LXR linux/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
  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/module.h>
  24#include <linux/types.h>
  25#include <linux/kernel.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 <linux/uaccess.h>
  38
  39/*
  40 * Create the HIPPI MAC header for an arbitrary protocol layer
  41 *
  42 * saddr=NULL   means use device source address
  43 * daddr=NULL   means leave destination address (eg unresolved arp)
  44 */
  45
  46static int hippi_header(struct sk_buff *skb, struct net_device *dev,
  47                        unsigned short type,
  48                        const void *daddr, const void *saddr, unsigned int len)
  49{
  50        struct hippi_hdr *hip = skb_push(skb, HIPPI_HLEN);
  51        struct hippi_cb *hcb = (struct hippi_cb *) skb->cb;
  52
  53        if (!len){
  54                len = skb->len - HIPPI_HLEN;
  55                printk("hippi_header(): length not supplied\n");
  56        }
  57
  58        /*
  59         * Due to the stupidity of the little endian byte-order we
  60         * have to set the fp field this way.
  61         */
  62        hip->fp.fixed           = htonl(0x04800018);
  63        hip->fp.d2_size         = htonl(len + 8);
  64        hip->le.fc              = 0;
  65        hip->le.double_wide     = 0;    /* only HIPPI 800 for the time being */
  66        hip->le.message_type    = 0;    /* Data PDU */
  67
  68        hip->le.dest_addr_type  = 2;    /* 12 bit SC address */
  69        hip->le.src_addr_type   = 2;    /* 12 bit SC address */
  70
  71        memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
  72        memset(&hip->le.reserved, 0, 16);
  73
  74        hip->snap.dsap          = HIPPI_EXTENDED_SAP;
  75        hip->snap.ssap          = HIPPI_EXTENDED_SAP;
  76        hip->snap.ctrl          = HIPPI_UI_CMD;
  77        hip->snap.oui[0]        = 0x00;
  78        hip->snap.oui[1]        = 0x00;
  79        hip->snap.oui[2]        = 0x00;
  80        hip->snap.ethertype     = htons(type);
  81
  82        if (daddr)
  83        {
  84                memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
  85                memcpy(&hcb->ifield, daddr + 2, 4);
  86                return HIPPI_HLEN;
  87        }
  88        hcb->ifield = 0;
  89        return -((int)HIPPI_HLEN);
  90}
  91
  92
  93/*
  94 *      Determine the packet's protocol ID.
  95 */
  96
  97__be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
  98{
  99        struct hippi_hdr *hip;
 100
 101        /*
 102         * This is actually wrong ... question is if we really should
 103         * set the raw address here.
 104         */
 105        skb->dev = dev;
 106        skb_reset_mac_header(skb);
 107        hip = (struct hippi_hdr *)skb_mac_header(skb);
 108        skb_pull(skb, HIPPI_HLEN);
 109
 110        /*
 111         * No fancy promisc stuff here now.
 112         */
 113
 114        return hip->snap.ethertype;
 115}
 116
 117EXPORT_SYMBOL(hippi_type_trans);
 118
 119/*
 120 * For HIPPI we will actually use the lower 4 bytes of the hardware
 121 * address as the I-FIELD rather than the actual hardware address.
 122 */
 123int hippi_mac_addr(struct net_device *dev, void *p)
 124{
 125        struct sockaddr *addr = p;
 126        if (netif_running(dev))
 127                return -EBUSY;
 128        memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
 129        return 0;
 130}
 131EXPORT_SYMBOL(hippi_mac_addr);
 132
 133int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
 134{
 135        /* Never send broadcast/multicast ARP messages */
 136        NEIGH_VAR_INIT(p, MCAST_PROBES, 0);
 137
 138        /* In IPv6 unicast probes are valid even on NBMA,
 139        * because they are encapsulated in normal IPv6 protocol.
 140        * Should be a generic flag.
 141        */
 142        if (p->tbl->family != AF_INET6)
 143                NEIGH_VAR_INIT(p, UCAST_PROBES, 0);
 144        return 0;
 145}
 146EXPORT_SYMBOL(hippi_neigh_setup_dev);
 147
 148static const struct header_ops hippi_header_ops = {
 149        .create         = hippi_header,
 150};
 151
 152
 153static void hippi_setup(struct net_device *dev)
 154{
 155        dev->header_ops                 = &hippi_header_ops;
 156
 157        /*
 158         * We don't support HIPPI `ARP' for the time being, and probably
 159         * never will unless someone else implements it. However we
 160         * still need a fake ARPHRD to make ifconfig and friends play ball.
 161         */
 162        dev->type               = ARPHRD_HIPPI;
 163        dev->hard_header_len    = HIPPI_HLEN;
 164        dev->mtu                = 65280;
 165        dev->min_mtu            = 68;
 166        dev->max_mtu            = 65280;
 167        dev->addr_len           = HIPPI_ALEN;
 168        dev->tx_queue_len       = 25 /* 5 */;
 169        memset(dev->broadcast, 0xFF, HIPPI_ALEN);
 170
 171
 172        /*
 173         * HIPPI doesn't support broadcast+multicast and we only use
 174         * static ARP tables. ARP is disabled by hippi_neigh_setup_dev.
 175         */
 176        dev->flags = 0;
 177}
 178
 179/**
 180 * alloc_hippi_dev - Register HIPPI device
 181 * @sizeof_priv: Size of additional driver-private structure to be allocated
 182 *      for this HIPPI device
 183 *
 184 * Fill in the fields of the device structure with HIPPI-generic values.
 185 *
 186 * Constructs a new net device, complete with a private data area of
 187 * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 188 * this private data area.
 189 */
 190
 191struct net_device *alloc_hippi_dev(int sizeof_priv)
 192{
 193        return alloc_netdev(sizeof_priv, "hip%d", NET_NAME_UNKNOWN,
 194                            hippi_setup);
 195}
 196
 197EXPORT_SYMBOL(alloc_hippi_dev);
 198