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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/can/bcm.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/can/bcm.c')
-rw-r--r--net/can/bcm.c1788
1 files changed, 1788 insertions, 0 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
new file mode 100644
index 000000000..925d48cc5
--- /dev/null
+++ b/net/can/bcm.c
@@ -0,0 +1,1788 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
+ *
+ * Copyright (c) 2002-2017 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
+
+/* limit timers to 400 days for sending/timeouts */
+#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
+
+/* use of last_frames[index].flags */
+#define RX_RECV 0x40 /* received data for this element */
+#define RX_THR 0x80 /* element not been sent due to throttle feature */
+#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
+
+/* 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))
+
+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");
+
+#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
+
+/*
+ * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
+ * 64 bit aligned so the offset has to be multiples of 8 which is ensured
+ * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
+ */
+static inline u64 get_u64(const struct canfd_frame *cp, int offset)
+{
+ return *(u64 *)(cp->data + offset);
+}
+
+struct bcm_op {
+ struct list_head list;
+ struct rcu_head rcu;
+ int ifindex;
+ canid_t can_id;
+ u32 flags;
+ unsigned long frames_abs, frames_filtered;
+ struct bcm_timeval ival1, ival2;
+ struct hrtimer timer, thrtimer;
+ ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
+ int rx_ifindex;
+ int cfsiz;
+ u32 count;
+ u32 nframes;
+ u32 currframe;
+ /* void pointers to arrays of struct can[fd]_frame */
+ void *frames;
+ void *last_frames;
+ struct canfd_frame sframe;
+ struct canfd_frame last_sframe;
+ struct sock *sk;
+ struct net_device *rx_reg_dev;
+};
+
+struct bcm_sock {
+ struct sock sk;
+ int bound;
+ int ifindex;
+ struct list_head 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 LIST_HEAD(bcm_notifier_list);
+static DEFINE_SPINLOCK(bcm_notifier_lock);
+static struct bcm_sock *bcm_busy_notifier;
+
+static inline struct bcm_sock *bcm_sk(const struct sock *sk)
+{
+ return (struct bcm_sock *)sk;
+}
+
+static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
+{
+ return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
+}
+
+/* check limitations for timeval provided by user */
+static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
+{
+ if ((msg_head->ival1.tv_sec < 0) ||
+ (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
+ (msg_head->ival1.tv_usec < 0) ||
+ (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
+ (msg_head->ival2.tv_sec < 0) ||
+ (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
+ (msg_head->ival2.tv_usec < 0) ||
+ (msg_head->ival2.tv_usec >= USEC_PER_SEC))
+ return true;
+
+ return false;
+}
+
+#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
+#define OPSIZ sizeof(struct bcm_op)
+#define MHSIZ sizeof(struct bcm_msg_head)
+
+/*
+ * procfs functions
+ */
+#if IS_ENABLED(CONFIG_PROC_FS)
+static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
+{
+ struct net_device *dev;
+
+ if (!ifindex)
+ return "any";
+
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(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 net *net = m->private;
+ struct sock *sk = (struct sock *)pde_data(m->file->f_inode);
+ 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(net, 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(net, ifname, op->ifindex));
+
+ if (op->flags & CAN_FD_FRAME)
+ seq_printf(m, "(%u)", op->nframes);
+ else
+ seq_printf(m, "[%u]", op->nframes);
+
+ seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
+
+ if (op->kt_ival1)
+ seq_printf(m, "timeo=%lld ",
+ (long long)ktime_to_us(op->kt_ival1));
+
+ if (op->kt_ival2)
+ 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 ", op->can_id,
