[net-next-2.6.git] / net / netrom / nr_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 Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 * Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
 */
#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>
#include <net/netrom.h>

static int nr_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
{
	struct sk_buff *skbo, *skbn = skb;
	struct nr_sock *nr = nr_sk(sk);

	skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);

	nr_start_idletimer(sk);

	if (more) {
		nr->fraglen += skb->len;
		skb_queue_tail(&nr->frag_queue, skb);
		return 0;
	}

	if (!more && nr->fraglen > 0) {	/* End of fragment */
		nr->fraglen += skb->len;
		skb_queue_tail(&nr->frag_queue, skb);

		if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
			return 1;

		skb_reset_transport_header(skbn);

		while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
			memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
			kfree_skb(skbo);
		}

		nr->fraglen = 0;
	}

	return sock_queue_rcv_skb(sk, skbn);
}

/*
 * State machine for state 1, Awaiting Connection State.
 * The handling of the timer(s) is in file nr_timer.c.
 * Handling of state 0 and connection release is in netrom.c.
 */
static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
	int frametype)
{
	switch (frametype) {
	case NR_CONNACK: {
		struct nr_sock *nr = nr_sk(sk);

		nr_stop_t1timer(sk);
		nr_start_idletimer(sk);
		nr->your_index = skb->data[17];
		nr->your_id    = skb->data[18];
		nr->vs	       = 0;
		nr->va	       = 0;
		nr->vr	       = 0;
		nr->vl	       = 0;
		nr->state      = NR_STATE_3;
		nr->n2count    = 0;
		nr->window     = skb->data[20];
		sk->sk_state   = TCP_ESTABLISHED;
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_state_change(sk);
		break;
	}

	case NR_CONNACK | NR_CHOKE_FLAG:
		nr_disconnect(sk, ECONNREFUSED);
		break;

	case NR_RESET:
		if (sysctl_netrom_reset_circuit)
			nr_disconnect(sk, ECONNRESET);
		break;

	default:
		break;
	}
	return 0;
}

/*
 * State machine for state 2, Awaiting Release State.
 * The handling of the timer(s) is in file nr_timer.c
 * Handling of state 0 and connection release is in netrom.c.
 */
static int nr_state2_machine(struct sock *sk, struct sk_buff *skb,
	int frametype)
{
	switch (frametype) {
	case NR_CONNACK | NR_CHOKE_FLAG:
		nr_disconnect(sk, ECONNRESET);
		break;

	case NR_DISCREQ:
		nr_write_internal(sk, NR_DISCACK);

	case NR_DISCACK:
		nr_disconnect(sk, 0);
		break;

	case NR_RESET:
		if (sysctl_netrom_reset_circuit)
			nr_disconnect(sk, ECONNRESET);
		break;

	default:
		break;
	}
	return 0;
}

/*
 * State machine for state 3, Connected State.
 * The handling of the timer(s) is in file nr_timer.c
 * Handling of state 0 and connection release is in netrom.c.
 */
static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
	struct nr_sock *nrom = nr_sk(sk);
	struct sk_buff_head temp_queue;
	struct sk_buff *skbn;
	unsigned short save_vr;
	unsigned short nr, ns;
	int queued = 0;

	nr = skb->data[18];
	ns = skb->data[17];

	switch (frametype) {
	case NR_CONNREQ:
		nr_write_internal(sk, NR_CONNACK);
		break;

	case NR_DISCREQ:
		nr_write_internal(sk, NR_DISCACK);
		nr_disconnect(sk, 0);
		break;

	case NR_CONNACK | NR_CHOKE_FLAG:
	case NR_DISCACK:
		nr_disconnect(sk, ECONNRESET);
		break;

	case NR_INFOACK:
	case NR_INFOACK | NR_CHOKE_FLAG:
	case NR_INFOACK | NR_NAK_FLAG:
	case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG:
		if (frametype & NR_CHOKE_FLAG) {
			nrom->condition |= NR_COND_PEER_RX_BUSY;
			nr_start_t4timer(sk);
		} else {
			nrom->condition &= ~NR_COND_PEER_RX_BUSY;
			nr_stop_t4timer(sk);
		}
		if (!nr_validate_nr(sk, nr)) {
			break;
		}
		if (frametype & NR_NAK_FLAG) {
			nr_frames_acked(sk, nr);
			nr_send_nak_frame(sk);
		} else {
			if (nrom->condition & NR_COND_PEER_RX_BUSY) {
				nr_frames_acked(sk, nr);
			} else {
				nr_check_iframes_acked(sk, nr);
			}
		}
		break;

