[CAN]: Add raw protocol

This patch adds the CAN raw protocol.

Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 763 insertions, 0 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
new file mode 100644
index 000000000000..aeefd1419d00
--- /dev/null
+++ b/net/can/raw.c
@@ -0,0 +1,763 @@
+/*
+ * 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.
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/uio.h>
+#include <linux/net.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/raw.h>
+#include <net/sock.h>
+#include <net/net_namespace.h>
+
+#define CAN_RAW_VERSION CAN_VERSION
+static __initdata const char banner[] =
+        KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";
+
+MODULE_DESCRIPTION("PF_CAN raw protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
+
+#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 raw_sock {
+        struct sock sk;
+        int bound;
+        int ifindex;
+        struct notifier_block notifier;
+        int loopback;
+        int recv_own_msgs;
+        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;
+};
+
+static inline struct raw_sock *raw_sk(const struct sock *sk)
+{
+        return (struct raw_sock *)sk;
+}
+
+static void raw_rcv(struct sk_buff *skb, void *data)
+{
+        struct sock *sk = (struct sock *)data;
+        struct raw_sock *ro = raw_sk(sk);
+        struct sockaddr_can *addr;
+        int error;
+
+        if (!ro->recv_own_msgs) {
+                /* check the received tx sock reference */
+                if (skb->sk == sk) {
+                        kfree_skb(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.
+         */
+
+        BUILD_BUG_ON(sizeof(skb->cb) < 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;
+
+        error = sock_queue_rcv_skb(sk, skb);
+        if (error < 0)
+                kfree_skb(skb);
+}
+
+static int raw_enable_filters(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(dev, filter[i].can_id,
+                                      filter[i].can_mask,
+                                      raw_rcv, sk, "raw");
+                if (err) {
+                        /* clean up successfully registered filters */
+                        while (--i >= 0)
+                                can_rx_unregister(dev, filter[i].can_id,
+                                                  filter[i].can_mask,
+                                                  raw_rcv, sk);
+                        break;
+                }
+        }
+
+        return err;
+}
+
+static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
+                                can_err_mask_t err_mask)
+{
+        int err = 0;
+
+        if (err_mask)
+                err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
+                                      raw_rcv, sk, "raw");
+
+        return err;
+}
+
+static void raw_disable_filters(struct net_device *dev, struct sock *sk,
+                              struct can_filter *filter,
+                              int count)
+{
+        int i;
+
+        for (i = 0; i < count; i++)
+                can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
+                                  raw_rcv, sk);
+}
+
+static inline void raw_disable_errfilter(struct net_device *dev,
+                                         struct sock *sk,
+                                         can_err_mask_t err_mask)
+
+{
+        if (err_mask)
+                can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
+                                  raw_rcv, sk);
+}
+
+static inline void raw_disable_allfilters(struct net_device *dev,
+                                          struct sock *sk)
+{
+        struct raw_sock *ro = raw_sk(sk);
+
+        raw_disable_filters(dev, sk, ro->filter, ro->count);
+        raw_disable_errfilter(dev, sk, ro->err_mask);
+}
+
+static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
+{
+        struct raw_sock *ro = raw_sk(sk);
+        int err;
+
+        err = raw_enable_filters(dev, sk, ro->filter, ro->count);
+        if (!err) {
+                err = raw_enable_errfilter(dev, sk, ro->err_mask);
+                if (err)
+                        raw_disable_filters(dev, sk, ro->filter, ro->count);
+        }
+
+        return err;
+}
+
+static int raw_notifier(struct notifier_block *nb,
+                        unsigned long msg, void *data)
+{
+        struct net_device *dev = (struct net_device *)data;
+        struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
+        struct sock *sk = &ro->sk;
+
+        if (dev->nd_net != &init_net)
+                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, 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;
+
+        /* 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 = 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(&init_net, ro->ifindex);
+                        if (dev) {
+                                raw_disable_allfilters(dev, sk);
+                                dev_put(dev);
+                        }
+                } else
+                        raw_disable_allfilters(NULL, sk);
+        }
+
+        if (ro->count > 1)
+                kfree(ro->filter);
+
+        ro->ifindex = 0;
+        ro->bound   = 0;
+        ro->count   = 0;
+
+        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 < sizeof(*addr))
+                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(&init_net, 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(dev, sk);
+                dev_put(dev);
+
+        } else {
+                ifindex = 0;
+
+                /* filters set by default/setsockopt */
+                err = raw_enable_allfilters(NULL, sk);
+        }
+
+        if (!err) {
+                if (ro->bound) {
+                        /* unregister old filters */
+                        if (ro->ifindex) {
+                                struct net_device *dev;
+
+                                dev = dev_get_by_index(&init_net, ro->ifindex);
+                                if (dev) {
+                                        raw_disable_allfilters(dev, sk);
+                                        dev_put(dev);
+                                }
+                        } else
+                                raw_disable_allfilters(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 *len, 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;
+
