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553 lines
11 KiB
553 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* LAPB release 002 |
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* |
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* This code REQUIRES 2.1.15 or higher/ NET3.038 |
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* |
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* History |
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* LAPB 001 Jonathan Naylor Started Coding |
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* LAPB 002 Jonathan Naylor New timer architecture. |
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* 2000-10-29 Henner Eisen lapb_data_indication() return status. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/socket.h> |
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#include <linux/in.h> |
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#include <linux/kernel.h> |
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#include <linux/jiffies.h> |
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#include <linux/timer.h> |
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#include <linux/string.h> |
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#include <linux/sockios.h> |
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#include <linux/net.h> |
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#include <linux/inet.h> |
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#include <linux/if_arp.h> |
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#include <linux/skbuff.h> |
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#include <linux/slab.h> |
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#include <net/sock.h> |
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#include <linux/uaccess.h> |
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#include <linux/fcntl.h> |
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#include <linux/mm.h> |
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#include <linux/interrupt.h> |
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#include <linux/stat.h> |
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#include <linux/init.h> |
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#include <net/lapb.h> |
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static LIST_HEAD(lapb_list); |
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static DEFINE_RWLOCK(lapb_list_lock); |
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/* |
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* Free an allocated lapb control block. |
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*/ |
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static void lapb_free_cb(struct lapb_cb *lapb) |
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{ |
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kfree(lapb); |
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} |
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static __inline__ void lapb_hold(struct lapb_cb *lapb) |
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{ |
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refcount_inc(&lapb->refcnt); |
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} |
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static __inline__ void lapb_put(struct lapb_cb *lapb) |
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{ |
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if (refcount_dec_and_test(&lapb->refcnt)) |
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lapb_free_cb(lapb); |
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} |
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/* |
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* Socket removal during an interrupt is now safe. |
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*/ |
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static void __lapb_remove_cb(struct lapb_cb *lapb) |
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{ |
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if (lapb->node.next) { |
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list_del(&lapb->node); |
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lapb_put(lapb); |
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} |
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} |
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/* |
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* Add a socket to the bound sockets list. |
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*/ |
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static void __lapb_insert_cb(struct lapb_cb *lapb) |
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{ |
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list_add(&lapb->node, &lapb_list); |
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lapb_hold(lapb); |
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} |
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static struct lapb_cb *__lapb_devtostruct(struct net_device *dev) |
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{ |
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struct lapb_cb *lapb, *use = NULL; |
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list_for_each_entry(lapb, &lapb_list, node) { |
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if (lapb->dev == dev) { |
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use = lapb; |
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break; |
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} |
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} |
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if (use) |
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lapb_hold(use); |
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return use; |
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} |
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static struct lapb_cb *lapb_devtostruct(struct net_device *dev) |
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{ |
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struct lapb_cb *rc; |
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read_lock_bh(&lapb_list_lock); |
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rc = __lapb_devtostruct(dev); |
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read_unlock_bh(&lapb_list_lock); |
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return rc; |
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} |
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/* |
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* Create an empty LAPB control block. |
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*/ |
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static struct lapb_cb *lapb_create_cb(void) |
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{ |
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struct lapb_cb *lapb = kzalloc(sizeof(*lapb), GFP_ATOMIC); |
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if (!lapb) |
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goto out; |
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skb_queue_head_init(&lapb->write_queue); |
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skb_queue_head_init(&lapb->ack_queue); |
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timer_setup(&lapb->t1timer, NULL, 0); |
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timer_setup(&lapb->t2timer, NULL, 0); |
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lapb->t1timer_running = false; |
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lapb->t2timer_running = false; |
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lapb->t1 = LAPB_DEFAULT_T1; |
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lapb->t2 = LAPB_DEFAULT_T2; |
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lapb->n2 = LAPB_DEFAULT_N2; |
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lapb->mode = LAPB_DEFAULT_MODE; |
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lapb->window = LAPB_DEFAULT_WINDOW; |
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lapb->state = LAPB_STATE_0; |
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spin_lock_init(&lapb->lock); |
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refcount_set(&lapb->refcnt, 1); |
