Now network timestamps use ktime_t infrastructure, we can add a new
ioctl() SIOCGSTAMPNS command to get timestamps in 'struct timespec'.
User programs can thus access to nanosecond resolution.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
CC: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows the write queue implementation to be changed,
for example, to one which allows fast interval searching.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch eliminates some duplicate code for the verification of
receive checksums between UDP-Lite and UDP.  It does this by
introducing __skb_checksum_complete_head which is identical to
__skb_checksum_complete_head apart from the fact that it takes
a length parameter rather than computing the first skb->len bytes.

As a result UDP-Lite will be able to use hardware checksum offload
for packets which do not use partial coverage checksums.  It also
means that UDP-Lite loopback no longer does unnecessary checksum
verification.

If any NICs start support UDP-Lite this would also start working
automatically.

This patch removes the assumption that msg_flags has MSG_TRUNC clear
upon entry in recvmsg.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Nominally an autoconfigured IPv6 address is added to an interface in the
Tentative state (as per RFC 2462).  Addresses in this state remain in this
state while the Duplicate Address Detection process operates on them to
determine their uniqueness on the network.  During this period, these
tentative addresses may not be used for communication, increasing the time
before a node may be able to communicate on a network.  Using Optimistic
Duplicate Address Detection, autoconfigured addresses may be used
immediately for communication on the network, as long as certain rules are
followed to avoid conflicts with other nodes during the Duplicate Address
Detection process.
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We currently use a special structure (struct skb_timeval) and plain
'struct timeval' to store packet timestamps in sk_buffs and struct
sock.

This has some drawbacks :
- Fixed resolution of micro second.
- Waste of space on 64bit platforms where sizeof(struct timeval)=16

I suggest using ktime_t that is a nice abstraction of high resolution
time services, currently capable of nanosecond resolution.

As sizeof(ktime_t) is 8 bytes, using ktime_t in 'struct sock' permits
a 8 byte shrink of this structure on 64bit architectures. Some other
structures also benefit from this size reduction (struct ipq in
ipv4/ip_fragment.c, struct frag_queue in ipv6/reassembly.c, ...)

Once this ktime infrastructure adopted, we can more easily provide
nanosecond resolution on top of it. (ioctl SIOCGSTAMPNS and/or
SO_TIMESTAMPNS/SCM_TIMESTAMPNS)

Note : this patch includes a bug correction in
compat_sock_get_timestamp() where a "err = 0;" was missing (so this
syscall returned -ENOENT instead of 0)
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
CC: Stephen Hemminger <shemminger@linux-foundation.org>
CC: John find <linux.kernel@free.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Where appropriate, convert references to xtime.tv_sec to the
get_seconds() helper function.
Signed-off-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sk_backlog is a critical field of struct sock. (known famous words)

It is (ab)used in hot paths, in particular in release_sock(), tcp_recvmsg(),
tcp_v4_rcv(), sk_receive_skb().

It really makes sense to place it next to sk_lock, because sk_backlog is only
used after sk_lock locked (and thus memory cache line in L1 cache). This
should reduce cache misses and sk_lock acquisition time.

(In theory, we could only move the head pointer near sk_lock, and leaving tail
far away, because 'tail' is normally not so hot, but keep it simple :) )
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New sysctl tcp_frto_response is added to select amongst these
responses:
	- Rate halving based; reuses CA_CWR state (default)
	- Very conservative; used to be the only one available (=1)
	- Undo cwr; undoes ssthresh and cwnd reductions (=2)

The response with rate halving requires a new parameter to
tcp_enter_cwr because FRTO has already reduced ssthresh and
doing a second reduction there has to be prevented. In addition,
to keep things nice on 80 cols screen, a local variable was
added.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJohn Heffner <jheffner@psc.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This interpretation comes from RFC4138:
    "If the sender implements some loss recovery algorithm other
     than Reno or NewReno [FHG04], the F-RTO algorithm SHOULD
     NOT be entered when earlier fast recovery is underway."

I think the RFC means to say (especially in the light of
Appendix B) that ...recovery is underway (not just fast recovery)
or was underway when it was interrupted by an earlier (F-)RTO
that hasn't yet been resolved (snd_una has not advanced enough).
Thus, my interpretation is that whenever TCP has ever
retransmitted other than head, basic version cannot be used
because then the order assumptions which are used as FRTO basis
do not hold.

NewReno has only the head segment retransmitted at a time.
Therefore, walk up to the segment that has not been SACKed, if
that segment is not retransmitted nor anything before it, we know
for sure, that nothing after the non-SACKed segment should be
either. This assumption is valid because TCPCB_EVER_RETRANS does
not leave holes but each non-SACKed segment is rexmitted
in-order.

