[mirror_ubuntu-bionic-kernel.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/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/tcp.h>
#include <net/ip.h>			/* For ip_rcv */
#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;

		skbn->h.raw = skbn->data;

		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;

	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;

	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;

	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>
	15	#include <linux/sched.h>
	16	#include <linux/timer.h>
	17	#include <linux/string.h>
	18	#include <linux/sockios.h>
	19	#include <linux/net.h>
	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>
	25	#include <net/tcp.h>
	26	#include <net/ip.h> /* For ip_rcv */
	27	#include <asm/uaccess.h>
	28	#include <asm/system.h>
	29	#include <linux/fcntl.h>
	30	#include <linux/mm.h>
	31	#include <linux/interrupt.h>
	32	#include <net/netrom.h>
	33
	34	static int nr_queue_rx_frame(struct sock sk, struct sk_buff skb, int more)
	35	{
	36	struct sk_buff skbo, skbn = skb;
	37	struct nr_sock *nr = nr_sk(sk);
	38
	39	skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
	40
	41	nr_start_idletimer(sk);
	42
	43	if (more) {
	44	nr->fraglen += skb->len;
	45	skb_queue_tail(&nr->frag_queue, skb);
	46	return 0;
	47	}
	48
	49	if (!more && nr->fraglen > 0) { /* End of fragment */
	50	nr->fraglen += skb->len;
	51	skb_queue_tail(&nr->frag_queue, skb);
	52
	53	if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
	54	return 1;
	55
	56	skbn->h.raw = skbn->data;
	57
	58	while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
	59	memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
	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
102	default:
103	break;
104	}
105	return 0;
106	}
107
108	/*
109	* State machine for state 2, Awaiting Release State.
110	* The handling of the timer(s) is in file nr_timer.c
111	* Handling of state 0 and connection release is in netrom.c.
112	*/
113	static int nr_state2_machine(struct sock sk, struct sk_buff skb,
114	int frametype)
115	{
116	switch (frametype) {
117	case NR_CONNACK \| NR_CHOKE_FLAG:
118	nr_disconnect(sk, ECONNRESET);
119	break;
120
121	case NR_DISCREQ:
122	nr_write_internal(sk, NR_DISCACK);
123
124	case NR_DISCACK:
125	nr_disconnect(sk, 0);
126	break;
127
128	default:
129	break;
130	}
131	return 0;
132	}
133
134	/*
135	* State machine for state 3, Connected State.
136	* The handling of the timer(s) is in file nr_timer.c
137	* Handling of state 0 and connection release is in netrom.c.
138	*/
139	static int nr_state3_machine(struct sock sk, struct sk_buff skb, int frametype)
140	{
141	struct nr_sock *nrom = nr_sk(sk);
142	struct sk_buff_head temp_queue;
143	struct sk_buff *skbn;
144	unsigned short save_vr;
145	unsigned short nr, ns;
146	int queued = 0;
147
148	nr = skb->data[18];
149	ns = skb->data[17];
150
151	switch (frametype) {
152	case NR_CONNREQ:
153	nr_write_internal(sk, NR_CONNACK);
154	break;
155
156	case NR_DISCREQ:
157	nr_write_internal(sk, NR_DISCACK);
158	nr_disconnect(sk, 0);
159	break;
160
161	case NR_CONNACK \| NR_CHOKE_FLAG:
162	case NR_DISCACK:
163	nr_disconnect(sk, ECONNRESET);
164	break;
165
166	case NR_INFOACK:
167	case NR_INFOACK \| NR_CHOKE_FLAG:
168	case NR_INFOACK \| NR_NAK_FLAG:
169	case NR_INFOACK \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
170	if (frametype & NR_CHOKE_FLAG) {
171	nrom->condition \|= NR_COND_PEER_RX_BUSY;
172	nr_start_t4timer(sk);
173	} else {
174	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
175	nr_stop_t4timer(sk);
176	}
177	if (!nr_validate_nr(sk, nr)) {
178	break;
179	}
180	if (frametype & NR_NAK_FLAG) {
181	nr_frames_acked(sk, nr);
182	nr_send_nak_frame(sk);
183	} else {
184	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
185	nr_frames_acked(sk, nr);
186	} else {
187	nr_check_iframes_acked(sk, nr);
188	}
189	}
190	break;
191
192	case NR_INFO:
193	case NR_INFO \| NR_NAK_FLAG:
194	case NR_INFO \| NR_CHOKE_FLAG:
195	case NR_INFO \| NR_MORE_FLAG:
196	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG:
197	case NR_INFO \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
198	case NR_INFO \| NR_NAK_FLAG \| NR_MORE_FLAG:
199	case NR_INFO \| NR_NAK_FLAG \| NR_CHOKE_FLAG \| NR_MORE_FLAG:
200	if (frametype & NR_CHOKE_FLAG) {
201	nrom->condition \|= NR_COND_PEER_RX_BUSY;
202	nr_start_t4timer(sk);
203	} else {
204	nrom->condition &= ~NR_COND_PEER_RX_BUSY;
205	nr_stop_t4timer(sk);
206	}
207	if (nr_validate_nr(sk, nr)) {
208	if (frametype & NR_NAK_FLAG) {
209	nr_frames_acked(sk, nr);
210	nr_send_nak_frame(sk);
211	} else {
212	if (nrom->condition & NR_COND_PEER_RX_BUSY) {
213	nr_frames_acked(sk, nr);
214	} else {
215	nr_check_iframes_acked(sk, nr);
216	}
217	}
218	}
219	queued = 1;
220	skb_queue_head(&nrom->reseq_queue, skb);
221	if (nrom->condition & NR_COND_OWN_RX_BUSY)
222	break;
223	skb_queue_head_init(&temp_queue);
224	do {
225	save_vr = nrom->vr;
226	while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
227	ns = skbn->data[17];
228	if (ns == nrom->vr) {
229	if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
230	nrom->vr = (nrom->vr + 1) % NR_MODULUS;
231	} else {
232	nrom->condition \|= NR_COND_OWN_RX_BUSY;
233	skb_queue_tail(&temp_queue, skbn);
234	}
235	} else if (nr_in_rx_window(sk, ns)) {
236	skb_queue_tail(&temp_queue, skbn);
237	} else {
238	kfree_skb(skbn);
239	}
240	}
241	while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
242	skb_queue_tail(&nrom->reseq_queue, skbn);
243	}
244	} while (save_vr != nrom->vr);
245	/*
246	* Window is full, ack it immediately.
247	*/
248	if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
249	nr_enquiry_response(sk);
250	} else {
251	if (!(nrom->condition & NR_COND_ACK_PENDING)) {
252	nrom->condition \|= NR_COND_ACK_PENDING;
253	nr_start_t2timer(sk);
254	}
255	}
256	break;
257
258	default:
259	break;
260	}
261	return queued;
262	}
263
264	/* Higher level upcall for a LAPB frame - called with sk locked */
265	int nr_process_rx_frame(struct sock sk, struct sk_buff skb)
266	{
267	struct nr_sock *nr = nr_sk(sk);
268	int queued = 0, frametype;
269
270	if (nr->state == NR_STATE_0)
271	return 0;
272
273	frametype = skb->data[19];
274
275	switch (nr->state) {
276	case NR_STATE_1:
277	queued = nr_state1_machine(sk, skb, frametype);
278	break;
279	case NR_STATE_2:
280	queued = nr_state2_machine(sk, skb, frametype);
281	break;
282	case NR_STATE_3:
283	queued = nr_state3_machine(sk, skb, frametype);
284	break;
285	}
286
287	nr_kick(sk);
288
289	return queued;
290	}