[linux.git] / net / ax25 / ax25_ds_in.c

/*
 * This program 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.
 *
 * Copyright (C) Jonathan Naylor G4KLX ([email protected])
 * Copyright (C) Joerg Reuter DL1BKE ([email protected])
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>

/*
 *	State machine for state 1, Awaiting Connection State.
 *	The handling of the timer(s) is in file ax25_ds_timer.c.
 *	Handling of state 0 and connection release is in ax25.c.
 */
static int ax25_ds_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
{
	switch (frametype) {
	case AX25_SABM:
		ax25->modulus = AX25_MODULUS;
		ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
		ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
		break;

	case AX25_SABME:
		ax25->modulus = AX25_EMODULUS;
		ax25->window  =  ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
		ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
		break;

	case AX25_DISC:
		ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
		break;

	case AX25_UA:
		ax25_calculate_rtt(ax25);
		ax25_stop_t1timer(ax25);
		ax25_start_t3timer(ax25);
		ax25_start_idletimer(ax25);
		ax25->vs      = 0;
		ax25->va      = 0;
		ax25->vr      = 0;
		ax25->state   = AX25_STATE_3;
		ax25->n2count = 0;
		if (ax25->sk != NULL) {
			bh_lock_sock(ax25->sk);
			ax25->sk->sk_state = TCP_ESTABLISHED;
			/*
			 * For WAIT_SABM connections we will produce an accept
			 * ready socket here
			 */
			if (!sock_flag(ax25->sk, SOCK_DEAD))
				ax25->sk->sk_state_change(ax25->sk);
			bh_unlock_sock(ax25->sk);
		}
		ax25_dama_on(ax25);

		/* according to DK4EG's spec we are required to
		 * send a RR RESPONSE FINAL NR=0.
		 */

		ax25_std_enquiry_response(ax25);
		break;

	case AX25_DM:
		if (pf)
			ax25_disconnect(ax25, ECONNREFUSED);
		break;

	default:
		if (pf)
			ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
		break;
	}

	return 0;
}

/*
 *	State machine for state 2, Awaiting Release State.
 *	The handling of the timer(s) is in file ax25_ds_timer.c
 *	Handling of state 0 and connection release is in ax25.c.
 */
static int ax25_ds_state2_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
{
	switch (frametype) {
	case AX25_SABM:
	case AX25_SABME:
		ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
		ax25_dama_off(ax25);
		break;

	case AX25_DISC:
		ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
		ax25_dama_off(ax25);
		ax25_disconnect(ax25, 0);
		break;

	case AX25_DM:
	case AX25_UA:
		if (pf) {
			ax25_dama_off(ax25);
			ax25_disconnect(ax25, 0);
		}
		break;

	case AX25_I:
	case AX25_REJ:
	case AX25_RNR:
	case AX25_RR:
		if (pf) {
			ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
			ax25_dama_off(ax25);
		}
		break;

	default:
		break;
	}

	return 0;
}

/*
 *	State machine for state 3, Connected State.
 *	The handling of the timer(s) is in file ax25_timer.c
 *	Handling of state 0 and connection release is in ax25.c.
 */
static int ax25_ds_state3_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int ns, int nr, int pf, int type)
{
	int queued = 0;

	switch (frametype) {
	case AX25_SABM:
	case AX25_SABME:
		if (frametype == AX25_SABM) {
			ax25->modulus   = AX25_MODULUS;
			ax25->window    = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
		} else {
			ax25->modulus   = AX25_EMODULUS;
			ax25->window    = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
		}
		ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
		ax25_stop_t1timer(ax25);
		ax25_start_t3timer(ax25);
		ax25_start_idletimer(ax25);
		ax25->condition = 0x00;
		ax25->vs        = 0;
		ax25->va        = 0;
		ax25->vr        = 0;
		ax25_requeue_frames(ax25);
		ax25_dama_on(ax25);
		break;

	case AX25_DISC:
		ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
		ax25_dama_off(ax25);
		ax25_disconnect(ax25, 0);
		break;

	case AX25_DM:
		ax25_dama_off(ax25);
		ax25_disconnect(ax25, ECONNRESET);
		break;

	case AX25_RR:
	case AX25_RNR:
		if (frametype == AX25_RR)
			ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
		else
			ax25->condition |= AX25_COND_PEER_RX_BUSY;

