Commit Graph

4926 Commits

Author SHA1 Message Date
Julian Anastasov
0cc535a299 ipv4: fix address selection in fib_compute_spec_dst
ip_options_compile can be called for forwarded packets,
make sure the specific-destionation address is a local one as
specified in RFC 1812, 4.2.2.2 Addresses in Options

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19 08:30:49 -07:00
Julian Anastasov
6255e5ead0 ipv4: optimize fib_compute_spec_dst call in ip_options_echo
Move fib_compute_spec_dst at the only place where it
is needed.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19 08:30:49 -07:00
Eric Dumazet
ddbe503203 ipv6: add ipv6_addr_hash() helper
Introduce ipv6_addr_hash() helper doing a XOR on all bits
of an IPv6 address, with an optimized x86_64 version.

Use it in flow dissector, as suggested by Andrew McGregor,
to reduce hash collision probabilities in fq_codel (and other
users of flow dissector)

Use it in ip6_tunnel.c and use more bit shuffling, as suggested
by David Laight, as existing hash was ignoring most of them.

Use it in sunrpc and use more bit shuffling, using hash_32().

Use it in net/ipv6/addrconf.c, using hash_32() as well.

As a cleanup, use it in net/ipv4/tcp_metrics.c

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew McGregor <andrewmcgr@gmail.com>
Cc: Dave Taht <dave.taht@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18 11:28:46 -07:00
Saurabh
1181412c1a net/ipv4: VTI support new module for ip_vti.
New VTI tunnel kernel module, Kconfig and Makefile changes.

Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com>
Reviewed-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18 09:36:12 -07:00
Saurabh
eb8637cd4a net/ipv4: VTI support rx-path hook in xfrm4_mode_tunnel.
Incorporated David and Steffen's comments.
Add hook for rx-path xfmr4_mode_tunnel for VTI tunnel module.

Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com>
Reviewed-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18 09:36:12 -07:00
Eric Dumazet
e371589917 tcp: refine SYN handling in tcp_validate_incoming
Followup of commit 0c24604b68 (tcp: implement RFC 5961 4.2)

As reported by Vijay Subramanian, we should send a challenge ACK
instead of a dup ack if a SYN flag is set on a packet received out of
window.

This permits the ratelimiting to work as intended, and to increase
correct SNMP counters.

Suggested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18 09:31:25 -07:00
Paul Moore
89d7ae34cd cipso: don't follow a NULL pointer when setsockopt() is called
As reported by Alan Cox, and verified by Lin Ming, when a user
attempts to add a CIPSO option to a socket using the CIPSO_V4_TAG_LOCAL
tag the kernel dies a terrible death when it attempts to follow a NULL
pointer (the skb argument to cipso_v4_validate() is NULL when called via
the setsockopt() syscall).

This patch fixes this by first checking to ensure that the skb is
non-NULL before using it to find the incoming network interface.  In
the unlikely case where the skb is NULL and the user attempts to add
a CIPSO option with the _TAG_LOCAL tag we return an error as this is
not something we want to allow.

A simple reproducer, kindly supplied by Lin Ming, although you must
have the CIPSO DOI #3 configure on the system first or you will be
caught early in cipso_v4_validate():

	#include <sys/types.h>
	#include <sys/socket.h>
	#include <linux/ip.h>
	#include <linux/in.h>
	#include <string.h>

	struct local_tag {
		char type;
		char length;
		char info[4];
	};

	struct cipso {
		char type;
		char length;
		char doi[4];
		struct local_tag local;
	};

	int main(int argc, char **argv)
	{
		int sockfd;
		struct cipso cipso = {
			.type = IPOPT_CIPSO,
			.length = sizeof(struct cipso),
			.local = {
				.type = 128,
				.length = sizeof(struct local_tag),
			},
		};

		memset(cipso.doi, 0, 4);
		cipso.doi[3] = 3;

		sockfd = socket(AF_INET, SOCK_DGRAM, 0);
		#define SOL_IP 0
		setsockopt(sockfd, SOL_IP, IP_OPTIONS,
			&cipso, sizeof(struct cipso));

		return 0;
	}

CC: Lin Ming <mlin@ss.pku.edu.cn>
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18 09:01:12 -07:00
Eric Dumazet
5abf7f7e0f ipv4: fix rcu splat
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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 13:47:33 -07:00
David S. Miller
d3a25c980f ipv4: Fix nexthop exception hash computation.
Need to mask it with (FNHE_HASH_SIZE - 1).

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 13:23:08 -07:00
David S. Miller
a6ff1a2f1e Merge branch 'nexthop_exceptions'
These patches implement the final mechanism necessary to really allow
us to go without the route cache in ipv4.

We need a place to have long-term storage of PMTU/redirect information
which is independent of the routes themselves, yet does not get us
back into a situation where we have to write to metrics or anything
like that.

