raw.c

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/*
 * INET     An implementation of the TCP/IP protocol suite for the LINUX
 *      operating system.  INET is implemented using the  BSD Socket
 *      interface as the means of communication with the user level.
 *
 *      RAW - implementation of IP "raw" sockets.
 *
 * Authors: Ross Biro
 *      Fred N. van Kempen, <[email protected]>
 *
 * Fixes:
 *      Alan Cox    :   verify_area() fixed up
 *      Alan Cox    :   ICMP error handling
 *      Alan Cox    :   EMSGSIZE if you send too big a packet
 *      Alan Cox    :   Now uses generic datagrams and shared
 *                  skbuff library. No more peek crashes,
 *                  no more backlogs
 *      Alan Cox    :   Checks sk->broadcast.
 *      Alan Cox    :   Uses skb_free_datagram/skb_copy_datagram
 *      Alan Cox    :   Raw passes ip options too
 *      Alan Cox    :   Setsocketopt added
 *      Alan Cox    :   Fixed error return for broadcasts
 *      Alan Cox    :   Removed wake_up calls
 *      Alan Cox    :   Use ttl/tos
 *      Alan Cox    :   Cleaned up old debugging
 *      Alan Cox    :   Use new kernel side addresses
 *  Arnt Gulbrandsen    :   Fixed MSG_DONTROUTE in raw sockets.
 *      Alan Cox    :   BSD style RAW socket demultiplexing.
 *      Alan Cox    :   Beginnings of mrouted support.
 *      Alan Cox    :   Added IP_HDRINCL option.
 *      Alan Cox    :   Skip broadcast check if BSDism set.
 *      David S. Miller :   New socket lookup architecture.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/types.h>
#include <linux/atomic.h>
#include <asm/byteorder.h>
#include <asm/current.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/stddef.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/aio.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/sockios.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/mroute.h>
#include <linux/netdevice.h>
#include <linux/in_route.h>
#include <linux/route.h>
#include <linux/skbuff.h>
#include <net/net_namespace.h>
#include <net/dst.h>
#include <net/sock.h>
#include <linux/ip.h>
#include <linux/net.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/raw.h>
#include <net/snmp.h>
#include <net/tcp_states.h>
#include <net/inet_common.h>
#include <net/checksum.h>
#include <net/xfrm.h>
#include <linux/rtnetlink.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/compat.h>

static struct raw_hashinfo raw_v4_hashinfo = {
    .lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock),
};

void raw_hash_sk(struct sock *sk)
{
    struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;
    struct hlist_head *head;

    head = &h->ht[inet_sk(sk)->inet_num & (RAW_HTABLE_SIZE - 1)];

    write_lock_bh(&h->lock);
    sk_add_node(sk, head);
    sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
    write_unlock_bh(&h->lock);
}
EXPORT_SYMBOL_GPL(raw_hash_sk);

void raw_unhash_sk(struct sock *sk)
{
    struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;

    write_lock_bh(&h->lock);
    if (sk_del_node_init(sk))
        sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
    write_unlock_bh(&h->lock);
}
EXPORT_SYMBOL_GPL(raw_unhash_sk);

static struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
        unsigned short num, __be32 raddr, __be32 laddr, int dif)
{
    struct hlist_node *node;

    sk_for_each_from(sk, node) {
        struct inet_sock *inet = inet_sk(sk);

        if (net_eq(sock_net(sk), net) && inet->inet_num == num  &&
            !(inet->inet_daddr && inet->inet_daddr != raddr)    &&
            !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
            !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
            goto found; /* gotcha */
    }
    sk = NULL;
found:
    return sk;
}

