diff options
Diffstat (limited to 'net/can')
| -rw-r--r-- | net/can/Kconfig | 56 | ||||
| -rw-r--r-- | net/can/Makefile | 17 | ||||
| -rw-r--r-- | net/can/af_can.c | 1038 | ||||
| -rw-r--r-- | net/can/af_can.h | 118 | ||||
| -rw-r--r-- | net/can/bcm.c | 1752 | ||||
| -rw-r--r-- | net/can/gw.c | 1111 | ||||
| -rw-r--r-- | net/can/proc.c | 501 | ||||
| -rw-r--r-- | net/can/raw.c | 942 |
8 files changed, 5535 insertions, 0 deletions
diff --git a/net/can/Kconfig b/net/can/Kconfig new file mode 100644 index 000000000..a4399be54 --- /dev/null +++ b/net/can/Kconfig @@ -0,0 +1,56 @@ +# +# Controller Area Network (CAN) network layer core configuration +# + +menuconfig CAN + depends on NET + tristate "CAN bus subsystem support" + ---help--- + Controller Area Network (CAN) is a slow (up to 1Mbit/s) serial + communications protocol which was developed by Bosch in + 1991, mainly for automotive, but now widely used in marine + (NMEA2000), industrial, and medical applications. + More information on the CAN network protocol family PF_CAN + is contained in <Documentation/networking/can.rst>. + + If you want CAN support you should say Y here and also to the + specific driver for your controller(s) below. + +if CAN + +config CAN_RAW + tristate "Raw CAN Protocol (raw access with CAN-ID filtering)" + default y + ---help--- + The raw CAN protocol option offers access to the CAN bus via + the BSD socket API. You probably want to use the raw socket in + most cases where no higher level protocol is being used. The raw + socket has several filter options e.g. ID masking / error frames. + To receive/send raw CAN messages, use AF_CAN with protocol CAN_RAW. + +config CAN_BCM + tristate "Broadcast Manager CAN Protocol (with content filtering)" + default y + ---help--- + The Broadcast Manager offers content filtering, timeout monitoring, + sending of RTR frames, and cyclic CAN messages without permanent user + interaction. The BCM can be 'programmed' via the BSD socket API and + informs you on demand e.g. only on content updates / timeouts. + You probably want to use the bcm socket in most cases where cyclic + CAN messages are used on the bus (e.g. in automotive environments). + To use the Broadcast Manager, use AF_CAN with protocol CAN_BCM. + +config CAN_GW + tristate "CAN Gateway/Router (with netlink configuration)" + default y + ---help--- + The CAN Gateway/Router is used to route (and modify) CAN frames. + It is based on the PF_CAN core infrastructure for msg filtering and + msg sending and can optionally modify routed CAN frames on the fly. + CAN frames can be routed between CAN network interfaces (one hop). + They can be modified with AND/OR/XOR/SET operations as configured + by the netlink configuration interface known e.g. from iptables. + +source "drivers/net/can/Kconfig" + +endif diff --git a/net/can/Makefile b/net/can/Makefile new file mode 100644 index 000000000..1242bbbfe --- /dev/null +++ b/net/can/Makefile @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the Linux Controller Area Network core. +# + +obj-$(CONFIG_CAN) += can.o +can-y := af_can.o +can-$(CONFIG_PROC_FS) += proc.o + +obj-$(CONFIG_CAN_RAW) += can-raw.o +can-raw-y := raw.o + +obj-$(CONFIG_CAN_BCM) += can-bcm.o +can-bcm-y := bcm.o + +obj-$(CONFIG_CAN_GW) += can-gw.o +can-gw-y := gw.o diff --git a/net/can/af_can.c b/net/can/af_can.c new file mode 100644 index 000000000..b3edb8092 --- /dev/null +++ b/net/can/af_can.c @@ -0,0 +1,1038 @@ +/* + * af_can.c - Protocol family CAN core module + * (used by different CAN protocol modules) + * + * 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/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, 0444); +MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); + +static struct kmem_cache *rcv_cache __read_mostly; + +/* table of registered CAN protocols */ +static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly; +static DEFINE_MUTEX(proto_tab_lock); + +static atomic_t skbcounter = ATOMIC_INIT(0); + +/* + * 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); + skb_queue_purge(&sk->sk_error_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; + + 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, kern); + 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; + struct s_stats *can_stats = dev_net(skb->dev)->can.can_stats; + 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 can_dev_rcv_lists *find_dev_rcv_lists(struct net *net, + struct net_device *dev) +{ + if (!dev) + return net->can.can_rx_alldev_list; + else + return (struct can_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 can_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 + * @sk: socket pointer (might be NULL) + * + * 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 *net, struct net_device *dev, canid_t can_id, + canid_t mask, void (*func)(struct sk_buff *, void *), + void *data, char *ident, struct sock *sk) +{ + struct receiver *r; + struct hlist_head *rl; + struct can_dev_rcv_lists *d; + struct s_pstats *can_pstats = net->can.can_pstats; + int err = 0; + + /* insert new receiver (dev,canid,mask) -> (func,data) */ + + if (dev && dev->type != ARPHRD_CAN) + return -ENODEV; + + if (dev && !net_eq(net, dev_net(dev))) + return -ENODEV; + + r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); + if (!r) + return -ENOMEM; + + spin_lock(&net->can.can_rcvlists_lock); + + d = find_dev_rcv_lists(net, 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; + r->sk = sk; + + 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(&net->can.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); + struct sock *sk = r->sk; + + kmem_cache_free(rcv_cache, r); + if (sk) + sock_put(sk); +} + +/** + * 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 *net, 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 s_pstats *can_pstats = net->can.can_pstats; + struct can_dev_rcv_lists *d; + + if (dev && dev->type != ARPHRD_CAN) + return; + + if (dev && !net_eq(net, dev_net(dev))) + return; + + spin_lock(&net->can.can_rcvlists_lock); + + d = find_dev_rcv_lists(net, 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(&net->can.can_rcvlists_lock); + + /* schedule the receiver item for deletion */ + if (r) { + if (r->sk) + sock_hold(r->sk); + 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 can_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 can_dev_rcv_lists *d; + struct net *net = dev_net(dev); + struct s_stats *can_stats = net->can.can_stats; + int matches; + + /* update statistics */ + can_stats->rx_frames++; + can_stats->rx_frames_delta++; + + /* create non-zero unique skb identifier together with *skb */ + while (!(can_skb_prv(skb)->skbcnt)) + can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); + + rcu_read_lock(); + + /* deliver the packet to sockets listening on all devices */ + matches = can_rcv_filter(net->can.can_rx_alldev_list, skb); + + /* find receive list for this device */ + d = find_dev_rcv_lists(net, 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(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) { + pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", + dev->type, skb->len); + goto free_skb; + } + + /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */ + if (unlikely(cfd->len > CAN_MAX_DLEN)) { + pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n", + dev->type, skb->len, cfd->len); + goto free_skb; + } + + can_receive(skb, dev); + return NET_RX_SUCCESS; + +free_skb: + 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(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) { + pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", + dev->type, skb->len); + goto free_skb; + } + + /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */ + if (unlikely(cfd->len > CANFD_MAX_DLEN)) { + pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n", + dev->type, skb->len, cfd->len); + goto free_skb; + } + + can_receive(skb, dev); + return NET_RX_SUCCESS; + +free_skb: + 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 (rcu_access_pointer(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(rcu_access_pointer(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 can_dev_rcv_lists *d; + + 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(&dev_net(dev)->can.