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Message-Id: <20210426171056.345271-12-pablo@netfilter.org>
Date: Mon, 26 Apr 2021 19:10:45 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net, netdev@...r.kernel.org, kuba@...nel.org
Subject: [PATCH net-next 11/22] netfilter: xt_nat: pass table to hookfn
From: Florian Westphal <fw@...len.de>
This changes how ip(6)table nat passes the ruleset/table to the
evaluation loop.
At the moment, it will fetch the table from struct net.
This change stores the table in the hook_ops 'priv' argument
instead.
This requires to duplicate the hook_ops for each netns, so
they can store the (per-net) xt_table structure.
The dupliated nat hook_ops get stored in net_generic data area.
They are free'd in the namespace exit path.
This is a pre-requisite to remove the xt_table/ruleset pointers
from struct net.
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
net/ipv4/netfilter/iptable_nat.c | 44 +++++++++++++++++++++++-------
net/ipv6/netfilter/ip6table_nat.c | 45 ++++++++++++++++++++++++-------
2 files changed, 69 insertions(+), 20 deletions(-)
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
index f4afd28ccc06..dfa9dc63a7b5 100644
--- a/net/ipv4/netfilter/iptable_nat.c
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -13,8 +13,14 @@
#include <net/netfilter/nf_nat.h>
+struct iptable_nat_pernet {
+ struct nf_hook_ops *nf_nat_ops;
+};
+
static int __net_init iptable_nat_table_init(struct net *net);
+static unsigned int iptable_nat_net_id __read_mostly;
+
static const struct xt_table nf_nat_ipv4_table = {
.name = "nat",
.valid_hooks = (1 << NF_INET_PRE_ROUTING) |
@@ -30,7 +36,7 @@ static unsigned int iptable_nat_do_chain(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
- return ipt_do_table(skb, state, state->net->ipv4.nat_table);
+ return ipt_do_table(skb, state, priv);
}
static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
@@ -60,50 +66,67 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
},
};
-static int ipt_nat_register_lookups(struct net *net)
+static int ipt_nat_register_lookups(struct net *net, struct xt_table *table)
{
+ struct nf_hook_ops *ops = kmemdup(nf_nat_ipv4_ops, sizeof(nf_nat_ipv4_ops), GFP_KERNEL);
+ struct iptable_nat_pernet *xt_nat_net = net_generic(net, iptable_nat_net_id);
int i, ret;
+ if (!ops)
+ return -ENOMEM;
+
for (i = 0; i < ARRAY_SIZE(nf_nat_ipv4_ops); i++) {
- ret = nf_nat_ipv4_register_fn(net, &nf_nat_ipv4_ops[i]);
+ ops[i].priv = table;
+ ret = nf_nat_ipv4_register_fn(net, &ops[i]);
if (ret) {
while (i)
- nf_nat_ipv4_unregister_fn(net, &nf_nat_ipv4_ops[--i]);
+ nf_nat_ipv4_unregister_fn(net, &ops[--i]);
+ kfree(ops);
return ret;
}
}
+ xt_nat_net->nf_nat_ops = ops;
return 0;
}
static void ipt_nat_unregister_lookups(struct net *net)
{
+ struct iptable_nat_pernet *xt_nat_net = net_generic(net, iptable_nat_net_id);
+ struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;
int i;
+ if (!ops)
+ return;
+
for (i = 0; i < ARRAY_SIZE(nf_nat_ipv4_ops); i++)
- nf_nat_ipv4_unregister_fn(net, &nf_nat_ipv4_ops[i]);
+ nf_nat_ipv4_unregister_fn(net, &ops[i]);
+
+ kfree(ops);
}
static int __net_init iptable_nat_table_init(struct net *net)
{
struct ipt_replace *repl;
+ struct xt_table *table;
int ret;
repl = ipt_alloc_initial_table(&nf_nat_ipv4_table);
if (repl == NULL)
return -ENOMEM;
ret = ipt_register_table(net, &nf_nat_ipv4_table, repl,
- NULL, &net->ipv4.nat_table);
+ NULL, &table);
if (ret < 0) {
kfree(repl);
return ret;
}
- ret = ipt_nat_register_lookups(net);
+ ret = ipt_nat_register_lookups(net, table);
if (ret < 0) {
ipt_unregister_table_exit(net, "nat");
- net->ipv4.nat_table = NULL;
+ } else {
+ net->ipv4.nat_table = table;
}
kfree(repl);
@@ -112,8 +135,7 @@ static int __net_init iptable_nat_table_init(struct net *net)