/*
 *  0 - deliver
 *  1 - block
 */
static int icmp_filter(const struct sock *sk, const struct sk_buff *skb)
{
    struct icmphdr _hdr;
    const struct icmphdr *hdr;

    hdr = skb_header_pointer(skb, skb_transport_offset(skb),
                 sizeof(_hdr), &_hdr);
    if (!hdr)
        return 1;

    if (hdr->type < 32) {
        __u32 data = raw_sk(sk)->filter.data;

        return ((1U << hdr->type) & data) != 0;
    }

    /* Do not block unknown ICMP types */
    return 0;
}

/* IP input processing comes here for RAW socket delivery.
 * Caller owns SKB, so we must make clones.
 *
 * RFC 1122: SHOULD pass TOS value up to the transport layer.
 * -> It does. And not only TOS, but all IP header.
 */
static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)
{
    struct sock *sk;
    struct hlist_head *head;
    int delivered = 0;
    struct net *net;

    read_lock(&raw_v4_hashinfo.lock);
    head = &raw_v4_hashinfo.ht[hash];
    if (hlist_empty(head))
        goto out;

    net = dev_net(skb->dev);
    sk = __raw_v4_lookup(net, __sk_head(head), iph->protocol,
                 iph->saddr, iph->daddr,
                 skb->dev->ifindex);

    while (sk) {
        delivered = 1;
        if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
            struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);

            /* Not releasing hash table! */
            if (clone)
                raw_rcv(sk, clone);
        }
        sk = __raw_v4_lookup(net, sk_next(sk), iph->protocol,
                     iph->saddr, iph->daddr,
                     skb->dev->ifindex);
    }
out:
    read_unlock(&raw_v4_hashinfo.lock);
    return delivered;
}

int raw_local_deliver(struct sk_buff *skb, int protocol)
{
    int hash;
    struct sock *raw_sk;

    hash = protocol & (RAW_HTABLE_SIZE - 1);
    raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);

    /* If there maybe a raw socket we must check - if not we
     * don't care less
     */
    if (raw_sk && !raw_v4_input(skb, ip_hdr(skb), hash))
        raw_sk = NULL;

    return raw_sk != NULL;

}

static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
{
    struct inet_sock *inet = inet_sk(sk);
    const int type = icmp_hdr(skb)->type;
    const int code = icmp_hdr(skb)->code;
    int err = 0;
    int harderr = 0;

    if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
        ipv4_sk_update_pmtu(skb, sk, info);
    else if (type == ICMP_REDIRECT)
        ipv4_sk_redirect(skb, sk);

    /* Report error on raw socket, if:
       1. User requested ip_recverr.
       2. Socket is connected (otherwise the error indication
          is useless without ip_recverr and error is hard.
     */
    if (!inet->recverr && sk->sk_state != TCP_ESTABLISHED)
        return;

    switch (type) {
    default:
    case ICMP_TIME_EXCEEDED:
        err = EHOSTUNREACH;
        break;
    case ICMP_SOURCE_QUENCH:
        return;
    case ICMP_PARAMETERPROB:
        err = EPROTO;
        harderr = 1;
        break;
    case ICMP_DEST_UNREACH:
        err = EHOSTUNREACH;
        if (code > NR_ICMP_UNREACH)
            break;
        err = icmp_err_convert[code].errno;
        harderr = icmp_err_convert[code].fatal;
        if (code == ICMP_FRAG_NEEDED) {
            harderr = inet->pmtudisc != IP_PMTUDISC_DONT;
            err = EMSGSIZE;
        }
    }

    if (inet->recverr) {
        const struct iphdr *iph = (const struct iphdr *)skb->data;
        u8 *payload = skb->data + (iph->ihl << 2);

        if (inet->hdrincl)
            payload = skb->data;
        ip_icmp_error(sk, skb, err, 0, info, payload);
    }

    if (inet->recverr || harderr) {
        sk->sk_err = err;
        sk->sk_error_report(sk);
    }
}

void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
{
    int hash;
    struct sock *raw_sk;
    const struct iphdr *iph;
    struct net *net;

    hash = protocol & (RAW_HTABLE_SIZE - 1);

    read_lock(&raw_v4_hashinfo.lock);
    raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);
    if (raw_sk != NULL) {
        iph = (const struct iphdr *)skb->data;
        net = dev_net(skb->dev);

        while ((raw_sk = __raw_v4_lookup(net, raw_sk, protocol,
                        iph->daddr, iph->saddr,
                        skb->dev->ifindex)) != NULL) {
            raw_err(raw_sk, skb, info);
            raw_sk = sk_next(raw_sk);
            iph = (const struct iphdr *)skb->data;
        }
    }
    read_unlock(&raw_v4_hashinfo.lock);
}

static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
    /* Charge it to the socket. */

