[linux.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 ([email protected])
 * Copyright Darryl Miles G7LED ([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 <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 <linux/uaccess.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 ([email protected])
	8	* Copyright Darryl Miles G7LED ([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>
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>
dc8e5416	26	#include <linux/uaccess.h>
1da177e4 LT	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
1da177e4 LT	56	while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
1a4e2d09 ACM	57	skb_copy_from_linear_data(skbo,
	58	skb_put(skbn, skbo->len),
	59	skbo->len);
1da177e4 LT	60	kfree_skb(skbo);
	61	}
	62
	63	nr->fraglen = 0;
	64	}
	65
	66	return sock_queue_rcv_skb(sk, skbn);
	67	}
	68
	69	/*
	70	* State machine for state 1, Awaiting Connection State.
	71	* The handling of the timer(s) is in file nr_timer.c.
	72	* Handling of state 0 and connection release is in netrom.c.
	73	*/
	74	static int nr_state1_machine(struct sock sk, struct sk_buff skb,
	75	int frametype)
	76	{
	77	switch (frametype) {
	78	case NR_CONNACK: {
	79	struct nr_sock *nr = nr_sk(sk);
	80
	81	nr_stop_t1timer(sk);
	82	nr_start_idletimer(sk);
	83	nr->your_index = skb->data[17];
	84	nr->your_id = skb->data[18];
	85	nr->vs = 0;
	86	nr->va = 0;
	87	nr->vr = 0;
	88	nr->vl = 0;
	89	nr->state = NR_STATE_3;
	90	nr->n2count = 0;
	91	nr->window = skb->data[20];
	92	sk->sk_state = TCP_ESTABLISHED;
	93	if (!sock_flag(sk, SOCK_DEAD))
	94	sk->sk_state_change(sk);
	95	break;
	96	}
	97
	98	case NR_CONNACK \| NR_CHOKE_FLAG:
	99	nr_disconnect(sk, ECONNREFUSED);
	100	break;
	101
e21ce8c7	102	case NR_RESET:
0d77d59f	103	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	104	nr_disconnect(sk, ECONNRESET);
	105	break;
	106
1da177e4 LT	107	default:
	108	break;
	109	}
	110	return 0;
	111	}
	112
	113	/*
	114	* State machine for state 2, Awaiting Release State.
	115	* The handling of the timer(s) is in file nr_timer.c
	116	* Handling of state 0 and connection release is in netrom.c.
	117	*/
	118	static int nr_state2_machine(struct sock sk, struct sk_buff skb,
	119	int frametype)
	120	{
	121	switch (frametype) {
	122	case NR_CONNACK \| NR_CHOKE_FLAG:
	123	nr_disconnect(sk, ECONNRESET);
	124	break;
	125
	126	case NR_DISCREQ:
	127	nr_write_internal(sk, NR_DISCACK);
	128
	129	case NR_DISCACK:
	130	nr_disconnect(sk, 0);
	131	break;
	132
e21ce8c7	133	case NR_RESET:
0d77d59f	134	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	135	nr_disconnect(sk, ECONNRESET);
	136	break;
	137
1da177e4 LT	138	default:
	139	break;
	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 nr_timer.c
	147	* Handling of state 0 and connection release is in netrom.c.
