raw.c

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/*
 *  RAW sockets for IPv6
 *  Linux INET6 implementation
 *
 *  Authors:
 *  Pedro Roque     <[email protected]>
 *
 *  Adapted from linux/net/ipv4/raw.c
 *
 *  Fixes:
 *  Hideaki YOSHIFUJI   :   sin6_scope_id support
 *  YOSHIFUJI,H.@USAGI  :   raw checksum (RFC2292(bis) compliance)
 *  Kazunori MIYAZAWA @USAGI:   change process style to use ip6_append_data
 *
 *  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/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/slab.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmpv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <linux/skbuff.h>
#include <linux/compat.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>

#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/ip6_route.h>
#include <net/ip6_checksum.h>
#include <net/addrconf.h>
#include <net/transp_v6.h>
#include <net/udp.h>
#include <net/inet_common.h>
#include <net/tcp_states.h>
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
#include <net/mip6.h>
#endif
#include <linux/mroute6.h>

#include <net/raw.h>
#include <net/rawv6.h>
#include <net/xfrm.h>

#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/export.h>

static struct raw_hashinfo raw_v6_hashinfo = {
    .lock = __RW_LOCK_UNLOCKED(raw_v6_hashinfo.lock),
};

static struct sock *__raw_v6_lookup(struct net *net, struct sock *sk,
        unsigned short num, const struct in6_addr *loc_addr,
        const struct in6_addr *rmt_addr, int dif)
{
    struct hlist_node *node;
    bool is_multicast = ipv6_addr_is_multicast(loc_addr);

    sk_for_each_from(sk, node)
        if (inet_sk(sk)->inet_num == num) {
            struct ipv6_pinfo *np = inet6_sk(sk);

            if (!net_eq(sock_net(sk), net))
                continue;

            if (!ipv6_addr_any(&np->daddr) &&
                !ipv6_addr_equal(&np->daddr, rmt_addr))
                continue;

            if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
                continue;

            if (!ipv6_addr_any(&np->rcv_saddr)) {
                if (ipv6_addr_equal(&np->rcv_saddr, loc_addr))
                    goto found;
                if (is_multicast &&
                    inet6_mc_check(sk, loc_addr, rmt_addr))
                    goto found;
                continue;
            }
            goto found;
        }
    sk = NULL;
found:
    return sk;
}

/*
 *  0 - deliver
 *  1 - block
 */
static int icmpv6_filter(const struct sock *sk, const struct sk_buff *skb)
{
    struct icmp6hdr *_hdr;
    const struct icmp6hdr *hdr;

    hdr = skb_header_pointer(skb, skb_transport_offset(skb),
                 sizeof(_hdr), &_hdr);
    if (hdr) {
        const __u32 *data = &raw6_sk(sk)->filter.data[0];
        unsigned int type = hdr->icmp6_type;

        return (data[type >> 5] & (1U << (type & 31))) != 0;
    }
    return 1;
}

#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
typedef int mh_filter_t(struct sock *sock, struct sk_buff *skb);

static mh_filter_t __rcu *mh_filter __read_mostly;

int rawv6_mh_filter_register(mh_filter_t filter)
{
    rcu_assign_pointer(mh_filter, filter);
    return 0;
}
EXPORT_SYMBOL(rawv6_mh_filter_register);

int rawv6_mh_filter_unregister(mh_filter_t filter)
{
    RCU_INIT_POINTER(mh_filter, NULL);
    synchronize_rcu();
    return 0;
}
EXPORT_SYMBOL(rawv6_mh_filter_unregister);

#endif

/*
 *  demultiplex raw sockets.
 *  (should consider queueing the skb in the sock receive_queue
 *  without calling rawv6.c)
 *
 *  Caller owns SKB so we must make clones.
 */
static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
{
    const struct in6_addr *saddr;
    const struct in6_addr *daddr;
    struct sock *sk;
    bool delivered = false;
    __u8 hash;
    struct net *net;

    saddr = &ipv6_hdr(skb)->saddr;
    daddr = saddr + 1;

    hash = nexthdr & (RAW_HTABLE_SIZE - 1);

    read_lock(&raw_v6_hashinfo.lock);
    sk = sk_head(&raw_v6_hashinfo.ht[hash]);

    if (sk == NULL)
        goto out;

    net = dev_net(skb->dev);
    sk = __raw_v6_lookup(net, sk, nexthdr, daddr, saddr, IP6CB(skb)->iif);

    while (sk) {
        int filtered;

        delivered = true;
        switch (nexthdr) {
        case IPPROTO_ICMPV6:
            filtered = icmpv6_filter(sk, skb);
            break;

