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

In order to allow prefixed routes, we have to adjust how rt_gateway
is set and interpreted.

The new interpretation is:

1) rt_gateway == 0, destination is on-link, nexthop is iph->daddr

2) rt_gateway != 0, destination requires a nexthop gateway

Abstract the fetching of the proper nexthop value using a new
inline helper, rt_nexthop(), as suggested by Joe Perches.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NVijay Subramanian <subramanian.vijay@gmail.com>

free_nh_exceptions() should use rcu_dereference_protected(..., 1)
since its called after one RCU grace period.

Also add some const-ification in recent code.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will be used so that we can compose a full flow key.

Even though we have a route in this context, we need more.  In the
future the routes will be without destination address, source address,
etc. keying.  One ipv4 route will cover entire subnets, etc.

In this environment we have to have a way to possess persistent storage
for redirects and PMTU information.  This persistent storage will exist
in the FIB tables, and that's why we'll need to be able to rebuild a
full lookup flow key here.  Using that flow key will do a fib_lookup()
and create/update the persistent entry.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This abstracts away the call to dst_ops->update_pmtu() so that we can
transparently handle the fact that, in the future, the dst itself can
be invalidated by the PMTU update (when we have non-host routes cached
in sockets).

So we try to rebuild the socket cached route after the method
invocation if necessary.

This isn't used by SCTP because it needs to cache dsts per-transport,
and thus will need it's own local version of this helper.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No longer needed.  TCP writes metrics, but now in it's own special
cache that does not dirty the route metrics.  Therefore there is no
longer any reason to pre-cow metrics in this way.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't cache output dst for syncookies, as this adds pressure on IP route
cache and rcu subsystem for no gain.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Another problem on SYNFLOOD/DDOS attack is the inetpeer cache getting
larger and larger, using lots of memory and cpu time.

tcp_v4_send_synack()
->inet_csk_route_req()
 ->ip_route_output_flow()
  ->rt_set_nexthop()
   ->rt_init_metrics()
    ->inet_getpeer( create = true)

This is a side effect of commit a4daad6b (net: Pre-COW metrics for
TCP) added in 2.6.39

Possible solution :

Instruct inet_csk_route_req() to remove FLOWI_FLAG_PRECOW_METRICS

Before patch :

# grep peer /proc/slabinfo
inet_peer_cache   4175430 4175430    192   42    2 : tunables    0    0    0 : slabdata  99415  99415      0

Samples: 41K of event 'cycles', Event count (approx.): 30716565122
+  20,24%      ksoftirqd/0  [kernel.kallsyms]           [k] inet_getpeer
+   8,19%      ksoftirqd/0  [kernel.kallsyms]           [k] peer_avl_rebalance.isra.1
+   4,81%      ksoftirqd/0  [kernel.kallsyms]           [k] sha_transform
+   3,64%      ksoftirqd/0  [kernel.kallsyms]           [k] fib_table_lookup
+   2,36%      ksoftirqd/0  [ixgbe]                     [k] ixgbe_poll
+   2,16%      ksoftirqd/0  [kernel.kallsyms]           [k] __ip_route_output_key
+   2,11%      ksoftirqd/0  [kernel.kallsyms]           [k] kernel_map_pages
+   2,11%      ksoftirqd/0  [kernel.kallsyms]           [k] ip_route_input_common
+   2,01%      ksoftirqd/0  [kernel.kallsyms]           [k] __inet_lookup_established
+   1,83%      ksoftirqd/0  [kernel.kallsyms]           [k] md5_transform
+   1,75%      ksoftirqd/0  [kernel.kallsyms]           [k] check_leaf.isra.9
+   1,49%      ksoftirqd/0  [kernel.kallsyms]           [k] ipt_do_table
+   1,46%      ksoftirqd/0  [kernel.kallsyms]           [k] hrtimer_interrupt
+   1,45%      ksoftirqd/0  [kernel.kallsyms]           [k] kmem_cache_alloc
+   1,29%      ksoftirqd/0  [kernel.kallsyms]           [k] inet_csk_search_req
+   1,29%      ksoftirqd/0  [kernel.kallsyms]           [k] __netif_receive_skb
+   1,16%      ksoftirqd/0  [kernel.kallsyms]           [k] copy_user_generic_string
+   1,15%      ksoftirqd/0  [kernel.kallsyms]           [k] kmem_cache_free
+   1,02%      ksoftirqd/0  [kernel.kallsyms]           [k] tcp_make_synack
+   0,93%      ksoftirqd/0  [kernel.kallsyms]           [k] _raw_spin_lock_bh
+   0,87%      ksoftirqd/0  [kernel.kallsyms]           [k] __call_rcu
+   0,84%      ksoftirqd/0  [kernel.kallsyms]           [k] rt_garbage_collect
+   0,84%      ksoftirqd/0  [kernel.kallsyms]           [k] fib_rules_lookup
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Name them in a "backward compatible" manner, i.e. reuse or not
are still 1 and 0 respectively. The reuse value of 2 means that
the socket with it will forcibly reuse everyone else's port.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We must try harder to get unique (addr, port) pairs when
doing port autoselection for sockets with SO_REUSEADDR
option set.

