/*
 * 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, <waltje@uWalt.NL.Mugnet.ORG>
 *
 * 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 <linux/uaccess.h>
#include <asm/ioctls.h>
#include <linux/stddef.h>
#include <linux/slab.h>
#include <linux/errno.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 <linux/igmp.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>
#include <linux/uio.h>

struct raw_frag_vec {
        struct msghdr *msg;
        union {
                struct icmphdr icmph;
                char c[1];
        } hdr;
        int hlen;
};

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

int 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);

        return 0;
}
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);

struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
                             unsigned short num, __be32 raddr, __be32 laddr,
                             int dif, int sdif)
{
        sk_for_each_from(sk) {
                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 &&
                      sk->sk_bound_dev_if != sdif))
                        goto found; /* gotcha */
        }
        sk = NULL;
found:
        return sk;
}
EXPORT_SYMBOL_GPL(__raw_v4_lookup);

/*
 *      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)
{
        int sdif = inet_sdif(skb);
        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, sdif);

        while (sk) {
                delivered = 1;
                if ((iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) &&
                    ip_mc_sf_allow(sk, iph->daddr, iph->saddr,
                                   skb->dev->ifindex, sdif)) {
                        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, sdif);
        }
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);
                return;
        }

        /* 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) {
                int dif = skb->dev->ifindex;
                int sdif = inet_sdif(skb);

                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,
                                                dif, sdif)) != 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(sk, 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,
                           struct msghdr *msg, size_t length,
                           struct rtable **rtp, unsigned int flags,
                           const struct sockcm_cookie *sockc)
{
        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 (length < sizeof(struct iphdr))
                return -EINVAL;

        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)
                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;

        sock_tx_timestamp(sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);

        if (flags & MSG_CONFIRM)
                skb_set_dst_pending_confirm(skb, 1);

        skb->transport_header = skb->network_header;
        err = -EFAULT;
        if (memcpy_from_msg(iph, msg, 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(net, skb, NULL);

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

        err = NF_HOOK(NFPROTO_IPV4, NF_INET_LOCAL_OUT,
                      net, sk, 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 raw_frag_vec *rfv, struct flowi4 *fl4)
{
        int err;

        if (fl4->flowi4_proto != IPPROTO_ICMP)
                return 0;

        /* We only need the first two bytes. */
        rfv->hlen = 2;

        err = memcpy_from_msg(rfv->hdr.c, rfv->msg, rfv->hlen);
        if (err)
                return err;

        fl4->fl4_icmp_type = rfv->hdr.icmph.type;
        fl4->fl4_icmp_code = rfv->hdr.icmph.code;

        return 0;
}

static int raw_getfrag(void *from, char *to, int offset, int len, int odd,
                       struct sk_buff *skb)
{
        struct raw_frag_vec *rfv = from;

        if (offset < rfv->hlen) {
                int copy = min(rfv->hlen - offset, len);

                if (skb->ip_summed == CHECKSUM_PARTIAL)
                        memcpy(to, rfv->hdr.c + offset, copy);
                else
                        skb->csum = csum_block_add(
                                skb->csum,
                                csum_partial_copy_nocheck(rfv->hdr.c + offset,
                                                          to, copy, 0),
                                odd);

                odd = 0;
                offset += copy;
                to += copy;
                len -= copy;

                if (!len)
                        return 0;
        }

        offset -= rfv->hlen;

        return ip_generic_getfrag(rfv->msg, to, offset, len, odd, skb);
}

static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
        struct inet_sock *inet = inet_sk(sk);
        struct net *net = sock_net(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;
        struct raw_frag_vec rfv;
        int hdrincl;

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

        /* hdrincl should be READ_ONCE(inet->hdrincl)
         * but READ_ONCE() doesn't work with bit fields.
         * Doing this indirectly yields the same result.
         */
        hdrincl = inet->hdrincl;
        hdrincl = READ_ONCE(hdrincl);
        /*
         *      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) {
                DECLARE_SOCKADDR(struct sockaddr_in *, usin, 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.sockc.tsflags = sk->sk_tsflags;
        ipc.addr = inet->inet_saddr;
        ipc.opt = NULL;
        ipc.tx_flags = 0;
        ipc.ttl = 0;
        ipc.tos = -1;
        ipc.oif = sk->sk_bound_dev_if;

