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
52static 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
97static 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
167EXPORT_SYMBOL(fddi_type_trans);
168
169int 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}
176EXPORT_SYMBOL(fddi_change_mtu);
177
178static const struct header_ops fddi_header_ops = {
179	.create		= fddi_header,
180	.rebuild	= fddi_rebuild_header,
181};
182
183
184static 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 */
208struct net_device *alloc_fddidev(int sizeof_priv)
209{
210	return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN,
211			    fddi_setup);
212}
213EXPORT_SYMBOL(alloc_fddidev);
214
215MODULE_LICENSE("GPL");
216