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899 commits

Author SHA1 Message Date
Gerrit Renker
113ced1f52 dccp ccid-2: Perform congestion-window validation
CCID-2's cwnd increases like TCP during slow-start, which has implications for
 * the local Sequence Window value (should be > cwnd),
 * the Ack Ratio value.
Hence an exponential growth, if it does not reflect the actual network
conditions, can quickly lead to instability.

This patch adds congestion-window validation (RFC2861) to CCID-2:
 * cwnd is constrained if the sender is application limited;
 * cwnd is reduced after a long idle period, as suggested in the '90 paper
   by Van Jacobson, in RFC 2581 (sec. 4.1);
 * cwnd is never reduced below the RFC 3390 initial window.

As marked in the comments, the code is actually almost a direct copy of the
TCP congestion-window-validation algorithms. By continuing this work, it may
in future be possible to use the TCP code (not possible at the moment).

The mechanism can be turned off using a module parameter. Sampling of the
currently-used window (moving-maximum) is however done constantly; this is
used to determine the expected window, which can be exploited to regulate
DCCP's Sequence Window value.

This patch also sets slow-start-after-idle (RFC 4341, 5.1), i.e. it behaves like
TCP when net.ipv4.tcp_slow_start_after_idle = 1.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-07-04 12:37:49 -06:00
Gerrit Renker
58fdea0f31 dccp ccid-2: Use existing function to test for data packets
This replaces a switch statement with a test, using the equivalent
function dccp_data_packet(skb).  It also doubles the range of the field
`rx_num_data_pkts' by changing the type from `int' to `u32', avoiding
signed/unsigned comparison with the u16 field `dccps_r_ack_ratio'.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-07-04 12:37:40 -06:00
Gerrit Renker
b4d5f4b288 dccp ccid-2: move rfc 3390 function into header file
This moves CCID-2's initial window function into the header file, since several
parts throughout the CCID-2 code need to call it (CCID-2 still uses RFC 3390).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Leandro Melo de Sales <leandro@ic.ufal.br>
2011-07-04 12:37:30 -06:00
Gerrit Renker
1fd9d2081a dccp: cosmetics of info message
Change the CCID (de)activation message to start with the
protocol name, as 'CCID' is already in there.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-07-04 12:37:13 -06:00
Gerrit Renker
8695e80193 dccp: combine the functionality of enqeueing and cloning
Realising the following call pattern,
 * first dccp_entail() is called to enqueue a new skb and
 * then skb_clone() is called to transmit a clone of that skb,
this patch integrates both into the same function.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-07-04 12:36:47 -06:00
Gerrit Renker
c0c2015056 dccp: Clean up slow-path input processing
This patch rearranges the order of statements of the slow-path input processing
(i.e. any other state than OPEN), to resolve the following issues.

 1. Dependencies: the order of statements now better matches RFC 4340, 8.5, i.e.
    step 7 is before step 9 (previously 9 was before 7), and parsing options in
    step 8 (which may consume resources) now comes after step 7.
 2. Sequence number checks are omitted if in state LISTEN/REQUEST, due to the
    note underneath the table in RFC 4340, 7.5.3.
    As a result, CCID processing is now indeed confined to OPEN/PARTOPEN states,
    i.e. congestion control is performed only on the flow of data packets. This
    avoids pathological cases of doing congestion control on those messages
    which set up and terminate the connection.
 3. Packets are now passed on to Ack Vector / CCID processing only after
    - step 7  (receive unexpected packets),
    - step 9  (receive Reset),
    - step 13 (receive CloseReq),
    - step 14 (receive Close)
    and only if the state is PARTOPEN. This simplifies CCID processing:
    - in LISTEN/CLOSED the CCIDs are non-existent;
    - in RESPOND/REQUEST the CCIDs have not yet been negotiated;
    - in CLOSEREQ and active-CLOSING the node has already closed this socket;
    - in passive-CLOSING the client is waiting for its Reset.
    In the last case, RFC 4340, 8.3 leaves it open to ignore further incoming
    data, which is the approach taken here.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-07-04 12:36:33 -06:00
David S. Miller
6bd023f3dd ipv4: Make caller provide flowi4 key to inet_csk_route_req().
This way the caller can get at the fully resolved fl4->{daddr,saddr}
etc.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-18 18:32:03 -04:00
David S. Miller
3c709f8fb4 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-3.6
Conflicts:
	drivers/net/benet/be_main.c
2011-05-11 14:26:58 -04:00
David S. Miller
d9d8da805d inet: Pass flowi to ->queue_xmit().
This allows us to acquire the exact route keying information from the
protocol, however that might be managed.

