1 files changed, 262 insertions, 0 deletions
diff --git a/src/expr/ct.c b/src/expr/ct.c
new file mode 100644
index 0000000..f4a2aea
--- /dev/null
+++ b/src/expr/ct.c
@@ -0,0 +1,262 @@
+/*
+ * (C) 2012-2013 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.
+ *
+ * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.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_ct {
+	enum nft_ct_keys        key;
+	enum nft_registers	dreg;
+	enum nft_registers	sreg;
+	uint8_t			dir;
+};
+
+#define IP_CT_DIR_ORIGINAL	0
+#define IP_CT_DIR_REPLY		1
+
+static int
+nftnl_expr_ct_set(struct nftnl_expr *e, uint16_t type,
+		       const void *data, uint32_t data_len)
+{
+	struct nftnl_expr_ct *ct = nftnl_expr_data(e);
+
+	switch(type) {
+	case NFTNL_EXPR_CT_KEY:
+		memcpy(&ct->key, data, sizeof(ct->key));
+		break;
+	case NFTNL_EXPR_CT_DIR:
+		memcpy(&ct->dir, data, sizeof(ct->dir));
+		break;
+	case NFTNL_EXPR_CT_DREG:
+		memcpy(&ct->dreg, data, sizeof(ct->dreg));
+		break;
+	case NFTNL_EXPR_CT_SREG:
+		memcpy(&ct->sreg, data, sizeof(ct->sreg));
+		break;
+	default:
+		return -1;
+	}
+	return 0;
+}
+
+static const void *
+nftnl_expr_ct_get(const struct nftnl_expr *e, uint16_t type,
+		     uint32_t *data_len)
+{
+	struct nftnl_expr_ct *ct = nftnl_expr_data(e);
+
+	switch(type) {
+	case NFTNL_EXPR_CT_KEY:
+		*data_len = sizeof(ct->key);
+		return &ct->key;
+	case NFTNL_EXPR_CT_DIR:
+		*data_len = sizeof(ct->dir);
+		return &ct->dir;
+	case NFTNL_EXPR_CT_DREG:
+		*data_len = sizeof(ct->dreg);
+		return &ct->dreg;
+	case NFTNL_EXPR_CT_SREG:
+		*data_len = sizeof(ct->sreg);
+		return &ct->sreg;
+	}
+	return NULL;
+}
+
+static int nftnl_expr_ct_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_CT_MAX) < 0)
+		return MNL_CB_OK;
+
+	switch(type) {
+	case NFTA_CT_KEY:
+	case NFTA_CT_DREG:
+	case NFTA_CT_SREG:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+			abi_breakage();
+		break;
+	case NFTA_CT_DIRECTION:
+		if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
+			abi_breakage();
+		break;
+	}
+
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_ct_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+	struct nftnl_expr_ct *ct = nftnl_expr_data(e);
+
+	if (e->flags & (1 << NFTNL_EXPR_CT_KEY))
+		mnl_attr_put_u32(nlh, NFTA_CT_KEY, htonl(ct->key));
+	if (e->flags & (1 << NFTNL_EXPR_CT_DREG))
+		mnl_attr_put_u32(nlh, NFTA_CT_DREG, htonl(ct->dreg));
+	if (e->flags & (1 << NFTNL_EXPR_CT_DIR))
+		mnl_attr_put_u8(nlh, NFTA_CT_DIRECTION, ct->dir);
+	if (e->flags & (1 << NFTNL_EXPR_CT_SREG))
+		mnl_attr_put_u32(nlh, NFTA_CT_SREG, htonl(ct->sreg));
+}
+
+static int
+nftnl_expr_ct_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+	struct nftnl_expr_ct *ct = nftnl_expr_data(e);
+	struct nlattr *tb[NFTA_CT_MAX+1] = {};
+
+	if (mnl_attr_parse_nested(attr, nftnl_expr_ct_cb, tb) < 0)
+		return -1;
+
+	if (tb[NFTA_CT_KEY]) {
+		ct->key = ntohl(mnl_attr_get_u32(tb[NFTA_CT_KEY]));
+		e->flags |= (1 << NFTNL_EXPR_CT_KEY);
+	}
+	if (tb[NFTA_CT_DREG]) {
+		ct->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_CT_DREG]));
