[linux.git] / net / rose / rose_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])
 *
 * Most of this code is based on the SDL diagrams published in the 7th ARRL
 * Computer Networking Conference papers. The diagrams have mistakes in them,
 * but are mostly correct. Before you modify the code could you read the SDL
 * diagrams as the code is not obvious and probably very easy to break.
 */
#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/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/rose.h>

/*
 * State machine for state 1, Awaiting Call Accepted State.
 * The handling of the timer(s) is in file rose_timer.c.
 * Handling of state 0 and connection release is in af_rose.c.
 */
static int rose_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	struct rose_sock *rose = rose_sk(sk);

	switch (frametype) {
	case ROSE_CALL_ACCEPTED:
		rose_stop_timer(sk);
		rose_start_idletimer(sk);
		rose->condition = 0x00;
		rose->vs        = 0;
		rose->va        = 0;
		rose->vr        = 0;
		rose->vl        = 0;
		rose->state     = ROSE_STATE_3;
		sk->sk_state	= TCP_ESTABLISHED;
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_state_change(sk);
		break;

	case ROSE_CLEAR_REQUEST:
		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
		rose_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
		rose->neighbour->use--;
		break;

	default:
		break;
	}

	return 0;
}

/*
 * State machine for state 2, Awaiting Clear Confirmation State.
 * The handling of the timer(s) is in file rose_timer.c
 * Handling of state 0 and connection release is in af_rose.c.
 */
static int rose_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	struct rose_sock *rose = rose_sk(sk);

	switch (frametype) {
	case ROSE_CLEAR_REQUEST:
		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
		rose->neighbour->use--;
		break;

	case ROSE_CLEAR_CONFIRMATION:
		rose_disconnect(sk, 0, -1, -1);
		rose->neighbour->use--;
		break;

	default:
		break;
	}

	return 0;
}

/*
 * State machine for state 3, Connected State.
 * The handling of the timer(s) is in file rose_timer.c
 * Handling of state 0 and connection release is in af_rose.c.
 */
static int rose_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
{
	struct rose_sock *rose = rose_sk(sk);
	int queued = 0;

	switch (frametype) {
	case ROSE_RESET_REQUEST:
		rose_stop_timer(sk);
		rose_start_idletimer(sk);
		rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
		rose->condition = 0x00;
		rose->vs        = 0;
		rose->vr        = 0;
		rose->va        = 0;
		rose->vl        = 0;
		rose_requeue_frames(sk);
		break;

	case ROSE_CLEAR_REQUEST:
		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
		rose->neighbour->use--;
		break;

	case ROSE_RR:
	case ROSE_RNR:
		if (!rose_validate_nr(sk, nr)) {
			rose_write_internal(sk, ROSE_RESET_REQUEST);
			rose->condition = 0x00;
			rose->vs        = 0;
			rose->vr        = 0;
			rose->va        = 0;
			rose->vl        = 0;
			rose->state     = ROSE_STATE_4;
			rose_start_t2timer(sk);
			rose_stop_idletimer(sk);
		} else {
			rose_frames_acked(sk, nr);
			if (frametype == ROSE_RNR) {
				rose->condition |= ROSE_COND_PEER_RX_BUSY;
			} else {
				rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
			}
		}
		break;

	case ROSE_DATA:	/* XXX */
		rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
		if (!rose_validate_nr(sk, nr)) {
			rose_write_internal(sk, ROSE_RESET_REQUEST);
			rose->condition = 0x00;
			rose->vs        = 0;
			rose->vr        = 0;
			rose->va        = 0;
			rose->vl        = 0;
			rose->state     = ROSE_STATE_4;
			rose_start_t2timer(sk);
			rose_stop_idletimer(sk);
			break;
		}
		rose_frames_acked(sk, nr);
		if (ns == rose->vr) {
			rose_start_idletimer(sk);
			if (sock_queue_rcv_skb(sk, skb) == 0) {
				rose->vr = (rose->vr + 1) % ROSE_MODULUS;
				queued = 1;
			} else {
				/* Should never happen ! */
				rose_write_internal(sk, ROSE_RESET_REQUEST);
				rose->condition = 0x00;
				rose->vs        = 0;
				rose->vr        = 0;
				rose->va        = 0;
				rose->vl        = 0;
				rose->state     = ROSE_STATE_4;
				rose_start_t2timer(sk);
				rose_stop_idletimer(sk);
				break;
			}
			if (atomic_read(&sk->sk_rmem_alloc) >
			    (sk->sk_rcvbuf / 2))
				rose->condition |= ROSE_COND_OWN_RX_BUSY;
		}
		/*
		 * If the window is full, ack the frame, else start the
		 * acknowledge hold back timer.
		 */
		if (((rose->vl + sysctl_rose_window_size) % ROSE_MODULUS) == rose->vr) {
			rose->condition &= ~ROSE_COND_ACK_PENDING;
			rose_stop_timer(sk);
			rose_enquiry_response(sk);
		} else {
			rose->condition |= ROSE_COND_ACK_PENDING;
			rose_start_hbtimer(sk);
		}
		break;

	default:
		printk(KERN_WARNING "ROSE: unknown %02X in state 3\n", frametype);
		break;
	}

	return queued;
}

/*
 * State machine for state 4, Awaiting Reset Confirmation State.
 * The handling of the timer(s) is in file rose_timer.c
 * Handling of state 0 and connection release is in af_rose.c.
 */
static int rose_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	struct rose_sock *rose = rose_sk(sk);

	switch (frametype) {
	case ROSE_RESET_REQUEST:
		rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
	case ROSE_RESET_CONFIRMATION:
		rose_stop_timer(sk);
		rose_start_idletimer(sk);
		rose->condition = 0x00;
		rose->va        = 0;
		rose->vr        = 0;
		rose->vs        = 0;
		rose->vl        = 0;
		rose->state     = ROSE_STATE_3;
		rose_requeue_frames(sk);
		break;

	case ROSE_CLEAR_REQUEST:
		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
		rose->neighbour->use--;
		break;

	default:
		break;
	}

	return 0;
}

/*
 * State machine for state 5, Awaiting Call Acceptance State.
 * The handling of the timer(s) is in file rose_timer.c
 * Handling of state 0 and connection release is in af_rose.c.
 */
static int rose_state5_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	if (frametype == ROSE_CLEAR_REQUEST) {
		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
		rose_sk(sk)->neighbour->use--;
	}

	return 0;
}

/* Higher level upcall for a LAPB frame */
int rose_process_rx_frame(struct sock *sk, struct sk_buff *skb)
{
	struct rose_sock *rose = rose_sk(sk);
	int queued = 0, frametype, ns, nr, q, d, m;

	if (rose->state == ROSE_STATE_0)
		return 0;

	frametype = rose_decode(skb, &ns, &nr, &q, &d, &m);

	switch (rose->state) {
	case ROSE_STATE_1:
		queued = rose_state1_machine(sk, skb, frametype);
		break;
	case ROSE_STATE_2:
		queued = rose_state2_machine(sk, skb, frametype);
		break;
	case ROSE_STATE_3:
		queued = rose_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
		break;
	case ROSE_STATE_4:
		queued = rose_state4_machine(sk, skb, frametype);
		break;
	case ROSE_STATE_5:
		queued = rose_state5_machine(sk, skb, frametype);
		break;
	}

	rose_kick(sk);

