ct.c
/*
* (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_default(char *buf, size_t size,
const struct nftnl_expr *e)
{
int ret, remain = size, offset = 0;
struct nftnl_expr_ct *ct = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_CT_SREG)) {
ret = snprintf(buf, size, "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;
}
static int
nftnl_expr_ct_snprintf(char *buf, size_t len, uint32_t type,
uint32_t flags, const struct nftnl_expr *e)
{
switch (type) {
case NFTNL_OUTPUT_DEFAULT:
return nftnl_expr_ct_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
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,
.snprintf = nftnl_expr_ct_snprintf,
};
nftnl_expr_ct
Definition: ct.c:24