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/*
* (C) 2012 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 "internal.h"
#include <stdio.h>
#include <stdint.h>
#include <string.h> /* for memcpy */
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/netfilter/x_tables.h>
#include <libnftables/expr.h>
#include "expr_ops.h"
struct nft_expr_match {
char name[XT_EXTENSION_MAXNAMELEN];
uint32_t rev;
uint32_t data_len;
const void *data;
};
static int
nft_rule_expr_match_set(struct nft_rule_expr *e, uint16_t type,
const void *data, size_t data_len)
{
struct nft_expr_match *mt = (struct nft_expr_match *)e->data;
switch(type) {
case NFT_EXPR_MT_NAME:
memcpy(mt->name, data, XT_EXTENSION_MAXNAMELEN);
mt->name[XT_EXTENSION_MAXNAMELEN-1] = '\0';
break;
case NFT_EXPR_MT_REV:
mt->rev = *((uint32_t *)data);
break;
case NFT_EXPR_MT_INFO:
if (mt->data)
free((void *)mt->data);
mt->data = data;
mt->data_len = data_len;
break;
default:
return -1;
}
return 0;
}
static const void *
nft_rule_expr_match_get(struct nft_rule_expr *e, uint16_t type,
size_t *data_len)
{
struct nft_expr_match *mt = (struct nft_expr_match *)e->data;
switch(type) {
case NFT_EXPR_MT_NAME:
if (e->flags & (1 << NFT_EXPR_MT_NAME)) {
*data_len = sizeof(mt->name);
return mt->name;
} else
return NULL;
break;
case NFT_EXPR_MT_REV:
if (e->flags & (1 << NFT_EXPR_MT_REV)) {
*data_len = sizeof(mt->rev);
return &mt->rev;
} else
return NULL;
break;
case NFT_EXPR_MT_INFO:
if (e->flags & (1 << NFT_EXPR_MT_INFO)) {
*data_len = mt->data_len;
return mt->data;
} else
return NULL;
break;
default:
break;
}
return NULL;
}
static int nft_rule_expr_match_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_MATCH_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_MATCH_NAME:
if (mnl_attr_validate(attr, MNL_TYPE_NUL_STRING) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case NFTA_MATCH_REV:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case NFTA_MATCH_INFO:
if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nft_rule_expr_match_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
{
struct nft_expr_match *mt = (struct nft_expr_match *)e->data;
if (e->flags & (1 << NFT_EXPR_MT_NAME))
mnl_attr_put_strz(nlh, NFTA_MATCH_NAME, mt->name);
if (e->flags & (1 << NFT_EXPR_MT_REV))
mnl_attr_put_u32(nlh, NFTA_MATCH_REV, htonl(mt->rev));
if (e->flags & (1 << NFT_EXPR_MT_INFO))
mnl_attr_put(nlh, NFTA_MATCH_INFO, XT_ALIGN(mt->data_len), mt->data);
}
static int nft_rule_expr_match_parse(struct nft_rule_expr *e, struct nlattr *attr)
{
struct nft_expr_match *match = (struct nft_expr_match *)e->data;
struct nlattr *tb[NFTA_MATCH_MAX+1] = {};
if (mnl_attr_parse_nested(attr, nft_rule_expr_match_cb, tb) < 0)
return -1;
if (tb[NFTA_MATCH_NAME]) {
snprintf(match->name, XT_EXTENSION_MAXNAMELEN, "%s",
mnl_attr_get_str(tb[NFTA_MATCH_NAME]));
match->name[XT_EXTENSION_MAXNAMELEN-1] = '\0';
e->flags |= (1 << NFTA_MATCH_NAME);
}
if (tb[NFTA_MATCH_REV]) {
match->rev = ntohl(mnl_attr_get_u32(tb[NFTA_MATCH_REV]));
e->flags |= (1 << NFTA_MATCH_REV);
}
if (tb[NFTA_MATCH_INFO]) {
uint32_t len = mnl_attr_get_payload_len(tb[NFTA_MATCH_INFO]);
void *match_data;
if (match->data)
free((void *) match->data);
match_data = calloc(1, len);
if (match_data == NULL)
return -1;
memcpy(match_data, mnl_attr_get_payload(tb[NFTA_MATCH_INFO]), len);
match->data = match_data;
match->data_len = len;
e->flags |= (1 << NFTA_MATCH_INFO);
}
return 0;
}
static int
nft_rule_expr_match_snprintf(char *buf, size_t len, struct nft_rule_expr *e)
{
struct nft_expr_match *match = (struct nft_expr_match *)e->data;
return snprintf(buf, len, "name=%s rev=%u ",
match->name, match->rev);
}
struct expr_ops expr_ops_match = {
.name = "match",
.alloc_len = sizeof(struct nft_expr_match),
.max_attr = NFTA_MATCH_MAX,
.set = nft_rule_expr_match_set,
.get = nft_rule_expr_match_get,
.parse = nft_rule_expr_match_parse,
.build = nft_rule_expr_match_build,
.snprintf = nft_rule_expr_match_snprintf,
};
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