// SPDX-License-Identifier: GPL-2.0-only
/*
 * xfrm_state.c
 *
 * Changes:
 *      Mitsuru KANDA @USAGI
 *      Kazunori MIYAZAWA @USAGI
 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 *              IPv6 support
 *      YOSHIFUJI Hideaki @USAGI
 *              Split up af-specific functions
 *      Derek Atkins <derek@ihtfp.com>
 *              Add UDP Encapsulation
 *
 */

#include <linux/workqueue.h>
#include <net/xfrm.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/module.h>
#include <linux/cache.h>
#include <linux/audit.h>
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>

#include <crypto/aead.h>

#include "xfrm_hash.h"

#define xfrm_state_deref_prot(table, net) \
        rcu_dereference_protected((table), lockdep_is_held(&(net)->xfrm.xfrm_state_lock))

static void xfrm_state_gc_task(struct work_struct *work);

/* Each xfrm_state may be linked to two tables:

   1. Hash table by (spi,daddr,ah/esp) to find SA by SPI. (input,ctl)
   2. Hash table by (daddr,family,reqid) to find what SAs exist for given
      destination/tunnel endpoint. (output)
 */

static unsigned int xfrm_state_hashmax __read_mostly = 1 * 1024 * 1024;
static struct kmem_cache *xfrm_state_cache __ro_after_init;

static DECLARE_WORK(xfrm_state_gc_work, xfrm_state_gc_task);
static HLIST_HEAD(xfrm_state_gc_list);

static inline bool xfrm_state_hold_rcu(struct xfrm_state __rcu *x)
{
        return refcount_inc_not_zero(&x->refcnt);
}

static inline unsigned int xfrm_dst_hash(struct net *net,
                                         const xfrm_address_t *daddr,
                                         const xfrm_address_t *saddr,
                                         u32 reqid,
                                         unsigned short family)
{
        return __xfrm_dst_hash(daddr, saddr, reqid, family, net->xfrm.state_hmask);
}

static inline unsigned int xfrm_src_hash(struct net *net,
                                         const xfrm_address_t *daddr,
                                         const xfrm_address_t *saddr,
                                         unsigned short family)
{
        return __xfrm_src_hash(daddr, saddr, family, net->xfrm.state_hmask);
}

static inline unsigned int
xfrm_spi_hash(struct net *net, const xfrm_address_t *daddr,
              __be32 spi, u8 proto, unsigned short family)
{
        return __xfrm_spi_hash(daddr, spi, proto, family, net->xfrm.state_hmask);
}

static unsigned int xfrm_seq_hash(struct net *net, u32 seq)
{
        return __xfrm_seq_hash(seq, net->xfrm.state_hmask);
}

static void xfrm_hash_transfer(struct hlist_head *list,
                               struct hlist_head *ndsttable,
                               struct hlist_head *nsrctable,
                               struct hlist_head *nspitable,
                               struct hlist_head *nseqtable,
                               unsigned int nhashmask)
{
        struct hlist_node *tmp;
        struct xfrm_state *x;

        hlist_for_each_entry_safe(x, tmp, list, bydst) {
                unsigned int h;

                h = __xfrm_dst_hash(&x->id.daddr, &x->props.saddr,
                                    x->props.reqid, x->props.family,
                                    nhashmask);
                hlist_add_head_rcu(&x->bydst, ndsttable + h);

                h = __xfrm_src_hash(&x->id.daddr, &x->props.saddr,
                                    x->props.family,
                                    nhashmask);
                hlist_add_head_rcu(&x->bysrc, nsrctable + h);

                if (x->id.spi) {
                        h = __xfrm_spi_hash(&x->id.daddr, x->id.spi,
                                            x->id.proto, x->props.family,
                                            nhashmask);
                        hlist_add_head_rcu(&x->byspi, nspitable + h);
                }

                if (x->km.seq) {
                        h = __xfrm_seq_hash(x->km.seq, nhashmask);
                        hlist_add_head_rcu(&x->byseq, nseqtable + h);
                }
        }
}

static unsigned long xfrm_hash_new_size(unsigned int state_hmask)
{
        return ((state_hmask + 1) << 1) * sizeof(struct hlist_head);
}

static void xfrm_hash_resize(struct work_struct *work)
{
        struct net *net = container_of(work, struct net, xfrm.state_hash_work);
        struct hlist_head *ndst, *nsrc, *nspi, *nseq, *odst, *osrc, *ospi, *oseq;
        unsigned long nsize, osize;
        unsigned int nhashmask, ohashmask;
        int i;

        nsize = xfrm_hash_new_size(net->xfrm.state_hmask);
        ndst = xfrm_hash_alloc(nsize);
        if (!ndst)
                return;
        nsrc = xfrm_hash_alloc(nsize);
        if (!nsrc) {
                xfrm_hash_free(ndst, nsize);
                return;
        }
        nspi = xfrm_hash_alloc(nsize);
        if (!nspi) {
                xfrm_hash_free(ndst, nsize);
                xfrm_hash_free(nsrc, nsize);
                return;
        }
        nseq = xfrm_hash_alloc(nsize);
        if (!nseq) {
                xfrm_hash_free(ndst, nsize);
                xfrm_hash_free(nsrc, nsize);
                xfrm_hash_free(nspi, nsize);
                return;
        }

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        write_seqcount_begin(&net->xfrm.xfrm_state_hash_generation);

        nhashmask = (nsize / sizeof(struct hlist_head)) - 1U;
        odst = xfrm_state_deref_prot(net->xfrm.state_bydst, net);
        for (i = net->xfrm.state_hmask; i >= 0; i--)
                xfrm_hash_transfer(odst + i, ndst, nsrc, nspi, nseq, nhashmask);

        osrc = xfrm_state_deref_prot(net->xfrm.state_bysrc, net);
        ospi = xfrm_state_deref_prot(net->xfrm.state_byspi, net);
        oseq = xfrm_state_deref_prot(net->xfrm.state_byseq, net);
        ohashmask = net->xfrm.state_hmask;

        rcu_assign_pointer(net->xfrm.state_bydst, ndst);
        rcu_assign_pointer(net->xfrm.state_bysrc, nsrc);
        rcu_assign_pointer(net->xfrm.state_byspi, nspi);
        rcu_assign_pointer(net->xfrm.state_byseq, nseq);
        net->xfrm.state_hmask = nhashmask;

        write_seqcount_end(&net->xfrm.xfrm_state_hash_generation);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);

        osize = (ohashmask + 1) * sizeof(struct hlist_head);

        synchronize_rcu();

        xfrm_hash_free(odst, osize);
        xfrm_hash_free(osrc, osize);
        xfrm_hash_free(ospi, osize);
        xfrm_hash_free(oseq, osize);
}

static DEFINE_SPINLOCK(xfrm_state_afinfo_lock);
static struct xfrm_state_afinfo __rcu *xfrm_state_afinfo[NPROTO];

static DEFINE_SPINLOCK(xfrm_state_gc_lock);

int __xfrm_state_delete(struct xfrm_state *x);

int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
static bool km_is_alive(const struct km_event *c);
void km_state_expired(struct xfrm_state *x, int hard, u32 portid);

int xfrm_register_type(const struct xfrm_type *type, unsigned short family)
{
        struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
        int err = 0;

        if (!afinfo)
                return -EAFNOSUPPORT;

#define X(afi, T, name) do {                    \
                WARN_ON((afi)->type_ ## name);  \
                (afi)->type_ ## name = (T);     \
        } while (0)

        switch (type->proto) {
        case IPPROTO_COMP:
                X(afinfo, type, comp);
                break;
        case IPPROTO_AH:
                X(afinfo, type, ah);
                break;
        case IPPROTO_ESP:
                X(afinfo, type, esp);
                break;
        case IPPROTO_IPIP:
                X(afinfo, type, ipip);
                break;
        case IPPROTO_DSTOPTS:
                X(afinfo, type, dstopts);
                break;
        case IPPROTO_ROUTING:
                X(afinfo, type, routing);
                break;
        case IPPROTO_IPV6:
                X(afinfo, type, ipip6);
                break;
        default:
                WARN_ON(1);
                err = -EPROTONOSUPPORT;
                break;
        }
#undef X
        rcu_read_unlock();
        return err;
}
EXPORT_SYMBOL(xfrm_register_type);

void xfrm_unregister_type(const struct xfrm_type *type, unsigned short family)
{
        struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);

        if (unlikely(afinfo == NULL))
                return;

#define X(afi, T, name) do {                            \
                WARN_ON((afi)->type_ ## name != (T));   \
                (afi)->type_ ## name = NULL;            \
        } while (0)

        switch (type->proto) {
        case IPPROTO_COMP:
                X(afinfo, type, comp);
                break;
        case IPPROTO_AH:
                X(afinfo, type, ah);
                break;
        case IPPROTO_ESP:
                X(afinfo, type, esp);
                break;
        case IPPROTO_IPIP:
                X(afinfo, type, ipip);
                break;
        case IPPROTO_DSTOPTS:
                X(afinfo, type, dstopts);
                break;
        case IPPROTO_ROUTING:
                X(afinfo, type, routing);
                break;
        case IPPROTO_IPV6:
                X(afinfo, type, ipip6);
                break;
        default:
                WARN_ON(1);
                break;
        }
#undef X
        rcu_read_unlock();
}
EXPORT_SYMBOL(xfrm_unregister_type);

static const struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
{
        const struct xfrm_type *type = NULL;
        struct xfrm_state_afinfo *afinfo;
        int modload_attempted = 0;

retry:
        afinfo = xfrm_state_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return NULL;

        switch (proto) {
        case IPPROTO_COMP:
                type = afinfo->type_comp;
                break;
        case IPPROTO_AH:
                type = afinfo->type_ah;
                break;
        case IPPROTO_ESP:
                type = afinfo->type_esp;
                break;
        case IPPROTO_IPIP:
                type = afinfo->type_ipip;
                break;
        case IPPROTO_DSTOPTS:
                type = afinfo->type_dstopts;
                break;
        case IPPROTO_ROUTING:
                type = afinfo->type_routing;
                break;
        case IPPROTO_IPV6:
                type = afinfo->type_ipip6;
                break;
        default:
                break;
        }

        if (unlikely(type && !try_module_get(type->owner)))
                type = NULL;

        rcu_read_unlock();

        if (!type && !modload_attempted) {
                request_module("xfrm-type-%d-%d", family, proto);
                modload_attempted = 1;
                goto retry;
        }

        return type;
}

static void xfrm_put_type(const struct xfrm_type *type)
{
        module_put(type->owner);
}

int xfrm_register_type_offload(const struct xfrm_type_offload *type,
                               unsigned short family)
{
        struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
        int err = 0;

        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;

        switch (type->proto) {
        case IPPROTO_ESP:
                WARN_ON(afinfo->type_offload_esp);
                afinfo->type_offload_esp = type;
                break;
        default:
                WARN_ON(1);
                err = -EPROTONOSUPPORT;
                break;
        }

        rcu_read_unlock();
        return err;
}
EXPORT_SYMBOL(xfrm_register_type_offload);

void xfrm_unregister_type_offload(const struct xfrm_type_offload *type,
                                  unsigned short family)
{
        struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);

        if (unlikely(afinfo == NULL))
                return;

        switch (type->proto) {
        case IPPROTO_ESP:
                WARN_ON(afinfo->type_offload_esp != type);
                afinfo->type_offload_esp = NULL;
                break;
        default:
                WARN_ON(1);
                break;
        }
        rcu_read_unlock();
}
EXPORT_SYMBOL(xfrm_unregister_type_offload);

static const struct xfrm_type_offload *
xfrm_get_type_offload(u8 proto, unsigned short family, bool try_load)
{
        const struct xfrm_type_offload *type = NULL;
        struct xfrm_state_afinfo *afinfo;

retry:
        afinfo = xfrm_state_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return NULL;

        switch (proto) {
        case IPPROTO_ESP:
                type = afinfo->type_offload_esp;
                break;
        default:
                break;
        }

        if ((type && !try_module_get(type->owner)))
                type = NULL;

        rcu_read_unlock();

        if (!type && try_load) {
                request_module("xfrm-offload-%d-%d", family, proto);
                try_load = false;
                goto retry;
        }

        return type;
}

static void xfrm_put_type_offload(const struct xfrm_type_offload *type)
{
        module_put(type->owner);
}

static const struct xfrm_mode xfrm4_mode_map[XFRM_MODE_MAX] = {
        [XFRM_MODE_BEET] = {
                .encap = XFRM_MODE_BEET,
                .flags = XFRM_MODE_FLAG_TUNNEL,
                .family = AF_INET,
        },
        [XFRM_MODE_TRANSPORT] = {
                .encap = XFRM_MODE_TRANSPORT,
                .family = AF_INET,
        },
        [XFRM_MODE_TUNNEL] = {
                .encap = XFRM_MODE_TUNNEL,
                .flags = XFRM_MODE_FLAG_TUNNEL,
                .family = AF_INET,
        },
};

static const struct xfrm_mode xfrm6_mode_map[XFRM_MODE_MAX] = {
        [XFRM_MODE_BEET] = {
                .encap = XFRM_MODE_BEET,
                .flags = XFRM_MODE_FLAG_TUNNEL,
                .family = AF_INET6,
        },
        [XFRM_MODE_ROUTEOPTIMIZATION] = {
                .encap = XFRM_MODE_ROUTEOPTIMIZATION,
                .family = AF_INET6,
        },
        [XFRM_MODE_TRANSPORT] = {
                .encap = XFRM_MODE_TRANSPORT,
                .family = AF_INET6,
        },
        [XFRM_MODE_TUNNEL] = {
                .encap = XFRM_MODE_TUNNEL,
                .flags = XFRM_MODE_FLAG_TUNNEL,
                .family = AF_INET6,
        },
};

static const struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
{
        const struct xfrm_mode *mode;

        if (unlikely(encap >= XFRM_MODE_MAX))
                return NULL;

        switch (family) {
        case AF_INET:
                mode = &xfrm4_mode_map[encap];
                if (mode->family == family)
                        return mode;
                break;
        case AF_INET6:
                mode = &xfrm6_mode_map[encap];
                if (mode->family == family)
                        return mode;
                break;
        default:
                break;
        }

        return NULL;
}

void xfrm_state_free(struct xfrm_state *x)
{
        kmem_cache_free(xfrm_state_cache, x);
}
EXPORT_SYMBOL(xfrm_state_free);

static void ___xfrm_state_destroy(struct xfrm_state *x)
{
        hrtimer_cancel(&x->mtimer);
        del_timer_sync(&x->rtimer);
        kfree(x->aead);
        kfree(x->aalg);
        kfree(x->ealg);
        kfree(x->calg);
        kfree(x->encap);
        kfree(x->coaddr);
        kfree(x->replay_esn);
        kfree(x->preplay_esn);
        if (x->type_offload)
                xfrm_put_type_offload(x->type_offload);
        if (x->type) {
                x->type->destructor(x);
                xfrm_put_type(x->type);
        }
        if (x->xfrag.page)
                put_page(x->xfrag.page);
        xfrm_dev_state_free(x);
        security_xfrm_state_free(x);
        xfrm_state_free(x);
}

static void xfrm_state_gc_task(struct work_struct *work)
{
        struct xfrm_state *x;
        struct hlist_node *tmp;
        struct hlist_head gc_list;

        spin_lock_bh(&xfrm_state_gc_lock);
        hlist_move_list(&xfrm_state_gc_list, &gc_list);
        spin_unlock_bh(&xfrm_state_gc_lock);

        synchronize_rcu();

        hlist_for_each_entry_safe(x, tmp, &gc_list, gclist)
                ___xfrm_state_destroy(x);
}

static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
{
        struct xfrm_state *x = container_of(me, struct xfrm_state, mtimer);
        enum hrtimer_restart ret = HRTIMER_NORESTART;
        time64_t now = ktime_get_real_seconds();
        time64_t next = TIME64_MAX;
        int warn = 0;
        int err = 0;

        spin_lock(&x->lock);
        if (x->km.state == XFRM_STATE_DEAD)
                goto out;
        if (x->km.state == XFRM_STATE_EXPIRED)
                goto expired;
        if (x->lft.hard_add_expires_seconds) {
                long tmo = x->lft.hard_add_expires_seconds +
                        x->curlft.add_time - now;
                if (tmo <= 0) {
                        if (x->xflags & XFRM_SOFT_EXPIRE) {
                                /* enter hard expire without soft expire first?!
                                 * setting a new date could trigger this.
                                 * workaround: fix x->curflt.add_time by below:
                                 */
                                x->curlft.add_time = now - x->saved_tmo - 1;
                                tmo = x->lft.hard_add_expires_seconds - x->saved_tmo;
                        } else
                                goto expired;
                }
                if (tmo < next)
                        next = tmo;
        }
        if (x->lft.hard_use_expires_seconds) {
                long tmo = x->lft.hard_use_expires_seconds +
                        (x->curlft.use_time ? : now) - now;
                if (tmo <= 0)
                        goto expired;
                if (tmo < next)
                        next = tmo;
        }
        if (x->km.dying)
                goto resched;
        if (x->lft.soft_add_expires_seconds) {
                long tmo = x->lft.soft_add_expires_seconds +
                        x->curlft.add_time - now;
                if (tmo <= 0) {
                        warn = 1;
                        x->xflags &= ~XFRM_SOFT_EXPIRE;
                } else if (tmo < next) {
                        next = tmo;
                        x->xflags |= XFRM_SOFT_EXPIRE;
                        x->saved_tmo = tmo;
                }
        }
        if (x->lft.soft_use_expires_seconds) {
                long tmo = x->lft.soft_use_expires_seconds +
                        (x->curlft.use_time ? : now) - now;
                if (tmo <= 0)
                        warn = 1;
                else if (tmo < next)
                        next = tmo;
        }

        x->km.dying = warn;
        if (warn)
                km_state_expired(x, 0, 0);
resched:
        if (next != TIME64_MAX) {
                hrtimer_forward_now(&x->mtimer, ktime_set(next, 0));
                ret = HRTIMER_RESTART;
        }

        goto out;

expired:
        if (x->km.state == XFRM_STATE_ACQ && x->id.spi == 0)
                x->km.state = XFRM_STATE_EXPIRED;

        err = __xfrm_state_delete(x);
        if (!err)
                km_state_expired(x, 1, 0);

        xfrm_audit_state_delete(x, err ? 0 : 1, true);

out:
        spin_unlock(&x->lock);
        return ret;
}

static void xfrm_replay_timer_handler(struct timer_list *t);

struct xfrm_state *xfrm_state_alloc(struct net *net)
{
        struct xfrm_state *x;

        x = kmem_cache_zalloc(xfrm_state_cache, GFP_ATOMIC);

        if (x) {
                write_pnet(&x->xs_net, net);
                refcount_set(&x->refcnt, 1);
                atomic_set(&x->tunnel_users, 0);
                INIT_LIST_HEAD(&x->km.all);
                INIT_HLIST_NODE(&x->bydst);
                INIT_HLIST_NODE(&x->bysrc);
                INIT_HLIST_NODE(&x->byspi);
                INIT_HLIST_NODE(&x->byseq);
                hrtimer_init(&x->mtimer, CLOCK_BOOTTIME, HRTIMER_MODE_ABS_SOFT);
                x->mtimer.function = xfrm_timer_handler;
                timer_setup(&x->rtimer, xfrm_replay_timer_handler, 0);
                x->curlft.add_time = ktime_get_real_seconds();
                x->lft.soft_byte_limit = XFRM_INF;
                x->lft.soft_packet_limit = XFRM_INF;
                x->lft.hard_byte_limit = XFRM_INF;
                x->lft.hard_packet_limit = XFRM_INF;
                x->replay_maxage = 0;
                x->replay_maxdiff = 0;
                spin_lock_init(&x->lock);
        }
        return x;
}
EXPORT_SYMBOL(xfrm_state_alloc);

void __xfrm_state_destroy(struct xfrm_state *x, bool sync)
{
        WARN_ON(x->km.state != XFRM_STATE_DEAD);

        if (sync) {
                synchronize_rcu();
                ___xfrm_state_destroy(x);
        } else {
                spin_lock_bh(&xfrm_state_gc_lock);
                hlist_add_head(&x->gclist, &xfrm_state_gc_list);
                spin_unlock_bh(&xfrm_state_gc_lock);
                schedule_work(&xfrm_state_gc_work);
        }
}
EXPORT_SYMBOL(__xfrm_state_destroy);

int __xfrm_state_delete(struct xfrm_state *x)
{
        struct net *net = xs_net(x);
        int err = -ESRCH;

        if (x->km.state != XFRM_STATE_DEAD) {
                x->km.state = XFRM_STATE_DEAD;
                spin_lock(&net->xfrm.xfrm_state_lock);
                list_del(&x->km.all);
                hlist_del_rcu(&x->bydst);
                hlist_del_rcu(&x->bysrc);
                if (x->km.seq)
                        hlist_del_rcu(&x->byseq);
                if (x->id.spi)
                        hlist_del_rcu(&x->byspi);
                net->xfrm.state_num--;
                spin_unlock(&net->xfrm.xfrm_state_lock);

                if (x->encap_sk)
                        sock_put(rcu_dereference_raw(x->encap_sk));

                xfrm_dev_state_delete(x);

                /* All xfrm_state objects are created by xfrm_state_alloc.
                 * The xfrm_state_alloc call gives a reference, and that
                 * is what we are dropping here.
                 */
                xfrm_state_put(x);
                err = 0;
        }

        return err;
}
EXPORT_SYMBOL(__xfrm_state_delete);

int xfrm_state_delete(struct xfrm_state *x)
{
        int err;

        spin_lock_bh(&x->lock);
        err = __xfrm_state_delete(x);
        spin_unlock_bh(&x->lock);

        return err;
}
EXPORT_SYMBOL(xfrm_state_delete);

#ifdef CONFIG_SECURITY_NETWORK_XFRM
static inline int
xfrm_state_flush_secctx_check(struct net *net, u8 proto, bool task_valid)
{
        int i, err = 0;

        for (i = 0; i <= net->xfrm.state_hmask; i++) {
                struct xfrm_state *x;

                hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
                        if (xfrm_id_proto_match(x->id.proto, proto) &&
                           (err = security_xfrm_state_delete(x)) != 0) {
                                xfrm_audit_state_delete(x, 0, task_valid);
                                return err;
                        }
                }
        }

        return err;
}

static inline int
xfrm_dev_state_flush_secctx_check(struct net *net, struct net_device *dev, bool task_valid)
{
        int i, err = 0;

        for (i = 0; i <= net->xfrm.state_hmask; i++) {
                struct xfrm_state *x;
                struct xfrm_state_offload *xso;

                hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
                        xso = &x->xso;

                        if (xso->dev == dev &&
                           (err = security_xfrm_state_delete(x)) != 0) {
                                xfrm_audit_state_delete(x, 0, task_valid);
                                return err;
                        }
                }
        }

        return err;
}
#else
static inline int
xfrm_state_flush_secctx_check(struct net *net, u8 proto, bool task_valid)
{
        return 0;
}

static inline int
xfrm_dev_state_flush_secctx_check(struct net *net, struct net_device *dev, bool task_valid)
{
        return 0;
}
#endif

int xfrm_state_flush(struct net *net, u8 proto, bool task_valid, bool sync)
{
        int i, err = 0, cnt = 0;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        err = xfrm_state_flush_secctx_check(net, proto, task_valid);
        if (err)
                goto out;

        err = -ESRCH;
        for (i = 0; i <= net->xfrm.state_hmask; i++) {
                struct xfrm_state *x;
restart:
                hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
                        if (!xfrm_state_kern(x) &&
                            xfrm_id_proto_match(x->id.proto, proto)) {
                                xfrm_state_hold(x);
                                spin_unlock_bh(&net->xfrm.xfrm_state_lock);

                                err = xfrm_state_delete(x);
                                xfrm_audit_state_delete(x, err ? 0 : 1,
                                                        task_valid);
                                if (sync)
                                        xfrm_state_put_sync(x);
                                else
                                        xfrm_state_put(x);
                                if (!err)
                                        cnt++;

                                spin_lock_bh(&net->xfrm.xfrm_state_lock);
                                goto restart;
                        }
                }
        }
out:
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
        if (cnt)
                err = 0;

        return err;
}
EXPORT_SYMBOL(xfrm_state_flush);

int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_valid)
{
        int i, err = 0, cnt = 0;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        err = xfrm_dev_state_flush_secctx_check(net, dev, task_valid);
        if (err)
                goto out;

        err = -ESRCH;
        for (i = 0; i <= net->xfrm.state_hmask; i++) {
                struct xfrm_state *x;
                struct xfrm_state_offload *xso;
restart:
                hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
                        xso = &x->xso;

                        if (!xfrm_state_kern(x) && xso->dev == dev) {
                                xfrm_state_hold(x);
                                spin_unlock_bh(&net->xfrm.xfrm_state_lock);

                                err = xfrm_state_delete(x);
                                xfrm_audit_state_delete(x, err ? 0 : 1,
                                                        task_valid);
                                xfrm_state_put(x);
                                if (!err)
                                        cnt++;

                                spin_lock_bh(&net->xfrm.xfrm_state_lock);
                                goto restart;
                        }
                }
        }
        if (cnt)
                err = 0;

out:
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
        return err;
}
EXPORT_SYMBOL(xfrm_dev_state_flush);

void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si)
{
        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        si->sadcnt = net->xfrm.state_num;
        si->sadhcnt = net->xfrm.state_hmask + 1;
        si->sadhmcnt = xfrm_state_hashmax;
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
}
EXPORT_SYMBOL(xfrm_sad_getinfo);

static void
__xfrm4_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
{
        const struct flowi4 *fl4 = &fl->u.ip4;

        sel->daddr.a4 = fl4->daddr;
        sel->saddr.a4 = fl4->saddr;
        sel->dport = xfrm_flowi_dport(fl, &fl4->uli);
        sel->dport_mask = htons(0xffff);
        sel->sport = xfrm_flowi_sport(fl, &fl4->uli);
        sel->sport_mask = htons(0xffff);
        sel->family = AF_INET;
        sel->prefixlen_d = 32;
        sel->prefixlen_s = 32;
        sel->proto = fl4->flowi4_proto;
        sel->ifindex = fl4->flowi4_oif;
}

static void
__xfrm6_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
{
        const struct flowi6 *fl6 = &fl->u.ip6;

        /* Initialize temporary selector matching only to current session. */
        *(struct in6_addr *)&sel->daddr = fl6->daddr;
        *(struct in6_addr *)&sel->saddr = fl6->saddr;
        sel->dport = xfrm_flowi_dport(fl, &fl6->uli);
        sel->dport_mask = htons(0xffff);
        sel->sport = xfrm_flowi_sport(fl, &fl6->uli);
        sel->sport_mask = htons(0xffff);
        sel->family = AF_INET6;
        sel->prefixlen_d = 128;
        sel->prefixlen_s = 128;
        sel->proto = fl6->flowi6_proto;
        sel->ifindex = fl6->flowi6_oif;
}

static void
xfrm_init_tempstate(struct xfrm_state *x, const struct flowi *fl,
                    const struct xfrm_tmpl *tmpl,
                    const xfrm_address_t *daddr, const xfrm_address_t *saddr,
                    unsigned short family)
{
        switch (family) {
        case AF_INET:
                __xfrm4_init_tempsel(&x->sel, fl);
                break;
        case AF_INET6:
                __xfrm6_init_tempsel(&x->sel, fl);
                break;
        }

        x->id = tmpl->id;

        switch (tmpl->encap_family) {
        case AF_INET:
                if (x->id.daddr.a4 == 0)
                        x->id.daddr.a4 = daddr->a4;
                x->props.saddr = tmpl->saddr;
                if (x->props.saddr.a4 == 0)
                        x->props.saddr.a4 = saddr->a4;
                break;
        case AF_INET6:
                if (ipv6_addr_any((struct in6_addr *)&x->id.daddr))
                        memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
                memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
                if (ipv6_addr_any((struct in6_addr *)&x->props.saddr))
                        memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
                break;
        }

        x->props.mode = tmpl->mode;
        x->props.reqid = tmpl->reqid;
        x->props.family = tmpl->encap_family;
}

static struct xfrm_state *__xfrm_state_lookup(struct net *net, u32 mark,
                                              const xfrm_address_t *daddr,
                                              __be32 spi, u8 proto,
                                              unsigned short family)
{
        unsigned int h = xfrm_spi_hash(net, daddr, spi, proto, family);
        struct xfrm_state *x;

        hlist_for_each_entry_rcu(x, net->xfrm.state_byspi + h, byspi) {
                if (x->props.family != family ||
                    x->id.spi       != spi ||
                    x->id.proto     != proto ||
                    !xfrm_addr_equal(&x->id.daddr, daddr, family))
                        continue;

                if ((mark & x->mark.m) != x->mark.v)
                        continue;
                if (!xfrm_state_hold_rcu(x))
                        continue;
                return x;
        }

        return NULL;
}

static struct xfrm_state *__xfrm_state_lookup_byaddr(struct net *net, u32 mark,
                                                     const xfrm_address_t *daddr,
                                                     const xfrm_address_t *saddr,
                                                     u8 proto, unsigned short family)
{
        unsigned int h = xfrm_src_hash(net, daddr, saddr, family);
        struct xfrm_state *x;

        hlist_for_each_entry_rcu(x, net->xfrm.state_bysrc + h, bysrc) {
                if (x->props.family != family ||
                    x->id.proto     != proto ||
                    !xfrm_addr_equal(&x->id.daddr, daddr, family) ||
                    !xfrm_addr_equal(&x->props.saddr, saddr, family))
                        continue;

                if ((mark & x->mark.m) != x->mark.v)
                        continue;
                if (!xfrm_state_hold_rcu(x))
                        continue;
                return x;
        }

        return NULL;

}

static inline struct xfrm_state *
__xfrm_state_locate(struct xfrm_state *x, int use_spi, int family)
{
        struct net *net = xs_net(x);
        u32 mark = x->mark.v & x->mark.m;

        if (use_spi)
                return __xfrm_state_lookup(net, mark, &x->id.daddr,
                                           x->id.spi, x->id.proto, family);
        else
                return __xfrm_state_lookup_byaddr(net, mark,
                                                  &x->id.daddr,
                                                  &x->props.saddr,
                                                  x->id.proto, family);
}

static void xfrm_hash_grow_check(struct net *net, int have_hash_collision)
{
        if (have_hash_collision &&
            (net->xfrm.state_hmask + 1) < xfrm_state_hashmax &&
            net->xfrm.state_num > net->xfrm.state_hmask)
                schedule_work(&net->xfrm.state_hash_work);
}

static void xfrm_state_look_at(struct xfrm_policy *pol, struct xfrm_state *x,
                               const struct flowi *fl, unsigned short family,
                               struct xfrm_state **best, int *acq_in_progress,
                               int *error)
{
        /* Resolution logic:
         * 1. There is a valid state with matching selector. Done.
         * 2. Valid state with inappropriate selector. Skip.
         *
         * Entering area of "sysdeps".
         *
         * 3. If state is not valid, selector is temporary, it selects
         *    only session which triggered previous resolution. Key
         *    manager will do something to install a state with proper
         *    selector.
         */
        if (x->km.state == XFRM_STATE_VALID) {
                if ((x->sel.family &&
                     (x->sel.family != family ||
                      !xfrm_selector_match(&x->sel, fl, family))) ||
                    !security_xfrm_state_pol_flow_match(x, pol,
                                                        &fl->u.__fl_common))
                        return;

                if (!*best ||
                    (*best)->km.dying > x->km.dying ||
                    ((*best)->km.dying == x->km.dying &&
                     (*best)->curlft.add_time < x->curlft.add_time))
                        *best = x;
        } else if (x->km.state == XFRM_STATE_ACQ) {
                *acq_in_progress = 1;
        } else if (x->km.state == XFRM_STATE_ERROR ||
                   x->km.state == XFRM_STATE_EXPIRED) {
                if ((!x->sel.family ||
                     (x->sel.family == family &&
                      xfrm_selector_match(&x->sel, fl, family))) &&
                    security_xfrm_state_pol_flow_match(x, pol,
                                                       &fl->u.__fl_common))
                        *error = -ESRCH;
        }
}

struct xfrm_state *
xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr,
                const struct flowi *fl, struct xfrm_tmpl *tmpl,
                struct xfrm_policy *pol, int *err,
                unsigned short family, u32 if_id)
{
        static xfrm_address_t saddr_wildcard = { };
        struct net *net = xp_net(pol);
        unsigned int h, h_wildcard;
        struct xfrm_state *x, *x0, *to_put;
        int acquire_in_progress = 0;
        int error = 0;
        struct xfrm_state *best = NULL;
        u32 mark = pol->mark.v & pol->mark.m;
        unsigned short encap_family = tmpl->encap_family;
        unsigned int sequence;
        struct km_event c;

        to_put = NULL;

        sequence = read_seqcount_begin(&net->xfrm.xfrm_state_hash_generation);

        rcu_read_lock();
        h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family);
        hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {
                if (x->props.family == encap_family &&
                    x->props.reqid == tmpl->reqid &&
                    (mark & x->mark.m) == x->mark.v &&
                    x->if_id == if_id &&
                    !(x->props.flags & XFRM_STATE_WILDRECV) &&
                    xfrm_state_addr_check(x, daddr, saddr, encap_family) &&
                    tmpl->mode == x->props.mode &&
                    tmpl->id.proto == x->id.proto &&
                    (tmpl->id.spi == x->id.spi || !tmpl->id.spi))
                        xfrm_state_look_at(pol, x, fl, family,
                                           &best, &acquire_in_progress, &error);
        }
        if (best || acquire_in_progress)
                goto found;

        h_wildcard = xfrm_dst_hash(net, daddr, &saddr_wildcard, tmpl->reqid, encap_family);
        hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h_wildcard, bydst) {
                if (x->props.family == encap_family &&
                    x->props.reqid == tmpl->reqid &&
                    (mark & x->mark.m) == x->mark.v &&
                    x->if_id == if_id &&
                    !(x->props.flags & XFRM_STATE_WILDRECV) &&
                    xfrm_addr_equal(&x->id.daddr, daddr, encap_family) &&
                    tmpl->mode == x->props.mode &&
                    tmpl->id.proto == x->id.proto &&
                    (tmpl->id.spi == x->id.spi || !tmpl->id.spi))
                        xfrm_state_look_at(pol, x, fl, family,
                                           &best, &acquire_in_progress, &error);
        }

found:
        x = best;
        if (!x && !error && !acquire_in_progress) {
                if (tmpl->id.spi &&
                    (x0 = __xfrm_state_lookup(net, mark, daddr, tmpl->id.spi,
                                              tmpl->id.proto, encap_family)) != NULL) {
                        to_put = x0;
                        error = -EEXIST;
                        goto out;
                }

                c.net = net;
                /* If the KMs have no listeners (yet...), avoid allocating an SA
                 * for each and every packet - garbage collection might not
                 * handle the flood.
                 */
                if (!km_is_alive(&c)) {
                        error = -ESRCH;
                        goto out;
                }

                x = xfrm_state_alloc(net);
                if (x == NULL) {
                        error = -ENOMEM;
                        goto out;
                }
                /* Initialize temporary state matching only
                 * to current session. */
                xfrm_init_tempstate(x, fl, tmpl, daddr, saddr, family);
                memcpy(&x->mark, &pol->mark, sizeof(x->mark));
                x->if_id = if_id;

                error = security_xfrm_state_alloc_acquire(x, pol->security, fl->flowi_secid);
                if (error) {
                        x->km.state = XFRM_STATE_DEAD;
                        to_put = x;
                        x = NULL;
                        goto out;
                }

                if (km_query(x, tmpl, pol) == 0) {
                        spin_lock_bh(&net->xfrm.xfrm_state_lock);
                        x->km.state = XFRM_STATE_ACQ;
                        list_add(&x->km.all, &net->xfrm.state_all);
                        hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);
                        h = xfrm_src_hash(net, daddr, saddr, encap_family);
                        hlist_add_head_rcu(&x->bysrc, net->xfrm.state_bysrc + h);
                        if (x->id.spi) {
                                h = xfrm_spi_hash(net, &x->id.daddr, x->id.spi, x->id.proto, encap_family);
                                hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
                        }
                        if (x->km.seq) {
                                h = xfrm_seq_hash(net, x->km.seq);
                                hlist_add_head_rcu(&x->byseq, net->xfrm.state_byseq + h);
                        }
                        x->lft.hard_add_expires_seconds = net->xfrm.sysctl_acq_expires;
                        hrtimer_start(&x->mtimer,
                                      ktime_set(net->xfrm.sysctl_acq_expires, 0),
                                      HRTIMER_MODE_REL_SOFT);
                        net->xfrm.state_num++;
                        xfrm_hash_grow_check(net, x->bydst.next != NULL);
                        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
                } else {
                        x->km.state = XFRM_STATE_DEAD;
                        to_put = x;
                        x = NULL;
                        error = -ESRCH;
                }
        }
out:
        if (x) {
                if (!xfrm_state_hold_rcu(x)) {
                        *err = -EAGAIN;
                        x = NULL;
                }
        } else {
                *err = acquire_in_progress ? -EAGAIN : error;
        }
        rcu_read_unlock();
        if (to_put)
                xfrm_state_put(to_put);

        if (read_seqcount_retry(&net->xfrm.xfrm_state_hash_generation, sequence)) {
                *err = -EAGAIN;
                if (x) {
                        xfrm_state_put(x);
                        x = NULL;
                }
        }

        return x;
}

struct xfrm_state *
xfrm_stateonly_find(struct net *net, u32 mark, u32 if_id,
                    xfrm_address_t *daddr, xfrm_address_t *saddr,
                    unsigned short family, u8 mode, u8 proto, u32 reqid)
{
        unsigned int h;
        struct xfrm_state *rx = NULL, *x = NULL;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        h = xfrm_dst_hash(net, daddr, saddr, reqid, family);
        hlist_for_each_entry(x, net->xfrm.state_bydst+h, bydst) {
                if (x->props.family == family &&
                    x->props.reqid == reqid &&
                    (mark & x->mark.m) == x->mark.v &&
                    x->if_id == if_id &&
                    !(x->props.flags & XFRM_STATE_WILDRECV) &&
                    xfrm_state_addr_check(x, daddr, saddr, family) &&
                    mode == x->props.mode &&
                    proto == x->id.proto &&
                    x->km.state == XFRM_STATE_VALID) {
                        rx = x;
                        break;
                }
        }

        if (rx)
                xfrm_state_hold(rx);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);


        return rx;
}
EXPORT_SYMBOL(xfrm_stateonly_find);

struct xfrm_state *xfrm_state_lookup_byspi(struct net *net, __be32 spi,
                                              unsigned short family)
{
        struct xfrm_state *x;
        struct xfrm_state_walk *w;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        list_for_each_entry(w, &net->xfrm.state_all, all) {
                x = container_of(w, struct xfrm_state, km);
                if (x->props.family != family ||
                        x->id.spi != spi)
                        continue;

                xfrm_state_hold(x);
                spin_unlock_bh(&net->xfrm.xfrm_state_lock);
                return x;
        }
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
        return NULL;
}
EXPORT_SYMBOL(xfrm_state_lookup_byspi);

static void __xfrm_state_insert(struct xfrm_state *x)
{
        struct net *net = xs_net(x);
        unsigned int h;

        list_add(&x->km.all, &net->xfrm.state_all);

        h = xfrm_dst_hash(net, &x->id.daddr, &x->props.saddr,
                          x->props.reqid, x->props.family);
        hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);

        h = xfrm_src_hash(net, &x->id.daddr, &x->props.saddr, x->props.family);
        hlist_add_head_rcu(&x->bysrc, net->xfrm.state_bysrc + h);

        if (x->id.spi) {
                h = xfrm_spi_hash(net, &x->id.daddr, x->id.spi, x->id.proto,
                                  x->props.family);

                hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
        }

        if (x->km.seq) {
                h = xfrm_seq_hash(net, x->km.seq);

                hlist_add_head_rcu(&x->byseq, net->xfrm.state_byseq + h);
        }

        hrtimer_start(&x->mtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
        if (x->replay_maxage)
                mod_timer(&x->rtimer, jiffies + x->replay_maxage);

        net->xfrm.state_num++;

        xfrm_hash_grow_check(net, x->bydst.next != NULL);
}

/* net->xfrm.xfrm_state_lock is held */
static void __xfrm_state_bump_genids(struct xfrm_state *xnew)
{
        struct net *net = xs_net(xnew);
        unsigned short family = xnew->props.family;
        u32 reqid = xnew->props.reqid;
        struct xfrm_state *x;
        unsigned int h;
        u32 mark = xnew->mark.v & xnew->mark.m;
        u32 if_id = xnew->if_id;

        h = xfrm_dst_hash(net, &xnew->id.daddr, &xnew->props.saddr, reqid, family);
        hlist_for_each_entry(x, net->xfrm.state_bydst+h, bydst) {
                if (x->props.family     == family &&
                    x->props.reqid      == reqid &&
                    x->if_id            == if_id &&
                    (mark & x->mark.m) == x->mark.v &&
                    xfrm_addr_equal(&x->id.daddr, &xnew->id.daddr, family) &&
                    xfrm_addr_equal(&x->props.saddr, &xnew->props.saddr, family))
                        x->genid++;
        }
}

void xfrm_state_insert(struct xfrm_state *x)
{
        struct net *net = xs_net(x);

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        __xfrm_state_bump_genids(x);
        __xfrm_state_insert(x);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
}
EXPORT_SYMBOL(xfrm_state_insert);

/* net->xfrm.xfrm_state_lock is held */
static struct xfrm_state *__find_acq_core(struct net *net,
                                          const struct xfrm_mark *m,
                                          unsigned short family, u8 mode,
                                          u32 reqid, u32 if_id, u8 proto,
                                          const xfrm_address_t *daddr,
                                          const xfrm_address_t *saddr,
                                          int create)
{
        unsigned int h = xfrm_dst_hash(net, daddr, saddr, reqid, family);
        struct xfrm_state *x;
        u32 mark = m->v & m->m;

        hlist_for_each_entry(x, net->xfrm.state_bydst+h, bydst) {
                if (x->props.reqid  != reqid ||
                    x->props.mode   != mode ||
                    x->props.family != family ||
                    x->km.state     != XFRM_STATE_ACQ ||
                    x->id.spi       != 0 ||
                    x->id.proto     != proto ||
                    (mark & x->mark.m) != x->mark.v ||
                    !xfrm_addr_equal(&x->id.daddr, daddr, family) ||
                    !xfrm_addr_equal(&x->props.saddr, saddr, family))
                        continue;

                xfrm_state_hold(x);
                return x;
        }

        if (!create)
                return NULL;

        x = xfrm_state_alloc(net);
        if (likely(x)) {
                switch (family) {
                case AF_INET:
                        x->sel.daddr.a4 = daddr->a4;
                        x->sel.saddr.a4 = saddr->a4;
                        x->sel.prefixlen_d = 32;
                        x->sel.prefixlen_s = 32;
                        x->props.saddr.a4 = saddr->a4;
                        x->id.daddr.a4 = daddr->a4;
                        break;

                case AF_INET6:
                        x->sel.daddr.in6 = daddr->in6;
                        x->sel.saddr.in6 = saddr->in6;
                        x->sel.prefixlen_d = 128;
                        x->sel.prefixlen_s = 128;
                        x->props.saddr.in6 = saddr->in6;
                        x->id.daddr.in6 = daddr->in6;
                        break;
                }

                x->km.state = XFRM_STATE_ACQ;
                x->id.proto = proto;
                x->props.family = family;
                x->props.mode = mode;
                x->props.reqid = reqid;
                x->if_id = if_id;
                x->mark.v = m->v;
                x->mark.m = m->m;
                x->lft.hard_add_expires_seconds = net->xfrm.sysctl_acq_expires;
                xfrm_state_hold(x);
                hrtimer_start(&x->mtimer,
                              ktime_set(net->xfrm.sysctl_acq_expires, 0),
                              HRTIMER_MODE_REL_SOFT);
                list_add(&x->km.all, &net->xfrm.state_all);
                hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);
                h = xfrm_src_hash(net, daddr, saddr, family);
                hlist_add_head_rcu(&x->bysrc, net->xfrm.state_bysrc + h);

                net->xfrm.state_num++;

                xfrm_hash_grow_check(net, x->bydst.next != NULL);
        }

        return x;
}

static struct xfrm_state *__xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq);

int xfrm_state_add(struct xfrm_state *x)
{
        struct net *net = xs_net(x);
        struct xfrm_state *x1, *to_put;
        int family;
        int err;
        u32 mark = x->mark.v & x->mark.m;
        int use_spi = xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY);

        family = x->props.family;

        to_put = NULL;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);

        x1 = __xfrm_state_locate(x, use_spi, family);
        if (x1) {
                to_put = x1;
                x1 = NULL;
                err = -EEXIST;
                goto out;
        }

        if (use_spi && x->km.seq) {
                x1 = __xfrm_find_acq_byseq(net, mark, x->km.seq);
                if (x1 && ((x1->id.proto != x->id.proto) ||
                    !xfrm_addr_equal(&x1->id.daddr, &x->id.daddr, family))) {
                        to_put = x1;
                        x1 = NULL;
                }
        }

        if (use_spi && !x1)
                x1 = __find_acq_core(net, &x->mark, family, x->props.mode,
                                     x->props.reqid, x->if_id, x->id.proto,
                                     &x->id.daddr, &x->props.saddr, 0);

        __xfrm_state_bump_genids(x);
        __xfrm_state_insert(x);
        err = 0;

out:
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);

        if (x1) {
                xfrm_state_delete(x1);
                xfrm_state_put(x1);
        }

        if (to_put)
                xfrm_state_put(to_put);

        return err;
}
EXPORT_SYMBOL(xfrm_state_add);

#ifdef CONFIG_XFRM_MIGRATE
static inline int clone_security(struct xfrm_state *x, struct xfrm_sec_ctx *security)
{
        struct xfrm_user_sec_ctx *uctx;
        int size = sizeof(*uctx) + security->ctx_len;
        int err;

        uctx = kmalloc(size, GFP_KERNEL);
        if (!uctx)
                return -ENOMEM;

        uctx->exttype = XFRMA_SEC_CTX;
        uctx->len = size;
        uctx->ctx_doi = security->ctx_doi;
        uctx->ctx_alg = security->ctx_alg;
        uctx->ctx_len = security->ctx_len;
        memcpy(uctx + 1, security->ctx_str, security->ctx_len);
        err = security_xfrm_state_alloc(x, uctx);
        kfree(uctx);
        if (err)
                return err;

        return 0;
}

static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig,
                                           struct xfrm_encap_tmpl *encap)
{
        struct net *net = xs_net(orig);
        struct xfrm_state *x = xfrm_state_alloc(net);
        if (!x)
                goto out;

        memcpy(&x->id, &orig->id, sizeof(x->id));
        memcpy(&x->sel, &orig->sel, sizeof(x->sel));
        memcpy(&x->lft, &orig->lft, sizeof(x->lft));
        x->props.mode = orig->props.mode;
        x->props.replay_window = orig->props.replay_window;
        x->props.reqid = orig->props.reqid;
        x->props.family = orig->props.family;
        x->props.saddr = orig->props.saddr;

        if (orig->aalg) {
                x->aalg = xfrm_algo_auth_clone(orig->aalg);
                if (!x->aalg)
                        goto error;
        }
        x->props.aalgo = orig->props.aalgo;

        if (orig->aead) {
                x->aead = xfrm_algo_aead_clone(orig->aead);
                x->geniv = orig->geniv;
                if (!x->aead)
                        goto error;
        }
        if (orig->ealg) {
                x->ealg = xfrm_algo_clone(orig->ealg);
                if (!x->ealg)
                        goto error;
        }
        x->props.ealgo = orig->props.ealgo;

        if (orig->calg) {
                x->calg = xfrm_algo_clone(orig->calg);
                if (!x->calg)
                        goto error;
        }
        x->props.calgo = orig->props.calgo;

        if (encap || orig->encap) {
                if (encap)
                        x->encap = kmemdup(encap, sizeof(*x->encap),
                                        GFP_KERNEL);
                else
                        x->encap = kmemdup(orig->encap, sizeof(*x->encap),
                                        GFP_KERNEL);

                if (!x->encap)
                        goto error;
        }

        if (orig->security)
                if (clone_security(x, orig->security))
                        goto error;

        if (orig->coaddr) {
                x->coaddr = kmemdup(orig->coaddr, sizeof(*x->coaddr),
                                    GFP_KERNEL);
                if (!x->coaddr)
                        goto error;
        }

        if (orig->replay_esn) {
                if (xfrm_replay_clone(x, orig))
                        goto error;
        }

        memcpy(&x->mark, &orig->mark, sizeof(x->mark));
        memcpy(&x->props.smark, &orig->props.smark, sizeof(x->props.smark));

        if (xfrm_init_state(x) < 0)
                goto error;

        x->props.flags = orig->props.flags;
        x->props.extra_flags = orig->props.extra_flags;

        x->if_id = orig->if_id;
        x->tfcpad = orig->tfcpad;
        x->replay_maxdiff = orig->replay_maxdiff;
        x->replay_maxage = orig->replay_maxage;
        memcpy(&x->curlft, &orig->curlft, sizeof(x->curlft));
        x->km.state = orig->km.state;
        x->km.seq = orig->km.seq;
        x->replay = orig->replay;
        x->preplay = orig->preplay;

        return x;

 error:
        xfrm_state_put(x);
out:
        return NULL;
}

struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *net)
{
        unsigned int h;
        struct xfrm_state *x = NULL;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);

        if (m->reqid) {
                h = xfrm_dst_hash(net, &m->old_daddr, &m->old_saddr,
                                  m->reqid, m->old_family);
                hlist_for_each_entry(x, net->xfrm.state_bydst+h, bydst) {
                        if (x->props.mode != m->mode ||
                            x->id.proto != m->proto)
                                continue;
                        if (m->reqid && x->props.reqid != m->reqid)
                                continue;
                        if (!xfrm_addr_equal(&x->id.daddr, &m->old_daddr,
                                             m->old_family) ||
                            !xfrm_addr_equal(&x->props.saddr, &m->old_saddr,
                                             m->old_family))
                                continue;
                        xfrm_state_hold(x);
                        break;
                }
        } else {
                h = xfrm_src_hash(net, &m->old_daddr, &m->old_saddr,
                                  m->old_family);
                hlist_for_each_entry(x, net->xfrm.state_bysrc+h, bysrc) {
                        if (x->props.mode != m->mode ||
                            x->id.proto != m->proto)
                                continue;
                        if (!xfrm_addr_equal(&x->id.daddr, &m->old_daddr,
                                             m->old_family) ||
                            !xfrm_addr_equal(&x->props.saddr, &m->old_saddr,
                                             m->old_family))
                                continue;
                        xfrm_state_hold(x);
                        break;
                }
        }

        spin_unlock_bh(&net->xfrm.xfrm_state_lock);

        return x;
}
EXPORT_SYMBOL(xfrm_migrate_state_find);

struct xfrm_state *xfrm_state_migrate(struct xfrm_state *x,
                                      struct xfrm_migrate *m,
                                      struct xfrm_encap_tmpl *encap)
{
        struct xfrm_state *xc;

        xc = xfrm_state_clone(x, encap);
        if (!xc)
                return NULL;

        memcpy(&xc->id.daddr, &m->new_daddr, sizeof(xc->id.daddr));
        memcpy(&xc->props.saddr, &m->new_saddr, sizeof(xc->props.saddr));

        /* add state */
        if (xfrm_addr_equal(&x->id.daddr, &m->new_daddr, m->new_family)) {
                /* a care is needed when the destination address of the
                   state is to be updated as it is a part of triplet */
                xfrm_state_insert(xc);
        } else {
                if (xfrm_state_add(xc) < 0)
                        goto error;
        }

        return xc;
error:
        xfrm_state_put(xc);
        return NULL;
}
EXPORT_SYMBOL(xfrm_state_migrate);
#endif

int xfrm_state_update(struct xfrm_state *x)
{
        struct xfrm_state *x1, *to_put;
        int err;
        int use_spi = xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY);
        struct net *net = xs_net(x);

        to_put = NULL;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        x1 = __xfrm_state_locate(x, use_spi, x->props.family);

        err = -ESRCH;
        if (!x1)
                goto out;

        if (xfrm_state_kern(x1)) {
                to_put = x1;
                err = -EEXIST;
                goto out;
        }

        if (x1->km.state == XFRM_STATE_ACQ) {
                __xfrm_state_insert(x);
                x = NULL;
        }
        err = 0;

out:
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);

        if (to_put)
                xfrm_state_put(to_put);

        if (err)
                return err;

        if (!x) {
                xfrm_state_delete(x1);
                xfrm_state_put(x1);
                return 0;
        }

        err = -EINVAL;
        spin_lock_bh(&x1->lock);
        if (likely(x1->km.state == XFRM_STATE_VALID)) {
                if (x->encap && x1->encap &&
                    x->encap->encap_type == x1->encap->encap_type)
                        memcpy(x1->encap, x->encap, sizeof(*x1->encap));
                else if (x->encap || x1->encap)
                        goto fail;

                if (x->coaddr && x1->coaddr) {
                        memcpy(x1->coaddr, x->coaddr, sizeof(*x1->coaddr));
                }
                if (!use_spi && memcmp(&x1->sel, &x->sel, sizeof(x1->sel)))
                        memcpy(&x1->sel, &x->sel, sizeof(x1->sel));
                memcpy(&x1->lft, &x->lft, sizeof(x1->lft));
                x1->km.dying = 0;

                hrtimer_start(&x1->mtimer, ktime_set(1, 0),
                              HRTIMER_MODE_REL_SOFT);
                if (x1->curlft.use_time)
                        xfrm_state_check_expire(x1);

                if (x->props.smark.m || x->props.smark.v || x->if_id) {
                        spin_lock_bh(&net->xfrm.xfrm_state_lock);

