af_key.c

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/*
 * net/key/af_key.c An implementation of PF_KEYv2 sockets.
 *
 *      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.
 *
 * Authors: Maxim Giryaev   <[email protected]>
 *      David S. Miller <[email protected]>
 *      Alexey Kuznetsov <[email protected]>
 *      Kunihiro Ishiguro <[email protected]>
 *      Kazunori MIYAZAWA / USAGI Project <[email protected]>
 *      Derek Atkins <[email protected]>
 */

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/socket.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/xfrm.h>

#include <net/sock.h>

#define _X2KEY(x) ((x) == XFRM_INF ? 0 : (x))
#define _KEY2X(x) ((x) == 0 ? XFRM_INF : (x))

static int pfkey_net_id __read_mostly;
struct netns_pfkey {
    /* List of all pfkey sockets. */
    struct hlist_head table;
    atomic_t socks_nr;
};
static DEFINE_MUTEX(pfkey_mutex);

#define DUMMY_MARK 0
static struct xfrm_mark dummy_mark = {0, 0};
struct pfkey_sock {
    /* struct sock must be the first member of struct pfkey_sock */
    struct sock sk;
    int     registered;
    int     promisc;

    struct {
        uint8_t     msg_version;
        uint32_t    msg_portid;
        int     (*dump)(struct pfkey_sock *sk);
        void        (*done)(struct pfkey_sock *sk);
        union {
            struct xfrm_policy_walk policy;
            struct xfrm_state_walk  state;
        } u;
        struct sk_buff  *skb;
    } dump;
};

static inline struct pfkey_sock *pfkey_sk(struct sock *sk)
{
    return (struct pfkey_sock *)sk;
}

static int pfkey_can_dump(const struct sock *sk)
{
    if (3 * atomic_read(&sk->sk_rmem_alloc) <= 2 * sk->sk_rcvbuf)
        return 1;
    return 0;
}

static void pfkey_terminate_dump(struct pfkey_sock *pfk)
{
    if (pfk->dump.dump) {
        if (pfk->dump.skb) {
            kfree_skb(pfk->dump.skb);
            pfk->dump.skb = NULL;
        }
        pfk->dump.done(pfk);
        pfk->dump.dump = NULL;
        pfk->dump.done = NULL;
    }
}

static void pfkey_sock_destruct(struct sock *sk)
{
    struct net *net = sock_net(sk);
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);

    pfkey_terminate_dump(pfkey_sk(sk));
    skb_queue_purge(&sk->sk_receive_queue);

    if (!sock_flag(sk, SOCK_DEAD)) {
        pr_err("Attempt to release alive pfkey socket: %p\n", sk);
        return;
    }

    WARN_ON(atomic_read(&sk->sk_rmem_alloc));
    WARN_ON(atomic_read(&sk->sk_wmem_alloc));

    atomic_dec(&net_pfkey->socks_nr);
}

static const struct proto_ops pfkey_ops;

static void pfkey_insert(struct sock *sk)
{
    struct net *net = sock_net(sk);
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);

    mutex_lock(&pfkey_mutex);
    sk_add_node_rcu(sk, &net_pfkey->table);
    mutex_unlock(&pfkey_mutex);
}

static void pfkey_remove(struct sock *sk)
{
    mutex_lock(&pfkey_mutex);
    sk_del_node_init_rcu(sk);
    mutex_unlock(&pfkey_mutex);
}

static struct proto key_proto = {
    .name     = "KEY",
    .owner    = THIS_MODULE,
    .obj_size = sizeof(struct pfkey_sock),
};

static int pfkey_create(struct net *net, struct socket *sock, int protocol,
            int kern)
{
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
    struct sock *sk;
    int err;

    if (!capable(CAP_NET_ADMIN))
        return -EPERM;
    if (sock->type != SOCK_RAW)
        return -ESOCKTNOSUPPORT;
    if (protocol != PF_KEY_V2)
        return -EPROTONOSUPPORT;

    err = -ENOMEM;
    sk = sk_alloc(net, PF_KEY, GFP_KERNEL, &key_proto);
    if (sk == NULL)
        goto out;

    sock->ops = &pfkey_ops;
    sock_init_data(sock, sk);

    sk->sk_family = PF_KEY;
    sk->sk_destruct = pfkey_sock_destruct;

    atomic_inc(&net_pfkey->socks_nr);

    pfkey_insert(sk);

    return 0;
out:
    return err;
}

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

    if (!sk)
        return 0;

    pfkey_remove(sk);

    sock_orphan(sk);
    sock->sk = NULL;
    skb_queue_purge(&sk->sk_write_queue);

    synchronize_rcu();
    sock_put(sk);

    return 0;
}

static int pfkey_broadcast_one(struct sk_buff *skb, struct sk_buff **skb2,
                   gfp_t allocation, struct sock *sk)
{
    int err = -ENOBUFS;

    sock_hold(sk);
    if (*skb2 == NULL) {
        if (atomic_read(&skb->users) != 1) {
            *skb2 = skb_clone(skb, allocation);
        } else {
            *skb2 = skb;
            atomic_inc(&skb->users);
        }
    }
    if (*skb2 != NULL) {
        if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
            skb_orphan(*skb2);
            skb_set_owner_r(*skb2, sk);
            skb_queue_tail(&sk->sk_receive_queue, *skb2);
            sk->sk_data_ready(sk, (*skb2)->len);
            *skb2 = NULL;
            err = 0;
        }
    }
    sock_put(sk);
    return err;
}

/* Send SKB to all pfkey sockets matching selected criteria.  */
#define BROADCAST_ALL       0
#define BROADCAST_ONE       1
#define BROADCAST_REGISTERED    2
#define BROADCAST_PROMISC_ONLY  4
static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation,
               int broadcast_flags, struct sock *one_sk,
               struct net *net)
{
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
    struct sock *sk;
    struct hlist_node *node;
    struct sk_buff *skb2 = NULL;
    int err = -ESRCH;

    /* XXX Do we need something like netlink_overrun?  I think
     * XXX PF_KEY socket apps will not mind current behavior.
     */
    if (!skb)
        return -ENOMEM;

    rcu_read_lock();
    sk_for_each_rcu(sk, node, &net_pfkey->table) {
        struct pfkey_sock *pfk = pfkey_sk(sk);
        int err2;

        /* Yes, it means that if you are meant to receive this
         * pfkey message you receive it twice as promiscuous
         * socket.
         */
        if (pfk->promisc)
            pfkey_broadcast_one(skb, &skb2, allocation, sk);

        /* the exact target will be processed later */
        if (sk == one_sk)
            continue;
        if (broadcast_flags != BROADCAST_ALL) {
            if (broadcast_flags & BROADCAST_PROMISC_ONLY)
                continue;
            if ((broadcast_flags & BROADCAST_REGISTERED) &&
                !pfk->registered)
                continue;
            if (broadcast_flags & BROADCAST_ONE)
                continue;
        }

        err2 = pfkey_broadcast_one(skb, &skb2, allocation, sk);

        /* Error is cleare after succecful sending to at least one
         * registered KM */
        if ((broadcast_flags & BROADCAST_REGISTERED) && err)
            err = err2;
    }
    rcu_read_unlock();

    if (one_sk != NULL)
        err = pfkey_broadcast_one(skb, &skb2, allocation, one_sk);

    kfree_skb(skb2);
    kfree_skb(skb);
    return err;
}

static int pfkey_do_dump(struct pfkey_sock *pfk)
{
    struct sadb_msg *hdr;
    int rc;

    rc = pfk->dump.dump(pfk);
    if (rc == -ENOBUFS)
        return 0;

    if (pfk->dump.skb) {
        if (!pfkey_can_dump(&pfk->sk))
            return 0;

        hdr = (struct sadb_msg *) pfk->dump.skb->data;
        hdr->sadb_msg_seq = 0;
        hdr->sadb_msg_errno = rc;
        pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE,
                &pfk->sk, sock_net(&pfk->sk));
        pfk->dump.skb = NULL;
    }

    pfkey_terminate_dump(pfk);
    return rc;
}

static inline void pfkey_hdr_dup(struct sadb_msg *new,
                 const struct sadb_msg *orig)
{
    *new = *orig;
}

static int pfkey_error(const struct sadb_msg *orig, int err, struct sock *sk)
{
    struct sk_buff *skb = alloc_skb(sizeof(struct sadb_msg) + 16, GFP_KERNEL);
    struct sadb_msg *hdr;

    if (!skb)
        return -ENOBUFS;

    /* Woe be to the platform trying to support PFKEY yet
     * having normal errnos outside the 1-255 range, inclusive.
     */
    err = -err;
    if (err == ERESTARTSYS ||
        err == ERESTARTNOHAND ||
        err == ERESTARTNOINTR)
        err = EINTR;
    if (err >= 512)
        err = EINVAL;
    BUG_ON(err <= 0 || err >= 256);

    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    pfkey_hdr_dup(hdr, orig);
    hdr->sadb_msg_errno = (uint8_t) err;
    hdr->sadb_msg_len = (sizeof(struct sadb_msg) /
                 sizeof(uint64_t));

    pfkey_broadcast(skb, GFP_KERNEL, BROADCAST_ONE, sk, sock_net(sk));

    return 0;
}

static u8 sadb_ext_min_len[] = {
    [SADB_EXT_RESERVED]     = (u8) 0,
    [SADB_EXT_SA]           = (u8) sizeof(struct sadb_sa),
    [SADB_EXT_LIFETIME_CURRENT] = (u8) sizeof(struct sadb_lifetime),
    [SADB_EXT_LIFETIME_HARD]    = (u8) sizeof(struct sadb_lifetime),
    [SADB_EXT_LIFETIME_SOFT]    = (u8) sizeof(struct sadb_lifetime),
    [SADB_EXT_ADDRESS_SRC]      = (u8) sizeof(struct sadb_address),
    [SADB_EXT_ADDRESS_DST]      = (u8) sizeof(struct sadb_address),
    [SADB_EXT_ADDRESS_PROXY]    = (u8) sizeof(struct sadb_address),
    [SADB_EXT_KEY_AUTH]     = (u8) sizeof(struct sadb_key),
    [SADB_EXT_KEY_ENCRYPT]      = (u8) sizeof(struct sadb_key),
    [SADB_EXT_IDENTITY_SRC]     = (u8) sizeof(struct sadb_ident),
    [SADB_EXT_IDENTITY_DST]     = (u8) sizeof(struct sadb_ident),
    [SADB_EXT_SENSITIVITY]      = (u8) sizeof(struct sadb_sens),
    [SADB_EXT_PROPOSAL]     = (u8) sizeof(struct sadb_prop),
    [SADB_EXT_SUPPORTED_AUTH]   = (u8) sizeof(struct sadb_supported),
    [SADB_EXT_SUPPORTED_ENCRYPT]    = (u8) sizeof(struct sadb_supported),
    [SADB_EXT_SPIRANGE]     = (u8) sizeof(struct sadb_spirange),
    [SADB_X_EXT_KMPRIVATE]      = (u8) sizeof(struct sadb_x_kmprivate),
    [SADB_X_EXT_POLICY]     = (u8) sizeof(struct sadb_x_policy),
    [SADB_X_EXT_SA2]        = (u8) sizeof(struct sadb_x_sa2),
    [SADB_X_EXT_NAT_T_TYPE]     = (u8) sizeof(struct sadb_x_nat_t_type),
    [SADB_X_EXT_NAT_T_SPORT]    = (u8) sizeof(struct sadb_x_nat_t_port),
    [SADB_X_EXT_NAT_T_DPORT]    = (u8) sizeof(struct sadb_x_nat_t_port),
    [SADB_X_EXT_NAT_T_OA]       = (u8) sizeof(struct sadb_address),
    [SADB_X_EXT_SEC_CTX]        = (u8) sizeof(struct sadb_x_sec_ctx),
    [SADB_X_EXT_KMADDRESS]      = (u8) sizeof(struct sadb_x_kmaddress),
};

/* Verify sadb_address_{len,prefixlen} against sa_family.  */
static int verify_address_len(const void *p)
{
    const struct sadb_address *sp = p;
    const struct sockaddr *addr = (const struct sockaddr *)(sp + 1);
    const struct sockaddr_in *sin;
#if IS_ENABLED(CONFIG_IPV6)
    const struct sockaddr_in6 *sin6;
#endif
    int len;

    switch (addr->sa_family) {
    case AF_INET:
        len = DIV_ROUND_UP(sizeof(*sp) + sizeof(*sin), sizeof(uint64_t));
        if (sp->sadb_address_len != len ||
            sp->sadb_address_prefixlen > 32)
            return -EINVAL;
        break;
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        len = DIV_ROUND_UP(sizeof(*sp) + sizeof(*sin6), sizeof(uint64_t));
        if (sp->sadb_address_len != len ||
            sp->sadb_address_prefixlen > 128)
            return -EINVAL;
        break;
#endif
    default:
        /* It is user using kernel to keep track of security
         * associations for another protocol, such as
         * OSPF/RSVP/RIPV2/MIP.  It is user's job to verify
         * lengths.
         *
         * XXX Actually, association/policy database is not yet
         * XXX able to cope with arbitrary sockaddr families.
         * XXX When it can, remove this -EINVAL.  -DaveM
         */
        return -EINVAL;
        break;
    }

    return 0;
}

static inline int pfkey_sec_ctx_len(const struct sadb_x_sec_ctx *sec_ctx)
{
    return DIV_ROUND_UP(sizeof(struct sadb_x_sec_ctx) +
                sec_ctx->sadb_x_ctx_len,
                sizeof(uint64_t));
}

static inline int verify_sec_ctx_len(const void *p)
{
    const struct sadb_x_sec_ctx *sec_ctx = p;
    int len = sec_ctx->sadb_x_ctx_len;

    if (len > PAGE_SIZE)
        return -EINVAL;

    len = pfkey_sec_ctx_len(sec_ctx);

    if (sec_ctx->sadb_x_sec_len != len)
        return -EINVAL;

    return 0;
}

static inline struct xfrm_user_sec_ctx *pfkey_sadb2xfrm_user_sec_ctx(const struct sadb_x_sec_ctx *sec_ctx)
{
    struct xfrm_user_sec_ctx *uctx = NULL;
    int ctx_size = sec_ctx->sadb_x_ctx_len;

    uctx = kmalloc((sizeof(*uctx)+ctx_size), GFP_KERNEL);

    if (!uctx)
        return NULL;

    uctx->len = pfkey_sec_ctx_len(sec_ctx);
    uctx->exttype = sec_ctx->sadb_x_sec_exttype;
    uctx->ctx_doi = sec_ctx->sadb_x_ctx_doi;
    uctx->ctx_alg = sec_ctx->sadb_x_ctx_alg;
    uctx->ctx_len = sec_ctx->sadb_x_ctx_len;
    memcpy(uctx + 1, sec_ctx + 1,
           uctx->ctx_len);

    return uctx;
}

static int present_and_same_family(const struct sadb_address *src,
                   const struct sadb_address *dst)
{
    const struct sockaddr *s_addr, *d_addr;

    if (!src || !dst)
        return 0;

    s_addr = (const struct sockaddr *)(src + 1);
    d_addr = (const struct sockaddr *)(dst + 1);
    if (s_addr->sa_family != d_addr->sa_family)
        return 0;
    if (s_addr->sa_family != AF_INET
#if IS_ENABLED(CONFIG_IPV6)
        && s_addr->sa_family != AF_INET6
#endif
        )
        return 0;

    return 1;
}

static int parse_exthdrs(struct sk_buff *skb, const struct sadb_msg *hdr, void **ext_hdrs)
{
    const char *p = (char *) hdr;
    int len = skb->len;

    len -= sizeof(*hdr);
    p += sizeof(*hdr);
    while (len > 0) {
        const struct sadb_ext *ehdr = (const struct sadb_ext *) p;
        uint16_t ext_type;
        int ext_len;

        ext_len  = ehdr->sadb_ext_len;
        ext_len *= sizeof(uint64_t);
        ext_type = ehdr->sadb_ext_type;
        if (ext_len < sizeof(uint64_t) ||
            ext_len > len ||
            ext_type == SADB_EXT_RESERVED)
            return -EINVAL;

        if (ext_type <= SADB_EXT_MAX) {
            int min = (int) sadb_ext_min_len[ext_type];
            if (ext_len < min)
                return -EINVAL;
            if (ext_hdrs[ext_type-1] != NULL)
                return -EINVAL;
            if (ext_type == SADB_EXT_ADDRESS_SRC ||
                ext_type == SADB_EXT_ADDRESS_DST ||
                ext_type == SADB_EXT_ADDRESS_PROXY ||
                ext_type == SADB_X_EXT_NAT_T_OA) {
                if (verify_address_len(p))
                    return -EINVAL;
            }
            if (ext_type == SADB_X_EXT_SEC_CTX) {
                if (verify_sec_ctx_len(p))
                    return -EINVAL;
            }
            ext_hdrs[ext_type-1] = (void *) p;
        }
        p   += ext_len;
        len -= ext_len;
    }

    return 0;
}

static uint16_t
pfkey_satype2proto(uint8_t satype)
{
    switch (satype) {
    case SADB_SATYPE_UNSPEC:
        return IPSEC_PROTO_ANY;
    case SADB_SATYPE_AH:
        return IPPROTO_AH;
    case SADB_SATYPE_ESP:
        return IPPROTO_ESP;
    case SADB_X_SATYPE_IPCOMP:
        return IPPROTO_COMP;
        break;
    default:
        return 0;
    }
    /* NOTREACHED */
}

static uint8_t
pfkey_proto2satype(uint16_t proto)
{
    switch (proto) {
    case IPPROTO_AH:
        return SADB_SATYPE_AH;
    case IPPROTO_ESP:
        return SADB_SATYPE_ESP;
    case IPPROTO_COMP:
        return SADB_X_SATYPE_IPCOMP;
        break;
    default:
        return 0;
    }
    /* NOTREACHED */
}

/* BTW, this scheme means that there is no way with PFKEY2 sockets to
 * say specifically 'just raw sockets' as we encode them as 255.
 */

static uint8_t pfkey_proto_to_xfrm(uint8_t proto)
{
    return proto == IPSEC_PROTO_ANY ? 0 : proto;
}

static uint8_t pfkey_proto_from_xfrm(uint8_t proto)
{
    return proto ? proto : IPSEC_PROTO_ANY;
}

static inline int pfkey_sockaddr_len(sa_family_t family)
{
    switch (family) {
    case AF_INET:
        return sizeof(struct sockaddr_in);
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        return sizeof(struct sockaddr_in6);
#endif
    }
    return 0;
}

static
int pfkey_sockaddr_extract(const struct sockaddr *sa, xfrm_address_t *xaddr)
{
    switch (sa->sa_family) {
    case AF_INET:
        xaddr->a4 =
            ((struct sockaddr_in *)sa)->sin_addr.s_addr;
        return AF_INET;
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        memcpy(xaddr->a6,
               &((struct sockaddr_in6 *)sa)->sin6_addr,
               sizeof(struct in6_addr));
        return AF_INET6;
#endif
    }
    return 0;
}

static
int pfkey_sadb_addr2xfrm_addr(const struct sadb_address *addr, xfrm_address_t *xaddr)
{
    return pfkey_sockaddr_extract((struct sockaddr *)(addr + 1),
                      xaddr);
}

static struct  xfrm_state *pfkey_xfrm_state_lookup(struct net *net, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    const struct sadb_sa *sa;
    const struct sadb_address *addr;
    uint16_t proto;
    unsigned short family;
    xfrm_address_t *xaddr;

    sa = ext_hdrs[SADB_EXT_SA - 1];
    if (sa == NULL)
        return NULL;

    proto = pfkey_satype2proto(hdr->sadb_msg_satype);
    if (proto == 0)
        return NULL;

    /* sadb_address_len should be checked by caller */
    addr = ext_hdrs[SADB_EXT_ADDRESS_DST - 1];
    if (addr == NULL)
        return NULL;

    family = ((const struct sockaddr *)(addr + 1))->sa_family;
    switch (family) {
    case AF_INET:
        xaddr = (xfrm_address_t *)&((const struct sockaddr_in *)(addr + 1))->sin_addr;
        break;
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        xaddr = (xfrm_address_t *)&((const struct sockaddr_in6 *)(addr + 1))->sin6_addr;
        break;
#endif
    default:
        xaddr = NULL;
    }

    if (!xaddr)
        return NULL;

    return xfrm_state_lookup(net, DUMMY_MARK, xaddr, sa->sadb_sa_spi, proto, family);
}

#define PFKEY_ALIGN8(a) (1 + (((a) - 1) | (8 - 1)))

static int
pfkey_sockaddr_size(sa_family_t family)
{
    return PFKEY_ALIGN8(pfkey_sockaddr_len(family));
}

static inline int pfkey_mode_from_xfrm(int mode)
{
    switch(mode) {
    case XFRM_MODE_TRANSPORT:
        return IPSEC_MODE_TRANSPORT;
    case XFRM_MODE_TUNNEL:
        return IPSEC_MODE_TUNNEL;
    case XFRM_MODE_BEET:
        return IPSEC_MODE_BEET;
    default:
        return -1;
    }
}

static inline int pfkey_mode_to_xfrm(int mode)
{
    switch(mode) {
    case IPSEC_MODE_ANY:    /*XXX*/
    case IPSEC_MODE_TRANSPORT:
        return XFRM_MODE_TRANSPORT;
    case IPSEC_MODE_TUNNEL:
        return XFRM_MODE_TUNNEL;
    case IPSEC_MODE_BEET:
        return XFRM_MODE_BEET;
    default:
        return -1;
    }
}

static unsigned int pfkey_sockaddr_fill(const xfrm_address_t *xaddr, __be16 port,
                    struct sockaddr *sa,
                    unsigned short family)
{
    switch (family) {
    case AF_INET:
        {
        struct sockaddr_in *sin = (struct sockaddr_in *)sa;
        sin->sin_family = AF_INET;
        sin->sin_port = port;
        sin->sin_addr.s_addr = xaddr->a4;
        memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
        return 32;
        }
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        {
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
        sin6->sin6_family = AF_INET6;
        sin6->sin6_port = port;
        sin6->sin6_flowinfo = 0;
        sin6->sin6_addr = *(struct in6_addr *)xaddr->a6;
        sin6->sin6_scope_id = 0;
        return 128;
        }
#endif
    }
    return 0;
}

static struct sk_buff *__pfkey_xfrm_state2msg(const struct xfrm_state *x,
                          int add_keys, int hsc)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;
    struct sadb_sa *sa;
    struct sadb_lifetime *lifetime;
    struct sadb_address *addr;
    struct sadb_key *key;
    struct sadb_x_sa2 *sa2;
    struct sadb_x_sec_ctx *sec_ctx;
    struct xfrm_sec_ctx *xfrm_ctx;
    int ctx_size = 0;
    int size;
    int auth_key_size = 0;
    int encrypt_key_size = 0;
    int sockaddr_size;
    struct xfrm_encap_tmpl *natt = NULL;
    int mode;

    /* address family check */
    sockaddr_size = pfkey_sockaddr_size(x->props.family);
    if (!sockaddr_size)
        return ERR_PTR(-EINVAL);

    /* base, SA, (lifetime (HSC),) address(SD), (address(P),)
       key(AE), (identity(SD),) (sensitivity)> */
    size = sizeof(struct sadb_msg) +sizeof(struct sadb_sa) +
        sizeof(struct sadb_lifetime) +
        ((hsc & 1) ? sizeof(struct sadb_lifetime) : 0) +
        ((hsc & 2) ? sizeof(struct sadb_lifetime) : 0) +
            sizeof(struct sadb_address)*2 +
                sockaddr_size*2 +
                    sizeof(struct sadb_x_sa2);

    if ((xfrm_ctx = x->security)) {
        ctx_size = PFKEY_ALIGN8(xfrm_ctx->ctx_len);
        size += sizeof(struct sadb_x_sec_ctx) + ctx_size;
    }

    /* identity & sensitivity */
    if (xfrm_addr_cmp(&x->sel.saddr, &x->props.saddr, x->props.family))
        size += sizeof(struct sadb_address) + sockaddr_size;

    if (add_keys) {
        if (x->aalg && x->aalg->alg_key_len) {
            auth_key_size =
                PFKEY_ALIGN8((x->aalg->alg_key_len + 7) / 8);
            size += sizeof(struct sadb_key) + auth_key_size;
        }
        if (x->ealg && x->ealg->alg_key_len) {
            encrypt_key_size =
                PFKEY_ALIGN8((x->ealg->alg_key_len+7) / 8);
            size += sizeof(struct sadb_key) + encrypt_key_size;
        }
    }
    if (x->encap)
        natt = x->encap;

    if (natt && natt->encap_type) {
        size += sizeof(struct sadb_x_nat_t_type);
        size += sizeof(struct sadb_x_nat_t_port);
        size += sizeof(struct sadb_x_nat_t_port);
    }

    skb =  alloc_skb(size + 16, GFP_ATOMIC);
    if (skb == NULL)
        return ERR_PTR(-ENOBUFS);

    /* call should fill header later */
    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    memset(hdr, 0, size);   /* XXX do we need this ? */
    hdr->sadb_msg_len = size / sizeof(uint64_t);

    /* sa */
    sa = (struct sadb_sa *)  skb_put(skb, sizeof(struct sadb_sa));
    sa->sadb_sa_len = sizeof(struct sadb_sa)/sizeof(uint64_t);
    sa->sadb_sa_exttype = SADB_EXT_SA;
    sa->sadb_sa_spi = x->id.spi;
    sa->sadb_sa_replay = x->props.replay_window;
    switch (x->km.state) {
    case XFRM_STATE_VALID:
        sa->sadb_sa_state = x->km.dying ?
            SADB_SASTATE_DYING : SADB_SASTATE_MATURE;
        break;
    case XFRM_STATE_ACQ:
        sa->sadb_sa_state = SADB_SASTATE_LARVAL;
        break;
    default:
        sa->sadb_sa_state = SADB_SASTATE_DEAD;
        break;
    }
    sa->sadb_sa_auth = 0;
    if (x->aalg) {
        struct xfrm_algo_desc *a = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
        sa->sadb_sa_auth = a ? a->desc.sadb_alg_id : 0;
    }
    sa->sadb_sa_encrypt = 0;
    BUG_ON(x->ealg && x->calg);
    if (x->ealg) {
        struct xfrm_algo_desc *a = xfrm_ealg_get_byname(x->ealg->alg_name, 0);
        sa->sadb_sa_encrypt = a ? a->desc.sadb_alg_id : 0;
    }
    /* KAME compatible: sadb_sa_encrypt is overloaded with calg id */
    if (x->calg) {
        struct xfrm_algo_desc *a = xfrm_calg_get_byname(x->calg->alg_name, 0);
        sa->sadb_sa_encrypt = a ? a->desc.sadb_alg_id : 0;
    }

    sa->sadb_sa_flags = 0;
    if (x->props.flags & XFRM_STATE_NOECN)
        sa->sadb_sa_flags |= SADB_SAFLAGS_NOECN;
    if (x->props.flags & XFRM_STATE_DECAP_DSCP)
        sa->sadb_sa_flags |= SADB_SAFLAGS_DECAP_DSCP;
    if (x->props.flags & XFRM_STATE_NOPMTUDISC)
        sa->sadb_sa_flags |= SADB_SAFLAGS_NOPMTUDISC;

    /* hard time */
    if (hsc & 2) {
        lifetime = (struct sadb_lifetime *)  skb_put(skb,
                                 sizeof(struct sadb_lifetime));
        lifetime->sadb_lifetime_len =
            sizeof(struct sadb_lifetime)/sizeof(uint64_t);
        lifetime->sadb_lifetime_exttype = SADB_EXT_LIFETIME_HARD;
        lifetime->sadb_lifetime_allocations =  _X2KEY(x->lft.hard_packet_limit);
        lifetime->sadb_lifetime_bytes = _X2KEY(x->lft.hard_byte_limit);
        lifetime->sadb_lifetime_addtime = x->lft.hard_add_expires_seconds;
        lifetime->sadb_lifetime_usetime = x->lft.hard_use_expires_seconds;
    }
    /* soft time */
    if (hsc & 1) {
        lifetime = (struct sadb_lifetime *)  skb_put(skb,
                                 sizeof(struct sadb_lifetime));
        lifetime->sadb_lifetime_len =
            sizeof(struct sadb_lifetime)/sizeof(uint64_t);
        lifetime->sadb_lifetime_exttype = SADB_EXT_LIFETIME_SOFT;
        lifetime->sadb_lifetime_allocations =  _X2KEY(x->lft.soft_packet_limit);
        lifetime->sadb_lifetime_bytes = _X2KEY(x->lft.soft_byte_limit);
        lifetime->sadb_lifetime_addtime = x->lft.soft_add_expires_seconds;
        lifetime->sadb_lifetime_usetime = x->lft.soft_use_expires_seconds;
    }
    /* current time */
    lifetime = (struct sadb_lifetime *)  skb_put(skb,
                             sizeof(struct sadb_lifetime));
    lifetime->sadb_lifetime_len =
        sizeof(struct sadb_lifetime)/sizeof(uint64_t);
    lifetime->sadb_lifetime_exttype = SADB_EXT_LIFETIME_CURRENT;
    lifetime->sadb_lifetime_allocations = x->curlft.packets;
    lifetime->sadb_lifetime_bytes = x->curlft.bytes;
    lifetime->sadb_lifetime_addtime = x->curlft.add_time;
    lifetime->sadb_lifetime_usetime = x->curlft.use_time;
    /* src address */
    addr = (struct sadb_address*) skb_put(skb,
                          sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC;
    /* "if the ports are non-zero, then the sadb_address_proto field,
       normally zero, MUST be filled in with the transport
       protocol's number." - RFC2367 */
    addr->sadb_address_proto = 0;
    addr->sadb_address_reserved = 0;

    addr->sadb_address_prefixlen =
        pfkey_sockaddr_fill(&x->props.saddr, 0,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    if (!addr->sadb_address_prefixlen)
        BUG();

    /* dst address */
    addr = (struct sadb_address*) skb_put(skb,
                          sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_DST;
    addr->sadb_address_proto = 0;
    addr->sadb_address_reserved = 0;

    addr->sadb_address_prefixlen =
        pfkey_sockaddr_fill(&x->id.daddr, 0,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    if (!addr->sadb_address_prefixlen)
        BUG();

    if (xfrm_addr_cmp(&x->sel.saddr, &x->props.saddr,
              x->props.family)) {
        addr = (struct sadb_address*) skb_put(skb,
            sizeof(struct sadb_address)+sockaddr_size);
        addr->sadb_address_len =
            (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
        addr->sadb_address_exttype = SADB_EXT_ADDRESS_PROXY;
        addr->sadb_address_proto =
            pfkey_proto_from_xfrm(x->sel.proto);
        addr->sadb_address_prefixlen = x->sel.prefixlen_s;
        addr->sadb_address_reserved = 0;

        pfkey_sockaddr_fill(&x->sel.saddr, x->sel.sport,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    }

    /* auth key */
    if (add_keys && auth_key_size) {
        key = (struct sadb_key *) skb_put(skb,
                          sizeof(struct sadb_key)+auth_key_size);
        key->sadb_key_len = (sizeof(struct sadb_key) + auth_key_size) /
            sizeof(uint64_t);
        key->sadb_key_exttype = SADB_EXT_KEY_AUTH;
        key->sadb_key_bits = x->aalg->alg_key_len;
        key->sadb_key_reserved = 0;
        memcpy(key + 1, x->aalg->alg_key, (x->aalg->alg_key_len+7)/8);
    }
    /* encrypt key */
    if (add_keys && encrypt_key_size) {
        key = (struct sadb_key *) skb_put(skb,
                          sizeof(struct sadb_key)+encrypt_key_size);
        key->sadb_key_len = (sizeof(struct sadb_key) +
                     encrypt_key_size) / sizeof(uint64_t);
        key->sadb_key_exttype = SADB_EXT_KEY_ENCRYPT;
        key->sadb_key_bits = x->ealg->alg_key_len;
        key->sadb_key_reserved = 0;
        memcpy(key + 1, x->ealg->alg_key,
               (x->ealg->alg_key_len+7)/8);
    }

    /* sa */
    sa2 = (struct sadb_x_sa2 *)  skb_put(skb, sizeof(struct sadb_x_sa2));
    sa2->sadb_x_sa2_len = sizeof(struct sadb_x_sa2)/sizeof(uint64_t);
    sa2->sadb_x_sa2_exttype = SADB_X_EXT_SA2;
    if ((mode = pfkey_mode_from_xfrm(x->props.mode)) < 0) {
        kfree_skb(skb);
        return ERR_PTR(-EINVAL);
    }
    sa2->sadb_x_sa2_mode = mode;
    sa2->sadb_x_sa2_reserved1 = 0;
    sa2->sadb_x_sa2_reserved2 = 0;
    sa2->sadb_x_sa2_sequence = 0;
    sa2->sadb_x_sa2_reqid = x->props.reqid;

    if (natt && natt->encap_type) {
        struct sadb_x_nat_t_type *n_type;
        struct sadb_x_nat_t_port *n_port;

        /* type */
        n_type = (struct sadb_x_nat_t_type*) skb_put(skb, sizeof(*n_type));
        n_type->sadb_x_nat_t_type_len = sizeof(*n_type)/sizeof(uint64_t);
        n_type->sadb_x_nat_t_type_exttype = SADB_X_EXT_NAT_T_TYPE;
        n_type->sadb_x_nat_t_type_type = natt->encap_type;
        n_type->sadb_x_nat_t_type_reserved[0] = 0;
        n_type->sadb_x_nat_t_type_reserved[1] = 0;
        n_type->sadb_x_nat_t_type_reserved[2] = 0;

        /* source port */
        n_port = (struct sadb_x_nat_t_port*) skb_put(skb, sizeof (*n_port));
        n_port->sadb_x_nat_t_port_len = sizeof(*n_port)/sizeof(uint64_t);
        n_port->sadb_x_nat_t_port_exttype = SADB_X_EXT_NAT_T_SPORT;
        n_port->sadb_x_nat_t_port_port = natt->encap_sport;
        n_port->sadb_x_nat_t_port_reserved = 0;

        /* dest port */
        n_port = (struct sadb_x_nat_t_port*) skb_put(skb, sizeof (*n_port));
        n_port->sadb_x_nat_t_port_len = sizeof(*n_port)/sizeof(uint64_t);
        n_port->sadb_x_nat_t_port_exttype = SADB_X_EXT_NAT_T_DPORT;
        n_port->sadb_x_nat_t_port_port = natt->encap_dport;
        n_port->sadb_x_nat_t_port_reserved = 0;
    }

    /* security context */
    if (xfrm_ctx) {
        sec_ctx = (struct sadb_x_sec_ctx *) skb_put(skb,
                sizeof(struct sadb_x_sec_ctx) + ctx_size);
        sec_ctx->sadb_x_sec_len =
          (sizeof(struct sadb_x_sec_ctx) + ctx_size) / sizeof(uint64_t);
        sec_ctx->sadb_x_sec_exttype = SADB_X_EXT_SEC_CTX;
        sec_ctx->sadb_x_ctx_doi = xfrm_ctx->ctx_doi;
        sec_ctx->sadb_x_ctx_alg = xfrm_ctx->ctx_alg;
        sec_ctx->sadb_x_ctx_len = xfrm_ctx->ctx_len;
        memcpy(sec_ctx + 1, xfrm_ctx->ctx_str,
               xfrm_ctx->ctx_len);
    }

    return skb;
}


static inline struct sk_buff *pfkey_xfrm_state2msg(const struct xfrm_state *x)
{
    struct sk_buff *skb;

    skb = __pfkey_xfrm_state2msg(x, 1, 3);

    return skb;
}

static inline struct sk_buff *pfkey_xfrm_state2msg_expire(const struct xfrm_state *x,
                              int hsc)
{
    return __pfkey_xfrm_state2msg(x, 0, hsc);
}

static struct xfrm_state * pfkey_msg2xfrm_state(struct net *net,
                        const struct sadb_msg *hdr,
                        void * const *ext_hdrs)
{
    struct xfrm_state *x;
    const struct sadb_lifetime *lifetime;
    const struct sadb_sa *sa;
    const struct sadb_key *key;
    const struct sadb_x_sec_ctx *sec_ctx;
    uint16_t proto;
    int err;


    sa = ext_hdrs[SADB_EXT_SA - 1];
    if (!sa ||
        !present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST-1]))
        return ERR_PTR(-EINVAL);
    if (hdr->sadb_msg_satype == SADB_SATYPE_ESP &&
        !ext_hdrs[SADB_EXT_KEY_ENCRYPT-1])
        return ERR_PTR(-EINVAL);
    if (hdr->sadb_msg_satype == SADB_SATYPE_AH &&
        !ext_hdrs[SADB_EXT_KEY_AUTH-1])
        return ERR_PTR(-EINVAL);
    if (!!ext_hdrs[SADB_EXT_LIFETIME_HARD-1] !=
        !!ext_hdrs[SADB_EXT_LIFETIME_SOFT-1])
        return ERR_PTR(-EINVAL);

    proto = pfkey_satype2proto(hdr->sadb_msg_satype);
    if (proto == 0)
        return ERR_PTR(-EINVAL);

    /* default error is no buffer space */
    err = -ENOBUFS;

    /* RFC2367:

   Only SADB_SASTATE_MATURE SAs may be submitted in an SADB_ADD message.
   SADB_SASTATE_LARVAL SAs are created by SADB_GETSPI and it is not
   sensible to add a new SA in the DYING or SADB_SASTATE_DEAD state.
   Therefore, the sadb_sa_state field of all submitted SAs MUST be
   SADB_SASTATE_MATURE and the kernel MUST return an error if this is
   not true.

       However, KAME setkey always uses SADB_SASTATE_LARVAL.
       Hence, we have to _ignore_ sadb_sa_state, which is also reasonable.
     */
    if (sa->sadb_sa_auth > SADB_AALG_MAX ||
        (hdr->sadb_msg_satype == SADB_X_SATYPE_IPCOMP &&
         sa->sadb_sa_encrypt > SADB_X_CALG_MAX) ||
        sa->sadb_sa_encrypt > SADB_EALG_MAX)
        return ERR_PTR(-EINVAL);
    key = ext_hdrs[SADB_EXT_KEY_AUTH - 1];
    if (key != NULL &&
        sa->sadb_sa_auth != SADB_X_AALG_NULL &&
        ((key->sadb_key_bits+7) / 8 == 0 ||
         (key->sadb_key_bits+7) / 8 > key->sadb_key_len * sizeof(uint64_t)))
        return ERR_PTR(-EINVAL);
    key = ext_hdrs[SADB_EXT_KEY_ENCRYPT-1];
    if (key != NULL &&
        sa->sadb_sa_encrypt != SADB_EALG_NULL &&
        ((key->sadb_key_bits+7) / 8 == 0 ||
         (key->sadb_key_bits+7) / 8 > key->sadb_key_len * sizeof(uint64_t)))
        return ERR_PTR(-EINVAL);

    x = xfrm_state_alloc(net);
    if (x == NULL)
        return ERR_PTR(-ENOBUFS);

    x->id.proto = proto;
    x->id.spi = sa->sadb_sa_spi;
    x->props.replay_window = sa->sadb_sa_replay;
    if (sa->sadb_sa_flags & SADB_SAFLAGS_NOECN)
        x->props.flags |= XFRM_STATE_NOECN;
    if (sa->sadb_sa_flags & SADB_SAFLAGS_DECAP_DSCP)
        x->props.flags |= XFRM_STATE_DECAP_DSCP;
    if (sa->sadb_sa_flags & SADB_SAFLAGS_NOPMTUDISC)
        x->props.flags |= XFRM_STATE_NOPMTUDISC;

    lifetime = ext_hdrs[SADB_EXT_LIFETIME_HARD - 1];
    if (lifetime != NULL) {
        x->lft.hard_packet_limit = _KEY2X(lifetime->sadb_lifetime_allocations);
        x->lft.hard_byte_limit = _KEY2X(lifetime->sadb_lifetime_bytes);
        x->lft.hard_add_expires_seconds = lifetime->sadb_lifetime_addtime;
        x->lft.hard_use_expires_seconds = lifetime->sadb_lifetime_usetime;
    }
    lifetime = ext_hdrs[SADB_EXT_LIFETIME_SOFT - 1];
    if (lifetime != NULL) {
        x->lft.soft_packet_limit = _KEY2X(lifetime->sadb_lifetime_allocations);
        x->lft.soft_byte_limit = _KEY2X(lifetime->sadb_lifetime_bytes);
        x->lft.soft_add_expires_seconds = lifetime->sadb_lifetime_addtime;
        x->lft.soft_use_expires_seconds = lifetime->sadb_lifetime_usetime;
    }

    sec_ctx = ext_hdrs[SADB_X_EXT_SEC_CTX - 1];
    if (sec_ctx != NULL) {
        struct xfrm_user_sec_ctx *uctx = pfkey_sadb2xfrm_user_sec_ctx(sec_ctx);

        if (!uctx)
            goto out;

        err = security_xfrm_state_alloc(x, uctx);
        kfree(uctx);

        if (err)
            goto out;
    }

    key = ext_hdrs[SADB_EXT_KEY_AUTH - 1];
    if (sa->sadb_sa_auth) {
        int keysize = 0;
        struct xfrm_algo_desc *a = xfrm_aalg_get_byid(sa->sadb_sa_auth);
        if (!a) {
            err = -ENOSYS;
            goto out;
        }
        if (key)
            keysize = (key->sadb_key_bits + 7) / 8;
        x->aalg = kmalloc(sizeof(*x->aalg) + keysize, GFP_KERNEL);
        if (!x->aalg)
            goto out;
        strcpy(x->aalg->alg_name, a->name);
        x->aalg->alg_key_len = 0;
        if (key) {
            x->aalg->alg_key_len = key->sadb_key_bits;
            memcpy(x->aalg->alg_key, key+1, keysize);
        }
        x->aalg->alg_trunc_len = a->uinfo.auth.icv_truncbits;
        x->props.aalgo = sa->sadb_sa_auth;
        /* x->algo.flags = sa->sadb_sa_flags; */
    }
    if (sa->sadb_sa_encrypt) {
        if (hdr->sadb_msg_satype == SADB_X_SATYPE_IPCOMP) {
            struct xfrm_algo_desc *a = xfrm_calg_get_byid(sa->sadb_sa_encrypt);
            if (!a) {
                err = -ENOSYS;
                goto out;
            }
            x->calg = kmalloc(sizeof(*x->calg), GFP_KERNEL);
            if (!x->calg)
                goto out;
            strcpy(x->calg->alg_name, a->name);
            x->props.calgo = sa->sadb_sa_encrypt;
        } else {
            int keysize = 0;
            struct xfrm_algo_desc *a = xfrm_ealg_get_byid(sa->sadb_sa_encrypt);
            if (!a) {
                err = -ENOSYS;
                goto out;
            }
            key = (struct sadb_key*) ext_hdrs[SADB_EXT_KEY_ENCRYPT-1];
            if (key)
                keysize = (key->sadb_key_bits + 7) / 8;
            x->ealg = kmalloc(sizeof(*x->ealg) + keysize, GFP_KERNEL);
            if (!x->ealg)
                goto out;
            strcpy(x->ealg->alg_name, a->name);
            x->ealg->alg_key_len = 0;
            if (key) {
                x->ealg->alg_key_len = key->sadb_key_bits;
                memcpy(x->ealg->alg_key, key+1, keysize);
            }
            x->props.ealgo = sa->sadb_sa_encrypt;
        }
    }
    /* x->algo.flags = sa->sadb_sa_flags; */

    x->props.family = pfkey_sadb_addr2xfrm_addr((struct sadb_address *) ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                            &x->props.saddr);
    if (!x->props.family) {
        err = -EAFNOSUPPORT;
        goto out;
    }
    pfkey_sadb_addr2xfrm_addr((struct sadb_address *) ext_hdrs[SADB_EXT_ADDRESS_DST-1],
                  &x->id.daddr);

    if (ext_hdrs[SADB_X_EXT_SA2-1]) {
        const struct sadb_x_sa2 *sa2 = ext_hdrs[SADB_X_EXT_SA2-1];
        int mode = pfkey_mode_to_xfrm(sa2->sadb_x_sa2_mode);
        if (mode < 0) {
            err = -EINVAL;
            goto out;
        }
        x->props.mode = mode;
        x->props.reqid = sa2->sadb_x_sa2_reqid;
    }

    if (ext_hdrs[SADB_EXT_ADDRESS_PROXY-1]) {
        const struct sadb_address *addr = ext_hdrs[SADB_EXT_ADDRESS_PROXY-1];

        /* Nobody uses this, but we try. */
        x->sel.family = pfkey_sadb_addr2xfrm_addr(addr, &x->sel.saddr);
        x->sel.prefixlen_s = addr->sadb_address_prefixlen;
    }

    if (!x->sel.family)
        x->sel.family = x->props.family;

    if (ext_hdrs[SADB_X_EXT_NAT_T_TYPE-1]) {
        const struct sadb_x_nat_t_type* n_type;
        struct xfrm_encap_tmpl *natt;

        x->encap = kmalloc(sizeof(*x->encap), GFP_KERNEL);
        if (!x->encap)
            goto out;

        natt = x->encap;
        n_type = ext_hdrs[SADB_X_EXT_NAT_T_TYPE-1];
        natt->encap_type = n_type->sadb_x_nat_t_type_type;

        if (ext_hdrs[SADB_X_EXT_NAT_T_SPORT-1]) {
            const struct sadb_x_nat_t_port *n_port =
                ext_hdrs[SADB_X_EXT_NAT_T_SPORT-1];
            natt->encap_sport = n_port->sadb_x_nat_t_port_port;
        }
        if (ext_hdrs[SADB_X_EXT_NAT_T_DPORT-1]) {
            const struct sadb_x_nat_t_port *n_port =
                ext_hdrs[SADB_X_EXT_NAT_T_DPORT-1];
            natt->encap_dport = n_port->sadb_x_nat_t_port_port;
        }
        memset(&natt->encap_oa, 0, sizeof(natt->encap_oa));
    }

    err = xfrm_init_state(x);
    if (err)
        goto out;

    x->km.seq = hdr->sadb_msg_seq;
    return x;

out:
    x->km.state = XFRM_STATE_DEAD;
    xfrm_state_put(x);
    return ERR_PTR(err);
}

static int pfkey_reserved(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    return -EOPNOTSUPP;
}

static int pfkey_getspi(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    struct sk_buff *resp_skb;
    struct sadb_x_sa2 *sa2;
    struct sadb_address *saddr, *daddr;
    struct sadb_msg *out_hdr;
    struct sadb_spirange *range;
    struct xfrm_state *x = NULL;
    int mode;
    int err;
    u32 min_spi, max_spi;
    u32 reqid;
    u8 proto;
    unsigned short family;
    xfrm_address_t *xsaddr = NULL, *xdaddr = NULL;

    if (!present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST-1]))
        return -EINVAL;

    proto = pfkey_satype2proto(hdr->sadb_msg_satype);
    if (proto == 0)
        return -EINVAL;

    if ((sa2 = ext_hdrs[SADB_X_EXT_SA2-1]) != NULL) {
        mode = pfkey_mode_to_xfrm(sa2->sadb_x_sa2_mode);
        if (mode < 0)
            return -EINVAL;
        reqid = sa2->sadb_x_sa2_reqid;
    } else {
        mode = 0;
        reqid = 0;
    }

    saddr = ext_hdrs[SADB_EXT_ADDRESS_SRC-1];
    daddr = ext_hdrs[SADB_EXT_ADDRESS_DST-1];

    family = ((struct sockaddr *)(saddr + 1))->sa_family;
    switch (family) {
    case AF_INET:
        xdaddr = (xfrm_address_t *)&((struct sockaddr_in *)(daddr + 1))->sin_addr.s_addr;
        xsaddr = (xfrm_address_t *)&((struct sockaddr_in *)(saddr + 1))->sin_addr.s_addr;
        break;
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        xdaddr = (xfrm_address_t *)&((struct sockaddr_in6 *)(daddr + 1))->sin6_addr;
        xsaddr = (xfrm_address_t *)&((struct sockaddr_in6 *)(saddr + 1))->sin6_addr;
        break;
#endif
    }

    if (hdr->sadb_msg_seq) {
        x = xfrm_find_acq_byseq(net, DUMMY_MARK, hdr->sadb_msg_seq);
        if (x && xfrm_addr_cmp(&x->id.daddr, xdaddr, family)) {
            xfrm_state_put(x);
            x = NULL;
        }
    }

    if (!x)
        x = xfrm_find_acq(net, &dummy_mark, mode, reqid, proto, xdaddr, xsaddr, 1, family);

    if (x == NULL)
        return -ENOENT;

    min_spi = 0x100;
    max_spi = 0x0fffffff;

    range = ext_hdrs[SADB_EXT_SPIRANGE-1];
    if (range) {
        min_spi = range->sadb_spirange_min;
        max_spi = range->sadb_spirange_max;
    }

    err = xfrm_alloc_spi(x, min_spi, max_spi);
    resp_skb = err ? ERR_PTR(err) : pfkey_xfrm_state2msg(x);

    if (IS_ERR(resp_skb)) {
        xfrm_state_put(x);
        return  PTR_ERR(resp_skb);
    }

    out_hdr = (struct sadb_msg *) resp_skb->data;
    out_hdr->sadb_msg_version = hdr->sadb_msg_version;
    out_hdr->sadb_msg_type = SADB_GETSPI;
    out_hdr->sadb_msg_satype = pfkey_proto2satype(proto);
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_reserved = 0;
    out_hdr->sadb_msg_seq = hdr->sadb_msg_seq;
    out_hdr->sadb_msg_pid = hdr->sadb_msg_pid;

    xfrm_state_put(x);

    pfkey_broadcast(resp_skb, GFP_KERNEL, BROADCAST_ONE, sk, net);

    return 0;
}

static int pfkey_acquire(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    struct xfrm_state *x;

    if (hdr->sadb_msg_len != sizeof(struct sadb_msg)/8)
        return -EOPNOTSUPP;

    if (hdr->sadb_msg_seq == 0 || hdr->sadb_msg_errno == 0)
        return 0;

    x = xfrm_find_acq_byseq(net, DUMMY_MARK, hdr->sadb_msg_seq);
    if (x == NULL)
        return 0;

    spin_lock_bh(&x->lock);
    if (x->km.state == XFRM_STATE_ACQ) {
        x->km.state = XFRM_STATE_ERROR;
        wake_up(&net->xfrm.km_waitq);
    }
    spin_unlock_bh(&x->lock);
    xfrm_state_put(x);
    return 0;
}

static inline int event2poltype(int event)
{
    switch (event) {
    case XFRM_MSG_DELPOLICY:
        return SADB_X_SPDDELETE;
    case XFRM_MSG_NEWPOLICY:
        return SADB_X_SPDADD;
    case XFRM_MSG_UPDPOLICY:
        return SADB_X_SPDUPDATE;
    case XFRM_MSG_POLEXPIRE:
    //  return SADB_X_SPDEXPIRE;
    default:
        pr_err("pfkey: Unknown policy event %d\n", event);
        break;
    }

    return 0;
}

static inline int event2keytype(int event)
{
    switch (event) {
    case XFRM_MSG_DELSA:
        return SADB_DELETE;
    case XFRM_MSG_NEWSA:
        return SADB_ADD;
    case XFRM_MSG_UPDSA:
        return SADB_UPDATE;
    case XFRM_MSG_EXPIRE:
        return SADB_EXPIRE;
    default:
        pr_err("pfkey: Unknown SA event %d\n", event);
        break;
    }

    return 0;
}

/* ADD/UPD/DEL */
static int key_notify_sa(struct xfrm_state *x, const struct km_event *c)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;

    skb = pfkey_xfrm_state2msg(x);

    if (IS_ERR(skb))
        return PTR_ERR(skb);

    hdr = (struct sadb_msg *) skb->data;
    hdr->sadb_msg_version = PF_KEY_V2;
    hdr->sadb_msg_type = event2keytype(c->event);
    hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto);
    hdr->sadb_msg_errno = 0;
    hdr->sadb_msg_reserved = 0;
    hdr->sadb_msg_seq = c->seq;
    hdr->sadb_msg_pid = c->portid;

    pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ALL, NULL, xs_net(x));

    return 0;
}

static int pfkey_add(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    struct xfrm_state *x;
    int err;
    struct km_event c;

    x = pfkey_msg2xfrm_state(net, hdr, ext_hdrs);
    if (IS_ERR(x))
        return PTR_ERR(x);

    xfrm_state_hold(x);
    if (hdr->sadb_msg_type == SADB_ADD)
        err = xfrm_state_add(x);
    else
        err = xfrm_state_update(x);

    xfrm_audit_state_add(x, err ? 0 : 1,
                 audit_get_loginuid(current),
                 audit_get_sessionid(current), 0);

    if (err < 0) {
        x->km.state = XFRM_STATE_DEAD;
        __xfrm_state_put(x);
        goto out;
    }

    if (hdr->sadb_msg_type == SADB_ADD)
        c.event = XFRM_MSG_NEWSA;
    else
        c.event = XFRM_MSG_UPDSA;
    c.seq = hdr->sadb_msg_seq;
    c.portid = hdr->sadb_msg_pid;
    km_state_notify(x, &c);
out:
    xfrm_state_put(x);
    return err;
}

static int pfkey_delete(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    struct xfrm_state *x;
    struct km_event c;
    int err;

    if (!ext_hdrs[SADB_EXT_SA-1] ||
        !present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST-1]))
        return -EINVAL;

    x = pfkey_xfrm_state_lookup(net, hdr, ext_hdrs);
    if (x == NULL)
        return -ESRCH;

    if ((err = security_xfrm_state_delete(x)))
        goto out;

    if (xfrm_state_kern(x)) {
        err = -EPERM;
        goto out;
    }

    err = xfrm_state_delete(x);

    if (err < 0)
        goto out;

    c.seq = hdr->sadb_msg_seq;
    c.portid = hdr->sadb_msg_pid;
    c.event = XFRM_MSG_DELSA;
    km_state_notify(x, &c);
out:
    xfrm_audit_state_delete(x, err ? 0 : 1,
                audit_get_loginuid(current),
                audit_get_sessionid(current), 0);
    xfrm_state_put(x);

    return err;
}

static int pfkey_get(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    __u8 proto;
    struct sk_buff *out_skb;
    struct sadb_msg *out_hdr;
    struct xfrm_state *x;

    if (!ext_hdrs[SADB_EXT_SA-1] ||
        !present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST-1]))
        return -EINVAL;

    x = pfkey_xfrm_state_lookup(net, hdr, ext_hdrs);
    if (x == NULL)
        return -ESRCH;

    out_skb = pfkey_xfrm_state2msg(x);
    proto = x->id.proto;
    xfrm_state_put(x);
    if (IS_ERR(out_skb))
        return  PTR_ERR(out_skb);

    out_hdr = (struct sadb_msg *) out_skb->data;
    out_hdr->sadb_msg_version = hdr->sadb_msg_version;
    out_hdr->sadb_msg_type = SADB_GET;
    out_hdr->sadb_msg_satype = pfkey_proto2satype(proto);
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_reserved = 0;
    out_hdr->sadb_msg_seq = hdr->sadb_msg_seq;
    out_hdr->sadb_msg_pid = hdr->sadb_msg_pid;
    pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, sk, sock_net(sk));

    return 0;
}

static struct sk_buff *compose_sadb_supported(const struct sadb_msg *orig,
                          gfp_t allocation)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;
    int len, auth_len, enc_len, i;

    auth_len = xfrm_count_auth_supported();
    if (auth_len) {
        auth_len *= sizeof(struct sadb_alg);
        auth_len += sizeof(struct sadb_supported);
    }

    enc_len = xfrm_count_enc_supported();
    if (enc_len) {
        enc_len *= sizeof(struct sadb_alg);
        enc_len += sizeof(struct sadb_supported);
    }

    len = enc_len + auth_len + sizeof(struct sadb_msg);

    skb = alloc_skb(len + 16, allocation);
    if (!skb)
        goto out_put_algs;

    hdr = (struct sadb_msg *) skb_put(skb, sizeof(*hdr));
    pfkey_hdr_dup(hdr, orig);
    hdr->sadb_msg_errno = 0;
    hdr->sadb_msg_len = len / sizeof(uint64_t);

    if (auth_len) {
        struct sadb_supported *sp;
        struct sadb_alg *ap;

        sp = (struct sadb_supported *) skb_put(skb, auth_len);
        ap = (struct sadb_alg *) (sp + 1);

        sp->sadb_supported_len = auth_len / sizeof(uint64_t);
        sp->sadb_supported_exttype = SADB_EXT_SUPPORTED_AUTH;

        for (i = 0; ; i++) {
            struct xfrm_algo_desc *aalg = xfrm_aalg_get_byidx(i);
            if (!aalg)
                break;
            if (aalg->available)
                *ap++ = aalg->desc;
        }
    }

    if (enc_len) {
        struct sadb_supported *sp;
        struct sadb_alg *ap;

        sp = (struct sadb_supported *) skb_put(skb, enc_len);
        ap = (struct sadb_alg *) (sp + 1);

        sp->sadb_supported_len = enc_len / sizeof(uint64_t);
        sp->sadb_supported_exttype = SADB_EXT_SUPPORTED_ENCRYPT;

        for (i = 0; ; i++) {
            struct xfrm_algo_desc *ealg = xfrm_ealg_get_byidx(i);
            if (!ealg)
                break;
            if (ealg->available)
                *ap++ = ealg->desc;
        }
    }

out_put_algs:
    return skb;
}

static int pfkey_register(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct pfkey_sock *pfk = pfkey_sk(sk);
    struct sk_buff *supp_skb;

    if (hdr->sadb_msg_satype > SADB_SATYPE_MAX)
        return -EINVAL;

    if (hdr->sadb_msg_satype != SADB_SATYPE_UNSPEC) {
        if (pfk->registered&(1<<hdr->sadb_msg_satype))
            return -EEXIST;
        pfk->registered |= (1<<hdr->sadb_msg_satype);
    }

    xfrm_probe_algs();

    supp_skb = compose_sadb_supported(hdr, GFP_KERNEL);
    if (!supp_skb) {
        if (hdr->sadb_msg_satype != SADB_SATYPE_UNSPEC)
            pfk->registered &= ~(1<<hdr->sadb_msg_satype);

        return -ENOBUFS;
    }

    pfkey_broadcast(supp_skb, GFP_KERNEL, BROADCAST_REGISTERED, sk, sock_net(sk));

    return 0;
}

static int unicast_flush_resp(struct sock *sk, const struct sadb_msg *ihdr)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;

    skb = alloc_skb(sizeof(struct sadb_msg) + 16, GFP_ATOMIC);
    if (!skb)
        return -ENOBUFS;

    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    memcpy(hdr, ihdr, sizeof(struct sadb_msg));
    hdr->sadb_msg_errno = (uint8_t) 0;
    hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t));

    return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ONE, sk, sock_net(sk));
}

static int key_notify_sa_flush(const struct km_event *c)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;

    skb = alloc_skb(sizeof(struct sadb_msg) + 16, GFP_ATOMIC);
    if (!skb)
        return -ENOBUFS;
    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    hdr->sadb_msg_satype = pfkey_proto2satype(c->data.proto);
    hdr->sadb_msg_type = SADB_FLUSH;
    hdr->sadb_msg_seq = c->seq;
    hdr->sadb_msg_pid = c->portid;
    hdr->sadb_msg_version = PF_KEY_V2;
    hdr->sadb_msg_errno = (uint8_t) 0;
    hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t));

    pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ALL, NULL, c->net);

    return 0;
}

static int pfkey_flush(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    unsigned int proto;
    struct km_event c;
    struct xfrm_audit audit_info;
    int err, err2;

    proto = pfkey_satype2proto(hdr->sadb_msg_satype);
    if (proto == 0)
        return -EINVAL;

    audit_info.loginuid = audit_get_loginuid(current);
    audit_info.sessionid = audit_get_sessionid(current);
    audit_info.secid = 0;
    err = xfrm_state_flush(net, proto, &audit_info);
    err2 = unicast_flush_resp(sk, hdr);
    if (err || err2) {
        if (err == -ESRCH) /* empty table - go quietly */
            err = 0;
        return err ? err : err2;
    }

    c.data.proto = proto;
    c.seq = hdr->sadb_msg_seq;
    c.portid = hdr->sadb_msg_pid;
    c.event = XFRM_MSG_FLUSHSA;
    c.net = net;
    km_state_notify(NULL, &c);

    return 0;
}

static int dump_sa(struct xfrm_state *x, int count, void *ptr)
{
    struct pfkey_sock *pfk = ptr;
    struct sk_buff *out_skb;
    struct sadb_msg *out_hdr;

    if (!pfkey_can_dump(&pfk->sk))
        return -ENOBUFS;

    out_skb = pfkey_xfrm_state2msg(x);
    if (IS_ERR(out_skb))
        return PTR_ERR(out_skb);

    out_hdr = (struct sadb_msg *) out_skb->data;
    out_hdr->sadb_msg_version = pfk->dump.msg_version;
    out_hdr->sadb_msg_type = SADB_DUMP;
    out_hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto);
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_reserved = 0;
    out_hdr->sadb_msg_seq = count + 1;
    out_hdr->sadb_msg_pid = pfk->dump.msg_portid;

    if (pfk->dump.skb)
        pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE,
                &pfk->sk, sock_net(&pfk->sk));
    pfk->dump.skb = out_skb;

    return 0;
}

static int pfkey_dump_sa(struct pfkey_sock *pfk)
{
    struct net *net = sock_net(&pfk->sk);
    return xfrm_state_walk(net, &pfk->dump.u.state, dump_sa, (void *) pfk);
}

static void pfkey_dump_sa_done(struct pfkey_sock *pfk)
{
    xfrm_state_walk_done(&pfk->dump.u.state);
}

static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    u8 proto;
    struct pfkey_sock *pfk = pfkey_sk(sk);

    if (pfk->dump.dump != NULL)
        return -EBUSY;

    proto = pfkey_satype2proto(hdr->sadb_msg_satype);
    if (proto == 0)
        return -EINVAL;

    pfk->dump.msg_version = hdr->sadb_msg_version;
    pfk->dump.msg_portid = hdr->sadb_msg_pid;
    pfk->dump.dump = pfkey_dump_sa;
    pfk->dump.done = pfkey_dump_sa_done;
    xfrm_state_walk_init(&pfk->dump.u.state, proto);

    return pfkey_do_dump(pfk);
}

static int pfkey_promisc(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct pfkey_sock *pfk = pfkey_sk(sk);
    int satype = hdr->sadb_msg_satype;
    bool reset_errno = false;

    if (hdr->sadb_msg_len == (sizeof(*hdr) / sizeof(uint64_t))) {
        reset_errno = true;
        if (satype != 0 && satype != 1)
            return -EINVAL;
        pfk->promisc = satype;
    }
    if (reset_errno && skb_cloned(skb))
        skb = skb_copy(skb, GFP_KERNEL);
    else
        skb = skb_clone(skb, GFP_KERNEL);

    if (reset_errno && skb) {
        struct sadb_msg *new_hdr = (struct sadb_msg *) skb->data;
        new_hdr->sadb_msg_errno = 0;
    }

    pfkey_broadcast(skb, GFP_KERNEL, BROADCAST_ALL, NULL, sock_net(sk));
    return 0;
}

static int check_reqid(struct xfrm_policy *xp, int dir, int count, void *ptr)
{
    int i;
    u32 reqid = *(u32*)ptr;

    for (i=0; i<xp->xfrm_nr; i++) {
        if (xp->xfrm_vec[i].reqid == reqid)
            return -EEXIST;
    }
    return 0;
}

static u32 gen_reqid(struct net *net)
{
    struct xfrm_policy_walk walk;
    u32 start;
    int rc;
    static u32 reqid = IPSEC_MANUAL_REQID_MAX;

    start = reqid;
    do {
        ++reqid;
        if (reqid == 0)
            reqid = IPSEC_MANUAL_REQID_MAX+1;
        xfrm_policy_walk_init(&walk, XFRM_POLICY_TYPE_MAIN);
        rc = xfrm_policy_walk(net, &walk, check_reqid, (void*)&reqid);
        xfrm_policy_walk_done(&walk);
        if (rc != -EEXIST)
            return reqid;
    } while (reqid != start);
    return 0;
}

static int
parse_ipsecrequest(struct xfrm_policy *xp, struct sadb_x_ipsecrequest *rq)
{
    struct net *net = xp_net(xp);
    struct xfrm_tmpl *t = xp->xfrm_vec + xp->xfrm_nr;
    int mode;

    if (xp->xfrm_nr >= XFRM_MAX_DEPTH)
        return -ELOOP;

    if (rq->sadb_x_ipsecrequest_mode == 0)
        return -EINVAL;

    t->id.proto = rq->sadb_x_ipsecrequest_proto; /* XXX check proto */
    if ((mode = pfkey_mode_to_xfrm(rq->sadb_x_ipsecrequest_mode)) < 0)
        return -EINVAL;
    t->mode = mode;
    if (rq->sadb_x_ipsecrequest_level == IPSEC_LEVEL_USE)
        t->optional = 1;
    else if (rq->sadb_x_ipsecrequest_level == IPSEC_LEVEL_UNIQUE) {
        t->reqid = rq->sadb_x_ipsecrequest_reqid;
        if (t->reqid > IPSEC_MANUAL_REQID_MAX)
            t->reqid = 0;
        if (!t->reqid && !(t->reqid = gen_reqid(net)))
            return -ENOBUFS;
    }

    /* addresses present only in tunnel mode */
    if (t->mode == XFRM_MODE_TUNNEL) {
        u8 *sa = (u8 *) (rq + 1);
        int family, socklen;

        family = pfkey_sockaddr_extract((struct sockaddr *)sa,
                        &t->saddr);
        if (!family)
            return -EINVAL;

        socklen = pfkey_sockaddr_len(family);
        if (pfkey_sockaddr_extract((struct sockaddr *)(sa + socklen),
                       &t->id.daddr) != family)
            return -EINVAL;
        t->encap_family = family;
    } else
        t->encap_family = xp->family;

    /* No way to set this via kame pfkey */
    t->allalgs = 1;
    xp->xfrm_nr++;
    return 0;
}

static int
parse_ipsecrequests(struct xfrm_policy *xp, struct sadb_x_policy *pol)
{
    int err;
    int len = pol->sadb_x_policy_len*8 - sizeof(struct sadb_x_policy);
    struct sadb_x_ipsecrequest *rq = (void*)(pol+1);

    if (pol->sadb_x_policy_len * 8 < sizeof(struct sadb_x_policy))
        return -EINVAL;

    while (len >= sizeof(struct sadb_x_ipsecrequest)) {
        if ((err = parse_ipsecrequest(xp, rq)) < 0)
            return err;
        len -= rq->sadb_x_ipsecrequest_len;
        rq = (void*)((u8*)rq + rq->sadb_x_ipsecrequest_len);
    }
    return 0;
}

static inline int pfkey_xfrm_policy2sec_ctx_size(const struct xfrm_policy *xp)
{
  struct xfrm_sec_ctx *xfrm_ctx = xp->security;

    if (xfrm_ctx) {
        int len = sizeof(struct sadb_x_sec_ctx);
        len += xfrm_ctx->ctx_len;
        return PFKEY_ALIGN8(len);
    }
    return 0;
}

static int pfkey_xfrm_policy2msg_size(const struct xfrm_policy *xp)
{
    const struct xfrm_tmpl *t;
    int sockaddr_size = pfkey_sockaddr_size(xp->family);
    int socklen = 0;
    int i;

    for (i=0; i<xp->xfrm_nr; i++) {
        t = xp->xfrm_vec + i;
        socklen += pfkey_sockaddr_len(t->encap_family);
    }

    return sizeof(struct sadb_msg) +
        (sizeof(struct sadb_lifetime) * 3) +
        (sizeof(struct sadb_address) * 2) +
        (sockaddr_size * 2) +
        sizeof(struct sadb_x_policy) +
        (xp->xfrm_nr * sizeof(struct sadb_x_ipsecrequest)) +
        (socklen * 2) +
        pfkey_xfrm_policy2sec_ctx_size(xp);
}

static struct sk_buff * pfkey_xfrm_policy2msg_prep(const struct xfrm_policy *xp)
{
    struct sk_buff *skb;
    int size;

    size = pfkey_xfrm_policy2msg_size(xp);

    skb =  alloc_skb(size + 16, GFP_ATOMIC);
    if (skb == NULL)
        return ERR_PTR(-ENOBUFS);

    return skb;
}

static int pfkey_xfrm_policy2msg(struct sk_buff *skb, const struct xfrm_policy *xp, int dir)
{
    struct sadb_msg *hdr;
    struct sadb_address *addr;
    struct sadb_lifetime *lifetime;
    struct sadb_x_policy *pol;
    struct sadb_x_sec_ctx *sec_ctx;
    struct xfrm_sec_ctx *xfrm_ctx;
    int i;
    int size;
    int sockaddr_size = pfkey_sockaddr_size(xp->family);
    int socklen = pfkey_sockaddr_len(xp->family);

    size = pfkey_xfrm_policy2msg_size(xp);

    /* call should fill header later */
    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    memset(hdr, 0, size);   /* XXX do we need this ? */

    /* src address */
    addr = (struct sadb_address*) skb_put(skb,
                          sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC;
    addr->sadb_address_proto = pfkey_proto_from_xfrm(xp->selector.proto);
    addr->sadb_address_prefixlen = xp->selector.prefixlen_s;
    addr->sadb_address_reserved = 0;
    if (!pfkey_sockaddr_fill(&xp->selector.saddr,
                 xp->selector.sport,
                 (struct sockaddr *) (addr + 1),
                 xp->family))
        BUG();

    /* dst address */
    addr = (struct sadb_address*) skb_put(skb,
                          sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_DST;
    addr->sadb_address_proto = pfkey_proto_from_xfrm(xp->selector.proto);
    addr->sadb_address_prefixlen = xp->selector.prefixlen_d;
    addr->sadb_address_reserved = 0;

    pfkey_sockaddr_fill(&xp->selector.daddr, xp->selector.dport,
                (struct sockaddr *) (addr + 1),
                xp->family);

    /* hard time */
    lifetime = (struct sadb_lifetime *)  skb_put(skb,
                             sizeof(struct sadb_lifetime));
    lifetime->sadb_lifetime_len =
        sizeof(struct sadb_lifetime)/sizeof(uint64_t);
    lifetime->sadb_lifetime_exttype = SADB_EXT_LIFETIME_HARD;
    lifetime->sadb_lifetime_allocations =  _X2KEY(xp->lft.hard_packet_limit);
    lifetime->sadb_lifetime_bytes = _X2KEY(xp->lft.hard_byte_limit);
    lifetime->sadb_lifetime_addtime = xp->lft.hard_add_expires_seconds;
    lifetime->sadb_lifetime_usetime = xp->lft.hard_use_expires_seconds;
    /* soft time */
    lifetime = (struct sadb_lifetime *)  skb_put(skb,
                             sizeof(struct sadb_lifetime));
    lifetime->sadb_lifetime_len =
        sizeof(struct sadb_lifetime)/sizeof(uint64_t);
    lifetime->sadb_lifetime_exttype = SADB_EXT_LIFETIME_SOFT;
    lifetime->sadb_lifetime_allocations =  _X2KEY(xp->lft.soft_packet_limit);
    lifetime->sadb_lifetime_bytes = _X2KEY(xp->lft.soft_byte_limit);
    lifetime->sadb_lifetime_addtime = xp->lft.soft_add_expires_seconds;
    lifetime->sadb_lifetime_usetime = xp->lft.soft_use_expires_seconds;
    /* current time */
    lifetime = (struct sadb_lifetime *)  skb_put(skb,
                             sizeof(struct sadb_lifetime));
    lifetime->sadb_lifetime_len =
        sizeof(struct sadb_lifetime)/sizeof(uint64_t);
    lifetime->sadb_lifetime_exttype = SADB_EXT_LIFETIME_CURRENT;
    lifetime->sadb_lifetime_allocations = xp->curlft.packets;
    lifetime->sadb_lifetime_bytes = xp->curlft.bytes;
    lifetime->sadb_lifetime_addtime = xp->curlft.add_time;
    lifetime->sadb_lifetime_usetime = xp->curlft.use_time;

    pol = (struct sadb_x_policy *)  skb_put(skb, sizeof(struct sadb_x_policy));
    pol->sadb_x_policy_len = sizeof(struct sadb_x_policy)/sizeof(uint64_t);
    pol->sadb_x_policy_exttype = SADB_X_EXT_POLICY;
    pol->sadb_x_policy_type = IPSEC_POLICY_DISCARD;
    if (xp->action == XFRM_POLICY_ALLOW) {
        if (xp->xfrm_nr)
            pol->sadb_x_policy_type = IPSEC_POLICY_IPSEC;
        else
            pol->sadb_x_policy_type = IPSEC_POLICY_NONE;
    }
    pol->sadb_x_policy_dir = dir+1;
    pol->sadb_x_policy_id = xp->index;
    pol->sadb_x_policy_priority = xp->priority;

    for (i=0; i<xp->xfrm_nr; i++) {
        const struct xfrm_tmpl *t = xp->xfrm_vec + i;
        struct sadb_x_ipsecrequest *rq;
        int req_size;
        int mode;

        req_size = sizeof(struct sadb_x_ipsecrequest);
        if (t->mode == XFRM_MODE_TUNNEL) {
            socklen = pfkey_sockaddr_len(t->encap_family);
            req_size += socklen * 2;
        } else {
            size -= 2*socklen;
        }
        rq = (void*)skb_put(skb, req_size);
        pol->sadb_x_policy_len += req_size/8;
        memset(rq, 0, sizeof(*rq));
        rq->sadb_x_ipsecrequest_len = req_size;
        rq->sadb_x_ipsecrequest_proto = t->id.proto;
        if ((mode = pfkey_mode_from_xfrm(t->mode)) < 0)
            return -EINVAL;
        rq->sadb_x_ipsecrequest_mode = mode;
        rq->sadb_x_ipsecrequest_level = IPSEC_LEVEL_REQUIRE;
        if (t->reqid)
            rq->sadb_x_ipsecrequest_level = IPSEC_LEVEL_UNIQUE;
        if (t->optional)
            rq->sadb_x_ipsecrequest_level = IPSEC_LEVEL_USE;
        rq->sadb_x_ipsecrequest_reqid = t->reqid;

        if (t->mode == XFRM_MODE_TUNNEL) {
            u8 *sa = (void *)(rq + 1);
            pfkey_sockaddr_fill(&t->saddr, 0,
                        (struct sockaddr *)sa,
                        t->encap_family);
            pfkey_sockaddr_fill(&t->id.daddr, 0,
                        (struct sockaddr *) (sa + socklen),
                        t->encap_family);
        }
    }

    /* security context */
    if ((xfrm_ctx = xp->security)) {
        int ctx_size = pfkey_xfrm_policy2sec_ctx_size(xp);

        sec_ctx = (struct sadb_x_sec_ctx *) skb_put(skb, ctx_size);
        sec_ctx->sadb_x_sec_len = ctx_size / sizeof(uint64_t);
        sec_ctx->sadb_x_sec_exttype = SADB_X_EXT_SEC_CTX;
        sec_ctx->sadb_x_ctx_doi = xfrm_ctx->ctx_doi;
        sec_ctx->sadb_x_ctx_alg = xfrm_ctx->ctx_alg;
        sec_ctx->sadb_x_ctx_len = xfrm_ctx->ctx_len;
        memcpy(sec_ctx + 1, xfrm_ctx->ctx_str,
               xfrm_ctx->ctx_len);
    }

    hdr->sadb_msg_len = size / sizeof(uint64_t);
    hdr->sadb_msg_reserved = atomic_read(&xp->refcnt);

    return 0;
}

static int key_notify_policy(struct xfrm_policy *xp, int dir, const struct km_event *c)
{
    struct sk_buff *out_skb;
    struct sadb_msg *out_hdr;
    int err;

    out_skb = pfkey_xfrm_policy2msg_prep(xp);
    if (IS_ERR(out_skb))
        return PTR_ERR(out_skb);

    err = pfkey_xfrm_policy2msg(out_skb, xp, dir);
    if (err < 0)
        return err;

    out_hdr = (struct sadb_msg *) out_skb->data;
    out_hdr->sadb_msg_version = PF_KEY_V2;

    if (c->data.byid && c->event == XFRM_MSG_DELPOLICY)
        out_hdr->sadb_msg_type = SADB_X_SPDDELETE2;
    else
        out_hdr->sadb_msg_type = event2poltype(c->event);
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_seq = c->seq;
    out_hdr->sadb_msg_pid = c->portid;
    pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ALL, NULL, xp_net(xp));
    return 0;

}

static int pfkey_spdadd(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    int err = 0;
    struct sadb_lifetime *lifetime;
    struct sadb_address *sa;
    struct sadb_x_policy *pol;
    struct xfrm_policy *xp;
    struct km_event c;
    struct sadb_x_sec_ctx *sec_ctx;

    if (!present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST-1]) ||
        !ext_hdrs[SADB_X_EXT_POLICY-1])
        return -EINVAL;

    pol = ext_hdrs[SADB_X_EXT_POLICY-1];
    if (pol->sadb_x_policy_type > IPSEC_POLICY_IPSEC)
        return -EINVAL;
    if (!pol->sadb_x_policy_dir || pol->sadb_x_policy_dir >= IPSEC_DIR_MAX)
        return -EINVAL;

    xp = xfrm_policy_alloc(net, GFP_KERNEL);
    if (xp == NULL)
        return -ENOBUFS;

    xp->action = (pol->sadb_x_policy_type == IPSEC_POLICY_DISCARD ?
              XFRM_POLICY_BLOCK : XFRM_POLICY_ALLOW);
    xp->priority = pol->sadb_x_policy_priority;

    sa = ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
    xp->family = pfkey_sadb_addr2xfrm_addr(sa, &xp->selector.saddr);
    if (!xp->family) {
        err = -EINVAL;
        goto out;
    }
    xp->selector.family = xp->family;
    xp->selector.prefixlen_s = sa->sadb_address_prefixlen;
    xp->selector.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);
    xp->selector.sport = ((struct sockaddr_in *)(sa+1))->sin_port;
    if (xp->selector.sport)
        xp->selector.sport_mask = htons(0xffff);

    sa = ext_hdrs[SADB_EXT_ADDRESS_DST-1],
    pfkey_sadb_addr2xfrm_addr(sa, &xp->selector.daddr);
    xp->selector.prefixlen_d = sa->sadb_address_prefixlen;

    /* Amusing, we set this twice.  KAME apps appear to set same value
     * in both addresses.
     */
    xp->selector.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);

    xp->selector.dport = ((struct sockaddr_in *)(sa+1))->sin_port;
    if (xp->selector.dport)
        xp->selector.dport_mask = htons(0xffff);

    sec_ctx = ext_hdrs[SADB_X_EXT_SEC_CTX - 1];
    if (sec_ctx != NULL) {
        struct xfrm_user_sec_ctx *uctx = pfkey_sadb2xfrm_user_sec_ctx(sec_ctx);

        if (!uctx) {
            err = -ENOBUFS;
            goto out;
        }

        err = security_xfrm_policy_alloc(&xp->security, uctx);
        kfree(uctx);

        if (err)
            goto out;
    }

    xp->lft.soft_byte_limit = XFRM_INF;
    xp->lft.hard_byte_limit = XFRM_INF;
    xp->lft.soft_packet_limit = XFRM_INF;
    xp->lft.hard_packet_limit = XFRM_INF;
    if ((lifetime = ext_hdrs[SADB_EXT_LIFETIME_HARD-1]) != NULL) {
        xp->lft.hard_packet_limit = _KEY2X(lifetime->sadb_lifetime_allocations);
        xp->lft.hard_byte_limit = _KEY2X(lifetime->sadb_lifetime_bytes);
        xp->lft.hard_add_expires_seconds = lifetime->sadb_lifetime_addtime;
        xp->lft.hard_use_expires_seconds = lifetime->sadb_lifetime_usetime;
    }
    if ((lifetime = ext_hdrs[SADB_EXT_LIFETIME_SOFT-1]) != NULL) {
        xp->lft.soft_packet_limit = _KEY2X(lifetime->sadb_lifetime_allocations);
        xp->lft.soft_byte_limit = _KEY2X(lifetime->sadb_lifetime_bytes);
        xp->lft.soft_add_expires_seconds = lifetime->sadb_lifetime_addtime;
        xp->lft.soft_use_expires_seconds = lifetime->sadb_lifetime_usetime;
    }
    xp->xfrm_nr = 0;
    if (pol->sadb_x_policy_type == IPSEC_POLICY_IPSEC &&
        (err = parse_ipsecrequests(xp, pol)) < 0)
        goto out;

    err = xfrm_policy_insert(pol->sadb_x_policy_dir-1, xp,
                 hdr->sadb_msg_type != SADB_X_SPDUPDATE);

    xfrm_audit_policy_add(xp, err ? 0 : 1,
                  audit_get_loginuid(current),
                  audit_get_sessionid(current), 0);

    if (err)
        goto out;

    if (hdr->sadb_msg_type == SADB_X_SPDUPDATE)
        c.event = XFRM_MSG_UPDPOLICY;
    else
        c.event = XFRM_MSG_NEWPOLICY;

    c.seq = hdr->sadb_msg_seq;
    c.portid = hdr->sadb_msg_pid;

    km_policy_notify(xp, pol->sadb_x_policy_dir-1, &c);
    xfrm_pol_put(xp);
    return 0;

out:
    xp->walk.dead = 1;
    xfrm_policy_destroy(xp);
    return err;
}

static int pfkey_spddelete(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    int err;
    struct sadb_address *sa;
    struct sadb_x_policy *pol;
    struct xfrm_policy *xp;
    struct xfrm_selector sel;
    struct km_event c;
    struct sadb_x_sec_ctx *sec_ctx;
    struct xfrm_sec_ctx *pol_ctx = NULL;

    if (!present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST-1]) ||
        !ext_hdrs[SADB_X_EXT_POLICY-1])
        return -EINVAL;

    pol = ext_hdrs[SADB_X_EXT_POLICY-1];
    if (!pol->sadb_x_policy_dir || pol->sadb_x_policy_dir >= IPSEC_DIR_MAX)
        return -EINVAL;

    memset(&sel, 0, sizeof(sel));

    sa = ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
    sel.family = pfkey_sadb_addr2xfrm_addr(sa, &sel.saddr);
    sel.prefixlen_s = sa->sadb_address_prefixlen;
    sel.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);
    sel.sport = ((struct sockaddr_in *)(sa+1))->sin_port;
    if (sel.sport)
        sel.sport_mask = htons(0xffff);

    sa = ext_hdrs[SADB_EXT_ADDRESS_DST-1],
    pfkey_sadb_addr2xfrm_addr(sa, &sel.daddr);
    sel.prefixlen_d = sa->sadb_address_prefixlen;
    sel.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);
    sel.dport = ((struct sockaddr_in *)(sa+1))->sin_port;
    if (sel.dport)
        sel.dport_mask = htons(0xffff);

    sec_ctx = ext_hdrs[SADB_X_EXT_SEC_CTX - 1];
    if (sec_ctx != NULL) {
        struct xfrm_user_sec_ctx *uctx = pfkey_sadb2xfrm_user_sec_ctx(sec_ctx);

        if (!uctx)
            return -ENOMEM;

        err = security_xfrm_policy_alloc(&pol_ctx, uctx);
        kfree(uctx);
        if (err)
            return err;
    }

    xp = xfrm_policy_bysel_ctx(net, DUMMY_MARK, XFRM_POLICY_TYPE_MAIN,
                   pol->sadb_x_policy_dir - 1, &sel, pol_ctx,
                   1, &err);
    security_xfrm_policy_free(pol_ctx);
    if (xp == NULL)
        return -ENOENT;

    xfrm_audit_policy_delete(xp, err ? 0 : 1,
                 audit_get_loginuid(current),
                 audit_get_sessionid(current), 0);

    if (err)
        goto out;

    c.seq = hdr->sadb_msg_seq;
    c.portid = hdr->sadb_msg_pid;
    c.data.byid = 0;
    c.event = XFRM_MSG_DELPOLICY;
    km_policy_notify(xp, pol->sadb_x_policy_dir-1, &c);

out:
    xfrm_pol_put(xp);
    return err;
}

static int key_pol_get_resp(struct sock *sk, struct xfrm_policy *xp, const struct sadb_msg *hdr, int dir)
{
    int err;
    struct sk_buff *out_skb;
    struct sadb_msg *out_hdr;
    err = 0;

    out_skb = pfkey_xfrm_policy2msg_prep(xp);
    if (IS_ERR(out_skb)) {
        err =  PTR_ERR(out_skb);
        goto out;
    }
    err = pfkey_xfrm_policy2msg(out_skb, xp, dir);
    if (err < 0)
        goto out;

    out_hdr = (struct sadb_msg *) out_skb->data;
    out_hdr->sadb_msg_version = hdr->sadb_msg_version;
    out_hdr->sadb_msg_type = hdr->sadb_msg_type;
    out_hdr->sadb_msg_satype = 0;
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_seq = hdr->sadb_msg_seq;
    out_hdr->sadb_msg_pid = hdr->sadb_msg_pid;
    pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, sk, xp_net(xp));
    err = 0;

out:
    return err;
}

#ifdef CONFIG_NET_KEY_MIGRATE
static int pfkey_sockaddr_pair_size(sa_family_t family)
{
    return PFKEY_ALIGN8(pfkey_sockaddr_len(family) * 2);
}

static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
                   xfrm_address_t *saddr, xfrm_address_t *daddr,
                   u16 *family)
{
    int af, socklen;

    if (ext_len < pfkey_sockaddr_pair_size(sa->sa_family))
        return -EINVAL;

    af = pfkey_sockaddr_extract(sa, saddr);
    if (!af)
        return -EINVAL;

    socklen = pfkey_sockaddr_len(af);
    if (pfkey_sockaddr_extract((struct sockaddr *) (((u8 *)sa) + socklen),
                   daddr) != af)
        return -EINVAL;

