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 * X.25 002 Jonathan Naylor Centralised disconnection processing.
18 * mar/20/00 Daniela Squassoni Disabling/enabling of facilities
20 * jun/24/01 Arnaldo C. Melo use skb_queue_purge, cleanups
23 #include <linux/errno.h>
24 #include <linux/types.h>
25 #include <linux/socket.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/timer.h>
30 #include <linux/string.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/inet.h>
34 #include <linux/netdevice.h>
35 #include <linux/skbuff.h>
37 #include <asm/segment.h>
38 #include <asm/system.h>
39 #include <linux/fcntl.h>
41 #include <linux/interrupt.h>
45 * This routine purges all of the queues of frames.
47 void x25_clear_queues(struct sock *sk)
49 skb_queue_purge(&sk->write_queue);
50 skb_queue_purge(&sk->protinfo.x25->ack_queue);
51 skb_queue_purge(&sk->protinfo.x25->interrupt_in_queue);
52 skb_queue_purge(&sk->protinfo.x25->interrupt_out_queue);
53 skb_queue_purge(&sk->protinfo.x25->fragment_queue);
58 * This routine purges the input queue of those frames that have been
59 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
62 void x25_frames_acked(struct sock *sk, unsigned short nr)
65 int modulus = sk->protinfo.x25->neighbour->extended ? X25_EMODULUS :
69 * Remove all the ack-ed frames from the ack queue.
71 if (sk->protinfo.x25->va != nr)
72 while (skb_peek(&sk->protinfo.x25->ack_queue) != NULL &&
73 sk->protinfo.x25->va != nr) {
74 skb = skb_dequeue(&sk->protinfo.x25->ack_queue);
76 sk->protinfo.x25->va = (sk->protinfo.x25->va + 1) %
81 void x25_requeue_frames(struct sock *sk)
83 struct sk_buff *skb, *skb_prev = NULL;
86 * Requeue all the un-ack-ed frames on the output queue to be picked
87 * up by x25_kick. This arrangement handles the possibility of an empty
90 while ((skb = skb_dequeue(&sk->protinfo.x25->ack_queue)) != NULL) {
92 skb_queue_head(&sk->write_queue, skb);
94 skb_append(skb_prev, skb);
100 * Validate that the value of nr is between va and vs. Return true or
103 int x25_validate_nr(struct sock *sk, unsigned short nr)
105 unsigned short vc = sk->protinfo.x25->va;
106 int modulus = sk->protinfo.x25->neighbour->extended ? X25_EMODULUS :
109 while (vc != sk->protinfo.x25->vs) {
110 if (nr == vc) return 1;
111 vc = (vc + 1) % modulus;
114 return nr == sk->protinfo.x25->vs ? 1 : 0;
118 * This routine is called when the packet layer internally generates a
121 void x25_write_internal(struct sock *sk, int frametype)
125 unsigned char facilities[X25_MAX_FAC_LEN];
126 unsigned char addresses[1 + X25_ADDR_LEN];
127 unsigned char lci1, lci2;
131 * Default safe frame size.
133 len = X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
139 case X25_CALL_REQUEST:
140 len += 1 + X25_ADDR_LEN + X25_MAX_FAC_LEN +
143 case X25_CALL_ACCEPTED:
144 len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN;
146 case X25_CLEAR_REQUEST:
147 case X25_RESET_REQUEST:
153 case X25_CLEAR_CONFIRMATION:
154 case X25_INTERRUPT_CONFIRMATION:
155 case X25_RESET_CONFIRMATION:
158 printk(KERN_ERR "X.25: invalid frame type %02X\n",
163 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
167 * Space for Ethernet and 802.2 LLC headers.
169 skb_reserve(skb, X25_MAX_L2_LEN);
172 * Make space for the GFI and LCI, and fill them in.
174 dptr = skb_put(skb, 2);
176 lci1 = (sk->protinfo.x25->lci >> 8) & 0x0F;
177 lci2 = (sk->protinfo.x25->lci >> 0) & 0xFF;
179 if (sk->protinfo.x25->neighbour->extended) {
180 *dptr++ = lci1 | X25_GFI_EXTSEQ;
183 *dptr++ = lci1 | X25_GFI_STDSEQ;
188 * Now fill in the frame type specific information.
