net/llc/llc_output.c

   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  */
  33 int 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  */
  67 int 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
  80 EXPORT_SYMBOL(llc_mac_hdr_init);
  81 EXPORT_SYMBOL(llc_build_and_send_ui_pkt);