rxrpc/rxkad.c:434:33: error: format specifies type 'unsigned short'
| but the argument has type 'u32' (aka 'unsigned int') [-Werror,-Wformat]
| _leave(" = %d [set %hx]", ret, y);

y is a u32 but the format specifier is `%hx`. Going from unsigned int to
short int results in a loss of data. This is surely not intended
behavior. If it is intended, the warning should be suppressed through
other means.

This patch should get us closer to the goal of enabling the -Wformat
flag for Clang builds.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20220707182052.769989-1-justinstitt@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rxrpc: rxkad: Remove redundant variable offset

Variable offset is being assigned a value from a calculation
however the variable is never read, so this redundant variable
can be removed.

Cleans up the following clang-analyzer warning:

net/rxrpc/rxkad.c:579:2: warning: Value stored to 'offset' is never read
[clang-analyzer-deadcode.DeadStores].

net/rxrpc/rxkad.c:485:2: warning: Value stored to 'offset' is never read
[clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

rxrpc: rxkad: Don't use pskb_pull() to advance through the response packet

In the rxkad security class, don't use pskb_pull() to advance through the
contents of the response packet. There's no point, especially as the next
and last access to the skbuff still has to allow for the wire header in the
offset (which we didn't advance over).

Better to just add the displacement to the next offset.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Organise connection security to use a union

Organise the security information in the rxrpc_connection struct to use a
union to allow for different data for different security classes.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Don't reserve security header in Tx DATA skbuff

Insert the security header into the skbuff representing a DATA packet to be
transmitted rather than using skb_reserve() when the packet is allocated.
This makes it easier to apply crypto that spans the security header and the
data, particularly in the upcoming RxGK class where we have a common
encrypt-and-checksum function that is used in a number of circumstances.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Merge prime_packet_security into init_connection_security

Merge the ->prime_packet_security() into the ->init_connection_security()
hook as they're always called together.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Hand server key parsing off to the security class

Hand responsibility for parsing a server key off to the security class. We
can determine which class from the description. This is necessary as rxgk
server keys have different lookup requirements and different content
requirements (dependent on crypto type) to those of rxkad server keys.

Signed-off-by: David Howells <dhowells@redhat.com>

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>

rxrpc: Support keys with multiple authentication tokens

rxrpc-type keys can have multiple tokens attached for different security
classes. Currently, rxrpc always picks the first one, whether or not the
security class it indicates is supported.

Add preliminary support for choosing which security class will be used
(this will need to be directed from a higher layer) and go through the
tokens to find one that's supported.

Signed-off-by: David Howells <dhowells@redhat.com>

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>

rxrpc: Fix memory leak in rxkad_verify_response()

Fix a memory leak in rxkad_verify_response() whereby the response buffer
doesn't get freed if we fail to allocate a ticket buffer.

Fixes: ef68622da9cc ("rxrpc: Handle temporary errors better in rxkad security")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Fix a memory leak in rxkad_verify_response()

A ticket was not released after a call of the function
"rxkad_decrypt_ticket" failed. Thus replace the jump target
"temporary_error_free_resp" by "temporary_error_free_ticket".

Fixes: 8c2f826dc3631 ("rxrpc: Don't put crypto buffers on the stack")
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Markus Elfring <Markus.Elfring@web.de>

rxrpc: Fix missing security check on incoming calls

Fix rxrpc_new_incoming_call() to check that we have a suitable service key
available for the combination of service ID and security class of a new
incoming call - and to reject calls for which we don't.

This causes an assertion like the following to appear:

rxrpc: Assertion failed - 6(0x6) == 12(0xc) is false
kernel BUG at net/rxrpc/call_object.c:456!

Where call->state is RXRPC_CALL_SERVER_SECURING (6) rather than
RXRPC_CALL_COMPLETE (12).