+ bcm_proc_getifname(net, ifname, op->ifindex));
+
+ if (op->flags & CAN_FD_FRAME)
+ seq_printf(m, "(%u) ", op->nframes);
+ else
+ seq_printf(m, "[%u] ", op->nframes);
+
+ if (op->kt_ival1)
+ seq_printf(m, "t1=%lld ",
+ (long long)ktime_to_us(op->kt_ival1));
+
+ if (op->kt_ival2)
+ 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;
+}
+#endif /* CONFIG_PROC_FS */
+
+/*
+ * 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 canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
+ int err;
+
+ /* no target device? => exit */
+ if (!op->ifindex)
+ return;
+
+ dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
+ if (!dev) {
+ /* RFC: should this bcm_op remove itself here? */
+ return;
+ }
+
+ skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
+ if (!skb)
+ goto out;
+
+ can_skb_reserve(skb);
+ can_skb_prv(skb)->ifindex = dev->ifindex;
+ can_skb_prv(skb)->skbcnt = 0;
+
+ skb_put_data(skb, cf, op->cfsiz);
+
+ /* send with loopback */
+ skb->dev = dev;
+ can_skb_set_owner(skb, op->sk);
+ err = can_send(skb, 1);
+ if (!err)
+ op->frames_abs++;
+
+ op->currframe++;
+
+ /* 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 canfd_frame *frames, int has_timestamp)
+{
+ struct sk_buff *skb;
+ struct canfd_frame *firstframe;
+ struct sockaddr_can *addr;
+ struct sock *sk = op->sk;
+ unsigned int datalen = head->nframes * op->cfsiz;
+ int err;
+
+ skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
+ if (!skb)
+ return;
+
+ skb_put_data(skb, head, sizeof(*head));
+
+ if (head->nframes) {
+ /* CAN frames starting here */
+ firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
+
+ skb_put_data(skb, frames, datalen);
+
+ /*
+ * the BCM uses the flags-element of the canfd_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->flags &= BCM_CAN_FLAGS_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 bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
+{
+ ktime_t ival;
+
+ if (op->kt_ival1 && op->count)
+ ival = op->kt_ival1;
+ else if (op->kt_ival2)
+ ival = op->kt_ival2;
+ else
+ return false;
+
+ hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
+ return true;
+}
+
+static void bcm_tx_start_timer(struct bcm_op *op)
+{
+ if (bcm_tx_set_expiry(op, &op->timer))
+ hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
+}
+
+/* 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);
+ struct bcm_msg_head msg_head;
+
+ if (op->kt_ival1 && (op->count > 0)) {
+ op->count--;
+ if (!op->count && (op->flags & TX_COUNTEVT)) {
+
+ /* create notification to user */
+ memset(&msg_head, 0, sizeof(msg_head));
+ 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) {
+ bcm_can_tx(op);
+ }
+
+ return bcm_tx_set_expiry(op, &op->timer) ?
+ HRTIMER_RESTART : HRTIMER_NORESTART;
+}
+
+/*
+ * bcm_rx_changed - create a RX_CHANGED notification due to changed content
+ */
+static void bcm_rx_changed(struct bcm_op *op, struct canfd_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->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
+
+ memset(&head, 0, sizeof(head));
+ 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 canfd_frame *lastdata,
+ const struct canfd_frame *rxdata)
+{
+ memcpy(lastdata, rxdata, op->cfsiz);
+
+ /* mark as used and throttled by default */
+ lastdata->flags |= (RX_RECV|RX_THR);
+
+ /* throttling mode inactive ? */
+ if (!op->kt_ival2) {
+ /* 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)
+ 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_SOFT);
+ 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 canfd_frame *rxdata)
+{
+ struct canfd_frame *cf = op->frames + op->cfsiz * index;
+ struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
+ int i;
+
+ /*
+ * no one uses the MSBs of flags for comparison,
+ * so we use it here to detect the first time of reception
+ */
+
+ if (!(lcf->flags & RX_RECV)) {
+ /* received data for the first time => send update to user */
+ bcm_rx_update_and_send(op, lcf, rxdata);
+ return;
+ }
+
+ /* do a real check in CAN frame data section */
