[mirror_ubuntu-eoan-kernel.git] / drivers / net / ethernet / qualcomm / rmnet / rmnet_config.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
 *
 * RMNET configuration engine
 */

#include <net/sock.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netdevice.h>
#include "rmnet_config.h"
#include "rmnet_handlers.h"
#include "rmnet_vnd.h"
#include "rmnet_private.h"

/* Locking scheme -
 * The shared resource which needs to be protected is realdev->rx_handler_data.
 * For the writer path, this is using rtnl_lock(). The writer paths are
 * rmnet_newlink(), rmnet_dellink() and rmnet_force_unassociate_device(). These
 * paths are already called with rtnl_lock() acquired in. There is also an
 * ASSERT_RTNL() to ensure that we are calling with rtnl acquired. For
 * dereference here, we will need to use rtnl_dereference(). Dev list writing
 * needs to happen with rtnl_lock() acquired for netdev_master_upper_dev_link().
 * For the reader path, the real_dev->rx_handler_data is called in the TX / RX
 * path. We only need rcu_read_lock() for these scenarios. In these cases,
 * the rcu_read_lock() is held in __dev_queue_xmit() and
 * netif_receive_skb_internal(), so readers need to use rcu_dereference_rtnl()
 * to get the relevant information. For dev list reading, we again acquire
 * rcu_read_lock() in rmnet_dellink() for netdev_master_upper_dev_get_rcu().
 * We also use unregister_netdevice_many() to free all rmnet devices in
 * rmnet_force_unassociate_device() so we dont lose the rtnl_lock() and free in
 * same context.
 */

/* Local Definitions and Declarations */

static const struct nla_policy rmnet_policy[IFLA_RMNET_MAX + 1] = {
	[IFLA_RMNET_MUX_ID]	= { .type = NLA_U16 },
	[IFLA_RMNET_FLAGS]	= { .len = sizeof(struct ifla_rmnet_flags) },
};

static int rmnet_is_real_dev_registered(const struct net_device *real_dev)
{
	return rcu_access_pointer(real_dev->rx_handler) == rmnet_rx_handler;
}

/* Needs rtnl lock */
static struct rmnet_port*
rmnet_get_port_rtnl(const struct net_device *real_dev)
{
	return rtnl_dereference(real_dev->rx_handler_data);
}

static int rmnet_unregister_real_device(struct net_device *real_dev,
					struct rmnet_port *port)
{
	if (port->nr_rmnet_devs)
		return -EINVAL;

	netdev_rx_handler_unregister(real_dev);

	kfree(port);

	/* release reference on real_dev */
	dev_put(real_dev);

	netdev_dbg(real_dev, "Removed from rmnet\n");
	return 0;
}

static int rmnet_register_real_device(struct net_device *real_dev)
{
	struct rmnet_port *port;
	int rc, entry;

	ASSERT_RTNL();

	if (rmnet_is_real_dev_registered(real_dev))
		return 0;

	port = kzalloc(sizeof(*port), GFP_ATOMIC);
	if (!port)
		return -ENOMEM;

	port->dev = real_dev;
	rc = netdev_rx_handler_register(real_dev, rmnet_rx_handler, port);
	if (rc) {
		kfree(port);
		return -EBUSY;
	}

	/* hold on to real dev for MAP data */
	dev_hold(real_dev);

	for (entry = 0; entry < RMNET_MAX_LOGICAL_EP; entry++)
		INIT_HLIST_HEAD(&port->muxed_ep[entry]);

	netdev_dbg(real_dev, "registered with rmnet\n");
	return 0;
}

static void rmnet_unregister_bridge(struct net_device *dev,
				    struct rmnet_port *port)
{
	struct rmnet_port *bridge_port;
	struct net_device *bridge_dev;

	if (port->rmnet_mode != RMNET_EPMODE_BRIDGE)
		return;

