linux-stable/net/802/hippi.c
Kees Cook e3617433c3 net: 802: Use memset_startat() to clear struct fields
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-19 11:23:23 +00:00

193 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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.
*
* HIPPI-type device handling.
*
* Version: @(#)hippi.c 1.0.0 05/29/97
*
* Authors: 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>
* Jes Sorensen, <Jes.Sorensen@cern.ch>
*/
#include <linux/module.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/hippidevice.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <net/arp.h>
#include <net/sock.h>
#include <linux/uaccess.h>
/*
* Create the HIPPI 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 hippi_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type,
const void *daddr, const void *saddr, unsigned int len)
{
struct hippi_hdr *hip = skb_push(skb, HIPPI_HLEN);
struct hippi_cb *hcb = (struct hippi_cb *) skb->cb;
if (!len){
len = skb->len - HIPPI_HLEN;
printk("hippi_header(): length not supplied\n");
}
/*
* Due to the stupidity of the little endian byte-order we
* have to set the fp field this way.
*/
hip->fp.fixed = htonl(0x04800018);
hip->fp.d2_size = htonl(len + 8);
hip->le.fc = 0;
hip->le.double_wide = 0; /* only HIPPI 800 for the time being */
hip->le.message_type = 0; /* Data PDU */
hip->le.dest_addr_type = 2; /* 12 bit SC address */
hip->le.src_addr_type = 2; /* 12 bit SC address */
memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
memset_startat(&hip->le, 0, reserved);
hip->snap.dsap = HIPPI_EXTENDED_SAP;
hip->snap.ssap = HIPPI_EXTENDED_SAP;
hip->snap.ctrl = HIPPI_UI_CMD;
hip->snap.oui[0] = 0x00;
hip->snap.oui[1] = 0x00;
hip->snap.oui[2] = 0x00;
hip->snap.ethertype = htons(type);
if (daddr)
{
memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
memcpy(&hcb->ifield, daddr + 2, 4);
return HIPPI_HLEN;
}
hcb->ifield = 0;
return -((int)HIPPI_HLEN);
}
/*
* Determine the packet's protocol ID.
*/
__be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
{
struct hippi_hdr *hip;
/*
* This is actually wrong ... question is if we really should
* set the raw address here.
*/
skb->dev = dev;
skb_reset_mac_header(skb);
hip = (struct hippi_hdr *)skb_mac_header(skb);
skb_pull(skb, HIPPI_HLEN);
/*
* No fancy promisc stuff here now.
*/
return hip->snap.ethertype;
}
EXPORT_SYMBOL(hippi_type_trans);
/*
* For HIPPI we will actually use the lower 4 bytes of the hardware
* address as the I-FIELD rather than the actual hardware address.
*/
int hippi_mac_addr(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
if (netif_running(dev))
return -EBUSY;
dev_addr_set(dev, addr->sa_data);
return 0;
}
EXPORT_SYMBOL(hippi_mac_addr);
int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
{
/* Never send broadcast/multicast ARP messages */
NEIGH_VAR_INIT(p, MCAST_PROBES, 0);
/* In IPv6 unicast probes are valid even on NBMA,
* because they are encapsulated in normal IPv6 protocol.
* Should be a generic flag.
*/
if (p->tbl->family != AF_INET6)
NEIGH_VAR_INIT(p, UCAST_PROBES, 0);
return 0;
}
EXPORT_SYMBOL(hippi_neigh_setup_dev);
static const struct header_ops hippi_header_ops = {
.create = hippi_header,
};
static void hippi_setup(struct net_device *dev)
{
dev->header_ops = &hippi_header_ops;
/*
* We don't support HIPPI `ARP' for the time being, and probably
* never will unless someone else implements it. However we
* still need a fake ARPHRD to make ifconfig and friends play ball.
*/
dev->type = ARPHRD_HIPPI;
dev->hard_header_len = HIPPI_HLEN;
dev->mtu = 65280;
dev->min_mtu = 68;
dev->max_mtu = 65280;
dev->addr_len = HIPPI_ALEN;
dev->tx_queue_len = 25 /* 5 */;
memset(dev->broadcast, 0xFF, HIPPI_ALEN);
/*
* HIPPI doesn't support broadcast+multicast and we only use
* static ARP tables. ARP is disabled by hippi_neigh_setup_dev.
*/
dev->flags = 0;
}
/**
* alloc_hippi_dev - Register HIPPI device
* @sizeof_priv: Size of additional driver-private structure to be allocated
* for this HIPPI device
*
* Fill in the fields of the device structure with HIPPI-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_hippi_dev(int sizeof_priv)
{
return alloc_netdev(sizeof_priv, "hip%d", NET_NAME_UNKNOWN,
hippi_setup);
}
EXPORT_SYMBOL(alloc_hippi_dev);