1 // SPDX-License-Identifier: (GPL-2.0 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 MODULE_DESCRIPTION("PF_CAN raw protocol");
59 MODULE_LICENSE("Dual BSD/GPL");
60 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
61 MODULE_ALIAS("can-proto-1");
63 #define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
67 /* A raw socket has a list of can_filters attached to it, each receiving
68 * the CAN frames matching that filter. If the filter list is empty,
69 * no CAN frames will be received by the socket. The default after
70 * opening the socket, is to have one filter which receives all frames.
71 * The filter list is allocated dynamically with the exception of the
72 * list containing only one item. This common case is optimized by
73 * storing the single filter in dfilter, to avoid using dynamic memory.
78 const struct sk_buff *skb;
79 unsigned int join_rx_count;
86 struct net_device *dev;
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;
103 /* Return pointer to store the extra msg flags for raw_recvmsg().
104 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
107 static inline unsigned int *raw_flags(struct sk_buff *skb)
109 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
110 sizeof(unsigned int));
112 /* return pointer after struct sockaddr_can */
113 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
116 static inline struct raw_sock *raw_sk(const struct sock *sk)
118 return (struct raw_sock *)sk;
121 static void raw_rcv(struct sk_buff *oskb, void *data)
123 struct sock *sk = (struct sock *)data;
124 struct raw_sock *ro = raw_sk(sk);
125 struct sockaddr_can *addr;
127 unsigned int *pflags;
129 /* check the received tx sock reference */
130 if (!ro->recv_own_msgs && oskb->sk == sk)
133 /* do not pass non-CAN2.0 frames to a legacy socket */
134 if (!ro->fd_frames && oskb->len != CAN_MTU)
137 /* eliminate multiple filter matches for the same skb */
138 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
139 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
140 if (ro->join_filters) {
141 this_cpu_inc(ro->uniq->join_rx_count);
142 /* drop frame until all enabled filters matched */
143 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
149 this_cpu_ptr(ro->uniq)->skb = oskb;
150 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
151 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
152 /* drop first frame to check all enabled filters? */
153 if (ro->join_filters && ro->count > 1)
157 /* clone the given skb to be able to enqueue it into the rcv queue */
158 skb = skb_clone(oskb, GFP_ATOMIC);
162 /* Put the datagram to the queue so that raw_recvmsg() can get
163 * it from there. We need to pass the interface index to
164 * raw_recvmsg(). We pass a whole struct sockaddr_can in
165 * skb->cb containing the interface index.
168 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
169 addr = (struct sockaddr_can *)skb->cb;
170 memset(addr, 0, sizeof(*addr));
171 addr->can_family = AF_CAN;
172 addr->can_ifindex = skb->dev->ifindex;
174 /* add CAN specific message flags for raw_recvmsg() */
175 pflags = raw_flags(skb);
178 *pflags |= MSG_DONTROUTE;
180 *pflags |= MSG_CONFIRM;
182 if (sock_queue_rcv_skb(sk, skb) < 0)
186 static int raw_enable_filters(struct net *net, struct net_device *dev,
187 struct sock *sk, struct can_filter *filter,
193 for (i = 0; i < count; i++) {
194 err = can_rx_register(net, dev, filter[i].can_id,
196 raw_rcv, sk, "raw", sk);
198 /* clean up successfully registered filters */
200 can_rx_unregister(net, dev, filter[i].can_id,
210 static int raw_enable_errfilter(struct net *net, struct net_device *dev,
211 struct sock *sk, can_err_mask_t err_mask)
