Commit Graph

433 Commits

Author SHA1 Message Date
Harald Welte
2cc7d57309 [NETFILTER]: Move reroute-after-queue code up to the nf_queue layer.
The rerouting functionality is required by the core, therefore it has
to be implemented by the core and not in individual queue handlers.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:36:19 -07:00
Harald Welte
4fdb3bb723 [NETLINK]: Add properly module refcounting for kernel netlink sockets.
- Remove bogus code for compiling netlink as module
- Add module refcounting support for modules implementing a netlink
  protocol
- Add support for autoloading modules that implement a netlink protocol
  as soon as someone opens a socket for that protocol

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:35:08 -07:00
Harald Welte
020b4c12db [NETFILTER]: Move ipv4 specific code from net/core/netfilter.c to net/ipv4/netfilter.c
Netfilter cleanup
- Move ipv4 code from net/core/netfilter.c to net/ipv4/netfilter.c
- Move ipv6 netfilter code from net/ipv6/ip6_output.c to net/ipv6/netfilter.c

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:35:01 -07:00
Harald Welte
089af26c70 [NETFILTER]: Rename skb_ip_make_writable() to skb_make_writable()
There is nothing IPv4-specific in it.  In fact, it was already used by
IPv6, too...  Upcoming nfnetlink_queue code will use it for any kind
of packet.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:34:40 -07:00
Patrick McHardy
373ac73595 [NETFILTER]: C99 initizalizers for NAT protocols
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:33:34 -07:00
David S. Miller
86e65da9c1 [NET]: Remove explicit initializations of skb->input_dev
Instead, set it in one place, namely the beginning of
netif_receive_skb().

Based upon suggestions from Jamal Hadi Salim.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:33:26 -07:00
Adrian Bunk
0742fd53a3 [IPV4]: possible cleanups
This patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 the following unused global function:
  - xfrm4_state.c: xfrm4_state_fini
- remove the following unneeded EXPORT_SYMBOL's:
  - ip_output.c: ip_finish_output
  - ip_output.c: sysctl_ip_default_ttl
  - fib_frontend.c: ip_dev_find
  - inetpeer.c: inet_peer_idlock
  - ip_options.c: ip_options_compile
  - ip_options.c: ip_options_undo
  - net/core/request_sock.c: sysctl_max_syn_backlog

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:33:20 -07:00
David S. Miller
f2ccd8fa06 [NET]: Kill skb->real_dev
Bonding just wants the device before the skb_bond()
decapsulation occurs, so simply pass that original
device into packet_type->func() as an argument.

It remains to be seen whether we can use this same
exact thing to get rid of skb->input_dev as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:32:25 -07:00
Arnaldo Carvalho de Melo
83e3609eba [REQSK]: Move the syn_table destroy from tcp_listen_stop to reqsk_queue_destroy
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:32:11 -07:00
Harald Welte
080774a243 [NETFILTER]: Add ctnetlink subsystem
Add ctnetlink subsystem for userspace-access to ip_conntrack table.
This allows reading and updating of existing entries, as well as
creating new ones (and new expect's) via nfnetlink.

Please note the 'strange' byte order: nfattr (tag+length) are in host
byte order, while the payload is always guaranteed to be in network
byte order.  This allows a simple userspace process to encapsulate netlink
messages into arch-independent udp packets by just processing/swapping the
headers and not knowing anything about the actual payload.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:49 -07:00
Stephen Hemminger
6f1cf16582 [NET]: Remove HIPPI private from skbuff.h
This removes the private element from skbuff, that is only used by
HIPPI. Instead it uses skb->cb[] to hold the additional data that is
needed in the output path from hard_header to device driver.

PS: The only qdisc that might potentially corrupt this cb[] is if
netem was used over HIPPI. I will take care of that by fixing netem
to use skb->stamp. I don't expect many users of netem over HIPPI

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:42 -07:00
Patrick McHardy
b0573dea1f [NET]: Introduce SO_{SND,RCV}BUFFORCE socket options
Allows overriding of sysctl_{wmem,rmrm}_max

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:35 -07:00
Harald Welte
f9e815b376 [NETFITLER]: Add nfnetlink layer.
Introduce "nfnetlink" (netfilter netlink) layer.  This layer is used as
transport layer for all userspace communication of the new upcoming
netfilter subsystems, such as ctnetlink, nfnetlink_queue and some day even
the mythical pkttables ;)

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:29 -07:00
Harald Welte
ac3247baf8 [NETFILTER]: connection tracking event notifiers
This adds a notifier chain based event mechanism for ip_conntrack state
changes.  As opposed to the previous implementations in patch-o-matic, we
do no longer need a field in the skb to achieve this.

