diff options
Diffstat (limited to 'net/wimax/stack.c')
| -rw-r--r-- | net/wimax/stack.c | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/net/wimax/stack.c b/net/wimax/stack.c new file mode 100644 index 000000000000..d4da92f8981a --- /dev/null +++ b/net/wimax/stack.c @@ -0,0 +1,599 @@ +/* + * 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) + goto out; + genlmsg_end(report_skb, header); + result = genlmsg_multicast(report_skb, 0, wimax_gnl_mcg.id, GFP_KERNEL); + if (result == -ESRCH) /* Nobody connected, ignore it */ + result = 0; /* btw, the skb is freed already */ + if (result < 0) { + dev_err(dev, "RE_STCH: Error sending: %d\n", result); + nlmsg_free(report_skb); + } +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) +{ + mutex_lock(&wimax_dev->mutex); + __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_UNINITIALIZED); + 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; + +static +struct genl_ops *wimax_gnl_ops[] = { + &wimax_gnl_msg_from_user, + &wimax_gnl_reset, + &wimax_gnl_rfkill, +}; + + +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); + +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"); + |