Also use some BUG_ON where appropriate and use LIMIT_NETDEBUG for the unlikely
cases where we, at this stage, want to know about, that in my tests hasn't
appeared in the radar.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

To match more closely what is described in RFC 3448.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NIan McDonald <iam4@cs.waikato.ac.nz>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

To start the timestamps with 0.0ms, easing the integer maths in the CCIDs, this
probably will be reworked to use the to be introduced struct timeval_offset
infrastructure out of skb_get_timestamp, etc.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

The initialization of ccid3hcrx_rtt to 5ms is just a bandaid, I'll continue
auditing the CCID3 HC rx codebase to fix this properly, probably I'll add a
feedback timer as suggested in the CCID3 draft.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

This makes the send rate calculations behave way more closely to what
is specified, with the jitter previously seen on x and x_recv
disappearing completely on non lossy setups.

This resembles the tcp_data_snd_check code, that possibly we'll end up
using in DCCP as well, perhaps moving this code to
inet_connection_sock.

For now I'm doing the simplest implementation tho.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So that applications can set dccp_sock->dccps_pkt_size, that in turn
is used in the CCID3 half connection init routines to set
ccid3hc[tr]x_s and use it in its rate calculations.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Renaming it to dccp_rx_hist_detect_loss.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Renaming it to dccp_rx_hist_add_packet.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

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

And put this into net/dccp/ccids/lib/, where packet_history.[ch] will also be
moved and then we'll have a tfrc_lib.ko module that will be used by
dccp_ccid3.ko and other CCIDs that are variations of TFRC (RFC 3448).
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

To avoid open coding this all over the place.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introducing functions to add to or subtract from a timeval variable
and renaming now_delta to timeval_new_delta that calls do_gettimeofday
and then timeval_delta, that should be used when there are several
deltas made relative to the current time or setting variables to it,
so as to avoid calling do_gettimeofday excessively.

I'm leaving these "timeval_" prefixed funcions internal to DCCP for a
while till we're sure there are no subtle bugs in it.

It also is more correct as it checks if the number of usecs added to
or subtracted from a tv_usec field is more than 2 seconds.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No code changes.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is not quite what I think we should have long term but improves
performance for now, so lets use it till we get CCID3 working well,
then we can think about using sk_write_queue, perhaps using some ideas
from Juwen Lai's old stack for 2.4.20.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch puts mostly read only data in the right section
(read_mostly), to help sharing of these data between CPUS without
memory ping pongs.

On one of my production machine, tcp_statistics was sitting in a
heavily modified cache line, so *every* SNMP update had to force a
reload.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And also hc_tx and hc_rx get_info functions for the CCIDs to fill in
information that is specific to them.

For now reusing struct tcp_info, later I'll try to figure out a better
solution, for now its really nice to get this kind of info:

[root@qemu ~]# ./ss -danemi
State       Recv-Q Send-Q  Local Addr:Port  Peer Addr:Port
LISTEN      0      0                *:5001          *:*     ino:628 sk:c1340040
         mem:(r0,w0,f0,t0) cwnd:0 ssthresh:0
ESTAB       0      0       172.20.0.2:5001 172.20.0.1:32785 ino:629 sk:c13409a0
         mem:(r0,w0,f0,t0) ts rto:1000 rtt:0.004/0 cwnd:0 ssthresh:0 rcv_rtt:61.377

This, for instance, shows that we're not congestion controlling ACKs,
as the above output is in the ttcp receiving host, and ttcp is a one
way app, i.e. the received never calls sendmsg, so
ccid_hc_tx_send_packet is never called, so the TX half connection
stays in TFRC_SSTATE_NO_SENT state and hctx_rtt is never calculated,
stays with the value set in ccid3_hc_tx_init, 4us, as show above in
milliseconds (0.004ms), upcoming patches will fix this.

rcv_rtt seems sane tho, matching ping results :-)
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using TIMESTAMP_ECHO and ELAPSED_TIME options received.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CCID3 keeps this variable in usecs, inet_connection_socks in jiffies,
so to avoid Mars orbiter losses lets reintroduce ccid3hctx_t_rto 8)
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This changes timestamp, timestamp echo, and elapsed time to use units of 10
usecs as per DCCP spec. This has been tested to verify that times are correct.
Also fixed up length and used hton/ntoh more.

Still to add in later patches:
- actually use elapsed time to adjust RTT
(commented out as was prior to this patch)
- send options at times more closely following the spec
(content is now correct)
Signed-off-by: NIan McDonald <iam4@cs.waikato.ac.nz>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

may be a false warning if there always is something on ccid3hcrx_hist:

net/dccp/ccids/ccid3.c: In function 'ccid3_hc_rx_packet_recv':
net/dccp/ccids/ccid3.c:1634: warning: 'tstamp.tv_usec' may be used uninitialized in this function
net/dccp/ccids/ccid3.c:1634: warning: 'tstamp.tv_sec' may be used uninitialized in this function

const on inline functions doesn't have any effect:

net/dccp/dccp.h:64: warning: type qualifiers ignored on function return type
net/dccp/dccp.h:70: warning: type qualifiers ignored on function return type
net/dccp/dccp.h:76: warning: type qualifiers ignored on function return type
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Only available if CONFIG_DEBUG_KERNEL is enabled in the "Kernel
Hacking" Menu.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As requested by Ian.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NIan McDonald <iam4@cs.waikato.ac.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

That is equivalent, no need to have a private one.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

This also changes the list_for_each_entry_safe_continue behaviour to match its
kerneldoc comment, that is, to start after the pos passed.

Also adds several helper functions from previously open coded fragments, making
the code more clear.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

This way it gets closer to the TCP flow, where congestion window
checks are done, it seems we can map ccid_hc_tx_send_packet in
dccp_write_xmit to tcp_snd_wnd_test in tcp_write_xmit, a CCID2
decision should just fit in here as well...
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
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>

Development to this point was done on a subversion repository at:

http://oops.ghostprotocols.net:81/cgi-bin/viewcvs.cgi/dccp-2.6/

This repository will be kept at this site for the foreseable future,
so that interested parties can see the history of this code,
attributions, etc.

If I ever decide to take this offline I'll provide the full history at
some other suitable place.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>