History log of /net/ipv6/inet6_hashtables.c
Revision Date Author Comments
4c83acbc565d53296f1731034c5041a0fbabcaeb 24-Aug-2014 Ian Morris <ipm@chirality.org.uk> ipv6: White-space cleansing : gaps between function and symbol export

This patch makes no changes to the logic of the code but simply addresses
coding style issues as detected by checkpatch.

Both objdump and diff -w show no differences.

This patch removes some blank lines between the end of a function
definition and the EXPORT_SYMBOL_GPL macro in order to prevent
checkpatch warning that EXPORT_SYMBOL must immediately follow
a function.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
67ba4152e8b77eada6a9c64e3c2c84d6112794fc 24-Aug-2014 Ian Morris <ipm@chirality.org.uk> ipv6: White-space cleansing : Line Layouts

This patch makes no changes to the logic of the code but simply addresses
coding style issues as detected by checkpatch.

Both objdump and diff -w show no differences.

A number of items are addressed in this patch:
* Multiple spaces converted to tabs
* Spaces before tabs removed.
* Spaces in pointer typing cleansed (char *)foo etc.
* Remove space after sizeof
* Ensure spacing around comparators such as if statements.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
8fc54f68919298ff9689d980efb495707ef43f30 23-Aug-2014 Daniel Borkmann <dborkman@redhat.com> net: use reciprocal_scale() helper

Replace open codings of (((u64) <x> * <y>) >> 32) with reciprocal_scale().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1bbdceef1e535add893bf71d7b7ab102e4eb69eb 19-Oct-2013 Hannes Frederic Sowa <hannes@stressinduktion.org> inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once

Initialize the ehash and ipv6_hash_secrets with net_get_random_once.

Each compilation unit gets its own secret now:
ipv4/inet_hashtables.o
ipv4/udp.o
ipv6/inet6_hashtables.o
ipv6/udp.o
rds/connection.o

The functions still get inlined into the hashing functions. In the fast
path we have at most two (needed in ipv6) if (unlikely(...)).

Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
b50026b5ac8fe2932e6af0c54b21da0913c4c1c7 19-Oct-2013 Hannes Frederic Sowa <hannes@stressinduktion.org> ipv6: split inet6_ehashfn to hash functions per compilation unit

This patch splits the inet6_ehashfn into separate ones in
ipv6/inet6_hashtables.o and ipv6/udp.o to ease the introduction of
seperate secrets keys later.

Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
efe4208f47f907b86f528788da711e8ab9dea44d 04-Oct-2013 Eric Dumazet <edumazet@google.com> ipv6: make lookups simpler and faster

TCP listener refactoring, part 4 :

To speed up inet lookups, we moved IPv4 addresses from inet to struct
sock_common

Now is time to do the same for IPv6, because it permits us to have fast
lookups for all kind of sockets, including upcoming SYN_RECV.

Getting IPv6 addresses in TCP lookups currently requires two extra cache
lines, plus a dereference (and memory stall).

inet6_sk(sk) does the dereference of inet_sk(__sk)->pinet6

This patch is way bigger than its IPv4 counter part, because for IPv4,
we could add aliases (inet_daddr, inet_rcv_saddr), while on IPv6,
it's not doable easily.

inet6_sk(sk)->daddr becomes sk->sk_v6_daddr
inet6_sk(sk)->rcv_saddr becomes sk->sk_v6_rcv_saddr

And timewait socket also have tw->tw_v6_daddr & tw->tw_v6_rcv_saddr
at the same offset.

We get rid of INET6_TW_MATCH() as INET6_MATCH() is now the generic
macro.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
05dbc7b59481ca891bbcfe6799a562d48159fbf7 03-Oct-2013 Eric Dumazet <edumazet@google.com> tcp/dccp: remove twchain

TCP listener refactoring, part 3 :

Our goal is to hash SYN_RECV sockets into main ehash for fast lookup,
and parallel SYN processing.

Current inet_ehash_bucket contains two chains, one for ESTABLISH (and
friend states) sockets, another for TIME_WAIT sockets only.

As the hash table is sized to get at most one socket per bucket, it
makes little sense to have separate twchain, as it makes the lookup
slightly more complicated, and doubles hash table memory usage.

