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authorFlorian Westphal <fw@strlen.de>2021-04-21 09:51:07 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2021-04-26 03:20:46 +0200
commitae689334225ff0e4ef112459ecd24aea932c2b00 (patch)
treec1bc1091f9f95be7de8745d578d95ed8368f730e /net
parentnetfilter: xt_nat: pass table to hookfn (diff)
downloadlinux-ae689334225ff0e4ef112459ecd24aea932c2b00.tar.xz
linux-ae689334225ff0e4ef112459ecd24aea932c2b00.zip
netfilter: ip_tables: pass table pointer via nf_hook_ops
iptable_x modules rely on 'struct net' to contain a pointer to the table that should be evaluated. In order to remove these pointers from struct net, pass them via the 'priv' pointer in a similar fashion as nf_tables passes the rule data. To do that, duplicate the nf_hook_info array passed in from the iptable_x modules, update the ops->priv pointers of the copy to refer to the table and then change the hookfn implementations to just pass the 'priv' argument to the traverser. After this patch, the xt_table pointers can already be removed from struct net. However, changes to struct net result in re-compile of the entire network stack, so do the removal after arptables and ip6tables have been converted as well. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/netfilter/ip_tables.c53
-rw-r--r--net/ipv4/netfilter/iptable_filter.c8
-rw-r--r--net/ipv4/netfilter/iptable_mangle.c14
-rw-r--r--net/ipv4/netfilter/iptable_nat.c26
-rw-r--r--net/ipv4/netfilter/iptable_raw.c8
-rw-r--r--net/ipv4/netfilter/iptable_security.c8
-rw-r--r--net/netfilter/x_tables.c1
7 files changed, 66 insertions, 52 deletions
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 0b859ec2d3f8..d6caaed5dd45 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1716,9 +1716,11 @@ static void __ipt_unregister_table(struct net *net, struct xt_table *table)
int ipt_register_table(struct net *net, const struct xt_table *table,
const struct ipt_replace *repl,
- const struct nf_hook_ops *ops, struct xt_table **res)
+ const struct nf_hook_ops *template_ops)
{
- int ret;
+ struct nf_hook_ops *ops;
+ unsigned int num_ops;
+ int ret, i;
struct xt_table_info *newinfo;
struct xt_table_info bootstrap = {0};
void *loc_cpu_entry;
@@ -1732,40 +1734,57 @@ int ipt_register_table(struct net *net, const struct xt_table *table,
memcpy(loc_cpu_entry, repl->entries, repl->size);
ret = translate_table(net, newinfo, loc_cpu_entry, repl);
- if (ret != 0)
- goto out_free;
+ if (ret != 0) {
+ xt_free_table_info(newinfo);
+ return ret;
+ }
new_table = xt_register_table(net, table, &bootstrap, newinfo);
if (IS_ERR(new_table)) {
- ret = PTR_ERR(new_table);
- goto out_free;
+ xt_free_table_info(newinfo);
+ return PTR_ERR(new_table);
}
- /* set res now, will see skbs right after nf_register_net_hooks */
- WRITE_ONCE(*res, new_table);
- if (!ops)
+ /* No template? No need to do anything. This is used by 'nat' table, it registers
+ * with the nat core instead of the netfilter core.
