Commit | Line | Data |
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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 (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> | |
1da177e4 LT |
14 | #include <linux/timer.h> |
15 | #include <linux/string.h> | |
16 | #include <linux/sockios.h> | |
17 | #include <linux/net.h> | |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
1da177e4 LT |
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> | |
1da177e4 LT |
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 | */ | |
33 | static 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 | ||
48 | void 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 | ||
112 | void 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 | } |