If we make sure all socket types have the lookup keys at the same
offsets, we can use a generic and faster lookup. It turns out TIME_WAIT
and ESTABLISHED sockets already have common lookup fields for IPv4.

[ INET_TW_MATCH() is no longer needed ]

I'll provide a follow-up to factorize IPv6 lookup as well, to remove
INET6_TW_MATCH()

This way, SYN_RECV pseudo sockets will be supported the same.

A new sock_gen_put() helper is added, doing either a sock_put() or
inet_twsk_put() [ and will support SYN_RECV later ].

Note this helper should only be called in real slow path, when rcu
lookup found a socket that was moved to another identity (freed/reused
immediately), but could eventually be used in other contexts, like
sock_edemux()

Before patch :

dmesg | grep "TCP established"

TCP established hash table entries: 524288 (order: 11, 8388608 bytes)

After patch :

TCP established hash table entries: 524288 (order: 10, 4194304 bytes)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
80ad1d61e72d626e30ebe8529a0455e660ca4693 02-Oct-2013 Eric Dumazet <edumazet@google.com> net: do not call sock_put() on TIMEWAIT sockets

commit 3ab5aee7fe84 ("net: Convert TCP & DCCP hash tables to use RCU /
hlist_nulls") incorrectly used sock_put() on TIMEWAIT sockets.

We should instead use inet_twsk_put()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
5ba24953e9707387cce87b07f0d5fbdd03c5c11b 22-Jan-2013 Tom Herbert <therbert@google.com> soreuseport: TCP/IPv6 implementation

Motivation for soreuseport would be something like a web server
binding to port 80 running with multiple threads, where each thread
might have it's own listener socket. This could be done as an
alternative to other models: 1) have one listener thread which
dispatches completed connections to workers. 2) accept on a single
listener socket from multiple threads. In case #1 the listener thread
can easily become the bottleneck with high connection turn-over rate.
In case #2, the proportion of connections accepted per thread tends
to be uneven under high connection load (assuming simple event loop:
while (1) { accept(); process() }, wakeup does not promote fairness
among the sockets. We have seen the disproportion to be as high
as 3:1 ratio between thread accepting most connections and the one
accepting the fewest. With so_reusport the distribution is
uniform.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ce43b03e8889475817d427b1f3724c7e294b76eb 30-Nov-2012 Eric Dumazet <edumazet@google.com> net: move inet_dport/inet_num in sock_common

commit 68835aba4d9b (net: optimize INET input path further)
moved some fields used for tcp/udp sockets lookup in the first cache
line of struct sock_common.

This patch moves inet_dport/inet_num as well, filling a 32bit hole
on 64 bit arches and reducing number of cache line misses in lookups.

Also change INET_MATCH()/INET_TW_MATCH() to perform the ports match
before addresses match, as this check is more discriminant.

Remove the hash check from MATCH() macros because we dont need to
re validate the hash value after taking a refcount on socket, and
use likely/unlikely compiler hints, as the sk_hash/hash check
makes the following conditional tests 100% predicted by cpu.

Introduce skc_addrpair/skc_portpair pair values to better
document the alignment requirements of the port/addr pairs
used in the various MATCH() macros, and remove some casts.

The namespace check can also be done at last.

This slightly improves TCP/UDP lookup times.

IP/TCP early demux needs inet->rx_dst_ifindex and
TCP needs inet->min_ttl, lets group them together in same cache line.

With help from Ben Hutchings & Joe Perches.

Idea of this patch came after Ling Ma proposal to move skc_hash
to the beginning of struct sock_common, and should allow him
to submit a final version of his patch. My tests show an improvement
doing so.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Joe Perches <joe@perches.com>
Cc: Ling Ma <ling.ma.program@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
6e5714eaf77d79ae1c8b47e3e040ff5411b717ec 04-Aug-2011 David S. Miller <davem@davemloft.net> net: Compute protocol sequence numbers and fragment IDs using MD5.

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation. So the periodic
regeneration and 8-bit counter have been removed. We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky <dan@doxpara.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
42b16b3fbb5ee4555f5dee6220f3ccaa6e1ebe47 17-Jan-2011 Jesper Juhl <jj@chaosbits.net> Kill off warning: ‘inline’ is not at beginning of declaration

Fix a bunch of
warning: ‘inline’ is not at beginning of declaration
messages when building a 'make allyesconfig' kernel with -Wextra.

