[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 <asm/system.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 LT	25	#include <asm/uaccess.h>
	26	#include <asm/system.h>
	27	#include <linux/fcntl.h>
	28	#include <linux/mm.h>
	29	#include <linux/interrupt.h>
	30
	31	/*
	32	* State machine for state 1, Awaiting Connection State.
	33	* The handling of the timer(s) is in file ax25_ds_timer.c.
	34	* Handling of state 0 and connection release is in ax25.c.
	35	*/
	36	static int ax25_ds_state1_machine(ax25_cb ax25, struct sk_buff skb, int frametype, int pf, int type)
	37	{
	38	switch (frametype) {
	39	case AX25_SABM:
	40	ax25->modulus = AX25_MODULUS;
	41	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
	42	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
	43	break;
	44
	45	case AX25_SABME:
	46	ax25->modulus = AX25_EMODULUS;
	47	ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
	48	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
	49	break;
	50
	51	case AX25_DISC:
	52	ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
	53	break;
	54
	55	case AX25_UA:
	56	ax25_calculate_rtt(ax25);
	57	ax25_stop_t1timer(ax25);
	58	ax25_start_t3timer(ax25);
	59	ax25_start_idletimer(ax25);
	60	ax25->vs = 0;
	61	ax25->va = 0;
	62	ax25->vr = 0;
	63	ax25->state = AX25_STATE_3;
	64	ax25->n2count = 0;
	65	if (ax25->sk != NULL) {
	66	bh_lock_sock(ax25->sk);
	67	ax25->sk->sk_state = TCP_ESTABLISHED;
	68	/*
	69	* For WAIT_SABM connections we will produce an accept
	70	* ready socket here
	71	*/
	72	if (!sock_flag(ax25->sk, SOCK_DEAD))
	73	ax25->sk->sk_state_change(ax25->sk);
	74	bh_unlock_sock(ax25->sk);
	75	}
	76	ax25_dama_on(ax25);
	77
96de0e25	78	/* according to DK4EG's spec we are required to
1da177e4 LT	79	* send a RR RESPONSE FINAL NR=0.
	80	*/
	81
	82	ax25_std_enquiry_response(ax25);
	83	break;
	84
	85	case AX25_DM:
	86	if (pf)
	87	ax25_disconnect(ax25, ECONNREFUSED);
	88	break;
	89
	90	default:
	91	if (pf)
	92	ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
	93	break;
	94	}
	95
	96	return 0;
	97	}
	98
	99	/*
	100	* State machine for state 2, Awaiting Release State.
	101	* The handling of the timer(s) is in file ax25_ds_timer.c
	102	* Handling of state 0 and connection release is in ax25.c.
	103	*/
	104	static int ax25_ds_state2_machine(ax25_cb ax25, struct sk_buff skb, int frametype, int pf, int type)
	105	{
	106	switch (frametype) {
	107	case AX25_SABM:
	108	case AX25_SABME:
	109	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	110	ax25_dama_off(ax25);
	111	break;
	112
	113	case AX25_DISC:
	114	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
	115	ax25_dama_off(ax25);
	116	ax25_disconnect(ax25, 0);
	117	break;
	118
	119	case AX25_DM:
	120	case AX25_UA:
	121	if (pf) {
	122	ax25_dama_off(ax25);
	123	ax25_disconnect(ax25, 0);
	124	}
	125	break;
	126
	127	case AX25_I:
	128	case AX25_REJ:
	129	case AX25_RNR:
	130	case AX25_RR:
	131	if (pf) {
	132	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	133	ax25_dama_off(ax25);
	134	}
	135	break;
	136
	137	default:
	138	break;
	139	}
	140
	141	return 0;
	142	}
143
144	/*
145	* State machine for state 3, Connected State.
146	* The handling of the timer(s) is in file ax25_timer.c
147	* Handling of state 0 and connection release is in ax25.c.
