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/sched.h> 27 #include <linux/string.h> 28 #include <linux/mm.h> 29 #include <linux/socket.h> 30 #include <linux/in.h> 31 #include <linux/inet.h> 32 #include <linux/netdevice.h> 33 #include <linux/hippidevice.h> 34 #include <linux/skbuff.h> 35 #include <linux/errno.h> 36 #include <net/arp.h> 37 #include <net/sock.h> 38 #include <asm/uaccess.h> 39 #include <asm/checksum.h> 40 #include <asm/system.h> 41 42 /* 43 * Create the HIPPI MAC header for an arbitrary protocol layer 44 * 45 * saddr=NULL means use device source address 46 * daddr=NULL means leave destination address (eg unresolved arp) 47 */ 48 49 static int hippi_header(struct sk_buff *skb, struct net_device *dev, 50 unsigned short type, void *daddr, void *saddr, 51 unsigned len) 52 { 53 struct hippi_hdr *hip = (struct hippi_hdr *)skb_push(skb, HIPPI_HLEN); 54 struct hippi_cb *hcb = (struct hippi_cb *) skb->cb; 55 56 if (!len){ 57 len = skb->len - HIPPI_HLEN; 58 printk("hippi_header(): length not supplied\n"); 59 } 60 61 /* 62 * Due to the stupidity of the little endian byte-order we 63 * have to set the fp field this way. 64 */ 65 hip->fp.fixed = __constant_htonl(0x04800018); 66 hip->fp.d2_size = htonl(len + 8); 67 hip->le.fc = 0; 68 hip->le.double_wide = 0; /* only HIPPI 800 for the time being */ 69 hip->le.message_type = 0; /* Data PDU */ 70 71 hip->le.dest_addr_type = 2; /* 12 bit SC address */ 72 hip->le.src_addr_type = 2; /* 12 bit SC address */ 73 74 memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3); 75 memset(&hip->le.reserved, 0, 16); 76 77 hip->snap.dsap = HIPPI_EXTENDED_SAP; 78 hip->snap.ssap = HIPPI_EXTENDED_SAP; 79 hip->snap.ctrl = HIPPI_UI_CMD; 80 hip->snap.oui[0] = 0x00; 81 hip->snap.oui[1] = 0x00; 82 hip->snap.oui[2] = 0x00; 83 hip->snap.ethertype = htons(type); 84 85 if (daddr) 86 { 87 memcpy(hip->le.dest_switch_addr, daddr + 3, 3); 88 memcpy(&hcb->ifield, daddr + 2, 4); 89 return HIPPI_HLEN; 90 } 91 hcb->ifield = 0; 92 return -((int)HIPPI_HLEN); 93 } 94 95 96 /* 97 * Rebuild the HIPPI MAC header. This is called after an ARP has 98 * completed on this sk_buff. We now let ARP fill in the other fields. 99 */ 100 101 static int hippi_rebuild_header(struct sk_buff *skb) 102 { 103 struct hippi_hdr *hip = (struct hippi_hdr *)skb->data; 104 105 /* 106 * Only IP is currently supported 107 */ 108 109 if(hip->snap.ethertype != __constant_htons(ETH_P_IP)) 110 { 111 printk(KERN_DEBUG "%s: unable to resolve type %X addresses.\n",skb->dev->name,ntohs(hip->snap.ethertype)); 112 return 0; 113 } 114 115 /* 116 * We don't support dynamic ARP on HIPPI, but we use the ARP 117 * static ARP tables to hold the I-FIELDs. 118 */ 119 return arp_find(hip->le.daddr, skb); 120 } 121 122 123 /* 124 * Determine the packet's protocol ID. 125 */ 126 127 __be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev) 128 { 129 struct hippi_hdr *hip; 130 131 hip = (struct hippi_hdr *) skb->data; 132 133 /* 134 * This is actually wrong ... question is if we really should 135 * set the raw address here. 136 */ 137 skb->mac.raw = skb->data; 138 skb_pull(skb, HIPPI_HLEN); 139 140 /* 141 * No fancy promisc stuff here now. 142 */ 143 144 return hip->snap.ethertype; 145 } 146 147 EXPORT_SYMBOL(hippi_type_trans); 148 149 static int hippi_change_mtu(struct net_device *dev, int new_mtu) 150 { 151 /* 152 * HIPPI's got these nice large MTUs. 153 */ 154 if ((new_mtu < 68) || (new_mtu > 65280)) 155 return -EINVAL; 156 dev->mtu = new_mtu; 157 return(0); 158 } 159 160 /* 161 * For HIPPI we will actually use the lower 4 bytes of the hardware 162 * address as the I-FIELD rather than the actual hardware address. 163 */ 164 static int hippi_mac_addr(struct net_device *dev, void *p) 165 { 166 struct sockaddr *addr = p; 167 if (netif_running(dev)) 168 return -EBUSY; 169 memcpy(dev->dev_addr, addr->sa_data, dev->addr_len); 170 return 0; 171 } 172 173 static 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 } 186 187 static void hippi_setup(struct net_device *dev) 188 { 189 dev->set_multicast_list = NULL; 190 dev->change_mtu = hippi_change_mtu; 191 dev->hard_header = hippi_header; 192 dev->rebuild_header = hippi_rebuild_header; 193 dev->set_mac_address = hippi_mac_addr; 194 dev->hard_header_parse = NULL; 195 dev->hard_header_cache = NULL; 196 dev->header_cache_update = NULL; 197 dev->neigh_setup = hippi_neigh_setup_dev; 198 199 /* 200 * We don't support HIPPI `ARP' for the time being, and probably 201 * never will unless someone else implements it. However we 202 * still need a fake ARPHRD to make ifconfig and friends play ball. 203 */ 204 dev->type = ARPHRD_HIPPI; 205 dev->hard_header_len = HIPPI_HLEN; 206 dev->mtu = 65280; 207 dev->addr_len = HIPPI_ALEN; 208 dev->tx_queue_len = 25 /* 5 */; 209 memset(dev->broadcast, 0xFF, HIPPI_ALEN); 210 211 212 /* 213 * HIPPI doesn't support broadcast+multicast and we only use 214 * static ARP tables. ARP is disabled by hippi_neigh_setup_dev. 215 */ 216 dev->flags = 0; 217 } 218 219 /** 220 * alloc_hippi_dev - Register HIPPI device 221 * @sizeof_priv: Size of additional driver-private structure to be allocated 222 * for this HIPPI device 223 * 224 * Fill in the fields of the device structure with HIPPI-generic values. 225 * 226 * Constructs a new net device, complete with a private data area of 227 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for 228 * this private data area. 229 */ 230 231 struct net_device *alloc_hippi_dev(int sizeof_priv) 232 { 233 return alloc_netdev(sizeof_priv, "hip%d", hippi_setup); 234 } 235 236 EXPORT_SYMBOL(alloc_hippi_dev); 237