| /* |
| * slcan.c - serial line CAN interface driver (using tty line discipline) |
| * |
| * This file is derived from linux/drivers/net/slip/slip.c |
| * |
| * slip.c Authors : Laurence Culhane <loz@holmes.demon.co.uk> |
| * Fred N. van Kempen <waltje@uwalt.nl.mugnet.org> |
| * slcan.c Author : Oliver Hartkopp <socketcan@hartkopp.net> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| * |
| * This program is distributed in the hope that 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/gpl.html |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
| * DAMAGE. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| |
| #include <linux/uaccess.h> |
| #include <linux/bitops.h> |
| #include <linux/string.h> |
| #include <linux/tty.h> |
| #include <linux/errno.h> |
| #include <linux/netdevice.h> |
| #include <linux/skbuff.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/if_arp.h> |
| #include <linux/if_ether.h> |
| #include <linux/sched.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/workqueue.h> |
| #include <linux/can.h> |
| #include <linux/can/skb.h> |
| #include <linux/can/can-ml.h> |
| |
| MODULE_ALIAS_LDISC(N_SLCAN); |
| MODULE_DESCRIPTION("serial line CAN interface"); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>"); |
| |
| #define SLCAN_MAGIC 0x53CA |
| |
| static int maxdev = 10; /* MAX number of SLCAN channels; |
| This can be overridden with |
| insmod slcan.ko maxdev=nnn */ |
| module_param(maxdev, int, 0); |
| MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces"); |
| |
| /* maximum rx buffer len: extended CAN frame with timestamp */ |
| #define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r")+1) |
| |
| #define SLC_CMD_LEN 1 |
| #define SLC_SFF_ID_LEN 3 |
| #define SLC_EFF_ID_LEN 8 |
| |
| struct slcan { |
| int magic; |
| |
| /* Various fields. */ |
| struct tty_struct *tty; /* ptr to TTY structure */ |
| struct net_device *dev; /* easy for intr handling */ |
| spinlock_t lock; |
| struct work_struct tx_work; /* Flushes transmit buffer */ |
| |
| /* These are pointers to the malloc()ed frame buffers. */ |
| unsigned char rbuff[SLC_MTU]; /* receiver buffer */ |
| int rcount; /* received chars counter */ |
| unsigned char xbuff[SLC_MTU]; /* transmitter buffer */ |
| unsigned char *xhead; /* pointer to next XMIT byte */ |
| int xleft; /* bytes left in XMIT queue */ |
| |
| unsigned long flags; /* Flag values/ mode etc */ |
| #define SLF_INUSE 0 /* Channel in use */ |
| #define SLF_ERROR 1 /* Parity, etc. error */ |
| }; |
| |
| static struct net_device **slcan_devs; |
| |
| /************************************************************************ |
| * SLCAN ENCAPSULATION FORMAT * |
| ************************************************************************/ |
| |
| /* |
| * A CAN frame has a can_id (11 bit standard frame format OR 29 bit extended |
| * frame format) a data length code (can_dlc) which can be from 0 to 8 |
| * and up to <can_dlc> data bytes as payload. |
| * Additionally a CAN frame may become a remote transmission frame if the |
| * RTR-bit is set. This causes another ECU to send a CAN frame with the |
| * given can_id. |
| * |
| * The SLCAN ASCII representation of these different frame types is: |
| * <type> <id> <dlc> <data>* |
| * |
| * Extended frames (29 bit) are defined by capital characters in the type. |
| * RTR frames are defined as 'r' types - normal frames have 't' type: |
| * t => 11 bit data frame |
| * r => 11 bit RTR frame |
| * T => 29 bit data frame |
