[tproxy] [PATCH 04/11] TProxy: split off ipv6 defragmentation to a separate module
Balazs Scheidler
bazsi at balabit.hu
Sun Aug 23 11:11:15 CEST 2009
Like with IPv4, TProxy needs IP defragmentation but does not
require connection tracking. Since defragmentation was coupled
with conntrack, I split off the two, creating an nf_defrag_ipv6 module,
similar to the already existing nf_defrag_ipv4.
Signed-off-by: Balazs Scheidler <bazsi at balabit.hu>
---
include/net/netfilter/ipv6/nf_defrag_ipv6.h | 6 ++
net/ipv6/netfilter/Makefile | 5 +-
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 58 +------------
net/ipv6/netfilter/nf_conntrack_reasm.c | 12 ++-
net/ipv6/netfilter/nf_defrag_ipv6_hooks.c | 109 ++++++++++++++++++++++++
5 files changed, 131 insertions(+), 59 deletions(-)
create mode 100644 include/net/netfilter/ipv6/nf_defrag_ipv6.h
create mode 100644 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
diff --git a/include/net/netfilter/ipv6/nf_defrag_ipv6.h b/include/net/netfilter/ipv6/nf_defrag_ipv6.h
new file mode 100644
index 0000000..94dd54d
--- /dev/null
+++ b/include/net/netfilter/ipv6/nf_defrag_ipv6.h
@@ -0,0 +1,6 @@
+#ifndef _NF_DEFRAG_IPV6_H
+#define _NF_DEFRAG_IPV6_H
+
+extern void nf_defrag_ipv6_enable(void);
+
+#endif /* _NF_DEFRAG_IPV6_H */
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index aafbba3..a78ee59 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -11,10 +11,11 @@ obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
obj-$(CONFIG_IP6_NF_SECURITY) += ip6table_security.o
# objects for l3 independent conntrack
-nf_conntrack_ipv6-objs := nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o nf_conntrack_reasm.o
+nf_conntrack_ipv6-objs := nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o
+nf_defrag_ipv6-objs := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o
# l3 independent conntrack
-obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o
+obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o nf_defrag_ipv6.o
# matches
obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 2a15c2d..158d14c 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -27,6 +27,7 @@
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
+#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
struct nf_conntrack_tuple *tuple)
@@ -183,34 +184,6 @@ out:
return nf_conntrack_confirm(skb);
}
-static unsigned int ipv6_defrag(unsigned int hooknum,
- struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
-{
- struct sk_buff *reasm;
-
- /* Previously seen (loopback)? */
- if (skb->nfct)
- return NF_ACCEPT;
-
- reasm = nf_ct_frag6_gather(skb);
-
- /* queued */
- if (reasm == NULL)
- return NF_STOLEN;
-
- /* error occured or not fragmented */
- if (reasm == skb)
- return NF_ACCEPT;
-
- nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
- (struct net_device *)out, okfn);
-
- return NF_STOLEN;
-}
-
static unsigned int __ipv6_conntrack_in(struct net *net,
unsigned int hooknum,
struct sk_buff *skb,
@@ -263,13 +236,6 @@ static unsigned int ipv6_conntrack_local(unsigned int hooknum,
static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
{
- .hook = ipv6_defrag,
- .owner = THIS_MODULE,
- .pf = PF_INET6,
- .hooknum = NF_INET_PRE_ROUTING,
- .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
- },
- {
.hook = ipv6_conntrack_in,
.owner = THIS_MODULE,
.pf = PF_INET6,
@@ -284,13 +250,6 @@ static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
.priority = NF_IP6_PRI_CONNTRACK,
},
{
- .hook = ipv6_defrag,
- .owner = THIS_MODULE,
- .pf = PF_INET6,
- .hooknum = NF_INET_LOCAL_OUT,
- .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
- },
- {
.hook = ipv6_confirm,
.owner = THIS_MODULE,
.pf = PF_INET6,
@@ -362,10 +321,6 @@ struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
.nlattr_to_tuple = ipv6_nlattr_to_tuple,
.nla_policy = ipv6_nla_policy,
#endif
-#ifdef CONFIG_SYSCTL
- .ctl_table_path = nf_net_netfilter_sysctl_path,
- .ctl_table = nf_ct_ipv6_sysctl_table,
-#endif
.me = THIS_MODULE,
};
@@ -378,16 +333,12 @@ static int __init nf_conntrack_l3proto_ipv6_init(void)
int ret = 0;
need_conntrack();
+ nf_defrag_ipv6_enable();
- ret = nf_ct_frag6_init();
- if (ret < 0) {
