![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
208 lines
4.1 KiB
C
208 lines
4.1 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.
|
|
* 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/sock.h>
|
|
#include <linux/if_arp.h>
|
|
#include <net/x25.h>
|
|
|
|
static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
|
|
{
|
|
struct sock *sk;
|
|
unsigned short frametype;
|
|
unsigned int lci;
|
|
|
|
frametype = skb->data[2];
|
|
lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
|
|
|
|
/*
|
|
* LCI of zero is always for us, and its always a link control
|
|
* frame.
|
|
*/
|
|
if (lci == 0) {
|
|
x25_link_control(skb, nb, frametype);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Find an existing socket.
|
|
*/
|
|
if ((sk = x25_find_socket(lci, nb)) != NULL) {
|
|
int queued = 1;
|
|
|
|
skb->h.raw = skb->data;
|
|
bh_lock_sock(sk);
|
|
if (!sock_owned_by_user(sk)) {
|
|
queued = x25_process_rx_frame(sk, skb);
|
|
} else {
|
|
sk_add_backlog(sk, skb);
|
|
}
|
|
bh_unlock_sock(sk);
|
|
return queued;
|
|
}
|
|
|
|
/*
|
|
* Is is a Call Request ? if so process it.
|
|
*/
|
|
if (frametype == X25_CALL_REQUEST)
|
|
return x25_rx_call_request(skb, nb, lci);
|
|
|
|
/*
|
|
* Its not a Call Request, nor is it a control frame.
|
|
* Let caller throw it away.
|
|
*/
|
|
/*
|
|
x25_transmit_clear_request(nb, lci, 0x0D);
|
|
*/
|
|
|
|
if (frametype != X25_CLEAR_CONFIRMATION)
|
|
printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
|
|
struct packet_type *ptype)
|
|
{
|
|
struct sk_buff *nskb;
|
|
struct x25_neigh *nb;
|
|
|
|
nskb = skb_copy(skb, GFP_ATOMIC);
|
|
if (!nskb)
|
|
goto drop;
|
|
kfree_skb(skb);
|
|
skb = nskb;
|
|
|
|
/*
|
|
* Packet received from unrecognised device, throw it away.
|
|
*/
|
|
nb = x25_get_neigh(dev);
|
|
if (!nb) {
|
|
printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
|
|
goto drop;
|
|
}
|
|
|
|
switch (skb->data[0]) {
|
|
case 0x00:
|
|
skb_pull(skb, 1);
|
|
if (x25_receive_data(skb, nb)) {
|
|
x25_neigh_put(nb);
|
|
goto out;
|
|
}
|
|
break;
|
|
case 0x01:
|
|
x25_link_established(nb);
|
|
break;
|
|
case 0x02:
|
|
x25_link_terminated(nb);
|
|
break;
|
|
}
|
|
x25_neigh_put(nb);
|
|
drop:
|
|
kfree_skb(skb);
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
void x25_establish_link(struct x25_neigh *nb)
|
|
{
|
|
struct sk_buff *skb;
|
|
unsigned char *ptr;
|
|
|
|
switch (nb->dev->type) {
|
|
case ARPHRD_X25:
|
|
if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
|
|
printk(KERN_ERR "x25_dev: out of memory\n");
|
|
return;
|
|
}
|
|
ptr = skb_put(skb, 1);
|
|
*ptr = 0x01;
|
|
break;
|
|
|
|
#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
|
|
case ARPHRD_ETHER:
|
|
return;
|
|
#endif
|
|
default:
|
|
return;
|
|
}
|
|
|
|
skb->protocol = htons(ETH_P_X25);
|
|
skb->dev = nb->dev;
|
|
|
|
dev_queue_xmit(skb);
|
|
}
|
|
|
|
void x25_terminate_link(struct x25_neigh *nb)
|
|
{
|
|
struct sk_buff *skb;
|
|
unsigned char *ptr;
|
|
|
|
#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
|
|
if (nb->dev->type == ARPHRD_ETHER)
|
|
return;
|
|
#endif
|
|
if (nb->dev->type != ARPHRD_X25)
|
|
return;
|
|
|
|
skb = alloc_skb(1, GFP_ATOMIC);
|
|
if (!skb) {
|
|
printk(KERN_ERR "x25_dev: out of memory\n");
|
|
return;
|
|
}
|
|
|
|
ptr = skb_put(skb, 1);
|
|
*ptr = 0x02;
|
|
|
|
skb->protocol = htons(ETH_P_X25);
|
|
skb->dev = nb->dev;
|
|
dev_queue_xmit(skb);
|
|
}
|
|
|
|
void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
|
|
{
|
|
unsigned char *dptr;
|
|
|
|
skb->nh.raw = skb->data;
|
|
|
|
switch (nb->dev->type) {
|
|
case ARPHRD_X25:
|
|
dptr = skb_push(skb, 1);
|
|
*dptr = 0x00;
|
|
break;
|
|
|
|
#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
|
|
case ARPHRD_ETHER:
|
|
kfree_skb(skb);
|
|
return;
|
|
#endif
|
|
default:
|
|
kfree_skb(skb);
|
|
return;
|
|
}
|
|
|
|
skb->protocol = htons(ETH_P_X25);
|
|
skb->dev = nb->dev;
|
|
|
|
dev_queue_xmit(skb);
|
|
}
|