reject.c
/*
* (C) 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 <stdint.h>
#include <string.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_reject {
uint32_t type;
uint8_t icmp_code;
};
static int nftnl_expr_reject_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_reject *reject = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_REJECT_TYPE:
memcpy(&reject->type, data, sizeof(reject->type));
break;
case NFTNL_EXPR_REJECT_CODE:
memcpy(&reject->icmp_code, data, sizeof(reject->icmp_code));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_reject_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_reject *reject = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_REJECT_TYPE:
*data_len = sizeof(reject->type);
return &reject->type;
case NFTNL_EXPR_REJECT_CODE:
*data_len = sizeof(reject->icmp_code);
return &reject->icmp_code;
}
return NULL;
}
static int nftnl_expr_reject_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_REJECT_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_REJECT_TYPE:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
case NFTA_REJECT_ICMP_CODE:
if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_reject_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_reject *reject = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_REJECT_TYPE))
mnl_attr_put_u32(nlh, NFTA_REJECT_TYPE, htonl(reject->type));
if (e->flags & (1 << NFTNL_EXPR_REJECT_CODE))
mnl_attr_put_u8(nlh, NFTA_REJECT_ICMP_CODE, reject->icmp_code);
}
static int
nftnl_expr_reject_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_reject *reject = nftnl_expr_data(e);
struct nlattr *tb[NFTA_REJECT_MAX+1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_reject_cb, tb) < 0)
return -1;
if (tb[NFTA_REJECT_TYPE]) {
reject->type = ntohl(mnl_attr_get_u32(tb[NFTA_REJECT_TYPE]));
e->flags |= (1 << NFTNL_EXPR_REJECT_TYPE);
}
if (tb[NFTA_REJECT_ICMP_CODE]) {
reject->icmp_code = mnl_attr_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
e->flags |= (1 << NFTNL_EXPR_REJECT_CODE);
}
return 0;
}
static int nftnl_expr_reject_snprintf_default(char *buf, size_t len,
const struct nftnl_expr *e)
{
struct nftnl_expr_reject *reject = nftnl_expr_data(e);
return snprintf(buf, len, "type %u code %u ",
reject->type, reject->icmp_code);
}
static int
nftnl_expr_reject_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_reject_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_reject = {
.name = "reject",
.alloc_len = sizeof(struct nftnl_expr_reject),
.max_attr = NFTA_REJECT_MAX,
.set = nftnl_expr_reject_set,
.get = nftnl_expr_reject_get,
.parse = nftnl_expr_reject_parse,
.build = nftnl_expr_reject_build,
.snprintf = nftnl_expr_reject_snprintf,
};
nftnl_expr_reject
Definition: reject.c:24