mirror of
https://github.com/torvalds/linux.git
synced 2024-11-01 01:31:44 +00:00
0e3cf7e916
single list_head variable initialized with LIST_HEAD_INIT could almost always can be replaced with LIST_HEAD declaration, this shrinks the code and looks better. Signed-off-by: Denis Cheng <crquan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
399 lines
8.7 KiB
C
399 lines
8.7 KiB
C
/*
|
|
* 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/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);
|
|
}
|
|
write_unlock_bh(&x25_neigh_list_lock);
|
|
}
|