From: Eric W Biederman <ebied...@xmission.com>
Add a new structure nf_hook_entry that makes up the nf_hook_lists, and
dynamically allocate it nf_register_hook and free it in
nf_unregister_hook.
This gives the netfilter hook code a little more freedom to evolve
and removes an error case when converting netfilter hooks to be
per nework namespace.
Signed-off-by: "Eric W. Biederman" <ebied...@xmission.com>
---
include/linux/netfilter.h | 12 +++---
include/net/netfilter/nf_queue.h | 4 +-
net/netfilter/core.c | 92 +++++++++++++++++++++++++---------------
net/netfilter/nf_internals.h | 13 +++++-
net/netfilter/nf_queue.c | 6 +--
5 files changed, 80 insertions(+), 47 deletions(-)
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 43db9eaf42f6..054cd9d45324 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -84,8 +84,6 @@ typedef unsigned int nf_hookfn(void *priv,
const struct nf_hook_state *state);
struct nf_hook_ops {
- struct list_head list;
-
/* User fills in from here down. */
nf_hookfn *hook;
struct net_device *dev;
@@ -122,10 +120,12 @@ struct nf_sockopt_ops {
};
/* Function to register/unregister hook points. */
-int nf_register_hook(struct net *net, struct nf_hook_ops *reg);
-void nf_unregister_hook(struct net *net, struct nf_hook_ops *reg);
-int nf_register_hooks(struct net *net, struct nf_hook_ops *reg, unsigned int
n);
-void nf_unregister_hooks(struct net *net, struct nf_hook_ops *reg, unsigned
int n);
+int nf_register_hook(struct net *net, const struct nf_hook_ops *reg);
+void nf_unregister_hook(struct net *net, const struct nf_hook_ops *reg);
+int nf_register_hooks(struct net *net, const struct nf_hook_ops *reg,
+ unsigned int n);
+void nf_unregister_hooks(struct net *net, const struct nf_hook_ops *reg,
+ unsigned int n);
/* Functions to register get/setsockopt ranges (non-inclusive). You
need to check permissions yourself! */
diff --git a/include/net/netfilter/nf_queue.h b/include/net/netfilter/nf_queue.h
index d81d584157e1..cad00472e3be 100644
--- a/include/net/netfilter/nf_queue.h
+++ b/include/net/netfilter/nf_queue.h
@@ -5,13 +5,15 @@
#include <linux/ipv6.h>
#include <linux/jhash.h>
+struct nf_hook_entry;
+
/* Each queued (to userspace) skbuff has one of these. */
struct nf_queue_entry {
struct list_head list;
struct sk_buff *skb;
unsigned int id;
- struct nf_hook_ops *elem;
+ struct nf_hook_entry *elem;
struct nf_hook_state state;
u16 size; /* sizeof(entry) + saved route keys */
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index ccf248607342..95456c09cf69 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -59,34 +59,46 @@ EXPORT_SYMBOL(nf_hooks_needed);
static DEFINE_MUTEX(nf_hook_mutex);
-int nf_register_hook(struct net *net, struct nf_hook_ops *reg)
+static struct list_head *find_nf_hook_list(struct net *net,
+ const struct nf_hook_ops *reg)
{
struct list_head *nf_hook_list;
- struct nf_hook_ops *elem;
- mutex_lock(&nf_hook_mutex);
- switch (reg->pf) {
- case NFPROTO_NETDEV:
+ nf_hook_list = &net->nf.hooks[reg->pf][reg->hooknum];
#ifdef CONFIG_NETFILTER_INGRESS
- if (reg->hooknum == NF_NETDEV_INGRESS) {
- BUG_ON(reg->dev == NULL);
- nf_hook_list = ®->dev->nf_hooks_ingress;
- net_inc_ingress_queue();
- break;
- }
+ if ((reg->pf == NFPROTO_NETDEV) && (reg->hooknum == NF_NETDEV_INGRESS))
+ nf_hook_list = ®->dev->nf_hooks_ingress;
#endif
- /* Fall through. */
- default:
- nf_hook_list = &net->nf.hooks[reg->pf][reg->hooknum];
- break;
- }
+ return nf_hook_list;
+}
+int nf_register_hook(struct net *net, const struct nf_hook_ops *reg)
+{
+ struct list_head *nf_hook_list;
+ struct nf_hook_entry *elem, *new;
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+
+ new->hook = reg->hook;
+ new->priv = reg->priv;
+ new->owner = reg->owner;
+ new->priority = reg->priority;
+
+ mutex_lock(&nf_hook_mutex);
+ nf_hook_list = find_nf_hook_list(net, reg);
list_for_each_entry(elem, nf_hook_list, list) {
- if (reg->priority < elem->priority)
+ if (new->priority < elem->priority)
break;
}
- list_add_rcu(®->list, elem->list.prev);
+ list_add_rcu(&new->list, elem->list.prev);
mutex_unlock(&nf_hook_mutex);
+
+#ifdef CONFIG_NETFILTER_INGRESS
+ if ((reg->pf == NFPROTO_NETDEV) && (reg->hooknum == NF_NETDEV_INGRESS))
+ net_inc_ingress_queue();
+#endif
#ifdef HAVE_JUMP_LABEL
static_key_slow_inc(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
