Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 029c8bb90f4c3dd470c56e5c29ebcfc05afb7b4d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
/*
 * 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)
 */
#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>

/*
 *	This routine purges all of the queues of frames.
 */
void nr_clear_queues(struct sock *sk)
{
	struct nr_sock *nr = nr_sk(sk);

	skb_queue_purge(&sk->sk_write_queue);
	skb_queue_purge(&nr->ack_queue);
	skb_queue_purge(&nr->reseq_queue);
	skb_queue_purge(&nr->frag_queue);
}

/*
 * This routine purges the input queue of those frames that have been
 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
 * SDL diagram.
 */
void nr_frames_acked(struct sock *sk, unsigned short nr)
{
	struct nr_sock *nrom = nr_sk(sk);
	struct sk_buff *skb;

	/*
	 * Remove all the ack-ed frames from the ack queue.
	 */
	if (nrom->va != nr) {
		while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
			skb = skb_dequeue(&nrom->ack_queue);
			kfree_skb(skb);
			nrom->va = (nrom->va + 1) % NR_MODULUS;
		}
	}
}

/*
 * Requeue all the un-ack-ed frames on the output queue to be picked
 * up by nr_kick called from the timer. This arrangement handles the
 * possibility of an empty output queue.
 */
void nr_requeue_frames(struct sock *sk)
{
	struct sk_buff *skb, *skb_prev = NULL;

	while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
		if (skb_prev == NULL)
			skb_queue_head(&sk->sk_write_queue, skb);
		else
			skb_append(skb_prev, skb, &sk->sk_write_queue);
		skb_prev = skb;
	}
}

/*
 *	Validate that the value of nr is between va and vs. Return true or
 *	false for testing.
 */
int nr_validate_nr(struct sock *sk, unsigned short nr)
{
	struct nr_sock *nrom = nr_sk(sk);
	unsigned short vc = nrom->va;

	while (vc != nrom->vs) {
		if (nr == vc) return 1;
		vc = (vc + 1) % NR_MODULUS;
	}

	return nr == nrom->vs;
}

/*
 *	Check that ns is within the receive window.
 */
int nr_in_rx_window(struct sock *sk, unsigned short ns)
{
	struct nr_sock *nr = nr_sk(sk);
	unsigned short vc = nr->vr;
	unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;

	while (vc != vt) {
		if (ns == vc) return 1;
		vc = (vc + 1) % NR_MODULUS;
	}

	return 0;
}

/*
 *  This routine is called when the HDLC layer internally generates a
 *  control frame.
 */
void nr_write_internal(struct sock *sk, int frametype)
{
	struct nr_sock *nr = nr_sk(sk);
	struct sk_buff *skb;
	unsigned char  *dptr;
	int len, timeout;

	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;

	switch (frametype & 0x0F) {
	case NR_CONNREQ:
		len += 17;
		break;
	case NR_CONNACK:
		len += (nr->bpqext) ? 2 : 1;
		break;
	case NR_DISCREQ:
	case NR_DISCACK:
	case NR_INFOACK:
		break;
	default:
		printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
		return;
	}

	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	/*
	 *	Space for AX.25 and NET/ROM network header
	 */
	skb_reserve(skb, NR_NETWORK_LEN);

	dptr = skb_put(skb, skb_tailroom(skb));

	switch (frametype & 0x0F) {
	case NR_CONNREQ:
		timeout  = nr->t1 / HZ;
		*dptr++  = nr->my_index;
		*dptr++  = nr->my_id;
		*dptr++  = 0;
		*dptr++  = 0;
		*dptr++  = frametype;
		*dptr++  = nr->window;
		memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
		dptr[6] &= ~AX25_CBIT;
		dptr[6] &= ~AX25_EBIT;
		dptr[6] |= AX25_SSSID_SPARE;
		dptr    += AX25_ADDR_LEN;
		memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
		dptr[6] &= ~AX25_CBIT;
		dptr[6] &= ~AX25_EBIT;
		dptr[6] |= AX25_SSSID_SPARE;
		dptr    += AX25_ADDR_LEN;
		*dptr++  = timeout % 256;
		*dptr++  = timeout / 256;
		break;

	case NR_CONNACK:
		*dptr++ = nr->your_index;
		*dptr++ = nr->your_id;
		*dptr++ = nr->my_index;
		*dptr++ = nr->my_id;
		*dptr++ = frametype;
		*dptr++ = nr->window;
		if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
		break;

	case NR_DISCREQ:
	case NR_DISCACK:
		*dptr++ = nr->your_index;
		*dptr++ = nr->your_id;
		*dptr++ = 0;
		*dptr++ = 0;
		*dptr++ = frametype;
		break;

	case NR_INFOACK:
		*dptr++ = nr->your_index;
		*dptr++ = nr->your_id;
		*dptr++ = 0;
		*dptr++ = nr->vr;
		*dptr++ = frametype;
		break;
	}

	nr_transmit_buffer(sk, skb);
}

/*
 * This routine is called to send an error reply.
 */
void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
{
	struct sk_buff *skbn;
	unsigned char *dptr;
	int len;

	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;

	if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skbn, 0);

	dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);

	skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
	dptr[6] &= ~AX25_CBIT;
	dptr[6] &= ~AX25_EBIT;
	dptr[6] |= AX25_SSSID_SPARE;
	dptr += AX25_ADDR_LEN;

	skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
	dptr[6] &= ~AX25_CBIT;
	dptr[6] |= AX25_EBIT;
	dptr[6] |= AX25_SSSID_SPARE;
	dptr += AX25_ADDR_LEN;

	*dptr++ = sysctl_netrom_network_ttl_initialiser;

	if (mine) {
		*dptr++ = 0;
		*dptr++ = 0;
		*dptr++ = skb->data[15];
		*dptr++ = skb->data[16];
	} else {
		*dptr++ = skb->data[15];
		*dptr++ = skb->data[16];
		*dptr++ = 0;
		*dptr++ = 0;
	}

	*dptr++ = cmdflags;
	*dptr++ = 0;

	if (!nr_route_frame(skbn, NULL))
		kfree_skb(skbn);
}

void nr_disconnect(struct sock *sk, int reason)
{
	nr_stop_t1timer(sk);
	nr_stop_t2timer(sk);
	nr_stop_t4timer(sk);
	nr_stop_idletimer(sk);

	nr_clear_queues(sk);

	nr_sk(sk)->state = NR_STATE_0;

	sk->sk_state     = TCP_CLOSE;
	sk->sk_err       = reason;
	sk->sk_shutdown |= SEND_SHUTDOWN;

	if (!sock_flag(sk, SOCK_DEAD)) {
		sk->sk_state_change(sk);
		sock_set_flag(sk, SOCK_DEAD);
	}
}