netfilter: nft_socket: add wildcard support
Add NFT_SOCKET_WILDCARD to match to wildcard socket listener.
Signed-off-by: Balazs Scheidler <bazsi77@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index aeb88cb..543dc69 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1010,10 +1010,12 @@ enum nft_socket_attributes {
*
* @NFT_SOCKET_TRANSPARENT: Value of the IP(V6)_TRANSPARENT socket option
* @NFT_SOCKET_MARK: Value of the socket mark
+ * @NFT_SOCKET_WILDCARD: Whether the socket is zero-bound (e.g. 0.0.0.0 or ::0)
*/
enum nft_socket_keys {
NFT_SOCKET_TRANSPARENT,
NFT_SOCKET_MARK,
+ NFT_SOCKET_WILDCARD,
__NFT_SOCKET_MAX
};
#define NFT_SOCKET_MAX (__NFT_SOCKET_MAX - 1)
diff --git a/net/netfilter/nft_socket.c b/net/netfilter/nft_socket.c
index 637ce3e..a28aca5 100644
--- a/net/netfilter/nft_socket.c
+++ b/net/netfilter/nft_socket.c
@@ -14,6 +14,25 @@ struct nft_socket {
};
};
+static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
+ struct nft_regs *regs, struct sock *sk,
+ u32 *dest)
+{
+ switch (nft_pf(pkt)) {
+ case NFPROTO_IPV4:
+ nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0);
+ break;
+#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
+ case NFPROTO_IPV6:
+ nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr));
+ break;
+#endif
+ default:
+ regs->verdict.code = NFT_BREAK;
+ return;
+ }
+}
+
static void nft_socket_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
@@ -59,6 +78,13 @@ static void nft_socket_eval(const struct nft_expr *expr,
return;
}
break;
+ case NFT_SOCKET_WILDCARD:
+ if (!sk_fullsock(sk)) {
+ regs->verdict.code = NFT_BREAK;
+ return;
+ }
+ nft_socket_wildcard(pkt, regs, sk, dest);
+ break;
default:
WARN_ON(1);
regs->verdict.code = NFT_BREAK;
@@ -97,6 +123,7 @@ static int nft_socket_init(const struct nft_ctx *ctx,
priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
switch(priv->key) {
case NFT_SOCKET_TRANSPARENT:
+ case NFT_SOCKET_WILDCARD:
len = sizeof(u8);
break;
case NFT_SOCKET_MARK:
