net/802/fddi.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  *              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
  52 static 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  * Determine the packet's protocol ID and fill in skb fields.
  92  * This routine is called before an incoming packet is passed
  93  * up.  It's used to fill in specific skb fields and to set
  94  * the proper pointer to the start of packet data (skb->data).
  95  */
  96
  97 __be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
  98 {
  99         struct fddihdr *fddi = (struct fddihdr *)skb->data;
 100         __be16 type;
 101
 102         /*
 103          * Set mac.raw field to point to FC byte, set data field to point
 104          * to start of packet data.  Assume 802.2 SNAP frames for now.
 105          */
 106
 107         skb->dev = dev;
 108         skb_reset_mac_header(skb);      /* point to frame control (FC) */
 109
 110         if(fddi->hdr.llc_8022_1.dsap==0xe0)
 111         {
 112                 skb_pull(skb, FDDI_K_8022_HLEN-3);
 113                 type = htons(ETH_P_802_2);
 114         }
 115         else
 116         {
 117                 skb_pull(skb, FDDI_K_SNAP_HLEN);                /* adjust for 21 byte header */
 118                 type=fddi->hdr.llc_snap.ethertype;
 119         }
 120
 121         /* Set packet type based on destination address and flag settings */
 122
 123         if (*fddi->daddr & 0x01)
 124         {
 125                 if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
 126                         skb->pkt_type = PACKET_BROADCAST;
 127                 else
 128                         skb->pkt_type = PACKET_MULTICAST;
 129         }
 130
 131         else if (dev->flags & IFF_PROMISC)
 132         {
 133                 if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
 134                         skb->pkt_type = PACKET_OTHERHOST;
 135         }
 136
 137         /* Assume 802.2 SNAP frames, for now */
 138
 139         return type;
 140 }
 141
 142 EXPORT_SYMBOL(fddi_type_trans);
 143
 144 int fddi_change_mtu(struct net_device *dev, int new_mtu)
 145 {
 146         if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
 147                 return -EINVAL;
 148         dev->mtu = new_mtu;
 149         return 0;
 150 }
 151 EXPORT_SYMBOL(fddi_change_mtu);
 152
 153 static const struct header_ops fddi_header_ops = {
 154         .create         = fddi_header,
 155 };
 156
 157
 158 static void fddi_setup(struct net_device *dev)
 159 {
 160         dev->header_ops         = &fddi_header_ops;
 161         dev->type               = ARPHRD_FDDI;
 162         dev->hard_header_len    = FDDI_K_SNAP_HLEN+3;   /* Assume 802.2 SNAP hdr len + 3 pad bytes */
 163         dev->mtu                = FDDI_K_SNAP_DLEN;     /* Assume max payload of 802.2 SNAP frame */
 164         dev->addr_len           = FDDI_K_ALEN;
 165         dev->tx_queue_len       = 100;                  /* Long queues on FDDI */
 166         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
 167
 168         memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
 169 }
 170
 171 /**
 172  * alloc_fddidev - Register FDDI device
 173  * @sizeof_priv: Size of additional driver-private structure to be allocated
 174  *      for this FDDI device
 175  *
 176  * Fill in the fields of the device structure with FDDI-generic values.
 177  *
 178  * Constructs a new net device, complete with a private data area of
 179  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 180  * this private data area.
 181  */
 182 struct net_device *alloc_fddidev(int sizeof_priv)
 183 {
 184         return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN,
 185                             fddi_setup);
 186 }
 187 EXPORT_SYMBOL(alloc_fddidev);
 188
 189 MODULE_LICENSE("GPL");