	/* bridge slave handling */
	if (!port->nr_rmnet_devs) {
		bridge_dev = port->bridge_ep;

		bridge_port = rmnet_get_port_rtnl(bridge_dev);
		bridge_port->bridge_ep = NULL;
		bridge_port->rmnet_mode = RMNET_EPMODE_VND;
	} else {
		bridge_dev = port->bridge_ep;

		bridge_port = rmnet_get_port_rtnl(bridge_dev);
		rmnet_unregister_real_device(bridge_dev, bridge_port);
	}
}

static int rmnet_newlink(struct net *src_net, struct net_device *dev,
			 struct nlattr *tb[], struct nlattr *data[],
			 struct netlink_ext_ack *extack)
{
	u32 data_format = RMNET_FLAGS_INGRESS_DEAGGREGATION;
	struct net_device *real_dev;
	int mode = RMNET_EPMODE_VND;
	struct rmnet_endpoint *ep;
	struct rmnet_port *port;
	int err = 0;
	u16 mux_id;

	real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
	if (!real_dev || !dev)
		return -ENODEV;

	if (!data[IFLA_RMNET_MUX_ID])
		return -EINVAL;

	ep = kzalloc(sizeof(*ep), GFP_ATOMIC);
	if (!ep)
		return -ENOMEM;

	mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);

	err = rmnet_register_real_device(real_dev);
	if (err)
		goto err0;

	port = rmnet_get_port_rtnl(real_dev);
	err = rmnet_vnd_newlink(mux_id, dev, port, real_dev, ep);
	if (err)
		goto err1;

	port->rmnet_mode = mode;

	hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]);

	if (data[IFLA_RMNET_FLAGS]) {
		struct ifla_rmnet_flags *flags;

		flags = nla_data(data[IFLA_RMNET_FLAGS]);
		data_format = flags->flags & flags->mask;
	}

	netdev_dbg(dev, "data format [0x%08X]\n", data_format);
	port->data_format = data_format;

	return 0;

err1:
	rmnet_unregister_real_device(real_dev, port);
err0:
	kfree(ep);
	return err;
}

static void rmnet_dellink(struct net_device *dev, struct list_head *head)
{
	struct rmnet_priv *priv = netdev_priv(dev);
	struct net_device *real_dev;
	struct rmnet_endpoint *ep;
	struct rmnet_port *port;
	u8 mux_id;

	real_dev = priv->real_dev;

	if (!real_dev || !rmnet_is_real_dev_registered(real_dev))
		return;

	port = rmnet_get_port_rtnl(real_dev);

	mux_id = rmnet_vnd_get_mux(dev);

	ep = rmnet_get_endpoint(port, mux_id);
	if (ep) {
		hlist_del_init_rcu(&ep->hlnode);
		rmnet_unregister_bridge(dev, port);
		rmnet_vnd_dellink(mux_id, port, ep);
		kfree(ep);
	}
	rmnet_unregister_real_device(real_dev, port);

	unregister_netdevice_queue(dev, head);
}

static void rmnet_force_unassociate_device(struct net_device *dev)
{
	struct net_device *real_dev = dev;
	struct hlist_node *tmp_ep;
	struct rmnet_endpoint *ep;
	struct rmnet_port *port;
	unsigned long bkt_ep;
	LIST_HEAD(list);

	if (!rmnet_is_real_dev_registered(real_dev))
		return;

	ASSERT_RTNL();

	port = rmnet_get_port_rtnl(dev);

	rcu_read_lock();
	rmnet_unregister_bridge(dev, port);

	hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
		unregister_netdevice_queue(ep->egress_dev, &list);
		rmnet_vnd_dellink(ep->mux_id, port, ep);

		hlist_del_init_rcu(&ep->hlnode);
		kfree(ep);
	}

	rcu_read_unlock();
	unregister_netdevice_many(&list);

	rmnet_unregister_real_device(real_dev, port);
}

static int rmnet_config_notify_cb(struct notifier_block *nb,
				  unsigned long event, void *data)
{
	struct net_device *dev = netdev_notifier_info_to_dev(data);

	if (!dev)
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_UNREGISTER:
		netdev_dbg(dev, "Kernel unregister\n");
		rmnet_force_unassociate_device(dev);
		break;

	default:
		break;
	}

	return NOTIFY_DONE;
}

static struct notifier_block rmnet_dev_notifier __read_mostly = {
	.notifier_call = rmnet_config_notify_cb,
};

static int rmnet_rtnl_validate(struct nlattr *tb[], struct nlattr *data[],
			       struct netlink_ext_ack *extack)
{
	u16 mux_id;

	if (!data || !data[IFLA_RMNET_MUX_ID])
		return -EINVAL;

	mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
	if (mux_id > (RMNET_MAX_LOGICAL_EP - 1))
		return -ERANGE;

	return 0;
}

static int rmnet_changelink(struct net_device *dev, struct nlattr *tb[],
			    struct nlattr *data[],
			    struct netlink_ext_ack *extack)
{
	struct rmnet_priv *priv = netdev_priv(dev);
	struct net_device *real_dev;
	struct rmnet_endpoint *ep;
	struct rmnet_port *port;
	u16 mux_id;

