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