BMC/Intel-BMC/linux.git/net/ipv4/fib_frontend.c, branch dev

net: ipv4 sysctl option to ignore routes when nexthop link is down

2015-06-24T09:15:54+00:00

This feature is only enabled with the new per-interface or ipv4 global sysctls called 'ignore_routes_with_linkdown'. net.ipv4.conf.all.ignore_routes_with_linkdown = 0 net.ipv4.conf.default.ignore_routes_with_linkdown = 0 net.ipv4.conf.lo.ignore_routes_with_linkdown = 0 ... When the above sysctls are set, will report to userspace that a route is dead and will no longer resolve to this nexthop when performing a fib lookup. This will signal to userspace that the route will not be selected. The signalling of a RTNH_F_DEAD is only passed to userspace if the sysctl is enabled and link is down. This was done as without it the netlink listeners would have no idea whether or not a nexthop would be selected. The kernel only sets RTNH_F_DEAD internally if the interface has IFF_UP cleared. With the new sysctl set, the following behavior can be observed (interface p8p1 is link-down): default via 10.0.5.2 dev p9p1 10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15 70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1 80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 dead linkdown 90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 dead linkdown 90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2 90.0.0.1 via 70.0.0.2 dev p7p1 src 70.0.0.1 cache local 80.0.0.1 dev lo src 80.0.0.1 cache 80.0.0.2 via 10.0.5.2 dev p9p1 src 10.0.5.15 cache While the route does remain in the table (so it can be modified if needed rather than being wiped away as it would be if IFF_UP was cleared), the proper next-hop is chosen automatically when the link is down. Now interface p8p1 is linked-up: default via 10.0.5.2 dev p9p1 10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15 70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1 80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2 192.168.56.0/24 dev p2p1 proto kernel scope link src 192.168.56.2 90.0.0.1 via 80.0.0.2 dev p8p1 src 80.0.0.1 cache local 80.0.0.1 dev lo src 80.0.0.1 cache 80.0.0.2 dev p8p1 src 80.0.0.1 cache and the output changes to what one would expect. If the sysctl is not set, the following output would be expected when p8p1 is down: default via 10.0.5.2 dev p9p1 10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15 70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1 80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 linkdown 90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 linkdown 90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2 Since the dead flag does not appear, there should be no expectation that the kernel would skip using this route due to link being down. v2: Split kernel changes into 2 patches, this actually makes a behavioral change if the sysctl is set. Also took suggestion from Alex to simplify code by only checking sysctl during fib lookup and suggestion from Scott to add a per-interface sysctl. v3: Code clean-ups to make it more readable and efficient as well as a reverse path check fix. v4: Drop binary sysctl v5: Whitespace fixups from Dave v6: Style changes from Dave and checkpatch suggestions v7: One more checkpatch fixup Signed-off-by: Andy Gospodarek Signed-off-by: Dinesh Dutt Acked-by: Scott Feldman Signed-off-by: David S. Miller

net: track link-status of ipv4 nexthops

2015-06-24T09:15:54+00:00

Add a fib flag called RTNH_F_LINKDOWN to any ipv4 nexthops that are reachable via an interface where carrier is off. No action is taken, but additional flags are passed to userspace to indicate carrier status. This also includes a cleanup to fib_disable_ip to more clearly indicate what event made the function call to replace the more cryptic force option previously used. v2: Split out kernel functionality into 2 patches, this patch simply sets and clears new nexthop flag RTNH_F_LINKDOWN. v3: Cleanups suggested by Alex as well as a bug noticed in fib_sync_down_dev and fib_sync_up when multipath was not enabled. v5: Whitespace and variable declaration fixups suggested by Dave. v6: Style fixups noticed by Dave; ran checkpatch to be sure I got them all. Signed-off-by: Andy Gospodarek Signed-off-by: Dinesh Dutt Acked-by: Scott Feldman Signed-off-by: David S. Miller

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

2015-04-07T02:34:15+00:00

Conflicts: drivers/net/ethernet/mellanox/mlx4/cmd.c net/core/fib_rules.c net/ipv4/fib_frontend.c The fib_rules.c and fib_frontend.c conflicts were locking adjustments in 'net' overlapping addition and removal of code in 'net-next'. The mlx4 conflict was a bug fix in 'net' happening in the same place a constant was being replaced with a more suitable macro. Signed-off-by: David S. Miller

ipv4: coding style: comparison for equality with NULL

2015-04-03T16:11:15+00:00

The ipv4 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x == NULL and sometimes as !x. !x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