#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
        case IPPROTO_MH:
        {
            /* XXX: To validate MH only once for each packet,
             * this is placed here. It should be after checking
             * xfrm policy, however it doesn't. The checking xfrm
             * policy is placed in rawv6_rcv() because it is
             * required for each socket.
             */
            mh_filter_t *filter;

            filter = rcu_dereference(mh_filter);
            filtered = filter ? (*filter)(sk, skb) : 0;
            break;
        }
#endif
        default:
            filtered = 0;
            break;
        }

        if (filtered < 0)
            break;
        if (filtered == 0) {
            struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);

            /* Not releasing hash table! */
            if (clone) {
                nf_reset(clone);
                rawv6_rcv(sk, clone);
            }
        }
        sk = __raw_v6_lookup(net, sk_next(sk), nexthdr, daddr, saddr,
                     IP6CB(skb)->iif);
    }
out:
    read_unlock(&raw_v6_hashinfo.lock);
    return delivered;
}

bool raw6_local_deliver(struct sk_buff *skb, int nexthdr)
{
    struct sock *raw_sk;

    raw_sk = sk_head(&raw_v6_hashinfo.ht[nexthdr & (RAW_HTABLE_SIZE - 1)]);
    if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
        raw_sk = NULL;

    return raw_sk != NULL;
}

/* This cleans up af_inet6 a bit. -DaveM */
static int rawv6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
    struct inet_sock *inet = inet_sk(sk);
    struct ipv6_pinfo *np = inet6_sk(sk);
    struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
    __be32 v4addr = 0;
    int addr_type;
    int err;

    if (addr_len < SIN6_LEN_RFC2133)
        return -EINVAL;
    addr_type = ipv6_addr_type(&addr->sin6_addr);

    /* Raw sockets are IPv6 only */
    if (addr_type == IPV6_ADDR_MAPPED)
        return -EADDRNOTAVAIL;

    lock_sock(sk);

    err = -EINVAL;
    if (sk->sk_state != TCP_CLOSE)
        goto out;

    rcu_read_lock();
    /* Check if the address belongs to the host. */
    if (addr_type != IPV6_ADDR_ANY) {
        struct net_device *dev = NULL;

        if (addr_type & IPV6_ADDR_LINKLOCAL) {
            if (addr_len >= sizeof(struct sockaddr_in6) &&
                addr->sin6_scope_id) {
                /* Override any existing binding, if another
                 * one is supplied by user.
                 */
                sk->sk_bound_dev_if = addr->sin6_scope_id;
            }

            /* Binding to link-local address requires an interface */
            if (!sk->sk_bound_dev_if)
                goto out_unlock;

            err = -ENODEV;
            dev = dev_get_by_index_rcu(sock_net(sk),
                           sk->sk_bound_dev_if);
            if (!dev)
                goto out_unlock;
        }

        /* ipv4 addr of the socket is invalid.  Only the
         * unspecified and mapped address have a v4 equivalent.
         */
        v4addr = LOOPBACK4_IPV6;
        if (!(addr_type & IPV6_ADDR_MULTICAST)) {
            err = -EADDRNOTAVAIL;
            if (!ipv6_chk_addr(sock_net(sk), &addr->sin6_addr,
                       dev, 0)) {
                goto out_unlock;
            }
        }
    }

    inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
    np->rcv_saddr = addr->sin6_addr;
    if (!(addr_type & IPV6_ADDR_MULTICAST))
        np->saddr = addr->sin6_addr;
    err = 0;
out_unlock:
    rcu_read_unlock();
out:
    release_sock(sk);
    return err;
}

static void rawv6_err(struct sock *sk, struct sk_buff *skb,
           struct inet6_skb_parm *opt,
           u8 type, u8 code, int offset, __be32 info)
{
    struct inet_sock *inet = inet_sk(sk);
    struct ipv6_pinfo *np = inet6_sk(sk);
    int err;
    int harderr;

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

    harderr = icmpv6_err_convert(type, code, &err);
    if (type == ICMPV6_PKT_TOOBIG) {
        ip6_sk_update_pmtu(skb, sk, info);
        harderr = (np->pmtudisc == IPV6_PMTUDISC_DO);
    }
    if (type == NDISC_REDIRECT)
        ip6_sk_redirect(skb, sk);
    if (np->recverr) {
        u8 *payload = skb->data;
        if (!inet->hdrincl)
            payload += offset;
        ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
    }

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

void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
        u8 type, u8 code, int inner_offset, __be32 info)
{
    struct sock *sk;
    int hash;
    const struct in6_addr *saddr, *daddr;
    struct net *net;

    hash = nexthdr & (RAW_HTABLE_SIZE - 1);

    read_lock(&raw_v6_hashinfo.lock);
    sk = sk_head(&raw_v6_hashinfo.ht[hash]);
    if (sk != NULL) {
        /* Note: ipv6_hdr(skb) != skb->data */
        const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;
        saddr = &ip6h->saddr;
        daddr = &ip6h->daddr;
        net = dev_net(skb->dev);

        while ((sk = __raw_v6_lookup(net, sk, nexthdr, saddr, daddr,
                        IP6CB(skb)->iif))) {
            rawv6_err(sk, skb, NULL, type, code,
                    inner_offset, info);
            sk = sk_next(sk);
        }
    }
    read_unlock(&raw_v6_hashinfo.lock);
}

static inline int rawv6_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
    if ((raw6_sk(sk)->checksum || rcu_access_pointer(sk->sk_filter)) &&
        skb_checksum_complete(skb)) {
        atomic_inc(&sk->sk_drops);
        kfree_skb(skb);
        return NET_RX_DROP;
    }

    /* Charge it to the socket. */
    skb_dst_drop(skb);
    if (sock_queue_rcv_skb(sk, skb) < 0) {
        kfree_skb(skb);
        return NET_RX_DROP;
    }

    return 0;
}

/*
 *  This is next to useless...
 *  if we demultiplex in network layer we don't need the extra call
 *  just to queue the skb...
 *  maybe we could have the network decide upon a hint if it
 *  should call raw_rcv for demultiplexing
 */
int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
{
    struct inet_sock *inet = inet_sk(sk);
    struct raw6_sock *rp = raw6_sk(sk);

    if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
        atomic_inc(&sk->sk_drops);
        kfree_skb(skb);
        return NET_RX_DROP;
    }

    if (!rp->checksum)
        skb->ip_summed = CHECKSUM_UNNECESSARY;

    if (skb->ip_summed == CHECKSUM_COMPLETE) {
        skb_postpull_rcsum(skb, skb_network_header(skb),
                   skb_network_header_len(skb));
        if (!csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
                     &ipv6_hdr(skb)->daddr,
                     skb->len, inet->inet_num, skb->csum))
            skb->ip_summed = CHECKSUM_UNNECESSARY;
    }
    if (!skb_csum_unnecessary(skb))
        skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
                             &ipv6_hdr(skb)->daddr,
                             skb->len,
                             inet->inet_num, 0));

    if (inet->hdrincl) {
        if (skb_checksum_complete(skb)) {
            atomic_inc(&sk->sk_drops);
            kfree_skb(skb);
            return NET_RX_DROP;
        }
    }

    rawv6_rcv_skb(sk, skb);
    return 0;
}


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

static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
          struct msghdr *msg, size_t len,
          int noblock, int flags, int *addr_len)
{
    struct ipv6_pinfo *np = inet6_sk(sk);
    struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)msg->msg_name;
    struct sk_buff *skb;
    size_t copied;
    int err;

    if (flags & MSG_OOB)
        return -EOPNOTSUPP;

    if (addr_len)
        *addr_len=sizeof(*sin6);

    if (flags & MSG_ERRQUEUE)
        return ipv6_recv_error(sk, msg, len);

    if (np->rxpmtu && np->rxopt.bits.rxpmtu)
        return ipv6_recv_rxpmtu(sk, msg, len);

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

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

    if (skb_csum_unnecessary(skb)) {
        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
    } else if (msg->msg_flags&MSG_TRUNC) {
        if (__skb_checksum_complete(skb))
            goto csum_copy_err;
        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
    } else {
        err = skb_copy_and_csum_datagram_iovec(skb, 0, msg->msg_iov);
        if (err == -EINVAL)
            goto csum_copy_err;
    }
    if (err)
        goto out_free;

    /* Copy the address. */
    if (sin6) {
        sin6->sin6_family = AF_INET6;
        sin6->sin6_port = 0;
        sin6->sin6_addr = ipv6_hdr(skb)->saddr;
        sin6->sin6_flowinfo = 0;
        sin6->sin6_scope_id = 0;
        if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
            sin6->sin6_scope_id = IP6CB(skb)->iif;
    }

    sock_recv_ts_and_drops(msg, sk, skb);

    if (np->rxopt.all)
        datagram_recv_ctl(sk, msg, skb);

    err = copied;
    if (flags & MSG_TRUNC)
        err = skb->len;

out_free:
    skb_free_datagram(sk, skb);
out:
    return err;

csum_copy_err:
    skb_kill_datagram(sk, skb, flags);

    /* Error for blocking case is chosen to masquerade
       as some normal condition.
     */
    err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
    goto out;
}

static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
                     struct raw6_sock *rp)
{
    struct sk_buff *skb;
    int err = 0;
    int offset;
    int len;
    int total_len;
    __wsum tmp_csum;
    __sum16 csum;

    if (!rp->checksum)
        goto send;

    if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
        goto out;

    offset = rp->offset;
    total_len = inet_sk(sk)->cork.base.length;
    if (offset >= total_len - 1) {
        err = -EINVAL;
        ip6_flush_pending_frames(sk);
        goto out;
    }

    /* should be check HW csum miyazawa */
    if (skb_queue_len(&sk->sk_write_queue) == 1) {
        /*
         * Only one fragment on the socket.
         */
        tmp_csum = skb->csum;
    } else {
        struct sk_buff *csum_skb = NULL;
        tmp_csum = 0;

        skb_queue_walk(&sk->sk_write_queue, skb) {
            tmp_csum = csum_add(tmp_csum, skb->csum);

            if (csum_skb)
                continue;

            len = skb->len - skb_transport_offset(skb);
            if (offset >= len) {
                offset -= len;
                continue;
            }

            csum_skb = skb;
        }

        skb = csum_skb;
    }

    offset += skb_transport_offset(skb);
    if (skb_copy_bits(skb, offset, &csum, 2))
        BUG();

    /* in case cksum was not initialized */
    if (unlikely(csum))
        tmp_csum = csum_sub(tmp_csum, csum_unfold(csum));

    csum = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
                   total_len, fl6->flowi6_proto, tmp_csum);

    if (csum == 0 && fl6->flowi6_proto == IPPROTO_UDP)
        csum = CSUM_MANGLED_0;

    if (skb_store_bits(skb, offset, &csum, 2))
        BUG();

send:
    err = ip6_push_pending_frames(sk);
out:
    return err;
}

static int rawv6_send_hdrinc(struct sock *sk, void *from, int length,
            struct flowi6 *fl6, struct dst_entry **dstp,
            unsigned int flags)
{
    struct ipv6_pinfo *np = inet6_sk(sk);
    struct ipv6hdr *iph;
    struct sk_buff *skb;
    int err;
    struct rt6_info *rt = (struct rt6_info *)*dstp;
    int hlen = LL_RESERVED_SPACE(rt->dst.dev);
    int tlen = rt->dst.dev->needed_tailroom;

    if (length > rt->dst.dev->mtu) {
        ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu);
        return -EMSGSIZE;
    }
    if (flags&MSG_PROBE)
        goto out;

    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);
    *dstp = NULL;

    skb_put(skb, length);
    skb_reset_network_header(skb);
    iph = ipv6_hdr(skb);

    skb->ip_summed = CHECKSUM_NONE;

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

    IP6_UPD_PO_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
    err = NF_HOOK(NFPROTO_IPV6, 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_fault:
    err = -EFAULT;
    kfree_skb(skb);
error:
    IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
    if (err == -ENOBUFS && !np->recverr)
        err = 0;
    return err;
}

static int rawv6_probe_proto_opt(struct flowi6 *fl6, struct msghdr *msg)
{
    struct iovec *iov;
    u8 __user *type = NULL;
    u8 __user *code = NULL;
    u8 len = 0;
    int probed = 0;
    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 (fl6->flowi6_proto) {
        case IPPROTO_ICMPV6:
            /* 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(fl6->fl6_icmp_type, type) ||
                    get_user(fl6->fl6_icmp_code, code))
                    return -EFAULT;
                probed = 1;
            }
            break;
        case IPPROTO_MH:
            if (iov->iov_base && iov->iov_len < 1)
                break;
            /* check if type field is readable or not. */
            if (iov->iov_len > 2 - len) {
                u8 __user *p = iov->iov_base;
                if (get_user(fl6->fl6_mh_type, &p[2 - len]))
                    return -EFAULT;
                probed = 1;
            } else
                len += iov->iov_len;

            break;
        default:
            probed = 1;
            break;
        }
        if (probed)
            break;
    }
    return 0;
}

static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
           struct msghdr *msg, size_t len)
{
    struct ipv6_txoptions opt_space;
    struct sockaddr_in6 * sin6 = (struct sockaddr_in6 *) msg->msg_name;
    struct in6_addr *daddr, *final_p, final;
    struct inet_sock *inet = inet_sk(sk);
    struct ipv6_pinfo *np = inet6_sk(sk);
    struct raw6_sock *rp = raw6_sk(sk);
    struct ipv6_txoptions *opt = NULL;
    struct ip6_flowlabel *flowlabel = NULL;
    struct dst_entry *dst = NULL;
    struct flowi6 fl6;
    int addr_len = msg->msg_namelen;
    int hlimit = -1;
    int tclass = -1;
    int dontfrag = -1;
    u16 proto;
    int err;

