--- /dev/null
+/*
+ * af_can.c - Protocol family CAN core module
+ * (used by different CAN protocol modules)
+ *
+ * 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/stddef.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/uaccess.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_ether.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/ratelimit.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "af_can.h"
+
+MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
+ "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+
+MODULE_ALIAS_NETPROTO(PF_CAN);
+
+static int stats_timer __read_mostly = 1;
+module_param(stats_timer, int, S_IRUGO);
+MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
+
+/* receive filters subscribed for 'all' CAN devices */
+struct dev_rcv_lists can_rx_alldev_list;
+static DEFINE_SPINLOCK(can_rcvlists_lock);
+
+static struct kmem_cache *rcv_cache __read_mostly;
+
+/* table of registered CAN protocols */
+static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
+static DEFINE_MUTEX(proto_tab_lock);
+
+struct timer_list can_stattimer; /* timer for statistics update */
+struct s_stats can_stats; /* packet statistics */
+struct s_pstats can_pstats; /* receive list statistics */
+
+/*
+ * af_can socket functions
+ */
+
+int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+ struct sock *sk = sock->sk;
+
+ switch (cmd) {
+
+ case SIOCGSTAMP:
+ return sock_get_timestamp(sk, (struct timeval __user *)arg);
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+EXPORT_SYMBOL(can_ioctl);
+
+static void can_sock_destruct(struct sock *sk)
+{
+ skb_queue_purge(&sk->sk_receive_queue);
+}
+
+static const struct can_proto *can_get_proto(int protocol)
+{
+ const struct can_proto *cp;
+
+ rcu_read_lock();
+ cp = rcu_dereference(proto_tab[protocol]);
+ if (cp && !try_module_get(cp->prot->owner))
+ cp = NULL;
+ rcu_read_unlock();
+
+ return cp;
+}
+
+static inline void can_put_proto(const struct can_proto *cp)
+{
+ module_put(cp->prot->owner);
+}
+
+static int can_create(struct net *net, struct socket *sock, int protocol,
+ int kern)
+{
+ struct sock *sk;
+ const struct can_proto *cp;
+ int err = 0;
+
+ sock->state = SS_UNCONNECTED;
+
+ if (protocol < 0 || protocol >= CAN_NPROTO)
+ return -EINVAL;
+
+ if (!net_eq(net, &init_net))
+ return -EAFNOSUPPORT;
+
+ cp = can_get_proto(protocol);
+
+#ifdef CONFIG_MODULES
+ if (!cp) {
+ /* try to load protocol module if kernel is modular */
+
+ err = request_module("can-proto-%d", protocol);
+
+ /*
+ * In case of error we only print a message but don't
+ * return the error code immediately. Below we will
+ * return -EPROTONOSUPPORT
+ */
+ if (err)
+ printk_ratelimited(KERN_ERR "can: request_module "
+ "(can-proto-%d) failed.\n", protocol);
+
+ cp = can_get_proto(protocol);
+ }
+#endif
+
+ /* check for available protocol and correct usage */
+
+ if (!cp)
+ return -EPROTONOSUPPORT;
+
+ if (cp->type != sock->type) {
+ err = -EPROTOTYPE;
+ goto errout;
+ }
+
+ sock->ops = cp->ops;
+
+ sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
+ if (!sk) {
+ err = -ENOMEM;
+ goto errout;
+ }
+
+ sock_init_data(sock, sk);
+ sk->sk_destruct = can_sock_destruct;
+
+ if (sk->sk_prot->init)
+ err = sk->sk_prot->init(sk);
+
+ if (err) {
+ /* release sk on errors */
+ sock_orphan(sk);
+ sock_put(sk);
+ }
+
+ errout:
+ can_put_proto(cp);
+ return err;
+}
+
+/*
+ * af_can tx path
+ */
+
+/**
+ * can_send - transmit a CAN frame (optional with local loopback)
+ * @skb: pointer to socket buffer with CAN frame in data section
+ * @loop: loopback for listeners on local CAN sockets (recommended default!)
+ *
+ * Due to the loopback this routine must not be called from hardirq context.
