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/*
* MKISS Driver
*
* 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 module implements the AX.25 protocol for kernel-based
* devices like TTYs. It interfaces between a raw TTY, and the
* kernel's AX.25 protocol layers, just like slip.c.
* AX.25 needs to be separated from slip.c while slip.c is no
* longer a static kernel device since it is a module.
* This method clears the way to implement other kiss protocols
* like mkiss smack g8bpq ..... so far only mkiss is implemented.
*
* Hans Alblas <hans@esrac.ele.tue.nl>
*
* History
* Jonathan (G4KLX) Fixed to match Linux networking changes - 2.1.15.
* Matthias (DG2FEF) Added support for FlexNet CRC (on special request)
* Fixed bug in ax25_close(): dev_lock_wait() was
* called twice, causing a deadlock.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <asm/system.h>
#include <asm/segment.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/tty.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <net/ax25.h>
#include "mkiss.h"
#ifdef CONFIG_INET
#include <linux/ip.h>
#include <linux/tcp.h>
#endif
static char banner[] __initdata = KERN_INFO "mkiss: AX.25 Multikiss, Hans Albas PE1AYX\n";
#define NR_MKISS 4
#define MKISS_SERIAL_TYPE_NORMAL 1
struct mkiss_channel {
int magic; /* magic word */
int init; /* channel exists? */
struct tty_struct *tty; /* link to tty control structure */
};
typedef struct ax25_ctrl {
struct ax_disp ctrl; /* */
struct net_device dev; /* the device */
} ax25_ctrl_t;
static ax25_ctrl_t **ax25_ctrls;
int ax25_maxdev = AX25_MAXDEV; /* Can be overridden with insmod! */
static struct tty_ldisc ax_ldisc;
static int ax25_init(struct net_device *);
static int kiss_esc(unsigned char *, unsigned char *, int);
static int kiss_esc_crc(unsigned char *, unsigned char *, unsigned short, int);
static void kiss_unesc(struct ax_disp *, unsigned char);
/*---------------------------------------------------------------------------*/
static const unsigned short Crc_flex_table[] = {
0x0f87, 0x1e0e, 0x2c95, 0x3d1c, 0x49a3, 0x582a, 0x6ab1, 0x7b38,
0x83cf, 0x9246, 0xa0dd, 0xb154, 0xc5eb, 0xd462, 0xe6f9, 0xf770,
0x1f06, 0x0e8f, 0x3c14, 0x2d9d, 0x5922, 0x48ab, 0x7a30, 0x6bb9,
0x934e, 0x82c7, 0xb05c, 0xa1d5, 0xd56a, 0xc4e3, 0xf678, 0xe7f1,
0x2e85, 0x3f0c, 0x0d97, 0x1c1e, 0x68a1, 0x7928, 0x4bb3, 0x5a3a,
0xa2cd, 0xb344, 0x81df, 0x9056, 0xe4e9, 0xf560, 0xc7fb, 0xd672,
0x3e04, 0x2f8d, 0x1d16, 0x0c9f, 0x7820, 0x69a9, 0x5b32, 0x4abb,
0xb24c, 0xa3c5, 0x915e, 0x80d7, 0xf468, 0xe5e1, 0xd77a, 0xc6f3,
0x4d83, 0x5c0a, 0x6e91, 0x7f18, 0x0ba7, 0x1a2e, 0x28b5, 0x393c,
0xc1cb, 0xd042, 0xe2d9, 0xf350, 0x87ef, 0x9666, 0xa4fd, 0xb574,
0x5d02, 0x4c8b, 0x7e10, 0x6f99, 0x1b26, 0x0aaf, 0x3834, 0x29bd,
0xd14a, 0xc0c3, 0xf258, 0xe3d1, 0x976e, 0x86e7, 0xb47c, 0xa5f5,
0x6c81, 0x7d08, 0x4f93, 0x5e1a, 0x2aa5, 0x3b2c, 0x09b7, 0x183e,
0xe0c9, 0xf140, 0xc3db, 0xd252, 0xa6ed, 0xb764, 0x85ff, 0x9476,
0x7c00, 0x6d89, 0x5f12, 0x4e9b, 0x3a24, 0x2bad, 0x1936, 0x08bf,
0xf048, 0xe1c1, 0xd35a, 0xc2d3, 0xb66c, 0xa7e5, 0x957e, 0x84f7,
0x8b8f, 0x9a06, 0xa89d, 0xb914, 0xcdab, 0xdc22, 0xeeb9, 0xff30,
0x07c7, 0x164e, 0x24d5, 0x355c, 0x41e3, 0x506a, 0x62f1, 0x7378,
0x9b0e, 0x8a87, 0xb81c, 0xa995, 0xdd2a, 0xcca3, 0xfe38, 0xefb1,
0x1746, 0x06cf, 0x3454, 0x25dd, 0x5162, 0x40eb, 0x7270, 0x63f9,
0xaa8d, 0xbb04, 0x899f, 0x9816, 0xeca9, 0xfd20, 0xcfbb, 0xde32,
0x26c5, 0x374c, 0x05d7, 0x145e, 0x60e1, 0x7168, 0x43f3, 0x527a,
0xba0c, 0xab85, 0x991e, 0x8897, 0xfc28, 0xeda1, 0xdf3a, 0xceb3,
0x3644, 0x27cd, 0x1556, 0x04df, 0x7060, 0x61e9, 0x5372, 0x42fb,
0xc98b, 0xd802, 0xea99, 0xfb10, 0x8faf, 0x9e26, 0xacbd, 0xbd34,
0x45c3, 0x544a, 0x66d1, 0x7758, 0x03e7, 0x126e, 0x20f5, 0x317c,
0xd90a, 0xc883, 0xfa18, 0xeb91, 0x9f2e, 0x8ea7, 0xbc3c, 0xadb5,
0x5542, 0x44cb, 0x7650, 0x67d9, 0x1366, 0x02ef, 0x3074, 0x21fd,
0xe889, 0xf900, 0xcb9b, 0xda12, 0xaead, 0xbf24, 0x8dbf, 0x9c36,
0x64c1, 0x7548, 0x47d3, 0x565a, 0x22e5, 0x336c, 0x01f7, 0x107e,
0xf808, 0xe981, 0xdb1a, 0xca93, 0xbe2c, 0xafa5, 0x9d3e, 0x8cb7,
0x7440, 0x65c9, 0x5752, 0x46db, 0x3264, 0x23ed, 0x1176, 0x00ff
};
/*---------------------------------------------------------------------------*/
static unsigned short calc_crc_flex(unsigned char *cp, int size)
{
unsigned short crc = 0xffff;
while (size--)
crc = (crc << 8) ^ Crc_flex_table[((crc >> 8) ^ *cp++) & 0xff];
return crc;
}
/*---------------------------------------------------------------------------*/
static int check_crc_flex(unsigned char *cp, int size)
{
unsigned short crc = 0xffff;
if (size < 3)
return -1;
while (size--)
crc = (crc << 8) ^ Crc_flex_table[((crc >> 8) ^ *cp++) & 0xff];
if ((crc & 0xffff) != 0x7070)
return -1;
return 0;
}
/*---------------------------------------------------------------------------*/
/* Find a free channel, and link in this `tty' line. */
static inline struct ax_disp *ax_alloc(void)
{
ax25_ctrl_t *axp=NULL;
int i;
for (i = 0; i < ax25_maxdev; i++) {
axp = ax25_ctrls[i];
/* Not allocated ? */
if (axp == NULL)
break;
/* Not in use ? */
if (!test_and_set_bit(AXF_INUSE, &axp->ctrl.flags))
break;
}
/* Sorry, too many, all slots in use */
if (i >= ax25_maxdev)
return NULL;
/* If no channels are available, allocate one */
if (axp == NULL && (ax25_ctrls[i] = kmalloc(sizeof(ax25_ctrl_t), GFP_KERNEL)) != NULL) {
axp = ax25_ctrls[i];
memset(axp, 0, sizeof(ax25_ctrl_t));
/* Initialize channel control data */
set_bit(AXF_INUSE, &axp->ctrl.flags);
sprintf(axp->dev.name, "ax%d", i++);
axp->ctrl.tty = NULL;
axp->dev.base_addr = i;
axp->dev.priv = (void *)&axp->ctrl;
axp->dev.next = NULL;
axp->dev.init = ax25_init;
}
if (axp != NULL) {
/*
* register device so that it can be ifconfig'ed
* ax25_init() will be called as a side-effect
* SIDE-EFFECT WARNING: ax25_init() CLEARS axp->ctrl !
*/
if (register_netdev(&axp->dev) == 0) {
/* (Re-)Set the INUSE bit. Very Important! */
set_bit(AXF_INUSE, &axp->ctrl.flags);
axp->ctrl.dev = &axp->dev;
axp->dev.priv = (void *) &axp->ctrl;
return &axp->ctrl;
} else {
clear_bit(AXF_INUSE,&axp->ctrl.flags);
printk(KERN_ERR "mkiss: ax_alloc() - register_netdev() failure.\n");
}
}
return NULL;
}
/* Free an AX25 channel. */
static inline void ax_free(struct ax_disp *ax)
{
/* Free all AX25 frame buffers. */
if (ax->rbuff)
kfree(ax->rbuff);
ax->rbuff = NULL;
if (ax->xbuff)
kfree(ax->xbuff);
ax->xbuff = NULL;
if (!test_and_clear_bit(AXF_INUSE, &ax->flags))
printk(KERN_ERR "mkiss: %s: ax_free for already free unit.\n", ax->dev->name);
}
static void ax_changedmtu(struct ax_disp *ax)
{
struct net_device *dev = ax->dev;
unsigned char *xbuff, *rbuff, *oxbuff, *orbuff;
int len;
unsigned long flags;
len = dev->mtu * 2;
/*
* allow for arrival of larger UDP packets, even if we say not to
* also fixes a bug in which SunOS sends 512-byte packets even with
* an MSS of 128
*/
if (len < 576 * 2)
len = 576 * 2;
xbuff = kmalloc(len + 4, GFP_ATOMIC);
rbuff = kmalloc(len + 4, GFP_ATOMIC);
if (xbuff == NULL || rbuff == NULL) {
printk(KERN_ERR "mkiss: %s: unable to grow ax25 buffers, MTU change cancelled.\n",
ax->dev->name);
dev->mtu = ax->mtu;
if (xbuff != NULL)
kfree(xbuff);
if (rbuff != NULL)
kfree(rbuff);
return;
}
save_flags(flags);
cli();
oxbuff = ax->xbuff;
ax->xbuff = xbuff;
orbuff = ax->rbuff;
ax->rbuff = rbuff;
if (ax->xleft) {
if (ax->xleft <= len) {
memcpy(ax->xbuff, ax->xhead, ax->xleft);
} else {
ax->xleft = 0;
ax->tx_dropped++;
}
}
ax->xhead = ax->xbuff;
if (ax->rcount) {
if (ax->rcount <= len) {
memcpy(ax->rbuff, orbuff, ax->rcount);
} else {
ax->rcount = 0;
ax->rx_over_errors++;
set_bit(AXF_ERROR, &ax->flags);
}
}
ax->mtu = dev->mtu + 73;
ax->buffsize = len;
restore_flags(flags);
if (oxbuff != NULL)
kfree(oxbuff);
if (orbuff != NULL)
kfree(orbuff);
}
/* Set the "sending" flag. This must be atomic. */
static inline void ax_lock(struct ax_disp *ax)
{
netif_stop_queue(ax->dev);
}
/* Clear the "sending" flag. This must be atomic. */
static inline void ax_unlock(struct ax_disp *ax)
{
netif_start_queue(ax->dev);
}
/* Send one completely decapsulated AX.25 packet to the AX.25 layer. */
static void ax_bump(struct ax_disp *ax)
{
struct ax_disp *tmp_ax;
struct sk_buff *skb;
struct mkiss_channel *mkiss;
int count;
tmp_ax = ax;
if (ax->rbuff[0] > 0x0f) {
if (ax->mkiss != NULL) {
mkiss= ax->mkiss->tty->driver_data;
if (mkiss->magic == MKISS_DRIVER_MAGIC)
tmp_ax = ax->mkiss;
} else if (ax->rbuff[0] & 0x20) {
ax->crcmode = CRC_MODE_FLEX;
if (check_crc_flex(ax->rbuff, ax->rcount) < 0) {
ax->rx_errors++;
return;
}
ax->rcount -= 2;
}
}
count = ax->rcount;
if ((skb = dev_alloc_skb(count)) == NULL) {
printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n", ax->dev->name);
ax->rx_dropped++;
return;
}
skb->dev = tmp_ax->dev;
memcpy(skb_put(skb,count), ax->rbuff, count);
skb->mac.raw = skb->data;
skb->protocol = htons(ETH_P_AX25);
netif_rx(skb);
tmp_ax->rx_packets++;
}
/* Encapsulate one AX.25 packet and stuff into a TTY queue. */
static void ax_encaps(struct ax_disp *ax, unsigned char *icp, int len)
{
unsigned char *p;
int actual, count;
struct mkiss_channel *mkiss = ax->tty->driver_data;
if (ax->mtu != ax->dev->mtu + 73) /* Someone has been ifconfigging */
ax_changedmtu(ax);
if (len > ax->mtu) { /* Sigh, shouldn't occur BUT ... */
len = ax->mtu;
printk(KERN_ERR "mkiss: %s: truncating oversized transmit packet!\n", ax->dev->name);
ax->tx_dropped++;
ax_unlock(ax);
return;
}
p = icp;
if (mkiss->magic != MKISS_DRIVER_MAGIC) {
switch (ax->crcmode) {
unsigned short crc;
case CRC_MODE_FLEX:
*p |= 0x20;
crc = calc_crc_flex(p, len);
count = kiss_esc_crc(p, (unsigned char *)ax->xbuff, crc, len+2);
break;
default:
count = kiss_esc(p, (unsigned char *)ax->xbuff, len);
break;
}
ax->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
actual = ax->tty->driver.write(ax->tty, 0, ax->xbuff, count);
ax->tx_packets++;
ax->dev->trans_start = jiffies;
ax->xleft = count - actual;
ax->xhead = ax->xbuff + actual;
} else {
count = kiss_esc(p, (unsigned char *) ax->mkiss->xbuff, len);
ax->mkiss->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
actual = ax->mkiss->tty->driver.write(ax->mkiss->tty, 0, ax->mkiss->xbuff, count);
ax->tx_packets++;
ax->mkiss->dev->trans_start = jiffies;
ax->mkiss->xleft = count - actual;
ax->mkiss->xhead = ax->mkiss->xbuff + actual;
}
}
/*
* Called by the driver when there's room for more data. If we have
* more packets to send, we send them here.
*/
static void ax25_write_wakeup(struct tty_struct *tty)
{
int actual;
struct ax_disp *ax = (struct ax_disp *) tty->disc_data;
struct mkiss_channel *mkiss;
/* First make sure we're connected. */
if (ax == NULL || ax->magic != AX25_MAGIC || !netif_running(ax->dev))
return;
if (ax->xleft <= 0) {
/* Now serial buffer is almost free & we can start
* transmission of another packet
*/
tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
if (ax->mkiss != NULL) {
mkiss= ax->mkiss->tty->driver_data;
if (mkiss->magic == MKISS_DRIVER_MAGIC)
ax_unlock(ax->mkiss);
}
netif_wake_queue(ax->dev);
return;
}
actual = tty->driver.write(tty, 0, ax->xhead, ax->xleft);
ax->xleft -= actual;
ax->xhead += actual;
}
/* Encapsulate an AX.25 packet and kick it into a TTY queue. */
static int ax_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ax_disp *ax = (struct ax_disp *) dev->priv;
struct mkiss_channel *mkiss = ax->tty->driver_data;
struct ax_disp *tmp_ax;
tmp_ax = NULL;
if (mkiss->magic == MKISS_DRIVER_MAGIC) {
if (skb->data[0] < 0x10)
skb->data[0] = skb->data[0] + 0x10;
tmp_ax = ax->mkiss;
}
if (!netif_running(dev)) {
printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name);
return 1;
}
if (tmp_ax != NULL)
if (netif_queue_stopped(tmp_ax->dev))
return 1;
if (tmp_ax != NULL)
if (netif_queue_stopped(dev)) {
printk(KERN_ERR "mkiss: dev busy while serial dev is free\n");
ax_unlock(ax);
}
if (netif_queue_stopped(dev)) {
/*
* May be we must check transmitter timeout here ?
* 14 Oct 1994 Dmitry Gorodchanin.
*/
if (jiffies - dev->trans_start < 20 * HZ) {
/* 20 sec timeout not reached */
return 1;
}
printk(KERN_ERR "mkiss: %s: transmit timed out, %s?\n", dev->name,
(ax->tty->driver.chars_in_buffer(ax->tty) || ax->xleft) ?
"bad line quality" : "driver error");
ax->xleft = 0;
ax->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
ax_unlock(ax);
}
/* We were not busy, so we are now... :-) */
if (skb != NULL) {
ax_lock(ax);
if (tmp_ax != NULL)
ax_lock(tmp_ax);
ax_encaps(ax, skb->data, skb->len);
kfree_skb(skb);
}
return 0;
}
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
/* Return the frame type ID */
static int ax_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
void *daddr, void *saddr, unsigned len)
{
#ifdef CONFIG_INET
if (type != htons(ETH_P_AX25))
return ax25_encapsulate(skb, dev, type, daddr, saddr, len);
#endif
return 0;
}
static int ax_rebuild_header(struct sk_buff *skb)
{
#ifdef CONFIG_INET
return ax25_rebuild_header(skb);
#else
return 0;
#endif
}
#endif /* CONFIG_{AX25,AX25_MODULE} */
/* Open the low-level part of the AX25 channel. Easy! */
static int ax_open(struct net_device *dev)
{
struct ax_disp *ax = (struct ax_disp *) dev->priv;
unsigned long len;
if (ax->tty == NULL)
return -ENODEV;
/*
* Allocate the frame buffers:
*
* rbuff Receive buffer.
* xbuff Transmit buffer.
*/
len = dev->mtu * 2;
/*
* allow for arrival of larger UDP packets, even if we say not to
* also fixes a bug in which SunOS sends 512-byte packets even with
* an MSS of 128
*/
if (len < 576 * 2)
len = 576 * 2;
if ((ax->rbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL)
goto norbuff;
if ((ax->xbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL)
goto noxbuff;
ax->mtu = dev->mtu + 73;
ax->buffsize = len;
ax->rcount = 0;
ax->xleft = 0;
ax->flags &= (1 << AXF_INUSE); /* Clear ESCAPE & ERROR flags */
netif_start_queue(dev);
return 0;
noxbuff:
kfree(ax->rbuff);
norbuff:
return -ENOMEM;
}
/* Close the low-level part of the AX25 channel. Easy! */
static int ax_close(struct net_device *dev)
{
struct ax_disp *ax = (struct ax_disp *) dev->priv;
if (ax->tty == NULL)
return -EBUSY;
ax->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
netif_stop_queue(dev);
return 0;
}
static int ax25_receive_room(struct tty_struct *tty)
{
return 65536; /* We can handle an infinite amount of data. :-) */
}
/*
* Handle the 'receiver data ready' interrupt.
* This function is called by the 'tty_io' module in the kernel when
* a block of data has been received, which can now be decapsulated
* and sent on to the AX.25 layer for further processing.
*/
static void ax25_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
{
struct ax_disp *ax = (struct ax_disp *) tty->disc_data;
if (ax == NULL || ax->magic != AX25_MAGIC || !netif_running(ax->dev))
return;
/*
* Argh! mtu change time! - costs us the packet part received
* at the change
*/
if (ax->mtu != ax->dev->mtu + 73)
ax_changedmtu(ax);
/* Read the characters out of the buffer */
while (count--) {
if (fp != NULL && *fp++) {
if (!test_and_set_bit(AXF_ERROR, &ax->flags))
ax->rx_errors++;
cp++;
continue;
}
kiss_unesc(ax, *cp++);
}
}
static int ax25_open(struct tty_struct *tty)
{
struct ax_disp *ax = (struct ax_disp *) tty->disc_data;
struct ax_disp *tmp_ax;
struct mkiss_channel *mkiss;
int err, cnt;
/* First make sure we're not already connected. */
if (ax && ax->magic == AX25_MAGIC)
return -EEXIST;
/* OK. Find a free AX25 channel to use. */
if ((ax = ax_alloc()) == NULL)
return -ENFILE;
ax->tty = tty;
tty->disc_data = ax;
ax->mkiss = NULL;
tmp_ax = NULL;
if (tty->driver.flush_buffer)
tty->driver.flush_buffer(tty);
if (tty->ldisc.flush_buffer)
tty->ldisc.flush_buffer(tty);
/* Restore default settings */
ax->dev->type = ARPHRD_AX25;
/* Perform the low-level AX25 initialization. */
if ((err = ax_open(ax->dev)))
return err;
mkiss = ax->tty->driver_data;
if (mkiss->magic == MKISS_DRIVER_MAGIC) {
for (cnt = 1; cnt < ax25_maxdev; cnt++) {
if (ax25_ctrls[cnt]) {
if (netif_running(&ax25_ctrls[cnt]->dev)) {
if (ax == &ax25_ctrls[cnt]->ctrl) {
cnt--;
tmp_ax = &ax25_ctrls[cnt]->ctrl;
break;
}
}
}
}
}
if (tmp_ax != NULL) {
ax->mkiss = tmp_ax;
tmp_ax->mkiss = ax;
}
MOD_INC_USE_COUNT;
/* Done. We have linked the TTY line to a channel. */
return ax->dev->base_addr;
}
static void ax25_close(struct tty_struct *tty)
{
struct ax_disp *ax = (struct ax_disp *) tty->disc_data;
/* First make sure we're connected. */
if (ax == NULL || ax->magic != AX25_MAGIC)
return;
unregister_netdev(ax->dev);
tty->disc_data = 0;
ax->tty = NULL;
ax_free(ax);
MOD_DEC_USE_COUNT;
}
static struct net_device_stats *ax_get_stats(struct net_device *dev)
{
static struct net_device_stats stats;
struct ax_disp *ax = (struct ax_disp *) dev->priv;
memset(&stats, 0, sizeof(struct net_device_stats));
stats.rx_packets = ax->rx_packets;
stats.tx_packets = ax->tx_packets;
stats.rx_dropped = ax->rx_dropped;
stats.tx_dropped = ax->tx_dropped;
stats.tx_errors = ax->tx_errors;
stats.rx_errors = ax->rx_errors;
stats.rx_over_errors = ax->rx_over_errors;
return &stats;
}
/************************************************************************
* STANDARD ENCAPSULATION *
************************************************************************/
static int kiss_esc(unsigned char *s, unsigned char *d, int len)
{
unsigned char *ptr = d;
unsigned char c;
/*
* Send an initial END character to flush out any
* data that may have accumulated in the receiver
* due to line noise.
*/
*ptr++ = END;
while (len-- > 0) {
switch (c = *s++) {
case END:
*ptr++ = ESC;
*ptr++ = ESC_END;
break;
case ESC:
*ptr++ = ESC;
*ptr++ = ESC_ESC;
break;
default:
*ptr++ = c;
break;
}
}
*ptr++ = END;
return ptr - d;
}
/*
* MW:
* OK its ugly, but tell me a better solution without copying the
* packet to a temporary buffer :-)
*/
static int kiss_esc_crc(unsigned char *s, unsigned char *d, unsigned short crc, int len)
{
unsigned char *ptr = d;
unsigned char c=0;
*ptr++ = END;
while (len > 0) {
if (len > 2)
c = *s++;
else if (len > 1)
c = crc >> 8;
else if (len > 0)
c = crc & 0xff;
len--;
switch (c) {
case END:
*ptr++ = ESC;
*ptr++ = ESC_END;
break;
case ESC:
*ptr++ = ESC;
*ptr++ = ESC_ESC;
break;
default:
*ptr++ = c;
break;
}
}
*ptr++ = END;
return ptr - d;
}
static void kiss_unesc(struct ax_disp *ax, unsigned char s)
{
switch (s) {
case END:
/* drop keeptest bit = VSV */
if (test_bit(AXF_KEEPTEST, &ax->flags))
clear_bit(AXF_KEEPTEST, &ax->flags);
if (!test_and_clear_bit(AXF_ERROR, &ax->flags) && (ax->rcount > 2))
ax_bump(ax);
clear_bit(AXF_ESCAPE, &ax->flags);
ax->rcount = 0;
return;
case ESC:
set_bit(AXF_ESCAPE, &ax->flags);
return;
case ESC_ESC:
if (test_and_clear_bit(AXF_ESCAPE, &ax->flags))
s = ESC;
break;
case ESC_END:
if (test_and_clear_bit(AXF_ESCAPE, &ax->flags))
s = END;
break;
}
if (!test_bit(AXF_ERROR, &ax->flags)) {
if (ax->rcount < ax->buffsize) {
ax->rbuff[ax->rcount++] = s;
return;
}
ax->rx_over_errors++;
set_bit(AXF_ERROR, &ax->flags);
}
}
static int ax_set_mac_address(struct net_device *dev, void *addr)
{
if (copy_from_user(dev->dev_addr, addr, AX25_ADDR_LEN))
return -EFAULT;
return 0;
}
static int ax_set_dev_mac_address(struct net_device *dev, void *addr)
{
struct sockaddr *sa = addr;
memcpy(dev->dev_addr, sa->sa_data, AX25_ADDR_LEN);
return 0;
}
/* Perform I/O control on an active ax25 channel. */
static int ax25_disp_ioctl(struct tty_struct *tty, void *file, int cmd, void *arg)
{
struct ax_disp *ax = (struct ax_disp *) tty->disc_data;
unsigned int tmp;
/* First make sure we're connected. */
if (ax == NULL || ax->magic != AX25_MAGIC)
return -EINVAL;
switch (cmd) {
case SIOCGIFNAME:
if (copy_to_user(arg, ax->dev->name, strlen(ax->dev->name) + 1))
return -EFAULT;
return 0;
case SIOCGIFENCAP:
return put_user(4, (int *)arg);
case SIOCSIFENCAP:
if (get_user(tmp, (int *)arg))
return -EFAULT;
ax->mode = tmp;
ax->dev->addr_len = AX25_ADDR_LEN; /* sizeof an AX.25 addr */
ax->dev->hard_header_len = AX25_KISS_HEADER_LEN + AX25_MAX_HEADER_LEN + 3;
ax->dev->type = ARPHRD_AX25;
return 0;
case SIOCSIFHWADDR:
return ax_set_mac_address(ax->dev, arg);
default:
return -ENOIOCTLCMD;
}
}
static int ax_open_dev(struct net_device *dev)
{
struct ax_disp *ax = (struct ax_disp *) dev->priv;
if (ax->tty == NULL)
return -ENODEV;
return 0;
}
/* Initialize the driver. Called by network startup. */
static int ax25_init(struct net_device *dev)
{
struct ax_disp *ax = (struct ax_disp *) dev->priv;
static char ax25_bcast[AX25_ADDR_LEN] =
{'Q'<<1,'S'<<1,'T'<<1,' '<<1,' '<<1,' '<<1,'0'<<1};
static char ax25_test[AX25_ADDR_LEN] =
{'L'<<1,'I'<<1,'N'<<1,'U'<<1,'X'<<1,' '<<1,'1'<<1};
if (ax == NULL) /* Allocation failed ?? */
return -ENODEV;
/* Set up the "AX25 Control Block". (And clear statistics) */
memset(ax, 0, sizeof (struct ax_disp));
ax->magic = AX25_MAGIC;
ax->dev = dev;
/* Finish setting up the DEVICE info. */
dev->mtu = AX_MTU;
dev->hard_start_xmit = ax_xmit;
dev->open = ax_open_dev;
dev->stop = ax_close;
dev->get_stats = ax_get_stats;
dev->set_mac_address = ax_set_dev_mac_address;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->type = ARPHRD_AX25;
dev->tx_queue_len = 10;
dev->hard_header = ax_header;
dev->rebuild_header = ax_rebuild_header;
memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN);
memcpy(dev->dev_addr, ax25_test, AX25_ADDR_LEN);
/* New-style flags. */
dev->flags = 0;
return 0;
}
/* ******************************************************************** */
/* * Init MKISS driver * */
/* ******************************************************************** */
static int __init mkiss_init_driver(void)
{
int status;
printk(banner);
if (ax25_maxdev < 4)
ax25_maxdev = 4; /* Sanity */
if ((ax25_ctrls = kmalloc(sizeof(void *) * ax25_maxdev, GFP_KERNEL)) == NULL) {
printk(KERN_ERR "mkiss: Can't allocate ax25_ctrls[] array!\n");
return -ENOMEM;
}
/* Clear the pointer array, we allocate devices when we need them */
memset(ax25_ctrls, 0, sizeof(void*) * ax25_maxdev); /* Pointers */
/* Fill in our line protocol discipline, and register it */
ax_ldisc.magic = TTY_LDISC_MAGIC;
ax_ldisc.name = "mkiss";
ax_ldisc.open = ax25_open;
ax_ldisc.close = ax25_close;
ax_ldisc.ioctl = (int (*)(struct tty_struct *, struct file *,
unsigned int, unsigned long))ax25_disp_ioctl;
ax_ldisc.receive_buf = ax25_receive_buf;
ax_ldisc.receive_room = ax25_receive_room;
ax_ldisc.write_wakeup = ax25_write_wakeup;
if ((status = tty_register_ldisc(N_AX25, &ax_ldisc)) != 0) {
printk(KERN_ERR "mkiss: can't register line discipline (err = %d)\n", status);
kfree(ax25_ctrls);
}
return status;
}
static void __exit mkiss_exit_driver(void)
{
int i;
for (i = 0; i < ax25_maxdev; i++) {
if (ax25_ctrls[i]) {
/*
* VSV = if dev->start==0, then device
* unregistered while close proc.
*/
if (netif_running(&ax25_ctrls[i]->dev))
unregister_netdev(&ax25_ctrls[i]->dev);
kfree(ax25_ctrls[i]);
}
}
kfree(ax25_ctrls);
ax25_ctrls = NULL;
if ((i = tty_register_ldisc(N_AX25, NULL)))
printk(KERN_ERR "mkiss: can't unregister line discipline (err = %d)\n", i);
}
MODULE_AUTHOR("Hans Albas PE1AYX <hans@esrac.ele.tue.nl>");
MODULE_DESCRIPTION("KISS driver for AX.25 over TTYs");
MODULE_PARM(ax25_maxdev, "i");
MODULE_PARM_DESC(ax25_maxdev, "number of MKISS devices");
MODULE_LICENSE("GPL");
module_init(mkiss_init_driver);
module_exit(mkiss_exit_driver);
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