+ */
+ if (!template_ops)
return 0;
- ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
- if (ret != 0) {
- __ipt_unregister_table(net, new_table);
- *res = NULL;
+ num_ops = hweight32(table->valid_hooks);
+ if (num_ops == 0) {
+ ret = -EINVAL;
+ goto out_free;
}
+ ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+ if (!ops) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+
+ for (i = 0; i < num_ops; i++)
+ ops[i].priv = new_table;
+
+ new_table->ops = ops;
+
+ ret = nf_register_net_hooks(net, ops, num_ops);
+ if (ret != 0)
+ goto out_free;
+
return ret;
out_free:
- xt_free_table_info(newinfo);
+ __ipt_unregister_table(net, new_table);
return ret;
}
-void ipt_unregister_table_pre_exit(struct net *net, const char *name,
- const struct nf_hook_ops *ops)
+void ipt_unregister_table_pre_exit(struct net *net, const char *name)
{
struct xt_table *table = xt_find_table(net, NFPROTO_IPV4, name);
if (table)
- nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
+ nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks));
}
void ipt_unregister_table_exit(struct net *net, const char *name)
diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
index 84573fa78d1e..8272df7c6ad5 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -34,7 +34,7 @@ static unsigned int
iptable_filter_hook(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
- return ipt_do_table(skb, state, state->net->ipv4.iptable_filter);
+ return ipt_do_table(skb, state, priv);
}
static struct nf_hook_ops *filter_ops __read_mostly;
@@ -55,8 +55,7 @@ static int __net_init iptable_filter_table_init(struct net *net)
((struct ipt_standard *)repl->entries)[1].target.verdict =
forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
- err = ipt_register_table(net, &packet_filter, repl, filter_ops,
- &net->ipv4.iptable_filter);
+ err = ipt_register_table(net, &packet_filter, repl, filter_ops);
kfree(repl);
return err;
}
@@ -71,13 +70,12 @@ static int __net_init iptable_filter_net_init(struct net *net)
static void __net_exit iptable_filter_net_pre_exit(struct net *net)
{
- ipt_unregister_table_pre_exit(net, "filter", filter_ops);
+ ipt_unregister_table_pre_exit(net, "filter");
}
static void __net_exit iptable_filter_net_exit(struct net *net)
{
ipt_unregister_table_exit(net, "filter");
- net->ipv4.iptable_filter = NULL;
}
static struct pernet_operations iptable_filter_net_ops = {
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index 98e9e9053d85..2abc3836f391 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -37,7 +37,7 @@ static const struct xt_table packet_mangler = {
};
static unsigned int
-ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state)
+ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state, void *priv)
{
unsigned int ret;
const struct iphdr *iph;
@@ -53,7 +53,7 @@ ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state)
daddr = iph->daddr;
tos = iph->tos;
- ret = ipt_do_table(skb, state, state->net->ipv4.iptable_mangle);
+ ret = ipt_do_table(skb, state, priv);
/* Reroute for ANY change. */
if (ret != NF_DROP && ret != NF_STOLEN) {
iph = ip_hdr(skb);
@@ -78,8 +78,8 @@ iptable_mangle_hook(void *priv,
const struct nf_hook_state *state)
{
if (state->hook == NF_INET_LOCAL_OUT)
- return ipt_mangle_out(skb, state);
- return ipt_do_table(skb, state, state->net->ipv4.iptable_mangle);
+ return ipt_mangle_out(skb, state, priv);
+ return ipt_do_table(skb, state, priv);
}
static struct nf_hook_ops *mangle_ops __read_mostly;
@@ -91,21 +91,19 @@ static int __net_init iptable_mangle_table_init(struct net *net)
repl = ipt_alloc_initial_table(&packet_mangler);
if (repl == NULL)
return -ENOMEM;
- ret = ipt_register_table(net, &packet_mangler, repl, mangle_ops,
- &net->ipv4.iptable_mangle);
+ 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", mangle_ops);
+ ipt_unregister_table_pre_exit(net, "mangle");
}
static void __net_exit iptable_mangle_net_exit(struct net *net)
{
ipt_unregister_table_exit(net, "mangle");
- net->ipv4.iptable_mangle = NULL;
}
static struct pernet_operations iptable_mangle_net_ops = {
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
index dfa9dc63a7b5..a9913842ef18 100644
--- a/net/ipv4/netfilter/iptable_nat.c