For this we use an "next-hop exception" table in the FIB nexthops.

The one thing I desperately want to avoid is having to create clone
routes in the FIB trie for this purpose, because that is very
expensive.   However, I'm willing to entertain such an idea later
if this current scheme proves to have downsides that the FIB trie
variant would not have.

In order to accomodate this any such scheme, we need to be able to
produce a full flow key at PMTU/redirect time.  That required an
adjustment of the interface call-sites used to propagate these events.

For a PMTU/redirect with a fully specified socket, we pass that socket
and use it to produce the flow key.

Otherwise we use a passed in SKB to formulate the key.  There are two
cases that need to be distinguished, ICMP message processing (in which
case the IP header is at skb->data) and output packet processing
(mostly tunnels, and in all such cases the IP header is at ip_hdr(skb)).

We also have to make the code able to handle the case where the dst
itself passed into the dst_ops->{update_pmtu,redirect} method is
invalidated.  This matters for calls from sockets that have cached
that route.  We provide a inet{,6} helper function for this purpose,
and edit SCTP specially since it caches routes at the transport rather
than socket level.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 10:48:26 -07:00
David S. Miller
4895c771c7 ipv4: Add FIB nexthop exceptions.
In a regime where we have subnetted route entries, we need a way to
store persistent storage about destination specific learned values
such as redirects and PMTU values.

This is implemented here via nexthop exceptions.

The initial implementation is a 2048 entry hash table with relaiming
starting at chain length 5.  A more sophisticated scheme can be
devised if that proves necessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 08:48:50 -07:00
Eric Dumazet
0c24604b68 tcp: implement RFC 5961 4.2
Implement the RFC 5691 mitigation against Blind
Reset attack using SYN bit.

Section 4.2 of RFC 5961 advises to send a Challenge ACK and drop
incoming packet, instead of resetting the session.

Add a new SNMP counter to count number of challenge acks sent
in response to SYN packets.
(netstat -s | grep TCPSYNChallenge)

Remove obsolete TCPAbortOnSyn, since we no longer abort a TCP session
because of a SYN flag.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 07:40:46 -07:00
David S. Miller
6700c2709c net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()
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: David S. Miller <davem@davemloft.net>
2012-07-17 03:29:28 -07:00
Eric Dumazet
282f23c6ee tcp: implement RFC 5961 3.2
Implement the RFC 5691 mitigation against Blind
Reset attack using RST bit.

Idea is to validate incoming RST sequence,
to match RCV.NXT value, instead of previouly accepted
window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND)

If sequence is in window but not an exact match, send
a "challenge ACK", so that the other part can resend an
RST with the appropriate sequence.

Add a new sysctl, tcp_challenge_ack_limit, to limit
number of challenge ACK sent per second.

Add a new SNMP counter to count number of challenge acks sent.
(netstat -s | grep TCPChallengeACK)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 01:36:20 -07:00
Andrey Vagin
51d7cccf07 net: make sock diag per-namespace
Before this patch sock_diag works for init_net only and dumps
information about sockets from all namespaces.

This patch expands sock_diag for all name-spaces.
It creates a netlink kernel socket for each netns and filters
data during dumping.

v2: filter accoding with netns in all places
    remove an unused variable.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16 22:31:34 -07:00
Eric Dumazet
a6df1ae938 tcp: add OFO snmp counters
Add three SNMP TCP counters, to better track TCP behavior
at global stage (netstat -s), when packets are received
Out Of Order (OFO)

TCPOFOQueue : Number of packets queued in OFO queue

TCPOFODrop  : Number of packets meant to be queued in OFO
              but dropped because socket rcvbuf limit hit.

TCPOFOMerge : Number of packets in OFO that were merged with
              other packets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16 22:12:00 -07:00
David S. Miller
80d0a69fc5 ipv4: Add helper inet_csk_update_pmtu().
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: David S. Miller <davem@davemloft.net>
2012-07-16 03:28:06 -07:00
David S. Miller
85b91b0339 ipv4: Don't store a rule pointer in fib_result.
We only use it to fetch the rule's tclassid, so just store the
tclassid there instead.

This also decreases the size of fib_result by a full 8 bytes on
64-bit.  On 32-bits it's a wash.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-13 08:21:29 -07:00
Eric Dumazet
d01cb20711 tcp: add LAST_ACK as a valid state for TSQ
Socket state LAST_ACK should allow TSQ to send additional frames,
or else we rely on incoming ACKS or timers to send them.

Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-13 05:48:36 -07:00
David S. Miller
391e5c22f5 ipv4: Remove tb_peers from fib_table.
No longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 09:39:28 -07:00
David S. Miller
f0a70e902f ipv4: Put proper checks into icmp_socket_deliver().
All handler->err() routines expect that we've done a pskb_may_pull()
test to make sure that IP header length + 8 bytes can be safely
pulled.