It handles all of the possibilities, from the simplest case of storing
the key in inet->cork.fl to the more complex setup SCTP has where
individual transports determine the flow.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08 15:28:28 -07:00
David S. Miller
0e73441992 ipv4: Use inet_csk_route_child_sock() in DCCP and TCP.
Operation order is now transposed, we first create the child
socket then we try to hook up the route.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08 15:28:03 -07:00
David S. Miller
2c42758cf6 dccp: Use cork flow in dccp_v4_connect()
Since this is invoked from inet_stream_connect() the socket is locked
and therefore this usage is safe.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08 13:18:53 -07:00
Dan Rosenberg
a294865978 dccp: handle invalid feature options length
A length of zero (after subtracting two for the type and len fields) for
the DCCPO_{CHANGE,CONFIRM}_{L,R} options will cause an underflow due to
the subtraction.  The subsequent code may read past the end of the
options value buffer when parsing.  I'm unsure of what the consequences
of this might be, but it's probably not good.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-06 13:05:50 -07:00
David S. Miller
f1390160dd dccp: Use flowi4->saddr in dccp_v4_connect()
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-03 20:06:41 -07:00
David S. Miller
91ab0b60a1 ipv4: Get route daddr from flow key in dccp_v4_connect().
Now that output route lookups update the flow with
destination address selection, we can fetch it from
fl4->daddr instead of rt->rt_dst

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-28 23:49:30 -07:00
Eric Dumazet
f6d8bd051c inet: add RCU protection to inet->opt
We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-28 13:16:35 -07:00
David S. Miller
2d7192d6cb ipv4: Sanitize and simplify ip_route_{connect,newports}()
These functions are used together as a unit for route resolution
during connect().  They address the chicken-and-egg problem that
exists when ports need to be allocated during connect() processing,
yet such port allocations require addressing information from the
routing code.

It's currently more heavy handed than it needs to be, and in
particular we allocate and initialize a flow object twice.

Let the callers provide the on-stack flow object.  That way we only
need to initialize it once in the ip_route_connect() call.

Later, if ip_route_newports() needs to do anything, it re-uses that
flow object as-is except for the ports which it updates before the
route re-lookup.

Also, describe why this set of facilities are needed and how it works
in a big comment.

Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
2011-04-27 13:59:04 -07:00
Eric Dumazet
b71d1d426d inet: constify ip headers and in6_addr
Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-22 11:04:14 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
David S. Miller
1958b856c1 net: Put fl6_* macros to struct flowi6 and use them again.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:55 -08:00
David S. Miller
4c9483b2fb ipv6: Convert to use flowi6 where applicable.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:54 -08:00
David S. Miller
9cce96df5b net: Put fl4_* macros to struct flowi4 and use them again.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:54 -08:00
David S. Miller
9d6ec93801 ipv4: Use flowi4 in public route lookup interfaces.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:48 -08:00
David S. Miller
6281dcc94a net: Make flowi ports AF dependent.
Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*

This will let us to create AF optimal flow instances.

It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:46 -08:00
David S. Miller
1d28f42c1b net: Put flowi_* prefix on AF independent members of struct flowi
I intend to turn struct flowi into a union of AF specific flowi
structs.  There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:44 -08:00
David S. Miller
0a0e9ae1bd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x/bnx2x.h
2011-03-03 21:27:42 -08:00
David S. Miller
b23dd4fe42 ipv4: Make output route lookup return rtable directly.
Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 14:31:35 -08:00
Gerrit Renker
720dc34bbb dccp: fix oops on Reset after close
This fixes a bug in the order of dccp_rcv_state_process() that still permitted
reception even after closing the socket. A Reset after close thus causes a NULL
pointer dereference by not preventing operations on an already torn-down socket.

