1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
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");
65 #define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
69 /* A raw socket has a list of can_filters attached to it, each receiving
70 * the CAN frames matching that filter. If the filter list is empty,
71 * no CAN frames will be received by the socket. The default after
72 * opening the socket, is to have one filter which receives all frames.
73 * The filter list is allocated dynamically with the exception of the
74 * list containing only one item. This common case is optimized by
75 * storing the single filter in dfilter, to avoid using dynamic memory.
80 const struct sk_buff *skb;
81 unsigned int join_rx_count;
88 struct list_head notifier;
93 int count; /* number of active filters */
94 struct can_filter dfilter; /* default/single filter */
95 struct can_filter *filter; /* pointer to filter(s) */
96 can_err_mask_t err_mask;
97 struct uniqframe __percpu *uniq;
100 static LIST_HEAD(raw_notifier_list);
101 static DEFINE_SPINLOCK(raw_notifier_lock);
102 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);
163 /* Put the datagram to the queue so that raw_recvmsg() can
164 * get it from there. We need to pass the interface index to
165 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
166 * containing the interface index.
169 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
170 addr = (struct sockaddr_can *)skb->cb;
171 memset(addr, 0, sizeof(*addr));
172 addr->can_family = AF_CAN;
173 addr->can_ifindex = skb->dev->ifindex;
175 /* add CAN specific message flags for raw_recvmsg() */
176 pflags = raw_flags(skb);
179 *pflags |= MSG_DONTROUTE;
181 *pflags |= MSG_CONFIRM;
183 if (sock_queue_rcv_skb(sk, skb) < 0)
187 static int raw_enable_filters(struct net *net, struct net_device *dev,
188 struct sock *sk, struct can_filter *filter,
194 for (i = 0; i < count; i++) {
195 err = can_rx_register(net, dev, filter[i].can_id,
197 raw_rcv, sk, "raw", sk);
199 /* clean up successfully registered filters */
201 can_rx_unregister(net, dev, filter[i].can_id,
211 static int raw_enable_errfilter(struct net *net, struct net_device *dev,
212 struct sock *sk, can_err_mask_t err_mask)
217 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
218 raw_rcv, sk, "raw", sk);
223 static void raw_disable_filters(struct net *net, struct net_device *dev,
224 struct sock *sk, struct can_filter *filter,
229 for (i = 0; i < count; i++)
230 can_rx_unregister(net, dev, filter[i].can_id,
231 filter[i].can_mask, raw_rcv, sk);
234 static inline void raw_disable_errfilter(struct net *net,
235 struct net_device *dev,
237 can_err_mask_t err_mask)
241 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
245 static inline void raw_disable_allfilters(struct net *net,
246 struct net_device *dev,
249 struct raw_sock *ro = raw_sk(sk);
251 raw_disable_filters(net, dev, sk, ro->filter, ro->count);
252 raw_disable_errfilter(net, dev, sk, ro->err_mask);
255 static int raw_enable_allfilters(struct net *net, struct net_device *dev,
258 struct raw_sock *ro = raw_sk(sk);
261 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
263 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
265 raw_disable_filters(net, dev, sk, ro->filter,
272 static void raw_notify(struct raw_sock *ro, unsigned long msg,
273 struct net_device *dev)
275 struct sock *sk = &ro->sk;
277 if (!net_eq(dev_net(dev), sock_net(sk)))
280 if (ro->ifindex != dev->ifindex)
284 case NETDEV_UNREGISTER:
286 /* remove current filters & unregister */
288 raw_disable_allfilters(dev_net(dev), dev, sk);
299 if (!sock_flag(sk, SOCK_DEAD))
300 sk->sk_error_report(sk);
304 sk->sk_err = ENETDOWN;
305 if (!sock_flag(sk, SOCK_DEAD))
306 sk->sk_error_report(sk);
311 static int raw_notifier(struct notifier_block *nb, unsigned long msg,
314 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
316 if (dev->type != ARPHRD_CAN)
318 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
320 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
323 spin_lock(&raw_notifier_lock);
324 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
325 spin_unlock(&raw_notifier_lock);
326 raw_notify(raw_busy_notifier, msg, dev);
327 spin_lock(&raw_notifier_lock);
329 raw_busy_notifier = NULL;
330 spin_unlock(&raw_notifier_lock);
334 static int raw_init(struct sock *sk)