	case NR_INFO:
	case NR_INFO | NR_NAK_FLAG:
	case NR_INFO | NR_CHOKE_FLAG:
	case NR_INFO | NR_MORE_FLAG:
	case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG:
	case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG:
	case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG:
	case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG:
		if (frametype & NR_CHOKE_FLAG) {
			nrom->condition |= NR_COND_PEER_RX_BUSY;
			nr_start_t4timer(sk);
		} else {
			nrom->condition &= ~NR_COND_PEER_RX_BUSY;
			nr_stop_t4timer(sk);
		}
		if (nr_validate_nr(sk, nr)) {
			if (frametype & NR_NAK_FLAG) {
				nr_frames_acked(sk, nr);
				nr_send_nak_frame(sk);
			} else {
				if (nrom->condition & NR_COND_PEER_RX_BUSY) {
					nr_frames_acked(sk, nr);
				} else {
					nr_check_iframes_acked(sk, nr);
				}
			}
		}
		queued = 1;
		skb_queue_head(&nrom->reseq_queue, skb);
		if (nrom->condition & NR_COND_OWN_RX_BUSY)
			break;
		skb_queue_head_init(&temp_queue);
		do {
			save_vr = nrom->vr;
			while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
				ns = skbn->data[17];
				if (ns == nrom->vr) {
					if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
						nrom->vr = (nrom->vr + 1) % NR_MODULUS;
					} else {
						nrom->condition |= NR_COND_OWN_RX_BUSY;
						skb_queue_tail(&temp_queue, skbn);
					}
				} else if (nr_in_rx_window(sk, ns)) {
					skb_queue_tail(&temp_queue, skbn);
				} else {
					kfree_skb(skbn);
				}
			}
			while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
				skb_queue_tail(&nrom->reseq_queue, skbn);
			}
		} while (save_vr != nrom->vr);
		/*
		 * Window is full, ack it immediately.
		 */
		if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
			nr_enquiry_response(sk);
		} else {
			if (!(nrom->condition & NR_COND_ACK_PENDING)) {
				nrom->condition |= NR_COND_ACK_PENDING;
				nr_start_t2timer(sk);
			}
		}
		break;

	case NR_RESET:
		if (sysctl_netrom_reset_circuit)
			nr_disconnect(sk, ECONNRESET);
		break;

	default:
		break;
	}
	return queued;
}

/* Higher level upcall for a LAPB frame - called with sk locked */
int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb)
{
	struct nr_sock *nr = nr_sk(sk);
	int queued = 0, frametype;

	if (nr->state == NR_STATE_0)
		return 0;

	frametype = skb->data[19];

	switch (nr->state) {
	case NR_STATE_1:
		queued = nr_state1_machine(sk, skb, frametype);
		break;
	case NR_STATE_2:
		queued = nr_state2_machine(sk, skb, frametype);
		break;
	case NR_STATE_3:
		queued = nr_state3_machine(sk, skb, frametype);
		break;
	}

