diff options
Diffstat (limited to 'net/can/bcm.c')
| -rw-r--r-- | net/can/bcm.c | 1634 |
1 files changed, 1634 insertions, 0 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c new file mode 100644 index 000000000..b52345358 --- /dev/null +++ b/net/can/bcm.c @@ -0,0 +1,1634 @@ +/* + * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content + * + * Copyright (c) 2002-2007 Volkswagen Group Electronic Research + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Volkswagen nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * Alternatively, provided that this notice is retained in full, this + * software may be distributed under the terms of the GNU General + * Public License ("GPL") version 2, in which case the provisions of the + * GPL apply INSTEAD OF those given above. + * + * The provided data structures and external interfaces from this code + * are not restricted to be used by modules with a GPL compatible license. + * + * 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/init.h> +#include <linux/interrupt.h> +#include <linux/hrtimer.h> +#include <linux/list.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/uio.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/socket.h> +#include <linux/if_arp.h> +#include <linux/skbuff.h> +#include <linux/can.h> +#include <linux/can/core.h> +#include <linux/can/skb.h> +#include <linux/can/bcm.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/net_namespace.h> + +/* + * To send multiple CAN frame content within TX_SETUP or to filter + * CAN messages with multiplex index within RX_SETUP, the number of + * different filters is limited to 256 due to the one byte index value. + */ +#define MAX_NFRAMES 256 + +/* use of last_frames[index].can_dlc */ +#define RX_RECV 0x40 /* received data for this element */ +#define RX_THR 0x80 /* element not been sent due to throttle feature */ +#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */ + +/* get best masking value for can_rx_register() for a given single can_id */ +#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ + (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ + (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) + +#define CAN_BCM_VERSION CAN_VERSION + +MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); +MODULE_ALIAS("can-proto-2"); + +/* easy access to can_frame payload */ +static inline u64 GET_U64(const struct can_frame *cp) +{ + return *(u64 *)cp->data; +} + +struct bcm_op { + struct list_head list; + int ifindex; + canid_t can_id; + u32 flags; + unsigned long frames_abs, frames_filtered; + struct timeval ival1, ival2; + struct hrtimer timer, thrtimer; + struct tasklet_struct tsklet, thrtsklet; + ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; + int rx_ifindex; + u32 count; + u32 nframes; + u32 currframe; + struct can_frame *frames; + struct can_frame *last_frames; + struct can_frame sframe; + struct can_frame last_sframe; + struct sock *sk; + struct net_device *rx_reg_dev; +}; + +static struct proc_dir_entry *proc_dir; + +struct bcm_sock { + struct sock sk; + int bound; + int ifindex; + struct notifier_block notifier; + struct list_head rx_ops; + struct list_head tx_ops; + unsigned long dropped_usr_msgs; + struct proc_dir_entry *bcm_proc_read; + char procname [32]; /* inode number in decimal with \0 */ +}; + +static inline struct bcm_sock *bcm_sk(const struct sock *sk) +{ + return (struct bcm_sock *)sk; +} + +#define CFSIZ sizeof(struct can_frame) +#define OPSIZ sizeof(struct bcm_op) +#define MHSIZ sizeof(struct bcm_msg_head) + +/* + * procfs functions + */ +static char *bcm_proc_getifname(char *result, int ifindex) +{ + struct net_device *dev; + + if (!ifindex) + return "any"; + + rcu_read_lock(); + dev = dev_get_by_index_rcu(&init_net, ifindex); + if (dev) + strcpy(result, dev->name); + else + strcpy(result, "???"); + rcu_read_unlock(); + + return result; +} + +static int bcm_proc_show(struct seq_file *m, void *v) +{ + char ifname[IFNAMSIZ]; + struct sock *sk = (struct sock *)m->private; + struct bcm_sock *bo = bcm_sk(sk); + struct bcm_op *op; + + seq_printf(m, ">>> socket %pK", sk->sk_socket); + seq_printf(m, " / sk %pK", sk); + seq_printf(m, " / bo %pK", bo); + seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); + seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex)); + seq_printf(m, " <<<\n"); + + list_for_each_entry(op, &bo->rx_ops, list) { + + unsigned long reduction; + + /* print only active entries & prevent division by zero */ + if (!op->frames_abs) + continue; + + seq_printf(m, "rx_op: %03X %-5s ", + op->can_id, bcm_proc_getifname(ifname, op->ifindex)); + seq_printf(m, "[%u]%c ", op->nframes, + (op->flags & RX_CHECK_DLC)?'d':' '); + if (op->kt_ival1.tv64) + seq_printf(m, "timeo=%lld ", + (long long) + ktime_to_us(op->kt_ival1)); + + if (op->kt_ival2.tv64) + seq_printf(m, "thr=%lld ", + (long long) + ktime_to_us(op->kt_ival2)); + + seq_printf(m, "# recv %ld (%ld) => reduction: ", + op->frames_filtered, op->frames_abs); + + reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; + + seq_printf(m, "%s%ld%%\n", + (reduction == 100)?"near ":"", reduction); + } + + list_for_each_entry(op, &bo->tx_ops, list) { + + seq_printf(m, "tx_op: %03X %s [%u] ", + op->can_id, + bcm_proc_getifname(ifname, op->ifindex), + op->nframes); + + if (op->kt_ival1.tv64) + seq_printf(m, "t1=%lld ", + (long long) ktime_to_us(op->kt_ival1)); + + if (op->kt_ival2.tv64) + seq_printf(m, "t2=%lld ", + (long long) ktime_to_us(op->kt_ival2)); + + seq_printf(m, "# sent %ld\n", op->frames_abs); + } + seq_putc(m, '\n'); + return 0; +} + +static int bcm_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, bcm_proc_show, PDE_DATA(inode)); +} + +static const struct file_operations bcm_proc_fops = { + .owner = THIS_MODULE, + .open = bcm_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +/* + * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface + * of the given bcm tx op + */ +static void bcm_can_tx(struct bcm_op *op) +{ + struct sk_buff *skb; + struct net_device *dev; + struct can_frame *cf = &op->frames[op->currframe]; + + /* no target device? => exit */ + if (!op->ifindex) + return; + + dev = dev_get_by_index(&init_net, op->ifindex); + if (!dev) { + /* RFC: should this bcm_op remove itself here? */ + return; + } + + skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), gfp_any()); + if (!skb) + goto out; + + can_skb_reserve(skb); + can_skb_prv(skb)->ifindex = dev->ifindex; + + memcpy(skb_put(skb, CFSIZ), cf, CFSIZ); + + /* send with loopback */ + skb->dev = dev; + can_skb_set_owner(skb, op->sk); + can_send(skb, 1); + + /* update statistics */ + op->currframe++; + op->frames_abs++; + + /* reached last frame? */ + if (op->currframe >= op->nframes) + op->currframe = 0; + out: + dev_put(dev); +} + +/* + * bcm_send_to_user - send a BCM message to the userspace + * (consisting of bcm_msg_head + x CAN frames) + */ +static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, + struct can_frame *frames, int has_timestamp) +{ + struct sk_buff *skb; + struct can_frame *firstframe; + struct sockaddr_can *addr; + struct sock *sk = op->sk; + unsigned int datalen = head->nframes * CFSIZ; + int err; + + skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); + if (!skb) + return; + + memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head)); + + if (head->nframes) { + /* can_frames starting here */ + firstframe = (struct can_frame *)skb_tail_pointer(skb); + + memcpy(skb_put(skb, datalen), frames, datalen); + + /* + * the BCM uses the can_dlc-element of the can_frame + * structure for internal purposes. This is only + * relevant for updates that are generated by the + * BCM, where nframes is 1 + */ + if (head->nframes == 1) + firstframe->can_dlc &= BCM_CAN_DLC_MASK; + } + + if (has_timestamp) { + /* restore rx timestamp */ + skb->tstamp = op->rx_stamp; + } + + /* + * Put the datagram to the queue so that bcm_recvmsg() can + * get it from there. We need to pass the interface index to + * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb + * containing the interface index. + */ + + sock_skb_cb_check_size(sizeof(struct sockaddr_can)); + addr = (struct sockaddr_can *)skb->cb; + memset(addr, 0, sizeof(*addr)); + addr->can_family = AF_CAN; + addr->can_ifindex = op->rx_ifindex; + + err = sock_queue_rcv_skb(sk, skb); + if (err < 0) { + struct bcm_sock *bo = bcm_sk(sk); + + kfree_skb(skb); + /* don't care about overflows in this statistic */ + bo->dropped_usr_msgs++; + } +} + +static void bcm_tx_start_timer(struct bcm_op *op) +{ + if (op->kt_ival1.tv64 && op->count) + hrtimer_start(&op->timer, + ktime_add(ktime_get(), op->kt_ival1), + HRTIMER_MODE_ABS); + else if (op->kt_ival2.tv64) + hrtimer_start(&op->timer, + ktime_add(ktime_get(), op->kt_ival2), + HRTIMER_MODE_ABS); +} + +static void bcm_tx_timeout_tsklet(unsigned long data) +{ + struct bcm_op *op = (struct bcm_op *)data; + struct bcm_msg_head msg_head; + + if (op->kt_ival1.tv64 && (op->count > 0)) { + + op->count--; + if (!op->count && (op->flags & TX_COUNTEVT)) { + + /* create notification to user */ + msg_head.opcode = TX_EXPIRED; + msg_head.flags = op->flags; + msg_head.count = op->count; + msg_head.ival1 = op->ival1; + msg_head.ival2 = op->ival2; + msg_head.can_id = op->can_id; + msg_head.nframes = 0; + + bcm_send_to_user(op, &msg_head, NULL, 0); + } + bcm_can_tx(op); + + } else if (op->kt_ival2.tv64) + bcm_can_tx(op); + + bcm_tx_start_timer(op); +} + +/* + * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions + */ +static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) +{ + struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); + + tasklet_schedule(&op->tsklet); + + return HRTIMER_NORESTART; +} + +/* + * bcm_rx_changed - create a RX_CHANGED notification due to changed content + */ +static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data) +{ + struct bcm_msg_head head; + + /* update statistics */ + op->frames_filtered++; + + /* prevent statistics overflow */ + if (op->frames_filtered > ULONG_MAX/100) + op->frames_filtered = op->frames_abs = 0; + + /* this element is not throttled anymore */ + data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV); + + head.opcode = RX_CHANGED; + head.flags = op->flags; + head.count = op->count; + head.ival1 = op->ival1; + head.ival2 = op->ival2; + head.can_id = op->can_id; + head.nframes = 1; + + bcm_send_to_user(op, &head, data, 1); +} + +/* + * bcm_rx_update_and_send - process a detected relevant receive content change + * 1. update the last received data + * 2. send a notification to the user (if possible) + */ +static void bcm_rx_update_and_send(struct bcm_op *op, + struct can_frame *lastdata, + const struct can_frame *rxdata) +{ + memcpy(lastdata, rxdata, CFSIZ); + + /* mark as used and throttled by default */ + lastdata->can_dlc |= (RX_RECV|RX_THR); + + /* throttling mode inactive ? */ + if (!op->kt_ival2.tv64) { + /* send RX_CHANGED to the user immediately */ + bcm_rx_changed(op, lastdata); + return; + } + + /* with active throttling timer we are just done here */ + if (hrtimer_active(&op->thrtimer)) + return; + + /* first reception with enabled throttling mode */ + if (!op->kt_lastmsg.tv64) + goto rx_changed_settime; + + /* got a second frame inside a potential throttle period? */ + if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < + ktime_to_us(op->kt_ival2)) { + /* do not send the saved data - only start throttle timer */ + hrtimer_start(&op->thrtimer, + ktime_add(op->kt_lastmsg, op->kt_ival2), + HRTIMER_MODE_ABS); + return; + } + + /* the gap was that big, that throttling was not needed here */ +rx_changed_settime: + bcm_rx_changed(op, lastdata); + op->kt_lastmsg = ktime_get(); +} + +/* + * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly + * received data stored in op->last_frames[] + */ +static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, + const struct can_frame *rxdata) +{ + /* + * no one uses the MSBs of can_dlc for comparison, + * so we use it here to detect the first time of reception + */ + + if (!(op->last_frames[index].can_dlc & RX_RECV)) { + /* received data for the first time => send update to user */ + bcm_rx_update_and_send(op, &op->last_frames[index], rxdata); + return; + } + + /* do a real check in can_frame data section */ + + if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) != + (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) { + bcm_rx_update_and_send(op, &op->last_frames[index], rxdata); + return; + } + + if (op->flags & RX_CHECK_DLC) { + /* do a real check in can_frame dlc */ + if (rxdata->can_dlc != (op->last_frames[index].can_dlc & + BCM_CAN_DLC_MASK)) { + bcm_rx_update_and_send(op, &op->last_frames[index], + rxdata); + return; + } + } +} + +/* + * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception + */ +static void bcm_rx_starttimer(struct bcm_op *op) +{ + if (op->flags & RX_NO_AUTOTIMER) + return; + + if (op->kt_ival1.tv64) + hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); +} + +static void bcm_rx_timeout_tsklet(unsigned long data) +{ + struct bcm_op *op = (struct bcm_op *)data; + struct bcm_msg_head msg_head; + + /* create notification to user */ + msg_head.opcode = RX_TIMEOUT; + msg_head.flags = op->flags; + msg_head.count = op->count; + msg_head.ival1 = op->ival1; + msg_head.ival2 = op->ival2; + msg_head.can_id = op->can_id; + msg_head.nframes = 0; + + bcm_send_to_user(op, &msg_head, NULL, 0); +} + +/* + * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out + */ +static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) +{ + struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); + + /* schedule before NET_RX_SOFTIRQ */ + tasklet_hi_schedule(&op->tsklet); + + /* no restart of the timer is done here! */ + + /* if user wants to be informed, when cyclic CAN-Messages come back */ + if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { + /* clear received can_frames to indicate 'nothing received' */ + memset(op->last_frames, 0, op->nframes * CFSIZ); + } + + return HRTIMER_NORESTART; +} + +/* + * bcm_rx_do_flush - helper for bcm_rx_thr_flush + */ +static inline int bcm_rx_do_flush(struct bcm_op *op, int update, + unsigned int index) +{ + if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) { + if (update) + bcm_rx_changed(op, &op->last_frames[index]); + return 1; + } + return 0; +} + +/* + * bcm_rx_thr_flush - Check for throttled data and send it to the userspace + * + * update == 0 : just check if throttled data is available (any irq context) + * update == 1 : check and send throttled data to userspace (soft_irq context) + */ +static int bcm_rx_thr_flush(struct bcm_op *op, int update) +{ + int updated = 0; + + if (op->nframes > 1) { + unsigned int i; + + /* for MUX filter we start at index 1 */ + for (i = 1; i < op->nframes; i++) + updated += bcm_rx_do_flush(op, update, i); + + } else { + /* for RX_FILTER_ID and simple filter */ + updated += bcm_rx_do_flush(op, update, 0); + } + + return updated; +} + +static void bcm_rx_thr_tsklet(unsigned long data) +{ + struct bcm_op *op = (struct bcm_op *)data; + + /* push the changed data to the userspace */ + bcm_rx_thr_flush(op, 1); +} + +/* + * bcm_rx_thr_handler - the time for blocked content updates is over now: + * Check for throttled data and send it to the userspace + */ +static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) +{ + struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); + + tasklet_schedule(&op->thrtsklet); + + if (bcm_rx_thr_flush(op, 0)) { + hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); + return HRTIMER_RESTART; + } else { + /* rearm throttle handling */ + op->kt_lastmsg = ktime_set(0, 0); + return HRTIMER_NORESTART; + } +} + +/* + * bcm_rx_handler - handle a CAN frame reception + */ +static void bcm_rx_handler(struct sk_buff *skb, void *data) +{ + struct bcm_op *op = (struct bcm_op *)data; + const struct can_frame *rxframe = (struct can_frame *)skb->data; + unsigned int i; + + /* disable timeout */ + hrtimer_cancel(&op->timer); + + if (op->can_id != rxframe->can_id) + return; + + /* save rx timestamp */ + op->rx_stamp = skb->tstamp; + /* save originator for recvfrom() */ + op->rx_ifindex = skb->dev->ifindex; + /* update statistics */ + op->frames_abs++; + + if (op->flags & RX_RTR_FRAME) { + /* send reply for RTR-request (placed in op->frames[0]) */ + bcm_can_tx(op); + return; + } + + if (op->flags & RX_FILTER_ID) { + /* the easiest case */ + bcm_rx_update_and_send(op, &op->last_frames[0], rxframe); + goto rx_starttimer; + } + + if (op->nframes == 1) { + /* simple compare with index 0 */ + bcm_rx_cmp_to_index(op, 0, rxframe); + goto rx_starttimer; + } + + if (op->nframes > 1) { + /* + * multiplex compare + * + * find the first multiplex mask that fits. + * Remark: The MUX-mask is stored in index 0 + */ + + for (i = 1; i < op->nframes; i++) { + if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) == + (GET_U64(&op->frames[0]) & + GET_U64(&op->frames[i]))) { + bcm_rx_cmp_to_index(op, i, rxframe); + break; + } + } + } + +rx_starttimer: + bcm_rx_starttimer(op); +} + +/* + * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements + */ +static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id, + int ifindex) +{ + struct bcm_op *op; + + list_for_each_entry(op, ops, list) { + if ((op->can_id == can_id) && (op->ifindex == ifindex)) + return op; + } + + return NULL; +} + +static void bcm_remove_op(struct bcm_op *op) +{ + hrtimer_cancel(&op->timer); + hrtimer_cancel(&op->thrtimer); + + if (op->tsklet.func) + tasklet_kill(&op->tsklet); + + if (op->thrtsklet.func) + tasklet_kill(&op->thrtsklet); + + if ((op->frames) && (op->frames != &op->sframe)) + kfree(op->frames); + + if ((op->last_frames) && (op->last_frames != &op->last_sframe)) + kfree(op->last_frames); + + kfree(op); +} + +static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) +{ + if (op->rx_reg_dev == dev) { + can_rx_unregister(dev, op->can_id, REGMASK(op->can_id), + bcm_rx_handler, op); + + /* mark as removed subscription */ + op->rx_reg_dev = NULL; + } else + printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " + "mismatch %p %p\n", op->rx_reg_dev, dev); +} + +/* + * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) + */ +static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex) +{ + struct bcm_op *op, *n; + + list_for_each_entry_safe(op, n, ops, list) { + if ((op->can_id == can_id) && (op->ifindex == ifindex)) { + + /* + * Don't care if we're bound or not (due to netdev + * problems) can_rx_unregister() is always a save + * thing to do here. + */ + if (op->ifindex) { + /* + * Only remove subscriptions that had not + * been removed due to NETDEV_UNREGISTER + * in bcm_notifier() + */ + if (op->rx_reg_dev) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, + op->ifindex); + if (dev) { + bcm_rx_unreg(dev, op); + dev_put(dev); + } + } + } else + can_rx_unregister(NULL, op->can_id, + REGMASK(op->can_id), + bcm_rx_handler, op); + + list_del(&op->list); + bcm_remove_op(op); + return 