	if (!dev)
		return -ENODEV;

	real_dev = __dev_get_by_index(dev_net(dev),
				      nla_get_u32(tb[IFLA_LINK]));

	if (!real_dev || !rmnet_is_real_dev_registered(real_dev))
		return -ENODEV;

	port = rmnet_get_port_rtnl(real_dev);

	if (data[IFLA_RMNET_MUX_ID]) {
		mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
		ep = rmnet_get_endpoint(port, priv->mux_id);
		if (!ep)
			return -ENODEV;

		hlist_del_init_rcu(&ep->hlnode);
		hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]);

		ep->mux_id = mux_id;
		priv->mux_id = mux_id;
	}

	if (data[IFLA_RMNET_FLAGS]) {
		struct ifla_rmnet_flags *flags;

		flags = nla_data(data[IFLA_RMNET_FLAGS]);
		port->data_format = flags->flags & flags->mask;
	}

	return 0;
}

static size_t rmnet_get_size(const struct net_device *dev)
{
	return
		/* IFLA_RMNET_MUX_ID */
		nla_total_size(2) +
		/* IFLA_RMNET_FLAGS */
		nla_total_size(sizeof(struct ifla_rmnet_flags));
}

static int rmnet_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
	struct rmnet_priv *priv = netdev_priv(dev);
	struct net_device *real_dev;
	struct ifla_rmnet_flags f;
	struct rmnet_port *port;

	real_dev = priv->real_dev;

	if (nla_put_u16(skb, IFLA_RMNET_MUX_ID, priv->mux_id))
		goto nla_put_failure;

	if (rmnet_is_real_dev_registered(real_dev)) {
		port = rmnet_get_port_rtnl(real_dev);
		f.flags = port->data_format;
	} else {
		f.flags = 0;
	}

	f.mask  = ~0;

	if (nla_put(skb, IFLA_RMNET_FLAGS, sizeof(f), &f))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

struct rtnl_link_ops rmnet_link_ops __read_mostly = {
	.kind		= "rmnet",
	.maxtype	= __IFLA_RMNET_MAX,
	.priv_size	= sizeof(struct rmnet_priv),
	.setup		= rmnet_vnd_setup,
	.validate	= rmnet_rtnl_validate,
	.newlink	= rmnet_newlink,
	.dellink	= rmnet_dellink,
	.get_size	= rmnet_get_size,
	.changelink     = rmnet_changelink,
	.policy		= rmnet_policy,
	.fill_info	= rmnet_fill_info,
};

/* Needs either rcu_read_lock() or rtnl lock */
struct rmnet_port *rmnet_get_port(struct net_device *real_dev)
{
	if (rmnet_is_real_dev_registered(real_dev))
		return rcu_dereference_rtnl(real_dev->rx_handler_data);
	else
		return NULL;
}

struct rmnet_endpoint *rmnet_get_endpoint(struct rmnet_port *port, u8 mux_id)
{
	struct rmnet_endpoint *ep;

	hlist_for_each_entry_rcu(ep, &port->muxed_ep[mux_id], hlnode) {
		if (ep->mux_id == mux_id)
			return ep;
	}

	return NULL;
}

int rmnet_add_bridge(struct net_device *rmnet_dev,
		     struct net_device *slave_dev,
		     struct netlink_ext_ack *extack)
{
	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
	struct net_device *real_dev = priv->real_dev;
	struct rmnet_port *port, *slave_port;
	int err;

	port = rmnet_get_port(real_dev);

	/* If there is more than one rmnet dev attached, its probably being
	 * used for muxing. Skip the briding in that case
	 */
	if (port->nr_rmnet_devs > 1)
		return -EINVAL;

	if (rmnet_is_real_dev_registered(slave_dev))
		return -EBUSY;

	err = rmnet_register_real_device(slave_dev);
	if (err)
		return -EBUSY;

	slave_port = rmnet_get_port(slave_dev);
	slave_port->rmnet_mode = RMNET_EPMODE_BRIDGE;
	slave_port->bridge_ep = real_dev;

	port->rmnet_mode = RMNET_EPMODE_BRIDGE;
	port->bridge_ep = slave_dev;

	netdev_dbg(slave_dev, "registered with rmnet as slave\n");
	return 0;
}

int rmnet_del_bridge(struct net_device *rmnet_dev,
		     struct net_device *slave_dev)
{
	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
	struct net_device *real_dev = priv->real_dev;
	struct rmnet_port *port, *slave_port;