148	*/
149	static int ax25_ds_state3_machine(ax25_cb ax25, struct sk_buff skb, int frametype, int ns, int nr, int pf, int type)
150	{
151	int queued = 0;
152
153	switch (frametype) {
154	case AX25_SABM:
155	case AX25_SABME:
156	if (frametype == AX25_SABM) {
157	ax25->modulus = AX25_MODULUS;
158	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
159	} else {
160	ax25->modulus = AX25_EMODULUS;
161	ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
162	}
163	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
164	ax25_stop_t1timer(ax25);
165	ax25_start_t3timer(ax25);
166	ax25_start_idletimer(ax25);
167	ax25->condition = 0x00;
168	ax25->vs = 0;
169	ax25->va = 0;
170	ax25->vr = 0;
171	ax25_requeue_frames(ax25);
172	ax25_dama_on(ax25);
173	break;
174
175	case AX25_DISC:
176	ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
177	ax25_dama_off(ax25);
178	ax25_disconnect(ax25, 0);
179	break;
180
181	case AX25_DM:
182	ax25_dama_off(ax25);
183	ax25_disconnect(ax25, ECONNRESET);
184	break;
185
186	case AX25_RR:
187	case AX25_RNR:
188	if (frametype == AX25_RR)
189	ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
190	else
191	ax25->condition \|= AX25_COND_PEER_RX_BUSY;
192
193	if (ax25_validate_nr(ax25, nr)) {
194	if (ax25_check_iframes_acked(ax25, nr))
195	ax25->n2count=0;
196	if (type == AX25_COMMAND && pf)
197	ax25_ds_enquiry_response(ax25);
198	} else {
199	ax25_ds_nr_error_recovery(ax25);
200	ax25->state = AX25_STATE_1;
201	}
202	break;
203
204	case AX25_REJ:
205	ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
206
207	if (ax25_validate_nr(ax25, nr)) {
208	if (ax25->va != nr)
209	ax25->n2count=0;
210
211	ax25_frames_acked(ax25, nr);
212	ax25_calculate_rtt(ax25);
213	ax25_stop_t1timer(ax25);
214	ax25_start_t3timer(ax25);
215	ax25_requeue_frames(ax25);
216
217	if (type == AX25_COMMAND && pf)
218	ax25_ds_enquiry_response(ax25);
219	} else {
220	ax25_ds_nr_error_recovery(ax25);
221	ax25->state = AX25_STATE_1;
222	}
223	break;
224
225	case AX25_I:
226	if (!ax25_validate_nr(ax25, nr)) {
227	ax25_ds_nr_error_recovery(ax25);
228	ax25->state = AX25_STATE_1;
229	break;
230	}
231	if (ax25->condition & AX25_COND_PEER_RX_BUSY) {
232	ax25_frames_acked(ax25, nr);
233	ax25->n2count = 0;
234	} else {
235	if (ax25_check_iframes_acked(ax25, nr))
236	ax25->n2count = 0;
237	}
238	if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
239	if (pf) ax25_ds_enquiry_response(ax25);
240	break;
241	}
242	if (ns == ax25->vr) {
243	ax25->vr = (ax25->vr + 1) % ax25->modulus;
244	queued = ax25_rx_iframe(ax25, skb);
245	if (ax25->condition & AX25_COND_OWN_RX_BUSY)
246	ax25->vr = ns; /* ax25->vr - 1 */
247	ax25->condition &= ~AX25_COND_REJECT;
248	if (pf) {
249	ax25_ds_enquiry_response(ax25);
250	} else {
251	if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
252	ax25->condition \|= AX25_COND_ACK_PENDING;
253	ax25_start_t2timer(ax25);
254	}
255	}
256	} else {
257	if (ax25->condition & AX25_COND_REJECT) {
258	if (pf) ax25_ds_enquiry_response(ax25);
259	} else {
260	ax25->condition \|= AX25_COND_REJECT;
261	ax25_ds_enquiry_response(ax25);
262	ax25->condition &= ~AX25_COND_ACK_PENDING;
263	}
264	}
265	break;
266
267	case AX25_FRMR:
268	case AX25_ILLEGAL:
269	ax25_ds_establish_data_link(ax25);
270	ax25->state = AX25_STATE_1;
271	break;
272
273	default:
274	break;
275	}
276
277	return queued;
278	}
279
280	/*
281	* Higher level upcall for a LAPB frame
282	*/
283	int ax25_ds_frame_in(ax25_cb ax25, struct sk_buff skb, int type)
284	{
285	int queued = 0, frametype, ns, nr, pf;
286
287	frametype = ax25_decode(ax25, skb, &ns, &nr, &pf);
288
289	switch (ax25->state) {
290	case AX25_STATE_1:
291	queued = ax25_ds_state1_machine(ax25, skb, frametype, pf, type);
292	break;
293	case AX25_STATE_2:
294	queued = ax25_ds_state2_machine(ax25, skb, frametype, pf, type);
295	break;
296	case AX25_STATE_3:
297	queued = ax25_ds_state3_machine(ax25, skb, frametype, ns, nr, pf, type);
298	break;
299	}
300
301	return queued;
302	}
303