diff options
Diffstat (limited to 'net/x25/x25_link.c')
| -rw-r--r-- | net/x25/x25_link.c | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c new file mode 100644 index 00000000..b25c6463 --- /dev/null +++ b/net/x25/x25_link.c @@ -0,0 +1,400 @@ +/* + * X.25 Packet Layer release 002 + * + * This is ALPHA test software. This code may break your machine, + * randomly fail to work with new releases, misbehave and/or generally + * screw up. It might even work. + * + * This code REQUIRES 2.1.15 or higher + * + * This module: + * This module is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * History + * X.25 001 Jonathan Naylor Started coding. + * X.25 002 Jonathan Naylor New timer architecture. + * mar/20/00 Daniela Squassoni Disabling/enabling of facilities + * negotiation. + * 2000-09-04 Henner Eisen dev_hold() / dev_put() for x25_neigh. + */ + +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/timer.h> +#include <linux/slab.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <asm/uaccess.h> +#include <linux/init.h> +#include <net/x25.h> + +static LIST_HEAD(x25_neigh_list); +static DEFINE_RWLOCK(x25_neigh_list_lock); + +static void x25_t20timer_expiry(unsigned long); + +static void x25_transmit_restart_confirmation(struct x25_neigh *nb); +static void x25_transmit_restart_request(struct x25_neigh *nb); + +/* + * Linux set/reset timer routines + */ +static inline void x25_start_t20timer(struct x25_neigh *nb) +{ + mod_timer(&nb->t20timer, jiffies + nb->t20); +} + +static void x25_t20timer_expiry(unsigned long param) +{ + struct x25_neigh *nb = (struct x25_neigh *)param; + + x25_transmit_restart_request(nb); + + x25_start_t20timer(nb); +} + +static inline void x25_stop_t20timer(struct x25_neigh *nb) +{ + del_timer(&nb->t20timer); +} + +static inline int x25_t20timer_pending(struct x25_neigh *nb) +{ + return timer_pending(&nb->t20timer); +} + +/* + * This handles all restart and diagnostic frames. + */ +void x25_link_control(struct sk_buff *skb, struct x25_neigh *nb, + unsigned short frametype) +{ + struct sk_buff *skbn; + int confirm; + + switch (frametype) { + case X25_RESTART_REQUEST: + confirm = !x25_t20timer_pending(nb); + x25_stop_t20timer(nb); + nb->state = X25_LINK_STATE_3; + if (confirm) + x25_transmit_restart_confirmation(nb); + break; + + case X25_RESTART_CONFIRMATION: + x25_stop_t20timer(nb); + nb->state = X25_LINK_STATE_3; + break; + + case X25_DIAGNOSTIC: + printk(KERN_WARNING "x25: diagnostic #%d - " + "%02X %02X %02X\n", + skb->data[3], skb->data[4], + skb->data[5], skb->data[6]); + break; + + default: + printk(KERN_WARNING "x25: received unknown %02X " + "with LCI 000\n", frametype); + break; + } + + if (nb->state == X25_LINK_STATE_3) + while ((skbn = skb_dequeue(&nb->queue)) != NULL) + x25_send_frame(skbn, nb); +} + +/* + * This routine is called when a Restart Request is needed + */ +static void x25_transmit_restart_request(struct x25_neigh *nb) +{ + unsigned char *dptr; + int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2; + struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); + + if (!skb) + return; + + skb_reserve(skb, X25_MAX_L2_LEN); + + dptr = skb_put(skb, X25_STD_MIN_LEN + 2); + + *dptr++ = nb->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ; + *dptr++ = 0x00; + *dptr++ = X25_RESTART_REQUEST; + *dptr++ = 0x00; + *dptr++ = 0; + + skb->sk = NULL; + + x25_send_frame(skb, nb); +} + +/* + * This routine is called when a Restart Confirmation is needed + */ +static void x25_transmit_restart_confirmation(struct x25_neigh *nb) +{ + unsigned char *dptr; + int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN; + struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); + + if (!skb) + return; + + skb_reserve(skb, X25_MAX_L2_LEN); + + dptr = skb_put(skb, X25_STD_MIN_LEN); + + *dptr++ = nb->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ; + *dptr++ = 0x00; + *dptr++ = X25_RESTART_CONFIRMATION; + + skb->sk = NULL; + + x25_send_frame(skb, nb); +} + +/* + * This routine is called when a Clear Request is needed outside of the context + * of a connected socket. + */ +void x25_transmit_clear_request(struct x25_neigh *nb, unsigned int lci, + unsigned char cause) +{ + unsigned char *dptr; + int len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2; + struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); + + if (!skb) + return; + + skb_reserve(skb, X25_MAX_L2_LEN); + + dptr = skb_put(skb, X25_STD_MIN_LEN + 2); + + *dptr++ = ((lci >> 8) & 0x0F) | (nb->extended ? + X25_GFI_EXTSEQ : + X25_GFI_STDSEQ); + *dptr++ = (lci >> 0) & 0xFF; + *dptr++ = X25_CLEAR_REQUEST; + *dptr++ = cause; + *dptr++ = 0x00; + + skb->sk = NULL; + + x25_send_frame(skb, nb); +} + +void x25_transmit_link(struct sk_buff *skb, struct x25_neigh *nb) +{ + switch (nb->state) { + case X25_LINK_STATE_0: + skb_queue_tail(&nb->queue, skb); + nb->state = X25_LINK_STATE_1; + x25_establish_link(nb); + break; + case X25_LINK_STATE_1: + case X25_LINK_STATE_2: + skb_queue_tail(&nb->queue, skb); + break; + case X25_LINK_STATE_3: + x25_send_frame(skb, nb); + break; + } +} + +/* + * Called when the link layer has become established. + */ +void x25_link_established(struct x25_neigh *nb) +{ + switch (nb->state) { + case X25_LINK_STATE_0: + nb->state = X25_LINK_STATE_2; + break; + case X25_LINK_STATE_1: + x25_transmit_restart_request(nb); + nb->state = X25_LINK_STATE_2; + x25_start_t20timer(nb); + break; + } +} + +/* + * Called when the link layer has terminated, or an establishment + * request has failed. + */ + +void x25_link_terminated(struct x25_neigh *nb) +{ + nb->state = X25_LINK_STATE_0; + /* Out of order: clear existing virtual calls (X.25 03/93 4.6.3) */ + x25_kill_by_neigh(nb); +} + +/* + * Add a new device. + */ +void x25_link_device_up(struct net_device *dev) +{ + struct x25_neigh *nb = kmalloc(sizeof(*nb), GFP_ATOMIC); + + if (!nb) + return; + + skb_queue_head_init(&nb->queue); + setup_timer(&nb->t20timer, x25_t20timer_expiry, (unsigned long)nb); + + dev_hold(dev); + nb->dev = dev; + nb->state = X25_LINK_STATE_0; + nb->extended = 0; + /* + * Enables negotiation + */ + nb->global_facil_mask = X25_MASK_REVERSE | + X25_MASK_THROUGHPUT | + X25_MASK_PACKET_SIZE | + X25_MASK_WINDOW_SIZE; + nb->t20 = sysctl_x25_restart_request_timeout; + atomic_set(&nb->refcnt, 1); + + write_lock_bh(&x25_neigh_list_lock); + list_add(&nb->node, &x25_neigh_list); + write_unlock_bh(&x25_neigh_list_lock); +} + +/** + * __x25_remove_neigh - remove neighbour from x25_neigh_list + * @nb - neigh to remove + * + * Remove neighbour from x25_neigh_list. If it was there. + * Caller must hold x25_neigh_list_lock. + */ +static void __x25_remove_neigh(struct x25_neigh *nb) +{ + skb_queue_purge(&nb->queue); + x25_stop_t20timer(nb); + + if (nb->node.next) { + list_del(&nb->node); + x25_neigh_put(nb); + } +} + +/* + * A device has been removed, remove its links. + */ +void x25_link_device_down(struct net_device *dev) +{ + struct x25_neigh *nb; + struct list_head *entry, *tmp; + + write_lock_bh(&x25_neigh_list_lock); + + list_for_each_safe(entry, tmp, &x25_neigh_list) { + nb = list_entry(entry, struct x25_neigh, node); + + if (nb->dev == dev) { + __x25_remove_neigh(nb); + dev_put(dev); + } + } + + write_unlock_bh(&x25_neigh_list_lock); +} + +/* + * Given a device, return the neighbour address. + */ +struct x25_neigh *x25_get_neigh(struct net_device *dev) +{ + struct x25_neigh *nb, *use = NULL; + struct list_head *entry; + + read_lock_bh(&x25_neigh_list_lock); + list_for_each(entry, &x25_neigh_list) { + nb = list_entry(entry, struct x25_neigh, node); + + if (nb->dev == dev) { + use = nb; + break; + } + } + + if (use) + x25_neigh_hold(use); + read_unlock_bh(&x25_neigh_list_lock); + return use; +} + +/* + * Handle the ioctls that control the subscription functions. + */ +int x25_subscr_ioctl(unsigned int cmd, void __user *arg) +{ + struct x25_subscrip_struct x25_subscr; + struct x25_neigh *nb; + struct net_device *dev; + int rc = -EINVAL; + + if (cmd != SIOCX25GSUBSCRIP && cmd != SIOCX25SSUBSCRIP) + goto out; + + rc = -EFAULT; + if (copy_from_user(&x25_subscr, arg, sizeof(x25_subscr))) + goto out; + + rc = -EINVAL; + if ((dev = x25_dev_get(x25_subscr.device)) == NULL) + goto out; + + if ((nb = x25_get_neigh(dev)) == NULL) + goto out_dev_put; + + dev_put(dev); + + if (cmd == SIOCX25GSUBSCRIP) { + x25_subscr.extended = nb->extended; + x25_subscr.global_facil_mask = nb->global_facil_mask; + rc = copy_to_user(arg, &x25_subscr, + sizeof(x25_subscr)) ? -EFAULT : 0; + } else { + rc = -EINVAL; + if (!(x25_subscr.extended && x25_subscr.extended != 1)) { + rc = 0; + nb->extended = x25_subscr.extended; + nb->global_facil_mask = x25_subscr.global_facil_mask; + } + } + x25_neigh_put(nb); +out: + return rc; +out_dev_put: + dev_put(dev); + goto out; +} + + +/* + * Release all memory associated with X.25 neighbour structures. + */ +void __exit x25_link_free(void) +{ + struct x25_neigh *nb; + struct list_head *entry, *tmp; + + write_lock_bh(&x25_neigh_list_lock); + + list_for_each_safe(entry, tmp, &x25_neigh_list) { + nb = list_entry(entry, struct x25_neigh, node); + __x25_remove_neigh(nb); + dev_put(nb->dev); + } + write_unlock_bh(&x25_neigh_list_lock); +} |