/*
 *      PF_INET6 socket protocol family
 *      Linux INET6 implementation
 *
 *      Authors:
 *      Pedro Roque             <roque@di.fc.ul.pt>
 *
 *      Adapted from linux/net/ipv4/af_inet.c
 *
 *      Fixes:
 *      piggy, Karl Knutson     :       Socket protocol table
 *      Hideaki YOSHIFUJI       :       sin6_scope_id support
 *      Arnaldo Melo            :       check proc_net_create return, cleanups
 *
 *      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.
 */

#define pr_fmt(fmt) "IPv6: " fmt

#include <linux/module.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/slab.h>

#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/icmpv6.h>
#include <linux/netfilter_ipv6.h>

#include <net/ip.h>
#include <net/ipv6.h>
#include <net/udp.h>
#include <net/udplite.h>
#include <net/tcp.h>
#include <net/ping.h>
#include <net/protocol.h>
#include <net/inet_common.h>
#include <net/route.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/ndisc.h>
#ifdef CONFIG_IPV6_TUNNEL
#include <net/ip6_tunnel.h>
#endif

#include <asm/uaccess.h>
#include <linux/mroute6.h>

MODULE_AUTHOR("Cast of dozens");
MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
MODULE_LICENSE("GPL");

/* The inetsw6 table contains everything that inet6_create needs to
 * build a new socket.
 */
static struct list_head inetsw6[SOCK_MAX];
static DEFINE_SPINLOCK(inetsw6_lock);

struct ipv6_params ipv6_defaults = {
        .disable_ipv6 = 0,
        .autoconf = 1,
};

static int disable_ipv6_mod;

module_param_named(disable, disable_ipv6_mod, int, 0444);
MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");

module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");

module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");

static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
{
        const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);

        return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
}

static int inet6_create(struct net *net, struct socket *sock, int protocol,
                        int kern)
{
        struct inet_sock *inet;
        struct ipv6_pinfo *np;
        struct sock *sk;
        struct inet_protosw *answer;
        struct proto *answer_prot;
        unsigned char answer_flags;
        int try_loading_module = 0;
        int err;

        /* Look for the requested type/protocol pair. */
lookup_protocol:
        err = -ESOCKTNOSUPPORT;
        rcu_read_lock();
        list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {

                err = 0;
                /* Check the non-wild match. */
                if (protocol == answer->protocol) {
                        if (protocol != IPPROTO_IP)
                                break;
                } else {
                        /* Check for the two wild cases. */
                        if (IPPROTO_IP == protocol) {
                                protocol = answer->protocol;
                                break;
                        }
                        if (IPPROTO_IP == answer->protocol)
                                break;
                }
                err = -EPROTONOSUPPORT;
        }

        if (err) {
                if (try_loading_module < 2) {
                        rcu_read_unlock();
                        /*
                         * Be more specific, e.g. net-pf-10-proto-132-type-1
                         * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
                         */
                        if (++try_loading_module == 1)
                                request_module("net-pf-%d-proto-%d-type-%d",
                                                PF_INET6, protocol, sock->type);
                        /*
                         * Fall back to generic, e.g. net-pf-10-proto-132
                         * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
                         */
                        else
                                request_module("net-pf-%d-proto-%d",
                                                PF_INET6, protocol);
                        goto lookup_protocol;
                } else
                        goto out_rcu_unlock;
        }

        err = -EPERM;
        if (sock->type == SOCK_RAW && !kern &&
            !ns_capable(net->user_ns, CAP_NET_RAW))
                goto out_rcu_unlock;

        sock->ops = answer->ops;
        answer_prot = answer->prot;
        answer_flags = answer->flags;
        rcu_read_unlock();

        WARN_ON(!answer_prot->slab);

        err = -ENOBUFS;
        sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot, kern);
        if (!sk)
                goto out;

        sock_init_data(sock, sk);

        err = 0;
        if (INET_PROTOSW_REUSE & answer_flags)
                sk->sk_reuse = SK_CAN_REUSE;

        inet = inet_sk(sk);
        inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;

        if (SOCK_RAW == sock->type) {
                inet->inet_num = protocol;
                if (IPPROTO_RAW == protocol)
                        inet->hdrincl = 1;
        }

        sk->sk_destruct         = inet_sock_destruct;
        sk->sk_family           = PF_INET6;
        sk->sk_protocol         = protocol;

        sk->sk_backlog_rcv      = answer->prot->backlog_rcv;

        inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
        np->hop_limit   = -1;
        np->mcast_hops  = IPV6_DEFAULT_MCASTHOPS;
        np->mc_loop     = 1;
        np->pmtudisc    = IPV6_PMTUDISC_WANT;
        sk->sk_ipv6only = net->ipv6.sysctl.bindv6only;

        /* Init the ipv4 part of the socket since we can have sockets
         * using v6 API for ipv4.
         */
        inet->uc_ttl    = -1;

        inet->mc_loop   = 1;
        inet->mc_ttl    = 1;
        inet->mc_index  = 0;
        inet->mc_list   = NULL;
        inet->rcv_tos   = 0;

        if (net->ipv4.sysctl_ip_no_pmtu_disc)
                inet->pmtudisc = IP_PMTUDISC_DONT;
        else
                inet->pmtudisc = IP_PMTUDISC_WANT;
        /*
         * Increment only the relevant sk_prot->socks debug field, this changes
         * the previous behaviour of incrementing both the equivalent to
         * answer->prot->socks (inet6_sock_nr) and inet_sock_nr.
         *
         * This allows better debug granularity as we'll know exactly how many
         * UDPv6, TCPv6, etc socks were allocated, not the sum of all IPv6
         * transport protocol socks. -acme
         */
        sk_refcnt_debug_inc(sk);

        if (inet->inet_num) {
                /* It assumes that any protocol which allows
                 * the user to assign a number at socket
                 * creation time automatically shares.
                 */
                inet->inet_sport = htons(inet->inet_num);
                sk->sk_prot->hash(sk);
        }
        if (sk->sk_prot->init) {
                err = sk->sk_prot->init(sk);
                if (err) {
                        sk_common_release(sk);
                        goto out;
                }
        }
out:
        return err;
out_rcu_unlock:
        rcu_read_unlock();
        goto out;
}


/* bind for INET6 API */
int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
        struct sockaddr_in6 *addr = (struct sockaddr_in6 *)uaddr;
        struct sock *sk = sock->sk;
        struct inet_sock *inet = inet_sk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct net *net = sock_net(sk);
        __be32 v4addr = 0;
        unsigned short snum;
        int addr_type = 0;
        int err = 0;

        /* If the socket has its own bind function then use it. */
        if (sk->sk_prot->bind)
                return sk->sk_prot->bind(sk, uaddr, addr_len);

        if (addr_len < SIN6_LEN_RFC2133)
                return -EINVAL;

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

        addr_type = ipv6_addr_type(&addr->sin6_addr);
        if ((addr_type & IPV6_ADDR_MULTICAST) && sock->type == SOCK_STREAM)
                return -EINVAL;

        snum = ntohs(addr->sin6_port);
        if (snum && snum < PROT_SOCK && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
                return -EACCES;

        lock_sock(sk);

        /* Check these errors (active socket, double bind). */
        if (sk->sk_state != TCP_CLOSE || inet->inet_num) {
                err = -EINVAL;
                goto out;
        }

        /* Check if the address belongs to the host. */
        if (addr_type == IPV6_ADDR_MAPPED) {
                int chk_addr_ret;

                /* Binding to v4-mapped address on a v6-only socket
                 * makes no sense
                 */
                if (sk->sk_ipv6only) {
                        err = -EINVAL;
                        goto out;
                }

                /* Reproduce AF_INET checks to make the bindings consistent */
                v4addr = addr->sin6_addr.s6_addr32[3];
                chk_addr_ret = inet_addr_type(net, v4addr);
                if (!net->ipv4.sysctl_ip_nonlocal_bind &&
                    !(inet->freebind || inet->transparent) &&
                    v4addr != htonl(INADDR_ANY) &&
                    chk_addr_ret != RTN_LOCAL &&
                    chk_addr_ret != RTN_MULTICAST &&
                    chk_addr_ret != RTN_BROADCAST) {
                        err = -EADDRNOTAVAIL;
                        goto out;
                }
        } else {
                if (addr_type != IPV6_ADDR_ANY) {
                        struct net_device *dev = NULL;

