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
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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");
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 notifier_block 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;
100 * Return pointer to store the extra msg flags for raw_recvmsg().
101 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
104 static inline unsigned int *raw_flags(struct sk_buff *skb)
106 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
107 sizeof(unsigned int));
109 /* return pointer after struct sockaddr_can */
110 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
113 static inline struct raw_sock *raw_sk(const struct sock *sk)
115 return (struct raw_sock *)sk;
118 static void raw_rcv(struct sk_buff *oskb, void *data)
120 struct sock *sk = (struct sock *)data;
121 struct raw_sock *ro = raw_sk(sk);
122 struct sockaddr_can *addr;
124 unsigned int *pflags;
126 /* check the received tx sock reference */
127 if (!ro->recv_own_msgs && oskb->sk == sk)
130 /* do not pass non-CAN2.0 frames to a legacy socket */
131 if (!ro->fd_frames && oskb->len != CAN_MTU)
134 /* eliminate multiple filter matches for the same skb */
135 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
136 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
137 if (ro->join_filters) {
138 this_cpu_inc(ro->uniq->join_rx_count);
139 /* drop frame until all enabled filters matched */
140 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
146 this_cpu_ptr(ro->uniq)->skb = oskb;
147 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
148 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
149 /* drop first frame to check all enabled filters? */
150 if (ro->join_filters && ro->count > 1)
154 /* clone the given skb to be able to enqueue it into the rcv queue */
155 skb = skb_clone(oskb, GFP_ATOMIC);
160 * Put the datagram to the queue so that raw_recvmsg() can
161 * get it from there. We need to pass the interface index to
162 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
163 * containing the interface index.
166 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
167 addr = (struct sockaddr_can *)skb->cb;
168 memset(addr, 0, sizeof(*addr));
169 addr->can_family = AF_CAN;
170 addr->can_ifindex = skb->dev->ifindex;
172 /* add CAN specific message flags for raw_recvmsg() */
173 pflags = raw_flags(skb);
176 *pflags |= MSG_DONTROUTE;
178 *pflags |= MSG_CONFIRM;
180 if (sock_queue_rcv_skb(sk, skb) < 0)
184 static int raw_enable_filters(struct net_device *dev, struct sock *sk,
185 struct can_filter *filter, int count)
190 for (i = 0; i < count; i++) {
191 err = can_rx_register(dev, filter[i].can_id,
195 /* clean up successfully registered filters */
197 can_rx_unregister(dev, filter[i].can_id,
207 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
208 can_err_mask_t err_mask)
213 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
219 static void raw_disable_filters(struct net_device *dev, struct sock *sk,
220 struct can_filter *filter, int count)
224 for (i = 0; i < count; i++)
225 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
229 static inline void raw_disable_errfilter(struct net_device *dev,
231 can_err_mask_t err_mask)
235 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
239 static inline void raw_disable_allfilters(struct net_device *dev,
242 struct raw_sock *ro = raw_sk(sk);
244 raw_disable_filters(dev, sk, ro->filter, ro->count);
245 raw_disable_errfilter(dev, sk, ro->err_mask);
248 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
250 struct raw_sock *ro = raw_sk(sk);
253 err = raw_enable_filters(dev, sk, ro->filter, ro->count);
255 err = raw_enable_errfilter(dev, sk, ro->err_mask);
257 raw_disable_filters(dev, sk, ro->filter, ro->count);
263 static int raw_notifier(struct notifier_block *nb,
264 unsigned long msg, void *ptr)
266 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
267 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
268 struct sock *sk = &ro->sk;
270 if (!net_eq(dev_net(dev), &init_net))
273 if (dev->type != ARPHRD_CAN)
276 if (ro->ifindex != dev->ifindex)
