LXR linux/net/llc/llc

   1/*
   2 * llc_output.c - LLC minimal output path
   3 *
   4 * Copyright (c) 1997 by Procom Technology, Inc.
   5 *               2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6 *
   7 * This program can be redistributed or modified under the terms of the
   8 * GNU General Public License version 2 as published by the Free Software
   9 * Foundation.
  10 * This program is distributed without any warranty or implied warranty
  11 * of merchantability or fitness for a particular purpose.
  12 *
  13 * See the GNU General Public License version 2 for more details.
  14 */
  15
  16#include <linux/if_arp.h>
  17#include <linux/if_tr.h>
  18#include <linux/netdevice.h>
  19#include <linux/trdevice.h>
  20#include <linux/skbuff.h>
  21#include <net/llc.h>
  22#include <net/llc_pdu.h>
  23
  24/**
  25 *      llc_mac_hdr_init - fills MAC header fields
  26 *      @skb: Address of the frame to initialize its MAC header
  27 *      @sa: The MAC source address
  28 *      @da: The MAC destination address
  29 *
  30 *      Fills MAC header fields, depending on MAC type. Returns 0, If MAC type
  31 *      is a valid type and initialization completes correctly 1, otherwise.
  32 */
  33int llc_mac_hdr_init(struct sk_buff *skb,
  34                     const unsigned char *sa, const unsigned char *da)
  35{
  36        int rc = -EINVAL;
  37
  38        switch (skb->dev->type) {
  39        case ARPHRD_IEEE802_TR:
  40        case ARPHRD_ETHER:
  41        case ARPHRD_LOOPBACK:
  42                rc = dev_hard_header(skb, skb->dev, ETH_P_802_2, da, sa,
  43                                     skb->len);
  44                if (rc > 0)
  45                        rc = 0;
  46                break;
  47        default:
  48                WARN(1, "device type not supported: %d\n", skb->dev->type);
  49        }
  50        return rc;
  51}
  52
  53/**
  54 *      llc_build_and_send_ui_pkt - unitdata request interface for upper layers
  55 *      @sap: sap to use
  56 *      @skb: packet to send
  57 *      @dmac: destination mac address
  58 *      @dsap: destination sap
  59 *
  60 *      Upper layers calls this function when upper layer wants to send data
  61 *      using connection-less mode communication (UI pdu).
  62 *
  63 *      Accept data frame from network layer to be sent using connection-
  64 *      less mode communication; timeout/retries handled by network layer;
  65 *      package primitive as an event and send to SAP event handler
  66 */
  67int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
  68                              unsigned char *dmac, unsigned char dsap)
  69{
  70        int rc;
  71        llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
  72                            dsap, LLC_PDU_CMD);
  73        llc_pdu_init_as_ui_cmd(skb);
  74        rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
  75        if (likely(!rc))
  76                rc = dev_queue_xmit(skb);
  77        return rc;
  78}
  79
  80EXPORT_SYMBOL(llc_mac_hdr_init);
  81EXPORT_SYMBOL(llc_build_and_send_ui_pkt);
  82