| * R => 29 bit RTR frame |
| * |
| * The <id> is 3 (standard) or 8 (extended) bytes in ASCII Hex (base64). |
| * The <dlc> is a one byte ASCII number ('0' - '8') |
| * The <data> section has at much ASCII Hex bytes as defined by the <dlc> |
| * |
| * Examples: |
| * |
| * t1230 : can_id 0x123, can_dlc 0, no data |
| * t4563112233 : can_id 0x456, can_dlc 3, data 0x11 0x22 0x33 |
| * T12ABCDEF2AA55 : extended can_id 0x12ABCDEF, can_dlc 2, data 0xAA 0x55 |
| * r1230 : can_id 0x123, can_dlc 0, no data, remote transmission request |
| * |
| */ |
| |
| /************************************************************************ |
| * STANDARD SLCAN DECAPSULATION * |
| ************************************************************************/ |
| |
| /* Send one completely decapsulated can_frame to the network layer */ |
| static void slc_bump(struct slcan *sl) |
| { |
| struct sk_buff *skb; |
| struct can_frame cf; |
| int i, tmp; |
| u32 tmpid; |
| char *cmd = sl->rbuff; |
| |
| cf.can_id = 0; |
| |
| switch (*cmd) { |
| case 'r': |
| cf.can_id = CAN_RTR_FLAG; |
| /* fallthrough */ |
| case 't': |
| /* store dlc ASCII value and terminate SFF CAN ID string */ |
| cf.can_dlc = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN]; |
| sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN] = 0; |
| /* point to payload data behind the dlc */ |
| cmd += SLC_CMD_LEN + SLC_SFF_ID_LEN + 1; |
| break; |
| case 'R': |
| cf.can_id = CAN_RTR_FLAG; |
| /* fallthrough */ |
| case 'T': |
| cf.can_id |= CAN_EFF_FLAG; |
| /* store dlc ASCII value and terminate EFF CAN ID string */ |
| cf.can_dlc = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN]; |
| sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN] = 0; |
| /* point to payload data behind the dlc */ |
| cmd += SLC_CMD_LEN + SLC_EFF_ID_LEN + 1; |
| break; |
| default: |
| return; |
| } |
| |
| if (kstrtou32(sl->rbuff + SLC_CMD_LEN, 16, &tmpid)) |
| return; |
| |
| cf.can_id |= tmpid; |
| |
| /* get can_dlc from sanitized ASCII value */ |
| if (cf.can_dlc >= '0' && cf.can_dlc < '9') |
| cf.can_dlc -= '0'; |
| else |
| return; |
| |
| *(u64 *) (&cf.data) = 0; /* clear payload */ |
| |
| /* RTR frames may have a dlc > 0 but they never have any data bytes */ |
| if (!(cf.can_id & CAN_RTR_FLAG)) { |
| for (i = 0; i < cf.can_dlc; i++) { |
| tmp = hex_to_bin(*cmd++); |
| if (tmp < 0) |
| return; |
| cf.data[i] = (tmp << 4); |
| tmp = hex_to_bin(*cmd++); |
| if (tmp < 0) |
| return; |
| cf.data[i] |= tmp; |
| } |
| } |
| |
| skb = dev_alloc_skb(sizeof(struct can_frame) + |
| sizeof(struct can_skb_priv)); |
| if (!skb) |
| return; |
| |
| skb->dev = sl->dev; |
| skb->protocol = htons(ETH_P_CAN); |
| skb->pkt_type = PACKET_BROADCAST; |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| |
| can_skb_reserve(skb); |
| can_skb_prv(skb)->ifindex = sl->dev->ifindex; |
| can_skb_prv(skb)->skbcnt = 0; |
| |
| skb_put_data(skb, &cf, sizeof(struct can_frame)); |
| |
| sl->dev->stats.rx_packets++; |
| sl->dev->stats.rx_bytes += cf.can_dlc; |
| netif_rx_ni(skb); |
| } |
| |
| /* parse tty input stream */ |
| static void slcan_unesc(struct slcan *sl, unsigned char s) |
| { |
| if ((s == '\r') || (s == '\a')) { /* CR or BEL ends the pdu */ |
| if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && |
| (sl->rcount > 4)) { |
| slc_bump(sl); |
| } |
| sl->rcount = 0; |
| } else { |
| if (!test_bit(SLF_ERROR, &sl->flags)) { |
| if (sl->rcount < SLC_MTU) { |
| sl->rbuff[sl->rcount++] = s; |
| return; |