	port = rmnet_get_port(real_dev);
	port->rmnet_mode = RMNET_EPMODE_VND;
	port->bridge_ep = NULL;

	slave_port = rmnet_get_port(slave_dev);
	rmnet_unregister_real_device(slave_dev, slave_port);

	netdev_dbg(slave_dev, "removed from rmnet as slave\n");
	return 0;
}

/* Startup/Shutdown */

static int __init rmnet_init(void)
{
	int rc;

	rc = register_netdevice_notifier(&rmnet_dev_notifier);
	if (rc != 0)
		return rc;

	rc = rtnl_link_register(&rmnet_link_ops);
	if (rc != 0) {
		unregister_netdevice_notifier(&rmnet_dev_notifier);
		return rc;
	}
	return rc;
}

static void __exit rmnet_exit(void)
{
	unregister_netdevice_notifier(&rmnet_dev_notifier);
	rtnl_link_unregister(&rmnet_link_ops);
}

module_init(rmnet_init)
module_exit(rmnet_exit)
MODULE_LICENSE("GPL v2");
Commit	Line	Data
97fb5e8d	1	// SPDX-License-Identifier: GPL-2.0-only
9dcaec04	2	/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
ceed73a2 SAK	3	*
ceed73a2 SAK	4	* RMNET configuration engine
ceed73a2 SAK	5	*/
	6
	7	#include <net/sock.h>
	8	#include <linux/module.h>
	9	#include <linux/netlink.h>
	10	#include <linux/netdevice.h>
	11	#include "rmnet_config.h"
	12	#include "rmnet_handlers.h"
	13	#include "rmnet_vnd.h"
	14	#include "rmnet_private.h"
	15
	16	/* Locking scheme -
	17	* The shared resource which needs to be protected is realdev->rx_handler_data.
	18	* For the writer path, this is using rtnl_lock(). The writer paths are
	19	* rmnet_newlink(), rmnet_dellink() and rmnet_force_unassociate_device(). These
	20	* paths are already called with rtnl_lock() acquired in. There is also an
	21	* ASSERT_RTNL() to ensure that we are calling with rtnl acquired. For
	22	* dereference here, we will need to use rtnl_dereference(). Dev list writing
	23	* needs to happen with rtnl_lock() acquired for netdev_master_upper_dev_link().
	24	* For the reader path, the real_dev->rx_handler_data is called in the TX / RX
	25	* path. We only need rcu_read_lock() for these scenarios. In these cases,
	26	* the rcu_read_lock() is held in __dev_queue_xmit() and
	27	* netif_receive_skb_internal(), so readers need to use rcu_dereference_rtnl()
	28	* to get the relevant information. For dev list reading, we again acquire
	29	* rcu_read_lock() in rmnet_dellink() for netdev_master_upper_dev_get_rcu().
	30	* We also use unregister_netdevice_many() to free all rmnet devices in
	31	* rmnet_force_unassociate_device() so we dont lose the rtnl_lock() and free in
	32	* same context.
	33	*/
	34
	35	/* Local Definitions and Declarations */
ceed73a2	36
14452ca3 SAK	37	static const struct nla_policy rmnet_policy[IFLA_RMNET_MAX + 1] = {
	38	[IFLA_RMNET_MUX_ID] = { .type = NLA_U16 },
	39	[IFLA_RMNET_FLAGS] = { .len = sizeof(struct ifla_rmnet_flags) },
	40	};
	41
ceed73a2 SAK	42	static int rmnet_is_real_dev_registered(const struct net_device *real_dev)
ceed73a2 SAK	43	{
5c346525	44	return rcu_access_pointer(real_dev->rx_handler) == rmnet_rx_handler;
ceed73a2 SAK	45	}
ceed73a2 SAK	46
ceed73a2	47	/* Needs rtnl lock */
b665f4f8 SAK	48	static struct rmnet_port*
b665f4f8 SAK	49	rmnet_get_port_rtnl(const struct net_device *real_dev)
ceed73a2 SAK	50	{
	51	return rtnl_dereference(real_dev->rx_handler_data);
	52	}