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(&dev_net(dev)->can.can_rcvlists_lock); + + break; + } + + return NOTIFY_DONE; +} + +static int can_pernet_init(struct net *net) +{ + spin_lock_init(&net->can.can_rcvlists_lock); + net->can.can_rx_alldev_list = + kzalloc(sizeof(struct can_dev_rcv_lists), GFP_KERNEL); + if (!net->can.can_rx_alldev_list) + goto out; + net->can.can_stats = kzalloc(sizeof(struct s_stats), GFP_KERNEL); + if (!net->can.can_stats) + goto out_free_alldev_list; + net->can.can_pstats = kzalloc(sizeof(struct s_pstats), GFP_KERNEL); + if (!net->can.can_pstats) + goto out_free_can_stats; + + if (IS_ENABLED(CONFIG_PROC_FS)) { + /* the statistics are updated every second (timer triggered) */ + if (stats_timer) { + timer_setup(&net->can.can_stattimer, can_stat_update, + 0); + mod_timer(&net->can.can_stattimer, + round_jiffies(jiffies + HZ)); + } + net->can.can_stats->jiffies_init = jiffies; + can_init_proc(net); + } + + return 0; + + out_free_can_stats: + kfree(net->can.can_stats); + out_free_alldev_list: + kfree(net->can.can_rx_alldev_list); + out: + return -ENOMEM; +} + +static void can_pernet_exit(struct net *net) +{ + struct net_device *dev; + + if (IS_ENABLED(CONFIG_PROC_FS)) { + can_remove_proc(net); + if (stats_timer) + del_timer_sync(&net->can.can_stattimer); + } + + /* remove created dev_rcv_lists from still registered CAN devices */ + rcu_read_lock(); + for_each_netdev_rcu(net, dev) { + if (dev->type == ARPHRD_CAN && dev->ml_priv) { + struct can_dev_rcv_lists *d = dev->ml_priv; + + BUG_ON(d->entries); + kfree(d); + dev->ml_priv = NULL; + } + } + rcu_read_unlock(); + + kfree(net->can.can_rx_alldev_list); + kfree(net->can.can_stats); + kfree(net->can.can_pstats); +} + +/* + * 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 struct pernet_operations can_pernet_ops __read_mostly = { + .init = can_pernet_init, + .exit = can_pernet_exit, +}; + +static __init int can_init(void) +{ + int err; + + /* 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"); + + rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), + 0, 0, NULL); + if (!rcv_cache) + return -ENOMEM; + + err = register_pernet_subsys(&can_pernet_ops); + if (err) + goto out_pernet; + + /* protocol register */ + err = sock_register(&can_family_ops); + if (err) + goto out_sock; + err = register_netdevice_notifier(&can_netdev_notifier); + if (err) + goto out_notifier; + + dev_add_pack(&can_packet); + dev_add_pack(&canfd_packet); + + return 0; + +out_notifier: + sock_unregister(PF_CAN); +out_sock: + unregister_pernet_subsys(&can_pernet_ops); +out_pernet: + kmem_cache_destroy(rcv_cache); + + return err; +} + +static __exit void can_exit(void) +{ + /* protocol unregister */ + dev_remove_pack(&canfd_packet); + dev_remove_pack(&can_packet); + unregister_netdevice_notifier(&can_netdev_notifier); + sock_unregister(PF_CAN); + + unregister_pernet_subsys(&can_pernet_ops); + + rcu_barrier(); /* Wait for completion of call_rcu()'s */ + + kmem_cache_destroy(rcv_cache); +} + +module_init(can_init); +module_exit(can_exit); diff --git a/net/can/af_can.h b/net/can/af_can.h new file mode 100644 index 000000000..9cb371963 --- /dev/null +++ b/net/can/af_can.h @@ -0,0 +1,118 @@ +/* + * 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. + * + */ + +#ifndef AF_CAN_H +#define AF_CAN_H + +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/can.h> + +/* af_can rx dispatcher structures */ + +struct receiver { + struct hlist_node list; + canid_t can_id; + canid_t mask; + unsigned long matches; + void (*func)(struct sk_buff *, void *); + void *data; + char *ident; + struct sock *sk; + struct rcu_head rcu; +}; + +#define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS) +#define CAN_EFF_RCV_HASH_BITS 10 +#define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS) + +enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_MAX }; + +/* per device receive filters linked at dev->ml_priv */ +struct can_dev_rcv_lists { + struct hlist_head rx[RX_MAX]; + struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ]; + struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ]; + int remove_on_zero_entries; + int entries; +}; + +/* statistic structures */ + +/* can be reset e.g. by can_init_stats() */ +struct s_stats { + unsigned long jiffies_init; + + unsigned long rx_frames; + unsigned long tx_frames; + unsigned long matches; + + unsigned long total_rx_rate; + unsigned long total_tx_rate; + unsigned long total_rx_match_ratio; + + unsigned long current_rx_rate; + unsigned long current_tx_rate; + unsigned long current_rx_match_ratio; + + unsigned long max_rx_rate; + unsigned long max_tx_rate; + unsigned long max_rx_match_ratio; + + unsigned long rx_frames_delta; + unsigned long tx_frames_delta; + unsigned long matches_delta; +}; + +/* persistent statistics */ +struct s_pstats { + unsigned long stats_reset; + unsigned long user_reset; + unsigned long rcv_entries; + unsigned long rcv_entries_max; +}; + +/* function prototypes for the CAN networklayer procfs (proc.c) */ +void can_init_proc(struct net *net); +void can_remove_proc(struct net *net); +void can_stat_update(struct timer_list *t); + +#endif /* AF_CAN_H */ diff --git a/net/can/bcm.c b/net/can/bcm.c new file mode 100644 index 000000000..353098166 --- /dev/null +++ b/net/can/bcm.c @@ -0,0 +1,1752 @@ +/* + * 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)) + +#define CAN_BCM_VERSION "20170425" + +MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); +MODULE_ALIAS("can-proto-2"); + +/* + * easy access to 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; + 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; + + /* 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); + can_send(skb, 1); + + /* update statistics */ + op->currframe++; + op->frames_abs++; + + /* reached last frame? */ + if (op->currframe >= op->nframes) + op->currframe = 0; +out: + dev_put(dev); +} + +/* + * bcm_send_to_user - send a BCM message to the userspace + * (consisting of bcm_msg_head + x CAN frames) + */ +static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, + struct 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(hrtimer, ktime_get(), 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 (skb->len != op->cfsiz) + 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_remove_op(struct bcm_op *op) +{ + hrtimer_cancel(&op->timer); + hrtimer_cancel(&op->thrtimer); + + if ((op->frames) && (op->frames != &op->sframe)) + kfree(op->frames); + + if ((op->last_frames) && (op->last_frames != &op->last_sframe)) + kfree(op->last_frames); + + kfree(op); +} + +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)) { + + /* + * 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); + synchronize_rcu(); + 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 (op->flags & CAN_FD_FRAME) { + if (cf->len > 64) + err = -EINVAL; + } else { + if (cf->len > 8) + err = -EINVAL; + } + + if (err < 0) { + if (op->frames != &op->sframe) + kfree(op->frames); + kfree(op); + return err; + } + + if (msg_head->flags & TX_CP_CAN_ID) { + /* copy can_id into frame */ + 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; +} + +/* + * 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 < sizeof(*addr)) + return -EINVAL; + + if (addr->can_family != AF_CAN) + return -EINVAL; + + /* ifindex from sendto() */ + ifindex = addr->can_ifindex; + + if (ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(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->sk_error_report(sk); + } + break; + + case NETDEV_DOWN: + if (bo->bound && bo->ifindex == dev->ifindex) { + sk->sk_err = ENETDOWN; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); + } + } +} + +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); + + 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); + +#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 */ + + /* 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 < sizeof(*addr)) + 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 noblock; + int err; + + noblock = flags & MSG_DONTWAIT; + flags &= ~MSG_DONTWAIT; + skb = skb_recv_datagram(sk, flags, noblock, &error); + if (!skb) + return error; + + if (skb->len < size) + size = skb->len; + + err = memcpy_to_msg(msg, skb->data, size); + if (err < 0) { + skb_free_datagram(sk, skb); + return err; + } + + sock_recv_ts_and_drops(msg, sk, skb); + + if (msg->msg_name) { + __sockaddr_check_size(sizeof(struct sockaddr_can)); + msg->msg_namelen = sizeof(struct sockaddr_can); + memcpy(msg->msg_name, skb->cb, msg->msg_namelen); + } + + skb_free_datagram(sk, skb); + + return size; +} + +static const struct proto_ops bcm_ops = { + .family = PF_CAN, + .release = bcm_release, + .bind = sock_no_bind, + .connect = bcm_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = datagram_poll, + .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = sock_no_setsockopt, + .getsockopt = sock_no_getsockopt, + .sendmsg = bcm_sendmsg, + .recvmsg = bcm_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static struct proto bcm_proto __read_mostly = { + .name = "CAN_BCM", + .owner = THIS_MODULE, + .obj_size = sizeof(struct bcm_sock), + .init = bcm_init, +}; + +static const struct can_proto bcm_can_proto = { + .type = SOCK_DGRAM, + .protocol = CAN_BCM, + .ops = &bcm_ops, + .prot = &bcm_proto, +}; + +static int 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 (rev " CAN_BCM_VERSION " t)\n"); + + err = can_proto_register(&bcm_can_proto); + if (err < 0) { + printk(KERN_ERR "can: registration of bcm protocol failed\n"); + return err; + } + + register_pernet_subsys(&canbcm_pernet_ops); + register_netdevice_notifier(&canbcm_notifier); + return 0; +} + +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); diff --git a/net/can/gw.c b/net/can/gw.c new file mode 100644 index 000000000..9c2066323 --- /dev/null +++ b/net/can/gw.c @@ -0,0 +1,1111 @@ +/* + * gw.c - CAN frame Gateway/Router/Bridge with netlink interface + * + * Copyright (c) 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/types.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/rculist.h> +#include <linux/net.h> +#include <linux/netdevice.