nat.c
/*
* (C) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org>
* (C) 2012 Intel Corporation
*
* 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.
*
* Authors:
* Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
*/
#include "internal.h"
#include <stdio.h>
#include <stdint.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter/nf_tables.h>
#include <libnftnl/expr.h>
#include <libnftnl/rule.h>
struct nftnl_expr_nat {
enum nft_registers sreg_addr_min;
enum nft_registers sreg_addr_max;
enum nft_registers sreg_proto_min;
enum nft_registers sreg_proto_max;
int family;
enum nft_nat_types type;
uint32_t flags;
};
static int
nftnl_expr_nat_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_nat *nat = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_NAT_TYPE:
memcpy(&nat->type, data, sizeof(nat->type));
break;
case NFTNL_EXPR_NAT_FAMILY:
memcpy(&nat->family, data, sizeof(nat->family));
break;
case NFTNL_EXPR_NAT_REG_ADDR_MIN:
memcpy(&nat->sreg_addr_min, data, sizeof(nat->sreg_addr_min));
break;
case NFTNL_EXPR_NAT_REG_ADDR_MAX:
memcpy(&nat->sreg_addr_max, data, sizeof(nat->sreg_addr_max));
break;
case NFTNL_EXPR_NAT_REG_PROTO_MIN:
memcpy(&nat->sreg_proto_min, data, sizeof(nat->sreg_proto_min));
break;
case NFTNL_EXPR_NAT_REG_PROTO_MAX:
memcpy(&nat->sreg_proto_max, data, sizeof(nat->sreg_proto_max));
break;
case NFTNL_EXPR_NAT_FLAGS:
memcpy(&nat->flags, data, sizeof(nat->flags));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_nat_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_nat *nat = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_NAT_TYPE:
*data_len = sizeof(nat->type);
return &nat->type;
case NFTNL_EXPR_NAT_FAMILY:
*data_len = sizeof(nat->family);
return &nat->family;
case NFTNL_EXPR_NAT_REG_ADDR_MIN:
*data_len = sizeof(nat->sreg_addr_min);
return &nat->sreg_addr_min;
case NFTNL_EXPR_NAT_REG_ADDR_MAX:
*data_len = sizeof(nat->sreg_addr_max);
return &nat->sreg_addr_max;
case NFTNL_EXPR_NAT_REG_PROTO_MIN:
*data_len = sizeof(nat->sreg_proto_min);
return &nat->sreg_proto_min;
case NFTNL_EXPR_NAT_REG_PROTO_MAX:
*data_len = sizeof(nat->sreg_proto_max);
return &nat->sreg_proto_max;
case NFTNL_EXPR_NAT_FLAGS:
*data_len = sizeof(nat->flags);
return &nat->flags;
}
return NULL;
}
static int nftnl_expr_nat_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_NAT_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_NAT_TYPE:
case NFTA_NAT_FAMILY:
case NFTA_NAT_REG_ADDR_MIN:
case NFTA_NAT_REG_ADDR_MAX:
case NFTA_NAT_REG_PROTO_MIN:
case NFTA_NAT_REG_PROTO_MAX:
case NFTA_NAT_FLAGS:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int
nftnl_expr_nat_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_nat *nat = nftnl_expr_data(e);
struct nlattr *tb[NFTA_NAT_MAX+1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_nat_cb, tb) < 0)
return -1;
if (tb[NFTA_NAT_TYPE]) {
nat->type = ntohl(mnl_attr_get_u32(tb[NFTA_NAT_TYPE]));
e->flags |= (1 << NFTNL_EXPR_NAT_TYPE);
}
if (tb[NFTA_NAT_FAMILY]) {
nat->family = ntohl(mnl_attr_get_u32(tb[NFTA_NAT_FAMILY]));
e->flags |= (1 << NFTNL_EXPR_NAT_FAMILY);
}
if (tb[NFTA_NAT_REG_ADDR_MIN]) {
nat->sreg_addr_min =
ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_ADDR_MIN]));
e->flags |= (1 << NFTNL_EXPR_NAT_REG_ADDR_MIN);
}
if (tb[NFTA_NAT_REG_ADDR_MAX]) {
nat->sreg_addr_max =
ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_ADDR_MAX]));