	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	*
	9	* Most of this code is based on the SDL diagrams published in the 7th ARRL
	10	* Computer Networking Conference papers. The diagrams have mistakes in them,
	11	* but are mostly correct. Before you modify the code could you read the SDL
	12	* diagrams as the code is not obvious and probably very easy to break.
	13	*/
	14	#include <linux/errno.h>
	15	#include <linux/types.h>
	16	#include <linux/socket.h>
	17	#include <linux/in.h>
	18	#include <linux/kernel.h>
1da177e4 LT	19	#include <linux/timer.h>
	20	#include <linux/string.h>
	21	#include <linux/sockios.h>
	22	#include <linux/net.h>
	23	#include <net/ax25.h>
	24	#include <linux/inet.h>
	25	#include <linux/netdevice.h>
	26	#include <linux/skbuff.h>
	27	#include <net/sock.h>
c752f073	28	#include <net/tcp_states.h>
1da177e4 LT	29	#include <asm/system.h>
	30	#include <linux/fcntl.h>
	31	#include <linux/mm.h>
	32	#include <linux/interrupt.h>
	33	#include <net/rose.h>
	34
	35	/*
	36	* State machine for state 1, Awaiting Call Accepted State.
	37	* The handling of the timer(s) is in file rose_timer.c.
	38	* Handling of state 0 and connection release is in af_rose.c.
	39	*/
	40	static int rose_state1_machine(struct sock sk, struct sk_buff skb, int frametype)
	41	{
	42	struct rose_sock *rose = rose_sk(sk);
	43
	44	switch (frametype) {
	45	case ROSE_CALL_ACCEPTED:
	46	rose_stop_timer(sk);
	47	rose_start_idletimer(sk);
	48	rose->condition = 0x00;
	49	rose->vs = 0;
	50	rose->va = 0;
	51	rose->vr = 0;
	52	rose->vl = 0;
	53	rose->state = ROSE_STATE_3;
	54	sk->sk_state = TCP_ESTABLISHED;
	55	if (!sock_flag(sk, SOCK_DEAD))
	56	sk->sk_state_change(sk);
	57	break;
	58
	59	case ROSE_CLEAR_REQUEST:
	60	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
	61	rose_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
	62	rose->neighbour->use--;
	63	break;
	64
	65	default:
	66	break;
	67	}
	68
	69	return 0;
	70	}
	71
	72	/*
	73	* State machine for state 2, Awaiting Clear Confirmation State.
	74	* The handling of the timer(s) is in file rose_timer.c
	75	* Handling of state 0 and connection release is in af_rose.c.
	76	*/
	77	static int rose_state2_machine(struct sock sk, struct sk_buff skb, int frametype)
	78	{
	79	struct rose_sock *rose = rose_sk(sk);
	80
	81	switch (frametype) {
	82	case ROSE_CLEAR_REQUEST:
	83	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
	84	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
	85	rose->neighbour->use--;
	86	break;
	87
	88	case ROSE_CLEAR_CONFIRMATION:
	89	rose_disconnect(sk, 0, -1, -1);
	90	rose->neighbour->use--;
	91	break;
	92
93	default:
94	break;
95	}
96
97	return 0;
98	}
99
100	/*
101	* State machine for state 3, Connected State.
102	* The handling of the timer(s) is in file rose_timer.c
103	* Handling of state 0 and connection release is in af_rose.c.
104	*/
105	static int rose_state3_machine(struct sock sk, struct sk_buff skb, int frametype, int ns, int nr, int q, int d, int m)
106	{
107	struct rose_sock *rose = rose_sk(sk);
108	int queued = 0;
109
110	switch (frametype) {
111	case ROSE_RESET_REQUEST:
112	rose_stop_timer(sk);
113	rose_start_idletimer(sk);
114	rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
115	rose->condition = 0x00;
116	rose->vs = 0;
117	rose->vr = 0;
118	rose->va = 0;
119	rose->vl = 0;
120	rose_requeue_frames(sk);
121	break;
122
123	case ROSE_CLEAR_REQUEST:
124	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
125	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
126	rose->neighbour->use--;
127	break;
128
129	case ROSE_RR:
130	case ROSE_RNR:
131	if (!rose_validate_nr(sk, nr)) {
132	rose_write_internal(sk, ROSE_RESET_REQUEST);
133	rose->condition = 0x00;
134	rose->vs = 0;
135	rose->vr = 0;
136	rose->va = 0;
137	rose->vl = 0;
138	rose->state = ROSE_STATE_4;
139	rose_start_t2timer(sk);
140	rose_stop_idletimer(sk);
141	} else {
142	rose_frames_acked(sk, nr);
143	if (frametype == ROSE_RNR) {
144	rose->condition \|= ROSE_COND_PEER_RX_BUSY;