	53
ceed73a2	54	static int rmnet_unregister_real_device(struct net_device *real_dev,
b665f4f8	55	struct rmnet_port *port)
ceed73a2	56	{
b665f4f8	57	if (port->nr_rmnet_devs)
ceed73a2 SAK	58	return -EINVAL;
ceed73a2 SAK	59
ceed73a2 SAK	60	netdev_rx_handler_unregister(real_dev);
ceed73a2 SAK	61
2c08b493 ST	62	kfree(port);
2c08b493 ST	63
ceed73a2 SAK	64	/* release reference on real_dev */
	65	dev_put(real_dev);
	66
	67	netdev_dbg(real_dev, "Removed from rmnet\n");
	68	return 0;
	69	}
	70
	71	static int rmnet_register_real_device(struct net_device *real_dev)
	72	{
b665f4f8	73	struct rmnet_port *port;
3352e6c4	74	int rc, entry;
ceed73a2 SAK	75
	76	ASSERT_RTNL();
	77
	78	if (rmnet_is_real_dev_registered(real_dev))
	79	return 0;
	80
b665f4f8 SAK	81	port = kzalloc(sizeof(*port), GFP_ATOMIC);
b665f4f8 SAK	82	if (!port)
ceed73a2 SAK	83	return -ENOMEM;
ceed73a2 SAK	84
b665f4f8 SAK	85	port->dev = real_dev;
b665f4f8 SAK	86	rc = netdev_rx_handler_register(real_dev, rmnet_rx_handler, port);
ceed73a2	87	if (rc) {
b665f4f8	88	kfree(port);
ceed73a2 SAK	89	return -EBUSY;
	90	}
	91
	92	/* hold on to real dev for MAP data */
	93	dev_hold(real_dev);
	94
3352e6c4 SAK	95	for (entry = 0; entry < RMNET_MAX_LOGICAL_EP; entry++)
	96	INIT_HLIST_HEAD(&port->muxed_ep[entry]);
	97
ceed73a2 SAK	98	netdev_dbg(real_dev, "registered with rmnet\n");
	99	return 0;
	100	}
	101
60d58f97 SAK	102	static void rmnet_unregister_bridge(struct net_device *dev,
	103	struct rmnet_port *port)
	104	{
60d58f97	105	struct rmnet_port *bridge_port;
b37f78f2	106	struct net_device *bridge_dev;
60d58f97 SAK	107
	108	if (port->rmnet_mode != RMNET_EPMODE_BRIDGE)
	109	return;
	110
	111	/* bridge slave handling */
	112	if (!port->nr_rmnet_devs) {
60d58f97 SAK	113	bridge_dev = port->bridge_ep;
	114
	115	bridge_port = rmnet_get_port_rtnl(bridge_dev);
	116	bridge_port->bridge_ep = NULL;
	117	bridge_port->rmnet_mode = RMNET_EPMODE_VND;
	118	} else {
	119	bridge_dev = port->bridge_ep;
	120
	121	bridge_port = rmnet_get_port_rtnl(bridge_dev);
60d58f97 SAK	122	rmnet_unregister_real_device(bridge_dev, bridge_port);
	123	}
	124	}
	125
ceed73a2 SAK	126	static int rmnet_newlink(struct net src_net, struct net_device dev,
	127	struct nlattr tb[], struct nlattr data[],
	128	struct netlink_ext_ack *extack)
	129	{
14452ca3	130	u32 data_format = RMNET_FLAGS_INGRESS_DEAGGREGATION;
ceed73a2 SAK	131	struct net_device *real_dev;
ceed73a2 SAK	132	int mode = RMNET_EPMODE_VND;
3352e6c4	133	struct rmnet_endpoint *ep;
b665f4f8	134	struct rmnet_port *port;
ceed73a2 SAK	135	int err = 0;
	136	u16 mux_id;
	137
	138	real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
	139	if (!real_dev \|\| !dev)
	140	return -ENODEV;
	141
14452ca3	142	if (!data[IFLA_RMNET_MUX_ID])
ceed73a2 SAK	143	return -EINVAL;
ceed73a2 SAK	144
3352e6c4 SAK	145	ep = kzalloc(sizeof(*ep), GFP_ATOMIC);
	146	if (!ep)
	147	return -ENOMEM;
	148
14452ca3	149	mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
ceed73a2 SAK	150
	151	err = rmnet_register_real_device(real_dev);
	152	if (err)
	153	goto err0;
	154
b665f4f8	155	port = rmnet_get_port_rtnl(real_dev);
3352e6c4	156	err = rmnet_vnd_newlink(mux_id, dev, port, real_dev, ep);
ceed73a2 SAK	157	if (err)