@@ -94,31 +106,41 @@ int nf_register_hook(struct net *net, struct nf_hook_ops
*reg)
}
EXPORT_SYMBOL(nf_register_hook);
-void nf_unregister_hook(struct net *net, struct nf_hook_ops *reg)
+void nf_unregister_hook(struct net *net, const struct nf_hook_ops *reg)
{
+ struct list_head *nf_hook_list;
+ struct nf_hook_entry *elem;
+
mutex_lock(&nf_hook_mutex);
- list_del_rcu(®->list);
- mutex_unlock(&nf_hook_mutex);
- switch (reg->pf) {
- case NFPROTO_NETDEV:
-#ifdef CONFIG_NETFILTER_INGRESS
- if (reg->hooknum == NF_NETDEV_INGRESS) {
- net_dec_ingress_queue();
+ nf_hook_list = find_nf_hook_list(net, reg);
+ list_for_each_entry(elem, nf_hook_list, list) {
+ if ((reg->hook == elem->hook) &&
+ (reg->priv == elem->priv) &&
+ (reg->owner == elem->owner) &&
+ (reg->priority == elem->priority)) {
+ list_del_rcu(&elem->list);
break;
}
- break;
-#endif
- default:
- break;
}
+ mutex_unlock(&nf_hook_mutex);
+ if (&elem->list == nf_hook_list) {
+ WARN(1, "nf_unregister_hook: hook not found!\n");
+ return;
+ }
+#ifdef CONFIG_NETFILTER_INGRESS
+ if ((reg->pf == NFPROTO_NETDEV) && (reg->hooknum == NF_NETDEV_INGRESS))
+ net_dec_ingress_queue();
+#endif
#ifdef HAVE_JUMP_LABEL
static_key_slow_dec(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
synchronize_net();
+ kfree(elem);
}
EXPORT_SYMBOL(nf_unregister_hook);
-int nf_register_hooks(struct net *net, struct nf_hook_ops *reg, unsigned int n)
+int nf_register_hooks(struct net *net, const struct nf_hook_ops *reg,
+ unsigned int n)
{
unsigned int i;
int err = 0;
@@ -137,7 +159,7 @@ err:
}
EXPORT_SYMBOL(nf_register_hooks);
-void nf_unregister_hooks(struct net *net, struct nf_hook_ops *reg,
+void nf_unregister_hooks(struct net *net, const struct nf_hook_ops *reg,
unsigned int n)
{
while (n-- > 0)
@@ -148,7 +170,7 @@ EXPORT_SYMBOL(nf_unregister_hooks);
unsigned int nf_iterate(struct list_head *head,
struct sk_buff *skb,
struct nf_hook_state *state,
- struct nf_hook_ops **elemp)
+ struct nf_hook_entry **elemp)
{
unsigned int verdict;
@@ -186,14 +208,14 @@ repeat:
* -EPERM for NF_DROP, 0 otherwise. */
int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state)
{
- struct nf_hook_ops *elem;
+ struct nf_hook_entry *elem;
unsigned int verdict;
int ret = 0;
/* We may already have this, but read-locks nest anyway */
rcu_read_lock();
- elem = list_entry_rcu(state->hook_list, struct nf_hook_ops, list);
+ elem = list_entry_rcu(state->hook_list, struct nf_hook_entry, list);
next_hook:
verdict = nf_iterate(state->hook_list, skb, state, &elem);
if (verdict == NF_ACCEPT || verdict == NF_STOP) {
diff --git a/net/netfilter/nf_internals.h b/net/netfilter/nf_internals.h
index ea7f36784b3d..ff8e1f7197dc 100644
--- a/net/netfilter/nf_internals.h
+++ b/net/netfilter/nf_internals.h
@@ -13,11 +13,20 @@
/* core.c */
+struct nf_hook_entry {
+ struct list_head list;
+ nf_hookfn *hook;
+ void *priv;
+ struct module *owner;
+ /* Hooks are ordered in ascending priority. */
+ int priority;
+};
+
unsigned int nf_iterate(struct list_head *head, struct sk_buff *skb,
- struct nf_hook_state *state, struct nf_hook_ops
**elemp);
+ struct nf_hook_state *state, struct nf_hook_entry
**elemp);
/* nf_queue.c */
-int nf_queue(struct sk_buff *skb, struct nf_hook_ops *elem,
+int nf_queue(struct sk_buff *skb, struct nf_hook_entry *elem,
struct nf_hook_state *state, unsigned int queuenum);
int __init netfilter_queue_init(void);
diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index ab077fe4c1b8..6ae3b2ccceb8 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -110,7 +110,7 @@ EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs);
* through nf_reinject().
*/
int nf_queue(struct sk_buff *skb,
- struct nf_hook_ops *elem,
+ struct nf_hook_entry *elem,
struct nf_hook_state *state,
unsigned int queuenum)
{
@@ -172,7 +172,7 @@ err:
void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
{
struct sk_buff *skb = entry->skb;
- struct nf_hook_ops *elem = entry->elem;
+ struct nf_hook_entry *elem = entry->elem;
const struct nf_afinfo *afinfo;
int err;
@@ -182,7 +182,7 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int
verdict)
/* Continue traversal iff userspace said ok... */
if (verdict == NF_REPEAT) {
- elem = list_entry(elem->list.prev, struct nf_hook_ops, list);
+ elem = list_entry(elem->list.prev, struct nf_hook_entry, list);
verdict = NF_ACCEPT;
}
--
2.2.1
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