linux.git/net/ipv6/route.c, branch v4.3

net: ipv6: Dont add RT6_LOOKUP_F_IFACE flag if saddr set

2015-10-22T14:36:19+00:00

741a11d9e410 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set")
adds the RT6_LOOKUP_F_IFACE flag to make device index mismatch fatal if
oif is given. Hajime reported that this change breaks the Mobile IPv6
use case that wants to force the message through one interface yet use
the source address from another interface. Handle this case by only
adding the flag if oif is set and saddr is not set.

Fixes: 741a11d9e410 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set")
Cc: Hajime Tazaki 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: Really fix vti6 with oif in dst lookups

2015-10-22T02:04:54+00:00

6e28b000825d ("net: Fix vti use case with oif in dst lookups for IPv6")
is missing the checks on FLOWI_FLAG_SKIP_NH_OIF. Add them.

Fixes: 42a7b32b73d6 ("xfrm: Add oif to dst lookups")
Cc: Steffen Klassert 
Signed-off-by: David Ahern 
Acked-by: Steffen Klassert 
Signed-off-by: David S. Miller

ipv6: Initialize rt6_info properly in ip6_blackhole_route()

2015-10-16T07:39:16+00:00

ip6_blackhole_route() does not initialize the newly allocated
rt6_info properly.  This patch:
1. Call rt6_info_init() to initialize rt6i_siblings and rt6i_uncached

2. The current rt->dst._metrics init code is incorrect:
   - 'rt->dst._metrics = ort->dst._metris' is not always safe
   - Not sure what dst_copy_metrics() is trying to do here
     considering ip6_rt_blackhole_cow_metrics() always returns
     NULL

   Fix:
   - Always do dst_copy_metrics()
   - Replace ip6_rt_blackhole_cow_metrics() with
     dst_cow_metrics_generic()

3. Mask out the RTF_PCPU bit from the newly allocated blackhole route.
   This bug triggers an oops (reported by Phil Sutter) in rt6_get_cookie().
   It is because RTF_PCPU is set while rt->dst.from is NULL.

Fixes: d52d3997f843 ("ipv6: Create percpu rt6_info")
Signed-off-by: Martin KaFai Lau 
Reported-by: Phil Sutter 
Tested-by: Phil Sutter 
Cc: Hannes Frederic Sowa 
Cc: Julian Anastasov 
Cc: Phil Sutter 
Cc: Steffen Klassert 
Signed-off-by: David S. Miller

ipv6: Move common init code for rt6_info to a new function rt6_info_init()

2015-10-16T07:39:14+00:00

Introduce rt6_info_init() to do the common init work for
'struct rt6_info' (after calling dst_alloc).

It is a prep work to fix the rt6_info init logic in the
ip6_blackhole_route().

Signed-off-by: Martin KaFai Lau 
Cc: Hannes Frederic Sowa 
Cc: Julian Anastasov 
Cc: Phil Sutter 
Cc: Steffen Klassert 
Signed-off-by: David S. Miller

ipv6: Don't call with rt6_uncached_list_flush_dev

2015-10-13T11:52:40+00:00

As originally written rt6_uncached_list_flush_dev makes no sense when
called with dev == NULL as it attempts to flush all uncached routes
regardless of network namespace when dev == NULL.  Which is simply
incorrect behavior.

Furthermore at the point rt6_ifdown is called with dev == NULL no more
network devices exist in the network namespace so even if the code in
rt6_uncached_list_flush_dev were to attempt something sensible it
would be meaningless.

Therefore remove support in rt6_uncached_list_flush_dev for handling
network devices where dev == NULL, and only call rt6_uncached_list_flush_dev
 when rt6_ifdown is called with a network device.

Fixes: 8d0b94afdca8 ("ipv6: Keep track of DST_NOCACHE routes in case of iface down/unregister")
Signed-off-by: "Eric W. Biederman" 
Reviewed-by: Martin KaFai Lau 
Tested-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set

2015-09-29T22:01:10+00:00

Wolfgang reported that IPv6 stack is ignoring oif in output route lookups:

    With ipv6, ip -6 route get always returns the specific route.

