Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At this point, skb->data points to skb_transport_header.
So, headroom check is wrong.

For some case:bridge(UFO is on) + eth device(UFO is off),
there is no enough headroom for IPv6 frag head.
But headroom check is always false.

This will bring about data be moved to there prior to skb->head,
when adding IPv6 frag header to skb.
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

properly record sk_rxhash in ipv6 sockets (v2)

Noticed while working on another project that flows to sockets which I had open
on a test systems weren't getting steered properly when I had RFS enabled.
Looking more closely I found that:

1) The affected sockets were all ipv6
2) They weren't getting steered because sk->sk_rxhash was never set from the
incomming skbs on that socket.

This was occuring because there are several points in the IPv4 tcp and udp code
which save the rxhash value when a new connection is established.  Those calls
to sock_rps_save_rxhash were never added to the corresponding ipv6 code paths.
This patch adds those calls.  Tested by myself to properly enable RFS
functionalty on ipv6.

Change notes:
v2:
	Filtered UDP to only arm RFS on bound sockets (Eric Dumazet)
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

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

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: NDavid S. Miller <davem@davemloft.net>

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: NDavid S. Miller <davem@davemloft.net>

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: NDavid S. Miller <davem@davemloft.net>

Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Special care is taken inside sk_port_alloc to avoid overwriting
skc_node/skc_nulls_node. We should also avoid overwriting
skc_bind_node/skc_portaddr_node.

The patch fixes the following crash:

 BUG: unable to handle kernel paging request at fffffffffffffff0
 IP: [<ffffffff812ec6dd>] udp4_lib_lookup2+0xad/0x370
 [<ffffffff812ecc22>] __udp4_lib_lookup+0x282/0x360
 [<ffffffff812ed63e>] __udp4_lib_rcv+0x31e/0x700
 [<ffffffff812bba45>] ? ip_local_deliver_finish+0x65/0x190
 [<ffffffff812bbbf8>] ? ip_local_deliver+0x88/0xa0
 [<ffffffff812eda35>] udp_rcv+0x15/0x20
 [<ffffffff812bba45>] ip_local_deliver_finish+0x65/0x190
 [<ffffffff812bbbf8>] ip_local_deliver+0x88/0xa0
 [<ffffffff812bb2cd>] ip_rcv_finish+0x32d/0x6f0
 [<ffffffff8128c14c>] ? netif_receive_skb+0x99c/0x11c0
 [<ffffffff812bb94b>] ip_rcv+0x2bb/0x350
 [<ffffffff8128c14c>] netif_receive_skb+0x99c/0x11c0
Signed-off-by: NLeonard Crestez <lcrestez@ixiacom.com>
Signed-off-by: NOctavian Purdila <opurdila@ixiacom.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb1 should be passed as parameter to sk_rcvqueues_full() here.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Followup of commit b178bb3d (net: reorder struct sock fields)

Optimize INET input path a bit further, by :

1) moving sk_refcnt close to sk_lock.

This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).

2) moving inet_daddr & inet_rcv_saddr at the beginning of sk

(same cache line than hash / family / bound_dev_if / nulls_node)

This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.

Before patch :

offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274

After patch :

offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4

compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

UDP sockets refcount is usually 2, unless an incoming frame is going to
be queued in receive or backlog queue.

Using atomic_inc_not_zero_hint() permits to reduce latency, because
processor issues less memory transactions.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add __rcu annotation to :
        (struct sock)->sk_filter

And use appropriate rcu primitives to reduce sparse warnings if
CONFIG_SPARSE_RCU_POINTER=y
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just like with IPv4, we need access to the UDP hash table to look up local
sockets, but instead of exporting the global udp_table, export a lookup
function.
Signed-off-by: NBalazs Scheidler <bazsi@balabit.hu>
Signed-off-by: NKOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

The parameters for various UDP lookup functions were non-const, even though
they could be const. TProxy has some const references and instead of
downcasting it, I added const specifiers along the path.
Signed-off-by: NBalazs Scheidler <bazsi@balabit.hu>
Signed-off-by: NKOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

commit 30fff923 introduced in linux-2.6.33 (udp: bind() optimisation)
added a secondary hash on UDP, hashed on (local addr, local port).

Problem is that following sequence :

fd = socket(...)
connect(fd, &remote, ...)

not only selects remote end point (address and port), but also sets
local address, while UDP stack stored in secondary hash table the socket
while its local address was INADDR_ANY (or ipv6 equivalent)

Sequence is :
 - autobind() : choose a random local port, insert socket in hash tables
              [while local address is INADDR_ANY]
 - connect() : set remote address and port, change local address to IP
              given by a route lookup.

When an incoming UDP frame comes, if more than 10 sockets are found in
primary hash table, we switch to secondary table, and fail to find
socket because its local address changed.

One solution to this problem is to rehash datagram socket if needed.

We add a new rehash(struct socket *) method in "struct proto", and
implement this method for UDP v4 & v6, using a common helper.

This rehashing only takes care of secondary hash table, since primary
hash (based on local port only) is not changed.
Reported-by: NKrzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Tested-by: NKrzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are more than a dozen occurrences of following code in the
IPv6 stack:

    if (opt && opt->srcrt) {
            struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
            ipv6_addr_copy(&final, &fl.fl6_dst);
            ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
            final_p = &final;
    }

Replace those with a helper. Note that the helper overrides final_p
in all cases. This is ok as final_p was previously initialized to
NULL when declared.
Signed-off-by: NArnaud Ebalard <arno@natisbad.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Correct sk_forward_alloc handling for error_queue would need to use a
backlog of frames that softirq handler could not deliver because socket
is owned by user thread. Or extend backlog processing to be able to
process normal and error packets.

Another possibility is to not use mem charge for error queue, this is
what I implemented in this patch.

Note: this reverts commit 29030374
(net: fix sk_forward_alloc corruptions), since we dont need to lock
socket anymore.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As David found out, sock_queue_err_skb() should be called with socket
lock hold, or we risk sk_forward_alloc corruption, since we use non
atomic operations to update this field.

This patch adds bh_lock_sock()/bh_unlock_sock() pair to three spots.
(BH already disabled)

1) skb_tstamp_tx() 
2) Before calling ip_icmp_error(), in __udp4_lib_err() 
3) Before calling ipv6_icmp_error(), in __udp6_lib_err()
Reported-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This new sock lock primitive was introduced to speedup some user context
socket manipulation. But it is unsafe to protect two threads, one using
regular lock_sock/release_sock, one using lock_sock_bh/unlock_sock_bh

This patch changes lock_sock_bh to be careful against 'owned' state.
If owned is found to be set, we must take the slow path.
lock_sock_bh() now returns a boolean to say if the slow path was taken,
and this boolean is used at unlock_sock_bh time to call the appropriate
unlock function.

After this change, BH are either disabled or enabled during the
lock_sock_bh/unlock_sock_bh protected section. This might be misleading,
so we rename these functions to lock_sock_fast()/unlock_sock_fast().
Reported-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Tested-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adding addresses and ports to the short packet log message,
like ipv4/udp.c does it, makes these messages a lot more useful:

[  822.182450] UDPv6: short packet: From [2001:db8:ffb4:3::1]:47839 23715/178 to [2001:db8:ffb4:3:5054:ff:feff:200]:1234

This requires us to drop logging in case pskb_may_pull() fails,
which also is consistent with ipv4/udp.c
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When queueing a skb to socket, we can immediately release its dst if
target socket do not use IP_CMSG_PKTINFO.

tcp_data_queue() can drop dst too.

This to benefit from a hot cache line and avoid the receiver, possibly
on another cpu, to dirty this cache line himself.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 95766fff ([UDP]: Add memory accounting.), 
each received packet needs one extra sock_lock()/sock_release() pair.

