From: Christoph Hellwig <hch@lst.de>

Date: Tue, 19 May 2020 15:03:13 +0200

Subject: net: add a new ndo_tunnel_ioctl method

Patch-mainline: v5.8-rc1

Git-commit: 607259a695312cdfac2b52fb9d5b5890c834d573

References: bsc#1176447

This method is used to properly allow kernel callers of the IPv4 route

management ioctls.  The exsting ip_tunnel_ioctl helper is renamed to

ip_tunnel_ctl to better reflect that it doesn't directly implement ioctls

touching user memory, and is used for the guts of ndo_tunnel_ctl

implementations. A new ip_tunnel_ioctl helper is added that can be wired

up directly to the ndo_do_ioctl method and takes care of the copy to and

from userspace.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: David S. Miller <davem@davemloft.net>

Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>

---

 include/linux/netdevice.h |    6 ++++++

 include/net/ip_tunnels.h  |    3 ++-

 net/ipv4/ip_gre.c         |   35 ++++++++++++++---------------------

 net/ipv4/ip_tunnel.c      |   16 +++++++++++++++-

 net/ipv4/ip_vti.c         |   32 +++++++++++++-------------------

 net/ipv4/ipip.c           |   30 +++++++++---------------------

 6 files changed, 59 insertions(+), 63 deletions(-)

--- a/include/linux/netdevice.h

+++ b/include/linux/netdevice.h

@@ -53,6 +53,7 @@ struct netpoll_info;

 struct device;

 struct phy_device;

 struct dsa_port;

+struct ip_tunnel_parm;

 struct macsec_context;

 struct macsec_ops;

@@ -1275,6 +1276,9 @@ struct netdev_net_notifier {

  *	Get devlink port instance associated with a given netdev.

  *	Called with a reference on the netdevice and devlink locks only,

  *	rtnl_lock is not held.

+ * int (*ndo_tunnel_ctl)(struct net_device *dev, struct ip_tunnel_parm *p,

+ *			 int cmd);

+ *	Add, change, delete or get information on an IPv4 tunnel.

  */

 struct net_device_ops {

 	int			(*ndo_init)(struct net_device *dev);

@@ -1480,6 +1484,8 @@ struct net_device_ops {

 	int			(*ndo_xsk_wakeup)(struct net_device *dev,

 						  u32 queue_id, u32 flags);

 	struct devlink_port *	(*ndo_get_devlink_port)(struct net_device *dev);

+	int			(*ndo_tunnel_ctl)(struct net_device *dev,

+						  struct ip_tunnel_parm *p, int cmd);

 };

 /**

--- a/include/net/ip_tunnels.h

+++ b/include/net/ip_tunnels.h

@@ -269,7 +269,8 @@ void ip_tunnel_xmit(struct sk_buff *skb,

 		    const struct iphdr *tnl_params, const u8 protocol);

 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,

 		       const u8 proto, int tunnel_hlen);

-int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);

+int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);

+int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);

 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);

 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);

--- a/net/ipv4/ip_gre.c

+++ b/net/ipv4/ip_gre.c

@@ -747,45 +747,37 @@ static void ipgre_link_update(struct net

 	}

 }

-static int ipgre_tunnel_ioctl(struct net_device *dev,

-			      struct ifreq *ifr, int cmd)

+static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p,

+			    int cmd)

 {

-	struct ip_tunnel_parm p;

 	int err;

-	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))

-		return -EFAULT;

-

 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {

-		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||

-		    p.iph.ihl != 5 || (p.iph.frag_off & htons(~IP_DF)) ||

-		    ((p.i_flags | p.o_flags) & (GRE_VERSION | GRE_ROUTING)))

+		if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||

+		    p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||

+		    ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING)))

 			return -EINVAL;

 	}

-	p.i_flags = gre_flags_to_tnl_flags(p.i_flags);

-	p.o_flags = gre_flags_to_tnl_flags(p.o_flags);

+	p->i_flags = gre_flags_to_tnl_flags(p->i_flags);

+	p->o_flags = gre_flags_to_tnl_flags(p->o_flags);

-	err = ip_tunnel_ioctl(dev, &p, cmd);

+	err = ip_tunnel_ctl(dev, p, cmd);

 	if (err)

 		return err;

 	if (cmd == SIOCCHGTUNNEL) {

 		struct ip_tunnel *t = netdev_priv(dev);

-		t->parms.i_flags = p.i_flags;

-		t->parms.o_flags = p.o_flags;

+		t->parms.i_flags = p->i_flags;

+		t->parms.o_flags = p->o_flags;

 		if (strcmp(dev->rtnl_link_ops->kind, "erspan"))

 			ipgre_link_update(dev, true);

 	}

-	p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags);

-	p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags);

-

-	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))

-		return -EFAULT;

-

+	p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);

+	p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);

 	return 0;

 }

@@ -903,10 +895,11 @@ static const struct net_device_ops ipgre

 	.ndo_stop		= ipgre_close,

 #endif

 	.ndo_start_xmit		= ipgre_xmit,

-	.ndo_do_ioctl		= ipgre_tunnel_ioctl,

+	.ndo_do_ioctl		= ip_tunnel_ioctl,

 	.ndo_change_mtu		= ip_tunnel_change_mtu,

 	.ndo_get_stats64	= ip_tunnel_get_stats64,

 	.ndo_get_iflink		= ip_tunnel_get_iflink,

+	.ndo_tunnel_ctl		= ipgre_tunnel_ctl,

 };

