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 * FDDI-type device handling. 8 * 9 * Version: @(#)fddi.c 1.0.0 08/12/96 10 * 11 * Authors: Lawrence V. Stefani, <stefani@lkg.dec.com> 12 * 13 * fddi.c is based on previous eth.c and tr.c work by 14 * Ross Biro 15 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 16 * Mark Evans, <evansmp@uhura.aston.ac.uk> 17 * Florian La Roche, <rzsfl@rz.uni-sb.de> 18 * Alan Cox, <gw4pts@gw4pts.ampr.org> 19 * 20 * Changes 21 * Alan Cox : New arp/rebuild header 22 * Maciej W. Rozycki : IPv6 support 23 */ 24 25 #include <linux/module.h> 26 #include <linux/types.h> 27 #include <linux/kernel.h> 28 #include <linux/string.h> 29 #include <linux/mm.h> 30 #include <linux/socket.h> 31 #include <linux/in.h> 32 #include <linux/inet.h> 33 #include <linux/netdevice.h> 34 #include <linux/fddidevice.h> 35 #include <linux/if_ether.h> 36 #include <linux/skbuff.h> 37 #include <linux/errno.h> 38 #include <net/arp.h> 39 #include <net/sock.h> 40 41 /* 42 * Create the FDDI MAC header for an arbitrary protocol layer 43 * 44 * saddr=NULL means use device source address 45 * daddr=NULL means leave destination address (eg unresolved arp) 46 */ 47 48 static int fddi_header(struct sk_buff *skb, struct net_device *dev, 49 unsigned short type, 50 const void *daddr, const void *saddr, unsigned int len) 51 { 52 int hl = FDDI_K_SNAP_HLEN; 53 struct fddihdr *fddi; 54 55 if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP) 56 hl=FDDI_K_8022_HLEN-3; 57 fddi = skb_push(skb, hl); 58 fddi->fc = FDDI_FC_K_ASYNC_LLC_DEF; 59 if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP) 60 { 61 fddi->hdr.llc_snap.dsap = FDDI_EXTENDED_SAP; 62 fddi->hdr.llc_snap.ssap = FDDI_EXTENDED_SAP; 63 fddi->hdr.llc_snap.ctrl = FDDI_UI_CMD; 64 fddi->hdr.llc_snap.oui[0] = 0x00; 65 fddi->hdr.llc_snap.oui[1] = 0x00; 66 fddi->hdr.llc_snap.oui[2] = 0x00; 67 fddi->hdr.llc_snap.ethertype = htons(type); 68 } 69 70 /* Set the source and destination hardware addresses */ 71 72 if (saddr != NULL) 73 memcpy(fddi->saddr, saddr, dev->addr_len); 74 else 75 memcpy(fddi->saddr, dev->dev_addr, dev->addr_len); 76 77 if (daddr != NULL) 78 { 79 memcpy(fddi->daddr, daddr, dev->addr_len); 80 return hl; 81 } 82 83 return -hl; 84 } 85 86 /* 87 * Determine the packet's protocol ID and fill in skb fields. 88 * This routine is called before an incoming packet is passed 89 * up. It's used to fill in specific skb fields and to set 90 * the proper pointer to the start of packet data (skb->data). 91 */ 92 93 __be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev) 94 { 95 struct fddihdr *fddi = (struct fddihdr *)skb->data; 96 __be16 type; 97 98 /* 99 * Set mac.raw field to point to FC byte, set data field to point 100 * to start of packet data. Assume 802.2 SNAP frames for now. 101 */ 102 103 skb->dev = dev; 104 skb_reset_mac_header(skb); /* point to frame control (FC) */ 105 106 if(fddi->hdr.llc_8022_1.dsap==0xe0) 107 { 108 skb_pull(skb, FDDI_K_8022_HLEN-3); 109 type = htons(ETH_P_802_2); 110 } 111 else 112 { 113 skb_pull(skb, FDDI_K_SNAP_HLEN); /* adjust for 21 byte header */ 114 type=fddi->hdr.llc_snap.ethertype; 115 } 116 117 /* Set packet type based on destination address and flag settings */ 118 119 if (*fddi->daddr & 0x01) 120 { 121 if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0) 122 skb->pkt_type = PACKET_BROADCAST; 123 else 124 skb->pkt_type = PACKET_MULTICAST; 125 } 126 127 else if (dev->flags & IFF_PROMISC) 128 { 129 if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN)) 130 skb->pkt_type = PACKET_OTHERHOST; 131 } 132 133 /* Assume 802.2 SNAP frames, for now */ 134 135 return type; 136 } 137 138 EXPORT_SYMBOL(fddi_type_trans); 139 140 static const struct header_ops fddi_header_ops = { 141 .create = fddi_header, 142 }; 143 144 145 static void fddi_setup(struct net_device *dev) 146 { 147 dev->header_ops = &fddi_header_ops; 148 dev->type = ARPHRD_FDDI; 149 dev->hard_header_len = FDDI_K_SNAP_HLEN+3; /* Assume 802.2 SNAP hdr len + 3 pad bytes */ 150 dev->mtu = FDDI_K_SNAP_DLEN; /* Assume max payload of 802.2 SNAP frame */ 151 dev->min_mtu = FDDI_K_SNAP_HLEN; 152 dev->max_mtu = FDDI_K_SNAP_DLEN; 153 dev->addr_len = FDDI_K_ALEN; 154 dev->tx_queue_len = 100; /* Long queues on FDDI */ 155 dev->flags = IFF_BROADCAST | IFF_MULTICAST; 156 157 memset(dev->broadcast, 0xFF, FDDI_K_ALEN); 158 } 159 160 /** 161 * alloc_fddidev - Register FDDI device 162 * @sizeof_priv: Size of additional driver-private structure to be allocated 163 * for this FDDI device 164 * 165 * Fill in the fields of the device structure with FDDI-generic values. 166 * 167 * Constructs a new net device, complete with a private data area of 168 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for 169 * this private data area. 170 */ 171 struct net_device *alloc_fddidev(int sizeof_priv) 172 { 173 return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN, 174 fddi_setup); 175 } 176 EXPORT_SYMBOL(alloc_fddidev); 177 178 MODULE_DESCRIPTION("Core routines for FDDI network devices"); 179 MODULE_LICENSE("GPL"); 180