+ *
+ * Return:
+ * 0 on success
+ * -ENETDOWN when the selected interface is down
+ * -ENOBUFS on full driver queue (see net_xmit_errno())
+ * -ENOMEM when local loopback failed at calling skb_clone()
+ * -EPERM when trying to send on a non-CAN interface
+ * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
+ * -EINVAL when the skb->data does not contain a valid CAN frame
+ */
+int can_send(struct sk_buff *skb, int loop)
+{
+ struct sk_buff *newskb = NULL;
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+ int err = -EINVAL;
+
+ if (skb->len == CAN_MTU) {
+ skb->protocol = htons(ETH_P_CAN);
+ if (unlikely(cfd->len > CAN_MAX_DLEN))
+ goto inval_skb;
+ } else if (skb->len == CANFD_MTU) {
+ skb->protocol = htons(ETH_P_CANFD);
+ if (unlikely(cfd->len > CANFD_MAX_DLEN))
+ goto inval_skb;
+ } else
+ goto inval_skb;
+
+ /*
+ * Make sure the CAN frame can pass the selected CAN netdevice.
+ * As structs can_frame and canfd_frame are similar, we can provide
+ * CAN FD frames to legacy CAN drivers as long as the length is <= 8
+ */
+ if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
+ err = -EMSGSIZE;
+ goto inval_skb;
+ }
+
+ if (unlikely(skb->dev->type != ARPHRD_CAN)) {
+ err = -EPERM;
+ goto inval_skb;
+ }
+
+ if (unlikely(!(skb->dev->flags & IFF_UP))) {
+ err = -ENETDOWN;
+ goto inval_skb;
+ }
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ skb_reset_mac_header(skb);
+ skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);
+
+ if (loop) {
+ /* local loopback of sent CAN frames */
+
+ /* indication for the CAN driver: do loopback */
+ skb->pkt_type = PACKET_LOOPBACK;
+
+ /*
+ * The reference to the originating sock may be required
+ * by the receiving socket to check whether the frame is
+ * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
+ * Therefore we have to ensure that skb->sk remains the
+ * reference to the originating sock by restoring skb->sk
+ * after each skb_clone() or skb_orphan() usage.
+ */
+
+ if (!(skb->dev->flags & IFF_ECHO)) {
+ /*
+ * If the interface is not capable to do loopback
+ * itself, we do it here.
+ */
+ newskb = skb_clone(skb, GFP_ATOMIC);
+ if (!newskb) {
+ kfree_skb(skb);
+ return -ENOMEM;
+ }
+
+ can_skb_set_owner(newskb, skb->sk);
+ newskb->ip_summed = CHECKSUM_UNNECESSARY;
+ newskb->pkt_type = PACKET_BROADCAST;
+ }
+ } else {
+ /* indication for the CAN driver: no loopback required */
+ skb->pkt_type = PACKET_HOST;
+ }
+
+ /* send to netdevice */
+ err = dev_queue_xmit(skb);
+ if (err > 0)
+ err = net_xmit_errno(err);
+
+ if (err) {
+ kfree_skb(newskb);
+ return err;
+ }
+
+ if (newskb) {
+ if (!(newskb->tstamp.tv64))
+ __net_timestamp(newskb);
+
+ netif_rx_ni(newskb);
+ }
+
+ /* update statistics */
+ can_stats.tx_frames++;
+ can_stats.tx_frames_delta++;
+
+ return 0;
+
+inval_skb:
+ kfree_skb(skb);
+ return err;
+}
+EXPORT_SYMBOL(can_send);
+
+/*
+ * af_can rx path
+ */
+
+static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
+{
+ if (!dev)
+ return &can_rx_alldev_list;
+ else
+ return (struct dev_rcv_lists *)dev->ml_priv;
+}
+
+/**
+ * effhash - hash function for 29 bit CAN identifier reduction
+ * @can_id: 29 bit CAN identifier
+ *
+ * Description:
+ * To reduce the linear traversal in one linked list of _single_ EFF CAN
+ * frame subscriptions the 29 bit identifier is mapped to 10 bits.