    $ ip -6 r
    2001:db8:e2::1 dev enp2s0  proto kernel  metric 256
    2001:db8:e2::/64 dev enp2s0  metric 1024
    2001:db8:e3::1 dev enp3s0  proto kernel  metric 256
    2001:db8:e3::/64 dev enp3s0  metric 1024
    fe80::/64 dev enp3s0  proto kernel  metric 256
    default via 2001:db8:e3::255 dev enp3s0  metric 1024

    $ ip -6 r get 2001:db8:e2::100
    2001:db8:e2::100 from :: dev enp2s0  src 2001:db8:e3::1  metric 0
        cache

    $ ip -6 r get 2001:db8:e2::100 oif enp3s0
    2001:db8:e2::100 from :: dev enp2s0  src 2001:db8:e3::1  metric 0
        cache

The stack does consider the oif but a mismatch in rt6_device_match is not
considered fatal because RT6_LOOKUP_F_IFACE is not set in the flags.

Cc: Wolfgang Nothdurft 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: Fix behaviour of unreachable, blackhole and prohibit routes

2015-09-21T04:45:08+00:00

Man page of ip-route(8) says following about route types:

  unreachable - these destinations are unreachable.  Packets are dis‐
  carded and the ICMP message host unreachable is generated.  The local
  senders get an EHOSTUNREACH error.

  blackhole - these destinations are unreachable.  Packets are dis‐
  carded silently.  The local senders get an EINVAL error.

  prohibit - these destinations are unreachable.  Packets are discarded
  and the ICMP message communication administratively prohibited is
  generated.  The local senders get an EACCES error.

In the inet6 address family, this was correct, except the local senders
got ENETUNREACH error instead of EHOSTUNREACH in case of unreachable route.
In the inet address family, all three route types generated ICMP message
net unreachable, and the local senders got ENETUNREACH error.

In both address families all three route types now behave consistently
with documentation.

Signed-off-by: Nikola Forró 
Signed-off-by: David S. Miller

ipv6: include NLM_F_REPLACE in route replace notifications

2015-09-17T22:00:27+00:00

This patch adds NLM_F_REPLACE flag to ipv6 route replace notifications.
This makes nlm_flags in ipv6 replace notifications consistent
with ipv4.

Signed-off-by: Roopa Prabhu 
Acked-by: Nicolas Dichtel 
Reviewed-by: Michal Kubecek 
Signed-off-by: David S. Miller

ipv6: Avoid double dst_free

2015-09-15T21:53:05+00:00

It is a prep work to get dst freeing from fib tree undergo
a rcu grace period.

The following is a common paradigm:
if (ip6_del_rt(rt))
	dst_free(rt)

which means, if rt cannot be deleted from the fib tree, dst_free(rt) now.
1. We don't know the ip6_del_rt(rt) failure is because it
   was not managed by fib tree (e.g. DST_NOCACHE) or it had already been
   removed from the fib tree.
2. If rt had been managed by the fib tree, ip6_del_rt(rt) failure means
   dst_free(rt) has been called already.  A second
   dst_free(rt) is not always obviously safe.  The rt may have
   been destroyed already.
3. If rt is a DST_NOCACHE, dst_free(rt) should not be called.
4. It is a stopper to make dst freeing from fib tree undergo a
   rcu grace period.

This patch is to use a DST_NOCACHE flag to indicate a rt is
not managed by the fib tree.

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

ipv6: fix ifnullfree.cocci warnings

2015-09-10T00:21:01+00:00

net/ipv6/route.c:2946:3-8: WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values.

 NULL check before some freeing functions is not needed.

 Based on checkpatch warning
 "kfree(NULL) is safe this check is probably not required"
 and kfreeaddr.cocci by Julia Lawall.

Generated by: scripts/coccinelle/free/ifnullfree.cocci

CC: Roopa Prabhu 
Signed-off-by: Fengguang Wu 
Signed-off-by: David S. Miller