| /* |
| * This program is free software; you can distribute it and/or modify it |
| * under the terms of the GNU General Public License (Version 2) as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, see <http://www.gnu.org/licenses/>. |
| * |
| * Copyright (C) Hans Alblas PE1AYX <hans@esrac.ele.tue.nl> |
| * Copyright (C) 2004, 05 Ralf Baechle DL5RB <ralf@linux-mips.org> |
| * Copyright (C) 2004, 05 Thomas Osterried DL9SAU <thomas@x-berg.in-berlin.de> |
| */ |
| #include <linux/module.h> |
| #include <linux/bitops.h> |
| #include <linux/uaccess.h> |
| #include <linux/crc16.h> |
| #include <linux/string.h> |
| #include <linux/mm.h> |
| #include <linux/interrupt.h> |
| #include <linux/in.h> |
| #include <linux/inet.h> |
| #include <linux/slab.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 <linux/jiffies.h> |
| #include <linux/compat.h> |
| |
| #include <net/ax25.h> |
| |
| #define AX_MTU 236 |
| |
| /* SLIP/KISS protocol characters. */ |
| #define END 0300 /* indicates end of frame */ |
| #define ESC 0333 /* indicates byte stuffing */ |
| #define ESC_END 0334 /* ESC ESC_END means END 'data' */ |
| #define ESC_ESC 0335 /* ESC ESC_ESC means ESC 'data' */ |
| |
| struct mkiss { |
| struct tty_struct *tty; /* ptr to TTY structure */ |
| struct net_device *dev; /* easy for intr handling */ |
| |
| /* These are pointers to the malloc()ed frame buffers. */ |
| spinlock_t buflock;/* lock for rbuf and xbuf */ |
| unsigned char *rbuff; /* receiver buffer */ |
| int rcount; /* received chars counter */ |
| unsigned char *xbuff; /* transmitter buffer */ |
| unsigned char *xhead; /* pointer to next byte to XMIT */ |
| int xleft; /* bytes left in XMIT queue */ |
| |
| /* Detailed SLIP statistics. */ |
| int mtu; /* Our mtu (to spot changes!) */ |
| int buffsize; /* Max buffers sizes */ |
| |
| unsigned long flags; /* Flag values/ mode etc */ |
| /* long req'd: used by set_bit --RR */ |
| #define AXF_INUSE 0 /* Channel in use */ |
| #define AXF_ESCAPE 1 /* ESC received */ |
| #define AXF_ERROR 2 /* Parity, etc. error */ |
| #define AXF_KEEPTEST 3 /* Keepalive test flag */ |
| #define AXF_OUTWAIT 4 /* is outpacket was flag */ |
| |
| int mode; |
| int crcmode; /* MW: for FlexNet, SMACK etc. */ |
| int crcauto; /* CRC auto mode */ |
| |
| #define CRC_MODE_NONE 0 |
| #define CRC_MODE_FLEX 1 |
| #define CRC_MODE_SMACK 2 |
| #define CRC_MODE_FLEX_TEST 3 |
| #define CRC_MODE_SMACK_TEST 4 |
| |
| atomic_t refcnt; |
| struct semaphore dead_sem; |
| }; |
| |
| /*---------------------------------------------------------------------------*/ |
| |
| 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; |
| } |
| |
| static int check_crc_16(unsigned char *cp, int size) |
| { |
| unsigned short crc = 0x0000; |
| |
| if (size < 3) |
| return -1; |
| |
| crc = crc16(0, cp, size); |
| |
| if (crc != 0x0000) |
| return -1; |
| |
| return 0; |
| } |
| |
| /* |
| * 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 |
| 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; |
| } |
| |
| /* Send one completely decapsulated AX.25 packet to the AX.25 layer. */ |
| static void ax_bump(struct mkiss *ax) |
| { |
| struct sk_buff *skb; |
| int count; |
| |
| spin_lock_bh(&ax->buflock); |
| if (ax->rbuff[0] > 0x0f) { |
| if (ax->rbuff[0] & 0x80) { |
| if (check_crc_16(ax->rbuff, ax->rcount) < 0) { |
| ax->dev->stats.rx_errors++; |
| spin_unlock_bh(&ax->buflock); |
| |
| return; |
| } |
| if (ax->crcmode != CRC_MODE_SMACK && ax->crcauto) { |
| printk(KERN_INFO |
| "mkiss: %s: Switching to crc-smack\n", |
| ax->dev->name); |
| ax->crcmode = CRC_MODE_SMACK; |
| } |
| ax->rcount -= 2; |
| *ax->rbuff &= ~0x80; |
| } else if (ax->rbuff[0] & 0x20) { |
| if (check_crc_flex(ax->rbuff, ax->rcount) < 0) { |
| ax->dev->stats.rx_errors++; |
| spin_unlock_bh(&ax->buflock); |
| return; |
| } |
| if (ax->crcmode != CRC_MODE_FLEX && ax->crcauto) { |
| printk(KERN_INFO |
| "mkiss: %s: Switching to crc-flexnet\n", |
| ax->dev->name); |
| ax->crcmode = CRC_MODE_FLEX; |
| } |
| 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; |
| } |
| } |
| |
| count = ax->rcount; |
| |
| if ((skb = dev_alloc_skb(count)) == NULL) { |
| printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n", |
| ax->dev->name); |
| ax->dev->stats.rx_dropped++; |
| spin_unlock_bh(&ax->buflock); |
| return; |
| } |
| |
| skb_put_data(skb, ax->rbuff, count); |
| skb->protocol = ax25_type_trans(skb, ax->dev); |
| netif_rx(skb); |
| ax->dev->stats.rx_packets++; |
| ax->dev->stats.rx_bytes += count; |
| spin_unlock_bh(&ax->buflock); |
| } |
| |
| static void kiss_unesc(struct mkiss *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->dev->stats.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 *addr) |
| { |
| struct sockaddr_ax25 *sa = addr; |
| |
| netif_tx_lock_bh(dev); |
| netif_addr_lock(dev); |
| memcpy(dev->dev_addr, &sa->sax25_call, AX25_ADDR_LEN); |
| netif_addr_unlock(dev); |
| netif_tx_unlock_bh(dev); |
| |
| return 0; |
| } |
| |
| /*---------------------------------------------------------------------------*/ |
| |
| static void ax_changedmtu(struct mkiss *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; |
| kfree(xbuff); |
| 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; |
| dev->stats.tx_dropped++; |
| } |
| } |
| |
| ax->xhead = ax->xbuff; |
| |
| if (ax->rcount) { |
| if (ax->rcount <= len) { |
| memcpy(ax->rbuff, orbuff, ax->rcount); |
| } else { |
| ax->rcount = 0; |
| dev->stats.rx_over_errors++; |
| set_bit(AXF_ERROR, &ax->flags); |
| } |
| } |
| |
| ax->mtu = dev->mtu + 73; |
| ax->buffsize = len; |
| |
| spin_unlock_bh(&ax->buflock); |
| |
| kfree(oxbuff); |
| kfree(orbuff); |
| } |
| |
| /* Encapsulate one AX.25 packet and stuff into a TTY queue. */ |
| static void ax_encaps(struct net_device *dev, unsigned char *icp, int len) |
| { |
| struct mkiss *ax = netdev_priv(dev); |
| 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 ... */ |
| printk(KERN_ERR "mkiss: %s: truncating oversized transmit packet!\n", ax->dev->name); |
| dev->stats.tx_dropped++; |
| netif_start_queue(dev); |
| return; |
| } |
| |
| 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; |
| 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); |