+		e->flags |= (1 << NFTNL_EXPR_CT_DREG);
+	}
+	if (tb[NFTA_CT_SREG]) {
+		ct->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_CT_SREG]));
+		e->flags |= (1 << NFTNL_EXPR_CT_SREG);
+	}
+	if (tb[NFTA_CT_DIRECTION]) {
+		ct->dir = mnl_attr_get_u8(tb[NFTA_CT_DIRECTION]);
+		e->flags |= (1 << NFTNL_EXPR_CT_DIR);
+	}
+
+	return 0;
+}
+
+static const char *ctkey2str_array[NFT_CT_MAX + 1] = {
+	[NFT_CT_STATE]		= "state",
+	[NFT_CT_DIRECTION]	= "direction",
+	[NFT_CT_STATUS]		= "status",
+	[NFT_CT_MARK]		= "mark",
+	[NFT_CT_SECMARK]	= "secmark",
+	[NFT_CT_EXPIRATION]	= "expiration",
+	[NFT_CT_HELPER]		= "helper",
+	[NFT_CT_L3PROTOCOL]	= "l3protocol",
+	[NFT_CT_PROTOCOL]	= "protocol",
+	[NFT_CT_SRC]		= "src",
+	[NFT_CT_DST]		= "dst",
+	[NFT_CT_PROTO_SRC]	= "proto_src",
+	[NFT_CT_PROTO_DST]	= "proto_dst",
+	[NFT_CT_LABELS]		= "label",
+	[NFT_CT_PKTS]		= "packets",
+	[NFT_CT_BYTES]		= "bytes",
+	[NFT_CT_AVGPKT]		= "avgpkt",
+	[NFT_CT_ZONE]		= "zone",
+	[NFT_CT_EVENTMASK]	= "event",
+	[NFT_CT_SRC_IP]		= "src_ip",
+	[NFT_CT_DST_IP]		= "dst_ip",
+	[NFT_CT_SRC_IP6]	= "src_ip6",
+	[NFT_CT_DST_IP6]	= "dst_ip6",
+	[NFT_CT_ID]		= "id",
+};
+
+static const char *ctkey2str(uint32_t ctkey)
+{
+	if (ctkey >= NFT_CT_MAX)
+		return "unknown";
+
+	return ctkey2str_array[ctkey];
+}
+
+static inline int str2ctkey(const char *ctkey)
+{
+	int i;
+
+	for (i = 0; i < NFT_CT_MAX; i++) {
+		if (strcmp(ctkey2str_array[i], ctkey) == 0)
+			return i;
+	}
+
+	return -1;
+}
+
+static const char *ctdir2str(uint8_t ctdir)
+{
+	switch (ctdir) {
+	case IP_CT_DIR_ORIGINAL:
+		return "original";
+	case IP_CT_DIR_REPLY:
+		return "reply";
+	default:
+		return "unknown";
+	}
+}
+
+static inline int str2ctdir(const char *str, uint8_t *ctdir)
+{
+	if (strcmp(str, "original") == 0) {
+		*ctdir = IP_CT_DIR_ORIGINAL;
+		return 0;
+	}
+
+	if (strcmp(str, "reply") == 0) {
+		*ctdir = IP_CT_DIR_REPLY;
+		return 0;
+	}
+
+	return -1;
+}
+
+static int
+nftnl_expr_ct_snprintf(char *buf, size_t remain,
+		       uint32_t flags, const struct nftnl_expr *e)
+{
+	struct nftnl_expr_ct *ct = nftnl_expr_data(e);
+	int ret, offset = 0;
+
+	if (e->flags & (1 << NFTNL_EXPR_CT_SREG)) {
+		ret = snprintf(buf, remain, "set %s with reg %u ",
+				ctkey2str(ct->key), ct->sreg);
+		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+	}
+
+	if (e->flags & (1 << NFTNL_EXPR_CT_DREG)) {
+		ret = snprintf(buf, remain, "load %s => reg %u ",
+			       ctkey2str(ct->key), ct->dreg);
+		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+	}
+
+	if (nftnl_expr_is_set(e, NFTNL_EXPR_CT_DIR)) {
+		ret = snprintf(buf + offset, remain, ", dir %s ",
+			       ctdir2str(ct->dir));
+		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+	}
+
+	return offset;
+}
+
+struct expr_ops expr_ops_ct = {
+	.name		= "ct",
+	.alloc_len	= sizeof(struct nftnl_expr_ct),
+	.max_attr	= NFTA_CT_MAX,
+	.set		= nftnl_expr_ct_set,
+	.get		= nftnl_expr_ct_get,
+	.parse		= nftnl_expr_ct_parse,
+	.build		= nftnl_expr_ct_build,
+	.output		= nftnl_expr_ct_snprintf,
+};