mnl: consistency checks across several netlink dumps

Obtain the generation ID before dumping the object lists. Then,
check for generation ID updates when dumping the several lists that
this needs. In case of interference, nft has to remove the stale
objects and retry from scratch.

This is complementary to the NLM_F_DUMP_INTR flag which is local
to one single netlink dump.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
index 04a98e35..2685b0db 100644
--- a/src/main.c
+++ b/src/main.c
@@ -173,6 +173,7 @@ static int nft_netlink(struct parser_state *state, struct list_head *msgs)
 	bool batch_supported = netlink_batch_supported();
 	int ret = 0;
 
+	netlink_genid_get();
 	mnl_batch_init();
 
 	batch_seqnum = mnl_batch_begin();