2 * raw.c - Raw sockets for protocol family CAN
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/uio.h>
45 #include <linux/net.h>
46 #include <linux/slab.h>
47 #include <linux/netdevice.h>
48 #include <linux/socket.h>
49 #include <linux/if_arp.h>
50 #include <linux/skbuff.h>
51 #include <linux/can.h>
52 #include <linux/can/core.h>
53 #include <linux/can/skb.h>
54 #include <linux/can/raw.h>
56 #include <net/net_namespace.h>
58 #define CAN_RAW_VERSION CAN_VERSION
60 MODULE_DESCRIPTION("PF_CAN raw protocol");
61 MODULE_LICENSE("Dual BSD/GPL");
62 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
63 MODULE_ALIAS("can-proto-1");
68 * A raw socket has a list of can_filters attached to it, each receiving
69 * the CAN frames matching that filter. If the filter list is empty,
70 * no CAN frames will be received by the socket. The default after
71 * opening the socket, is to have one filter which receives all frames.
72 * The filter list is allocated dynamically with the exception of the
73 * list containing only one item. This common case is optimized by
74 * storing the single filter in dfilter, to avoid using dynamic memory.
79 const struct sk_buff *skb;
80 unsigned int join_rx_count;
87 struct list_head notifier;
92 int count; /* number of active filters */
93 struct can_filter dfilter; /* default/single filter */
94 struct can_filter *filter; /* pointer to filter(s) */
95 can_err_mask_t err_mask;
96 struct uniqframe __percpu *uniq;
99 static LIST_HEAD(raw_notifier_list);
100 static DEFINE_SPINLOCK(raw_notifier_lock);
101 static struct raw_sock *raw_busy_notifier;
104 * Return pointer to store the extra msg flags for raw_recvmsg().
105 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
108 static inline unsigned int *raw_flags(struct sk_buff *skb)
110 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
111 sizeof(unsigned int));
113 /* return pointer after struct sockaddr_can */
114 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
117 static inline struct raw_sock *raw_sk(const struct sock *sk)
119 return (struct raw_sock *)sk;
122 static void raw_rcv(struct sk_buff *oskb, void *data)
124 struct sock *sk = (struct sock *)data;
125 struct raw_sock *ro = raw_sk(sk);
126 struct sockaddr_can *addr;
128 unsigned int *pflags;
130 /* check the received tx sock reference */
131 if (!ro->recv_own_msgs && oskb->sk == sk)
134 /* do not pass non-CAN2.0 frames to a legacy socket */
135 if (!ro->fd_frames && oskb->len != CAN_MTU)
138 /* eliminate multiple filter matches for the same skb */
139 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
140 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
141 if (ro->join_filters) {
142 this_cpu_inc(ro->uniq->join_rx_count);
143 /* drop frame until all enabled filters matched */
144 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
150 this_cpu_ptr(ro->uniq)->skb = oskb;
151 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
152 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
153 /* drop first frame to check all enabled filters? */
154 if (ro->join_filters && ro->count > 1)
158 /* clone the given skb to be able to enqueue it into the rcv queue */
159 skb = skb_clone(oskb, GFP_ATOMIC);
164 * Put the datagram to the queue so that raw_recvmsg() can
165 * get it from there. We need to pass the interface index to
166 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
167 * containing the interface index.