These warnings are trivial to kill, yet rather annoying when building with
-Wextra.
The more we can cut down on pointless crap like this the better (IMHO).

A previous patch to do this for a 'allnoconfig' build has already been
merged. This just takes the cleanup a little further.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
9327f7053e3993c125944fdb137a0618319ef2a0 04-Dec-2009 Eric Dumazet <eric.dumazet@gmail.com> tcp: Fix a connect() race with timewait sockets

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: kapil dakhane <kdakhane@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
13475a30b66cdb9250a34052c19ac98847373030 02-Dec-2009 Eric Dumazet <eric.dumazet@gmail.com> tcp: connect() race with timewait reuse

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>
c720c7e8383aff1cb219bddf474ed89d850336e3 15-Oct-2009 Eric Dumazet <eric.dumazet@gmail.com> inet: rename some inet_sock fields

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: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
f373b53b5fe67aa4a6f28f921a529cc90f88e79b 09-Oct-2009 Eric Dumazet <eric.dumazet@gmail.com> tcp: replace ehash_size by ehash_mask

Storing the mask (size - 1) instead of the size allows fast path to be
a bit faster.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3f53a38131a4e7a053c0aa060aba0411242fb6b9 26-Feb-2009 Pavel Emelyanov <xemul@openvz.org> ipv6: don't use tw net when accounting for recycled tw

We already have a valid net in that place, but this is not just a
cleanup - the tw pointer can be NULL there sometimes, thus causing
an oops in NET_NS=y case.

The same place in ipv4 code already works correctly using existing
net, rather than tw's one.

The bug exists since 2.6.27.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
c25eb3bfb97294d0543a81230fbc237046b4b84c 24-Nov-2008 Eric Dumazet <dada1@cosmosbay.com> net: Convert TCP/DCCP listening hash tables to use RCU

This is the last step to be able to perform full RCU lookups
in __inet_lookup() : After established/timewait tables, we
add RCU lookups to listening hash table.

The only trick here is that a socket of a given type (TCP ipv4,
TCP ipv6, ...) can now flight between two different tables
(established and listening) during a RCU grace period, so we
must use different 'nulls' end-of-chain values for two tables.

We define a large value :

#define LISTENING_NULLS_BASE (1U << 29)

So that slots in listening table are guaranteed to have different
end-of-chain values than slots in established table. A reader can
still detect it finished its lookup in the right chain.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
9db66bdcc83749affe61c61eb8ff3cf08f42afec 21-Nov-2008 Eric Dumazet <dada1@cosmosbay.com> net: convert TCP/DCCP ehash rwlocks to spinlocks

Now TCP & DCCP use RCU lookups, we can convert ehash rwlocks to spinlocks.

/proc/net/tcp and other seq_file 'readers' can safely be converted to 'writers'.

This should speedup writers, since spin_lock()/spin_unlock()
only use one atomic operation instead of two for write_lock()/write_unlock()

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
5caea4ea7088e80ac5410d04660346094608b909 20-Nov-2008 Eric Dumazet <dada1@cosmosbay.com> net: listening_hash get a spinlock per bucket

This patch prepares RCU migration of listening_hash table for
TCP/DCCP protocols.

listening_hash table being small (32 slots per protocol), we add
a spinlock for each slot, instead of a single rwlock for whole table.

This should reduce hold time of readers, and writers concurrency.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3ab5aee7fe840b5b1b35a8d1ac11c3de5281e611 17-Nov-2008 Eric Dumazet <dada1@cosmosbay.com> net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls

RCU was added to UDP lookups, using a fast infrastructure :
- sockets kmem_cache use SLAB_DESTROY_BY_RCU and dont pay the
price of call_rcu() at freeing time.
- hlist_nulls permits to use few memory barriers.

This patch uses same infrastructure for TCP/DCCP established
and timewait sockets.

Thanks to SLAB_DESTROY_BY_RCU, no slowdown for applications
using short lived TCP connections. A followup patch, converting
rwlocks to spinlocks will even speedup this case.