We achieve this by adding a relaxation parameter to
inet_csk_bind_conflict. When 'relax' parameter is off
we return a conflict whenever the current searched
pair (addr, port) is not unique.

This tries to address the problems reported in patch:
	8d238b25
	Revert "tcp: bind() fix when many ports are bound"

Tests where ran for creating and binding(0) many sockets
on 100 IPs. The results are, on average:

	* 60000 sockets, 600 ports / IP:
		* 0.210 s, 620 (IP, port) duplicates without patch
		* 0.219 s, no duplicates with patch
	* 100000 sockets, 1000 ports / IP:
		* 0.371 s, 1720 duplicates without patch
		* 0.373 s, no duplicates with patch
	* 200000 sockets, 2000 ports / IP:
		* 0.766 s, 6900 duplicates without patch
		* 0.768 s, no duplicates with patch
	* 500000 sockets, 5000 ports / IP:
		* 2.227 s, 41500 duplicates without patch
		* 2.284 s, no duplicates with patch
Signed-off-by: NAlex Copot <alex.mihai.c@gmail.com>
Signed-off-by: NDaniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two struct request_sock_ops providers, tcp and dccp.

inet_csk_reqsk_queue_prune() can avoid testing syn_ack_timeout being
NULL if we make it non NULL like syn_ack_timeout
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Updates some comments to track RFC6298
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: H.K. Jerry Chu <hkchu@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Port autoselection finds a port and then drop the lock,
then right after that, gets the hash bucket again and lock it.

Fix it to go direct.
Signed-off-by: NFlavio Leitner <fbl@redhat.com>
Signed-off-by: NMarcelo Ricardo Leitner <mleitner@redhat.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current code checks for conflicts when the application
requests a specific port.  If there is no conflict, then
the request is granted.

On the other hand, the port autoselection done by the kernel
fails when all ports are bound even when there is a port
with no conflict available.

The fix changes port autoselection to check if there is a
conflict and use it if not.
Signed-off-by: NFlavio Leitner <fbl@redhat.com>
Signed-off-by: NMarcelo Ricardo Leitner <mleitner@redhat.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make clear that sk_clone() and inet_csk_clone() return a locked socket.

Add _lock() prefix and kerneldoc.
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All static seqlock should be initialized with the lockdep friendly
__SEQLOCK_UNLOCKED() macro.

Remove legacy SEQLOCK_UNLOCKED() macro.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/%3C1306238888.3026.31.camel%40edumazet-laptop%3ESigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This way the caller can get at the fully resolved fl4->{daddr,saddr}
etc.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is just like inet_csk_route_req() except that it operates after
we've created the new child socket.

In this way we can use the new socket's cork flow for proper route
key storage.

This will be used by DCCP and TCP child socket creation handling.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

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: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit c191a836.

It causes known regressions for programs that expect to be able to use
SO_REUSEADDR to shutdown a socket, then successfully rebind another
socket to the same ID.

Programs such as haproxy and amavisd expect this to work.

This should fix kernel bugzilla 32832.
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>

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>

Instead of on the stack.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This boolean state is now available in the flow flags.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since that is what the current vague "flags" argument means.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

inet_csk_bind_conflict() logic currently disallows a bind() if
it finds a friend socket (a socket bound on same address/port)
satisfying a set of conditions :

1) Current (to be bound) socket doesnt have sk_reuse set
OR
2) other socket doesnt have sk_reuse set
OR
3) other socket is in LISTEN state

We should add the CLOSE state in the 3) condition, in order to avoid two
REUSEADDR sockets in CLOSE state with same local address/port, since
this can deny further operations.

Note : a prior patch tried to address the problem in a different (and
buggy) way. (commit fda48a0d tcp: bind() fix when many ports
are bound).
Reported-by: NGaspar Chilingarov <gasparch@gmail.com>
Reported-by: NDaniel Baluta <daniel.baluta@gmail.com>
Tested-by: NDaniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.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>

Use the macros defined for the members of flowi to clean the code up.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

(Dropped the infiniband part, because Tetsuo modified the related code,
I will send a separate patch for it once this is accepted.)

This patch introduces /proc/sys/net/ipv4/ip_local_reserved_ports which
allows users to reserve ports for third-party applications.

The reserved ports will not be used by automatic port assignments
(e.g. when calling connect() or bind() with port number 0). Explicit
port allocation behavior is unchanged.
Signed-off-by: NOctavian Purdila <opurdila@ixiacom.com>
Signed-off-by: NWANG Cong <amwang@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts two commits:

fda48a0d
tcp: bind() fix when many ports are bound

and a follow-on fix for it:

6443bb1f
ipv6: Fix inet6_csk_bind_conflict()

It causes problems with binding listening sockets when time-wait
sockets from a previous instance still are alive.

It's too late to keep fiddling with this so late in the -rc
series, and we'll deal with it in net-next-2.6 instead.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Port autoselection done by kernel only works when number of bound
sockets is under a threshold (typically 30000).

When this threshold is over, we must check if there is a conflict before
exiting first loop in inet_csk_get_port()

Change inet_csk_bind_conflict() to forbid two reuse-enabled sockets to
bind on same (address,port) tuple (with a non ANY address)

Same change for inet6_csk_bind_conflict()
Reported-by: NGaspar Chilingarov <gasparch@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>