Reported-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 08:06:04 -07:00
David S. Miller
99ee038d41 ipv4: Fix warnings in ip_do_redirect() for some configurations.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 07:40:05 -07:00
David S. Miller
1ed5c48f23 net: Remove checks for dst_ops->redirect being NULL.
No longer necessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 00:41:25 -07:00
David S. Miller
b587ee3ba2 net: Add dummy dst_ops->redirect method where needed.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 00:39:24 -07:00
David S. Miller
1f42539d25 ipv4: Kill ip_rt_redirect().
No longer needed, as the protocol handlers now all properly
propagate the redirect back into the routing code.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 21:30:08 -07:00
David S. Miller
55be7a9c60 ipv4: Add redirect support to all protocol icmp error handlers.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 21:27:49 -07:00
David S. Miller
b42597e2f3 ipv4: Add ipv4_redirect() and ipv4_sk_redirect() helper functions.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 21:25:45 -07:00
David S. Miller
e47a185b31 ipv4: Generalize ip_do_redirect() and hook into new dst_ops->redirect.
All of the redirect acceptance policy is now contained within.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 20:55:47 -07:00
David S. Miller
94206125c4 ipv4: Rearrange arguments to ip_rt_redirect()
Pass in the SKB rather than just the IP addresses, so that policy
and other aspects can reside in ip_rt_redirect() rather then
icmp_redirect().

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 20:38:08 -07:00
David S. Miller
d0da720f9f ipv4: Pull redirect instantiation out into a helper function.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 20:27:54 -07:00
David S. Miller
d3351b75a7 ipv4: Deliver ICMP redirects to sockets too.
And thus, we can remove the ping_err() hack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 18:35:12 -07:00
David S. Miller
1de9243bbf ipv4: Pull icmp socket delivery out into a helper function.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 18:32:17 -07:00
Eric Dumazet
46d3ceabd8 tcp: TCP Small Queues
This introduce TSQ (TCP Small Queues)

TSQ goal is to reduce number of TCP packets in xmit queues (qdisc &
device queues), to reduce RTT and cwnd bias, part of the bufferbloat
problem.

sk->sk_wmem_alloc not allowed to grow above a given limit,
allowing no more than ~128KB [1] per tcp socket in qdisc/dev layers at a
given time.

TSO packets are sized/capped to half the limit, so that we have two
TSO packets in flight, allowing better bandwidth use.

As a side effect, setting the limit to 40000 automatically reduces the
standard gso max limit (65536) to 40000/2 : It can help to reduce
latencies of high prio packets, having smaller TSO packets.

This means we divert sock_wfree() to a tcp_wfree() handler, to
queue/send following frames when skb_orphan() [2] is called for the
already queued skbs.

Results on my dev machines (tg3/ixgbe nics) are really impressive,
using standard pfifo_fast, and with or without TSO/GSO.

Without reduction of nominal bandwidth, we have reduction of buffering
per bulk sender :
< 1ms on Gbit (instead of 50ms with TSO)
< 8ms on 100Mbit (instead of 132 ms)

I no longer have 4 MBytes backlogged in qdisc by a single netperf
session, and both side socket autotuning no longer use 4 Mbytes.

As skb destructor cannot restart xmit itself ( as qdisc lock might be
taken at this point ), we delegate the work to a tasklet. We use one
tasklest per cpu for performance reasons.

If tasklet finds a socket owned by the user, it sets TSQ_OWNED flag.
This flag is tested in a new protocol method called from release_sock(),
to eventually send new segments.

[1] New /proc/sys/net/ipv4/tcp_limit_output_bytes tunable
[2] skb_orphan() is usually called at TX completion time,
  but some drivers call it in their start_xmit() handler.
  These drivers should at least use BQL, or else a single TCP
  session can still fill the whole NIC TX ring, since TSQ will
  have no effect.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dave Taht <dave.taht@bufferbloat.net>
Cc: Tom Herbert <therbert@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 18:12:59 -07:00
Alexander Duyck
2100844ca9 tcp: Fix out of bounds access to tcpm_vals
The recent patch "tcp: Maintain dynamic metrics in local cache." introduced
an out of bounds access due to what appears to be a typo.   I believe this
change should resolve the issue by replacing the access to RTAX_CWND with
TCP_METRIC_CWND.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 17:30:41 -07:00
Ben Hutchings
ae86b9e384 net: Fix non-kernel-doc comments with kernel-doc start marker
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:13:45 -07:00
Ben Hutchings
2c53040f01 net: Fix (nearly-)kernel-doc comments for various functions
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:13:45 -07:00
David S. Miller
f185071ddf ipv4: Remove inetpeer from routes.
No longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:18 -07:00
David S. Miller
312487313d ipv4: Calling ->cow_metrics() now is a bug.
Nothing every writes to ipv4 metrics any longer.

