netfilter: nft_log: request explicit logger when loading rules

This includes the special handling for NFPROTO_INET. There is
no real inet logger since we don't see packets of this family.
However, rules are loaded using this special family type. So
let's just request both IPV4 and IPV6 loggers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_log.c

@@ -50,6 +50,7 @@ static int nft_log_init(const struct nft_ctx *ctx,
 	struct nft_log *priv = nft_expr_priv(expr);
 	struct nf_loginfo *li = &priv->loginfo;
 	const struct nlattr *nla;
+	int ret;
 
 	nla = tb[NFTA_LOG_PREFIX];
 	if (nla != NULL) {
@@ -71,16 +72,37 @@ static int nft_log_init(const struct nft_ctx *ctx,
 			ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
 	}
 
-	return 0;
+	if (ctx->afi->family == NFPROTO_INET) {
+		ret = nf_logger_find_get(NFPROTO_IPV4, li->type);
+		if (ret < 0)
+			return ret;
+
+		ret = nf_logger_find_get(NFPROTO_IPV6, li->type);
+		if (ret < 0) {
+			nf_logger_put(NFPROTO_IPV4, li->type);
+			return ret;
+		}
+		return 0;
+	}
+
+	return nf_logger_find_get(ctx->afi->family, li->type);
 }
 
 static void nft_log_destroy(const struct nft_ctx *ctx,
 			    const struct nft_expr *expr)
 {
 	struct nft_log *priv = nft_expr_priv(expr);
+	struct nf_loginfo *li = &priv->loginfo;
 
 	if (priv->prefix != nft_log_null_prefix)
 		kfree(priv->prefix);
+
+	if (ctx->afi->family == NFPROTO_INET) {
+		nf_logger_put(NFPROTO_IPV4, li->type);
+		nf_logger_put(NFPROTO_IPV6, li->type);
+	} else {
+		nf_logger_put(ctx->afi->family, li->type);
+	}
 }
 
 static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)