aboutsummaryrefslogtreecommitdiffstats
path: root/net/802/fddi.c
blob: 5ab25cd4314b6f18292c2c34603de70cb955d435 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		FDDI-type device handling.
 *
 * Version:	@(#)fddi.c	1.0.0	08/12/96
 *
 * Authors:	Lawrence V. Stefani, <stefani@lkg.dec.com>
 *
 *		fddi.c is based on previous eth.c and tr.c work by
 *			Ross Biro
 *			Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *			Mark Evans, <evansmp@uhura.aston.ac.uk>
 *			Florian La Roche, <rzsfl@rz.uni-sb.de>
 *			Alan Cox, <gw4pts@gw4pts.ampr.org>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	Changes
 *		Alan Cox		:	New arp/rebuild header
 *		Maciej W. Rozycki	:	IPv6 support
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/fddidevice.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <net/arp.h>
#include <net/sock.h>

/*
 * Create the FDDI MAC header for an arbitrary protocol layer
 *
 * saddr=NULL	means use device source address
 * daddr=NULL	means leave destination address (eg unresolved arp)
 */

static int fddi_header(struct sk_buff *skb, struct net_device *dev,
		       unsigned short type,
		       const void *daddr, const void *saddr, unsigned len)
{
	int hl = FDDI_K_SNAP_HLEN;
	struct fddihdr *fddi;

	if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP)
		hl=FDDI_K_8022_HLEN-3;
	fddi = (struct fddihdr *)skb_push(skb, hl);
	fddi->fc			 = FDDI_FC_K_ASYNC_LLC_DEF;
	if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
	{
		fddi->hdr.llc_snap.dsap		 = FDDI_EXTENDED_SAP;
		fddi->hdr.llc_snap.ssap		 = FDDI_EXTENDED_SAP;
		fddi->hdr.llc_snap.ctrl		 = FDDI_UI_CMD;
		fddi->hdr.llc_snap.oui[0]	 = 0x00;
		fddi->hdr.llc_snap.oui[1]	 = 0x00;
		fddi->hdr.llc_snap.oui[2]	 = 0x00;
		fddi->hdr.llc_snap.ethertype	 = htons(type);
	}

	/* Set the source and destination hardware addresses */

	if (saddr != NULL)
		memcpy(fddi->saddr, saddr, dev->addr_len);
	else
		memcpy(fddi->saddr, dev->dev_addr, dev->addr_len);

	if (daddr != NULL)
	{
		memcpy(fddi->daddr, daddr, dev->addr_len);
		return hl;
	}

	return -hl;
}


/*
 * Rebuild the FDDI MAC header. This is called after an ARP
 * (or in future other address resolution) has completed on
 * this sk_buff.  We now let ARP fill in the other fields.
 */

static int fddi_rebuild_header(struct sk_buff	*skb)
{
	struct fddihdr *fddi = (struct fddihdr *)skb->data;

#ifdef CONFIG_INET
	if (fddi->hdr.llc_snap.ethertype == htons(ETH_P_IP))
		/* Try to get ARP to resolve the header and fill destination address */
		return arp_find(fddi->daddr, skb);
	else
#endif
	{
		printk("%s: Don't know how to resolve type %04X addresses.\n",
		       skb->dev->name, ntohs(fddi->hdr.llc_snap.ethertype));
		return 0;
	}
}


/*
 * Determine the packet's protocol ID and fill in skb fields.
 * This routine is called before an incoming packet is passed
 * up.  It's used to fill in specific skb fields and to set
 * the proper pointer to the start of packet data (skb->data).
 */

__be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
{
	struct fddihdr *fddi = (struct fddihdr *)skb->data;
	__be16 type;

	/*
	 * Set mac.raw field to point to FC byte, set data field to point
	 * to start of packet data.  Assume 802.2 SNAP frames for now.
	 */

	skb->dev = dev;
	skb_reset_mac_header(skb);	/* point to frame control (FC) */

	if(fddi->hdr.llc_8022_1.dsap==0xe0)
	{
		skb_pull(skb, FDDI_K_8022_HLEN-3);
		type = htons(ETH_P_802_2);
	}
	else
	{
		skb_pull(skb, FDDI_K_SNAP_HLEN);		/* adjust for 21 byte header */
		type=fddi->hdr.llc_snap.ethertype;
	}

	/* Set packet type based on destination address and flag settings */

	if (*fddi->daddr & 0x01)
	{
		if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
			skb->pkt_type = PACKET_BROADCAST;
		else
			skb->pkt_type = PACKET_MULTICAST;
	}

	else if (dev->flags & IFF_PROMISC)
	{
		if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
			skb->pkt_type = PACKET_OTHERHOST;
	}

	/* Assume 802.2 SNAP frames, for now */

	return type;
}

EXPORT_SYMBOL(fddi_type_trans);

int fddi_change_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}
EXPORT_SYMBOL(fddi_change_mtu);

static const struct header_ops fddi_header_ops = {
	.create		= fddi_header,
	.rebuild	= fddi_rebuild_header,
};


static void fddi_setup(struct net_device *dev)
{
	dev->header_ops		= &fddi_header_ops;
	dev->type		= ARPHRD_FDDI;
	dev->hard_header_len	= FDDI_K_SNAP_HLEN+3;	/* Assume 802.2 SNAP hdr len + 3 pad bytes */
	dev->mtu		= FDDI_K_SNAP_DLEN;	/* Assume max payload of 802.2 SNAP frame */
	dev->addr_len		= FDDI_K_ALEN;
	dev->tx_queue_len	= 100;			/* Long queues on FDDI */
	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;

	memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
}

/**
 * alloc_fddidev - Register FDDI device
 * @sizeof_priv: Size of additional driver-private structure to be allocated
 *	for this FDDI device
 *
 * Fill in the fields of the device structure with FDDI-generic values.
 *
 * Constructs a new net device, complete with a private data area of
 * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 * this private data area.
 */
struct net_device *alloc_fddidev(int sizeof_priv)
{
	return alloc_netdev(sizeof_priv, "fddi%d", fddi_setup);
}
EXPORT_SYMBOL(alloc_fddidev);

MODULE_LICENSE("GPL");