336 struct raw_sock *ro = raw_sk(sk);
341 /* set default filter to single entry dfilter */
342 ro->dfilter.can_id = 0;
343 ro->dfilter.can_mask = MASK_ALL;
344 ro->filter = &ro->dfilter;
347 /* set default loopback behaviour */
349 ro->recv_own_msgs = 0;
351 ro->join_filters = 0;
353 /* alloc_percpu provides zero'ed memory */
354 ro->uniq = alloc_percpu(struct uniqframe);
355 if (unlikely(!ro->uniq))
359 spin_lock(&raw_notifier_lock);
360 list_add_tail(&ro->notifier, &raw_notifier_list);
361 spin_unlock(&raw_notifier_lock);
366 static int raw_release(struct socket *sock)
368 struct sock *sk = sock->sk;
376 spin_lock(&raw_notifier_lock);
377 while (raw_busy_notifier == ro) {
378 spin_unlock(&raw_notifier_lock);
379 schedule_timeout_uninterruptible(1);
380 spin_lock(&raw_notifier_lock);
382 list_del(&ro->notifier);
383 spin_unlock(&raw_notifier_lock);
387 /* remove current filters & unregister */
390 struct net_device *dev;
392 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
394 raw_disable_allfilters(dev_net(dev), dev, sk);
398 raw_disable_allfilters(sock_net(sk), NULL, sk);
408 free_percpu(ro->uniq);
419 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
421 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
422 struct sock *sk = sock->sk;
423 struct raw_sock *ro = raw_sk(sk);
426 int notify_enetdown = 0;
428 if (len < RAW_MIN_NAMELEN)
430 if (addr->can_family != AF_CAN)
435 if (ro->bound && addr->can_ifindex == ro->ifindex)
438 if (addr->can_ifindex) {
439 struct net_device *dev;
441 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
446 if (dev->type != ARPHRD_CAN) {
451 if (!(dev->flags & IFF_UP))
454 ifindex = dev->ifindex;
456 /* filters set by default/setsockopt */
457 err = raw_enable_allfilters(sock_net(sk), dev, sk);
462 /* filters set by default/setsockopt */
463 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
468 /* unregister old filters */
470 struct net_device *dev;
472 dev = dev_get_by_index(sock_net(sk),
475 raw_disable_allfilters(dev_net(dev),
480 raw_disable_allfilters(sock_net(sk), NULL, sk);
483 ro->ifindex = ifindex;
490 if (notify_enetdown) {
491 sk->sk_err = ENETDOWN;
492 if (!sock_flag(sk, SOCK_DEAD))
493 sk->sk_error_report(sk);
499 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
502 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
503 struct sock *sk = sock->sk;
504 struct raw_sock *ro = raw_sk(sk);
509 memset(addr, 0, RAW_MIN_NAMELEN);
510 addr->can_family = AF_CAN;
511 addr->can_ifindex = ro->ifindex;
513 return RAW_MIN_NAMELEN;
516 static int raw_setsockopt(struct socket *sock, int level, int optname,
517 char __user *optval, unsigned int optlen)
519 struct sock *sk = sock->sk;
520 struct raw_sock *ro = raw_sk(sk);
521 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
522 struct can_filter sfilter; /* single filter */
523 struct net_device *dev = NULL;
524 can_err_mask_t err_mask = 0;
528 if (level != SOL_CAN_RAW)
533 if (optlen % sizeof(struct can_filter) != 0)
536 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
539 count = optlen / sizeof(struct can_filter);
542 /* filter does not fit into dfilter => alloc space */
543 filter = memdup_user(optval, optlen);
545 return PTR_ERR(filter);
546 } else if (count == 1) {
547 if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
554 if (ro->bound && ro->ifindex) {
555 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
565 /* (try to) register the new filters */
567 err = raw_enable_filters(sock_net(sk), dev, sk,
570 err = raw_enable_filters(sock_net(sk), dev, sk,
578 /* remove old filter registrations */
579 raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
583 /* remove old filter space */
587 /* link new filters to the socket */
589 /* copy filter data for single filter */
590 ro->dfilter = sfilter;
591 filter = &ro->dfilter;
605 case CAN_RAW_ERR_FILTER:
606 if (optlen != sizeof(err_mask))
609 if (copy_from_user(&err_mask, optval, optlen))
612 err_mask &= CAN_ERR_MASK;
617 if (ro->bound && ro->ifindex) {
618 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
625 /* remove current error mask */
627 /* (try to) register the new err_mask */
628 err = raw_enable_errfilter(sock_net(sk), dev, sk,
634 /* remove old err_mask registration */
635 raw_disable_errfilter(sock_net(sk), dev, sk,
639 /* link new err_mask to the socket */
640 ro->err_mask = err_mask;