| } else { |
| sl->dev->stats.rx_over_errors++; |
| set_bit(SLF_ERROR, &sl->flags); |
| } |
| } |
| } |
| } |
| |
| /************************************************************************ |
| * STANDARD SLCAN ENCAPSULATION * |
| ************************************************************************/ |
| |
| /* Encapsulate one can_frame and stuff into a TTY queue. */ |
| static void slc_encaps(struct slcan *sl, struct can_frame *cf) |
| { |
| int actual, i; |
| unsigned char *pos; |
| unsigned char *endpos; |
| canid_t id = cf->can_id; |
| |
| pos = sl->xbuff; |
| |
| if (cf->can_id & CAN_RTR_FLAG) |
| *pos = 'R'; /* becomes 'r' in standard frame format (SFF) */ |
| else |
| *pos = 'T'; /* becomes 't' in standard frame format (SSF) */ |
| |
| /* determine number of chars for the CAN-identifier */ |
| if (cf->can_id & CAN_EFF_FLAG) { |
| id &= CAN_EFF_MASK; |
| endpos = pos + SLC_EFF_ID_LEN; |
| } else { |
| *pos |= 0x20; /* convert R/T to lower case for SFF */ |
| id &= CAN_SFF_MASK; |
| endpos = pos + SLC_SFF_ID_LEN; |
| } |
| |
| /* build 3 (SFF) or 8 (EFF) digit CAN identifier */ |
| pos++; |
| while (endpos >= pos) { |
| *endpos-- = hex_asc_upper[id & 0xf]; |
| id >>= 4; |
| } |
| |
| pos += (cf->can_id & CAN_EFF_FLAG) ? SLC_EFF_ID_LEN : SLC_SFF_ID_LEN; |
| |
| *pos++ = cf->can_dlc + '0'; |
| |
| /* RTR frames may have a dlc > 0 but they never have any data bytes */ |
| if (!(cf->can_id & CAN_RTR_FLAG)) { |
| for (i = 0; i < cf->can_dlc; i++) |
| pos = hex_byte_pack_upper(pos, cf->data[i]); |
| } |
| |
| *pos++ = '\r'; |
| |
| /* Order of next two lines is *very* important. |
| * When we are sending a little amount of data, |
| * the transfer may be completed inside the ops->write() |
| * routine, because it's running with interrupts enabled. |
| * In this case we *never* got WRITE_WAKEUP event, |
| * if we did not request it before write operation. |
| * 14 Oct 1994 Dmitry Gorodchanin. |
| */ |
| set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
| actual = sl->tty->ops->write(sl->tty, sl->xbuff, pos - sl->xbuff); |
| sl->xleft = (pos - sl->xbuff) - actual; |
| sl->xhead = sl->xbuff + actual; |
| sl->dev->stats.tx_bytes += cf->can_dlc; |
| } |
| |
| /* Write out any remaining transmit buffer. Scheduled when tty is writable */ |
| static void slcan_transmit(struct work_struct *work) |
| { |
| struct slcan *sl = container_of(work, struct slcan, tx_work); |
| int actual; |
| |
| spin_lock_bh(&sl->lock); |
| /* First make sure we're connected. */ |
| if (!sl->tty || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) { |
| spin_unlock_bh(&sl->lock); |
| return; |
| } |
| |
| if (sl->xleft <= 0) { |
| /* Now serial buffer is almost free & we can start |
| * transmission of another packet */ |
| sl->dev->stats.tx_packets++; |
| clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
| spin_unlock_bh(&sl->lock); |
| netif_wake_queue(sl->dev); |
| return; |
| } |
| |
| actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft); |
| sl->xleft -= actual; |
| sl->xhead += actual; |
| spin_unlock_bh(&sl->lock); |
| } |
| |
| /* |
| * Called by the driver when there's room for more data. |
| * Schedule the transmit. |
| */ |
| static void slcan_write_wakeup(struct tty_struct *tty) |
| { |
| struct slcan *sl; |
| |
| rcu_read_lock(); |
| sl = rcu_dereference(tty->disc_data); |
| if (!sl) |
| goto out; |
| |
| schedule_work(&sl->tx_work); |
| out: |
| rcu_read_unlock(); |
| } |
| |
| /* Send a can_frame to a TTY queue. */ |
