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linux/net/wimax/stack.c

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/*
* Linux WiMAX
* Initialization, addition and removal of wimax devices
*
*
* Copyright (C) 2005-2006 Intel Corporation <linux-wimax@intel.com>
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*
* This implements:
*
* - basic life cycle of 'struct wimax_dev' [wimax_dev_*()]; on
* addition/registration initialize all subfields and allocate
* generic netlink resources for user space communication. On
* removal/unregistration, undo all that.
*
* - device state machine [wimax_state_change()] and support to send
* reports to user space when the state changes
* [wimax_gnl_re_state_change*()].
*
* See include/net/wimax.h for rationales and design.
*
* ROADMAP
*
* [__]wimax_state_change() Called by drivers to update device's state
* wimax_gnl_re_state_change_alloc()
* wimax_gnl_re_state_change_send()
*
* wimax_dev_init() Init a device
* wimax_dev_add() Register
* wimax_rfkill_add()
* wimax_gnl_add() Register all the generic netlink resources.
* wimax_id_table_add()
* wimax_dev_rm() Unregister
* wimax_id_table_rm()
* wimax_gnl_rm()
* wimax_rfkill_rm()
*/
#include <linux/device.h>
#include <net/genetlink.h>
#include <linux/netdevice.h>
#include <linux/wimax.h>
#include "wimax-internal.h"
#define D_SUBMODULE stack
#include "debug-levels.h"
/*
* Authoritative source for the RE_STATE_CHANGE attribute policy
*
* We don't really use it here, but /me likes to keep the definition
* close to where the data is generated.
*/
/*
static const
struct nla_policy wimax_gnl_re_status_change[WIMAX_GNL_ATTR_MAX + 1] = {
[WIMAX_GNL_STCH_STATE_OLD] = { .type = NLA_U8 },
[WIMAX_GNL_STCH_STATE_NEW] = { .type = NLA_U8 },
};
*/
/*
* Allocate a Report State Change message
*
* @header: save it, you need it for _send()
*
* Creates and fills a basic state change message; different code
* paths can then add more attributes to the message as needed.
*
* Use wimax_gnl_re_state_change_send() to send the returned skb.
*
* Returns: skb with the genl message if ok, IS_ERR() ptr on error
* with an errno code.
*/
static
struct sk_buff *wimax_gnl_re_state_change_alloc(
struct wimax_dev *wimax_dev,
enum wimax_st new_state, enum wimax_st old_state,
void **header)
{
int result;
struct device *dev = wimax_dev_to_dev(wimax_dev);
void *data;
struct sk_buff *report_skb;
d_fnstart(3, dev, "(wimax_dev %p new_state %u old_state %u)\n",
wimax_dev, new_state, old_state);
result = -ENOMEM;
report_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (report_skb == NULL) {
dev_err(dev, "RE_STCH: can't create message\n");
goto error_new;
}
data = genlmsg_put(report_skb, 0, wimax_gnl_mcg.id, &wimax_gnl_family,
0, WIMAX_GNL_RE_STATE_CHANGE);
if (data == NULL) {
dev_err(dev, "RE_STCH: can't put data into message\n");
goto error_put;
}
*header = data;
result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_OLD, old_state);
if (result < 0) {
dev_err(dev, "RE_STCH: Error adding OLD attr: %d\n", result);
goto error_put;
}
result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_NEW, new_state);
if (result < 0) {
dev_err(dev, "RE_STCH: Error adding NEW attr: %d\n", result);
goto error_put;
}
result = nla_put_u32(report_skb, WIMAX_GNL_STCH_IFIDX,
wimax_dev->net_dev->ifindex);
if (result < 0) {
dev_err(dev, "RE_STCH: Error adding IFINDEX attribute\n");
goto error_put;
}
d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %p\n",
wimax_dev, new_state, old_state, report_skb);
return report_skb;
error_put:
nlmsg_free(report_skb);
error_new:
d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %d\n",
wimax_dev, new_state, old_state, result);
return ERR_PTR(result);
}
/*
* Send a Report State Change message (as created with _alloc).