    ipv4_pktinfo_prepare(skb);
    if (sock_queue_rcv_skb(sk, skb) < 0) {
        kfree_skb(skb);
        return NET_RX_DROP;
    }

    return NET_RX_SUCCESS;
}

int raw_rcv(struct sock *sk, struct sk_buff *skb)
{
    if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
        atomic_inc(&sk->sk_drops);
        kfree_skb(skb);
        return NET_RX_DROP;
    }
    nf_reset(skb);

    skb_push(skb, skb->data - skb_network_header(skb));

    raw_rcv_skb(sk, skb);
    return 0;
}

static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,
               void *from, size_t length,
               struct rtable **rtp,
               unsigned int flags)
{
    struct inet_sock *inet = inet_sk(sk);
    struct net *net = sock_net(sk);
    struct iphdr *iph;
    struct sk_buff *skb;
    unsigned int iphlen;
    int err;
    struct rtable *rt = *rtp;
    int hlen, tlen;

    if (length > rt->dst.dev->mtu) {
        ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport,
                   rt->dst.dev->mtu);
        return -EMSGSIZE;
    }
    if (flags&MSG_PROBE)
        goto out;

    hlen = LL_RESERVED_SPACE(rt->dst.dev);
    tlen = rt->dst.dev->needed_tailroom;
    skb = sock_alloc_send_skb(sk,
                  length + hlen + tlen + 15,
                  flags & MSG_DONTWAIT, &err);
    if (skb == NULL)
        goto error;
    skb_reserve(skb, hlen);

    skb->priority = sk->sk_priority;
    skb->mark = sk->sk_mark;
    skb_dst_set(skb, &rt->dst);
    *rtp = NULL;

    skb_reset_network_header(skb);
    iph = ip_hdr(skb);
    skb_put(skb, length);

    skb->ip_summed = CHECKSUM_NONE;

    skb->transport_header = skb->network_header;
    err = -EFAULT;
    if (memcpy_fromiovecend((void *)iph, from, 0, length))
        goto error_free;

    iphlen = iph->ihl * 4;

    /*
     * We don't want to modify the ip header, but we do need to
     * be sure that it won't cause problems later along the network
     * stack.  Specifically we want to make sure that iph->ihl is a
     * sane value.  If ihl points beyond the length of the buffer passed
     * in, reject the frame as invalid
     */
    err = -EINVAL;
    if (iphlen > length)
        goto error_free;

    if (iphlen >= sizeof(*iph)) {
        if (!iph->saddr)
            iph->saddr = fl4->saddr;
        iph->check   = 0;
        iph->tot_len = htons(length);
        if (!iph->id)
            ip_select_ident(iph, &rt->dst, NULL);

        iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
    }
    if (iph->protocol == IPPROTO_ICMP)
        icmp_out_count(net, ((struct icmphdr *)
            skb_transport_header(skb))->type);

    err = NF_HOOK(NFPROTO_IPV4, NF_INET_LOCAL_OUT, skb, NULL,
              rt->dst.dev, dst_output);
    if (err > 0)
        err = net_xmit_errno(err);
    if (err)
        goto error;
out:
    return 0;

error_free:
    kfree_skb(skb);
error:
    IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);
    if (err == -ENOBUFS && !inet->recverr)
        err = 0;
    return err;
}

static int raw_probe_proto_opt(struct flowi4 *fl4, struct msghdr *msg)
{
    struct iovec *iov;
    u8 __user *type = NULL;
    u8 __user *code = NULL;
    int probed = 0;
    unsigned int i;

    if (!msg->msg_iov)
        return 0;

    for (i = 0; i < msg->msg_iovlen; i++) {
        iov = &msg->msg_iov[i];
        if (!iov)
            continue;

        switch (fl4->flowi4_proto) {
        case IPPROTO_ICMP:
            /* check if one-byte field is readable or not. */
            if (iov->iov_base && iov->iov_len < 1)
                break;

            if (!type) {
                type = iov->iov_base;
                /* check if code field is readable or not. */
                if (iov->iov_len > 1)
                    code = type + 1;
            } else if (!code)
                code = iov->iov_base;

            if (type && code) {
                if (get_user(fl4->fl4_icmp_type, type) ||
                    get_user(fl4->fl4_icmp_code, code))
                    return -EFAULT;
                probed = 1;
            }
            break;
        default:
            probed = 1;
            break;
        }
        if (probed)
            break;
    }
    return 0;
}

static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
               size_t len)
{
    struct inet_sock *inet = inet_sk(sk);
    struct ipcm_cookie ipc;
    struct rtable *rt = NULL;
    struct flowi4 fl4;
    int free = 0;
    __be32 daddr;
    __be32 saddr;
    u8  tos;
    int err;
    struct ip_options_data opt_copy;

    err = -EMSGSIZE;
    if (len > 0xFFFF)
        goto out;

