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 dev_addr_set(dev, addr->sa_data); 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); 194