meta.c
/*
* (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 <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>
#ifndef NFT_META_MAX
#define NFT_META_MAX (NFT_META_SDIFNAME + 1)
#endif
struct nftnl_expr_meta {
enum nft_meta_keys key;
enum nft_registers dreg;
enum nft_registers sreg;
};
static int
nftnl_expr_meta_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_meta *meta = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_META_KEY:
memcpy(&meta->key, data, sizeof(meta->key));
break;
case NFTNL_EXPR_META_DREG:
memcpy(&meta->dreg, data, sizeof(meta->dreg));
break;
case NFTNL_EXPR_META_SREG:
memcpy(&meta->sreg, data, sizeof(meta->sreg));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_meta_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_meta *meta = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_META_KEY:
*data_len = sizeof(meta->key);
return &meta->key;
case NFTNL_EXPR_META_DREG:
*data_len = sizeof(meta->dreg);
return &meta->dreg;
case NFTNL_EXPR_META_SREG:
*data_len = sizeof(meta->sreg);
return &meta->sreg;
}
return NULL;
}
static int nftnl_expr_meta_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_META_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_META_KEY:
case NFTA_META_DREG:
case NFTA_META_SREG:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_meta_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_meta *meta = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_META_KEY))
mnl_attr_put_u32(nlh, NFTA_META_KEY, htonl(meta->key));
if (e->flags & (1 << NFTNL_EXPR_META_DREG))
mnl_attr_put_u32(nlh, NFTA_META_DREG, htonl(meta->dreg));
if (e->flags & (1 << NFTNL_EXPR_META_SREG))
mnl_attr_put_u32(nlh, NFTA_META_SREG, htonl(meta->sreg));
}
static int
nftnl_expr_meta_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_meta *meta = nftnl_expr_data(e);
struct nlattr *tb[NFTA_META_MAX+1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_meta_cb, tb) < 0)
return -1;
if (tb[NFTA_META_KEY]) {
meta->key = ntohl(mnl_attr_get_u32(tb[NFTA_META_KEY]));
e->flags |= (1 << NFTNL_EXPR_META_KEY);
}
if (tb[NFTA_META_DREG]) {
meta->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_META_DREG]));
e->flags |= (1 << NFTNL_EXPR_META_DREG);
}
if (tb[NFTA_META_SREG]) {
meta->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_META_SREG]));
e->flags |= (1 << NFTNL_EXPR_META_SREG);
}
return 0;
}
static const char *meta_key2str_array[NFT_META_MAX] = {
[NFT_META_LEN] = "len",
[NFT_META_PROTOCOL] = "protocol",
[NFT_META_NFPROTO] = "nfproto",
[NFT_META_L4PROTO] = "l4proto",
[NFT_META_PRIORITY] = "priority",
[NFT_META_MARK] = "mark",
[NFT_META_IIF] = "iif",
[NFT_META_OIF] = "oif",
[NFT_META_IIFNAME] = "iifname",
[NFT_META_OIFNAME] = "oifname",
[NFT_META_IIFTYPE] = "iiftype",
[NFT_META_OIFTYPE] = "oiftype",
[NFT_META_SKUID] = "skuid",
[NFT_META_SKGID] = "skgid",
[NFT_META_NFTRACE] = "nftrace",
[NFT_META_RTCLASSID] = "rtclassid",
[NFT_META_SECMARK] = "secmark",
[NFT_META_BRI_IIFNAME] = "bri_iifname",
[NFT_META_BRI_OIFNAME] = "bri_oifname",
[NFT_META_PKTTYPE] = "pkttype",
[NFT_META_CPU] = "cpu",
[NFT_META_IIFGROUP] = "iifgroup",
[NFT_META_OIFGROUP] = "oifgroup",
[NFT_META_CGROUP] = "cgroup",
[NFT_META_PRANDOM] = "prandom",
[NFT_META_SECPATH] = "secpath",
[NFT_META_IIFKIND] = "iifkind",
[NFT_META_OIFKIND] = "oifkind",
[NFT_META_BRI_IIFPVID] = "bri_iifpvid",
[NFT_META_BRI_IIFVPROTO] = "bri_iifvproto",
[NFT_META_TIME_NS] = "time",
[NFT_META_TIME_DAY] = "day",
[NFT_META_TIME_HOUR] = "hour",
[NFT_META_SDIF] = "sdif",
[NFT_META_SDIFNAME] = "sdifname",
};
static const char *meta_key2str(uint8_t key)
{
if (key < NFT_META_MAX)
return meta_key2str_array[key];
return "unknown";
}
static inline int str2meta_key(const char *str)
{
int i;
for (i = 0; i < NFT_META_MAX; i++) {
if (strcmp(str, meta_key2str_array[i]) == 0)
return i;
}
errno = EINVAL;
return -1;
}
static int
nftnl_expr_meta_snprintf_default(char *buf, size_t len,
const struct nftnl_expr *e)
{
struct nftnl_expr_meta *meta = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_META_SREG)) {
return snprintf(buf, len, "set %s with reg %u ",
meta_key2str(meta->key), meta->sreg);
}
if (e->flags & (1 << NFTNL_EXPR_META_DREG)) {
return snprintf(buf, len, "load %s => reg %u ",
meta_key2str(meta->key), meta->dreg);
}
return 0;
}
static int
nftnl_expr_meta_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_meta_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_meta = {
.name = "meta",
.alloc_len = sizeof(struct nftnl_expr_meta),
.max_attr = NFTA_META_MAX,
.set = nftnl_expr_meta_set,
.get = nftnl_expr_meta_get,
.parse = nftnl_expr_meta_parse,
.build = nftnl_expr_meta_build,
.snprintf = nftnl_expr_meta_snprintf,
};
nftnl_expr_meta
Definition: meta.c:28