lookup.c
/*
* (C) 2012-2013 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 "internal.h"
#include <stdio.h>
#include <stdint.h>
#include <string.h> /* for memcpy */
#include <arpa/inet.h>
#include <errno.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter/nf_tables.h>
#include <libnftnl/rule.h>
#include <libnftnl/expr.h>
struct nftnl_expr_lookup {
enum nft_registers sreg;
enum nft_registers dreg;
char *set_name;
uint32_t set_id;
uint32_t flags;
};
static int
nftnl_expr_lookup_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_lookup *lookup = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_LOOKUP_SREG:
memcpy(&lookup->sreg, data, sizeof(lookup->sreg));
break;
case NFTNL_EXPR_LOOKUP_DREG:
memcpy(&lookup->dreg, data, sizeof(lookup->dreg));
break;
case NFTNL_EXPR_LOOKUP_SET:
lookup->set_name = strdup((const char *)data);
if (!lookup->set_name)
return -1;
break;
case NFTNL_EXPR_LOOKUP_SET_ID:
memcpy(&lookup->set_id, data, sizeof(lookup->set_id));
break;
case NFTNL_EXPR_LOOKUP_FLAGS:
memcpy(&lookup->flags, data, sizeof(lookup->flags));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_lookup_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_lookup *lookup = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_LOOKUP_SREG:
*data_len = sizeof(lookup->sreg);
return &lookup->sreg;
case NFTNL_EXPR_LOOKUP_DREG:
*data_len = sizeof(lookup->dreg);
return &lookup->dreg;
case NFTNL_EXPR_LOOKUP_SET:
*data_len = strlen(lookup->set_name) + 1;
return lookup->set_name;
case NFTNL_EXPR_LOOKUP_SET_ID:
*data_len = sizeof(lookup->set_id);
return &lookup->set_id;
case NFTNL_EXPR_LOOKUP_FLAGS:
*data_len = sizeof(lookup->flags);
return &lookup->flags;
}
return NULL;
}
static int nftnl_expr_lookup_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_LOOKUP_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_LOOKUP_SREG:
case NFTA_LOOKUP_DREG:
case NFTA_LOOKUP_SET_ID:
case NFTA_LOOKUP_FLAGS:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
case NFTA_LOOKUP_SET:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_lookup_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_lookup *lookup = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_SREG))
mnl_attr_put_u32(nlh, NFTA_LOOKUP_SREG, htonl(lookup->sreg));
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_DREG))
mnl_attr_put_u32(nlh, NFTA_LOOKUP_DREG, htonl(lookup->dreg));
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_SET))
mnl_attr_put_strz(nlh, NFTA_LOOKUP_SET, lookup->set_name);
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_SET_ID))
mnl_attr_put_u32(nlh, NFTA_LOOKUP_SET_ID,
htonl(lookup->set_id));
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_FLAGS))
mnl_attr_put_u32(nlh, NFTA_LOOKUP_FLAGS, htonl(lookup->flags));
}
static int
nftnl_expr_lookup_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_lookup *lookup = nftnl_expr_data(e);
struct nlattr *tb[NFTA_LOOKUP_MAX+1] = {};
int ret = 0;
if (mnl_attr_parse_nested(attr, nftnl_expr_lookup_cb, tb) < 0)
return -1;
if (tb[NFTA_LOOKUP_SREG]) {
lookup->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_SREG]));
e->flags |= (1 << NFTNL_EXPR_LOOKUP_SREG);
}
if (tb[NFTA_LOOKUP_DREG]) {
lookup->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_DREG]));
e->flags |= (1 << NFTNL_EXPR_LOOKUP_DREG);
}
if (tb[NFTA_LOOKUP_SET]) {
lookup->set_name =
strdup(mnl_attr_get_str(tb[NFTA_LOOKUP_SET]));
if (!lookup->set_name)
return -1;
e->flags |= (1 << NFTNL_EXPR_LOOKUP_SET);
}
if (tb[NFTA_LOOKUP_SET_ID]) {
lookup->set_id =
ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_SET_ID]));
e->flags |= (1 << NFTNL_EXPR_LOOKUP_SET_ID);
}
if (tb[NFTA_LOOKUP_FLAGS]) {
lookup->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOOKUP_FLAGS]));
e->flags |= (1 << NFTNL_EXPR_LOOKUP_FLAGS);
}
return ret;
}
static int
nftnl_expr_lookup_snprintf_default(char *buf, size_t size,
const struct nftnl_expr *e)
{
int remain = size, offset = 0, ret;
struct nftnl_expr_lookup *l = nftnl_expr_data(e);
ret = snprintf(buf, remain, "reg %u set %s ", l->sreg, l->set_name);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_DREG)) {
ret = snprintf(buf + offset, remain, "dreg %u ", l->dreg);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (e->flags & (1 << NFTNL_EXPR_LOOKUP_FLAGS)) {
ret = snprintf(buf + offset, remain, "0x%x ", l->flags);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
return offset;
}
static int
nftnl_expr_lookup_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_lookup_snprintf_default(buf, size, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
static void nftnl_expr_lookup_free(const struct nftnl_expr *e)
{
struct nftnl_expr_lookup *lookup = nftnl_expr_data(e);
xfree(lookup->set_name);
}
struct expr_ops expr_ops_lookup = {
.name = "lookup",
.alloc_len = sizeof(struct nftnl_expr_lookup),
.max_attr = NFTA_LOOKUP_MAX,
.free = nftnl_expr_lookup_free,
.set = nftnl_expr_lookup_set,
.get = nftnl_expr_lookup_get,
.parse = nftnl_expr_lookup_parse,
.build = nftnl_expr_lookup_build,
.snprintf = nftnl_expr_lookup_snprintf,
};
nftnl_expr_lookup
Definition: lookup.c:24