Thanks to the valuable input from Patrick McHardy and Rusty on the idea
of a per_cpu implementation.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:24 -07:00
Patrick McHardy
abc3bc5804 [NET]: Kill skb->tc_classid
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:18 -07:00
David S. Miller
8728b834b2 [NET]: Kill skb->list
Remove the "list" member of struct sk_buff, as it is entirely
redundant.  All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.

Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
2005-08-29 15:31:14 -07:00
Harald Welte
6869c4d8e0 [NETFILTER]: reduce netfilter sk_buff enlargement
As discussed at netconf'05, we're trying to save every bit in sk_buff.
The patch below makes sk_buff 8 bytes smaller.  I did some basic
testing on my notebook and it seems to work.

The only real in-tree user of nfcache was IPVS, who only needs a
single bit.  Unfortunately I couldn't find some other free bit in
sk_buff to stuff that bit into, so I introduced a separate field for
them.  Maybe the IPVS guys can resolve that to further save space.

Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
alike are only 6 values defined), but unfortunately the bluetooth code
overloads pkt_type :(

The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just
came up with a way how to do it without any skb fields, so it's safe
to remove it.

- remove all never-implemented 'nfcache' code
- don't have ipvs code abuse 'nfcache' field. currently get's their own
  compile-conditional skb->ipvs_property field.  IPVS maintainers can
  decide to move this bit elswhere, but nfcache needs to die.
- remove skb->nfcache field to save 4 bytes
- move skb->nfctinfo into three unused bits to save further 4 bytes

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:04 -07:00
Harald Welte
bf3a46aa9b [NETFILTER]: convert nfmark and conntrack mark to 32bit
As discussed at netconf'05, we convert nfmark and conntrack-mark to be
32bits even on 64bit architectures.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:29:31 -07:00
Patrick McHardy
06c7427021 [FIB_TRIE]: Don't ignore negative results from fib_semantic_match
When a semantic match occurs either success, not found or an error
(for matching unreachable routes/blackholes) is returned. fib_trie
ignores the errors and looks for a different matching route. Treat
results other than "no match" as success and end lookup.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 22:06:09 -07:00
David S. Miller
c1cc168442 [ROSE]: Fix typo in rose_route_frame() locking fix.
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 14:55:32 -07:00
David S. Miller
dc16aaf29d [ROSE]: Fix missing unlocks in rose_route_frame()
Noticed by Coverity checker.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:50:09 -07:00
David S. Miller
d5d283751e [TCP]: Document non-trivial locking path in tcp_v{4,6}_get_port().
This trips up a lot of folks reading this code.
Put an unlikely() around the port-exhaustion test
for good measure.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:49:54 -07:00
David S. Miller
89ebd197eb [TCP]: Unconditionally clear TCP_NAGLE_PUSH in skb_entail().
Intention of this bit is to force pushing of the existing
send queue when TCP_CORK or TCP_NODELAY state changes via
setsockopt().

But it's easy to create a situation where the bit never
clears.  For example, if the send queue starts empty:

1) set TCP_NODELAY
2) clear TCP_NODELAY
3) set TCP_CORK
4) do small write()

The current code will leave TCP_NAGLE_PUSH set after that
sequence.  Unconditionally clearing the bit when new data
is added via skb_entail() solves the problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:13:06 -07:00
Thomas Graf
0fbbeb1ba4 [PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()
qdisc_create_dflt() is missing to destroy the newly allocated
default qdisc if the initialization fails resulting in leaks
of all kinds. The only caller in mainline which may trigger
this bug is sch_tbf.c in tbf_create_dflt_qdisc().

Note: qdisc_create_dflt() doesn't fulfill the official locking
      requirements of qdisc_destroy() but since the qdisc could
      never be seen by the outside world this doesn't matter
      and it can stay as-is until the locking of pkt_sched
      is cleaned up.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:12:44 -07:00
Vlad Yasevich
d2287f8441 [SCTP]: Add SENTINEL to SCTP MIB stats
Add SNMP_MIB_SENTINEL to the definition of the sctp_snmp_list so that
the output routine in proc correctly terminates.  This was causing some
problems running on ia64 systems.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:12:04 -07:00
Ralf Baechle
01d7dd0e9f [AX25]: UID fixes
o Brown paperbag bug - ax25_findbyuid() was always returning a NULL pointer
   as the result.  Breaks ROSE completly and AX.25 if UID policy set to deny.

 o While the list structure of AX.25's UID to callsign mapping table was
   properly protected by a spinlock, it's elements were not refcounted
   resulting in a race between removal and usage of an element.

Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:11:45 -07:00
Ralf Baechle
53b924b31f [NET]: Fix socket bitop damage
The socket flag cleanups that went into 2.6.12-rc1 are basically oring
the flags of an old socket into the socket just being created.
Unfortunately that one was just initialized by sock_init_data(), so already
has SOCK_ZAPPED set.  As the result zapped sockets are created and all
incoming connection will fail due to this bug which again was carefully
replicated to at least AX.25, NET/ROM or ROSE.

In order to keep the abstraction alive I've introduced sock_copy_flags()
to copy the socket flags from one sockets to another and used that
instead of the bitwise copy thing.  Anyway, the idea here has probably
been to copy all flags, so sock_copy_flags() should be the right thing.
With this the ham radio protocols are usable again, so I hope this will
make it into 2.6.13.

Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:11:30 -07:00
Patrick McHardy
66a79a19a7 [NETFILTER]: Fix HW checksum handling in ip_queue/ip6_queue
The checksum needs to be filled in on output, after mangling a packet
ip_summed needs to be reset.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:10:35 -07:00
Dave Johnson
1344a41637 [IPV4]: Fix negative timer loop with lots of ipv4 peers.
From: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>

Found this bug while doing some scaling testing that created 500K inet
peers.

peer_check_expire() in net/ipv4/inetpeer.c isn't using inet_peer_gc_mintime
correctly and will end up creating an expire timer with less than the
minimum duration, and even zero/negative if enough active peers are
present.

If >65K peers, the timer will be less than inet_peer_gc_mintime, and with
>70K peers, the timer duration will reach zero and go negative.

The timer handler will continue to schedule another zero/negative timer in
a loop until peers can be aged.  This can continue for at least a few
minutes or even longer if the peers remain active due to arriving packets
while the loop is occurring.

Bug is present in both 2.4 and 2.6.  Same patch will apply to both just
fine.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:10:15 -07:00
Herbert Xu
c3a20692ca [RPC]: Kill bogus kmap in krb5
While I was going through the crypto users recently, I noticed this
bogus kmap in sunrpc.  It's totally unnecessary since the crypto
layer will do its own kmap before touching the data.  Besides, the
kmap is throwing the return value away.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:09:53 -07:00
Dmitry Yusupov
14869c3886 [TCP]: Do TSO deferral even if tail SKB can go out now.
If the tail SKB fits into the window, it is still
benefitical to defer until the goal percentage of
the window is available.  This give the application
time to feed more data into the send queue and thus
results in larger TSO frames going out.

Patch from Dmitry Yusupov <dima@neterion.com>.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-23 10:09:27 -07:00
Patrick McHardy
7e71af49d4 [NETFILTER]: Fix HW checksum handling in TCPMSS target
Most importantly, remove bogus BUG() in receive path.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-20 17:40:41 -07:00
Patrick McHardy
f93592ff4f [NETFILTER]: Fix HW checksum handling in ECN target
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-20 17:39:15 -07:00
Patrick McHardy
fd841326d7 [NETFILTER]: Fix ECN target TCP marking
An incorrect check made it bail out before doing anything.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-20 17:38:40 -07:00
Herbert Xu
6fc8b9e7c6 [IPCOMP]: Fix false smp_processor_id warning
This patch fixes a false-positive from debug_smp_processor_id().

The processor ID is only used to look up crypto_tfm objects.
Any processor ID is acceptable here as long as it is one that is
iterated on by for_each_cpu().

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-18 14:36:59 -07:00
Patrick McHardy
cb94c62c25 [IPV4]: Fix DST leak in icmp_push_reply()
Based upon a bug report and initial patch by
Ollie Wild.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-18 14:05:44 -07:00
Jay Vosburgh
001dd250c1 [TOKENRING]: Use interrupt-safe locking with rif_lock.
Change operations on rif_lock from spin_{un}lock_bh to
spin_{un}lock_irq{save,restore} equivalents.  Some of the
rif_lock critical sections are called from interrupt context via
tr_type_trans->tr_add_rif_info.  The TR NIC drivers call tr_type_trans
from their packet receive handlers.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-18 14:04:51 -07:00
Paul E. McKenney
1f07247de5 [DECNET]: Fix RCU race condition in dn_neigh_construct().
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-17 12:05:27 -07:00
Patrick McHardy
bfd272b1ca [IPV6]: Fix SKB leak in ip6_input_finish()
Changing it to how ip_input handles should fix it.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-17 12:04:22 -07:00
Herbert Xu
35d59efd10 [TCP]: Fix bug #5070: kernel BUG at net/ipv4/tcp_output.c:864
1) We send out a normal sized packet with TSO on to start off.
2) ICMP is received indicating a smaller MTU.
3) We send the current sk_send_head which needs to be fragmented
since it was created before the ICMP event.  The first fragment
is then sent out.