		if (ax25_validate_nr(ax25, nr)) {
			if (ax25_check_iframes_acked(ax25, nr))
				ax25->n2count=0;
			if (type == AX25_COMMAND && pf)
				ax25_ds_enquiry_response(ax25);
		} else {
			ax25_ds_nr_error_recovery(ax25);
			ax25->state = AX25_STATE_1;
		}
		break;

	case AX25_REJ:
		ax25->condition &= ~AX25_COND_PEER_RX_BUSY;

		if (ax25_validate_nr(ax25, nr)) {
			if (ax25->va != nr)
				ax25->n2count=0;

			ax25_frames_acked(ax25, nr);
			ax25_calculate_rtt(ax25);
			ax25_stop_t1timer(ax25);
			ax25_start_t3timer(ax25);
			ax25_requeue_frames(ax25);

			if (type == AX25_COMMAND && pf)
				ax25_ds_enquiry_response(ax25);
		} else {
			ax25_ds_nr_error_recovery(ax25);
			ax25->state = AX25_STATE_1;
		}
		break;

	case AX25_I:
		if (!ax25_validate_nr(ax25, nr)) {
			ax25_ds_nr_error_recovery(ax25);
			ax25->state = AX25_STATE_1;
			break;
		}
		if (ax25->condition & AX25_COND_PEER_RX_BUSY) {
			ax25_frames_acked(ax25, nr);
			ax25->n2count = 0;
		} else {
			if (ax25_check_iframes_acked(ax25, nr))
				ax25->n2count = 0;
		}
		if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
			if (pf) ax25_ds_enquiry_response(ax25);
			break;
		}
		if (ns == ax25->vr) {
			ax25->vr = (ax25->vr + 1) % ax25->modulus;
			queued = ax25_rx_iframe(ax25, skb);
			if (ax25->condition & AX25_COND_OWN_RX_BUSY)
				ax25->vr = ns;	/* ax25->vr - 1 */
			ax25->condition &= ~AX25_COND_REJECT;
			if (pf) {
				ax25_ds_enquiry_response(ax25);
			} else {
				if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
					ax25->condition |= AX25_COND_ACK_PENDING;
					ax25_start_t2timer(ax25);
				}
			}
		} else {
			if (ax25->condition & AX25_COND_REJECT) {
				if (pf) ax25_ds_enquiry_response(ax25);
			} else {
				ax25->condition |= AX25_COND_REJECT;
				ax25_ds_enquiry_response(ax25);
				ax25->condition &= ~AX25_COND_ACK_PENDING;
			}
		}
		break;

	case AX25_FRMR:
	case AX25_ILLEGAL:
		ax25_ds_establish_data_link(ax25);
		ax25->state = AX25_STATE_1;
		break;

	default:
		break;
	}

	return queued;
}

/*
 *	Higher level upcall for a LAPB frame
 */
int ax25_ds_frame_in(ax25_cb *ax25, struct sk_buff *skb, int type)
{
	int queued = 0, frametype, ns, nr, pf;

	frametype = ax25_decode(ax25, skb, &ns, &nr, &pf);

	switch (ax25->state) {
	case AX25_STATE_1:
		queued = ax25_ds_state1_machine(ax25, skb, frametype, pf, type);
		break;
	case AX25_STATE_2:
		queued = ax25_ds_state2_machine(ax25, skb, frametype, pf, type);
		break;
	case AX25_STATE_3:
		queued = ax25_ds_state3_machine(ax25, skb, frametype, ns, nr, pf, type);
		break;
	}