    /*
     *  Check the flags.
     */

    err = -EOPNOTSUPP;
    if (msg->msg_flags & MSG_OOB)   /* Mirror BSD error message */
        goto out;               /* compatibility */

    /*
     *  Get and verify the address.
     */

    if (msg->msg_namelen) {
        struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
        err = -EINVAL;
        if (msg->msg_namelen < sizeof(*usin))
            goto out;
        if (usin->sin_family != AF_INET) {
            pr_info_once("%s: %s forgot to set AF_INET. Fix it!\n",
                     __func__, current->comm);
            err = -EAFNOSUPPORT;
            if (usin->sin_family)
                goto out;
        }
        daddr = usin->sin_addr.s_addr;
        /* ANK: I did not forget to get protocol from port field.
         * I just do not know, who uses this weirdness.
         * IP_HDRINCL is much more convenient.
         */
    } else {
        err = -EDESTADDRREQ;
        if (sk->sk_state != TCP_ESTABLISHED)
            goto out;
        daddr = inet->inet_daddr;
    }

    ipc.addr = inet->inet_saddr;
    ipc.opt = NULL;
    ipc.tx_flags = 0;
    ipc.oif = sk->sk_bound_dev_if;

    if (msg->msg_controllen) {
        err = ip_cmsg_send(sock_net(sk), msg, &ipc);
        if (err)
            goto out;
        if (ipc.opt)
            free = 1;
    }

    saddr = ipc.addr;
    ipc.addr = daddr;

    if (!ipc.opt) {
        struct ip_options_rcu *inet_opt;

        rcu_read_lock();
        inet_opt = rcu_dereference(inet->inet_opt);
        if (inet_opt) {
            memcpy(&opt_copy, inet_opt,
                   sizeof(*inet_opt) + inet_opt->opt.optlen);
            ipc.opt = &opt_copy.opt;
        }
        rcu_read_unlock();
    }

    if (ipc.opt) {
        err = -EINVAL;
        /* Linux does not mangle headers on raw sockets,
         * so that IP options + IP_HDRINCL is non-sense.
         */
        if (inet->hdrincl)
            goto done;
        if (ipc.opt->opt.srr) {
            if (!daddr)
                goto done;
            daddr = ipc.opt->opt.faddr;
        }
    }
    tos = RT_CONN_FLAGS(sk);
    if (msg->msg_flags & MSG_DONTROUTE)
        tos |= RTO_ONLINK;

    if (ipv4_is_multicast(daddr)) {
        if (!ipc.oif)
            ipc.oif = inet->mc_index;
        if (!saddr)
            saddr = inet->mc_addr;
    } else if (!ipc.oif)
        ipc.oif = inet->uc_index;

    flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
               RT_SCOPE_UNIVERSE,
               inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
               inet_sk_flowi_flags(sk) | FLOWI_FLAG_CAN_SLEEP,
               daddr, saddr, 0, 0);

    if (!inet->hdrincl) {
        err = raw_probe_proto_opt(&fl4, msg);
        if (err)
            goto done;
    }

    security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
    rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
    if (IS_ERR(rt)) {
        err = PTR_ERR(rt);
        rt = NULL;
        goto done;
    }

    err = -EACCES;
    if (rt->rt_flags & RTCF_BROADCAST && !sock_flag(sk, SOCK_BROADCAST))
        goto done;

    if (msg->msg_flags & MSG_CONFIRM)
        goto do_confirm;
back_from_confirm:

    if (inet->hdrincl)
        err = raw_send_hdrinc(sk, &fl4, msg->msg_iov, len,
                      &rt, msg->msg_flags);