216 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
217 raw_rcv, sk, "raw", sk);
222 static void raw_disable_filters(struct net *net, struct net_device *dev,
223 struct sock *sk, struct can_filter *filter,
228 for (i = 0; i < count; i++)
229 can_rx_unregister(net, dev, filter[i].can_id,
230 filter[i].can_mask, raw_rcv, sk);
233 static inline void raw_disable_errfilter(struct net *net,
234 struct net_device *dev,
236 can_err_mask_t err_mask)
240 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
244 static inline void raw_disable_allfilters(struct net *net,
245 struct net_device *dev,
248 struct raw_sock *ro = raw_sk(sk);
250 raw_disable_filters(net, dev, sk, ro->filter, ro->count);
251 raw_disable_errfilter(net, dev, sk, ro->err_mask);
254 static int raw_enable_allfilters(struct net *net, struct net_device *dev,
257 struct raw_sock *ro = raw_sk(sk);
260 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
262 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
264 raw_disable_filters(net, dev, sk, ro->filter,
271 static void raw_notify(struct raw_sock *ro, unsigned long msg,
272 struct net_device *dev)
274 struct sock *sk = &ro->sk;
276 if (!net_eq(dev_net(dev), sock_net(sk)))
283 case NETDEV_UNREGISTER:
285 /* remove current filters & unregister */
287 raw_disable_allfilters(dev_net(dev), dev, sk);
301 if (!sock_flag(sk, SOCK_DEAD))
306 sk->sk_err = ENETDOWN;
307 if (!sock_flag(sk, SOCK_DEAD))
313 static int raw_notifier(struct notifier_block *nb, unsigned long msg,
316 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
318 if (dev->type != ARPHRD_CAN)
320 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
322 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
325 spin_lock(&raw_notifier_lock);
326 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
327 spin_unlock(&raw_notifier_lock);
328 raw_notify(raw_busy_notifier, msg, dev);
329 spin_lock(&raw_notifier_lock);
331 raw_busy_notifier = NULL;
332 spin_unlock(&raw_notifier_lock);
336 static int raw_init(struct sock *sk)
338 struct raw_sock *ro = raw_sk(sk);
344 /* set default filter to single entry dfilter */
345 ro->dfilter.can_id = 0;
346 ro->dfilter.can_mask = MASK_ALL;
347 ro->filter = &ro->dfilter;
350 /* set default loopback behaviour */
352 ro->recv_own_msgs = 0;
354 ro->join_filters = 0;
356 /* alloc_percpu provides zero'ed memory */
357 ro->uniq = alloc_percpu(struct uniqframe);
358 if (unlikely(!ro->uniq))
362 spin_lock(&raw_notifier_lock);
363 list_add_tail(&ro->notifier, &raw_notifier_list);
364 spin_unlock(&raw_notifier_lock);
369 static int raw_release(struct socket *sock)
371 struct sock *sk = sock->sk;
379 spin_lock(&raw_notifier_lock);
380 while (raw_busy_notifier == ro) {
381 spin_unlock(&raw_notifier_lock);
382 schedule_timeout_uninterruptible(1);
383 spin_lock(&raw_notifier_lock);
385 list_del(&ro->notifier);
386 spin_unlock(&raw_notifier_lock);
391 /* remove current filters & unregister */
394 raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
397 raw_disable_allfilters(sock_net(sk), NULL, sk);
408 free_percpu(ro->uniq);
421 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
423 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
424 struct sock *sk = sock->sk;
425 struct raw_sock *ro = raw_sk(sk);
426 struct net_device *dev = NULL;
429 int notify_enetdown = 0;
431 if (len < RAW_MIN_NAMELEN)
433 if (addr->can_family != AF_CAN)
439 if (ro->bound && addr->can_ifindex == ro->ifindex)
442 if (addr->can_ifindex) {
443 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
448 if (dev->type != ARPHRD_CAN) {
453 if (!(dev->flags & IFF_UP))
456 ifindex = dev->ifindex;