+ for (i = 0; i < rxdata->len; i += 8) {
+ if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
+ (get_u64(cf, i) & get_u64(lcf, i))) {
+ bcm_rx_update_and_send(op, lcf, rxdata);
+ return;
+ }
+ }
+
+ if (op->flags & RX_CHECK_DLC) {
+ /* do a real check in CAN frame length */
+ if (rxdata->len != lcf->len) {
+ bcm_rx_update_and_send(op, lcf, 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)
+ hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
+}
+
+/* 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);
+ struct bcm_msg_head msg_head;
+
+ /* 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 * op->cfsiz);
+ }
+
+ /* create notification to user */
+ memset(&msg_head, 0, sizeof(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);
+
+ return HRTIMER_NORESTART;
+}
+
+/*
+ * bcm_rx_do_flush - helper for bcm_rx_thr_flush
+ */
+static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
+{
+ struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
+
+ if ((op->last_frames) && (lcf->flags & RX_THR)) {
+ bcm_rx_changed(op, lcf);
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * 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) {
+ unsigned int i;
+
+ /* for MUX filter we start at index 1 */
+ for (i = 1; i < op->nframes; i++)
+ updated += bcm_rx_do_flush(op, i);
+
+ } else {
+ /* for RX_FILTER_ID and simple filter */
+ updated += bcm_rx_do_flush(op, 0);
+ }
+
+ 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_now(hrtimer, op->kt_ival2);
+ return HRTIMER_RESTART;
+ } else {
+ /* rearm throttle handling */
+ op->kt_lastmsg = 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 canfd_frame *rxframe = (struct canfd_frame *)skb->data;
+ unsigned int i;
+
+ if (op->can_id != rxframe->can_id)
+ return;
+
+ /* make sure to handle the correct frame type (CAN / CAN FD) */
+ if (op->flags & CAN_FD_FRAME) {
+ if (!can_is_canfd_skb(skb))
+ return;
+ } else {
+ if (!can_is_can_skb(skb))
+ return;
+ }
+
+ /* disable timeout */
+ hrtimer_cancel(&op->timer);
+
+ /* 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, 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 - but only the
+ * first 64 bits of the frame data[] are relevant (CAN FD)
+ */
+
+ for (i = 1; i < op->nframes; i++) {
+ if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
+ (get_u64(op->frames, 0) &
+ get_u64(op->frames + op->cfsiz * i, 0))) {
+ 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,
+ struct bcm_msg_head *mh, int ifindex)
+{
+ struct bcm_op *op;
+
+ list_for_each_entry(op, ops, list) {
+ if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
+ (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
+ return op;
+ }
+
+ return NULL;
+}
+
+static void bcm_free_op_rcu(struct rcu_head *rcu_head)
+{
+ struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
+
+ 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_remove_op(struct bcm_op *op)
+{
+ hrtimer_cancel(&op->timer);
+ hrtimer_cancel(&op->thrtimer);
+
+ call_rcu(&op->rcu, bcm_free_op_rcu);
+}
+
+static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
+{
+ if (op->rx_reg_dev == dev) {
+ can_rx_unregister(dev_net(dev), 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, struct bcm_msg_head *mh,
+ int ifindex)
+{
+ struct bcm_op *op, *n;
+
+ list_for_each_entry_safe(op, n, ops, list) {
+ if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
+ (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
+
+ /* disable automatic timer on frame reception */
+ op->flags |= RX_NO_AUTOTIMER;
+
+ /*
+ * 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(sock_net(op->sk),
+ op->ifindex);
+ if (dev) {
+ bcm_rx_unreg(dev, op);
+ dev_put(dev);
+ }
+ }
+ } else
+ can_rx_unregister(sock_net(op->sk), 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, struct bcm_msg_head *mh,
+ int ifindex)
+{
+ struct bcm_op *op, *n;
+
+ list_for_each_entry_safe(op, n, ops, list) {
+ if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
+ (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