| static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct slcan *sl = netdev_priv(dev); |
| |
| if (skb->len != CAN_MTU) |
| goto out; |
| |
| spin_lock(&sl->lock); |
| if (!netif_running(dev)) { |
| spin_unlock(&sl->lock); |
| printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name); |
| goto out; |
| } |
| if (sl->tty == NULL) { |
| spin_unlock(&sl->lock); |
| goto out; |
| } |
| |
| netif_stop_queue(sl->dev); |
| slc_encaps(sl, (struct can_frame *) skb->data); /* encaps & send */ |
| spin_unlock(&sl->lock); |
| |
| out: |
| kfree_skb(skb); |
| return NETDEV_TX_OK; |
| } |
| |
| |
| /****************************************** |
| * Routines looking at netdevice side. |
| ******************************************/ |
| |
| /* Netdevice UP -> DOWN routine */ |
| static int slc_close(struct net_device *dev) |
| { |
| struct slcan *sl = netdev_priv(dev); |
| |
| spin_lock_bh(&sl->lock); |
| if (sl->tty) { |
| /* TTY discipline is running. */ |
| clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
| } |
| netif_stop_queue(dev); |
| sl->rcount = 0; |
| sl->xleft = 0; |
| spin_unlock_bh(&sl->lock); |
| |
| return 0; |
| } |
| |
| /* Netdevice DOWN -> UP routine */ |
| static int slc_open(struct net_device *dev) |
| { |
| struct slcan *sl = netdev_priv(dev); |
| |
| if (sl->tty == NULL) |
| return -ENODEV; |
| |
| sl->flags &= (1 << SLF_INUSE); |
| netif_start_queue(dev); |
| return 0; |
| } |
| |
| /* Hook the destructor so we can free slcan devs at the right point in time */ |
| static void slc_free_netdev(struct net_device *dev) |
| { |
| int i = dev->base_addr; |
| |
| slcan_devs[i] = NULL; |
| } |
| |
| static int slcan_change_mtu(struct net_device *dev, int new_mtu) |
| { |
| return -EINVAL; |
| } |
| |
| static const struct net_device_ops slc_netdev_ops = { |
| .ndo_open = slc_open, |
| .ndo_stop = slc_close, |
| .ndo_start_xmit = slc_xmit, |
| .ndo_change_mtu = slcan_change_mtu, |
| }; |
| |
| static void slc_setup(struct net_device *dev) |
| { |
| dev->netdev_ops = &slc_netdev_ops; |
| dev->needs_free_netdev = true; |
| dev->priv_destructor = slc_free_netdev; |
| |
| dev->hard_header_len = 0; |
| dev->addr_len = 0; |
| dev->tx_queue_len = 10; |
| |
| dev->mtu = CAN_MTU; |
| dev->type = ARPHRD_CAN; |
| |
| /* New-style flags. */ |
| dev->flags = IFF_NOARP; |
| dev->features = NETIF_F_HW_CSUM; |
| } |
| |
| /****************************************** |
| Routines looking at TTY side. |
| ******************************************/ |
| |
| /* |
| * Handle the 'receiver data ready' interrupt. |
| * This function is called by the 'tty_io' module in the kernel when |
| * a block of SLCAN data has been received, which can now be decapsulated |
| * and sent on to some IP layer for further processing. This will not |
| * be re-entered while running but other ldisc functions may be called |
| * in parallel |
| */ |
| |
| static void slcan_receive_buf(struct tty_struct *tty, |
| const unsigned char *cp, char *fp, int count) |
| { |
| struct slcan *sl = (struct slcan *) tty->disc_data; |
| |
| if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) |
| return; |
| |
| /* Read the characters out of the buffer */ |
| while (count--) { |
| if (fp && *fp++) { |
| if (!test_and_set_bit(SLF_ERROR, &sl->flags)) |
| sl->dev->stats.rx_errors++; |
| cp++; |
| continue; |
| } |
| slcan_unesc(sl, *cp++); |
| } |
| } |
| |
| /************************************ |
| * slcan_open helper routines. |
| ************************************/ |
