After TCP RCU conversion, tw->tw_refcnt should not be set to 1 in
inet_twsk_alloc(). It allows a RCU reader to get this timewait socket,
while we not yet stabilized it.
Only choice we have is to set tw_refcnt to 0 in inet_twsk_alloc(),
then atomic_add() it later, once everything is done.
Location of this atomic_add() is tricky, because we dont want another
writer to find this timewait in ehash, while tw_refcnt is still zero !
Thanks to Kapil Dakhane tests and reports.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its currently possible that several threads issuing a connect() find
the same timewait socket and try to reuse it, leading to list
corruptions.
Condition for bug is that these threads bound their socket on same
address/port of to-be-find timewait socket, and connected to same
target. (SO_REUSEADDR needed)
To fix this problem, we could unhash timewait socket while holding
ehash lock, to make sure lookups/changes will be serialized. Only
first thread finds the timewait socket, other ones find the
established socket and return an EADDRNOTAVAIL error.
This second version takes into account Evgeniy's review and makes sure
inet_twsk_put() is called outside of locked sections.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both netlink and /proc/net/tcp interfaces can report transient
negative values for rx queue.
ss ->
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB -6 6 127.0.0.1:45956 127.0.0.1:3333
netstat ->
tcp 4294967290 6 127.0.0.1:37784 127.0.0.1:3333 ESTABLISHED
This is because we dont lock socket while computing
tp->rcv_nxt - tp->copied_seq,
and another CPU can update copied_seq before rcv_next in RX path.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Provide common routine for the transition of operational state for a leaf
device during a root device transition.
Signed-off-by: Patrick Mullaney <pmullaney@novell.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce soft connect behavior for UDP transports. In this case, a
major timeout returns ETIMEDOUT instead of EIO.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, if a remote RPC service is unreachable, an RPC ping will
hang until the underlying transport connect attempt times out. A more
desirable behavior might be to have the ping fail immediately so upper
layers can recover appropriately.
In the case of an NFS mount, for instance, this would mean the
mount(2) system call could fail immediately if the server isn't
listening, rather than hanging uninterruptibly for more than 3
minutes.
Change rpc_ping() so that it fails immediately for connection-oriented
transports. rpc_create() will then fail immediately for such
transports if an RPC ping was requested.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Autobinding is handled by the rpciod process, not in user processes
that are generating regular RPC requests. Thus autobinding is usually
not affected by signals targetting user processes, such as KILL or
timer expiration events.
In addition, an RPC request generated by a user process that has
RPC_TASK_SOFTCONN set and needs to perform an autobind will hang if
the remote rpcbind service is not available.
For rpcbind queries on connection-oriented transports, let's use the
new soft connect semantic to return control to the user's process
quickly, if the kernel's rpcbind client can't connect to the remote
rpcbind service.
Logic is introduced in call_bind_status() to handle connection errors
that occurred during an asynchronous rpcbind query. The logic
abandons the rpcbind query if the RPC request has SOFTCONN set, and
retries after a few seconds in the normal case.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use TCP with the soft connect semantic for local rpcbind upcalls so
the kernel can detect immediately if the local rpcbind daemon is not
running.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The kernel's rpcbind client creates and deletes an rpc_clnt and its
underlying transport socket for every upcall to the local rpcbind
daemon.
When starting a typical NFS server on IPv4 and IPv6, the NFS service
itself does three upcalls (one per version) times two upcalls (one
per transport) times two upcalls (one per address family), making 12,
plus another one for the initial call to unregister previous NFS
services. Starting the NLM service adds an additional 13 upcalls,
for similar reasons.
(Currently the NFS service doesn't start IPv6 listeners, but it will
soon enough).
Instead, let's create an rpc_clnt for rpcbind upcalls during the
first local rpcbind query, and cache it. This saves the overhead of
creating and destroying an rpc_clnt and a socket for every upcall.
