Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 22265a5c authored by Patrick McHardy's avatar Patrick McHardy
Browse files

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: default avatarPatrick McHardy <kaber@trash.net>
parent 5b775eb1

include/linux/netfilter/xt_TEE.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */

net/netfilter/xt_TEE.c

+80 −23
Original line number Diff line number Diff line
@@ -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))

	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))

	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;



	/* 0.0.0.0 and :: not allowed */

	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;

	/* 0.0.0.0 and :: not allowed */

	return (memcmp(&info->gw, &tee_zero_address,

	       sizeof(tee_zero_address)) == 0) ? -EINVAL : 0;



		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