145	} else {
146	rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
147	}
148	}
149	break;
150
151	case ROSE_DATA: /* XXX */
152	rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
153	if (!rose_validate_nr(sk, nr)) {
154	rose_write_internal(sk, ROSE_RESET_REQUEST);
155	rose->condition = 0x00;
156	rose->vs = 0;
157	rose->vr = 0;
158	rose->va = 0;
159	rose->vl = 0;
160	rose->state = ROSE_STATE_4;
161	rose_start_t2timer(sk);
162	rose_stop_idletimer(sk);
163	break;
164	}
165	rose_frames_acked(sk, nr);
166	if (ns == rose->vr) {
167	rose_start_idletimer(sk);
168	if (sock_queue_rcv_skb(sk, skb) == 0) {
169	rose->vr = (rose->vr + 1) % ROSE_MODULUS;
170	queued = 1;
171	} else {
172	/* Should never happen ! */
173	rose_write_internal(sk, ROSE_RESET_REQUEST);
174	rose->condition = 0x00;
175	rose->vs = 0;
176	rose->vr = 0;
177	rose->va = 0;
178	rose->vl = 0;
179	rose->state = ROSE_STATE_4;
180	rose_start_t2timer(sk);
181	rose_stop_idletimer(sk);
182	break;
183	}
184	if (atomic_read(&sk->sk_rmem_alloc) >
185	(sk->sk_rcvbuf / 2))
186	rose->condition \|= ROSE_COND_OWN_RX_BUSY;
187	}
188	/*
189	* If the window is full, ack the frame, else start the
190	* acknowledge hold back timer.
191	*/
192	if (((rose->vl + sysctl_rose_window_size) % ROSE_MODULUS) == rose->vr) {
193	rose->condition &= ~ROSE_COND_ACK_PENDING;
194	rose_stop_timer(sk);
195	rose_enquiry_response(sk);
196	} else {
197	rose->condition \|= ROSE_COND_ACK_PENDING;
198	rose_start_hbtimer(sk);
199	}
200	break;
201
202	default:
203	printk(KERN_WARNING "ROSE: unknown %02X in state 3\n", frametype);
204	break;
205	}
206
207	return queued;
208	}
209
210	/*
211	* State machine for state 4, Awaiting Reset Confirmation State.
212	* The handling of the timer(s) is in file rose_timer.c
213	* Handling of state 0 and connection release is in af_rose.c.
214	*/
215	static int rose_state4_machine(struct sock sk, struct sk_buff skb, int frametype)
216	{
217	struct rose_sock *rose = rose_sk(sk);
218
219	switch (frametype) {
220	case ROSE_RESET_REQUEST:
221	rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
222	case ROSE_RESET_CONFIRMATION:
223	rose_stop_timer(sk);
224	rose_start_idletimer(sk);
225	rose->condition = 0x00;
226	rose->va = 0;
227	rose->vr = 0;
228	rose->vs = 0;
229	rose->vl = 0;
230	rose->state = ROSE_STATE_3;
231	rose_requeue_frames(sk);
232	break;
233
234	case ROSE_CLEAR_REQUEST:
235	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
236	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
237	rose->neighbour->use--;
238	break;
239
240	default:
241	break;
242	}
243
244	return 0;
245	}
246
247	/*
248	* State machine for state 5, Awaiting Call Acceptance State.
249	* The handling of the timer(s) is in file rose_timer.c
250	* Handling of state 0 and connection release is in af_rose.c.
251	*/
252	static int rose_state5_machine(struct sock sk, struct sk_buff skb, int frametype)
253	{
254	if (frametype == ROSE_CLEAR_REQUEST) {
255	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
256	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
257	rose_sk(sk)->neighbour->use--;
258	}
259
260	return 0;
261	}
262
263	/* Higher level upcall for a LAPB frame */
264	int rose_process_rx_frame(struct sock sk, struct sk_buff skb)
265	{
266	struct rose_sock *rose = rose_sk(sk);
267	int queued = 0, frametype, ns, nr, q, d, m;
268
269	if (rose->state == ROSE_STATE_0)
270	return 0;
271
272	frametype = rose_decode(skb, &ns, &nr, &q, &d, &m);
273
274	switch (rose->state) {
275	case ROSE_STATE_1:
276	queued = rose_state1_machine(sk, skb, frametype);
277	break;
278	case ROSE_STATE_2:
279	queued = rose_state2_machine(sk, skb, frametype);
280	break;
281	case ROSE_STATE_3:
282	queued = rose_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
283	break;
284	case ROSE_STATE_4:
285	queued = rose_state4_machine(sk, skb, frametype);
286	break;
287	case ROSE_STATE_5:
288	queued = rose_state5_machine(sk, skb, frametype);
289	break;
290	}
291
292	rose_kick(sk);
293
294	return queued;
295	}