458 /* filters set by default/setsockopt */
459 err = raw_enable_allfilters(sock_net(sk), dev, sk);
466 /* filters set by default/setsockopt */
467 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
472 /* unregister old filters */
474 raw_disable_allfilters(dev_net(ro->dev),
476 /* drop reference to old ro->dev */
479 raw_disable_allfilters(sock_net(sk), NULL, sk);
482 ro->ifindex = ifindex;
484 /* bind() ok -> hold a reference for new ro->dev */
491 /* remove potential reference from dev_get_by_index() */
498 if (notify_enetdown) {
499 sk->sk_err = ENETDOWN;
500 if (!sock_flag(sk, SOCK_DEAD))
507 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
510 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
511 struct sock *sk = sock->sk;
512 struct raw_sock *ro = raw_sk(sk);
517 memset(addr, 0, RAW_MIN_NAMELEN);
518 addr->can_family = AF_CAN;
519 addr->can_ifindex = ro->ifindex;
521 return RAW_MIN_NAMELEN;
524 static int raw_setsockopt(struct socket *sock, int level, int optname,
525 sockptr_t optval, unsigned int optlen)
527 struct sock *sk = sock->sk;
528 struct raw_sock *ro = raw_sk(sk);
529 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
530 struct can_filter sfilter; /* single filter */
531 struct net_device *dev = NULL;
532 can_err_mask_t err_mask = 0;
536 if (level != SOL_CAN_RAW)
541 if (optlen % sizeof(struct can_filter) != 0)
544 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
547 count = optlen / sizeof(struct can_filter);
550 /* filter does not fit into dfilter => alloc space */
551 filter = memdup_sockptr(optval, optlen);
553 return PTR_ERR(filter);
554 } else if (count == 1) {
555 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
563 if (ro->bound && dev) {
564 if (dev->reg_state != NETREG_REGISTERED) {
573 /* (try to) register the new filters */
575 err = raw_enable_filters(sock_net(sk), dev, sk,
578 err = raw_enable_filters(sock_net(sk), dev, sk,
586 /* remove old filter registrations */
587 raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
591 /* remove old filter space */
595 /* link new filters to the socket */
597 /* copy filter data for single filter */
598 ro->dfilter = sfilter;
599 filter = &ro->dfilter;
610 case CAN_RAW_ERR_FILTER:
611 if (optlen != sizeof(err_mask))
614 if (copy_from_sockptr(&err_mask, optval, optlen))
617 err_mask &= CAN_ERR_MASK;
623 if (ro->bound && dev) {
624 if (dev->reg_state != NETREG_REGISTERED) {
630 /* remove current error mask */
632 /* (try to) register the new err_mask */
633 err = raw_enable_errfilter(sock_net(sk), dev, sk,
639 /* remove old err_mask registration */
640 raw_disable_errfilter(sock_net(sk), dev, sk,
644 /* link new err_mask to the socket */
645 ro->err_mask = err_mask;
653 case CAN_RAW_LOOPBACK:
654 if (optlen != sizeof(ro->loopback))
657 if (copy_from_sockptr(&ro->loopback, optval, optlen))
662 case CAN_RAW_RECV_OWN_MSGS:
663 if (optlen != sizeof(ro->recv_own_msgs))
666 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen))
671 case CAN_RAW_FD_FRAMES:
672 if (optlen != sizeof(ro->fd_frames))
675 if (copy_from_sockptr(&ro->fd_frames, optval, optlen))
680 case CAN_RAW_JOIN_FILTERS:
681 if (optlen != sizeof(ro->join_filters))
684 if (copy_from_sockptr(&ro->join_filters, optval, optlen))
695 static int raw_getsockopt(struct socket *sock, int level, int optname,
696 char __user *optval, int __user *optlen)
698 struct sock *sk = sock->sk;
699 struct raw_sock *ro = raw_sk(sk);
704 if (level != SOL_CAN_RAW)
706 if (get_user(len, optlen))
715 int fsize = ro->count * sizeof(struct can_filter);
717 /* user space buffer to small for filter list? */
719 /* return -ERANGE and needed space in optlen */
721 if (put_user(fsize, optlen))
