linux/net/802/fddi.c
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   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 *              FDDI-type device handling.
   7 *
   8 * Version:     @(#)fddi.c      1.0.0   08/12/96
   9 *
  10 * Authors:     Lawrence V. Stefani, <stefani@lkg.dec.com>
  11 *
  12 *              fddi.c is based on previous eth.c and tr.c work by
  13 *                      Ross Biro
  14 *                      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  15 *                      Mark Evans, <evansmp@uhura.aston.ac.uk>
  16 *                      Florian La Roche, <rzsfl@rz.uni-sb.de>
  17 *                      Alan Cox, <gw4pts@gw4pts.ampr.org>
  18 *
  19 *              This program is free software; you can redistribute it and/or
  20 *              modify it under the terms of the GNU General Public License
  21 *              as published by the Free Software Foundation; either version
  22 *              2 of the License, or (at your option) any later version.
  23 *
  24 *      Changes
  25 *              Alan Cox                :       New arp/rebuild header
  26 *              Maciej W. Rozycki       :       IPv6 support
  27 */
  28
  29#include <linux/module.h>
  30#include <linux/types.h>
  31#include <linux/kernel.h>
  32#include <linux/string.h>
  33#include <linux/mm.h>
  34#include <linux/socket.h>
  35#include <linux/in.h>
  36#include <linux/inet.h>
  37#include <linux/netdevice.h>
  38#include <linux/fddidevice.h>
  39#include <linux/if_ether.h>
  40#include <linux/skbuff.h>
  41#include <linux/errno.h>
  42#include <net/arp.h>
  43#include <net/sock.h>
  44
  45/*
  46 * Create the FDDI MAC header for an arbitrary protocol layer
  47 *
  48 * saddr=NULL   means use device source address
  49 * daddr=NULL   means leave destination address (eg unresolved arp)
  50 */
  51
  52static int fddi_header(struct sk_buff *skb, struct net_device *dev,
  53                       unsigned short type,
  54                       const void *daddr, const void *saddr, unsigned int len)
  55{
  56        int hl = FDDI_K_SNAP_HLEN;
  57        struct fddihdr *fddi;
  58
  59        if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP)
  60                hl=FDDI_K_8022_HLEN-3;
  61        fddi = (struct fddihdr *)skb_push(skb, hl);
  62        fddi->fc                         = FDDI_FC_K_ASYNC_LLC_DEF;
  63        if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
  64        {
  65                fddi->hdr.llc_snap.dsap          = FDDI_EXTENDED_SAP;
  66                fddi->hdr.llc_snap.ssap          = FDDI_EXTENDED_SAP;
  67                fddi->hdr.llc_snap.ctrl          = FDDI_UI_CMD;
  68                fddi->hdr.llc_snap.oui[0]        = 0x00;
  69                fddi->hdr.llc_snap.oui[1]        = 0x00;
  70                fddi->hdr.llc_snap.oui[2]        = 0x00;
  71                fddi->hdr.llc_snap.ethertype     = htons(type);
  72        }
  73
  74        /* Set the source and destination hardware addresses */
  75
  76        if (saddr != NULL)
  77                memcpy(fddi->saddr, saddr, dev->addr_len);
  78        else
  79                memcpy(fddi->saddr, dev->dev_addr, dev->addr_len);
  80
  81        if (daddr != NULL)
  82        {
  83                memcpy(fddi->daddr, daddr, dev->addr_len);
  84                return hl;
  85        }
  86
  87        return -hl;
  88}
  89
  90
  91/*
  92 * Rebuild the FDDI MAC header. This is called after an ARP
  93 * (or in future other address resolution) has completed on
  94 * this sk_buff.  We now let ARP fill in the other fields.
