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 <asm/system.h>
  31 #include <linux/types.h>
  32 #include <linux/kernel.h>
  33 #include <linux/string.h>
  34 #include <linux/mm.h>
  35 #include <linux/socket.h>
  36 #include <linux/in.h>
  37 #include <linux/inet.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/fddidevice.h>
  40 #include <linux/if_ether.h>
  41 #include <linux/skbuff.h>
  42 #include <linux/errno.h>
  43 #include <net/arp.h>
  44 #include <net/sock.h>
  45
  46 /*
  47  * Create the FDDI MAC header for an arbitrary protocol layer
  48  *
  49  * saddr=NULL   means use device source address
  50  * daddr=NULL   means leave destination address (eg unresolved arp)
  51  */
  52
  53 static int fddi_header(struct sk_buff *skb, struct net_device *dev,
  54                        unsigned short type,
  55                        const void *daddr, const void *saddr, unsigned len)
  56 {
  57         int hl = FDDI_K_SNAP_HLEN;
  58         struct fddihdr *fddi;
  59
  60         if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP)
  61                 hl=FDDI_K_8022_HLEN-3;
  62         fddi = (struct fddihdr *)skb_push(skb, hl);
  63         fddi->fc                         = FDDI_FC_K_ASYNC_LLC_DEF;
  64         if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
  65         {
  66                 fddi->hdr.llc_snap.dsap          = FDDI_EXTENDED_SAP;
  67                 fddi->hdr.llc_snap.ssap          = FDDI_EXTENDED_SAP;
  68                 fddi->hdr.llc_snap.ctrl          = FDDI_UI_CMD;
  69                 fddi->hdr.llc_snap.oui[0]        = 0x00;
  70                 fddi->hdr.llc_snap.oui[1]        = 0x00;
  71                 fddi->hdr.llc_snap.oui[2]        = 0x00;
  72                 fddi->hdr.llc_snap.ethertype     = htons(type);
  73         }
  74
  75         /* Set the source and destination hardware addresses */
  76
  77         if (saddr != NULL)
  78                 memcpy(fddi->saddr, saddr, dev->addr_len);
  79         else
  80                 memcpy(fddi->saddr, dev->dev_addr, dev->addr_len);
  81
  82         if (daddr != NULL)
  83         {
  84                 memcpy(fddi->daddr, daddr, dev->addr_len);
  85                 return(hl);
  86         }
  87
  88         return(-hl);
  89 }
  90
  91
  92 /*
  93  * Rebuild the FDDI MAC header. This is called after an ARP
  94  * (or in future other address resolution) has completed on
  95  * this sk_buff.  We now let ARP fill in the other fields.
  96  */
  97
  98 static int fddi_rebuild_header(struct sk_buff   *skb)
  99 {
 100         struct fddihdr *fddi = (struct fddihdr *)skb->data;
 101
 102 #ifdef CONFIG_INET
 103         if (fddi->hdr.llc_snap.ethertype == htons(ETH_P_IP))
 104                 /* Try to get ARP to resolve the header and fill destination address */
 105                 return arp_find(fddi->daddr, skb);
 106         else
 107 #endif
 108         {
 109                 printk("%s: Don't know how to resolve type %04X addresses.\n",
 110                        skb->dev->name, ntohs(fddi->hdr.llc_snap.ethertype));
 111                 return(0);
 112         }
 113 }
 114
 115
 116 /*
 117  * Determine the packet's protocol ID and fill in skb fields.
 118  * This routine is called before an incoming packet is passed
 119  * up.  It's used to fill in specific skb fields and to set
 120  * the proper pointer to the start of packet data (skb->data).
 121  */
 122
 123 __be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
 124 {
 125         struct fddihdr *fddi = (struct fddihdr *)skb->data;
 126         __be16 type;
 127
 128         /*
 129          * Set mac.raw field to point to FC byte, set data field to point
 130          * to start of packet data.  Assume 802.2 SNAP frames for now.
 131          */
 132
 133         skb->dev = dev;
 134         skb_reset_mac_header(skb);      /* point to frame control (FC) */
 135
 136         if(fddi->hdr.llc_8022_1.dsap==0xe0)
 137         {
 138                 skb_pull(skb, FDDI_K_8022_HLEN-3);
 139                 type = htons(ETH_P_802_2);
 140         }
 141         else
 142         {
 143                 skb_pull(skb, FDDI_K_SNAP_HLEN);                /* adjust for 21 byte header */
 144                 type=fddi->hdr.llc_snap.ethertype;
 145         }
 146
 147         /* Set packet type based on destination address and flag settings */
 148
 149         if (*fddi->daddr & 0x01)
 150         {
 151                 if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
 152                         skb->pkt_type = PACKET_BROADCAST;
 153                 else
 154                         skb->pkt_type = PACKET_MULTICAST;
 155         }
 156
 157         else if (dev->flags & IFF_PROMISC)
 158         {
 159                 if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
 160                         skb->pkt_type = PACKET_OTHERHOST;
 161         }
 162
 163         /* Assume 802.2 SNAP frames, for now */
 164
 165         return(type);
 166 }
 167
 168 EXPORT_SYMBOL(fddi_type_trans);
 169
 170 static int fddi_change_mtu(struct net_device *dev, int new_mtu)
 171 {
 172         if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
 173                 return(-EINVAL);
 174         dev->mtu = new_mtu;
 175         return(0);
 176 }
 177
 178 static const struct header_ops fddi_header_ops = {
 179         .create         = fddi_header,
 180         .rebuild        = fddi_rebuild_header,
 181 };
 182
 183 static void fddi_setup(struct net_device *dev)
 184 {
 185         dev->change_mtu         = fddi_change_mtu;
 186         dev->header_ops         = &fddi_header_ops;
 187
 188         dev->type               = ARPHRD_FDDI;
 189         dev->hard_header_len    = FDDI_K_SNAP_HLEN+3;   /* Assume 802.2 SNAP hdr len + 3 pad bytes */
 190         dev->mtu                = FDDI_K_SNAP_DLEN;     /* Assume max payload of 802.2 SNAP frame */
 191         dev->addr_len           = FDDI_K_ALEN;
 192         dev->tx_queue_len       = 100;                  /* Long queues on FDDI */
 193         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
 194
 195         memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
 196 }
 197
 198 /**
 199  * alloc_fddidev - Register FDDI device
 200  * @sizeof_priv: Size of additional driver-private structure to be allocated
 201  *      for this FDDI device
 202  *
 203  * Fill in the fields of the device structure with FDDI-generic values.
 204  *
 205  * Constructs a new net device, complete with a private data area of
 206  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 207  * this private data area.
 208  */
 209 struct net_device *alloc_fddidev(int sizeof_priv)
 210 {
 211         return alloc_netdev(sizeof_priv, "fddi%d", fddi_setup);
 212 }
 213 EXPORT_SYMBOL(alloc_fddidev);