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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/net/hamradio/mkiss.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/net/hamradio/mkiss.c')
-rw-r--r--drivers/net/hamradio/mkiss.c951
1 files changed, 951 insertions, 0 deletions
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
new file mode 100644
index 00000000000..d9ea080aea0
--- /dev/null
+++ b/drivers/net/hamradio/mkiss.c
@@ -0,0 +1,951 @@
+/*
+ * 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.
+ * Jeroen (PE1RXQ) Removed old MKISS_MAGIC stuff and calls to
+ * MOD_*_USE_COUNT
+ * Remove cli() and fix rtnl lock usage.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/system.h>
+#include <linux/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";
+
+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;
+
+ 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;
+ }
+
+ spin_lock_bh(&ax->buflock);
+
+ 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;
+
+ spin_unlock_bh(&ax->buflock);
+
+ 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 sk_buff *skb;
+ int count;
+
+ spin_lock_bh(&ax->buflock);
+ if (ax->rbuff[0] > 0x0f) {
+ 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;
+ /* dl9sau bugfix: the trailling two bytes flexnet crc
+ * will not be passed to the kernel. thus we have
+ * to correct the kissparm signature, because it
+ * indicates a crc but there's none
+ */
+ *ax->rbuff &= ~0x20;
+ }
+ }
+ spin_unlock_bh(&ax->buflock);
+
+ 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 = ax->dev;
+ spin_lock_bh(&ax->buflock);
+ memcpy(skb_put(skb,count), ax->rbuff, count);
+ spin_unlock_bh(&ax->buflock);
+ skb->mac.raw = skb->data;
+ skb->protocol = htons(ETH_P_AX25);
+ netif_rx(skb);
+ ax->dev->last_rx = jiffies;
+ ax->rx_packets++;
+ 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;
+
+ 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;
+
+ spin_lock_bh(&ax->buflock);
+ 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, ax->xbuff, count);
+ ax->tx_packets++;
+ ax->tx_bytes+=actual;
+ ax->dev->trans_start = jiffies;
+ ax->xleft = count - actual;
+ ax->xhead = ax->xbuff + actual;
+
+ spin_unlock_bh(&ax->buflock);
+}
+
+/*
+ * 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;
+
+ /* 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);
+
+ netif_wake_queue(ax->dev);
+ return;
+ }
+
+ actual = tty->driver->write(tty, 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 = netdev_priv(dev);
+
+ if (!netif_running(dev)) {
+ printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name);
+ return 1;
+ }
+
+ 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);
+ 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 = netdev_priv(dev);
+ 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 */
+
+ spin_lock_init(&ax->buflock);
+
+ 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 = netdev_priv(dev);
+
+ 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;
+ int err;
+
+ /* 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;
+
+ if (tty->driver->flush_buffer)
+ tty->driver->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;
+
+ /* 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 = NULL;
+ ax->tty = NULL;
+
+ ax_free(ax);
+}
+
+
+static struct net_device_stats *ax_get_stats(struct net_device *dev)
+{
+ static struct net_device_stats stats;
+ struct ax_disp *ax = netdev_priv(dev);
+
+ 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;
+ }
+
+ spin_lock_bh(&ax->buflock);
+ if (!test_bit(AXF_ERROR, &ax->flags)) {
+ if (ax->rcount < ax->buffsize) {
+ ax->rbuff[ax->rcount++] = s;
+ spin_unlock_bh(&ax->buflock);
+ return;
+ }
+
+ ax->rx_over_errors++;
+ set_bit(AXF_ERROR, &ax->flags);
+ }
+ spin_unlock_bh(&ax->buflock);
+}
+
+
+static int ax_set_mac_address(struct net_device *dev, void __user *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 __user *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 __user *)arg);
+
+ case SIOCSIFENCAP:
+ if (get_user(tmp, (int __user *)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 = netdev_priv(dev);
+
+ 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 = netdev_priv(dev);
+
+ 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_ALIAS_LDISC(N_AX25);
+module_init(mkiss_init_driver);
+module_exit(mkiss_exit_driver);
+