diff options
Diffstat (limited to 'net/rose/rose_out.c')
-rw-r--r-- | net/rose/rose_out.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/net/rose/rose_out.c b/net/rose/rose_out.c new file mode 100644 index 0000000..2965ffc --- /dev/null +++ b/net/rose/rose_out.c @@ -0,0 +1,126 @@ +/* + * 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 (C) 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/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 <asm/system.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <net/rose.h> + +/* + * This procedure is passed a buffer descriptor for an iframe. It builds + * the rest of the control part of the frame and then writes it out. + */ +static void rose_send_iframe(struct sock *sk, struct sk_buff *skb) +{ + struct rose_sock *rose = rose_sk(sk); + + if (skb == NULL) + return; + + skb->data[2] |= (rose->vr << 5) & 0xE0; + skb->data[2] |= (rose->vs << 1) & 0x0E; + + rose_start_idletimer(sk); + + rose_transmit_link(skb, rose->neighbour); +} + +void rose_kick(struct sock *sk) +{ + struct rose_sock *rose = rose_sk(sk); + struct sk_buff *skb, *skbn; + unsigned short start, end; + + if (rose->state != ROSE_STATE_3) + return; + + if (rose->condition & ROSE_COND_PEER_RX_BUSY) + return; + + if (!skb_peek(&sk->sk_write_queue)) + return; + + start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs; + end = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS; + + if (start == end) + return; + + rose->vs = start; + + /* + * Transmit data until either we're out of data to send or + * the window is full. + */ + + skb = skb_dequeue(&sk->sk_write_queue); + + do { + if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { + skb_queue_head(&sk->sk_write_queue, skb); + break; + } + + skb_set_owner_w(skbn, sk); + + /* + * Transmit the frame copy. + */ + rose_send_iframe(sk, skbn); + + rose->vs = (rose->vs + 1) % ROSE_MODULUS; + + /* + * Requeue the original data frame. + */ + skb_queue_tail(&rose->ack_queue, skb); + + } while (rose->vs != end && + (skb = skb_dequeue(&sk->sk_write_queue)) != NULL); + + rose->vl = rose->vr; + rose->condition &= ~ROSE_COND_ACK_PENDING; + + rose_stop_timer(sk); +} + +/* + * The following routines are taken from page 170 of the 7th ARRL Computer + * Networking Conference paper, as is the whole state machine. + */ + +void rose_enquiry_response(struct sock *sk) +{ + struct rose_sock *rose = rose_sk(sk); + + if (rose->condition & ROSE_COND_OWN_RX_BUSY) + rose_write_internal(sk, ROSE_RNR); + else + rose_write_internal(sk, ROSE_RR); + + rose->vl = rose->vr; + rose->condition &= ~ROSE_COND_ACK_PENDING; + + rose_stop_timer(sk); +} |