Check for retrans_out > 1 avoids more expensive walk through the
skb list, as we can know the result beforehand: F-RTO will not be
allowed.

SACKed skb can turn into non-SACked only in the extremely rare
case of SACK reneging, in this case we might fail to detect
retransmissions if there were them for any other than head. To
get rid of that feature, whole rexmit queue would have to be
walked (always) or FRTO should be prevented when SACK reneging
happens. Of course RTO should still trigger after reneging which
makes this issue even less likely to show up. And as long as the
response is as conservative as it's now, nothing bad happens even
then.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

The input_device pointer is not refcounted, which means the device may
disappear while packets are queued, causing a crash when ifb passes packets
with a stale skb->dev pointer to netif_rx().

Fix by storing the interface index instead and do a lookup where neccessary.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Acked-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

 	Johannes Berg discovered that kernel space was leaking to
userspace on 64 bit platform. He made a first patch to fix that. This
is an improved version of his patch.
Signed-off-by: NJean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As per RFC2461, section 6.3.6, item #2, when no routers on the
matching list are known to be reachable or probably reachable we
do round robin on those available routes so that we make sure
to probe as many of them as possible to detect when one becomes
reachable faster.

Each routing table has a rwlock protecting the tree and the linked
list of routes at each leaf.  The round robin code executes during
lookup and thus with the rwlock taken as a reader.  A small local
spinlock tries to provide protection but this does not work at all
for two reasons:

1) The round-robin list manipulation, as coded, goes like this (with
   read lock held):

	walk routes finding head and tail

	spin_lock();
	rotate list using head and tail
	spin_unlock();

   While one thread is rotating the list, another thread can
   end up with stale values of head and tail and then proceed
   to corrupt the list when it gets the lock.  This ends up causing
   the OOPS in fib6_add() later onthat many people have been hitting.

2) All the other code paths that run with the rwlock held as
   a reader do not expect the list to change on them, they
   expect it to remain completely fixed while they hold the
   lock in that way.

So, simply stated, it is impossible to implement this correctly using
a manipulation of the list without violating the rwlock locking
semantics.

Reimplement using a per-fib6_node round-robin pointer.  This way we
don't need to manipulate the list at all, and since the round-robin
pointer can only ever point to real existing entries we don't need
to perform any locking on the changing of the round-robin pointer
itself.  We only need to reset the round-robin pointer to NULL when
the entry it is pointing to is removed.

The idea is from Thomas Graf and it is very similar to how this
was implemented before the advanced router selection code when in.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

->neigh_destructor() is killed (not used), replaced with
->neigh_cleanup(), which is called when neighbor entry goes to dead
state. At this point everything is still valid: neigh->dev,
neigh->parms etc.

The device should guarantee that dead neighbor entries (neigh->dead !=
0) do not get private part initialized, otherwise nobody will cleanup
it.

I think this is enough for ipoib which is the only user of this thing.
Initialization private part of neighbor entries happens in ipib
start_xmit routine, which is not reached when device is down.  But it
would be better to add explicit test for neigh->dead in any case.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon a patch from Patrick McHardy.

The fib_rules netlink attribute policy introduced in 2.6.19 broke
userspace compatibilty. When specifying a rule with "from all"
or "to all", iproute adds a zero byte long netlink attribute,
but the policy requires all addresses to have a size equal to
sizeof(struct in_addr)/sizeof(struct in6_addr), resulting in a
validation error.

Check attribute length of FRA_SRC/FRA_DST in the generic framework
by letting the family specific rules implementation provide the
length of an address. Report an error if address length is non
zero but no address attribute is provided. Fix actual bug by
checking address length for non-zero instead of relying on
availability of attribute.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the association has been restarted, we need to reset the
transport congestion variables as well as accumulated error
counts and CACC variables.  If we do not, the association
will use the wrong values and may terminate prematurely.

This was found with a scenario where the peer restarted
the association when lksctp was in the last HB timeout for
its association.  The restart happened, but the error counts
have not been reset and when the timeout occurred, a newly
restarted association was terminated due to excessive
retransmits.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During association restart we may have stale data sitting
on the ULP queue waiting for ordering or reassembly.  This
data may cause severe problems if not cleaned up.  In particular
stale data pending ordering may cause problems with receive
window exhaustion if our peer has decided to restart the
association.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The security hooks to check permissions to remove an xfrm_policy were
actually done after the policy was removed.  Since the unlinking and
deletion are done in xfrm_policy_by* functions this moves the hooks
inside those 2 functions.  There we have all the information needed to
do the security check and it can be done before the deletion.  Since
auditing requires the result of that security check err has to be passed
back and forth from the xfrm_policy_by* functions.