 dccp_v4_do_rcv() 
	|
	| state other than OPEN
	v
 dccp_rcv_state_process()
	|
	| DCCP_PKT_RESET
	v
 dccp_rcv_reset()
	|
	v
 dccp_time_wait()

 WARNING: at net/ipv4/inet_timewait_sock.c:141 __inet_twsk_hashdance+0x48/0x128()
 Modules linked in: arc4 ecb carl9170 rt2870sta(C) mac80211 r8712u(C) crc_ccitt ah
 [<c0038850>] (unwind_backtrace+0x0/0xec) from [<c0055364>] (warn_slowpath_common)
 [<c0055364>] (warn_slowpath_common+0x4c/0x64) from [<c0055398>] (warn_slowpath_n)
 [<c0055398>] (warn_slowpath_null+0x1c/0x24) from [<c02b72d0>] (__inet_twsk_hashd)
 [<c02b72d0>] (__inet_twsk_hashdance+0x48/0x128) from [<c031caa0>] (dccp_time_wai)
 [<c031caa0>] (dccp_time_wait+0x40/0xc8) from [<c031c15c>] (dccp_rcv_state_proces)
 [<c031c15c>] (dccp_rcv_state_process+0x120/0x538) from [<c032609c>] (dccp_v4_do_)
 [<c032609c>] (dccp_v4_do_rcv+0x11c/0x14c) from [<c0286594>] (release_sock+0xac/0)
 [<c0286594>] (release_sock+0xac/0x110) from [<c031fd34>] (dccp_close+0x28c/0x380)
 [<c031fd34>] (dccp_close+0x28c/0x380) from [<c02d9a78>] (inet_release+0x64/0x70)

The fix is by testing the socket state first. Receiving a packet in Closed state
now also produces the required "No connection" Reset reply of RFC 4340, 8.3.1.

Reported-and-tested-by: Johan Hovold <jhovold@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 23:02:07 -08:00
David S. Miller
273447b352 ipv4: Kill can_sleep arg to ip_route_output_flow()
This boolean state is now available in the flow flags.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:27:04 -08:00
David S. Miller
420d44daa7 ipv4: Make final arg to ip_route_output_flow to be boolean "can_sleep"
Since that is what the current vague "flags" argument means.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:19:23 -08:00
David S. Miller
abdf7e7239 ipv4: Can final ip_route_connect() arg to boolean "can_sleep".
Since that's what the current vague "flags" thing means.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:15:24 -08:00
David S. Miller
68d0c6d34d ipv6: Consolidate route lookup sequences.
Route lookups follow a general pattern in the ipv6 code wherein
we first find the non-IPSEC route, potentially override the
flow destination address due to ipv6 options settings, and then
finally make an IPSEC search using either xfrm_lookup() or
__xfrm_lookup().

__xfrm_lookup() is used when we want to generate a blackhole route
if the key manager needs to resolve the IPSEC rules (in this case
-EREMOTE is returned and the original 'dst' is left unchanged).

Otherwise plain xfrm_lookup() is used and when asynchronous IPSEC
resolution is necessary, we simply fail the lookup completely.

All of these cases are encapsulated into two routines,
ip6_dst_lookup_flow and ip6_sk_dst_lookup_flow.  The latter of which
handles unconnected UDP datagram sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 13:19:07 -08:00
Hagen Paul Pfeifer
3b193ade59 dccp: newdp is declared/assigned but never be used
Declaration and assignment of newdp is removed. Usage of dccp_sk()
exhibit no side effects.

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-25 14:00:21 -08:00
David S. Miller
dca8b089c9 ipv4: Rearrange how ip_route_newports() gets port keys.
ip_route_newports() is the only place in the entire kernel that
cares about the port members in the routing cache entry's lookup
flow key.

Therefore the only reason we store an entire flow inside of the
struct rtentry is for this one special case.

Rewrite ip_route_newports() such that:

1) The caller passes in the original port values, so we don't need
   to use the rth->fl.fl_ip_{s,d}port values to remember them.