    /* Rough check on arithmetic overflow,
       better check is made in ip6_append_data().
     */
    if (len > INT_MAX)
        return -EMSGSIZE;

    /* Mirror BSD error message compatibility */
    if (msg->msg_flags & MSG_OOB)
        return -EOPNOTSUPP;

    /*
     *  Get and verify the address.
     */
    memset(&fl6, 0, sizeof(fl6));

    fl6.flowi6_mark = sk->sk_mark;

    if (sin6) {
        if (addr_len < SIN6_LEN_RFC2133)
            return -EINVAL;

        if (sin6->sin6_family && sin6->sin6_family != AF_INET6)
            return -EAFNOSUPPORT;

        /* port is the proto value [0..255] carried in nexthdr */
        proto = ntohs(sin6->sin6_port);

        if (!proto)
            proto = inet->inet_num;
        else if (proto != inet->inet_num)
            return -EINVAL;

        if (proto > 255)
            return -EINVAL;

        daddr = &sin6->sin6_addr;
        if (np->sndflow) {
            fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
            if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
                flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
                if (flowlabel == NULL)
                    return -EINVAL;
                daddr = &flowlabel->dst;
            }
        }

        /*
         * Otherwise it will be difficult to maintain
         * sk->sk_dst_cache.
         */
        if (sk->sk_state == TCP_ESTABLISHED &&
            ipv6_addr_equal(daddr, &np->daddr))
            daddr = &np->daddr;

        if (addr_len >= sizeof(struct sockaddr_in6) &&
            sin6->sin6_scope_id &&
            ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
            fl6.flowi6_oif = sin6->sin6_scope_id;
    } else {
        if (sk->sk_state != TCP_ESTABLISHED)
            return -EDESTADDRREQ;

        proto = inet->inet_num;
        daddr = &np->daddr;
        fl6.flowlabel = np->flow_label;
    }

    if (fl6.flowi6_oif == 0)
        fl6.flowi6_oif = sk->sk_bound_dev_if;

    if (msg->msg_controllen) {
        opt = &opt_space;
        memset(opt, 0, sizeof(struct ipv6_txoptions));
        opt->tot_len = sizeof(struct ipv6_txoptions);

        err = datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
                    &hlimit, &tclass, &dontfrag);
        if (err < 0) {
            fl6_sock_release(flowlabel);
            return err;
        }
        if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
            flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
            if (flowlabel == NULL)
                return -EINVAL;
        }
        if (!(opt->opt_nflen|opt->opt_flen))
            opt = NULL;
    }
    if (opt == NULL)
        opt = np->opt;
    if (flowlabel)
        opt = fl6_merge_options(&opt_space, flowlabel, opt);
    opt = ipv6_fixup_options(&opt_space, opt);

    fl6.flowi6_proto = proto;
    err = rawv6_probe_proto_opt(&fl6, msg);
    if (err)
        goto out;

    if (!ipv6_addr_any(daddr))
        fl6.daddr = *daddr;
    else
        fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
    if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
        fl6.saddr = np->saddr;

    final_p = fl6_update_dst(&fl6, opt, &final);

    if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
        fl6.flowi6_oif = np->mcast_oif;
    else if (!fl6.flowi6_oif)
        fl6.flowi6_oif = np->ucast_oif;
    security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));

    dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
    if (IS_ERR(dst)) {
        err = PTR_ERR(dst);
        goto out;
    }
    if (hlimit < 0) {
        if (ipv6_addr_is_multicast(&fl6.daddr))
            hlimit = np->mcast_hops;
        else
            hlimit = np->hop_limit;
        if (hlimit < 0)
            hlimit = ip6_dst_hoplimit(dst);
    }

    if (tclass < 0)
        tclass = np->tclass;

    if (dontfrag < 0)
        dontfrag = np->dontfrag;

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

back_from_confirm:
    if (inet->hdrincl)
        err = rawv6_send_hdrinc(sk, msg->msg_iov, len, &fl6, &dst, msg->msg_flags);
    else {
        lock_sock(sk);
        err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov,
            len, 0, hlimit, tclass, opt, &fl6, (struct rt6_info*)dst,
            msg->msg_flags, dontfrag);

        if (err)
            ip6_flush_pending_frames(sk);
        else if (!(msg->msg_flags & MSG_MORE))
            err = rawv6_push_pending_frames(sk, &fl6, rp);
        release_sock(sk);
    }
done:
    dst_release(dst);
out:
    fl6_sock_release(flowlabel);
    return err<0?err:len;
do_confirm:
    dst_confirm(dst);
    if (!(msg->msg_flags & MSG_PROBE) || len)
        goto back_from_confirm;
    err = 0;
    goto done;
}

static int rawv6_seticmpfilter(struct sock *sk, int level, int optname,
                   char __user *optval, int optlen)
{
    switch (optname) {
    case ICMPV6_FILTER:
        if (optlen > sizeof(struct icmp6_filter))
            optlen = sizeof(struct icmp6_filter);
        if (copy_from_user(&raw6_sk(sk)->filter, optval, optlen))
            return -EFAULT;
        return 0;
    default:
        return -ENOPROTOOPT;
    }

    return 0;
}

static int rawv6_geticmpfilter(struct sock *sk, int level, int optname,
                   char __user *optval, int __user *optlen)
{
    int len;

    switch (optname) {
    case ICMPV6_FILTER:
        if (get_user(len, optlen))
            return -EFAULT;
        if (len < 0)
            return -EINVAL;
        if (len > sizeof(struct icmp6_filter))
            len = sizeof(struct icmp6_filter);
        if (put_user(len, optlen))
            return -EFAULT;
        if (copy_to_user(optval, &raw6_sk(sk)->filter, len))
            return -EFAULT;
        return 0;
    default:
        return -ENOPROTOOPT;
    }

    return 0;
}


static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,
                char __user *optval, unsigned int optlen)
{
    struct raw6_sock *rp = raw6_sk(sk);
    int val;

    if (get_user(val, (int __user *)optval))
        return -EFAULT;

    switch (optname) {
    case IPV6_CHECKSUM:
        if (inet_sk(sk)->inet_num == IPPROTO_ICMPV6 &&
            level == IPPROTO_IPV6) {
            /*
             * RFC3542 tells that IPV6_CHECKSUM socket
             * option in the IPPROTO_IPV6 level is not
             * allowed on ICMPv6 sockets.
             * If you want to set it, use IPPROTO_RAW
             * level IPV6_CHECKSUM socket option
             * (Linux extension).
             */
            return -EINVAL;
        }

        /* You may get strange result with a positive odd offset;
           RFC2292bis agrees with me. */
        if (val > 0 && (val&1))
            return -EINVAL;
        if (val < 0) {
            rp->checksum = 0;
        } else {
            rp->checksum = 1;
            rp->offset = val;
        }

        return 0;

    default:
        return -ENOPROTOOPT;
    }
}

static int rawv6_setsockopt(struct sock *sk, int level, int optname,
              char __user *optval, unsigned int optlen)
{
    switch (level) {
    case SOL_RAW:
        break;

    case SOL_ICMPV6:
        if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
            return -EOPNOTSUPP;
        return rawv6_seticmpfilter(sk, level, optname, optval, optlen);
    case SOL_IPV6:
        if (optname == IPV6_CHECKSUM)
            break;
    default:
        return ipv6_setsockopt(sk, level, optname, optval, optlen);
    }

    return do_rawv6_setsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
static int compat_rawv6_setsockopt(struct sock *sk, int level, int optname,
                   char __user *optval, unsigned int optlen)
{
    switch (level) {
    case SOL_RAW:
        break;
    case SOL_ICMPV6:
        if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
            return -EOPNOTSUPP;
        return rawv6_seticmpfilter(sk, level, optname, optval, optlen);
    case SOL_IPV6:
        if (optname == IPV6_CHECKSUM)
            break;
    default:
        return compat_ipv6_setsockopt(sk, level, optname,
                          optval, optlen);
    }
    return do_rawv6_setsockopt(sk, level, optname, optval, optlen);
}
#endif

static int do_rawv6_getsockopt(struct sock *sk, int level, int optname,
                char __user *optval, int __user *optlen)
{
    struct raw6_sock *rp = raw6_sk(sk);
    int val, len;

    if (get_user(len,optlen))
        return -EFAULT;

