linux-toradex.git/include/net/ip_fib.h, branch v3.2.74

fib_trie: Fix /proc/net/fib_trie when CONFIG_IP_MULTIPLE_TABLES is not defined

2015-02-20T00:49:29+00:00

commit a5a519b2710be43fce3cf9ce7bd8de8db3f2a9de upstream.

In recent testing I had disabled CONFIG_IP_MULTIPLE_TABLES and as a result
when I ran "cat /proc/net/fib_trie" the main trie was displayed multiple
times.  I found that the problem line of code was in the function
fib_trie_seq_next.  Specifically the line below caused the indexes to go in
the opposite direction of our traversal:

	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);

This issue was that the RT tables are defined such that RT_TABLE_LOCAL is ID
255, while it is located at TABLE_LOCAL_INDEX of 0, and RT_TABLE_MAIN is 254
with a TABLE_MAIN_INDEX of 1.  This means that the above line will return 1
for the local table and 0 for main.  The result is that fib_trie_seq_next
will return NULL at the end of the local table, fib_trie_seq_start will
return the start of the main table, and then fib_trie_seq_next will loop on
main forever as h will always return 0.

The fix for this is to reverse the ordering of the two tables.  It has the
advantage of making it so that the tables now print in the same order
regardless of if multiple tables are enabled or not.  In order to make the
definition consistent with the multiple tables case I simply masked the to
RT_TABLE_XXX values by (FIB_TABLE_HASHSZ - 1).  This way the two table
layouts should always stay consistent.

Fixes: 93456b6 ("[IPV4]: Unify access to the routing tables")
Signed-off-by: Alexander Duyck 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv4: fix definition of FIB_TABLE_HASHSZ

2013-03-27T02:41:06+00:00

[ Upstream commit 5b9e12dbf92b441b37136ea71dac59f05f2673a9 ]

a long time ago by the commit

  commit 93456b6d7753def8760b423ac6b986eb9d5a4a95
  Author: Denis V. Lunev 
  Date:   Thu Jan 10 03:23:38 2008 -0800

    [IPV4]: Unify access to the routing tables.

the defenition of FIB_HASH_TABLE size has obtained wrong dependency:
it should depend upon CONFIG_IP_MULTIPLE_TABLES (as was in the original
code) but it was depended from CONFIG_IP_ROUTE_MULTIPATH

This patch returns the situation to the original state.

The problem was spotted by Tingwei Liu.

Signed-off-by: Denis V. Lunev 
CC: Tingwei Liu 
CC: Alexey Kuznetsov 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv4: Call fib_select_default() only when actually necessary.

2011-04-14T22:05:22+00:00

fib_select_default() is a complete NOP, and completely pointless
to invoke, when we have no more than 1 default route installed.

And this is far and away the common case.

So remember how many prefixlen==0 routes we have in the routing
table, and elide the call when we have no more than one of those.

This cuts output route creation time by 157 cycles on Niagara2+.

In order to add the new int to fib_table, we have to correct the type
of ->tb_data[] to unsigned long, otherwise the private area will be
unaligned on 64-bit systems.

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

fib_validate_source(): pass sk_buff instead of mark

2011-04-11T01:50:59+00:00

This makes sk_buff available for other use in fib_validate_source().

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

ipv4: Fix nexthop caching wrt. scoping.

2011-03-25T01:06:47+00:00

Move the scope value out of the fib alias entries and into fib_info,
so that we always use the correct scope when recomputing the nexthop
cached source address.

Reported-by: Julian Anastasov 
Signed-off-by: David S. Miller

ipv4: Invalidate nexthop cache nh_saddr more correctly.

2011-03-25T00:42:21+00:00

Any operation that:

1) Brings up an interface
2) Adds an IP address to an interface
3) Deletes an IP address from an interface

can potentially invalidate the nh_saddr value, requiring
it to be recomputed.

Perform the recomputation lazily using a generation ID.

Reported-by: Julian Anastasov 
Signed-off-by: David S. Miller

ipv4: Pass ipv4 flow objects into fib_lookup() paths.

2011-03-12T23:08:47+00:00

To start doing these conversions, we need to add some temporary
flow4_* macros which will eventually go away when all the protocol
code paths are changed to work on AF specific flowi objects.

Signed-off-by: David S. Miller

ipv4: Kill flowi arg to fib_select_multipath()

2011-03-11T01:03:45+00:00

Completely unused.

Signed-off-by: David S. Miller

ipv4: Fix scope value used in route src-address caching.

2011-03-08T19:03:21+00:00

We have to use cfg->fc_scope not the final nh_scope value.

Reported-by: Julian Anastasov 
Signed-off-by: David S. Miller

ipv4: Cache source address in nexthop entries.

2011-03-08T04:54:48+00:00

When doing output route lookups, we have to select the source address
if the user has not specified an explicit one.

First, if the route has an explicit preferred source address
specified, then we use that.

Otherwise we search the route's outgoing interface for a suitable
address.

This search can be precomputed and cached at route insertion time.

The only missing part is that we have to refresh this precomputed
value any time addresses are added or removed from the interface, and
this is accomplished by fib_update_nh_saddrs().

Signed-off-by: David S. Miller