This will also improve handling of ipv6 tcp socket request
backlog when syncookies are not enabled.  When backlog
becomes very deep, last quarter of backlog is limited to
validated destinations.  Previously only ipv4 implemented
this logic, but now ipv6 does too.

Now we are only one step away from enabling timewait
recycling for ipv6, and that step is simply filling in
the implementation of tcp_v6_get_peer() and
tcp_v6_tw_get_peer().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The only thing AF-specific about remembering the timestamp
for a time-wait TCP socket is getting the peer.

Abstract that behind a new timewait_sock_ops vector.

Support for real IPV6 sockets is not filled in yet, but
curiously this makes timewait recycling start to work
for v4-mapped ipv6 sockets.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Then we can make a completely generic tcp_remember_stamp()
that uses ->get_peer() as a helper, minimizing the AF specific
code and minimizing the eventual code duplication when we implement
the ipv6 side of TW recycling.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When __inet_inherit_port() is called on a tproxy connection the wrong locks are
held for the inet_bind_bucket it is added to. __inet_inherit_port() made an
implicit assumption that the listener's port number (and thus its bind bucket).
Unfortunately, if you're using the TPROXY target to redirect skbs to a
transparent proxy that assumption is not true anymore and things break.

This patch adds code to __inet_inherit_port() so that it can handle this case
by looking up or creating a new bind bucket for the child socket and updates
callers of __inet_inherit_port() to gracefully handle __inet_inherit_port()
failing.

Reported by and original patch from Stephen Buck <stephen.buck@exinda.com>.
See http://marc.info/?t=128169268200001&r=1&w=2 for the original discussion.
Signed-off-by: NKOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

a new boolean flag no_autobind is added to structure proto to avoid the autobind
calls when the protocol is TCP. Then sock_rps_record_flow() is called int the
TCP's sendmsg() and sendpage() pathes.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
----
 include/net/inet_common.h |    4 ++++
 include/net/sock.h        |    1 +
 include/net/tcp.h         |    8 ++++----
 net/ipv4/af_inet.c        |   15 +++++++++------
 net/ipv4/tcp.c            |   11 +++++------
 net/ipv4/tcp_ipv4.c       |    3 +++
 net/ipv6/af_inet6.c       |    8 ++++----
 net/ipv6/tcp_ipv6.c       |    3 +++
 8 files changed, 33 insertions(+), 20 deletions(-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allows use of ECN when syncookies are in effect by encoding ecn_ok
into the syn-ack tcp timestamp.

While at it, remove a uneeded #ifdef CONFIG_SYN_COOKIES.
With CONFIG_SYN_COOKIES=nm want_cookie is ifdef'd to 0 and gcc
removes the "if (0)".
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When syncookies are in effect, req->iif is left uninitialized.
In case of e.g. link-local addresses the route lookup then fails
and no syn-ack is sent.

Rearrange things so ->iif is also initialized in the syncookie case.

want_cookie can only be true when the isn was zero, thus move the want_cookie
check into the "!isn" branch.

Cc: Glenn Griffin <ggriffin.kernel@gmail.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

caller: if (!th->rst && !th->syn && th->ack)
callee: if (!th->ack)

make the caller only check for !syn (common for 3whs), and move
the !rst / ack test to the callee.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are more than a dozen occurrences of following code in the
IPv6 stack:

    if (opt && opt->srcrt) {
            struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
            ipv6_addr_copy(&final, &fl.fl6_dst);
            ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
            final_p = &final;
    }

Replace those with a helper. Note that the helper overrides final_p
in all cases. This is ok as final_p was previously initialized to
NULL when declared.
Signed-off-by: NArnaud Ebalard <arno@natisbad.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TCP-MD5 sessions have intermittent failures, when route cache is
invalidated. ip_queue_xmit() has to find a new route, calls
sk_setup_caps(sk, &rt->u.dst), destroying the 

sk->sk_route_caps &= ~NETIF_F_GSO_MASK

that MD5 desperately try to make all over its way (from
tcp_transmit_skb() for example)

So we send few bad packets, and everything is fine when
tcp_transmit_skb() is called again for this socket.

Since ip_queue_xmit() is at a lower level than TCP-MD5, I chose to use a
socket field, sk_route_nocaps, containing bits to mask on sk_route_caps.
Reported-by: NBhaskar Dutta <bhaskie@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds IPv6 support for RFC5082 Generalized TTL Security Mechanism.  