+ * (see CAN_EFF_RCV_HASH_BITS definition)
+ *
+ * Return:
+ * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
+ */
+static unsigned int effhash(canid_t can_id)
+{
+ unsigned int hash;
+
+ hash = can_id;
+ hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
+ hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
+
+ return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
+}
+
+/**
+ * find_rcv_list - determine optimal filterlist inside device filter struct
+ * @can_id: pointer to CAN identifier of a given can_filter
+ * @mask: pointer to CAN mask of a given can_filter
+ * @d: pointer to the device filter struct
+ *
+ * Description:
+ * Returns the optimal filterlist to reduce the filter handling in the
+ * receive path. This function is called by service functions that need
+ * to register or unregister a can_filter in the filter lists.
+ *
+ * A filter matches in general, when
+ *
+ * <received_can_id> & mask == can_id & mask
+ *
+ * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
+ * relevant bits for the filter.
+ *
+ * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
+ * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
+ * frames there is a special filterlist and a special rx path filter handling.
+ *
+ * Return:
+ * Pointer to optimal filterlist for the given can_id/mask pair.
+ * Constistency checked mask.
+ * Reduced can_id to have a preprocessed filter compare value.
+ */
+static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
+ struct dev_rcv_lists *d)
+{
+ canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
+
+ /* filter for error message frames in extra filterlist */
+ if (*mask & CAN_ERR_FLAG) {
+ /* clear CAN_ERR_FLAG in filter entry */
+ *mask &= CAN_ERR_MASK;
+ return &d->rx[RX_ERR];
+ }
+
+ /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
+
+#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
+
+ /* ensure valid values in can_mask for 'SFF only' frame filtering */
+ if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
+ *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
+
+ /* reduce condition testing at receive time */
+ *can_id &= *mask;
+
+ /* inverse can_id/can_mask filter */
+ if (inv)
+ return &d->rx[RX_INV];
+
+ /* mask == 0 => no condition testing at receive time */
+ if (!(*mask))
+ return &d->rx[RX_ALL];
+
+ /* extra filterlists for the subscription of a single non-RTR can_id */
+ if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
+ !(*can_id & CAN_RTR_FLAG)) {
+
+ if (*can_id & CAN_EFF_FLAG) {
+ if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
+ return &d->rx_eff[effhash(*can_id)];
+ } else {
+ if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
+ return &d->rx_sff[*can_id];
+ }
+ }
+
+ /* default: filter via can_id/can_mask */
+ return &d->rx[RX_FIL];
+}
+
+/**
+ * can_rx_register - subscribe CAN frames from a specific interface
+ * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
+ * @can_id: CAN identifier (see description)
+ * @mask: CAN mask (see description)
+ * @func: callback function on filter match
+ * @data: returned parameter for callback function
+ * @ident: string for calling module identification
+ *
+ * Description:
+ * Invokes the callback function with the received sk_buff and the given
+ * parameter 'data' on a matching receive filter. A filter matches, when
+ *
+ * <received_can_id> & mask == can_id & mask
+ *
+ * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
+ * filter for error message frames (CAN_ERR_FLAG bit set in mask).
+ *
+ * The provided pointer to the sk_buff is guaranteed to be valid as long as
+ * the callback function is running. The callback function must *not* free
+ * the given sk_buff while processing it's task. When the given sk_buff is
+ * needed after the end of the callback function it must be cloned inside
+ * the callback function with skb_clone().
