net/802/hippi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4  *              operating system.  INET is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              HIPPI-type device handling.
   8  *
   9  * Version:     @(#)hippi.c     1.0.0   05/29/97
  10  *
  11  * Authors:     Ross Biro
  12  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  13  *              Mark Evans, <evansmp@uhura.aston.ac.uk>
  14  *              Florian  La Roche, <rzsfl@rz.uni-sb.de>
  15  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  16  *              Jes Sorensen, <Jes.Sorensen@cern.ch>
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/types.h>
  21 #include <linux/kernel.h>
  22 #include <linux/string.h>
  23 #include <linux/mm.h>
  24 #include <linux/socket.h>
  25 #include <linux/in.h>
  26 #include <linux/inet.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/hippidevice.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/errno.h>
  31 #include <net/arp.h>
  32 #include <net/sock.h>
  33 #include <linux/uaccess.h>
  34
  35 /*
  36  * Create the HIPPI MAC header for an arbitrary protocol layer
  37  *
  38  * saddr=NULL   means use device source address
  39  * daddr=NULL   means leave destination address (eg unresolved arp)
  40  */
  41
  42 static int hippi_header(struct sk_buff *skb, struct net_device *dev,
  43                         unsigned short type,
  44                         const void *daddr, const void *saddr, unsigned int len)
  45 {
  46         struct hippi_hdr *hip = skb_push(skb, HIPPI_HLEN);
  47         struct hippi_cb *hcb = (struct hippi_cb *) skb->cb;
  48
  49         if (!len){
  50                 len = skb->len - HIPPI_HLEN;
  51                 printk("hippi_header(): length not supplied\n");
  52         }
  53
  54         /*
  55          * Due to the stupidity of the little endian byte-order we
  56          * have to set the fp field this way.
  57          */
  58         hip->fp.fixed           = htonl(0x04800018);
  59         hip->fp.d2_size         = htonl(len + 8);
  60         hip->le.fc              = 0;
  61         hip->le.double_wide     = 0;    /* only HIPPI 800 for the time being */
  62         hip->le.message_type    = 0;    /* Data PDU */
  63
  64         hip->le.dest_addr_type  = 2;    /* 12 bit SC address */
  65         hip->le.src_addr_type   = 2;    /* 12 bit SC address */
  66
  67         memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
  68         memset(&hip->le.reserved, 0, 16);
  69
  70         hip->snap.dsap          = HIPPI_EXTENDED_SAP;
  71         hip->snap.ssap          = HIPPI_EXTENDED_SAP;
  72         hip->snap.ctrl          = HIPPI_UI_CMD;
  73         hip->snap.oui[0]        = 0x00;
  74         hip->snap.oui[1]        = 0x00;
  75         hip->snap.oui[2]        = 0x00;
  76         hip->snap.ethertype     = htons(type);
  77
  78         if (daddr)
  79         {
  80                 memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
  81                 memcpy(&hcb->ifield, daddr + 2, 4);
  82                 return HIPPI_HLEN;
  83         }
  84         hcb->ifield = 0;
  85         return -((int)HIPPI_HLEN);
  86 }
  87
  88
  89 /*
  90  *      Determine the packet's protocol ID.
  91  */
  92
  93 __be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
  94 {
  95         struct hippi_hdr *hip;
  96
  97         /*
  98          * This is actually wrong ... question is if we really should
  99          * set the raw address here.
 100          */
 101         skb->dev = dev;
 102         skb_reset_mac_header(skb);
 103         hip = (struct hippi_hdr *)skb_mac_header(skb);
 104         skb_pull(skb, HIPPI_HLEN);
 105
 106         /*
 107          * No fancy promisc stuff here now.
 108          */
 109
 110         return hip->snap.ethertype;
 111 }
 112
 113 EXPORT_SYMBOL(hippi_type_trans);
 114
 115 /*
 116  * For HIPPI we will actually use the lower 4 bytes of the hardware
 117  * address as the I-FIELD rather than the actual hardware address.
 118  */
 119 int hippi_mac_addr(struct net_device *dev, void *p)
 120 {
 121         struct sockaddr *addr = p;
 122         if (netif_running(dev))
 123                 return -EBUSY;
 124         memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
 125         return 0;
 126 }
 127 EXPORT_SYMBOL(hippi_mac_addr);
 128
 129 int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
 130 {
 131         /* Never send broadcast/multicast ARP messages */
 132         NEIGH_VAR_INIT(p, MCAST_PROBES, 0);
 133
 134         /* In IPv6 unicast probes are valid even on NBMA,
 135         * because they are encapsulated in normal IPv6 protocol.
 136         * Should be a generic flag.
 137         */
 138         if (p->tbl->family != AF_INET6)
 139                 NEIGH_VAR_INIT(p, UCAST_PROBES, 0);
 140         return 0;
 141 }
 142 EXPORT_SYMBOL(hippi_neigh_setup_dev);
 143
 144 static const struct header_ops hippi_header_ops = {
 145         .create         = hippi_header,
 146 };
 147
 148
 149 static void hippi_setup(struct net_device *dev)
 150 {
 151         dev->header_ops                 = &hippi_header_ops;
 152
 153         /*
 154          * We don't support HIPPI `ARP' for the time being, and probably
 155          * never will unless someone else implements it. However we
 156          * still need a fake ARPHRD to make ifconfig and friends play ball.
 157          */
 158         dev->type               = ARPHRD_HIPPI;
 159         dev->hard_header_len    = HIPPI_HLEN;
 160         dev->mtu                = 65280;
 161         dev->min_mtu            = 68;
 162         dev->max_mtu            = 65280;
 163         dev->addr_len           = HIPPI_ALEN;
 164         dev->tx_queue_len       = 25 /* 5 */;
 165         memset(dev->broadcast, 0xFF, HIPPI_ALEN);
 166
 167
 168         /*
 169          * HIPPI doesn't support broadcast+multicast and we only use
 170          * static ARP tables. ARP is disabled by hippi_neigh_setup_dev.
 171          */
 172         dev->flags = 0;
 173 }
 174
 175 /**
 176  * alloc_hippi_dev - Register HIPPI device
 177  * @sizeof_priv: Size of additional driver-private structure to be allocated
 178  *      for this HIPPI device
 179  *
 180  * Fill in the fields of the device structure with HIPPI-generic values.
 181  *
 182  * Constructs a new net device, complete with a private data area of
 183  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 184  * this private data area.
 185  */
 186
 187 struct net_device *alloc_hippi_dev(int sizeof_priv)
 188 {
 189         return alloc_netdev(sizeof_priv, "hip%d", NET_NAME_UNKNOWN,
 190                             hippi_setup);
 191 }
 192
 193 EXPORT_SYMBOL(alloc_hippi_dev);