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Date: Mon, 10 May 2010 22:18:47 +0200
From: kaber@...sh.net
To: davem@...emloft.net
Cc: netfilter-devel@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH 76/84] netfilter: xt_TEE: resolve oif using netdevice notifiers
From: Patrick McHardy <kaber@...sh.net>
Replace the runtime oif name resolving by netdevice notifier based
resolving. When an oif is given, a netdevice notifier is registered
to resolve the name on NETDEV_REGISTER or NETDEV_CHANGE and unresolve
it again on NETDEV_UNREGISTER or NETDEV_CHANGE to a different name.
Signed-off-by: Patrick McHardy <kaber@...sh.net>
---
include/linux/netfilter/xt_TEE.h | 3 +
net/netfilter/xt_TEE.c | 103 +++++++++++++++++++++++++++++--------
2 files changed, 83 insertions(+), 23 deletions(-)
diff --git a/include/linux/netfilter/xt_TEE.h b/include/linux/netfilter/xt_TEE.h
index 55d4a50..5c21d5c 100644
--- a/include/linux/netfilter/xt_TEE.h
+++ b/include/linux/netfilter/xt_TEE.h
@@ -4,6 +4,9 @@
struct xt_tee_tginfo {
union nf_inet_addr gw;
char oif[16];
+
+ /* used internally by the kernel */
+ struct xt_tee_priv *priv __attribute__((aligned(8)));
};
#endif /* _XT_TEE_TARGET_H */
diff --git a/net/netfilter/xt_TEE.c b/net/netfilter/xt_TEE.c
index 842e701..49da6c0 100644
--- a/net/netfilter/xt_TEE.c
+++ b/net/netfilter/xt_TEE.c
@@ -15,6 +15,7 @@
#include <linux/percpu.h>
#include <linux/route.h>
#include <linux/skbuff.h>
+#include <linux/notifier.h>
#include <net/checksum.h>
#include <net/icmp.h>
#include <net/ip.h>
@@ -32,6 +33,12 @@
# define WITH_IPV6 1
#endif
+struct xt_tee_priv {
+ struct notifier_block notifier;
+ struct xt_tee_tginfo *tginfo;
+ int oif;
+};
+
static const union nf_inet_addr tee_zero_address;
static DEFINE_PER_CPU(bool, tee_active);
@@ -49,20 +56,6 @@ static struct net *pick_net(struct sk_buff *skb)
return &init_net;
}
-static bool tee_tg_route_oif(struct flowi *f, struct net *net,
- const struct xt_tee_tginfo *info)
-{
- const struct net_device *dev;
-
- if (*info->oif != '\0')
- return true;
- dev = dev_get_by_name(net, info->oif);
- if (dev == NULL)
- return false;
- f->oif = dev->ifindex;
- return true;
-}
-
static bool
tee_tg_route4(struct sk_buff *skb, const struct xt_tee_tginfo *info)
{
@@ -72,8 +65,11 @@ tee_tg_route4(struct sk_buff *skb, const struct xt_tee_tginfo *info)
struct flowi fl;
memset(&fl, 0, sizeof(fl));
- if (!tee_tg_route_oif(&fl, net, info))
- return false;
+ if (info->priv) {
+ if (info->priv->oif == -1)
+ return false;
+ fl.oif = info->priv->oif;
+ }
fl.nl_u.ip4_u.daddr = info->gw.ip;
fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
fl.nl_u.ip4_u.scope = RT_SCOPE_UNIVERSE;
@@ -149,8 +145,11 @@ tee_tg_route6(struct sk_buff *skb, const struct xt_tee_tginfo *info)
struct flowi fl;
memset(&fl, 0, sizeof(fl));
- if (!tee_tg_route_oif(&fl, net, info))
- return false;
+ if (info->priv) {
+ if (info->priv->oif == -1)
+ return false;
+ fl.oif = info->priv->oif;
+ }
fl.nl_u.ip6_u.daddr = info->gw.in6;
fl.nl_u.ip6_u.flowlabel = ((iph->flow_lbl[0] & 0xF) << 16) |
(iph->flow_lbl[1] << 8) | iph->flow_lbl[2];
@@ -198,15 +197,71 @@ tee_tg6(struct sk_buff *skb, const struct xt_target_param *par)
}
#endif /* WITH_IPV6 */
+static int tee_netdev_event(struct notifier_block *this, unsigned long event,
+ void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct xt_tee_priv *priv;
+
+ priv = container_of(this, struct xt_tee_priv, notifier);
+ switch (event) {
+ case NETDEV_REGISTER:
+ if (!strcmp(dev->name, priv->tginfo->oif))
+ priv->oif = dev->ifindex;
+ break;
+ case NETDEV_UNREGISTER:
+ if (dev->ifindex == priv->oif)
+ priv->oif = -1;
+ break;
+ case NETDEV_CHANGENAME:
+ if (!strcmp(dev->name, priv->tginfo->oif))
+ priv->oif = dev->ifindex;
+ else if (dev->ifindex == priv->oif)
+ priv->oif = -1;
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
static int tee_tg_check(const struct xt_tgchk_param *par)
{
- const struct xt_tee_tginfo *info = par->targinfo;
+ struct xt_tee_tginfo *info = par->targinfo;
+ struct xt_tee_priv *priv;
- if (info->oif[sizeof(info->oif)-1] != '\0')
- return -EINVAL;
/* 0.0.0.0 and :: not allowed */
- return (memcmp(&info->gw, &tee_zero_address,
- sizeof(tee_zero_address)) == 0) ? -EINVAL : 0;
+ if (memcmp(&info->gw, &tee_zero_address,
+ sizeof(tee_zero_address)) == 0)
+ return -EINVAL;
+
+ if (info->oif[0]) {
+ if (info->oif[sizeof(info->oif)-1] != '\0')
+ return -EINVAL;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (priv == NULL)
+ return -ENOMEM;
+
+ priv->tginfo = info;
+ priv->oif = -1;
+ priv->notifier.notifier_call = tee_netdev_event;
+ info->priv = priv;
+
+ register_netdevice_notifier(&priv->notifier);
+ } else
+ info->priv = NULL;
+
+ return 0;
+}
+
+static void tee_tg_destroy(const struct xt_tgdtor_param *par)
+{
+ struct xt_tee_tginfo *info = par->targinfo;
+
+ if (info->priv) {
+ unregister_netdevice_notifier(&info->priv->notifier);
+ kfree(info->priv);
+ }
}
static struct xt_target tee_tg_reg[] __read_mostly = {
@@ -217,6 +272,7 @@ static struct xt_target tee_tg_reg[] __read_mostly = {
.target = tee_tg4,
.targetsize = sizeof(struct xt_tee_tginfo),
.checkentry = tee_tg_check,
+ .destroy = tee_tg_destroy,
.me = THIS_MODULE,
},
#ifdef WITH_IPV6
@@ -227,6 +283,7 @@ static struct xt_target tee_tg_reg[] __read_mostly = {
.target = tee_tg6,
.targetsize = sizeof(struct xt_tee_tginfo),
.checkentry = tee_tg_check,
+ .destroy = tee_tg_destroy,
.me = THIS_MODULE,
},
#endif
--
1.7.0.4
--
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