![Alexey Dobriyan](/assets/img/avatar_default.png)
tty_register_ldisc(N_FOO, NULL) => tty_unregister_ldisc(N_FOO) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
950 lines
24 KiB
C
950 lines
24 KiB
C
/*
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* MKISS Driver
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*
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* This module:
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* This module is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* This module implements the AX.25 protocol for kernel-based
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* devices like TTYs. It interfaces between a raw TTY, and the
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* kernel's AX.25 protocol layers, just like slip.c.
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* AX.25 needs to be separated from slip.c while slip.c is no
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* longer a static kernel device since it is a module.
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* This method clears the way to implement other kiss protocols
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* like mkiss smack g8bpq ..... so far only mkiss is implemented.
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*
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* Hans Alblas <hans@esrac.ele.tue.nl>
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*
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* History
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* Jonathan (G4KLX) Fixed to match Linux networking changes - 2.1.15.
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* Matthias (DG2FEF) Added support for FlexNet CRC (on special request)
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* Fixed bug in ax25_close(): dev_lock_wait() was
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* called twice, causing a deadlock.
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* Jeroen (PE1RXQ) Removed old MKISS_MAGIC stuff and calls to
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* MOD_*_USE_COUNT
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* Remove cli() and fix rtnl lock usage.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <asm/system.h>
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#include <linux/bitops.h>
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#include <asm/uaccess.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/tty.h>
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#include <linux/errno.h>
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#include <linux/netdevice.h>
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#include <linux/major.h>
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#include <linux/init.h>
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#include <linux/rtnetlink.h>
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#include <linux/etherdevice.h>
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#include <linux/skbuff.h>
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#include <linux/if_arp.h>
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#include <net/ax25.h>
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#include "mkiss.h"
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#ifdef CONFIG_INET
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#include <linux/ip.h>
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#include <linux/tcp.h>
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#endif
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static char banner[] __initdata = KERN_INFO "mkiss: AX.25 Multikiss, Hans Albas PE1AYX\n";
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typedef struct ax25_ctrl {
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struct ax_disp ctrl; /* */
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struct net_device dev; /* the device */
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} ax25_ctrl_t;
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static ax25_ctrl_t **ax25_ctrls;
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int ax25_maxdev = AX25_MAXDEV; /* Can be overridden with insmod! */
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static struct tty_ldisc ax_ldisc;
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static int ax25_init(struct net_device *);
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static int kiss_esc(unsigned char *, unsigned char *, int);
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static int kiss_esc_crc(unsigned char *, unsigned char *, unsigned short, int);
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static void kiss_unesc(struct ax_disp *, unsigned char);
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/*---------------------------------------------------------------------------*/
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static const unsigned short Crc_flex_table[] = {
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0x0f87, 0x1e0e, 0x2c95, 0x3d1c, 0x49a3, 0x582a, 0x6ab1, 0x7b38,
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0x83cf, 0x9246, 0xa0dd, 0xb154, 0xc5eb, 0xd462, 0xe6f9, 0xf770,
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0x1f06, 0x0e8f, 0x3c14, 0x2d9d, 0x5922, 0x48ab, 0x7a30, 0x6bb9,
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0x934e, 0x82c7, 0xb05c, 0xa1d5, 0xd56a, 0xc4e3, 0xf678, 0xe7f1,
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0x2e85, 0x3f0c, 0x0d97, 0x1c1e, 0x68a1, 0x7928, 0x4bb3, 0x5a3a,
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0xa2cd, 0xb344, 0x81df, 0x9056, 0xe4e9, 0xf560, 0xc7fb, 0xd672,
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0x3e04, 0x2f8d, 0x1d16, 0x0c9f, 0x7820, 0x69a9, 0x5b32, 0x4abb,
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0xb24c, 0xa3c5, 0x915e, 0x80d7, 0xf468, 0xe5e1, 0xd77a, 0xc6f3,
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0x4d83, 0x5c0a, 0x6e91, 0x7f18, 0x0ba7, 0x1a2e, 0x28b5, 0x393c,
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0xc1cb, 0xd042, 0xe2d9, 0xf350, 0x87ef, 0x9666, 0xa4fd, 0xb574,
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0x5d02, 0x4c8b, 0x7e10, 0x6f99, 0x1b26, 0x0aaf, 0x3834, 0x29bd,
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0xd14a, 0xc0c3, 0xf258, 0xe3d1, 0x976e, 0x86e7, 0xb47c, 0xa5f5,
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0x6c81, 0x7d08, 0x4f93, 0x5e1a, 0x2aa5, 0x3b2c, 0x09b7, 0x183e,
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0xe0c9, 0xf140, 0xc3db, 0xd252, 0xa6ed, 0xb764, 0x85ff, 0x9476,