+ *
+ * Return:
+ * 0 on success
+ * -ENOMEM on missing cache mem to create subscription entry
+ * -ENODEV unknown device
+ */
+int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
+ void (*func)(struct sk_buff *, void *), void *data,
+ char *ident)
+{
+ struct receiver *r;
+ struct hlist_head *rl;
+ struct dev_rcv_lists *d;
+ int err = 0;
+
+ /* insert new receiver (dev,canid,mask) -> (func,data) */
+
+ if (dev && dev->type != ARPHRD_CAN)
+ return -ENODEV;
+
+ r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
+ if (!r)
+ return -ENOMEM;
+
+ spin_lock(&can_rcvlists_lock);
+
+ d = find_dev_rcv_lists(dev);
+ if (d) {
+ rl = find_rcv_list(&can_id, &mask, d);
+
+ r->can_id = can_id;
+ r->mask = mask;
+ r->matches = 0;
+ r->func = func;
+ r->data = data;
+ r->ident = ident;
+
+ hlist_add_head_rcu(&r->list, rl);
+ d->entries++;
+
+ can_pstats.rcv_entries++;
+ if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
+ can_pstats.rcv_entries_max = can_pstats.rcv_entries;
+ } else {
+ kmem_cache_free(rcv_cache, r);
+ err = -ENODEV;
+ }
+
+ spin_unlock(&can_rcvlists_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(can_rx_register);
+
+/*
+ * can_rx_delete_receiver - rcu callback for single receiver entry removal
+ */
+static void can_rx_delete_receiver(struct rcu_head *rp)
+{
+ struct receiver *r = container_of(rp, struct receiver, rcu);
+
+ kmem_cache_free(rcv_cache, r);
+}
+
+/**
+ * can_rx_unregister - unsubscribe CAN frames from a specific interface
+ * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
+ * @can_id: CAN identifier
+ * @mask: CAN mask
+ * @func: callback function on filter match
+ * @data: returned parameter for callback function
+ *
+ * Description:
+ * Removes subscription entry depending on given (subscription) values.
+ */
+void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
+ void (*func)(struct sk_buff *, void *), void *data)
+{
+ struct receiver *r = NULL;
+ struct hlist_head *rl;
+ struct dev_rcv_lists *d;
+
+ if (dev && dev->type != ARPHRD_CAN)
+ return;
+
+ spin_lock(&can_rcvlists_lock);
+
+ d = find_dev_rcv_lists(dev);
+ if (!d) {
+ pr_err("BUG: receive list not found for "
+ "dev %s, id %03X, mask %03X\n",
+ DNAME(dev), can_id, mask);
+ goto out;
+ }
+
+ rl = find_rcv_list(&can_id, &mask, d);
+
+ /*
+ * Search the receiver list for the item to delete. This should
+ * exist, since no receiver may be unregistered that hasn't
+ * been registered before.
+ */
+
+ hlist_for_each_entry_rcu(r, rl, list) {
+ if (r->can_id == can_id && r->mask == mask &&
+ r->func == func && r->data == data)
+ break;
+ }
+
+ /*
+ * Check for bugs in CAN protocol implementations using af_can.c:
+ * 'r' will be NULL if no matching list item was found for removal.
+ */
+
+ if (!r) {
+ WARN(1, "BUG: receive list entry not found for dev %s, "
+ "id %03X, mask %03X\n", DNAME(dev), can_id, mask);
+ goto out;
+ }
+
+ hlist_del_rcu(&r->list);
+ d->entries--;
+
+ if (can_pstats.rcv_entries > 0)
+ can_pstats.rcv_entries--;
+
+ /* remove device structure requested by NETDEV_UNREGISTER */
+ if (d->remove_on_zero_entries && !d->entries) {
+ kfree(d);
+ dev->ml_priv = NULL;
+ }
+
+ out:
+ spin_unlock(&can_rcvlists_lock);
+
+ /* schedule the receiver item for deletion */
+ if (r)
+ call_rcu(&r->rcu, can_rx_delete_receiver);
+}
+EXPORT_SYMBOL(can_rx_unregister);
+
+static inline void deliver(struct sk_buff *skb, struct receiver *r)
+{
+ r->func(skb, r->data);
+ r->matches++;
+}
+
+static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
+{
+ struct receiver *r;
+ int matches = 0;
+ struct can_frame *cf = (struct can_frame *)skb->data;
+ canid_t can_id = cf->can_id;
+