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/gw.h> +#include <net/rtnetlink.h> +#include <net/net_namespace.h> +#include <net/sock.h> + +#define CAN_GW_VERSION "20170425" +#define CAN_GW_NAME "can-gw" + +MODULE_DESCRIPTION("PF_CAN netlink gateway"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); +MODULE_ALIAS(CAN_GW_NAME); + +#define CGW_MIN_HOPS 1 +#define CGW_MAX_HOPS 6 +#define CGW_DEFAULT_HOPS 1 + +static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS; +module_param(max_hops, uint, 0444); +MODULE_PARM_DESC(max_hops, + "maximum " CAN_GW_NAME " routing hops for CAN frames " + "(valid values: " __stringify(CGW_MIN_HOPS) "-" + __stringify(CGW_MAX_HOPS) " hops, " + "default: " __stringify(CGW_DEFAULT_HOPS) ")"); + +static struct notifier_block notifier; +static struct kmem_cache *cgw_cache __read_mostly; + +/* structure that contains the (on-the-fly) CAN frame modifications */ +struct cf_mod { + struct { + struct can_frame and; + struct can_frame or; + struct can_frame xor; + struct can_frame set; + } modframe; + struct { + u8 and; + u8 or; + u8 xor; + u8 set; + } modtype; + void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf, + struct cf_mod *mod); + + /* CAN frame checksum calculation after CAN frame modifications */ + struct { + struct cgw_csum_xor xor; + struct cgw_csum_crc8 crc8; + } csum; + struct { + void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor); + void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8); + } csumfunc; + u32 uid; +}; + + +/* + * So far we just support CAN -> CAN routing and frame modifications. + * + * The internal can_can_gw structure contains data and attributes for + * a CAN -> CAN gateway job. + */ +struct can_can_gw { + struct can_filter filter; + int src_idx; + int dst_idx; +}; + +/* list entry for CAN gateways jobs */ +struct cgw_job { + struct hlist_node list; + struct rcu_head rcu; + u32 handled_frames; + u32 dropped_frames; + u32 deleted_frames; + struct cf_mod mod; + union { + /* CAN frame data source */ + struct net_device *dev; + } src; + union { + /* CAN frame data destination */ + struct net_device *dev; + } dst; + union { + struct can_can_gw ccgw; + /* tbc */ + }; + u8 gwtype; + u8 limit_hops; + u16 flags; +}; + +/* modification functions that are invoked in the hot path in can_can_gw_rcv */ + +#define MODFUNC(func, op) static void func(struct can_frame *cf, \ + struct cf_mod *mod) { op ; } + +MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id) +MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc) +MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data) +MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id) +MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc) +MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data) +MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id) +MODFUNC(mod_xor_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc) +MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data) +MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id) +MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc) +MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data) + +static inline void canframecpy(struct can_frame *dst, struct can_frame *src) +{ + /* + * Copy the struct members separately to ensure that no uninitialized + * data are copied in the 3 bytes hole of the struct. This is needed + * to make easy compares of the data in the struct cf_mod. + */ + + dst->can_id = src->can_id; + dst->can_dlc = src->can_dlc; + *(u64 *)dst->data = *(u64 *)src->data; +} + +static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re) +{ + /* + * absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0] + * relative to received dlc -1 .. -8 : + * e.g. for received dlc = 8 + * -1 => index = 7 (data[7]) + * -3 => index = 5 (data[5]) + * -8 => index = 0 (data[0]) + */ + + if (fr > -9 && fr < 8 && + to > -9 && to < 8 && + re > -9 && re < 8) + return 0; + else + return -EINVAL; +} + +static inline int calc_idx(int idx, int rx_dlc) +{ + if (idx < 0) + return rx_dlc + idx; + else + return idx; +} + +static void cgw_csum_xor_rel(struct can_frame *cf, struct cgw_csum_xor *xor) +{ + int from = calc_idx(xor->from_idx, cf->can_dlc); + int to = calc_idx(xor->to_idx, cf->can_dlc); + int res = calc_idx(xor->result_idx, cf->can_dlc); + u8 val = xor->init_xor_val; + int i; + + if (from < 0 || to < 0 || res < 0) + return; + + if (from <= to) { + for (i = from; i <= to; i++) + val ^= cf->data[i]; + } else { + for (i = from; i >= to; i--) + val ^= cf->data[i]; + } + + cf->data[res] = val; +} + +static void cgw_csum_xor_pos(struct can_frame *cf, struct cgw_csum_xor *xor) +{ + u8 val = xor->init_xor_val; + int i; + + for (i = xor->from_idx; i <= xor->to_idx; i++) + val ^= cf->data[i]; + + cf->data[xor->result_idx] = val; +} + +static void cgw_csum_xor_neg(struct can_frame *cf, struct cgw_csum_xor *xor) +{ + u8 val = xor->init_xor_val; + int i; + + for (i = xor->from_idx; i >= xor->to_idx; i--) + val ^= cf->data[i]; + + cf->data[xor->result_idx] = val; +} + +static void cgw_csum_crc8_rel(struct can_frame *cf, struct cgw_csum_crc8 *crc8) +{ + int from = calc_idx(crc8->from_idx, cf->can_dlc); + int to = calc_idx(crc8->to_idx, cf->can_dlc); + int res = calc_idx(crc8->result_idx, cf->can_dlc); + u8 crc = crc8->init_crc_val; + int i; + + if (from < 0 || to < 0 || res < 0) + return; + + if (from <= to) { + for (i = crc8->from_idx; i <= crc8->to_idx; i++) + crc = crc8->crctab[crc^cf->data[i]]; + } else { + for (i = crc8->from_idx; i >= crc8->to_idx; i--) + crc = crc8->crctab[crc^cf->data[i]]; + } + + switch (crc8->profile) { + + case CGW_CRC8PRF_1U8: + crc = crc8->crctab[crc^crc8->profile_data[0]]; + break; + + case CGW_CRC8PRF_16U8: + crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]]; + break; + + case CGW_CRC8PRF_SFFID_XOR: + crc = crc8->crctab[crc^(cf->can_id & 0xFF)^ + (cf->can_id >> 8 & 0xFF)]; + break; + + } + + cf->data[crc8->result_idx] = crc^crc8->final_xor_val; +} + +static void cgw_csum_crc8_pos(struct can_frame *cf, struct cgw_csum_crc8 *crc8) +{ + u8 crc = crc8->init_crc_val; + int i; + + for (i = crc8->from_idx; i <= crc8->to_idx; i++) + crc = crc8->crctab[crc^cf->data[i]]; + + switch (crc8->profile) { + + case CGW_CRC8PRF_1U8: + crc = crc8->crctab[crc^crc8->profile_data[0]]; + break; + + case CGW_CRC8PRF_16U8: + crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]]; + break; + + case CGW_CRC8PRF_SFFID_XOR: + crc = crc8->crctab[crc^(cf->can_id & 0xFF)^ + (cf->can_id >> 8 & 0xFF)]; + break; + } + + cf->data[crc8->result_idx] = crc^crc8->final_xor_val; +} + +static void cgw_csum_crc8_neg(struct can_frame *cf, struct cgw_csum_crc8 *crc8) +{ + u8 crc = crc8->init_crc_val; + int i; + + for (i = crc8->from_idx; i >= crc8->to_idx; i--) + crc = crc8->crctab[crc^cf->data[i]]; + + switch (crc8->profile) { + + case CGW_CRC8PRF_1U8: + crc = crc8->crctab[crc^crc8->profile_data[0]]; + break; + + case CGW_CRC8PRF_16U8: + crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]]; + break; + + case CGW_CRC8PRF_SFFID_XOR: + crc = crc8->crctab[crc^(cf->can_id & 0xFF)^ + (cf->can_id >> 8 & 0xFF)]; + break; + } + + cf->data[crc8->result_idx] = crc^crc8->final_xor_val; +} + +/* the receive & process & send function */ +static void can_can_gw_rcv(struct sk_buff *skb, void *data) +{ + struct cgw_job *gwj = (struct cgw_job *)data; + struct can_frame *cf; + struct sk_buff *nskb; + int modidx = 0; + + /* + * Do not handle CAN frames routed more than 'max_hops' times. + * In general we should never catch this delimiter which is intended + * to cover a misconfiguration protection (e.g. circular CAN routes). + * + * The Controller Area Network controllers only accept CAN frames with + * correct CRCs - which are not visible in the controller registers. + * According to skbuff.h documentation the csum_start element for IP + * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY. + * Only CAN skbs can be processed here which already have this property. + */ + +#define cgw_hops(skb) ((skb)->csum_start) + + BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY); + + if (cgw_hops(skb) >= max_hops) { + /* indicate deleted frames due to misconfiguration */ + gwj->deleted_frames++; + return; + } + + if (!(gwj->dst.dev->flags & IFF_UP)) { + gwj->dropped_frames++; + return; + } + + /* is sending the skb back to the incoming interface not allowed? */ + if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && + can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex) + return; + + /* + * clone the given skb, which has not been done in can_rcv() + * + * When there is at least one modification function activated, + * we need to copy the skb as we want to modify skb->data. + */ + if (gwj->mod.modfunc[0]) + nskb = skb_copy(skb, GFP_ATOMIC); + else + nskb = skb_clone(skb, GFP_ATOMIC); + + if (!nskb) { + gwj->dropped_frames++; + return; + } + + /* put the incremented hop counter in the cloned skb */ + cgw_hops(nskb) = cgw_hops(skb) + 1; + + /* first processing of this CAN frame -> adjust to private hop limit */ + if (gwj->limit_hops && cgw_hops(nskb) == 1) + cgw_hops(nskb) = max_hops - gwj->limit_hops + 1; + + nskb->dev = gwj->dst.dev; + + /* pointer to modifiable CAN frame */ + cf = (struct can_frame *)nskb->data; + + /* perform preprocessed modification functions if there are any */ + while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx]) + (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod); + + /* Has the CAN frame been modified? */ + if (modidx) { + /* get available space for the processed CAN frame type */ + int max_len = nskb->len - offsetof(struct can_frame, data); + + /* dlc may have changed, make sure it fits to the CAN frame */ + if (cf->can_dlc > max_len) + goto out_delete; + + /* check for checksum updates in classic CAN length only */ + if (gwj->mod.csumfunc.crc8) { + if (cf->can_dlc > 8) + goto out_delete; + + (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8); + } + + if (gwj->mod.csumfunc.xor) { + if (cf->can_dlc > 8) + goto out_delete; + + (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor); + } + } + + /* clear the skb timestamp if not configured the other way */ + if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP)) + nskb->tstamp = 0; + + /* send to netdevice */ + if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO)) + gwj->dropped_frames++; + else + gwj->handled_frames++; + + return; + + out_delete: + /* delete frame due to misconfiguration */ + gwj->deleted_frames++; + kfree_skb(nskb); + return; +} + +static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj) +{ + return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id, + gwj->ccgw.filter.can_mask, can_can_gw_rcv, + gwj, "gw", NULL); +} + +static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj) +{ + can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id, + gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj); +} + +static int cgw_notifier(struct notifier_block *nb, + unsigned long msg, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + + if (dev->type != ARPHRD_CAN) + return NOTIFY_DONE; + + if (msg == NETDEV_UNREGISTER) { + + struct cgw_job *gwj = NULL; + struct hlist_node *nx; + + ASSERT_RTNL(); + + hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { + + if (gwj->src.dev == dev || gwj->dst.dev == dev) { + hlist_del(&gwj->list); + cgw_unregister_filter(net, gwj); + synchronize_rcu(); + kmem_cache_free(cgw_cache, gwj); + } + } + } + + return NOTIFY_DONE; +} + +static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type, + u32 pid, u32 seq, int flags) +{ + struct cgw_frame_mod mb; + struct rtcanmsg *rtcan; + struct nlmsghdr *nlh; + + nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags); + if (!nlh) + return -EMSGSIZE; + + rtcan = nlmsg_data(nlh); + rtcan->can_family = AF_CAN; + rtcan->gwtype = gwj->gwtype; + rtcan->flags = gwj->flags; + + /* add statistics if available */ + + if (gwj->handled_frames) { + if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0) + goto cancel; + } + + if (gwj->dropped_frames) { + if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0) + goto cancel; + } + + if (gwj->deleted_frames) { + if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0) + goto cancel; + } + + /* check non default settings of attributes */ + + if (gwj->limit_hops) { + if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0) + goto cancel; + } + + if (gwj->mod.modtype.and) { + memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); + mb.modtype = gwj->mod.modtype.and; + if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0) + goto cancel; + } + + if (gwj->mod.modtype.or) { + memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); + mb.modtype = gwj->mod.modtype.or; + if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0) + goto cancel; + } + + if (gwj->mod.modtype.xor) { + memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); + mb.modtype = gwj->mod.modtype.xor; + if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0) + goto cancel; + } + + if (gwj->mod.modtype.set) { + memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); + mb.modtype = gwj->mod.modtype.set; + if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0) + goto cancel; + } + + if (gwj->mod.uid) { + if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0) + goto cancel; + } + + if (gwj->mod.csumfunc.crc8) { + if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN, + &gwj->mod.csum.crc8) < 0) + goto cancel; + } + + if (gwj->mod.csumfunc.xor) { + if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN, + &gwj->mod.csum.xor) < 0) + goto cancel; + } + + if (gwj->gwtype == CGW_TYPE_CAN_CAN) { + + if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) { + if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter), + &gwj->ccgw.filter) < 0) + goto cancel; + } + + if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0) + goto cancel; + + if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0) + goto cancel; + } + + nlmsg_end(skb, nlh); + return 0; + +cancel: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +/* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */ +static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + struct cgw_job *gwj = NULL; + int idx = 0; + int s_idx = cb->args[0]; + + rcu_read_lock(); + hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) { + if (idx < s_idx) + goto cont; + + if (cgw_put_job(skb, gwj, RTM_NEWROUTE, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0) + break; +cont: + idx++; + } + rcu_read_unlock(); + + cb->args[0] = idx; + + return skb->len; +} + +static const struct nla_policy cgw_policy[CGW_MAX+1] = { + [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) }, + [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) }, + [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) }, + [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) }, + [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) }, + [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) }, + [CGW_SRC_IF] = { .type = NLA_U32 }, + [CGW_DST_IF] = { .type = NLA_U32 }, + [CGW_FILTER] = { .len = sizeof(struct can_filter) }, + [CGW_LIM_HOPS] = { .type = NLA_U8 }, + [CGW_MOD_UID] = { .type = NLA_U32 }, +}; + +/* check for common and gwtype specific attributes */ +static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, + u8 gwtype, void *gwtypeattr, u8 *limhops) +{ + struct nlattr *tb[CGW_MAX+1]; + struct cgw_frame_mod mb; + int modidx = 0; + int err = 0; + + /* initialize modification & checksum data space */ + memset(mod, 0, sizeof(*mod)); + + err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, + cgw_policy, NULL); + if (err < 0) + return err; + + if (tb[CGW_LIM_HOPS]) { + *limhops = nla_get_u8(tb[CGW_LIM_HOPS]); + + if (*limhops < 1 || *limhops > max_hops) + return -EINVAL; + } + + /* check for AND/OR/XOR/SET modifications */ + + if (tb[CGW_MOD_AND]) { + nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN); + + canframecpy(&mod->modframe.and, &mb.cf); + mod->modtype.and = mb.modtype; + + if (mb.modtype & CGW_MOD_ID) + mod->modfunc[modidx++] = mod_and_id; + + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_and_dlc; + + if (mb.modtype & CGW_MOD_DATA) + mod->modfunc[modidx++] = mod_and_data; + } + + if (tb[CGW_MOD_OR]) { + nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN); + + canframecpy(&mod->modframe.or, &mb.cf); + mod->modtype.or = mb.modtype; + + if (mb.modtype & CGW_MOD_ID) + mod->modfunc[modidx++] = mod_or_id; + + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_or_dlc; + + if (mb.modtype & CGW_MOD_DATA) + mod->modfunc[modidx++] = mod_or_data; + } + + if (tb[CGW_MOD_XOR]) { + nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN); + + canframecpy(&mod->modframe.xor, &mb.cf); + mod->modtype.xor = mb.modtype; + + if (mb.modtype & CGW_MOD_ID) + mod->modfunc[modidx++] = mod_xor_id; + + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_xor_dlc; + + if (mb.modtype & CGW_MOD_DATA) + mod->modfunc[modidx++] = mod_xor_data; + } + + if (tb[CGW_MOD_SET]) { + nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN); + + canframecpy(&mod->modframe.set, &mb.cf); + mod->modtype.set = mb.modtype; + + if (mb.modtype & CGW_MOD_ID) + mod->modfunc[modidx++] = mod_set_id; + + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_set_dlc; + + if (mb.modtype & CGW_MOD_DATA) + mod->modfunc[modidx++] = mod_set_data; + } + + /* check for checksum operations after CAN frame modifications */ + if (modidx) { + + if (tb[CGW_CS_CRC8]) { + struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]); + + err = cgw_chk_csum_parms(c->from_idx, c->to_idx, + c->result_idx); + if (err) + return err; + + nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8], + CGW_CS_CRC8_LEN); + + /* + * select dedicated processing function to reduce + * runtime operations in receive hot path. + */ + if (c->from_idx < 0 || c->to_idx < 0 || + c->result_idx < 0) + mod->csumfunc.crc8 = cgw_csum_crc8_rel; + else if (c->from_idx <= c->to_idx) + mod->csumfunc.crc8 = cgw_csum_crc8_pos; + else + mod->csumfunc.crc8 = cgw_csum_crc8_neg; + } + + if (tb[CGW_CS_XOR]) { + struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]); + + err = cgw_chk_csum_parms(c->from_idx, c->to_idx, + c->result_idx); + if (err) + return err; + + nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR], + CGW_CS_XOR_LEN); + + /* + * select dedicated processing function to reduce + * runtime operations in receive hot path. + */ + if (c->from_idx < 0 || c->to_idx < 0 || + c->result_idx < 0) + mod->csumfunc.xor = cgw_csum_xor_rel; + else if (c->from_idx <= c->to_idx) + mod->csumfunc.xor = cgw_csum_xor_pos; + else + mod->csumfunc.xor = cgw_csum_xor_neg; + } + + if (tb[CGW_MOD_UID]) { + nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32)); + } + } + + if (gwtype == CGW_TYPE_CAN_CAN) { + + /* check CGW_TYPE_CAN_CAN specific attributes */ + + struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr; + memset(ccgw, 0, sizeof(*ccgw)); + + /* check for can_filter in attributes */ + if (tb[CGW_FILTER]) + nla_memcpy(&ccgw->filter, tb[CGW_FILTER], + sizeof(struct can_filter)); + + err = -ENODEV; + + /* specifying two interfaces is mandatory */ + if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF]) + return err; + + ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]); + ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]); + + /* both indices set to 0 for flushing all routing entries */ + if (!ccgw->src_idx && !ccgw->dst_idx) + return 0; + + /* only one index set to 0 is an error */ + if (!ccgw->src_idx || !ccgw->dst_idx) + return err; + } + + /* add the checks for other gwtypes here */ + + return 0; +} + +static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct rtcanmsg *r; + struct cgw_job *gwj; + struct cf_mod mod; + struct can_can_gw