Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In DSACK case, some events are not extraordinary, such as packet
duplication generated DSACK. They can arrive easily below
snd_una when undo_marker is not set (TCP being in CA_Open),
counting such DSACKs amoung SACK discards will likely just
mislead if they occur in some scenario when there are other
problems as well. Similarly, excessively delayed packets could
cause "normal" DSACKs. Therefore, separate counters are
allocated for DSACK events.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SACK processing code has been a sort of russian roulette as no
validation of SACK blocks is previously attempted. Besides, it
is not very clear what all kinds of broken SACK blocks really
mean (e.g., one that has start and end sequence numbers
reversed). So now close the roulette once and for all.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only thing that tiny function does is rearming the RTO (if
necessary), name it accordingly.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Makes caller side more obvious, there's no need to have
a wrapper for this oneliner!
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch converts the messy macro for MASK_PFX to inline function
and expands TKEY_GET_MASK in the one place it is used.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Try this out:
     * replace macro's with inlines
     * get rid of places doing multiple evaluations of NODE_PARENT

[akpm@linux-foundation.org: rcu_dereference wants an lval]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously code had IsReno/IsFack defined as macros that were
local to tcp_input.c though sack_ok field has user elsewhere too
for the same purpose. This changes them to static inlines as
preferred according the current coding style and unifies the
access to sack_ok across multiple files. Magic bitops of sack_ok
for FACK and DSACK are also abstracted to functions with
appropriate names.

Note:
- One sack_ok = 1 remains but that's self explanary, i.e., it
  enables sack
- Couple of !IsReno cases are changed to tcp_is_sack
- There were no users for IsDSack => I dropped it
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously TCP had a transitional state during which reno
counted segments that are already below the current window into
sacked_out, which is now prevented. In addition, re-try now
the unconditional S+L skb catching.

This approach conservatively calls just remove_sack and leaves
reset_sack() calls alone. The best solution to the whole problem
would be to first calculate the new sacked_out fully (this patch
does not move reno_sack_reset calls from original sites and thus
does not implement this). However, that would require very
invasive change to fastretrans_alert (perhaps even slicing it to
two halves). Alternatively, all callers of tcp_packets_in_flight
(i.e., users that depend on sacked_out) should be postponed
until the new sacked_out has been calculated but it isn't any
simpler alternative.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This happens rather infrequently and is only possible during
FRTO. We must not allow TCP to slip to Open state because
tcp_fastretrans_alert might then not be called on it's time
when FRTO has exited. This become a problem when left_out
got removed and was replaced by just sacked_out.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_verify_left_out is useful for verifying S+L condition, so
add it back to couple of places in where the code was not
calling to tcp_sync_left_out but used own ad-hoc solution
(before the tcp_sync_left_out got removed).
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Left_out was dropped a while ago, thus leaving verifying
consistency of the "left out" as only task for the function in
question. Thus make it's name more appropriate.

In addition, it is intentionally converted to #define instead
of static inline because the location of the invariant failure
is the most important thing to have if this ever triggers. I
think it would have been helpful e.g. in this case where the
location of the failure point had to be based on some quesswork:
    http://lkml.org/lkml/2007/5/2/464
...Luckily the guesswork seems to have proved to be correct.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tp->left_out got removed but nothing came to replace it back
then (users just did addition by themselves), so add function
for users now.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is easily calculable when needed and user are not that many
after all.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need for such check in pkts_acked because the
callback is not invoked unless at least one segment got fully
ACKed (i.e., the snd_una moved past skb's end_seq) by the
cumulative ACK's snd_una advancement.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No other users exist for tcp_ecn.h. Very few things remain in
tcp.h, for most TCP ECN functions callers reside within a
single .c file and can be placed there.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In addition, added a reference about the purpose of the loop.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

F-RTO does not touch SACKED_ACKED bits at all, so there is no
need to recount them in tcp_enter_frto_loss. After removal of
the else branch, nested ifs can be combined.

This must also reset sacked_out when SACK is not in use as TCP
could have received some duplicate ACKs prior RTO. To achieve
that in a sane manner, tcp_reset_reno_sack was re-placed by the
previous patch.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Stupid error from my side. Even though now that I noticed this,
I hoped it would have been an optimization but no, the counter
hint is then incorrect. Thus clearing is necessary for now (I
still suspect though that this path is never executed).
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is guaranteed to be valid only when !tp->sacked_out. In most
cases this seqno is available in the last ACK but there is no
guarantee for that. The new fast recovery loss marking algorithm
needs this as entry point.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch provides generic Large Receive Offload (LRO) functionality
for IPv4/TCP traffic.