Not to users of mapped address; the IPV6 and IPV4 socket options are seperate.
The server does have to deal with both IPv4 and IPv6 socket options
and the client has to handle the different for each family.

On client:
	int ttl = 255;
	getaddrinfo(argv[1], argv[2], &hint, &result);

	for (rp = result; rp != NULL; rp = rp->ai_next) {
		s = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
		if (s < 0) continue;

		if (rp->ai_family == AF_INET) {
			setsockopt(s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
		} else if (rp->ai_family == AF_INET6) {
			setsockopt(s, IPPROTO_IPV6,  IPV6_UNICAST_HOPS, 
					&ttl, sizeof(ttl)))
		}
			
		if (connect(s, rp->ai_addr, rp->ai_addrlen) == 0) {
		   ...

On server:
	int minttl = 255 - maxhops;
   
	getaddrinfo(NULL, port, &hints, &result);
	for (rp = result; rp != NULL; rp = rp->ai_next) {
		s = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
		if (s < 0) continue;

		if (rp->ai_family == AF_INET6)
			setsockopt(s, IPPROTO_IPV6,  IPV6_MINHOPCOUNT,
					&minttl, sizeof(minttl));
		setsockopt(s, IPPROTO_IP, IP_MINTTL, &minttl, sizeof(minttl));
			
		if (bind(s, rp->ai_addr, rp->ai_addrlen) == 0)
			break
...
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Otherwise we only get the checksum right for data-less TCP responses.

Noticed by Herbert Xu.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 6651ffc8
("ipv6: Fix tcp_v6_send_response transport header setting.")
fixed one half of why ipv6 tcp response checksums were
invalid, but it's not the whole story.

If we're going to use CHECKSUM_PARTIAL for these things (which we are
since commit 2e8e18ef "tcp: Set
CHECKSUM_UNNECESSARY in tcp_init_nondata_skb"), we can't be setting
buff->csum as we always have been here in tcp_v6_send_response.  We
need to leave it at zero.

Kill that line and checksums are good again.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

My recent patch to remove the open-coded checksum sequence in
tcp_v6_send_response broke it as we did not set the transport
header pointer on the new packet.

Actually, there is code there trying to set the transport
header properly, but it sets it for the wrong skb ('skb'
instead of 'buff').

This bug was introduced by commit
a8fdf2b3 ("ipv6: Fix
tcp_v6_send_response(): it didn't set skb transport header")
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sparse can help us find endianness bugs, but we need to make some
cleanups to be able to more easily spot real bugs.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Herbert Xu said: we should be able to simply replace ipfragok
with skb->local_df. commit f88037(sctp: Drop ipfargok in sctp_xmit function)
has droped ipfragok and set local_df value properly.

The patch kills the ipfragok parameter of .queue_xmit().
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

inet: Remove unused send_check length argument

This patch removes the unused length argument from the send_check
function in struct inet_connection_sock_af_ops.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Tested-by: NYinghai <yinghai.lu@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv6

This patch moves the common code between tcp_v6_send_check and
tcp_v6_gso_send_check into a new function __tcp_v6_send_check.

It then uses the new function in tcp_v6_send_synack as well as
tcp_v6_send_response so that they handle CHECKSUM_PARTIAL properly.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Tested-by: NYinghai <yinghai.lu@oracle.com>
Signed-off-by: NDavid 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: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Commit 6b03a53a (tcp: use limited socket backlog) added the possibility
of dropping frames when backlog queue is full.

Commit d218d111 (tcp: Generalized TTL Security Mechanism) added the
possibility of dropping frames when TTL is under a given limit.

This patch adds new SNMP MIB entries, named TCPBacklogDrop and
TCPMinTTLDrop, published in /proc/net/netstat in TcpExt: line

netstat -s | egrep "TCPBacklogDrop|TCPMinTTLDrop"
    TCPBacklogDrop: 0
    TCPMinTTLDrop: 0
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sk_add_backlog -> __sk_add_backlog
sk_add_backlog_limited -> sk_add_backlog
Signed-off-by: NZhu Yi <yi.zhu@intel.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make tcp adapt to the limited socket backlog change.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "Pekka Savola (ipv6)" <pekkas@netcore.fi>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: NZhu Yi <yi.zhu@intel.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__net_init/__net_exit are apparently not going away, so use them
to full extent.

In some cases __net_init was removed, because it was called from
__net_exit code.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we don't increment SYN-ACK timeouts & retransmissions
although we do increment the same stats for SYN. We seem to have lost
the SYN-ACK accounting with the introduction of tcp_syn_recv_timer
(commit 2248761e in the netdev-vger-cvs tree).