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Use skb_unshare() rather than skb_cow_data()

The in-place decryption routines in AF_RXRPC's rxkad security module
currently call skb_cow_data() to make sure the data isn't shared and that
the skb can be written over. This has a problem, however, as the softirq
handler may be still holding a ref or the Rx ring may be holding multiple
refs when skb_cow_data() is called in rxkad_verify_packet() - and so
skb_shared() returns true and __pskb_pull_tail() dislikes that. If this
occurs, something like the following report will be generated.

kernel BUG at net/core/skbuff.c:1463!
...
RIP: 0010:pskb_expand_head+0x253/0x2b0
...
Call Trace:
__pskb_pull_tail+0x49/0x460
skb_cow_data+0x6f/0x300
rxkad_verify_packet+0x18b/0xb10 [rxrpc]
rxrpc_recvmsg_data.isra.11+0x4a8/0xa10 [rxrpc]
rxrpc_kernel_recv_data+0x126/0x240 [rxrpc]
afs_extract_data+0x51/0x2d0 [kafs]
afs_deliver_fs_fetch_data+0x188/0x400 [kafs]
afs_deliver_to_call+0xac/0x430 [kafs]
afs_wait_for_call_to_complete+0x22f/0x3d0 [kafs]
afs_make_call+0x282/0x3f0 [kafs]
afs_fs_fetch_data+0x164/0x300 [kafs]
afs_fetch_data+0x54/0x130 [kafs]
afs_readpages+0x20d/0x340 [kafs]
read_pages+0x66/0x180
__do_page_cache_readahead+0x188/0x1a0
ondemand_readahead+0x17d/0x2e0
generic_file_read_iter+0x740/0xc10
__vfs_read+0x145/0x1a0
vfs_read+0x8c/0x140
ksys_read+0x4a/0xb0
do_syscall_64+0x43/0xf0
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by using skb_unshare() instead in the input path for DATA packets
that have a security index != 0. Non-DATA packets don't need in-place
encryption and neither do unencrypted DATA packets.

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Reported-by: Julian Wollrath <jwollrath@web.de>
Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Fix -Wframe-larger-than= warnings from on-stack crypto

rxkad sometimes triggers a warning about oversized stack frames when
building with clang for a 32-bit architecture:

net/rxrpc/rxkad.c:243:12: error: stack frame size of 1088 bytes in function 'rxkad_secure_packet' [-Werror,-Wframe-larger-than=]
net/rxrpc/rxkad.c:501:12: error: stack frame size of 1088 bytes in function 'rxkad_verify_packet' [-Werror,-Wframe-larger-than=]

The problem is the combination of SYNC_SKCIPHER_REQUEST_ON_STACK() in
rxkad_verify_packet()/rxkad_secure_packet() with the relatively large
scatterlist in rxkad_verify_packet_1()/rxkad_secure_packet_encrypt().

The warning does not show up when using gcc, which does not inline the
functions as aggressively, but the problem is still the same.

Allocate the cipher buffers from the slab instead, caching the allocated
packet crypto request memory used for DATA packet crypto in the rxrpc_call
struct.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

rxrpc: Remove VLA usage of skcipher

In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: David Howells <dhowells@redhat.com>
Cc: linux-afs@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

rxrpc: Fix the keepalive generator [ver #2]

AF_RXRPC has a keepalive message generator that generates a message for a
peer ~20s after the last transmission to that peer to keep firewall ports
open. The implementation is incorrect in the following ways:

(1) It mixes up ktime_t and time64_t types.

(2) It uses ktime_get_real(), the output of which may jump forward or
backward due to adjustments to the time of day.

(3) If the current time jumps forward too much or jumps backwards, the
generator function will crank the base of the time ring round one slot
at a time (ie. a 1s period) until it catches up, spewing out VERSION
packets as it goes.

Fix the problem by:

(1) Only using time64_t. There's no need for sub-second resolution.

(2) Use ktime_get_seconds() rather than ktime_get_real() so that time
isn't perceived to go backwards.

(3) Simplifying rxrpc_peer_keepalive_worker() by splitting it into two
parts:

(a) The "worker" function that manages the buckets and the timer.

(b) The "dispatch" function that takes the pending peers and
potentially transmits a keepalive packet before putting them back
in the ring into the slot appropriate to the revised last-Tx time.

(4) Taking everything that's pending out of the ring and splicing it into
a temporary collector list for processing.