    switch (optname) {
    case IPV6_CHECKSUM:
        /*
         * We allow getsockopt() for IPPROTO_IPV6-level
         * IPV6_CHECKSUM socket option on ICMPv6 sockets
         * since RFC3542 is silent about it.
         */
        if (rp->checksum == 0)
            val = -1;
        else
            val = rp->offset;
        break;

    default:
        return -ENOPROTOOPT;
    }

    len = min_t(unsigned int, sizeof(int), len);

    if (put_user(len, optlen))
        return -EFAULT;
    if (copy_to_user(optval,&val,len))
        return -EFAULT;
    return 0;
}

static int rawv6_getsockopt(struct sock *sk, int level, int optname,
              char __user *optval, int __user *optlen)
{
    switch (level) {
    case SOL_RAW:
        break;

    case SOL_ICMPV6:
        if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
            return -EOPNOTSUPP;
        return rawv6_geticmpfilter(sk, level, optname, optval, optlen);
    case SOL_IPV6:
        if (optname == IPV6_CHECKSUM)
            break;
    default:
        return ipv6_getsockopt(sk, level, optname, optval, optlen);
    }

    return do_rawv6_getsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
static int compat_rawv6_getsockopt(struct sock *sk, int level, int optname,
                   char __user *optval, int __user *optlen)
{
    switch (level) {
    case SOL_RAW:
        break;
    case SOL_ICMPV6:
        if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
            return -EOPNOTSUPP;
        return rawv6_geticmpfilter(sk, level, optname, optval, optlen);
    case SOL_IPV6:
        if (optname == IPV6_CHECKSUM)
            break;
    default:
        return compat_ipv6_getsockopt(sk, level, optname,
                          optval, optlen);
    }
    return do_rawv6_getsockopt(sk, level, optname, optval, optlen);
}
#endif

static int rawv6_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->tail - skb->transport_header;
        spin_unlock_bh(&sk->sk_receive_queue.lock);
        return put_user(amount, (int __user *)arg);
    }

    default:
#ifdef CONFIG_IPV6_MROUTE
        return ip6mr_ioctl(sk, cmd, (void __user *)arg);
#else
        return -ENOIOCTLCMD;
#endif
    }
}

#ifdef CONFIG_COMPAT
static int compat_rawv6_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg)
{
    switch (cmd) {
    case SIOCOUTQ:
    case SIOCINQ:
        return -ENOIOCTLCMD;
    default:
#ifdef CONFIG_IPV6_MROUTE
        return ip6mr_compat_ioctl(sk, cmd, compat_ptr(arg));
#else
        return -ENOIOCTLCMD;
#endif
    }
}
#endif

static void rawv6_close(struct sock *sk, long timeout)
{
    if (inet_sk(sk)->inet_num == IPPROTO_RAW)
        ip6_ra_control(sk, -1);
    ip6mr_sk_done(sk);
    sk_common_release(sk);
}

static void raw6_destroy(struct sock *sk)
{
    lock_sock(sk);
    ip6_flush_pending_frames(sk);
    release_sock(sk);

    inet6_destroy_sock(sk);
}

static int rawv6_init_sk(struct sock *sk)
{
    struct raw6_sock *rp = raw6_sk(sk);

    switch (inet_sk(sk)->inet_num) {
    case IPPROTO_ICMPV6:
        rp->checksum = 1;
        rp->offset   = 2;
        break;
    case IPPROTO_MH:
        rp->checksum = 1;
        rp->offset   = 4;
        break;
    default:
        break;
    }
    return 0;
}

struct proto rawv6_prot = {
    .name          = "RAWv6",
    .owner         = THIS_MODULE,
    .close         = rawv6_close,
    .destroy       = raw6_destroy,
    .connect       = ip6_datagram_connect,
    .disconnect    = udp_disconnect,
    .ioctl         = rawv6_ioctl,
    .init          = rawv6_init_sk,
    .setsockopt    = rawv6_setsockopt,
    .getsockopt    = rawv6_getsockopt,
    .sendmsg       = rawv6_sendmsg,
    .recvmsg       = rawv6_recvmsg,
    .bind          = rawv6_bind,
    .backlog_rcv       = rawv6_rcv_skb,
    .hash          = raw_hash_sk,
    .unhash        = raw_unhash_sk,
    .obj_size      = sizeof(struct raw6_sock),
    .h.raw_hash    = &raw_v6_hashinfo,
#ifdef CONFIG_COMPAT
    .compat_setsockopt = compat_rawv6_setsockopt,
    .compat_getsockopt = compat_rawv6_getsockopt,
    .compat_ioctl      = compat_rawv6_ioctl,
#endif
};

