netfilter: nfnetlink_hook: translate inet ingress to netdev

The NFPROTO_INET pseudofamily is not exposed through this new netlink
interface. The netlink dump either shows NFPROTO_IPV4 or NFPROTO_IPV6
for NFPROTO_INET prerouting/input/forward/output/postrouting hooks.
The NFNLA_CHAIN_FAMILY attribute provides the family chain, which
specifies if this hook applies to inet traffic only (either IPv4 or
IPv6).

Translate the inet/ingress hook to netdev/ingress to fully hide the
NFPROTO_INET implementation details.

Fixes: e2cf17d3 ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nfnetlink_hook.c

@@ -119,6 +119,7 @@ static int nfnl_hook_dump_one(struct sk_buff *nlskb,
 	unsigned int portid = NETLINK_CB(nlskb).portid;
 	struct nlmsghdr *nlh;
 	int ret = -EMSGSIZE;
+	u32 hooknum;
 #ifdef CONFIG_KALLSYMS
 	char sym[KSYM_SYMBOL_LEN];
 	char *module_name;
@@ -156,7 +157,12 @@ static int nfnl_hook_dump_one(struct sk_buff *nlskb,
 		goto nla_put_failure;
 #endif
 
-	ret = nla_put_be32(nlskb, NFNLA_HOOK_HOOKNUM, htonl(ops->hooknum));
+	if (ops->pf == NFPROTO_INET && ops->hooknum == NF_INET_INGRESS)
+		hooknum = NF_NETDEV_INGRESS;
+	else
+		hooknum = ops->hooknum;
+
+	ret = nla_put_be32(nlskb, NFNLA_HOOK_HOOKNUM, htonl(hooknum));
 	if (ret)
 		goto nla_put_failure;