PMTU is stored in rt->rt_pmtu.

Dynamic TCP metrics are stored in a special TCP metrics cache,
completely outside of the routes.

Therefore ->cow_metrics() can simply nothing more than a WARN_ON
trigger so we can catch anyone who tries to add new writes to
ipv4 route metrics.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:17 -07:00
David S. Miller
2db2d67e4c ipv4: Kill dst_copy_metrics() call from ipv4_blackhole_route().
Blackhole routes have a COW metrics operation that returns NULL
always, therefore this dst_copy_metrics() call did absolutely
nothing.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:16 -07:00
David S. Miller
710ab6c031 ipv4: Enforce max MTU metric at route insertion time.
Rather than at every struct rtable creation.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:15 -07:00
David S. Miller
5943634fc5 ipv4: Maintain redirect and PMTU info in struct rtable again.
Maintaining this in the inetpeer entries was not the right way to do
this at all.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:14 -07:00
David S. Miller
87a50699cb rtnetlink: Remove ts/tsage args to rtnl_put_cacheinfo().
Nobody provides non-zero values any longer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:13 -07:00
David S. Miller
3e12939a2a inet: Kill FLOWI_FLAG_PRECOW_METRICS.
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: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:12 -07:00
David S. Miller
1d861aa4b3 inet: Minimize use of cached route inetpeer.
Only use it in the absolutely required cases:

1) COW'ing metrics

2) ipv4 PMTU

3) ipv4 redirects

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:11 -07:00
David S. Miller
16d1839907 inet: Remove ->get_peer() method.
No longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:10 -07:00
David S. Miller
b6242b9b45 tcp: Remove tw->tw_peer
No longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:09 -07:00
David S. Miller
81166dd6fa tcp: Move timestamps from inetpeer to metrics cache.
With help from Lin Ming.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:08 -07:00
David S. Miller
794785bf12 net: Don't report route RTT metric value in cache dumps.
We don't maintain it dynamically any longer, so reporting it would
be extremely misleading.  Report zero instead.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:06 -07:00
David S. Miller
51c5d0c4b1 tcp: Maintain dynamic metrics in local cache.
Maintain a local hash table of TCP dynamic metrics blobs.

Computed TCP metrics are no longer maintained in the route metrics.

The table uses RCU and an extremely simple hash so that it has low
latency and low overhead.  A simple hash is legitimate because we only
make metrics blobs for fully established connections.

Some tweaking of the default hash table sizes, metric timeouts, and
the hash chain length limit certainly could use some tweaking.  But
the basic design seems sound.

With help from Eric Dumazet and Joe Perches.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:39:57 -07:00
David S. Miller
ab92bb2f67 tcp: Abstract back handling peer aliveness test into helper function.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 20:33:49 -07:00
David S. Miller
4aabd8ef8c tcp: Move dynamnic metrics handling into seperate file.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 20:31:36 -07:00
David S. Miller
d3a5ea6e21 Merge branch 'master' of git://1984.lsi.us.es/nf-next 2012-07-07 16:18:50 -07:00
David S. Miller
f4530fa574 ipv4: Avoid overhead when no custom FIB rules are installed.
If the user hasn't actually installed any custom rules, or fiddled
with the default ones, don't go through the whole FIB rules layer.

It's just pure overhead.

Instead do what we do with CONFIG_IP_MULTIPLE_TABLES disabled, check
the individual tables by hand, one by one.

Also, move fib_num_tclassid_users into the ipv4 network namespace.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 22:13:13 -07:00
Eric Dumazet
bf5e53e371 ipv4: defer fib_compute_spec_dst() call
ip_options_compile() can avoid calling fib_compute_spec_dst()
by default, and perform the call only if needed.

David suggested to add a helper to make the call only once.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 03:03:32 -07:00
David S. Miller
f187bc6efb ipv4: No need to set generic neighbour pointer.
Nobody reads it any longer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 02:41:59 -07:00
David S. Miller
f894cbf847 net: Add optional SKB arg to dst_ops->neigh_lookup().
Causes the handler to use the daddr in the ipv4/ipv6 header when
the route gateway is unspecified (local subnet).

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 01:04:01 -07:00
David S. Miller
5110effee8 net: Do delayed neigh confirmation.
When a dst_confirm() happens, mark the confirmation as pending in the
dst.  Then on the next packet out, when we have the neigh in-hand, do
the update.

This removes the dependency in dst_confirm() of dst's having an
attached neigh.