| |
| /* Collect hanged up channels */ |
| static void slc_sync(void) |
| { |
| int i; |
| struct net_device *dev; |
| struct slcan *sl; |
| |
| for (i = 0; i < maxdev; i++) { |
| dev = slcan_devs[i]; |
| if (dev == NULL) |
| break; |
| |
| sl = netdev_priv(dev); |
| if (sl->tty) |
| continue; |
| if (dev->flags & IFF_UP) |
| dev_close(dev); |
| } |
| } |
| |
| /* Find a free SLCAN channel, and link in this `tty' line. */ |
| static struct slcan *slc_alloc(void) |
| { |
| int i; |
| char name[IFNAMSIZ]; |
| struct net_device *dev = NULL; |
| struct slcan *sl; |
| int size; |
| |
| for (i = 0; i < maxdev; i++) { |
| dev = slcan_devs[i]; |
| if (dev == NULL) |
| break; |
| |
| } |
| |
| /* Sorry, too many, all slots in use */ |
| if (i >= maxdev) |
| return NULL; |
| |
| sprintf(name, "slcan%d", i); |
| size = ALIGN(sizeof(*sl), NETDEV_ALIGN) + sizeof(struct can_ml_priv); |
| dev = alloc_netdev(size, name, NET_NAME_UNKNOWN, slc_setup); |
| if (!dev) |
| return NULL; |
| |
| dev->base_addr = i; |
| sl = netdev_priv(dev); |
| dev->ml_priv = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN); |
| |
| /* Initialize channel control data */ |
| sl->magic = SLCAN_MAGIC; |
| sl->dev = dev; |
| spin_lock_init(&sl->lock); |
| INIT_WORK(&sl->tx_work, slcan_transmit); |
| slcan_devs[i] = dev; |
| |
| return sl; |
| } |
| |
| /* |
| * Open the high-level part of the SLCAN channel. |
| * This function is called by the TTY module when the |
| * SLCAN line discipline is called for. Because we are |
| * sure the tty line exists, we only have to link it to |
| * a free SLCAN channel... |
| * |
| * Called in process context serialized from other ldisc calls. |
| */ |
| |
| static int slcan_open(struct tty_struct *tty) |
| { |
| struct slcan *sl; |
| int err; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| if (tty->ops->write == NULL) |
| return -EOPNOTSUPP; |
| |
| /* RTnetlink lock is misused here to serialize concurrent |
| opens of slcan channels. There are better ways, but it is |
| the simplest one. |
| */ |
| rtnl_lock(); |
| |
| /* Collect hanged up channels. */ |
| slc_sync(); |
| |
| sl = tty->disc_data; |
| |
| err = -EEXIST; |
| /* First make sure we're not already connected. */ |
| if (sl && sl->magic == SLCAN_MAGIC) |
| goto err_exit; |
| |
| /* OK. Find a free SLCAN channel to use. */ |
| err = -ENFILE; |
| sl = slc_alloc(); |
| if (sl == NULL) |
| goto err_exit; |
| |
| sl->tty = tty; |
| tty->disc_data = sl; |
| |
| if (!test_bit(SLF_INUSE, &sl->flags)) { |
| /* Perform the low-level SLCAN initialization. */ |
| sl->rcount = 0; |
| sl->xleft = 0; |
| |
| set_bit(SLF_INUSE, &sl->flags); |
| |
| err = register_netdevice(sl->dev); |
| if (err) |
| goto err_free_chan; |
| } |
| |
| /* Done. We have linked the TTY line to a channel. */ |
| rtnl_unlock(); |
| tty->receive_room = 65536; /* We don't flow control */ |
| |
| /* TTY layer expects 0 on success */ |
| return 0; |
| |
| err_free_chan: |
| sl->tty = NULL; |
| tty->disc_data = NULL; |
| clear_bit(SLF_INUSE, &sl->flags); |
| slc_free_netdev(sl->dev); |
| free_netdev(sl->dev); |
| |
| err_exit: |
| rtnl_unlock(); |
| |
| /* Count references from TTY module */ |
| return err; |
| } |
| |
| /* |
| * Close down a SLCAN channel. |
| * This means flushing out any pending queues, and then returning. This |
| * call is serialized against other ldisc functions. |
| * |
| * We also use this method for a hangup event. |
| */ |
| |
| static void slcan_close(struct tty_struct *tty) |