    *family = af;
    return 0;
}

static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
                    struct xfrm_migrate *m)
{
    int err;
    struct sadb_x_ipsecrequest *rq2;
    int mode;

    if (len <= sizeof(struct sadb_x_ipsecrequest) ||
        len < rq1->sadb_x_ipsecrequest_len)
        return -EINVAL;

    /* old endoints */
    err = parse_sockaddr_pair((struct sockaddr *)(rq1 + 1),
                  rq1->sadb_x_ipsecrequest_len,
                  &m->old_saddr, &m->old_daddr,
                  &m->old_family);
    if (err)
        return err;

    rq2 = (struct sadb_x_ipsecrequest *)((u8 *)rq1 + rq1->sadb_x_ipsecrequest_len);
    len -= rq1->sadb_x_ipsecrequest_len;

    if (len <= sizeof(struct sadb_x_ipsecrequest) ||
        len < rq2->sadb_x_ipsecrequest_len)
        return -EINVAL;

    /* new endpoints */
    err = parse_sockaddr_pair((struct sockaddr *)(rq2 + 1),
                  rq2->sadb_x_ipsecrequest_len,
                  &m->new_saddr, &m->new_daddr,
                  &m->new_family);
    if (err)
        return err;

    if (rq1->sadb_x_ipsecrequest_proto != rq2->sadb_x_ipsecrequest_proto ||
        rq1->sadb_x_ipsecrequest_mode != rq2->sadb_x_ipsecrequest_mode ||
        rq1->sadb_x_ipsecrequest_reqid != rq2->sadb_x_ipsecrequest_reqid)
        return -EINVAL;

    m->proto = rq1->sadb_x_ipsecrequest_proto;
    if ((mode = pfkey_mode_to_xfrm(rq1->sadb_x_ipsecrequest_mode)) < 0)
        return -EINVAL;
    m->mode = mode;
    m->reqid = rq1->sadb_x_ipsecrequest_reqid;

    return ((int)(rq1->sadb_x_ipsecrequest_len +
              rq2->sadb_x_ipsecrequest_len));
}

static int pfkey_migrate(struct sock *sk, struct sk_buff *skb,
             const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    int i, len, ret, err = -EINVAL;
    u8 dir;
    struct sadb_address *sa;
    struct sadb_x_kmaddress *kma;
    struct sadb_x_policy *pol;
    struct sadb_x_ipsecrequest *rq;
    struct xfrm_selector sel;
    struct xfrm_migrate m[XFRM_MAX_DEPTH];
    struct xfrm_kmaddress k;

    if (!present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC - 1],
                     ext_hdrs[SADB_EXT_ADDRESS_DST - 1]) ||
        !ext_hdrs[SADB_X_EXT_POLICY - 1]) {
        err = -EINVAL;
        goto out;
    }

    kma = ext_hdrs[SADB_X_EXT_KMADDRESS - 1];
    pol = ext_hdrs[SADB_X_EXT_POLICY - 1];

    if (pol->sadb_x_policy_dir >= IPSEC_DIR_MAX) {
        err = -EINVAL;
        goto out;
    }

    if (kma) {
        /* convert sadb_x_kmaddress to xfrm_kmaddress */
        k.reserved = kma->sadb_x_kmaddress_reserved;
        ret = parse_sockaddr_pair((struct sockaddr *)(kma + 1),
                      8*(kma->sadb_x_kmaddress_len) - sizeof(*kma),
                      &k.local, &k.remote, &k.family);
        if (ret < 0) {
            err = ret;
            goto out;
        }
    }

    dir = pol->sadb_x_policy_dir - 1;
    memset(&sel, 0, sizeof(sel));

    /* set source address info of selector */
    sa = ext_hdrs[SADB_EXT_ADDRESS_SRC - 1];
    sel.family = pfkey_sadb_addr2xfrm_addr(sa, &sel.saddr);
    sel.prefixlen_s = sa->sadb_address_prefixlen;
    sel.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);
    sel.sport = ((struct sockaddr_in *)(sa + 1))->sin_port;
    if (sel.sport)
        sel.sport_mask = htons(0xffff);

    /* set destination address info of selector */
    sa = ext_hdrs[SADB_EXT_ADDRESS_DST - 1],
    pfkey_sadb_addr2xfrm_addr(sa, &sel.daddr);
    sel.prefixlen_d = sa->sadb_address_prefixlen;
    sel.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);
    sel.dport = ((struct sockaddr_in *)(sa + 1))->sin_port;
    if (sel.dport)
        sel.dport_mask = htons(0xffff);

    rq = (struct sadb_x_ipsecrequest *)(pol + 1);

    /* extract ipsecrequests */
    i = 0;
    len = pol->sadb_x_policy_len * 8 - sizeof(struct sadb_x_policy);

    while (len > 0 && i < XFRM_MAX_DEPTH) {
        ret = ipsecrequests_to_migrate(rq, len, &m[i]);
        if (ret < 0) {
            err = ret;
            goto out;
        } else {
            rq = (struct sadb_x_ipsecrequest *)((u8 *)rq + ret);
            len -= ret;
            i++;
        }
    }

    if (!i || len > 0) {
        err = -EINVAL;
        goto out;
    }

    return xfrm_migrate(&sel, dir, XFRM_POLICY_TYPE_MAIN, m, i,
                kma ? &k : NULL);

 out:
    return err;
}
#else
static int pfkey_migrate(struct sock *sk, struct sk_buff *skb,
             const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    return -ENOPROTOOPT;
}
#endif


static int pfkey_spdget(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    unsigned int dir;
    int err = 0, delete;
    struct sadb_x_policy *pol;
    struct xfrm_policy *xp;
    struct km_event c;

    if ((pol = ext_hdrs[SADB_X_EXT_POLICY-1]) == NULL)
        return -EINVAL;

    dir = xfrm_policy_id2dir(pol->sadb_x_policy_id);
    if (dir >= XFRM_POLICY_MAX)
        return -EINVAL;

    delete = (hdr->sadb_msg_type == SADB_X_SPDDELETE2);
    xp = xfrm_policy_byid(net, DUMMY_MARK, XFRM_POLICY_TYPE_MAIN,
                  dir, pol->sadb_x_policy_id, delete, &err);
    if (xp == NULL)
        return -ENOENT;

    if (delete) {
        xfrm_audit_policy_delete(xp, err ? 0 : 1,
                audit_get_loginuid(current),
                audit_get_sessionid(current), 0);

        if (err)
            goto out;
        c.seq = hdr->sadb_msg_seq;
        c.portid = hdr->sadb_msg_pid;
        c.data.byid = 1;
        c.event = XFRM_MSG_DELPOLICY;
        km_policy_notify(xp, dir, &c);
    } else {
        err = key_pol_get_resp(sk, xp, hdr, dir);
    }

out:
    xfrm_pol_put(xp);
    return err;
}

static int dump_sp(struct xfrm_policy *xp, int dir, int count, void *ptr)
{
    struct pfkey_sock *pfk = ptr;
    struct sk_buff *out_skb;
    struct sadb_msg *out_hdr;
    int err;

    if (!pfkey_can_dump(&pfk->sk))
        return -ENOBUFS;

    out_skb = pfkey_xfrm_policy2msg_prep(xp);
    if (IS_ERR(out_skb))
        return PTR_ERR(out_skb);

    err = pfkey_xfrm_policy2msg(out_skb, xp, dir);
    if (err < 0)
        return err;

    out_hdr = (struct sadb_msg *) out_skb->data;
    out_hdr->sadb_msg_version = pfk->dump.msg_version;
    out_hdr->sadb_msg_type = SADB_X_SPDDUMP;
    out_hdr->sadb_msg_satype = SADB_SATYPE_UNSPEC;
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_seq = count + 1;
    out_hdr->sadb_msg_pid = pfk->dump.msg_portid;

    if (pfk->dump.skb)
        pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE,
                &pfk->sk, sock_net(&pfk->sk));
    pfk->dump.skb = out_skb;

    return 0;
}

static int pfkey_dump_sp(struct pfkey_sock *pfk)
{
    struct net *net = sock_net(&pfk->sk);
    return xfrm_policy_walk(net, &pfk->dump.u.policy, dump_sp, (void *) pfk);
}

static void pfkey_dump_sp_done(struct pfkey_sock *pfk)
{
    xfrm_policy_walk_done(&pfk->dump.u.policy);
}

static int pfkey_spddump(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct pfkey_sock *pfk = pfkey_sk(sk);

    if (pfk->dump.dump != NULL)
        return -EBUSY;

    pfk->dump.msg_version = hdr->sadb_msg_version;
    pfk->dump.msg_portid = hdr->sadb_msg_pid;
    pfk->dump.dump = pfkey_dump_sp;
    pfk->dump.done = pfkey_dump_sp_done;
    xfrm_policy_walk_init(&pfk->dump.u.policy, XFRM_POLICY_TYPE_MAIN);

    return pfkey_do_dump(pfk);
}

static int key_notify_policy_flush(const struct km_event *c)
{
    struct sk_buff *skb_out;
    struct sadb_msg *hdr;

    skb_out = alloc_skb(sizeof(struct sadb_msg) + 16, GFP_ATOMIC);
    if (!skb_out)
        return -ENOBUFS;
    hdr = (struct sadb_msg *) skb_put(skb_out, sizeof(struct sadb_msg));
    hdr->sadb_msg_type = SADB_X_SPDFLUSH;
    hdr->sadb_msg_seq = c->seq;
    hdr->sadb_msg_pid = c->portid;
    hdr->sadb_msg_version = PF_KEY_V2;
    hdr->sadb_msg_errno = (uint8_t) 0;
    hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t));
    pfkey_broadcast(skb_out, GFP_ATOMIC, BROADCAST_ALL, NULL, c->net);
    return 0;

}

static int pfkey_spdflush(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
    struct net *net = sock_net(sk);
    struct km_event c;
    struct xfrm_audit audit_info;
    int err, err2;

    audit_info.loginuid = audit_get_loginuid(current);
    audit_info.sessionid = audit_get_sessionid(current);
    audit_info.secid = 0;
    err = xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
    err2 = unicast_flush_resp(sk, hdr);
    if (err || err2) {
        if (err == -ESRCH) /* empty table - old silent behavior */
            return 0;
        return err;
    }

    c.data.type = XFRM_POLICY_TYPE_MAIN;
    c.event = XFRM_MSG_FLUSHPOLICY;
    c.portid = hdr->sadb_msg_pid;
    c.seq = hdr->sadb_msg_seq;
    c.net = net;
    km_policy_notify(NULL, 0, &c);

    return 0;
}

typedef int (*pfkey_handler)(struct sock *sk, struct sk_buff *skb,
                 const struct sadb_msg *hdr, void * const *ext_hdrs);
static pfkey_handler pfkey_funcs[SADB_MAX + 1] = {
    [SADB_RESERVED]     = pfkey_reserved,
    [SADB_GETSPI]       = pfkey_getspi,
    [SADB_UPDATE]       = pfkey_add,
    [SADB_ADD]      = pfkey_add,
    [SADB_DELETE]       = pfkey_delete,
    [SADB_GET]      = pfkey_get,
    [SADB_ACQUIRE]      = pfkey_acquire,
    [SADB_REGISTER]     = pfkey_register,
    [SADB_EXPIRE]       = NULL,
    [SADB_FLUSH]        = pfkey_flush,
    [SADB_DUMP]     = pfkey_dump,
    [SADB_X_PROMISC]    = pfkey_promisc,
    [SADB_X_PCHANGE]    = NULL,
    [SADB_X_SPDUPDATE]  = pfkey_spdadd,
    [SADB_X_SPDADD]     = pfkey_spdadd,
    [SADB_X_SPDDELETE]  = pfkey_spddelete,
    [SADB_X_SPDGET]     = pfkey_spdget,
    [SADB_X_SPDACQUIRE] = NULL,
    [SADB_X_SPDDUMP]    = pfkey_spddump,
    [SADB_X_SPDFLUSH]   = pfkey_spdflush,
    [SADB_X_SPDSETIDX]  = pfkey_spdadd,
    [SADB_X_SPDDELETE2] = pfkey_spdget,
    [SADB_X_MIGRATE]    = pfkey_migrate,
};

static int pfkey_process(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr)
{
    void *ext_hdrs[SADB_EXT_MAX];
    int err;

    pfkey_broadcast(skb_clone(skb, GFP_KERNEL), GFP_KERNEL,
            BROADCAST_PROMISC_ONLY, NULL, sock_net(sk));

    memset(ext_hdrs, 0, sizeof(ext_hdrs));
    err = parse_exthdrs(skb, hdr, ext_hdrs);
    if (!err) {
        err = -EOPNOTSUPP;
        if (pfkey_funcs[hdr->sadb_msg_type])
            err = pfkey_funcs[hdr->sadb_msg_type](sk, skb, hdr, ext_hdrs);
    }
    return err;
}

static struct sadb_msg *pfkey_get_base_msg(struct sk_buff *skb, int *errp)
{
    struct sadb_msg *hdr = NULL;

    if (skb->len < sizeof(*hdr)) {
        *errp = -EMSGSIZE;
    } else {
        hdr = (struct sadb_msg *) skb->data;
        if (hdr->sadb_msg_version != PF_KEY_V2 ||
            hdr->sadb_msg_reserved != 0 ||
            (hdr->sadb_msg_type <= SADB_RESERVED ||
             hdr->sadb_msg_type > SADB_MAX)) {
            hdr = NULL;
            *errp = -EINVAL;
        } else if (hdr->sadb_msg_len != (skb->len /
                         sizeof(uint64_t)) ||
               hdr->sadb_msg_len < (sizeof(struct sadb_msg) /
                        sizeof(uint64_t))) {
            hdr = NULL;
            *errp = -EMSGSIZE;
        } else {
            *errp = 0;
        }
    }
    return hdr;
}

static inline int aalg_tmpl_set(const struct xfrm_tmpl *t,
                const struct xfrm_algo_desc *d)
{
    unsigned int id = d->desc.sadb_alg_id;

    if (id >= sizeof(t->aalgos) * 8)
        return 0;

    return (t->aalgos >> id) & 1;
}

static inline int ealg_tmpl_set(const struct xfrm_tmpl *t,
                const struct xfrm_algo_desc *d)
{
    unsigned int id = d->desc.sadb_alg_id;

    if (id >= sizeof(t->ealgos) * 8)
        return 0;

    return (t->ealgos >> id) & 1;
}

static int count_ah_combs(const struct xfrm_tmpl *t)
{
    int i, sz = 0;