170 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
171 addr = (struct sockaddr_can *)skb->cb;
172 memset(addr, 0, sizeof(*addr));
173 addr->can_family = AF_CAN;
174 addr->can_ifindex = skb->dev->ifindex;
176 /* add CAN specific message flags for raw_recvmsg() */
177 pflags = raw_flags(skb);
180 *pflags |= MSG_DONTROUTE;
182 *pflags |= MSG_CONFIRM;
184 if (sock_queue_rcv_skb(sk, skb) < 0)
188 static int raw_enable_filters(struct net_device *dev, struct sock *sk,
189 struct can_filter *filter, int count)
194 for (i = 0; i < count; i++) {
195 err = can_rx_register(dev, filter[i].can_id,
197 raw_rcv, sk, "raw", sk);
199 /* clean up successfully registered filters */
201 can_rx_unregister(dev, filter[i].can_id,
211 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
212 can_err_mask_t err_mask)
217 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
218 raw_rcv, sk, "raw", sk);
223 static void raw_disable_filters(struct net_device *dev, struct sock *sk,
224 struct can_filter *filter, int count)
228 for (i = 0; i < count; i++)
229 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
233 static inline void raw_disable_errfilter(struct net_device *dev,
235 can_err_mask_t err_mask)
239 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
243 static inline void raw_disable_allfilters(struct net_device *dev,
246 struct raw_sock *ro = raw_sk(sk);
248 raw_disable_filters(dev, sk, ro->filter, ro->count);
249 raw_disable_errfilter(dev, sk, ro->err_mask);
252 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
254 struct raw_sock *ro = raw_sk(sk);
257 err = raw_enable_filters(dev, sk, ro->filter, ro->count);
259 err = raw_enable_errfilter(dev, sk, ro->err_mask);
261 raw_disable_filters(dev, sk, ro->filter, ro->count);
267 static void raw_notify(struct raw_sock *ro, unsigned long msg,
268 struct net_device *dev)
270 struct sock *sk = &ro->sk;
272 if (!net_eq(dev_net(dev), &init_net))
275 if (ro->ifindex != dev->ifindex)
280 case NETDEV_UNREGISTER:
282 /* remove current filters & unregister */
284 raw_disable_allfilters(dev, sk);
295 if (!sock_flag(sk, SOCK_DEAD))
296 sk->sk_error_report(sk);
300 sk->sk_err = ENETDOWN;
301 if (!sock_flag(sk, SOCK_DEAD))
302 sk->sk_error_report(sk);
307 static int raw_notifier(struct notifier_block *nb, unsigned long msg,
310 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
312 if (dev->type != ARPHRD_CAN)
314 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
316 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
319 spin_lock(&raw_notifier_lock);
320 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
321 spin_unlock(&raw_notifier_lock);
322 raw_notify(raw_busy_notifier, msg, dev);
323 spin_lock(&raw_notifier_lock);
325 raw_busy_notifier = NULL;
326 spin_unlock(&raw_notifier_lock);
330 static int raw_init(struct sock *sk)
332 struct raw_sock *ro = raw_sk(sk);
337 /* set default filter to single entry dfilter */
338 ro->dfilter.can_id = 0;
339 ro->dfilter.can_mask = MASK_ALL;
340 ro->filter = &ro->dfilter;
343 /* set default loopback behaviour */
345 ro->recv_own_msgs = 0;
347 ro->join_filters = 0;
349 /* alloc_percpu provides zero'ed memory */
350 ro->uniq = alloc_percpu(struct uniqframe);
351 if (unlikely(!ro->uniq))
355 spin_lock(&raw_notifier_lock);
356 list_add_tail(&ro->notifier, &raw_notifier_list);
357 spin_unlock(&raw_notifier_lock);
362 static int raw_release(struct socket *sock)
364 struct sock *sk = sock->sk;
372 spin_lock(&raw_notifier_lock);
373 while (raw_busy_notifier == ro) {
374 spin_unlock(&raw_notifier_lock);
375 schedule_timeout_uninterruptible(1);
376 spin_lock(&raw_notifier_lock);
378 list_del(&ro->notifier);
379 spin_unlock(&raw_notifier_lock);
383 /* remove current filters & unregister */
386 struct net_device *dev;