+ if (d->entries == 0)
+ return 0;
+
+ if (can_id & CAN_ERR_FLAG) {
+ /* check for error message frame entries only */
+ hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) {
+ if (can_id & r->mask) {
+ deliver(skb, r);
+ matches++;
+ }
+ }
+ return matches;
+ }
+
+ /* check for unfiltered entries */
+ hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) {
+ deliver(skb, r);
+ matches++;
+ }
+
+ /* check for can_id/mask entries */
+ hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) {
+ if ((can_id & r->mask) == r->can_id) {
+ deliver(skb, r);
+ matches++;
+ }
+ }
+
+ /* check for inverted can_id/mask entries */
+ hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) {
+ if ((can_id & r->mask) != r->can_id) {
+ deliver(skb, r);
+ matches++;
+ }
+ }
+
+ /* check filterlists for single non-RTR can_ids */
+ if (can_id & CAN_RTR_FLAG)
+ return matches;
+
+ if (can_id & CAN_EFF_FLAG) {
+ hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
+ if (r->can_id == can_id) {
+ deliver(skb, r);
+ matches++;
+ }
+ }
+ } else {
+ can_id &= CAN_SFF_MASK;
+ hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) {
+ deliver(skb, r);
+ matches++;
+ }
+ }
+
+ return matches;
+}
+
+static void can_receive(struct sk_buff *skb, struct net_device *dev)
+{
+ struct dev_rcv_lists *d;
+ int matches;
+
+ /* update statistics */
+ can_stats.rx_frames++;
+ can_stats.rx_frames_delta++;
+
+ rcu_read_lock();
+
+ /* deliver the packet to sockets listening on all devices */
+ matches = can_rcv_filter(&can_rx_alldev_list, skb);
+
+ /* find receive list for this device */
+ d = find_dev_rcv_lists(dev);
+ if (d)
+ matches += can_rcv_filter(d, skb);
+
+ rcu_read_unlock();
+
+ /* consume the skbuff allocated by the netdevice driver */
+ consume_skb(skb);
+
+ if (matches > 0) {
+ can_stats.matches++;
+ can_stats.matches_delta++;
+ }
+}
+
+static int can_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (unlikely(!net_eq(dev_net(dev), &init_net)))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != CAN_MTU ||
+ cfd->len > CAN_MAX_DLEN,
+ "PF_CAN: dropped non conform CAN skbuf: "
+ "dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len))
+ goto drop;
+
+ can_receive(skb, dev);
+ return NET_RX_SUCCESS;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (unlikely(!net_eq(dev_net(dev), &init_net)))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != CANFD_MTU ||
+ cfd->len > CANFD_MAX_DLEN,
+ "PF_CAN: dropped non conform CAN FD skbuf: "
+ "dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len))
+ goto drop;
+
+ can_receive(skb, dev);
+ return NET_RX_SUCCESS;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+/*
+ * af_can protocol functions
+ */
+
+/**
+ * can_proto_register - register CAN transport protocol
+ * @cp: pointer to CAN protocol structure
+ *
+ * Return:
+ * 0 on success
+ * -EINVAL invalid (out of range) protocol number
+ * -EBUSY protocol already in use
+ * -ENOBUF if proto_register() fails
+ */
+int can_proto_register(const struct can_proto *cp)
+{
+ int proto = cp->protocol;
+ int err = 0;
+
+ if (proto < 0 || proto >= CAN_NPROTO) {
+ pr_err("can: protocol number %d out of range\n", proto);
+ return -EINVAL;
+ }
+
+ err = proto_register(cp->prot, 0);
+ if (err < 0)
+ return err;
+
+ mutex_lock(&proto_tab_lock);
+
+ if (proto_tab[proto]) {
+ pr_err("can: protocol %d already registered\n", proto);
+ err = -EBUSY;
+ } else
+ RCU_INIT_POINTER(proto_tab[proto], cp);
+
+ mutex_unlock(&proto_tab_lock);
+
+ if (err < 0)
+ proto_unregister(cp->prot);
+
+ return err;
+}
+EXPORT_SYMBOL(can_proto_register);
+
+/**
+ * can_proto_unregister - unregister CAN transport protocol