This patch fixes this issue. In the process we also rename the v4/v6
syn/ack retransmit functions for clarity. We also add a new
request_socket operations (syn_ack_timeout) so we can keep code in
inet_connection_sock.c protocol agnostic.
Signed-off-by: NOctavian Purdila <opurdila@ixiacom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use "[compressed ipv6]:port" form suggested by:
http://tools.ietf.org/id/draft-ietf-6man-text-addr-representation-03.txtSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It creates a regression, triggering badness for SYN_RECV
sockets, for example:

[19148.022102] Badness at net/ipv4/inet_connection_sock.c:293
[19148.022570] NIP: c02a0914 LR: c02a0904 CTR: 00000000
[19148.023035] REGS: eeecbd30 TRAP: 0700   Not tainted  (2.6.32)
[19148.023496] MSR: 00029032 <EE,ME,CE,IR,DR>  CR: 24002442  XER: 00000000
[19148.024012] TASK = eee9a820[1756] 'privoxy' THREAD: eeeca000

This is likely caused by the change in the 'estab' parameter
passed to tcp_parse_options() when invoked by the functions
in net/ipv4/tcp_minisocks.c

But even if that is fixed, the ->conn_request() changes made in
this patch series is fundamentally wrong.  They try to use the
listening socket's 'dst' to probe the route settings.  The
listening socket doesn't even have a route, and you can't
get the right route (the child request one) until much later
after we setup all of the state, and it must be done by hand.

This stuff really isn't ready, so the best thing to do is a
full revert.  This reverts the following commits:

f55017a9
022c3f7d
1aba721e
cda42ebd
345cda2f
dc343475
05eaade2
6a2a2d6bSigned-off-by: NDavid S. Miller <davem@davemloft.net>

First patch changes __inet_hash_nolisten() and __inet6_hash()
to get a timewait parameter to be able to unhash it from ehash
at same time the new socket is inserted in hash.

This makes sure timewait socket wont be found by a concurrent
writer in __inet_check_established()
Reported-by: Nkapil dakhane <kdakhane@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid 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: NDavid 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: NDavid S. Miller <davem@davemloft.net>

Add optional function parameters associated with sending SYNACK.
These parameters are not needed after sending SYNACK, and are not
used for retransmission.  Avoids extending struct tcp_request_sock,
and avoids allocating kernel memory.

Also affects DCCP as it uses common struct request_sock_ops,
but this parameter is currently reserved for future use.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define two symbols needed in both kernel and user space.

Remove old (somewhat incorrect) kernel variant that wasn't used in
most cases.  Default should apply to both RMSS and SMSS (RFC2581).

Replace numeric constants with defined symbols.

Stand-alone patch, originally developed for TCPCT.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct can_proto had a capability field which wasn't ever used.  It is
dropped entirely.

struct inet_protosw had a capability field which can be more clearly
expressed in the code by just checking if sock->type = SOCK_RAW.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need tcp_parse_options to be aware of dst_entry to
take into account per dst_entry TCP options settings
Signed-off-by: NGilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: NOri Finkelman <ori@comsleep.com>
Sigend-off-by: NYony Amit <yony@comsleep.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to have better cache layouts of struct sock (separate zones
for rx/tx paths), we need this preliminary patch.

Goal is to transfert fields used at lookup time in the first
read-mostly cache line (inside struct sock_common) and move sk_refcnt
to a separate cache line (only written by rx path)

This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr,
sport and id fields. This allows a future patch to define these
fields as macros, like sk_refcnt, without name clashes.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Might as well use the ipv6_addr_set_v4mapped() inline we created last
year.
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Atis Elsts wrote:
> Not sure if there is need to fill the mark from skb in tunnel xmit functions. In any case, it's not done for GRE or IPIP tunnels at the moment.

Ok, I'll just drop that part, I'm not sure what should be done in this case.

> Also, in this patch you are doing that for SIT (v6-in-v4) tunnels only, and not doing it for v4-in-v6 or v6-in-v6 tunnels. Any reason for that?

I just sent that patch out too quickly, here's a better one with the updates.

Add support for IPv6 route lookups using sk_mark.
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It was once upon time so that snd_sthresh was a 16-bit quantity.
...That has not been true for long period of time. I run across
some ancient compares which still seem to trust such legacy.
Put all that magic into a single place, I hopefully found all
of them.

Compile tested, though linking of allyesconfig is ridiculous
nowadays it seems.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>