	148	*/
	149	static int nr_state3_machine(struct sock sk, struct sk_buff skb, int frametype)
	150	{
	151	struct nr_sock *nrom = nr_sk(sk);
	152	struct sk_buff_head temp_queue;
	153	struct sk_buff *skbn;
	154	unsigned short save_vr;
	155	unsigned short nr, ns;
	156	int queued = 0;
	157
	158	nr = skb->data[18];
	159	ns = skb->data[17];
	160
	161	switch (frametype) {
	162	case NR_CONNREQ:
	163	nr_write_internal(sk, NR_CONNACK);
	164	break;
	165
	166	case NR_DISCREQ:
	167	nr_write_internal(sk, NR_DISCACK);
	168	nr_disconnect(sk, 0);
	169	break;
	170
	171	case NR_CONNACK \| NR_CHOKE_FLAG:
	172	case NR_DISCACK:
	173	nr_disconnect(sk, ECONNRESET);
	174	break;
	175
	176	case NR_INFOACK:
	177	case NR_INFOACK \| NR_CHOKE_FLAG:
	178	case NR_INFOACK \| NR_NAK_FLAG:
	179	case NR_INFOACK \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
	180	if (frametype & NR_CHOKE_FLAG) {
	181	nrom->condition \|= NR_COND_PEER_RX_BUSY;
	182	nr_start_t4timer(sk);
	183	} else {
	184	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
	185	nr_stop_t4timer(sk);
	186	}
	187	if (!nr_validate_nr(sk, nr)) {
	188	break;
	189	}
	190	if (frametype & NR_NAK_FLAG) {
	191	nr_frames_acked(sk, nr);
	192	nr_send_nak_frame(sk);
	193	} else {
	194	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
	195	nr_frames_acked(sk, nr);
	196	} else {
	197	nr_check_iframes_acked(sk, nr);
	198	}
	199	}
	200	break;
	201
202	case NR_INFO:
203	case NR_INFO \| NR_NAK_FLAG:
204	case NR_INFO \| NR_CHOKE_FLAG:
205	case NR_INFO \| NR_MORE_FLAG:
206	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
207	case NR_INFO \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
208	case NR_INFO \| NR_NAK_FLAG \| NR_MORE_FLAG:
209	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
210	if (frametype & NR_CHOKE_FLAG) {
211	nrom->condition \|= NR_COND_PEER_RX_BUSY;
212	nr_start_t4timer(sk);
213	} else {
214	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
215	nr_stop_t4timer(sk);
216	}
217	if (nr_validate_nr(sk, nr)) {
218	if (frametype & NR_NAK_FLAG) {
219	nr_frames_acked(sk, nr);
220	nr_send_nak_frame(sk);
221	} else {
222	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
223	nr_frames_acked(sk, nr);
224	} else {
225	nr_check_iframes_acked(sk, nr);
226	}
227	}
228	}
229	queued = 1;
230	skb_queue_head(&nrom->reseq_queue, skb);
231	if (nrom->condition & NR_COND_OWN_RX_BUSY)
232	break;
233	skb_queue_head_init(&temp_queue);
234	do {
235	save_vr = nrom->vr;
236	while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
237	ns = skbn->data[17];
238	if (ns == nrom->vr) {
239	if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
240	nrom->vr = (nrom->vr + 1) % NR_MODULUS;
241	} else {
242	nrom->condition \|= NR_COND_OWN_RX_BUSY;
243	skb_queue_tail(&temp_queue, skbn);
244	}
245	} else if (nr_in_rx_window(sk, ns)) {
246	skb_queue_tail(&temp_queue, skbn);
247	} else {
248	kfree_skb(skbn);
249	}
250	}
251	while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
252	skb_queue_tail(&nrom->reseq_queue, skbn);
253	}
254	} while (save_vr != nrom->vr);
255	/*
256	* Window is full, ack it immediately.
257	*/
258	if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
259	nr_enquiry_response(sk);
260	} else {
261	if (!(nrom->condition & NR_COND_ACK_PENDING)) {
262	nrom->condition \|= NR_COND_ACK_PENDING;
263	nr_start_t2timer(sk);
264	}
265	}
266	break;
267
e21ce8c7	268	case NR_RESET:
0d77d59f	269	if (sysctl_netrom_reset_circuit)
e21ce8c7 RB	270	nr_disconnect(sk, ECONNRESET);
	271	break;
	272
1da177e4 LT	273	default:
	274	break;
	275	}
	276	return queued;
	277	}
	278
	279	/* Higher level upcall for a LAPB frame - called with sk locked */
	280	int nr_process_rx_frame(struct sock sk, struct sk_buff skb)
	281	{
	282	struct nr_sock *nr = nr_sk(sk);
	283	int queued = 0, frametype;
	284
	285	if (nr->state == NR_STATE_0)
	286	return 0;
	287
	288	frametype = skb->data[19];
	289
	290	switch (nr->state) {
	291	case NR_STATE_1:
	292	queued = nr_state1_machine(sk, skb, frametype);
	293	break;
	294	case NR_STATE_2:
	295	queued = nr_state2_machine(sk, skb, frametype);
	296	break;
	297	case NR_STATE_3:
	298	queued = nr_state3_machine(sk, skb, frametype);
	299	break;
	300	}
	301
	302	nr_kick(sk);
	303
	304	return queued;
	305	}