+ * @cp: pointer to CAN protocol structure
+ */
+void can_proto_unregister(const struct can_proto *cp)
+{
+ int proto = cp->protocol;
+
+ mutex_lock(&proto_tab_lock);
+ BUG_ON(proto_tab[proto] != cp);
+ RCU_INIT_POINTER(proto_tab[proto], NULL);
+ mutex_unlock(&proto_tab_lock);
+
+ synchronize_rcu();
+
+ proto_unregister(cp->prot);
+}
+EXPORT_SYMBOL(can_proto_unregister);
+
+/*
+ * af_can notifier to create/remove CAN netdevice specific structs
+ */
+static int can_notifier(struct notifier_block *nb, unsigned long msg,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct dev_rcv_lists *d;
+
+ if (!net_eq(dev_net(dev), &init_net))
+ return NOTIFY_DONE;
+
+ if (dev->type != ARPHRD_CAN)
+ return NOTIFY_DONE;
+
+ switch (msg) {
+
+ case NETDEV_REGISTER:
+
+ /* create new dev_rcv_lists for this device */
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return NOTIFY_DONE;
+ BUG_ON(dev->ml_priv);
+ dev->ml_priv = d;
+
+ break;
+
+ case NETDEV_UNREGISTER:
+ spin_lock(&can_rcvlists_lock);
+
+ d = dev->ml_priv;
+ if (d) {
+ if (d->entries)
+ d->remove_on_zero_entries = 1;
+ else {
+ kfree(d);
+ dev->ml_priv = NULL;
+ }
+ } else
+ pr_err("can: notifier: receive list not found for dev "
+ "%s\n", dev->name);
+
+ spin_unlock(&can_rcvlists_lock);
+
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * af_can module init/exit functions
+ */
+
+static struct packet_type can_packet __read_mostly = {
+ .type = cpu_to_be16(ETH_P_CAN),
+ .func = can_rcv,
+};
+
+static struct packet_type canfd_packet __read_mostly = {
+ .type = cpu_to_be16(ETH_P_CANFD),
+ .func = canfd_rcv,
+};
+
+static const struct net_proto_family can_family_ops = {
+ .family = PF_CAN,
+ .create = can_create,
+ .owner = THIS_MODULE,
+};
+
+/* notifier block for netdevice event */
+static struct notifier_block can_netdev_notifier __read_mostly = {
+ .notifier_call = can_notifier,
+};
+
+static __init int can_init(void)
+{
+ /* check for correct padding to be able to use the structs similarly */
+ BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
+ offsetof(struct canfd_frame, len) ||
+ offsetof(struct can_frame, data) !=
+ offsetof(struct canfd_frame, data));
+
+ pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");
+
+ memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
+
+ rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
+ 0, 0, NULL);
+ if (!rcv_cache)
+ return -ENOMEM;
+
+ if (stats_timer) {
+ /* the statistics are updated every second (timer triggered) */
+ setup_timer(&can_stattimer, can_stat_update, 0);
+ mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
+ } else
+ can_stattimer.function = NULL;
+
+ can_init_proc();
+
+ /* protocol register */
+ sock_register(&can_family_ops);
+ register_netdevice_notifier(&can_netdev_notifier);
+ dev_add_pack(&can_packet);
+ dev_add_pack(&canfd_packet);
+
+ return 0;
+}
+
+static __exit void can_exit(void)
+{
+ struct net_device *dev;
+
+ if (stats_timer)
+ del_timer_sync(&can_stattimer);
+
+ can_remove_proc();
+
+ /* protocol unregister */
+ dev_remove_pack(&canfd_packet);
+ dev_remove_pack(&can_packet);
+ unregister_netdevice_notifier(&can_netdev_notifier);
+ sock_unregister(PF_CAN);
+
+ /* remove created dev_rcv_lists from still registered CAN devices */
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
+ if (dev->type == ARPHRD_CAN && dev->ml_priv) {
+
+ struct dev_rcv_lists *d = dev->ml_priv;
+
+ BUG_ON(d->entries);
+ kfree(d);
+ dev->ml_priv = NULL;
+ }
+ }
+ rcu_read_unlock();
+
+ rcu_barrier(); /* Wait for completion of call_rcu()'s */
+
+ kmem_cache_destroy(rcv_cache);
+}
+
+module_init(can_init);
+module_exit(can_exit);
Code Review / kvmfornfv.git / blobdiff