__inet_lookup_established() is pretty fast now we dont have to
dirty a contended cache line (read_lock/read_unlock)

Only established and timewait hashtable are converted to RCU
(bind table and listen table are still using traditional locking)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
547b792cac0a038b9dbf958d3c120df3740b5572 26-Jul-2008 Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> net: convert BUG_TRAP to generic WARN_ON

Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
de0744af1fe2d0a3d428f6af0f2fe1f6179b1a9c 17-Jul-2008 Pavel Emelyanov <xemul@openvz.org> mib: add net to NET_INC_STATS_BH

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
33de014c63646f69f36f3673e3b4676f931dc878 17-Jun-2008 Pavel Emelyanov <xemul@openvz.org> inet6: add struct net argument to inet6_ehashfn

Same as for inet_hashfn, prepare its ipv6 incarnation.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2086a65078bd24682bdcf413d9c91d81988b8359 17-Jun-2008 Pavel Emelyanov <xemul@openvz.org> inet: add struct net argument to inet_lhashfn

Listening-on-one-port sockets in many namespaces produce long
chains in the listening_hash-es, so prepare the inet_lhashfn to
take struct net into account.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
c29a0bc4dfc4d833eb702b1929cec96a3eeb9f7a 01-Apr-2008 Pavel Emelyanov <xemul@openvz.org> [SOCK][NETNS]: Add a struct net argument to sock_prot_inuse_add and _get.

This counter is about to become per-proto-and-per-net, so we'll need
two arguments to determine which cell in this "table" to work with.

All the places, but proc already pass proper net to it - proc will be
tuned a bit later.

Some indentation with spaces in proc files is done to keep the file
coding style consistent.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
878628fbf2589eb24357e42027d5f54b1dafd3c8 25-Mar-2008 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [NET] NETNS: Omit namespace comparision without CONFIG_NET_NS.

Introduce an inline net_eq() to compare two namespaces.
Without CONFIG_NET_NS, since no namespace other than &init_net
exists, it is always 1.

We do not need to convert 1) inline vs inline and
2) inline vs &init_net comparisons.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
3b1e0a655f8eba44ab1ee2a1068d169ccfb853b9 25-Mar-2008 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.

Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
39d8cda76cfb1178455f9d196b39e773878e6c05 23-Mar-2008 Pavel Emelyanov <xemul@openvz.org> [SOCK]: Add udp_hash member to struct proto.

Inspired by the commit ab1e0a13 ([SOCK] proto: Add hashinfo member to
struct proto) from Arnaldo, I made similar thing for UDP/-Lite IPv4
and -v6 protocols.

The result is not that exciting, but it removes some levels of
indirection in udpxxx_get_port and saves some space in code and text.

The first step is to union existing hashinfo and new udp_hash on the
struct proto and give a name to this union, since future initialization
of tcpxxx_prot, dccp_vx_protinfo and udpxxx_protinfo will cause gcc
warning about inability to initialize anonymous member this way.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
5d8c0aa9433b09387d9021358baef7939f9b32c4 05-Feb-2008 Pavel Emelyanov <xemul@openvz.org> [INET]: Fix accidentally broken inet(6)_hash_connect's port offset calculations.

The port offset calculations depend on the protocol family, but, as
Adrian noticed, I broke this logic with the commit

5ee31fc1ecdcbc234c8c56dcacef87c8e09909d8
[INET]: Consolidate inet(6)_hash_connect.

Return this logic back, by passing the port offset directly into the
consolidated function.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Noticed-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
ab1e0a13d70299e792fd0527cefd070c1405fa5b 03-Feb-2008 Arnaldo Carvalho de Melo <acme@redhat.com> [SOCK] proto: Add hashinfo member to struct proto

This way we can remove TCP and DCCP specific versions of

sk->sk_prot->get_port: both v4 and v6 use inet_csk_get_port
sk->sk_prot->hash: inet_hash is directly used, only v6 need
a specific version to deal with mapped sockets
sk->sk_prot->unhash: both v4 and v6 use inet_hash directly

struct inet_connection_sock_af_ops also gets a new member, bind_conflict, so
that inet_csk_get_port can find the per family routine.

Now only the lookup routines receive as a parameter a struct inet_hashtable.

With this we further reuse code, reducing the difference among INET transport
protocols.

Eventually work has to be done on UDP and SCTP to make them share this
infrastructure and get as a bonus inet_diag interfaces so that iproute can be
used with these protocols.

net-2.6/net/ipv4/inet_hashtables.c:
struct proto | +8
struct inet_connection_sock_af_ops | +8
2 structs changed
__inet_hash_nolisten | +18
__inet_hash | -210
inet_put_port | +8
inet_bind_bucket_create | +1
__inet_hash_connect | -8
5 functions changed, 27 bytes added, 218 bytes removed, diff: -191

net-2.6/net/core/sock.c:
proto_seq_show | +3
1 function changed, 3 bytes added, diff: +3

net-2.6/net/ipv4/inet_connection_sock.c:
inet_csk_get_port | +15
1 function changed, 15 bytes added, diff: +15

net-2.6/net/ipv4/tcp.c:
tcp_set_state | -7
1 function changed, 7 bytes removed, diff: -7

net-2.6/net/ipv4/tcp_ipv4.c:
tcp_v4_get_port | -31
tcp_v4_hash | -48
tcp_v4_destroy_sock | -7
tcp_v4_syn_recv_sock | -2
tcp_unhash | -179
5 functions changed, 267 bytes removed, diff: -267

net-2.6/net/ipv6/inet6_hashtables.c:
__inet6_hash | +8
1 function changed, 8 bytes added, diff: +8

net-2.6/net/ipv4/inet_hashtables.c:
inet_unhash | +190
inet_hash | +242
2 functions changed, 432 bytes added, diff: +432

vmlinux:
16 functions changed, 485 bytes added, 492 bytes removed, diff: -7

/home/acme/git/net-2.6/net/ipv6/tcp_ipv6.c:
tcp_v6_get_port | -31
tcp_v6_hash | -7
tcp_v6_syn_recv_sock | -9
3 functions changed, 47 bytes removed, diff: -47

/home/acme/git/net-2.6/net/dccp/proto.c:
dccp_destroy_sock | -7
dccp_unhash | -179
dccp_hash | -49
dccp_set_state | -7
dccp_done | +1
5 functions changed, 1 bytes added, 242 bytes removed, diff: -241

/home/acme/git/net-2.6/net/dccp/ipv4.c:
dccp_v4_get_port | -31
dccp_v4_request_recv_sock | -2
2 functions changed, 33 bytes removed, diff: -33

/home/acme/git/net-2.6/net/dccp/ipv6.c:
dccp_v6_get_port | -31
dccp_v6_hash | -7
dccp_v6_request_recv_sock | +5
3 functions changed, 5 bytes added, 38 bytes removed, diff: -33

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d86e0dac2ce412715181f792aa0749fe3effff11 31-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS]: Tcp-v6 sockets per-net lookup.

Add a net argument to inet6_lookup and propagate it further.
Actually, this is tcp-v6 implementation of what was done for
tcp-v4 sockets in a previous patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
5ee31fc1ecdcbc234c8c56dcacef87c8e09909d8 31-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate inet(6)_hash_connect.

These two functions are the same except for what they call
to "check_established" and "hash" for a socket.

This saves half-a-kilo for ipv4 and ipv6.

add/remove: 1/0 grow/shrink: 1/4 up/down: 582/-1128 (-546)
function old new delta
__inet_hash_connect - 577 +577
arp_ignore 108 113 +5
static.hint 8 4 -4
rt_worker_func 376 372 -4
inet6_hash_connect 584 25 -559
inet_hash_connect 586 25 -561

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
535174efbe0f0454f0595c31b823498c197eeb4f 31-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [IPV6]: Introduce the INET6_TW_MATCH macro.

We have INET_MATCH, INET_TW_MATCH and INET6_MATCH to test sockets and
twbuckets for matching, but ipv6 twbuckets are tested manually.

Here's the INET6_TW_MATCH to help with it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
65f7651788e18fadb2fbb7276af935d7871e1803 04-Jan-2008 Eric Dumazet <dada1@cosmosbay.com> [NET]: prot_inuse cleanups and optimizations

1) Cleanups (all functions are prefixed by sock_prot_inuse)

sock_prot_inc_use(prot) -> sock_prot_inuse_add(prot,-1)
sock_prot_dec_use(prot) -> sock_prot_inuse_add(prot,-1)
sock_prot_inuse() -> sock_prot_inuse_get()

New functions :

sock_prot_inuse_init() and sock_prot_inuse_free() to abstract pcounter use.

