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 <linux/types.h> 31 #include <linux/kernel.h> 32 #include <linux/string.h> 33 #include <linux/mm.h> 34 #include <linux/socket.h> 35 #include <linux/in.h> 36 #include <linux/inet.h> 37 #include <linux/netdevice.h> 38 #include <linux/fddidevice.h> 39 #include <linux/if_ether.h> 40 #include <linux/skbuff.h> 41 #include <linux/errno.h> 42 #include <net/arp.h> 43 #include <net/sock.h> 44 45 /* 46 * Create the FDDI MAC header for an arbitrary protocol layer 47 * 48 * saddr=NULL means use device source address 49 * daddr=NULL means leave destination address (eg unresolved arp) 50 */ 51 52 static int fddi_header(struct sk_buff *skb, struct net_device *dev, 53 unsigned short type, 54 const void *daddr, const void *saddr, unsigned int len) 55 { 56 int hl = FDDI_K_SNAP_HLEN; 57 struct fddihdr *fddi; 58 59 if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP) 60 hl=FDDI_K_8022_HLEN-3; 61 fddi = (struct fddihdr *)skb_push(skb, hl); 62 fddi->fc = FDDI_FC_K_ASYNC_LLC_DEF; 63 if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP) 64 { 65 fddi->hdr.llc_snap.dsap = FDDI_EXTENDED_SAP; 66 fddi->hdr.llc_snap.ssap = FDDI_EXTENDED_SAP; 67 fddi->hdr.llc_snap.ctrl = FDDI_UI_CMD; 68 fddi->hdr.llc_snap.oui[0] = 0x00; 69 fddi->hdr.llc_snap.oui[1] = 0x00; 70 fddi->hdr.llc_snap.oui[2] = 0x00; 71 fddi->hdr.llc_snap.ethertype = htons(type); 72 } 73 74 /* Set the source and destination hardware addresses */ 75 76 if (saddr != NULL) 77 memcpy(fddi->saddr, saddr, dev->addr_len); 78 else 79 memcpy(fddi->saddr, dev->dev_addr, dev->addr_len); 80 81 if (daddr != NULL) 82 { 83 memcpy(fddi->daddr, daddr, dev->addr_len); 84 return hl; 85 } 86 87 return -hl; 88 } 89 90 91 /* 92 * Rebuild the FDDI MAC header. This is called after an ARP 93 * (or in future other address resolution) has completed on 94 * this sk_buff. We now let ARP fill in the other fields. 95 */ 96 97 static int fddi_rebuild_header(struct sk_buff *skb) 98 { 99 struct fddihdr *fddi = (struct fddihdr *)skb->data; 100 101 #ifdef CONFIG_INET 102 if (fddi->hdr.llc_snap.ethertype == htons(ETH_P_IP)) 103 /* Try to get ARP to resolve the header and fill destination address */ 104 return arp_find(fddi->daddr, skb); 105 else 106 #endif 107 { 108 printk("%s: Don't know how to resolve type %04X addresses.\n", 109 skb->dev->name, ntohs(fddi->hdr.llc_snap.ethertype)); 110 return 0; 111 } 112 } 113 114 115 /* 116 * Determine the packet's protocol ID and fill in skb fields. 117 * This routine is called before an incoming packet is passed 118 * up. It's used to fill in specific skb fields and to set 119 * the proper pointer to the start of packet data (skb->data). 120 */ 121 122 __be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev) 123 { 124 struct fddihdr *fddi = (struct fddihdr *)skb->data; 125 __be16 type; 126 127 /* 128 * Set mac.raw field to point to FC byte, set data field to point 129 * to start of packet data. Assume 802.2 SNAP frames for now. 130 */ 131 132 skb->dev = dev; 133 skb_reset_mac_header(skb); /* point to frame control (FC) */ 134 135 if(fddi->hdr.llc_8022_1.dsap==0xe0) 136 { 137 skb_pull(skb, FDDI_K_8022_HLEN-3); 138 type = htons(ETH_P_802_2); 139 } 140 else 141 { 142 skb_pull(skb, FDDI_K_SNAP_HLEN); /* adjust for 21 byte header */ 143 type=fddi->hdr.llc_snap.ethertype; 144 } 145 146 /* Set packet type based on destination address and flag settings */ 147 148 if (*fddi->daddr & 0x01) 149 { 150 if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0) 151 skb->pkt_type = PACKET_BROADCAST; 152 else 153 skb->pkt_type = PACKET_MULTICAST; 154 } 155 156 else if (dev->flags & IFF_PROMISC) 157 { 158 if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN)) 159 skb->pkt_type = PACKET_OTHERHOST; 160 } 161 162 /* Assume 802.2 SNAP frames, for now */ 163 164 return type; 165 } 166 167 EXPORT_SYMBOL(fddi_type_trans); 168 169 int fddi_change_mtu(struct net_device *dev, int new_mtu) 170 { 171 if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN)) 172 return -EINVAL; 173 dev->mtu = new_mtu; 174 return 0; 175 } 176 EXPORT_SYMBOL(fddi_change_mtu); 177 178 static const struct header_ops fddi_header_ops = { 179 .create = fddi_header, 180 .rebuild = fddi_rebuild_header, 181 }; 182 183 184 static void fddi_setup(struct net_device *dev) 185 { 186 dev->header_ops = &fddi_header_ops; 187 dev->type = ARPHRD_FDDI; 188 dev->hard_header_len = FDDI_K_SNAP_HLEN+3; /* Assume 802.2 SNAP hdr len + 3 pad bytes */ 189 dev->mtu = FDDI_K_SNAP_DLEN; /* Assume max payload of 802.2 SNAP frame */ 190 dev->addr_len = FDDI_K_ALEN; 191 dev->tx_queue_len = 100; /* Long queues on FDDI */ 192 dev->flags = IFF_BROADCAST | IFF_MULTICAST; 193 194 memset(dev->broadcast, 0xFF, FDDI_K_ALEN); 195 } 196 197 /** 198 * alloc_fddidev - Register FDDI device 199 * @sizeof_priv: Size of additional driver-private structure to be allocated 200 * for this FDDI device 201 * 202 * Fill in the fields of the device structure with FDDI-generic values. 203 * 204 * Constructs a new net device, complete with a private data area of 205 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for 206 * this private data area. 207 */ 208 struct net_device *alloc_fddidev(int sizeof_priv) 209 { 210 return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN, 211 fddi_setup); 212 } 213 EXPORT_SYMBOL(alloc_fddidev); 214 215 MODULE_LICENSE("GPL"); 216