[PATCH 26/33] netns ct: GRE conntracking in netns

Alexey Dobriyan
2008-09-08T03:03:03Z

* make keymap list per-netns
* per-netns keymal lock (not strictly necessary)
* flush keymap at netns stop and module unload.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>

diff --git a/include/linux/netfilter/nf_conntrack_proto_gre.h b/include/linux/netfilter/nf_conntrack_proto_gre.h
index 535e421..2a10efd 100644
--- a/include/linux/netfilter/nf_conntrack_proto_gre.h
+++ b/include/linux/netfilter/nf_conntrack_proto_gre.h
@@ -87,7 +87,7 @@ int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
/* delete keymap entries */
void nf_ct_gre_keymap_destroy(struct nf_conn *ct);

-extern void nf_ct_gre_keymap_flush(void);
+extern void nf_ct_gre_keymap_flush(struct net *net);
extern void nf_nat_need_gre(void);

#endif /* __KERNEL__ */
diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c
index 5db7df5..e47d5de 100644
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -602,7 +602,7 @@ static int __init nf_conntrack_pptp_init(void)
static void __exit nf_conntrack_pptp_fini(void)
{
nf_conntrack_helper_unregister(&pptp);
- nf_ct_gre_keymap_flush();
+ nf_ct_gre_keymap_flush(&init_net);
}

module_init(nf_conntrack_pptp_init);
diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index 5b1273a..a2cdbcb 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -29,8 +29,11 @@
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/in.h>
+#include <linux/netdevice.h>
#include <linux/skbuff.h>
-
+#include <net/dst.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_core.h>
@@ -40,19 +43,23 @@
#define GRE_TIMEOUT (30 * HZ)
#define GRE_STREAM_TIMEOUT (180 * HZ)

-static DEFINE_RWLOCK(nf_ct_gre_lock);
-static LIST_HEAD(gre_keymap_list);
+static int proto_gre_net_id;
+struct netns_proto_gre {
+ rwlock_t keymap_lock;
+ struct list_head keymap_list;
+};

-void nf_ct_gre_keymap_flush(void)
+void nf_ct_gre_keymap_flush(struct net *net)
{
+ struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
struct nf_ct_gre_keymap *km, *tmp;

- write_lock_bh(&nf_ct_gre_lock);
- list_for_each_entry_safe(km, tmp, &gre_keymap_list, list) {
+ write_lock_bh(&net_gre->keymap_lock);
+ list_for_each_entry_safe(km, tmp, &net_gre->keymap_list, list) {
list_del(&km->list);
kfree(km);
}
- write_unlock_bh(&nf_ct_gre_lock);
+ write_unlock_bh(&net_gre->keymap_lock);
}
EXPORT_SYMBOL(nf_ct_gre_keymap_flush);

@@ -67,19 +74,20 @@ static inline int gre_key_cmpfn(const struct nf_ct_gre_keymap *km,
}

/* look up the source key for a given tuple */
-static __be16 gre_keymap_lookup(struct nf_conntrack_tuple *t)
+static __be16 gre_keymap_lookup(struct net *net, struct nf_conntrack_tuple *t)
{
+ struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
struct nf_ct_gre_keymap *km;
__be16 key = 0;

- read_lock_bh(&nf_ct_gre_lock);
- list_for_each_entry(km, &gre_keymap_list, list) {
+ read_lock_bh(&net_gre->keymap_lock);
+ list_for_each_entry(km, &net_gre->keymap_list, list) {
if (gre_key_cmpfn(km, t)) {
key = km->tuple.src.u.gre.key;
break;
}
}
- read_unlock_bh(&nf_ct_gre_lock);
+ read_unlock_bh(&net_gre->keymap_lock);

pr_debug("lookup src key 0x%x for ", key);
nf_ct_dump_tuple(t);
@@ -91,20 +99,22 @@ static __be16 gre_keymap_lookup(struct nf_conntrack_tuple *t)
int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
struct nf_conntrack_tuple *t)
{
+ struct net *net = nf_ct_net(ct);
+ struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
struct nf_conn_help *help = nfct_help(ct);
struct nf_ct_gre_keymap **kmp, *km;