 #define GRE_FEATURES (NETIF_F_SG |		\

--- a/net/ipv4/ip_tunnel.c

+++ b/net/ipv4/ip_tunnel.c

@@ -860,7 +860,7 @@ static void ip_tunnel_update(struct ip_t

 	netdev_state_change(dev);

 }

-int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)

+int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)

 {

 	int err = 0;

 	struct ip_tunnel *t = netdev_priv(dev);

@@ -960,6 +960,20 @@ int ip_tunnel_ioctl(struct net_device *d

 done:

 	return err;

 }

+EXPORT_SYMBOL_GPL(ip_tunnel_ctl);

+

+int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)

+{

+	struct ip_tunnel_parm p;

+	int err;

+

+	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))

+		return -EFAULT;

+	err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, cmd);

+	if (!err && copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))

+		return -EFAULT;

+	return err;

+}

 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);

 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict)

--- a/net/ipv4/ip_vti.c

+++ b/net/ipv4/ip_vti.c

@@ -378,38 +378,31 @@ static int vti4_err(struct sk_buff *skb,

 }

 static int

-vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)

+vti_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)

 {

 	int err = 0;

-	struct ip_tunnel_parm p;

-

-	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))

-		return -EFAULT;

 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {

-		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||

-		    p.iph.ihl != 5)

+		if (p->iph.version != 4 || p->iph.protocol != IPPROTO_IPIP ||

+		    p->iph.ihl != 5)

 			return -EINVAL;

 	}

-	if (!(p.i_flags & GRE_KEY))

-		p.i_key = 0;

-	if (!(p.o_flags & GRE_KEY))

-		p.o_key = 0;

+	if (!(p->i_flags & GRE_KEY))

+		p->i_key = 0;

+	if (!(p->o_flags & GRE_KEY))

+		p->o_key = 0;

-	p.i_flags = VTI_ISVTI;

+	p->i_flags = VTI_ISVTI;

-	err = ip_tunnel_ioctl(dev, &p, cmd);

+	err = ip_tunnel_ctl(dev, p, cmd);

 	if (err)

 		return err;

 	if (cmd != SIOCDELTUNNEL) {

-		p.i_flags |= GRE_KEY;

-		p.o_flags |= GRE_KEY;

+		p->i_flags |= GRE_KEY;

+		p->o_flags |= GRE_KEY;

 	}

-

-	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))

-		return -EFAULT;

 	return 0;

 }

@@ -417,10 +410,11 @@ static const struct net_device_ops vti_n

 	.ndo_init	= vti_tunnel_init,

 	.ndo_uninit	= ip_tunnel_uninit,

 	.ndo_start_xmit	= vti_tunnel_xmit,

-	.ndo_do_ioctl	= vti_tunnel_ioctl,

+	.ndo_do_ioctl	= ip_tunnel_ioctl,

 	.ndo_change_mtu	= ip_tunnel_change_mtu,

 	.ndo_get_stats64 = ip_tunnel_get_stats64,

 	.ndo_get_iflink = ip_tunnel_get_iflink,

+	.ndo_tunnel_ctl	= vti_tunnel_ctl,

 };

 static void vti_tunnel_setup(struct net_device *dev)

--- a/net/ipv4/ipip.c

+++ b/net/ipv4/ipip.c

@@ -327,41 +327,29 @@ static bool ipip_tunnel_ioctl_verify_pro

 }

 static int

-ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)

+ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)

 {

-	int err = 0;

-	struct ip_tunnel_parm p;

-

-	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))

-		return -EFAULT;

-

 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {

-		if (p.iph.version != 4 ||

-		    !ipip_tunnel_ioctl_verify_protocol(p.iph.protocol) ||

-		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))

+		if (p->iph.version != 4 ||

+		    !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) ||

+		    p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))

 			return -EINVAL;

 	}

-	p.i_key = p.o_key = 0;

-	p.i_flags = p.o_flags = 0;

-	err = ip_tunnel_ioctl(dev, &p, cmd);

-	if (err)

-		return err;

-

-	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))

-		return -EFAULT;

-

-	return 0;

+	p->i_key = p->o_key = 0;

+	p->i_flags = p->o_flags = 0;

+	return ip_tunnel_ctl(dev, p, cmd);

 }

 static const struct net_device_ops ipip_netdev_ops = {

 	.ndo_init       = ipip_tunnel_init,

 	.ndo_uninit     = ip_tunnel_uninit,

 	.ndo_start_xmit	= ipip_tunnel_xmit,

-	.ndo_do_ioctl	= ipip_tunnel_ioctl,

+	.ndo_do_ioctl	= ip_tunnel_ioctl,

 	.ndo_change_mtu = ip_tunnel_change_mtu,

 	.ndo_get_stats64 = ip_tunnel_get_stats64,

 	.ndo_get_iflink = ip_tunnel_get_iflink,

+	.ndo_tunnel_ctl	= ipip_tunnel_ctl,

 };

 #define IPIP_FEATURES (NETIF_F_SG |		\