	158	goto err1;
	159
91489632	160	port->rmnet_mode = mode;
032ee468	161
3352e6c4	162	hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]);
6b8ecc23	163
14452ca3 SAK	164	if (data[IFLA_RMNET_FLAGS]) {
14452ca3 SAK	165	struct ifla_rmnet_flags *flags;
6b8ecc23	166
14452ca3	167	flags = nla_data(data[IFLA_RMNET_FLAGS]);
b23e722e	168	data_format = flags->flags & flags->mask;
6b8ecc23 SAK	169	}
6b8ecc23 SAK	170
b23e722e SAK	171	netdev_dbg(dev, "data format [0x%08X]\n", data_format);
b23e722e SAK	172	port->data_format = data_format;
6b8ecc23	173
ceed73a2 SAK	174	return 0;
ceed73a2 SAK	175
ceed73a2	176	err1:
b665f4f8	177	rmnet_unregister_real_device(real_dev, port);
ceed73a2	178	err0:
6296928f	179	kfree(ep);
ceed73a2 SAK	180	return err;
	181	}
	182
	183	static void rmnet_dellink(struct net_device dev, struct list_head head)
	184	{
b37f78f2	185	struct rmnet_priv *priv = netdev_priv(dev);
ceed73a2	186	struct net_device *real_dev;
3352e6c4	187	struct rmnet_endpoint *ep;
b665f4f8	188	struct rmnet_port *port;
ceed73a2 SAK	189	u8 mux_id;
ceed73a2 SAK	190
b37f78f2	191	real_dev = priv->real_dev;
ceed73a2 SAK	192
	193	if (!real_dev \|\| !rmnet_is_real_dev_registered(real_dev))
	194	return;
	195
b665f4f8	196	port = rmnet_get_port_rtnl(real_dev);
ceed73a2 SAK	197
ceed73a2 SAK	198	mux_id = rmnet_vnd_get_mux(dev);
3352e6c4 SAK	199
	200	ep = rmnet_get_endpoint(port, mux_id);
	201	if (ep) {
	202	hlist_del_init_rcu(&ep->hlnode);
60d58f97	203	rmnet_unregister_bridge(dev, port);
3352e6c4 SAK	204	rmnet_vnd_dellink(mux_id, port, ep);
	205	kfree(ep);
	206	}
b665f4f8	207	rmnet_unregister_real_device(real_dev, port);
ceed73a2 SAK	208
	209	unregister_netdevice_queue(dev, head);
	210	}
	211
ceed73a2 SAK	212	static void rmnet_force_unassociate_device(struct net_device *dev)
	213	{
	214	struct net_device *real_dev = dev;
b37f78f2 SAK	215	struct hlist_node *tmp_ep;
b37f78f2 SAK	216	struct rmnet_endpoint *ep;
b665f4f8	217	struct rmnet_port *port;
b37f78f2	218	unsigned long bkt_ep;
ceed73a2 SAK	219	LIST_HEAD(list);
	220
	221	if (!rmnet_is_real_dev_registered(real_dev))
	222	return;
	223
	224	ASSERT_RTNL();
	225
b665f4f8	226	port = rmnet_get_port_rtnl(dev);
ceed73a2 SAK	227
ceed73a2 SAK	228	rcu_read_lock();
60d58f97 SAK	229	rmnet_unregister_bridge(dev, port);
60d58f97 SAK	230
b37f78f2 SAK	231	hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
	232	unregister_netdevice_queue(ep->egress_dev, &list);
	233	rmnet_vnd_dellink(ep->mux_id, port, ep);
	234
	235	hlist_del_init_rcu(&ep->hlnode);
	236	kfree(ep);
	237	}
	238
ceed73a2 SAK	239	rcu_read_unlock();
	240	unregister_netdevice_many(&list);
	241
b665f4f8	242	rmnet_unregister_real_device(real_dev, port);
ceed73a2 SAK	243	}
	244
	245	static int rmnet_config_notify_cb(struct notifier_block *nb,
	246	unsigned long event, void *data)
	247	{
	248	struct net_device *dev = netdev_notifier_info_to_dev(data);
	249
	250	if (!dev)
	251	return NOTIFY_DONE;
	252
	253	switch (event) {
	254	case NETDEV_UNREGISTER:
	255	netdev_dbg(dev, "Kernel unregister\n");
	256	rmnet_force_unassociate_device(dev);
	257	break;
	258
	259	default:
	260	break;
	261	}
	262
	263	return NOTIFY_DONE;
	264	}
	265