726 if (copy_to_user(optval, ro->filter, len))
735 err = put_user(len, optlen);
738 case CAN_RAW_ERR_FILTER:
739 if (len > sizeof(can_err_mask_t))
740 len = sizeof(can_err_mask_t);
744 case CAN_RAW_LOOPBACK:
745 if (len > sizeof(int))
750 case CAN_RAW_RECV_OWN_MSGS:
751 if (len > sizeof(int))
753 val = &ro->recv_own_msgs;
756 case CAN_RAW_FD_FRAMES:
757 if (len > sizeof(int))
759 val = &ro->fd_frames;
762 case CAN_RAW_JOIN_FILTERS:
763 if (len > sizeof(int))
765 val = &ro->join_filters;
772 if (put_user(len, optlen))
774 if (copy_to_user(optval, val, len))
779 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
781 struct sock *sk = sock->sk;
782 struct raw_sock *ro = raw_sk(sk);
784 struct net_device *dev;
789 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
791 if (msg->msg_namelen < RAW_MIN_NAMELEN)
794 if (addr->can_family != AF_CAN)
797 ifindex = addr->can_ifindex;
799 ifindex = ro->ifindex;
802 dev = dev_get_by_index(sock_net(sk), ifindex);
807 if (ro->fd_frames && dev->mtu == CANFD_MTU) {
808 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
811 if (unlikely(size != CAN_MTU))
815 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
816 msg->msg_flags & MSG_DONTWAIT, &err);
820 can_skb_reserve(skb);
821 can_skb_prv(skb)->ifindex = dev->ifindex;
822 can_skb_prv(skb)->skbcnt = 0;
824 err = memcpy_from_msg(skb_put(skb, size), msg, size);
828 skb_setup_tx_timestamp(skb, sk->sk_tsflags);
832 skb->priority = sk->sk_priority;
834 err = can_send(skb, ro->loopback);
851 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
854 struct sock *sk = sock->sk;
859 noblock = flags & MSG_DONTWAIT;
860 flags &= ~MSG_DONTWAIT;
862 if (flags & MSG_ERRQUEUE)
863 return sock_recv_errqueue(sk, msg, size,
864 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
866 skb = skb_recv_datagram(sk, flags, noblock, &err);
871 msg->msg_flags |= MSG_TRUNC;
875 err = memcpy_to_msg(msg, skb->data, size);
877 skb_free_datagram(sk, skb);
881 sock_recv_ts_and_drops(msg, sk, skb);
884 __sockaddr_check_size(RAW_MIN_NAMELEN);
885 msg->msg_namelen = RAW_MIN_NAMELEN;
886 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
889 /* assign the flags that have been recorded in raw_rcv() */
890 msg->msg_flags |= *(raw_flags(skb));
892 skb_free_datagram(sk, skb);
897 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
900 /* no ioctls for socket layer -> hand it down to NIC layer */
904 static const struct proto_ops raw_ops = {
906 .release = raw_release,
908 .connect = sock_no_connect,
909 .socketpair = sock_no_socketpair,
910 .accept = sock_no_accept,
911 .getname = raw_getname,
912 .poll = datagram_poll,
913 .ioctl = raw_sock_no_ioctlcmd,
914 .gettstamp = sock_gettstamp,
915 .listen = sock_no_listen,
916 .shutdown = sock_no_shutdown,
917 .setsockopt = raw_setsockopt,
918 .getsockopt = raw_getsockopt,
919 .sendmsg = raw_sendmsg,
920 .recvmsg = raw_recvmsg,
921 .mmap = sock_no_mmap,
922 .sendpage = sock_no_sendpage,
925 static struct proto raw_proto __read_mostly = {
927 .owner = THIS_MODULE,
928 .obj_size = sizeof(struct raw_sock),
932 static const struct can_proto raw_can_proto = {
939 static struct notifier_block canraw_notifier = {
940 .notifier_call = raw_notifier
943 static __init int raw_module_init(void)
947 pr_info("can: raw protocol\n");
949 err = can_proto_register(&raw_can_proto);
951 pr_err("can: registration of raw protocol failed\n");
953 register_netdevice_notifier(&canraw_notifier);
958 static __exit void raw_module_exit(void)
960 can_proto_unregister(&raw_can_proto);
961 unregister_netdevice_notifier(&canraw_notifier);
964 module_init(raw_module_init);
965 module_exit(raw_module_exit);