    for (i = 0; ; i++) {
        const struct xfrm_algo_desc *aalg = xfrm_aalg_get_byidx(i);
        if (!aalg)
            break;
        if (aalg_tmpl_set(t, aalg) && aalg->available)
            sz += sizeof(struct sadb_comb);
    }
    return sz + sizeof(struct sadb_prop);
}

static int count_esp_combs(const struct xfrm_tmpl *t)
{
    int i, k, sz = 0;

    for (i = 0; ; i++) {
        const struct xfrm_algo_desc *ealg = xfrm_ealg_get_byidx(i);
        if (!ealg)
            break;

        if (!(ealg_tmpl_set(t, ealg) && ealg->available))
            continue;

        for (k = 1; ; k++) {
            const struct xfrm_algo_desc *aalg = xfrm_aalg_get_byidx(k);
            if (!aalg)
                break;

            if (aalg_tmpl_set(t, aalg) && aalg->available)
                sz += sizeof(struct sadb_comb);
        }
    }
    return sz + sizeof(struct sadb_prop);
}

static void dump_ah_combs(struct sk_buff *skb, const struct xfrm_tmpl *t)
{
    struct sadb_prop *p;
    int i;

    p = (struct sadb_prop*)skb_put(skb, sizeof(struct sadb_prop));
    p->sadb_prop_len = sizeof(struct sadb_prop)/8;
    p->sadb_prop_exttype = SADB_EXT_PROPOSAL;
    p->sadb_prop_replay = 32;
    memset(p->sadb_prop_reserved, 0, sizeof(p->sadb_prop_reserved));

    for (i = 0; ; i++) {
        const struct xfrm_algo_desc *aalg = xfrm_aalg_get_byidx(i);
        if (!aalg)
            break;

        if (aalg_tmpl_set(t, aalg) && aalg->available) {
            struct sadb_comb *c;
            c = (struct sadb_comb*)skb_put(skb, sizeof(struct sadb_comb));
            memset(c, 0, sizeof(*c));
            p->sadb_prop_len += sizeof(struct sadb_comb)/8;
            c->sadb_comb_auth = aalg->desc.sadb_alg_id;
            c->sadb_comb_auth_minbits = aalg->desc.sadb_alg_minbits;
            c->sadb_comb_auth_maxbits = aalg->desc.sadb_alg_maxbits;
            c->sadb_comb_hard_addtime = 24*60*60;
            c->sadb_comb_soft_addtime = 20*60*60;
            c->sadb_comb_hard_usetime = 8*60*60;
            c->sadb_comb_soft_usetime = 7*60*60;
        }
    }
}

static void dump_esp_combs(struct sk_buff *skb, const struct xfrm_tmpl *t)
{
    struct sadb_prop *p;
    int i, k;

    p = (struct sadb_prop*)skb_put(skb, sizeof(struct sadb_prop));
    p->sadb_prop_len = sizeof(struct sadb_prop)/8;
    p->sadb_prop_exttype = SADB_EXT_PROPOSAL;
    p->sadb_prop_replay = 32;
    memset(p->sadb_prop_reserved, 0, sizeof(p->sadb_prop_reserved));

    for (i=0; ; i++) {
        const struct xfrm_algo_desc *ealg = xfrm_ealg_get_byidx(i);
        if (!ealg)
            break;

        if (!(ealg_tmpl_set(t, ealg) && ealg->available))
            continue;

        for (k = 1; ; k++) {
            struct sadb_comb *c;
            const struct xfrm_algo_desc *aalg = xfrm_aalg_get_byidx(k);
            if (!aalg)
                break;
            if (!(aalg_tmpl_set(t, aalg) && aalg->available))
                continue;
            c = (struct sadb_comb*)skb_put(skb, sizeof(struct sadb_comb));
            memset(c, 0, sizeof(*c));
            p->sadb_prop_len += sizeof(struct sadb_comb)/8;
            c->sadb_comb_auth = aalg->desc.sadb_alg_id;
            c->sadb_comb_auth_minbits = aalg->desc.sadb_alg_minbits;
            c->sadb_comb_auth_maxbits = aalg->desc.sadb_alg_maxbits;
            c->sadb_comb_encrypt = ealg->desc.sadb_alg_id;
            c->sadb_comb_encrypt_minbits = ealg->desc.sadb_alg_minbits;
            c->sadb_comb_encrypt_maxbits = ealg->desc.sadb_alg_maxbits;
            c->sadb_comb_hard_addtime = 24*60*60;
            c->sadb_comb_soft_addtime = 20*60*60;
            c->sadb_comb_hard_usetime = 8*60*60;
            c->sadb_comb_soft_usetime = 7*60*60;
        }
    }
}

static int key_notify_policy_expire(struct xfrm_policy *xp, const struct km_event *c)
{
    return 0;
}

static int key_notify_sa_expire(struct xfrm_state *x, const struct km_event *c)
{
    struct sk_buff *out_skb;
    struct sadb_msg *out_hdr;
    int hard;
    int hsc;

    hard = c->data.hard;
    if (hard)
        hsc = 2;
    else
        hsc = 1;

    out_skb = pfkey_xfrm_state2msg_expire(x, hsc);
    if (IS_ERR(out_skb))
        return PTR_ERR(out_skb);

    out_hdr = (struct sadb_msg *) out_skb->data;
    out_hdr->sadb_msg_version = PF_KEY_V2;
    out_hdr->sadb_msg_type = SADB_EXPIRE;
    out_hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto);
    out_hdr->sadb_msg_errno = 0;
    out_hdr->sadb_msg_reserved = 0;
    out_hdr->sadb_msg_seq = 0;
    out_hdr->sadb_msg_pid = 0;

    pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x));
    return 0;
}

static int pfkey_send_notify(struct xfrm_state *x, const struct km_event *c)
{
    struct net *net = x ? xs_net(x) : c->net;
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);

    if (atomic_read(&net_pfkey->socks_nr) == 0)
        return 0;

    switch (c->event) {
    case XFRM_MSG_EXPIRE:
        return key_notify_sa_expire(x, c);
    case XFRM_MSG_DELSA:
    case XFRM_MSG_NEWSA:
    case XFRM_MSG_UPDSA:
        return key_notify_sa(x, c);
    case XFRM_MSG_FLUSHSA:
        return key_notify_sa_flush(c);
    case XFRM_MSG_NEWAE: /* not yet supported */
        break;
    default:
        pr_err("pfkey: Unknown SA event %d\n", c->event);
        break;
    }

    return 0;
}

static int pfkey_send_policy_notify(struct xfrm_policy *xp, int dir, const struct km_event *c)
{
    if (xp && xp->type != XFRM_POLICY_TYPE_MAIN)
        return 0;

    switch (c->event) {
    case XFRM_MSG_POLEXPIRE:
        return key_notify_policy_expire(xp, c);
    case XFRM_MSG_DELPOLICY:
    case XFRM_MSG_NEWPOLICY:
    case XFRM_MSG_UPDPOLICY:
        return key_notify_policy(xp, dir, c);
    case XFRM_MSG_FLUSHPOLICY:
        if (c->data.type != XFRM_POLICY_TYPE_MAIN)
            break;
        return key_notify_policy_flush(c);
    default:
        pr_err("pfkey: Unknown policy event %d\n", c->event);
        break;
    }

    return 0;
}

static u32 get_acqseq(void)
{
    u32 res;
    static atomic_t acqseq;

    do {
        res = atomic_inc_return(&acqseq);
    } while (!res);
    return res;
}

static int pfkey_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *xp)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;
    struct sadb_address *addr;
    struct sadb_x_policy *pol;
    int sockaddr_size;
    int size;
    struct sadb_x_sec_ctx *sec_ctx;
    struct xfrm_sec_ctx *xfrm_ctx;
    int ctx_size = 0;

    sockaddr_size = pfkey_sockaddr_size(x->props.family);
    if (!sockaddr_size)
        return -EINVAL;

    size = sizeof(struct sadb_msg) +
        (sizeof(struct sadb_address) * 2) +
        (sockaddr_size * 2) +
        sizeof(struct sadb_x_policy);

    if (x->id.proto == IPPROTO_AH)
        size += count_ah_combs(t);
    else if (x->id.proto == IPPROTO_ESP)
        size += count_esp_combs(t);

    if ((xfrm_ctx = x->security)) {
        ctx_size = PFKEY_ALIGN8(xfrm_ctx->ctx_len);
        size +=  sizeof(struct sadb_x_sec_ctx) + ctx_size;
    }

    skb =  alloc_skb(size + 16, GFP_ATOMIC);
    if (skb == NULL)
        return -ENOMEM;

    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    hdr->sadb_msg_version = PF_KEY_V2;
    hdr->sadb_msg_type = SADB_ACQUIRE;
    hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto);
    hdr->sadb_msg_len = size / sizeof(uint64_t);
    hdr->sadb_msg_errno = 0;
    hdr->sadb_msg_reserved = 0;
    hdr->sadb_msg_seq = x->km.seq = get_acqseq();
    hdr->sadb_msg_pid = 0;

    /* src address */
    addr = (struct sadb_address*) skb_put(skb,
                          sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC;
    addr->sadb_address_proto = 0;
    addr->sadb_address_reserved = 0;
    addr->sadb_address_prefixlen =
        pfkey_sockaddr_fill(&x->props.saddr, 0,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    if (!addr->sadb_address_prefixlen)
        BUG();

    /* dst address */
    addr = (struct sadb_address*) skb_put(skb,
                          sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_DST;
    addr->sadb_address_proto = 0;
    addr->sadb_address_reserved = 0;
    addr->sadb_address_prefixlen =
        pfkey_sockaddr_fill(&x->id.daddr, 0,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    if (!addr->sadb_address_prefixlen)
        BUG();

    pol = (struct sadb_x_policy *)  skb_put(skb, sizeof(struct sadb_x_policy));
    pol->sadb_x_policy_len = sizeof(struct sadb_x_policy)/sizeof(uint64_t);
    pol->sadb_x_policy_exttype = SADB_X_EXT_POLICY;
    pol->sadb_x_policy_type = IPSEC_POLICY_IPSEC;
    pol->sadb_x_policy_dir = XFRM_POLICY_OUT + 1;
    pol->sadb_x_policy_id = xp->index;

    /* Set sadb_comb's. */
    if (x->id.proto == IPPROTO_AH)
        dump_ah_combs(skb, t);
    else if (x->id.proto == IPPROTO_ESP)
        dump_esp_combs(skb, t);

    /* security context */
    if (xfrm_ctx) {
        sec_ctx = (struct sadb_x_sec_ctx *) skb_put(skb,
                sizeof(struct sadb_x_sec_ctx) + ctx_size);
        sec_ctx->sadb_x_sec_len =
          (sizeof(struct sadb_x_sec_ctx) + ctx_size) / sizeof(uint64_t);
        sec_ctx->sadb_x_sec_exttype = SADB_X_EXT_SEC_CTX;
        sec_ctx->sadb_x_ctx_doi = xfrm_ctx->ctx_doi;
        sec_ctx->sadb_x_ctx_alg = xfrm_ctx->ctx_alg;
        sec_ctx->sadb_x_ctx_len = xfrm_ctx->ctx_len;
        memcpy(sec_ctx + 1, xfrm_ctx->ctx_str,
               xfrm_ctx->ctx_len);
    }

    return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x));
}

static struct xfrm_policy *pfkey_compile_policy(struct sock *sk, int opt,
                        u8 *data, int len, int *dir)
{
    struct net *net = sock_net(sk);
    struct xfrm_policy *xp;
    struct sadb_x_policy *pol = (struct sadb_x_policy*)data;
    struct sadb_x_sec_ctx *sec_ctx;

    switch (sk->sk_family) {
    case AF_INET:
        if (opt != IP_IPSEC_POLICY) {
            *dir = -EOPNOTSUPP;
            return NULL;
        }
        break;
#if IS_ENABLED(CONFIG_IPV6)
    case AF_INET6:
        if (opt != IPV6_IPSEC_POLICY) {
            *dir = -EOPNOTSUPP;
            return NULL;
        }
        break;
#endif
    default:
        *dir = -EINVAL;
        return NULL;
    }

    *dir = -EINVAL;

    if (len < sizeof(struct sadb_x_policy) ||
        pol->sadb_x_policy_len*8 > len ||
        pol->sadb_x_policy_type > IPSEC_POLICY_BYPASS ||
        (!pol->sadb_x_policy_dir || pol->sadb_x_policy_dir > IPSEC_DIR_OUTBOUND))
        return NULL;

    xp = xfrm_policy_alloc(net, GFP_ATOMIC);
    if (xp == NULL) {
        *dir = -ENOBUFS;
        return NULL;
    }

    xp->action = (pol->sadb_x_policy_type == IPSEC_POLICY_DISCARD ?
              XFRM_POLICY_BLOCK : XFRM_POLICY_ALLOW);

    xp->lft.soft_byte_limit = XFRM_INF;
    xp->lft.hard_byte_limit = XFRM_INF;
    xp->lft.soft_packet_limit = XFRM_INF;
    xp->lft.hard_packet_limit = XFRM_INF;
    xp->family = sk->sk_family;

    xp->xfrm_nr = 0;
    if (pol->sadb_x_policy_type == IPSEC_POLICY_IPSEC &&
        (*dir = parse_ipsecrequests(xp, pol)) < 0)
        goto out;

    /* security context too */
    if (len >= (pol->sadb_x_policy_len*8 +
        sizeof(struct sadb_x_sec_ctx))) {
        char *p = (char *)pol;
        struct xfrm_user_sec_ctx *uctx;

        p += pol->sadb_x_policy_len*8;
        sec_ctx = (struct sadb_x_sec_ctx *)p;
        if (len < pol->sadb_x_policy_len*8 +
            sec_ctx->sadb_x_sec_len) {
            *dir = -EINVAL;
            goto out;
        }
        if ((*dir = verify_sec_ctx_len(p)))
            goto out;
        uctx = pfkey_sadb2xfrm_user_sec_ctx(sec_ctx);
        *dir = security_xfrm_policy_alloc(&xp->security, uctx);
        kfree(uctx);

        if (*dir)
            goto out;
    }

    *dir = pol->sadb_x_policy_dir-1;
    return xp;

out:
    xp->walk.dead = 1;
    xfrm_policy_destroy(xp);
    return NULL;
}

static int pfkey_send_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport)
{
    struct sk_buff *skb;
    struct sadb_msg *hdr;
    struct sadb_sa *sa;
    struct sadb_address *addr;
    struct sadb_x_nat_t_port *n_port;
    int sockaddr_size;
    int size;
    __u8 satype = (x->id.proto == IPPROTO_ESP ? SADB_SATYPE_ESP : 0);
    struct xfrm_encap_tmpl *natt = NULL;

    sockaddr_size = pfkey_sockaddr_size(x->props.family);
    if (!sockaddr_size)
        return -EINVAL;

    if (!satype)
        return -EINVAL;

    if (!x->encap)
        return -EINVAL;

    natt = x->encap;

    /* Build an SADB_X_NAT_T_NEW_MAPPING message:
     *
     * HDR | SA | ADDRESS_SRC (old addr) | NAT_T_SPORT (old port) |
     * ADDRESS_DST (new addr) | NAT_T_DPORT (new port)
     */

    size = sizeof(struct sadb_msg) +
        sizeof(struct sadb_sa) +
        (sizeof(struct sadb_address) * 2) +
        (sockaddr_size * 2) +
        (sizeof(struct sadb_x_nat_t_port) * 2);

    skb =  alloc_skb(size + 16, GFP_ATOMIC);
    if (skb == NULL)
        return -ENOMEM;

    hdr = (struct sadb_msg *) skb_put(skb, sizeof(struct sadb_msg));
    hdr->sadb_msg_version = PF_KEY_V2;
    hdr->sadb_msg_type = SADB_X_NAT_T_NEW_MAPPING;
    hdr->sadb_msg_satype = satype;
    hdr->sadb_msg_len = size / sizeof(uint64_t);
    hdr->sadb_msg_errno = 0;
    hdr->sadb_msg_reserved = 0;
    hdr->sadb_msg_seq = x->km.seq = get_acqseq();
    hdr->sadb_msg_pid = 0;

    /* SA */
    sa = (struct sadb_sa *) skb_put(skb, sizeof(struct sadb_sa));
    sa->sadb_sa_len = sizeof(struct sadb_sa)/sizeof(uint64_t);
    sa->sadb_sa_exttype = SADB_EXT_SA;
    sa->sadb_sa_spi = x->id.spi;
    sa->sadb_sa_replay = 0;
    sa->sadb_sa_state = 0;
    sa->sadb_sa_auth = 0;
    sa->sadb_sa_encrypt = 0;
    sa->sadb_sa_flags = 0;

    /* ADDRESS_SRC (old addr) */
    addr = (struct sadb_address*)
        skb_put(skb, sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC;
    addr->sadb_address_proto = 0;
    addr->sadb_address_reserved = 0;
    addr->sadb_address_prefixlen =
        pfkey_sockaddr_fill(&x->props.saddr, 0,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    if (!addr->sadb_address_prefixlen)
        BUG();