281 case NETDEV_UNREGISTER:
283 /* remove current filters & unregister */
285 raw_disable_allfilters(dev, sk);
296 if (!sock_flag(sk, SOCK_DEAD))
297 sk->sk_error_report(sk);
301 sk->sk_err = ENETDOWN;
302 if (!sock_flag(sk, SOCK_DEAD))
303 sk->sk_error_report(sk);
310 static int raw_init(struct sock *sk)
312 struct raw_sock *ro = raw_sk(sk);
317 /* set default filter to single entry dfilter */
318 ro->dfilter.can_id = 0;
319 ro->dfilter.can_mask = MASK_ALL;
320 ro->filter = &ro->dfilter;
323 /* set default loopback behaviour */
325 ro->recv_own_msgs = 0;
327 ro->join_filters = 0;
329 /* alloc_percpu provides zero'ed memory */
330 ro->uniq = alloc_percpu(struct uniqframe);
331 if (unlikely(!ro->uniq))
335 ro->notifier.notifier_call = raw_notifier;
337 register_netdevice_notifier(&ro->notifier);
342 static int raw_release(struct socket *sock)
344 struct sock *sk = sock->sk;
352 unregister_netdevice_notifier(&ro->notifier);
356 /* remove current filters & unregister */
359 struct net_device *dev;
361 dev = dev_get_by_index(&init_net, ro->ifindex);
363 raw_disable_allfilters(dev, sk);
367 raw_disable_allfilters(NULL, sk);
376 free_percpu(ro->uniq);
387 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
389 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
390 struct sock *sk = sock->sk;
391 struct raw_sock *ro = raw_sk(sk);
394 int notify_enetdown = 0;
396 if (len < sizeof(*addr))
401 if (ro->bound && addr->can_ifindex == ro->ifindex)
404 if (addr->can_ifindex) {
405 struct net_device *dev;
407 dev = dev_get_by_index(&init_net, addr->can_ifindex);
412 if (dev->type != ARPHRD_CAN) {
417 if (!(dev->flags & IFF_UP))
420 ifindex = dev->ifindex;
422 /* filters set by default/setsockopt */
423 err = raw_enable_allfilters(dev, sk);
428 /* filters set by default/setsockopt */
429 err = raw_enable_allfilters(NULL, sk);
434 /* unregister old filters */
436 struct net_device *dev;
438 dev = dev_get_by_index(&init_net, ro->ifindex);
440 raw_disable_allfilters(dev, sk);
444 raw_disable_allfilters(NULL, sk);
446 ro->ifindex = ifindex;
453 if (notify_enetdown) {
454 sk->sk_err = ENETDOWN;
455 if (!sock_flag(sk, SOCK_DEAD))
456 sk->sk_error_report(sk);
462 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
465 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
466 struct sock *sk = sock->sk;
467 struct raw_sock *ro = raw_sk(sk);
472 memset(addr, 0, sizeof(*addr));
473 addr->can_family = AF_CAN;
474 addr->can_ifindex = ro->ifindex;
476 *len = sizeof(*addr);
481 static int raw_setsockopt(struct socket *sock, int level, int optname,
482 char __user *optval, unsigned int optlen)
484 struct sock *sk = sock->sk;
485 struct raw_sock *ro = raw_sk(sk);
486 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
487 struct can_filter sfilter; /* single filter */
488 struct net_device *dev = NULL;
489 can_err_mask_t err_mask = 0;
493 if (level != SOL_CAN_RAW)
499 if (optlen % sizeof(struct can_filter) != 0)
502 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
505 count = optlen / sizeof(struct can_filter);
508 /* filter does not fit into dfilter => alloc space */
509 filter = memdup_user(optval, optlen);
511 return PTR_ERR(filter);
512 } else if (count == 1) {
513 if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
519 if (ro->bound && ro->ifindex)
520 dev = dev_get_by_index(&init_net, ro->ifindex);
523 /* (try to) register the new filters */
525 err = raw_enable_filters(dev, sk, &sfilter, 1);
527 err = raw_enable_filters(dev, sk, filter,
535 /* remove old filter registrations */
536 raw_disable_filters(dev, sk, ro->filter, ro->count);
539 /* remove old filter space */
543 /* link new filters to the socket */
545 /* copy filter data for single filter */
546 ro->dfilter = sfilter;
547 filter = &ro->dfilter;
560 case CAN_RAW_ERR_FILTER:
561 if (optlen != sizeof(err_mask))
564 if (copy_from_user(&err_mask, optval, optlen))
567 err_mask &= CAN_ERR_MASK;
571 if (ro->bound && ro->ifindex)
572 dev = dev_get_by_index(&init_net, ro->ifindex);
574 /* remove current error mask */
576 /* (try to) register the new err_mask */
577 err = raw_enable_errfilter(dev, sk, err_mask);
582 /* remove old err_mask registration */
