The NLM_F_ACK flag is not processed for nfnetlink batch messages. This
is a problem for ynl which wants to receive an ack for every message it
sends. Add processing for ACK and provide responses when requested.
I have checked that iproute2, pyroute2 and systemd are unaffected by
this change since none of them use NLM_F_ACK for batch begin/end. I also
ran a search on github and did not spot any usage that would break.
Signed-off-by: Donald Hunter <donald.hunter@xxxxxxxxx>
---
net/netfilter/nfnetlink.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index c9fbe0f707b5..37762941c288 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -427,6 +427,9 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
nfnl_unlock(subsys_id);
+ if (nlh->nlmsg_flags & NLM_F_ACK)
+ nfnl_err_add(&err_list, nlh, 0, &extack);
+
while (skb->len >= nlmsg_total_size(0)) {
int msglen, type;
@@ -463,6 +466,8 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
goto done;
} else if (type == NFNL_MSG_BATCH_END) {
status |= NFNL_BATCH_DONE;
+ if (nlh->nlmsg_flags & NLM_F_ACK)
+ nfnl_err_add(&err_list, nlh, 0, &extack);
goto done;
} else if (type < NLMSG_MIN_TYPE) {
err = -EINVAL;
--
2.43.0
