blob: 9005f6daeab583458b370a9385f5b7f10d19908c [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <net/sock.h>
25#include <linux/if_arp.h>
26#include <net/x25.h>
Andrew Hendry5ebfbc02010-04-22 16:12:36 -070027#include <net/x25device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
30{
31 struct sock *sk;
32 unsigned short frametype;
33 unsigned int lci;
34
35 frametype = skb->data[2];
YOSHIFUJI Hideakif8e1d2012007-02-09 23:25:27 +090036 lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38 /*
39 * LCI of zero is always for us, and its always a link control
40 * frame.
41 */
42 if (lci == 0) {
43 x25_link_control(skb, nb, frametype);
44 return 0;
45 }
46
47 /*
48 * Find an existing socket.
49 */
50 if ((sk = x25_find_socket(lci, nb)) != NULL) {
51 int queued = 1;
52
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -030053 skb_reset_transport_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 bh_lock_sock(sk);
55 if (!sock_owned_by_user(sk)) {
56 queued = x25_process_rx_frame(sk, skb);
57 } else {
Zhu Yia3a858f2010-03-04 18:01:47 +000058 queued = !sk_add_backlog(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 }
60 bh_unlock_sock(sk);
Andrew Hendry9d0f7d22007-01-15 19:29:31 -080061 sock_put(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 return queued;
63 }
64
65 /*
66 * Is is a Call Request ? if so process it.
67 */
68 if (frametype == X25_CALL_REQUEST)
69 return x25_rx_call_request(skb, nb, lci);
70
71 /*
Andrew Hendry95a9dc42007-02-08 13:34:02 -080072 * Its not a Call Request, nor is it a control frame.
73 * Can we forward it?
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 */
Andrew Hendry95a9dc42007-02-08 13:34:02 -080075
76 if (x25_forward_data(lci, nb, skb)) {
77 if (frametype == X25_CLEAR_CONFIRMATION) {
78 x25_clear_forward_by_lci(lci);
79 }
80 kfree_skb(skb);
81 return 1;
82 }
83
Linus Torvalds1da177e2005-04-16 15:20:36 -070084/*
85 x25_transmit_clear_request(nb, lci, 0x0D);
86*/
87
88 if (frametype != X25_CLEAR_CONFIRMATION)
89 printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
90
91 return 0;
92}
93
94int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -070095 struct packet_type *ptype, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
97 struct sk_buff *nskb;
98 struct x25_neigh *nb;
99
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700100 if (!net_eq(dev_net(dev), &init_net))
Eric W. Biedermane730c152007-09-17 11:53:39 -0700101 goto drop;
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 nskb = skb_copy(skb, GFP_ATOMIC);
104 if (!nskb)
105 goto drop;
106 kfree_skb(skb);
107 skb = nskb;
108
109 /*
110 * Packet received from unrecognised device, throw it away.
111 */
112 nb = x25_get_neigh(dev);
113 if (!nb) {
114 printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
115 goto drop;
116 }
117
118 switch (skb->data[0]) {
Andrew Hendry5ebfbc02010-04-22 16:12:36 -0700119
120 case X25_IFACE_DATA:
121 skb_pull(skb, 1);
122 if (x25_receive_data(skb, nb)) {
123 x25_neigh_put(nb);
124 goto out;
125 }
126 break;
127
128 case X25_IFACE_CONNECT:
129 x25_link_established(nb);
130 break;
131
132 case X25_IFACE_DISCONNECT:
133 x25_link_terminated(nb);
134 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 }
136 x25_neigh_put(nb);
137drop:
138 kfree_skb(skb);
139out:
140 return 0;
141}
142
143void x25_establish_link(struct x25_neigh *nb)
144{
145 struct sk_buff *skb;
146 unsigned char *ptr;
147
148 switch (nb->dev->type) {
149 case ARPHRD_X25:
150 if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
151 printk(KERN_ERR "x25_dev: out of memory\n");
152 return;
153 }
154 ptr = skb_put(skb, 1);
Andrew Hendry5ebfbc02010-04-22 16:12:36 -0700155 *ptr = X25_IFACE_CONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 break;
157
158#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
159 case ARPHRD_ETHER:
160 return;
161#endif
162 default:
163 return;
164 }
165
166 skb->protocol = htons(ETH_P_X25);
167 skb->dev = nb->dev;
168
169 dev_queue_xmit(skb);
170}
171
172void x25_terminate_link(struct x25_neigh *nb)
173{
174 struct sk_buff *skb;
175 unsigned char *ptr;
176
177#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
178 if (nb->dev->type == ARPHRD_ETHER)
179 return;
180#endif
181 if (nb->dev->type != ARPHRD_X25)
182 return;
183
184 skb = alloc_skb(1, GFP_ATOMIC);
185 if (!skb) {
186 printk(KERN_ERR "x25_dev: out of memory\n");
187 return;
188 }
189
190 ptr = skb_put(skb, 1);
Andrew Hendry5ebfbc02010-04-22 16:12:36 -0700191 *ptr = X25_IFACE_DISCONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 skb->protocol = htons(ETH_P_X25);
194 skb->dev = nb->dev;
195 dev_queue_xmit(skb);
196}
197
198void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
199{
200 unsigned char *dptr;
201
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700202 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 switch (nb->dev->type) {
205 case ARPHRD_X25:
206 dptr = skb_push(skb, 1);
Andrew Hendry5ebfbc02010-04-22 16:12:36 -0700207 *dptr = X25_IFACE_DATA;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 break;
209
210#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
211 case ARPHRD_ETHER:
212 kfree_skb(skb);
213 return;
214#endif
215 default:
216 kfree_skb(skb);
217 return;
218 }
219
220 skb->protocol = htons(ETH_P_X25);
221 skb->dev = nb->dev;
222
223 dev_queue_xmit(skb);
224}