| { |
| struct slcan *sl = (struct slcan *) tty->disc_data; |
| |
| /* First make sure we're connected. */ |
| if (!sl || sl->magic != SLCAN_MAGIC || sl->tty != tty) |
| return; |
| |
| spin_lock_bh(&sl->lock); |
| rcu_assign_pointer(tty->disc_data, NULL); |
| sl->tty = NULL; |
| spin_unlock_bh(&sl->lock); |
| |
| synchronize_rcu(); |
| flush_work(&sl->tx_work); |
| |
| /* Flush network side */ |
| unregister_netdev(sl->dev); |
| /* This will complete via sl_free_netdev */ |
| } |
| |
| static int slcan_hangup(struct tty_struct *tty) |
| { |
| slcan_close(tty); |
| return 0; |
| } |
| |
| /* Perform I/O control on an active SLCAN channel. */ |
| static int slcan_ioctl(struct tty_struct *tty, struct file *file, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct slcan *sl = (struct slcan *) tty->disc_data; |
| unsigned int tmp; |
| |
| /* First make sure we're connected. */ |
| if (!sl || sl->magic != SLCAN_MAGIC) |
| return -EINVAL; |
| |
| switch (cmd) { |
| case SIOCGIFNAME: |
| tmp = strlen(sl->dev->name) + 1; |
| if (copy_to_user((void __user *)arg, sl->dev->name, tmp)) |
| return -EFAULT; |
| return 0; |
| |
| case SIOCSIFHWADDR: |
| return -EINVAL; |
| |
| default: |
| return tty_mode_ioctl(tty, file, cmd, arg); |
| } |
| } |
| |
| static struct tty_ldisc_ops slc_ldisc = { |
| .owner = THIS_MODULE, |
| .magic = TTY_LDISC_MAGIC, |
| .name = "slcan", |
| .open = slcan_open, |
| .close = slcan_close, |
| .hangup = slcan_hangup, |
| .ioctl = slcan_ioctl, |
| .receive_buf = slcan_receive_buf, |
| .write_wakeup = slcan_write_wakeup, |
| }; |
| |
| static int __init slcan_init(void) |
| { |
| int status; |
| |
| if (maxdev < 4) |
| maxdev = 4; /* Sanity */ |
| |
| pr_info("slcan: serial line CAN interface driver\n"); |
| pr_info("slcan: %d dynamic interface channels.\n", maxdev); |
| |
| slcan_devs = kcalloc(maxdev, sizeof(struct net_device *), GFP_KERNEL); |
| if (!slcan_devs) |
| return -ENOMEM; |
| |
| /* Fill in our line protocol discipline, and register it */ |
| status = tty_register_ldisc(N_SLCAN, &slc_ldisc); |
| if (status) { |
| printk(KERN_ERR "slcan: can't register line discipline\n"); |
| kfree(slcan_devs); |
| } |
| return status; |
| } |
| |
| static void __exit slcan_exit(void) |
| { |
| int i; |
| struct net_device *dev; |
| struct slcan *sl; |
| unsigned long timeout = jiffies + HZ; |
| int busy = 0; |
| |
| if (slcan_devs == NULL) |
| return; |
| |
| /* First of all: check for active disciplines and hangup them. |
| */ |
| do { |
| if (busy) |
| msleep_interruptible(100); |
| |
| busy = 0; |
| for (i = 0; i < maxdev; i++) { |
| dev = slcan_devs[i]; |
| if (!dev) |
| continue; |
| sl = netdev_priv(dev); |
| spin_lock_bh(&sl->lock); |
| if (sl->tty) { |
| busy++; |
| tty_hangup(sl->tty); |
| } |
| spin_unlock_bh(&sl->lock); |
| } |
| } while (busy && time_before(jiffies, timeout)); |
| |
| /* FIXME: hangup is async so we should wait when doing this second |
| phase */ |
| |
| for (i = 0; i < maxdev; i++) { |
| dev = slcan_devs[i]; |
| if (!dev) |
| continue; |
| slcan_devs[i] = NULL; |
| |
| sl = netdev_priv(dev); |
| if (sl->tty) { |
| printk(KERN_ERR "%s: tty discipline still running\n", |
| dev->name); |
| } |
| |
| unregister_netdev(dev); |
| } |
| |
| kfree(slcan_devs); |
| slcan_devs = NULL; |
| |
| i = tty_unregister_ldisc(N_SLCAN); |
| if (i) |
| printk(KERN_ERR "slcan: can't unregister ldisc (err %d)\n", i); |
| } |
| |
| module_init(slcan_init); |
| module_exit(slcan_exit); |