- printk("nf_conntrack_ipv6: can't initialize frag6.\n");
- return ret;
- }
ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6);
if (ret < 0) {
printk("nf_conntrack_ipv6: can't register tcp.\n");
- goto cleanup_frag6;
+ return ret;
}
ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6);
@@ -425,8 +376,6 @@ static int __init nf_conntrack_l3proto_ipv6_init(void)
nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
cleanup_tcp:
nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
- cleanup_frag6:
- nf_ct_frag6_cleanup();
return ret;
}
@@ -438,7 +387,6 @@ static void __exit nf_conntrack_l3proto_ipv6_fini(void)
nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
- nf_ct_frag6_cleanup();
}
module_init(nf_conntrack_l3proto_ipv6_init);
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index f3aba25..b7b08fe 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -73,8 +73,8 @@ struct nf_ct_frag6_queue
static struct inet_frags nf_frags;
static struct netns_frags nf_init_frags;
-#ifdef CONFIG_SYSCTL
-struct ctl_table nf_ct_ipv6_sysctl_table[] = {
+#if defined(CONFIG_SYSCTL)
+struct ctl_table nf_ct_frag6_sysctl_table[] = {
{
.procname = "nf_conntrack_frag6_timeout",
.data = &nf_init_frags.timeout,
@@ -100,6 +100,8 @@ struct ctl_table nf_ct_ipv6_sysctl_table[] = {
},
{ .ctl_name = 0 }
};
+
+static struct ctl_table_header *nf_ct_frag6_sysctl_header = NULL;
#endif
static unsigned int nf_hashfn(struct inet_frag_queue *q)
@@ -675,11 +677,17 @@ int nf_ct_frag6_init(void)
inet_frags_init_net(&nf_init_frags);
inet_frags_init(&nf_frags);
+ if (!(nf_ct_frag6_sysctl_header = register_sysctl_paths(nf_net_netfilter_sysctl_path, nf_ct_frag6_sysctl_table))) {
+ return -ENOMEM;
+ }
return 0;
}
void nf_ct_frag6_cleanup(void)
{
+ unregister_sysctl_table(nf_ct_frag6_sysctl_header);
+ nf_ct_frag6_sysctl_header = NULL;
+
inet_frags_fini(&nf_frags);
nf_init_frags.low_thresh = 0;
diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
new file mode 100644
index 0000000..6f07971
--- /dev/null
+++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
@@ -0,0 +1,109 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam at netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/ipv6.h>
+#include <linux/in6.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/icmp.h>
+#include <linux/sysctl.h>
+#include <net/ipv6.h>
+#include <net/inet_frag.h>
+
+#include <linux/netfilter_ipv6.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
+#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
+
+static unsigned int ipv6_defrag(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct sk_buff *reasm;
+
+ /* Previously seen (loopback)? */
+ if (skb->nfct)
+ return NF_ACCEPT;
+
+ reasm = nf_ct_frag6_gather(skb);
+
+ /* queued */
+ if (reasm == NULL)
+ return NF_STOLEN;
+
+ /* error occured or not fragmented */
+ if (reasm == skb)
+ return NF_ACCEPT;
+
+ nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
+ (struct net_device *)out, okfn);
+
+ return NF_STOLEN;
+}
+
+static struct nf_hook_ops ipv6_defrag_ops[] = {
+ {
+ .hook = ipv6_defrag,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_INET_PRE_ROUTING,
+ .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
+ },
+ {
+ .hook = ipv6_defrag,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_INET_LOCAL_OUT,
+ .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
+ },
+};
+
+static int __init nf_defrag_init(void)
+{
+ int ret = 0;
+
+ ret = nf_ct_frag6_init();
+ if (ret < 0) {
+ printk("nf_conntrack_ipv6: can't initialize frag6.\n");
+ return ret;
+ }
+ ret = nf_register_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
+ if (ret < 0) {
+ printk("nf_defrag_ipv6: can't register hooks\n");
+ goto cleanup_frag6;
+ }
+ return ret;
+ cleanup_frag6:
+ nf_ct_frag6_cleanup();
+ return ret;
+
+}
+
+static void __exit nf_defrag_fini(void)
+{
+ nf_unregister_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
+ nf_ct_frag6_cleanup();
+}
+
+void nf_defrag_ipv6_enable(void)
+{
+}
+EXPORT_SYMBOL_GPL(nf_defrag_ipv6_enable);
+
+module_init(nf_defrag_init);
+module_exit(nf_defrag_fini);
+
+MODULE_LICENSE("GPL");
--
1.6.0.4
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