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