	nr_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 Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
	8	* Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
	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	#include <net/netrom.h>
	31
	32	static int nr_queue_rx_frame(struct sock sk, struct sk_buff skb, int more)
	33	{
	34	struct sk_buff skbo, skbn = skb;
	35	struct nr_sock *nr = nr_sk(sk);
	36
	37	skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
	38
	39	nr_start_idletimer(sk);
	40
	41	if (more) {
	42	nr->fraglen += skb->len;
	43	skb_queue_tail(&nr->frag_queue, skb);
	44	return 0;
	45	}
	46
	47	if (!more && nr->fraglen > 0) { /* End of fragment */
	48	nr->fraglen += skb->len;
	49	skb_queue_tail(&nr->frag_queue, skb);
	50
	51	if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
	52	return 1;
	53
badff6d0	54	skb_reset_transport_header(skbn);
1da177e4 LT	55
	56	while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
	57	memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
	58	kfree_skb(skbo);
	59	}
	60
	61	nr->fraglen = 0;
	62	}
	63
	64	return sock_queue_rcv_skb(sk, skbn);
	65	}
	66
	67	/*
	68	* State machine for state 1, Awaiting Connection State.
	69	* The handling of the timer(s) is in file nr_timer.c.
	70	* Handling of state 0 and connection release is in netrom.c.
	71	*/
	72	static int nr_state1_machine(struct sock sk, struct sk_buff skb,
	73	int frametype)
	74	{
	75	switch (frametype) {
	76	case NR_CONNACK: {
	77	struct nr_sock *nr = nr_sk(sk);
	78
	79	nr_stop_t1timer(sk);
	80	nr_start_idletimer(sk);
	81	nr->your_index = skb->data[17];
	82	nr->your_id = skb->data[18];
	83	nr->vs = 0;
	84	nr->va = 0;
	85	nr->vr = 0;
	86	nr->vl = 0;
	87	nr->state = NR_STATE_3;
	88	nr->n2count = 0;
	89	nr->window = skb->data[20];
	90	sk->sk_state = TCP_ESTABLISHED;
	91	if (!sock_flag(sk, SOCK_DEAD))
	92	sk->sk_state_change(sk);
	93	break;
	94	}
	95
	96	case NR_CONNACK \| NR_CHOKE_FLAG:
	97	nr_disconnect(sk, ECONNREFUSED);
	98	break;
	99
e21ce8c7	100	case NR_RESET:
0d77d59f	101	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	102	nr_disconnect(sk, ECONNRESET);
	103	break;
	104
1da177e4 LT	105	default:
	106	break;
	107	}
	108	return 0;
	109	}
	110
	111	/*
	112	* State machine for state 2, Awaiting Release State.
	113	* The handling of the timer(s) is in file nr_timer.c
	114	* Handling of state 0 and connection release is in netrom.c.
	115	*/
	116	static int nr_state2_machine(struct sock sk, struct sk_buff skb,
	117	int frametype)
	118	{
	119	switch (frametype) {
	120	case NR_CONNACK \| NR_CHOKE_FLAG:
	121	nr_disconnect(sk, ECONNRESET);
	122	break;
	123
	124	case NR_DISCREQ:
	125	nr_write_internal(sk, NR_DISCACK);
	126
	127	case NR_DISCACK:
	128	nr_disconnect(sk, 0);
	129	break;
	130
e21ce8c7	131	case NR_RESET:
0d77d59f	132	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	133	nr_disconnect(sk, ECONNRESET);
	134	break;
	135
1da177e4 LT	136	default:
	137	break;
	138	}
	139	return 0;
	140	}
	141
	142	/*
	143	* State machine for state 3, Connected State.
	144	* The handling of the timer(s) is in file nr_timer.c
	145	* Handling of state 0 and connection release is in netrom.c.
	146	*/
	147	static int nr_state3_machine(struct sock sk, struct sk_buff skb, int frametype)
	148	{
	149	struct nr_sock *nrom = nr_sk(sk);
	150	struct sk_buff_head temp_queue;
	151	struct sk_buff *skbn;
	152	unsigned short save_vr;
	153	unsigned short nr, ns;
	154	int queued = 0;
	155
	156	nr = skb->data[18];
	157	ns = skb->data[17];
	158
	159	switch (frametype) {
	160	case NR_CONNREQ:
	161	nr_write_internal(sk, NR_CONNACK);
	162	break;
	163
	164	case NR_DISCREQ:
	165	nr_write_internal(sk, NR_DISCACK);
	166	nr_disconnect(sk, 0);