This patch also fixes a bug where a deletion that failed the security
check could cause improper accounting on the xfrm_policy
(xfrm_get_policy didn't have a put on the exit path for the hold taken
by xfrm_policy_by*)

It also fixes the return code when no policy is found in
xfrm_add_pol_expire.  In old code (at least back in the 2.6.18 days) err
wasn't used before the return when no policy is found and so the
initialization would cause err to be ENOENT.  But since err has since
been used above when we don't get a policy back from the xfrm_policy_by*
function we would always return 0 instead of the intended ENOENT.  Also
fixed some white space damage in the same area.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NVenkat Yekkirala <vyekkirala@trustedcs.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts two changes:

8488df89
248f0672

A backlog value of N really does mean allow "N + 1" connections
to queue to a listening socket.  This allows one to specify
"0" as the backlog and still get 1 connection.

Noticed by Gerrit Renker and Rick Jones.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix {nf,ip}_ct_iterate_cleanup unconfirmed list handling:

- unconfirmed entries can not be killed manually, they are removed on
  confirmation or final destruction of the conntrack entry, which means
  we might iterate forever without making forward progress.

  This can happen in combination with the conntrack event cache, which
  holds a reference to the conntrack entry, which is only released when
  the packet makes it all the way through the stack or a different
  packet is handled.

- taking references to an unconfirmed entry and using it outside the
  locked section doesn't work, the list entries are not refcounted and
  another CPU might already be waiting to destroy the entry

What the code really wants to do is make sure the references of the hash
table to the selected conntrack entries are released, so they will be
destroyed once all references from skbs and the event cache are dropped.

Since unconfirmed entries haven't even entered the hash yet, simply mark
them as dying and skip confirmation based on that.

Reported and tested by Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

	when I use linux TCP socket, and find there is a bug in function
sk_acceptq_is_full().

	When a new SYN comes, TCP module first checks its validation. If valid,
send SYN,ACK to the client and add the sock to the syn hash table. Next
time if received the valid ACK for SYN,ACK from the client. server will
accept this connection and increase the sk->sk_ack_backlog -- which is
done in function tcp_check_req().We check wether acceptq is full in
function tcp_v4_syn_recv_sock().

Consider an example:

 After listen(sockfd, 1) system call, sk->sk_max_ack_backlog is set to
1. As we know, sk->sk_ack_backlog is initialized to 0. Assuming accept()
system call is not invoked now.

1. 1st connection comes. invoke sk_acceptq_is_full(). sk-
>sk_ack_backlog=0 sk->sk_max_ack_backlog=1, function return 0 accept
this connection. Increase the sk->sk_ack_backlog
2. 2nd connection comes. invoke sk_acceptq_is_full(). sk-
>sk_ack_backlog=1 sk->sk_max_ack_backlog=1, function return 0 accept
this connection. Increase the sk->sk_ack_backlog
3. 3rd connection comes. invoke sk_acceptq_is_full(). sk-
>sk_ack_backlog=2 sk->sk_max_ack_backlog=1, function return 1. Refuse
this connection.

I think it has bugs. after listen system call. sk->sk_max_ack_backlog=1
but now it can accept 2 connections.
Signed-off-by: NWei Dong <weid@np.css.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ctnetlink uses netlink_unicast from an atomic_notifier_chain
(which is called within a RCU read side critical section)
without holding further locks. netlink_unicast calls netlink_trim
with the result of gfp_any() for the gfp flags, which are passed
down to pskb_expand_header. gfp_any() only checks for softirq
context and returns GFP_KERNEL, resulting in this warning:

BUG: sleeping function called from invalid context at mm/slab.c:3032
in_atomic():1, irqs_disabled():0
no locks held by rmmod/7010.

