linux/net/lapb/lapb_out.c
Thomas Gleixner ee5d8f4d89 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 41
Based on 1 normalized pattern(s):

  this module 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 18 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170858.008906948@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:27:12 +02:00

205 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* LAPB release 002
*
* This code REQUIRES 2.1.15 or higher/ NET3.038
*
* History
* LAPB 001 Jonathan Naylor Started Coding
* LAPB 002 Jonathan Naylor New timer architecture.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/inet.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/lapb.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 lapb_send_iframe(struct lapb_cb *lapb, struct sk_buff *skb, int poll_bit)
{
unsigned char *frame;
if (!skb)
return;
if (lapb->mode & LAPB_EXTENDED) {
frame = skb_push(skb, 2);
frame[0] = LAPB_I;
frame[0] |= lapb->vs << 1;
frame[1] = poll_bit ? LAPB_EPF : 0;
frame[1] |= lapb->vr << 1;
} else {
frame = skb_push(skb, 1);
*frame = LAPB_I;
*frame |= poll_bit ? LAPB_SPF : 0;
*frame |= lapb->vr << 5;
*frame |= lapb->vs << 1;
}
lapb_dbg(1, "(%p) S%d TX I(%d) S%d R%d\n",
lapb->dev, lapb->state, poll_bit, lapb->vs, lapb->vr);
lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);
}
void lapb_kick(struct lapb_cb *lapb)
{
struct sk_buff *skb, *skbn;
unsigned short modulus, start, end;
modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
start = !skb_peek(&lapb->ack_queue) ? lapb->va : lapb->vs;
end = (lapb->va + lapb->window) % modulus;
if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) &&
start != end && skb_peek(&lapb->write_queue)) {
lapb->vs = start;
/*
* Dequeue the frame and copy it.
*/
skb = skb_dequeue(&lapb->write_queue);
do {
if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
skb_queue_head(&lapb->write_queue, skb);
break;
}
if (skb->sk)
skb_set_owner_w(skbn, skb->sk);
/*
* Transmit the frame copy.
*/
lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);
lapb->vs = (lapb->vs + 1) % modulus;
/*
* Requeue the original data frame.
*/
skb_queue_tail(&lapb->ack_queue, skb);
} while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
if (!lapb_t1timer_running(lapb))
lapb_start_t1timer(lapb);
}
}
void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *skb, int type)
{
unsigned char *ptr;
ptr = skb_push(skb, 1);
if (lapb->mode & LAPB_MLP) {
if (lapb->mode & LAPB_DCE) {
if (type == LAPB_COMMAND)
*ptr = LAPB_ADDR_C;
if (type == LAPB_RESPONSE)
*ptr = LAPB_ADDR_D;
} else {
if (type == LAPB_COMMAND)
*ptr = LAPB_ADDR_D;
if (type == LAPB_RESPONSE)
*ptr = LAPB_ADDR_C;
}
} else {
if (lapb->mode & LAPB_DCE) {
if (type == LAPB_COMMAND)
*ptr = LAPB_ADDR_A;
if (type == LAPB_RESPONSE)
*ptr = LAPB_ADDR_B;
} else {
if (type == LAPB_COMMAND)
*ptr = LAPB_ADDR_B;
if (type == LAPB_RESPONSE)
*ptr = LAPB_ADDR_A;
}
}
lapb_dbg(2, "(%p) S%d TX %3ph\n", lapb->dev, lapb->state, skb->data);
if (!lapb_data_transmit(lapb, skb))
kfree_skb(skb);
}
void lapb_establish_data_link(struct lapb_cb *lapb)
{
lapb->condition = 0x00;
lapb->n2count = 0;
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S%d TX SABME(1)\n", lapb->dev, lapb->state);
lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
} else {
lapb_dbg(1, "(%p) S%d TX SABM(1)\n", lapb->dev, lapb->state);
lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
}
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
}
void lapb_enquiry_response(struct lapb_cb *lapb)
{
lapb_dbg(1, "(%p) S%d TX RR(1) R%d\n",
lapb->dev, lapb->state, lapb->vr);
lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
}
void lapb_timeout_response(struct lapb_cb *lapb)
{
lapb_dbg(1, "(%p) S%d TX RR(0) R%d\n",
lapb->dev, lapb->state, lapb->vr);
lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE);
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
}
void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short nr)
{
if (lapb->vs == nr) {
lapb_frames_acked(lapb, nr);
lapb_stop_t1timer(lapb);
lapb->n2count = 0;
} else if (lapb->va != nr) {
lapb_frames_acked(lapb, nr);
lapb_start_t1timer(lapb);
}
}
void lapb_check_need_response(struct lapb_cb *lapb, int type, int pf)
{
if (type == LAPB_COMMAND && pf)
lapb_enquiry_response(lapb);
}