+ 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, 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;
+ struct canfd_frame *cf;
+ 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 timeval limitations */
+ if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+ return -EINVAL;
+
+ /* check the given can_id */
+ op = bcm_find_op(&bo->tx_ops, msg_head, 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++) {
+
+ cf = op->frames + op->cfsiz * i;
+ err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
+
+ if (op->flags & CAN_FD_FRAME) {
+ if (cf->len > 64)
+ err = -EINVAL;
+ } else {
+ if (cf->len > 8)
+ err = -EINVAL;
+ }
+
+ if (err < 0)
+ return err;
+
+ if (msg_head->flags & TX_CP_CAN_ID) {
+ /* copy can_id into frame */
+ cf->can_id = msg_head->can_id;
+ }
+ }
+ op->flags = msg_head->flags;
+
+ } 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->cfsiz = CFSIZ(msg_head->flags);
+ op->flags = msg_head->flags;
+
+ /* create array for CAN frames and copy the data */
+ if (msg_head->nframes > 1) {
+ op->frames = kmalloc_array(msg_head->nframes,
+ op->cfsiz,
+ GFP_KERNEL);
+ if (!op->frames) {
+ kfree(op);
+ return -ENOMEM;
+ }
+ } else
+ op->frames = &op->sframe;
+
+ for (i = 0; i < msg_head->nframes; i++) {
+
+ cf = op->frames + op->cfsiz * i;
+ err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
+ if (err < 0)
+ goto free_op;
+
+ if (op->flags & CAN_FD_FRAME) {
+ if (cf->len > 64)
+ err = -EINVAL;
+ } else {
+ if (cf->len > 8)
+ err = -EINVAL;
+ }
+
+ if (err < 0)
+ goto free_op;
+
+ if (msg_head->flags & TX_CP_CAN_ID) {
+ /* copy can_id into frame */
+ cf->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_SOFT);
+ op->timer.function = bcm_tx_timeout_handler;
+
+ /* currently unused in tx_ops */
+ hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL_SOFT);
+
+ /* 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 */
+
+ 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 = bcm_timeval_to_ktime(msg_head->ival1);
+ op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
+
+ /* disable an active timer due to zero values? */
+ if (!op->kt_ival1 && !op->kt_ival2)
+ 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 * op->cfsiz + MHSIZ;
+
+free_op:
+ if (op->frames != &op->sframe)
+ kfree(op->frames);
+ kfree(op);
+ return err;
+}
+
+/*
+ * 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 timeval limitations */
+ if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+ return -EINVAL;
+
+ /* check the given can_id */
+ op = bcm_find_op(&bo->rx_ops, msg_head, 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(op->frames, msg,
+ msg_head->nframes * op->cfsiz);
+ if (err < 0)
+ return err;
+
+ /* clear last_frames to indicate 'nothing received' */
+ memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
+ }
+
+ op->nframes = msg_head->nframes;
+ op->flags = msg_head->flags;
+
+ /* 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;
+ op->cfsiz = CFSIZ(msg_head->flags);
+ op->flags = msg_head->flags;
+
+ if (msg_head->nframes > 1) {
+ /* create array for CAN frames and copy the data */
+ op->frames = kmalloc_array(msg_head->nframes,
+ op->cfsiz,
+ GFP_KERNEL);
+ if (!op->frames) {
+ kfree(op);
+ return -ENOMEM;
+ }
+
+ /* create and init array for received CAN frames */
+ op->last_frames = kcalloc(msg_head->nframes,
+ op->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(op->frames, msg,
+ msg_head->nframes * op->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_SOFT);
+ op->timer.function = bcm_rx_timeout_handler;
+
+ hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL_SOFT);
+ 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 */
+
+ if (op->flags & RX_RTR_FRAME) {
+ struct canfd_frame *frame0 = op->frames;
+
+ /* 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) ||
+ (frame0->can_id == op->can_id))
+ frame0->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 = bcm_timeval_to_ktime(msg_head->ival1);
