xref: /linux/net/802/fddi.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
30 #include <linux/module.h>
31 #include <asm/system.h>
32 #include <linux/types.h>
33 #include <linux/kernel.h>
34 #include <linux/sched.h>
35 #include <linux/string.h>
36 #include <linux/mm.h>
37 #include <linux/socket.h>
38 #include <linux/in.h>
39 #include <linux/inet.h>
40 #include <linux/netdevice.h>
41 #include <linux/fddidevice.h>
42 #include <linux/if_ether.h>
43 #include <linux/skbuff.h>
44 #include <linux/errno.h>
45 #include <net/arp.h>
46 #include <net/sock.h>
47 
48 /*
49  * Create the FDDI MAC header for an arbitrary protocol layer
50  *
51  * saddr=NULL	means use device source address
52  * daddr=NULL	means leave destination address (eg unresolved arp)
53  */
54 
55 static int fddi_header(struct sk_buff *skb, struct net_device *dev,
56 		       unsigned short type,
57 		       void *daddr, void *saddr, unsigned len)
58 {
59 	int hl = FDDI_K_SNAP_HLEN;
60 	struct fddihdr *fddi;
61 
62 	if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP)
63 		hl=FDDI_K_8022_HLEN-3;
64 	fddi = (struct fddihdr *)skb_push(skb, hl);
65 	fddi->fc			 = FDDI_FC_K_ASYNC_LLC_DEF;
66 	if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
67 	{
68 		fddi->hdr.llc_snap.dsap		 = FDDI_EXTENDED_SAP;
69 		fddi->hdr.llc_snap.ssap		 = FDDI_EXTENDED_SAP;
70 		fddi->hdr.llc_snap.ctrl		 = FDDI_UI_CMD;
71 		fddi->hdr.llc_snap.oui[0]	 = 0x00;
72 		fddi->hdr.llc_snap.oui[1]	 = 0x00;
73 		fddi->hdr.llc_snap.oui[2]	 = 0x00;
74 		fddi->hdr.llc_snap.ethertype	 = htons(type);
75 	}
76 
77 	/* Set the source and destination hardware addresses */
78 
79 	if (saddr != NULL)
80 		memcpy(fddi->saddr, saddr, dev->addr_len);
81 	else
82 		memcpy(fddi->saddr, dev->dev_addr, dev->addr_len);
83 
84 	if (daddr != NULL)
85 	{
86 		memcpy(fddi->daddr, daddr, dev->addr_len);
87 		return(hl);
88 	}
89 
90 	return(-hl);
91 }
92 
93 
94 /*
95  * Rebuild the FDDI MAC header. This is called after an ARP
96  * (or in future other address resolution) has completed on
97  * this sk_buff.  We now let ARP fill in the other fields.
98  */
99 
100 static int fddi_rebuild_header(struct sk_buff	*skb)
101 {
102 	struct fddihdr *fddi = (struct fddihdr *)skb->data;
103 
104 #ifdef CONFIG_INET
105 	if (fddi->hdr.llc_snap.ethertype == __constant_htons(ETH_P_IP))
106 		/* Try to get ARP to resolve the header and fill destination address */
107 		return arp_find(fddi->daddr, skb);
108 	else
109 #endif
110 	{
111 		printk("%s: Don't know how to resolve type %04X addresses.\n",
112 		       skb->dev->name, ntohs(fddi->hdr.llc_snap.ethertype));
113 		return(0);
114 	}
115 }
116 
117 
118 /*
119  * Determine the packet's protocol ID and fill in skb fields.
120  * This routine is called before an incoming packet is passed
121  * up.  It's used to fill in specific skb fields and to set
122  * the proper pointer to the start of packet data (skb->data).
123  */
124 
125 __be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
126 {
127 	struct fddihdr *fddi = (struct fddihdr *)skb->data;
128 	__be16 type;
129 
130 	/*
131 	 * Set mac.raw field to point to FC byte, set data field to point
132 	 * to start of packet data.  Assume 802.2 SNAP frames for now.
133 	 */
134 
135 	skb->mac.raw = skb->data;	/* point to frame control (FC) */
136 
137 	if(fddi->hdr.llc_8022_1.dsap==0xe0)
138 	{
139 		skb_pull(skb, FDDI_K_8022_HLEN-3);
140 		type = __constant_htons(ETH_P_802_2);
141 	}
142 	else
143 	{
144 		skb_pull(skb, FDDI_K_SNAP_HLEN);		/* adjust for 21 byte header */
145 		type=fddi->hdr.llc_snap.ethertype;
146 	}
147 
148 	/* Set packet type based on destination address and flag settings */
149 
150 	if (*fddi->daddr & 0x01)
151 	{
152 		if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
153 			skb->pkt_type = PACKET_BROADCAST;
154 		else
155 			skb->pkt_type = PACKET_MULTICAST;
156 	}
157 
158 	else if (dev->flags & IFF_PROMISC)
159 	{
160 		if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
161 			skb->pkt_type = PACKET_OTHERHOST;
162 	}
163 
164 	/* Assume 802.2 SNAP frames, for now */
165 
166 	return(type);
167 }
168 
169 EXPORT_SYMBOL(fddi_type_trans);
170 
171 static int fddi_change_mtu(struct net_device *dev, int new_mtu)
172 {
173 	if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
174 		return(-EINVAL);
175 	dev->mtu = new_mtu;
176 	return(0);
177 }
178 
179 static void fddi_setup(struct net_device *dev)
180 {
181 	dev->change_mtu		= fddi_change_mtu;
182 	dev->hard_header	= fddi_header;
183 	dev->rebuild_header	= fddi_rebuild_header;
184 
185 	dev->type		= ARPHRD_FDDI;
186 	dev->hard_header_len	= FDDI_K_SNAP_HLEN+3;	/* Assume 802.2 SNAP hdr len + 3 pad bytes */
187 	dev->mtu		= FDDI_K_SNAP_DLEN;	/* Assume max payload of 802.2 SNAP frame */
188 	dev->addr_len		= FDDI_K_ALEN;
189 	dev->tx_queue_len	= 100;			/* Long queues on FDDI */
190 	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
191 
192 	memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
193 }
194 
195 /**
196  * alloc_fddidev - Register FDDI device
197  * @sizeof_priv: Size of additional driver-private structure to be allocated
198  *	for this FDDI device
199  *
200  * Fill in the fields of the device structure with FDDI-generic values.
201  *
202  * Constructs a new net device, complete with a private data area of
203  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
204  * this private data area.
205  */
206 struct net_device *alloc_fddidev(int sizeof_priv)
207 {
208 	return alloc_netdev(sizeof_priv, "fddi%d", fddi_setup);
209 }
210 EXPORT_SYMBOL(alloc_fddidev);
211