In the case that there's been a significant jump forward, the ring
gets entirely emptied and then the time base can be warped forward
before the peers are processed.

The warping can't happen if the ring isn't empty because the slot a
peer is in is keepalive-time dependent, relative to the base time.

(5) Limit the number of iterations of the bucket array when scanning it.

(6) Set the timer to skip any empty slots as there's no point waking up if
there's nothing to do yet.

This can be triggered by an incoming call from a server after a reboot with
AF_RXRPC and AFS built into the kernel causing a peer record to be set up
before userspace is started. The system clock is then adjusted by
userspace, thereby potentially causing the keepalive generator to have a
meltdown - which leads to a message like:

watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/0:1:23]
...
Workqueue: krxrpcd rxrpc_peer_keepalive_worker
EIP: lock_acquire+0x69/0x80
...
Call Trace:
? rxrpc_peer_keepalive_worker+0x5e/0x350
? _raw_spin_lock_bh+0x29/0x60
? rxrpc_peer_keepalive_worker+0x5e/0x350
? rxrpc_peer_keepalive_worker+0x5e/0x350
? __lock_acquire+0x3d3/0x870
? process_one_work+0x110/0x340
? process_one_work+0x166/0x340
? process_one_work+0x110/0x340
? worker_thread+0x39/0x3c0
? kthread+0xdb/0x110
? cancel_delayed_work+0x90/0x90
? kthread_stop+0x70/0x70
? ret_from_fork+0x19/0x24

Fixes: ace45bec6d77 ("rxrpc: Fix firewall route keepalive")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Reuse SKCIPHER_REQUEST_ON_STACK buffer

The use of SKCIPHER_REQUEST_ON_STACK() will trigger FRAME_WARN warnings
(when less than 2048) once the VLA is no longer hidden from the check:

net/rxrpc/rxkad.c:398:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=]
net/rxrpc/rxkad.c:242:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=]

This passes the initial SKCIPHER_REQUEST_ON_STACK allocation to the leaf
functions for reuse. Two requests allocated on the stack is not needed
when only one is used at a time.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Trace packet transmission

Trace successful packet transmission (kernel_sendmsg() succeeded, that is)
in AF_RXRPC. We can share the enum that defines the transmission points
with the trace_rxrpc_tx_fail() tracepoint, so rename its constants to be
applicable to both.

Also, save the internal call->debug_id in the rxrpc_channel struct so that
it can be used in retransmission trace lines.

Signed-off-by: David Howells <dhowells@redhat.com>

treewide: kmalloc() -> kmalloc_array()

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

as well as handling cases of:

kmalloc(a * b * c, gfp)

with:

kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

rxrpc: Trace UDP transmission failure

Add a tracepoint to log transmission failure from the UDP transport socket
being used by AF_RXRPC.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Fix firewall route keepalive

Fix the firewall route keepalive part of AF_RXRPC which is currently
function incorrectly by replying to VERSION REPLY packets from the server
with VERSION REQUEST packets.

Instead, send VERSION REPLY packets to the peers of service connections to
act as keep-alives 20s after the latest packet was transmitted to that
peer.

Also, just discard VERSION REPLY packets rather than replying to them.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Don't put crypto buffers on the stack

Don't put buffers of data to be handed to crypto on the stack as this may
cause an assertion failure in the kernel (see below). Fix this by using an
kmalloc'd buffer instead.

kernel BUG at ./include/linux/scatterlist.h:147!
...
RIP: 0010:rxkad_encrypt_response.isra.6+0x191/0x1b0 [rxrpc]
RSP: 0018:ffffbe2fc06cfca8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff989277d59900 RCX: 0000000000000028
RDX: 0000259dc06cfd88 RSI: 0000000000000025 RDI: ffffbe30406cfd88
RBP: ffffbe2fc06cfd60 R08: ffffbe2fc06cfd08 R09: ffffbe2fc06cfd08
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff7c5f80d9f95
R13: ffffbe2fc06cfd88 R14: ffff98927a3f7aa0 R15: ffffbe2fc06cfd08
FS: 0000000000000000(0000) GS:ffff98927fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b1ff28f0f8 CR3: 000000001b412003 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rxkad_respond_to_challenge+0x297/0x330 [rxrpc]
rxrpc_process_connection+0xd1/0x690 [rxrpc]
? process_one_work+0x1c3/0x680
? __lock_is_held+0x59/0xa0
process_one_work+0x249/0x680
worker_thread+0x3a/0x390
? process_one_work+0x680/0x680
kthread+0x121/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50

Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

net: rxrpc: Replace time_t type with time64_t type

Since the 'expiry' variable of 'struct key_preparsed_payload' has been
changed to 'time64_t' type, which is year 2038 safe on 32bits system.

