socket.c
/*
* Copyright (c) 2018 Máté Eckl <ecklm94@gmail.com>
*
* 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 <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_socket {
enum nft_socket_keys key;
enum nft_registers dreg;
};
static int
nftnl_expr_socket_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_socket *socket = nftnl_expr_data(e);
switch (type) {
case NFTNL_EXPR_SOCKET_KEY:
memcpy(&socket->key, data, sizeof(socket->key));
break;
case NFTNL_EXPR_SOCKET_DREG:
memcpy(&socket->dreg, data, sizeof(socket->dreg));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_socket_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_socket *socket = nftnl_expr_data(e);
switch (type) {
case NFTNL_EXPR_SOCKET_KEY:
*data_len = sizeof(socket->key);
return &socket->key;
case NFTNL_EXPR_SOCKET_DREG:
*data_len = sizeof(socket->dreg);
return &socket->dreg;
}
return NULL;
}
static int nftnl_expr_socket_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_SOCKET_MAX) < 0)
return MNL_CB_OK;
switch (type) {
case NFTA_SOCKET_KEY:
case NFTA_SOCKET_DREG:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_socket_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_socket *socket = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_SOCKET_KEY))
mnl_attr_put_u32(nlh, NFTA_SOCKET_KEY, htonl(socket->key));
if (e->flags & (1 << NFTNL_EXPR_SOCKET_DREG))
mnl_attr_put_u32(nlh, NFTA_SOCKET_DREG, htonl(socket->dreg));
}
static int
nftnl_expr_socket_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_socket *socket = nftnl_expr_data(e);
struct nlattr *tb[NFTA_SOCKET_MAX+1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_socket_cb, tb) < 0)
return -1;
if (tb[NFTA_SOCKET_KEY]) {
socket->key = ntohl(mnl_attr_get_u32(tb[NFTA_SOCKET_KEY]));
e->flags |= (1 << NFTNL_EXPR_SOCKET_KEY);
}
if (tb[NFTA_SOCKET_DREG]) {
socket->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_SOCKET_DREG]));
e->flags |= (1 << NFTNL_EXPR_SOCKET_DREG);
}
return 0;
}
static const char *socket_key2str_array[NFT_SOCKET_MAX + 1] = {
[NFT_SOCKET_TRANSPARENT] = "transparent",
[NFT_SOCKET_MARK] = "mark",
[NFT_SOCKET_WILDCARD] = "wildcard",
};
static const char *socket_key2str(uint8_t key)
{
if (key < NFT_SOCKET_MAX + 1)
return socket_key2str_array[key];
return "unknown";
}
static inline int str2socket_key(const char *str)
{
int i;
for (i = 0; i < NFT_SOCKET_MAX + 1; i++) {
if (strcmp(str, socket_key2str_array[i]) == 0)
return i;
}
errno = EINVAL;
return -1;
}
static int
nftnl_expr_socket_snprintf_default(char *buf, size_t len,
const struct nftnl_expr *e)
{
struct nftnl_expr_socket *socket = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_SOCKET_DREG)) {
return snprintf(buf, len, "load %s => reg %u ",
socket_key2str(socket->key), socket->dreg);
}
return 0;
}
static int
nftnl_expr_socket_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_socket_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_socket = {
.name = "socket",
.alloc_len = sizeof(struct nftnl_expr_socket),
.max_attr = NFTA_SOCKET_MAX,
.set = nftnl_expr_socket_set,
.get = nftnl_expr_socket_get,
.parse = nftnl_expr_socket_parse,
.build = nftnl_expr_socket_build,
.snprintf = nftnl_expr_socket_snprintf,
};
nftnl_expr_socket
Definition: socket.c:22