        if (msg->msg_controllen) {
                err = ip_cmsg_send(sk, msg, &ipc, false);
                if (unlikely(err)) {
                        kfree(ipc.opt);
                        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 (hdrincl)
                        goto done;
                if (ipc.opt->opt.srr) {
                        if (!daddr)
                                goto done;
                        daddr = ipc.opt->opt.faddr;
                }
        }
        tos = get_rtconn_flags(&ipc, 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;
        } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
                /* oif is set, packet is to local broadcast and
                 * and uc_index is set. oif is most likely set
                 * by sk_bound_dev_if. If uc_index != oif check if the
                 * oif is an L3 master and uc_index is an L3 slave.
                 * If so, we want to allow the send using the uc_index.
                 */
                if (ipc.oif != inet->uc_index &&
                    ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
                                                              inet->uc_index)) {
                        ipc.oif = inet->uc_index;
                }
        }

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

        if (!hdrincl) {
                rfv.msg = msg;
                rfv.hlen = 0;

                err = raw_probe_proto_opt(&rfv, &fl4);
                if (err)
                        goto done;
        }

        security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
        rt = ip_route_output_flow(net, &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 (hdrincl)
                err = raw_send_hdrinc(sk, &fl4, msg, len,
                                      &rt, msg->msg_flags, &ipc.sockc);

         else {
                sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);

                if (!ipc.addr)
                        ipc.addr = fl4.daddr;
                lock_sock(sk);
                err = ip_append_data(sk, &fl4, raw_getfrag,
                                     &rfv, 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:
        if (msg->msg_flags & MSG_PROBE)
                dst_confirm_neigh(&rt->dst, &fl4.daddr);
        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;
        u32 tb_id = RT_TABLE_LOCAL;
        int ret = -EINVAL;
        int chk_addr_ret;

        if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in))
                goto out;

        if (sk->sk_bound_dev_if)
                tb_id = l3mdev_fib_table_by_index(sock_net(sk),
                                                 sk->sk_bound_dev_if) ? : tb_id;

        chk_addr_ret = inet_addr_type_table(sock_net(sk), addr->sin_addr.s_addr,
                                            tb_id);

        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 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;
        DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
        struct sk_buff *skb;

        if (flags & MSG_OOB)
                goto out;

        if (flags & MSG_ERRQUEUE) {
                err = ip_recv_error(sk, msg, len, addr_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_msg(skb, 0, msg, 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));
                *addr_len = sizeof(*sin);
        }
        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)
                        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

int raw_abort(struct sock *sk, int err)
{
        lock_sock(sk);

        sk->sk_err = err;
        sk->sk_error_report(sk);
        __udp_disconnect(sk, 0);

        release_sock(sk);

        return 0;
}
EXPORT_SYMBOL_GPL(raw_abort);

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,
        .release_cb        = ip4_datagram_release_cb,
        .hash              = raw_hash_sk,
        .unhash            = raw_unhash_sk,
        .obj_size          = sizeof(struct raw_sock),
        .useroffset        = offsetof(struct raw_sock, filter),
        .usersize          = sizeof_field(struct raw_sock, filter),
        .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
        .diag_destroy      = raw_abort,
};

#ifdef CONFIG_PROC_FS
static struct sock *raw_get_first(struct seq_file *seq)
{
        struct sock *sk;
        struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file));
        struct raw_iter_state *state = raw_seq_private(seq);

        for (state->bucket = 0; state->bucket < RAW_HTABLE_SIZE;
                        ++state->bucket) {
                sk_for_each(sk, &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_hashinfo *h = PDE_DATA(file_inode(seq->file));
        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(&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_hashinfo *h = PDE_DATA(file_inode(seq->file));

        read_lock(&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_hashinfo *h = PDE_DATA(file_inode(seq->file));

        read_unlock(&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 %5u %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),
                refcount_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,
};

static __net_init int raw_init_net(struct net *net)
{
        if (!proc_create_net_data("raw", 0444, net->proc_net, &raw_seq_ops,
                        sizeof(struct raw_iter_state), &raw_v4_hashinfo))
                return -ENOMEM;

        return 0;
}

static __net_exit void raw_exit_net(struct net *net)
{
        remove_proc_entry("raw", net->proc_net);
}

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 */