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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/rose/rose_out.c
Initial import
Diffstat (limited to 'net/rose/rose_out.c')
-rw-r--r--net/rose/rose_out.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/net/rose/rose_out.c b/net/rose/rose_out.c
new file mode 100644
index 000000000..9ad98b524
--- /dev/null
+++ b/net/rose/rose_out.c
@@ -0,0 +1,125 @@
+/*
+ * 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/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <net/ax25.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.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);
+}