	167	break;
	168
	169	case NR_CONNACK \| NR_CHOKE_FLAG:
	170	case NR_DISCACK:
	171	nr_disconnect(sk, ECONNRESET);
	172	break;
	173
	174	case NR_INFOACK:
	175	case NR_INFOACK \| NR_CHOKE_FLAG:
	176	case NR_INFOACK \| NR_NAK_FLAG:
	177	case NR_INFOACK \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
	178	if (frametype & NR_CHOKE_FLAG) {
	179	nrom->condition \|= NR_COND_PEER_RX_BUSY;
	180	nr_start_t4timer(sk);
	181	} else {
	182	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
	183	nr_stop_t4timer(sk);
	184	}
	185	if (!nr_validate_nr(sk, nr)) {
	186	break;
	187	}
	188	if (frametype & NR_NAK_FLAG) {
	189	nr_frames_acked(sk, nr);
	190	nr_send_nak_frame(sk);
	191	} else {
	192	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
	193	nr_frames_acked(sk, nr);
	194	} else {
	195	nr_check_iframes_acked(sk, nr);
	196	}
	197	}
	198	break;
	199
200	case NR_INFO:
201	case NR_INFO \| NR_NAK_FLAG:
202	case NR_INFO \| NR_CHOKE_FLAG:
203	case NR_INFO \| NR_MORE_FLAG:
204	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
205	case NR_INFO \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
206	case NR_INFO \| NR_NAK_FLAG \| NR_MORE_FLAG:
207	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
208	if (frametype & NR_CHOKE_FLAG) {
209	nrom->condition \|= NR_COND_PEER_RX_BUSY;
210	nr_start_t4timer(sk);
211	} else {
212	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
213	nr_stop_t4timer(sk);
214	}
215	if (nr_validate_nr(sk, nr)) {
216	if (frametype & NR_NAK_FLAG) {
217	nr_frames_acked(sk, nr);
218	nr_send_nak_frame(sk);
219	} else {
220	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
221	nr_frames_acked(sk, nr);
222	} else {
223	nr_check_iframes_acked(sk, nr);
224	}
225	}
226	}
227	queued = 1;
228	skb_queue_head(&nrom->reseq_queue, skb);
229	if (nrom->condition & NR_COND_OWN_RX_BUSY)
230	break;
231	skb_queue_head_init(&temp_queue);
232	do {
233	save_vr = nrom->vr;
234	while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
235	ns = skbn->data[17];
236	if (ns == nrom->vr) {
237	if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
238	nrom->vr = (nrom->vr + 1) % NR_MODULUS;
239	} else {
240	nrom->condition \|= NR_COND_OWN_RX_BUSY;
241	skb_queue_tail(&temp_queue, skbn);
242	}
243	} else if (nr_in_rx_window(sk, ns)) {
244	skb_queue_tail(&temp_queue, skbn);
245	} else {
246	kfree_skb(skbn);
247	}
248	}
249	while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
250	skb_queue_tail(&nrom->reseq_queue, skbn);
251	}
252	} while (save_vr != nrom->vr);
253	/*
254	* Window is full, ack it immediately.
255	*/
256	if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
257	nr_enquiry_response(sk);
258	} else {
259	if (!(nrom->condition & NR_COND_ACK_PENDING)) {
260	nrom->condition \|= NR_COND_ACK_PENDING;
261	nr_start_t2timer(sk);
262	}
263	}
264	break;
265
e21ce8c7	266	case NR_RESET:
0d77d59f	267	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	268	nr_disconnect(sk, ECONNRESET);
	269	break;
	270
1da177e4 LT	271	default:
	272	break;
	273	}
	274	return queued;
	275	}
	276
	277	/* Higher level upcall for a LAPB frame - called with sk locked */
	278	int nr_process_rx_frame(struct sock sk, struct sk_buff skb)
	279	{
	280	struct nr_sock *nr = nr_sk(sk);
	281	int queued = 0, frametype;
	282
	283	if (nr->state == NR_STATE_0)
	284	return 0;
	285
	286	frametype = skb->data[19];
	287
	288	switch (nr->state) {
	289	case NR_STATE_1:
	290	queued = nr_state1_machine(sk, skb, frametype);
	291	break;
	292	case NR_STATE_2:
	293	queued = nr_state2_machine(sk, skb, frametype);
	294	break;
	295	case NR_STATE_3:
	296	queued = nr_state3_machine(sk, skb, frametype);
	297	break;
	298	}
	299
	300	nr_kick(sk);
	301
	302	return queued;
	303	}