*
* @report_skb: as returned by wimax_gnl_re_state_change_alloc()
* @header: as returned by wimax_gnl_re_state_change_alloc()
*
* Returns: 0 if ok, < 0 errno code on error.
*
* If the message is NULL, pretend it didn't happen.
*/
static
int wimax_gnl_re_state_change_send(
struct wimax_dev *wimax_dev, struct sk_buff *report_skb,
void *header)
{
int result = 0;
struct device *dev = wimax_dev_to_dev(wimax_dev);
d_fnstart(3, dev, "(wimax_dev %p report_skb %p)\n",
wimax_dev, report_skb);
if (report_skb == NULL) {
result = -ENOMEM;
goto out;
}
genlmsg_end(report_skb, header);
genlmsg_multicast(report_skb, 0, wimax_gnl_mcg.id, GFP_KERNEL);
out:
d_fnend(3, dev, "(wimax_dev %p report_skb %p) = %d\n",
wimax_dev, report_skb, result);
return result;
}
static
void __check_new_state(enum wimax_st old_state, enum wimax_st new_state,
unsigned allowed_states_bm)
{
if (WARN_ON(((1 << new_state) & allowed_states_bm) == 0)) {
printk(KERN_ERR "SW BUG! Forbidden state change %u -> %u\n",
old_state, new_state);
}
}
/*
* Set the current state of a WiMAX device [unlocking version of
* wimax_state_change().
*/
void __wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
{
struct device *dev = wimax_dev_to_dev(wimax_dev);
enum wimax_st old_state = wimax_dev->state;
struct sk_buff *stch_skb;
void *header;
d_fnstart(3, dev, "(wimax_dev %p new_state %u [old %u])\n",
wimax_dev, new_state, old_state);
if (WARN_ON(new_state >= __WIMAX_ST_INVALID)) {
dev_err(dev, "SW BUG: requesting invalid state %u\n",
new_state);
goto out;
}
if (old_state == new_state)
goto out;
header = NULL; /* gcc complains? can't grok why */
stch_skb = wimax_gnl_re_state_change_alloc(
wimax_dev, new_state, old_state, &header);
/* Verify the state transition and do exit-from-state actions */
switch (old_state) {
case __WIMAX_ST_NULL:
__check_new_state(old_state, new_state,
1 << WIMAX_ST_DOWN);
break;
case WIMAX_ST_DOWN:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_UNINITIALIZED
| 1 << WIMAX_ST_RADIO_OFF);
break;
case __WIMAX_ST_QUIESCING:
__check_new_state(old_state, new_state, 1 << WIMAX_ST_DOWN);
break;
case WIMAX_ST_UNINITIALIZED:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_RADIO_OFF);
break;
case WIMAX_ST_RADIO_OFF:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_READY);
break;
case WIMAX_ST_READY:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_RADIO_OFF
| 1 << WIMAX_ST_SCANNING
| 1 << WIMAX_ST_CONNECTING
| 1 << WIMAX_ST_CONNECTED);
break;
case WIMAX_ST_SCANNING:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_RADIO_OFF
| 1 << WIMAX_ST_READY
| 1 << WIMAX_ST_CONNECTING
| 1 << WIMAX_ST_CONNECTED);
break;
case WIMAX_ST_CONNECTING:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_RADIO_OFF
| 1 << WIMAX_ST_READY
| 1 << WIMAX_ST_SCANNING
| 1 << WIMAX_ST_CONNECTED);
break;
case WIMAX_ST_CONNECTED:
__check_new_state(old_state, new_state,
1 << __WIMAX_ST_QUIESCING
| 1 << WIMAX_ST_RADIO_OFF
| 1 << WIMAX_ST_READY);
netif_tx_disable(wimax_dev->net_dev);
netif_carrier_off(wimax_dev->net_dev);
break;
case __WIMAX_ST_INVALID:
default:
dev_err(dev, "SW BUG: wimax_dev %p is in unknown state %u\n",
wimax_dev, wimax_dev->state);
WARN_ON(1);
goto out;
}
/* Execute the actions of entry to the new state */
switch (new_state) {
case __WIMAX_ST_NULL:
dev_err(dev, "SW BUG: wimax_dev %p entering NULL state "
"from %u\n", wimax_dev, wimax_dev->state);
WARN_ON(1); /* Nobody can enter this state */
break;
case WIMAX_ST_DOWN:
break;
case __WIMAX_ST_QUIESCING:
break;
case WIMAX_ST_UNINITIALIZED:
break;
case WIMAX_ST_RADIO_OFF:
break;
case WIMAX_ST_READY:
break;
case WIMAX_ST_SCANNING:
break;
case WIMAX_ST_CONNECTING:
break;
case WIMAX_ST_CONNECTED:
netif_carrier_on(wimax_dev->net_dev);
netif_wake_queue(wimax_dev->net_dev);
break;
case __WIMAX_ST_INVALID:
default:
BUG();
}
__wimax_state_set(wimax_dev, new_state);
if (stch_skb)
wimax_gnl_re_state_change_send(wimax_dev, stch_skb, header);
out:
d_fnend(3, dev, "(wimax_dev %p new_state %u [old %u]) = void\n",
wimax_dev, new_state, old_state);
return;
}
/**
* wimax_state_change - Set the current state of a WiMAX device
*
* @wimax_dev: WiMAX device descriptor (properly referenced)
* @new_state: New state to switch to
*
* This implements the state changes for the wimax devices. It will
*
* - verify that the state transition is legal (for now it'll just
* print a warning if not) according to the table in
* linux/wimax.h's documentation for 'enum wimax_st'.
*
* - perform the actions needed for leaving the current state and
* whichever are needed for entering the new state.
*
* - issue a report to user space indicating the new state (and an
* optional payload with information about the new state).
*
* NOTE: @wimax_dev must be locked
*/
void wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
{
/*
* A driver cannot take the wimax_dev out of the
* __WIMAX_ST_NULL state unless by calling wimax_dev_add(). If
* the wimax_dev's state is still NULL, we ignore any request
* to change its state because it means it hasn't been yet
* registered.
*
* There is no need to complain about it, as routines that
* call this might be shared from different code paths that
* are called before or after wimax_dev_add() has done its
* job.
*/
mutex_lock(&wimax_dev->mutex);
if (wimax_dev->state > __WIMAX_ST_NULL)
__wimax_state_change(wimax_dev, new_state);
mutex_unlock(&wimax_dev->mutex);
return;
}
EXPORT_SYMBOL_GPL(wimax_state_change);
/**
* wimax_state_get() - Return the current state of a WiMAX device
*
* @wimax_dev: WiMAX device descriptor
*
* Returns: Current state of the device according to its driver.
*/
enum wimax_st wimax_state_get(struct wimax_dev *wimax_dev)
{
enum wimax_st state;
mutex_lock(&wimax_dev->mutex);
state = wimax_dev->state;
mutex_unlock(&wimax_dev->mutex);
return state;
}
EXPORT_SYMBOL_GPL(wimax_state_get);
/**
* wimax_dev_init - initialize a newly allocated instance
*
* @wimax_dev: WiMAX device descriptor to initialize.
*
* Initializes fields of a freshly allocated @wimax_dev instance. This
* function assumes that after allocation, the memory occupied by
* @wimax_dev was zeroed.