                        rcu_read_lock();
                        if (__ipv6_addr_needs_scope_id(addr_type)) {
                                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) {
                                        err = -EINVAL;
                                        goto out_unlock;
                                }
                                dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
                                if (!dev) {
                                        err = -ENODEV;
                                        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)) {
                                if (!(inet->freebind || inet->transparent) &&
                                    !ipv6_chk_addr(net, &addr->sin6_addr,
                                                   dev, 0)) {
                                        err = -EADDRNOTAVAIL;
                                        goto out_unlock;
                                }
                        }
                        rcu_read_unlock();
                }
        }

        inet->inet_rcv_saddr = v4addr;
        inet->inet_saddr = v4addr;

        sk->sk_v6_rcv_saddr = addr->sin6_addr;

        if (!(addr_type & IPV6_ADDR_MULTICAST))
                np->saddr = addr->sin6_addr;

        /* Make sure we are allowed to bind here. */
        if ((snum || !inet->bind_address_no_port) &&
            sk->sk_prot->get_port(sk, snum)) {
                inet_reset_saddr(sk);
                err = -EADDRINUSE;
                goto out;
        }

        if (addr_type != IPV6_ADDR_ANY) {
                sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
                if (addr_type != IPV6_ADDR_MAPPED)
                        sk->sk_ipv6only = 1;
        }
        if (snum)
                sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
        inet->inet_sport = htons(inet->inet_num);
        inet->inet_dport = 0;
        inet->inet_daddr = 0;
out:
        release_sock(sk);
        return err;
out_unlock:
        rcu_read_unlock();
        goto out;
}
EXPORT_SYMBOL(inet6_bind);

int inet6_release(struct socket *sock)
{
        struct sock *sk = sock->sk;

        if (!sk)
                return -EINVAL;

        /* Free mc lists */
        ipv6_sock_mc_close(sk);

        /* Free ac lists */
        ipv6_sock_ac_close(sk);

        return inet_release(sock);
}
EXPORT_SYMBOL(inet6_release);

void inet6_destroy_sock(struct sock *sk)
{
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct sk_buff *skb;
        struct ipv6_txoptions *opt;

        /* Release rx options */

        skb = xchg(&np->pktoptions, NULL);
        if (skb)
                kfree_skb(skb);

        skb = xchg(&np->rxpmtu, NULL);
        if (skb)
                kfree_skb(skb);

        /* Free flowlabels */
        fl6_free_socklist(sk);

        /* Free tx options */

        opt = xchg(&np->opt, NULL);
        if (opt)
                sock_kfree_s(sk, opt, opt->tot_len);
}
EXPORT_SYMBOL_GPL(inet6_destroy_sock);

/*
 *      This does both peername and sockname.
 */

int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
                 int *uaddr_len, int peer)
{
        struct sockaddr_in6 *sin = (struct sockaddr_in6 *)uaddr;
        struct sock *sk = sock->sk;
        struct inet_sock *inet = inet_sk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);

        sin->sin6_family = AF_INET6;
        sin->sin6_flowinfo = 0;
        sin->sin6_scope_id = 0;
        if (peer) {
                if (!inet->inet_dport)
                        return -ENOTCONN;
                if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
                    peer == 1)
                        return -ENOTCONN;
                sin->sin6_port = inet->inet_dport;
                sin->sin6_addr = sk->sk_v6_daddr;
                if (np->sndflow)
                        sin->sin6_flowinfo = np->flow_label;
        } else {
                if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
                        sin->sin6_addr = np->saddr;
                else
                        sin->sin6_addr = sk->sk_v6_rcv_saddr;

                sin->sin6_port = inet->inet_sport;
        }
        sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr,
                                                 sk->sk_bound_dev_if);
        *uaddr_len = sizeof(*sin);
        return 0;
}
EXPORT_SYMBOL(inet6_getname);

int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
        struct sock *sk = sock->sk;
        struct net *net = sock_net(sk);

