linux/net/802/fddi.c
Arnaldo Carvalho de Melo 459a98ed88 [SK_BUFF]: Introduce skb_reset_mac_header(skb)
For the common, open coded 'skb->mac.raw = skb->data' operation, so that we can
later turn skb->mac.raw into a offset, reducing the size of struct sk_buff in
64bit land while possibly keeping it as a pointer on 32bit.

This one touches just the most simple case, next will handle the slightly more
"complex" cases.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:24:32 -07:00

210 lines
5.6 KiB
C

/*
* 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 <asm/system.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,
void *daddr, 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);
static 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);
}
static void fddi_setup(struct net_device *dev)
{
dev->change_mtu = fddi_change_mtu;
dev->hard_header = fddi_header;
dev->rebuild_header = fddi_rebuild_header;
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);