+ op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
+
+ /* disable an active timer due to zero value? */
+ if (!op->kt_ival1)
+ hrtimer_cancel(&op->timer);
+
+ /*
+ * In any case cancel the throttle timer, flush
+ * potentially blocked msgs and reset throttle handling
+ */
+ op->kt_lastmsg = 0;
+ hrtimer_cancel(&op->thrtimer);
+ bcm_rx_thr_flush(op);
+ }
+
+ if ((op->flags & STARTTIMER) && op->kt_ival1)
+ hrtimer_start(&op->timer, op->kt_ival1,
+ HRTIMER_MODE_REL_SOFT);
+ }
+
+ /* 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(sock_net(sk), ifindex);
+ if (dev) {
+ err = can_rx_register(sock_net(sk), dev,
+ op->can_id,
+ REGMASK(op->can_id),
+ bcm_rx_handler, op,
+ "bcm", sk);
+
+ op->rx_reg_dev = dev;
+ dev_put(dev);
+ }
+
+ } else
+ err = can_rx_register(sock_net(sk), NULL, op->can_id,
+ REGMASK(op->can_id),
+ bcm_rx_handler, op, "bcm", sk);
+ if (err) {
+ /* this bcm rx op is broken -> remove it */
+ list_del(&op->list);
+ bcm_remove_op(op);
+ return err;
+ }
+ }
+
+ return msg_head->nframes * op->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,
+ int cfsiz)
+{
+ 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(sock_net(sk), ifindex);
+ if (!dev) {
+ kfree_skb(skb);
+ return -ENODEV;
+ }
+
+ can_skb_prv(skb)->ifindex = dev->ifindex;
+ can_skb_prv(skb)->skbcnt = 0;
+ 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 cfsiz;
+ 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)
+ return -EINVAL;
+
+ /* read message head information */
+ ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
+ if (ret < 0)
+ return ret;
+
+ cfsiz = CFSIZ(msg_head.flags);
+ if ((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 < BCM_MIN_NAMELEN)
+ 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(sock_net(sk), ifindex);
+ if (!dev)
+ return -ENODEV;
+
+ if (dev->type != ARPHRD_CAN) {
+ dev_put(dev);
+ return -ENODEV;
+ }
+
+ dev_put(dev);
+ }
+ }
+
+ 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, ifindex))
+ ret = MHSIZ;
+ else
+ ret = -EINVAL;
+ break;
+
+ case RX_DELETE:
+ if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, 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, cfsiz);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ release_sock(sk);
+
+ return ret;
+}
+
+/*
+ * notification handler for netdevice status changes
+ */
+static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
+ struct net_device *dev)
+{
+ struct sock *sk = &bo->sk;
+ struct bcm_op *op;
+ int notify_enodev = 0;
+
+ if (!net_eq(dev_net(dev), sock_net(sk)))
+ return;
+
+ 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_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_error_report(sk);
+ }
+ }
+}
+
+static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+ if (dev->type != ARPHRD_CAN)
+ return NOTIFY_DONE;
+ if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
+ return NOTIFY_DONE;
+ if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
+ return NOTIFY_DONE;
+
+ spin_lock(&bcm_notifier_lock);
+ list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
+ spin_unlock(&bcm_notifier_lock);
+ bcm_notify(bcm_busy_notifier, msg, dev);
+ spin_lock(&bcm_notifier_lock);
+ }
+ bcm_busy_notifier = NULL;
+ spin_unlock(&bcm_notifier_lock);
+ 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 */
+ spin_lock(&bcm_notifier_lock);
+ list_add_tail(&bo->notifier, &bcm_notifier_list);
+ spin_unlock(&bcm_notifier_lock);
+
+ return 0;
+}
+
+/*
+ * standard socket functions
+ */
+static int bcm_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct net *net;
+ struct bcm_sock *bo;
+ struct bcm_op *op, *next;
+
+ if (!sk)
+ return 0;
+
+ net = sock_net(sk);
+ bo = bcm_sk(sk);
+
+ /* remove bcm_ops, timer, rx_unregister(), etc. */
+
+ spin_lock(&bcm_notifier_lock);
+ while (bcm_busy_notifier == bo) {
+ spin_unlock(&bcm_notifier_lock);
+ schedule_timeout_uninterruptible(1);
+ spin_lock(&bcm_notifier_lock);
+ }
+ list_del(&bo->notifier);
+ spin_unlock(&bcm_notifier_lock);
+
+ lock_sock(sk);
+
