// 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"
#include "rmnet_map.h"
/* 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 */
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 = rmnet_get_port_rtnl(real_dev);
if (port->nr_rmnet_devs)
return -EINVAL;
rmnet_map_tx_aggregate_exit(port);
netdev_rx_handler_unregister(real_dev);
kfree(port);
netdev_dbg(real_dev, "Removed from rmnet\n");
return 0;
}
static int rmnet_register_real_device(struct net_device *real_dev,
struct netlink_ext_ack *extack)
{
struct rmnet_port *port;
int rc, entry;
ASSERT_RTNL();
if (rmnet_is_real_dev_registered(real_dev)) {
port = rmnet_get_port_rtnl(real_dev);
if (port->rmnet_mode != RMNET_EPMODE_VND) {
NL_SET_ERR_MSG_MOD(extack, "bridge device already exists");
return -EINVAL;
}
return 0;
}
port = kzalloc(sizeof(*port), GFP_KERNEL);
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;
}
for (entry = 0; entry < RMNET_MAX_LOGICAL_EP; entry++)
INIT_HLIST_HEAD(&port->muxed_ep[entry]);
rmnet_map_tx_aggregate_init(port);
netdev_dbg(real_dev, "registered with rmnet\n");
return 0;
}
static void rmnet_unregister_bridge(struct rmnet_port *port)
{
struct net_device *bridge_dev, *real_dev, *rmnet_dev;
struct rmnet_port *real_port;
if (port->rmnet_mode != RMNET_EPMODE_BRIDGE)
return;
rmnet_dev = port->rmnet_dev;
if (!port->nr_rmnet_devs) {
/* bridge device */
real_dev = port->bridge_ep;
bridge_dev = port->dev;
real_port = rmnet_get_port_rtnl(real_dev);
real_port->bridge_ep = NULL;
real_port->rmnet_mode = RMNET_EPMODE_VND;
} else {
/* real device */
bridge_dev = port->bridge_ep;
port->bridge_ep = NULL;
port->rmnet_mode = RMNET_EPMODE_VND;
}
netdev_upper_dev_unlink(bridge_dev, rmnet_dev);
rmnet_unregister_real_device(bridge_dev);
}
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;
if (!tb[IFLA_LINK]) {
NL_SET_ERR_MSG_MOD(extack, "link not specified");
return -EINVAL;
}
real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
if (!real_dev) {
NL_SET_ERR_MSG_MOD(extack, "link does not exist");
return -ENODEV;
}
ep = kzalloc(sizeof(*ep), GFP_KERNEL);
if (!ep)
return -ENOMEM;
mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
err = rmnet_register_real_device(real_dev, extack);
if (err)
goto err0;
port = rmnet_get_port_rtnl(real_dev);
err = rmnet_vnd_newlink(mux_id, dev, port, real_dev, ep, extack);
if (err)
goto err1;
err = netdev_upper_dev_link(real_dev, dev, extack);
if (err < 0)
goto err2;
port->rmnet_mode = mode;
port->rmnet_dev = dev;
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->mask;
data_format |= flags->flags & flags->mask;
}
netdev_dbg(dev, "data format [0x%08X]\n", data_format);
port->data_format = data_format;
return 0;
err2:
unregister_netdevice(dev);
rmnet_vnd_dellink(mux_id, port, ep);
err1:
rmnet_unregister_real_device(real_dev);
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, *bridge_dev;
struct rmnet_port *real_port, *bridge_port;
struct rmnet_endpoint *ep;
u8 mux_id = priv->mux_id;
real_dev = priv->real_dev;
if (!rmnet_is_real_dev_registered(real_dev))
return;
real_port = rmnet_get_port_rtnl(real_dev);
bridge_dev = real_port->bridge_ep;
if (bridge_dev) {
bridge_port = rmnet_get_port_rtnl(bridge_dev);
rmnet_unregister_bridge(bridge_port);
}
ep = rmnet_get_endpoint(real_port, mux_id);
if (ep) {
hlist_del_init_rcu(&ep->hlnode);
rmnet_vnd_dellink(mux_id, real_port, ep);
kfree(ep);
}
netdev_upper_dev_unlink(real_dev, dev);
rmnet_unregister_real_device(real_dev);
unregister_netdevice_queue(dev, head);
}
static void rmnet_force_unassociate_device(struct net_device *real_dev)
{
struct hlist_node *tmp_ep;