                        if (x->props.smark.m || x->props.smark.v)
                                x1->props.smark = x->props.smark;

                        if (x->if_id)
                                x1->if_id = x->if_id;

                        __xfrm_state_bump_genids(x1);
                        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
                }

                err = 0;
                x->km.state = XFRM_STATE_DEAD;
                __xfrm_state_put(x);
        }

fail:
        spin_unlock_bh(&x1->lock);

        xfrm_state_put(x1);

        return err;
}
EXPORT_SYMBOL(xfrm_state_update);

int xfrm_state_check_expire(struct xfrm_state *x)
{
        if (!x->curlft.use_time)
                x->curlft.use_time = ktime_get_real_seconds();

        if (x->curlft.bytes >= x->lft.hard_byte_limit ||
            x->curlft.packets >= x->lft.hard_packet_limit) {
                x->km.state = XFRM_STATE_EXPIRED;
                hrtimer_start(&x->mtimer, 0, HRTIMER_MODE_REL_SOFT);
                return -EINVAL;
        }

        if (!x->km.dying &&
            (x->curlft.bytes >= x->lft.soft_byte_limit ||
             x->curlft.packets >= x->lft.soft_packet_limit)) {
                x->km.dying = 1;
                km_state_expired(x, 0, 0);
        }
        return 0;
}
EXPORT_SYMBOL(xfrm_state_check_expire);

struct xfrm_state *
xfrm_state_lookup(struct net *net, u32 mark, const xfrm_address_t *daddr, __be32 spi,
                  u8 proto, unsigned short family)
{
        struct xfrm_state *x;

        rcu_read_lock();
        x = __xfrm_state_lookup(net, mark, daddr, spi, proto, family);
        rcu_read_unlock();
        return x;
}
EXPORT_SYMBOL(xfrm_state_lookup);

struct xfrm_state *
xfrm_state_lookup_byaddr(struct net *net, u32 mark,
                         const xfrm_address_t *daddr, const xfrm_address_t *saddr,
                         u8 proto, unsigned short family)
{
        struct xfrm_state *x;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        x = __xfrm_state_lookup_byaddr(net, mark, daddr, saddr, proto, family);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
        return x;
}
EXPORT_SYMBOL(xfrm_state_lookup_byaddr);

struct xfrm_state *
xfrm_find_acq(struct net *net, const struct xfrm_mark *mark, u8 mode, u32 reqid,
              u32 if_id, u8 proto, const xfrm_address_t *daddr,
              const xfrm_address_t *saddr, int create, unsigned short family)
{
        struct xfrm_state *x;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        x = __find_acq_core(net, mark, family, mode, reqid, if_id, proto, daddr, saddr, create);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);

        return x;
}
EXPORT_SYMBOL(xfrm_find_acq);

#ifdef CONFIG_XFRM_SUB_POLICY
#if IS_ENABLED(CONFIG_IPV6)
/* distribution counting sort function for xfrm_state and xfrm_tmpl */
static void
__xfrm6_sort(void **dst, void **src, int n,
             int (*cmp)(const void *p), int maxclass)
{
        int count[XFRM_MAX_DEPTH] = { };
        int class[XFRM_MAX_DEPTH];
        int i;

        for (i = 0; i < n; i++) {
                int c = cmp(src[i]);

                class[i] = c;
                count[c]++;
        }

        for (i = 2; i < maxclass; i++)
                count[i] += count[i - 1];

        for (i = 0; i < n; i++) {
                dst[count[class[i] - 1]++] = src[i];
                src[i] = NULL;
        }
}

/* Rule for xfrm_state:
 *
 * rule 1: select IPsec transport except AH
 * rule 2: select MIPv6 RO or inbound trigger
 * rule 3: select IPsec transport AH
 * rule 4: select IPsec tunnel
 * rule 5: others
 */
static int __xfrm6_state_sort_cmp(const void *p)
{
        const struct xfrm_state *v = p;

        switch (v->props.mode) {
        case XFRM_MODE_TRANSPORT:
                if (v->id.proto != IPPROTO_AH)
                        return 1;
                else
                        return 3;
#if IS_ENABLED(CONFIG_IPV6_MIP6)
        case XFRM_MODE_ROUTEOPTIMIZATION:
        case XFRM_MODE_IN_TRIGGER:
                return 2;
#endif
        case XFRM_MODE_TUNNEL:
        case XFRM_MODE_BEET:
                return 4;
        }
        return 5;
}

/* Rule for xfrm_tmpl:
 *
 * rule 1: select IPsec transport
 * rule 2: select MIPv6 RO or inbound trigger
 * rule 3: select IPsec tunnel
 * rule 4: others
 */
static int __xfrm6_tmpl_sort_cmp(const void *p)
{
        const struct xfrm_tmpl *v = p;

        switch (v->mode) {
        case XFRM_MODE_TRANSPORT:
                return 1;
#if IS_ENABLED(CONFIG_IPV6_MIP6)
        case XFRM_MODE_ROUTEOPTIMIZATION:
        case XFRM_MODE_IN_TRIGGER:
                return 2;
#endif
        case XFRM_MODE_TUNNEL:
        case XFRM_MODE_BEET:
                return 3;
        }
        return 4;
}
#else
static inline int __xfrm6_state_sort_cmp(const void *p) { return 5; }
static inline int __xfrm6_tmpl_sort_cmp(const void *p) { return 4; }

static inline void
__xfrm6_sort(void **dst, void **src, int n,
             int (*cmp)(const void *p), int maxclass)
{
        int i;

        for (i = 0; i < n; i++)
                dst[i] = src[i];
}
#endif /* CONFIG_IPV6 */

void
xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
               unsigned short family)
{
        int i;

        if (family == AF_INET6)
                __xfrm6_sort((void **)dst, (void **)src, n,
                             __xfrm6_tmpl_sort_cmp, 5);
        else
                for (i = 0; i < n; i++)
                        dst[i] = src[i];
}

void
xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
                unsigned short family)
{
        int i;

        if (family == AF_INET6)
                __xfrm6_sort((void **)dst, (void **)src, n,
                             __xfrm6_state_sort_cmp, 6);
        else
                for (i = 0; i < n; i++)
                        dst[i] = src[i];
}
#endif

/* Silly enough, but I'm lazy to build resolution list */

static struct xfrm_state *__xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq)
{
        unsigned int h = xfrm_seq_hash(net, seq);
        struct xfrm_state *x;

        hlist_for_each_entry_rcu(x, net->xfrm.state_byseq + h, byseq) {
                if (x->km.seq == seq &&
                    (mark & x->mark.m) == x->mark.v &&
                    x->km.state == XFRM_STATE_ACQ) {
                        xfrm_state_hold(x);
                        return x;
                }
        }

        return NULL;
}

struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq)
{
        struct xfrm_state *x;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        x = __xfrm_find_acq_byseq(net, mark, seq);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
        return x;
}
EXPORT_SYMBOL(xfrm_find_acq_byseq);

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

        do {

                res = atomic_inc_return(&acqseq);
        } while (!res);

        return res;
}
EXPORT_SYMBOL(xfrm_get_acqseq);

int verify_spi_info(u8 proto, u32 min, u32 max)
{
        switch (proto) {
        case IPPROTO_AH:
        case IPPROTO_ESP:
                break;

        case IPPROTO_COMP:
                /* IPCOMP spi is 16-bits. */
                if (max >= 0x10000)
                        return -EINVAL;
                break;

        default:
                return -EINVAL;
        }

        if (min > max)
                return -EINVAL;

        return 0;
}
EXPORT_SYMBOL(verify_spi_info);

int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
{
        struct net *net = xs_net(x);
        unsigned int h;
        struct xfrm_state *x0;
        int err = -ENOENT;
        __be32 minspi = htonl(low);
        __be32 maxspi = htonl(high);
        __be32 newspi = 0;
        u32 mark = x->mark.v & x->mark.m;

        spin_lock_bh(&x->lock);
        if (x->km.state == XFRM_STATE_DEAD)
                goto unlock;

        err = 0;
        if (x->id.spi)
                goto unlock;

        err = -ENOENT;

        if (minspi == maxspi) {
                x0 = xfrm_state_lookup(net, mark, &x->id.daddr, minspi, x->id.proto, x->props.family);
                if (x0) {
                        xfrm_state_put(x0);
                        goto unlock;
                }
                newspi = minspi;
        } else {
                u32 spi = 0;
                for (h = 0; h < high-low+1; h++) {
                        spi = low + prandom_u32()%(high-low+1);
                        x0 = xfrm_state_lookup(net, mark, &x->id.daddr, htonl(spi), x->id.proto, x->props.family);
                        if (x0 == NULL) {
                                newspi = htonl(spi);
                                break;
                        }
                        xfrm_state_put(x0);
                }
        }
        if (newspi) {
                spin_lock_bh(&net->xfrm.xfrm_state_lock);
                x->id.spi = newspi;
                h = xfrm_spi_hash(net, &x->id.daddr, x->id.spi, x->id.proto, x->props.family);
                hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
                spin_unlock_bh(&net->xfrm.xfrm_state_lock);

                err = 0;
        }

unlock:
        spin_unlock_bh(&x->lock);

        return err;
}
EXPORT_SYMBOL(xfrm_alloc_spi);

static bool __xfrm_state_filter_match(struct xfrm_state *x,
                                      struct xfrm_address_filter *filter)
{
        if (filter) {
                if ((filter->family == AF_INET ||
                     filter->family == AF_INET6) &&
                    x->props.family != filter->family)
                        return false;

                return addr_match(&x->props.saddr, &filter->saddr,
                                  filter->splen) &&
                       addr_match(&x->id.daddr, &filter->daddr,
                                  filter->dplen);
        }
        return true;
}

int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
                    int (*func)(struct xfrm_state *, int, void*),
                    void *data)
{
        struct xfrm_state *state;
        struct xfrm_state_walk *x;
        int err = 0;

        if (walk->seq != 0 && list_empty(&walk->all))
                return 0;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        if (list_empty(&walk->all))
                x = list_first_entry(&net->xfrm.state_all, struct xfrm_state_walk, all);
        else
                x = list_first_entry(&walk->all, struct xfrm_state_walk, all);
        list_for_each_entry_from(x, &net->xfrm.state_all, all) {
                if (x->state == XFRM_STATE_DEAD)
                        continue;
                state = container_of(x, struct xfrm_state, km);
                if (!xfrm_id_proto_match(state->id.proto, walk->proto))
                        continue;
                if (!__xfrm_state_filter_match(state, walk->filter))
                        continue;
                err = func(state, walk->seq, data);
                if (err) {
                        list_move_tail(&walk->all, &x->all);
                        goto out;
                }
                walk->seq++;
        }
        if (walk->seq == 0) {
                err = -ENOENT;
                goto out;
        }
        list_del_init(&walk->all);
out:
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
        return err;
}
EXPORT_SYMBOL(xfrm_state_walk);

void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto,
                          struct xfrm_address_filter *filter)
{
        INIT_LIST_HEAD(&walk->all);
        walk->proto = proto;
        walk->state = XFRM_STATE_DEAD;
        walk->seq = 0;
        walk->filter = filter;
}
EXPORT_SYMBOL(xfrm_state_walk_init);

void xfrm_state_walk_done(struct xfrm_state_walk *walk, struct net *net)
{
        kfree(walk->filter);

        if (list_empty(&walk->all))
                return;

        spin_lock_bh(&net->xfrm.xfrm_state_lock);
        list_del(&walk->all);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
}
EXPORT_SYMBOL(xfrm_state_walk_done);

static void xfrm_replay_timer_handler(struct timer_list *t)
{
        struct xfrm_state *x = from_timer(x, t, rtimer);

        spin_lock(&x->lock);

        if (x->km.state == XFRM_STATE_VALID) {
                if (xfrm_aevent_is_on(xs_net(x)))
                        xfrm_replay_notify(x, XFRM_REPLAY_TIMEOUT);
                else
                        x->xflags |= XFRM_TIME_DEFER;
        }

        spin_unlock(&x->lock);
}

static LIST_HEAD(xfrm_km_list);

void km_policy_notify(struct xfrm_policy *xp, int dir, const struct km_event *c)
{
        struct xfrm_mgr *km;