  95 */
  96
  97static int fddi_rebuild_header(struct sk_buff   *skb)
  98{
  99        struct fddihdr *fddi = (struct fddihdr *)skb->data;
 100
 101#ifdef CONFIG_INET
 102        if (fddi->hdr.llc_snap.ethertype == htons(ETH_P_IP))
 103                /* Try to get ARP to resolve the header and fill destination address */
 104                return arp_find(fddi->daddr, skb);
 105        else
 106#endif
 107        {
 108                printk("%s: Don't know how to resolve type %04X addresses.\n",
 109                       skb->dev->name, ntohs(fddi->hdr.llc_snap.ethertype));
 110                return 0;
 111        }
 112}
 113
 114
 115/*
 116 * Determine the packet's protocol ID and fill in skb fields.
 117 * This routine is called before an incoming packet is passed
 118 * up.  It's used to fill in specific skb fields and to set
 119 * the proper pointer to the start of packet data (skb->data).
 120 */
 121
 122__be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
 123{
 124        struct fddihdr *fddi = (struct fddihdr *)skb->data;
 125        __be16 type;
 126
 127        /*
 128         * Set mac.raw field to point to FC byte, set data field to point
 129         * to start of packet data.  Assume 802.2 SNAP frames for now.
 130         */
 131
 132        skb->dev = dev;
 133        skb_reset_mac_header(skb);      /* point to frame control (FC) */
 134
 135        if(fddi->hdr.llc_8022_1.dsap==0xe0)
 136        {
 137                skb_pull(skb, FDDI_K_8022_HLEN-3);
 138                type = htons(ETH_P_802_2);
 139        }
 140        else
 141        {
 142                skb_pull(skb, FDDI_K_SNAP_HLEN);                /* adjust for 21 byte header */
 143                type=fddi->hdr.llc_snap.ethertype;
 144        }
 145
 146        /* Set packet type based on destination address and flag settings */
 147
 148        if (*fddi->daddr & 0x01)
 149        {
 150                if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
 151                        skb->pkt_type = PACKET_BROADCAST;
 152                else
 153                        skb->pkt_type = PACKET_MULTICAST;
 154        }
 155
 156        else if (dev->flags & IFF_PROMISC)
 157        {
 158                if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
 159                        skb->pkt_type = PACKET_OTHERHOST;
 160        }
 161
 162        /* Assume 802.2 SNAP frames, for now */
 163
 164        return type;
 165}
 166
 167EXPORT_SYMBOL(fddi_type_trans);
 168
 169int fddi_change_mtu(struct net_device *dev, int new_mtu)
 170{
 171        if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
 172                return -EINVAL;
 173        dev->mtu = new_mtu;
 174        return 0;
 175}
 176EXPORT_SYMBOL(fddi_change_mtu);
 177
 178static const struct header_ops fddi_header_ops = {
 179        .create         = fddi_header,
 180        .rebuild        = fddi_rebuild_header,
 181};
 182
 183
 184static void fddi_setup(struct net_device *dev)
 185{
 186        dev->header_ops         = &fddi_header_ops;
 187        dev->type               = ARPHRD_FDDI;
 188        dev->hard_header_len    = FDDI_K_SNAP_HLEN+3;   /* Assume 802.2 SNAP hdr len + 3 pad bytes */
 189        dev->mtu                = FDDI_K_SNAP_DLEN;     /* Assume max payload of 802.2 SNAP frame */
 190        dev->addr_len           = FDDI_K_ALEN;
 191        dev->tx_queue_len       = 100;                  /* Long queues on FDDI */
 192        dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
 193
 194        memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
 195}
 196
 197/**
 198 * alloc_fddidev - Register FDDI device
 199 * @sizeof_priv: Size of additional driver-private structure to be allocated
 200 *      for this FDDI device
 201 *
 202 * Fill in the fields of the device structure with FDDI-generic values.
 203 *
 204 * Constructs a new net device, complete with a private data area of
 205 * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 206 * this private data area.
 207 */
 208struct net_device *alloc_fddidev(int sizeof_priv)
 209{
 210        return alloc_netdev(sizeof_priv, "fddi%d", fddi_setup);
 211}
 212EXPORT_SYMBOL(alloc_fddidev);
 213
 214MODULE_LICENSE("GPL");
 215
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