While we're here, remove the explicit 'dst' NULL check, all except 2
or 3 call sites ensure it's not NULL.  So just fix those cases up.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 01:03:06 -07:00
David S. Miller
3c521f2ba9 ipv4: Don't report neigh uptodate state in rtcache procfs.
Soon routes will not have a cached neigh attached, nor will we
be able to necessarily go directly to a neigh from an arbitrary
route.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 01:02:31 -07:00
David S. Miller
a263b30936 ipv4: Make neigh lookups directly in output packet path.
Do not use the dst cached neigh, we'll be getting rid of that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 01:02:12 -07:00
David S. Miller
11604721a3 ipv4: Fix crashes in ip_options_compile().
The spec_dst uses should be guarded by skb_rtable() being non-NULL
not just the SKB being non-null.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-04 16:13:17 -07:00
Pablo Neira Ayuso
08911475d1 netfilter: nf_conntrack: generalize nf_ct_l4proto_net
This patch generalizes nf_ct_l4proto_net by splitting it into chunks and
moving the corresponding protocol part to where it really belongs to.

To clarify, note that we follow two different approaches to support per-net
depending if it's built-in or run-time loadable protocol tracker.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
2012-07-04 19:37:22 +02:00
Pablo Neira Ayuso
a31f2d17b3 netlink: add netlink_kernel_cfg parameter to netlink_kernel_create
This patch adds the following structure:

struct netlink_kernel_cfg {
        unsigned int    groups;
        void            (*input)(struct sk_buff *skb);
        struct mutex    *cb_mutex;
};

That can be passed to netlink_kernel_create to set optional configurations
for netlink kernel sockets.

I've populated this structure by looking for NULL and zero parameters at the
existing code. The remaining parameters that always need to be set are still
left in the original interface.

That includes optional parameters for the netlink socket creation. This allows
easy extensibility of this interface in the future.

This patch also adapts all callers to use this new interface.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 16:46:02 -07:00
David S. Miller
7a9bc9b81a ipv4: Elide fib_validate_source() completely when possible.
If rpfilter is off (or the SKB has an IPSEC path) and there are not
tclassid users, we don't have to do anything at all when
fib_validate_source() is invoked besides setting the itag to zero.

We monitor tclassid uses with a counter (modified only under RTNL and
marked __read_mostly) and we protect the fib_validate_source() real
work with a test against this counter and whether rpfilter is to be
done.

Having a way to know whether we need no tclassid processing or not
also opens the door for future optimized rpfilter algorithms that do
not perform full FIB lookups.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 01:36:36 -07:00
David S. Miller
3085a4b7d3 ipv4: Remove extraneous assignment of dst->tclassid.
We already set it several lines above.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 22:17:39 -07:00
David S. Miller
9e56e3800e ipv4: Adjust in_dev handling in fib_validate_source()
Checking for in_dev being NULL is pointless.

In fact, all of our callers have in_dev precomputed already,
so just pass it in and remove the NULL checking.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 18:54:02 -07:00
David S. Miller
a207a4b2e8 ipv4: Fix bugs in fib_compute_spec_dst().
Based upon feedback from Julian Anastasov.

1) Use route flags to determine multicast/broadcast, not the
   packet flags.

2) Leave saddr unspecified in flow key.

3) Adjust how we invoke inet_select_addr().  Pass ip_hdr(skb)->saddr as
   second arg, and if it was zeronet use link scope.

4) Use loopback as input interface in flow key.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 18:33:58 -07:00
David S. Miller
41347dcdd8 ipv4: Kill rt->rt_spec_dst, no longer used.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 04:05:27 -07:00
David S. Miller
35ebf65e85 ipv4: Create and use fib_compute_spec_dst() helper.
The specific destination is the host we direct unicast replies to.
Usually this is the original packet source address, but if we are
responding to a multicast or broadcast packet we have to use something
different.

Specifically we must use the source address we would use if we were to
send a packet to the unicast source of the original packet.

The routing cache precomputes this value, but we want to remove that
precomputation because it creates a hard dependency on the expensive
rpfilter source address validation which we'd like to make cheaper.

There are only three places where this matters:

1) ICMP replies.

2) pktinfo CMSG

3) IP options

Now there will be no real users of rt->rt_spec_dst and we can simply
remove it altogether.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 03:59:11 -07:00
David S. Miller
70e7341673 ipv4: Show that ip_send_reply() is purely unicast routine.
Rename it to ip_send_unicast_reply() and add explicit 'saddr'
argument.

This removed one of the few users of rt->rt_spec_dst.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 03:21:41 -07:00
David S. Miller
160eb5a6b1 ipv4: Kill early demux method return value.
It's completely unnecessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 22:01:22 -07:00
David S. Miller
c10237e077 Revert "ipv4: tcp: dont cache unconfirmed intput dst"
This reverts commit c074da2810.

This change has several unwanted side effects:

1) Sockets will cache the DST_NOCACHE route in sk->sk_rx_dst and we'll
   thus never create a real cached route.

2) All TCP traffic will use DST_NOCACHE and never use the routing
   cache at all.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 17:05:06 -07:00
Eric Dumazet
22911fc581 net: skb_free_datagram_locked() doesnt drop all packets
dropwatch wrongly diagnose all received UDP packets as drops.

