/* * 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. * * Send feedback to <socketcan-users@lists.berlios.de> * */ #include <linux/module.h> #include <linux/init.h> #include <linux/hrtimer.h> #include <linux/list.h> #include <linux/proc_fs.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/bcm.h> #include <net/sock.h> #include <net/net_namespace.h> /* 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_RTR_FLAG) | ((id & CAN_EFF_FLAG) ? \ (CAN_EFF_MASK | CAN_EFF_FLAG) : CAN_SFF_MASK)) #define CAN_BCM_VERSION "20080415" static __initdata const char banner[] = KERN_INFO "can: broadcast manager protocol (rev " CAN_BCM_VERSION ")\n"; MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); /* 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; int flags; unsigned long frames_abs, frames_filtered; struct timeval ival1, ival2; struct hrtimer timer, thrtimer; ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; int rx_ifindex; int count; int nframes; int 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 [9]; /* pointer printed in ASCII 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(int ifindex) { struct net_device *dev; if (!ifindex) return "any"; /* no usage counting */ dev = __dev_get_by_index(&init_net, ifindex); if (dev) return dev->name; return "???"; } static int bcm_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { int len = 0; struct sock *sk = (struct sock *)data; struct bcm_sock *bo = bcm_sk(sk); struct bcm_op *op; len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p", sk->sk_socket); len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk); len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo); len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu", bo->dropped_usr_msgs); len += snprintf(page + len, PAGE_SIZE - len, " / bound %s", bcm_proc_getifname(bo->ifindex)); len += snprintf(page + len, PAGE_SIZE - len, " <<<\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; len += snprintf(page + len, PAGE_SIZE - len, "rx_op: %03X %-5s ", op->can_id, bcm_proc_getifname(op->ifindex)); len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ", op->nframes, (op->flags & RX_CHECK_DLC)?'d':' '); if (op->kt_ival1.tv64) len += snprintf(page + len, PAGE_SIZE - len, "timeo=%lld ", (long long) ktime_to_us(op->kt_ival1)); if (op->kt_ival2.tv64) len += snprintf(page + len, PAGE_SIZE - len, "thr=%lld ", (long long) ktime_to_us(op->kt_ival2)); len += snprintf(page + len, PAGE_SIZE - len, "# recv %ld (%ld) => reduction: ", op->frames_filtered, op->frames_abs); reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n", (reduction == 100)?"near ":"", reduction); if (len > PAGE_SIZE - 200) { /* mark output cut off */ len += snprintf(page + len, PAGE_SIZE - len, "(..)\n"); break; } } list_for_each_entry(op, &bo->tx_ops, list) { len += snprintf(page + len, PAGE_SIZE - len, "tx_op: %03X %s [%d] ", op->can_id, bcm_proc_getifname(op->ifindex), op->nframes); if (op->kt_ival1.tv64) len += snprintf(page + len, PAGE_SIZE - len, "t1=%lld ", (long long) ktime_to_us(op->kt_ival1)); if (op->kt_ival2.tv64) len += snprintf(page + len, PAGE_SIZE - len, "t2=%lld ", (long long) ktime_to_us(op->kt_ival2)); len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n", op->frames_abs); if (len > PAGE_SIZE - 100) { /* mark output cut off */ len += snprintf(page + len, PAGE_SIZE - len, "(..)\n"); break; } } len += snprintf(page + len, PAGE_SIZE - len, "\n"); *eof = 1; return len; } /* * 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, gfp_any()); if (!skb) goto out; memcpy(skb_put(skb, CFSIZ), cf, CFSIZ); /* send with loopback */ skb->dev = dev; skb->sk = 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; 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. */ BUILD_BUG_ON(sizeof(skb->cb) < 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++; } } /* * bcm_tx_timeout_handler - performes 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); enum hrtimer_restart ret = HRTIMER_NORESTART; if (op->kt_ival1.tv64 && (op->count > 0)) { op->count--; if (!op->count && (op->flags & TX_COUNTEVT)) { struct bcm_msg_head msg_head; /* 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); } } if (op->kt_ival1.tv64 && (op->count > 0)) { /* send (next) frame */ bcm_can_tx(op); hrtimer_forward(hrtimer, ktime_get(), op->kt_ival1); ret = HRTIMER_RESTART; } else { if (op->kt_ival2.tv64) { /* send (next) frame */ bcm_can_tx(op); hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); ret = HRTIMER_RESTART; } } return ret; } /* * 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; 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); } /* TODO: move to linux/hrtimer.h */ static inline int hrtimer_callback_running(struct hrtimer *timer) { return timer->state & HRTIMER_STATE_CALLBACK; } /* * 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, struct can_frame *rxdata) { memcpy(lastdata, rxdata, CFSIZ); /* mark as used */ lastdata->can_dlc |= RX_RECV; /* throtteling mode inactive OR data update already on the run ? */ if (!op->kt_ival2.tv64 || hrtimer_callback_running(&op->thrtimer)) { /* send RX_CHANGED to the user immediately */ bcm_rx_changed(op, rxdata); return; } if (hrtimer_active(&op->thrtimer)) { /* mark as 'throttled' */ lastdata->can_dlc |= RX_THR; return; } if (!op->kt_lastmsg.tv64) { /* send first RX_CHANGED to the user immediately */ bcm_rx_changed(op, rxdata); op->kt_lastmsg = ktime_get(); return; } if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < ktime_to_us(op->kt_ival2)) { /* mark as 'throttled' and start timer */ lastdata->can_dlc |= RX_THR; 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 */ bcm_rx_changed(op, rxdata); 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, int index, struct can_frame *rxdata) { /* * no one uses the MSBs of can_dlc for comparation, * 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 receiption */ 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); } /* * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out */ static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) { struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); struct