blob: f0679d283110885e4e7f29f7358e07df3c753e49 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * X.25 Packet Layer release 002
3 *
YOSHIFUJI Hideakif8e1d2012007-02-09 23:25:27 +09004 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * This code REQUIRES 2.1.15 or higher
8 *
9 * This module:
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.
14 *
15 * History
16 * X.25 001 Jonathan Naylor Started coding.
17 * 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
18 */
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/kernel.h>
21#include <linux/netdevice.h>
22#include <linux/skbuff.h>
23#include <net/sock.h>
24#include <linux/if_arp.h>
25#include <net/x25.h>
26
27static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
28{
29 struct sock *sk;
30 unsigned short frametype;
31 unsigned int lci;
32
33 frametype = skb->data[2];
YOSHIFUJI Hideakif8e1d2012007-02-09 23:25:27 +090034 lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36 /*
37 * LCI of zero is always for us, and its always a link control
38 * frame.
39 */
40 if (lci == 0) {
41 x25_link_control(skb, nb, frametype);
42 return 0;
43 }
44
45 /*
46 * Find an existing socket.
47 */
48 if ((sk = x25_find_socket(lci, nb)) != NULL) {
49 int queued = 1;
50
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -030051 skb_reset_transport_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 bh_lock_sock(sk);
53 if (!sock_owned_by_user(sk)) {
54 queued = x25_process_rx_frame(sk, skb);
55 } else {
56 sk_add_backlog(sk, skb);
57 }
58 bh_unlock_sock(sk);
Andrew Hendry9d0f7d22007-01-15 19:29:31 -080059 sock_put(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 return queued;
61 }
62
63 /*
64 * Is is a Call Request ? if so process it.
65 */
66 if (frametype == X25_CALL_REQUEST)
67 return x25_rx_call_request(skb, nb, lci);
68
69 /*
Andrew Hendry95a9dc42007-02-08 13:34:02 -080070 * Its not a Call Request, nor is it a control frame.
71 * Can we forward it?
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 */
Andrew Hendry95a9dc42007-02-08 13:34:02 -080073
74 if (x25_forward_data(lci, nb, skb)) {
75 if (frametype == X25_CLEAR_CONFIRMATION) {
76 x25_clear_forward_by_lci(lci);
77 }
78 kfree_skb(skb);
79 return 1;
80 }
81
Linus Torvalds1da177e2005-04-16 15:20:36 -070082/*
83 x25_transmit_clear_request(nb, lci, 0x0D);
84*/
85
86 if (frametype != X25_CLEAR_CONFIRMATION)
87 printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
88
89 return 0;
90}
91
92int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -070093 struct packet_type *ptype, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
95 struct sk_buff *nskb;
96 struct x25_neigh *nb;
97
Eric W. Biedermane730c152007-09-17 11:53:39 -070098 if (dev->nd_net != &init_net)
99 goto drop;
100
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 nskb = skb_copy(skb, GFP_ATOMIC);
102 if (!nskb)
103 goto drop;
104 kfree_skb(skb);
105 skb = nskb;
106
107 /*
108 * Packet received from unrecognised device, throw it away.
109 */
110 nb = x25_get_neigh(dev);
111 if (!nb) {
112 printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
113 goto drop;
114 }
115
116 switch (skb->data[0]) {
117 case 0x00:
118 skb_pull(skb, 1);
119 if (x25_receive_data(skb, nb)) {
120 x25_neigh_put(nb);
121 goto out;
122 }
123 break;
124 case 0x01:
125 x25_link_established(nb);
126 break;
127 case 0x02:
128 x25_link_terminated(nb);
129 break;
130 }
131 x25_neigh_put(nb);
132drop:
133 kfree_skb(skb);
134out:
135 return 0;
136}
137
138void x25_establish_link(struct x25_neigh *nb)
139{
140 struct sk_buff *skb;
141 unsigned char *ptr;
142
143 switch (nb->dev->type) {
144 case ARPHRD_X25:
145 if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
146 printk(KERN_ERR "x25_dev: out of memory\n");
147 return;
148 }
149 ptr = skb_put(skb, 1);
150 *ptr = 0x01;
151 break;
152
153#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
154 case ARPHRD_ETHER:
155 return;
156#endif
157 default:
158 return;
159 }
160
161 skb->protocol = htons(ETH_P_X25);
162 skb->dev = nb->dev;
163
164 dev_queue_xmit(skb);
165}
166
167void x25_terminate_link(struct x25_neigh *nb)
168{
169 struct sk_buff *skb;
170 unsigned char *ptr;
171
172#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
173 if (nb->dev->type == ARPHRD_ETHER)
174 return;
175#endif
176 if (nb->dev->type != ARPHRD_X25)
177 return;
178
179 skb = alloc_skb(1, GFP_ATOMIC);
180 if (!skb) {
181 printk(KERN_ERR "x25_dev: out of memory\n");
182 return;
183 }
184
185 ptr = skb_put(skb, 1);
186 *ptr = 0x02;
187
188 skb->protocol = htons(ETH_P_X25);
189 skb->dev = nb->dev;
190 dev_queue_xmit(skb);
191}
192
193void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
194{
195 unsigned char *dptr;
196
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700197 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 switch (nb->dev->type) {
200 case ARPHRD_X25:
201 dptr = skb_push(skb, 1);
202 *dptr = 0x00;
203 break;
204
205#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
206 case ARPHRD_ETHER:
207 kfree_skb(skb);
208 return;
209#endif
210 default:
211 kfree_skb(skb);
212 return;
213 }
214
215 skb->protocol = htons(ETH_P_X25);
216 skb->dev = nb->dev;
217
218 dev_queue_xmit(skb);
219}