        switch (cmd) {
        case SIOCGSTAMP:
                return sock_get_timestamp(sk, (struct timeval __user *)arg);

        case SIOCGSTAMPNS:
                return sock_get_timestampns(sk, (struct timespec __user *)arg);

        case SIOCADDRT:
        case SIOCDELRT:

                return ipv6_route_ioctl(net, cmd, (void __user *)arg);

        case SIOCSIFADDR:
                return addrconf_add_ifaddr(net, (void __user *) arg);
        case SIOCDIFADDR:
                return addrconf_del_ifaddr(net, (void __user *) arg);
        case SIOCSIFDSTADDR:
                return addrconf_set_dstaddr(net, (void __user *) arg);
        default:
                if (!sk->sk_prot->ioctl)
                        return -ENOIOCTLCMD;
                return sk->sk_prot->ioctl(sk, cmd, arg);
        }
        /*NOTREACHED*/
        return 0;
}
EXPORT_SYMBOL(inet6_ioctl);

const struct proto_ops inet6_stream_ops = {
        .family            = PF_INET6,
        .owner             = THIS_MODULE,
        .release           = inet6_release,
        .bind              = inet6_bind,
        .connect           = inet_stream_connect,       /* ok           */
        .socketpair        = sock_no_socketpair,        /* a do nothing */
        .accept            = inet_accept,               /* ok           */
        .getname           = inet6_getname,
        .poll              = tcp_poll,                  /* ok           */
        .ioctl             = inet6_ioctl,               /* must change  */
        .listen            = inet_listen,               /* ok           */
        .shutdown          = inet_shutdown,             /* ok           */
        .setsockopt        = sock_common_setsockopt,    /* ok           */
        .getsockopt        = sock_common_getsockopt,    /* ok           */
        .sendmsg           = inet_sendmsg,              /* ok           */
        .recvmsg           = inet_recvmsg,              /* ok           */
        .mmap              = sock_no_mmap,
        .sendpage          = inet_sendpage,
        .splice_read       = tcp_splice_read,
#ifdef CONFIG_COMPAT
        .compat_setsockopt = compat_sock_common_setsockopt,
        .compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

const struct proto_ops inet6_dgram_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              = udp_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           = inet_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 const struct net_proto_family inet6_family_ops = {
        .family = PF_INET6,
        .create = inet6_create,
        .owner  = THIS_MODULE,
};

int inet6_register_protosw(struct inet_protosw *p)
{
        struct list_head *lh;
        struct inet_protosw *answer;
        struct list_head *last_perm;
        int protocol = p->protocol;
        int ret;

        spin_lock_bh(&inetsw6_lock);

        ret = -EINVAL;
        if (p->type >= SOCK_MAX)
                goto out_illegal;

        /* If we are trying to override a permanent protocol, bail. */
        answer = NULL;
        ret = -EPERM;
        last_perm = &inetsw6[p->type];
        list_for_each(lh, &inetsw6[p->type]) {
                answer = list_entry(lh, struct inet_protosw, list);

                /* Check only the non-wild match. */
                if (INET_PROTOSW_PERMANENT & answer->flags) {
                        if (protocol == answer->protocol)
                                break;
                        last_perm = lh;
                }

                answer = NULL;
        }
        if (answer)
                goto out_permanent;

        /* Add the new entry after the last permanent entry if any, so that
         * the new entry does not override a permanent entry when matched with
         * a wild-card protocol. But it is allowed to override any existing
         * non-permanent entry.  This means that when we remove this entry, the
         * system automatically returns to the old behavior.
         */
        list_add_rcu(&p->list, last_perm);
        ret = 0;
out:
        spin_unlock_bh(&inetsw6_lock);
        return ret;

out_permanent:
        pr_err("Attempt to override permanent protocol %d\n", protocol);
        goto out;

out_illegal:
        pr_err("Ignoring attempt to register invalid socket type %d\n",
               p->type);
        goto out;
}
EXPORT_SYMBOL(inet6_register_protosw);

void
inet6_unregister_protosw(struct inet_protosw *p)
{
        if (INET_PROTOSW_PERMANENT & p->flags) {
                pr_err("Attempt to unregister permanent protocol %d\n",
                       p->protocol);
        } else {
                spin_lock_bh(&inetsw6_lock);
                list_del_rcu(&p->list);
                spin_unlock_bh(&inetsw6_lock);

                synchronize_net();
        }
}
EXPORT_SYMBOL(inet6_unregister_protosw);

int inet6_sk_rebuild_header(struct sock *sk)
{
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct dst_entry *dst;

        dst = __sk_dst_check(sk, np->dst_cookie);

        if (!dst) {
                struct inet_sock *inet = inet_sk(sk);
                struct in6_addr *final_p, final;
                struct flowi6 fl6;

                memset(&fl6, 0, sizeof(fl6));
                fl6.flowi6_proto = sk->sk_protocol;
                fl6.daddr = sk->sk_v6_daddr;
                fl6.saddr = np->saddr;
                fl6.flowlabel = np->flow_label;
                fl6.flowi6_oif = sk->sk_bound_dev_if;
                fl6.flowi6_mark = sk->sk_mark;
                fl6.fl6_dport = inet->inet_dport;
                fl6.fl6_sport = inet->inet_sport;
                security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));

                final_p = fl6_update_dst(&fl6, np->opt, &final);

                dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
                if (IS_ERR(dst)) {
                        sk->sk_route_caps = 0;
                        sk->sk_err_soft = -PTR_ERR(dst);
                        return PTR_ERR(dst);
                }

                __ip6_dst_store(sk, dst, NULL, NULL);
        }

        return 0;
}
EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);

bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
                       const struct inet6_skb_parm *opt)
{
        const struct ipv6_pinfo *np = inet6_sk(sk);

        if (np->rxopt.all) {
                if ((opt->hop && (np->rxopt.bits.hopopts ||
                                  np->rxopt.bits.ohopopts)) ||
                    (ip6_flowinfo((struct ipv6hdr *) skb_network_header(skb)) &&
                     np->rxopt.bits.rxflow) ||
                    (opt->srcrt && (np->rxopt.bits.srcrt ||
                     np->rxopt.bits.osrcrt)) ||
                    ((opt->dst1 || opt->dst0) &&
                     (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
                        return true;
        }
        return false;
}
EXPORT_SYMBOL_GPL(ipv6_opt_accepted);

static struct packet_type ipv6_packet_type __read_mostly = {
        .type = cpu_to_be16(ETH_P_IPV6),
        .func = ipv6_rcv,
};

static int __init ipv6_packet_init(void)
{
        dev_add_pack(&ipv6_packet_type);
        return 0;
}

static void ipv6_packet_cleanup(void)
{
        dev_remove_pack(&ipv6_packet_type);
}

static int __net_init ipv6_init_mibs(struct net *net)
{
        int i;

        net->mib.udp_stats_in6 = alloc_percpu(struct udp_mib);
        if (!net->mib.udp_stats_in6)
                return -ENOMEM;
        net->mib.udplite_stats_in6 = alloc_percpu(struct udp_mib);
        if (!net->mib.udplite_stats_in6)
                goto err_udplite_mib;
        net->mib.ipv6_statistics = alloc_percpu(struct ipstats_mib);
        if (!net->mib.ipv6_statistics)
                goto err_ip_mib;

        for_each_possible_cpu(i) {
                struct ipstats_mib *af_inet6_stats;
                af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics, i);
                u64_stats_init(&af_inet6_stats->syncp);
        }


        net->mib.icmpv6_statistics = alloc_percpu(struct icmpv6_mib);
        if (!net->mib.icmpv6_statistics)
                goto err_icmp_mib;
        net->mib.icmpv6msg_statistics = kzalloc(sizeof(struct icmpv6msg_mib),
                                                GFP_KERNEL);
        if (!net->mib.icmpv6msg_statistics)
                goto err_icmpmsg_mib;
        return 0;

err_icmpmsg_mib:
        free_percpu(net->mib.icmpv6_statistics);
err_icmp_mib:
        free_percpu(net->mib.ipv6_statistics);
err_ip_mib:
        free_percpu(net->mib.udplite_stats_in6);
err_udplite_mib:
        free_percpu(net->mib.udp_stats_in6);
        return -ENOMEM;
}