     else {
        if (!ipc.addr)
            ipc.addr = fl4.daddr;
        lock_sock(sk);
        err = ip_append_data(sk, &fl4, ip_generic_getfrag,
                     msg->msg_iov, len, 0,
                     &ipc, &rt, msg->msg_flags);
        if (err)
            ip_flush_pending_frames(sk);
        else if (!(msg->msg_flags & MSG_MORE)) {
            err = ip_push_pending_frames(sk, &fl4);
            if (err == -ENOBUFS && !inet->recverr)
                err = 0;
        }
        release_sock(sk);
    }
done:
    if (free)
        kfree(ipc.opt);
    ip_rt_put(rt);

out:
    if (err < 0)
        return err;
    return len;

do_confirm:
    dst_confirm(&rt->dst);
    if (!(msg->msg_flags & MSG_PROBE) || len)
        goto back_from_confirm;
    err = 0;
    goto done;
}

static void raw_close(struct sock *sk, long timeout)
{
    /*
     * Raw sockets may have direct kernel references. Kill them.
     */
    ip_ra_control(sk, 0, NULL);

    sk_common_release(sk);
}

static void raw_destroy(struct sock *sk)
{
    lock_sock(sk);
    ip_flush_pending_frames(sk);
    release_sock(sk);
}

/* This gets rid of all the nasties in af_inet. -DaveM */
static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
    struct inet_sock *inet = inet_sk(sk);
    struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
    int ret = -EINVAL;
    int chk_addr_ret;

    if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in))
        goto out;
    chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
    ret = -EADDRNOTAVAIL;
    if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
        chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
        goto out;
    inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
    if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
        inet->inet_saddr = 0;  /* Use device */
    sk_dst_reset(sk);
    ret = 0;
out:    return ret;
}

/*
 *  This should be easy, if there is something there
 *  we return it, otherwise we block.
 */

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

    if (flags & MSG_OOB)
        goto out;

    if (addr_len)
        *addr_len = sizeof(*sin);

    if (flags & MSG_ERRQUEUE) {
        err = ip_recv_error(sk, msg, len);
        goto out;
    }

    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);

    /* Copy the address. */
    if (sin) {
        sin->sin_family = AF_INET;
        sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
        sin->sin_port = 0;
        memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
    }
    if (inet->cmsg_flags)
        ip_cmsg_recv(msg, skb);
    if (flags & MSG_TRUNC)
        copied = skb->len;
done:
    skb_free_datagram(sk, skb);
out:
    if (err)
        return err;
    return copied;
}

static int raw_init(struct sock *sk)
{
    struct raw_sock *rp = raw_sk(sk);

    if (inet_sk(sk)->inet_num == IPPROTO_ICMP)
        memset(&rp->filter, 0, sizeof(rp->filter));
    return 0;
}

static int raw_seticmpfilter(struct sock *sk, char __user *optval, int optlen)
{
    if (optlen > sizeof(struct icmp_filter))
        optlen = sizeof(struct icmp_filter);
    if (copy_from_user(&raw_sk(sk)->filter, optval, optlen))
        return -EFAULT;
    return 0;
}

static int raw_geticmpfilter(struct sock *sk, char __user *optval, int __user *optlen)
{
    int len, ret = -EFAULT;

    if (get_user(len, optlen))
        goto out;
    ret = -EINVAL;
    if (len < 0)
        goto out;
    if (len > sizeof(struct icmp_filter))
        len = sizeof(struct icmp_filter);
    ret = -EFAULT;
    if (put_user(len, optlen) ||
        copy_to_user(optval, &raw_sk(sk)->filter, len))
        goto out;
    ret = 0;
out:    return ret;
}

static int do_raw_setsockopt(struct sock *sk, int level, int optname,
              char __user *optval, unsigned int optlen)
{
    if (optname == ICMP_FILTER) {
        if (inet_sk(sk)->inet_num != IPPROTO_ICMP)
            return -EOPNOTSUPP;
        else
            return raw_seticmpfilter(sk, optval, optlen);
    }
    return -ENOPROTOOPT;
}