The new logic also prevents the kernel from attempting an RPCB_SET or
RPCB_UNSET if it knows from the start that the local portmapper does
not support rpcbind protocol version 4. This will cut down on the
number of rpcbind upcalls in legacy environments.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: At one point, rpcb_local_clnt() handled IPv6 loopback
addresses too, but it doesn't any more; only IPv4 loopback is used
now. Get rid of the @addr and @addrlen arguments to
rpcb_local_clnt().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The kernel sometimes makes RPC calls to services that aren't running.
Because the kernel's RPC client always assumes the hard retry semantic
when reconnecting a connection-oriented RPC transport, the underlying
reconnect logic takes a long while to time out, even though the remote
may have responded immediately with ECONNREFUSED.
In certain cases, like upcalls to our local rpcbind daemon, or for NFS
mount requests, we'd like the kernel to fail immediately if the remote
service isn't reachable. This allows another transport to be tried
immediately, or the pending request can be abandoned quickly.
Introduce a per-request flag which controls how call_transmit_status()
behaves when request transmission fails because the server cannot be
reached.
We don't want soft connection semantics to apply to other errors. The
default case of the switch statement in call_transmit_status() no
longer falls through; the fall through code is copied to the default
case, and a "break;" is added.
The transport's connection re-establishment timeout is also ignored for
such requests. We want the request to fail immediately, so the
reconnect delay is skipped. Additionally, we don't want a connect
failure here to further increase the reconnect timeout value, since
this request will not be retried.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The success case, where task->tk_status == 0, is by far the most
frequent case in call_transmit_status().
The default: arm of the switch statement in call_transmit_status()
handles the 0 case. default: was moved close to the top of the switch
statement in call_transmit_status() under the theory that the compiler
places object code for the earliest arms of a switch statement first,
making the CPU do less work.
The default: arm of a switch statement, however, is executed only
after all the other cases have been checked. Even if the compiler
rearranges the object code, the default: arm is the "last resort",
meaning all of the other cases have been explicitly exhausted. That
makes the current arrangement about as inefficient as it gets for the
common case.
To fix this, add an explicit check for zero before the switch
statement. That forces the compiler to do the zero check first, no
matter what optimizations it might try to do to the switch statement.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Recent changes to snprintf() introduced the %pI6c formatter, which can
display an IPv6 address with standard shorthanding. Using a
shorthanded address can save us a few bytes of memory for each stored
presentation address, or a few bytes on the wire when sending these in
a universal address.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This function walks the whole hashtable so there is no point in
passing it a network namespace. Instead I purge all timewait
sockets from dead network namespaces that I find. If the namespace
is one of the once I am trying to purge I am guaranteed no new timewait
sockets can be formed so this will get them all. If the namespace
is one I am not acting for it might form a few more but I will
call inet_twsk_purge again and shortly to get rid of them. In
any even if the network namespace is dead timewait sockets are
useless.
Move the calls of inet_twsk_purge into batch_exit routines so
that if I am killing a bunch of namespaces at once I will just
call inet_twsk_purge once and save a lot of redundant unnecessary
work.
My simple 4k network namespace exit test the cleanup time dropped from
roughly 8.2s to 1.6s. While the time spent running inet_twsk_purge fell
to about 2ms. 1ms for ipv4 and 1ms for ipv6.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While we are looking up entries to free there is no reason to take
the lock in inet_twsk_purge. We have to drop locks and restart
occassionally anyway so adding a few more in case we get on the
wrong list because of a timewait move is no big deal. At the
same time not taking the lock for long periods of time is much
more polite to the rest of the users of the hash table.
In my test configuration of killing 4k network namespaces
this change causes 4k back to back runs of inet_twsk_purge on an
empty hash table to go from roughly 20.7s to 3.3s, and the total
time to destroy 4k network namespaces goes from roughly 44s to
3.3s.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Refactor the code so fib_rules_register always takes a template instead
of the actual fib_rules_ops structure that will be used. This is
required for network namespace support so 2 out of the 3 callers already
do this, it allows the error handling to be made common, and it allows
fib_rules_unregister to free the template for hte caller.