2) The lookup flow is constructed by hand instead of being copied
   from the routing cache entry's flow.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-24 13:38:12 -08:00
David S. Miller
442b9635c5 tcp: Increase the initial congestion window to 10.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Nandita Dukkipati <nanditad@google.com>
2011-02-02 20:48:47 -08:00
Linus Torvalds
008d23e485 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  Documentation/trace/events.txt: Remove obsolete sched_signal_send.
  writeback: fix global_dirty_limits comment runtime -> real-time
  ppc: fix comment typo singal -> signal
  drivers: fix comment typo diable -> disable.
  m68k: fix comment typo diable -> disable.
  wireless: comment typo fix diable -> disable.
  media: comment typo fix diable -> disable.
  remove doc for obsolete dynamic-printk kernel-parameter
  remove extraneous 'is' from Documentation/iostats.txt
  Fix spelling milisec -> ms in snd_ps3 module parameter description
  Fix spelling mistakes in comments
  Revert conflicting V4L changes
  i7core_edac: fix typos in comments
  mm/rmap.c: fix comment
  sound, ca0106: Fix assignment to 'channel'.
  hrtimer: fix a typo in comment
  init/Kconfig: fix typo
  anon_inodes: fix wrong function name in comment
  fix comment typos concerning "consistent"
  poll: fix a typo in comment
  ...

Fix up trivial conflicts in:
 - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
 - fs/ext4/ext4.h

Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2011-01-13 10:05:56 -08:00
Gerrit Renker
bfbb23466a dccp: make upper bound for seq_window consistent on 32/64 bit
The 'seq_window' sysctl sets the initial value for the DCCP Sequence Window,
which may range from 32..2^46-1 (RFC 4340, 7.5.2). The patch sets the upper
bound consistently to 2^32-1 on both 32 and 64 bit systems, which should be
sufficient - with a RTT of 1sec and 1-byte packets, a seq_window of 2^32-1
corresponds to a link speed of 34 Gbps.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-01-07 12:22:44 +01:00
Samuel Jero
763dadd47c dccp: fix bug in updating the GSR
Currently dccp_check_seqno allows any valid packet to update the Greatest
Sequence Number Received, even if that packet's sequence number is less than
the current GSR. This patch adds a check to make sure that the new packet's
sequence number is greater than GSR.

Signed-off-by: Samuel Jero <sj323707@ohio.edu>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-01-07 12:22:43 +01:00
Samuel Jero
2cf5be93d1 dccp: fix return value for sequence-invalid packets
Currently dccp_check_seqno returns 0 (indicating a valid packet) if the
acknowledgment number is out of bounds and the sync that RFC 4340 mandates at
this point is currently being rate-limited. This function should return -1,
indicating an invalid packet.

Signed-off-by: Samuel Jero <sj323707@ohio.edu>
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2011-01-07 12:22:43 +01:00
Jiri Kosina
4b7bd36470 Merge branch 'master' into for-next
Conflicts:
	MAINTAINERS
	arch/arm/mach-omap2/pm24xx.c
	drivers/scsi/bfa/bfa_fcpim.c

Needed to update to apply fixes for which the old branch was too
outdated.
2010-12-22 18:57:02 +01:00
Shan Wei
b7ec19af63 dccp: remove unused macros
Remove macros which have been unused since the initial implementation
(commit 7c657876b6, [DCCP]: Initial
 implementation from Tue Aug 9 20:14:34 2005 -0700).

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-10 12:49:23 +01:00
David S. Miller
fe6c791570 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
	net/llc/af_llc.c
2010-12-08 13:47:38 -08:00
Tomasz Grobelny
0491026507 dccp qpolicy: Parameter checking of cmsg qpolicy parameters
Ensure that cmsg->cmsg_type value is valid for qpolicy
that is currently in use.

Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-07 13:47:12 +01:00
Tomasz Grobelny
871a2c16c2 dccp: Policy-based packet dequeueing infrastructure
This patch adds a generic infrastructure for policy-based dequeueing of
TX packets and provides two policies:
 * a simple FIFO policy (which is the default) and
 * a priority based policy (set via socket options).
Both policies honour the tx_qlen sysctl for the maximum size of the write
queue (can be overridden via socket options).

The priority policy uses skb->priority internally to assign an u32 priority
identifier, using the same ranking as SO_PRIORITY. The skb->priority field
is set to 0 when the packet leaves DCCP. The priority is supplied as ancillary
data using cmsg(3), the patch also provides the requisite parsing routines.

Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-07 13:47:12 +01:00
Gerrit Renker
0ac7887022 dccp: fix error in updating the GAR
This fixes a bug in updating the Greatest Acknowledgment number Received (GAR):
the current implementation does not track the greatest received value -
lower values in the range AWL..AWH (RFC 4340, 7.5.1) erase higher ones.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28 11:29:27 -08:00
Gerrit Renker
f72f2f4cde dccp ccid-2: whitespace fix-up
This fixes whitespace noise introduced in commit "dccp ccid-2: Algorithm to
update buffer state", 5753fdfe8b, 14 Nov 2010.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-18 09:37:07 -08:00
Changli Gao
5811662b15 net: use the macros defined for the members of flowi
Use the macros defined for the members of flowi to clean the code up.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-17 12:27:45 -08:00
Michael Witten
c996d8b9a8 Docs/Kconfig: Update: osdl.org -> linuxfoundation.org
Some of the documentation refers to web pages under
the domain `osdl.org'. However, `osdl.org' now
redirects to `linuxfoundation.org'.

Rather than rely on redirections, this patch updates
the addresses appropriately; for the most part, only
documentation that is meant to be current has been
updated.

The patch should be pretty quick to scan and check;
each new web-page url was gotten by trying out the
original URL in a browser and then simply copying the
the redirected URL (formatting as necessary).

There is some conflict as to which one of these domain
names is preferred:

  linuxfoundation.org
  linux-foundation.org

So, I wrote:

  info@linuxfoundation.org

and got this reply:

  Message-ID: <4CE17EE6.9040807@linuxfoundation.org>
  Date: Mon, 15 Nov 2010 10:41:42 -0800
  From: David Ames <david@linuxfoundation.org>

  ...

  linuxfoundation.org is preferred. The canonical name for our web site is
  www.linuxfoundation.org. Our list site is actually
  lists.linux-foundation.org.

  Regarding email linuxfoundation.org is preferred there are a few people
  who choose to use linux-foundation.org for their own reasons.

Consequently, I used `linuxfoundation.org' for web pages and
`lists.linux-foundation.org' for mailing-list web pages and email addresses;
the only personal email address I updated from `@osdl.org' was that of
Andrew Morton, who prefers `linux-foundation.org' according `git log'.

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-15 23:50:13 +01:00
Gerrit Renker
7e87fe8430 dccp ccid-2: Separate option parsing from CCID processing
This patch replaces an almost identical replication of code: large parts
of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c.

Apart from the duplication, this caused two more problems:
 1. CCIDs should not need to be concerned with parsing header options;
 2. one can not assume that Ack Vectors appear as a contiguous area within an
    skb, it is legal to insert other options and/or padding in between. The
    current code would throw an error and stop reading in such a case.

Since Ack Vectors provide CCID-specific information, they are now processed
by the CCID directly, separating this functionality from the main DCCP code.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-11-15 07:12:01 +01:00
Gerrit Renker
52394eecec dccp ccid-2: Remove old infrastructure
This removes
 * functions for which updates have been provided in the preceding patches and
 * the @av_vec_len field - it is no longer necessary since the buffer length is
   now always computed dynamically.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-11-15 07:12:00 +01:00
Gerrit Renker
d83447f094 dccp ccid-2: Schedule Sync as out-of-band mechanism
The problem with Ack Vectors is that
  i) their length is variable and can in principle grow quite large,
 ii) it is hard to predict exactly how large they will be.

Due to the second point it seems not a good idea to reduce the MPS; in
particular when on average there is enough room for the Ack Vector and an
increase in length is momentarily due to some burst loss, after which the
Ack Vector returns to its normal/average length.

The solution taken by this patch is to subtract a minimum-expected Ack Vector
length from the MPS, and to defer any larger Ack Vectors onto a separate
Sync - but only if indeed there is no space left on the skb.

This patch provides the infrastructure to schedule Sync-packets for transporting
(urgent) out-of-band data. Its signalling is quicker than scheduling an Ack, since
it does not need to wait for new application data.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-11-15 07:12:00 +01:00