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0x7c00, 0x6d89, 0x5f12, 0x4e9b, 0x3a24, 0x2bad, 0x1936, 0x08bf,
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0xf048, 0xe1c1, 0xd35a, 0xc2d3, 0xb66c, 0xa7e5, 0x957e, 0x84f7,
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0x8b8f, 0x9a06, 0xa89d, 0xb914, 0xcdab, 0xdc22, 0xeeb9, 0xff30,
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0x07c7, 0x164e, 0x24d5, 0x355c, 0x41e3, 0x506a, 0x62f1, 0x7378,
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0x9b0e, 0x8a87, 0xb81c, 0xa995, 0xdd2a, 0xcca3, 0xfe38, 0xefb1,
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0x1746, 0x06cf, 0x3454, 0x25dd, 0x5162, 0x40eb, 0x7270, 0x63f9,
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0xaa8d, 0xbb04, 0x899f, 0x9816, 0xeca9, 0xfd20, 0xcfbb, 0xde32,
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0x26c5, 0x374c, 0x05d7, 0x145e, 0x60e1, 0x7168, 0x43f3, 0x527a,
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0xba0c, 0xab85, 0x991e, 0x8897, 0xfc28, 0xeda1, 0xdf3a, 0xceb3,
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0x3644, 0x27cd, 0x1556, 0x04df, 0x7060, 0x61e9, 0x5372, 0x42fb,
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0xc98b, 0xd802, 0xea99, 0xfb10, 0x8faf, 0x9e26, 0xacbd, 0xbd34,
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0x45c3, 0x544a, 0x66d1, 0x7758, 0x03e7, 0x126e, 0x20f5, 0x317c,
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0xd90a, 0xc883, 0xfa18, 0xeb91, 0x9f2e, 0x8ea7, 0xbc3c, 0xadb5,
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0x5542, 0x44cb, 0x7650, 0x67d9, 0x1366, 0x02ef, 0x3074, 0x21fd,
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0xe889, 0xf900, 0xcb9b, 0xda12, 0xaead, 0xbf24, 0x8dbf, 0x9c36,
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0x64c1, 0x7548, 0x47d3, 0x565a, 0x22e5, 0x336c, 0x01f7, 0x107e,
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0xf808, 0xe981, 0xdb1a, 0xca93, 0xbe2c, 0xafa5, 0x9d3e, 0x8cb7,
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0x7440, 0x65c9, 0x5752, 0x46db, 0x3264, 0x23ed, 0x1176, 0x00ff
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};
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/*---------------------------------------------------------------------------*/
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static unsigned short calc_crc_flex(unsigned char *cp, int size)
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{
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unsigned short crc = 0xffff;
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while (size--)
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crc = (crc << 8) ^ Crc_flex_table[((crc >> 8) ^ *cp++) & 0xff];
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return crc;
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}
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/*---------------------------------------------------------------------------*/
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static int check_crc_flex(unsigned char *cp, int size)
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{
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unsigned short crc = 0xffff;
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if (size < 3)
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return -1;
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while (size--)
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crc = (crc << 8) ^ Crc_flex_table[((crc >> 8) ^ *cp++) & 0xff];
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if ((crc & 0xffff) != 0x7070)
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return -1;
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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/* Find a free channel, and link in this `tty' line. */
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static inline struct ax_disp *ax_alloc(void)
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{
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ax25_ctrl_t *axp=NULL;
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int i;
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for (i = 0; i < ax25_maxdev; i++) {
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axp = ax25_ctrls[i];
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/* Not allocated ? */
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if (axp == NULL)
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break;
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/* Not in use ? */
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if (!test_and_set_bit(AXF_INUSE, &axp->ctrl.flags))
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break;
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}
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/* Sorry, too many, all slots in use */
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if (i >= ax25_maxdev)
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return NULL;
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/* If no channels are available, allocate one */
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if (axp == NULL && (ax25_ctrls[i] = kmalloc(sizeof(ax25_ctrl_t), GFP_KERNEL)) != NULL) {
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axp = ax25_ctrls[i];
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}
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memset(axp, 0, sizeof(ax25_ctrl_t));
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/* Initialize channel control data */
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set_bit(AXF_INUSE, &axp->ctrl.flags);
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sprintf(axp->dev.name, "ax%d", i++);
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axp->ctrl.tty = NULL;
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axp->dev.base_addr = i;
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axp->dev.priv = (void *)&axp->ctrl;
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axp->dev.next = NULL;
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axp->dev.init = ax25_init;
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if (axp != NULL) {
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/*
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* register device so that it can be ifconfig'ed
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* ax25_init() will be called as a side-effect
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* SIDE-EFFECT WARNING: ax25_init() CLEARS axp->ctrl !
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*/
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if (register_netdev(&axp->dev) == 0) {
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/* (Re-)Set the INUSE bit. Very Important! */
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set_bit(AXF_INUSE, &axp->ctrl.flags);
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axp->ctrl.dev = &axp->dev;
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axp->dev.priv = (void *) &axp->ctrl;
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return &axp->ctrl;
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} else {
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clear_bit(AXF_INUSE,&axp->ctrl.flags);
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printk(KERN_ERR "mkiss: ax_alloc() - register_netdev() failure.\n");
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}
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}
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return NULL;
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}
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/* Free an AX25 channel. */
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static inline void ax_free(struct ax_disp *ax)
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{
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/* Free all AX25 frame buffers. */
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if (ax->rbuff)
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kfree(ax->rbuff);
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ax->rbuff = NULL;
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if (ax->xbuff)
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kfree(ax->xbuff);
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ax->xbuff = NULL;
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if (!test_and_clear_bit(AXF_INUSE, &ax->flags))
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printk(KERN_ERR "mkiss: %s: ax_free for already free unit.\n", ax->dev->name);
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}
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static void ax_changedmtu(struct ax_disp *ax)
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{
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struct net_device *dev = ax->dev;
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unsigned char *xbuff, *rbuff, *oxbuff, *orbuff;
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int len;
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len = dev->mtu * 2;
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/*
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* allow for arrival of larger UDP packets, even if we say not to
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* also fixes a bug in which SunOS sends 512-byte packets even with
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* an MSS of 128
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*/
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if (len < 576 * 2)
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len = 576 * 2;
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xbuff = kmalloc(len + 4, GFP_ATOMIC);
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rbuff = kmalloc(len + 4, GFP_ATOMIC);
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if (xbuff == NULL || rbuff == NULL) {
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printk(KERN_ERR "mkiss: %s: unable to grow ax25 buffers, MTU change cancelled.\n",
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ax->dev->name);
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dev->mtu = ax->mtu;
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if (xbuff != NULL)
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kfree(xbuff);
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if (rbuff != NULL)
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kfree(rbuff);
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return;
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}
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spin_lock_bh(&ax->buflock);
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oxbuff = ax->xbuff;
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ax->xbuff = xbuff;
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orbuff = ax->rbuff;
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ax->rbuff = rbuff;
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if (ax->xleft) {
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if (ax->xleft <= len) {
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memcpy(ax->xbuff, ax->xhead, ax->xleft);
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} else {
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ax->xleft = 0;
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ax->tx_dropped++;
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}
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}
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ax->xhead = ax->xbuff;
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if (ax->rcount) {
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if (ax->rcount <= len) {
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memcpy(ax->rbuff, orbuff, ax->rcount);
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} else {
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ax->rcount = 0;
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ax->rx_over_errors++;
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set_bit(AXF_ERROR, &ax->flags);
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}
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}
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ax->mtu = dev->mtu + 73;
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ax->buffsize = len;
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spin_unlock_bh(&ax->buflock);
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if (oxbuff != NULL)
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kfree(oxbuff);
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if (orbuff != NULL)
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kfree(orbuff);
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}
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/* Set the "sending" flag. This must be atomic. */
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static inline void ax_lock(struct ax_disp *ax)
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{
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netif_stop_queue(ax->dev);
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}
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/* Clear the "sending" flag. This must be atomic. */
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static inline void ax_unlock(struct ax_disp *ax)
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{
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netif_start_queue(ax->dev);
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}
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/* Send one completely decapsulated AX.25 packet to the AX.25 layer. */
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static void ax_bump(struct ax_disp *ax)
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{
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struct sk_buff *skb;
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int count;
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spin_lock_bh(&ax->buflock);
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if (ax->rbuff[0] > 0x0f) {
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if (ax->rbuff[0] & 0x20) {
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ax->crcmode = CRC_MODE_FLEX;
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if (check_crc_flex(ax->rbuff, ax->rcount) < 0) {
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ax->rx_errors++;
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return;
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}
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ax->rcount -= 2;
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/* dl9sau bugfix: the trailling two bytes flexnet crc
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* will not be passed to the kernel. thus we have