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out: |
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return lapb; |
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} |
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int lapb_register(struct net_device *dev, |
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const struct lapb_register_struct *callbacks) |
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{ |
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struct lapb_cb *lapb; |
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int rc = LAPB_BADTOKEN; |
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write_lock_bh(&lapb_list_lock); |
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lapb = __lapb_devtostruct(dev); |
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if (lapb) { |
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lapb_put(lapb); |
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goto out; |
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} |
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lapb = lapb_create_cb(); |
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rc = LAPB_NOMEM; |
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if (!lapb) |
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goto out; |
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lapb->dev = dev; |
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lapb->callbacks = callbacks; |
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__lapb_insert_cb(lapb); |
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lapb_start_t1timer(lapb); |
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rc = LAPB_OK; |
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out: |
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write_unlock_bh(&lapb_list_lock); |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_register); |
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int lapb_unregister(struct net_device *dev) |
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{ |
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struct lapb_cb *lapb; |
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int rc = LAPB_BADTOKEN; |
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write_lock_bh(&lapb_list_lock); |
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lapb = __lapb_devtostruct(dev); |
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if (!lapb) |
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goto out; |
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lapb_put(lapb); |
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/* Wait for other refs to "lapb" to drop */ |
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while (refcount_read(&lapb->refcnt) > 2) |
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usleep_range(1, 10); |
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spin_lock_bh(&lapb->lock); |
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lapb_stop_t1timer(lapb); |
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lapb_stop_t2timer(lapb); |
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lapb_clear_queues(lapb); |
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spin_unlock_bh(&lapb->lock); |
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/* Wait for running timers to stop */ |
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del_timer_sync(&lapb->t1timer); |
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del_timer_sync(&lapb->t2timer); |
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__lapb_remove_cb(lapb); |
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lapb_put(lapb); |
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rc = LAPB_OK; |
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out: |
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write_unlock_bh(&lapb_list_lock); |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_unregister); |
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int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms) |
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{ |
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int rc = LAPB_BADTOKEN; |
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struct lapb_cb *lapb = lapb_devtostruct(dev); |
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if (!lapb) |
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goto out; |
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spin_lock_bh(&lapb->lock); |
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parms->t1 = lapb->t1 / HZ; |
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parms->t2 = lapb->t2 / HZ; |
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parms->n2 = lapb->n2; |
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parms->n2count = lapb->n2count; |
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parms->state = lapb->state; |
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parms->window = lapb->window; |
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parms->mode = lapb->mode; |
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if (!timer_pending(&lapb->t1timer)) |
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parms->t1timer = 0; |
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else |
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parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ; |
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if (!timer_pending(&lapb->t2timer)) |
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parms->t2timer = 0; |
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else |
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parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ; |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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rc = LAPB_OK; |
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out: |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_getparms); |
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int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms) |
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{ |
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int rc = LAPB_BADTOKEN; |
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struct lapb_cb *lapb = lapb_devtostruct(dev); |
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if (!lapb) |
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goto out; |
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spin_lock_bh(&lapb->lock); |
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rc = LAPB_INVALUE; |
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if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1) |
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goto out_put; |
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if (lapb->state == LAPB_STATE_0) { |
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if (parms->mode & LAPB_EXTENDED) { |
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if (parms->window < 1 || parms->window > 127) |
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goto out_put; |
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} else { |
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if (parms->window < 1 || parms->window > 7) |
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goto out_put; |
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} |
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lapb->mode = parms->mode; |
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lapb->window = parms->window; |
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} |
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lapb->t1 = parms->t1 * HZ; |
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lapb->t2 = parms->t2 * HZ; |
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lapb->n2 = parms->n2; |
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rc = LAPB_OK; |
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out_put: |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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out: |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_setparms); |
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int lapb_connect_request(struct net_device *dev) |
