diff options
Diffstat (limited to 'net/lapb/lapb_iface.c')
| -rw-r--r-- | net/lapb/lapb_iface.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c new file mode 100644 index 0000000000..0971ca48ba --- /dev/null +++ b/net/lapb/lapb_iface.c @@ -0,0 +1,553 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * LAPB release 002 + * + * This code REQUIRES 2.1.15 or higher/ NET3.038 + * + * History + * LAPB 001 Jonathan Naylor Started Coding + * LAPB 002 Jonathan Naylor New timer architecture. + * 2000-10-29 Henner Eisen lapb_data_indication() return status. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/inet.h> +#include <linux/if_arp.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <linux/uaccess.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <net/lapb.h> + +static LIST_HEAD(lapb_list); +static DEFINE_RWLOCK(lapb_list_lock); + +/* + * Free an allocated lapb control block. + */ +static void lapb_free_cb(struct lapb_cb *lapb) +{ + kfree(lapb); +} + +static __inline__ void lapb_hold(struct lapb_cb *lapb) +{ + refcount_inc(&lapb->refcnt); +} + +static __inline__ void lapb_put(struct lapb_cb *lapb) +{ + if (refcount_dec_and_test(&lapb->refcnt)) + lapb_free_cb(lapb); +} + +/* + * Socket removal during an interrupt is now safe. + */ +static void __lapb_remove_cb(struct lapb_cb *lapb) +{ + if (lapb->node.next) { + list_del(&lapb->node); + lapb_put(lapb); + } +} + +/* + * Add a socket to the bound sockets list. + */ +static void __lapb_insert_cb(struct lapb_cb *lapb) +{ + list_add(&lapb->node, &lapb_list); + lapb_hold(lapb); +} + +static struct lapb_cb *__lapb_devtostruct(struct net_device *dev) +{ + struct lapb_cb *lapb, *use = NULL; + + list_for_each_entry(lapb, &lapb_list, node) { + if (lapb->dev == dev) { + use = lapb; + break; + } + } + + if (use) + lapb_hold(use); + + return use; +} + +static struct lapb_cb *lapb_devtostruct(struct net_device *dev) +{ + struct lapb_cb *rc; + + read_lock_bh(&lapb_list_lock); + rc = __lapb_devtostruct(dev); + read_unlock_bh(&lapb_list_lock); + + return rc; +} +/* + * Create an empty LAPB control block. + */ +static struct lapb_cb *lapb_create_cb(void) +{ + struct lapb_cb *lapb = kzalloc(sizeof(*lapb), GFP_ATOMIC); + + if (!lapb) + goto out; + + skb_queue_head_init(&lapb->write_queue); + skb_queue_head_init(&lapb->ack_queue); + + timer_setup(&lapb->t1timer, NULL, 0); + timer_setup(&lapb->t2timer, NULL, 0); + lapb->t1timer_running = false; + lapb->t2timer_running = false; + + lapb->t1 = LAPB_DEFAULT_T1; + lapb->t2 = LAPB_DEFAULT_T2; + lapb->n2 = LAPB_DEFAULT_N2; + lapb->mode = LAPB_DEFAULT_MODE; + lapb->window = LAPB_DEFAULT_WINDOW; + lapb->state = LAPB_STATE_0; + + spin_lock_init(&lapb->lock); + refcount_set(&lapb->refcnt, 1); +out: + return lapb; +} + +int lapb_register(struct net_device *dev, + const struct lapb_register_struct *callbacks) +{ + struct lapb_cb *lapb; + int rc = LAPB_BADTOKEN; + + write_lock_bh(&lapb_list_lock); + + lapb = __lapb_devtostruct(dev); + if (lapb) { + lapb_put(lapb); + goto out; + } + + lapb = lapb_create_cb(); + rc = LAPB_NOMEM; + if (!lapb) + goto out; + + lapb->dev = dev; + lapb->callbacks = callbacks; + + __lapb_insert_cb(lapb); + + lapb_start_t1timer(lapb); + + rc = LAPB_OK; +out: + write_unlock_bh(&lapb_list_lock); + return rc; +} +EXPORT_SYMBOL(lapb_register); + +int lapb_unregister(struct net_device *dev) +{ + struct lapb_cb *lapb; + int rc = LAPB_BADTOKEN; + + write_lock_bh(&lapb_list_lock); + lapb = __lapb_devtostruct(dev); + if (!lapb) + goto out; + lapb_put(lapb); + + /* Wait for other refs to "lapb" to drop */ + while (refcount_read(&lapb->refcnt) > 2) + usleep_range(1, 10); + + spin_lock_bh(&lapb->lock); + + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + + lapb_clear_queues(lapb); + + spin_unlock_bh(&lapb->lock); + + /* Wait for running timers to stop */ + del_timer_sync(&lapb->t1timer); + del_timer_sync(&lapb->t2timer); + + __lapb_remove_cb(lapb); + + lapb_put(lapb); + rc = LAPB_OK; +out: + write_unlock_bh(&lapb_list_lock); + return rc; +} +EXPORT_SYMBOL(lapb_unregister); + +int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms) +{ + int rc = LAPB_BADTOKEN; + struct lapb_cb *lapb = lapb_devtostruct(dev); + + if (!lapb) + goto out; + + spin_lock_bh(&lapb->lock); + + parms->t1 = lapb->t1 / HZ; + parms->t2 = lapb->t2 / HZ; + parms->n2 = lapb->n2; + parms->n2count = lapb->n2count; + parms->state = lapb->state; + parms->window = lapb->window; + parms->mode = lapb->mode; + + if (!timer_pending(&lapb->t1timer)) + parms->t1timer = 0; + else + parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ; + + if (!timer_pending(&lapb->t2timer)) + parms->t2timer = 0; + else + parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ; + + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); + rc = LAPB_OK; +out: + return rc; +} +EXPORT_SYMBOL(lapb_getparms); + +int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms) +{ + int rc = LAPB_BADTOKEN; + struct lapb_cb *lapb = lapb_devtostruct(dev); + + if (!lapb) + goto out; + + spin_lock_bh(&lapb->lock); + + rc = LAPB_INVALUE; + if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1) + goto out_put; + + if (lapb->state == LAPB_STATE_0) { + if (parms->mode & LAPB_EXTENDED) { + if (parms->window < 1 || parms->window > 127) + goto out_put; + } else { + if (parms->window < 1 || parms->window > 7) + goto out_put; + } + lapb->mode = parms->mode; + lapb->window = parms->window; + } + + lapb->t1 = parms->t1 * HZ; + lapb->t2 = parms->t2 * HZ; + lapb->n2 = parms->n2; + + rc = LAPB_OK; +out_put: + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); +out: + return rc; +} +EXPORT_SYMBOL(lapb_setparms); + +int lapb_connect_request(struct net_device *dev) +{ + struct lapb_cb *lapb = lapb_devtostruct(dev); + int rc = LAPB_BADTOKEN; + + if (!lapb) + goto out; + + spin_lock_bh(&lapb->lock); + + rc = LAPB_OK; + if (lapb->state == LAPB_STATE_1) + goto out_put; + + rc = LAPB_CONNECTED; + if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4) + goto out_put; + + lapb_establish_data_link(lapb); + + lapb_dbg(0, "(%p) S0 -> S1\n", lapb->dev); + lapb->state = LAPB_STATE_1; + + rc = LAPB_OK; +out_put: + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); +out: + return rc; +} +EXPORT_SYMBOL(lapb_connect_request); + +static int __lapb_disconnect_request(struct lapb_cb *lapb) +{ + switch (lapb->state) { + case LAPB_STATE_0: + return LAPB_NOTCONNECTED; + + case LAPB_STATE_1: + lapb_dbg(1, "(%p) S1 TX DISC(1)\n", lapb->dev); + lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev); + lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); + lapb->state = LAPB_STATE_0; + lapb_start_t1timer(lapb); + return LAPB_NOTCONNECTED; + + case LAPB_STATE_2: + return LAPB_OK; + } + + lapb_clear_queues(lapb); + lapb->n2count = 0; + lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); + lapb_start_t1timer(lapb); + lapb_stop_t2timer(lapb); + lapb->state = LAPB_STATE_2; + + lapb_dbg(1, "(%p) S3 DISC(1)\n", lapb->dev); + lapb_dbg(0, "(%p) S3 -> S2\n", lapb->dev); + + return LAPB_OK; +} + +int lapb_disconnect_request(struct net_device *dev) +{ + struct lapb_cb *lapb = lapb_devtostruct(dev); + int rc = LAPB_BADTOKEN; + + if (!lapb) + goto out; + + spin_lock_bh(&lapb->lock); + + rc = __lapb_disconnect_request(lapb); + + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); +out: + return rc; +} +EXPORT_SYMBOL(lapb_disconnect_request); + +int lapb_data_request(struct net_device *dev, struct sk_buff *skb) +{ + struct lapb_cb *lapb = lapb_devtostruct(dev); + int rc = LAPB_BADTOKEN; + + if (!lapb) + goto out; + + spin_lock_bh(&lapb->lock); + + rc = LAPB_NOTCONNECTED; + if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4) + goto out_put; + + skb_queue_tail(&lapb->write_queue, skb); + lapb_kick(lapb); + rc = LAPB_OK; +out_put: + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); +out: + return rc; +} +EXPORT_SYMBOL(lapb_data_request); + +int lapb_data_received(struct net_device *dev, struct sk_buff *skb) +{ + struct lapb_cb *lapb = lapb_devtostruct(dev); + int rc = LAPB_BADTOKEN; + + if (lapb) { + spin_lock_bh(&lapb->lock); + lapb_data_input(lapb, skb); + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); + rc = LAPB_OK; + } + + return rc; +} +EXPORT_SYMBOL(lapb_data_received); + +void lapb_connect_confirmation(struct lapb_cb *lapb, int reason) +{ + if (lapb->callbacks->connect_confirmation) + lapb->callbacks->connect_confirmation(lapb->dev, reason); +} + +void lapb_connect_indication(struct lapb_cb *lapb, int reason) +{ + if (lapb->callbacks->connect_indication) + lapb->callbacks->connect_indication(lapb->dev, reason); +} + +void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason) +{ + if (lapb->callbacks->disconnect_confirmation) + lapb->callbacks->disconnect_confirmation(lapb->dev, reason); +} + +void lapb_disconnect_indication(struct lapb_cb *lapb, int reason) +{ + if (lapb->callbacks->disconnect_indication) + lapb->callbacks->disconnect_indication(lapb->dev, reason); +} + +int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb) +{ + if (lapb->callbacks->data_indication) + return lapb->callbacks->data_indication(lapb->dev, skb); + + kfree_skb(skb); + return NET_RX_SUCCESS; /* For now; must be != NET_RX_DROP */ +} + +int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb) +{ + int used = 0; + + if (lapb->callbacks->data_transmit) { + lapb->callbacks->data_transmit(lapb->dev, skb); + used = 1; + } + + return used; +} + +/* Handle device status changes. */ +static int lapb_device_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct lapb_cb *lapb; + + if (!net_eq(dev_net(dev), &init_net)) + return NOTIFY_DONE; + + if (dev->type != ARPHRD_X25) + return NOTIFY_DONE; + + lapb = lapb_devtostruct(dev); + if (!lapb) + return NOTIFY_DONE; + + spin_lock_bh(&lapb->lock); + + switch (event) { + case NETDEV_UP: + lapb_dbg(0, "(%p) Interface up: %s\n", dev, dev->name); + + if (netif_carrier_ok(dev)) { + lapb_dbg(0, "(%p): Carrier is already up: %s\n", dev, + dev->name); + if (lapb->mode & LAPB_DCE) { + lapb_start_t1timer(lapb); + } else { + if (lapb->state == LAPB_STATE_0) { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } + } + } + break; + case NETDEV_GOING_DOWN: + if (netif_carrier_ok(dev)) + __lapb_disconnect_request(lapb); + break; + case NETDEV_DOWN: + lapb_dbg(0, "(%p) Interface down: %s\n", dev, dev->name); + lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); + lapb_clear_queues(lapb); + lapb->state = LAPB_STATE_0; + lapb->n2count = 0; + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + break; + case NETDEV_CHANGE: + if (netif_carrier_ok(dev)) { + lapb_dbg(0, "(%p): Carrier detected: %s\n", dev, + dev->name); + if (lapb->mode & LAPB_DCE) { + lapb_start_t1timer(lapb); + } else { + if (lapb->state == LAPB_STATE_0) { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } + } + } else { + lapb_dbg(0, "(%p) Carrier lost: %s\n", dev, dev->name); + lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); + lapb_clear_queues(lapb); + lapb->state = LAPB_STATE_0; + lapb->n2count = 0; + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + } + break; + } + + spin_unlock_bh(&lapb->lock); + lapb_put(lapb); + return NOTIFY_DONE; +} + +static struct notifier_block lapb_dev_notifier = { + .notifier_call = lapb_device_event, +}; + +static int __init lapb_init(void) +{ + return register_netdevice_notifier(&lapb_dev_notifier); +} + +static void __exit lapb_exit(void) +{ + WARN_ON(!list_empty(&lapb_list)); + + unregister_netdevice_notifier(&lapb_dev_notifier); +} + +MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>"); +MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol"); +MODULE_LICENSE("GPL"); + +module_init(lapb_init); +module_exit(lapb_exit); |