raw.c

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/*
 * Raw IEEE 802.15.4 sockets
 *
 * Copyright 2007, 2008 Siemens AG
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Written by:
 * Sergey Lapin <[email protected]>
 * Dmitry Eremin-Solenikov <[email protected]>
 */

#include <linux/net.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/af_ieee802154.h>

#include "af802154.h"

static HLIST_HEAD(raw_head);
static DEFINE_RWLOCK(raw_lock);

static void raw_hash(struct sock *sk)
{
    write_lock_bh(&raw_lock);
    sk_add_node(sk, &raw_head);
    sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
    write_unlock_bh(&raw_lock);
}

static void raw_unhash(struct sock *sk)
{
    write_lock_bh(&raw_lock);
    if (sk_del_node_init(sk))
        sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
    write_unlock_bh(&raw_lock);
}

static void raw_close(struct sock *sk, long timeout)
{
    sk_common_release(sk);
}

static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int len)
{
    struct sockaddr_ieee802154 *addr = (struct sockaddr_ieee802154 *)uaddr;
    int err = 0;
    struct net_device *dev = NULL;

    if (len < sizeof(*addr))
        return -EINVAL;

    if (addr->family != AF_IEEE802154)
        return -EINVAL;

    lock_sock(sk);

    dev = ieee802154_get_dev(sock_net(sk), &addr->addr);
    if (!dev) {
        err = -ENODEV;
        goto out;
    }

    if (dev->type != ARPHRD_IEEE802154) {
        err = -ENODEV;
        goto out_put;
    }

    sk->sk_bound_dev_if = dev->ifindex;
    sk_dst_reset(sk);

out_put:
    dev_put(dev);
out:
    release_sock(sk);

    return err;
}

static int raw_connect(struct sock *sk, struct sockaddr *uaddr,
            int addr_len)
{
    return -ENOTSUPP;
}

static int raw_disconnect(struct sock *sk, int flags)
{
    return 0;
}

static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
               size_t size)
{
    struct net_device *dev;
    unsigned int mtu;
    struct sk_buff *skb;
    int hlen, tlen;
    int err;

    if (msg->msg_flags & MSG_OOB) {
        pr_debug("msg->msg_flags = 0x%x\n", msg->msg_flags);
        return -EOPNOTSUPP;
    }

    lock_sock(sk);
    if (!sk->sk_bound_dev_if)
        dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);
    else
        dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if);
    release_sock(sk);

    if (!dev) {
        pr_debug("no dev\n");
        err = -ENXIO;
        goto out;
    }

    mtu = dev->mtu;
    pr_debug("name = %s, mtu = %u\n", dev->name, mtu);

    if (size > mtu) {
        pr_debug("size = %Zu, mtu = %u\n", size, mtu);
        err = -EINVAL;
        goto out_dev;
    }

    hlen = LL_RESERVED_SPACE(dev);
    tlen = dev->needed_tailroom;
    skb = sock_alloc_send_skb(sk, hlen + tlen + size,
            msg->msg_flags & MSG_DONTWAIT, &err);
    if (!skb)
        goto out_dev;

    skb_reserve(skb, hlen);

    skb_reset_mac_header(skb);
    skb_reset_network_header(skb);

    err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
    if (err < 0)
        goto out_skb;

    skb->dev = dev;
    skb->sk  = sk;
    skb->protocol = htons(ETH_P_IEEE802154);

    dev_put(dev);

    err = dev_queue_xmit(skb);
    if (err > 0)
        err = net_xmit_errno(err);

    return err ?: size;

out_skb:
    kfree_skb(skb);
out_dev:
    dev_put(dev);
out:
    return err;
}

static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
               size_t len, int noblock, int flags, int *addr_len)
{
    size_t copied = 0;
    int err = -EOPNOTSUPP;
    struct sk_buff *skb;

    skb = skb_recv_datagram(sk, flags, noblock, &err);
    if (!skb)
        goto out;

    copied = skb->len;
    if (len < copied) {
        msg->msg_flags |= MSG_TRUNC;
        copied = len;
    }

    err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
    if (err)
        goto done;

    sock_recv_ts_and_drops(msg, sk, skb);

    if (flags & MSG_TRUNC)
        copied = skb->len;
done:
    skb_free_datagram(sk, skb);
out:
    if (err)
        return err;
    return copied;
}

static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
    if (sock_queue_rcv_skb(sk, skb) < 0) {
        kfree_skb(skb);
        return NET_RX_DROP;
    }

    return NET_RX_SUCCESS;
}


void ieee802154_raw_deliver(struct net_device *dev, struct sk_buff *skb)
{
    struct sock *sk;
    struct hlist_node *node;

    read_lock(&raw_lock);
    sk_for_each(sk, node, &raw_head) {
        bh_lock_sock(sk);
        if (!sk->sk_bound_dev_if ||
            sk->sk_bound_dev_if == dev->ifindex) {

            struct sk_buff *clone;

            clone = skb_clone(skb, GFP_ATOMIC);
            if (clone)
                raw_rcv_skb(sk, clone);
        }
        bh_unlock_sock(sk);
    }
    read_unlock(&raw_lock);
}

static int raw_getsockopt(struct sock *sk, int level, int optname,
            char __user *optval, int __user *optlen)
{
    return -EOPNOTSUPP;
}

static int raw_setsockopt(struct sock *sk, int level, int optname,
            char __user *optval, unsigned int optlen)
{
    return -EOPNOTSUPP;
}

struct proto ieee802154_raw_prot = {
    .name       = "IEEE-802.15.4-RAW",
    .owner      = THIS_MODULE,
    .obj_size   = sizeof(struct sock),
    .close      = raw_close,
    .bind       = raw_bind,
    .sendmsg    = raw_sendmsg,
    .recvmsg    = raw_recvmsg,
    .hash       = raw_hash,
    .unhash     = raw_unhash,
    .connect    = raw_connect,
    .disconnect = raw_disconnect,
    .getsockopt = raw_getsockopt,
    .setsockopt = raw_setsockopt,
};