In net/rxrpc subsystem, we need convert 'u32' type to 'time64_t' type
when copying ticket expires time to 'prep->expiry', then this patch
introduces two helper functions to help convert 'u32' to 'time64_t'
type.

This patch also uses ktime_get_real_seconds() to get current time instead
of get_seconds() which is not year 2038 safe on 32bits system.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: David Howells <dhowells@redhat.com>

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>

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>

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>

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>

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>

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>

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>

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>

rxrpc: Rewrite the data and ack handling code

Rewrite the data and ack handling code such that:

(1) Parsing of received ACK and ABORT packets and the distribution and the
filing of DATA packets happens entirely within the data_ready context
called from the UDP socket. This allows us to process and discard ACK
and ABORT packets much more quickly (they're no longer stashed on a
queue for a background thread to process).

(2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead
keep track of the offset and length of the content of each packet in
the sk_buff metadata. This means we don't do any allocation in the
receive path.

(3) Jumbo DATA packet parsing is now done in data_ready context. Rather
than cloning the packet once for each subpacket and pulling/trimming
it, we file the packet multiple times with an annotation for each
indicating which subpacket is there. From that we can directly
calculate the offset and length.

(4) A call's receive queue can be accessed without taking locks (memory
barriers do have to be used, though).

(5) Incoming calls are set up from preallocated resources and immediately
made live. They can than have packets queued upon them and ACKs
generated. If insufficient resources exist, DATA packet #1 is given a
BUSY reply and other DATA packets are discarded).

(6) sk_buffs no longer take a ref on their parent call.

To make this work, the following changes are made:

(1) Each call's receive buffer is now a circular buffer of sk_buff
pointers (rxtx_buffer) rather than a number of sk_buff_heads spread
between the call and the socket. This permits each sk_buff to be in
the buffer multiple times. The receive buffer is reused for the
transmit buffer.

(2) A circular buffer of annotations (rxtx_annotations) is kept parallel
to the data buffer. Transmission phase annotations indicate whether a
buffered packet has been ACK'd or not and whether it needs
retransmission.

Receive phase annotations indicate whether a slot holds a whole packet
or a jumbo subpacket and, if the latter, which subpacket. They also
note whether the packet has been decrypted in place.

(3) DATA packet window tracking is much simplified. Each phase has just
two numbers representing the window (rx_hard_ack/rx_top and
tx_hard_ack/tx_top).

The hard_ack number is the sequence number before base of the window,
representing the last packet the other side says it has consumed.
hard_ack starts from 0 and the first packet is sequence number 1.

The top number is the sequence number of the highest-numbered packet
residing in the buffer. Packets between hard_ack+1 and top are
soft-ACK'd to indicate they've been received, but not yet consumed.

Four macros, before(), before_eq(), after() and after_eq() are added
to compare sequence numbers within the window. This allows for the
top of the window to wrap when the hard-ack sequence number gets close
to the limit.

Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also
to indicate when rx_top and tx_top point at the packets with the
LAST_PACKET bit set, indicating the end of the phase.

(4) Calls are queued on the socket 'receive queue' rather than packets.
This means that we don't need have to invent dummy packets to queue to
indicate abnormal/terminal states and we don't have to keep metadata
packets (such as ABORTs) around

(5) The offset and length of a (sub)packet's content are now passed to
the verify_packet security op. This is currently expected to decrypt
the packet in place and validate it.

However, there's now nowhere to store the revised offset and length of
the actual data within the decrypted blob (there may be a header and
padding to skip) because an sk_buff may represent multiple packets, so
a locate_data security op is added to retrieve these details from the
sk_buff content when needed.