        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list)
                if (km->notify_policy)
                        km->notify_policy(xp, dir, c);
        rcu_read_unlock();
}

void km_state_notify(struct xfrm_state *x, const struct km_event *c)
{
        struct xfrm_mgr *km;
        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list)
                if (km->notify)
                        km->notify(x, c);
        rcu_read_unlock();
}

EXPORT_SYMBOL(km_policy_notify);
EXPORT_SYMBOL(km_state_notify);

void km_state_expired(struct xfrm_state *x, int hard, u32 portid)
{
        struct km_event c;

        c.data.hard = hard;
        c.portid = portid;
        c.event = XFRM_MSG_EXPIRE;
        km_state_notify(x, &c);
}

EXPORT_SYMBOL(km_state_expired);
/*
 * We send to all registered managers regardless of failure
 * We are happy with one success
*/
int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol)
{
        int err = -EINVAL, acqret;
        struct xfrm_mgr *km;

        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list) {
                acqret = km->acquire(x, t, pol);
                if (!acqret)
                        err = acqret;
        }
        rcu_read_unlock();
        return err;
}
EXPORT_SYMBOL(km_query);

int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport)
{
        int err = -EINVAL;
        struct xfrm_mgr *km;

        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list) {
                if (km->new_mapping)
                        err = km->new_mapping(x, ipaddr, sport);
                if (!err)
                        break;
        }
        rcu_read_unlock();
        return err;
}
EXPORT_SYMBOL(km_new_mapping);

void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 portid)
{
        struct km_event c;

        c.data.hard = hard;
        c.portid = portid;
        c.event = XFRM_MSG_POLEXPIRE;
        km_policy_notify(pol, dir, &c);
}
EXPORT_SYMBOL(km_policy_expired);

#ifdef CONFIG_XFRM_MIGRATE
int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
               const struct xfrm_migrate *m, int num_migrate,
               const struct xfrm_kmaddress *k,
               const struct xfrm_encap_tmpl *encap)
{
        int err = -EINVAL;
        int ret;
        struct xfrm_mgr *km;

        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list) {
                if (km->migrate) {
                        ret = km->migrate(sel, dir, type, m, num_migrate, k,
                                          encap);
                        if (!ret)
                                err = ret;
                }
        }
        rcu_read_unlock();
        return err;
}
EXPORT_SYMBOL(km_migrate);
#endif

int km_report(struct net *net, u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr)
{
        int err = -EINVAL;
        int ret;
        struct xfrm_mgr *km;

        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list) {
                if (km->report) {
                        ret = km->report(net, proto, sel, addr);
                        if (!ret)
                                err = ret;
                }
        }
        rcu_read_unlock();
        return err;
}
EXPORT_SYMBOL(km_report);

static bool km_is_alive(const struct km_event *c)
{
        struct xfrm_mgr *km;
        bool is_alive = false;

        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list) {
                if (km->is_alive && km->is_alive(c)) {
                        is_alive = true;
                        break;
                }
        }
        rcu_read_unlock();

        return is_alive;
}

#if IS_ENABLED(CONFIG_XFRM_USER_COMPAT)
static DEFINE_SPINLOCK(xfrm_translator_lock);
static struct xfrm_translator __rcu *xfrm_translator;

struct xfrm_translator *xfrm_get_translator(void)
{
        struct xfrm_translator *xtr;

        rcu_read_lock();
        xtr = rcu_dereference(xfrm_translator);
        if (unlikely(!xtr))
                goto out;
        if (!try_module_get(xtr->owner))
                xtr = NULL;
out:
        rcu_read_unlock();
        return xtr;
}
EXPORT_SYMBOL_GPL(xfrm_get_translator);

void xfrm_put_translator(struct xfrm_translator *xtr)
{
        module_put(xtr->owner);
}
EXPORT_SYMBOL_GPL(xfrm_put_translator);

int xfrm_register_translator(struct xfrm_translator *xtr)
{
        int err = 0;

        spin_lock_bh(&xfrm_translator_lock);
        if (unlikely(xfrm_translator != NULL))
                err = -EEXIST;
        else
                rcu_assign_pointer(xfrm_translator, xtr);
        spin_unlock_bh(&xfrm_translator_lock);

        return err;
}
EXPORT_SYMBOL_GPL(xfrm_register_translator);

int xfrm_unregister_translator(struct xfrm_translator *xtr)
{
        int err = 0;

        spin_lock_bh(&xfrm_translator_lock);
        if (likely(xfrm_translator != NULL)) {
                if (rcu_access_pointer(xfrm_translator) != xtr)
                        err = -EINVAL;
                else
                        RCU_INIT_POINTER(xfrm_translator, NULL);
        }
        spin_unlock_bh(&xfrm_translator_lock);
        synchronize_rcu();

        return err;
}
EXPORT_SYMBOL_GPL(xfrm_unregister_translator);
#endif

int xfrm_user_policy(struct sock *sk, int optname, sockptr_t optval, int optlen)
{
        int err;
        u8 *data;
        struct xfrm_mgr *km;
        struct xfrm_policy *pol = NULL;

        if (sockptr_is_null(optval) && !optlen) {
                xfrm_sk_policy_insert(sk, XFRM_POLICY_IN, NULL);
                xfrm_sk_policy_insert(sk, XFRM_POLICY_OUT, NULL);
                __sk_dst_reset(sk);
                return 0;
        }

        if (optlen <= 0 || optlen > PAGE_SIZE)
                return -EMSGSIZE;

        data = memdup_sockptr(optval, optlen);
        if (IS_ERR(data))
                return PTR_ERR(data);

        if (in_compat_syscall()) {
                struct xfrm_translator *xtr = xfrm_get_translator();

                if (!xtr) {
                        kfree(data);
                        return -EOPNOTSUPP;
                }

                err = xtr->xlate_user_policy_sockptr(&data, optlen);
                xfrm_put_translator(xtr);
                if (err) {
                        kfree(data);
                        return err;
                }
        }

        err = -EINVAL;
        rcu_read_lock();
        list_for_each_entry_rcu(km, &xfrm_km_list, list) {
                pol = km->compile_policy(sk, optname, data,
                                         optlen, &err);
                if (err >= 0)
                        break;
        }
        rcu_read_unlock();

        if (err >= 0) {
                xfrm_sk_policy_insert(sk, err, pol);
                xfrm_pol_put(pol);
                __sk_dst_reset(sk);
                err = 0;
        }

        kfree(data);
        return err;
}
EXPORT_SYMBOL(xfrm_user_policy);

static DEFINE_SPINLOCK(xfrm_km_lock);

int xfrm_register_km(struct xfrm_mgr *km)
{
        spin_lock_bh(&xfrm_km_lock);
        list_add_tail_rcu(&km->list, &xfrm_km_list);
        spin_unlock_bh(&xfrm_km_lock);
        return 0;
}
EXPORT_SYMBOL(xfrm_register_km);

int xfrm_unregister_km(struct xfrm_mgr *km)
{
        spin_lock_bh(&xfrm_km_lock);
        list_del_rcu(&km->list);
        spin_unlock_bh(&xfrm_km_lock);
        synchronize_rcu();
        return 0;
}
EXPORT_SYMBOL(xfrm_unregister_km);

int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo)
{
        int err = 0;

        if (WARN_ON(afinfo->family >= NPROTO))
                return -EAFNOSUPPORT;

        spin_lock_bh(&xfrm_state_afinfo_lock);
        if (unlikely(xfrm_state_afinfo[afinfo->family] != NULL))
                err = -EEXIST;
        else
                rcu_assign_pointer(xfrm_state_afinfo[afinfo->family], afinfo);
        spin_unlock_bh(&xfrm_state_afinfo_lock);
        return err;
}
EXPORT_SYMBOL(xfrm_state_register_afinfo);

int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo)
{
        int err = 0, family = afinfo->family;

        if (WARN_ON(family >= NPROTO))
                return -EAFNOSUPPORT;

        spin_lock_bh(&xfrm_state_afinfo_lock);
        if (likely(xfrm_state_afinfo[afinfo->family] != NULL)) {
                if (rcu_access_pointer(xfrm_state_afinfo[family]) != afinfo)
                        err = -EINVAL;
                else
                        RCU_INIT_POINTER(xfrm_state_afinfo[afinfo->family], NULL);
        }
        spin_unlock_bh(&xfrm_state_afinfo_lock);
        synchronize_rcu();
        return err;
}
EXPORT_SYMBOL(xfrm_state_unregister_afinfo);

struct xfrm_state_afinfo *xfrm_state_afinfo_get_rcu(unsigned int family)
{
        if (unlikely(family >= NPROTO))
                return NULL;

        return rcu_dereference(xfrm_state_afinfo[family]);
}
EXPORT_SYMBOL_GPL(xfrm_state_afinfo_get_rcu);

struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family)
{
        struct xfrm_state_afinfo *afinfo;
        if (unlikely(family >= NPROTO))
                return NULL;
        rcu_read_lock();
        afinfo = rcu_dereference(xfrm_state_afinfo[family]);
        if (unlikely(!afinfo))
                rcu_read_unlock();
        return afinfo;
}

void xfrm_flush_gc(void)
{
        flush_work(&xfrm_state_gc_work);
}
EXPORT_SYMBOL(xfrm_flush_gc);