583 raw_disable_errfilter(dev, sk, ro->err_mask);
586 /* link new err_mask to the socket */
587 ro->err_mask = err_mask;
597 case CAN_RAW_LOOPBACK:
598 if (optlen != sizeof(ro->loopback))
601 if (copy_from_user(&ro->loopback, optval, optlen))
606 case CAN_RAW_RECV_OWN_MSGS:
607 if (optlen != sizeof(ro->recv_own_msgs))
610 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
615 case CAN_RAW_FD_FRAMES:
616 if (optlen != sizeof(ro->fd_frames))
619 if (copy_from_user(&ro->fd_frames, optval, optlen))
624 case CAN_RAW_JOIN_FILTERS:
625 if (optlen != sizeof(ro->join_filters))
628 if (copy_from_user(&ro->join_filters, optval, optlen))
639 static int raw_getsockopt(struct socket *sock, int level, int optname,
640 char __user *optval, int __user *optlen)
642 struct sock *sk = sock->sk;
643 struct raw_sock *ro = raw_sk(sk);
648 if (level != SOL_CAN_RAW)
650 if (get_user(len, optlen))
660 int fsize = ro->count * sizeof(struct can_filter);
663 if (copy_to_user(optval, ro->filter, len))
670 err = put_user(len, optlen);
673 case CAN_RAW_ERR_FILTER:
674 if (len > sizeof(can_err_mask_t))
675 len = sizeof(can_err_mask_t);
679 case CAN_RAW_LOOPBACK:
680 if (len > sizeof(int))
685 case CAN_RAW_RECV_OWN_MSGS:
686 if (len > sizeof(int))
688 val = &ro->recv_own_msgs;
691 case CAN_RAW_FD_FRAMES:
692 if (len > sizeof(int))
694 val = &ro->fd_frames;
697 case CAN_RAW_JOIN_FILTERS:
698 if (len > sizeof(int))
700 val = &ro->join_filters;
707 if (put_user(len, optlen))
709 if (copy_to_user(optval, val, len))
714 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
716 struct sock *sk = sock->sk;
717 struct raw_sock *ro = raw_sk(sk);
719 struct net_device *dev;
724 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
726 if (msg->msg_namelen < sizeof(*addr))
729 if (addr->can_family != AF_CAN)
732 ifindex = addr->can_ifindex;
734 ifindex = ro->ifindex;
737 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
740 if (unlikely(size != CAN_MTU))
744 dev = dev_get_by_index(&init_net, ifindex);
748 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
749 msg->msg_flags & MSG_DONTWAIT, &err);
753 can_skb_reserve(skb);
754 can_skb_prv(skb)->ifindex = dev->ifindex;
755 can_skb_prv(skb)->skbcnt = 0;
757 err = memcpy_from_msg(skb_put(skb, size), msg, size);
761 sock_tx_timestamp(sk, sk->sk_tsflags, &skb_shinfo(skb)->tx_flags);
765 skb->priority = sk->sk_priority;
767 err = can_send(skb, ro->loopback);
784 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
787 struct sock *sk = sock->sk;
792 noblock = flags & MSG_DONTWAIT;
793 flags &= ~MSG_DONTWAIT;
795 skb = skb_recv_datagram(sk, flags, noblock, &err);
800 msg->msg_flags |= MSG_TRUNC;
804 err = memcpy_to_msg(msg, skb->data, size);
806 skb_free_datagram(sk, skb);
810 sock_recv_ts_and_drops(msg, sk, skb);
813 __sockaddr_check_size(sizeof(struct sockaddr_can));
814 msg->msg_namelen = sizeof(struct sockaddr_can);
815 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
818 /* assign the flags that have been recorded in raw_rcv() */
819 msg->msg_flags |= *(raw_flags(skb));
821 skb_free_datagram(sk, skb);
826 static const struct proto_ops raw_ops = {
828 .release = raw_release,
830 .connect = sock_no_connect,
831 .socketpair = sock_no_socketpair,
832 .accept = sock_no_accept,
833 .getname = raw_getname,
834 .poll = datagram_poll,
835 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
836 .listen = sock_no_listen,
837 .shutdown = sock_no_shutdown,
838 .setsockopt = raw_setsockopt,
839 .getsockopt = raw_getsockopt,
840 .sendmsg = raw_sendmsg,
841 .recvmsg = raw_recvmsg,
842 .mmap = sock_no_mmap,
843 .sendpage = sock_no_sendpage,
846 static struct proto raw_proto __read_mostly = {
848 .owner = THIS_MODULE,
849 .obj_size = sizeof(struct raw_sock),
853 static const struct can_proto raw_can_proto = {
860 static __init int raw_module_init(void)
864 pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n");
866 err = can_proto_register(&raw_can_proto);
868 printk(KERN_ERR "can: registration of raw protocol failed\n");
873 static __exit void raw_module_exit(void)
875 can_proto_unregister(&raw_can_proto);
878 module_init(raw_module_init);
879 module_exit(raw_module_exit);