diff options
Diffstat (limited to 'kernel/net/can/raw.c')
| -rw-r--r-- | kernel/net/can/raw.c | 875 |
1 files changed, 875 insertions, 0 deletions
diff --git a/kernel/net/can/raw.c b/kernel/net/can/raw.c new file mode 100644 index 000000000..31b9748cb --- /dev/null +++ b/kernel/net/can/raw.c @@ -0,0 +1,875 @@ +/* + * 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 { + ktime_t tstamp; + const struct sk_buff *skb; + unsigned int join_rx_count; +}; + +struct raw_sock { + struct sock sk; + int bound; + int ifindex; + struct notifier_block 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; +}; + +/* + * 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 && + ktime_equal(this_cpu_ptr(ro->uniq)->tstamp, oskb->tstamp)) { + 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)->tstamp = oskb->tstamp; + 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_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(dev, filter[i].can_id, + filter[i].can_mask, + raw_rcv, sk, "raw"); + if (err) { + /* clean up successfully registered filters */ + while (--i >= 0) + can_rx_unregister(dev, filter[i].can_id, + filter[i].can_mask, + raw_rcv, sk); + break; + } + } + + return err; +} + +static int raw_enable_errfilter(struct net_device *dev, struct sock *sk, + can_err_mask_t err_mask) +{ + int err = 0; + + if (err_mask) + err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG, + raw_rcv, sk, "raw"); + + return err; +} + +static void raw_disable_filters(struct net_device *dev, struct sock *sk, + struct can_filter *filter, int count) +{ + int i; + + for (i = 0; i < count; i++) + can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask, + raw_rcv, sk); +} + +static inline void raw_disable_errfilter(struct net_device *dev, + struct sock *sk, + can_err_mask_t err_mask) + +{ + if (err_mask) + can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG, + raw_rcv, sk); +} + +static inline void raw_disable_allfilters(struct net_device *dev, + struct sock *sk) +{ + struct raw_sock *ro = raw_sk(sk); + + raw_disable_filters(dev, sk, ro->filter, ro->count); + raw_disable_errfilter(dev, sk, ro->err_mask); +} + +static int raw_enable_allfilters(struct net_device *dev, struct sock *sk) +{ + struct raw_sock *ro = raw_sk(sk); + int err; + + err = raw_enable_filters(dev, sk, ro->filter, ro->count); + if (!err) { + err = raw_enable_errfilter(dev, sk, ro->err_mask); + if (err) + raw_disable_filters(dev, sk, ro->filter, ro->count); + } + + return err; +} + +static int raw_notifier(struct notifier_block *nb, + unsigned long msg, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct raw_sock *ro = container_of(nb, struct raw_sock, notifier); + struct sock *sk = &ro->sk; + + if (!net_eq(dev_net(dev), &init_net)) + return NOTIFY_DONE; + + if (dev->type != ARPHRD_CAN) + return NOTIFY_DONE; + + if (ro->ifindex != dev->ifindex) + return NOTIFY_DONE; + + switch (msg) { + + case NETDEV_UNREGISTER: + lock_sock(sk); + /* remove current filters & unregister */ + if (ro->bound) + raw_disable_allfilters(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; + } + + 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 */ + ro->notifier.notifier_call = raw_notifier; + + register_netdevice_notifier(&ro->notifier); + + 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); + + unregister_netdevice_notifier(&ro->notifier); + + lock_sock(sk); + + /* remove current filters & unregister */ + if (ro->bound) { + if (ro->ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, ro->ifindex); + if (dev) { + raw_disable_allfilters(dev, sk); + dev_put(dev); + } + } else + raw_disable_allfilters(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; + + 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(&init_net, 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(dev, sk); + dev_put(dev); + } else { + ifindex = 0; + + /* filters set by default/setsockopt */ + err = raw_enable_allfilters(NULL, sk); + } + + if (!err) { + if (ro->bound) { + /* unregister old filters */ + if (ro->ifindex) { + struct net_device *dev; + + dev = dev_get_by_index(&init_net, ro->ifindex); + if (dev) { + raw_disable_allfilters(dev, sk); + dev_put(dev); + } + } else + raw_disable_allfilters(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 *len, 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; + + *len = sizeof(*addr); + + return 0; +} + +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; + + 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; + } + + lock_sock(sk); + + if (ro->bound && ro->ifindex) + dev = dev_get_by_index(&init_net, ro->ifindex); + + if (ro->bound) { + /* (try to) register the new filters */ + if (count == 1) + err = raw_enable_filters(dev, sk, &sfilter, 1); + else + err = raw_enable_filters(dev, sk, filter, + count); + if (err) { + if (count > 1) + kfree(filter); + goto out_fil; + } + + /* remove old filter registrations */ + raw_disable_filters(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); + + 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; + + lock_sock(sk); + + if (ro->bound && ro->ifindex) + dev = dev_get_by_index(&init_net, ro->ifindex); + + /* remove current error mask */ + if (ro->bound) { + /* (try to) register the new err_mask */ + err = raw_enable_errfilter(dev, sk, err_mask); + + if (err) + goto out_err; + + /* remove old err_mask registration */ + raw_disable_errfilter(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); + + 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; + + if (ro->fd_frames) { + if (unlikely(size != CANFD_MTU && size != CAN_MTU)) + return -EINVAL; + } else { + if (unlikely(size != CAN_MTU)) + return -EINVAL; + } + + dev = dev_get_by_index(&init_net, ifindex); + if (!dev) + return -ENXIO; + + 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; + + err = memcpy_from_msg(skb_put(skb, size), msg, size); + if (err < 0) + goto free_skb; + + sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); + + 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 __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"); + + return err; +} + +static __exit void raw_module_exit(void) +{ + can_proto_unregister(&raw_can_proto); +} + +module_init(raw_module_init); +module_exit(raw_module_exit); |