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, 5 insertions, 0 deletions

diff --git a/src/netlink.c b/src/netlink.c
index 84d5db3c..17b82ee8 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -75,6 +75,11 @@ void netlink_restart(void)
 	netlink_open_sock();
 }
 
+void netlink_genid_get(void)
+{
+	mnl_genid_get(nf_sock);
+}
+
 static void netlink_open_mon_sock(void)
 {
 	nf_mon_sock = nfsock_open();