ccgw; + u8 limhops = 0; + int err = 0; + + if (!netlink_capable(skb, CAP_NET_ADMIN)) + return -EPERM; + + if (nlmsg_len(nlh) < sizeof(*r)) + return -EINVAL; + + r = nlmsg_data(nlh); + if (r->can_family != AF_CAN) + return -EPFNOSUPPORT; + + /* so far we only support CAN -> CAN routings */ + if (r->gwtype != CGW_TYPE_CAN_CAN) + return -EINVAL; + + err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); + if (err < 0) + return err; + + if (mod.uid) { + + ASSERT_RTNL(); + + /* check for updating an existing job with identical uid */ + hlist_for_each_entry(gwj, &net->can.cgw_list, list) { + + if (gwj->mod.uid != mod.uid) + continue; + + /* interfaces & filters must be identical */ + if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) + return -EINVAL; + + /* update modifications with disabled softirq & quit */ + local_bh_disable(); + memcpy(&gwj->mod, &mod, sizeof(mod)); + local_bh_enable(); + return 0; + } + } + + /* ifindex == 0 is not allowed for job creation */ + if (!ccgw.src_idx || !ccgw.dst_idx) + return -ENODEV; + + gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL); + if (!gwj) + return -ENOMEM; + + gwj->handled_frames = 0; + gwj->dropped_frames = 0; + gwj->deleted_frames = 0; + gwj->flags = r->flags; + gwj->gwtype = r->gwtype; + gwj->limit_hops = limhops; + + /* insert already parsed information */ + memcpy(&gwj->mod, &mod, sizeof(mod)); + memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw)); + + err = -ENODEV; + + gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx); + + if (!gwj->src.dev) + goto out; + + if (gwj->src.dev->type != ARPHRD_CAN) + goto out; + + gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx); + + if (!gwj->dst.dev) + goto out; + + if (gwj->dst.dev->type != ARPHRD_CAN) + goto out; + + ASSERT_RTNL(); + + err = cgw_register_filter(net, gwj); + if (!err) + hlist_add_head_rcu(&gwj->list, &net->can.cgw_list); +out: + if (err) + kmem_cache_free(cgw_cache, gwj); + + return err; +} + +static void cgw_remove_all_jobs(struct net *net) +{ + struct cgw_job *gwj = NULL; + struct hlist_node *nx; + + ASSERT_RTNL(); + + hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { + hlist_del(&gwj->list); + cgw_unregister_filter(net, gwj); + synchronize_rcu(); + kmem_cache_free(cgw_cache, gwj); + } +} + +static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct cgw_job *gwj = NULL; + struct hlist_node *nx; + struct rtcanmsg *r; + struct cf_mod mod; + struct can_can_gw ccgw; + u8 limhops = 0; + int err = 0; + + if (!netlink_capable(skb, CAP_NET_ADMIN)) + return -EPERM; + + if (nlmsg_len(nlh) < sizeof(*r)) + return -EINVAL; + + r = nlmsg_data(nlh); + if (r->can_family != AF_CAN) + return -EPFNOSUPPORT; + + /* so far we only support CAN -> CAN routings */ + if (r->gwtype != CGW_TYPE_CAN_CAN) + return -EINVAL; + + err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); + if (err < 0) + return err; + + /* two interface indices both set to 0 => remove all entries */ + if (!ccgw.src_idx && !ccgw.dst_idx) { + cgw_remove_all_jobs(net); + return 0; + } + + err = -EINVAL; + + ASSERT_RTNL(); + + /* remove only the first matching entry */ + hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { + + if (gwj->flags != r->flags) + continue; + + if (gwj->limit_hops != limhops) + continue; + + /* we have a match when uid is enabled and identical */ + if (gwj->mod.uid || mod.uid) { + if (gwj->mod.uid != mod.uid) + continue; + } else { + /* no uid => check for identical modifications */ + if (memcmp(&gwj->mod, &mod, sizeof(mod))) + continue; + } + + /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */ + if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) + continue; + + hlist_del(&gwj->list); + cgw_unregister_filter(net, gwj); + synchronize_rcu(); + kmem_cache_free(cgw_cache, gwj); + err = 0; + break; + } + + return err; +} + +static int __net_init cangw_pernet_init(struct net *net) +{ + INIT_HLIST_HEAD(&net->can.cgw_list); + return 0; +} + +static void __net_exit cangw_pernet_exit(struct net *net) +{ + rtnl_lock(); + cgw_remove_all_jobs(net); + rtnl_unlock(); +} + +static struct pernet_operations cangw_pernet_ops = { + .init = cangw_pernet_init, + .exit = cangw_pernet_exit, +}; + +static __init int cgw_module_init(void) +{ + int ret; + + /* sanitize given module parameter */ + max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS); + + pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n", + max_hops); + + ret = register_pernet_subsys(&cangw_pernet_ops); + if (ret) + return ret; + + ret = -ENOMEM; + cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job), + 0, 0, NULL); + if (!cgw_cache) + goto out_cache_create; + + /* set notifier */ + notifier.notifier_call = cgw_notifier; + ret = register_netdevice_notifier(¬ifier); + if (ret) + goto out_register_notifier; + + ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE, + NULL, cgw_dump_jobs, 0); + if (ret) + goto out_rtnl_register1; + + ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE, + cgw_create_job, NULL, 0); + if (ret) + goto out_rtnl_register2; + ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE, + cgw_remove_job, NULL, 0); + if (ret) + goto out_rtnl_register3; + + return 0; + +out_rtnl_register3: + rtnl_unregister(PF_CAN, RTM_NEWROUTE); +out_rtnl_register2: + rtnl_unregister(PF_CAN, RTM_GETROUTE); +out_rtnl_register1: + unregister_netdevice_notifier(¬ifier); +out_register_notifier: + kmem_cache_destroy(cgw_cache); +out_cache_create: + unregister_pernet_subsys(&cangw_pernet_ops); + + return ret; +} + +static __exit void cgw_module_exit(void) +{ + rtnl_unregister_all(PF_CAN); + + unregister_netdevice_notifier(¬ifier); + + unregister_pernet_subsys(&cangw_pernet_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ + + kmem_cache_destroy(cgw_cache); +} + +module_init(cgw_module_init); +module_exit(cgw_module_exit); diff --git a/net/can/proc.c b/net/can/proc.c new file mode 100644 index 000000000..a3071f43a --- /dev/null +++ b/net/can/proc.c @@ -0,0 +1,501 @@ +/* + * proc.c - procfs support for Protocol family CAN core module + * + * 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/proc_fs.h> +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/if_arp.h> +#include <linux/can/core.h> + +#include "af_can.h" + +/* + * proc filenames for the PF_CAN core + */ + +#define CAN_PROC_VERSION "version" +#define CAN_PROC_STATS "stats" +#define CAN_PROC_RESET_STATS "reset_stats" +#define CAN_PROC_RCVLIST_ALL "rcvlist_all" +#define CAN_PROC_RCVLIST_FIL "rcvlist_fil" +#define CAN_PROC_RCVLIST_INV "rcvlist_inv" +#define CAN_PROC_RCVLIST_SFF "rcvlist_sff" +#define CAN_PROC_RCVLIST_EFF "rcvlist_eff" +#define CAN_PROC_RCVLIST_ERR "rcvlist_err" + +static int user_reset; + +static const char rx_list_name[][8] = { + [RX_ERR] = "rx_err", + [RX_ALL] = "rx_all", + [RX_FIL] = "rx_fil", + [RX_INV] = "rx_inv", +}; + +/* + * af_can statistics stuff + */ + +static void can_init_stats(struct net *net) +{ + struct s_stats *can_stats = net->can.can_stats; + struct s_pstats *can_pstats = net->can.can_pstats; + /* + * This memset function is called from a timer context (when + * can_stattimer is active which is the default) OR in a process + * context (reading the proc_fs when can_stattimer is disabled). + */ + memset(can_stats, 0, sizeof(struct s_stats)); + can_stats->jiffies_init = jiffies; + + can_pstats->stats_reset++; + + if (user_reset) { + user_reset = 0; + can_pstats->user_reset++; + } +} + +static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif, + unsigned long count) +{ + unsigned long rate; + + if (oldjif == newjif) + return 0; + + /* see can_stat_update() - this should NEVER happen! */ + if (count > (ULONG_MAX / HZ)) { + printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n", + count); + return 99999999; + } + + rate = (count * HZ) / (newjif - oldjif); + + return rate; +} + +void can_stat_update(struct timer_list *t) +{ + struct net *net = from_timer(net, t, can.can_stattimer); + struct s_stats *can_stats = net->can.can_stats; + unsigned long j = jiffies; /* snapshot */ + + /* restart counting in timer context on user request */ + if (user_reset) + can_init_stats(net); + + /* restart counting on jiffies overflow */ + if (j < can_stats->jiffies_init) + can_init_stats(net); + + /* prevent overflow in calc_rate() */ + if (can_stats->rx_frames > (ULONG_MAX / HZ)) + can_init_stats(net); + + /* prevent overflow in calc_rate() */ + if (can_stats->tx_frames > (ULONG_MAX / HZ)) + can_init_stats(net); + + /* matches overflow - very improbable */ + if (can_stats->matches > (ULONG_MAX / 100)) + can_init_stats(net); + + /* calc total values */ + if (can_stats->rx_frames) + can_stats->total_rx_match_ratio = (can_stats->matches * 100) / + can_stats->rx_frames; + + can_stats->total_tx_rate = calc_rate(can_stats->jiffies_init, j, + can_stats->tx_frames); + can_stats->total_rx_rate = calc_rate(can_stats->jiffies_init, j, + can_stats->rx_frames); + + /* calc current values */ + if (can_stats->rx_frames_delta) + can_stats->current_rx_match_ratio = + (can_stats->matches_delta * 100) / + can_stats->rx_frames_delta; + + can_stats->current_tx_rate = calc_rate(0, HZ, can_stats->tx_frames_delta); + can_stats->current_rx_rate = calc_rate(0, HZ, can_stats->rx_frames_delta); + + /* check / update maximum values */ + if (can_stats->max_tx_rate < can_stats->current_tx_rate) + can_stats->max_tx_rate = can_stats->current_tx_rate; + + if (can_stats->max_rx_rate < can_stats->current_rx_rate) + can_stats->max_rx_rate = can_stats->current_rx_rate; + + if (can_stats->max_rx_match_ratio < can_stats->current_rx_match_ratio) + can_stats->max_rx_match_ratio = can_stats->current_rx_match_ratio; + + /* clear values for 'current rate' calculation */ + can_stats->tx_frames_delta = 0; + can_stats->rx_frames_delta = 0; + can_stats->matches_delta = 0; + + /* restart timer (one second) */ + mod_timer(&net->can.can_stattimer, round_jiffies(jiffies + HZ)); +} + +/* + * proc read functions + */ + +static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list, + struct net_device *dev) +{ + struct receiver *r; + + hlist_for_each_entry_rcu(r, rx_list, list) { + char *fmt = (r->can_id & CAN_EFF_FLAG)? + " %-5s %08x %08x %pK %pK %8ld %s\n" : + " %-5s %03x %08x %pK %pK %8ld %s\n"; + + seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask, + r->func, r->data, r->matches, r->ident); + } +} + +static void can_print_recv_banner(struct seq_file *m) +{ + /* + * can1. 