static void ipv6_cleanup_mibs(struct net *net)
{
        free_percpu(net->mib.udp_stats_in6);
        free_percpu(net->mib.udplite_stats_in6);
        free_percpu(net->mib.ipv6_statistics);
        free_percpu(net->mib.icmpv6_statistics);
        kfree(net->mib.icmpv6msg_statistics);
}

static int __net_init inet6_net_init(struct net *net)
{
        int err = 0;

        net->ipv6.sysctl.bindv6only = 0;
        net->ipv6.sysctl.icmpv6_time = 1*HZ;
        net->ipv6.sysctl.flowlabel_consistency = 1;
        net->ipv6.sysctl.auto_flowlabels = 0;
        net->ipv6.sysctl.idgen_retries = 3;
        net->ipv6.sysctl.idgen_delay = 1 * HZ;
        net->ipv6.sysctl.flowlabel_state_ranges = 1;
        atomic_set(&net->ipv6.fib6_sernum, 1);

        err = ipv6_init_mibs(net);
        if (err)
                return err;
#ifdef CONFIG_PROC_FS
        err = udp6_proc_init(net);
        if (err)
                goto out;
        err = tcp6_proc_init(net);
        if (err)
                goto proc_tcp6_fail;
        err = ac6_proc_init(net);
        if (err)
                goto proc_ac6_fail;
#endif
        return err;

#ifdef CONFIG_PROC_FS
proc_ac6_fail:
        tcp6_proc_exit(net);
proc_tcp6_fail:
        udp6_proc_exit(net);
out:
        ipv6_cleanup_mibs(net);
        return err;
#endif
}

static void __net_exit inet6_net_exit(struct net *net)
{
#ifdef CONFIG_PROC_FS
        udp6_proc_exit(net);
        tcp6_proc_exit(net);
        ac6_proc_exit(net);
#endif
        ipv6_cleanup_mibs(net);
}

static struct pernet_operations inet6_net_ops = {
        .init = inet6_net_init,
        .exit = inet6_net_exit,
};

static const struct ipv6_stub ipv6_stub_impl = {
        .ipv6_sock_mc_join = ipv6_sock_mc_join,
        .ipv6_sock_mc_drop = ipv6_sock_mc_drop,
        .ipv6_dst_lookup = ip6_dst_lookup,
        .udpv6_encap_enable = udpv6_encap_enable,
        .ndisc_send_na = ndisc_send_na,
        .nd_tbl = &nd_tbl,
};

static int __init inet6_init(void)
{
        struct list_head *r;
        int err = 0;

        sock_skb_cb_check_size(sizeof(struct inet6_skb_parm));

        /* Register the socket-side information for inet6_create.  */
        for (r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
                INIT_LIST_HEAD(r);

        if (disable_ipv6_mod) {
                pr_info("Loaded, but administratively disabled, reboot required to enable\n");
                goto out;
        }

        err = proto_register(&tcpv6_prot, 1);
        if (err)
                goto out;

        err = proto_register(&udpv6_prot, 1);
        if (err)
                goto out_unregister_tcp_proto;

        err = proto_register(&udplitev6_prot, 1);
        if (err)
                goto out_unregister_udp_proto;

        err = proto_register(&rawv6_prot, 1);
        if (err)
                goto out_unregister_udplite_proto;

        err = proto_register(&pingv6_prot, 1);
        if (err)
                goto out_unregister_ping_proto;

        /* We MUST register RAW sockets before we create the ICMP6,
         * IGMP6, or NDISC control sockets.
         */
        err = rawv6_init();
        if (err)
                goto out_unregister_raw_proto;

        /* Register the family here so that the init calls below will
         * be able to create sockets. (?? is this dangerous ??)
         */
        err = sock_register(&inet6_family_ops);
        if (err)
                goto out_sock_register_fail;