*/
void wimax_dev_init(struct wimax_dev *wimax_dev)
{
INIT_LIST_HEAD(&wimax_dev->id_table_node);
__wimax_state_set(wimax_dev, __WIMAX_ST_NULL);
mutex_init(&wimax_dev->mutex);
mutex_init(&wimax_dev->mutex_reset);
}
EXPORT_SYMBOL_GPL(wimax_dev_init);
/*
* This extern is declared here because it's easier to keep track --
* both declarations are a list of the same
*/
extern struct genl_ops
wimax_gnl_msg_from_user,
wimax_gnl_reset,
wimax_gnl_rfkill,
wimax_gnl_state_get;
static
struct genl_ops *wimax_gnl_ops[] = {
&wimax_gnl_msg_from_user,
&wimax_gnl_reset,
&wimax_gnl_rfkill,
&wimax_gnl_state_get,
};
static
size_t wimax_addr_scnprint(char *addr_str, size_t addr_str_size,
unsigned char *addr, size_t addr_len)
{
unsigned cnt, total;
for (total = cnt = 0; cnt < addr_len; cnt++)
total += scnprintf(addr_str + total, addr_str_size - total,
"%02x%c", addr[cnt],
cnt == addr_len - 1 ? '\0' : ':');
return total;
}
/**
* wimax_dev_add - Register a new WiMAX device
*
* @wimax_dev: WiMAX device descriptor (as embedded in your @net_dev's
* priv data). You must have called wimax_dev_init() on it before.
*
* @net_dev: net device the @wimax_dev is associated with. The
* function expects SET_NETDEV_DEV() and register_netdev() were
* already called on it.
*
* Registers the new WiMAX device, sets up the user-kernel control
* interface (generic netlink) and common WiMAX infrastructure.
*
* Note that the parts that will allow interaction with user space are
* setup at the very end, when the rest is in place, as once that
* happens, the driver might get user space control requests via
* netlink or from debugfs that might translate into calls into
* wimax_dev->op_*().
*/
int wimax_dev_add(struct wimax_dev *wimax_dev, struct net_device *net_dev)
{
int result;
struct device *dev = net_dev->dev.parent;
char addr_str[32];
d_fnstart(3, dev, "(wimax_dev %p net_dev %p)\n", wimax_dev, net_dev);
/* Do the RFKILL setup before locking, as RFKILL will call
* into our functions. */
wimax_dev->net_dev = net_dev;
result = wimax_rfkill_add(wimax_dev);
if (result < 0)
goto error_rfkill_add;
/* Set up user-space interaction */
mutex_lock(&wimax_dev->mutex);
wimax_id_table_add(wimax_dev);
result = wimax_debugfs_add(wimax_dev);
if (result < 0) {
dev_err(dev, "cannot initialize debugfs: %d\n",
result);
goto error_debugfs_add;
}
__wimax_state_set(wimax_dev, WIMAX_ST_DOWN);
mutex_unlock(&wimax_dev->mutex);
wimax_addr_scnprint(addr_str, sizeof(addr_str),
net_dev->dev_addr, net_dev->addr_len);
dev_err(dev, "WiMAX interface %s (%s) ready\n",
net_dev->name, addr_str);
d_fnend(3, dev, "(wimax_dev %p net_dev %p) = 0\n", wimax_dev, net_dev);
return 0;
error_debugfs_add:
wimax_id_table_rm(wimax_dev);
mutex_unlock(&wimax_dev->mutex);
wimax_rfkill_rm(wimax_dev);
error_rfkill_add:
d_fnend(3, dev, "(wimax_dev %p net_dev %p) = %d\n",
wimax_dev, net_dev, result);
return result;
}
EXPORT_SYMBOL_GPL(wimax_dev_add);
/**
* wimax_dev_rm - Unregister an existing WiMAX device
*
* @wimax_dev: WiMAX device descriptor
*
* Unregisters a WiMAX device previously registered for use with
* wimax_add_rm().
*
* IMPORTANT! Must call before calling unregister_netdev().
*
* After this function returns, you will not get any more user space
* control requests (via netlink or debugfs) and thus to wimax_dev->ops.
*
* Reentrancy control is ensured by setting the state to
* %__WIMAX_ST_QUIESCING. rfkill operations coming through
* wimax_*rfkill*() will be stopped by the quiescing state; ops coming
* from the rfkill subsystem will be stopped by the support being
* removed by wimax_rfkill_rm().
*/
void wimax_dev_rm(struct wimax_dev *wimax_dev)
{
d_fnstart(3, NULL, "(wimax_dev %p)\n", wimax_dev);
mutex_lock(&wimax_dev->mutex);
__wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
wimax_debugfs_rm(wimax_dev);
wimax_id_table_rm(wimax_dev);
__wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
mutex_unlock(&wimax_dev->mutex);
wimax_rfkill_rm(wimax_dev);
d_fnend(3, NULL, "(wimax_dev %p) = void\n", wimax_dev);
}
EXPORT_SYMBOL_GPL(wimax_dev_rm);
/* Debug framework control of debug levels */
struct d_level D_LEVEL[] = {
D_SUBMODULE_DEFINE(debugfs),
D_SUBMODULE_DEFINE(id_table),
D_SUBMODULE_DEFINE(op_msg),
D_SUBMODULE_DEFINE(op_reset),
D_SUBMODULE_DEFINE(op_rfkill),
D_SUBMODULE_DEFINE(op_state_get),
D_SUBMODULE_DEFINE(stack),
};
size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
struct genl_family wimax_gnl_family = {
.id = GENL_ID_GENERATE,
.name = "WiMAX",
.version = WIMAX_GNL_VERSION,
.hdrsize = 0,
.maxattr = WIMAX_GNL_ATTR_MAX,
};
struct genl_multicast_group wimax_gnl_mcg = {
.name = "msg",
};
/* Shutdown the wimax stack */
static
int __init wimax_subsys_init(void)
{
int result, cnt;
d_fnstart(4, NULL, "()\n");
snprintf(wimax_gnl_family.name, sizeof(wimax_gnl_family.name),
"WiMAX");
result = genl_register_family(&wimax_gnl_family);
if (unlikely(result < 0)) {
printk(KERN_ERR "cannot register generic netlink family: %d\n",
result);
goto error_register_family;
}
for (cnt = 0; cnt < ARRAY_SIZE(wimax_gnl_ops); cnt++) {
result = genl_register_ops(&wimax_gnl_family,
wimax_gnl_ops[cnt]);
d_printf(4, NULL, "registering generic netlink op code "
"%u: %d\n", wimax_gnl_ops[cnt]->cmd, result);
if (unlikely(result < 0)) {
printk(KERN_ERR "cannot register generic netlink op "
"code %u: %d\n",
wimax_gnl_ops[cnt]->cmd, result);
goto error_register_ops;
}
}
result = genl_register_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
if (result < 0)
goto error_mc_group;
d_fnend(4, NULL, "() = 0\n");
return 0;
error_mc_group:
error_register_ops:
for (cnt--; cnt >= 0; cnt--)
genl_unregister_ops(&wimax_gnl_family,
wimax_gnl_ops[cnt]);
genl_unregister_family(&wimax_gnl_family);
error_register_family:
d_fnend(4, NULL, "() = %d\n", result);
return result;
}
module_init(wimax_subsys_init);
/* Shutdown the wimax stack */
static
void __exit wimax_subsys_exit(void)
{
int cnt;
wimax_id_table_release();
genl_unregister_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
for (cnt = ARRAY_SIZE(wimax_gnl_ops) - 1; cnt >= 0; cnt--)
genl_unregister_ops(&wimax_gnl_family,
wimax_gnl_ops[cnt]);
genl_unregister_family(&wimax_gnl_family);
}
module_exit(wimax_subsys_exit);
MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
MODULE_DESCRIPTION("Linux WiMAX stack");
MODULE_LICENSE("GPL");
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