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{ |
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struct lapb_cb *lapb = lapb_devtostruct(dev); |
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int rc = LAPB_BADTOKEN; |
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if (!lapb) |
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goto out; |
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spin_lock_bh(&lapb->lock); |
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rc = LAPB_OK; |
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if (lapb->state == LAPB_STATE_1) |
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goto out_put; |
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rc = LAPB_CONNECTED; |
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if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4) |
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goto out_put; |
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lapb_establish_data_link(lapb); |
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lapb_dbg(0, "(%p) S0 -> S1\n", lapb->dev); |
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lapb->state = LAPB_STATE_1; |
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rc = LAPB_OK; |
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out_put: |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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out: |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_connect_request); |
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static int __lapb_disconnect_request(struct lapb_cb *lapb) |
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{ |
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switch (lapb->state) { |
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case LAPB_STATE_0: |
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return LAPB_NOTCONNECTED; |
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case LAPB_STATE_1: |
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lapb_dbg(1, "(%p) S1 TX DISC(1)\n", lapb->dev); |
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lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev); |
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lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); |
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lapb->state = LAPB_STATE_0; |
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lapb_start_t1timer(lapb); |
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return LAPB_NOTCONNECTED; |
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case LAPB_STATE_2: |
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return LAPB_OK; |
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} |
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lapb_clear_queues(lapb); |
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lapb->n2count = 0; |
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lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); |
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lapb_start_t1timer(lapb); |
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lapb_stop_t2timer(lapb); |
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lapb->state = LAPB_STATE_2; |
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lapb_dbg(1, "(%p) S3 DISC(1)\n", lapb->dev); |
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lapb_dbg(0, "(%p) S3 -> S2\n", lapb->dev); |
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return LAPB_OK; |
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} |
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int lapb_disconnect_request(struct net_device *dev) |
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{ |
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struct lapb_cb *lapb = lapb_devtostruct(dev); |
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int rc = LAPB_BADTOKEN; |
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if (!lapb) |
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goto out; |
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spin_lock_bh(&lapb->lock); |
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rc = __lapb_disconnect_request(lapb); |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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out: |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_disconnect_request); |
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int lapb_data_request(struct net_device *dev, struct sk_buff *skb) |
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{ |
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struct lapb_cb *lapb = lapb_devtostruct(dev); |
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int rc = LAPB_BADTOKEN; |
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if (!lapb) |
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goto out; |
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spin_lock_bh(&lapb->lock); |
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rc = LAPB_NOTCONNECTED; |
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if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4) |
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goto out_put; |
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skb_queue_tail(&lapb->write_queue, skb); |
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lapb_kick(lapb); |
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rc = LAPB_OK; |
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out_put: |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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out: |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_data_request); |
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int lapb_data_received(struct net_device *dev, struct sk_buff *skb) |
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{ |
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struct lapb_cb *lapb = lapb_devtostruct(dev); |
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int rc = LAPB_BADTOKEN; |
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if (lapb) { |
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spin_lock_bh(&lapb->lock); |
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lapb_data_input(lapb, skb); |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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rc = LAPB_OK; |
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} |
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return rc; |
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} |
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EXPORT_SYMBOL(lapb_data_received); |
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void lapb_connect_confirmation(struct lapb_cb *lapb, int reason) |
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{ |
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if (lapb->callbacks->connect_confirmation) |
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lapb->callbacks->connect_confirmation(lapb->dev, reason); |
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} |
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void lapb_connect_indication(struct lapb_cb *lapb, int reason) |
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{ |
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if (lapb->callbacks->connect_indication) |
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lapb->callbacks->connect_indication(lapb->dev, reason); |
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} |
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void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason) |
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{ |
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if (lapb->callbacks->disconnect_confirmation) |
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lapb->callbacks->disconnect_confirmation(lapb->dev, reason); |
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} |
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void lapb_disconnect_indication(struct lapb_cb *lapb, int reason) |
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{ |
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if (lapb->callbacks->disconnect_indication) |
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lapb->callbacks->disconnect_indication(lapb->dev, reason); |