This patch removes trace_kfree_skb() done in skb_free_datagram_locked().

Locations calling skb_free_datagram_locked() should do it on their own.

As a result, drops are accounted on the right function.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 15:40:57 -07:00
Thomas Graf
92a395e52f ipmr: Do not use RTA_PUT() macros
Also fix a needless skb tailroom check for a 4 bytes area
after after each rtnexthop block.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 15:36:44 -07:00
Thomas Graf
6e277ed59a inet_diag: Do not use RTA_PUT() macros
Also, no need to trim on nlmsg_put() failure, nothing has been added
yet.  We also want to use nlmsg_end(), nlmsg_new() and nlmsg_free().

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 15:36:44 -07:00
Eric Dumazet
c074da2810 ipv4: tcp: dont cache unconfirmed intput dst
DDOS synflood attacks hit badly IP route cache.

On typical machines, this cache is allowed to hold up to 8 Millions dst
entries, 256 bytes for each, for a total of 2GB of memory.

rt_garbage_collect() triggers and tries to cleanup things.

Eventually route cache is disabled but machine is under fire and might
OOM and crash.

This patch exploits the new TCP early demux, to set a nocache
boolean in case incoming TCP frame is for a not yet ESTABLISHED or
TIMEWAIT socket.

This 'nocache' boolean is then used in case dst entry is not found in
route cache, to create an unhashed dst entry (DST_NOCACHE)

SYN-cookie-ACK sent use a similar mechanism (ipv4: tcp: dont cache
output dst for syncookies), so after this patch, a machine is able to
absorb a DDOS synflood attack without polluting its IP route cache.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 15:34:24 -07:00
Gao feng
a9082b45ad netfilter: nf_ct_icmp: add icmp_kmemdup[_compat]_sysctl_table function
Split sysctl function into smaller chucks to cleanup code and prepare
patches to reduce ifdef pollution.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-27 19:14:55 +02:00
Gao feng
f1caad2745 netfilter: nf_conntrack: prepare l4proto->init_net cleanup
l4proto->init contain quite redundant code. We can simplify this
by adding a new parameter l3proto.

This patch prepares that code simplification.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-27 18:31:14 +02:00
David S. Miller
c2bd4baf41 netfilter: ipt_ULOG: Move away from NLMSG_PUT().
And use nlmsg_data() while we're here too.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 21:30:49 -07:00
David S. Miller
d106352d9f inet_diag: Move away from NLMSG_PUT().
And use nlmsg_data() while we're here too, and remove useless
casts.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 21:28:54 -07:00
David S. Miller
251da41301 ipv4: Cache ip_error() routes even when not forwarding.
And account for the fact that, when we are not forwarding, we should
bump statistic counters rather than emit an ICMP response.

RP-filter rejected lookups are still not cached.

Since -EHOSTUNREACH and -ENETUNREACH can now no longer be seen in
ip_rcv_finish(), remove those checks.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 16:27:09 -07:00
David S. Miller
df67e6c9a6 ipv4: Remove unnecessary code from rt_check_expire().
IPv4 routing cache entries no longer use dst->expires, because the
metrics, PMTU, and redirect information are stored in the inetpeer
cache.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 00:10:09 -07:00
Vijay Subramanian
7011d0851b tcp: Fix bug in tcp socket early demux
The dest port for the call to __inet_lookup_established() in TCP early demux
code is passed with the wrong endian-ness. This causes the lookup to fail
leading to early demux not being used.

Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-23 23:22:38 -07:00
David S. Miller
0b4a9e1a59 Merge branch 'master' of git://1984.lsi.us.es/nf-next
Pablo says:

====================
The following four patches provide Netfilter fixes for the cthelper
infrastructure that was recently merged mainstream, they are:

* two fixes for compilation breakage with two different configurations:

  - CONFIG_NF_NAT=m and CONFIG_NF_CT_NETLINK=y
  - NF_CONNTRACK_EVENTS=n and CONFIG_NETFILTER_NETLINK_QUEUE_CT=y

* two fixes for sparse warnings.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-23 17:10:10 -07:00
Eric Dumazet
7586eceb0a ipv4: tcp: dont cache output dst for syncookies
Don't cache output dst for syncookies, as this adds pressure on IP route
cache and rcu subsystem for no gain.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-22 21:47:33 -07:00
Alexander Duyck
6648bd7e0e ipv4: Add sysctl knob to control early socket demux
This change is meant to add a control for disabling early socket demux.
The main motivation behind this patch is to provide an option to disable
the feature as it adds an additional cost to routing that reduces overall
throughput by up to 5%.  For example one of my systems went from 12.1Mpps
to 11.6 after the early socket demux was added.  It looks like the reason
for the regression is that we are now having to perform two lookups, first
the one for an established socket, and then the one for the routing table.