net: move fib_rules_unregister() under rtnl lock

2015-04-03T00:52:34+00:00

We have to hold rtnl lock for fib_rules_unregister() otherwise the following race could happen: fib_rules_unregister(): fib_nl_delrule(): ... ... ... ops = lookup_rules_ops(); list_del_rcu(&ops->list); list_for_each_entry(ops->rules) { fib_rules_cleanup_ops(ops); ... list_del_rcu(); list_del_rcu(); } Note, net->rules_mod_lock is actually not needed at all, either upper layer netns code or rtnl lock guarantees we are safe. Cc: Alexander Duyck Cc: Thomas Graf Signed-off-by: Cong Wang Signed-off-by: David S. Miller

fib_trie: Cleanup ip_fib_net_exit code path

2015-03-31T17:18:56+00:00

While fixing a recent issue I noticed that we are doing some unnecessary work inside the loop for ip_fib_net_exit. As such I am pulling out the initialization to NULL for the locally stored fib_local, fib_main, and fib_default. In addition I am restoring the original code for flushing the table as there is no need to split up the fib_table_flush and hlist_del work since the code for packing the tnodes with multiple key vectors was dropped. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

fib_trie: Fix warning on fib4_rules_exit

2015-03-31T17:18:56+00:00

This fixes the following warning: BUG: sleeping function called from invalid context at mm/slub.c:1268 in_atomic(): 1, irqs_disabled(): 0, pid: 6, name: kworker/u8:0 INFO: lockdep is turned off. CPU: 3 PID: 6 Comm: kworker/u8:0 Tainted: G W 4.0.0-rc5+ #895 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: netns cleanup_net 0000000000000006 ffff88011953fa68 ffffffff81a203b6 000000002c3a2c39 ffff88011952a680 ffff88011953fa98 ffffffff8109daf0 ffff8801186c6aa8 ffffffff81fbc9e5 00000000000004f4 0000000000000000 ffff88011953fac8 Call Trace: [] dump_stack+0x4c/0x65 [] ___might_sleep+0x1c3/0x1cb [] __might_sleep+0x78/0x80 [] slab_pre_alloc_hook+0x31/0x8f [] __kmalloc+0x69/0x14e [] ? kzalloc.constprop.20+0xe/0x10 [] kzalloc.constprop.20+0xe/0x10 [] fib_trie_table+0x27/0x8b [] fib_trie_unmerge+0x37/0x2a6 [] ? arch_local_irq_save+0x9/0xc [] fib_unmerge+0x2d/0xb3 [] fib4_rule_delete+0x1f/0x52 [] ? fib_rules_unregister+0x30/0xb2 [] fib_rules_unregister+0x7c/0xb2 [] fib4_rules_exit+0x15/0x18 [] ip_fib_net_exit+0x23/0xf2 [] fib_net_exit+0x32/0x36 [] ops_exit_list+0x45/0x57 [] cleanup_net+0x13c/0x1cd [] process_one_work+0x255/0x4ad [] ? process_one_work+0x161/0x4ad [] worker_thread+0x1cd/0x2ab [] ? process_scheduled_works+0x2f/0x2f [] kthread+0xd4/0xdc [] ? local_clock+0x19/0x22 [] ? __kthread_parkme+0x83/0x83 [] ret_from_fork+0x58/0x90 [] ? __kthread_parkme+0x83/0x83 The issue was that as a part of exiting the default rules were being deleted which resulted in the local trie being unmerged. By moving the freeing of the FIB tables up we can avoid the unmerge since there is no local table left when we call the fib4_rules_exit function. Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse") Reported-by: Cong Wang Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

fib_trie: Avoid NULL pointer if local table is not allocated

2015-03-12T22:26:51+00:00

The function fib_unmerge assumed the local table had already been allocated. If that is not the case however when custom rules are applied then this can result in a NULL pointer dereference. In order to prevent this we must check the value of the local table pointer and if it is NULL simply return 0 as there is no local table to separate from the main. Fixes: 0ddcf43d5 ("ipv4: FIB Local/MAIN table collapse") Reported-by: Madhu Challa Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

fib_trie: Fix uninitialized variable warning

2015-03-11T21:33:44+00:00

The 0-day kernel test infrastructure reported a use of uninitialized variable warning for local_table due to the fact that the local and main allocations had been swapped from the original setup. This change corrects that by making it so that we free the main table if the local table allocation fails. Fixes: 0ddcf43d5 ("ipv4: FIB Local/MAIN table collapse") Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

fib_trie: call fib_table_flush_external under RTNL

2015-03-11T20:46:26+00:00

Move rtnl_lock() before the call to fib4_rules_exit so that fib_table_flush_external is called under RTNL. Fixes: 104616e74e0b ("switchdev: don't support custom ip rules, for now") Signed-off-by: Sabrina Dubroca Acked-by: Alexander Duyck Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller