/*
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* This program is free software; you can distribute it and/or modify it
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* under the terms of the GNU General Public License (Version 2) as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, see <http://www.gnu.org/licenses/>.
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*
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* Copyright (C) Hans Alblas PE1AYX <hans@esrac.ele.tue.nl>
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* Copyright (C) 2004, 05 Ralf Baechle DL5RB <ralf@linux-mips.org>
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* Copyright (C) 2004, 05 Thomas Osterried DL9SAU <thomas@x-berg.in-berlin.de>
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*/
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/uaccess.h>
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#include <linux/crc16.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/slab.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 <linux/jiffies.h>
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#include <linux/compat.h>
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#include <net/ax25.h>
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#define AX_MTU 236
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/* SLIP/KISS protocol characters. */
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#define END 0300 /* indicates end of frame */
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#define ESC 0333 /* indicates byte stuffing */
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#define ESC_END 0334 /* ESC ESC_END means END 'data' */
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#define ESC_ESC 0335 /* ESC ESC_ESC means ESC 'data' */
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struct mkiss {
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struct tty_struct *tty; /* ptr to TTY structure */
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struct net_device *dev; /* easy for intr handling */
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/* These are pointers to the malloc()ed frame buffers. */
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spinlock_t buflock;/* lock for rbuf and xbuf */
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unsigned char *rbuff; /* receiver buffer */
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int rcount; /* received chars counter */
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unsigned char *xbuff; /* transmitter buffer */
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unsigned char *xhead; /* pointer to next byte to XMIT */
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int xleft; /* bytes left in XMIT queue */
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/* Detailed SLIP statistics. */
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int mtu; /* Our mtu (to spot changes!) */
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int buffsize; /* Max buffers sizes */
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unsigned long flags; /* Flag values/ mode etc */
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/* long req'd: used by set_bit --RR */
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#define AXF_INUSE 0 /* Channel in use */
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#define AXF_ESCAPE 1 /* ESC received */
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#define AXF_ERROR 2 /* Parity, etc. error */
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#define AXF_KEEPTEST 3 /* Keepalive test flag */
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#define AXF_OUTWAIT 4 /* is outpacket was flag */
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int mode;
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int crcmode; /* MW: for FlexNet, SMACK etc. */
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int crcauto; /* CRC auto mode */
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#define CRC_MODE_NONE 0
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#define CRC_MODE_FLEX 1
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#define CRC_MODE_SMACK 2
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#define CRC_MODE_FLEX_TEST 3
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#define CRC_MODE_SMACK_TEST 4
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atomic_t refcnt;
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struct semaphore dead_sem;
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};
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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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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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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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static int check_crc_16(unsigned char *cp, int size)
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{
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unsigned short crc = 0x0000;
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if (size < 3)
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return -1;
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crc = crc16(0, cp, size);
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if (crc != 0x0000)
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return -1;
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return 0;
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}
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/*
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* Standard encapsulation
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*/
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static int kiss_esc(unsigned char *s, unsigned char *d, int len)
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{
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unsigned char *ptr = d;
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unsigned char c;
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/*
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* Send an initial END character to flush out any data that may have
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* accumulated in the receiver due to line noise.
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*/
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*ptr++ = END;
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while (len-- > 0) {
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switch (c = *s++) {
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case END:
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*ptr++ = ESC;
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*ptr++ = ESC_END;
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break;
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case ESC:
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*ptr++ = ESC;
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*ptr++ = ESC_ESC;
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break;
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default:
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*ptr++ = c;
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break;
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}
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}
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*ptr++ = END;
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return ptr - d;
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}
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/*
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* MW:
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* OK its ugly, but tell me a better solution without copying the
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* packet to a temporary buffer :-)
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*/
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static int kiss_esc_crc(unsigned char *s, unsigned char *d, unsigned short crc,
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int len)
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{
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unsigned char *ptr = d;
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unsigned char c=0;
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*ptr++ = END;
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while (len > 0) {
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if (len > 2)
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c = *s++;
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else if (len > 1)
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c = crc >> 8;
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else
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c = crc & 0xff;
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len--;
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switch (c) {
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case END:
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*ptr++ = ESC;
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*ptr++ = ESC_END;
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break;
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case ESC:
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*ptr++ = ESC;
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*ptr++ = ESC_ESC;
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break;
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default:
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*ptr++ = c;
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break;
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}
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}
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*ptr++ = END;
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return ptr - d;
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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 mkiss *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] & 0x80) {
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if (check_crc_16(ax->rbuff, ax->rcount) < 0) {
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ax->dev->stats.rx_errors++;
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spin_unlock_bh(&ax->buflock);
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return;
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}
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if (ax->crcmode != CRC_MODE_SMACK && ax->crcauto) {
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printk(KERN_INFO
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"mkiss: %s: Switching to crc-smack\n",
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ax->dev->name);
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ax->crcmode = CRC_MODE_SMACK;
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}
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ax->rcount -= 2;
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*ax->rbuff &= ~0x80;
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} else if (ax->rbuff[0] & 0x20) {
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if (check_crc_flex(ax->rbuff, ax->rcount) < 0) {
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ax->dev->stats.rx_errors++;
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spin_unlock_bh(&ax->buflock);
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return;
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}
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if (ax->crcmode != CRC_MODE_FLEX && ax->crcauto) {
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printk(KERN_INFO
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"mkiss: %s: Switching to crc-flexnet\n",
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ax->dev->name);
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ax->crcmode = CRC_MODE_FLEX;
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}
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ax->rcount -= 2;
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/*
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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 to
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* correct the kissparm signature, because it indicates
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* 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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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",
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ax->dev->name);
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ax->dev->stats.rx_dropped++;
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spin_unlock_bh(&ax->buflock);
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return;
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}
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skb_put_data(skb, ax->rbuff, count);
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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->stats.rx_packets++;
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ax->dev->stats.rx_bytes += count;
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spin_unlock_bh(&ax->buflock);
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}
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static void kiss_unesc(struct mkiss *ax, unsigned char s)
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{
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switch (s) {
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case END:
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/* drop keeptest bit = VSV */
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if (test_bit(AXF_KEEPTEST, &ax->flags))
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clear_bit(AXF_KEEPTEST, &ax->flags);
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if (!test_and_clear_bit(AXF_ERROR, &ax->flags) && (ax->rcount > 2))
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ax_bump(ax);
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clear_bit(AXF_ESCAPE, &ax->flags);
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ax->rcount = 0;
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return;
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case ESC:
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set_bit(AXF_ESCAPE, &ax->flags);
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return;
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case ESC_ESC:
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if (test_and_clear_bit(AXF_ESCAPE, &ax->flags))
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s = ESC;
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break;
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case ESC_END:
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if (test_and_clear_bit(AXF_ESCAPE, &ax->flags))
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s = END;
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break;
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}
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spin_lock_bh(&ax->buflock);
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if (!test_bit(AXF_ERROR, &ax->flags)) {
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if (ax->rcount < ax->buffsize) {
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ax->rbuff[ax->rcount++] = s;
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spin_unlock_bh(&ax->buflock);
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return;
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}
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ax->dev->stats.rx_over_errors++;
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set_bit(AXF_ERROR, &ax->flags);
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}
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spin_unlock_bh(&ax->buflock);
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}
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static int ax_set_mac_address(struct net_device *dev, void *addr)
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{
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struct sockaddr_ax25 *sa = addr;
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netif_tx_lock_bh(dev);
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netif_addr_lock(dev);
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memcpy(dev->dev_addr, &sa->sax25_call, AX25_ADDR_LEN);
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netif_addr_unlock(dev);
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netif_tx_unlock_bh(dev);
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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static void ax_changedmtu(struct mkiss *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, "
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"MTU change cancelled.\n",
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ax->dev->name);
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dev->mtu = ax->mtu;
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kfree(xbuff);
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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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dev->stats.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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dev->stats.rx_over_errors++;
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set_bit(AXF_ERROR, &ax->flags);
|
}
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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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kfree(oxbuff);
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kfree(orbuff);
|
}
|
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/* Encapsulate one AX.25 packet and stuff into a TTY queue. */
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static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
|
{
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struct mkiss *ax = netdev_priv(dev);
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unsigned char *p;
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int actual, count;
|
|
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 ... */
|
printk(KERN_ERR "mkiss: %s: truncating oversized transmit packet!\n", ax->dev->name);
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dev->stats.tx_dropped++;
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netif_start_queue(dev);
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return;
|
}
|
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p = icp;
|
|
spin_lock_bh(&ax->buflock);
|
if ((*p & 0x0f) != 0) {
|
/* Configuration Command (kissparms(1).