Modify fib_rules_unregister to use call_rcu instead of syncrhonize_rcu
to allw multiple namespaces to be cleaned up in the same rcu grace
period.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows namespace exit methods to batch work that comes requires an
rcu barrier using call_rcu without having to treat the
unregister_pernet_operations cases specially.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
xfrm.nlsk is provided by the xfrm_user module and is access via rcu from
other parts of the xfrm code. Add xfrm.nlsk_stash a copy of xfrm.nlsk that
will never be set to NULL. This allows the synchronize_net and
netlink_kernel_release to be deferred until a whole batch of xfrm.nlsk sockets
have been set to NULL.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move network device exit batching from a special case in
net_namespace.c to using common mechanisms in dev.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Add exit_list to struct net to support building lists of network
namespaces to cleanup.
- Add exit_batch to pernet_operations to allow running operations only
once during a network namespace exit. Instead of once per network
namespace.
- Factor opt ops_exit_list and ops_exit_free so the logic with cleanup
up a network namespace does not need to be duplicated.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 8ec1e0ebe26087bfc5c0394ada5feb5758014fc8
Author: Patrick McHardy <kaber@trash.net>
Date: Thu Dec 3 12:16:35 2009 +0100
ipv4: add sysctl to accept packets with local source addresses
Change fib_validate_source() to accept packets with a local source address when
the "accept_local" sysctl is set for the incoming inet device. Combined with the
previous patches, this allows to communicate between multiple local interfaces
over the wire.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit d124356ce314fff22a047ea334379d5105b2d834
Author: Patrick McHardy <kaber@trash.net>
Date: Thu Dec 3 12:16:35 2009 +0100
net: fib_rules: allow to delete local rule
Allow to delete the local rule and recreate it with a higher priority. This
can be used to force packets with a local destination out on the wire instead
of routing them to loopback. Additionally this patch allows to recreate rules
with a priority of 0.
Combined with the previous patch to allow oif classification, a socket can
be bound to the desired interface and packets routed to the wire like this:
# move local rule to lower priority
ip rule add pref 1000 lookup local
ip rule del pref 0
# route packets of sockets bound to eth0 to the wire independant
# of the destination address
ip rule add pref 100 oif eth0 lookup 100
ip route add default dev eth0 table 100
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 68144d350f4f6c348659c825cde6a82b34c27a91
Author: Patrick McHardy <kaber@trash.net>
Date: Thu Dec 3 12:05:25 2009 +0100
net: fib_rules: add oif classification
Support routing table lookup based on the flow's oif. This is useful to
classify packets originating from sockets bound to interfaces differently.
The route cache already includes the oif and needs no changes.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 229e77eec406ad68662f18e49fda8b5d366768c5
Author: Patrick McHardy <kaber@trash.net>
Date: Thu Dec 3 12:05:23 2009 +0100
net: fib_rules: rename ifindex/ifname/FRA_IFNAME to iifindex/iifname/FRA_IIFNAME
The next patch will add oif classification, rename interface related members
and attributes to reflect that they're used for iif classification.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
By default the RFCOMM layer would still use L2CAP basic mode. For testing
purposes this option enables RFCOMM to select enhanced retransmission
mode.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
SendRRorRNR needs to acknowledge received I-frames (actually every packet
needs to acknowledge received I-frames by sending the proper packet
sequence number), so ReqSeq is set to the next I-frame number sequence to
be pulled by the reassembly function.
SendRRorRNR tells the remote side about local busy conditions, it sends
a Receiver Ready frame if local busy is false or a Receiver Not Ready
if local busy is true.
ReqSeq is the packet's field to send the number of the acknowledged
packets.
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
RejActioned is used to prevent retransmission when a entity is on the
WAIT_F state, i.e., waiting for a frame with F-bit set due local busy
condition or a expired retransmission timer. (When these two events raise
they send a frame with the Poll bit set and enters in the WAIT_F state to
wait for a frame with the Final bit set.)