Call Trace:
 [<ffffffff8109467f>] debug_show_held_locks+0x9/0xb
 [<ffffffff8100b0b4>] __might_sleep+0xd9/0xdb
 [<ffffffff810b5082>] __kmalloc+0x68/0x110
 [<ffffffff811ba8f2>] pskb_expand_head+0x4d/0x13b
 [<ffffffff81053147>] netlink_broadcast+0xa5/0x2e0
 [<ffffffff881cd1d7>] :nfnetlink:nfnetlink_send+0x83/0x8a
 [<ffffffff8834f6a6>] :nf_conntrack_netlink:ctnetlink_conntrack_event+0x94c/0x96a
 [<ffffffff810624d6>] notifier_call_chain+0x29/0x3e
 [<ffffffff8106251d>] atomic_notifier_call_chain+0x32/0x60
 [<ffffffff881d266d>] :nf_conntrack:destroy_conntrack+0xa5/0x1d3
 [<ffffffff881d194e>] :nf_conntrack:nf_ct_cleanup+0x8c/0x12c
 [<ffffffff881d4614>] :nf_conntrack:kill_l3proto+0x0/0x13
 [<ffffffff881d482a>] :nf_conntrack:nf_conntrack_l3proto_unregister+0x90/0x94
 [<ffffffff883551b3>] :nf_conntrack_ipv4:nf_conntrack_l3proto_ipv4_fini+0x2b/0x5d
 [<ffffffff8109d44f>] sys_delete_module+0x1b5/0x1e6
 [<ffffffff8105f245>] trace_hardirqs_on_thunk+0x35/0x37
 [<ffffffff8105911e>] system_call+0x7e/0x83

Since netlink_unicast is supposed to be callable from within RCU
read side critical sections, make gfp_any() check for in_atomic()
instead of in_softirq().

Additionally nfnetlink_send needs to use gfp_any() as well for the
call to netlink_broadcast).
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds proper prototypes for some functions in
include/net/irda/irda.h
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch changes xfrm6_tunnel register and deregister
interface to prepare for solving the conflict of device
tunnels with inter address family IPsec tunnel.
There is no device which conflicts with IPv4 over IPv6
IPsec tunnel.
Signed-off-by: NKazunori MIYAZAWA <miyazawa@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch changes xfrm4_tunnel register and deregister
interface to prepare for solving the conflict of device
tunnels with inter address family IPsec tunnel.
Signed-off-by: NKazunori MIYAZAWA <miyazawa@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No caller checks the return value, and since its usually called within the
module unload path there's nothing a module could do about errors anyway,
so BUG on invalid conditions and return void.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NF_CT_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding nf_conntrack_lock.

Add NF_CT_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
all paths not obviously only used within packet process context
(nfnetlink_conntrack).
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This last patch (but not least :) ) finally moves the next pointer at
the end of struct dst_entry. This permits to perform route cache
lookups with a minimal cost of one cache line per entry, instead of
two.

Both 32bits and 64bits platforms benefit from this new layout.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the next pointer from 'struct dn_route.u' union,
and renames u.rt_next to u.dst.dn_next.

It also moves 'struct flowi' right after 'struct dst_entry' to prepare
speedup lookups.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the next pointer from 'struct rt6_info.u' union,
and renames u.next to u.dst.rt6_next.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the rt_next pointer from 'struct rtable.u' union,
and renames u.rt_next to u.dst_rt_next.

It also moves 'struct flowi' right after 'struct dst_entry' to prepare
the gain on lookups.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces an anonymous union to nicely express the fact that all
objects inherited from struct dst_entry should access to the generic 'next'
pointer but with appropriate type verification.

This patch is a prereq before following patches.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ehash table layout is currently this one :

First half of this table is used by sockets not in TIME_WAIT state
Second half of it is used by sockets in TIME_WAIT state.

This is non optimal because of for a given hash or socket, the two chain heads 
are located in separate cache lines.
Moreover the locks of the second half are never used.

If instead of this halving, we use two list heads in inet_ehash_bucket instead 
of only one, we probably can avoid one cache miss, and reduce ram usage, 
particularly if sizeof(rwlock_t) is big (various CONFIG_DEBUG_SPINLOCK, 
CONFIG_DEBUG_LOCK_ALLOC settings). So we still halves the table but we keep 
together related chains to speedup lookups and socket state change.

In this patch I did not try to align struct inet_ehash_bucket, but a future 
patch could try to make this structure have a convenient size (a power of two 
or a multiple of L1_CACHE_SIZE).
I guess rwlock will just vanish as soon as RCU is plugged into ehash :) , so 
maybe we dont need to scratch our heads to align the bucket...

Note : In case struct inet_ehash_bucket is not a power of two, we could 
probably change alloc_large_system_hash() (in case it use __get_free_pages()) 
to free the unused space. It currently allocates a big zone, but the last 
quarter of it could be freed. Again, this should be a temporary 'problem'.

Patch tested on ipv4 tcp only, but should be OK for IPV6 and DCCP.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

From: Jennifer Hunt <jenhunt@us.ibm.com>

This patch adds AF_IUCV socket support.
Signed-off-by: NFrank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add rewritten IUCV base code to net/iucv.
Signed-off-by: NFrank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

echo "1" > /proc/sys/net/x25/x25_forward 
To turn on x25_forwarding, defaults to off
Requires the previous patch.
Signed-off-by: NAndrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>