LRO combines received tcp packets to a single larger tcp packet and
passes them then to the network stack in order to increase performance
(throughput). The interface supports two modes: Drivers can either
pass SKBs or fragment lists to the LRO engine.
Signed-off-by: NJan-Bernd Themann <themann@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When only GSO skb was partially ACKed, no hints are reset,
therefore fastpath_cnt_hint must be tweaked too or else it can
corrupt fackets_out. The corruption to occur, one must have
non-trivial ACK/SACK sequence, so this bug is not very often
that harmful. There's a fackets_out state reset in TCP because
fackets_out is known to be inaccurate and that fixes the issue
eventually anyway.

In case there was also at least one skb that got fully ACKed,
the fastpath_skb_hint is set to NULL which causes a recount for
fastpath_cnt_hint (the old value won't be accessed anymore),
thus it can safely be decremented without additional checking.

Reported by Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon a report and initial patch by Peter Lieven.

tcp4_md5sig_key and tcp6_md5sig_key need to start with
the exact same members as tcp_md5sig_key.  Because they
are both cast to that type by tcp_v{4,6}_md5_do_lookup().

Unfortunately tcp{4,6}_md5sig_key use a u16 for the key
length instead of a u8, which is what tcp_md5sig_key
uses.  This just so happens to work by accident on
little-endian, but on big-endian it doesn't.

Instead of casting, just place tcp_md5sig_key as the first member of
the address-family specific structures, adjust the access sites, and
kill off the ugly casts.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

netlink_run_queue() doesn't handle multiple processes processing the
queue concurrently. Serialize queue processing in inet_diag to fix
a oops in netlink_rcv_skb caused by netlink_run_queue passing a
NULL for the skb.

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000054
[349587.500454]  printing eip:
[349587.500457] c03318ae
[349587.500459] *pde = 00000000
[349587.500464] Oops: 0000 [#1]
[349587.500466] PREEMPT SMP
[349587.500474] Modules linked in: w83627hf hwmon_vid i2c_isa
[349587.500483] CPU:    0
[349587.500485] EIP:    0060:[<c03318ae>]    Not tainted VLI
[349587.500487] EFLAGS: 00010246   (2.6.22.3 #1)
[349587.500499] EIP is at netlink_rcv_skb+0xa/0x7e
[349587.500506] eax: 00000000   ebx: 00000000   ecx: c148d2a0   edx: c0398819
[349587.500510] esi: 00000000   edi: c0398819   ebp: c7a21c8c   esp: c7a21c80
[349587.500517] ds: 007b   es: 007b   fs: 00d8  gs: 0033  ss: 0068
[349587.500521] Process oidentd (pid: 17943, ti=c7a20000 task=cee231c0 task.ti=c7a20000)
[349587.500527] Stack: 00000000 c7a21cac f7c8ba78 c7a21ca4 c0331962 c0398819 f7c8ba00 0000004c
[349587.500542]        f736f000 c7a21cb4 c03988e3 00000001 f7c8ba00 c7a21cc4 c03312a5 0000004c
[349587.500558]        f7c8ba00 c7a21cd4 c0330681 f7c8ba00 e4695280 c7a21d00 c03307c6 7fffffff
[349587.500578] Call Trace:
[349587.500581]  [<c010361a>] show_trace_log_lvl+0x1c/0x33
[349587.500591]  [<c01036d4>] show_stack_log_lvl+0x8d/0xaa
[349587.500595]  [<c010390e>] show_registers+0x1cb/0x321
[349587.500604]  [<c0103bff>] die+0x112/0x1e1
[349587.500607]  [<c01132d2>] do_page_fault+0x229/0x565
[349587.500618]  [<c03c8d3a>] error_code+0x72/0x78
[349587.500625]  [<c0331962>] netlink_run_queue+0x40/0x76
[349587.500632]  [<c03988e3>] inet_diag_rcv+0x1f/0x2c
[349587.500639]  [<c03312a5>] netlink_data_ready+0x57/0x59
[349587.500643]  [<c0330681>] netlink_sendskb+0x24/0x45
[349587.500651]  [<c03307c6>] netlink_unicast+0x100/0x116
[349587.500656]  [<c0330f83>] netlink_sendmsg+0x1c2/0x280
[349587.500664]  [<c02fcce9>] sock_sendmsg+0xba/0xd5
[349587.500671]  [<c02fe4d1>] sys_sendmsg+0x17b/0x1e8
[349587.500676]  [<c02fe92d>] sys_socketcall+0x230/0x24d
[349587.500684]  [<c01028d2>] syscall_call+0x7/0xb
[349587.500691]  =======================
[349587.500693] Code: f0 ff 4e 18 0f 94 c0 84 c0 0f 84 66 ff ff ff 89 f0 e8 86 e2 fc ff e9 5a ff ff ff f0 ff 40 10 eb be 55 89 e5 57 89 d7 56 89 c6 53 <8b> 50 54 83 fa 10 72 55 8b 9e 9c 00 00 00 31 c9 8b 03 83 f8 0f

