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 = 0;
  37
  38         switch (skb->dev->type) {
  39 #ifdef CONFIG_TR
  40         case ARPHRD_IEEE802_TR: {
  41                 struct net_device *dev = skb->dev;
  42                 struct trh_hdr *trh;
  43
  44                 skb_push(skb, sizeof(*trh));
  45                 skb_reset_mac_header(skb);
  46                 trh = tr_hdr(skb);
  47                 trh->ac = AC;
  48                 trh->fc = LLC_FRAME;
  49                 if (sa)
  50                         memcpy(trh->saddr, sa, dev->addr_len);
  51                 else
  52                         memset(trh->saddr, 0, dev->addr_len);
  53                 if (da) {
  54                         memcpy(trh->daddr, da, dev->addr_len);
  55                         tr_source_route(skb, trh, dev);
  56                         skb_reset_mac_header(skb);
  57                 }
  58                 break;
  59         }
  60 #endif
  61         case ARPHRD_ETHER:
  62         case ARPHRD_LOOPBACK: {
  63                 unsigned short len = skb->len;
  64                 struct ethhdr *eth;
  65
  66                 skb_push(skb, sizeof(*eth));
  67                 skb_reset_mac_header(skb);
  68                 eth = eth_hdr(skb);
  69                 eth->h_proto = htons(len);
  70                 memcpy(eth->h_dest, da, ETH_ALEN);
  71                 memcpy(eth->h_source, sa, ETH_ALEN);
  72                 break;
  73         }
  74         default:
  75                 printk(KERN_WARNING "device type not supported: %d\n",
  76                        skb->dev->type);
  77                 rc = -EINVAL;
  78         }
  79         return rc;
  80 }
  81
  82 /**
  83  *      llc_build_and_send_ui_pkt - unitdata request interface for upper layers
  84  *      @sap: sap to use
  85  *      @skb: packet to send
  86  *      @dmac: destination mac address
  87  *      @dsap: destination sap
  88  *
  89  *      Upper layers calls this function when upper layer wants to send data
  90  *      using connection-less mode communication (UI pdu).
  91  *
  92  *      Accept data frame from network layer to be sent using connection-
  93  *      less mode communication; timeout/retries handled by network layer;
  94  *      package primitive as an event and send to SAP event handler
  95  */
  96 int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
  97                               unsigned char *dmac, unsigned char dsap)
  98 {
  99         int rc;
 100         llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 101                             dsap, LLC_PDU_CMD);
 102         llc_pdu_init_as_ui_cmd(skb);
 103         rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
 104         if (likely(!rc))
 105                 rc = dev_queue_xmit(skb);
 106         return rc;
 107 }
 108
 109 EXPORT_SYMBOL(llc_mac_hdr_init);
 110 EXPORT_SYMBOL(llc_build_and_send_ui_pkt);