kmp = &help->help.ct_pptp_info.keymap[dir];
if (*kmp) {
/* check whether it's a retransmission */
- read_lock_bh(&nf_ct_gre_lock);
- list_for_each_entry(km, &gre_keymap_list, list) {
+ read_lock_bh(&net_gre->keymap_lock);
+ list_for_each_entry(km, &net_gre->keymap_list, list) {
if (gre_key_cmpfn(km, t) && km == *kmp) {
- read_unlock_bh(&nf_ct_gre_lock);
+ read_unlock_bh(&net_gre->keymap_lock);
return 0;
}
}
- read_unlock_bh(&nf_ct_gre_lock);
+ read_unlock_bh(&net_gre->keymap_lock);
pr_debug("trying to override keymap_%s for ct %p\n",
dir == IP_CT_DIR_REPLY ? "reply" : "orig", ct);
return -EEXIST;
@@ -119,9 +129,9 @@ int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
pr_debug("adding new entry %p: ", km);
nf_ct_dump_tuple(&km->tuple);

- write_lock_bh(&nf_ct_gre_lock);
- list_add_tail(&km->list, &gre_keymap_list);
- write_unlock_bh(&nf_ct_gre_lock);
+ write_lock_bh(&net_gre->keymap_lock);
+ list_add_tail(&km->list, &net_gre->keymap_list);
+ write_unlock_bh(&net_gre->keymap_lock);

return 0;
}
@@ -130,12 +140,14 @@ EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_add);
/* destroy the keymap entries associated with specified master ct */
void nf_ct_gre_keymap_destroy(struct nf_conn *ct)
{
+ struct net *net = nf_ct_net(ct);
+ struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
struct nf_conn_help *help = nfct_help(ct);
enum ip_conntrack_dir dir;

pr_debug("entering for ct %p\n", ct);

- write_lock_bh(&nf_ct_gre_lock);
+ write_lock_bh(&net_gre->keymap_lock);
for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {
if (help->help.ct_pptp_info.keymap[dir]) {
pr_debug("removing %p from list\n",
@@ -145,7 +157,7 @@ void nf_ct_gre_keymap_destroy(struct nf_conn *ct)
help->help.ct_pptp_info.keymap[dir] = NULL;
}
}
- write_unlock_bh(&nf_ct_gre_lock);
+ write_unlock_bh(&net_gre->keymap_lock);
}
EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_destroy);

@@ -164,6 +176,7 @@ static bool gre_invert_tuple(struct nf_conntrack_tuple *tuple,
static bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
struct nf_conntrack_tuple *tuple)
{
+ struct net *net = dev_net(skb->dev ? skb->dev : skb->dst->dev);
const struct gre_hdr_pptp *pgrehdr;
struct gre_hdr_pptp _pgrehdr;
__be16 srckey;
@@ -190,7 +203,7 @@ static bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
}

tuple->dst.u.gre.key = pgrehdr->call_id;
- srckey = gre_keymap_lookup(tuple);
+ srckey = gre_keymap_lookup(net, tuple);
tuple->src.u.gre.key = srckey;

return true;
@@ -285,15 +298,53 @@ static struct nf_conntrack_l4proto nf_conntrack_l4proto_gre4 __read_mostly = {
#endif
};

+static int proto_gre_net_init(struct net *net)
+{
+ struct netns_proto_gre *net_gre;
+ int rv;
+
+ net_gre = kmalloc(sizeof(struct netns_proto_gre), GFP_KERNEL);
+ if (!net_gre)
+ return -ENOMEM;
+ rwlock_init(&net_gre->keymap_lock);
+ INIT_LIST_HEAD(&net_gre->keymap_list);
+
+ rv = net_assign_generic(net, proto_gre_net_id, net_gre);
+ if (rv < 0)
+ kfree(net_gre);
+ return rv;
+}
+
+static void proto_gre_net_exit(struct net *net)
+{
+ struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
+
+ nf_ct_gre_keymap_flush(net);
+ kfree(net_gre);
+}
+
+static struct pernet_operations proto_gre_net_ops = {
+ .init = proto_gre_net_init,
+ .exit = proto_gre_net_exit,
+};
+
static int __init nf_ct_proto_gre_init(void)
{
- return nf_conntrack_l4proto_register(&nf_conntrack_l4proto_gre4);
+ int rv;
+
+ rv = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_gre4);
+ if (rv < 0)
+ return rv;
+ rv = register_pernet_gen_device(&proto_gre_net_id, &proto_gre_net_ops);
+ if (rv < 0)
+ nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_gre4);
+ return rv;
}

static void nf_ct_proto_gre_fini(void)
{
nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_gre4);
- nf_ct_gre_keymap_flush();
+ unregister_pernet_gen_device(proto_gre_net_id, &proto_gre_net_ops);
}

module_init(nf_ct_proto_gre_init);