388 dev = dev_get_by_index(&init_net, ro->ifindex);
390 raw_disable_allfilters(dev, sk);
394 raw_disable_allfilters(NULL, sk);
403 free_percpu(ro->uniq);
414 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
416 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
417 struct sock *sk = sock->sk;
418 struct raw_sock *ro = raw_sk(sk);
421 int notify_enetdown = 0;
423 if (len < sizeof(*addr))
428 if (ro->bound && addr->can_ifindex == ro->ifindex)
431 if (addr->can_ifindex) {
432 struct net_device *dev;
434 dev = dev_get_by_index(&init_net, addr->can_ifindex);
439 if (dev->type != ARPHRD_CAN) {
444 if (!(dev->flags & IFF_UP))
447 ifindex = dev->ifindex;
449 /* filters set by default/setsockopt */
450 err = raw_enable_allfilters(dev, sk);
455 /* filters set by default/setsockopt */
456 err = raw_enable_allfilters(NULL, sk);
461 /* unregister old filters */
463 struct net_device *dev;
465 dev = dev_get_by_index(&init_net, ro->ifindex);
467 raw_disable_allfilters(dev, sk);
471 raw_disable_allfilters(NULL, sk);
473 ro->ifindex = ifindex;
480 if (notify_enetdown) {
481 sk->sk_err = ENETDOWN;
482 if (!sock_flag(sk, SOCK_DEAD))
483 sk->sk_error_report(sk);
489 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
492 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
493 struct sock *sk = sock->sk;
494 struct raw_sock *ro = raw_sk(sk);
499 memset(addr, 0, sizeof(*addr));
500 addr->can_family = AF_CAN;
501 addr->can_ifindex = ro->ifindex;
503 *len = sizeof(*addr);
508 static int raw_setsockopt(struct socket *sock, int level, int optname,
509 char __user *optval, unsigned int optlen)
511 struct sock *sk = sock->sk;
512 struct raw_sock *ro = raw_sk(sk);
513 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
514 struct can_filter sfilter; /* single filter */
515 struct net_device *dev = NULL;
516 can_err_mask_t err_mask = 0;
520 if (level != SOL_CAN_RAW)
526 if (optlen % sizeof(struct can_filter) != 0)
529 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
532 count = optlen / sizeof(struct can_filter);
535 /* filter does not fit into dfilter => alloc space */
536 filter = memdup_user(optval, optlen);
538 return PTR_ERR(filter);
539 } else if (count == 1) {
540 if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
547 if (ro->bound && ro->ifindex) {
548 dev = dev_get_by_index(&init_net, ro->ifindex);
558 /* (try to) register the new filters */
560 err = raw_enable_filters(dev, sk, &sfilter, 1);
562 err = raw_enable_filters(dev, sk, filter,
570 /* remove old filter registrations */
571 raw_disable_filters(dev, sk, ro->filter, ro->count);
574 /* remove old filter space */
578 /* link new filters to the socket */
580 /* copy filter data for single filter */
581 ro->dfilter = sfilter;
582 filter = &ro->dfilter;
596 case CAN_RAW_ERR_FILTER:
597 if (optlen != sizeof(err_mask))
600 if (copy_from_user(&err_mask, optval, optlen))
603 err_mask &= CAN_ERR_MASK;
608 if (ro->bound && ro->ifindex) {
609 dev = dev_get_by_index(&init_net, ro->ifindex);
616 /* remove current error mask */
618 /* (try to) register the new err_mask */
619 err = raw_enable_errfilter(dev, sk, err_mask);
624 /* remove old err_mask registration */
625 raw_disable_errfilter(dev, sk, ro->err_mask);
628 /* link new err_mask to the socket */
629 ro->err_mask = err_mask;
640 case CAN_RAW_LOOPBACK:
641 if (optlen != sizeof(ro->loopback))
644 if (copy_from_user(&ro->loopback, optval, optlen))
649 case CAN_RAW_RECV_OWN_MSGS:
650 if (optlen != sizeof(ro->recv_own_msgs))
653 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
658 case CAN_RAW_FD_FRAMES:
659 if (optlen != sizeof(ro->fd_frames))
662 if (copy_from_user(&ro->fd_frames, optval, optlen))
667 case CAN_RAW_JOIN_FILTERS:
668 if (optlen != sizeof(ro->join_filters))
