diff options
author | Phil Sutter <phil@nwl.cc> | 2020-10-05 16:06:49 +0200 |
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committer | Phil Sutter <phil@nwl.cc> | 2020-10-13 12:08:37 +0200 |
commit | dac904bdcd9a18aabafee7275ccf0c2bd53800f3 (patch) | |
tree | e29b5f964110b6d213f8791fb2e42bc18a0631cb /iptables/tests | |
parent | c6cff7ddd4ee8ac8b500a9c928612acf39bfa9ec (diff) |
nft: Fix for concurrent noflush restore calls
Transaction refresh was broken with regards to nft_chain_restore(): It
created a rule flush batch object only if the chain was found in cache
and a chain add object only if the chain was not found. Yet with
concurrent ruleset updates, one has to expect both situations:
* If a chain vanishes, the rule flush job must be skipped and instead
the chain add job become active.
* If a chain appears, the chain add job must be skipped and instead
rules flushed.
Change the code accordingly: Create both batch objects and set their
'skip' field depending on the situation in cache and adjust both in
nft_refresh_transaction().
As a side-effect, the implicit rule flush becomes explicit and all
handling of implicit batch jobs is dropped along with the related field
indicating such.
Reuse the 'implicit' parameter of __nft_rule_flush() to control the
initial 'skip' field value instead.
A subtle caveat is vanishing of existing chains: Creating the chain add
job based on the chain in cache causes a netlink message containing that
chain's handle which the kernel dislikes. Therefore unset the chain's
handle in that case.
Fixes: 58d7de0181f61 ("xtables: handle concurrent ruleset modifications")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Diffstat (limited to 'iptables/tests')
-rwxr-xr-x | iptables/tests/shell/testcases/ipt-restore/0016-concurrent-restores_0 | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/iptables/tests/shell/testcases/ipt-restore/0016-concurrent-restores_0 b/iptables/tests/shell/testcases/ipt-restore/0016-concurrent-restores_0 new file mode 100755 index 00000000..53ec12fa --- /dev/null +++ b/iptables/tests/shell/testcases/ipt-restore/0016-concurrent-restores_0 @@ -0,0 +1,53 @@ +#!/bin/bash + +set -e + +RS="*filter +:INPUT ACCEPT [12024:3123388] +:FORWARD ACCEPT [0:0] +:OUTPUT ACCEPT [12840:2144421] +:FOO - [0:0] +:BAR0 - [0:0] +:BAR1 - [0:0] +:BAR2 - [0:0] +:BAR3 - [0:0] +:BAR4 - [0:0] +:BAR5 - [0:0] +:BAR6 - [0:0] +:BAR7 - [0:0] +:BAR8 - [0:0] +:BAR9 - [0:0] +" + +RS1="$RS +-X BAR3 +-X BAR6 +-X BAR9 +-A FOO -s 9.9.0.1/32 -j BAR1 +-A FOO -s 9.9.0.2/32 -j BAR2 +-A FOO -s 9.9.0.4/32 -j BAR4 +-A FOO -s 9.9.0.5/32 -j BAR5 +-A FOO -s 9.9.0.7/32 -j BAR7 +-A FOO -s 9.9.0.8/32 -j BAR8 +COMMIT +" + +RS2="$RS +-X BAR2 +-X BAR5 +-X BAR7 +-A FOO -s 9.9.0.1/32 -j BAR1 +-A FOO -s 9.9.0.3/32 -j BAR3 +-A FOO -s 9.9.0.4/32 -j BAR4 +-A FOO -s 9.9.0.6/32 -j BAR6 +-A FOO -s 9.9.0.8/32 -j BAR8 +-A FOO -s 9.9.0.9/32 -j BAR9 +COMMIT +" + +for n in $(seq 1 10); do + $XT_MULTI iptables-restore --noflush -w <<< "$RS1" & + $XT_MULTI iptables-restore --noflush -w <<< "$RS2" & + wait -n + wait -n +done |