path: root/net/irda/irlap_frame.c

/*********************************************************************
 *
 * Filename:      irlap_frame.c
 * Version:       1.0
 * Description:   Build and transmit IrLAP frames
 * Status:        Stable
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Tue Aug 19 10:27:26 1997
 * Modified at:   Wed Jan  5 08:59:04 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
 *     All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     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.
 *
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is
 *     provided "AS-IS" and at no charge.
 *
 ********************************************************************/

#include <linux/skbuff.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/irda.h>
#include <linux/slab.h>

#include <net/pkt_sched.h>
#include <net/sock.h>

#include <asm/byteorder.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h>
#include <net/irda/irlap.h>
#include <net/irda/wrapper.h>
#include <net/irda/timer.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/qos.h>

static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
			       int command);

/*
 * Function irlap_insert_info (self, skb)
 *
 *    Insert minimum turnaround time and speed information into the skb. We
 *    need to do this since it's per packet relevant information. Safe to
 *    have this function inlined since it's only called from one place
 */
static inline void irlap_insert_info(struct irlap_cb *self,
				     struct sk_buff *skb)
{
	struct irda_skb_cb *cb = (struct irda_skb_cb *) skb->cb;

	/*
	 * Insert MTT (min. turn time) and speed into skb, so that the
	 * device driver knows which settings to use
	 */
	cb->magic = LAP_MAGIC;
	cb->mtt = self->mtt_required;
	cb->next_speed = self->speed;

	/* Reset */
	self->mtt_required = 0;

	/*
	 * Delay equals negotiated BOFs count, plus the number of BOFs to
	 * force the negotiated minimum turnaround time
	 */
	cb->xbofs = self->bofs_count;
	cb->next_xbofs = self->next_bofs;
	cb->xbofs_delay = self->xbofs_delay;

	/* Reset XBOF's delay (used only for getting min turn time) */
	self->xbofs_delay = 0;
	/* Put the correct xbofs value for the next packet */
	self->bofs_count = self->next_bofs;
}

/*
 * Function irlap_queue_xmit (self, skb)
 *
 *    A little wrapper for dev_queue_xmit, so we can insert some common
 *    code into it.
 */
void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb)
{
	/* Some common init stuff */
	skb->dev = self->netdev;
	skb_reset_mac_header(skb);
	skb_reset_network_header(skb);
	skb_reset_transport_header(skb);
	skb->protocol = htons(ETH_P_IRDA);
	skb->priority = TC_PRIO_BESTEFFORT;

	irlap_insert_info(self, skb);

	if (unlikely(self->mode & IRDA_MODE_MONITOR)) {
		IRDA_DEBUG(3, "%s(): %s is in monitor mode\n", __func__,
			   self->netdev->name);
		dev_kfree_skb(skb);
		return;
	}

	dev_queue_xmit(skb);
}

/*
 * Function irlap_send_snrm_cmd (void)
 *
 *    Transmits a connect SNRM command frame
 */
void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos)
{
	struct sk_buff *tx_skb;
	struct snrm_frame *frame;
	int ret;

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Allocate frame */
	tx_skb = alloc_skb(sizeof(struct snrm_frame) +
			   IRLAP_NEGOCIATION_PARAMS_LEN,
			   GFP_ATOMIC);
	if (!tx_skb)
		return;

	frame = (struct snrm_frame *) skb_put(tx_skb, 2<