	266	static struct notifier_block rmnet_dev_notifier __read_mostly = {
	267	.notifier_call = rmnet_config_notify_cb,
	268	};
	269
	270	static int rmnet_rtnl_validate(struct nlattr tb[], struct nlattr data[],
	271	struct netlink_ext_ack *extack)
	272	{
	273	u16 mux_id;
	274
14452ca3	275	if (!data \|\| !data[IFLA_RMNET_MUX_ID])
ceed73a2 SAK	276	return -EINVAL;
ceed73a2 SAK	277
14452ca3	278	mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
ceed73a2 SAK	279	if (mux_id > (RMNET_MAX_LOGICAL_EP - 1))
	280	return -ERANGE;
	281
	282	return 0;
	283	}
	284
23790ef1 SAK	285	static int rmnet_changelink(struct net_device dev, struct nlattr tb[],
	286	struct nlattr *data[],
	287	struct netlink_ext_ack *extack)
	288	{
	289	struct rmnet_priv *priv = netdev_priv(dev);
	290	struct net_device *real_dev;
	291	struct rmnet_endpoint *ep;
	292	struct rmnet_port *port;
	293	u16 mux_id;
	294
3c18aa14 CIK	295	if (!dev)
	296	return -ENODEV;
	297
23790ef1 SAK	298	real_dev = __dev_get_by_index(dev_net(dev),
	299	nla_get_u32(tb[IFLA_LINK]));
	300
3c18aa14	301	if (!real_dev \|\| !rmnet_is_real_dev_registered(real_dev))
23790ef1 SAK	302	return -ENODEV;
	303
	304	port = rmnet_get_port_rtnl(real_dev);
	305
14452ca3 SAK	306	if (data[IFLA_RMNET_MUX_ID]) {
14452ca3 SAK	307	mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
23790ef1	308	ep = rmnet_get_endpoint(port, priv->mux_id);
0c29ba1b CIK	309	if (!ep)
0c29ba1b CIK	310	return -ENODEV;
23790ef1 SAK	311
	312	hlist_del_init_rcu(&ep->hlnode);
	313	hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]);
	314
	315	ep->mux_id = mux_id;
	316	priv->mux_id = mux_id;
	317	}
	318
14452ca3 SAK	319	if (data[IFLA_RMNET_FLAGS]) {
14452ca3 SAK	320	struct ifla_rmnet_flags *flags;
23790ef1	321
14452ca3	322	flags = nla_data(data[IFLA_RMNET_FLAGS]);
b23e722e	323	port->data_format = flags->flags & flags->mask;
23790ef1 SAK	324	}
	325
	326	return 0;
	327	}
	328
ceed73a2 SAK	329	static size_t rmnet_get_size(const struct net_device *dev)
ceed73a2 SAK	330	{
14452ca3 SAK	331	return
	332	/* IFLA_RMNET_MUX_ID */
	333	nla_total_size(2) +
	334	/* IFLA_RMNET_FLAGS */
	335	nla_total_size(sizeof(struct ifla_rmnet_flags));
ceed73a2 SAK	336	}
ceed73a2 SAK	337
be81a85f SAK	338	static int rmnet_fill_info(struct sk_buff skb, const struct net_device dev)
	339	{
	340	struct rmnet_priv *priv = netdev_priv(dev);
	341	struct net_device *real_dev;
	342	struct ifla_rmnet_flags f;
	343	struct rmnet_port *port;
	344
	345	real_dev = priv->real_dev;
	346
be81a85f SAK	347	if (nla_put_u16(skb, IFLA_RMNET_MUX_ID, priv->mux_id))
	348	goto nla_put_failure;
	349
64e86fec SAK	350	if (rmnet_is_real_dev_registered(real_dev)) {
	351	port = rmnet_get_port_rtnl(real_dev);
	352	f.flags = port->data_format;
	353	} else {
	354	f.flags = 0;
	355	}
be81a85f	356
be81a85f SAK	357	f.mask = ~0;
	358
	359	if (nla_put(skb, IFLA_RMNET_FLAGS, sizeof(f), &f))
	360	goto nla_put_failure;
	361
	362	return 0;
	363
	364	nla_put_failure:
	365	return -EMSGSIZE;
	366	}
	367
ceed73a2 SAK	368	struct rtnl_link_ops rmnet_link_ops __read_mostly = {
ceed73a2 SAK	369	.kind = "rmnet",
14452ca3	370	.maxtype = __IFLA_RMNET_MAX,
ceed73a2 SAK	371	.priv_size = sizeof(struct rmnet_priv),
	372	.setup = rmnet_vnd_setup,