e->flags |= (1 << NFTNL_EXPR_NAT_REG_ADDR_MAX);
}
if (tb[NFTA_NAT_REG_PROTO_MIN]) {
nat->sreg_proto_min =
ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_PROTO_MIN]));
e->flags |= (1 << NFTNL_EXPR_NAT_REG_PROTO_MIN);
}
if (tb[NFTA_NAT_REG_PROTO_MAX]) {
nat->sreg_proto_max =
ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_PROTO_MAX]));
e->flags |= (1 << NFTNL_EXPR_NAT_REG_PROTO_MAX);
}
if (tb[NFTA_NAT_FLAGS]) {
nat->flags = ntohl(mnl_attr_get_u32(tb[NFTA_NAT_FLAGS]));
e->flags |= (1 << NFTNL_EXPR_NAT_FLAGS);
}
return 0;
}
static void
nftnl_expr_nat_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_nat *nat = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_NAT_TYPE))
mnl_attr_put_u32(nlh, NFTA_NAT_TYPE, htonl(nat->type));
if (e->flags & (1 << NFTNL_EXPR_NAT_FAMILY))
mnl_attr_put_u32(nlh, NFTA_NAT_FAMILY, htonl(nat->family));
if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MIN))
mnl_attr_put_u32(nlh, NFTA_NAT_REG_ADDR_MIN,
htonl(nat->sreg_addr_min));
if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MAX))
mnl_attr_put_u32(nlh, NFTA_NAT_REG_ADDR_MAX,
htonl(nat->sreg_addr_max));
if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MIN))
mnl_attr_put_u32(nlh, NFTA_NAT_REG_PROTO_MIN,
htonl(nat->sreg_proto_min));
if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MAX))
mnl_attr_put_u32(nlh, NFTA_NAT_REG_PROTO_MAX,
htonl(nat->sreg_proto_max));
if (e->flags & (1 << NFTNL_EXPR_NAT_FLAGS))
mnl_attr_put_u32(nlh, NFTA_NAT_FLAGS, htonl(nat->flags));
}
static inline const char *nat2str(uint16_t nat)
{
switch (nat) {
case NFT_NAT_SNAT:
return "snat";
case NFT_NAT_DNAT:
return "dnat";
default:
return "unknown";
}
}
static inline int nftnl_str2nat(const char *nat)
{
if (strcmp(nat, "snat") == 0)
return NFT_NAT_SNAT;
else if (strcmp(nat, "dnat") == 0)
return NFT_NAT_DNAT;
else {
errno = EINVAL;
return -1;
}
}
static int
nftnl_expr_nat_snprintf_default(char *buf, size_t size,
const struct nftnl_expr *e)
{
struct nftnl_expr_nat *nat = nftnl_expr_data(e);
int remain = size, offset = 0, ret = 0;
ret = snprintf(buf, remain, "%s ", nat2str(nat->type));
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
ret = snprintf(buf + offset, remain, "%s ",
nftnl_family2str(nat->family));
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MIN)) {
ret = snprintf(buf + offset, remain,
"addr_min reg %u addr_max reg %u ",
nat->sreg_addr_min, nat->sreg_addr_max);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MIN)) {
ret = snprintf(buf + offset, remain,
"proto_min reg %u proto_max reg %u ",
nat->sreg_proto_min, nat->sreg_proto_max);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (e->flags & (1 << NFTNL_EXPR_NAT_FLAGS)) {
ret = snprintf(buf + offset, remain, "flags 0x%x ", nat->flags);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
return offset;
}
static int
nftnl_expr_nat_snprintf(char *buf, size_t size, uint32_t type,
uint32_t flags, const struct nftnl_expr *e)
{
switch (type) {
case NFTNL_OUTPUT_DEFAULT:
return nftnl_expr_nat_snprintf_default(buf, size, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_nat = {
.name = "nat",
.alloc_len = sizeof(struct nftnl_expr_nat),
.max_attr = NFTA_NAT_MAX,
.set = nftnl_expr_nat_set,
.get = nftnl_expr_nat_get,
.parse = nftnl_expr_nat_parse,
.build = nftnl_expr_nat_build,
.snprintf = nftnl_expr_nat_snprintf,
};
nftnl_expr_nat
Definition: nat.c:27