|
* Protocol spec says: never append CRC.
|
* This fixes a very old bug in the linux
|
* kiss driver. -- dl9sau */
|
switch (*p & 0xff) {
|
case 0x85:
|
/* command from userspace especially for us,
|
* not for delivery to the tnc */
|
if (len > 1) {
|
int cmd = (p[1] & 0xff);
|
switch(cmd) {
|
case 3:
|
ax->crcmode = CRC_MODE_SMACK;
|
break;
|
case 2:
|
ax->crcmode = CRC_MODE_FLEX;
|
break;
|
case 1:
|
ax->crcmode = CRC_MODE_NONE;
|
break;
|
case 0:
|
default:
|
ax->crcmode = CRC_MODE_SMACK_TEST;
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cmd = 0;
|
}
|
ax->crcauto = (cmd ? 0 : 1);
|
printk(KERN_INFO "mkiss: %s: crc mode set to %d\n",
|
ax->dev->name, cmd);
|
}
|
spin_unlock_bh(&ax->buflock);
|
netif_start_queue(dev);
|
|
return;
|
default:
|
count = kiss_esc(p, ax->xbuff, len);
|
}
|
} else {
|
unsigned short crc;
|
switch (ax->crcmode) {
|
case CRC_MODE_SMACK_TEST:
|
ax->crcmode = CRC_MODE_FLEX_TEST;
|
printk(KERN_INFO "mkiss: %s: Trying crc-smack\n", ax->dev->name);
|
// fall through
|
case CRC_MODE_SMACK:
|
*p |= 0x80;
|
crc = swab16(crc16(0, p, len));
|
count = kiss_esc_crc(p, ax->xbuff, crc, len+2);
|
break;
|
case CRC_MODE_FLEX_TEST:
|
ax->crcmode = CRC_MODE_NONE;
|
printk(KERN_INFO "mkiss: %s: Trying crc-flexnet\n", ax->dev->name);
|
// fall through
|
case CRC_MODE_FLEX:
|
*p |= 0x20;
|
crc = calc_crc_flex(p, len);
|
count = kiss_esc_crc(p, ax->xbuff, crc, len+2);
|
break;
|
|
default:
|
count = kiss_esc(p, ax->xbuff, len);
|
}
|
}
|
spin_unlock_bh(&ax->buflock);
|
|
set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags);
|
actual = ax->tty->ops->write(ax->tty, ax->xbuff, count);
|
dev->stats.tx_packets++;
|
dev->stats.tx_bytes += actual;
|
|
netif_trans_update(ax->dev);
|
ax->xleft = count - actual;
|
ax->xhead = ax->xbuff + actual;
|
}
|
|
/* Encapsulate an AX.25 packet and kick it into a TTY queue. */
|
static netdev_tx_t ax_xmit(struct sk_buff *skb, struct net_device *dev)
|
{
|
struct mkiss *ax = netdev_priv(dev);
|
|
if (skb->protocol == htons(ETH_P_IP))
|
return ax25_ip_xmit(skb);
|
|
if (!netif_running(dev)) {
|
printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name);
|
return NETDEV_TX_BUSY;
|
}
|
|
if (netif_queue_stopped(dev)) {
|
/*
|
* May be we must check transmitter timeout here ?
|
* 14 Oct 1994 Dmitry Gorodchanin.
|
*/
|
if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) {
|
/* 20 sec timeout not reached */
|
return NETDEV_TX_BUSY;
|
}
|
|
printk(KERN_ERR "mkiss: %s: transmit timed out, %s?\n", dev->name,
|
(tty_chars_in_buffer(ax->tty) || ax->xleft) ?
|
"bad line quality" : "driver error");
|
|
ax->xleft = 0;
|
clear_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags);
|
netif_start_queue(dev);
|
}
|
|
/* We were not busy, so we are now... :-) */
|
netif_stop_queue(dev);
|
ax_encaps(dev, skb->data, skb->len);
|
kfree_skb(skb);
|
|
return NETDEV_TX_OK;
|
}
|
|
static int ax_open_dev(struct net_device *dev)
|
{
|
struct mkiss *ax = netdev_priv(dev);
|
|
if (ax->tty == NULL)
|
return -ENODEV;
|
|
return 0;
|
}
|
|
/* Open the low-level part of the AX25 channel. Easy! */
|
static int ax_open(struct net_device *dev)
|
{
|
struct mkiss *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);
|
|
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 mkiss *ax = netdev_priv(dev);
|
|
if (ax->tty)
|
clear_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags);
|
|
netif_stop_queue(dev);
|
|
return 0;
|
}
|
|
static const struct net_device_ops ax_netdev_ops = {
|
.ndo_open = ax_open_dev,
|
.ndo_stop = ax_close,
|
.ndo_start_xmit = ax_xmit,
|
.ndo_set_mac_address = ax_set_mac_address,
|
};
|
|
static void ax_setup(struct net_device *dev)
|
{
|
/* Finish setting up the DEVICE info. */
|
dev->mtu = AX_MTU;
|
dev->hard_header_len = AX25_MAX_HEADER_LEN;
|
dev->addr_len = AX25_ADDR_LEN;
|
dev->type = ARPHRD_AX25;
|
dev->tx_queue_len = 10;
|
dev->header_ops = &ax25_header_ops;
|
dev->netdev_ops = &ax_netdev_ops;
|
|
|
memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
|
memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
|
|
dev->flags = IFF_BROADCAST | IFF_MULTICAST;
|
}
|
|
/*
|
* We have a potential race on dereferencing tty->disc_data, because the tty
|
* layer provides no locking at all - thus one cpu could be running
|
* sixpack_receive_buf while another calls sixpack_close, which zeroes
|
* tty->disc_data and frees the memory that sixpack_receive_buf is using. The
|
* best way to fix this is to use a rwlock in the tty struct, but for now we
|
* use a single global rwlock for all ttys in ppp line discipline.
|
*/
|
static DEFINE_RWLOCK(disc_data_lock);
|
|
static struct mkiss *mkiss_get(struct tty_struct *tty)
|
{
|
struct mkiss *ax;
|
|
read_lock(&disc_data_lock);
|
ax = tty->disc_data;
|
if (ax)
|
atomic_inc(&ax->refcnt);
|
read_unlock(&disc_data_lock);
|
|
return ax;
|
}
|
|
static void mkiss_put(struct mkiss *ax)
|
{
|
if (atomic_dec_and_test(&ax->refcnt))
|
up(&ax->dead_sem);
|
}
|
|
static int crc_force = 0; /* Can be overridden with insmod */
|
|
static int mkiss_open(struct tty_struct *tty)
|
{
|
struct net_device *dev;
|
struct mkiss *ax;
|
int err;
|
|
if (!capable(CAP_NET_ADMIN))
|
return -EPERM;
|
if (tty->ops->write == NULL)
|
return -EOPNOTSUPP;
|
|
dev = alloc_netdev(sizeof(struct mkiss), "ax%d", NET_NAME_UNKNOWN,
|
ax_setup);
|
if (!dev) {
|
err = -ENOMEM;
|
goto out;
|
}
|
|
ax = netdev_priv(dev);
|
ax->dev = dev;
|
|
spin_lock_init(&ax->buflock);
|
atomic_set(&ax->refcnt, 1);
|
sema_init(&ax->dead_sem, 0);
|
|
ax->tty = tty;
|
tty->disc_data = ax;
|
tty->receive_room = 65535;
|
|
tty_driver_flush_buffer(tty);
|
|
/* Restore default settings */
|
dev->type = ARPHRD_AX25;
|
|
/* Perform the low-level AX25 initialization. */
|
err = ax_open(ax->dev);
|
if (err)
|
goto out_free_netdev;
|
|
err = register_netdev(dev);
|
if (err)
|
goto out_free_buffers;
|
|
/* after register_netdev() - because else printk smashes the kernel */
|
switch (crc_force) {
|
case 3:
|
ax->crcmode = CRC_MODE_SMACK;
|
printk(KERN_INFO "mkiss: %s: crc mode smack forced.\n",
|
ax->dev->name);
|
break;
|
case 2:
|
ax->crcmode = CRC_MODE_FLEX;
|
printk(KERN_INFO "mkiss: %s: crc mode flexnet forced.\n",
|
ax->dev->name);
|
break;
|
case 1:
|
ax->crcmode = CRC_MODE_NONE;
|
printk(KERN_INFO "mkiss: %s: crc mode disabled.\n",
|
ax->dev->name);
|
break;
|
case 0:
|
/* fall through */
|
default:
|
crc_force = 0;
|
printk(KERN_INFO "mkiss: %s: crc mode is auto.\n",
|
ax->dev->name);
|
ax->crcmode = CRC_MODE_SMACK_TEST;
|
}
|
ax->crcauto = (crc_force ? 0 : 1);
|
|
netif_start_queue(dev);
|
|
/* Done. We have linked the TTY line to a channel. */
|
return 0;
|
|
out_free_buffers:
|
kfree(ax->rbuff);
|
kfree(ax->xbuff);
|
|
out_free_netdev:
|
free_netdev(dev);
|
|
out:
|
return err;
|
}
|
|
static void mkiss_close(struct tty_struct *tty)
|
{
|
struct mkiss *ax;
|
|
write_lock_irq(&disc_data_lock);
|
ax = tty->disc_data;
|
tty->disc_data = NULL;
|
write_unlock_irq(&disc_data_lock);
|
|
if (!ax)
|
return;
|
|
/*
|
* We have now ensured that nobody can start using ap from now on, but
|
* we have to wait for all existing users to finish.
|
*/
|
if (!atomic_dec_and_test(&ax->refcnt))
|
down(&ax->dead_sem);
|
/*
|
* Halt the transmit queue so that a new transmit cannot scribble
|
* on our buffers
|
*/
|
netif_stop_queue(ax->dev);
|
|
unregister_netdev(ax->dev);
|
|
/* Free all AX25 frame buffers after unreg. */
|
kfree(ax->rbuff);
|
kfree(ax->xbuff);
|
|
ax->tty = NULL;
|
|
free_netdev(ax->dev);
|
}
|
|
/* Perform I/O control on an active ax25 channel. */
|
static int mkiss_ioctl(struct tty_struct *tty, struct file *file,
|
unsigned int cmd, unsigned long arg)
|
{
|
struct mkiss *ax = mkiss_get(tty);
|
struct net_device *dev;
|
unsigned int tmp, err;
|
|
/* First make sure we're connected. */
|
if (ax == NULL)
|
return -ENXIO;
|
dev = ax->dev;
|
|
switch (cmd) {
|
case SIOCGIFNAME:
|
err = copy_to_user((void __user *) arg, ax->dev->name,
|
strlen(ax->dev->name) + 1) ? -EFAULT : 0;
|
break;
|
|
case SIOCGIFENCAP:
|
err = put_user(4, (int __user *) arg);
|
break;
|
|
case SIOCSIFENCAP:
|
if (get_user(tmp, (int __user *) arg)) {
|
err = -EFAULT;
|
break;
|
}
|
|
ax->mode = tmp;
|
dev->addr_len = AX25_ADDR_LEN;
|
dev->hard_header_len = AX25_KISS_HEADER_LEN +
|
AX25_MAX_HEADER_LEN + 3;
|
dev->type = ARPHRD_AX25;
|
|
err = 0;
|
break;
|
|
case SIOCSIFHWADDR: {
|
char addr[AX25_ADDR_LEN];
|
|
if (copy_from_user(&addr,
|
(void __user *) arg, AX25_ADDR_LEN)) {
|
err = -EFAULT;
|
break;
|
}
|
|
netif_tx_lock_bh(dev);
|
memcpy(dev->dev_addr, addr, AX25_ADDR_LEN);
|
netif_tx_unlock_bh(dev);
|
|
err = 0;
|
break;
|
}
|
default:
|
err = -ENOIOCTLCMD;
|
}
|
|
mkiss_put(ax);
|
|
return err;
|
}
|
|
#ifdef CONFIG_COMPAT
|
static long mkiss_compat_ioctl(struct tty_struct *tty, struct file *file,
|
unsigned int cmd, unsigned long arg)
|
{
|
switch (cmd) {
|
case SIOCGIFNAME:
|
case SIOCGIFENCAP:
|
case SIOCSIFENCAP:
|
case SIOCSIFHWADDR:
|
return mkiss_ioctl(tty, file, cmd,
|
(unsigned long)compat_ptr(arg));
|
}
|
|
return -ENOIOCTLCMD;
|
}
|
#endif
|
|
/*
|
* 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 mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp,
|
char *fp, int count)
|
{
|
struct mkiss *ax = mkiss_get(tty);
|
|
if (!ax)
|
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->dev->stats.rx_errors++;
|
cp++;
|
continue;
|
}
|
|
kiss_unesc(ax, *cp++);
|
}
|
|
mkiss_put(ax);
|
tty_unthrottle(tty);
|
}
|
|
/*
|
* Called by the driver when there's room for more data. If we have
|
* more packets to send, we send them here.
|
*/
|
static void mkiss_write_wakeup(struct tty_struct *tty)
|
{
|
struct mkiss *ax = mkiss_get(tty);
|
int actual;
|
|
if (!ax)
|
return;
|
|
if (ax->xleft <= 0) {
|
/* Now serial buffer is almost free & we can start
|
* transmission of another packet
|
*/
|
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
|
|
netif_wake_queue(ax->dev);
|
goto out;
|
}
|
|
actual = tty->ops->write(tty, ax->xhead, ax->xleft);
|
ax->xleft -= actual;
|
ax->xhead += actual;
|
|
out:
|
mkiss_put(ax);
|
}
|
|
static struct tty_ldisc_ops ax_ldisc = {
|
.owner = THIS_MODULE,
|
.magic = TTY_LDISC_MAGIC,
|
.name = "mkiss",
|
.open = mkiss_open,
|
.close = mkiss_close,
|
.ioctl = mkiss_ioctl,
|
#ifdef CONFIG_COMPAT
|
.compat_ioctl = mkiss_compat_ioctl,
|
#endif
|
.receive_buf = mkiss_receive_buf,
|
.write_wakeup = mkiss_write_wakeup
|
};
|
|
static const char banner[] __initconst = KERN_INFO \
|
"mkiss: AX.25 Multikiss, Hans Albas PE1AYX\n";
|
static const char msg_regfail[] __initconst = KERN_ERR \
|
"mkiss: can't register line discipline (err = %d)\n";
|
|
static int __init mkiss_init_driver(void)
|
{
|
int status;
|
|
printk(banner);
|
|
status = tty_register_ldisc(N_AX25, &ax_ldisc);
|
if (status != 0)
|
printk(msg_regfail, status);
|
|
return status;
|
}
|
|
static const char msg_unregfail[] = KERN_ERR \
|
"mkiss: can't unregister line discipline (err = %d)\n";
|
|
static void __exit mkiss_exit_driver(void)
|
{
|
int ret;
|
|
if ((ret = tty_unregister_ldisc(N_AX25)))
|
printk(msg_unregfail, ret);
|
}
|
|
MODULE_AUTHOR("Ralf Baechle DL5RB <ralf@linux-mips.org>");
|
MODULE_DESCRIPTION("KISS driver for AX.25 over TTYs");
|
module_param(crc_force, int, 0);
|
MODULE_PARM_DESC(crc_force, "crc [0 = auto | 1 = none | 2 = flexnet | 3 = smack]");
|
MODULE_LICENSE("GPL");
|
MODULE_ALIAS_LDISC(N_AX25);
|
|
module_init(mkiss_init_driver);
|
module_exit(mkiss_exit_driver);
|