#ifdef CONFIG_PROC_FS
static void raw6_sock_seq_show(struct seq_file *seq, struct sock *sp, int i)
{
    struct ipv6_pinfo *np = inet6_sk(sp);
    const struct in6_addr *dest, *src;
    __u16 destp, srcp;

    dest  = &np->daddr;
    src   = &np->rcv_saddr;
    destp = 0;
    srcp  = inet_sk(sp)->inet_num;
    seq_printf(seq,
           "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
           "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n",
           i,
           src->s6_addr32[0], src->s6_addr32[1],
           src->s6_addr32[2], src->s6_addr32[3], srcp,
           dest->s6_addr32[0], dest->s6_addr32[1],
           dest->s6_addr32[2], dest->s6_addr32[3], 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 raw6_seq_show(struct seq_file *seq, void *v)
{
    if (v == SEQ_START_TOKEN)
        seq_printf(seq,
               "  sl  "
               "local_address                         "
               "remote_address                        "
               "st tx_queue rx_queue tr tm->when retrnsmt"
               "   uid  timeout inode ref pointer drops\n");
    else
        raw6_sock_seq_show(seq, v, raw_seq_private(seq)->bucket);
    return 0;
}

static const struct seq_operations raw6_seq_ops = {
    .start =    raw_seq_start,
    .next =     raw_seq_next,
    .stop =     raw_seq_stop,
    .show =     raw6_seq_show,
};

static int raw6_seq_open(struct inode *inode, struct file *file)
{
    return raw_seq_open(inode, file, &raw_v6_hashinfo, &raw6_seq_ops);
}

static const struct file_operations raw6_seq_fops = {
    .owner =    THIS_MODULE,
    .open =     raw6_seq_open,
    .read =     seq_read,
    .llseek =   seq_lseek,
    .release =  seq_release_net,
};

static int __net_init raw6_init_net(struct net *net)
{
    if (!proc_net_fops_create(net, "raw6", S_IRUGO, &raw6_seq_fops))
        return -ENOMEM;

    return 0;
}

static void __net_exit raw6_exit_net(struct net *net)
{
    proc_net_remove(net, "raw6");
}

static struct pernet_operations raw6_net_ops = {
    .init = raw6_init_net,
    .exit = raw6_exit_net,
};

int __init raw6_proc_init(void)
{
    return register_pernet_subsys(&raw6_net_ops);
}

void raw6_proc_exit(void)
{
    unregister_pernet_subsys(&raw6_net_ops);
}
#endif  /* CONFIG_PROC_FS */

/* Same as inet6_dgram_ops, sans udp_poll.  */
static const struct proto_ops inet6_sockraw_ops = {
    .family        = PF_INET6,
    .owner         = THIS_MODULE,
    .release       = inet6_release,
    .bind          = inet6_bind,
    .connect       = inet_dgram_connect,    /* ok       */
    .socketpair    = sock_no_socketpair,    /* a do nothing */
    .accept        = sock_no_accept,        /* a do nothing */
    .getname       = inet6_getname,
    .poll          = datagram_poll,     /* ok       */
    .ioctl         = inet6_ioctl,       /* must change  */
    .listen        = sock_no_listen,        /* ok       */
    .shutdown      = inet_shutdown,     /* ok       */
    .setsockopt    = sock_common_setsockopt,    /* ok       */
    .getsockopt    = sock_common_getsockopt,    /* ok       */
    .sendmsg       = inet_sendmsg,      /* ok       */
    .recvmsg       = sock_common_recvmsg,   /* ok       */
    .mmap          = sock_no_mmap,
    .sendpage      = sock_no_sendpage,
#ifdef CONFIG_COMPAT
    .compat_setsockopt = compat_sock_common_setsockopt,
    .compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

static struct inet_protosw rawv6_protosw = {
    .type       = SOCK_RAW,
    .protocol   = IPPROTO_IP,   /* wild card */
    .prot       = &rawv6_prot,
    .ops        = &inet6_sockraw_ops,
    .no_check   = UDP_CSUM_DEFAULT,
    .flags      = INET_PROTOSW_REUSE,
};

int __init rawv6_init(void)
{
    int ret;

    ret = inet6_register_protosw(&rawv6_protosw);
    if (ret)
        goto out;
out:
    return ret;
}

void rawv6_exit(void)
{
    inet6_unregister_protosw(&rawv6_protosw);
}