        /*
         *      ipngwg API draft makes clear that the correct semantics
         *      for TCP and UDP is to consider one TCP and UDP instance
         *      in a host available by both INET and INET6 APIs and
         *      able to communicate via both network protocols.
         */

        err = register_pernet_subsys(&inet6_net_ops);
        if (err)
                goto register_pernet_fail;
        err = icmpv6_init();
        if (err)
                goto icmp_fail;
        err = ip6_mr_init();
        if (err)
                goto ipmr_fail;
        err = ndisc_init();
        if (err)
                goto ndisc_fail;
        err = igmp6_init();
        if (err)
                goto igmp_fail;

        ipv6_stub = &ipv6_stub_impl;

        err = ipv6_netfilter_init();
        if (err)
                goto netfilter_fail;
        /* Create /proc/foo6 entries. */
#ifdef CONFIG_PROC_FS
        err = -ENOMEM;
        if (raw6_proc_init())
                goto proc_raw6_fail;
        if (udplite6_proc_init())
                goto proc_udplite6_fail;
        if (ipv6_misc_proc_init())
                goto proc_misc6_fail;
        if (if6_proc_init())
                goto proc_if6_fail;
#endif
        err = ip6_route_init();
        if (err)
                goto ip6_route_fail;
        err = ndisc_late_init();
        if (err)
                goto ndisc_late_fail;
        err = ip6_flowlabel_init();
        if (err)
                goto ip6_flowlabel_fail;
        err = addrconf_init();
        if (err)
                goto addrconf_fail;

        /* Init v6 extension headers. */
        err = ipv6_exthdrs_init();
        if (err)
                goto ipv6_exthdrs_fail;

        err = ipv6_frag_init();
        if (err)
                goto ipv6_frag_fail;

        /* Init v6 transport protocols. */
        err = udpv6_init();
        if (err)
                goto udpv6_fail;

        err = udplitev6_init();
        if (err)
                goto udplitev6_fail;

        err = tcpv6_init();
        if (err)
                goto tcpv6_fail;

        err = ipv6_packet_init();
        if (err)
                goto ipv6_packet_fail;

        err = pingv6_init();
        if (err)
                goto pingv6_fail;

#ifdef CONFIG_SYSCTL
        err = ipv6_sysctl_register();
        if (err)
                goto sysctl_fail;
#endif
out:
        return err;

#ifdef CONFIG_SYSCTL
sysctl_fail:
        pingv6_exit();
#endif
pingv6_fail:
        ipv6_packet_cleanup();
ipv6_packet_fail:
        tcpv6_exit();
tcpv6_fail:
        udplitev6_exit();
udplitev6_fail:
        udpv6_exit();
udpv6_fail:
        ipv6_frag_exit();
ipv6_frag_fail:
        ipv6_exthdrs_exit();
ipv6_exthdrs_fail:
        addrconf_cleanup();
addrconf_fail:
        ip6_flowlabel_cleanup();
ip6_flowlabel_fail:
        ndisc_late_cleanup();
ndisc_late_fail:
        ip6_route_cleanup();
ip6_route_fail:
#ifdef CONFIG_PROC_FS
        if6_proc_exit();
proc_if6_fail:
        ipv6_misc_proc_exit();
proc_misc6_fail:
        udplite6_proc_exit();
proc_udplite6_fail:
        raw6_proc_exit();
proc_raw6_fail:

#endif
        ipv6_netfilter_fini();
netfilter_fail:
        igmp6_cleanup();
igmp_fail:
        ndisc_cleanup();
ndisc_fail:
        ip6_mr_cleanup();
ipmr_fail:
        icmpv6_cleanup();
icmp_fail:
        unregister_pernet_subsys(&inet6_net_ops);
register_pernet_fail:
        sock_unregister(PF_INET6);
        rtnl_unregister_all(PF_INET6);
out_sock_register_fail:
        rawv6_exit();
out_unregister_ping_proto:
        proto_unregister(&pingv6_prot);
out_unregister_raw_proto:
        proto_unregister(&rawv6_prot);
out_unregister_udplite_proto:
        proto_unregister(&udplitev6_prot);
out_unregister_udp_proto:
        proto_unregister(&udpv6_prot);
out_unregister_tcp_proto:
        proto_unregister(&tcpv6_prot);
        goto out;
}
module_init(inet6_init);

MODULE_ALIAS_NETPROTO(PF_INET6);