1; /* done */ + } + } + + return 0; /* not found */ +} + +/* + * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) + */ +static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex) +{ + struct bcm_op *op, *n; + + list_for_each_entry_safe(op, n, ops, list) { + if ((op->can_id == can_id) && (op->ifindex == ifindex)) { + list_del(&op->list); + bcm_remove_op(op); + return 1; /* done */ + } + } + + return 0; /* not found */ +} + +/* + * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) + */ +static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, + int ifindex) +{ + struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex); + + if (!op) + return -EINVAL; + + /* put current values into msg_head */ + msg_head->flags = op->flags; + msg_head->count = op->count; + msg_head->ival1 = op->ival1; + msg_head->ival2 = op->ival2; + msg_head->nframes = op->nframes; + + bcm_send_to_user(op, msg_head, op->frames, 0); + + return MHSIZ; +} + +/* + * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) + */ +static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, + int ifindex, struct sock *sk) +{ + struct bcm_sock *bo = bcm_sk(sk); + struct bcm_op *op; + unsigned int i; + int err; + + /* we need a real device to send frames */ + if (!ifindex) + return -ENODEV; + + /* check nframes boundaries - we need at least one can_frame */ + if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) + return -EINVAL; + + /* check the given can_id */ + op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex); + + if (op) { + /* update existing BCM operation */ + + /* + * Do we need more space for the can_frames than currently + * allocated? -> This is a _really_ unusual use-case and + * therefore (complexity / locking) it is not supported. + */ + if (msg_head->nframes > op->nframes) + return -E2BIG; + + /* update can_frames content */ + for (i = 0; i < msg_head->nframes; i++) { + err = memcpy_from_msg((u8 *)&op->frames[i], msg, CFSIZ); + + if (op->frames[i].can_dlc > 8) + err = -EINVAL; + + if (err < 0) + return err; + + if (msg_head->flags & TX_CP_CAN_ID) { + /* copy can_id into frame */ + op->frames[i].can_id = msg_head->can_id; + } + } + + } else { + /* insert new BCM operation for the given can_id */ + + op = kzalloc(OPSIZ, GFP_KERNEL); + if (!op) + return -ENOMEM; + + op->can_id = msg_head->can_id; + + /* create array for can_frames and copy the data */ + if (msg_head->nframes > 1) { + op->frames = kmalloc(msg_head->nframes * CFSIZ, + GFP_KERNEL); + if (!op->frames) { + kfree(op); + return -ENOMEM; + } + } else + op->frames = &op->sframe; + + for (i = 0; i < msg_head->nframes; i++) { + err = memcpy_from_msg((u8 *)&op->frames[i], msg, CFSIZ); + + if (op->frames[i].can_dlc > 8) + err = -EINVAL; + + if (err < 0) { + if (op->frames != &op->sframe) + kfree(op->frames); + kfree(op); + return err; + } + + if (msg_head->flags & TX_CP_CAN_ID) { + /* copy can_id into frame */ + op->frames[i].can_id = msg_head->can_id; + } + } + + /* tx_ops never compare with previous received messages */ + op->last_frames = NULL; + + /* bcm_can_tx / bcm_tx_timeout_handler needs this */ + op->sk = sk; + op->ifindex = ifindex; + + /* initialize uninitialized (kzalloc) structure */ + hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + op->timer.function = bcm_tx_timeout_handler; + + /* initialize tasklet for tx countevent notification */ + tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, + (unsigned long) op); + + /* currently unused in tx_ops */ + hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + + /* add this bcm_op to the list of the tx_ops */ + list_add(&op->list, &bo->tx_ops); + + } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ + + if (op->nframes != msg_head->nframes) { + op->nframes = msg_head->nframes; + /* start multiple frame transmission with index 0 */ + op->currframe = 0; + } + + /* check flags */ + + op->flags = msg_head->flags; + + if (op->flags & TX_RESET_MULTI_IDX) { + /* start multiple frame transmission with index 0 */ + op->currframe = 0; + } + + if (op->flags & SETTIMER) { + /* set timer values */ + op->count = msg_head->count; + op->ival1 = msg_head->ival1; + op->ival2 = msg_head->ival2; + op->kt_ival1 = timeval_to_ktime(msg_head->ival1); + op->kt_ival2 = timeval_to_ktime(msg_head->ival2); + + /* disable an active timer due to zero values? */ + if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64) + hrtimer_cancel(&op->timer); + } + + if (op->flags & STARTTIMER) { + hrtimer_cancel(&op->timer); + /* spec: send can_frame when starting timer */ + op->flags |= TX_ANNOUNCE; + } + + if (op->flags & TX_ANNOUNCE) { + bcm_can_tx(op); + if (op->count) + op->count--; + } + + if (op->flags & STARTTIMER) + bcm_tx_start_timer(op); + + return msg_head->nframes * CFSIZ + MHSIZ; +} + +/* + * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) + */ +static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, + int ifindex, struct sock *sk) +{ + struct bcm_sock *bo = bcm_sk(sk); + struct bcm_op *op; + int do_rx_register; + int err = 0; + + if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { + /* be robust against wrong usage ... */ + msg_head->flags |= RX_FILTER_ID; + /* ignore trailing garbage */ + msg_head->nframes = 0; + } + + /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ + if (msg_head->nframes > MAX_NFRAMES + 1) + return -EINVAL; + + if ((msg_head->flags & RX_RTR_FRAME) && + ((msg_head->nframes != 1) || + (!