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 <asm/uaccess.h> 38 #include <asm/system.h> 39 40 /* 41 * Create the HIPPI MAC header for an arbitrary protocol layer 42 * 43 * saddr=NULL means use device source address 44 * daddr=NULL means leave destination address (eg unresolved arp) 45 */ 46 47 static int hippi_header(struct sk_buff *skb, struct net_device *dev, 48 unsigned short type, 49 const void *daddr, const void *saddr, unsigned len) 50 { 51 struct hippi_hdr *hip = (struct hippi_hdr *)skb_push(skb, HIPPI_HLEN); 52 struct hippi_cb *hcb = (struct hippi_cb *) skb->cb; 53 54 if (!len){ 55 len = skb->len - HIPPI_HLEN; 56 printk("hippi_header(): length not supplied\n"); 57 } 58 59 /* 60 * Due to the stupidity of the little endian byte-order we 61 * have to set the fp field this way. 62 */ 63 hip->fp.fixed = htonl(0x04800018); 64 hip->fp.d2_size = htonl(len + 8); 65 hip->le.fc = 0; 66 hip->le.double_wide = 0; /* only HIPPI 800 for the time being */ 67 hip->le.message_type = 0; /* Data PDU */ 68 69 hip->le.dest_addr_type = 2; /* 12 bit SC address */ 70 hip->le.src_addr_type = 2; /* 12 bit SC address */ 71 72 memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3); 73 memset(&hip->le.reserved, 0, 16); 74 75 hip->snap.dsap = HIPPI_EXTENDED_SAP; 76 hip->snap.ssap = HIPPI_EXTENDED_SAP; 77 hip->snap.ctrl = HIPPI_UI_CMD; 78 hip->snap.oui[0] = 0x00; 79 hip->snap.oui[1] = 0x00; 80 hip->snap.oui[2] = 0x00; 81 hip->snap.ethertype = htons(type); 82 83 if (daddr) 84 { 85 memcpy(hip->le.dest_switch_addr, daddr + 3, 3); 86 memcpy(&hcb->ifield, daddr + 2, 4); 87 return HIPPI_HLEN; 88 } 89 hcb->ifield = 0; 90 return -((int)HIPPI_HLEN); 91 } 92 93 94 /* 95 * Rebuild the HIPPI MAC header. This is called after an ARP has 96 * completed on this sk_buff. We now let ARP fill in the other fields. 97 */ 98 99 static int hippi_rebuild_header(struct sk_buff *skb) 100 { 101 struct hippi_hdr *hip = (struct hippi_hdr *)skb->data; 102 103 /* 104 * Only IP is currently supported 105 */ 106 107 if(hip->snap.ethertype != htons(ETH_P_IP)) 108 { 109 printk(KERN_DEBUG "%s: unable to resolve type %X addresses.\n",skb->dev->name,ntohs(hip->snap.ethertype)); 110 return 0; 111 } 112 113 /* 114 * We don't support dynamic ARP on HIPPI, but we use the ARP 115 * static ARP tables to hold the I-FIELDs. 116 */ 117 return arp_find(hip->le.daddr, skb); 118 } 119 120 121 /* 122 * Determine the packet's protocol ID. 123 */ 124 125 __be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev) 126 { 127 struct hippi_hdr *hip; 128 129 /* 130 * This is actually wrong ... question is if we really should 131 * set the raw address here. 132 */ 133 skb->dev = dev; 134 skb_reset_mac_header(skb); 135 hip = (struct hippi_hdr *)skb_mac_header(skb); 136 skb_pull(skb, HIPPI_HLEN); 137 138 /* 139 * No fancy promisc stuff here now. 140 */ 141 142 return hip->snap.ethertype; 143 } 144 145 EXPORT_SYMBOL(hippi_type_trans); 146 147 int hippi_change_mtu(struct net_device *dev, int new_mtu) 148 { 149 /* 150 * HIPPI's got these nice large MTUs. 151 */ 152 if ((new_mtu < 68) || (new_mtu > 65280)) 153 return -EINVAL; 154 dev->mtu = new_mtu; 155 return 0; 156 } 157 EXPORT_SYMBOL(hippi_change_mtu); 158 159 /* 160 * For HIPPI we will actually use the lower 4 bytes of the hardware 161 * address as the I-FIELD rather than the actual hardware address. 162 */ 163 int hippi_mac_addr(struct net_device *dev, void *p) 164 { 165 struct sockaddr *addr = p; 166 if (netif_running(dev)) 167 return -EBUSY; 168 memcpy(dev->dev_addr, addr->sa_data, dev->addr_len); 169 return 0; 170 } 171 EXPORT_SYMBOL(hippi_mac_addr); 172 173 int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p) 174 { 175 /* Never send broadcast/multicast ARP messages */ 176 p->mcast_probes = 0; 177 178 /* In IPv6 unicast probes are valid even on NBMA, 179 * because they are encapsulated in normal IPv6 protocol. 180 * Should be a generic flag. 181 */ 182 if (p->tbl->family != AF_INET6) 183 p->ucast_probes = 0; 184 return 0; 185 } 186 EXPORT_SYMBOL(hippi_neigh_setup_dev); 187 188 static const struct header_ops hippi_header_ops = { 189 .create = hippi_header, 190 .rebuild = hippi_rebuild_header, 191 }; 192 193 194 static void hippi_setup(struct net_device *dev) 195 { 196 dev->header_ops = &hippi_header_ops; 197 198 /* 199 * We don't support HIPPI `ARP' for the time being, and probably 200 * never will unless someone else implements it. However we 201 * still need a fake ARPHRD to make ifconfig and friends play ball. 202 */ 203 dev->type = ARPHRD_HIPPI; 204 dev->hard_header_len = HIPPI_HLEN; 205 dev->mtu = 65280; 206 dev->addr_len = HIPPI_ALEN; 207 dev->tx_queue_len = 25 /* 5 */; 208 memset(dev->broadcast, 0xFF, HIPPI_ALEN); 209 210 211 /* 212 * HIPPI doesn't support broadcast+multicast and we only use 213 * static ARP tables. ARP is disabled by hippi_neigh_setup_dev. 214 */ 215 dev->flags = 0; 216 } 217 218 /** 219 * alloc_hippi_dev - Register HIPPI device 220 * @sizeof_priv: Size of additional driver-private structure to be allocated 221 * for this HIPPI device 222 * 223 * Fill in the fields of the device structure with HIPPI-generic values. 224 * 225 * Constructs a new net device, complete with a private data area of 226 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for 227 * this private data area. 228 */ 229 230 struct net_device *alloc_hippi_dev(int sizeof_priv) 231 { 232 return alloc_netdev(sizeof_priv, "hip%d", hippi_setup); 233 } 234 235 EXPORT_SYMBOL(alloc_hippi_dev); 236