range.c
/*
* (C) 2016 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 "internal.h"
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter/nf_tables.h>
#include <libnftnl/expr.h>
#include <libnftnl/rule.h>
struct nftnl_expr_range {
union nftnl_data_reg data_from;
union nftnl_data_reg data_to;
enum nft_registers sreg;
enum nft_range_ops op;
};
static int nftnl_expr_range_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_range *range = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_RANGE_SREG:
memcpy(&range->sreg, data, sizeof(range->sreg));
break;
case NFTNL_EXPR_RANGE_OP:
memcpy(&range->op, data, sizeof(range->op));
break;
case NFTNL_EXPR_RANGE_FROM_DATA:
memcpy(&range->data_from.val, data, data_len);
range->data_from.len = data_len;
break;
case NFTNL_EXPR_RANGE_TO_DATA:
memcpy(&range->data_to.val, data, data_len);
range->data_to.len = data_len;
break;
default:
return -1;
}
return 0;
}
static const void *nftnl_expr_range_get(const struct nftnl_expr *e,
uint16_t type, uint32_t *data_len)
{
struct nftnl_expr_range *range = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_RANGE_SREG:
*data_len = sizeof(range->sreg);
return &range->sreg;
case NFTNL_EXPR_RANGE_OP:
*data_len = sizeof(range->op);
return &range->op;
case NFTNL_EXPR_RANGE_FROM_DATA:
*data_len = range->data_from.len;
return &range->data_from.val;
case NFTNL_EXPR_RANGE_TO_DATA:
*data_len = range->data_to.len;
return &range->data_to.val;
}
return NULL;
}
static int nftnl_expr_range_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_RANGE_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_RANGE_SREG:
case NFTA_RANGE_OP:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
case NFTA_RANGE_FROM_DATA:
case NFTA_RANGE_TO_DATA:
if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_range_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_range *range = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_RANGE_SREG))
mnl_attr_put_u32(nlh, NFTA_RANGE_SREG, htonl(range->sreg));
if (e->flags & (1 << NFTNL_EXPR_RANGE_OP))
mnl_attr_put_u32(nlh, NFTA_RANGE_OP, htonl(range->op));
if (e->flags & (1 << NFTNL_EXPR_RANGE_FROM_DATA)) {
struct nlattr *nest;
nest = mnl_attr_nest_start(nlh, NFTA_RANGE_FROM_DATA);
mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_from.len,
range->data_from.val);
mnl_attr_nest_end(nlh, nest);
}
if (e->flags & (1 << NFTNL_EXPR_RANGE_TO_DATA)) {
struct nlattr *nest;
nest = mnl_attr_nest_start(nlh, NFTA_RANGE_TO_DATA);
mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_to.len,
range->data_to.val);
mnl_attr_nest_end(nlh, nest);
}
}
static int
nftnl_expr_range_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_range *range = nftnl_expr_data(e);
struct nlattr *tb[NFTA_RANGE_MAX+1] = {};
int ret = 0;
if (mnl_attr_parse_nested(attr, nftnl_expr_range_cb, tb) < 0)
return -1;
if (tb[NFTA_RANGE_SREG]) {
range->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_SREG]));
e->flags |= (1 << NFTA_RANGE_SREG);
}
if (tb[NFTA_RANGE_OP]) {
range->op = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_OP]));
e->flags |= (1 << NFTA_RANGE_OP);
}
if (tb[NFTA_RANGE_FROM_DATA]) {
ret = nftnl_parse_data(&range->data_from,
tb[NFTA_RANGE_FROM_DATA], NULL);
e->flags |= (1 << NFTA_RANGE_FROM_DATA);
}
if (tb[NFTA_RANGE_TO_DATA]) {
ret = nftnl_parse_data(&range->data_to,
tb[NFTA_RANGE_TO_DATA], NULL);
e->flags |= (1 << NFTA_RANGE_TO_DATA);
}
return ret;
}
static const char *expr_range_str[] = {
[NFT_RANGE_EQ] = "eq",
[NFT_RANGE_NEQ] = "neq",
};
static const char *range2str(uint32_t op)
{
if (op > NFT_RANGE_NEQ)
return "unknown";
return expr_range_str[op];
}
static inline int nftnl_str2range(const char *op)
{
if (strcmp(op, "eq") == 0)
return NFT_RANGE_EQ;
else if (strcmp(op, "neq") == 0)
return NFT_RANGE_NEQ;
else {
errno = EINVAL;
return -1;
}
}
static int nftnl_expr_range_snprintf_default(char *buf, size_t size,
const struct nftnl_expr *e)
{
struct nftnl_expr_range *range = nftnl_expr_data(e);
int remain = size, offset = 0, ret;
ret = snprintf(buf, remain, "%s reg %u ",
range2str(range->op), range->sreg);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_from,
NFTNL_OUTPUT_DEFAULT, 0, DATA_VALUE);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_to,
NFTNL_OUTPUT_DEFAULT, 0, DATA_VALUE);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
return offset;
}
static int nftnl_expr_range_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_range_snprintf_default(buf, size, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_range = {
.name = "range",
.alloc_len = sizeof(struct nftnl_expr_range),
.max_attr = NFTA_RANGE_MAX,
.set = nftnl_expr_range_set,
.get = nftnl_expr_range_get,
.parse = nftnl_expr_range_parse,
.build = nftnl_expr_range_build,
.snprintf = nftnl_expr_range_snprintf,
};
nftnl_expr_range
Definition: range.c:23