ct_helper.c
/*
* (C) 2017 Red Hat GmbH
* Author: Florian Westphal <fw@strlen.de>
*
* 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/object.h>
#include "obj.h"
static int nftnl_obj_ct_helper_set(struct nftnl_obj *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_obj_ct_helper *helper = nftnl_obj_data(e);
switch (type) {
case NFTNL_OBJ_CT_HELPER_NAME:
snprintf(helper->name, sizeof(helper->name), "%s", (const char *)data);
break;
case NFTNL_OBJ_CT_HELPER_L3PROTO:
memcpy(&helper->l3proto, data, sizeof(helper->l3proto));
break;
case NFTNL_OBJ_CT_HELPER_L4PROTO:
memcpy(&helper->l4proto, data, sizeof(helper->l4proto));
break;
default:
return -1;
}
return 0;
}
static const void *nftnl_obj_ct_helper_get(const struct nftnl_obj *e,
uint16_t type, uint32_t *data_len)
{
struct nftnl_obj_ct_helper *helper = nftnl_obj_data(e);
switch (type) {
case NFTNL_OBJ_CT_HELPER_NAME:
*data_len = strlen(helper->name);
return helper->name;
case NFTNL_OBJ_CT_HELPER_L3PROTO:
*data_len = sizeof(helper->l3proto);
return &helper->l3proto;
case NFTNL_OBJ_CT_HELPER_L4PROTO:
*data_len = sizeof(helper->l4proto);
return &helper->l4proto;
}
return NULL;
}
static int nftnl_obj_ct_helper_cb(const struct nlattr *attr, void *data)
{
const struct nftnl_obj_ct_helper *helper = NULL;
int type = mnl_attr_get_type(attr);
const struct nlattr **tb = data;
if (mnl_attr_type_valid(attr, NFTA_CT_HELPER_MAX) < 0)
return MNL_CB_OK;
switch (type) {
case NFTA_CT_HELPER_NAME:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
abi_breakage();
if (mnl_attr_get_payload_len(attr) >= sizeof(helper->name))
abi_breakage();
break;
case NFTA_CT_HELPER_L3PROTO:
if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
abi_breakage();
break;
case NFTA_CT_HELPER_L4PROTO:
if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_obj_ct_helper_build(struct nlmsghdr *nlh, const struct nftnl_obj *e)
{
struct nftnl_obj_ct_helper *helper = nftnl_obj_data(e);
if (e->flags & (1 << NFTNL_OBJ_CT_HELPER_NAME))
mnl_attr_put_str(nlh, NFTA_CT_HELPER_NAME, helper->name);
if (e->flags & (1 << NFTNL_OBJ_CT_HELPER_L3PROTO))
mnl_attr_put_u16(nlh, NFTA_CT_HELPER_L3PROTO, htons(helper->l3proto));
if (e->flags & (1 << NFTNL_OBJ_CT_HELPER_L4PROTO))
mnl_attr_put_u8(nlh, NFTA_CT_HELPER_L4PROTO, helper->l4proto);
}
static int
nftnl_obj_ct_helper_parse(struct nftnl_obj *e, struct nlattr *attr)
{
struct nftnl_obj_ct_helper *helper = nftnl_obj_data(e);
struct nlattr *tb[NFTA_CT_HELPER_MAX + 1] = {};
if (mnl_attr_parse_nested(attr, nftnl_obj_ct_helper_cb, tb) < 0)
return -1;
if (tb[NFTA_CT_HELPER_NAME]) {
snprintf(helper->name, sizeof(helper->name), "%s",
mnl_attr_get_str(tb[NFTA_CT_HELPER_NAME]));
e->flags |= (1 << NFTNL_OBJ_CT_HELPER_NAME);
}
if (tb[NFTA_CT_HELPER_L3PROTO]) {
helper->l3proto = ntohs(mnl_attr_get_u16(tb[NFTA_CT_HELPER_L3PROTO]));
e->flags |= (1 << NFTNL_OBJ_CT_HELPER_L3PROTO);
}
if (tb[NFTA_CT_HELPER_L4PROTO]) {
helper->l4proto = mnl_attr_get_u8(tb[NFTA_CT_HELPER_L4PROTO]);
e->flags |= (1 << NFTNL_OBJ_CT_HELPER_L4PROTO);
}
return 0;
}
static int nftnl_obj_ct_helper_snprintf_default(char *buf, size_t len,
const struct nftnl_obj *e)
{
struct nftnl_obj_ct_helper *helper = nftnl_obj_data(e);
return snprintf(buf, len, "name %s family %d protocol %d ",
helper->name, helper->l3proto, helper->l4proto);
}
static int nftnl_obj_ct_helper_snprintf(char *buf, size_t len, uint32_t type,
uint32_t flags,
const struct nftnl_obj *e)
{
if (len)
buf[0] = '\0';
switch (type) {
case NFTNL_OUTPUT_DEFAULT:
return nftnl_obj_ct_helper_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct obj_ops obj_ops_ct_helper = {
.name = "ct_helper",
.type = NFT_OBJECT_CT_HELPER,
.alloc_len = sizeof(struct nftnl_obj_ct_helper),
.max_attr = NFTA_CT_HELPER_MAX,
.set = nftnl_obj_ct_helper_set,
.get = nftnl_obj_ct_helper_get,
.parse = nftnl_obj_ct_helper_parse,
.build = nftnl_obj_ct_helper_build,
.snprintf = nftnl_obj_ct_helper_snprintf,
};