struct rmnet_endpoint *ep;
struct rmnet_port *port;
unsigned long bkt_ep;
LIST_HEAD(list);
port = rmnet_get_port_rtnl(real_dev);
if (port->nr_rmnet_devs) {
/* real device */
rmnet_unregister_bridge(port);
hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
unregister_netdevice_queue(ep->egress_dev, &list);
netdev_upper_dev_unlink(real_dev, ep->egress_dev);
rmnet_vnd_dellink(ep->mux_id, port, ep);
hlist_del_init_rcu(&ep->hlnode);
kfree(ep);
}
rmnet_unregister_real_device(real_dev);
unregister_netdevice_many(&list);
} else {
rmnet_unregister_bridge(port);
}
}
static int rmnet_config_notify_cb(struct notifier_block *nb,
unsigned long event, void *data)
{
struct net_device *real_dev = netdev_notifier_info_to_dev(data);
if (!rmnet_is_real_dev_registered(real_dev))
return NOTIFY_DONE;
switch (event) {
case NETDEV_UNREGISTER:
netdev_dbg(real_dev, "Kernel unregister\n");
rmnet_force_unassociate_device(real_dev);
break;
case NETDEV_CHANGEMTU:
if (rmnet_vnd_validate_real_dev_mtu(real_dev))
return NOTIFY_BAD;
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]) {
NL_SET_ERR_MSG_MOD(extack, "MUX ID not specified");
return -EINVAL;
}
mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
if (mux_id > (RMNET_MAX_LOGICAL_EP - 1)) {
NL_SET_ERR_MSG_MOD(extack, "invalid MUX ID");
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_port *port;
u16 mux_id;
if (!dev)
return -ENODEV;
real_dev = priv->real_dev;
if (!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]);
if (mux_id != priv->mux_id) {
struct rmnet_endpoint *ep;
ep = rmnet_get_endpoint(port, priv->mux_id);
if (!ep)
return -ENODEV;
if (rmnet_get_endpoint(port, mux_id)) {
NL_SET_ERR_MSG_MOD(extack,
"MUX ID already exists");
return -EINVAL;
}
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;
u32 old_data_format;
old_data_format = port->data_format;
flags = nla_data(data[IFLA_RMNET_FLAGS]);
port->data_format &= ~flags->mask;
port->data_format |= flags->flags & flags->mask;
if (rmnet_vnd_update_dev_mtu(port, real_dev)) {
port->data_format = old_data_format;
NL_SET_ERR_MSG_MOD(extack, "Invalid MTU on real dev");
return -EINVAL;
}
}
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,
};
struct rmnet_port *rmnet_get_port_rcu(struct net_device *real_dev)
{
if (rmnet_is_real_dev_registered(real_dev))
return rcu_dereference_bh(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_rtnl(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) {
NL_SET_ERR_MSG_MOD(extack, "more than one rmnet dev attached");
return -EINVAL;
}
if (port->rmnet_mode != RMNET_EPMODE_VND) {
NL_SET_ERR_MSG_MOD(extack, "more than one bridge dev attached");
return -EINVAL;
}
if (rmnet_is_real_dev_registered(slave_dev)) {
NL_SET_ERR_MSG_MOD(extack,
"slave cannot be another rmnet dev");
return -EBUSY;
}
err = rmnet_register_real_device(slave_dev, extack);
if (err)
return -EBUSY;
err = netdev_master_upper_dev_link(slave_dev, rmnet_dev, NULL, NULL,
extack);
if (err) {
rmnet_unregister_real_device(slave_dev);
return err;
}
slave_port = rmnet_get_port_rtnl(slave_dev);
slave_port->rmnet_mode = RMNET_EPMODE_BRIDGE;
slave_port->bridge_ep = real_dev;
slave_port->rmnet_dev = rmnet_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_port *port = rmnet_get_port_rtnl(slave_dev);
rmnet_unregister_bridge(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)
{
rtnl_link_unregister(&rmnet_link_ops);
unregister_netdevice_notifier(&rmnet_dev_notifier);
}
module_init(rmnet_init)
module_exit(rmnet_exit)
MODULE_ALIAS_RTNL_LINK("rmnet");
MODULE_DESCRIPTION("Qualcomm RmNet MAP driver");
MODULE_LICENSE("GPL v2");