00000000 00000000 00000000 + * ....... 0 tp20 + */ + seq_puts(m, " device can_id can_mask function" + " userdata matches ident\n"); +} + +static int can_stats_proc_show(struct seq_file *m, void *v) +{ + struct net *net = m->private; + struct s_stats *can_stats = net->can.can_stats; + struct s_pstats *can_pstats = net->can.can_pstats; + + seq_putc(m, '\n'); + seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats->tx_frames); + seq_printf(m, " %8ld received frames (RXF)\n", can_stats->rx_frames); + seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats->matches); + + seq_putc(m, '\n'); + + if (net->can.can_stattimer.function == can_stat_update) { + seq_printf(m, " %8ld %% total match ratio (RXMR)\n", + can_stats->total_rx_match_ratio); + + seq_printf(m, " %8ld frames/s total tx rate (TXR)\n", + can_stats->total_tx_rate); + seq_printf(m, " %8ld frames/s total rx rate (RXR)\n", + can_stats->total_rx_rate); + + seq_putc(m, '\n'); + + seq_printf(m, " %8ld %% current match ratio (CRXMR)\n", + can_stats->current_rx_match_ratio); + + seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n", + can_stats->current_tx_rate); + seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n", + can_stats->current_rx_rate); + + seq_putc(m, '\n'); + + seq_printf(m, " %8ld %% max match ratio (MRXMR)\n", + can_stats->max_rx_match_ratio); + + seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n", + can_stats->max_tx_rate); + seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n", + can_stats->max_rx_rate); + + seq_putc(m, '\n'); + } + + seq_printf(m, " %8ld current receive list entries (CRCV)\n", + can_pstats->rcv_entries); + seq_printf(m, " %8ld maximum receive list entries (MRCV)\n", + can_pstats->rcv_entries_max); + + if (can_pstats->stats_reset) + seq_printf(m, "\n %8ld statistic resets (STR)\n", + can_pstats->stats_reset); + + if (can_pstats->user_reset) + seq_printf(m, " %8ld user statistic resets (USTR)\n", + can_pstats->user_reset); + + seq_putc(m, '\n'); + return 0; +} + +static int can_reset_stats_proc_show(struct seq_file *m, void *v) +{ + struct net *net = m->private; + struct s_pstats *can_pstats = net->can.can_pstats; + struct s_stats *can_stats = net->can.can_stats; + + user_reset = 1; + + if (net->can.can_stattimer.function == can_stat_update) { + seq_printf(m, "Scheduled statistic reset #%ld.\n", + can_pstats->stats_reset + 1); + } else { + if (can_stats->jiffies_init != jiffies) + can_init_stats(net); + + seq_printf(m, "Performed statistic reset #%ld.\n", + can_pstats->stats_reset); + } + return 0; +} + +static int can_version_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%s\n", CAN_VERSION_STRING); + return 0; +} + +static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx, + struct net_device *dev, + struct can_dev_rcv_lists *d) +{ + if (!hlist_empty(&d->rx[idx])) { + can_print_recv_banner(m); + can_print_rcvlist(m, &d->rx[idx], dev); + } else + seq_printf(m, " (%s: no entry)\n", DNAME(dev)); + +} + +static int can_rcvlist_proc_show(struct seq_file *m, void *v) +{ + /* double cast to prevent GCC warning */ + int idx = (int)(long)PDE_DATA(m->file->f_inode); + struct net_device *dev; + struct can_dev_rcv_lists *d; + struct net *net = m->private; + + seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]); + + rcu_read_lock(); + + /* receive list for 'all' CAN devices (dev == NULL) */ + d = net->can.can_rx_alldev_list; + can_rcvlist_proc_show_one(m, idx, NULL, d); + + /* receive list for registered CAN devices */ + for_each_netdev_rcu(net, dev) { + if (dev->type == ARPHRD_CAN && dev->ml_priv) + can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv); + } + + rcu_read_unlock(); + + seq_putc(m, '\n'); + return 0; +} + +static inline void can_rcvlist_proc_show_array(struct seq_file *m, + struct net_device *dev, + struct hlist_head *rcv_array, + unsigned int rcv_array_sz) +{ + unsigned int i; + int all_empty = 1; + + /* check whether at least one list is non-empty */ + for (i = 0; i < rcv_array_sz; i++) + if (!hlist_empty(&rcv_array[i])) { + all_empty = 0; + break; + } + + if (!all_empty) { + can_print_recv_banner(m); + for (i = 0; i < rcv_array_sz; i++) { + if (!hlist_empty(&rcv_array[i])) + can_print_rcvlist(m, &rcv_array[i], dev); + } + } else + seq_printf(m, " (%s: no entry)\n", DNAME(dev)); +} + +static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v) +{ + struct net_device *dev; + struct can_dev_rcv_lists *d; + struct net *net = m->private; + + /* RX_SFF */ + seq_puts(m, "\nreceive list 'rx_sff':\n"); + + rcu_read_lock(); + + /* sff receive list for 'all' CAN devices (dev == NULL) */ + d = net->can.can_rx_alldev_list; + can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff)); + + /* sff receive list for registered CAN devices */ + for_each_netdev_rcu(net, dev) { + if (dev->type == ARPHRD_CAN && dev->ml_priv) { + d = dev->ml_priv; + can_rcvlist_proc_show_array(m, dev, d->rx_sff, + ARRAY_SIZE(d->rx_sff)); + } + } + + rcu_read_unlock(); + + seq_putc(m, '\n'); + return 0; +} + +static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v) +{ + struct net_device *dev; + struct can_dev_rcv_lists *d; + struct net *net = m->private; + + /* RX_EFF */ + seq_puts(m, "\nreceive list 'rx_eff':\n"); + + rcu_read_lock(); + + /* eff receive list for 'all' CAN devices (dev == NULL) */ + d = net->can.can_rx_alldev_list; + can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff)); + + /* eff receive list for registered CAN devices */ + for_each_netdev_rcu(net, dev) { + if (dev->type == ARPHRD_CAN && dev->ml_priv) { + d = dev->ml_priv; + can_rcvlist_proc_show_array(m, dev, d->rx_eff, + ARRAY_SIZE(d->rx_eff)); + } + } + + rcu_read_unlock(); + + seq_putc(m, '\n'); + return 0; +} + +/* + * can_init_proc - create main CAN proc directory and procfs entries + */ +void can_init_proc(struct net *net) +{ + /* create /proc/net/can directory */ + net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net); + + if (!net->can.proc_dir) { + printk(KERN_INFO "can: failed to create /proc/net/can . " + "CONFIG_PROC_FS missing?\n"); + return; + } + + /* own procfs entries from the AF_CAN core */ + net->can.pde_version = proc_create_net_single(CAN_PROC_VERSION, 0644, + net->can.proc_dir, can_version_proc_show, NULL); + net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644, + net->can.proc_dir, can_stats_proc_show, NULL); + net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS, + 0644, net->can.proc_dir, can_reset_stats_proc_show, + NULL); + net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR, + 0644, net->can.proc_dir, can_rcvlist_proc_show, + (void *)RX_ERR); + net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL, + 0644, net->can.proc_dir, can_rcvlist_proc_show, + (void *)RX_ALL); + net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL, + 0644, net->can.proc_dir, can_rcvlist_proc_show, + (void *)RX_FIL); + net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV, + 0644, net->can.proc_dir, can_rcvlist_proc_show, + (void *)RX_INV); + net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF, + 0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL); + net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF, + 0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL); +} + +/* + * can_remove_proc - remove procfs entries and main CAN proc directory + */ +void can_remove_proc(struct net *net) +{ + if (!net->can.proc_dir) + return; + + if (net->can.pde_version) + remove_proc_entry(CAN_PROC_VERSION, net->can.proc_dir); + + if (net->can.pde_stats) + remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir); + + if (net->can.pde_reset_stats) + remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir); + + if (net->can.pde_rcvlist_err) + remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir); + + if (net->can.pde_rcvlist_all) + remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir); + + if (net->can.pde_rcvlist_fil) + remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir); + + if (net->can.pde_rcvlist_inv) + remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir); + + if (net->can.pde_rcvlist_eff) + remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir); + + if (net->can.pde_rcvlist_sff) + remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir); + + remove_proc_entry("can", net->proc_net); +} diff --git a/net/can/raw.c b/net/can/raw.c new file mode 100644 index 000000000..2a6db8752 --- /dev/null +++ b/net/can/raw.c @@ -0,0 +1,942 @@ +/* + * raw.c - Raw sockets for protocol family CAN + * + * Copyright (c) 2002-2007 Volkswagen Group Electronic Research + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Volkswagen nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * Alternatively, provided that this notice is retained in full, this + * software may be distributed under the terms of the GNU General + * Public License ("GPL") version 2, in which case the provisions of the + * GPL apply INSTEAD OF those given above. + * + * The provided data structures and external interfaces from this code + * are not restricted to be used by modules with a GPL compatible license. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/uio.h> +#include <linux/net.h> +#include <linux/slab.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/raw.h> +#include <net/sock.h> +#include <net/net_namespace.h> + +#define CAN_RAW_VERSION CAN_VERSION + +MODULE_DESCRIPTION("PF_CAN raw protocol"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>"); +MODULE_ALIAS("can-proto-1"); + +#define MASK_ALL 0 + +/* + * A raw socket has a list of can_filters attached to it, each receiving + * the CAN frames matching that filter. If the filter list is empty, + * no CAN frames will be received by the socket. The default after + * opening the socket, is to have one filter which receives all frames. + * The filter list is allocated dynamically with the exception of the + * list containing only one item. This common case is optimized by + * storing the single filter in dfilter, to avoid using dynamic memory. + */ + +struct uniqframe { + int skbcnt; + const struct sk_buff *skb; + unsigned int join_rx_count; +}; + +struct raw_sock { + struct sock sk; + int bound; + int ifindex; + struct list_head notifier; + int loopback; + int recv_own_msgs; + int fd_frames; + int join_filters; + int count; /* number of active filters */ + struct can_filter dfilter; /* default/single filter */ + struct can_filter *filter; /* pointer to filter(s) */ + can_err_mask_t err_mask; + struct uniqframe __percpu *uniq; +}; + +static LIST_HEAD(raw_notifier_list); +static DEFINE_SPINLOCK(raw_notifier_lock); +static struct raw_sock *raw_busy_notifier; + +/* + * Return pointer to store the extra msg flags for raw_recvmsg(). + * We use the space of one unsigned int beyond the 'struct sockaddr_can' + * in skb->cb. + */ +static inline unsigned int *raw_flags(struct sk_buff *skb) +{ + sock_skb_cb_check_size(sizeof(struct sockaddr_can) + + sizeof(unsigned int)); + + /* return pointer after struct sockaddr_can */ + return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); +} + +static inline struct raw_sock *raw_sk(const struct sock *sk) +{ + return (struct raw_sock *)sk; +} + +static void raw_rcv(struct sk_buff *oskb, void *data) +{ + struct sock *sk = (struct sock *)data; + struct raw_sock *ro = raw_sk(sk); + struct sockaddr_can *addr; + struct sk_buff *skb; + unsigned int *pflags; + + /* check the received tx sock reference */ + if (!ro->recv_own_msgs && oskb->sk == sk) + return; + + /* do not pass non-CAN2.0 frames to a legacy socket */ + if (!ro->fd_frames && oskb->len != CAN_MTU) + return; + + /* eliminate multiple filter matches for the same skb */ + if (this_cpu_ptr(ro->uniq)->skb == oskb && + this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { + if (ro->join_filters) { + this_cpu_inc(ro->uniq->join_rx_count); + /* drop frame until all enabled filters matched */ + if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) + return; + } else { + return; + } + } else { + this_cpu_ptr(ro->uniq)->skb = oskb; + this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; + this_cpu_ptr(ro->uniq)->join_rx_count = 1; + /* drop first frame to check all enabled filters? */ + if (ro->join_filters && ro->count > 1) + return; + } + + /* clone the given skb to be able to enqueue it into the rcv queue */ + skb = skb_clone(oskb, GFP_ATOMIC); + if (!skb) + return; + + /* + * Put the datagram to the queue so that raw_recvmsg() can + * get it from there. We need to pass the interface index to + * raw_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 = skb->dev->ifindex; + + /* add CAN specific message flags for raw_recvmsg() */ + pflags = raw_flags(skb); + *pflags = 0; + if (oskb->sk) + *pflags |= MSG_DONTROUTE; + if (oskb->sk == sk) + *pflags |= MSG_CONFIRM; + + if (sock_queue_rcv_skb(sk, skb) < 0) + kfree_skb(skb); +} + +static int raw_enable_filters(struct net *net, struct net_device *dev, + struct sock *sk, struct can_filter *filter, + int count) +{ + int err = 0; + int i; + + for (i = 0; i < count; i++) { + err = can_rx_register(net, dev, filter[i].can_id, + filter[i].can_mask, + raw_rcv, sk, "raw", sk); + if (err) { + /* clean up successfully registered filters */ + while (--i >= 0) + can_rx_unregister(net, dev, filter[i].can_id, + filter[i].can_mask, + raw_rcv, sk); + break; + } + } + + return err; +} + +static int raw_enable_errfilter(struct net *net, struct net_device *dev, + struct sock *sk, can_err_mask_t err_mask) +{ + int err = 0; + + if (err_mask) + err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG, + raw_rcv, sk, "raw", sk); + + return err; +} + +static void raw_disable_filters(struct net *net, struct net_device *dev, + struct sock *sk, struct can_filter *filter, + int count) +{ + int i; + + for (i = 0; i < count; i++) + can_rx_unregister(net, dev, filter[i].can_id, + filter[i].can_mask, raw_rcv, sk); +} + +static inline void raw_disable_errfilter(struct net *net, + struct net_device *dev, + struct sock *sk, + can_err_mask_t err_mask) + +{ + if (err_mask) + can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG, + raw_rcv, sk); +} + +static inline void raw_disable_allfilters(struct net *net, + struct net_device *dev, + struct sock *sk) +{ + struct raw_sock *ro = raw_sk(sk); + + raw_disable_filters(net, dev, sk, ro->filter, ro->count); + raw_disable_errfilter(net, dev, sk, ro->err_mask); +} + +static int raw_enable_allfilters(struct net *net, struct net_device *dev, + struct sock *sk) +{ + struct raw_sock *ro = raw_sk(sk); + int err; + + err = raw_enable_filters(net, dev, sk, ro->filter, ro->count); + if (!err) { + err = raw_enable_errfilter(net, dev, sk, ro->err_mask); + if (err) + raw_disable_filters(net, dev, sk, ro->filter, + ro->count); + } + + return err; +} + +static void raw_notify(struct raw_sock *ro, unsigned long msg, + struct net_device *dev) +{ + struct sock *sk = &ro->sk; + + if (!net_eq(dev_net(dev), sock_net(sk))) + return; + + if (ro->ifindex != dev->ifindex) + return; + + switch (msg) { + + case NETDEV_UNREGISTER: + lock_sock(sk); + /* remove current filters & unregister */ + if (ro->bound) + raw_disable_allfilters(dev_net(dev), dev, sk); + + if (ro->count > 1) + kfree(ro->filter); + + ro->ifindex = 0; + ro->bound = 0; + ro->count = 0; + release_sock(sk); + + sk->sk_err = ENODEV; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); + break; + + case NETDEV_DOWN: + sk->sk_err = ENETDOWN; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); + break; + } +} + +static int raw_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(raw_busy_notifier)) /* Check for reentrant bug. */ + return NOTIFY_DONE; + + spin_lock(&raw_notifier_lock); + list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) { + spin_unlock(&raw_notifier_lock); + raw_notify(raw_busy_notifier, msg, dev); + spin_lock(&raw_notifier_lock); + } + raw_busy_notifier = NULL; + spin_unlock(&raw_notifier_lock); + return NOTIFY_DONE; +} + +static int raw_init(struct sock *sk) +{ + struct raw_sock *ro = raw_sk(sk); + + ro->bound = 0; + ro->ifindex = 0; + + /* set default filter to single entry dfilter */ + ro->dfilter.can_id = 0; + ro->dfilter.can_mask = MASK_ALL; + ro->filter = &ro->dfilter; + ro->count = 1; + + /* set default loopback behaviour */ + ro->loopback = 1; + ro->recv_own_msgs = 0; + ro->fd_frames = 0; + ro->join_filters = 0; + + /* alloc_percpu provides zero'ed memory */ + ro->uniq = alloc_percpu(struct uniqframe); + if (unlikely(!ro->uniq)) + return -ENOMEM; + + /* set notifier */ + spin_lock(&raw_notifier_lock); + list_add_tail(&ro->notifier, &raw_notifier_list); + spin_unlock(&raw_notifier_lock); + + return 0; +} + +static int raw_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct raw_sock *ro; + + if (!sk) + return 0; + + ro = raw_sk(sk); + + spin_lock(&raw_notifier_lock); + while (raw_busy_notifier == ro) { + spin_unlock(&raw_notifier_lock); + schedule_timeout_uninterruptible(1); + spin_lock(&raw_notifier_lock); + } + list_del(&ro->notifier); + spin_unlock(&raw_notifier_lock); + + lock_sock(sk); + + /* remove current filters & unregister */ + if (ro->bound) { + if (ro->ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(sock_net(sk), ro->ifindex); + if (dev) { + raw_disable_allfilters(dev_net(dev), dev, sk); + dev_put(dev); + } + } else + raw_disable_allfilters(sock_net(sk), NULL, sk); + } + + if (ro->count > 1) + kfree(ro->filter); + + ro->ifindex = 0; + ro->bound = 0; + ro->count = 0; + free_percpu(ro->uniq); + + sock_orphan(sk); + sock->sk = NULL; + + release_sock(sk); + sock_put(sk); + + return 0; +} + +static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) +{ + struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; + struct sock *sk = sock->sk; + struct raw_sock *ro = raw_sk(sk); + int ifindex; + int err = 0; + int notify_enetdown = 0; + + if (len < sizeof(*addr)) + return -EINVAL; + if (addr->can_family != AF_CAN) + return -EINVAL; + + lock_sock(sk); + + if (ro->bound && addr->can_ifindex == ro->ifindex) + goto out; + + if (addr->can_ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); + if (!dev) { + err = -ENODEV; + goto out; + } + if (dev->type != ARPHRD_CAN) { + dev_put(dev); + err = -ENODEV; + goto out; + } + if (!