+#if IS_ENABLED(CONFIG_PROC_FS)
+ /* remove procfs entry */
+ if (net->can.bcmproc_dir && bo->bcm_proc_read)
+ remove_proc_entry(bo->procname, net->can.bcmproc_dir);
+#endif /* CONFIG_PROC_FS */
+
+ 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(net, op->ifindex);
+ if (dev) {
+ bcm_rx_unreg(dev, op);
+ dev_put(dev);
+ }
+ }
+ } else
+ can_rx_unregister(net, NULL, op->can_id,
+ REGMASK(op->can_id),
+ bcm_rx_handler, op);
+
+ }
+
+ synchronize_rcu();
+
+ list_for_each_entry_safe(op, next, &bo->rx_ops, list)
+ bcm_remove_op(op);
+
+ /* 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);
+ struct net *net = sock_net(sk);
+ int ret = 0;
+
+ if (len < BCM_MIN_NAMELEN)
+ return -EINVAL;
+
+ lock_sock(sk);
+
+ if (bo->bound) {
+ ret = -EISCONN;
+ goto fail;
+ }
+
+ /* bind a device to this socket */
+ if (addr->can_ifindex) {
+ struct net_device *dev;
+
+ dev = dev_get_by_index(net, addr->can_ifindex);
+ if (!dev) {
+ ret = -ENODEV;
+ goto fail;
+ }
+ if (dev->type != ARPHRD_CAN) {
+ dev_put(dev);
+ ret = -ENODEV;
+ goto fail;
+ }
+
+ bo->ifindex = dev->ifindex;
+ dev_put(dev);
+
+ } else {
+ /* no interface reference for ifindex = 0 ('any' CAN device) */
+ bo->ifindex = 0;
+ }
+
+#if IS_ENABLED(CONFIG_PROC_FS)
+ if (net->can.bcmproc_dir) {
+ /* unique socket address as filename */
+ sprintf(bo->procname, "%lu", sock_i_ino(sk));
+ bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
+ net->can.bcmproc_dir,
+ bcm_proc_show, sk);
+ if (!bo->bcm_proc_read) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ }
+#endif /* CONFIG_PROC_FS */
+
+ bo->bound = 1;
+
+fail:
+ release_sock(sk);
+
+ return ret;
+}
+
+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 err;
+
+ skb = skb_recv_datagram(sk, flags, &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_cmsgs(msg, sk, skb);
+
+ if (msg->msg_name) {
+ __sockaddr_check_size(BCM_MIN_NAMELEN);
+ msg->msg_namelen = BCM_MIN_NAMELEN;
+ memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+ }
+
+ skb_free_datagram(sk, skb);
+
+ return size;
+}
+
+static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+ unsigned long arg)
+{
+ /* no ioctls for socket layer -> hand it down to NIC layer */
+ return -ENOIOCTLCMD;
+}
+
+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 = bcm_sock_no_ioctlcmd,
+ .gettstamp = sock_gettstamp,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .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 canbcm_pernet_init(struct net *net)
+{
+#if IS_ENABLED(CONFIG_PROC_FS)
+ /* create /proc/net/can-bcm directory */
+ net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
+#endif /* CONFIG_PROC_FS */
+
+ return 0;
+}
+
+static void canbcm_pernet_exit(struct net *net)
+{
+#if IS_ENABLED(CONFIG_PROC_FS)
+ /* remove /proc/net/can-bcm directory */
+ if (net->can.bcmproc_dir)
+ remove_proc_entry("can-bcm", net->proc_net);
+#endif /* CONFIG_PROC_FS */
+}
+
+static struct pernet_operations canbcm_pernet_ops __read_mostly = {
+ .init = canbcm_pernet_init,
+ .exit = canbcm_pernet_exit,
+};
+
+static struct notifier_block canbcm_notifier = {
+ .notifier_call = bcm_notifier
+};
+
+static int __init bcm_module_init(void)
+{
+ int err;
+
+ pr_info("can: broadcast manager protocol\n");
+
+ err = register_pernet_subsys(&canbcm_pernet_ops);
+ if (err)
+ return err;
+
+ err = register_netdevice_notifier(&canbcm_notifier);
+ if (err)
+ goto register_notifier_failed;
+
+ err = can_proto_register(&bcm_can_proto);
+ if (err < 0) {
+ printk(KERN_ERR "can: registration of bcm protocol failed\n");
+ goto register_proto_failed;
+ }
+
+ return 0;
+
+register_proto_failed:
+ unregister_netdevice_notifier(&canbcm_notifier);
+register_notifier_failed:
+ unregister_pernet_subsys(&canbcm_pernet_ops);
+ return err;
+}
+
+static void __exit bcm_module_exit(void)
+{
+ can_proto_unregister(&bcm_can_proto);
+ unregister_netdevice_notifier(&canbcm_notifier);
+ unregister_pernet_subsys(&canbcm_pernet_ops);
+}
+
+module_init(bcm_module_init);
+module_exit(bcm_module_exit);