xref: /openbmc/linux/net/802/fddi.c (revision 2874c5fd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		FDDI-type device handling.
8  *
9  * Version:	@(#)fddi.c	1.0.0	08/12/96
10  *
11  * Authors:	Lawrence V. Stefani, <stefani@lkg.dec.com>
12  *
13  *		fddi.c is based on previous eth.c and tr.c work by
14  *			Ross Biro
15  *			Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
16  *			Mark Evans, <evansmp@uhura.aston.ac.uk>
17  *			Florian La Roche, <rzsfl@rz.uni-sb.de>
18  *			Alan Cox, <gw4pts@gw4pts.ampr.org>
19  *
20  *	Changes
21  *		Alan Cox		:	New arp/rebuild header
22  *		Maciej W. Rozycki	:	IPv6 support
23  */
24 
25 #include <linux/module.h>
26 #include <linux/types.h>
27 #include <linux/kernel.h>
28 #include <linux/string.h>
29 #include <linux/mm.h>
30 #include <linux/socket.h>
31 #include <linux/in.h>
32 #include <linux/inet.h>
33 #include <linux/netdevice.h>
34 #include <linux/fddidevice.h>
35 #include <linux/if_ether.h>
36 #include <linux/skbuff.h>
37 #include <linux/errno.h>
38 #include <net/arp.h>
39 #include <net/sock.h>
40 
41 /*
42  * Create the FDDI MAC header for an arbitrary protocol layer
43  *
44  * saddr=NULL	means use device source address
45  * daddr=NULL	means leave destination address (eg unresolved arp)
46  */
47 
fddi_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned int len)48 static int fddi_header(struct sk_buff *skb, struct net_device *dev,
49 		       unsigned short type,
50 		       const void *daddr, const void *saddr, unsigned int len)
51 {
52 	int hl = FDDI_K_SNAP_HLEN;
53 	struct fddihdr *fddi;
54 
55 	if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP)
56 		hl=FDDI_K_8022_HLEN-3;
57 	fddi = skb_push(skb, hl);
58 	fddi->fc			 = FDDI_FC_K_ASYNC_LLC_DEF;
59 	if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
60 	{
61 		fddi->hdr.llc_snap.dsap		 = FDDI_EXTENDED_SAP;
62 		fddi->hdr.llc_snap.ssap		 = FDDI_EXTENDED_SAP;
63 		fddi->hdr.llc_snap.ctrl		 = FDDI_UI_CMD;
64 		fddi->hdr.llc_snap.oui[0]	 = 0x00;
65 		fddi->hdr.llc_snap.oui[1]	 = 0x00;
66 		fddi->hdr.llc_snap.oui[2]	 = 0x00;
67 		fddi->hdr.llc_snap.ethertype	 = htons(type);
68 	}
69 
70 	/* Set the source and destination hardware addresses */
71 
72 	if (saddr != NULL)
73 		memcpy(fddi->saddr, saddr, dev->addr_len);
74 	else
75 		memcpy(fddi->saddr, dev->dev_addr, dev->addr_len);
76 
77 	if (daddr != NULL)
78 	{
79 		memcpy(fddi->daddr, daddr, dev->addr_len);
80 		return hl;
81 	}
82 
83 	return -hl;
84 }
85 
86 /*
87  * Determine the packet's protocol ID and fill in skb fields.
88  * This routine is called before an incoming packet is passed
89  * up.  It's used to fill in specific skb fields and to set
90  * the proper pointer to the start of packet data (skb->data).
91  */
92 
fddi_type_trans(struct sk_buff * skb,struct net_device * dev)93 __be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
94 {
95 	struct fddihdr *fddi = (struct fddihdr *)skb->data;
96 	__be16 type;
97 
98 	/*
99 	 * Set mac.raw field to point to FC byte, set data field to point
100 	 * to start of packet data.  Assume 802.2 SNAP frames for now.
101 	 */
102 
103 	skb->dev = dev;
104 	skb_reset_mac_header(skb);	/* point to frame control (FC) */
105 
106 	if(fddi->hdr.llc_8022_1.dsap==0xe0)
107 	{
108 		skb_pull(skb, FDDI_K_8022_HLEN-3);
109 		type = htons(ETH_P_802_2);
110 	}
111 	else
112 	{
113 		skb_pull(skb, FDDI_K_SNAP_HLEN);		/* adjust for 21 byte header */
114 		type=fddi->hdr.llc_snap.ethertype;
115 	}
116 
117 	/* Set packet type based on destination address and flag settings */
118 
119 	if (*fddi->daddr & 0x01)
120 	{
121 		if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
122 			skb->pkt_type = PACKET_BROADCAST;
123 		else
124 			skb->pkt_type = PACKET_MULTICAST;
125 	}
126 
127 	else if (dev->flags & IFF_PROMISC)
128 	{
129 		if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
130 			skb->pkt_type = PACKET_OTHERHOST;
131 	}
132 
133 	/* Assume 802.2 SNAP frames, for now */
134 
135 	return type;
136 }
137 
138 EXPORT_SYMBOL(fddi_type_trans);
139 
140 static const struct header_ops fddi_header_ops = {
141 	.create		= fddi_header,
142 };
143 
144 
fddi_setup(struct net_device * dev)145 static void fddi_setup(struct net_device *dev)
146 {
147 	dev->header_ops		= &fddi_header_ops;
148 	dev->type		= ARPHRD_FDDI;
149 	dev->hard_header_len	= FDDI_K_SNAP_HLEN+3;	/* Assume 802.2 SNAP hdr len + 3 pad bytes */
150 	dev->mtu		= FDDI_K_SNAP_DLEN;	/* Assume max payload of 802.2 SNAP frame */
151 	dev->min_mtu		= FDDI_K_SNAP_HLEN;
152 	dev->max_mtu		= FDDI_K_SNAP_DLEN;
153 	dev->addr_len		= FDDI_K_ALEN;
154 	dev->tx_queue_len	= 100;			/* Long queues on FDDI */
155 	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
156 
157 	memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
158 }
159 
160 /**
161  * alloc_fddidev - Register FDDI device
162  * @sizeof_priv: Size of additional driver-private structure to be allocated
163  *	for this FDDI device
164  *
165  * Fill in the fields of the device structure with FDDI-generic values.
166  *
167  * Constructs a new net device, complete with a private data area of
168  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
169  * this private data area.
170  */
alloc_fddidev(int sizeof_priv)171 struct net_device *alloc_fddidev(int sizeof_priv)
172 {
173 	return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN,
174 			    fddi_setup);
175 }
176 EXPORT_SYMBOL(alloc_fddidev);
177 
178 MODULE_LICENSE("GPL");
179