/*
   * llc_output.c - LLC minimal output path
   *
   * Copyright (c) 1997 by Procom Technology, Inc.
   * 		 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   *
   * This program can be redistributed or modified under the terms of the
   * GNU General Public License version 2 as published by the Free Software
   * Foundation.
   * This program is distributed without any warranty or implied warranty
   * of merchantability or fitness for a particular purpose.
   *
   * See the GNU General Public License version 2 for more details.
   */
  
  #include <linux/if_arp.h>
  #include <linux/if_tr.h>
  #include <linux/netdevice.h>
  #include <linux/trdevice.h>
  #include <linux/skbuff.h>
  #include <net/llc.h>
  #include <net/llc_pdu.h>
  
  /**
   *	llc_mac_hdr_init - fills MAC header fields
   *	@skb: Address of the frame to initialize its MAC header
   *	@sa: The MAC source address
   *	@da: The MAC destination address
   *
   *	Fills MAC header fields, depending on MAC type. Returns 0, If MAC type
   *	is a valid type and initialization completes correctly 1, otherwise.
   */

  int llc_mac_hdr_init(struct sk_buff *skb,
  		     const unsigned char *sa, const unsigned char *da)

  {
  	int rc = 0;
  
  	switch (skb->dev->type) {
  #ifdef CONFIG_TR
  	case ARPHRD_IEEE802_TR: {
  		struct net_device *dev = skb->dev;
  		struct trh_hdr *trh;

  		skb_push(skb, sizeof(*trh));
  		skb_reset_mac_header(skb);

  		trh = tr_hdr(skb);
  		trh->ac = AC;
  		trh->fc = LLC_FRAME;
  		if (sa)
  			memcpy(trh->saddr, sa, dev->addr_len);
  		else
  			memset(trh->saddr, 0, dev->addr_len);
  		if (da) {
  			memcpy(trh->daddr, da, dev->addr_len);
  			tr_source_route(skb, trh, dev);

  			skb_reset_mac_header(skb);

  		}
  		break;
  	}
  #endif
  	case ARPHRD_ETHER:
  	case ARPHRD_LOOPBACK: {
  		unsigned short len = skb->len;
  		struct ethhdr *eth;

  		skb_push(skb, sizeof(*eth));
  		skb_reset_mac_header(skb);

  		eth = eth_hdr(skb);
  		eth->h_proto = htons(len);
  		memcpy(eth->h_dest, da, ETH_ALEN);
  		memcpy(eth->h_source, sa, ETH_ALEN);
  		break;
  	}
  	default:
  		printk(KERN_WARNING "device type not supported: %d
  ",
  		       skb->dev->type);
  		rc = -EINVAL;
  	}
  	return rc;
  }
  
  /**
   *	llc_build_and_send_ui_pkt - unitdata request interface for upper layers
   *	@sap: sap to use
   *	@skb: packet to send
   *	@dmac: destination mac address
   *	@dsap: destination sap
   *
   *	Upper layers calls this function when upper layer wants to send data
   *	using connection-less mode communication (UI pdu).
   *
   *	Accept data frame from network layer to be sent using connection-
   *	less mode communication; timeout/retries handled by network layer;
   *	package primitive as an event and send to SAP event handler
   */
  int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
  			      unsigned char *dmac, unsigned char dsap)
  {
  	int rc;
  	llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
  			    dsap, LLC_PDU_CMD);
  	llc_pdu_init_as_ui_cmd(skb);
  	rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);

  	if (likely(!rc))

  		rc = dev_queue_xmit(skb);
  	return rc;
  }
  
  EXPORT_SYMBOL(llc_mac_hdr_init);
  EXPORT_SYMBOL(llc_build_and_send_ui_pkt);