(msg_head->can_id & CAN_RTR_FLAG)))) + return -EINVAL; + + /* check the given can_id */ + op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex); + if (op) { + /* update existing BCM operation */ + + /* + * Do we need more space for the can_frames than currently + * allocated? -> This is a _really_ unusual use-case and + * therefore (complexity / locking) it is not supported. + */ + if (msg_head->nframes > op->nframes) + return -E2BIG; + + if (msg_head->nframes) { + /* update can_frames content */ + err = memcpy_from_msg((u8 *)op->frames, msg, + msg_head->nframes * CFSIZ); + if (err < 0) + return err; + + /* clear last_frames to indicate 'nothing received' */ + memset(op->last_frames, 0, msg_head->nframes * CFSIZ); + } + + op->nframes = msg_head->nframes; + + /* Only an update -> do not call can_rx_register() */ + do_rx_register = 0; + + } else { + /* insert new BCM operation for the given can_id */ + op = kzalloc(OPSIZ, GFP_KERNEL); + if (!op) + return -ENOMEM; + + op->can_id = msg_head->can_id; + op->nframes = msg_head->nframes; + + if (msg_head->nframes > 1) { + /* create array for can_frames and copy the data */ + op->frames = kmalloc(msg_head->nframes * CFSIZ, + GFP_KERNEL); + if (!op->frames) { + kfree(op); + return -ENOMEM; + } + + /* create and init array for received can_frames */ + op->last_frames = kzalloc(msg_head->nframes * CFSIZ, + GFP_KERNEL); + if (!op->last_frames) { + kfree(op->frames); + kfree(op); + return -ENOMEM; + } + + } else { + op->frames = &op->sframe; + op->last_frames = &op->last_sframe; + } + + if (msg_head->nframes) { + err = memcpy_from_msg((u8 *)op->frames, msg, + msg_head->nframes * CFSIZ); + if (err < 0) { + if (op->frames != &op->sframe) + kfree(op->frames); + if (op->last_frames != &op->last_sframe) + kfree(op->last_frames); + kfree(op); + return err; + } + } + + /* bcm_can_tx / bcm_tx_timeout_handler needs this */ + op->sk = sk; + op->ifindex = ifindex; + + /* ifindex for timeout events w/o previous frame reception */ + op->rx_ifindex = ifindex; + + /* initialize uninitialized (kzalloc) structure */ + hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + op->timer.function = bcm_rx_timeout_handler; + + /* initialize tasklet for rx timeout notification */ + tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, + (unsigned long) op); + + hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + op->thrtimer.function = bcm_rx_thr_handler; + + /* initialize tasklet for rx throttle handling */ + tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, + (unsigned long) op); + + /* add this bcm_op to the list of the rx_ops */ + list_add(&op->list, &bo->rx_ops); + + /* call can_rx_register() */ + do_rx_register = 1; + + } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ + + /* check flags */ + op->flags = msg_head->flags; + + if (op->flags & RX_RTR_FRAME) { + + /* no timers in RTR-mode */ + hrtimer_cancel(&op->thrtimer); + hrtimer_cancel(&op->timer); + + /* + * funny feature in RX(!)_SETUP only for RTR-mode: + * copy can_id into frame BUT without RTR-flag to + * prevent a full-load-loopback-test ... ;-] + */ + if ((op->flags & TX_CP_CAN_ID) || + (op->frames[0].can_id == op->can_id)) + op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG; + + } else { + if (op->flags & SETTIMER) { + + /* set timer value */ + op->ival1 = msg_head->ival1; + op->ival2 = msg_head->ival2; + op->kt_ival1 = timeval_to_ktime(msg_head->ival1); + op->kt_ival2 = timeval_to_ktime(msg_head->ival2); + + /* disable an active timer due to zero value? */ + if (!op->kt_ival1.tv64) + hrtimer_cancel(&op->timer); + + /* + * In any case cancel the throttle timer, flush + * potentially blocked msgs and reset throttle handling + */ + op->kt_lastmsg = ktime_set(0, 0); + hrtimer_cancel(&op->thrtimer); + bcm_rx_thr_flush(op, 1); + } + + if ((op->flags & STARTTIMER) && op->kt_ival1.tv64) + hrtimer_start(&op->timer, op->kt_ival1, + HRTIMER_MODE_REL); + } + + /* now we can register for can_ids, if we added a new bcm_op */ + if (do_rx_register) { + if (ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, ifindex); + if (dev) { + err = can_rx_register(dev, op->can_id, + REGMASK(op->can_id), + bcm_rx_handler, op, + "bcm"); + + op->rx_reg_dev = dev; + dev_put(dev); + } + + } else + err = can_rx_register(NULL, op->can_id, + REGMASK(op->can_id), + bcm_rx_handler, op, "bcm"); + if (err) { + /* this bcm rx op is broken -> remove it */ + list_del(&op->list); + bcm_remove_op(op); + return err; + } + } + + return msg_head->nframes * CFSIZ + MHSIZ; +} + +/* + * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) + */ +static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk) +{ + struct sk_buff *skb; + struct net_device *dev; + int err; + + /* we need a real device to send frames */ + if (!ifindex) + return -ENODEV; + + skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), GFP_KERNEL); + if (!skb) + return -ENOMEM; + + can_skb_reserve(skb); + + err = memcpy_from_msg(skb_put(skb, CFSIZ), msg, CFSIZ); + if (err < 0) { + kfree_skb(skb); + return err; + } + + dev = dev_get_by_index(&init_net, ifindex); + if (!dev) { + kfree_skb(skb); + return -ENODEV; + } + + can_skb_prv(skb)->ifindex = dev->ifindex; + skb->dev = dev; + can_skb_set_owner(skb, sk); + err = can_send(skb, 1); /* send with loopback */ + dev_put(dev); + + if (err) + return err; + + return CFSIZ + MHSIZ; +} + +/* + * bcm_sendmsg - process BCM commands (opcodes) from the userspace + */ +static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) +{ + struct sock *sk = sock->sk; + struct bcm_sock *bo = bcm_sk(sk); + int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ + struct bcm_msg_head msg_head; + int ret; /* read bytes or error codes as return value */ + + if (!bo->bound) + return -ENOTCONN; + + /* check for valid message length from userspace */ + if (size < MHSIZ || (size - MHSIZ) % CFSIZ) + return -EINVAL; + + /* check for alternative ifindex for this bcm_op */ + + if (!ifindex && msg->msg_name) { + /* no bound device as default => check msg_name */ + DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); + + if (msg->msg_namelen < sizeof(*addr)) + return -EINVAL; + + if (addr->can_family != AF_CAN) + return -EINVAL; + + /* ifindex from sendto() */ + ifindex = addr->can_ifindex; + + if (ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, ifindex); + if (!dev) + return -ENODEV; + + if (dev->type != ARPHRD_CAN) { + dev_put(dev); + return -ENODEV; + } + + dev_put(dev); + } + } + + /* read message head information */ + + ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); + if (ret < 0) + return ret; + + lock_sock(sk); + + switch (msg_head.opcode) { + + case TX_SETUP: + ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); + break; + + case RX_SETUP: + ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); + break; + + case TX_DELETE: + if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex)) + ret = MHSIZ; + else + ret = -EINVAL; + break; + + case RX_DELETE: + if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex)) + ret = MHSIZ; + else + ret = -EINVAL; + break; + + case TX_READ: + /* reuse msg_head for the reply to TX_READ */ + msg_head.opcode = TX_STATUS; + ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); + break; + + case RX_READ: + /* reuse msg_head for the reply to RX_READ */ + msg_head.opcode = RX_STATUS; + ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); + break; + + case TX_SEND: + /* we need exactly one can_frame behind the msg head */ + if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ)) + ret = -EINVAL; + else + ret = bcm_tx_send(msg, ifindex, sk); + break; + + default: + ret = -EINVAL; + break; + } + + release_sock(sk); + + return ret; +} + +/* + * notification handler for netdevice status changes + */ +static int bcm_notifier(struct notifier_block *nb, unsigned long msg, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); + struct sock *sk = &bo->sk; + struct bcm_op *op; + int notify_enodev = 0; + + if (!net_eq(dev_net(dev), &init_net)) + return NOTIFY_DONE; + + if (dev->type != ARPHRD_CAN) + return NOTIFY_DONE; + + switch (msg) { + + case NETDEV_UNREGISTER: + lock_sock(sk); + + /* remove device specific receive entries */ + list_for_each_entry(op, &bo->rx_ops, list) + if (op->rx_reg_dev == dev) + bcm_rx_unreg(dev, op); + + /* remove device reference, if this is our bound device */ + if (bo->bound && bo->ifindex == dev->ifindex) { + bo->bound = 0; + bo->ifindex = 0; + notify_enodev = 1; + } + + release_sock(sk); + + if (notify_enodev) { + sk->sk_err = ENODEV; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); + } + break; + + case NETDEV_DOWN: + if (bo->bound && bo->ifindex == dev->ifindex) { + sk->sk_err = ENETDOWN; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); + } + } + + return NOTIFY_DONE; +} + +/* + * initial