192 case X25_CALL_REQUEST:
193 dptr = skb_put(skb, 1);
194 *dptr++ = X25_CALL_REQUEST;
195 len = x25_addr_aton(addresses, &sk->protinfo.x25->dest_addr, &sk->protinfo.x25->source_addr);
196 dptr = skb_put(skb, len);
197 memcpy(dptr, addresses, len);
198 len = x25_create_facilities(facilities, &sk->protinfo.x25->facilities, sk->protinfo.x25->neighbour->global_facil_mask);
199 dptr = skb_put(skb, len);
200 memcpy(dptr, facilities, len);
201 dptr = skb_put(skb, sk->protinfo.x25->calluserdata.cudlength);
202 memcpy(dptr, sk->protinfo.x25->calluserdata.cuddata, sk->protinfo.x25->calluserdata.cudlength);
203 sk->protinfo.x25->calluserdata.cudlength = 0;
206 case X25_CALL_ACCEPTED:
207 dptr = skb_put(skb, 2);
208 *dptr++ = X25_CALL_ACCEPTED;
209 *dptr++ = 0x00; /* Address lengths */
210 len = x25_create_facilities(facilities, &sk->protinfo.x25->facilities, sk->protinfo.x25->vc_facil_mask);
211 dptr = skb_put(skb, len);
212 memcpy(dptr, facilities, len);
213 dptr = skb_put(skb, sk->protinfo.x25->calluserdata.cudlength);
214 memcpy(dptr, sk->protinfo.x25->calluserdata.cuddata, sk->protinfo.x25->calluserdata.cudlength);
215 sk->protinfo.x25->calluserdata.cudlength = 0;
218 case X25_CLEAR_REQUEST:
219 case X25_RESET_REQUEST:
220 dptr = skb_put(skb, 3);
222 *dptr++ = 0x00; /* XXX */
223 *dptr++ = 0x00; /* XXX */
229 if (sk->protinfo.x25->neighbour->extended) {
230 dptr = skb_put(skb, 2);
232 *dptr++ = (sk->protinfo.x25->vr << 1) & 0xFE;
234 dptr = skb_put(skb, 1);
236 *dptr++ |= (sk->protinfo.x25->vr << 5) & 0xE0;
240 case X25_CLEAR_CONFIRMATION:
241 case X25_INTERRUPT_CONFIRMATION:
242 case X25_RESET_CONFIRMATION:
243 dptr = skb_put(skb, 1);
248 x25_transmit_link(skb, sk->protinfo.x25->neighbour);
252 * Unpick the contents of the passed X.25 Packet Layer frame.
254 int x25_decode(struct sock *sk, struct sk_buff *skb, int *ns, int *nr, int *q,
257 unsigned char *frame = skb->data;
259 *ns = *nr = *q = *d = *m = 0;
262 case X25_CALL_REQUEST:
263 case X25_CALL_ACCEPTED:
264 case X25_CLEAR_REQUEST:
265 case X25_CLEAR_CONFIRMATION:
267 case X25_INTERRUPT_CONFIRMATION:
268 case X25_RESET_REQUEST:
269 case X25_RESET_CONFIRMATION:
270 case X25_RESTART_REQUEST:
271 case X25_RESTART_CONFIRMATION:
272 case X25_REGISTRATION_REQUEST:
273 case X25_REGISTRATION_CONFIRMATION:
278 if (sk->protinfo.x25->neighbour->extended) {
279 if (frame[2] == X25_RR ||
280 frame[2] == X25_RNR ||
281 frame[2] == X25_REJ) {
282 *nr = (frame[3] >> 1) & 0x7F;
286 if ((frame[2] & 0x1F) == X25_RR ||
287 (frame[2] & 0x1F) == X25_RNR ||
288 (frame[2] & 0x1F) == X25_REJ) {
289 *nr = (frame[2] >> 5) & 0x07;
290 return frame[2] & 0x1F;
294 if (sk->protinfo.x25->neighbour->extended) {
295 if ((frame[2] & 0x01) == X25_DATA) {
296 *q = (frame[0] & X25_Q_BIT) == X25_Q_BIT;
297 *d = (frame[0] & X25_D_BIT) == X25_D_BIT;
298 *m = (frame[3] & X25_EXT_M_BIT) == X25_EXT_M_BIT;
299 *nr = (frame[3] >> 1) & 0x7F;
300 *ns = (frame[2] >> 1) & 0x7F;
304 if ((frame[2] & 0x01) == X25_DATA) {
305 *q = (frame[0] & X25_Q_BIT) == X25_Q_BIT;
306 *d = (frame[0] & X25_D_BIT) == X25_D_BIT;
307 *m = (frame[2] & X25_STD_M_BIT) == X25_STD_M_BIT;
308 *nr = (frame[2] >> 5) & 0x07;
309 *ns = (frame[2] >> 1) & 0x07;
314 printk(KERN_DEBUG "X.25: invalid PLP frame %02X %02X %02X\n",
315 frame[0], frame[1], frame[2]);
320 void x25_disconnect(struct sock *sk, int reason, unsigned char cause,
321 unsigned char diagnostic)
323 x25_clear_queues(sk);
326 sk->protinfo.x25->lci = 0;
327 sk->protinfo.x25->state = X25_STATE_0;
329 sk->protinfo.x25->causediag.cause = cause;
330 sk->protinfo.x25->causediag.diagnostic = diagnostic;
332 sk->state = TCP_CLOSE;
334 sk->shutdown |= SEND_SHUTDOWN;
337 sk->state_change(sk);
343 * Clear an own-rx-busy condition and tell the peer about this, provided
344 * that there is a significant amount of free receive buffer space available.
346 void x25_check_rbuf(struct sock *sk)
348 if (atomic_read(&sk->rmem_alloc) < (sk->rcvbuf / 2) &&
349 (sk->protinfo.x25->condition & X25_COND_OWN_RX_BUSY)) {
350 sk->protinfo.x25->condition &= ~X25_COND_OWN_RX_BUSY;
351 sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
352 sk->protinfo.x25->vl = sk->protinfo.x25->vr;
353 x25_write_internal(sk, X25_RR);