	return queued;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright (C) Jonathan Naylor G4KLX ([email protected])
	8	* Copyright (C) Joerg Reuter DL1BKE ([email protected])
	9	*/
	10	#include <linux/errno.h>
	11	#include <linux/types.h>
	12	#include <linux/socket.h>
	13	#include <linux/in.h>
	14	#include <linux/kernel.h>
1da177e4 LT	15	#include <linux/timer.h>
	16	#include <linux/string.h>
	17	#include <linux/sockios.h>
	18	#include <linux/net.h>
	19	#include <net/ax25.h>
	20	#include <linux/inet.h>
	21	#include <linux/netdevice.h>
	22	#include <linux/skbuff.h>
	23	#include <net/sock.h>
c752f073	24	#include <net/tcp_states.h>
1da177e4	25	#include <asm/uaccess.h>
1da177e4 LT	26	#include <linux/fcntl.h>
	27	#include <linux/mm.h>
	28	#include <linux/interrupt.h>
	29
	30	/*
	31	* State machine for state 1, Awaiting Connection State.
	32	* The handling of the timer(s) is in file ax25_ds_timer.c.
	33	* Handling of state 0 and connection release is in ax25.c.
	34	*/
	35	static int ax25_ds_state1_machine(ax25_cb ax25, struct sk_buff skb, int frametype, int pf, int type)
	36	{
	37	switch (frametype) {
	38	case AX25_SABM:
	39	ax25->modulus = AX25_MODULUS;
	40	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
	41	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
	42	break;
	43
	44	case AX25_SABME:
	45	ax25->modulus = AX25_EMODULUS;
	46	ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
	47	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
	48	break;
	49
	50	case AX25_DISC:
	51	ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
	52	break;
	53
	54	case AX25_UA:
	55	ax25_calculate_rtt(ax25);
	56	ax25_stop_t1timer(ax25);
	57	ax25_start_t3timer(ax25);
	58	ax25_start_idletimer(ax25);
	59	ax25->vs = 0;
	60	ax25->va = 0;
	61	ax25->vr = 0;
	62	ax25->state = AX25_STATE_3;
	63	ax25->n2count = 0;
	64	if (ax25->sk != NULL) {
	65	bh_lock_sock(ax25->sk);
	66	ax25->sk->sk_state = TCP_ESTABLISHED;
	67	/*
	68	* For WAIT_SABM connections we will produce an accept
	69	* ready socket here
	70	*/
	71	if (!sock_flag(ax25->sk, SOCK_DEAD))
	72	ax25->sk->sk_state_change(ax25->sk);
	73	bh_unlock_sock(ax25->sk);
	74	}
	75	ax25_dama_on(ax25);
	76
96de0e25	77	/* according to DK4EG's spec we are required to
1da177e4 LT	78	* send a RR RESPONSE FINAL NR=0.
	79	*/
	80
	81	ax25_std_enquiry_response(ax25);
	82	break;
	83
	84	case AX25_DM:
	85	if (pf)
	86	ax25_disconnect(ax25, ECONNREFUSED);
	87	break;
	88
	89	default:
	90	if (pf)
	91	ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
	92	break;
	93	}
	94
	95	return 0;
	96	}
	97
	98	/*
	99	* State machine for state 2, Awaiting Release State.
	100	* The handling of the timer(s) is in file ax25_ds_timer.c
	101	* Handling of state 0 and connection release is in ax25.c.
	102	*/
	103	static int ax25_ds_state2_machine(ax25_cb ax25, struct sk_buff skb, int frametype, int pf, int type)
	104	{
	105	switch (frametype) {
	106	case AX25_SABM:
	107	case AX25_SABME:
	108	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	109	ax25_dama_off(ax25);
	110	break;
	111
	112	case AX25_DISC:
	113	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
	114	ax25_dama_off(ax25);
	115	ax25_disconnect(ax25, 0);
	116	break;
	117
	118	case AX25_DM:
	119	case AX25_UA:
	120	if (pf) {
	121	ax25_dama_off(ax25);
	122	ax25_disconnect(ax25, 0);
	123	}
	124	break;
	125
	126	case AX25_I:
	127	case AX25_REJ:
	128	case AX25_RNR:
	129	case AX25_RR:
	130	if (pf) {
	131	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	132	ax25_dama_off(ax25);
	133	}
	134	break;
	135
	136	default:
	137	break;
	138	}
	139
	140	return 0;
	141	}
142
143	/*
144	* State machine for state 3, Connected State.
145	* The handling of the timer(s) is in file ax25_timer.c
146	* Handling of state 0 and connection release is in ax25.c.
147	*/
148	static int ax25_ds_state3_machine(ax25_cb ax25, struct sk_buff skb, int frametype, int ns, int nr, int pf, int type)
