diff options
Diffstat (limited to 'drivers/net/can/slcan.c')
| -rw-r--r-- | drivers/net/can/slcan.c | 790 |
1 files changed, 0 insertions, 790 deletions
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c deleted file mode 100644 index 9a4ebda30510..000000000000 --- a/drivers/net/can/slcan.c +++ /dev/null @@ -1,790 +0,0 @@ -/* - * 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 (len) which can be from 0 to 8 - * and up to <len> 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, len 0, no data - * t4563112233 : can_id 0x456, len 3, data 0x11 0x22 0x33 - * T12ABCDEF2AA55 : extended can_id 0x12ABCDEF, len 2, data 0xAA 0x55 - * r1230 : can_id 0x123, len 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; - - memset(&cf, 0, sizeof(cf)); - - switch (*cmd) { - case 'r': - cf.can_id = CAN_RTR_FLAG; - fallthrough; - case 't': - /* store dlc ASCII value and terminate SFF CAN ID string */ - cf.len = 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.len = 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 len from sanitized ASCII value */ - if (cf.len >= '0' && cf.len < '9') - cf.len -= '0'; - else - return; - - /* 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.len; 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.len; - 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->len + '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->len; 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->len; -} - -/* 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) - schedule_work(&sl->tx_work); - 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, const 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 can_ml_priv *can_ml; - 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); - can_ml = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN); - can_set_ml_priv(dev, can_ml); - - /* 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); - /* do not call free_netdev before rtnl_unlock */ - rtnl_unlock(); - free_netdev(sl->dev); - return err; - -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 void slcan_hangup(struct tty_struct *tty) -{ - slcan_close(tty); -} - -/* 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, cmd, arg); - } -} - -static struct tty_ldisc_ops slc_ldisc = { - .owner = THIS_MODULE, - .num = N_SLCAN, - .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(&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; - - tty_unregister_ldisc(&slc_ldisc); -} - -module_init(slcan_init); -module_exit(slcan_exit); |