| /* |
| * 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) |
| 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); |