+        addr->can_family  = AF_CAN;
+        addr->can_ifindex = ro->ifindex;
+
+        *len = sizeof(*addr);
+
+        return 0;
+}
+
+static int raw_setsockopt(struct socket *sock, int level, int optname,
+                          char __user *optval, 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;
+        if (optlen < 0)
+                return -EINVAL;
+
+        switch (optname) {
+
+        case CAN_RAW_FILTER:
+                if (optlen % sizeof(struct can_filter) != 0)
+                        return -EINVAL;
+
+                count = optlen / sizeof(struct can_filter);
+
+                if (count > 1) {
+                        /* filter does not fit into dfilter => alloc space */
+                        filter = kmalloc(optlen, GFP_KERNEL);
+                        if (!filter)
+                                return -ENOMEM;
+
+                        err = copy_from_user(filter, optval, optlen);
+                        if (err) {
+                                kfree(filter);
+                                return err;
+                        }
+                } else if (count == 1) {
+                        err = copy_from_user(&sfilter, optval, optlen);
+                        if (err)
+                                return err;
+                }
+
+                lock_sock(sk);
+
+                if (ro->bound && ro->ifindex)
+                        dev = dev_get_by_index(&init_net, ro->ifindex);
+
+                if (ro->bound) {
+                        /* (try to) register the new filters */
+                        if (count == 1)
+                                err = raw_enable_filters(dev, sk, &sfilter, 1);
+                        else
+                                err = raw_enable_filters(dev, sk, filter,
+                                                         count);
+                        if (err) {
+                                if (count > 1)
+                                        kfree(filter);
+
+                                goto out_fil;
+                        }
+
+                        /* remove old filter registrations */
+                        raw_disable_filters(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;
+
+                err = copy_from_user(&err_mask, optval, optlen);
+                if (err)
+                        return err;
+
+                err_mask &= CAN_ERR_MASK;
+
+                lock_sock(sk);
+
+                if (ro->bound && ro->ifindex)
+                        dev = dev_get_by_index(&init_net, ro->ifindex);
+
+                /* remove current error mask */
+                if (ro->bound) {
+                        /* (try to) register the new err_mask */
+                        err = raw_enable_errfilter(dev, sk, err_mask);
+
+                        if (err)
+                                goto out_err;
+
+                        /* remove old err_mask registration */
+                        raw_disable_errfilter(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;
+
+                err = copy_from_user(&ro->loopback, optval, optlen);
+
+                break;
+
+        case CAN_RAW_RECV_OWN_MSGS:
+                if (optlen != sizeof(ro->recv_own_msgs))
+                        return -EINVAL;
+
+                err = copy_from_user(&ro->recv_own_msgs, optval, optlen);
+
+                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;
+                        err = copy_to_user(optval, ro->filter, len);
+                } 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;
+
+        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 kiocb *iocb, 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) {
+                struct sockaddr_can *addr =
+                        (struct sockaddr_can *)msg->msg_name;
+
+                if (addr->can_family != AF_CAN)
+                        return -EINVAL;
+
+                ifindex = addr->can_ifindex;
+        } else
+                ifindex = ro->ifindex;
+
+        dev = dev_get_by_index(&init_net, ifindex);
+        if (!dev)
+                return -ENXIO;
+
+        skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
+                                  &err);
+        if (!skb) {
+                dev_put(dev);
+                return err;
+        }
+
+        err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
+        if (err < 0) {
+                kfree_skb(skb);
+                dev_put(dev);
+                return err;
+        }
+        skb->dev = dev;
+        skb->sk  = sk;
+
+        err = can_send(skb, ro->loopback);
+
+        dev_put(dev);
+
+        if (err)
+                return err;
+
+        return size;
+}
+
+static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
+                       struct msghdr *msg, size_t size, int flags)
+{
+        struct sock *sk = sock->sk;
+        struct sk_buff *skb;
+        int error = 0;
+        int noblock;
+
+        noblock =  flags & MSG_DONTWAIT;
+        flags   &= ~MSG_DONTWAIT;
+
+        skb = skb_recv_datagram(sk, flags, noblock, &error);
+        if (!skb)
+                return error;
+
+        if (size < skb->len)
+                msg->msg_flags |= MSG_TRUNC;
+        else
+                size = skb->len;
+
+        error = memcpy_toiovec(msg->msg_iov, skb->data, size);
+        if (error < 0) {
+                skb_free_datagram(sk, skb);
+                return error;
+        }
+
+        sock_recv_timestamp(msg, sk, skb);
+
+        if (msg->msg_name) {
+                msg->msg_namelen = sizeof(struct sockaddr_can);
+                memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+        }
+
+        skb_free_datagram(sk, skb);
+
+        return size;
+}
+
+static struct proto_ops raw_ops __read_mostly = {
+        .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         = NULL,          /* use can_ioctl() from af_can.c */
+        .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 struct can_proto raw_can_proto __read_mostly = {
+        .type       = SOCK_RAW,
+        .protocol   = CAN_RAW,
+        .capability = -1,
+        .ops        = &raw_ops,
+        .prot       = &raw_proto,
+};
+
+static __init int raw_module_init(void)
+{
+        int err;
+
+        printk(banner);
+
+        err = can_proto_register(&raw_can_proto);
+        if (err < 0)
+                printk(KERN_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);