linux-stable/net/netfilter/nft_reject.c
Florian Westphal fa5950e498 netfilter: nf_tables: avoid BUG_ON usage
None of these spots really needs to crash the kernel.
In one two cases we can jsut report error to userspace, in the other
cases we can just use WARN_ON (and leak memory instead).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-17 16:11:12 +02:00

124 lines
3.2 KiB
C

/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
* Copyright (c) 2013 Eric Leblond <eric@regit.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_reject.h>
#include <linux/icmp.h>
#include <linux/icmpv6.h>
const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
[NFTA_REJECT_TYPE] = { .type = NLA_U32 },
[NFTA_REJECT_ICMP_CODE] = { .type = NLA_U8 },
};
EXPORT_SYMBOL_GPL(nft_reject_policy);
int nft_reject_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
return nft_chain_validate_hooks(ctx->chain,
(1 << NF_INET_LOCAL_IN) |
(1 << NF_INET_FORWARD) |
(1 << NF_INET_LOCAL_OUT));
}
EXPORT_SYMBOL_GPL(nft_reject_validate);
int nft_reject_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_reject *priv = nft_expr_priv(expr);
if (tb[NFTA_REJECT_TYPE] == NULL)
return -EINVAL;
priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
switch (priv->type) {
case NFT_REJECT_ICMP_UNREACH:
if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
return -EINVAL;
priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
case NFT_REJECT_TCP_RST:
break;
default:
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL_GPL(nft_reject_init);
int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_reject *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
goto nla_put_failure;
switch (priv->type) {
case NFT_REJECT_ICMP_UNREACH:
if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
goto nla_put_failure;
break;
default:
break;
}
return 0;
nla_put_failure:
return -1;
}
EXPORT_SYMBOL_GPL(nft_reject_dump);
static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
[NFT_REJECT_ICMPX_NO_ROUTE] = ICMP_NET_UNREACH,
[NFT_REJECT_ICMPX_PORT_UNREACH] = ICMP_PORT_UNREACH,
[NFT_REJECT_ICMPX_HOST_UNREACH] = ICMP_HOST_UNREACH,
[NFT_REJECT_ICMPX_ADMIN_PROHIBITED] = ICMP_PKT_FILTERED,
};
int nft_reject_icmp_code(u8 code)
{
if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
return ICMP_NET_UNREACH;
return icmp_code_v4[code];
}
EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
[NFT_REJECT_ICMPX_NO_ROUTE] = ICMPV6_NOROUTE,
[NFT_REJECT_ICMPX_PORT_UNREACH] = ICMPV6_PORT_UNREACH,
[NFT_REJECT_ICMPX_HOST_UNREACH] = ICMPV6_ADDR_UNREACH,
[NFT_REJECT_ICMPX_ADMIN_PROHIBITED] = ICMPV6_ADM_PROHIBITED,
};
int nft_reject_icmpv6_code(u8 code)
{
if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
return ICMPV6_NOROUTE;
return icmp_code_v6[code];
}
EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");