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* to correct the kissparm signature, because it
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* indicates a crc but there's none
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*/
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*ax->rbuff &= ~0x20;
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}
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}
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spin_unlock_bh(&ax->buflock);
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count = ax->rcount;
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if ((skb = dev_alloc_skb(count)) == NULL) {
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printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n", ax->dev->name);
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ax->rx_dropped++;
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return;
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}
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spin_lock_bh(&ax->buflock);
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memcpy(skb_put(skb,count), ax->rbuff, count);
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spin_unlock_bh(&ax->buflock);
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skb->protocol = ax25_type_trans(skb, ax->dev);
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netif_rx(skb);
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ax->dev->last_rx = jiffies;
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ax->rx_packets++;
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ax->rx_bytes+=count;
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}
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/* Encapsulate one AX.25 packet and stuff into a TTY queue. */
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static void ax_encaps(struct ax_disp *ax, unsigned char *icp, int len)
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{
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unsigned char *p;
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int actual, count;
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if (ax->mtu != ax->dev->mtu + 73) /* Someone has been ifconfigging */
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ax_changedmtu(ax);
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if (len > ax->mtu) { /* Sigh, shouldn't occur BUT ... */
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len = ax->mtu;
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printk(KERN_ERR "mkiss: %s: truncating oversized transmit packet!\n", ax->dev->name);
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ax->tx_dropped++;
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ax_unlock(ax);
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return;
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}
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p = icp;
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spin_lock_bh(&ax->buflock);
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switch (ax->crcmode) {
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unsigned short crc;
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case CRC_MODE_FLEX:
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*p |= 0x20;
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crc = calc_crc_flex(p, len);
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count = kiss_esc_crc(p, (unsigned char *)ax->xbuff, crc, len+2);
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break;
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default:
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count = kiss_esc(p, (unsigned char *)ax->xbuff, len);
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break;
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}
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ax->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
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actual = ax->tty->driver->write(ax->tty, ax->xbuff, count);
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ax->tx_packets++;
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ax->tx_bytes+=actual;
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ax->dev->trans_start = jiffies;
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ax->xleft = count - actual;
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ax->xhead = ax->xbuff + actual;
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spin_unlock_bh(&ax->buflock);
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}
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/*
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* Called by the driver when there's room for more data. If we have
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* more packets to send, we send them here.
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*/
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static void ax25_write_wakeup(struct tty_struct *tty)
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{
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int actual;
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struct ax_disp *ax = (struct ax_disp *) tty->disc_data;
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/* First make sure we're connected. */
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if (ax == NULL || ax->magic != AX25_MAGIC || !netif_running(ax->dev))
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return;
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if (ax->xleft <= 0) {
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/* Now serial buffer is almost free & we can start
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* transmission of another packet
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*/
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tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
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netif_wake_queue(ax->dev);
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return;
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}
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actual = tty->driver->write(tty, ax->xhead, ax->xleft);
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ax->xleft -= actual;
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ax->xhead += actual;
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}
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/* Encapsulate an AX.25 packet and kick it into a TTY queue. */
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static int ax_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct ax_disp *ax = netdev_priv(dev);
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if (!netif_running(dev)) {
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printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name);
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return 1;
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}
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if (netif_queue_stopped(dev)) {
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/*
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* May be we must check transmitter timeout here ?
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* 14 Oct 1994 Dmitry Gorodchanin.
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*/
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if (jiffies - dev->trans_start < 20 * HZ) {
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/* 20 sec timeout not reached */
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return 1;
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}
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printk(KERN_ERR "mkiss: %s: transmit timed out, %s?\n", dev->name,
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(ax->tty->driver->chars_in_buffer(ax->tty) || ax->xleft) ?
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"bad line quality" : "driver error");
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ax->xleft = 0;
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ax->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
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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_unregister_ldisc(N_AX25)))
|
|
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);
|
|
|