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
fddi_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned len)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 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
fddi_rebuild_header(struct sk_buff * skb)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
fddi_type_trans(struct sk_buff * skb,struct net_device * dev)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
fddi_change_mtu(struct net_device * dev,int new_mtu)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
fddi_setup(struct net_device * dev)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 */
alloc_fddidev(int sizeof_priv)208 struct net_device *alloc_fddidev(int sizeof_priv)
209 {
210 return alloc_netdev(sizeof_priv, "fddi%d", fddi_setup);
211 }
212 EXPORT_SYMBOL(alloc_fddidev);
213
214 MODULE_LICENSE("GPL");
215