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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 */
6#include <linux/errno.h>
7#include <linux/types.h>
8#include <linux/socket.h>
9#include <linux/in.h>
10#include <linux/kernel.h>
11#include <linux/timer.h>
12#include <linux/string.h>
13#include <linux/sockios.h>
14#include <linux/net.h>
15#include <linux/gfp.h>
16#include <net/ax25.h>
17#include <linux/inet.h>
18#include <linux/netdevice.h>
19#include <linux/skbuff.h>
20#include <net/sock.h>
21#include <linux/fcntl.h>
22#include <linux/mm.h>
23#include <linux/interrupt.h>
24#include <net/rose.h>
25
26/*
27 * This procedure is passed a buffer descriptor for an iframe. It builds
28 * the rest of the control part of the frame and then writes it out.
29 */
30static void rose_send_iframe(struct sock *sk, struct sk_buff *skb)
31{
32 struct rose_sock *rose = rose_sk(sk);
33
34 if (skb == NULL)
35 return;
36
37 skb->data[2] |= (rose->vr << 5) & 0xE0;
38 skb->data[2] |= (rose->vs << 1) & 0x0E;
39
40 rose_start_idletimer(sk);
41
42 rose_transmit_link(skb, rose->neighbour);
43}
44
45void rose_kick(struct sock *sk)
46{
47 struct rose_sock *rose = rose_sk(sk);
48 struct sk_buff *skb, *skbn;
49 unsigned short start, end;
50
51 if (rose->state != ROSE_STATE_3)
52 return;
53
54 if (rose->condition & ROSE_COND_PEER_RX_BUSY)
55 return;
56
57 if (!skb_peek(&sk->sk_write_queue))
58 return;
59
60 start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs;
61 end = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS;
62
63 if (start == end)
64 return;
65
66 rose->vs = start;
67
68 /*
69 * Transmit data until either we're out of data to send or
70 * the window is full.
71 */
72
73 skb = skb_dequeue(&sk->sk_write_queue);
74
75 do {
76 if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
77 skb_queue_head(&sk->sk_write_queue, skb);
78 break;
79 }
80
81 skb_set_owner_w(skbn, sk);
82
83 /*
84 * Transmit the frame copy.
85 */
86 rose_send_iframe(sk, skbn);
87
88 rose->vs = (rose->vs + 1) % ROSE_MODULUS;
89
90 /*
91 * Requeue the original data frame.
92 */
93 skb_queue_tail(&rose->ack_queue, skb);
94
95 } while (rose->vs != end &&
96 (skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
97
98 rose->vl = rose->vr;
99 rose->condition &= ~ROSE_COND_ACK_PENDING;
100
101 rose_stop_timer(sk);
102}
103
104/*
105 * The following routines are taken from page 170 of the 7th ARRL Computer
106 * Networking Conference paper, as is the whole state machine.
107 */
108
109void rose_enquiry_response(struct sock *sk)
110{
111 struct rose_sock *rose = rose_sk(sk);
112
113 if (rose->condition & ROSE_COND_OWN_RX_BUSY)
114 rose_write_internal(sk, ROSE_RNR);
115 else
116 rose_write_internal(sk, ROSE_RR);
117
118 rose->vl = rose->vr;
119 rose->condition &= ~ROSE_COND_ACK_PENDING;
120
121 rose_stop_timer(sk);
122}
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 (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 */
9#include <linux/errno.h>
10#include <linux/types.h>
11#include <linux/socket.h>
12#include <linux/in.h>
13#include <linux/kernel.h>
14#include <linux/timer.h>
15#include <linux/string.h>
16#include <linux/sockios.h>
17#include <linux/net.h>
18#include <linux/gfp.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>
24#include <linux/fcntl.h>
25#include <linux/mm.h>
26#include <linux/interrupt.h>
27#include <net/rose.h>
28
29/*
30 * This procedure is passed a buffer descriptor for an iframe. It builds
31 * the rest of the control part of the frame and then writes it out.
32 */
33static void rose_send_iframe(struct sock *sk, struct sk_buff *skb)
34{
35 struct rose_sock *rose = rose_sk(sk);
36
37 if (skb == NULL)
38 return;
39
40 skb->data[2] |= (rose->vr << 5) & 0xE0;
41 skb->data[2] |= (rose->vs << 1) & 0x0E;
42
43 rose_start_idletimer(sk);
44
45 rose_transmit_link(skb, rose->neighbour);
46}
47
48void rose_kick(struct sock *sk)
49{
50 struct rose_sock *rose = rose_sk(sk);
51 struct sk_buff *skb, *skbn;
52 unsigned short start, end;
53
54 if (rose->state != ROSE_STATE_3)
55 return;
56
57 if (rose->condition & ROSE_COND_PEER_RX_BUSY)
58 return;
59
60 if (!skb_peek(&sk->sk_write_queue))
61 return;
62
63 start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs;
64 end = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS;
65
66 if (start == end)
67 return;
68
69 rose->vs = start;
70
71 /*
72 * Transmit data until either we're out of data to send or
73 * the window is full.
74 */
75
76 skb = skb_dequeue(&sk->sk_write_queue);
77
78 do {
79 if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
80 skb_queue_head(&sk->sk_write_queue, skb);
81 break;
82 }
83
84 skb_set_owner_w(skbn, sk);
85
86 /*
87 * Transmit the frame copy.
88 */
89 rose_send_iframe(sk, skbn);
90
91 rose->vs = (rose->vs + 1) % ROSE_MODULUS;
92
93 /*
94 * Requeue the original data frame.
95 */
96 skb_queue_tail(&rose->ack_queue, skb);
97
98 } while (rose->vs != end &&
99 (skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
100
101 rose->vl = rose->vr;
102 rose->condition &= ~ROSE_COND_ACK_PENDING;
103
104 rose_stop_timer(sk);
105}
106
107/*
108 * The following routines are taken from page 170 of the 7th ARRL Computer
109 * Networking Conference paper, as is the whole state machine.
110 */
111
112void rose_enquiry_response(struct sock *sk)
113{
114 struct rose_sock *rose = rose_sk(sk);
115
116 if (rose->condition & ROSE_COND_OWN_RX_BUSY)
117 rose_write_internal(sk, ROSE_RNR);
118 else
119 rose_write_internal(sk, ROSE_RR);
120
121 rose->vl = rose->vr;
122 rose->condition &= ~ROSE_COND_ACK_PENDING;
123
124 rose_stop_timer(sk);
125}