(6) recvmsg() now has to handle jumbo subpackets, where each subpacket is
individually secured and needs to be individually decrypted. The code
to do this is broken out into rxrpc_recvmsg_data() and shared with the
kernel API. It now iterates over the call's receive buffer rather
than walking the socket receive queue.

Additional changes:

(1) The timers are condensed to a single timer that is set for the soonest
of three timeouts (delayed ACK generation, DATA retransmission and
call lifespan).

(2) Transmission of ACK and ABORT packets is effected immediately from
process-context socket ops/kernel API calls that cause them instead of
them being punted off to a background work item. The data_ready
handler still has to defer to the background, though.

(3) A shutdown op is added to the AF_RXRPC socket so that the AFS
filesystem can shut down the socket and flush its own work items
before closing the socket to deal with any in-progress service calls.

Future additional changes that will need to be considered:

(1) Make sure that a call doesn't hog the front of the queue by receiving
data from the network as fast as userspace is consuming it to the
exclusion of other calls.

(2) Transmit delayed ACKs from within recvmsg() when we've consumed
sufficiently more packets to avoid the background work item needing to
run.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Add tracepoint for working out where aborts happen

Add a tracepoint for working out where local aborts happen. Each
tracepoint call is labelled with a 3-letter code so that they can be
distinguished - and the DATA sequence number is added too where available.

rxrpc_kernel_abort_call() also takes a 3-letter code so that AFS can
indicate the circumstances when it aborts a call.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Drop channel number field from rxrpc_call struct

Drop the channel number (channel) field from the rxrpc_call struct to
reduce the size of the call struct. The field is redundant: if the call is
attached to a connection, the channel can be obtained from there by AND'ing
with RXRPC_CHANNELMASK.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Call channels should have separate call number spaces

Each channel on a connection has a separate, independent number space from
which to allocate callNumber values. It is entirely possible, for example,
to have a connection with four active calls, each with call number 1.

Note that the callNumber values for any particular channel don't have to
start at 1, but they are supposed to increment monotonically for that
channel from a client's perspective and may not be reused once the call
number is transmitted (until the epoch cycles all the way back round).

Currently, however, call numbers are allocated on a per-connection basis
and, further, are held in an rb-tree. The rb-tree is redundant as the four
channel pointers in the rxrpc_connection struct are entirely capable of
pointing to all the calls currently in progress on a connection.

To this end, make the following changes:

(1) Handle call number allocation independently per channel.

(2) Get rid of the conn->calls rb-tree. This is overkill as a connection
may have a maximum of four calls in progress at any one time. Use the
pointers in the channels[] array instead, indexed by the channel
number from the packet.

(3) For each channel, save the result of the last call that was in
progress on that channel in conn->channels[] so that the final ACK or
ABORT packet can be replayed if necessary. Any call earlier than that
is just ignored. If we've seen the next call number in a packet, the
last one is most definitely defunct.

(4) When generating a RESPONSE packet for a connection, the call number
counter for each channel must be included in it.

(5) When parsing a RESPONSE packet for a connection, the call number
counters contained therein should be used to set the minimum expected
call numbers on each channel.

To do in future commits:

(1) Replay terminal packets based on the last call stored in
conn->channels[].

(2) Connections should be retired before the callNumber space on any
channel runs out.

(3) A server is expected to disregard or reject any new incoming call that
has a call number less than the current call number counter. The call
number counter for that channel must be advanced to the new call
number.

Note that the server cannot just require that the next call that it
sees on a channel be exactly the call number counter + 1 because then
there's a scenario that could cause a problem: The client transmits a
packet to initiate a connection, the network goes out, the server
sends an ACK (which gets lost), the client sends an ABORT (which also
gets lost); the network then reconnects, the client then reuses the
call number for the next call (it doesn't know the server already saw
the call number), but the server thinks it already has the first
packet of this call (it doesn't know that the client doesn't know that
it saw the call number the first time).

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Avoid using stack memory in SG lists in rxkad

rxkad uses stack memory in SG lists which would not work if stacks were
allocated from vmalloc memory. In fact, in most cases this isn't even
necessary as the stack memory ends up getting copied over to kmalloc
memory.

