[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/sched.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/ip.h>			/* For ip_rcv */
#include <net/tcp.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>
	19	#include <linux/sched.h>
	20	#include <linux/timer.h>
	21	#include <linux/string.h>
	22	#include <linux/sockios.h>
	23	#include <linux/net.h>
	24	#include <net/ax25.h>
	25	#include <linux/inet.h>
	26	#include <linux/netdevice.h>
	27	#include <linux/skbuff.h>
	28	#include <net/sock.h>
	29	#include <net/ip.h> /* For ip_rcv */
	30	#include <net/tcp.h>
	31	#include <asm/system.h>
	32	#include <linux/fcntl.h>
	33	#include <linux/mm.h>
	34	#include <linux/interrupt.h>
	35	#include <net/rose.h>
	36
	37	/*
	38	* State machine for state 1, Awaiting Call Accepted State.
	39	* The handling of the timer(s) is in file rose_timer.c.
	40	* Handling of state 0 and connection release is in af_rose.c.
	41	*/
	42	static int rose_state1_machine(struct sock sk, struct sk_buff skb, int frametype)
	43	{
	44	struct rose_sock *rose = rose_sk(sk);
	45
	46	switch (frametype) {
	47	case ROSE_CALL_ACCEPTED:
	48	rose_stop_timer(sk);
	49	rose_start_idletimer(sk);
	50	rose->condition = 0x00;
	51	rose->vs = 0;
	52	rose->va = 0;
	53	rose->vr = 0;
	54	rose->vl = 0;
	55	rose->state = ROSE_STATE_3;
	56	sk->sk_state = TCP_ESTABLISHED;
	57	if (!sock_flag(sk, SOCK_DEAD))
	58	sk->sk_state_change(sk);
	59	break;
	60
	61	case ROSE_CLEAR_REQUEST:
	62	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
	63	rose_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
	64	rose->neighbour->use--;
65	break;
66
67	default:
68	break;
69	}
70
71	return 0;
72	}
73
74	/*
75	* State machine for state 2, Awaiting Clear Confirmation State.
76	* The handling of the timer(s) is in file rose_timer.c
77	* Handling of state 0 and connection release is in af_rose.c.
78	*/
79	static int rose_state2_machine(struct sock sk, struct sk_buff skb, int frametype)
80	{
81	struct rose_sock *rose = rose_sk(sk);
82
83	switch (frametype) {
84	case ROSE_CLEAR_REQUEST:
85	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
86	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
87	rose->neighbour->use--;
88	break;
89
90	case ROSE_CLEAR_CONFIRMATION:
91	rose_disconnect(sk, 0, -1, -1);
92	rose->neighbour->use--;
93	break;
94
95	default:
96	break;
97	}
98
99	return 0;
100	}
101
102	/*
103	* State machine for state 3, Connected State.
104	* The handling of the timer(s) is in file rose_timer.c
105	* Handling of state 0 and connection release is in af_rose.c.
106	*/
107	static int rose_state3_machine(struct sock sk, struct sk_buff skb, int frametype, int ns, int nr, int q, int d, int m)
108	{
109	struct rose_sock *rose = rose_sk(sk);
110	int queued = 0;
111
112	switch (frametype) {
113	case ROSE_RESET_REQUEST:
114	rose_stop_timer(sk);
115	rose_start_idletimer(sk);
116	rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
117	rose->condition = 0x00;
118	rose->vs = 0;
119	rose->vr = 0;
120	rose->va = 0;
121	rose->vl = 0;
122	rose_requeue_frames(sk);
123	break;
124
125	case ROSE_CLEAR_REQUEST:
126	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
127	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
128	rose->neighbour->use--;
129	break;
130
131	case ROSE_RR:
132	case ROSE_RNR:
133	if (!rose_validate_nr(sk, nr)) {
134	rose_write_internal(sk, ROSE_RESET_REQUEST);
135	rose->condition = 0x00;
136	rose->vs = 0;
137	rose->vr = 0;
138	rose->va = 0;
139	rose->vl = 0;
140	rose->state = ROSE_STATE_4;
141	rose_start_t2timer(sk);
142	rose_stop_idletimer(sk);
143	} else {
144	rose_frames_acked(sk, nr);
145	if (frametype == ROSE_RNR) {
146	rose->condition \|= ROSE_COND_PEER_RX_BUSY;
147	} else {
148	rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
149	}
150	}
151	break;
152
153	case ROSE_DATA: /* XXX */
154	rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
155	if (!rose_validate_nr(sk, nr)) {
156	rose_write_internal(sk, ROSE_RESET_REQUEST);
157	rose->condition = 0x00;
158	rose->vs = 0;
159	rose->vr = 0;
160	rose->va = 0;
161	rose->vl = 0;
162	rose->state = ROSE_STATE_4;
163	rose_start_t2timer(sk);
164	rose_stop_idletimer(sk);
165	break;
166	}
167	rose_frames_acked(sk, nr);
168	if (ns == rose->vr) {
169	rose_start_idletimer(sk);
170	if (sock_queue_rcv_skb(sk, skb) == 0) {
171	rose->vr = (rose->vr + 1) % ROSE_MODULUS;
172	queued = 1;
173	} else {
174	/* Should never happen ! */
175	rose_write_internal(sk, ROSE_RESET_REQUEST);
176	rose->condition = 0x00;
177	rose->vs = 0;
178	rose->vr = 0;
179	rose->va = 0;
180	rose->vl = 0;
181	rose->state = ROSE_STATE_4;
182	rose_start_t2timer(sk);
183	rose_stop_idletimer(sk);
184	break;
185	}
186	if (atomic_read(&sk->sk_rmem_alloc) >
187	(sk->sk_rcvbuf / 2))
188	rose->condition \|= ROSE_COND_OWN_RX_BUSY;
189	}
190	/*
191	* If the window is full, ack the frame, else start the
192	* acknowledge hold back timer.
193	*/
194	if (((rose->vl + sysctl_rose_window_size) % ROSE_MODULUS) == rose->vr) {
195	rose->condition &= ~ROSE_COND_ACK_PENDING;
196	rose_stop_timer(sk);
197	rose_enquiry_response(sk);
198	} else {
199	rose->condition \|= ROSE_COND_ACK_PENDING;
200	rose_start_hbtimer(sk);
201	}
202	break;
203
204	default:
205	printk(KERN_WARNING "ROSE: unknown %02X in state 3\n", frametype);
206	break;
207	}
208
209	return queued;
210	}
211
212	/*
213	* State machine for state 4, Awaiting Reset Confirmation State.
214	* The handling of the timer(s) is in file rose_timer.c
215	* Handling of state 0 and connection release is in af_rose.c.
216	*/
217	static int rose_state4_machine(struct sock sk, struct sk_buff skb, int frametype)
218	{
219	struct rose_sock *rose = rose_sk(sk);
220
221	switch (frametype) {
222	case ROSE_RESET_REQUEST:
223	rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
224	case ROSE_RESET_CONFIRMATION:
225	rose_stop_timer(sk);
226	rose_start_idletimer(sk);
227	rose->condition = 0x00;
228	rose->va = 0;
229	rose->vr = 0;
230	rose->vs = 0;
231	rose->vl = 0;
232	rose->state = ROSE_STATE_3;
233	rose_requeue_frames(sk);
234	break;
235
236	case ROSE_CLEAR_REQUEST:
237	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
238	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
239	rose->neighbour->use--;
240	break;
241
242	default:
243	break;
244	}
245
246	return 0;
247	}
248
249	/*
250	* State machine for state 5, Awaiting Call Acceptance State.
251	* The handling of the timer(s) is in file rose_timer.c
252	* Handling of state 0 and connection release is in af_rose.c.
253	*/
254	static int rose_state5_machine(struct sock sk, struct sk_buff skb, int frametype)
255	{
256	if (frametype == ROSE_CLEAR_REQUEST) {
257	rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
258	rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
259	rose_sk(sk)->neighbour->use--;
260	}
261
262	return 0;
263	}
264
265	/* Higher level upcall for a LAPB frame */
266	int rose_process_rx_frame(struct sock sk, struct sk_buff skb)
267	{
268	struct rose_sock *rose = rose_sk(sk);
269	int queued = 0, frametype, ns, nr, q, d, m;
270
271	if (rose->state == ROSE_STATE_0)
272	return 0;
273
274	frametype = rose_decode(skb, &ns, &nr, &q, &d, &m);
275
276	switch (rose->state) {
277	case ROSE_STATE_1:
278	queued = rose_state1_machine(sk, skb, frametype);
279	break;
280	case ROSE_STATE_2:
281	queued = rose_state2_machine(sk, skb, frametype);
282	break;
283	case ROSE_STATE_3:
284	queued = rose_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
285	break;
286	case ROSE_STATE_4:
287	queued = rose_state4_machine(sk, skb, frametype);
288	break;
289	case ROSE_STATE_5:
290	queued = rose_state5_machine(sk, skb, frametype);
291	break;
292	}
293
294	rose_kick(sk);
295
296	return queued;
297	}