bcm_msg_head msg_head; 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); /* 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_thr_flush - Check for throttled data and send it to the userspace */ static int bcm_rx_thr_flush(struct bcm_op *op) { int updated = 0; if (op->nframes > 1) { int i; /* for MUX filter we start at index 1 */ for (i = 1; i < op->nframes; i++) { if ((op->last_frames) && (op->last_frames[i].can_dlc & RX_THR)) { op->last_frames[i].can_dlc &= ~RX_THR; bcm_rx_changed(op, &op->last_frames[i]); updated++; } } } else { /* for RX_FILTER_ID and simple filter */ if (op->last_frames && (op->last_frames[0].can_dlc & RX_THR)) { op->last_frames[0].can_dlc &= ~RX_THR; bcm_rx_changed(op, &op->last_frames[0]); updated++; } } return updated; } /* * 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); if (bcm_rx_thr_flush(op)) { 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 receiption */ static void bcm_rx_handler(struct sk_buff *skb, void *data) { struct bcm_op *op = (struct bcm_op *)data; struct can_frame rxframe; int i; /* disable timeout */ hrtimer_cancel(&op->timer); if (skb->len == sizeof(rxframe)) { memcpy(&rxframe, skb->data, sizeof(rxframe)); /* save rx timestamp */ op->rx_stamp = skb->tstamp; /* save originator for recvfrom() */ op->rx_ifindex = skb->dev->ifindex; /* update statistics */ op->frames_abs++; kfree_skb(skb); } else { kfree_skb(skb); return; } if (op->can_id != rxframe.can_id) return; 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); bcm_rx_starttimer(op); return; } if (op->nframes == 1) { /* simple compare with index 0 */ bcm_rx_cmp_to_index(op, 0, &rxframe); bcm_rx_starttimer(op); return; } 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; } } 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->frames) && (op->frames != &op->sframe)) kfree(op->frames); if ((op->last_frames) && (op->last_frames != &op->last_sframe)) kfree(op->last_frames); kfree(op); return; } 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; int i, err; /* we need a real device to send frames */ if (!ifindex) return -ENODEV; /* we need at least one can_frame */ if (msg_head->nframes < 1) 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_fromiovec((u8 *)&op->frames[i], msg->msg_iov, CFSIZ); 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_fromiovec((u8 *)&op->frames[i], msg->msg_iov, CFSIZ); 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; /* 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) && ((op->kt_ival1.tv64 && op->count) || op->kt_ival2.tv64)) { /* spec: send can_frame when starting timer */ op->flags |= TX_ANNOUNCE; if (op->kt_ival1.tv64 && (op->count > 0)) { /* op->count-- is done in bcm_tx_timeout_handler */ hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); } else hrtimer_start(&op->timer, op->kt_ival2, HRTIMER_MODE_REL); } if (op->flags & TX_ANNOUNCE) bcm_can_tx(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; } 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_fromiovec((u8 *)op->frames, msg->msg_iov, 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_fromiovec((u8 *)op->frames, msg->msg_iov, 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; /* initialize uninitialized (kzalloc) structure */ hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); op->timer.function = bcm_rx_timeout_handler; hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); op->thrtimer.function = bcm_rx_thr_handler; /* 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); } 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, GFP_KERNEL); if (!skb) return -ENOMEM; err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ); if (err < 0) { kfree_skb(skb); return err; } dev = dev_get_by_index(&init_net, ifindex); if (!dev) { kfree_skb(skb); return -ENODEV; } skb->dev = dev; skb->sk = sk; can_send(skb, 1); /* send with loopback */ dev_put(dev); return CFSIZ + MHSIZ; } /* * bcm_sendmsg - process BCM commands (opcodes) from the userspace */ static int bcm_sendmsg(struct kiocb *iocb, 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 alternative ifindex for this bcm_op */ if (!ifindex && msg->msg_name) { /* no bound device as default => check msg_name */ struct sockaddr_can *addr = (struct sockaddr_can *)msg->msg_name; 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_fromiovec((u8 *)&msg_head, msg->msg_iov, 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 at least one can_frame */ if (msg_head.nframes < 1) 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 *data) { struct net_device *dev = (struct net_device *)data; 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 (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 = bcm_sk(sk); struct bcm_op *op, *next; /* 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; } 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 (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, "%p", sock); bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644, proc_dir, bcm_read_proc, sk); } return 0; } static int bcm_recvmsg(struct kiocb *iocb, 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_toiovec(msg->msg_iov, skb->data, size); if (err < 0) { skb_free_datagram(sk, skb); return err; } sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) { msg->msg_namelen = sizeof(struct sockaddr_can); memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } skb_free_datagram(sk, skb); return size; } static struct proto_ops bcm_ops __read_mostly = { .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 = NULL, /* 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 struct can_proto bcm_can_proto __read_mostly = { .type = SOCK_DGRAM, .protocol = CAN_BCM, .capability = -1, .ops = &bcm_ops, .prot = &bcm_proto, }; static int __init bcm_module_init(void) { int err; printk(banner); 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); if (proc_dir) proc_dir->owner = THIS_MODULE; return 0; } static void __exit bcm_module_exit(void) { can_proto_unregister(&bcm_can_proto); if (proc_dir) proc_net_remove(&init_net, "can-bcm"); } module_init(bcm_module_init); module_exit(bcm_module_exit);