This patch eliminates all the unnecessary stack memory uses by supplying
the final destination directly to the crypto API. In two instances where a
temporary buffer is actually needed we also switch use a scratch area in
the rxrpc_call struct (only one DATA packet will be being secured or
verified at a time).

Finally there is no need to split a split-page buffer into two SG entries
so code dealing with that has been removed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Replace conn->trans->{local,peer} with conn->params.{local,peer}

Replace accesses of conn->trans->{local,peer} with
conn->params.{local,peer} thus making it easier for a future commit to
remove the rxrpc_transport struct.

This also reduces the number of memory accesses involved.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Use structs to hold connection params and protocol info

Define and use a structure to hold connection parameters. This makes it
easier to pass multiple connection parameters around.

Define and use a structure to hold protocol information used to hash a
connection for lookup on incoming packet. Most of these fields will be
disposed of eventually, including the duplicate local pointer.

Whilst we're at it rename "proto" to "family" when referring to a protocol
family.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: fix ptr_ret.cocci warnings

net/rxrpc/rxkad.c:1165:1-3: WARNING: PTR_ERR_OR_ZERO can be used

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

CC: David Howells <dhowells@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Use pr_<level> and pr_fmt, reduce object size a few KB

Use the more common kernel logging style and reduce object size.

The logging message prefix changes from a mixture of
"RxRPC:" and "RXRPC:" to "af_rxrpc: ".

$ size net/rxrpc/built-in.o*
text data bss dec hex filename
64172 1972 8304 74448 122d0 net/rxrpc/built-in.o.new
67512 1972 8304 77788 12fdc net/rxrpc/built-in.o.old

Miscellanea:

o Consolidate the ASSERT macros to use a single pr_err call with
decimal and hexadecimal output and a stringified #OP argument

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: Absorb the rxkad security module

Absorb the rxkad security module into the af_rxrpc module so that there's
only one module file. This avoids a circular dependency whereby rxkad pins
af_rxrpc and cached connections pin rxkad but can't be manually evicted
(they will expire eventually and cease pinning).

With this change, af_rxrpc can just be unloaded, despite having cached
connections.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rxrpc: rxkad: Casts are needed when comparing be32 values

Forced casts are needed to avoid sparse warning when directly comparing
be32 values.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: rxkad: The version number in the response should be net byte order

The version number rxkad places in the response should be network byte
order.

Whilst we're at it, rearrange the code to be more readable.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Adjust some whitespace and comments

Remove some excess whitespace, insert some missing spaces and adjust a
couple of comments.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Keep the skb private record of the Rx header in host byte order

Currently, a copy of the Rx packet header is copied into the the sk_buff
private data so that we can advance the pointer into the buffer,
potentially discarding the original. At the moment, this copy is held in
network byte order, but this means we're doing a lot of unnecessary
translations.

The reasons it was done this way are that we need the values in network
byte order occasionally and we can use the copy, slightly modified, as part
of an iov array when sending an ack or an abort packet.

However, it seems more reasonable on review that it would be better kept in
host byte order and that we make up a new header when we want to send
another packet.

To this end, rename the original header struct to rxrpc_wire_header (with
BE fields) and institute a variant called rxrpc_host_header that has host
order fields. Change the struct in the sk_buff private data into an
rxrpc_host_header and translate the values when filling it in.

This further allows us to keep values kept in various structures in host
byte order rather than network byte order and allows removal of some fields
that are byteswapped duplicates.

Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc: Use skcipher

This patch replaces uses of blkcipher with skcipher.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

KEYS: Merge the type-specific data with the payload data

Merge the type-specific data with the payload data into one four-word chunk
as it seems pointless to keep them separate.

