This should really be in a inet_connection_sock, but I'm leaving it
for a later optimization, when some more fields common to INET
transport protocols now in tcp_sk or inet_sk will be chunked out into
inet_connection_sock, for now its better to concentrate on getting the
changes in the core merged to leave the DCCP tree with only DCCP
specific code.

Next changesets will take advantage of this move to generalise things
like tcp_bind_hash, tcp_put_port, tcp_inherit_port, making the later
receive a inet_hashinfo parameter, and even __tcp_tw_hashdance, etc in
the future, when tcp_tw_bucket gets transformed into the struct
timewait_sock hierarchy.

tcp_destroy_sock also is eligible as soon as tcp_orphan_count gets
moved to sk_prot.

A cascade of incremental changes will ultimately make the tcp_lookup
functions be fully generic.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is to break down the complexity of the series of patches,
making it very clear that this one just does:

1. renames tcp_ prefixed hashtable functions and data structures that
   were already mostly generic to inet_ to share it with DCCP and
   other INET transport protocols.

2. Removes not used functions (__tb_head & tb_head)

3. Removes some leftover prototypes in the headers (tcp_bucket_unlock &
   tcp_v4_build_header)

Next changesets will move tcp_sk(sk)->bind_hash to inet_sock so that we can
make functions such as tcp_inherit_port, __tcp_inherit_port, tcp_v4_get_port,
__tcp_put_port,  generic and get others like tcp_destroy_sock closer to generic
(tcp_orphan_count will go to sk->sk_prot to allow this).

Eventually most of these functions will be used passing the transport protocol
inet_hashinfo structure.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

From tcp_v4_rebuild_header, that already was pretty generic, I only
needed to use sk->sk_protocol instead of the hardcoded IPPROTO_TCP and
establish the requirement that INET transport layer protocols that
want to use this function map TCP_SYN_SENT to its equivalent state.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

From tcp_v4_setup_caps, that always is preceded by a call to
__sk_dst_set, so coalesce this sequence into sk_setup_caps, removing
one call to a TCP function in the IP layer.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just simple spelling mistake fixes.
Signed-Off-By: NBaruch Even <baruch@ev-en.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

From: Victor Fusco <victor@cetuc.puc-rio.br>

Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: NVictor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: NDomen Puncer <domen@coderock.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make TSO segment transmit size decisions at send time not earlier.

The basic scheme is that we try to build as large a TSO frame as
possible when pulling in the user data, but the size of the TSO frame
output to the card is determined at transmit time.

This is guided by tp->xmit_size_goal.  It is always set to a multiple
of MSS and tells sendmsg/sendpage how large an SKB to try and build.

Later, tcp_write_xmit() and tcp_push_one() chop up the packet if
necessary and conditions warrant.  These routines can also decide to
"defer" in order to wait for more ACKs to arrive and thus allow larger
TSO frames to be emitted.

A general observation is that TSO elongates the pipe, thus requiring a
larger congestion window and larger buffering especially at the sender
side.  Therefore, it is important that applications 1) get a large
enough socket send buffer (this is accomplished by our dynamic send
buffer expansion code) 2) do large enough writes.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

'nonagle' should be passed to the tcp_snd_test() function
as 'TCP_NAGLE_PUSH' if we are checking an SKB not at the
tail of the write_queue.  This is because Nagle does not
apply to such frames since we cannot possibly tack more
data onto them.

However, while doing this __tcp_push_pending_frames() makes
all of the packets in the write_queue use this modified
'nonagle' value.

Fix the bug and simplify this function by just calling
tcp_write_xmit() directly if sk_send_head is non-NULL.

As a result, we can now make tcp_data_snd_check() just call
tcp_push_pending_frames() instead of the specialized
__tcp_data_snd_check().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_write_xmit() uses tcp_current_mss(), but some of it's callers,
namely __tcp_push_pending_frames(), already has this value available
already.

While we're here, fix the "cur_mss" argument to be "unsigned int"
instead of plain "unsigned".
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The tcp_cwnd_validate() function should only be invoked
if we actually send some frames, yet __tcp_push_pending_frames()
will always invoke it.  tcp_write_xmit() does the call for us,
so the call here can simply be removed.

Also, tcp_write_xmit() can be marked static.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It reimplements portions of tcp_snd_check(), so it
we move it to tcp_output.c we can consolidate it's
logic much easier in a later change.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This just moves the code into tcp_output.c, no code logic changes are
made by this patch.

Using this as a baseline, we can begin to untangle the mess of
comparisons for the Nagle test et al.  We will also be able to reduce
all of the redundant computation that occurs when outputting data
packets.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On each packet output, we call tcp_dec_quickack_mode()
if the ACK flag is set.  It drops tp->ack.quick until
it hits zero, at which time we deflate the ATO value.

When doing TSO, we are emitting multiple packets with
ACK set, so we should decrement tp->ack.quick that many
segments.

Note that, unlike this case, tcp_enter_cwr() should not
take the tcp_skb_pcount(skb) into consideration.  That
function, one time, readjusts tp->snd_cwnd and moves
into TCP_CA_CWR state.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Allow using setsockopt to set TCP congestion control to use on a per
socket basis.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow TCP to have multiple pluggable congestion control algorithms.
Algorithms are defined by a set of operations and can be built in
or modules.  The legacy "new RENO" algorithm is used as a starting
point and fallback.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes the CONFIG_INET=n build failure noticed
by Andrew Morton.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This chunks out the accept_queue and tcp_listen_opt code and moves
them to net/core/request_sock.c and include/net/request_sock.h, to
make it useful for other transport protocols, DCCP being the first one
to use it.

Next patches will rename tcp_listen_opt to accept_sock and remove the
inline tcp functions that just call a reqsk_queue_ function.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ok, this one just renames some stuff to have a better namespace and to
dissassociate it from TCP:

struct open_request  -> struct request_sock
tcp_openreq_alloc    -> reqsk_alloc
tcp_openreq_free     -> reqsk_free
tcp_openreq_fastfree -> __reqsk_free

With this most of the infrastructure closely resembles a struct
sock methods subset.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Kept this first changeset minimal, without changing existing names to
ease peer review.

Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:

->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
  a specific protocol

The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.

I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.

Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)

Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ross moved.  Remove the bad email address so people will find the correct
one in ./CREDITS.
Signed-off-by: NJesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The problem is that when doing MTU discovery, the too-large segments in
the write queue will be calculated as having a pcount of >1.  When
tcp_write_xmit() is trying to send, tcp_snd_test() fails the cwnd test
when pcount > cwnd.

The segments are eventually transmitted one at a time by keepalive, but
this can take a long time.

This patch checks if TSO is enabled when setting pcount.
Signed-off-by: NJohn Heffner <jheffner@psc.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!