(dev->flags & IFF_UP)) + notify_enetdown = 1; + + ifindex = dev->ifindex; + + /* filters set by default/setsockopt */ + err = raw_enable_allfilters(sock_net(sk), dev, sk); + dev_put(dev); + } else { + ifindex = 0; + + /* filters set by default/setsockopt */ + err = raw_enable_allfilters(sock_net(sk), NULL, sk); + } + + if (!err) { + if (ro->bound) { + /* unregister old filters */ + if (ro->ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(sock_net(sk), + ro->ifindex); + if (dev) { + raw_disable_allfilters(dev_net(dev), + dev, sk); + dev_put(dev); + } + } else + raw_disable_allfilters(sock_net(sk), NULL, sk); + } + ro->ifindex = ifindex; + ro->bound = 1; + } + + out: + release_sock(sk); + + if (notify_enetdown) { + sk->sk_err = ENETDOWN; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); + } + + return err; +} + +static int raw_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; + struct sock *sk = sock->sk; + struct raw_sock *ro = raw_sk(sk); + + if (peer) + return -EOPNOTSUPP; + + memset(addr, 0, sizeof(*addr)); + addr->can_family = AF_CAN; + addr->can_ifindex = ro->ifindex; + + return sizeof(*addr); +} + +static int raw_setsockopt(struct socket *sock, int level, int optname, + char __user *optval, unsigned int optlen) +{ + struct sock *sk = sock->sk; + struct raw_sock *ro = raw_sk(sk); + struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ + struct can_filter sfilter; /* single filter */ + struct net_device *dev = NULL; + can_err_mask_t err_mask = 0; + int count = 0; + int err = 0; + + if (level != SOL_CAN_RAW) + return -EINVAL; + + switch (optname) { + + case CAN_RAW_FILTER: + if (optlen % sizeof(struct can_filter) != 0) + return -EINVAL; + + if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) + return -EINVAL; + + count = optlen / sizeof(struct can_filter); + + if (count > 1) { + /* filter does not fit into dfilter => alloc space */ + filter = memdup_user(optval, optlen); + if (IS_ERR(filter)) + return PTR_ERR(filter); + } else if (count == 1) { + if (copy_from_user(&sfilter, optval, sizeof(sfilter))) + return -EFAULT; + } + + rtnl_lock(); + lock_sock(sk); + + if (ro->bound && ro->ifindex) { + dev = dev_get_by_index(sock_net(sk), ro->ifindex); + if (!dev) { + if (count > 1) + kfree(filter); + err = -ENODEV; + goto out_fil; + } + } + + if (ro->bound) { + /* (try to) register the new filters */ + if (count == 1) + err = raw_enable_filters(sock_net(sk), dev, sk, + &sfilter, 1); + else + err = raw_enable_filters(sock_net(sk), dev, sk, + filter, count); + if (err) { + if (count > 1) + kfree(filter); + goto out_fil; + } + + /* remove old filter registrations */ + raw_disable_filters(sock_net(sk), dev, sk, ro->filter, + ro->count); + } + + /* remove old filter space */ + if (ro->count > 1) + kfree(ro->filter); + + /* link new filters to the socket */ + if (count == 1) { + /* copy filter data for single filter */ + ro->dfilter = sfilter; + filter = &ro->dfilter; + } + ro->filter = filter; + ro->count = count; + + out_fil: + if (dev) + dev_put(dev); + + release_sock(sk); + rtnl_unlock(); + + break; + + case CAN_RAW_ERR_FILTER: + if (optlen != sizeof(err_mask)) + return -EINVAL; + + if (copy_from_user(&err_mask, optval, optlen)) + return -EFAULT; + + err_mask &= CAN_ERR_MASK; + + rtnl_lock(); + lock_sock(sk); + + if (ro->bound && ro->ifindex) { + dev = dev_get_by_index(sock_net(sk), ro->ifindex); + if (!dev) { + err = -ENODEV; + goto out_err; + } + } + + /* remove current error mask */ + if (ro->bound) { + /* (try to) register the new err_mask */ + err = raw_enable_errfilter(sock_net(sk), dev, sk, + err_mask); + + if (err) + goto out_err; + + /* remove old err_mask registration */ + raw_disable_errfilter(sock_net(sk), dev, sk, + ro->err_mask); + } + + /* link new err_mask to the socket */ + ro->err_mask = err_mask; + + out_err: + if (dev) + dev_put(dev); + + release_sock(sk); + rtnl_unlock(); + + break; + + case CAN_RAW_LOOPBACK: + if (optlen != sizeof(ro->loopback)) + return -EINVAL; + + if (copy_from_user(&ro->loopback, optval, optlen)) + return -EFAULT; + + break; + + case CAN_RAW_RECV_OWN_MSGS: + if (optlen != sizeof(ro->recv_own_msgs)) + return -EINVAL; + + if (copy_from_user(&ro->recv_own_msgs, optval, optlen)) + return -EFAULT; + + break; + + case CAN_RAW_FD_FRAMES: + if (optlen != sizeof(ro->fd_frames)) + return -EINVAL; + + if (copy_from_user(&ro->fd_frames, optval, optlen)) + return -EFAULT; + + break; + + case CAN_RAW_JOIN_FILTERS: + if (optlen != sizeof(ro->join_filters)) + return -EINVAL; + + if (copy_from_user(&ro->join_filters, optval, optlen)) + return -EFAULT; + + break; + + default: + return -ENOPROTOOPT; + } + return err; +} + +static int raw_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct sock *sk = sock->sk; + struct raw_sock *ro = raw_sk(sk); + int len; + void *val; + int err = 0; + + if (level != SOL_CAN_RAW) + return -EINVAL; + if (get_user(len, optlen)) + return -EFAULT; + if (len < 0) + return -EINVAL; + + switch (optname) { + + case CAN_RAW_FILTER: + lock_sock(sk); + if (ro->count > 0) { + int fsize = ro->count * sizeof(struct can_filter); + if (len > fsize) + len = fsize; + if (copy_to_user(optval, ro->filter, len)) + err = -EFAULT; + } else + len = 0; + release_sock(sk); + + if (!err) + err = put_user(len, optlen); + return err; + + case CAN_RAW_ERR_FILTER: + if (len > sizeof(can_err_mask_t)) + len = sizeof(can_err_mask_t); + val = &ro->err_mask; + break; + + case CAN_RAW_LOOPBACK: + if (len > sizeof(int)) + len = sizeof(int); + val = &ro->loopback; + break; + + case CAN_RAW_RECV_OWN_MSGS: + if (len > sizeof(int)) + len = sizeof(int); + val = &ro->recv_own_msgs; + break; + + case CAN_RAW_FD_FRAMES: + if (len > sizeof(int)) + len = sizeof(int); + val = &ro->fd_frames; + break; + + case CAN_RAW_JOIN_FILTERS: + if (len > sizeof(int)) + len = sizeof(int); + val = &ro->join_filters; + break; + + default: + return -ENOPROTOOPT; + } + + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, val, len)) + return -EFAULT; + return 0; +} + +static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) +{ + struct sock *sk = sock->sk; + struct raw_sock *ro = raw_sk(sk); + struct sk_buff *skb; + struct net_device *dev; + int ifindex; + int err; + + if (msg->msg_name) { + DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); + + if (msg->msg_namelen < sizeof(*addr)) + return -EINVAL; + + if (addr->can_family != AF_CAN) + return -EINVAL; + + ifindex = addr->can_ifindex; + } else + ifindex = ro->ifindex; + + dev = dev_get_by_index(sock_net(sk), ifindex); + if (!dev) + return -ENXIO; + + err = -EINVAL; + if (ro->fd_frames && dev->mtu == CANFD_MTU) { + if (unlikely(size != CANFD_MTU && size != CAN_MTU)) + goto put_dev; + } else { + if (unlikely(size != CAN_MTU)) + goto put_dev; + } + + skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), + msg->msg_flags & MSG_DONTWAIT, &err); + if (!skb) + goto put_dev; + + can_skb_reserve(skb); + can_skb_prv(skb)->ifindex = dev->ifindex; + can_skb_prv(skb)->skbcnt = 0; + + err = memcpy_from_msg(skb_put(skb, size), msg, size); + if (err < 0) + goto free_skb; + + skb_setup_tx_timestamp(skb, sk->sk_tsflags); + + skb->dev = dev; + skb->sk = sk; + skb->priority = sk->sk_priority; + + err = can_send(skb, ro->loopback); + + dev_put(dev); + + if (err) + goto send_failed; + + return size; + +free_skb: + kfree_skb(skb); +put_dev: + dev_put(dev); +send_failed: + return err; +} + +static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, + int flags) +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int err = 0; + int noblock; + + noblock = flags & MSG_DONTWAIT; + flags &= ~MSG_DONTWAIT; + + skb = skb_recv_datagram(sk, flags, noblock, &err); + if (!skb) + return err; + + if (size < skb->len) + msg->msg_flags |= MSG_TRUNC; + else + size = skb->len; + + err = memcpy_to_msg(msg, skb->data, size); + if (err < 0) { + skb_free_datagram(sk, skb); + return err; + } + + sock_recv_ts_and_drops(msg, sk, skb); + + if (msg->msg_name) { + __sockaddr_check_size(sizeof(struct sockaddr_can)); + msg->msg_namelen = sizeof(struct sockaddr_can); + memcpy(msg->msg_name, skb->cb, msg->msg_namelen); + } + + /* assign the flags that have been recorded in raw_rcv() */ + msg->msg_flags |= *(raw_flags(skb)); + + skb_free_datagram(sk, skb); + + return size; +} + +static const struct proto_ops raw_ops = { + .family = PF_CAN, + .release = raw_release, + .bind = raw_bind, + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = raw_getname, + .poll = datagram_poll, + .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = raw_setsockopt, + .getsockopt = raw_getsockopt, + .sendmsg = raw_sendmsg, + .recvmsg = raw_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static struct proto raw_proto __read_mostly = { + .name = "CAN_RAW", + .owner = THIS_MODULE, + .obj_size = sizeof(struct raw_sock), + .init = raw_init, +}; + +static const struct can_proto raw_can_proto = { + .type = SOCK_RAW, + .protocol = CAN_RAW, + .ops = &raw_ops, + .prot = &raw_proto, +}; + +static struct notifier_block canraw_notifier = { + .notifier_call = raw_notifier +}; + +static __init int raw_module_init(void) +{ + int err; + + pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n"); + + err = can_proto_register(&raw_can_proto); + if (err < 0) + printk(KERN_ERR "can: registration of raw protocol failed\n"); + else + register_netdevice_notifier(&canraw_notifier); + + return err; +} + +static __exit void raw_module_exit(void) +{ + can_proto_unregister(&raw_can_proto); + unregister_netdevice_notifier(&canraw_notifier); +} + +module_init(raw_module_init); +module_exit(raw_module_exit); |