149	{
150	int queued = 0;
151
152	switch (frametype) {
153	case AX25_SABM:
154	case AX25_SABME:
155	if (frametype == AX25_SABM) {
156	ax25->modulus = AX25_MODULUS;
157	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
158	} else {
159	ax25->modulus = AX25_EMODULUS;
160	ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
161	}
162	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
163	ax25_stop_t1timer(ax25);
164	ax25_start_t3timer(ax25);
165	ax25_start_idletimer(ax25);
166	ax25->condition = 0x00;
167	ax25->vs = 0;
168	ax25->va = 0;
169	ax25->vr = 0;
170	ax25_requeue_frames(ax25);
171	ax25_dama_on(ax25);
172	break;
173
174	case AX25_DISC:
175	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
176	ax25_dama_off(ax25);
177	ax25_disconnect(ax25, 0);
178	break;
179
180	case AX25_DM:
181	ax25_dama_off(ax25);
182	ax25_disconnect(ax25, ECONNRESET);
183	break;
184
185	case AX25_RR:
186	case AX25_RNR:
187	if (frametype == AX25_RR)
188	ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
189	else
190	ax25->condition \|= AX25_COND_PEER_RX_BUSY;
191
192	if (ax25_validate_nr(ax25, nr)) {
193	if (ax25_check_iframes_acked(ax25, nr))
194	ax25->n2count=0;
195	if (type == AX25_COMMAND && pf)
196	ax25_ds_enquiry_response(ax25);
197	} else {
198	ax25_ds_nr_error_recovery(ax25);
199	ax25->state = AX25_STATE_1;
200	}
201	break;
202
203	case AX25_REJ:
204	ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
205
206	if (ax25_validate_nr(ax25, nr)) {
207	if (ax25->va != nr)
208	ax25->n2count=0;
209
210	ax25_frames_acked(ax25, nr);
211	ax25_calculate_rtt(ax25);
212	ax25_stop_t1timer(ax25);
213	ax25_start_t3timer(ax25);
214	ax25_requeue_frames(ax25);
215
216	if (type == AX25_COMMAND && pf)
217	ax25_ds_enquiry_response(ax25);
218	} else {
219	ax25_ds_nr_error_recovery(ax25);
220	ax25->state = AX25_STATE_1;
221	}
222	break;
223
224	case AX25_I:
225	if (!ax25_validate_nr(ax25, nr)) {
226	ax25_ds_nr_error_recovery(ax25);
227	ax25->state = AX25_STATE_1;
228	break;
229	}
230	if (ax25->condition & AX25_COND_PEER_RX_BUSY) {
231	ax25_frames_acked(ax25, nr);
232	ax25->n2count = 0;
233	} else {
234	if (ax25_check_iframes_acked(ax25, nr))
235	ax25->n2count = 0;
236	}
237	if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
238	if (pf) ax25_ds_enquiry_response(ax25);
239	break;
240	}
241	if (ns == ax25->vr) {
242	ax25->vr = (ax25->vr + 1) % ax25->modulus;
243	queued = ax25_rx_iframe(ax25, skb);
244	if (ax25->condition & AX25_COND_OWN_RX_BUSY)
245	ax25->vr = ns; /* ax25->vr - 1 */
246	ax25->condition &= ~AX25_COND_REJECT;
247	if (pf) {
248	ax25_ds_enquiry_response(ax25);
249	} else {
250	if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
251	ax25->condition \|= AX25_COND_ACK_PENDING;
252	ax25_start_t2timer(ax25);
253	}
254	}
255	} else {
256	if (ax25->condition & AX25_COND_REJECT) {
257	if (pf) ax25_ds_enquiry_response(ax25);
258	} else {
259	ax25->condition \|= AX25_COND_REJECT;
260	ax25_ds_enquiry_response(ax25);
261	ax25->condition &= ~AX25_COND_ACK_PENDING;
262	}
263	}
264	break;
265
266	case AX25_FRMR:
267	case AX25_ILLEGAL:
268	ax25_ds_establish_data_link(ax25);
269	ax25->state = AX25_STATE_1;
270	break;
271
272	default:
273	break;
274	}
275
276	return queued;
277	}
278
279	/*
280	* Higher level upcall for a LAPB frame
281	*/
282	int ax25_ds_frame_in(ax25_cb ax25, struct sk_buff skb, int type)
283	{
284	int queued = 0, frametype, ns, nr, pf;
285
286	frametype = ax25_decode(ax25, skb, &ns, &nr, &pf);
287
288	switch (ax25->state) {
289	case AX25_STATE_1:
290	queued = ax25_ds_state1_machine(ax25, skb, frametype, pf, type);
291	break;
292	case AX25_STATE_2:
293	queued = ax25_ds_state2_machine(ax25, skb, frametype, pf, type);
294	break;
295	case AX25_STATE_3:
296	queued = ax25_ds_state3_machine(ax25, skb, frametype, ns, nr, pf, type);
297	break;
298	}
299
300	return queued;
301	}
302