The local entity doesn't send I-frames(the data frames) until the receipt
of a frame with F-bit set. When that happens it also set RejActioned to false.
RejActioned is a mandatory feature of ERTM spec.
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
As specified by ERTM spec an ERTM channel can acknowledge received
I-frames(the data frames) by sending an I-frame with the proper ReqSeq
value (i.e. ReqSeq is set to BufferSeq). Until now we aren't setting the
ReqSeq value on I-frame control bits. That way we can save sending
S-frames(Supervise frames) only to acknowledge receipt of I-frames. It
is very helpful to the full-duplex channel.
ReqSeq is the packet sequence number sent in an acknowledgement frame to
acknowledge receipt of frames up to (ReqSeq - 1).
BufferSeq controls the receiver buffer, it is used to delay
acknowledgement of new frames to not cause buffer overflow. BufferSeq
value is not increased until frames are pulled by reassembly function.
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
SrejActioned is a flag that when set prevents local side to retransmit a
I-frame(the data frame) already retransmitted. The local entity can
retransmit again only when it receives a SREJ frame with the F-bit set.
SREJ frame - Selective Reject frame - is sent when an entity wants the
retransmission of a specific I-frame that was lost or corrupted.
This bug can put ERTM in an unknown state once the entity can't
retransmit.
A frame with the Final bit set is expected when the local side sends a
frame with the Poll bit set due to a local busy condition or a
retransmission timer expired. (Receipt of P-bit shall always be replied by
a frame with the F-bit set).
pi->conn_state keeps informations about many ERTM flags including
SrejActioned.
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Fix ERTM's full-duplex channel to work as specified by ERTM spec. ERTM
needs to handle state vars, timers and counters to send and receive
I-frames(the data frames), i.e., for both sides of data communication.
We initialize all of them to the default values here.
Full-duplex channel is a mandatory feature of ERTM spec.
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
According to BNEP test specification the proper response should be sent
for a setup connection request message after the BNEP connection setup
has been completed.
Signed-off-by: Vikram Kandukuri <vikram.kandukuri@atheros.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The tasklet schedule function helpers are just an obfuscation. So remove
them and call the schedule functions directly.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For future simplification it is important that the hci_recv_frame
function is no longer an inline function. So move it into the module
itself and export it.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Sending commands to a down interface results in a timeout while clearly
it should just return ENETDOWN. When using the ioctls this works fine,
but not when using the HCI sockets sendmsg interface.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Implement raw output callback which is used by hidraw to send raw data to
the underlying device.
Without this patch, the userspace hidraw-based applications can't send
output reports to HID Bluetooth devices.
Reported-and-tested-by: Brian Gunn <bgunn@solekai.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
It is possible for rpcauth_destroy_credcache() to cause the rpc credentials
to be unhashed while put_rpccred is waiting for the rpc_credcache_lock on
another cpu. Should this happen, then we can end up calling
hlist_del_rcu(&cred->cr_hash) a second time in put_rpccred, thus causing
list corruption.
Should the credential actually be hashed, it is also possible for
rpcauth_lookup_credcache to find and reference it before we get round to
unhashing it. In this case, the call to rpcauth_unhash_cred will fail, and
so we should just exit without destroying the cred.
Reported-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the XPRT_CLOSE_WAIT flag is set, we need to ensure that we call
xprt->ops->close() while holding xprt_lock_write() before we can
start reconnecting.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Otherwise:
ERROR: "sysctl_tcp_cookie_size" [net/ipv6/ipv6.ko] undefined!
make[1]: *** [__modpost] Error 1
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_output.c: In function ‘tcp_make_synack’:
net/ipv4/tcp_output.c:2488: warning: cast from pointer to integer of different size
Signed-off-by: David S. Miller <davem@davemloft.net>
Take advantage of the fact that an explicit rtnl_kill_links is
unnecessary (and skipping it improves batching), as network namespace
exit calls dellink on all remaining virtual devices, and
rtnl_link_unregister calls dellink on all outstanding devices in that
network namespace. To do this we need to leave the vlan proc
directories in place until after network device exit time, which is
done by using register_pernet_subsys instead of
register_pernet_device.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Parse incoming TCP_COOKIE option(s).