651 case CAN_RAW_LOOPBACK:
652 if (optlen != sizeof(ro->loopback))
655 if (copy_from_user(&ro->loopback, optval, optlen))
660 case CAN_RAW_RECV_OWN_MSGS:
661 if (optlen != sizeof(ro->recv_own_msgs))
664 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
669 case CAN_RAW_FD_FRAMES:
670 if (optlen != sizeof(ro->fd_frames))
673 if (copy_from_user(&ro->fd_frames, optval, optlen))
678 case CAN_RAW_JOIN_FILTERS:
679 if (optlen != sizeof(ro->join_filters))
682 if (copy_from_user(&ro->join_filters, optval, optlen))
693 static int raw_getsockopt(struct socket *sock, int level, int optname,
694 char __user *optval, int __user *optlen)
696 struct sock *sk = sock->sk;
697 struct raw_sock *ro = raw_sk(sk);
702 if (level != SOL_CAN_RAW)
704 if (get_user(len, optlen))
713 int fsize = ro->count * sizeof(struct can_filter);
717 if (copy_to_user(optval, ro->filter, len))
725 err = put_user(len, optlen);
728 case CAN_RAW_ERR_FILTER:
729 if (len > sizeof(can_err_mask_t))
730 len = sizeof(can_err_mask_t);
734 case CAN_RAW_LOOPBACK:
735 if (len > sizeof(int))
740 case CAN_RAW_RECV_OWN_MSGS:
741 if (len > sizeof(int))
743 val = &ro->recv_own_msgs;
746 case CAN_RAW_FD_FRAMES:
747 if (len > sizeof(int))
749 val = &ro->fd_frames;
752 case CAN_RAW_JOIN_FILTERS:
753 if (len > sizeof(int))
755 val = &ro->join_filters;
762 if (put_user(len, optlen))
764 if (copy_to_user(optval, val, len))
769 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
771 struct sock *sk = sock->sk;
772 struct raw_sock *ro = raw_sk(sk);
774 struct net_device *dev;
779 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
781 if (msg->msg_namelen < RAW_MIN_NAMELEN)
784 if (addr->can_family != AF_CAN)
787 ifindex = addr->can_ifindex;
789 ifindex = ro->ifindex;
792 dev = dev_get_by_index(sock_net(sk), ifindex);
797 if (ro->fd_frames && dev->mtu == CANFD_MTU) {
798 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
801 if (unlikely(size != CAN_MTU))
805 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
806 msg->msg_flags & MSG_DONTWAIT, &err);
810 can_skb_reserve(skb);
811 can_skb_prv(skb)->ifindex = dev->ifindex;
812 can_skb_prv(skb)->skbcnt = 0;
814 err = memcpy_from_msg(skb_put(skb, size), msg, size);
818 skb_setup_tx_timestamp(skb, sk->sk_tsflags);
822 skb->priority = sk->sk_priority;
824 err = can_send(skb, ro->loopback);
841 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
844 struct sock *sk = sock->sk;
849 noblock = flags & MSG_DONTWAIT;
850 flags &= ~MSG_DONTWAIT;
852 skb = skb_recv_datagram(sk, flags, noblock, &err);
857 msg->msg_flags |= MSG_TRUNC;
861 err = memcpy_to_msg(msg, skb->data, size);
863 skb_free_datagram(sk, skb);
867 sock_recv_ts_and_drops(msg, sk, skb);
870 __sockaddr_check_size(RAW_MIN_NAMELEN);
871 msg->msg_namelen = RAW_MIN_NAMELEN;
872 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
875 /* assign the flags that have been recorded in raw_rcv() */
876 msg->msg_flags |= *(raw_flags(skb));
878 skb_free_datagram(sk, skb);
883 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
886 /* no ioctls for socket layer -> hand it down to NIC layer */
890 static const struct proto_ops raw_ops = {
892 .release = raw_release,
894 .connect = sock_no_connect,
895 .socketpair = sock_no_socketpair,
896 .accept = sock_no_accept,
897 .getname = raw_getname,
898 .poll = datagram_poll,
899 .ioctl = raw_sock_no_ioctlcmd,
900 .gettstamp = sock_gettstamp,
901 .listen = sock_no_listen,
902 .shutdown = sock_no_shutdown,
903 .setsockopt = raw_setsockopt,
904 .getsockopt = raw_getsockopt,
905 .sendmsg = raw_sendmsg,
906 .recvmsg = raw_recvmsg,
907 .mmap = sock_no_mmap,
908 .sendpage = sock_no_sendpage,
911 static struct proto raw_proto __read_mostly = {
913 .owner = THIS_MODULE,
914 .obj_size = sizeof(struct raw_sock),
918 static const struct can_proto raw_can_proto = {
925 static struct notifier_block canraw_notifier = {
926 .notifier_call = raw_notifier
929 static __init int raw_module_init(void)
933 pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n");
935 err = can_proto_register(&raw_can_proto);
937 pr_err("can: registration of raw protocol failed\n");
939 register_netdevice_notifier(&canraw_notifier);
944 static __exit void raw_module_exit(void)
946 can_proto_unregister(&raw_can_proto);
947 unregister_netdevice_notifier(&canraw_notifier);
950 module_init(raw_module_init);
951 module_exit(raw_module_exit);