    /* NAT_T_SPORT (old port) */
    n_port = (struct sadb_x_nat_t_port*) skb_put(skb, sizeof (*n_port));
    n_port->sadb_x_nat_t_port_len = sizeof(*n_port)/sizeof(uint64_t);
    n_port->sadb_x_nat_t_port_exttype = SADB_X_EXT_NAT_T_SPORT;
    n_port->sadb_x_nat_t_port_port = natt->encap_sport;
    n_port->sadb_x_nat_t_port_reserved = 0;

    /* ADDRESS_DST (new addr) */
    addr = (struct sadb_address*)
        skb_put(skb, sizeof(struct sadb_address)+sockaddr_size);
    addr->sadb_address_len =
        (sizeof(struct sadb_address)+sockaddr_size)/
            sizeof(uint64_t);
    addr->sadb_address_exttype = SADB_EXT_ADDRESS_DST;
    addr->sadb_address_proto = 0;
    addr->sadb_address_reserved = 0;
    addr->sadb_address_prefixlen =
        pfkey_sockaddr_fill(ipaddr, 0,
                    (struct sockaddr *) (addr + 1),
                    x->props.family);
    if (!addr->sadb_address_prefixlen)
        BUG();

    /* NAT_T_DPORT (new port) */
    n_port = (struct sadb_x_nat_t_port*) skb_put(skb, sizeof (*n_port));
    n_port->sadb_x_nat_t_port_len = sizeof(*n_port)/sizeof(uint64_t);
    n_port->sadb_x_nat_t_port_exttype = SADB_X_EXT_NAT_T_DPORT;
    n_port->sadb_x_nat_t_port_port = sport;
    n_port->sadb_x_nat_t_port_reserved = 0;

    return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x));
}

#ifdef CONFIG_NET_KEY_MIGRATE
static int set_sadb_address(struct sk_buff *skb, int sasize, int type,
                const struct xfrm_selector *sel)
{
    struct sadb_address *addr;
    addr = (struct sadb_address *)skb_put(skb, sizeof(struct sadb_address) + sasize);
    addr->sadb_address_len = (sizeof(struct sadb_address) + sasize)/8;
    addr->sadb_address_exttype = type;
    addr->sadb_address_proto = sel->proto;
    addr->sadb_address_reserved = 0;

    switch (type) {
    case SADB_EXT_ADDRESS_SRC:
        addr->sadb_address_prefixlen = sel->prefixlen_s;
        pfkey_sockaddr_fill(&sel->saddr, 0,
                    (struct sockaddr *)(addr + 1),
                    sel->family);
        break;
    case SADB_EXT_ADDRESS_DST:
        addr->sadb_address_prefixlen = sel->prefixlen_d;
        pfkey_sockaddr_fill(&sel->daddr, 0,
                    (struct sockaddr *)(addr + 1),
                    sel->family);
        break;
    default:
        return -EINVAL;
    }

    return 0;
}


static int set_sadb_kmaddress(struct sk_buff *skb, const struct xfrm_kmaddress *k)
{
    struct sadb_x_kmaddress *kma;
    u8 *sa;
    int family = k->family;
    int socklen = pfkey_sockaddr_len(family);
    int size_req;

    size_req = (sizeof(struct sadb_x_kmaddress) +
            pfkey_sockaddr_pair_size(family));

    kma = (struct sadb_x_kmaddress *)skb_put(skb, size_req);
    memset(kma, 0, size_req);
    kma->sadb_x_kmaddress_len = size_req / 8;
    kma->sadb_x_kmaddress_exttype = SADB_X_EXT_KMADDRESS;
    kma->sadb_x_kmaddress_reserved = k->reserved;

    sa = (u8 *)(kma + 1);
    if (!pfkey_sockaddr_fill(&k->local, 0, (struct sockaddr *)sa, family) ||
        !pfkey_sockaddr_fill(&k->remote, 0, (struct sockaddr *)(sa+socklen), family))
        return -EINVAL;

    return 0;
}

static int set_ipsecrequest(struct sk_buff *skb,
                uint8_t proto, uint8_t mode, int level,
                uint32_t reqid, uint8_t family,
                const xfrm_address_t *src, const xfrm_address_t *dst)
{
    struct sadb_x_ipsecrequest *rq;
    u8 *sa;
    int socklen = pfkey_sockaddr_len(family);
    int size_req;

    size_req = sizeof(struct sadb_x_ipsecrequest) +
           pfkey_sockaddr_pair_size(family);

    rq = (struct sadb_x_ipsecrequest *)skb_put(skb, size_req);
    memset(rq, 0, size_req);
    rq->sadb_x_ipsecrequest_len = size_req;
    rq->sadb_x_ipsecrequest_proto = proto;
    rq->sadb_x_ipsecrequest_mode = mode;
    rq->sadb_x_ipsecrequest_level = level;
    rq->sadb_x_ipsecrequest_reqid = reqid;

    sa = (u8 *) (rq + 1);
    if (!pfkey_sockaddr_fill(src, 0, (struct sockaddr *)sa, family) ||
        !pfkey_sockaddr_fill(dst, 0, (struct sockaddr *)(sa + socklen), family))
        return -EINVAL;

    return 0;
}
#endif

#ifdef CONFIG_NET_KEY_MIGRATE
static int pfkey_send_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
                  const struct xfrm_migrate *m, int num_bundles,
                  const struct xfrm_kmaddress *k)
{
    int i;
    int sasize_sel;
    int size = 0;
    int size_pol = 0;
    struct sk_buff *skb;
    struct sadb_msg *hdr;
    struct sadb_x_policy *pol;
    const struct xfrm_migrate *mp;

    if (type != XFRM_POLICY_TYPE_MAIN)
        return 0;

    if (num_bundles <= 0 || num_bundles > XFRM_MAX_DEPTH)
        return -EINVAL;

    if (k != NULL) {
        /* addresses for KM */
        size += PFKEY_ALIGN8(sizeof(struct sadb_x_kmaddress) +
                     pfkey_sockaddr_pair_size(k->family));
    }

    /* selector */
    sasize_sel = pfkey_sockaddr_size(sel->family);
    if (!sasize_sel)
        return -EINVAL;
    size += (sizeof(struct sadb_address) + sasize_sel) * 2;

    /* policy info */
    size_pol += sizeof(struct sadb_x_policy);

    /* ipsecrequests */
    for (i = 0, mp = m; i < num_bundles; i++, mp++) {
        /* old locator pair */
        size_pol += sizeof(struct sadb_x_ipsecrequest) +
                pfkey_sockaddr_pair_size(mp->old_family);
        /* new locator pair */
        size_pol += sizeof(struct sadb_x_ipsecrequest) +
                pfkey_sockaddr_pair_size(mp->new_family);
    }

    size += sizeof(struct sadb_msg) + size_pol;

    /* alloc buffer */
    skb = alloc_skb(size, GFP_ATOMIC);
    if (skb == NULL)
        return -ENOMEM;

    hdr = (struct sadb_msg *)skb_put(skb, sizeof(struct sadb_msg));
    hdr->sadb_msg_version = PF_KEY_V2;
    hdr->sadb_msg_type = SADB_X_MIGRATE;
    hdr->sadb_msg_satype = pfkey_proto2satype(m->proto);
    hdr->sadb_msg_len = size / 8;
    hdr->sadb_msg_errno = 0;
    hdr->sadb_msg_reserved = 0;
    hdr->sadb_msg_seq = 0;
    hdr->sadb_msg_pid = 0;

    /* Addresses to be used by KM for negotiation, if ext is available */
    if (k != NULL && (set_sadb_kmaddress(skb, k) < 0))
        goto err;

    /* selector src */
    set_sadb_address(skb, sasize_sel, SADB_EXT_ADDRESS_SRC, sel);

    /* selector dst */
    set_sadb_address(skb, sasize_sel, SADB_EXT_ADDRESS_DST, sel);

    /* policy information */
    pol = (struct sadb_x_policy *)skb_put(skb, sizeof(struct sadb_x_policy));
    pol->sadb_x_policy_len = size_pol / 8;
    pol->sadb_x_policy_exttype = SADB_X_EXT_POLICY;
    pol->sadb_x_policy_type = IPSEC_POLICY_IPSEC;
    pol->sadb_x_policy_dir = dir + 1;
    pol->sadb_x_policy_id = 0;
    pol->sadb_x_policy_priority = 0;

    for (i = 0, mp = m; i < num_bundles; i++, mp++) {
        /* old ipsecrequest */
        int mode = pfkey_mode_from_xfrm(mp->mode);
        if (mode < 0)
            goto err;
        if (set_ipsecrequest(skb, mp->proto, mode,
                     (mp->reqid ?  IPSEC_LEVEL_UNIQUE : IPSEC_LEVEL_REQUIRE),
                     mp->reqid, mp->old_family,
                     &mp->old_saddr, &mp->old_daddr) < 0)
            goto err;

        /* new ipsecrequest */
        if (set_ipsecrequest(skb, mp->proto, mode,
                     (mp->reqid ? IPSEC_LEVEL_UNIQUE : IPSEC_LEVEL_REQUIRE),
                     mp->reqid, mp->new_family,
                     &mp->new_saddr, &mp->new_daddr) < 0)
            goto err;
    }

    /* broadcast migrate message to sockets */
    pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ALL, NULL, &init_net);

    return 0;

err:
    kfree_skb(skb);
    return -EINVAL;
}
#else
static int pfkey_send_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
                  const struct xfrm_migrate *m, int num_bundles,
                  const struct xfrm_kmaddress *k)
{
    return -ENOPROTOOPT;
}
#endif

static int pfkey_sendmsg(struct kiocb *kiocb,
             struct socket *sock, struct msghdr *msg, size_t len)
{
    struct sock *sk = sock->sk;
    struct sk_buff *skb = NULL;
    struct sadb_msg *hdr = NULL;
    int err;

    err = -EOPNOTSUPP;
    if (msg->msg_flags & MSG_OOB)
        goto out;

    err = -EMSGSIZE;
    if ((unsigned int)len > sk->sk_sndbuf - 32)
        goto out;

    err = -ENOBUFS;
    skb = alloc_skb(len, GFP_KERNEL);
    if (skb == NULL)
        goto out;

    err = -EFAULT;
    if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len))
        goto out;

    hdr = pfkey_get_base_msg(skb, &err);
    if (!hdr)
        goto out;

    mutex_lock(&xfrm_cfg_mutex);
    err = pfkey_process(sk, skb, hdr);
    mutex_unlock(&xfrm_cfg_mutex);

out:
    if (err && hdr && pfkey_error(hdr, err, sk) == 0)
        err = 0;
    kfree_skb(skb);

    return err ? : len;
}

static int pfkey_recvmsg(struct kiocb *kiocb,
             struct socket *sock, struct msghdr *msg, size_t len,
             int flags)
{
    struct sock *sk = sock->sk;
    struct pfkey_sock *pfk = pfkey_sk(sk);
    struct sk_buff *skb;
    int copied, err;

    err = -EINVAL;
    if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT))
        goto out;

    msg->msg_namelen = 0;
    skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
    if (skb == NULL)
        goto out;

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

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

    sock_recv_ts_and_drops(msg, sk, skb);

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

    if (pfk->dump.dump != NULL &&
        3 * atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
        pfkey_do_dump(pfk);

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

static const struct proto_ops pfkey_ops = {
    .family     =   PF_KEY,
    .owner      =   THIS_MODULE,
    /* Operations that make no sense on pfkey sockets. */
    .bind       =   sock_no_bind,
    .connect    =   sock_no_connect,
    .socketpair =   sock_no_socketpair,
    .accept     =   sock_no_accept,
    .getname    =   sock_no_getname,
    .ioctl      =   sock_no_ioctl,
    .listen     =   sock_no_listen,
    .shutdown   =   sock_no_shutdown,
    .setsockopt =   sock_no_setsockopt,
    .getsockopt =   sock_no_getsockopt,
    .mmap       =   sock_no_mmap,
    .sendpage   =   sock_no_sendpage,

    /* Now the operations that really occur. */
    .release    =   pfkey_release,
    .poll       =   datagram_poll,
    .sendmsg    =   pfkey_sendmsg,
    .recvmsg    =   pfkey_recvmsg,
};

static const struct net_proto_family pfkey_family_ops = {
    .family =   PF_KEY,
    .create =   pfkey_create,
    .owner  =   THIS_MODULE,
};

#ifdef CONFIG_PROC_FS
static int pfkey_seq_show(struct seq_file *f, void *v)
{
    struct sock *s = sk_entry(v);

    if (v == SEQ_START_TOKEN)
        seq_printf(f ,"sk       RefCnt Rmem   Wmem   User   Inode\n");
    else
        seq_printf(f, "%pK %-6d %-6u %-6u %-6u %-6lu\n",
                   s,
                   atomic_read(&s->sk_refcnt),
                   sk_rmem_alloc_get(s),
                   sk_wmem_alloc_get(s),
                   from_kuid_munged(seq_user_ns(f), sock_i_uid(s)),
                   sock_i_ino(s)
                   );
    return 0;
}

static void *pfkey_seq_start(struct seq_file *f, loff_t *ppos)
    __acquires(rcu)
{
    struct net *net = seq_file_net(f);
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);

    rcu_read_lock();
    return seq_hlist_start_head_rcu(&net_pfkey->table, *ppos);
}

static void *pfkey_seq_next(struct seq_file *f, void *v, loff_t *ppos)
{
    struct net *net = seq_file_net(f);
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);

    return seq_hlist_next_rcu(v, &net_pfkey->table, ppos);
}

static void pfkey_seq_stop(struct seq_file *f, void *v)
    __releases(rcu)
{
    rcu_read_unlock();
}

static const struct seq_operations pfkey_seq_ops = {
    .start  = pfkey_seq_start,
    .next   = pfkey_seq_next,
    .stop   = pfkey_seq_stop,
    .show   = pfkey_seq_show,
};

static int pfkey_seq_open(struct inode *inode, struct file *file)
{
    return seq_open_net(inode, file, &pfkey_seq_ops,
                sizeof(struct seq_net_private));
}

static const struct file_operations pfkey_proc_ops = {
    .open    = pfkey_seq_open,
    .read    = seq_read,
    .llseek  = seq_lseek,
    .release = seq_release_net,
};

static int __net_init pfkey_init_proc(struct net *net)
{
    struct proc_dir_entry *e;

    e = proc_net_fops_create(net, "pfkey", 0, &pfkey_proc_ops);
    if (e == NULL)
        return -ENOMEM;

    return 0;
}

static void __net_exit pfkey_exit_proc(struct net *net)
{
    proc_net_remove(net, "pfkey");
}
#else
static inline int pfkey_init_proc(struct net *net)
{
    return 0;
}

static inline void pfkey_exit_proc(struct net *net)
{
}
#endif

static struct xfrm_mgr pfkeyv2_mgr =
{
    .id     = "pfkeyv2",
    .notify     = pfkey_send_notify,
    .acquire    = pfkey_send_acquire,
    .compile_policy = pfkey_compile_policy,
    .new_mapping    = pfkey_send_new_mapping,
    .notify_policy  = pfkey_send_policy_notify,
    .migrate    = pfkey_send_migrate,
};

static int __net_init pfkey_net_init(struct net *net)
{
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
    int rv;

    INIT_HLIST_HEAD(&net_pfkey->table);
    atomic_set(&net_pfkey->socks_nr, 0);

    rv = pfkey_init_proc(net);

    return rv;
}

static void __net_exit pfkey_net_exit(struct net *net)
{
    struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);

    pfkey_exit_proc(net);
    BUG_ON(!hlist_empty(&net_pfkey->table));
}

static struct pernet_operations pfkey_net_ops = {
    .init = pfkey_net_init,
    .exit = pfkey_net_exit,
    .id   = &pfkey_net_id,
    .size = sizeof(struct netns_pfkey),
};

static void __exit ipsec_pfkey_exit(void)
{
    xfrm_unregister_km(&pfkeyv2_mgr);
    sock_unregister(PF_KEY);
    unregister_pernet_subsys(&pfkey_net_ops);
    proto_unregister(&key_proto);
}

static int __init ipsec_pfkey_init(void)
{
    int err = proto_register(&key_proto, 0);

    if (err != 0)
        goto out;

    err = register_pernet_subsys(&pfkey_net_ops);
    if (err != 0)
        goto out_unregister_key_proto;
    err = sock_register(&pfkey_family_ops);
    if (err != 0)
        goto out_unregister_pernet;
    err = xfrm_register_km(&pfkeyv2_mgr);
    if (err != 0)
        goto out_sock_unregister;
out:
    return err;

out_sock_unregister:
    sock_unregister(PF_KEY);
out_unregister_pernet:
    unregister_pernet_subsys(&pfkey_net_ops);
out_unregister_key_proto:
    proto_unregister(&key_proto);
    goto out;
}

module_init(ipsec_pfkey_init);
module_exit(ipsec_pfkey_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_KEY);