Use user_key_payload() for accessing the payloads of overloaded
user-defined keys.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
cc: ecryptfs@vger.kernel.org
cc: linux-ext4@vger.kernel.org
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-ima-devel@lists.sourceforge.net

net: cleanup unsigned to unsigned int

Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

RxRPC: Allow key payloads to be passed in XDR form

Allow add_key() and KEYCTL_INSTANTIATE to accept key payloads in XDR form as
described by openafs-1.4.10/src/auth/afs_token.xg. This provides a way of
passing kaserver, Kerberos 4, Kerberos 5 and GSSAPI keys from userspace, and
allows for future expansion.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RxRPC: Declare the security index constants symbolically

Declare the security index constants symbolically rather than just referring
to them numerically.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: replace NIPQUAD() in net/*/

Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RxRPC: Fix a regression in the RXKAD security module

Fix a regression in the RXKAD security module introduced in:

commit 91e916cffec7c0153c5cbaa447151862a7a9a047
Author: Al Viro <viro@ftp.linux.org.uk>
Date: Sat Mar 29 03:08:38 2008 +0000

net/rxrpc trivial annotations

A variable was declared as a 16-bit type rather than a 32-bit type.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-with-apologies-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>

AFS: Do not describe debug parameters with their value

Describe debug parameters with their names (and not their values).

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/rxrpc trivial annotations

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[RXRPC]: Use cpu_to_be32() where appropriate.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[AF_RXRPC]: Add a missing goto

Add a missing goto to error handling in the RXKAD security module for
AF_RXRPC.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[SG] Get rid of __sg_mark_end()

sg_mark_end() overwrites the page_link information, but all users want
__sg_mark_end() behaviour where we just set the end bit. That is the most
natural way to use the sg list, since you'll fill it in and then mark the
end point.

So change sg_mark_end() to only set the termination bit. Add a sg_magic
debug check as well, and clear a chain pointer if it is set.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[NET]: Fix incorrect sg_mark_end() calls.

This fixes scatterlist corruptions added by

commit 68e3f5dd4db62619fdbe520d36c9ebf62e672256
[CRYPTO] users: Fix up scatterlist conversion errors

The issue is that the code calls sg_mark_end() which clobbers the
sg_page() pointer of the final scatterlist entry.

The first part fo the fix makes skb_to_sgvec() do __sg_mark_end().

After considering all skb_to_sgvec() call sites the most correct
solution is to call __sg_mark_end() in skb_to_sgvec() since that is
what all of the callers would end up doing anyways.

I suspect this might have fixed some problems in virtio_net which is
the sole non-crypto user of skb_to_sgvec().

Other similar sg_mark_end() cases were converted over to
__sg_mark_end() as well.

Arguably sg_mark_end() is a poorly named function because it doesn't
just "mark", it clears out the page pointer as a side effect, which is
what led to these bugs in the first place.

The one remaining plain sg_mark_end() call is in scsi_alloc_sgtable()
and arguably it could be converted to __sg_mark_end() if only so that
we can delete this confusing interface from linux/scatterlist.h

Signed-off-by: David S. Miller <davem@davemloft.net>

[CRYPTO] users: Fix up scatterlist conversion errors

This patch fixes the errors made in the users of the crypto layer during
the sg_init_table conversion. It also adds a few conversions that were
missing altogether.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Cleanup non-arch xtime uses, use get_seconds() or current_kernel_time().

This avoids use of the kernel-internal "xtime" variable directly outside
of the actual time-related functions. Instead, use the helper functions
that we already have available to us.

This doesn't actually change any behaviour, but this will allow us to
fix the fact that "xtime" isn't updated very often with CONFIG_NO_HZ
(because much of the realtime information is maintained as separate
offsets to 'xtime'), which has caused interfaces that use xtime directly
to get a time that is out of sync with the real-time clock by up to a
third of a second or so.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[AF_RXRPC/AFS]: Arch-specific fixes.

Fixes for various arch compilation problems:

(*) Missing module exports.

(*) Variable name collision when rxkad and af_rxrpc both built in
(rxrpc_debug).

(*) Large constant representation problem (AFS_UUID_TO_UNIX_TIME).

(*) Configuration dependencies.

(*) printk() format warnings.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both

Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve
answers to AFS clients. KerberosIV security is fully supported. The patches
and some example test programs can be found in:

http://people.redhat.com/~dhowells/rxrpc/

This will eventually replace the old implementation of kernel-only RxRPC
currently resident in net/rxrpc/.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>