[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 <linux/slab.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) {
			skb_copy_from_linear_data(skbo,
						  skb_put(skbn, skbo->len),
						  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>
5a0e3ad6	19	#include <linux/slab.h>
1da177e4 LT	20	#include <net/ax25.h>
	21	#include <linux/inet.h>
	22	#include <linux/netdevice.h>
	23	#include <linux/skbuff.h>
	24	#include <net/sock.h>
c752f073	25	#include <net/tcp_states.h>
1da177e4 LT	26	#include <asm/uaccess.h>
	27	#include <asm/system.h>
	28	#include <linux/fcntl.h>
	29	#include <linux/mm.h>
	30	#include <linux/interrupt.h>
	31	#include <net/netrom.h>
	32
	33	static int nr_queue_rx_frame(struct sock sk, struct sk_buff skb, int more)
	34	{
	35	struct sk_buff skbo, skbn = skb;
	36	struct nr_sock *nr = nr_sk(sk);
	37
	38	skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
	39
	40	nr_start_idletimer(sk);
	41
	42	if (more) {
	43	nr->fraglen += skb->len;
	44	skb_queue_tail(&nr->frag_queue, skb);
	45	return 0;
	46	}
	47
	48	if (!more && nr->fraglen > 0) { /* End of fragment */
	49	nr->fraglen += skb->len;
	50	skb_queue_tail(&nr->frag_queue, skb);
	51
	52	if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
	53	return 1;
	54
badff6d0	55	skb_reset_transport_header(skbn);
1da177e4 LT	56
1da177e4 LT	57	while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
1a4e2d09 ACM	58	skb_copy_from_linear_data(skbo,
	59	skb_put(skbn, skbo->len),
	60	skbo->len);
1da177e4 LT	61	kfree_skb(skbo);
	62	}
	63
	64	nr->fraglen = 0;
	65	}
	66
	67	return sock_queue_rcv_skb(sk, skbn);
	68	}
	69
	70	/*
	71	* State machine for state 1, Awaiting Connection State.
	72	* The handling of the timer(s) is in file nr_timer.c.
	73	* Handling of state 0 and connection release is in netrom.c.
	74	*/
	75	static int nr_state1_machine(struct sock sk, struct sk_buff skb,
	76	int frametype)
	77	{
	78	switch (frametype) {
	79	case NR_CONNACK: {
	80	struct nr_sock *nr = nr_sk(sk);
	81
	82	nr_stop_t1timer(sk);
	83	nr_start_idletimer(sk);
	84	nr->your_index = skb->data[17];
	85	nr->your_id = skb->data[18];
	86	nr->vs = 0;
	87	nr->va = 0;
	88	nr->vr = 0;
	89	nr->vl = 0;
	90	nr->state = NR_STATE_3;
	91	nr->n2count = 0;
	92	nr->window = skb->data[20];
	93	sk->sk_state = TCP_ESTABLISHED;
	94	if (!sock_flag(sk, SOCK_DEAD))
	95	sk->sk_state_change(sk);
	96	break;
	97	}
	98
	99	case NR_CONNACK \| NR_CHOKE_FLAG:
	100	nr_disconnect(sk, ECONNREFUSED);
	101	break;
	102
e21ce8c7	103	case NR_RESET:
0d77d59f	104	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	105	nr_disconnect(sk, ECONNRESET);
	106	break;
	107
1da177e4 LT	108	default:
	109	break;
	110	}
	111	return 0;
	112	}
	113
	114	/*
	115	* State machine for state 2, Awaiting Release State.
	116	* The handling of the timer(s) is in file nr_timer.c
	117	* Handling of state 0 and connection release is in netrom.c.
	118	*/
	119	static int nr_state2_machine(struct sock sk, struct sk_buff skb,
	120	int frametype)
	121	{
	122	switch (frametype) {
	123	case NR_CONNACK \| NR_CHOKE_FLAG:
	124	nr_disconnect(sk, ECONNRESET);
	125	break;
	126
	127	case NR_DISCREQ:
	128	nr_write_internal(sk, NR_DISCACK);
	129
	130	case NR_DISCACK:
	131	nr_disconnect(sk, 0);
	132	break;
	133
e21ce8c7	134	case NR_RESET:
0d77d59f	135	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	136	nr_disconnect(sk, ECONNRESET);
	137	break;
	138
1da177e4 LT	139	default:
	140	break;
	141	}
	142	return 0;
	143	}
	144
	145	/*
	146	* State machine for state 3, Connected State.
	147	* The handling of the timer(s) is in file nr_timer.c
	148	* Handling of state 0 and connection release is in netrom.c.
