mkiss.c
上传用户:jlfgdled
上传日期:2013-04-10
资源大小:33168k
文件大小:25k
- /*
- * 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 PE1AYXn";
- #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++;
- tmp_ax->rx_bytes+=count;
- }
- /* 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->tx_bytes+=actual;
- 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->tx_bytes+=actual;
- 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 downn", 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 freen");
- 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_bytes = ax->rx_bytes;
- stats.tx_bytes = ax->tx_bytes;
- 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 = IFF_BROADCAST | IFF_MULTICAST;
- 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);