	373	.validate = rmnet_rtnl_validate,
	374	.newlink = rmnet_newlink,
	375	.dellink = rmnet_dellink,
	376	.get_size = rmnet_get_size,
23790ef1	377	.changelink = rmnet_changelink,
14452ca3	378	.policy = rmnet_policy,
be81a85f	379	.fill_info = rmnet_fill_info,
ceed73a2 SAK	380	};
ceed73a2 SAK	381
032ee468	382	/* Needs either rcu_read_lock() or rtnl lock */
b665f4f8	383	struct rmnet_port rmnet_get_port(struct net_device real_dev)
ceed73a2	384	{
032ee468 SAK	385	if (rmnet_is_real_dev_registered(real_dev))
	386	return rcu_dereference_rtnl(real_dev->rx_handler_data);
	387	else
	388	return NULL;
ceed73a2 SAK	389	}
ceed73a2 SAK	390
3352e6c4 SAK	391	struct rmnet_endpoint rmnet_get_endpoint(struct rmnet_port port, u8 mux_id)
	392	{
	393	struct rmnet_endpoint *ep;
	394
	395	hlist_for_each_entry_rcu(ep, &port->muxed_ep[mux_id], hlnode) {
	396	if (ep->mux_id == mux_id)
	397	return ep;
	398	}
	399
	400	return NULL;
	401	}
	402
60d58f97 SAK	403	int rmnet_add_bridge(struct net_device *rmnet_dev,
	404	struct net_device *slave_dev,
	405	struct netlink_ext_ack *extack)
	406	{
	407	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
	408	struct net_device *real_dev = priv->real_dev;
	409	struct rmnet_port port, slave_port;
	410	int err;
	411
	412	port = rmnet_get_port(real_dev);
	413
	414	/* If there is more than one rmnet dev attached, its probably being
	415	* used for muxing. Skip the briding in that case
	416	*/
	417	if (port->nr_rmnet_devs > 1)
	418	return -EINVAL;
	419
	420	if (rmnet_is_real_dev_registered(slave_dev))
	421	return -EBUSY;
	422
	423	err = rmnet_register_real_device(slave_dev);
	424	if (err)
	425	return -EBUSY;
	426
60d58f97 SAK	427	slave_port = rmnet_get_port(slave_dev);
	428	slave_port->rmnet_mode = RMNET_EPMODE_BRIDGE;
	429	slave_port->bridge_ep = real_dev;
	430
	431	port->rmnet_mode = RMNET_EPMODE_BRIDGE;
	432	port->bridge_ep = slave_dev;
	433
	434	netdev_dbg(slave_dev, "registered with rmnet as slave\n");
	435	return 0;
	436	}
	437
	438	int rmnet_del_bridge(struct net_device *rmnet_dev,
	439	struct net_device *slave_dev)
	440	{
	441	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
	442	struct net_device *real_dev = priv->real_dev;
	443	struct rmnet_port port, slave_port;
	444
	445	port = rmnet_get_port(real_dev);
	446	port->rmnet_mode = RMNET_EPMODE_VND;
	447	port->bridge_ep = NULL;
	448
60d58f97 SAK	449	slave_port = rmnet_get_port(slave_dev);
	450	rmnet_unregister_real_device(slave_dev, slave_port);
	451
	452	netdev_dbg(slave_dev, "removed from rmnet as slave\n");
	453	return 0;
	454	}
	455
ceed73a2 SAK	456	/* Startup/Shutdown */
	457
	458	static int __init rmnet_init(void)
	459	{
	460	int rc;
	461
	462	rc = register_netdevice_notifier(&rmnet_dev_notifier);
	463	if (rc != 0)
	464	return rc;
	465
	466	rc = rtnl_link_register(&rmnet_link_ops);
	467	if (rc != 0) {
	468	unregister_netdevice_notifier(&rmnet_dev_notifier);
	469	return rc;
	470	}
	471	return rc;
	472	}
	473
	474	static void __exit rmnet_exit(void)
	475	{
	476	unregister_netdevice_notifier(&rmnet_dev_notifier);
	477	rtnl_link_unregister(&rmnet_link_ops);
	478	}
	479
	480	module_init(rmnet_init)
	481	module_exit(rmnet_exit)
	482	MODULE_LICENSE("GPL v2");