/* Temporarily located here until net/xfrm/xfrm_tunnel.c is created */
void xfrm_state_delete_tunnel(struct xfrm_state *x)
{
        if (x->tunnel) {
                struct xfrm_state *t = x->tunnel;

                if (atomic_read(&t->tunnel_users) == 2)
                        xfrm_state_delete(t);
                atomic_dec(&t->tunnel_users);
                xfrm_state_put_sync(t);
                x->tunnel = NULL;
        }
}
EXPORT_SYMBOL(xfrm_state_delete_tunnel);

u32 __xfrm_state_mtu(struct xfrm_state *x, int mtu)
{
        const struct xfrm_type *type = READ_ONCE(x->type);
        struct crypto_aead *aead;
        u32 blksize, net_adj = 0;

        if (x->km.state != XFRM_STATE_VALID ||
            !type || type->proto != IPPROTO_ESP)
                return mtu - x->props.header_len;

        aead = x->data;
        blksize = ALIGN(crypto_aead_blocksize(aead), 4);

        switch (x->props.mode) {
        case XFRM_MODE_TRANSPORT:
        case XFRM_MODE_BEET:
                if (x->props.family == AF_INET)
                        net_adj = sizeof(struct iphdr);
                else if (x->props.family == AF_INET6)
                        net_adj = sizeof(struct ipv6hdr);
                break;
        case XFRM_MODE_TUNNEL:
                break;
        default:
                WARN_ON_ONCE(1);
                break;
        }

        return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
                 net_adj) & ~(blksize - 1)) + net_adj - 2;
}
EXPORT_SYMBOL_GPL(__xfrm_state_mtu);

u32 xfrm_state_mtu(struct xfrm_state *x, int mtu)
{
        mtu = __xfrm_state_mtu(x, mtu);

        if (x->props.family == AF_INET6 && mtu < IPV6_MIN_MTU)
                return IPV6_MIN_MTU;

        return mtu;
}

int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
{
        const struct xfrm_mode *inner_mode;
        const struct xfrm_mode *outer_mode;
        int family = x->props.family;
        int err;

        if (family == AF_INET &&
            xs_net(x)->ipv4.sysctl_ip_no_pmtu_disc)
                x->props.flags |= XFRM_STATE_NOPMTUDISC;

        err = -EPROTONOSUPPORT;

        if (x->sel.family != AF_UNSPEC) {
                inner_mode = xfrm_get_mode(x->props.mode, x->sel.family);
                if (inner_mode == NULL)
                        goto error;

                if (!(inner_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
                    family != x->sel.family)
                        goto error;

                x->inner_mode = *inner_mode;
        } else {
                const struct xfrm_mode *inner_mode_iaf;
                int iafamily = AF_INET;

                inner_mode = xfrm_get_mode(x->props.mode, x->props.family);
                if (inner_mode == NULL)
                        goto error;

                if (!(inner_mode->flags & XFRM_MODE_FLAG_TUNNEL))
                        goto error;

                x->inner_mode = *inner_mode;

                if (x->props.family == AF_INET)
                        iafamily = AF_INET6;

                inner_mode_iaf = xfrm_get_mode(x->props.mode, iafamily);
                if (inner_mode_iaf) {
                        if (inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)
                                x->inner_mode_iaf = *inner_mode_iaf;
                }
        }

        x->type = xfrm_get_type(x->id.proto, family);
        if (x->type == NULL)
                goto error;

        x->type_offload = xfrm_get_type_offload(x->id.proto, family, offload);

        err = x->type->init_state(x);
        if (err)
                goto error;

        outer_mode = xfrm_get_mode(x->props.mode, family);
        if (!outer_mode) {
                err = -EPROTONOSUPPORT;
                goto error;
        }

        x->outer_mode = *outer_mode;
        if (init_replay) {
                err = xfrm_init_replay(x);
                if (err)
                        goto error;
        }

error:
        return err;
}

EXPORT_SYMBOL(__xfrm_init_state);

int xfrm_init_state(struct xfrm_state *x)
{
        int err;

        err = __xfrm_init_state(x, true, false);
        if (!err)
                x->km.state = XFRM_STATE_VALID;

        return err;
}

EXPORT_SYMBOL(xfrm_init_state);

int __net_init xfrm_state_init(struct net *net)
{
        unsigned int sz;

        if (net_eq(net, &init_net))
                xfrm_state_cache = KMEM_CACHE(xfrm_state,
                                              SLAB_HWCACHE_ALIGN | SLAB_PANIC);

        INIT_LIST_HEAD(&net->xfrm.state_all);

        sz = sizeof(struct hlist_head) * 8;

        net->xfrm.state_bydst = xfrm_hash_alloc(sz);
        if (!net->xfrm.state_bydst)
                goto out_bydst;
        net->xfrm.state_bysrc = xfrm_hash_alloc(sz);
        if (!net->xfrm.state_bysrc)
                goto out_bysrc;
        net->xfrm.state_byspi = xfrm_hash_alloc(sz);
        if (!net->xfrm.state_byspi)
                goto out_byspi;
        net->xfrm.state_byseq = xfrm_hash_alloc(sz);
        if (!net->xfrm.state_byseq)
                goto out_byseq;
        net->xfrm.state_hmask = ((sz / sizeof(struct hlist_head)) - 1);

        net->xfrm.state_num = 0;
        INIT_WORK(&net->xfrm.state_hash_work, xfrm_hash_resize);
        spin_lock_init(&net->xfrm.xfrm_state_lock);
        seqcount_spinlock_init(&net->xfrm.xfrm_state_hash_generation,
                               &net->xfrm.xfrm_state_lock);
        return 0;

out_byseq:
        xfrm_hash_free(net->xfrm.state_byspi, sz);
out_byspi:
        xfrm_hash_free(net->xfrm.state_bysrc, sz);
out_bysrc:
        xfrm_hash_free(net->xfrm.state_bydst, sz);
out_bydst:
        return -ENOMEM;
}

void xfrm_state_fini(struct net *net)
{
        unsigned int sz;

        flush_work(&net->xfrm.state_hash_work);
        flush_work(&xfrm_state_gc_work);
        xfrm_state_flush(net, 0, false, true);

        WARN_ON(!list_empty(&net->xfrm.state_all));

        sz = (net->xfrm.state_hmask + 1) * sizeof(struct hlist_head);
        WARN_ON(!hlist_empty(net->xfrm.state_byseq));
        xfrm_hash_free(net->xfrm.state_byseq, sz);
        WARN_ON(!hlist_empty(net->xfrm.state_byspi));
        xfrm_hash_free(net->xfrm.state_byspi, sz);
        WARN_ON(!hlist_empty(net->xfrm.state_bysrc));
        xfrm_hash_free(net->xfrm.state_bysrc, sz);
        WARN_ON(!hlist_empty(net->xfrm.state_bydst));
        xfrm_hash_free(net->xfrm.state_bydst, sz);
}

#ifdef CONFIG_AUDITSYSCALL
static void xfrm_audit_helper_sainfo(struct xfrm_state *x,
                                     struct audit_buffer *audit_buf)
{
        struct xfrm_sec_ctx *ctx = x->security;
        u32 spi = ntohl(x->id.spi);

        if (ctx)
                audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
                                 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);

        switch (x->props.family) {
        case AF_INET:
                audit_log_format(audit_buf, " src=%pI4 dst=%pI4",
                                 &x->props.saddr.a4, &x->id.daddr.a4);
                break;
        case AF_INET6:
                audit_log_format(audit_buf, " src=%pI6 dst=%pI6",
                                 x->props.saddr.a6, x->id.daddr.a6);
                break;
        }

        audit_log_format(audit_buf, " spi=%u(0x%x)", spi, spi);
}

static void xfrm_audit_helper_pktinfo(struct sk_buff *skb, u16 family,
                                      struct audit_buffer *audit_buf)
{
        const struct iphdr *iph4;
        const struct ipv6hdr *iph6;

        switch (family) {
        case AF_INET:
                iph4 = ip_hdr(skb);
                audit_log_format(audit_buf, " src=%pI4 dst=%pI4",
                                 &iph4->saddr, &iph4->daddr);
                break;
        case AF_INET6:
                iph6 = ipv6_hdr(skb);
                audit_log_format(audit_buf,
                                 " src=%pI6 dst=%pI6 flowlbl=0x%x%02x%02x",
                                 &iph6->saddr, &iph6->daddr,
                                 iph6->flow_lbl[0] & 0x0f,
                                 iph6->flow_lbl[1],
                                 iph6->flow_lbl[2]);
                break;
        }
}

void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid)
{
        struct audit_buffer *audit_buf;

        audit_buf = xfrm_audit_start("SAD-add");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_usrinfo(task_valid, audit_buf);
        xfrm_audit_helper_sainfo(x, audit_buf);
        audit_log_format(audit_buf, " res=%u", result);
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_add);

void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid)
{
        struct audit_buffer *audit_buf;

        audit_buf = xfrm_audit_start("SAD-delete");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_usrinfo(task_valid, audit_buf);
        xfrm_audit_helper_sainfo(x, audit_buf);
        audit_log_format(audit_buf, " res=%u", result);
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_delete);

void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
                                      struct sk_buff *skb)
{
        struct audit_buffer *audit_buf;
        u32 spi;

        audit_buf = xfrm_audit_start("SA-replay-overflow");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
        /* don't record the sequence number because it's inherent in this kind
         * of audit message */
        spi = ntohl(x->id.spi);
        audit_log_format(audit_buf, " spi=%u(0x%x)", spi, spi);
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_replay_overflow);

void xfrm_audit_state_replay(struct xfrm_state *x,
                             struct sk_buff *skb, __be32 net_seq)
{
        struct audit_buffer *audit_buf;
        u32 spi;

        audit_buf = xfrm_audit_start("SA-replayed-pkt");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
        spi = ntohl(x->id.spi);
        audit_log_format(audit_buf, " spi=%u(0x%x) seqno=%u",
                         spi, spi, ntohl(net_seq));
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_replay);

void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family)
{
        struct audit_buffer *audit_buf;

        audit_buf = xfrm_audit_start("SA-notfound");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_pktinfo(skb, family, audit_buf);
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_notfound_simple);

void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
                               __be32 net_spi, __be32 net_seq)
{
        struct audit_buffer *audit_buf;
        u32 spi;

        audit_buf = xfrm_audit_start("SA-notfound");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_pktinfo(skb, family, audit_buf);
        spi = ntohl(net_spi);
        audit_log_format(audit_buf, " spi=%u(0x%x) seqno=%u",
                         spi, spi, ntohl(net_seq));
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_notfound);

void xfrm_audit_state_icvfail(struct xfrm_state *x,
                              struct sk_buff *skb, u8 proto)
{
        struct audit_buffer *audit_buf;
        __be32 net_spi;
        __be32 net_seq;

        audit_buf = xfrm_audit_start("SA-icv-failure");
        if (audit_buf == NULL)
                return;
        xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
        if (xfrm_parse_spi(skb, proto, &net_spi, &net_seq) == 0) {
                u32 spi = ntohl(net_spi);
                audit_log_format(audit_buf, " spi=%u(0x%x) seqno=%u",
                                 spi, spi, ntohl(net_seq));
        }
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_icvfail);
#endif /* CONFIG_AUDITSYSCALL */