Reported by Athanasius <link@miggy.org>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So I've had a deadlock reported to me.  I've found that the sequence of
events goes like this:

1) process A (modprobe) runs to remove ip_tables.ko

2) process B (iptables-restore) runs and calls setsockopt on a netfilter socket,
increasing the ip_tables socket_ops use count

3) process A acquires a file lock on the file ip_tables.ko, calls remove_module
in the kernel, which in turn executes the ip_tables module cleanup routine,
which calls nf_unregister_sockopt

4) nf_unregister_sockopt, seeing that the use count is non-zero, puts the
calling process into uninterruptible sleep, expecting the process using the
socket option code to wake it up when it exits the kernel

4) the user of the socket option code (process B) in do_ipt_get_ctl, calls
ipt_find_table_lock, which in this case calls request_module to load
ip_tables_nat.ko

5) request_module forks a copy of modprobe (process C) to load the module and
blocks until modprobe exits.

6) Process C. forked by request_module process the dependencies of
ip_tables_nat.ko, of which ip_tables.ko is one.

7) Process C attempts to lock the request module and all its dependencies, it
blocks when it attempts to lock ip_tables.ko (which was previously locked in
step 3)

Theres not really any great permanent solution to this that I can see, but I've
developed a two part solution that corrects the problem

Part 1) Modifies the nf_sockopt registration code so that, instead of using a
use counter internal to the nf_sockopt_ops structure, we instead use a pointer
to the registering modules owner to do module reference counting when nf_sockopt
calls a modules set/get routine.  This prevents the deadlock by preventing set 4
from happening.

Part 2) Enhances the modprobe utilty so that by default it preforms non-blocking
remove operations (the same way rmmod does), and add an option to explicity
request blocking operation.  So if you select blocking operation in modprobe you
can still cause the above deadlock, but only if you explicity try (and since
root can do any old stupid thing it would like....  :)  ).
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since we're now using a generic tuple decoding function in ICMP
connection tracking, ipv4_get_l4proto() might get called with a
fragmented packet from within an ICMP error. Remove the error
message we used to print when this happens.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bug: http://bugzilla.kernel.org/show_bug.cgi?id=8876

Not all ips are shown by "ip addr show" command when IPs number assigned to an
interface is more than 60-80 (in fact it depends on broadcast/label etc
presence on each address).

Steps to reproduce:
It's terribly simple to reproduce:

# for i in $(seq 1 100); do ip ad add 10.0.$i.1/24 dev eth10 ; done
# ip addr show

this will _not_ show all IPs.
Looks like the problem is in netlink/ipv4 message processing.

This is fix from bug submitter, it looks correct.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Cell phone networks do link layer retransmissions and other
things that cause unnecessary timeout retransmits.  So allow
the minimum RTO to be inflated per-route to deal with this.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

People often get tripped up by this function and think that
it does not implemented the prescribed algorithms from
RFC2414 and RFC3390, even though it does.

So add a comment to head off such misunderstandings in the
future.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix IP[V6]_ADD_MEMBERSHIP and IP[V6]_DROP_MEMBERSHIP to
return -EPROTO for connection oriented sockets.
Signed-off-by: NFlavio Leitner <fleitner@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In testing our ESP/AH offload hardware, I discovered an issue with how
AH handles mutable fields in IPv4.  RFC 4302 (AH) states the following
on the subject:

        For IPv4, the entire option is viewed as a unit; so even
        though the type and length fields within most options are immutable
        in transit, if an option is classified as mutable, the entire option
        is zeroed for ICV computation purposes.

The current implementation does not zero the type and length fields,
resulting in authentication failures when communicating with hosts
that do (i.e. FreeBSD).

I have tested record route and timestamp options (ping -R and ping -T)
on a small network involving Windows XP, FreeBSD 6.2, and Linux hosts,
with one router.  In the presence of these options, the FreeBSD and
Linux hosts (with the patch or with the hardware) can communicate.
The Windows XP host simply fails to accept these packets with or
without the patch.

I have also been trying to test source routing options (using
traceroute -g), but haven't had much luck getting this option to work
*without* AH, let alone with.
Signed-off-by: NNick Bowler <nbowler@ellipticsemi.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't drop packets shorter than "SIP/2.0", just ignore them. Keep-alives
can validly be shorter for example.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For architectures that don't have a volatile atomic_ts constructs like
while (atomic_read(&something)); might result in endless loops since a
barrier() is missing which forces the compiler to generate code that
actually reads memory contents.
Fix this in ipvs by using the IP_VS_WAIT_WHILE macro which resolves to
while (expr) { cpu_relax(); }
(why isn't this open coded btw?)
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>