// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) /* 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 { int skbcnt; 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 && this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { 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)->skbcnt = can_skb_prv(oskb)->skbcnt; 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 *net, 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(net, dev, filter[i].can_id, filter[i].can_mask, raw_rcv, sk, "raw", sk); if (err) { /* clean up successfully registered filters */ while (--i >= 0) can_rx_unregister(net, dev, filter[i].can_id, filter[i].can_mask, raw_rcv, sk); break; } } return err; } static int raw_enable_errfilter(struct net *net, struct net_device *dev, struct sock *sk, can_err_mask_t err_mask) { int err = 0; if (err_mask) err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG, raw_rcv, sk, "raw", sk); return err; } static void raw_disable_filters(struct net *net, struct net_device *dev, struct sock *sk, struct can_filter *filter, int count) { int i; for (i = 0; i < count; i++) can_rx_unregister(net, dev, filter[i].can_id, filter[i].can_mask, raw_rcv, sk); } static inline void raw_disable_errfilter(struct net *net, struct net_device *dev, struct sock *sk, can_err_mask_t err_mask) { if (err_mask) can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG, raw_rcv, sk); } static inline void raw_disable_allfilters(struct net *net, struct net_device *dev, struct sock *sk) { struct raw_sock *ro = raw_sk(sk); raw_disable_filters(net, dev, sk, ro->filter, ro->count); raw_disable_errfilter(net, dev, sk, ro->err_mask); } static int raw_enable_allfilters(struct net *net, struct net_device *dev, struct sock *sk) { struct raw_sock *ro = raw_sk(sk); int err; err = raw_enable_filters(net, dev, sk, ro->filter, ro->count); if (!err) { err = raw_enable_errfilter(net, dev, sk, ro->err_mask); if (err) raw_disable_filters(net, 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), sock_net(sk))) 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_net(dev), 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(sock_net(sk), ro->ifindex); if (dev) { raw_disable_allfilters(dev_net(dev), dev, sk); dev_put(dev); } } else { raw_disable_allfilters(sock_net(sk), 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 < CAN_REQUIRED_SIZE(*addr, can_ifindex)) return -EINVAL; if (addr->can_family != AF_CAN) 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(sock_net(sk), 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(sock_net(sk), dev, sk); dev_put(dev); } else { ifindex = 0; /* filters set by default/setsockopt */ err = raw_enable_allfilters(sock_net(sk), NULL, sk); } if (!err) { if (ro->bound) { /* unregister old filters */ if (ro->ifindex) { struct net_device *dev; dev = dev_get_by_index(sock_net(sk), ro->ifindex); if (dev) { raw_disable_allfilters(dev_net(dev), dev, sk); dev_put(dev); } } else { raw_disable_allfilters(sock_net(sk), 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 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; return sizeof(*addr); } 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; if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) 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(sock_net(sk), ro->ifindex); if (ro->bound) { /* (try to) register the new filters */ if (count == 1) err = raw_enable_filters(sock_net(sk), dev, sk, &sfilter, 1); else err = raw_enable_filters(sock_net(sk), dev, sk, filter, count); if (err) { if (count > 1) kfree(filter); goto out_fil; } /* remove old filter registrations */ raw_disable_filters(sock_net(sk), 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(sock_net(sk), ro->ifindex); /* remove current error mask */ if (ro->bound) { /* (try to) register the new err_mask */ err = raw_enable_errfilter(sock_net(sk), dev, sk, err_mask); if (err) goto out_err; /* remove old err_mask registration */ raw_disable_errfilter(sock_net(sk), 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 < CAN_REQUIRED_SIZE(*addr, can_ifindex)) return -EINVAL; if (addr->can_family != AF_CAN) return -EINVAL; ifindex = addr->can_ifindex; } else { ifindex = ro->ifindex; } dev = dev_get_by_index(sock_net(sk), ifindex); if (!dev) return -ENXIO; err = -EINVAL; if (ro->fd_frames && dev->mtu == CANFD_MTU) { if (unlikely(size != CANFD_MTU && size != CAN_MTU)) goto put_dev; } else { if (unlikely(size != CAN_MTU)) goto put_dev; } 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; can_skb_prv(skb)->skbcnt = 0; err = memcpy_from_msg(skb_put(skb, size), msg, size); if (err < 0) goto free_skb; skb_setup_tx_timestamp(skb, sk->sk_tsflags); 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 int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, unsigned long arg) { /* no ioctls for socket layer -> hand it down to NIC layer */ return -ENOIOCTLCMD; } 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 = raw_sock_no_ioctlcmd, .gettstamp = sock_gettstamp, .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) pr_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);