Calculate <SYN,ACK> TCP_COOKIE option.
Send optional <SYN,ACK> data.
This is a significantly revised implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):
http://thread.gmane.org/gmane.linux.network/102586
Requires:
TCPCT part 1a: add request_values parameter for sending SYNACK
TCPCT part 1b: generate Responder Cookie secret
TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS
TCPCT part 1d: define TCP cookie option, extend existing struct's
TCPCT part 1e: implement socket option TCP_COOKIE_TRANSACTIONS
TCPCT part 1f: Initiator Cookie => Responder
Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Calculate and format <SYN> TCP_COOKIE option.
This is a significantly revised implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):
http://thread.gmane.org/gmane.linux.network/102586
Requires:
TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS
TCPCT part 1d: define TCP cookie option, extend existing struct's
Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Provide per socket control of the TCP cookie option and SYN/SYNACK data.
This is a straightforward re-implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):
http://thread.gmane.org/gmane.linux.network/102586
The principle difference is using a TCP option to carry the cookie nonce,
instead of a user configured offset in the data.
Allocations have been rearranged to avoid requiring GFP_ATOMIC.
Requires:
net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED
TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS
TCPCT part 1d: define TCP cookie option, extend existing struct's
Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Data structures are carefully composed to require minimal additions.
For example, the struct tcp_options_received cookie_plus variable fits
between existing 16-bit and 8-bit variables, requiring no additional
space (taking alignment into consideration). There are no additions to
tcp_request_sock, and only 1 pointer in tcp_sock.
This is a significantly revised implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):
http://thread.gmane.org/gmane.linux.network/102586
The principle difference is using a TCP option to carry the cookie nonce,
instead of a user configured offset in the data. This is more flexible and
less subject to user configuration error. Such a cookie option has been
suggested for many years, and is also useful without SYN data, allowing
several related concepts to use the same extension option.
"Re: SYN floods (was: does history repeat itself?)", September 9, 1996.
http://www.merit.net/mail.archives/nanog/1996-09/msg00235.html
"Re: what a new TCP header might look like", May 12, 1998.
ftp://ftp.isi.edu/end2end/end2end-interest-1998.mail
These functions will also be used in subsequent patches that implement
additional features.
Requires:
TCPCT part 1a: add request_values parameter for sending SYNACK
TCPCT part 1b: generate Responder Cookie secret
TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS
Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Define sysctl (tcp_cookie_size) to turn on and off the cookie option
default globally, instead of a compiled configuration option.
Define per socket option (TCP_COOKIE_TRANSACTIONS) for setting constant
data values, retrieving variable cookie values, and other facilities.
Move inline tcp_clear_options() unchanged from net/tcp.h to linux/tcp.h,
near its corresponding struct tcp_options_received (prior to changes).
This is a straightforward re-implementation of an earlier (year-old)
patch that no longer applies cleanly, with permission of the original
author (Adam Langley):
http://thread.gmane.org/gmane.linux.network/102586
These functions will also be used in subsequent patches that implement
additional features.
Requires:
net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED
Signed-off-by: William.Allen.Simpson@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Define (missing) hash message size for SHA1.
Define hashing size constants specific to TCP cookies.
Add new function: tcp_cookie_generator().
Maintain global secret values for tcp_cookie_generator().
This is a significantly revised implementation of earlier (15-year-old)
Photuris [RFC-2522] code for the KA9Q cooperative multitasking platform.
Linux RCU technique appears to be well-suited to this application, though
neither of the circular queue items are freed.
These functions will also be used in subsequent patches that implement
additional features.
Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
