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 * Determine the packet's protocol ID and fill in skb fields.
92 * This routine is called before an incoming packet is passed
93 * up.  It's used to fill in specific skb fields and to set
94 * the proper pointer to the start of packet data (skb->data).
95 */
96
97__be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
98{
99	struct fddihdr *fddi = (struct fddihdr *)skb->data;
100	__be16 type;
101
102	/*
103	 * Set mac.raw field to point to FC byte, set data field to point
104	 * to start of packet data.  Assume 802.2 SNAP frames for now.
105	 */
106
107	skb->dev = dev;
108	skb_reset_mac_header(skb);	/* point to frame control (FC) */
109
110	if(fddi->hdr.llc_8022_1.dsap==0xe0)
111	{
112		skb_pull(skb, FDDI_K_8022_HLEN-3);
113		type = htons(ETH_P_802_2);
114	}
115	else
116	{
117		skb_pull(skb, FDDI_K_SNAP_HLEN);		/* adjust for 21 byte header */
118		type=fddi->hdr.llc_snap.ethertype;
119	}
120
121	/* Set packet type based on destination address and flag settings */
122
123	if (*fddi->daddr & 0x01)
124	{
125		if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
126			skb->pkt_type = PACKET_BROADCAST;
127		else
128			skb->pkt_type = PACKET_MULTICAST;
129	}
130
131	else if (dev->flags & IFF_PROMISC)
132	{
133		if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
134			skb->pkt_type = PACKET_OTHERHOST;
135	}
136
137	/* Assume 802.2 SNAP frames, for now */
138
139	return type;
140}
141
142EXPORT_SYMBOL(fddi_type_trans);
143
144int fddi_change_mtu(struct net_device *dev, int new_mtu)
145{
146	if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
147		return -EINVAL;
148	dev->mtu = new_mtu;
149	return 0;
150}
151EXPORT_SYMBOL(fddi_change_mtu);
152
153static const struct header_ops fddi_header_ops = {
154	.create		= fddi_header,
155};
156
157
158static void fddi_setup(struct net_device *dev)
159{
160	dev->header_ops		= &fddi_header_ops;
161	dev->type		= ARPHRD_FDDI;
162	dev->hard_header_len	= FDDI_K_SNAP_HLEN+3;	/* Assume 802.2 SNAP hdr len + 3 pad bytes */
163	dev->mtu		= FDDI_K_SNAP_DLEN;	/* Assume max payload of 802.2 SNAP frame */
164	dev->addr_len		= FDDI_K_ALEN;
165	dev->tx_queue_len	= 100;			/* Long queues on FDDI */
166	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
167
168	memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
169}
170
171/**
172 * alloc_fddidev - Register FDDI device
173 * @sizeof_priv: Size of additional driver-private structure to be allocated
174 *	for this FDDI device
175 *
176 * Fill in the fields of the device structure with FDDI-generic values.
177 *
178 * Constructs a new net device, complete with a private data area of
179 * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
180 * this private data area.
181 */
182struct net_device *alloc_fddidev(int sizeof_priv)
183{
184	return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN,
185			    fddi_setup);
186}
187EXPORT_SYMBOL(alloc_fddidev);
188
189MODULE_LICENSE("GPL");
190