By adding this patch and toggling the value for ip_early_demux to 0 I am
able to get back to the 12.1Mpps I was previously seeing.

[ Move local variables in ip_rcv_finish() down into the basic
  block in which they are actually used.  -DaveM ]

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-22 17:11:13 -07:00
Pablo Neira Ayuso
d584a61a93 netfilter: nfnetlink_queue: fix compilation with CONFIG_NF_NAT=m and CONFIG_NF_CT_NETLINK=y
LD      init/built-in.o
net/built-in.o:(.data+0x4408): undefined reference to `nf_nat_tcp_seq_adjust'
make: *** [vmlinux] Error 1

This patch adds a new pointer hook (nfq_ct_nat_hook) similar to other existing
in Netfilter to solve our complicated configuration dependencies.

Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-22 02:49:52 +02:00
David S. Miller
fd62e09b94 tcp: Validate route interface in early demux.
Otherwise we might violate reverse path filtering.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-21 14:58:10 -07:00
Eric Dumazet
da55737467 inetpeer: inetpeer_invalidate_tree() cleanup
No need to use cmpxchg() in inetpeer_invalidate_tree() since we hold
base lock.

Also use correct rcu annotations to remove sparse errors
(CONFIG_SPARSE_RCU_POINTER=y)

net/ipv4/inetpeer.c:144:19: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:149:20: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:595:10: error: incompatible types in comparison
expression (different address spaces)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-20 14:38:55 -07:00
David S. Miller
41063e9dd1 ipv4: Early TCP socket demux.
Input packet processing for local sockets involves two major demuxes.
One for the route and one for the socket.

But we can optimize this down to one demux for certain kinds of local
sockets.

Currently we only do this for established TCP sockets, but it could
at least in theory be expanded to other kinds of connections.

If a TCP socket is established then it's identity is fully specified.

This means that whatever input route was used during the three-way
handshake must work equally well for the rest of the connection since
the keys will not change.

Once we move to established state, we cache the receive packet's input
route to use later.

Like the existing cached route in sk->sk_dst_cache used for output
packets, we have to check for route invalidations using dst->obsolete
and dst->ops->check().

Early demux occurs outside of a socket locked section, so when a route
invalidation occurs we defer the fixup of sk->sk_rx_dst until we are
actually inside of established state packet processing and thus have
the socket locked.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-19 21:22:05 -07:00
David S. Miller
f9242b6b28 inet: Sanitize inet{,6} protocol demux.
Don't pretend that inet_protos[] and inet6_protos[] are hashes, thay
are just a straight arrays.  Remove all unnecessary hash masking.

Document MAX_INET_PROTOS.

Use RAW_HTABLE_SIZE when appropriate.

Reported-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-19 18:56:21 -07:00
David S. Miller
6fac262526 ipv4: Cap ADVMSS metric in the FIB rather than the routing cache.
It makes no sense to execute this limit test every time we create a
routing cache entry.

We can't simply error out on these things since we've silently
accepted and truncated them forever.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-17 19:47:34 -07:00
David S. Miller
82f437b950 Merge branch 'master' of git://1984.lsi.us.es/nf-next
Pablo says:

====================
This is the second batch of Netfilter updates for net-next. It contains the
kernel changes for the new user-space connection tracking helper
infrastructure.

More details on this infrastructure are provides here:
http://lwn.net/Articles/500196/

Still, I plan to provide some official documentation through the
conntrack-tools user manual on how to setup user-space utilities for this.
So far, it provides two helper in user-space, one for NFSv3 and another for
Oracle/SQLnet/TNS. Yet in my TODO list.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-16 15:23:35 -07:00
Pablo Neira Ayuso
12f7a50533 netfilter: add user-space connection tracking helper infrastructure
There are good reasons to supports helpers in user-space instead:

* Rapid connection tracking helper development, as developing code
  in user-space is usually faster.

* Reliability: A buggy helper does not crash the kernel. Moreover,
  we can monitor the helper process and restart it in case of problems.

* Security: Avoid complex string matching and mangling in kernel-space
  running in privileged mode. Going further, we can even think about
  running user-space helpers as a non-root process.

* Extensibility: It allows the development of very specific helpers (most
  likely non-standard proprietary protocols) that are very likely not to be
  accepted for mainline inclusion in the form of kernel-space connection
  tracking helpers.

This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).

I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.

Basic operation, in a few steps:

1) Register user-space helper by means of `nfct':

 nfct helper add ftp inet tcp

 [ It must be a valid existing helper supported by conntrack-tools ]

2) Add rules to enable the FTP user-space helper which is
   used to track traffic going to TCP port 21.

