// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2021, Linaro Ltd <[email protected]> */
#include <linux/bitmap.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/termios.h>
#include <linux/wwan.h>
#include <net/rtnetlink.h>
#include <uapi/linux/wwan.h>
/* Maximum number of minors in use */
#define WWAN_MAX_MINORS (1 << MINORBITS)
static DEFINE_MUTEX(wwan_register_lock); /* WWAN device create|remove lock */
static DEFINE_IDA(minors); /* minors for WWAN port chardevs */
static DEFINE_IDA(wwan_dev_ids); /* for unique WWAN device IDs */
static const struct class wwan_class = {
.name = "wwan",
};
static int wwan_major;
static struct dentry *wwan_debugfs_dir;
#define to_wwan_dev(d) container_of(d, struct wwan_device, dev)
#define to_wwan_port(d) container_of(d, struct wwan_port, dev)
/* WWAN port flags */
#define WWAN_PORT_TX_OFF 0
/**
* struct wwan_device - The structure that defines a WWAN device
*
* @id: WWAN device unique ID.
* @dev: Underlying device.
* @port_id: Current available port ID to pick.
* @ops: wwan device ops
* @ops_ctxt: context to pass to ops
* @debugfs_dir: WWAN device debugfs dir
*/
struct wwan_device {
unsigned int id;
struct device dev;
atomic_t port_id;
const struct wwan_ops *ops;
void *ops_ctxt;
#ifdef CONFIG_WWAN_DEBUGFS
struct dentry *debugfs_dir;
#endif
};
/**
* struct wwan_port - The structure that defines a WWAN port
* @type: Port type
* @start_count: Port start counter
* @flags: Store port state and capabilities
* @ops: Pointer to WWAN port operations
* @ops_lock: Protect port ops
* @dev: Underlying device
* @rxq: Buffer inbound queue
* @waitqueue: The waitqueue for port fops (read/write/poll)
* @data_lock: Port specific data access serialization
* @headroom_len: SKB reserved headroom size
* @frag_len: Length to fragment packet
* @at_data: AT port specific data
*/
struct wwan_port {
enum wwan_port_type type;
unsigned int start_count;
unsigned long flags;
const struct wwan_port_ops *ops;
struct mutex ops_lock; /* Serialize ops + protect against removal */
struct device dev;
struct sk_buff_head rxq;
wait_queue_head_t waitqueue;
struct mutex data_lock; /* Port specific data access serialization */
size_t headroom_len;
size_t frag_len;
union {
struct {
struct ktermios termios;
int mdmbits;
} at_data;
};
};
static ssize_t index_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct wwan_device *wwan = to_wwan_dev(dev);
return sprintf(buf, "%d\n", wwan->id);
}
static DEVICE_ATTR_RO(index);
static struct attribute *wwan_dev_attrs[] = {
&dev_attr_index.attr,
NULL,
};
ATTRIBUTE_GROUPS(wwan_dev);
static void wwan_dev_destroy(struct device *dev)
{
struct wwan_device *wwandev = to_wwan_dev(dev);
ida_free(&wwan_dev_ids, wwandev->id);
kfree(wwandev);
}
static const struct device_type wwan_dev_type = {
.name = "wwan_dev",
.release = wwan_dev_destroy,
.groups = wwan_dev_groups,
};
static int wwan_dev_parent_match(struct device *dev, const void *parent)
{
return (dev->type == &wwan_dev_type &&
(dev->parent == parent || dev == parent));
}
static struct wwan_device *wwan_dev_get_by_parent(struct device *parent)
{
struct device *dev;
dev = class_find_device(&wwan_class, NULL, parent, wwan_dev_parent_match);
if (!dev)
return ERR_PTR(-ENODEV);
return to_wwan_dev(dev);
}
static int wwan_dev_name_match(struct device *dev, const void *name)
{
return dev->type == &wwan_dev_type &&
strcmp(dev_name(dev), name) == 0;
}
static struct wwan_device *wwan_dev_get_by_name(const char *name)
{
struct device *dev;
dev = class_find_device(&wwan_class, NULL, name, wwan_dev_name_match);
if (!dev)
return ERR_PTR(-ENODEV);
return to_wwan_dev(dev);
}
#ifdef CONFIG_WWAN_DEBUGFS
struct dentry *wwan_get_debugfs_dir(struct device *parent)
{
struct wwan_device *wwandev;
wwandev = wwan_dev_get_by_parent(parent);
if (IS_ERR(wwandev))
return ERR_CAST(wwandev);
return wwandev->debugfs_dir;
}
EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir);
static int wwan_dev_debugfs_match(struct device *dev, const void *dir)
{
struct wwan_device *wwandev;
if (dev->type != &wwan_dev_type)
return 0;
wwandev = to_wwan_dev(dev);
return wwandev->debugfs_dir == dir;
}
static struct wwan_device *wwan_dev_get_by_debugfs(struct dentry *dir)
{
struct device *dev;
dev = class_find_device(&wwan_class, NULL, dir, wwan_dev_debugfs_match);
if (!dev)
return ERR_PTR(-ENODEV);
return to_wwan_dev(dev);
}
void wwan_put_debugfs_dir(struct dentry *dir)
{
struct wwan_device *wwandev = wwan_dev_get_by_debugfs(dir);
if (WARN_ON(IS_ERR(wwandev)))
return;
/* wwan_dev_get_by_debugfs() also got a reference */
put_device(&wwandev->dev);
put_device(&wwandev->dev);
}
EXPORT_SYMBOL_GPL(wwan_put_debugfs_dir);
#endif
/* This function allocates and registers a new WWAN device OR if a WWAN device
* already exist for the given parent, it gets a reference and return it.
* This function is not exported (for now), it is called indirectly via
* wwan_create_port().
*/
static struct wwan_device *wwan_create_dev(struct device *parent)
{
struct wwan_device *wwandev;
int err, id;
/* The 'find-alloc-register' operation must be protected against
* concurrent execution, a WWAN device is possibly shared between
* multiple callers or concurrently unregistered from wwan_remove_dev().
*/
mutex_lock(&wwan_register_lock);
/* If wwandev already exists, return it */
wwandev = wwan_dev_get_by_parent(parent);
if (!IS_ERR(wwandev))
goto done_unlock;
id = ida_alloc(&wwan_dev_ids, GFP_KERNEL);
if (id < 0) {
wwandev = ERR_PTR(id);
goto done_unlock;
}
wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL);
if (!wwandev) {
wwandev = ERR_PTR(-ENOMEM);
ida_free(&wwan_dev_ids, id);
goto done_unlock;
}
wwandev->dev.parent = parent;
wwandev->dev.class = &wwan_class;
wwandev->dev.type = &wwan_dev_type;
wwandev->id = id;
dev_set_name(&wwandev->dev, "wwan%d", wwandev->id);
err = device_register(&wwandev->dev);
if (err) {
put_device(&wwandev->dev);
wwandev = ERR_PTR(err);
goto done_unlock;
}
#ifdef CONFIG_WWAN_DEBUGFS
wwandev->debugfs_dir =
debugfs_create_dir(kobject_name(&wwandev->dev.kobj),
wwan_debugfs_dir);
#endif
done_unlock:
mutex_unlock(&wwan_register_lock);
return wwandev;
}
static int is_wwan_child(struct device *dev, void *data)
{
return dev->class == &wwan_class;
}
static void wwan_remove_dev(struct wwan_device *wwandev)
{
int ret;
/* Prevent concurrent picking from wwan_create_dev */
mutex_lock(&wwan_register_lock);
/* WWAN device is created and registered (get+add) along with its first
* child port, and subsequent port registrations only grab a reference
* (get). The WWAN device must then be unregistered (del+put) along with
* its last port, and reference simply dropped (put) otherwise. In the
* same fashion, we must not unregister it when the ops are still there.
*/
if (wwandev->ops)
ret = 1;
else
ret = device_for_each_child(&wwandev->dev, NULL, is_wwan_child);
if (!ret) {
#ifdef CONFIG_WWAN_DEBUGFS
debugfs_remove_recursive(wwandev->debugfs_dir);
#endif
device_unregister(&wwandev->dev);
} else {
put_device(&wwandev->dev);
}
mutex_unlock(&wwan_register_lock);
}
/* ------- WWAN port management ------- */
static const struct {
const char * const name; /* Port type name */
const char * const devsuf; /* Port device name suffix */
} wwan_port_types[WWAN_PORT_MAX + 1] = {
[WWAN_PORT_AT] = {
.name = "AT",
.devsuf = "at",
},
[WWAN_PORT_MBIM] = {
.name = "MBIM",
.devsuf = "mbim",
},
[WWAN_PORT_QMI] = {
.name = "QMI",
.devsuf = "qmi",
},
[WWAN_PORT_QCDM] = {
.name = "QCDM",
.devsuf = "qcdm",
},
[WWAN_PORT_FIREHOSE] = {
.name = "FIREHOSE",
.devsuf = "firehose",
},
[WWAN_PORT_XMMRPC] = {
.name = "XMMRPC",
.devsuf = "xmmrpc",
},
[WWAN_PORT_FASTBOOT] = {
.name = "FASTBOOT",
.devsuf = "fastboot",
},
};
static ssize_t type_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct wwan_port *port = to_wwan_port(dev);
return sprintf(buf, "%s\n", wwan_port_types[port->type].name);
}
static DEVICE_ATTR_RO(type);
static struct attribute *wwan_port_attrs[] = {
&dev_attr_type.attr,
NULL,
};
ATTRIBUTE_GROUPS(wwan_port);
static void wwan_port_destroy(struct device *dev)
{
struct wwan_port *port = to_wwan_port(dev);
ida_free(&minors, MINOR(port->dev.devt));
mutex_destroy(&port->data_lock);
mutex_destroy(&port->ops_lock);
kfree(port);
}
static const struct device_type wwan_port_dev_type = {
.name = "wwan_port",
.release = wwan_port_destroy,
.groups = wwan_port_groups,
};
static int wwan_port_minor_match(struct device *dev, const void *minor)
{
return (dev->type == &wwan_port_dev_type &&
MINOR(dev->devt) == *(unsigned int *)minor);
}
static struct wwan_port *wwan_port_get_by_minor(unsigned int minor)
{
struct device *dev;
dev = class_find_device(&wwan_class, NULL, &minor, wwan_port_minor_match);
if (!dev)
return ERR_PTR(-ENODEV);
return to_wwan_port(dev);
}
/* Allocate and set unique name based on passed format
*
* Name allocation approach is highly inspired by the __dev_alloc_name()
* function.
*
* To avoid names collision, the caller must prevent the new port device
* registration as well as concurrent invocation of this function.
*/
static int __wwan_port_dev_assign_name(struct wwan_port *port, const char *fmt)
{
struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
const unsigned int max_ports = PAGE_SIZE * 8;
struct class_dev_iter iter;
unsigned long *idmap;
struct device *dev;
char buf[0x20];
int id;
idmap = bitmap_zalloc(max_ports, GFP_KERNEL);
if (!idmap)
return -ENOMEM;
/* Collect ids of same name format ports */
class_dev_iter_init(&iter, &wwan_class, NULL, &wwan_port_dev_type);
while ((dev = class_dev_iter_next(&iter))) {
if (dev->parent != &wwandev->dev)
continue;
if (sscanf(dev_name(dev), fmt, &id) != 1)
continue;
if (id < 0 || id >= max_ports)
continue;
set_bit(id, idmap);
}
class_dev_iter_exit(&iter);
/* Allocate unique id */
id = find_first_zero_bit(idmap, max_ports);
bitmap_free(idmap);
snprintf(buf, sizeof(buf), fmt, id); /* Name generation */
dev = device_find_child_by_name(&wwandev->dev, buf);
if (dev) {
put_device(dev);
return -ENFILE;
}
return dev_set_name(&port->dev, buf);
}
struct wwan_port *wwan_create_port(struct device *parent,
enum wwan_port_type type,
const struct wwan_port_ops *ops,
struct wwan_port_caps *caps,
void *drvdata)
{
struct wwan_device *wwandev;
struct wwan_port *port;
char namefmt[0x20];
int minor, err;
if (type > WWAN_PORT_MAX || !ops)
return ERR_PTR(-EINVAL);
/* A port is always a child of a WWAN device, retrieve (allocate or
* pick) the WWAN device based on the provided parent device.
*/
wwandev = wwan_create_dev(parent);
if (IS_ERR(wwandev))
return ERR_CAST(wwandev);
/* A port is exposed as character device, get a minor */
minor = ida_alloc_range(&minors, 0, WWAN_MAX_MINORS - 1, GFP_KERNEL);
if (minor < 0) {
err = minor;
goto error_wwandev_remove;
}
port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port) {
err = -ENOMEM;
ida_free(&minors, minor);
goto error_wwandev_remove;
}
port->type = type;
port->ops = ops;
port->frag_len = caps ? caps->frag_len : SIZE_MAX;
port->headroom_len = caps ? caps->headroom_len : 0;
mutex_init(&port->ops_lock);
skb_queue_head_init(&port->rxq);
init_waitqueue_head(&port->waitqueue);
mutex_init(&port->data_lock);
port->dev.parent = &wwandev->dev;
port->dev.class = &wwan_class;
port->dev.type = &wwan_port_dev_type;
port->dev.devt = MKDEV(wwan_major, minor);
dev_set_drvdata(&port->dev, drvdata);
/* allocate unique name based on wwan device id, port type and number */
snprintf(namefmt, sizeof(namefmt), "wwan%u%s%%d", wwandev->id,
wwan_port_types[port->type].devsuf);
/* Serialize ports registration */
mutex_lock(&wwan_register_lock);
__wwan_port_dev_assign_name(port, namefmt);
err = device_register(&port->dev);
mutex_unlock(&wwan_register_lock);
if (err)
goto error_put_device;
dev_info(&wwandev->dev, "port %s attached\n", dev_name(&port->dev));
return port;
error_put_device:
put_device(&port->dev);
error_wwandev_remove:
wwan_remove_dev(wwandev);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(wwan_create_port);
void wwan_remove_port(struct wwan_port *port)
{
struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
mutex_lock(&port->ops_lock);
if (port->start_count)
port->ops->stop(port);
port->ops = NULL; /* Prevent any new port operations (e.g. from fops) */
mutex_unlock(&port->ops_lock);
wake_up_interruptible(&port->waitqueue);
skb_queue_purge(&port->rxq);
dev_set_drvdata(&port->dev, NULL);
dev_info(&wwandev->dev, "port %s disconnected\n", dev_name(&port->dev));
device_unregister(&port->dev);
/* Release related wwan device */
wwan_remove_dev(wwandev);
}
EXPORT_SYMBOL_GPL(wwan_remove_port);
void wwan_port_rx(struct wwan_port *port, struct sk_buff *skb)
{
skb_queue_tail(&port->rxq, skb);
wake_up_interruptible(&port->waitqueue);
}
EXPORT_SYMBOL_GPL(wwan_port_rx);
void wwan_port_txon(struct wwan_port *port)
{
clear_bit(WWAN_PORT_TX_OFF, &port->flags);
wake_up_interruptible(&port->waitqueue);
}
EXPORT_SYMBOL_GPL(wwan_port_txon);
void wwan_port_txoff(struct wwan_port *port)
{
set_bit(WWAN_PORT_TX_OFF, &port->flags);
}
EXPORT_SYMBOL_GPL(wwan_port_txoff);
void *wwan_port_get_drvdata(struct wwan_port *port)
{
return dev_get_drvdata(&port->dev);
}
EXPORT_SYMBOL_GPL(wwan_port_get_drvdata);
static int wwan_port_op_start(struct wwan_port *port)
{
int ret = 0;
mutex_lock(&port->ops_lock);
if (!port->ops) { /* Port got unplugged */
ret = -ENODEV;
goto out_unlock;
}
/* If port is already started, don't start again */
if (!port->start_count)
ret = port->ops->start(port);
if (!ret)
port->start_count++;
out_unlock:
mutex_unlock(&port->ops_lock);
return ret;
}
static void wwan_port_op_stop(struct wwan_port *port)
{
mutex_lock(&port->ops_lock);
port->start_count--;
if (!port->start_count) {
if (port->ops)
port->ops->stop(port);
skb_queue_purge(&port->rxq);
}
mutex_unlock(&port->ops_lock);
}
static int wwan_port_op_tx(struct wwan_port *port, struct sk_buff *skb,
bool nonblock)
{
int ret;
mutex_lock(&port->ops_lock);
if (!port->ops) { /* Port got unplugged */
ret = -ENODEV;
goto out_unlock;
}
if (nonblock || !port->ops->tx_blocking)
ret = port->ops->tx(port, skb);
else
ret = port->ops->tx_blocking(port, skb);
out_unlock:
mutex_unlock(&port->ops_lock);
return ret;
}
static bool is_read_blocked(struct wwan_port *port)
{
return skb_queue_empty(&port->rxq) && port->ops;
}
static bool is_write_blocked(struct wwan_port *port)
{
return test_bit(WWAN_PORT_TX_OFF, &port->flags) && port->ops;
}
static int wwan_wait_rx(struct wwan_port *port, bool nonblock)
{
if (!is_read_blocked(port))
return 0;
if (nonblock)
return -EAGAIN;
if (wait_event_interruptible(port->waitqueue, !is_read_blocked(port)))
return -ERESTARTSYS;
return 0;
}
static int wwan_wait_tx(struct wwan_port *port, bool nonblock)
{
if (!is_write_blocked(port))
return 0;
if (nonblock)
return -EAGAIN;
if (wait_event_interruptible(port->waitqueue, !is_write_blocked(port)))
return -ERESTARTSYS;
return 0;
}
static int wwan_port_fops_open(struct inode *inode, struct file *file)
{
struct wwan_port *port;
int err = 0;
port = wwan_port_get_by_minor(iminor(inode));
if (IS_ERR(port))
return PTR_ERR(port);
file->private_data = port;
stream_open(inode, file);
err = wwan_port_op_start(port);
if (err)
put_device(&port->dev);
return err;
}
static int wwan_port_fops_release(struct inode *inode, struct file *filp)
{
struct wwan_port *port = filp->private_data;
wwan_port_op_stop(port);
put_device(&port->dev);
return 0;
}
static ssize_t wwan_port_fops_read(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
struct wwan_port *port = filp->private_data;
struct sk_buff *skb;
size_t copied;
int ret;
ret = wwan_wait_rx(port, !!(filp->f_flags & O_NONBLOCK));
if (ret)
return ret;
skb = skb_dequeue(&port->rxq);
if (!skb)
return -EIO;
copied = min_t(size_t, count, skb->len);
if (copy_to_user(buf, skb->data, copied)) {
kfree_skb(skb);
return -EFAULT;
}
skb_pull(skb, copied);
/* skb is not fully consumed, keep it in the queue */
if (skb->len)
skb_queue_head(&port->rxq, skb);
else
consume_skb(skb);
return copied;
}
static ssize_t wwan_port_fops_write(struct file *filp, const char __user *buf,
size_t count, loff_t *offp)
{
struct sk_buff *skb, *head = NULL, *tail = NULL;
struct wwan_port *port = filp->private_data;
size_t frag_len, remain = count;
int ret;
ret = wwan_wait_tx(port, !!(filp->f_flags & O_NONBLOCK));
if (ret)
return ret;
do {
frag_len = min(remain, port->frag_len);
skb = alloc_skb(frag_len + port->headroom_len, GFP_KERNEL);
if (!skb) {
ret = -ENOMEM;
goto freeskb;
}
skb_reserve(skb, port->headroom_len);
if (!head) {
head = skb;
} else if (!tail) {
skb_shinfo(head)->frag_list = skb;
tail = skb;
} else {
tail->next = skb;
tail = skb;
}
if (copy_from_user(skb_put(skb, frag_len), buf + count - remain, frag_len)) {
ret = -EFAULT;
goto freeskb;
}
if (skb != head) {
head->data_len += skb->len;
head->len += skb->len;
head->truesize += skb->truesize;
}
} while (remain -= frag_len);
ret = wwan_port_op_tx(port, head, !!(filp->f_flags & O_NONBLOCK));
if (!ret)
return count;
freeskb:
kfree_skb(head);
return ret;
}
static __poll_t wwan_port_fops_poll(struct file *filp, poll_table *wait)
{
struct wwan_port *port = filp->private_data;
__poll_t mask = 0;
poll_wait(filp, &port->waitqueue, wait);
mutex_lock(&port->ops_lock);
if (port->ops && port->ops->tx_poll)
mask |= port->ops->tx_poll(port, filp, wait);
else if (!is_write_blocked(port))
mask |= EPOLLOUT | EPOLLWRNORM;
if (!is_read_blocked(port))
mask |= EPOLLIN | EPOLLRDNORM;
if (!port->ops)
mask |= EPOLLHUP | EPOLLERR;
mutex_unlock(&port->ops_lock);
return mask;
}
/* Implements minimalistic stub terminal IOCTLs support */
static long wwan_port_fops_at_ioctl(struct wwan_port *port, unsigned int cmd,
unsigned long arg)
{
int ret = 0;
mutex_lock(&port->data_lock);
switch (cmd) {
case TCFLSH:
break;
case TCGETS:
if (copy_to_user((void __user *)arg, &port->at_data.termios,
sizeof(struct termios)))
ret = -EFAULT;
break;
case TCSETS:
case TCSETSW:
case TCSETSF:
if (copy_from_user(&port->at_data.termios, (void __user *)arg,
sizeof(struct termios)))
ret = -EFAULT;
break;
#ifdef TCGETS2
case TCGETS2:
if (copy_to_user((void __user *)arg, &port->at_data.termios,
sizeof(struct termios2)))
ret = -EFAULT;
break;
case TCSETS2:
case TCSETSW2:
case TCSETSF2:
if (copy_from_user(&port->at_data.termios, (void __user *)arg,
sizeof(struct termios2)))
ret = -EFAULT;
break;
#endif
case TIOCMGET:
ret = put_user(port->at_data.mdmbits, (int __user *)arg);
break;
case TIOCMSET:
case TIOCMBIC:
case TIOCMBIS: {
int mdmbits;
if (copy_from_user(&mdmbits, (int __user *)arg, sizeof(int))) {
ret = -EFAULT;
break;
}
if (cmd == TIOCMBIC)
port->at_data.mdmbits &= ~mdmbits;
else if (cmd == TIOCMBIS)
port->at_data.mdmbits |= mdmbits;
else
port->at_data.mdmbits = mdmbits;
break;
}
default:
ret = -ENOIOCTLCMD;
}
mutex_unlock(&port->data_lock);
return ret;
}
static long wwan_port_fops_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
struct wwan_port *port = filp->private_data;
int res;
if (port->type == WWAN_PORT_AT) { /* AT port specific IOCTLs */
res = wwan_port_fops_at_ioctl(port, cmd, arg);
if (res != -ENOIOCTLCMD)
return res;
}
switch (cmd) {
case TIOCINQ: { /* aka SIOCINQ aka FIONREAD */
unsigned long flags;
struct sk_buff *skb;
int amount = 0;
spin_lock_irqsave(&port->rxq.lock, flags);
skb_queue_walk(&port->rxq, skb)
amount += skb->len;
spin_unlock_irqrestore(&port->rxq.lock, flags);
return put_user(amount, (int __user *)arg);
}
default:
return -ENOIOCTLCMD;
}
}
static const struct file_operations wwan_port_fops = {
.owner = THIS_MODULE,
.open = wwan_port_fops_open,
.release = wwan_port_fops_release,
.read = wwan_port_fops_read,
.write = wwan_port_fops_write,
.poll = wwan_port_fops_poll,
.unlocked_ioctl = wwan_port_fops_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = compat_ptr_ioctl,
#endif
.llseek = noop_llseek,
};
static int wwan_rtnl_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
if (!data)
return -EINVAL;
if (!tb[IFLA_PARENT_DEV_NAME])
return -EINVAL;
if (!data[IFLA_WWAN_LINK_ID])
return -EINVAL;
return 0;
}
static const struct device_type wwan_type = { .name = "wwan" };
static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[],
const char *ifname,
unsigned char name_assign_type,
unsigned int num_tx_queues,
unsigned int num_rx_queues)
{
const char *devname = nla_data(tb[IFLA_PARENT_DEV_NAME]);
struct wwan_device *wwandev = wwan_dev_get_by_name(devname);
struct net_device *dev;
unsigned int priv_size;
if (IS_ERR(wwandev))
return ERR_CAST(wwandev);
/* only supported if ops were registered (not just ports) */
if (!wwandev->ops) {
dev = ERR_PTR(-EOPNOTSUPP);
goto out;
}
priv_size = sizeof(struct wwan_netdev_priv) + wwandev->ops->priv_size;
dev = alloc_netdev_mqs(priv_size, ifname, name_assign_type,
wwandev->ops->setup, num_tx_queues, num_rx_queues);
if (dev) {
SET_NETDEV_DEV(dev, &wwandev->dev);
SET_NETDEV_DEVTYPE(dev, &wwan_type);
}
out:
/* release the reference */
put_device(&wwandev->dev);
return dev;
}
static int wwan_rtnl_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent);
u32 link_id = nla_get_u32(data[IFLA_WWAN_LINK_ID]);
struct wwan_netdev_priv *priv = netdev_priv(dev);
int ret;
if (IS_ERR(wwandev))
return PTR_ERR(wwandev);
/* shouldn't have a netdev (left) with us as parent so WARN */
if (WARN_ON(!wwandev->ops)) {
ret = -EOPNOTSUPP;
goto out;
}
priv->link_id = link_id;
if (wwandev->ops->newlink)
ret = wwandev->ops->newlink(wwandev->ops_ctxt, dev,
link_id, extack);
else
ret = register_netdevice(dev);
out:
/* release the reference */
put_device(&wwandev->dev);
return ret;
}
static void wwan_rtnl_dellink(struct net_device *dev, struct list_head *head)
{
struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent);
if (IS_ERR(wwandev))
return;
/* shouldn't have a netdev (left) with us as parent so WARN */
if (WARN_ON(!wwandev->ops))
goto out;
if (wwandev->ops->dellink)
wwandev->ops->dellink(wwandev->ops_ctxt, dev, head);
else
unregister_netdevice_queue(dev, head);
out:
/* release the reference */
put_device(&wwandev->dev);
}
static size_t wwan_rtnl_get_size(const struct net_device *dev)
{
return
nla_total_size(4) + /* IFLA_WWAN_LINK_ID */
0;
}
static int wwan_rtnl_fill_info(struct sk_buff *skb,
const struct net_device *dev)
{
struct wwan_netdev_priv *priv = netdev_priv(dev);
if (nla_put_u32(skb, IFLA_WWAN_LINK_ID, priv->link_id))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static const struct nla_policy wwan_rtnl_policy[IFLA_WWAN_MAX + 1] = {
[IFLA_WWAN_LINK_ID] = { .type = NLA_U32 },
};
static struct rtnl_link_ops wwan_rtnl_link_ops __read_mostly = {
.kind = "wwan",
.maxtype = __IFLA_WWAN_MAX,
.alloc = wwan_rtnl_alloc,
.validate = wwan_rtnl_validate,
.newlink = wwan_rtnl_newlink,
.dellink = wwan_rtnl_dellink,
.get_size = wwan_rtnl_get_size,
.fill_info = wwan_rtnl_fill_info,
.policy = wwan_rtnl_policy,
};
static void wwan_create_default_link(struct wwan_device *wwandev,
u32 def_link_id)
{
struct nlattr *tb[IFLA_MAX + 1], *linkinfo[IFLA_INFO_MAX + 1];
struct nlattr *data[IFLA_WWAN_MAX + 1];
struct net_device *dev;
struct nlmsghdr *nlh;
struct sk_buff *msg;
/* Forge attributes required to create a WWAN netdev. We first
* build a netlink message and then parse it. This looks
* odd, but such approach is less error prone.
*/
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (WARN_ON(!msg))
return;
nlh = nlmsg_put(msg, 0, 0, RTM_NEWLINK, 0, 0);
if (WARN_ON(!nlh))
goto free_attrs;
if (nla_put_string(msg, IFLA_PARENT_DEV_NAME, dev_name(&wwandev->dev)))
goto free_attrs;
tb[IFLA_LINKINFO] = nla_nest_start(msg, IFLA_LINKINFO);
if (!tb[IFLA_LINKINFO])
goto free_attrs;
linkinfo[IFLA_INFO_DATA] = nla_nest_start(msg, IFLA_INFO_DATA);
if (!linkinfo[IFLA_INFO_DATA])
goto free_attrs;
if (nla_put_u32(msg, IFLA_WWAN_LINK_ID, def_link_id))
goto free_attrs;
nla_nest_end(msg, linkinfo[IFLA_INFO_DATA]);
nla_nest_end(msg, tb[IFLA_LINKINFO]);
nlmsg_end(msg, nlh);
/* The next three parsing calls can not fail */
nlmsg_parse_deprecated(nlh, 0, tb, IFLA_MAX, NULL, NULL);
nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO],
NULL, NULL);
nla_parse_nested_deprecated(data, IFLA_WWAN_MAX,
linkinfo[IFLA_INFO_DATA], NULL, NULL);
rtnl_lock();
dev = rtnl_create_link(&init_net, "wwan%d", NET_NAME_ENUM,
&wwan_rtnl_link_ops, tb, NULL);
if (WARN_ON(IS_ERR(dev)))
goto unlock;
if (WARN_ON(wwan_rtnl_newlink(&init_net, dev, tb, data, NULL))) {
free_netdev(dev);
goto unlock;
}
rtnl_configure_link(dev, NULL, 0, NULL); /* Link initialized, notify new link */
unlock:
rtnl_unlock();
free_attrs:
nlmsg_free(msg);
}
/**
* wwan_register_ops - register WWAN device ops
* @parent: Device to use as parent and shared by all WWAN ports and
* created netdevs
* @ops: operations to register
* @ctxt: context to pass to operations
* @def_link_id: id of the default link that will be automatically created by
* the WWAN core for the WWAN device. The default link will not be created
* if the passed value is WWAN_NO_DEFAULT_LINK.
*
* Returns: 0 on success, a negative error code on failure
*/
int wwan_register_ops(struct device *parent, const struct wwan_ops *ops,
void *ctxt, u32 def_link_id)
{
struct wwan_device *wwandev;
if (WARN_ON(!parent || !ops || !ops->setup))
return -EINVAL;
wwandev = wwan_create_dev(parent);
if (IS_ERR(wwandev))
return PTR_ERR(wwandev);
if (WARN_ON(wwandev->ops)) {
wwan_remove_dev(wwandev);
return -EBUSY;
}
wwandev->ops = ops;
wwandev->ops_ctxt = ctxt;
/* NB: we do not abort ops registration in case of default link
* creation failure. Link ops is the management interface, while the
* default link creation is a service option. And we should not prevent
* a user from manually creating a link latter if service option failed
* now.
*/
if (def_link_id != WWAN_NO_DEFAULT_LINK)
wwan_create_default_link(wwandev, def_link_id);
return 0;
}
EXPORT_SYMBOL_GPL(wwan_register_ops);
/* Enqueue child netdev deletion */
static int wwan_child_dellink(struct device *dev, void *data)
{
struct list_head *kill_list = data;
if (dev->type == &wwan_type)
wwan_rtnl_dellink(to_net_dev(dev), kill_list);
return 0;
}
/**
* wwan_unregister_ops - remove WWAN device ops
* @parent: Device to use as parent and shared by all WWAN ports and
* created netdevs
*/
void wwan_unregister_ops(struct device *parent)
{
struct wwan_device *wwandev = wwan_dev_get_by_parent(parent);
LIST_HEAD(kill_list);
if (WARN_ON(IS_ERR(wwandev)))
return;
if (WARN_ON(!wwandev->ops)) {
put_device(&wwandev->dev);
return;
}
/* put the reference obtained by wwan_dev_get_by_parent(),
* we should still have one (that the owner is giving back
* now) due to the ops being assigned.
*/
put_device(&wwandev->dev);
rtnl_lock(); /* Prevent concurrent netdev(s) creation/destroying */
/* Remove all child netdev(s), using batch removing */
device_for_each_child(&wwandev->dev, &kill_list,
wwan_child_dellink);
unregister_netdevice_many(&kill_list);
wwandev->ops = NULL; /* Finally remove ops */
rtnl_unlock();
wwandev->ops_ctxt = NULL;
wwan_remove_dev(wwandev);
}
EXPORT_SYMBOL_GPL(wwan_unregister_ops);
static int __init wwan_init(void)
{
int err;
err = rtnl_link_register(&wwan_rtnl_link_ops);
if (err)
return err;
err = class_register(&wwan_class);
if (err)
goto unregister;
/* chrdev used for wwan ports */
wwan_major = __register_chrdev(0, 0, WWAN_MAX_MINORS, "wwan_port",
&wwan_port_fops);
if (wwan_major < 0) {
err = wwan_major;
goto destroy;
}
#ifdef CONFIG_WWAN_DEBUGFS
wwan_debugfs_dir = debugfs_create_dir("wwan", NULL);
#endif
return 0;
destroy:
class_unregister(&wwan_class);
unregister:
rtnl_link_unregister(&wwan_rtnl_link_ops);
return err;
}
static void __exit wwan_exit(void)
{
debugfs_remove_recursive(wwan_debugfs_dir);
__unregister_chrdev(wwan_major, 0, WWAN_MAX_MINORS, "wwan_port");
rtnl_link_unregister(&wwan_rtnl_link_ops);
class_unregister(&wwan_class);
}
module_init(wwan_init);
module_exit(wwan_exit);
MODULE_AUTHOR("Loic Poulain <[email protected]>");
MODULE_DESCRIPTION("WWAN core");
MODULE_LICENSE("GPL v2");
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