static int raw_setsockopt(struct sock *sk, int level, int optname,
              char __user *optval, unsigned int optlen)
{
    if (level != SOL_RAW)
        return ip_setsockopt(sk, level, optname, optval, optlen);
    return do_raw_setsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
static int compat_raw_setsockopt(struct sock *sk, int level, int optname,
                 char __user *optval, unsigned int optlen)
{
    if (level != SOL_RAW)
        return compat_ip_setsockopt(sk, level, optname, optval, optlen);
    return do_raw_setsockopt(sk, level, optname, optval, optlen);
}
#endif

static int do_raw_getsockopt(struct sock *sk, int level, int optname,
              char __user *optval, int __user *optlen)
{
    if (optname == ICMP_FILTER) {
        if (inet_sk(sk)->inet_num != IPPROTO_ICMP)
            return -EOPNOTSUPP;
        else
            return raw_geticmpfilter(sk, optval, optlen);
    }
    return -ENOPROTOOPT;
}

static int raw_getsockopt(struct sock *sk, int level, int optname,
              char __user *optval, int __user *optlen)
{
    if (level != SOL_RAW)
        return ip_getsockopt(sk, level, optname, optval, optlen);
    return do_raw_getsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
static int compat_raw_getsockopt(struct sock *sk, int level, int optname,
                 char __user *optval, int __user *optlen)
{
    if (level != SOL_RAW)
        return compat_ip_getsockopt(sk, level, optname, optval, optlen);
    return do_raw_getsockopt(sk, level, optname, optval, optlen);
}
#endif

static int raw_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
    switch (cmd) {
    case SIOCOUTQ: {
        int amount = sk_wmem_alloc_get(sk);

        return put_user(amount, (int __user *)arg);
    }
    case SIOCINQ: {
        struct sk_buff *skb;
        int amount = 0;

        spin_lock_bh(&sk->sk_receive_queue.lock);
        skb = skb_peek(&sk->sk_receive_queue);
        if (skb != NULL)
            amount = skb->len;
        spin_unlock_bh(&sk->sk_receive_queue.lock);
        return put_user(amount, (int __user *)arg);
    }

    default:
#ifdef CONFIG_IP_MROUTE
        return ipmr_ioctl(sk, cmd, (void __user *)arg);
#else
        return -ENOIOCTLCMD;
#endif
    }
}

#ifdef CONFIG_COMPAT
static int compat_raw_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg)
{
    switch (cmd) {
    case SIOCOUTQ:
    case SIOCINQ:
        return -ENOIOCTLCMD;
    default:
#ifdef CONFIG_IP_MROUTE
        return ipmr_compat_ioctl(sk, cmd, compat_ptr(arg));
#else
        return -ENOIOCTLCMD;
#endif
    }
}
#endif

struct proto raw_prot = {
    .name          = "RAW",
    .owner         = THIS_MODULE,
    .close         = raw_close,
    .destroy       = raw_destroy,
    .connect       = ip4_datagram_connect,
    .disconnect    = udp_disconnect,
    .ioctl         = raw_ioctl,
    .init          = raw_init,
    .setsockopt    = raw_setsockopt,
    .getsockopt    = raw_getsockopt,
    .sendmsg       = raw_sendmsg,
    .recvmsg       = raw_recvmsg,
    .bind          = raw_bind,
    .backlog_rcv       = raw_rcv_skb,
    .hash          = raw_hash_sk,
    .unhash        = raw_unhash_sk,
    .obj_size      = sizeof(struct raw_sock),
    .h.raw_hash    = &raw_v4_hashinfo,
#ifdef CONFIG_COMPAT
    .compat_setsockopt = compat_raw_setsockopt,
    .compat_getsockopt = compat_raw_getsockopt,
    .compat_ioctl      = compat_raw_ioctl,
#endif
};

#ifdef CONFIG_PROC_FS
static struct sock *raw_get_first(struct seq_file *seq)
{
    struct sock *sk;
    struct raw_iter_state *state = raw_seq_private(seq);

    for (state->bucket = 0; state->bucket < RAW_HTABLE_SIZE;
            ++state->bucket) {
        struct hlist_node *node;

        sk_for_each(sk, node, &state->h->ht[state->bucket])
            if (sock_net(sk) == seq_file_net(seq))
                goto found;
    }
    sk = NULL;
found:
    return sk;
}

static struct sock *raw_get_next(struct seq_file *seq, struct sock *sk)
{
    struct raw_iter_state *state = raw_seq_private(seq);