	149	*/
	150	static int nr_state3_machine(struct sock sk, struct sk_buff skb, int frametype)
	151	{
	152	struct nr_sock *nrom = nr_sk(sk);
	153	struct sk_buff_head temp_queue;
	154	struct sk_buff *skbn;
	155	unsigned short save_vr;
	156	unsigned short nr, ns;
	157	int queued = 0;
	158
	159	nr = skb->data[18];
	160	ns = skb->data[17];
	161
	162	switch (frametype) {
	163	case NR_CONNREQ:
	164	nr_write_internal(sk, NR_CONNACK);
	165	break;
	166
	167	case NR_DISCREQ:
	168	nr_write_internal(sk, NR_DISCACK);
	169	nr_disconnect(sk, 0);
	170	break;
	171
	172	case NR_CONNACK \| NR_CHOKE_FLAG:
	173	case NR_DISCACK:
	174	nr_disconnect(sk, ECONNRESET);
	175	break;
	176
	177	case NR_INFOACK:
	178	case NR_INFOACK \| NR_CHOKE_FLAG:
	179	case NR_INFOACK \| NR_NAK_FLAG:
	180	case NR_INFOACK \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
	181	if (frametype & NR_CHOKE_FLAG) {
	182	nrom->condition \|= NR_COND_PEER_RX_BUSY;
	183	nr_start_t4timer(sk);
	184	} else {
	185	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
	186	nr_stop_t4timer(sk);
	187	}
	188	if (!nr_validate_nr(sk, nr)) {
	189	break;
	190	}
	191	if (frametype & NR_NAK_FLAG) {
	192	nr_frames_acked(sk, nr);
	193	nr_send_nak_frame(sk);
	194	} else {
	195	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
	196	nr_frames_acked(sk, nr);
	197	} else {
	198	nr_check_iframes_acked(sk, nr);
	199	}
	200	}
	201	break;
	202
203	case NR_INFO:
204	case NR_INFO \| NR_NAK_FLAG:
205	case NR_INFO \| NR_CHOKE_FLAG:
206	case NR_INFO \| NR_MORE_FLAG:
207	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
208	case NR_INFO \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
209	case NR_INFO \| NR_NAK_FLAG \| NR_MORE_FLAG:
210	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
211	if (frametype & NR_CHOKE_FLAG) {
212	nrom->condition \|= NR_COND_PEER_RX_BUSY;
213	nr_start_t4timer(sk);
214	} else {
215	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
216	nr_stop_t4timer(sk);
217	}
218	if (nr_validate_nr(sk, nr)) {
219	if (frametype & NR_NAK_FLAG) {
220	nr_frames_acked(sk, nr);
221	nr_send_nak_frame(sk);
222	} else {
223	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
224	nr_frames_acked(sk, nr);
225	} else {
226	nr_check_iframes_acked(sk, nr);
227	}
228	}
229	}
230	queued = 1;
231	skb_queue_head(&nrom->reseq_queue, skb);
232	if (nrom->condition & NR_COND_OWN_RX_BUSY)
233	break;
234	skb_queue_head_init(&temp_queue);
235	do {
236	save_vr = nrom->vr;
237	while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
238	ns = skbn->data[17];
239	if (ns == nrom->vr) {
240	if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
241	nrom->vr = (nrom->vr + 1) % NR_MODULUS;
242	} else {
243	nrom->condition \|= NR_COND_OWN_RX_BUSY;
244	skb_queue_tail(&temp_queue, skbn);
245	}
246	} else if (nr_in_rx_window(sk, ns)) {
247	skb_queue_tail(&temp_queue, skbn);
248	} else {
249	kfree_skb(skbn);
250	}
251	}
252	while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
253	skb_queue_tail(&nrom->reseq_queue, skbn);
254	}
255	} while (save_vr != nrom->vr);
256	/*
257	* Window is full, ack it immediately.
258	*/
259	if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
260	nr_enquiry_response(sk);
261	} else {
262	if (!(nrom->condition & NR_COND_ACK_PENDING)) {
263	nrom->condition \|= NR_COND_ACK_PENDING;
264	nr_start_t2timer(sk);
265	}
266	}
267	break;
268
e21ce8c7	269	case NR_RESET:
0d77d59f	270	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	271	nr_disconnect(sk, ECONNRESET);
	272	break;
	273
1da177e4 LT	274	default:
	275	break;
	276	}
	277	return queued;
	278	}
	279
	280	/* Higher level upcall for a LAPB frame - called with sk locked */
	281	int nr_process_rx_frame(struct sock sk, struct sk_buff skb)
	282	{
	283	struct nr_sock *nr = nr_sk(sk);
	284	int queued = 0, frametype;
	285
	286	if (nr->state == NR_STATE_0)
	287	return 0;
	288
	289	frametype = skb->data[19];
	290
	291	switch (nr->state) {
	292	case NR_STATE_1:
	293	queued = nr_state1_machine(sk, skb, frametype);
	294	break;
	295	case NR_STATE_2:
	296	queued = nr_state2_machine(sk, skb, frametype);
	297	break;
	298	case NR_STATE_3:
	299	queued = nr_state3_machine(sk, skb, frametype);
	300	break;
	301	}
	302
	303	nr_kick(sk);
	304
	305	return queued;
	306	}