net/802/hippi.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              HIPPI-type device handling.
   7  *
   8  * Version:     @(#)hippi.c     1.0.0   05/29/97
   9  *
  10  * Authors:     Ross Biro, <bir7@leland.Stanford.Edu>
  11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *              Mark Evans, <evansmp@uhura.aston.ac.uk>
  13  *              Florian  La Roche, <rzsfl@rz.uni-sb.de>
  14  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  15  *              Jes Sorensen, <Jes.Sorensen@cern.ch>
  16  *
  17  *              This program is free software; you can redistribute it and/or
  18  *              modify it under the terms of the GNU General Public License
  19  *              as published by the Free Software Foundation; either version
  20  *              2 of the License, or (at your option) any later version.
  21  */
  22
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/string.h>
  27 #include <linux/mm.h>
  28 #include <linux/socket.h>
  29 #include <linux/in.h>
  30 #include <linux/inet.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/hippidevice.h>
  33 #include <linux/skbuff.h>
  34 #include <linux/errno.h>
  35 #include <net/arp.h>
  36 #include <net/sock.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/checksum.h>
  39 #include <asm/segment.h>
  40 #include <asm/system.h>
  41
  42 /*
  43  * hippi_net_init()
  44  *
  45  * Do nothing, this is just to pursuade the stupid linker to behave.
  46  */
  47
  48 void hippi_net_init(void)
  49 {
  50         return;
  51 }
  52
  53 /*
  54  * Create the HIPPI MAC header for an arbitrary protocol layer
  55  *
  56  * saddr=NULL   means use device source address
  57  * daddr=NULL   means leave destination address (eg unresolved arp)
  58  */
  59
  60 int hippi_header(struct sk_buff *skb, struct net_device *dev,
  61                  unsigned short type, void *daddr, void *saddr,
  62                  unsigned len)
  63 {
  64         struct hippi_hdr *hip = (struct hippi_hdr *)skb_push(skb, HIPPI_HLEN);
  65
  66         if (!len){
  67                 len = skb->len - HIPPI_HLEN;
  68                 printk("hippi_header(): length not supplied\n");
  69         }
  70
  71         /*
  72          * Due to the stupidity of the little endian byte-order we
  73          * have to set the fp field this way.
  74          */
  75         hip->fp.fixed           = __constant_htonl(0x04800018);
  76         hip->fp.d2_size         = htonl(len + 8);
  77         hip->le.fc              = 0;
  78         hip->le.double_wide     = 0;    /* only HIPPI 800 for the time being */
  79         hip->le.message_type    = 0;    /* Data PDU */
  80
  81         hip->le.dest_addr_type  = 2;    /* 12 bit SC address */
  82         hip->le.src_addr_type   = 2;    /* 12 bit SC address */
  83
  84         memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
  85         memset(&hip->le.reserved, 0, 16);
  86
  87         hip->snap.dsap          = HIPPI_EXTENDED_SAP;
  88         hip->snap.ssap          = HIPPI_EXTENDED_SAP;
  89         hip->snap.ctrl          = HIPPI_UI_CMD;
  90         hip->snap.oui[0]        = 0x00;
  91         hip->snap.oui[1]        = 0x00;
  92         hip->snap.oui[2]        = 0x00;
  93         hip->snap.ethertype     = htons(type);
  94
  95         if (daddr)
  96         {
  97                 memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
  98                 memcpy(&skb->private.ifield, daddr + 2, 4);
  99                 return HIPPI_HLEN;
 100         }
 101         return -HIPPI_HLEN;
 102 }
 103
 104
 105 /*
 106  * Rebuild the HIPPI MAC header. This is called after an ARP has
 107  * completed on this sk_buff. We now let ARP fill in the other fields.
 108  */
 109
 110 int hippi_rebuild_header(struct sk_buff *skb)
 111 {
 112         struct hippi_hdr *hip = (struct hippi_hdr *)skb->data;
 113
 114         /*
 115          * Only IP is currently supported
 116          */
 117
 118         if(hip->snap.ethertype != __constant_htons(ETH_P_IP))
 119         {
 120                 printk(KERN_DEBUG "%s: unable to resolve type %X addresses.\n",skb->dev->name,ntohs(hip->snap.ethertype));
 121                 return 0;
 122         }
 123
 124         /*
 125          * We don't support dynamic ARP on HIPPI, but we use the ARP
 126          * static ARP tables to hold the I-FIELDs.
 127          */
 128         return arp_find(hip->le.daddr, skb);
 129 }
 130
 131
 132 /*
 133  *      Determine the packet's protocol ID.
 134  */
 135
 136 unsigned short hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
 137 {
 138         struct hippi_hdr *hip;
 139
 140         hip = (struct hippi_hdr *) skb->data;
 141
 142         /*
 143          * This is actually wrong ... question is if we really should
 144          * set the raw address here.
 145          */
 146          skb->mac.raw = skb->data;
 147          skb_pull(skb, HIPPI_HLEN);
 148
 149         /*
 150          * No fancy promisc stuff here now.
 151          */
 152
 153         return hip->snap.ethertype;
 154 }