1 files changed, 149 insertions, 0 deletions
diff --git a/src/expr/tunnel.c b/src/expr/tunnel.c
new file mode 100644
index 0000000..a00f620
--- /dev/null
+++ b/src/expr/tunnel.c
@@ -0,0 +1,149 @@
+/*
+ * (C) 2018 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <libnftnl/expr.h>
+#include <libnftnl/rule.h>
+
+struct nftnl_expr_tunnel {
+	enum nft_tunnel_keys	key;
+	enum nft_registers	dreg;
+};
+
+static int nftnl_expr_tunnel_set(struct nftnl_expr *e, uint16_t type,
+				 const void *data, uint32_t data_len)
+{
+	struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+	switch(type) {
+	case NFTNL_EXPR_TUNNEL_KEY:
+		memcpy(&tunnel->key, data, sizeof(tunnel->key));
+		break;
+	case NFTNL_EXPR_TUNNEL_DREG:
+		memcpy(&tunnel->dreg, data, sizeof(tunnel->dreg));
+		break;
+	default:
+		return -1;
+	}
+	return 0;
+}
+
+static const void *
+nftnl_expr_tunnel_get(const struct nftnl_expr *e, uint16_t type,
+		       uint32_t *data_len)
+{
+	struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+	switch(type) {
+	case NFTNL_EXPR_TUNNEL_KEY:
+		*data_len = sizeof(tunnel->key);
+		return &tunnel->key;
+	case NFTNL_EXPR_TUNNEL_DREG:
+		*data_len = sizeof(tunnel->dreg);
+		return &tunnel->dreg;
+	}
+	return NULL;
+}
+
+static int nftnl_expr_tunnel_cb(const struct nlattr *attr, void *data)
+{
+	const struct nlattr **tb = data;
+	int type = mnl_attr_get_type(attr);
+
+	if (mnl_attr_type_valid(attr, NFTA_TUNNEL_MAX) < 0)
+		return MNL_CB_OK;
+
+	switch(type) {
+	case NFTA_TUNNEL_KEY:
+	case NFTA_TUNNEL_DREG:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+			abi_breakage();
+		break;
+	}
+
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_tunnel_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+	struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+	if (e->flags & (1 << NFTNL_EXPR_TUNNEL_KEY))
+		mnl_attr_put_u32(nlh, NFTA_TUNNEL_KEY, htonl(tunnel->key));
+	if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG))
+		mnl_attr_put_u32(nlh, NFTA_TUNNEL_DREG, htonl(tunnel->dreg));
+}
+
+static int
+nftnl_expr_tunnel_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+	struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+	struct nlattr *tb[NFTA_TUNNEL_MAX + 1] = {};
+
+	if (mnl_attr_parse_nested(attr, nftnl_expr_tunnel_cb, tb) < 0)
+		return -1;
+
+	if (tb[NFTA_TUNNEL_KEY]) {
+		tunnel->key = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_KEY]));
+		e->flags |= (1 << NFTNL_EXPR_TUNNEL_KEY);
+	}
+	if (tb[NFTA_TUNNEL_DREG]) {
+		tunnel->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_DREG]));
+		e->flags |= (1 << NFTNL_EXPR_TUNNEL_DREG);
+	}
+
+	return 0;
+}
+
+static const char *tunnel_key2str_array[NFT_TUNNEL_MAX + 1] = {
+	[NFT_TUNNEL_PATH]	= "path",
+	[NFT_TUNNEL_ID]		= "id",
+};
+
+static const char *tunnel_key2str(uint8_t key)
+{
+	if (key <= NFT_TUNNEL_MAX)
+		return tunnel_key2str_array[key];
+
+	return "unknown";
+}
+
+static int
+nftnl_expr_tunnel_snprintf(char *buf, size_t len,
+			 uint32_t flags, const struct nftnl_expr *e)
+{
+	struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+	if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG)) {
+		return snprintf(buf, len, "load %s => reg %u ",
+				tunnel_key2str(tunnel->key), tunnel->dreg);
+	}
+	return 0;
+}
+
+struct expr_ops expr_ops_tunnel = {
+	.name		= "tunnel",
+	.alloc_len	= sizeof(struct nftnl_expr_tunnel),
+	.max_attr	= NFTA_TUNNEL_MAX,
+	.set		= nftnl_expr_tunnel_set,
+	.get		= nftnl_expr_tunnel_get,
+	.parse		= nftnl_expr_tunnel_parse,
+	.build		= nftnl_expr_tunnel_build,
+	.output		= nftnl_expr_tunnel_snprintf,
+};