projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 1da177e4 | 2 | /* |
| 1da177e4 LT |
3 | * |
| 4 | * Copyright (C) Jonathan Naylor G4KLX ([email protected]) | |
| 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> | |
| 1da177e4 LT |
11 | #include <linux/timer.h> |
| 12 | #include <linux/string.h> | |
| 13 | #include <linux/sockios.h> | |
| 14 | #include <linux/net.h> | |
| 5a0e3ad6 | 15 | #include <linux/gfp.h> |
| 1da177e4 LT |
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> | |
| 1da177e4 LT |
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 | */ | |
| 30 | static 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 | ||
| 45 | void 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 | ||
| 109 | void 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 | } |