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} |
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int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb) |
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{ |
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if (lapb->callbacks->data_indication) |
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return lapb->callbacks->data_indication(lapb->dev, skb); |
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kfree_skb(skb); |
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return NET_RX_SUCCESS; /* For now; must be != NET_RX_DROP */ |
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} |
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int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb) |
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{ |
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int used = 0; |
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if (lapb->callbacks->data_transmit) { |
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lapb->callbacks->data_transmit(lapb->dev, skb); |
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used = 1; |
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} |
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return used; |
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} |
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/* Handle device status changes. */ |
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static int lapb_device_event(struct notifier_block *this, unsigned long event, |
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void *ptr) |
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{ |
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struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
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struct lapb_cb *lapb; |
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if (!net_eq(dev_net(dev), &init_net)) |
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return NOTIFY_DONE; |
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if (dev->type != ARPHRD_X25) |
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return NOTIFY_DONE; |
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lapb = lapb_devtostruct(dev); |
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if (!lapb) |
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return NOTIFY_DONE; |
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spin_lock_bh(&lapb->lock); |
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switch (event) { |
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case NETDEV_UP: |
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lapb_dbg(0, "(%p) Interface up: %s\n", dev, dev->name); |
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if (netif_carrier_ok(dev)) { |
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lapb_dbg(0, "(%p): Carrier is already up: %s\n", dev, |
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dev->name); |
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if (lapb->mode & LAPB_DCE) { |
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lapb_start_t1timer(lapb); |
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} else { |
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if (lapb->state == LAPB_STATE_0) { |
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lapb->state = LAPB_STATE_1; |
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lapb_establish_data_link(lapb); |
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} |
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} |
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} |
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break; |
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case NETDEV_GOING_DOWN: |
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if (netif_carrier_ok(dev)) |
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__lapb_disconnect_request(lapb); |
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break; |
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case NETDEV_DOWN: |
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lapb_dbg(0, "(%p) Interface down: %s\n", dev, dev->name); |
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lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); |
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lapb_clear_queues(lapb); |
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lapb->state = LAPB_STATE_0; |
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lapb->n2count = 0; |
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lapb_stop_t1timer(lapb); |
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lapb_stop_t2timer(lapb); |
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break; |
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case NETDEV_CHANGE: |
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if (netif_carrier_ok(dev)) { |
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lapb_dbg(0, "(%p): Carrier detected: %s\n", dev, |
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dev->name); |
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if (lapb->mode & LAPB_DCE) { |
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lapb_start_t1timer(lapb); |
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} else { |
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if (lapb->state == LAPB_STATE_0) { |
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lapb->state = LAPB_STATE_1; |
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lapb_establish_data_link(lapb); |
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} |
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} |
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} else { |
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lapb_dbg(0, "(%p) Carrier lost: %s\n", dev, dev->name); |
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lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); |
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lapb_clear_queues(lapb); |
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lapb->state = LAPB_STATE_0; |
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lapb->n2count = 0; |
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lapb_stop_t1timer(lapb); |
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lapb_stop_t2timer(lapb); |
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} |
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break; |
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} |
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spin_unlock_bh(&lapb->lock); |
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lapb_put(lapb); |
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return NOTIFY_DONE; |
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} |
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static struct notifier_block lapb_dev_notifier = { |
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.notifier_call = lapb_device_event, |
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}; |
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static int __init lapb_init(void) |
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{ |
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return register_netdevice_notifier(&lapb_dev_notifier); |
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} |
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static void __exit lapb_exit(void) |
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{ |
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WARN_ON(!list_empty(&lapb_list)); |
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unregister_netdevice_notifier(&lapb_dev_notifier); |
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} |
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MODULE_AUTHOR("Jonathan Naylor <[email protected]>"); |
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MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol"); |
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MODULE_LICENSE("GPL"); |
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module_init(lapb_init); |
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module_exit(lapb_exit);
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