671 if (copy_from_user(&ro->join_filters, optval, optlen))
682 static int raw_getsockopt(struct socket *sock, int level, int optname,
683 char __user *optval, int __user *optlen)
685 struct sock *sk = sock->sk;
686 struct raw_sock *ro = raw_sk(sk);
691 if (level != SOL_CAN_RAW)
693 if (get_user(len, optlen))
703 int fsize = ro->count * sizeof(struct can_filter);
706 if (copy_to_user(optval, ro->filter, len))
713 err = put_user(len, optlen);
716 case CAN_RAW_ERR_FILTER:
717 if (len > sizeof(can_err_mask_t))
718 len = sizeof(can_err_mask_t);
722 case CAN_RAW_LOOPBACK:
723 if (len > sizeof(int))
728 case CAN_RAW_RECV_OWN_MSGS:
729 if (len > sizeof(int))
731 val = &ro->recv_own_msgs;
734 case CAN_RAW_FD_FRAMES:
735 if (len > sizeof(int))
737 val = &ro->fd_frames;
740 case CAN_RAW_JOIN_FILTERS:
741 if (len > sizeof(int))
743 val = &ro->join_filters;
750 if (put_user(len, optlen))
752 if (copy_to_user(optval, val, len))
757 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
759 struct sock *sk = sock->sk;
760 struct raw_sock *ro = raw_sk(sk);
762 struct net_device *dev;
767 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
769 if (msg->msg_namelen < sizeof(*addr))
772 if (addr->can_family != AF_CAN)
775 ifindex = addr->can_ifindex;
777 ifindex = ro->ifindex;
780 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
783 if (unlikely(size != CAN_MTU))
787 dev = dev_get_by_index(&init_net, ifindex);
791 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
792 msg->msg_flags & MSG_DONTWAIT, &err);
796 can_skb_reserve(skb);
797 can_skb_prv(skb)->ifindex = dev->ifindex;
798 can_skb_prv(skb)->skbcnt = 0;
800 err = memcpy_from_msg(skb_put(skb, size), msg, size);
804 sock_tx_timestamp(sk, sk->sk_tsflags, &skb_shinfo(skb)->tx_flags);
808 skb->priority = sk->sk_priority;
810 err = can_send(skb, ro->loopback);
827 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
830 struct sock *sk = sock->sk;
835 noblock = flags & MSG_DONTWAIT;
836 flags &= ~MSG_DONTWAIT;
838 skb = skb_recv_datagram(sk, flags, noblock, &err);
843 msg->msg_flags |= MSG_TRUNC;
847 err = memcpy_to_msg(msg, skb->data, size);
849 skb_free_datagram(sk, skb);
853 sock_recv_ts_and_drops(msg, sk, skb);
856 __sockaddr_check_size(sizeof(struct sockaddr_can));
857 msg->msg_namelen = sizeof(struct sockaddr_can);
858 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
861 /* assign the flags that have been recorded in raw_rcv() */
862 msg->msg_flags |= *(raw_flags(skb));
864 skb_free_datagram(sk, skb);
869 static const struct proto_ops raw_ops = {
871 .release = raw_release,
873 .connect = sock_no_connect,
874 .socketpair = sock_no_socketpair,
875 .accept = sock_no_accept,
876 .getname = raw_getname,
877 .poll = datagram_poll,
878 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
879 .listen = sock_no_listen,
880 .shutdown = sock_no_shutdown,
881 .setsockopt = raw_setsockopt,
882 .getsockopt = raw_getsockopt,
883 .sendmsg = raw_sendmsg,
884 .recvmsg = raw_recvmsg,
885 .mmap = sock_no_mmap,
886 .sendpage = sock_no_sendpage,
889 static struct proto raw_proto __read_mostly = {
891 .owner = THIS_MODULE,
892 .obj_size = sizeof(struct raw_sock),
896 static const struct can_proto raw_can_proto = {
903 static struct notifier_block canraw_notifier = {
904 .notifier_call = raw_notifier
907 static __init int raw_module_init(void)
911 pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n");
913 err = can_proto_register(&raw_can_proto);
915 printk(KERN_ERR "can: registration of raw protocol failed\n");
917 register_netdevice_notifier(&canraw_notifier);
922 static __exit void raw_module_exit(void)
924 can_proto_unregister(&raw_can_proto);
925 unregister_netdevice_notifier(&canraw_notifier);
928 module_init(raw_module_init);
929 module_exit(raw_module_exit);