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/net/802/fddi.c

http://github.com/mirrors/linux
C | 178 lines | 100 code | 25 blank | 53 comment | 23 complexity | 6718d3239ae94a89ab80f52c550ca28e MD5 | raw file
  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
 48static 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
 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
138EXPORT_SYMBOL(fddi_type_trans);
139
140static const struct header_ops fddi_header_ops = {
141	.create		= fddi_header,
142};
143
144
145static 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 */
171struct net_device *alloc_fddidev(int sizeof_priv)
172{
173	return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN,
174			    fddi_setup);
175}
176EXPORT_SYMBOL(alloc_fddidev);
177
178MODULE_LICENSE("GPL");