    do {
        sk = sk_next(sk);
try_again:
        ;
    } while (sk && sock_net(sk) != seq_file_net(seq));

    if (!sk && ++state->bucket < RAW_HTABLE_SIZE) {
        sk = sk_head(&state->h->ht[state->bucket]);
        goto try_again;
    }
    return sk;
}

static struct sock *raw_get_idx(struct seq_file *seq, loff_t pos)
{
    struct sock *sk = raw_get_first(seq);

    if (sk)
        while (pos && (sk = raw_get_next(seq, sk)) != NULL)
            --pos;
    return pos ? NULL : sk;
}

void *raw_seq_start(struct seq_file *seq, loff_t *pos)
{
    struct raw_iter_state *state = raw_seq_private(seq);

    read_lock(&state->h->lock);
    return *pos ? raw_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
EXPORT_SYMBOL_GPL(raw_seq_start);

void *raw_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
    struct sock *sk;

    if (v == SEQ_START_TOKEN)
        sk = raw_get_first(seq);
    else
        sk = raw_get_next(seq, v);
    ++*pos;
    return sk;
}
EXPORT_SYMBOL_GPL(raw_seq_next);

void raw_seq_stop(struct seq_file *seq, void *v)
{
    struct raw_iter_state *state = raw_seq_private(seq);

    read_unlock(&state->h->lock);
}
EXPORT_SYMBOL_GPL(raw_seq_stop);

static void raw_sock_seq_show(struct seq_file *seq, struct sock *sp, int i)
{
    struct inet_sock *inet = inet_sk(sp);
    __be32 dest = inet->inet_daddr,
           src = inet->inet_rcv_saddr;
    __u16 destp = 0,
          srcp  = inet->inet_num;

    seq_printf(seq, "%4d: %08X:%04X %08X:%04X"
        " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n",
        i, src, srcp, dest, destp, sp->sk_state,
        sk_wmem_alloc_get(sp),
        sk_rmem_alloc_get(sp),
        0, 0L, 0,
        from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
        0, sock_i_ino(sp),
        atomic_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops));
}

static int raw_seq_show(struct seq_file *seq, void *v)
{
    if (v == SEQ_START_TOKEN)
        seq_printf(seq, "  sl  local_address rem_address   st tx_queue "
                "rx_queue tr tm->when retrnsmt   uid  timeout "
                "inode ref pointer drops\n");
    else
        raw_sock_seq_show(seq, v, raw_seq_private(seq)->bucket);
    return 0;
}

static const struct seq_operations raw_seq_ops = {
    .start = raw_seq_start,
    .next  = raw_seq_next,
    .stop  = raw_seq_stop,
    .show  = raw_seq_show,
};

int raw_seq_open(struct inode *ino, struct file *file,
         struct raw_hashinfo *h, const struct seq_operations *ops)
{
    int err;
    struct raw_iter_state *i;

    err = seq_open_net(ino, file, ops, sizeof(struct raw_iter_state));
    if (err < 0)
        return err;

    i = raw_seq_private((struct seq_file *)file->private_data);
    i->h = h;
    return 0;
}
EXPORT_SYMBOL_GPL(raw_seq_open);

static int raw_v4_seq_open(struct inode *inode, struct file *file)
{
    return raw_seq_open(inode, file, &raw_v4_hashinfo, &raw_seq_ops);
}

static const struct file_operations raw_seq_fops = {
    .owner   = THIS_MODULE,
    .open    = raw_v4_seq_open,
    .read    = seq_read,
    .llseek  = seq_lseek,
    .release = seq_release_net,
};

static __net_init int raw_init_net(struct net *net)
{
    if (!proc_net_fops_create(net, "raw", S_IRUGO, &raw_seq_fops))
        return -ENOMEM;

    return 0;
}

static __net_exit void raw_exit_net(struct net *net)
{
    proc_net_remove(net, "raw");
}

static __net_initdata struct pernet_operations raw_net_ops = {
    .init = raw_init_net,
    .exit = raw_exit_net,
};

int __init raw_proc_init(void)
{
    return register_pernet_subsys(&raw_net_ops);
}

void __init raw_proc_exit(void)
{
    unregister_pernet_subsys(&raw_net_ops);
}
#endif /* CONFIG_PROC_FS */