linux-toradex.git/net/ipv6/route.c, branch v4.0.1

ipv6: fix ipv6_cow_metrics for non DST_HOST case

2015-02-15T04:26:16+00:00

ipv6_cow_metrics() currently assumes only DST_HOST routes require
dynamic metrics allocation from inetpeer.  The assumption breaks
when ndisc discovered router with RTAX_MTU and RTAX_HOPLIMIT metric.
Refer to ndisc_router_discovery() in ndisc.c and note that dst_metric_set()
is called after the route is created.

This patch creates the metrics array (by calling dst_cow_metrics_generic) in
ipv6_cow_metrics().

Test:
radvd.conf:
interface qemubr0
{
	AdvLinkMTU 1300;
	AdvCurHopLimit 30;

	prefix fd00:face:face:face::/64
	{
		AdvOnLink on;
		AdvAutonomous on;
		AdvRouterAddr off;
	};
};

Before:
[root@qemu1 ~]# ip -6 r show | egrep -v unreachable
fd00:face:face:face::/64 dev eth0  proto kernel  metric 256  expires 27sec
fe80::/64 dev eth0  proto kernel  metric 256
default via fe80::74df:d0ff:fe23:8ef2 dev eth0  proto ra  metric 1024  expires 27sec

After:
[root@qemu1 ~]# ip -6 r show | egrep -v unreachable
fd00:face:face:face::/64 dev eth0  proto kernel  metric 256  expires 27sec mtu 1300
fe80::/64 dev eth0  proto kernel  metric 256  mtu 1300
default via fe80::74df:d0ff:fe23:8ef2 dev eth0  proto ra  metric 1024  expires 27sec mtu 1300 hoplimit 30

Fixes: 8e2ec639173f325 (ipv6: don't use inetpeer to store metrics for routes.)
Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

rt6_probe_deferred: Do not depend on struct ordering

2015-02-08T21:00:43+00:00

rt6_probe allocates a struct __rt6_probe_work and schedules a work handler rt6_probe_deferred.
But rt6_probe_deferred kfree's the struct work_struct instead of struct __rt6_probe_work.
This works, because struct work_struct is the first element of struct __rt6_probe_work.

Change it to kfree struct __rt6_probe_work to not implicitly depend on
struct work_struct being the first element.

This does not affect the generated code.

Signed-off-by: Michael Buesch 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-01-28T00:59:56+00:00

Conflicts:
	arch/arm/boot/dts/imx6sx-sdb.dts
	net/sched/cls_bpf.c

Two simple sets of overlapping changes.

Signed-off-by: David S. Miller

ipv6: Fix __ip6_route_redirect

2015-01-26T06:09:51+00:00

In my last commit (a3c00e4: ipv6: Remove BACKTRACK macro), the changes in
__ip6_route_redirect is incorrect.  The following case is missed:
1. The for loop tries to find a valid gateway rt. If it fails to find
   one, rt will be NULL.
2. When rt is NULL, it is set to the ip6_null_entry.
3. The newly added 'else if', from a3c00e4, will stop the backtrack from
   happening.

Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

ipv6: stop sending PTB packets for MTU < 1280

2015-01-19T19:52:07+00:00

Reduce the attack vector and stop generating IPv6 Fragment Header for
paths with an MTU smaller than the minimum required IPv6 MTU
size (1280 byte) - called atomic fragments.

See IETF I-D "Deprecating the Generation of IPv6 Atomic Fragments" [1]
for more information and how this "feature" can be misused.

[1] https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-00

Signed-off-by: Fernando Gont 
Signed-off-by: Hagen Paul Pfeifer 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

netlink: make nlmsg_end() and genlmsg_end() void

2015-01-18T06:03:45+00:00

Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.

This makes the very common pattern of

  if (genlmsg_end(...) < 0) { ... }

be a whole bunch of dead code. Many places also simply do

  return nlmsg_end(...);

and the caller is expected to deal with it.

This also commonly (at least for me) causes errors, because it is very
common to write

  if (my_function(...))
    /* error condition */

and if my_function() does "return nlmsg_end()" this is of course wrong.

Additionally, there's not a single place in the kernel that actually
needs the message length returned, and if anyone needs it later then
it'll be very easy to just use skb->len there.

Remove this, and make the functions void. This removes a bunch of dead
code as described above. The patch adds lines because I did

-	return nlmsg_end(...);
+	nlmsg_end(...);
+	return 0;

I could have preserved all the function's return values by returning
skb->len, but instead I've audited all the places calling the affected
functions and found that none cared. A few places actually compared
the return value with <= 0 in dump functionality, but that could just
be changed to < 0 with no change in behaviour, so I opted for the more
efficient version.

One instance of the error I've made numerous times now is also present
in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't
check for <0 or <=0 and thus broke out of the loop every single time.
I've preserved this since it will (I think) have caused the messages to
userspace to be formatted differently with just a single message for
every SKB returned to userspace. It's possible that this isn't needed
for the tools that actually use this, but I don't even know what they
are so couldn't test that changing this behaviour would be acceptable.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

net: tcp: add RTAX_CC_ALGO fib handling

2015-01-06T03:55:24+00:00

This patch adds the minimum necessary for the RTAX_CC_ALGO congestion
control metric to be set up and dumped back to user space.

While the internal representation of RTAX_CC_ALGO is handled as a u32
key, we avoided to expose this implementation detail to user space, thus
instead, we chose the netlink attribute that is being exchanged between
user space to be the actual congestion control algorithm name, similarly
as in the setsockopt(2) API in order to allow for maximum flexibility,
even for 3rd party modules.

It is a bit unfortunate that RTAX_QUICKACK used up a whole RTAX slot as
it should have been stored in RTAX_FEATURES instead, we first thought
about reusing it for the congestion control key, but it brings more
complications and/or confusion than worth it.

Joint work with Florian Westphal.

Signed-off-by: Florian Westphal 
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: fib6: convert cfg metric to u32 outside of table write lock

2015-01-06T03:55:24+00:00

Do the nla validation earlier, outside the write lock.

This is needed by followup patch which needs to be able to call
request_module (which can sleep) if needed.

Joint work with Daniel Borkmann.

Signed-off-by: Daniel Borkmann 
Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

ipv6: Avoid redoing fib6_lookup() with reachable = 0 by saving fn

2014-10-24T04:14:39+00:00

This patch save the fn before doing rt6_backtrack.
Hence, without redo-ing the fib6_lookup(), saved_fn can be used
to redo rt6_select() with RT6_LOOKUP_F_REACHABLE off.

Some minor changes I think make sense to review as a single patch:
* Remove the 'out:' goto label.
* Remove the 'reachable' variable. Only use the 'strict' variable instead.

After this patch, "failing ip6_ins_rt()" should be the only case that
requires a redo of fib6_lookup().

Cc: David Miller 
Cc: Hannes Frederic Sowa 
Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

ipv6: Avoid redoing fib6_lookup() for RTF_CACHE hit case

2014-10-24T04:14:39+00:00

When there is a RTF_CACHE hit, no need to redo fib6_lookup()
with reachable=0.

Cc: David Miller 
Cc: Hannes Frederic Sowa 
Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller