Import 2.1.15

[davej-history.git] / drivers / net / bpqether.c

/*
 * G8BPQ compatible "AX.25 via ethernet" driver release 003
 *
 * This is ALPHA test software. This code may break your machine, randomly 
 * fail to work with new releases, misbehave and/or generally screw up. 
 * It might even work. 
 *
 * This code REQUIRES 2.0.0 or higher/ NET3.029
 *
 * This module:
 * This module 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.
 *
 * This is a "pseudo" network driver to allow AX.25 over Ethernet
 * using G8BPQ encapsulation. It has been extracted from the protocol
 * implementation because 
 *
 * - things got unreadable within the protocol stack
 * - to cure the protocol stack from "feature-ism"
 * - a protocol implementation shouldn't need to know on 
 * which hardware it is running
 * - user-level programs like the AX.25 utilities shouldn't
 * need to know about the hardware.
 * - IP over ethernet encapsulated AX.25 was impossible
 * - rxecho.c did not work
 * - to have room for extensions
 * - it just deserves to "live" as an own driver
 *
 * This driver can use any ethernet destination address, and can be 
 * limited to accept frames from one dedicated ethernet card only.
 *
 * Note that the driver sets up the BPQ devices automagically on
 * startup or (if started before the "insmod" of an ethernet device)
 * on "ifconfig up". It hopefully will remove the BPQ on "rmmod"ing
 * the ethernet device (in fact: as soon as another ethernet or bpq
 * device gets "ifconfig"ured).
 *
 * I have heard that several people are thinking of experiments
 * with highspeed packet radio using existing ethernet cards.
 * Well, this driver is prepared for this purpose, just add
 * your tx key control and a txdelay / tailtime algorithm,
 * probably some buffering, and /voila/...
 *
 * History
 * BPQ 001 Joerg(DL1BKE) Extracted BPQ code from AX.25 
 * protocol stack and added my own
 * yet existing patches
 * BPQ 002 Joerg(DL1BKE) Scan network device list on
 * startup.
 * BPQ 003 Joerg(DL1BKE) Ethernet destination address
 * and accepted source address
 * can be configured by an ioctl()
 * call.
 */

#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/firewall.h>
#include <linux/module.h>
#include <linux/net_alias.h>

#include <net/ip.h>
#include <net/arp.h>

#include <linux/bpqether.h>

static unsigned char ax25_bcast[AX25_ADDR_LEN] =
{'Q'<<1,'S'<<1,'T'<<1,' '<<1,' '<<1,' '<<1,'0'<<1};
static unsigned char ax25_defaddr[AX25_ADDR_LEN] =
{'L'<<1,'I'<<1,'N'<<1,'U'<<1,'X'<<1,' '<<1,'1'<<1};

static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};

static char bpq_eth_addr[6];

static intbpq_rcv(struct sk_buff *,struct device *,struct packet_type *);
static intbpq_device_event(struct notifier_block *,unsigned long,void*);
static char*bpq_print_ethaddr(unsigned char*);

static struct packet_type bpq_packet_type = {
0,/* ntohs(ETH_P_BPQ),*/
0,/* copy */
 bpq_rcv,
 NULL,
 NULL,
};

static struct notifier_block bpq_dev_notifier = {
 bpq_device_event,
0
};


#define MAXBPQDEV 100

static struct bpqdev {
struct bpqdev *next;
char ethname[14];/* ether device name */
struct device *ethdev;/* link to ethernet device */
struct device axdev;/* bpq device (bpq#) */
struct enet_statistics stats;/* some statistics */
char dest_addr[6];/* ether destination address */
char acpt_addr[6];/* accept ether frames from this address only */
} *bpq_devices = NULL;


/* ------------------------------------------------------------------------ */


/*
 * Get the ethernet device for a BPQ device
 */
static __inline__ struct device *bpq_get_ether_dev(struct device *dev)
{
struct bpqdev *bpq;

 bpq = (struct bpqdev *)dev->priv;

return(bpq != NULL) ? bpq->ethdev : NULL;
}

/*
 * Get the BPQ device for the ethernet device
 */
static __inline__ struct device *bpq_get_ax25_dev(struct device *dev)
{
struct bpqdev *bpq;

for(bpq = bpq_devices; bpq != NULL; bpq = bpq->next)
if(bpq->ethdev == dev)
return&bpq->axdev;

return NULL;
}

static __inline__ intdev_is_ethdev(struct device *dev)
{
return(
 dev->type == ARPHRD_ETHER
&&strncmp(dev->name,"dummy",5)
#ifdef CONFIG_NET_ALIAS
&& !net_alias_is(dev)
#endif
);
}

/*
 * Sanity check: remove all devices that ceased to exists and
 * return '1' if the given BPQ device was affected.
 */
static intbpq_check_devices(struct device *dev)
{
struct bpqdev *bpq, *bpq_prev;
int result =0;
unsigned long flags;

save_flags(flags);
cli();

 bpq_prev = NULL;

for(bpq = bpq_devices; bpq != NULL; bpq = bpq->next) {
if(!dev_get(bpq->ethname)) {
if(bpq_prev)
 bpq_prev->next = bpq->next;
else
 bpq_devices = bpq->next;

if(&bpq->axdev == dev)
 result =1;

unregister_netdev(&bpq->axdev);
kfree(bpq);
}

 bpq_prev = bpq;
}

restore_flags(flags);

return result;
}


/* ------------------------------------------------------------------------ */


/*
 * Receive an AX.25 frame via an ethernet interface.
 */
static intbpq_rcv(struct sk_buff *skb,struct device *dev,struct packet_type *ptype)
{
int len;
char* ptr;
struct ethhdr *eth = (struct ethhdr *)skb->mac.raw;
struct bpqdev *bpq;

 skb->sk = NULL;/* Initially we don't know who it's for */

 dev =bpq_get_ax25_dev(dev);

if(dev == NULL || dev->start ==0) {
kfree_skb(skb, FREE_READ);
return0;
}

/*
 * if we want to accept frames from just one ethernet device
 * we check the source address of the sender.
 */

 bpq = (struct bpqdev *)dev->priv;

if(!(bpq->acpt_addr[0] &0x01) &&memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN)) {
printk(KERN_DEBUG "bpqether: wrong dest %s\n",bpq_print_ethaddr(eth->h_source));
kfree_skb(skb, FREE_READ);
return0;
}

((struct bpqdev *)dev->priv)->stats.rx_packets++;

 len = skb->data[0] + skb->data[1] *256-5;

skb_pull(skb,2);/* Remove the length bytes */
skb_trim(skb, len);/* Set the length of the data */

 ptr =skb_push(skb,1);
*ptr =0;

 skb->dev = dev;
 skb->protocol =htons(ETH_P_AX25);
 skb->mac.raw = skb->data;
 skb->pkt_type = PACKET_HOST;

netif_rx(skb);

return0;
}

/*
 * Send an AX.25 frame via an ethernet interface
 */
static intbpq_xmit(struct sk_buff *skb,struct device *dev)
{
unsigned char*ptr;
struct bpqdev *bpq;
int size;

/*
 * Just to be *really* sure not to send anything if the interface
 * is down, the ethernet device may have gone.
 */
if(!dev->start) {
bpq_check_devices(dev);
dev_kfree_skb(skb, FREE_WRITE);
return-ENODEV;
}

skb_pull(skb,1);
 size = skb->len;

/* 
 * The AX.25 code leaves enough room for the ethernet header, but 
 * sendto() does not.
 */
if(skb_headroom(skb) < AX25_BPQ_HEADER_LEN) {/* Ough! */
struct sk_buff *newskb =alloc_skb(skb->len + AX25_BPQ_HEADER_LEN, GFP_ATOMIC);

if(newskb == NULL) {/* Argh! */
printk(KERN_WARNING "bpq_xmit: not enough space to add BPQ Ether header\n");
dev_kfree_skb(skb, FREE_WRITE);
return-ENOMEM;
}

 newskb->arp =1;
if(skb->sk)
skb_set_owner_w(newskb, skb->sk);

skb_reserve(newskb, AX25_BPQ_HEADER_LEN);
memcpy(skb_put(newskb, size), skb->data, size);
dev_kfree_skb(skb, FREE_WRITE);
 skb = newskb;
}

 skb->protocol =htons(ETH_P_AX25);

 ptr =skb_push(skb,2);

*ptr++ = (size +5) %256;
*ptr++ = (size +5) /256;

 bpq = (struct bpqdev *)dev->priv;
 bpq->stats.tx_packets++;

if((dev =bpq_get_ether_dev(dev)) == NULL) {
 bpq->stats.tx_dropped++;
dev_kfree_skb(skb, FREE_WRITE);
return-ENODEV;
}

 skb->dev = dev;
 dev->hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL,0);

return dev->hard_start_xmit(skb, dev);
}

/*
 * Statistics
 */
static struct enet_statistics *bpq_get_stats(struct device *dev)
{
struct bpqdev *bpq;

 bpq = (struct bpqdev *)dev->priv;

return&bpq->stats;
}


/*
 * Rebuild header...
 */
static intbpq_rebuild_header(void*buff,struct device *dev,unsigned long raddr,struct sk_buff *skb)
{
returnax25_rebuild_header((unsigned char*)buff, dev, raddr, skb);
}

/*
 * Set AX.25 callsign
 */
static intbpq_set_mac_address(struct device *dev,void*addr)
{
struct sockaddr *sa = (struct sockaddr *)addr;

memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);

return0;
}

/* Ioctl commands
 *
 * SIOCSBPQETHOPT reserved for enhancements
 * SIOCSBPQETHADDR set the destination and accepted
 * source ethernet address (broadcast
 * or multicast: accept all)
 */
static intbpq_ioctl(struct device *dev,struct ifreq *ifr,int cmd)
{
int err;
struct bpq_ethaddr *ethaddr = (struct bpq_ethaddr *)ifr->ifr_data;
struct bpqdev *bpq = dev->priv;
struct bpq_req req;

if(!suser())
return-EPERM;

if(bpq == NULL)/* woops! */
return-ENODEV;

switch(cmd) {
case SIOCSBPQETHOPT:
if((err =verify_area(VERIFY_WRITE, ifr->ifr_data,sizeof(struct bpq_req))) !=0)
return err;
copy_from_user(&req, ifr->ifr_data,sizeof(struct bpq_req));
switch(req.cmd) {
case SIOCGBPQETHPARAM:
case SIOCSBPQETHPARAM:
default:
return-EINVAL;
}

break;

case SIOCSBPQETHADDR:
if((err =verify_area(VERIFY_READ, ethaddr,sizeof(struct bpq_ethaddr))) !=0)
return err;
copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN);
copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN);
break;

default:
return-EINVAL;
}

return0;
}

/*
 * open/close a device
 */
static intbpq_open(struct device *dev)
{
if(bpq_check_devices(dev))
return-ENODEV;/* oops, it's gone */

 dev->tbusy =0;
 dev->start =1;

 MOD_INC_USE_COUNT;

return0;
}

static intbpq_close(struct device *dev)
{
 dev->tbusy =1;
 dev->start =0;

 MOD_DEC_USE_COUNT;

return0;
}

/*
 * currently unused
 */
static intbpq_dev_init(struct device *dev)
{
return0;
}


/* ------------------------------------------------------------------------ */


/*
 * Proc filesystem
 */
static char*bpq_print_ethaddr(unsigned char*e)
{
static char buf[18];

sprintf(buf,"%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X",
 e[0], e[1], e[2], e[3], e[4], e[5]);

return buf;
}

intbpq_get_info(char*buffer,char**start, off_t offset,int length,int dummy)
{
struct bpqdev *bpqdev;
int len =0;
 off_t pos =0;
 off_t begin =0;

cli();

 len +=sprintf(buffer,"dev ether destination accept from\n");

for(bpqdev = bpq_devices; bpqdev != NULL; bpqdev = bpqdev->next) {
 len +=sprintf(buffer + len,"%-5s %-10s %s ",
 bpqdev->axdev.name, bpqdev->ethname,
bpq_print_ethaddr(bpqdev->dest_addr));

 len +=sprintf(buffer + len,"%s\n",
(bpqdev->acpt_addr[0] &0x01) ?"*":bpq_print_ethaddr(bpqdev->acpt_addr));

 pos = begin + len;

if(pos < offset) {
 len =0;
 begin = pos;
}

if(pos > offset + length)
break;
}

sti();

*start = buffer + (offset - begin);
 len -= (offset - begin);

if(len > length) len = length;

return len;
}


/* ------------------------------------------------------------------------ */


/*
 * Setup a new device.
 */
static intbpq_new_device(struct device *dev)
{
int k;
unsigned char*buf;
struct bpqdev *bpq, *bpq2;

if((bpq = (struct bpqdev *)kmalloc(sizeof(struct bpqdev), GFP_KERNEL)) == NULL)
return-ENOMEM;

memset(bpq,0,sizeof(struct bpqdev));

 bpq->ethdev = dev;

 bpq->ethname[sizeof(bpq->ethname)-1] ='\0';
strncpy(bpq->ethname, dev->name,sizeof(bpq->ethname)-1);

memcpy(bpq->dest_addr, bcast_addr,sizeof(bpq_eth_addr));
memcpy(bpq->acpt_addr, bcast_addr,sizeof(bpq_eth_addr));

 dev = &bpq->axdev;
 buf = (unsigned char*)kmalloc(14, GFP_KERNEL);

for(k =0; k < MAXBPQDEV; k++) {
struct device *odev;

sprintf(buf,"bpq%d", k);

if((odev =dev_get(buf)) == NULL ||bpq_check_devices(odev))
break;
}

if(k == MAXBPQDEV) {
kfree(bpq);
return-ENODEV;
}

 dev->priv = (void*)bpq;/* pointer back */
 dev->name = buf;
 dev->init = bpq_dev_init;

if(register_netdev(dev) !=0) {
kfree(bpq);
return-EIO;
}

for(k=0; k < DEV_NUMBUFFS; k++)
skb_queue_head_init(&dev->buffs[k]);

 dev->hard_start_xmit = bpq_xmit;
 dev->hard_header = ax25_encapsulate;
 dev->rebuild_header = bpq_rebuild_header;
 dev->open = bpq_open;
 dev->stop = bpq_close;
 dev->set_mac_address = bpq_set_mac_address;
 dev->get_stats = bpq_get_stats;
 dev->do_ioctl = bpq_ioctl;

memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN);
memcpy(dev->dev_addr, ax25_defaddr, AX25_ADDR_LEN);

/* preset with reasonable values */

#if CONFIG_INET
 dev->flags =0;
 dev->family = AF_INET;
 dev->pa_addr =0;
 dev->pa_brdaddr =0;
 dev->pa_mask =0;
 dev->pa_alen =4;
#endif

 dev->type = ARPHRD_AX25;
 dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 dev->mtu = AX25_DEF_PACLEN;
 dev->addr_len = AX25_ADDR_LEN;

cli();

if(bpq_devices == NULL) {
 bpq_devices = bpq;
}else{
for(bpq2 = bpq_devices; bpq2->next != NULL; bpq2 = bpq2->next);
 bpq2->next = bpq;
}

sti();

return0;
}


/*
 * Handle device status changes.
 */
static intbpq_device_event(struct notifier_block *this,unsigned long event,void*ptr)
{
struct device *dev = (struct device *)ptr;

if(!dev_is_ethdev(dev))
return NOTIFY_DONE;

bpq_check_devices(NULL);

switch(event) {
case NETDEV_UP:/* new ethernet device -> new BPQ interface */
if(bpq_get_ax25_dev(dev) == NULL)
bpq_new_device(dev);
break;

case NETDEV_DOWN:/* ethernet device closed -> close BPQ interface */
if((dev =bpq_get_ax25_dev(dev)) != NULL)
dev_close(dev);
break;

default:
break;
}

return NOTIFY_DONE;
}


/* ------------------------------------------------------------------------ */

/*
 * Initialize driver. To be called from af_ax25 if not compiled as a
 * module
 */
intbpq_init(void)
{
struct device *dev;

 bpq_packet_type.type =htons(ETH_P_BPQ);
dev_add_pack(&bpq_packet_type);

register_netdevice_notifier(&bpq_dev_notifier);

printk(KERN_INFO "AX.25 ethernet driver version 0.01\n");

#ifdef CONFIG_PROC_FS
proc_net_register(&(struct proc_dir_entry) {
 PROC_NET_AX25_BPQETHER,8,"bpqether",
 S_IFREG | S_IRUGO,1,0,0,
0, &proc_net_inode_operations,
 bpq_get_info
});
#endif

for(dev = dev_base; dev != NULL; dev = dev->next) {
if(dev_is_ethdev(dev))
bpq_new_device(dev);
}

return0;
}

#ifdef MODULE
intinit_module(void)
{
register_symtab(NULL);

returnbpq_init();
}

voidcleanup_module(void)
{
struct bpqdev *bpq;

dev_remove_pack(&bpq_packet_type);

unregister_netdevice_notifier(&bpq_dev_notifier);

#ifdef CONFIG_PROC_FS
proc_net_unregister(PROC_NET_AX25_BPQETHER);
#endif 

for(bpq = bpq_devices; bpq != NULL; bpq = bpq->next)
unregister_netdev(&bpq->axdev);
}
#endif