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -66,12 +66,19 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
},
};
-static int ipt_nat_register_lookups(struct net *net, struct xt_table *table)
+static int ipt_nat_register_lookups(struct net *net)
{
- 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);
+ struct iptable_nat_pernet *xt_nat_net;
+ struct nf_hook_ops *ops;
+ struct xt_table *table;
int i, ret;
+ xt_nat_net = net_generic(net, iptable_nat_net_id);
+ table = xt_find_table(net, NFPROTO_IPV4, "nat");
+ if (WARN_ON_ONCE(!table))
+ return -ENOENT;
+
+ ops = kmemdup(nf_nat_ipv4_ops, sizeof(nf_nat_ipv4_ops), GFP_KERNEL);
if (!ops)
return -ENOMEM;
@@ -109,25 +116,21 @@ static void ipt_nat_unregister_lookups(struct net *net)
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, &table);
+
+ ret = ipt_register_table(net, &nf_nat_ipv4_table, repl, NULL);
if (ret < 0) {
kfree(repl);
return ret;
}
- ret = ipt_nat_register_lookups(net, table);
- if (ret < 0) {
+ ret = ipt_nat_register_lookups(net);
+ if (ret < 0)
ipt_unregister_table_exit(net, "nat");
- } else {
- net->ipv4.nat_table = table;
- }
kfree(repl);
return ret;
@@ -141,7 +144,6 @@ static void __net_exit iptable_nat_net_pre_exit(struct net *net)
static void __net_exit iptable_nat_net_exit(struct net *net)
{
ipt_unregister_table_exit(net, "nat");
- net->ipv4.nat_table = NULL;
}
static struct pernet_operations iptable_nat_net_ops = {
diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c
index 18776f5a4055..ceef397c1f5f 100644
--- a/net/ipv4/netfilter/iptable_raw.c
+++ b/net/ipv4/netfilter/iptable_raw.c
@@ -41,7 +41,7 @@ static unsigned int
iptable_raw_hook(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
- return ipt_do_table(skb, state, state->net->ipv4.iptable_raw);
+ return ipt_do_table(skb, state, priv);
}
static struct nf_hook_ops *rawtable_ops __read_mostly;
@@ -58,21 +58,19 @@ static int __net_init iptable_raw_table_init(struct net *net)
repl = ipt_alloc_initial_table(table);
if (repl == NULL)
return -ENOMEM;
- ret = ipt_register_table(net, table, repl, rawtable_ops,
- &net->ipv4.iptable_raw);
+ ret = ipt_register_table(net, table, repl, rawtable_ops);
kfree(repl);
return ret;
}
static void __net_exit iptable_raw_net_pre_exit(struct net *net)
{
- ipt_unregister_table_pre_exit(net, "raw", rawtable_ops);
+ ipt_unregister_table_pre_exit(net, "raw");
}
static void __net_exit iptable_raw_net_exit(struct net *net)
{
ipt_unregister_table_exit(net, "raw");
- net->ipv4.iptable_raw = NULL;
}
static struct pernet_operations iptable_raw_net_ops = {
diff --git a/net/ipv4/netfilter/iptable_security.c b/net/ipv4/netfilter/iptable_security.c
index 3df92fb394c5..77973f5fd8f6 100644
--- a/net/ipv4/netfilter/iptable_security.c
+++ b/net/ipv4/netfilter/iptable_security.c
@@ -40,7 +40,7 @@ static unsigned int
iptable_security_hook(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
- return ipt_do_table(skb, state, state->net->ipv4.iptable_security);
+ return ipt_do_table(skb, state, priv);
}
static struct nf_hook_ops *sectbl_ops __read_mostly;
@@ -53,21 +53,19 @@ static int __net_init iptable_security_table_init(struct net *net)
repl = ipt_alloc_initial_table(&security_table);
if (repl == NULL)
return -ENOMEM;
- ret = ipt_register_table(net, &security_table, repl, sectbl_ops,
- &net->ipv4.iptable_security);
+ ret = ipt_register_table(net, &security_table, repl, sectbl_ops);
kfree(repl);
return ret;
}
static void __net_exit iptable_security_net_pre_exit(struct net *net)
{
- ipt_unregister_table_pre_exit(net, "security", sectbl_ops);
+ ipt_unregister_table_pre_exit(net, "security");
}
static void __net_exit iptable_security_net_exit(struct net *net)
{
ipt_unregister_table_exit(net, "security");
- net->ipv4.iptable_security = NULL;
}
static struct pernet_operations iptable_security_net_ops = {
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 1caba9507228..ef37deff8405 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1498,6 +1498,7 @@ void *xt_unregister_table(struct xt_table *table)
mutex_unlock(&xt[table->af].mutex);
audit_log_nfcfg(table->name, table->af, private->number,
AUDIT_XT_OP_UNREGISTER, GFP_KERNEL);
+ kfree(table->ops);
kfree(table);
return private;