static void __net_exit iptable_nat_net_pre_exit(struct net *net)
{
- if (net->ipv4.nat_table)
- ipt_nat_unregister_lookups(net);
+ ipt_nat_unregister_lookups(net);
}
static void __net_exit iptable_nat_net_exit(struct net *net)
@@ -125,6 +147,8 @@ static void __net_exit iptable_nat_net_exit(struct net *net)
static struct pernet_operations iptable_nat_net_ops = {
.pre_exit = iptable_nat_net_pre_exit,
.exit = iptable_nat_net_exit,
+ .id = &iptable_nat_net_id,
+ .size = sizeof(struct iptable_nat_pernet),
};
static int __init iptable_nat_init(void)
diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c
index c7f98755191b..69b7f9601d03 100644
--- a/net/ipv6/netfilter/ip6table_nat.c
+++ b/net/ipv6/netfilter/ip6table_nat.c
@@ -15,8 +15,14 @@
#include <net/netfilter/nf_nat.h>
+struct ip6table_nat_pernet {
+ struct nf_hook_ops *nf_nat_ops;
+};
+
static int __net_init ip6table_nat_table_init(struct net *net);
+static unsigned int ip6table_nat_net_id __read_mostly;
+
static const struct xt_table nf_nat_ipv6_table = {
.name = "nat",
.valid_hooks = (1 << NF_INET_PRE_ROUTING) |
@@ -32,7 +38,7 @@ static unsigned int ip6table_nat_do_chain(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
- return ip6t_do_table(skb, state, state->net->ipv6.ip6table_nat);
+ return ip6t_do_table(skb, state, priv);
}
static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
@@ -62,59 +68,76 @@ static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
},
};
-static int ip6t_nat_register_lookups(struct net *net)
+static int ip6t_nat_register_lookups(struct net *net, struct xt_table *table)
{
+ struct nf_hook_ops *ops = kmemdup(nf_nat_ipv6_ops, sizeof(nf_nat_ipv6_ops), GFP_KERNEL);
+ struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);
int i, ret;
+ if (!ops)
+ return -ENOMEM;
+
for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) {
- ret = nf_nat_ipv6_register_fn(net, &nf_nat_ipv6_ops[i]);
+ ops[i].priv = table;
+ ret = nf_nat_ipv6_register_fn(net, &ops[i]);
if (ret) {
while (i)
- nf_nat_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[--i]);
+ nf_nat_ipv6_unregister_fn(net, &ops[--i]);
+ kfree(ops);
return ret;
}
}
+ xt_nat_net->nf_nat_ops = ops;
return 0;
}
static void ip6t_nat_unregister_lookups(struct net *net)
{
+ struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);
+ struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;
int i;
+ if (!ops)
+ return;
+
for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++)
- nf_nat_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[i]);
+ nf_nat_ipv6_unregister_fn(net, &ops[i]);
+
+ kfree(ops);
}
static int __net_init ip6table_nat_table_init(struct net *net)
{
struct ip6t_replace *repl;
+ struct xt_table *table;
int ret;
repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
if (repl == NULL)
return -ENOMEM;
ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl,
- NULL, &net->ipv6.ip6table_nat);
+ NULL, &table);
if (ret < 0) {
kfree(repl);
return ret;
}
- ret = ip6t_nat_register_lookups(net);
+ ret = ip6t_nat_register_lookups(net, table);
if (ret < 0) {
ip6t_unregister_table_exit(net, "nat");
- net->ipv6.ip6table_nat = NULL;
+ } else {
+ net->ipv6.ip6table_nat = table;
}
+
kfree(repl);
return ret;
}
static void __net_exit ip6table_nat_net_pre_exit(struct net *net)
{
- if (net->ipv6.ip6table_nat)
- ip6t_nat_unregister_lookups(net);
+ ip6t_nat_unregister_lookups(net);
}
static void __net_exit ip6table_nat_net_exit(struct net *net)
@@ -126,6 +149,8 @@ static void __net_exit ip6table_nat_net_exit(struct net *net)
static struct pernet_operations ip6table_nat_net_ops = {
.pre_exit = ip6table_nat_net_pre_exit,
.exit = ip6table_nat_net_exit,
+ .id = &ip6table_nat_net_id,
+ .size = sizeof(struct ip6table_nat_pernet),
};
static int __init ip6table_nat_init(void)
--
2.30.2
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