linux-stable.git/include/net/ip6_fib.h, branch v3.2.99

ipv6: fix sparse warning on rt6i_node

2017-11-11T13:34:35+00:00

commit 4e587ea71bf924f7dac621f1351653bd41e446cb upstream.

Commit c5cff8561d2d adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
  net/ipv6/route.c:1394:30: error: incompatible types in comparison
  expression (different address spaces)
  ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
  expression (different address spaces)

This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.

Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - fib6_add_rt2node() has only one assignment to update
 - Drop changes in rt6_cache_allowed_for_pmtu()
 - Adjust context]
Signed-off-by: Ben Hutchings

ipv6: add rcu grace period before freeing fib6_node

2017-11-11T13:34:32+00:00

commit c5cff8561d2d0006e972bd114afd51f082fee77c upstream.

We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().

Note: there is no "Fixes" tag because this bug was there in a very
early stage.

Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

ipv6: Add rt6_get_cookie() function

2017-11-11T13:34:32+00:00

commit b197df4f0f3782782e9ea8996e91b65ae33e8dd9 upstream.

Instead of doing the rt6->rt6i_node check whenever we need
to get the route's cookie.  Refactor it into rt6_get_cookie().
It is a prep work to handle FLOWI_FLAG_KNOWN_NH and also
percpu rt6_info later.

Signed-off-by: Martin KaFai Lau 
Cc: Hannes Frederic Sowa 
Cc: Steffen Klassert 
Cc: Julian Anastasov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Drop changes in inet6_sk_rx_dst_set(), sctp_v6_get_dst()
 - Adjust context]
Signed-off-by: Ben Hutchings

ipv6: prevent fib6_run_gc() contention

2015-10-13T02:46:13+00:00

commit 2ac3ac8f86f2fe065d746d9a9abaca867adec577 upstream.

On a high-traffic router with many processors and many IPv6 dst
entries, soft lockup in fib6_run_gc() can occur when number of
entries reaches gc_thresh.

This happens because fib6_run_gc() uses fib6_gc_lock to allow
only one thread to run the garbage collector but ip6_dst_gc()
doesn't update net->ipv6.ip6_rt_last_gc until fib6_run_gc()
returns. On a system with many entries, this can take some time
so that in the meantime, other threads pass the tests in
ip6_dst_gc() (ip6_rt_last_gc is still not updated) and wait for
the lock. They then have to run the garbage collector one after
another which blocks them for quite long.

Resolve this by replacing special value ~0UL of expire parameter
to fib6_run_gc() by explicit "force" parameter to choose between
spin_lock_bh() and spin_trylock_bh() and call fib6_run_gc() with
force=false if gc_thresh is reached but not max_size.

Signed-off-by: Michal Kubecek 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Cc: Konstantin Khlebnikov

ipv6: Get rid of rt6i_nexthop macro.

2011-07-18T06:11:35+00:00

It just makes it harder to see 1) what the code is doing
and 2) grep for all users of dst{->,.}neighbour

Signed-off-by: David S. Miller

net: Remove KERNEL cpp checks from include/net

2011-04-24T17:54:56+00:00

These header files are never installed to user consumption, so any
__KERNEL__ cpp checks are superfluous.

Projects should also not copy these files into their userland utility
sources and try to use them there.  If they insist on doing so, the
onus is on them to sanitize the headers as needed.

Signed-off-by: David S. Miller

inet: constify ip headers and in6_addr

2011-04-22T18:04:14+00:00

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv6: RTA_PREFSRC support for ipv6 route source address selection

2011-04-15T22:44:37+00:00

[ipv6] Add support for RTA_PREFSRC

This patch allows a user to select the preferred source address
for a specific IPv6-Route. It can be set via a netlink message
setting RTA_PREFSRC to a valid IPv6 address which must be
up on the device the route will be bound to.

Signed-off-by: Daniel Walter 
Signed-off-by: David S. Miller

ipv6: Convert to use flowi6 where applicable.

2011-03-12T23:08:54+00:00

Signed-off-by: David S. Miller

inet: Create a mechanism for upward inetpeer propagation into routes.

2011-02-10T21:33:41+00:00

If we didn't have a routing cache, we would not be able to properly
propagate certain kinds of dynamic path attributes, for example
PMTU information and redirects.

The reason is that if we didn't have a routing cache, then there would
be no way to lookup all of the active cached routes hanging off of
sockets, tunnels, IPSEC bundles, etc.

Consider the case where we created a cached route, but no inetpeer
entry existed and also we were not asked to pre-COW the route metrics
and therefore did not force the creation a new inetpeer entry.

If we later get a PMTU message, or a redirect, and store this
information in a new inetpeer entry, there is no way to teach that
cached route about the newly existing inetpeer entry.

The facilities implemented here handle this problem.

First we create a generation ID.  When we create a cached route of any
kind, we remember the generation ID at the time of attachment.  Any
time we force-create an inetpeer entry in response to new path
information, we bump that generation ID.

The dst_ops->check() callback is where the knowledge of this event
is propagated.  If the global generation ID does not equal the one
stored in the cached route, and the cached route has not attached
to an inetpeer yet, we look it up and attach if one is found.  Now
that we've updated the cached route's information, we update the
route's generation ID too.

This clears the way for implementing PMTU and redirects directly in
the inetpeer cache.  There is absolutely no need to consult cached
route information in order to maintain this information.

At this point nothing bumps the inetpeer genids, that comes in the
later changes which handle PMTUs and redirects using inetpeers.

Signed-off-by: David S. Miller