This added latency because of possible backlog handling. Then later,
ticket spinlocks added yet another latency source in case of DDOS.

This patch introduces lock_sock_bh() and unlock_sock_bh()
synchronization primitives, avoiding one atomic operation and backlog
processing.

skb_free_datagram_locked() uses them instead of full blown
lock_sock()/release_sock(). skb is orphaned inside locked section for
proper socket memory reclaim, and finally freed outside of it.

UDP receive path now take the socket spinlock only once.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current socket backlog limit is not enough to really stop DDOS attacks,
because user thread spend many time to process a full backlog each
round, and user might crazy spin on socket lock.

We should add backlog size and receive_queue size (aka rmem_alloc) to
pace writers, and let user run without being slow down too much.

Introduce a sk_rcvqueues_full() helper, to avoid taking socket lock in
stress situations.

Under huge stress from a multiqueue/RPS enabled NIC, a single flow udp
receiver can now process ~200.000 pps (instead of ~100 pps before the
patch) on a 8 core machine.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Finally add support to detect a local IPV6_DONTFRAG event
and return the relevant data to the user if they've enabled
IPV6_RECVPATHMTU on the socket.  The next recvmsg() will
return no data, but have an IPV6_PATHMTU as ancillary data.
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add dontfrag argument to relevant functions for
IPV6_DONTFRAG support, as well as allowing the value
to be passed-in via ancillary cmsg data.
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sparse can help us find endianness bugs, but we need to make some
cleanups to be able to more easily spot real bugs.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commits 5051ebd2 and
5051ebd2 ("ipv[46]: udp: optimize unicast RX
path") broke some programs.

	After upgrading a L2TP server to 2.6.33 it started to fail, tunnels going up an
down, after the 10th tunnel came up. My modified rp-l2tp uses a global
unconnected socket bound to (INADDR_ANY, 1701) and one connected socket per
tunnel after parameter negotiation.

	After ten sockets were open and due to mixed parameters to
udp[46]_lib_lookup2() kernel started to drop packets.
Signed-off-by: NJorge Boncompte [DTI2] <jorge@dti2.net>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

sk_add_backlog -> __sk_add_backlog
sk_add_backlog_limited -> sk_add_backlog
Signed-off-by: NZhu Yi <yi.zhu@intel.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make udp adapt to the limited socket backlog change.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "Pekka Savola (ipv6)" <pekkas@netcore.fi>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: NZhu Yi <yi.zhu@intel.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dunno, what was the idea, it wasn't used for a long time.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The variable 'copied' is used in udp_recvmsg() to emphasize that the passed
'len' is adjusted to fit the actual datagram length. But the same can be
done by adjusting 'len' directly. This patch thus removes the indirection.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__net_init/__net_exit are apparently not going away, so use them
to full extent.

In some cases __net_init was removed, because it was called from
__net_exit code.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change udp6_portaddr_hash() to use ipv6_addr_v4mapped()
inline instead of ipv6_addr_type().
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

UDP bind() can be O(N^2) in some pathological cases.

Thanks to secondary hash tables, we can make it O(N)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When skb_clone() fails, we should increment sk_drops and SNMP counters.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPV6 UDP multicast rx path is a bit complex and can hold a spinlock
for a long time.

Using a small (32 or 64 entries) stack of socket pointers can help
to perform expensive operations (skb_clone(), udp_queue_rcv_skb())
outside of the lock, in most cases.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We first locate the (local port) hash chain head
If few sockets are in this chain, we proceed with previous lookup algo.

If too many sockets are listed, we take a look at the secondary
(port, address) hash chain.

We choose the shortest chain and proceed with a RCU lookup on the elected chain.

But, if we chose (port, address) chain, and fail to find a socket on given address,
 we must try another lookup on (port, in6addr_any) chain to find sockets not bound
to a particular IP.

-> No extra cost for typical setups, where the first lookup will probabbly
be performed.

RCU lookups everywhere, we dont acquire spinlock.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>