提交 22265a5c 编写于 作者: P Patrick McHardy

netfilter: xt_TEE: resolve oif using netdevice notifiers

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: NPatrick McHardy <kaber@trash.net>
上级 5b775eb1
......@@ -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 */
......@@ -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
......
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