2) if CONFIG_PROC_FS=n, we can zap 'inuse' member from "struct proto",
since nobody wants to read the inuse value.

This saves 1372 bytes on i386/SMP and some cpu cycles.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
b3652b2dc5ec6ccd946ae9136b30c6babb81305a 18-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [IPV6]: Mischecked tw match in __inet6_check_established.

When looking for a conflicting connection the !sk->sk_bound_dev_if
check is performed only for live sockets, but not for timewait-ed.

This is not the case for ipv4, for __inet6_lookup_established in
both ipv4 and ipv6 and for other places that check for tw-s.

Was this missed accidentally? If so, then this patch fixes it and
besides makes use if the dif variable declared in the function.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
230140cffa7feae90ad50bf259db1fa07674f3a7 07-Nov-2007 Eric Dumazet <dada1@cosmosbay.com> [INET]: Remove per bucket rwlock in tcp/dccp ehash table.

As done two years ago on IP route cache table (commit
22c047ccbc68fa8f3fa57f0e8f906479a062c426) , we can avoid using one
lock per hash bucket for the huge TCP/DCCP hash tables.

On a typical x86_64 platform, this saves about 2MB or 4MB of ram, for
litle performance differences. (we hit a different cache line for the
rwlock, but then the bucket cache line have a better sharing factor
among cpus, since we dirty it less often). For netstat or ss commands
that want a full scan of hash table, we perform fewer memory accesses.

Using a 'small' table of hashed rwlocks should be more than enough to
provide correct SMP concurrency between different buckets, without
using too much memory. Sizing of this table depends on
num_possible_cpus() and various CONFIG settings.

This patch provides some locking abstraction that may ease a future
work using a different model for TCP/DCCP table.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
a25de534f89c515c82d3553c42d3bb02c2d1a7da 19-Oct-2007 Anton Arapov <aarapov@redhat.com> [INET]: Justification for local port range robustness.

There is a justifying patch for Stephen's patches. Stephen's patches
disallows using a port range of one single port and brakes the meaning
of the 'remaining' variable, in some places it has different meaning.
My patch gives back the sense of 'remaining' variable. It should mean
how many ports are remaining and nothing else. Also my patch allows
using a single port.

I sure we must be able to use mentioned port range, this does not
restricted by documentation and does not brake current behavior.

usefull links:
Patches posted by Stephen Hemminger
http://marc.info/?l=linux-netdev&m=119206106218187&w=2
http://marc.info/?l=linux-netdev&m=119206109918235&w=2

Andrew Morton's comment
http://marc.info/?l=linux-kernel&m=119248225007737&w=2

1. Allows using a port range of one single port.
2. Gives back sense of 'remaining' variable.

Signed-off-by: Anton Arapov <aarapov@redhat.com>
Acked-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
227b60f5102cda4e4ab792b526a59c8cb20cd9f8 11-Oct-2007 Stephen Hemminger <shemminger@linux-foundation.org> [INET]: local port range robustness

Expansion of original idea from Denis V. Lunev <den@openvz.org>

Add robustness and locking to the local_port_range sysctl.
1. Enforce that low < high when setting.
2. Use seqlock to ensure atomic update.

The locking might seem like overkill, but there are
cases where sysadmin might want to change value in the
middle of a DoS attack.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
6e1d9d04c4004361fb327abcbde74a20e8dca2ff 13-Feb-2007 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [IPV6] HASHTABLES: Use appropriate seed for caluculating ehash index.

Tetsuo Handa <handat@pm.nttdata.co.jp> told me that connect(2) with TCPv6
socket almost always took a few minutes to return when we did not have any
ports available in the range of net.ipv4.ip_local_port_range.

The reason was that we used incorrect seed for calculating index of
hash when we check established sockets in __inet6_check_established().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1ab1457c42bc078e5a9becd82a7f9f940b55c53a 09-Feb-2007 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [NET] IPV6: Fix whitespace errors.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
dbca9b2750e3b1ee6f56a616160ccfc12e8b161f 08-Feb-2007 Eric Dumazet <dada1@cosmosbay.com> [NET]: change layout of ehash table

ehash table layout is currently this one :

First half of this table is used by sockets not in TIME_WAIT state
Second half of it is used by sockets in TIME_WAIT state.