At this point the remaining fragment is allocated by tcp_fragment.
However, its size is padded to fit the L1 cache-line size therefore
creating tail-room up to 124 bytes long.

This fragment will also be sitting at sk_send_head.

4) tcp_sendmsg is called again and it stores data in the tail-room of
of the fragment.
5) tcp_push_one is called by tcp_sendmsg which then calls tso_fragment
since the packet as a whole exceeds the MTU.

At this point we have a packet that has data in the head area being
fed to tso_fragment which bombs out.

My take on this is that we shouldn't ever call tcp_fragment on a TSO
socket for a packet that is yet to be transmitted since this creates
a packet on sk_send_head that cannot be extended.

So here is a patch to change it so that tso_fragment is always used
in this case.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-17 12:03:59 -07:00
Patrick McHardy
97077c4a98 [IPV6]: Fix raw socket hardware checksum failures
When packets hit raw sockets the csum update isn't done yet, do it manually.
Packets can also reach rawv6_rcv on the output path through
ip6_call_ra_chain, in this case skb->ip_summed is CHECKSUM_NONE and this
codepath isn't executed.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-17 12:03:32 -07:00
Trond Myklebust
58fcb8df0b [PATCH] NFS: Ensure ACL xdr code doesn't overflow.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-16 08:52:11 -07:00
Matt Mackall
d7b9dfc8ea [NETPOLL]: remove unused variable
Remove unused variable

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:28:05 -07:00
Matt Mackall
53fb95d3c1 [NETPOLL]: fix initialization/NAPI race
This fixes a race during initialization with the NAPI softirq
processing by using an RCU approach.

This race was discovered when refill_skbs() was added to
the setup code.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:27:43 -07:00
Ingo Molnar
2652076507 [NETPOLL]: pre-fill skb pool
we could do one thing (see the patch below): i think it would be useful 
to fill up the netlogging skb queue straight at initialization time.  
Especially if netpoll is used for dumping alone, the system might not be 
in a situation to fill up the queue at the point of crash, so better be 
a bit more prepared and keep the pipeline filled.

[ I've modified this to be called earlier - mpm ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:26:42 -07:00
Matt Mackall
0db1d6fc1e [NETPOLL]: add retry timeout
Add limited retry logic to netpoll_send_skb

Each time we attempt to send, decrement our per-device retry counter.
On every successful send, we reset the counter. 

We delay 50us between attempts with up to 20000 retries for a total of
1 second. After we've exhausted our retries, subsequent failed
attempts will try only once until reset by success.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:25:54 -07:00
Matt Mackall
f0d3459d07 [NETPOLL]: netpoll_send_skb simplify
Minor netpoll_send_skb restructuring

Restructure to avoid confusing goto and move some bits out of the
retry loop.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:25:11 -07:00
Jeff Moyer
a636e13579 [NETPOLL]: deadlock bugfix
This fixes an obvious deadlock in the netpoll code.  netpoll_rx takes the
npinfo->rx_lock.  netpoll_rx is also the only caller of arp_reply (through
__netpoll_rx).  As such, it is not necessary to take this lock.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:23:50 -07:00
Jeff Moyer
11513128bb [NETPOLL]: rx_flags bugfix
Initialize npinfo->rx_flags.  The way it stands now, this will have random
garbage, and so will incur a locking penalty even when an rx_hook isn't
registered and we are not active in the netpoll polling code.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-11 19:23:04 -07:00
Herbert Xu
b5da623ae9 [TCP]: Adjust {p,f}ackets_out correctly in tcp_retransmit_skb()
Well I've only found one potential cause for the assertion
failure in tcp_mark_head_lost.  First of all, this can only
occur if cnt > 1 since tp->packets_out is never zero here.
If it did hit zero we'd have much bigger problems.

So cnt is equal to fackets_out - reordering.  Normally
fackets_out is less than packets_out.  The only reason
I've found that might cause fackets_out to exceed packets_out
is if tcp_fragment is called from tcp_retransmit_skb with a
TSO skb and the current MSS is greater than the MSS stored
in the TSO skb.  This might occur as the result of an expiring
dst entry.

In that case, packets_out may decrease (line 1380-1381 in
tcp_output.c).  However, fackets_out is unchanged which means
that it may in fact exceed packets_out.

Previously tcp_retrans_try_collapse was the only place where
packets_out can go down and it takes care of this by decrementing
fackets_out.

So we should make sure that fackets_out is reduced by an appropriate
amount here as well.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-10 18:32:36 -07:00