redir.c
/*
* (C) 2014 by Arturo Borrero Gonzalez <arturo@debian.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 <stdio.h>
#include <stdint.h>
#include <arpa/inet.h>
#include <errno.h>
#include <inttypes.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_redir {
enum nft_registers sreg_proto_min;
enum nft_registers sreg_proto_max;
uint32_t flags;
};
static int
nftnl_expr_redir_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_redir *redir = nftnl_expr_data(e);
switch (type) {
case NFTNL_EXPR_REDIR_REG_PROTO_MIN:
memcpy(&redir->sreg_proto_min, data, sizeof(redir->sreg_proto_min));
break;
case NFTNL_EXPR_REDIR_REG_PROTO_MAX:
memcpy(&redir->sreg_proto_max, data, sizeof(redir->sreg_proto_max));
break;
case NFTNL_EXPR_REDIR_FLAGS:
memcpy(&redir->flags, data, sizeof(redir->flags));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_redir_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_redir *redir = nftnl_expr_data(e);
switch (type) {
case NFTNL_EXPR_REDIR_REG_PROTO_MIN:
*data_len = sizeof(redir->sreg_proto_min);
return &redir->sreg_proto_min;
case NFTNL_EXPR_REDIR_REG_PROTO_MAX:
*data_len = sizeof(redir->sreg_proto_max);
return &redir->sreg_proto_max;
case NFTNL_EXPR_REDIR_FLAGS:
*data_len = sizeof(redir->flags);
return &redir->flags;
}
return NULL;
}
static int nftnl_expr_redir_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_REDIR_MAX) < 0)
return MNL_CB_OK;
switch (type) {
case NFTA_REDIR_REG_PROTO_MIN:
case NFTA_REDIR_REG_PROTO_MAX:
case NFTA_REDIR_FLAGS:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_redir_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_redir *redir = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_REDIR_REG_PROTO_MIN))
mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MIN,
htobe32(redir->sreg_proto_min));
if (e->flags & (1 << NFTNL_EXPR_REDIR_REG_PROTO_MAX))
mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MAX,
htobe32(redir->sreg_proto_max));
if (e->flags & (1 << NFTNL_EXPR_REDIR_FLAGS))
mnl_attr_put_u32(nlh, NFTA_REDIR_FLAGS, htobe32(redir->flags));
}
static int
nftnl_expr_redir_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_redir *redir = nftnl_expr_data(e);
struct nlattr *tb[NFTA_REDIR_MAX + 1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_redir_cb, tb) < 0)
return -1;
if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
redir->sreg_proto_min =
ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MIN]));
e->flags |= (1 << NFTNL_EXPR_REDIR_REG_PROTO_MIN);
}
if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
redir->sreg_proto_max =
ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MAX]));
e->flags |= (1 << NFTNL_EXPR_REDIR_REG_PROTO_MAX);
}
if (tb[NFTA_REDIR_FLAGS]) {
redir->flags = be32toh(mnl_attr_get_u32(tb[NFTA_REDIR_FLAGS]));
e->flags |= (1 << NFTNL_EXPR_REDIR_FLAGS);
}
return 0;
}
static int nftnl_expr_redir_snprintf_default(char *buf, size_t len,
const struct nftnl_expr *e)
{
int ret, remain = len, offset = 0;
struct nftnl_expr_redir *redir = nftnl_expr_data(e);
if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_REG_PROTO_MIN)) {
ret = snprintf(buf + offset, len, "proto_min reg %u ",
redir->sreg_proto_min);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_REG_PROTO_MAX)) {
ret = snprintf(buf + offset, len, "proto_max reg %u ",
redir->sreg_proto_max);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_FLAGS)) {
ret = snprintf(buf + offset, len, "flags 0x%x ",
redir->flags);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
return offset;
}
static int
nftnl_expr_redir_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_redir_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_redir = {
.name = "redir",
.alloc_len = sizeof(struct nftnl_expr_redir),
.max_attr = NFTA_REDIR_MAX,
.set = nftnl_expr_redir_set,
.get = nftnl_expr_redir_get,
.parse = nftnl_expr_redir_parse,
.build = nftnl_expr_redir_build,
.snprintf = nftnl_expr_redir_snprintf,
};
nftnl_expr_redir
Definition: redir.c:23