2 * X.25 Packet Layer release 002
4 * This is ALPHA test software. This code may break your machine, randomly fail to work with new
5 * releases, misbehave and/or generally screw up. It might even work.
7 * This code REQUIRES 2.1.15 or higher
10 * This module is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
16 * X.25 001 Jonathan Naylor Started coding.
17 * 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
20 #include <linux/kernel.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <linux/slab.h>
25 #include <linux/if_arp.h>
28 static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
31 unsigned short frametype;
34 frametype = skb->data[2];
35 lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
38 * LCI of zero is always for us, and its always a link control
42 x25_link_control(skb, nb, frametype);
47 * Find an existing socket.
49 if ((sk = x25_find_socket(lci, nb)) != NULL) {
52 skb_reset_transport_header(skb);
54 if (!sock_owned_by_user(sk)) {
55 queued = x25_process_rx_frame(sk, skb);
57 queued = !sk_add_backlog(sk, skb);
65 * Is is a Call Request ? if so process it.
67 if (frametype == X25_CALL_REQUEST)
68 return x25_rx_call_request(skb, nb, lci);
71 * Its not a Call Request, nor is it a control frame.
75 if (x25_forward_data(lci, nb, skb)) {
76 if (frametype == X25_CLEAR_CONFIRMATION) {
77 x25_clear_forward_by_lci(lci);
84 x25_transmit_clear_request(nb, lci, 0x0D);
87 if (frametype != X25_CLEAR_CONFIRMATION)
88 printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
93 int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
94 struct packet_type *ptype, struct net_device *orig_dev)
99 if (!net_eq(dev_net(dev), &init_net))
102 nskb = skb_copy(skb, GFP_ATOMIC);
109 * Packet received from unrecognised device, throw it away.
111 nb = x25_get_neigh(dev);
113 printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
117 switch (skb->data[0]) {
120 if (x25_receive_data(skb, nb)) {
126 x25_link_established(nb);
129 x25_link_terminated(nb);
139 void x25_establish_link(struct x25_neigh *nb)
144 switch (nb->dev->type) {
146 if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
147 printk(KERN_ERR "x25_dev: out of memory\n");
150 ptr = skb_put(skb, 1);
154 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
162 skb->protocol = htons(ETH_P_X25);
168 void x25_terminate_link(struct x25_neigh *nb)
173 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
174 if (nb->dev->type == ARPHRD_ETHER)
177 if (nb->dev->type != ARPHRD_X25)
180 skb = alloc_skb(1, GFP_ATOMIC);
182 printk(KERN_ERR "x25_dev: out of memory\n");
186 ptr = skb_put(skb, 1);
189 skb->protocol = htons(ETH_P_X25);
194 void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
198 skb_reset_network_header(skb);
200 switch (nb->dev->type) {
202 dptr = skb_push(skb, 1);
206 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
216 skb->protocol = htons(ETH_P_X25);