settings for all BCM sockets to be set at socket creation time + */ +static int bcm_init(struct sock *sk) +{ + struct bcm_sock *bo = bcm_sk(sk); + + bo->bound = 0; + bo->ifindex = 0; + bo->dropped_usr_msgs = 0; + bo->bcm_proc_read = NULL; + + INIT_LIST_HEAD(&bo->tx_ops); + INIT_LIST_HEAD(&bo->rx_ops); + + /* set notifier */ + bo->notifier.notifier_call = bcm_notifier; + + register_netdevice_notifier(&bo->notifier); + + return 0; +} + +/* + * standard socket functions + */ +static int bcm_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct bcm_sock *bo; + struct bcm_op *op, *next; + + if (sk == NULL) + return 0; + + bo = bcm_sk(sk); + + /* remove bcm_ops, timer, rx_unregister(), etc. */ + + unregister_netdevice_notifier(&bo->notifier); + + lock_sock(sk); + + list_for_each_entry_safe(op, next, &bo->tx_ops, list) + bcm_remove_op(op); + + list_for_each_entry_safe(op, next, &bo->rx_ops, list) { + /* + * Don't care if we're bound or not (due to netdev problems) + * can_rx_unregister() is always a save thing to do here. + */ + if (op->ifindex) { + /* + * Only remove subscriptions that had not + * been removed due to NETDEV_UNREGISTER + * in bcm_notifier() + */ + if (op->rx_reg_dev) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, op->ifindex); + if (dev) { + bcm_rx_unreg(dev, op); + dev_put(dev); + } + } + } else + can_rx_unregister(NULL, op->can_id, + REGMASK(op->can_id), + bcm_rx_handler, op); + + bcm_remove_op(op); + } + + /* remove procfs entry */ + if (proc_dir && bo->bcm_proc_read) + remove_proc_entry(bo->procname, proc_dir); + + /* remove device reference */ + if (bo->bound) { + bo->bound = 0; + bo->ifindex = 0; + } + + sock_orphan(sk); + sock->sk = NULL; + + release_sock(sk); + sock_put(sk); + + return 0; +} + +static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, + int flags) +{ + struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; + struct sock *sk = sock->sk; + struct bcm_sock *bo = bcm_sk(sk); + + if (len < sizeof(*addr)) + return -EINVAL; + + if (bo->bound) + return -EISCONN; + + /* bind a device to this socket */ + if (addr->can_ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, addr->can_ifindex); + if (!dev) + return -ENODEV; + + if (dev->type != ARPHRD_CAN) { + dev_put(dev); + return -ENODEV; + } + + bo->ifindex = dev->ifindex; + dev_put(dev); + + } else { + /* no interface reference for ifindex = 0 ('any' CAN device) */ + bo->ifindex = 0; + } + + bo->bound = 1; + + if (proc_dir) { + /* unique socket address as filename */ + sprintf(bo->procname, "%lu", sock_i_ino(sk)); + bo->bcm_proc_read = proc_create_data(bo->procname, 0644, + proc_dir, + &bcm_proc_fops, sk); + } + + return 0; +} + +static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, + int flags) +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int error = 0; + int noblock; + int err; + + noblock = flags & MSG_DONTWAIT; + flags &= ~MSG_DONTWAIT; + skb = skb_recv_datagram(sk, flags, noblock, &error); + if (!skb) + return error; + + if (skb->len < size) + size = skb->len; + + err = memcpy_to_msg(msg, skb->data, size); + if (err < 0) { + skb_free_datagram(sk, skb); + return err; + } + + sock_recv_ts_and_drops(msg, sk, skb); + + if (msg->msg_name) { + __sockaddr_check_size(sizeof(struct sockaddr_can)); + msg->msg_namelen = sizeof(struct sockaddr_can); + memcpy(msg->msg_name, skb->cb, msg->msg_namelen); + } + + skb_free_datagram(sk, skb); + + return size; +} + +static const struct proto_ops bcm_ops = { + .family = PF_CAN, + .release = bcm_release, + .bind = sock_no_bind, + .connect = bcm_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = datagram_poll, + .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = sock_no_setsockopt, + .getsockopt = sock_no_getsockopt, + .sendmsg = bcm_sendmsg, + .recvmsg = bcm_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static struct proto bcm_proto __read_mostly = { + .name = "CAN_BCM", + .owner = THIS_MODULE, + .obj_size = sizeof(struct bcm_sock), + .init = bcm_init, +}; + +static const struct can_proto bcm_can_proto = { + .type = SOCK_DGRAM, + .protocol = CAN_BCM, + .ops = &bcm_ops, + .prot = &bcm_proto, +}; + +static int __init bcm_module_init(void) +{ + int err; + + pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"); + + err = can_proto_register(&bcm_can_proto); + if (err < 0) { + printk(KERN_ERR "can: registration of bcm protocol failed\n"); + return err; + } + + /* create /proc/net/can-bcm directory */ + proc_dir = proc_mkdir("can-bcm", init_net.proc_net); + return 0; +} + +static void __exit bcm_module_exit(void) +{ + can_proto_unregister(&bcm_can_proto); + + if (proc_dir) + remove_proc_entry("can-bcm", init_net.proc_net); +} + +module_init(bcm_module_init); +module_exit(bcm_module_exit); |