For locally generated packets:

 iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp

For non-locally generated packets:

 iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp

3) Run the test conntrackd in helper mode (see example files under
   doc/helper/conntrackd.conf

 conntrackd

4) Generate FTP traffic going, if everything is OK, then conntrackd
   should create expectations (you can check that with `conntrack':

 conntrack -E expect

    [NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp

This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.

The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:40:02 +02:00
Pablo Neira Ayuso
8c88f87cb2 netfilter: nfnetlink_queue: add NAT TCP sequence adjustment if packet mangled
User-space programs that receive traffic via NFQUEUE may mangle packets.
If NAT is enabled, this usually puzzles sequence tracking, leading to
traffic disruptions.

With this patch, nfnl_queue will make the corresponding NAT TCP sequence
adjustment if:

1) The packet has been mangled,
2) the NFQA_CFG_F_CONNTRACK flag has been set, and
3) NAT is detected.

There are some records on the Internet complaning about this issue:
http://stackoverflow.com/questions/260757/packet-mangling-utilities-besides-iptables

By now, we only support TCP since we have no helpers for DCCP or SCTP.
Better to add this if we ever have some helper over those layer 4 protocols.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:09:08 +02:00
Pablo Neira Ayuso
1afc56794e netfilter: nf_ct_helper: implement variable length helper private data
This patch uses the new variable length conntrack extensions.

Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.

This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:08:55 +02:00
David S. Miller
3639339553 ipv4: Handle PMTU in all ICMP error handlers.
With ip_rt_frag_needed() removed, we have to explicitly update PMTU
information in every ICMP error handler.

Create two helper functions to facilitate this.

1) ipv4_sk_update_pmtu()

   This updates the PMTU when we have a socket context to
   work with.

2) ipv4_update_pmtu()

   Raw version, used when no socket context is available.  For this
   interface, we essentially just pass in explicit arguments for
   the flow identity information we would have extracted from the
   socket.

   And you'll notice that ipv4_sk_update_pmtu() is simply implemented
   in terms of ipv4_update_pmtu()

Note that __ip_route_output_key() is used, rather than something like
ip_route_output_flow() or ip_route_output_key().  This is because we
absolutely do not want to end up with a route that does IPSEC
encapsulation and the like.  Instead, we only want the route that
would get us to the node described by the outermost IP header.

Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-14 22:22:07 -07:00
David S. Miller
43b03f1f6d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	MAINTAINERS
	drivers/net/wireless/iwlwifi/pcie/trans.c

The iwlwifi conflict was resolved by keeping the code added
in 'net' that turns off the buggy chip feature.

The MAINTAINERS conflict was merely overlapping changes, one
change updated all the wireless web site URLs and the other
changed some GIT trees to be Johannes's instead of John's.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-12 21:59:18 -07:00
Michel Machado
95603e2293 net-next: add dev_loopback_xmit() to avoid duplicate code
Add dev_loopback_xmit() in order to deduplicate functions
ip_dev_loopback_xmit() (in net/ipv4/ip_output.c) and
ip6_dev_loopback_xmit() (in net/ipv6/ip6_output.c).

I was about to reinvent the wheel when I noticed that
ip_dev_loopback_xmit() and ip6_dev_loopback_xmit() do exactly what I
need and are not IP-only functions, but they were not available to reuse
elsewhere.

ip6_dev_loopback_xmit() does not have line "skb_dst_force(skb);", but I
understand that this is harmless, and should be in dev_loopback_xmit().

Signed-off-by: Michel Machado <michel@digirati.com.br>
CC: "David S. Miller" <davem@davemloft.net>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
CC: James Morris <jmorris@namei.org>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Patrick McHardy <kaber@trash.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jpirko@redhat.com>
CC: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-12 18:51:09 -07:00
Thomas Graf
d0daebc3d6 ipv4: Add interface option to enable routing of 127.0.0.0/8
Routing of 127/8 is tradtionally forbidden, we consider
packets from that address block martian when routing and do
not process corresponding ARP requests.

This is a sane default but renders a huge address space
practically unuseable.

The RFC states that no address within the 127/8 block should
ever appear on any network anywhere but it does not forbid
the use of such addresses outside of the loopback device in
particular. For example to address a pool of virtual guests
behind a load balancer.

This patch adds a new interface option 'route_localnet'
enabling routing of the 127/8 address block and processing
of ARP requests on a specific interface.

Note that for the feature to work, the default local route
covering 127/8 dev lo needs to be removed.

Example:
  $ sysctl -w net.ipv4.conf.eth0.route_localnet=1
  $ ip route del 127.0.0.0/8 dev lo table local
  $ ip addr add 127.1.0.1/16 dev eth0
  $ ip route flush cache

V2: Fix invalid check to auto flush cache (thanks davem)

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-12 15:25:46 -07:00
David S. Miller
67da255210 Merge branch 'master' of git://1984.lsi.us.es/net-next 2012-06-11 12:56:14 -07:00