This is non optimal because of for a given hash or socket, the two chain heads
are located in separate cache lines.
Moreover the locks of the second half are never used.

If instead of this halving, we use two list heads in inet_ehash_bucket instead
of only one, we probably can avoid one cache miss, and reduce ram usage,
particularly if sizeof(rwlock_t) is big (various CONFIG_DEBUG_SPINLOCK,
CONFIG_DEBUG_LOCK_ALLOC settings). So we still halves the table but we keep
together related chains to speedup lookups and socket state change.

In this patch I did not try to align struct inet_ehash_bucket, but a future
patch could try to make this structure have a convenient size (a power of two
or a multiple of L1_CACHE_SIZE).
I guess rwlock will just vanish as soon as RCU is plugged into ehash :) , so
maybe we dont need to scratch our heads to align the bucket...

Note : In case struct inet_ehash_bucket is not a power of two, we could
probably change alloc_large_system_hash() (in case it use __get_free_pages())
to free the unused space. It currently allocates a big zone, but the last
quarter of it could be freed. Again, this should be a temporary 'problem'.

Patch tested on ipv4 tcp only, but should be OK for IPV6 and DCCP.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d2ecd9ccd0694278a8c1fa179d1d058ee66e2297 08-Nov-2006 Al Viro <viro@zeniv.linux.org.uk> [IPV6]: annotate inet6_hashtables

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
4f765d842fa6e6fe15d555b247b640118d65b4dd 28-Sep-2006 Al Viro <viro@zeniv.linux.org.uk> [IPV4]: INET_MATCH() annotations

INET_MATCH() and friends depend on an interesting set of kludges:
* there's a pair of adjacent fields in struct inet_sock - __be16 dport
followed by __u16 num. We want to search by pair, so we combine the keys into
a single 32bit value and compare with 32bit value read from &...->dport.
* on 64bit targets we combine comparisons with pair of adjacent __be32
fields in the same way.

Make sure that we don't mix those values with anything else and that pairs
we form them from have correct types.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
6ab3d5624e172c553004ecc862bfeac16d9d68b7 30-Jun-2006 Jörn Engel <joern@wohnheim.fh-wedel.de> Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
b1a7ffcb7a047e99ab02424e651e0492f36095f7 10-Apr-2006 Denis Vlasenko <vda@ilport.com.ua> [IPV6]: Deinline few large functions in inet6 code

Deinline a few functions which produce 200+ bytes of code.

Size Uses Wasted Name and definition
===== ==== ====== ================================================
429 3 818 __inet6_lookup include/net/inet6_hashtables.h
404 2 384 __inet6_lookup_established include/net/inet6_hashtables.h
206 3 372 __inet6_hash include/net/inet6_hashtables.h

Signed-off-by: Denis Vlasenko <vda@ilport.com.ua>
Signed-off-by: David S. Miller <davem@davemloft.net>
3759fa9c55923f719ae944a3f8fbb029b36f759d 13-Mar-2006 Herbert Xu <herbert@gondor.apana.org.au> [TCP]: Fix zero port problem in IPv6

When we link a socket into the hash table, we need to make sure that we
set the num/port fields so that it shows us with a non-zero port value
in proc/netlink and on the wire. This code and comment is copied over
from the IPv4 stack as is.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
d8313f5ca2b1f86b7df6c99fc4b3fffa1f84e92b 14-Dec-2005 Arnaldo Carvalho de Melo <acme@mandriva.com> [INET6]: Generalise tcp_v6_hash_connect

Renaming it to inet6_hash_connect, making it possible to ditch
dccp_v6_hash_connect and share the same code with TCP instead.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
5324a040ccc708998e61ea93e669b81312f0ae11 12-Aug-2005 Arnaldo Carvalho de Melo <acme@mandriva.com> [INET6_HASHTABLES]: Move inet6_lookup functions to net/ipv6/inet6_hashtables.c

Doing this we allow tcp_diag to support IPV6 even if tcp_diag is compiled
statically and IPV6 is compiled as a module, removing the previous restriction
while not building any IPV6 code if it is not selected.

Now to work on the tcpdiag_register infrastructure and then to rename the whole
thing to inetdiag, reflecting its by then completely generic nature.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>