linux-toradex.git/net/ipv4/fib_trie.c, branch v4.9.35

net: Improve handling of failures on link and route dumps

2017-06-07T10:07:44+00:00

[ Upstream commit f6c5775ff0bfa62b072face6bf1d40f659f194b2 ]

In general, rtnetlink dumps do not anticipate failure to dump a single
object (e.g., link or route) on a single pass. As both route and link
objects have grown via more attributes, that is no longer a given.

netlink dumps can handle a failure if the dump function returns an
error; specifically, netlink_dump adds the return code to the response
if it is <= 0 so userspace is notified of the failure. The missing
piece is the rtnetlink dump functions returning the error.

Fix route and link dump functions to return the errors if no object is
added to an skb (detected by skb->len != 0). IPv6 route dumps
(rt6_dump_route) already return the error; this patch updates IPv4 and
link dumps. Other dump functions may need to be ajusted as well.

Reported-by: Jan Moskyto Matejka 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: Drop suffix update from resize code

2016-12-05T18:15:58+00:00

It has been reported that update_suffix can be expensive when it is called
on a large node in which most of the suffix lengths are the same.  The time
required to add 200K entries had increased from around 3 seconds to almost
49 seconds.

In order to address this we need to move the code for updating the suffix
out of resize and instead just have it handled in the cases where we are
pushing a node that increases the suffix length, or will decrease the
suffix length.

Fixes: 5405afd1a306 ("fib_trie: Add tracking value for suffix length")
Reported-by: Robert Shearman 
Signed-off-by: Alexander Duyck 
Reviewed-by: Robert Shearman 
Tested-by: Robert Shearman 
Signed-off-by: David S. Miller

ipv4: Drop leaf from suffix pull/push functions

2016-12-05T18:15:58+00:00

It wasn't necessary to pass a leaf in when doing the suffix updates so just
drop it.  Instead just pass the suffix and work with that.

Since we dropped the leaf there is no need to include that in the name so
the names are updated to node_push_suffix and node_pull_suffix.

Finally I noticed that the logic for pulling the suffix length back
actually had some issues.  Specifically it would stop prematurely if there
was a longer suffix, but it was not as long as the original suffix.  I
updated the code to address that in node_pull_suffix.

Fixes: 5405afd1a306 ("fib_trie: Add tracking value for suffix length")
Suggested-by: Robert Shearman 
Signed-off-by: Alexander Duyck 
Reviewed-by: Robert Shearman 
Tested-by: Robert Shearman 
Signed-off-by: David S. Miller

ipv4: Fix memory leak in exception case for splitting tries

2016-11-16T18:24:50+00:00

Fix a small memory leak that can occur where we leak a fib_alias in the
event of us not being able to insert it into the local table.

Fixes: 0ddcf43d5d4a0 ("ipv4: FIB Local/MAIN table collapse")
Reported-by: Eric Dumazet 
Signed-off-by: Alexander Duyck 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv4: Restore fib_trie_flush_external function and fix call ordering

2016-11-16T18:24:50+00:00

The patch that removed the FIB offload infrastructure was a bit too
aggressive and also removed code needed to clean up us splitting the table
if additional rules were added.  Specifically the function
fib_trie_flush_external was called at the end of a new rule being added to
flush the foreign trie entries from the main trie.

I updated the code so that we only call fib_trie_flush_external on the main
table so that we flush the entries for local from main.  This way we don't
call it for every rule change which is what was happening previously.

Fixes: 347e3b28c1ba2 ("switchdev: remove FIB offload infrastructure")
Reported-by: Eric Dumazet 
Cc: Jiri Pirko 
Signed-off-by: Alexander Duyck 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

fib_trie: Correct /proc/net/route off by one error

2016-11-08T01:40:27+00:00

The display of /proc/net/route has had a couple issues due to the fact that
when I originally rewrote most of fib_trie I made it so that the iterator
was tracking the next value to use instead of the current.

In addition it had an off by 1 error where I was tracking the first piece
of data as position 0, even though in reality that belonged to the
SEQ_START_TOKEN.

This patch updates the code so the iterator tracks the last reported
position and key instead of the next expected position and key.  In
addition it shifts things so that all of the leaves start at 1 instead of
trying to report leaves starting with offset 0 as being valid.  With these
two issues addressed this should resolve any off by one errors that were
present in the display of /proc/net/route.

Fixes: 25b97c016b26 ("ipv4: off-by-one in continuation handling in /proc/net/route")
Cc: Andy Whitcroft 
Reported-by: Jason Baron 
Tested-by: Jason Baron 
Signed-off-by: Alexander Duyck 
Signed-off-by: David S. Miller

switchdev: remove FIB offload infrastructure

2016-09-28T08:48:00+00:00

Since this is now taken care of by FIB notifier, remove the code, with
all unused dependencies.

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

fib: introduce FIB notification infrastructure

2016-09-28T08:48:00+00:00

This allows to pass information about added/deleted FIB entries/rules to
whoever is interested. This is done in a very similar way as devinet
notifies address additions/removals.

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

ipv4: fix value of ->nlmsg_flags reported in RTM_NEWROUTE events

2016-09-09T23:50:23+00:00

fib_table_insert() inconsistently fills the nlmsg_flags field in its
notification messages.

Since commit b8f558313506 ("[RTNETLINK]: Fix sending netlink message
when replace route."), the netlink message has its nlmsg_flags set to
NLM_F_REPLACE if the route replaced a preexisting one.

Then commit a2bb6d7d6f42 ("ipv4: include NLM_F_APPEND flag in append
route notifications") started setting nlmsg_flags to NLM_F_APPEND if
the route matched a preexisting one but was appended.

In other cases (exclusive creation or prepend), nlmsg_flags is 0.

This patch sets ->nlmsg_flags in all situations, preserving the
semantic of the NLM_F_* bits:

  * NLM_F_CREATE: a new fib entry has been created for this route.
  * NLM_F_EXCL: no other fib entry existed for this route.
  * NLM_F_REPLACE: this route has overwritten a preexisting fib entry.
  * NLM_F_APPEND: the new fib entry was added after other entries for
    the same route.

As a result, the possible flag combination can now be reported
(iproute2's terminology into parentheses):

  * NLM_F_CREATE | NLM_F_EXCL: route didn't exist, exclusive creation
    ("add").
  * NLM_F_CREATE | NLM_F_APPEND: route did already exist, new route
    added after preexisting ones ("append").
  * NLM_F_CREATE: route did already exist, new route added before
    preexisting ones ("prepend").
  * NLM_F_REPLACE: route did already exist, new route replaced the
    first preexisting one ("change").

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

fib_trie: Fix the description of pos and bits

2016-08-19T06:51:23+00:00

1) Fix one typo: s/tn/tp/
2) Fix the description about the "u" bits.

Signed-off-by: Xunlei Pang 
Acked-by: Alexander Duyck 
Signed-off-by: David S. Miller