mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Lukas Bulwahn](/assets/img/avatar_default.png)
Commit fdacd57c79
("netfilter: x_tables: never register tables by
default") introduces the function xt_register_template(), and in one case,
a call to that function was missing the error-case handling.
Handle when xt_register_template() returns an error value.
This was identified with the clang-analyzer's Dead-Store analysis.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
143 lines
3.4 KiB
C
143 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
|
|
*
|
|
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
|
|
* Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/netfilter_ipv4/ip_tables.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/slab.h>
|
|
#include <net/sock.h>
|
|
#include <net/route.h>
|
|
#include <linux/ip.h>
|
|
#include <net/ip.h>
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
|
|
MODULE_DESCRIPTION("iptables mangle table");
|
|
|
|
#define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \
|
|
(1 << NF_INET_LOCAL_IN) | \
|
|
(1 << NF_INET_FORWARD) | \
|
|
(1 << NF_INET_LOCAL_OUT) | \
|
|
(1 << NF_INET_POST_ROUTING))
|
|
|
|
static const struct xt_table packet_mangler = {
|
|
.name = "mangle",
|
|
.valid_hooks = MANGLE_VALID_HOOKS,
|
|
.me = THIS_MODULE,
|
|
.af = NFPROTO_IPV4,
|
|
.priority = NF_IP_PRI_MANGLE,
|
|
};
|
|
|
|
static unsigned int
|
|
ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state, void *priv)
|
|
{
|
|
unsigned int ret;
|
|
const struct iphdr *iph;
|
|
u_int8_t tos;
|
|
__be32 saddr, daddr;
|
|
u_int32_t mark;
|
|
int err;
|
|
|
|
/* Save things which could affect route */
|
|
mark = skb->mark;
|
|
iph = ip_hdr(skb);
|
|
saddr = iph->saddr;
|
|
daddr = iph->daddr;
|
|
tos = iph->tos;
|
|
|
|
ret = ipt_do_table(skb, state, priv);
|
|
/* Reroute for ANY change. */
|
|
if (ret != NF_DROP && ret != NF_STOLEN) {
|
|
iph = ip_hdr(skb);
|
|
|
|
if (iph->saddr != saddr ||
|
|
iph->daddr != daddr ||
|
|
skb->mark != mark ||
|
|
iph->tos != tos) {
|
|
err = ip_route_me_harder(state->net, state->sk, skb, RTN_UNSPEC);
|
|
if (err < 0)
|
|
ret = NF_DROP_ERR(err);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* The work comes in here from netfilter.c. */
|
|
static unsigned int
|
|
iptable_mangle_hook(void *priv,
|
|
struct sk_buff *skb,
|
|
const struct nf_hook_state *state)
|
|
{
|
|
if (state->hook == NF_INET_LOCAL_OUT)
|
|
return ipt_mangle_out(skb, state, priv);
|
|
return ipt_do_table(skb, state, priv);
|
|
}
|
|
|
|
static struct nf_hook_ops *mangle_ops __read_mostly;
|
|
static int iptable_mangle_table_init(struct net *net)
|
|
{
|
|
struct ipt_replace *repl;
|
|
int ret;
|
|
|
|
repl = ipt_alloc_initial_table(&packet_mangler);
|
|
if (repl == NULL)
|
|
return -ENOMEM;
|
|
ret = ipt_register_table(net, &packet_mangler, repl, mangle_ops);
|
|
kfree(repl);
|
|
return ret;
|
|
}
|
|
|
|
static void __net_exit iptable_mangle_net_pre_exit(struct net *net)
|
|
{
|
|
ipt_unregister_table_pre_exit(net, "mangle");
|
|
}
|
|
|
|
static void __net_exit iptable_mangle_net_exit(struct net *net)
|
|
{
|
|
ipt_unregister_table_exit(net, "mangle");
|
|
}
|
|
|
|
static struct pernet_operations iptable_mangle_net_ops = {
|
|
.pre_exit = iptable_mangle_net_pre_exit,
|
|
.exit = iptable_mangle_net_exit,
|
|
};
|
|
|
|
static int __init iptable_mangle_init(void)
|
|
{
|
|
int ret = xt_register_template(&packet_mangler,
|
|
iptable_mangle_table_init);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
mangle_ops = xt_hook_ops_alloc(&packet_mangler, iptable_mangle_hook);
|
|
if (IS_ERR(mangle_ops)) {
|
|
xt_unregister_template(&packet_mangler);
|
|
ret = PTR_ERR(mangle_ops);
|
|
return ret;
|
|
}
|
|
|
|
ret = register_pernet_subsys(&iptable_mangle_net_ops);
|
|
if (ret < 0) {
|
|
xt_unregister_template(&packet_mangler);
|
|
kfree(mangle_ops);
|
|
return ret;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit iptable_mangle_fini(void)
|
|
{
|
|
unregister_pernet_subsys(&iptable_mangle_net_ops);
|
|
xt_unregister_template(&packet_mangler);
|
|
kfree(mangle_ops);
|
|
}
|
|
|
|
module_init(iptable_mangle_init);
|
|
module_exit(iptable_mangle_fini);
|