Commit fd3a4590 authored by Remi Pommarel's avatar Remi Pommarel Committed by David S. Miller
Browse files

net: bridge: Get SIOCGIFBR/SIOCSIFBR ioctl working in compat mode 



In compat mode SIOC{G,S}IFBR ioctls were only supporting
BRCTL_GET_VERSION returning an artificially version to spur userland
tool to use SIOCDEVPRIVATE instead. But some userland tools ignore that
and use SIOC{G,S}IFBR unconditionally as seen with busybox's brctl.

Example of non working 32-bit brctl with CONFIG_COMPAT=y:
$ brctl show
brctl: SIOCGIFBR: Invalid argument

Example of fixed 32-bit brctl with CONFIG_COMPAT=y:
$ brctl show
bridge name     bridge id               STP enabled     interfaces
br0

Signed-off-by: default avatarRemi Pommarel <repk@triplefau.lt>
Co-developed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 32f52e8e

net/bridge/br_ioctl.c

+50 −25
Original line number Diff line number Diff line
@@ -102,37 +102,56 @@ static int add_del_if(struct net_bridge *br, int ifindex, int isadd) 
	return ret;

}



#define BR_UARGS_MAX 4

static int br_dev_read_uargs(unsigned long *args, size_t nr_args,

			     void __user **argp, void __user *data)

{

	int ret;



	if (nr_args < 2 || nr_args > BR_UARGS_MAX)

		return -EINVAL;



	if (in_compat_syscall()) {

		unsigned int cargs[BR_UARGS_MAX];

		int i;



		ret = copy_from_user(cargs, data, nr_args * sizeof(*cargs));

		if (ret)

			goto fault;



		for (i = 0; i < nr_args; ++i)

			args[i] = cargs[i];



		*argp = compat_ptr(args[1]);

	} else {

		ret = copy_from_user(args, data, nr_args * sizeof(*args));

		if (ret)

			goto fault;

		*argp = (void __user *)args[1];

	}



	return 0;

fault:

	return -EFAULT;

}



/*

 * Legacy ioctl's through SIOCDEVPRIVATE

 * This interface is deprecated because it was too difficult

 * to do the translation for 32/64bit ioctl compatibility.

 */

int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd)

int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq,

			  void __user *data, int cmd)

{

	struct net_bridge *br = netdev_priv(dev);

	struct net_bridge_port *p = NULL;

	unsigned long args[4];

	void __user *argp;

	int ret = -EOPNOTSUPP;



	if (in_compat_syscall()) {

		unsigned int cargs[4];



		if (copy_from_user(cargs, data, sizeof(cargs)))

			return -EFAULT;



		args[0] = cargs[0];

		args[1] = cargs[1];

		args[2] = cargs[2];

		args[3] = cargs[3];



		argp = compat_ptr(args[1]);

	} else {

		if (copy_from_user(args, data, sizeof(args)))

			return -EFAULT;

	int ret;



		argp = (void __user *)args[1];

	}

	ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);

	if (ret)

		return ret;



	switch (args[0]) {

	case BRCTL_ADD_IF:
@@ -301,6 +320,9 @@ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user 


	case BRCTL_GET_FDB_ENTRIES:

		return get_fdb_entries(br, argp, args[2], args[3]);



	default:

		ret = -EOPNOTSUPP;

	}



	if (!ret) {
@@ -313,12 +335,15 @@ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user 
	return ret;

}



static int old_deviceless(struct net *net, void __user *uarg)

static int old_deviceless(struct net *net, void __user *data)

{

	unsigned long args[3];

	void __user *argp;

	int ret;



	if (copy_from_user(args, uarg, sizeof(args)))

		return -EFAULT;

	ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);

	if (ret)

		return ret;



	switch (args[0]) {

	case BRCTL_GET_VERSION:
@@ -337,7 +362,7 @@ static int old_deviceless(struct net *net, void __user *uarg) 


		args[2] = get_bridge_ifindices(net, indices, args[2]);



		ret = copy_to_user((void __user *)args[1], indices,

		ret = copy_to_user(argp, indices,

				   array_size(args[2], sizeof(int)))

			? -EFAULT : args[2];
@@ -353,7 +378,7 @@ static int old_deviceless(struct net *net, void __user *uarg) 
		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))

			return -EPERM;



		if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))

		if (copy_from_user(buf, argp, IFNAMSIZ))

			return -EFAULT;



		buf[IFNAMSIZ-1] = 0;

net/socket.c

+2 −18
Original line number Diff line number Diff line
@@ -3233,21 +3233,6 @@ static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd, 
	return dev_ioctl(net, cmd, &ifreq, data, NULL);

}



/* Since old style bridge ioctl's endup using SIOCDEVPRIVATE

 * for some operations; this forces use of the newer bridge-utils that

 * use compatible ioctls

 */

static int old_bridge_ioctl(compat_ulong_t __user *argp)

{

	compat_ulong_t tmp;



	if (get_user(tmp, argp))

		return -EFAULT;

	if (tmp == BRCTL_GET_VERSION)

		return BRCTL_VERSION + 1;

	return -EINVAL;

}



static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,

			 unsigned int cmd, unsigned long arg)

{
@@ -3259,9 +3244,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, 
		return sock_ioctl(file, cmd, (unsigned long)argp);



	switch (cmd) {

	case SIOCSIFBR:

	case SIOCGIFBR:

		return old_bridge_ioctl(argp);

	case SIOCWANDEV:

		return compat_siocwandev(net, argp);

	case SIOCGSTAMP_OLD:
@@ -3290,6 +3272,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, 
	case SIOCGSTAMP_NEW:

	case SIOCGSTAMPNS_NEW:

	case SIOCGIFCONF:

	case SIOCSIFBR:

	case SIOCGIFBR:

		return sock_ioctl(file, cmd, arg);



	case SIOCGIFFLAGS: