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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [net/] [xfrm/] [xfrm_policy.c] - Blame information for rev 3

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/*
 * xfrm_policy.c
 *
 * Changes:
 *      Mitsuru KANDA @USAGI
 *      Kazunori MIYAZAWA @USAGI
 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 *              IPv6 support
 *      Kazunori MIYAZAWA @USAGI
 *      YOSHIFUJI Hideaki
 *              Split up af-specific portion
 *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
 *
 */
 
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/cache.h>
#include <net/xfrm.h>
#include <net/ip.h>
 
#include "xfrm_hash.h"
 
int sysctl_xfrm_larval_drop __read_mostly;
 
DEFINE_MUTEX(xfrm_cfg_mutex);
EXPORT_SYMBOL(xfrm_cfg_mutex);
 
static DEFINE_RWLOCK(xfrm_policy_lock);
 
unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];
EXPORT_SYMBOL(xfrm_policy_count);
 
static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
 
static struct kmem_cache *xfrm_dst_cache __read_mostly;
 
static struct work_struct xfrm_policy_gc_work;
static HLIST_HEAD(xfrm_policy_gc_list);
static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
 
static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
 
static inline int
__xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
{
        return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
                addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
                !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
                !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
                (fl->proto == sel->proto || !sel->proto) &&
                (fl->oif == sel->ifindex || !sel->ifindex);
}
 
static inline int
__xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
{
        return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
                addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
                !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
                !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
                (fl->proto == sel->proto || !sel->proto) &&
                (fl->oif == sel->ifindex || !sel->ifindex);
}
 
int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
                    unsigned short family)
{
        switch (family) {
        case AF_INET:
                return __xfrm4_selector_match(sel, fl);
        case AF_INET6:
                return __xfrm6_selector_match(sel, fl);
        }
        return 0;
}
 
int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
                    unsigned short family)
{
        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
        int err = 0;
 
        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;
 
        if (likely(afinfo->dst_lookup != NULL))
                err = afinfo->dst_lookup(dst, fl);
        else
                err = -EINVAL;
        xfrm_policy_put_afinfo(afinfo);
        return err;
}
EXPORT_SYMBOL(xfrm_dst_lookup);
 
static inline unsigned long make_jiffies(long secs)
{
        if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
                return MAX_SCHEDULE_TIMEOUT-1;
        else
                return secs*HZ;
}
 
static void xfrm_policy_timer(unsigned long data)
{
        struct xfrm_policy *xp = (struct xfrm_policy*)data;
        unsigned long now = get_seconds();
        long next = LONG_MAX;
        int warn = 0;
        int dir;
 
        read_lock(&xp->lock);
 
        if (xp->dead)
                goto out;
 
        dir = xfrm_policy_id2dir(xp->index);
 
        if (xp->lft.hard_add_expires_seconds) {
                long tmo = xp->lft.hard_add_expires_seconds +
                        xp->curlft.add_time - now;
                if (tmo <= 0)
                        goto expired;
                if (tmo < next)
                        next = tmo;
        }
        if (xp->lft.hard_use_expires_seconds) {
                long tmo = xp->lft.hard_use_expires_seconds +
                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
                if (tmo <= 0)
                        goto expired;
                if (tmo < next)
                        next = tmo;
        }
        if (xp->lft.soft_add_expires_seconds) {
                long tmo = xp->lft.soft_add_expires_seconds +
                        xp->curlft.add_time - now;
                if (tmo <= 0) {
                        warn = 1;
                        tmo = XFRM_KM_TIMEOUT;
                }
                if (tmo < next)
                        next = tmo;
        }
        if (xp->lft.soft_use_expires_seconds) {
                long tmo = xp->lft.soft_use_expires_seconds +
                        (xp->curlft.use_time ? : xp->curlft.add_time) - now;
                if (tmo <= 0) {
                        warn = 1;
                        tmo = XFRM_KM_TIMEOUT;
                }
                if (tmo < next)
                        next = tmo;
        }
 
        if (warn)
                km_policy_expired(xp, dir, 0, 0);
        if (next != LONG_MAX &&
            !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
                xfrm_pol_hold(xp);
 
out:
        read_unlock(&xp->lock);
        xfrm_pol_put(xp);
        return;
 
expired:
        read_unlock(&xp->lock);
        if (!xfrm_policy_delete(xp, dir))
                km_policy_expired(xp, dir, 1, 0);
        xfrm_pol_put(xp);
}
 
 
/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 * SPD calls.
 */
 
struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
{
        struct xfrm_policy *policy;
 
        policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 
        if (policy) {
                INIT_HLIST_NODE(&policy->bydst);
                INIT_HLIST_NODE(&policy->byidx);
                rwlock_init(&policy->lock);
                atomic_set(&policy->refcnt, 1);
                init_timer(&policy->timer);
                policy->timer.data = (unsigned long)policy;
                policy->timer.function = xfrm_policy_timer;
        }
        return policy;
}
EXPORT_SYMBOL(xfrm_policy_alloc);
 
/* Destroy xfrm_policy: descendant resources must be released to this moment. */
 
void __xfrm_policy_destroy(struct xfrm_policy *policy)
{
        BUG_ON(!policy->dead);
 
        BUG_ON(policy->bundles);
 
        if (del_timer(&policy->timer))
                BUG();
 
        security_xfrm_policy_free(policy);
        kfree(policy);
}
EXPORT_SYMBOL(__xfrm_policy_destroy);
 
static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
{
        struct dst_entry *dst;
 
        while ((dst = policy->bundles) != NULL) {
                policy->bundles = dst->next;
                dst_free(dst);
        }
 
        if (del_timer(&policy->timer))
                atomic_dec(&policy->refcnt);
 
        if (atomic_read(&policy->refcnt) > 1)
                flow_cache_flush();
 
        xfrm_pol_put(policy);
}
 
static void xfrm_policy_gc_task(struct work_struct *work)
{
        struct xfrm_policy *policy;
        struct hlist_node *entry, *tmp;
        struct hlist_head gc_list;
 
        spin_lock_bh(&xfrm_policy_gc_lock);
        gc_list.first = xfrm_policy_gc_list.first;
        INIT_HLIST_HEAD(&xfrm_policy_gc_list);
        spin_unlock_bh(&xfrm_policy_gc_lock);
 
        hlist_for_each_entry_safe(policy, entry, tmp, &gc_list, bydst)
                xfrm_policy_gc_kill(policy);
}
 
/* Rule must be locked. Release descentant resources, announce
 * entry dead. The rule must be unlinked from lists to the moment.
 */
 
static void xfrm_policy_kill(struct xfrm_policy *policy)
{
        int dead;
 
        write_lock_bh(&policy->lock);
        dead = policy->dead;
        policy->dead = 1;
        write_unlock_bh(&policy->lock);
 
        if (unlikely(dead)) {
                WARN_ON(1);
                return;
        }
 
        spin_lock(&xfrm_policy_gc_lock);
        hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
        spin_unlock(&xfrm_policy_gc_lock);
 
        schedule_work(&xfrm_policy_gc_work);
}
 
struct xfrm_policy_hash {
        struct hlist_head       *table;
        unsigned int            hmask;
};
 
static struct hlist_head xfrm_policy_inexact[XFRM_POLICY_MAX*2];
static struct xfrm_policy_hash xfrm_policy_bydst[XFRM_POLICY_MAX*2] __read_mostly;
static struct hlist_head *xfrm_policy_byidx __read_mostly;
static unsigned int xfrm_idx_hmask __read_mostly;
static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 
static inline unsigned int idx_hash(u32 index)
{
        return __idx_hash(index, xfrm_idx_hmask);
}
 
static struct hlist_head *policy_hash_bysel(struct xfrm_selector *sel, unsigned short family, int dir)
{
        unsigned int hmask = xfrm_policy_bydst[dir].hmask;
        unsigned int hash = __sel_hash(sel, family, hmask);
 
        return (hash == hmask + 1 ?
                &xfrm_policy_inexact[dir] :
                xfrm_policy_bydst[dir].table + hash);
}
 
static struct hlist_head *policy_hash_direct(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
{
        unsigned int hmask = xfrm_policy_bydst[dir].hmask;
        unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 
        return xfrm_policy_bydst[dir].table + hash;
}
 
static void xfrm_dst_hash_transfer(struct hlist_head *list,
                                   struct hlist_head *ndsttable,
                                   unsigned int nhashmask)
{
        struct hlist_node *entry, *tmp;
        struct xfrm_policy *pol;
 
        hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
                unsigned int h;
 
                h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
                                pol->family, nhashmask);
                hlist_add_head(&pol->bydst, ndsttable+h);
        }
}
 
static void xfrm_idx_hash_transfer(struct hlist_head *list,
                                   struct hlist_head *nidxtable,
                                   unsigned int nhashmask)
{
        struct hlist_node *entry, *tmp;
        struct xfrm_policy *pol;
 
        hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
                unsigned int h;
 
                h = __idx_hash(pol->index, nhashmask);
                hlist_add_head(&pol->byidx, nidxtable+h);
        }
}
 
static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
{
        return ((old_hmask + 1) << 1) - 1;
}
 
static void xfrm_bydst_resize(int dir)
{
        unsigned int hmask = xfrm_policy_bydst[dir].hmask;
        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
        struct hlist_head *odst = xfrm_policy_bydst[dir].table;
        struct hlist_head *ndst = xfrm_hash_alloc(nsize);
        int i;
 
        if (!ndst)
                return;
 
        write_lock_bh(&xfrm_policy_lock);
 
        for (i = hmask; i >= 0; i--)
                xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 
        xfrm_policy_bydst[dir].table = ndst;
        xfrm_policy_bydst[dir].hmask = nhashmask;
 
        write_unlock_bh(&xfrm_policy_lock);
 
        xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
}
 
static void xfrm_byidx_resize(int total)
{
        unsigned int hmask = xfrm_idx_hmask;
        unsigned int nhashmask = xfrm_new_hash_mask(hmask);
        unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
        struct hlist_head *oidx = xfrm_policy_byidx;
        struct hlist_head *nidx = xfrm_hash_alloc(nsize);
        int i;
 
        if (!nidx)
                return;
 
        write_lock_bh(&xfrm_policy_lock);
 
        for (i = hmask; i >= 0; i--)
                xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 
        xfrm_policy_byidx = nidx;
        xfrm_idx_hmask = nhashmask;
 
        write_unlock_bh(&xfrm_policy_lock);
 
        xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
}
 
static inline int xfrm_bydst_should_resize(int dir, int *total)
{
        unsigned int cnt = xfrm_policy_count[dir];
        unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 
        if (total)
                *total += cnt;
 
        if ((hmask + 1) < xfrm_policy_hashmax &&
            cnt > hmask)
                return 1;
 
        return 0;
}
 
static inline int xfrm_byidx_should_resize(int total)
{
        unsigned int hmask = xfrm_idx_hmask;
 
        if ((hmask + 1) < xfrm_policy_hashmax &&
            total > hmask)
                return 1;
 
        return 0;
}
 
void xfrm_spd_getinfo(struct xfrmk_spdinfo *si)
{
        read_lock_bh(&xfrm_policy_lock);
        si->incnt = xfrm_policy_count[XFRM_POLICY_IN];
        si->outcnt = xfrm_policy_count[XFRM_POLICY_OUT];
        si->fwdcnt = xfrm_policy_count[XFRM_POLICY_FWD];
        si->inscnt = xfrm_policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
        si->outscnt = xfrm_policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
        si->fwdscnt = xfrm_policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
        si->spdhcnt = xfrm_idx_hmask;
        si->spdhmcnt = xfrm_policy_hashmax;
        read_unlock_bh(&xfrm_policy_lock);
}
EXPORT_SYMBOL(xfrm_spd_getinfo);
 
static DEFINE_MUTEX(hash_resize_mutex);
static void xfrm_hash_resize(struct work_struct *__unused)
{
        int dir, total;
 
        mutex_lock(&hash_resize_mutex);
 
        total = 0;
        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
                if (xfrm_bydst_should_resize(dir, &total))
                        xfrm_bydst_resize(dir);
        }
        if (xfrm_byidx_should_resize(total))
                xfrm_byidx_resize(total);
 
        mutex_unlock(&hash_resize_mutex);
}
 
static DECLARE_WORK(xfrm_hash_work, xfrm_hash_resize);
 
/* Generate new index... KAME seems to generate them ordered by cost
 * of an absolute inpredictability of ordering of rules. This will not pass. */
static u32 xfrm_gen_index(u8 type, int dir)
{
        static u32 idx_generator;
 
        for (;;) {
                struct hlist_node *entry;
                struct hlist_head *list;
                struct xfrm_policy *p;
                u32 idx;
                int found;
 
                idx = (idx_generator | dir);
                idx_generator += 8;
                if (idx == 0)
                        idx = 8;
                list = xfrm_policy_byidx + idx_hash(idx);
                found = 0;
                hlist_for_each_entry(p, entry, list, byidx) {
                        if (p->index == idx) {
                                found = 1;
                                break;
                        }
                }
                if (!found)
                        return idx;
        }
}
 
static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
{
        u32 *p1 = (u32 *) s1;
        u32 *p2 = (u32 *) s2;
        int len = sizeof(struct xfrm_selector) / sizeof(u32);
        int i;
 
        for (i = 0; i < len; i++) {
                if (p1[i] != p2[i])
                        return 1;
        }
 
        return 0;
}
 
int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
{
        struct xfrm_policy *pol;
        struct xfrm_policy *delpol;
        struct hlist_head *chain;
        struct hlist_node *entry, *newpos;
        struct dst_entry *gc_list;
 
        write_lock_bh(&xfrm_policy_lock);
        chain = policy_hash_bysel(&policy->selector, policy->family, dir);
        delpol = NULL;
        newpos = NULL;
        hlist_for_each_entry(pol, entry, chain, bydst) {
                if (pol->type == policy->type &&
                    !selector_cmp(&pol->selector, &policy->selector) &&
                    xfrm_sec_ctx_match(pol->security, policy->security) &&
                    !WARN_ON(delpol)) {
                        if (excl) {
                                write_unlock_bh(&xfrm_policy_lock);
                                return -EEXIST;
                        }
                        delpol = pol;
                        if (policy->priority > pol->priority)
                                continue;
                } else if (policy->priority >= pol->priority) {
                        newpos = &pol->bydst;
                        continue;
                }
                if (delpol)
                        break;
        }
        if (newpos)
                hlist_add_after(newpos, &policy->bydst);
        else
                hlist_add_head(&policy->bydst, chain);
        xfrm_pol_hold(policy);
        xfrm_policy_count[dir]++;
        atomic_inc(&flow_cache_genid);
        if (delpol) {
                hlist_del(&delpol->bydst);
                hlist_del(&delpol->byidx);
                xfrm_policy_count[dir]--;
        }
        policy->index = delpol ? delpol->index : xfrm_gen_index(policy->type, dir);
        hlist_add_head(&policy->byidx, xfrm_policy_byidx+idx_hash(policy->index));
        policy->curlft.add_time = get_seconds();
        policy->curlft.use_time = 0;
        if (!mod_timer(&policy->timer, jiffies + HZ))
                xfrm_pol_hold(policy);
        write_unlock_bh(&xfrm_policy_lock);
 
        if (delpol)
                xfrm_policy_kill(delpol);
        else if (xfrm_bydst_should_resize(dir, NULL))
                schedule_work(&xfrm_hash_work);
 
        read_lock_bh(&xfrm_policy_lock);
        gc_list = NULL;
        entry = &policy->bydst;
        hlist_for_each_entry_continue(policy, entry, bydst) {
                struct dst_entry *dst;
 
                write_lock(&policy->lock);
                dst = policy->bundles;
                if (dst) {
                        struct dst_entry *tail = dst;
                        while (tail->next)
                                tail = tail->next;
                        tail->next = gc_list;
                        gc_list = dst;
 
                        policy->bundles = NULL;
                }
                write_unlock(&policy->lock);
        }
        read_unlock_bh(&xfrm_policy_lock);
 
        while (gc_list) {
                struct dst_entry *dst = gc_list;
 
                gc_list = dst->next;
                dst_free(dst);
        }
 
        return 0;
}
EXPORT_SYMBOL(xfrm_policy_insert);
 
struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
                                          struct xfrm_selector *sel,
                                          struct xfrm_sec_ctx *ctx, int delete,
                                          int *err)
{
        struct xfrm_policy *pol, *ret;
        struct hlist_head *chain;
        struct hlist_node *entry;
 
        *err = 0;
        write_lock_bh(&xfrm_policy_lock);
        chain = policy_hash_bysel(sel, sel->family, dir);
        ret = NULL;
        hlist_for_each_entry(pol, entry, chain, bydst) {
                if (pol->type == type &&
                    !selector_cmp(sel, &pol->selector) &&
                    xfrm_sec_ctx_match(ctx, pol->security)) {
                        xfrm_pol_hold(pol);
                        if (delete) {
                                *err = security_xfrm_policy_delete(pol);
                                if (*err) {
                                        write_unlock_bh(&xfrm_policy_lock);
                                        return pol;
                                }
                                hlist_del(&pol->bydst);
                                hlist_del(&pol->byidx);
                                xfrm_policy_count[dir]--;
                        }
                        ret = pol;
                        break;
                }
        }
        write_unlock_bh(&xfrm_policy_lock);
 
        if (ret && delete) {
                atomic_inc(&flow_cache_genid);
                xfrm_policy_kill(ret);
        }
        return ret;
}
EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 
struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete,
                                     int *err)
{
        struct xfrm_policy *pol, *ret;
        struct hlist_head *chain;
        struct hlist_node *entry;
 
        *err = -ENOENT;
        if (xfrm_policy_id2dir(id) != dir)
                return NULL;
 
        *err = 0;
        write_lock_bh(&xfrm_policy_lock);
        chain = xfrm_policy_byidx + idx_hash(id);
        ret = NULL;
        hlist_for_each_entry(pol, entry, chain, byidx) {
                if (pol->type == type && pol->index == id) {
                        xfrm_pol_hold(pol);
                        if (delete) {
                                *err = security_xfrm_policy_delete(pol);
                                if (*err) {
                                        write_unlock_bh(&xfrm_policy_lock);
                                        return pol;
                                }
                                hlist_del(&pol->bydst);
                                hlist_del(&pol->byidx);
                                xfrm_policy_count[dir]--;
                        }
                        ret = pol;
                        break;
                }
        }
        write_unlock_bh(&xfrm_policy_lock);
 
        if (ret && delete) {
                atomic_inc(&flow_cache_genid);
                xfrm_policy_kill(ret);
        }
        return ret;
}
EXPORT_SYMBOL(xfrm_policy_byid);
 
#ifdef CONFIG_SECURITY_NETWORK_XFRM
static inline int
xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
{
        int dir, err = 0;
 
        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
                struct xfrm_policy *pol;
                struct hlist_node *entry;
                int i;
 
                hlist_for_each_entry(pol, entry,
                                     &xfrm_policy_inexact[dir], bydst) {
                        if (pol->type != type)
                                continue;
                        err = security_xfrm_policy_delete(pol);
                        if (err) {
                                xfrm_audit_policy_delete(pol, 0,
                                                         audit_info->loginuid,
                                                         audit_info->secid);
                                return err;
                        }
                }
                for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
                        hlist_for_each_entry(pol, entry,
                                             xfrm_policy_bydst[dir].table + i,
                                             bydst) {
                                if (pol->type != type)
                                        continue;
                                err = security_xfrm_policy_delete(pol);
                                if (err) {
                                        xfrm_audit_policy_delete(pol, 0,
                                                        audit_info->loginuid,
                                                        audit_info->secid);
                                        return err;
                                }
                        }
                }
        }
        return err;
}
#else
static inline int
xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
{
        return 0;
}
#endif
 
int xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info)
{
        int dir, err = 0;
 
        write_lock_bh(&xfrm_policy_lock);
 
        err = xfrm_policy_flush_secctx_check(type, audit_info);
        if (err)
                goto out;
 
        for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
                struct xfrm_policy *pol;
                struct hlist_node *entry;
                int i, killed;
 
                killed = 0;
        again1:
                hlist_for_each_entry(pol, entry,
                                     &xfrm_policy_inexact[dir], bydst) {
                        if (pol->type != type)
                                continue;
                        hlist_del(&pol->bydst);
                        hlist_del(&pol->byidx);
                        write_unlock_bh(&xfrm_policy_lock);
 
                        xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
                                                 audit_info->secid);
 
                        xfrm_policy_kill(pol);
                        killed++;
 
                        write_lock_bh(&xfrm_policy_lock);
                        goto again1;
                }
 
                for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
        again2:
                        hlist_for_each_entry(pol, entry,
                                             xfrm_policy_bydst[dir].table + i,
                                             bydst) {
                                if (pol->type != type)
                                        continue;
                                hlist_del(&pol->bydst);
                                hlist_del(&pol->byidx);
                                write_unlock_bh(&xfrm_policy_lock);
 
                                xfrm_audit_policy_delete(pol, 1,
                                                         audit_info->loginuid,
                                                         audit_info->secid);
                                xfrm_policy_kill(pol);
                                killed++;
 
                                write_lock_bh(&xfrm_policy_lock);
                                goto again2;
                        }
                }
 
                xfrm_policy_count[dir] -= killed;
        }
        atomic_inc(&flow_cache_genid);
out:
        write_unlock_bh(&xfrm_policy_lock);
        return err;
}
EXPORT_SYMBOL(xfrm_policy_flush);
 
int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*),
                     void *data)
{
        struct xfrm_policy *pol, *last = NULL;
        struct hlist_node *entry;
        int dir, last_dir = 0, count, error;
 
        read_lock_bh(&xfrm_policy_lock);
        count = 0;
 
        for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
                struct hlist_head *table = xfrm_policy_bydst[dir].table;
                int i;
 
                hlist_for_each_entry(pol, entry,
                                     &xfrm_policy_inexact[dir], bydst) {
                        if (pol->type != type)
                                continue;
                        if (last) {
                                error = func(last, last_dir % XFRM_POLICY_MAX,
                                             count, data);
                                if (error)
                                        goto out;
                        }
                        last = pol;
                        last_dir = dir;
                        count++;
                }
                for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
                        hlist_for_each_entry(pol, entry, table + i, bydst) {
                                if (pol->type != type)
                                        continue;
                                if (last) {
                                        error = func(last, last_dir % XFRM_POLICY_MAX,
                                                     count, data);
                                        if (error)
                                                goto out;
                                }
                                last = pol;
                                last_dir = dir;
                                count++;
                        }
                }
        }
        if (count == 0) {
                error = -ENOENT;
                goto out;
        }
        error = func(last, last_dir % XFRM_POLICY_MAX, 0, data);
out:
        read_unlock_bh(&xfrm_policy_lock);
        return error;
}
EXPORT_SYMBOL(xfrm_policy_walk);
 
/*
 * Find policy to apply to this flow.
 *
 * Returns 0 if policy found, else an -errno.
 */
static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
                             u8 type, u16 family, int dir)
{
        struct xfrm_selector *sel = &pol->selector;
        int match, ret = -ESRCH;
 
        if (pol->family != family ||
            pol->type != type)
                return ret;
 
        match = xfrm_selector_match(sel, fl, family);
        if (match)
                ret = security_xfrm_policy_lookup(pol, fl->secid, dir);
 
        return ret;
}
 
static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
                                                     u16 family, u8 dir)
{
        int err;
        struct xfrm_policy *pol, *ret;
        xfrm_address_t *daddr, *saddr;
        struct hlist_node *entry;
        struct hlist_head *chain;
        u32 priority = ~0U;
 
        daddr = xfrm_flowi_daddr(fl, family);
        saddr = xfrm_flowi_saddr(fl, family);
        if (unlikely(!daddr || !saddr))
                return NULL;
 
        read_lock_bh(&xfrm_policy_lock);
        chain = policy_hash_direct(daddr, saddr, family, dir);
        ret = NULL;
        hlist_for_each_entry(pol, entry, chain, bydst) {
                err = xfrm_policy_match(pol, fl, type, family, dir);
                if (err) {
                        if (err == -ESRCH)
                                continue;
                        else {
                                ret = ERR_PTR(err);
                                goto fail;
                        }
                } else {
                        ret = pol;
                        priority = ret->priority;
                        break;
                }
        }
        chain = &xfrm_policy_inexact[dir];
        hlist_for_each_entry(pol, entry, chain, bydst) {
                err = xfrm_policy_match(pol, fl, type, family, dir);
                if (err) {
                        if (err == -ESRCH)
                                continue;
                        else {
                                ret = ERR_PTR(err);
                                goto fail;
                        }
                } else if (pol->priority < priority) {
                        ret = pol;
                        break;
                }
        }
        if (ret)
                xfrm_pol_hold(ret);
fail:
        read_unlock_bh(&xfrm_policy_lock);
 
        return ret;
}
 
static int xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
                               void **objp, atomic_t **obj_refp)
{
        struct xfrm_policy *pol;
        int err = 0;
 
#ifdef CONFIG_XFRM_SUB_POLICY
        pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
        if (IS_ERR(pol)) {
                err = PTR_ERR(pol);
                pol = NULL;
        }
        if (pol || err)
                goto end;
#endif
        pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
        if (IS_ERR(pol)) {
                err = PTR_ERR(pol);
                pol = NULL;
        }
#ifdef CONFIG_XFRM_SUB_POLICY
end:
#endif
        if ((*objp = (void *) pol) != NULL)
                *obj_refp = &pol->refcnt;
        return err;
}
 
static inline int policy_to_flow_dir(int dir)
{
        if (XFRM_POLICY_IN == FLOW_DIR_IN &&
            XFRM_POLICY_OUT == FLOW_DIR_OUT &&
            XFRM_POLICY_FWD == FLOW_DIR_FWD)
                return dir;
        switch (dir) {
        default:
        case XFRM_POLICY_IN:
                return FLOW_DIR_IN;
        case XFRM_POLICY_OUT:
                return FLOW_DIR_OUT;
        case XFRM_POLICY_FWD:
                return FLOW_DIR_FWD;
        }
}
 
static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
{
        struct xfrm_policy *pol;
 
        read_lock_bh(&xfrm_policy_lock);
        if ((pol = sk->sk_policy[dir]) != NULL) {
                int match = xfrm_selector_match(&pol->selector, fl,
                                                sk->sk_family);
                int err = 0;
 
                if (match) {
                        err = security_xfrm_policy_lookup(pol, fl->secid,
                                        policy_to_flow_dir(dir));
                        if (!err)
                                xfrm_pol_hold(pol);
                        else if (err == -ESRCH)
                                pol = NULL;
                        else
                                pol = ERR_PTR(err);
                } else
                        pol = NULL;
        }
        read_unlock_bh(&xfrm_policy_lock);
        return pol;
}
 
static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
{
        struct hlist_head *chain = policy_hash_bysel(&pol->selector,
                                                     pol->family, dir);
 
        hlist_add_head(&pol->bydst, chain);
        hlist_add_head(&pol->byidx, xfrm_policy_byidx+idx_hash(pol->index));
        xfrm_policy_count[dir]++;
        xfrm_pol_hold(pol);
 
        if (xfrm_bydst_should_resize(dir, NULL))
                schedule_work(&xfrm_hash_work);
}
 
static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
                                                int dir)
{
        if (hlist_unhashed(&pol->bydst))
                return NULL;
 
        hlist_del(&pol->bydst);
        hlist_del(&pol->byidx);
        xfrm_policy_count[dir]--;
 
        return pol;
}
 
int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
{
        write_lock_bh(&xfrm_policy_lock);
        pol = __xfrm_policy_unlink(pol, dir);
        write_unlock_bh(&xfrm_policy_lock);
        if (pol) {
                if (dir < XFRM_POLICY_MAX)
                        atomic_inc(&flow_cache_genid);
                xfrm_policy_kill(pol);
                return 0;
        }
        return -ENOENT;
}
EXPORT_SYMBOL(xfrm_policy_delete);
 
int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
{
        struct xfrm_policy *old_pol;
 
#ifdef CONFIG_XFRM_SUB_POLICY
        if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
                return -EINVAL;
#endif
 
        write_lock_bh(&xfrm_policy_lock);
        old_pol = sk->sk_policy[dir];
        sk->sk_policy[dir] = pol;
        if (pol) {
                pol->curlft.add_time = get_seconds();
                pol->index = xfrm_gen_index(pol->type, XFRM_POLICY_MAX+dir);
                __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
        }
        if (old_pol)
                __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
        write_unlock_bh(&xfrm_policy_lock);
 
        if (old_pol) {
                xfrm_policy_kill(old_pol);
        }
        return 0;
}
 
static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
{
        struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
 
        if (newp) {
                newp->selector = old->selector;
                if (security_xfrm_policy_clone(old, newp)) {
                        kfree(newp);
                        return NULL;  /* ENOMEM */
                }
                newp->lft = old->lft;
                newp->curlft = old->curlft;
                newp->action = old->action;
                newp->flags = old->flags;
                newp->xfrm_nr = old->xfrm_nr;
                newp->index = old->index;
                newp->type = old->type;
                memcpy(newp->xfrm_vec, old->xfrm_vec,
                       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
                write_lock_bh(&xfrm_policy_lock);
                __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
                write_unlock_bh(&xfrm_policy_lock);
                xfrm_pol_put(newp);
        }
        return newp;
}
 
int __xfrm_sk_clone_policy(struct sock *sk)
{
        struct xfrm_policy *p0 = sk->sk_policy[0],
                           *p1 = sk->sk_policy[1];
 
        sk->sk_policy[0] = sk->sk_policy[1] = NULL;
        if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
                return -ENOMEM;
        if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
                return -ENOMEM;
        return 0;
}
 
static int
xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
               unsigned short family)
{
        int err;
        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 
        if (unlikely(afinfo == NULL))
                return -EINVAL;
        err = afinfo->get_saddr(local, remote);
        xfrm_policy_put_afinfo(afinfo);
        return err;
}
 
/* Resolve list of templates for the flow, given policy. */
 
static int
xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
                      struct xfrm_state **xfrm,
                      unsigned short family)
{
        int nx;
        int i, error;
        xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
        xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
        xfrm_address_t tmp;
 
        for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
                struct xfrm_state *x;
                xfrm_address_t *remote = daddr;
                xfrm_address_t *local  = saddr;
                struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
 
                if (tmpl->mode == XFRM_MODE_TUNNEL ||
                    tmpl->mode == XFRM_MODE_BEET) {
                        remote = &tmpl->id.daddr;
                        local = &tmpl->saddr;
                        family = tmpl->encap_family;
                        if (xfrm_addr_any(local, family)) {
                                error = xfrm_get_saddr(&tmp, remote, family);
                                if (error)
                                        goto fail;
                                local = &tmp;
                        }
                }
 
                x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
 
                if (x && x->km.state == XFRM_STATE_VALID) {
                        xfrm[nx++] = x;
                        daddr = remote;
                        saddr = local;
                        continue;
                }
                if (x) {
                        error = (x->km.state == XFRM_STATE_ERROR ?
                                 -EINVAL : -EAGAIN);
                        xfrm_state_put(x);
                }
 
                if (!tmpl->optional)
                        goto fail;
        }
        return nx;
 
fail:
        for (nx--; nx>=0; nx--)
                xfrm_state_put(xfrm[nx]);
        return error;
}
 
static int
xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
                  struct xfrm_state **xfrm,
                  unsigned short family)
{
        struct xfrm_state *tp[XFRM_MAX_DEPTH];
        struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
        int cnx = 0;
        int error;
        int ret;
        int i;
 
        for (i = 0; i < npols; i++) {
                if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
                        error = -ENOBUFS;
                        goto fail;
                }
 
                ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
                if (ret < 0) {
                        error = ret;
                        goto fail;
                } else
                        cnx += ret;
        }
 
        /* found states are sorted for outbound processing */
        if (npols > 1)
                xfrm_state_sort(xfrm, tpp, cnx, family);
 
        return cnx;
 
 fail:
        for (cnx--; cnx>=0; cnx--)
                xfrm_state_put(tpp[cnx]);
        return error;
 
}
 
/* Check that the bundle accepts the flow and its components are
 * still valid.
 */
 
static struct dst_entry *
xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
{
        struct dst_entry *x;
        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return ERR_PTR(-EINVAL);
        x = afinfo->find_bundle(fl, policy);
        xfrm_policy_put_afinfo(afinfo);
        return x;
}
 
/* Allocate chain of dst_entry's, attach known xfrm's, calculate
 * all the metrics... Shortly, bundle a bundle.
 */
 
static int
xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
                   struct flowi *fl, struct dst_entry **dst_p,
                   unsigned short family)
{
        int err;
        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return -EINVAL;
        err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
        xfrm_policy_put_afinfo(afinfo);
        return err;
}
 
static int inline
xfrm_dst_alloc_copy(void **target, void *src, int size)
{
        if (!*target) {
                *target = kmalloc(size, GFP_ATOMIC);
                if (!*target)
                        return -ENOMEM;
        }
        memcpy(*target, src, size);
        return 0;
}
 
static int inline
xfrm_dst_update_parent(struct dst_entry *dst, struct xfrm_selector *sel)
{
#ifdef CONFIG_XFRM_SUB_POLICY
        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
        return xfrm_dst_alloc_copy((void **)&(xdst->partner),
                                   sel, sizeof(*sel));
#else
        return 0;
#endif
}
 
static int inline
xfrm_dst_update_origin(struct dst_entry *dst, struct flowi *fl)
{
#ifdef CONFIG_XFRM_SUB_POLICY
        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
        return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
#else
        return 0;
#endif
}
 
static int stale_bundle(struct dst_entry *dst);
 
/* Main function: finds/creates a bundle for given flow.
 *
 * At the moment we eat a raw IP route. Mostly to speed up lookups
 * on interfaces with disabled IPsec.
 */
int __xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
                  struct sock *sk, int flags)
{
        struct xfrm_policy *policy;
        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
        int npols;
        int pol_dead;
        int xfrm_nr;
        int pi;
        struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
        struct dst_entry *dst, *dst_orig = *dst_p;
        int nx = 0;
        int err;
        u32 genid;
        u16 family;
        u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
 
restart:
        genid = atomic_read(&flow_cache_genid);
        policy = NULL;
        for (pi = 0; pi < ARRAY_SIZE(pols); pi++)
                pols[pi] = NULL;
        npols = 0;
        pol_dead = 0;
        xfrm_nr = 0;
 
        if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
                policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
                err = PTR_ERR(policy);
                if (IS_ERR(policy))
                        goto dropdst;
        }
 
        if (!policy) {
                /* To accelerate a bit...  */
                if ((dst_orig->flags & DST_NOXFRM) ||
                    !xfrm_policy_count[XFRM_POLICY_OUT])
                        return 0;
 
                policy = flow_cache_lookup(fl, dst_orig->ops->family,
                                           dir, xfrm_policy_lookup);
                err = PTR_ERR(policy);
                if (IS_ERR(policy))
                        goto dropdst;
        }
 
        if (!policy)
                return 0;
 
        family = dst_orig->ops->family;
        policy->curlft.use_time = get_seconds();
        pols[0] = policy;
        npols ++;
        xfrm_nr += pols[0]->xfrm_nr;
 
        switch (policy->action) {
        default:
        case XFRM_POLICY_BLOCK:
                /* Prohibit the flow */
                err = -EPERM;
                goto error;
 
        case XFRM_POLICY_ALLOW:
#ifndef CONFIG_XFRM_SUB_POLICY
                if (policy->xfrm_nr == 0) {
                        /* Flow passes not transformed. */
                        xfrm_pol_put(policy);
                        return 0;
                }
#endif
 
                /* Try to find matching bundle.
                 *
                 * LATER: help from flow cache. It is optional, this
                 * is required only for output policy.
                 */
                dst = xfrm_find_bundle(fl, policy, family);
                if (IS_ERR(dst)) {
                        err = PTR_ERR(dst);
                        goto error;
                }
 
                if (dst)
                        break;
 
#ifdef CONFIG_XFRM_SUB_POLICY
                if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
                        pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
                                                            fl, family,
                                                            XFRM_POLICY_OUT);
                        if (pols[1]) {
                                if (IS_ERR(pols[1])) {
                                        err = PTR_ERR(pols[1]);
                                        goto error;
                                }
                                if (pols[1]->action == XFRM_POLICY_BLOCK) {
                                        err = -EPERM;
                                        goto error;
                                }
                                npols ++;
                                xfrm_nr += pols[1]->xfrm_nr;
                        }
                }
 
                /*
                 * Because neither flowi nor bundle information knows about
                 * transformation template size. On more than one policy usage
                 * we can realize whether all of them is bypass or not after
                 * they are searched. See above not-transformed bypass
                 * is surrounded by non-sub policy configuration, too.
                 */
                if (xfrm_nr == 0) {
                        /* Flow passes not transformed. */
                        xfrm_pols_put(pols, npols);
                        return 0;
                }
 
#endif
                nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
 
                if (unlikely(nx<0)) {
                        err = nx;
                        if (err == -EAGAIN && sysctl_xfrm_larval_drop) {
                                /* EREMOTE tells the caller to generate
                                 * a one-shot blackhole route.
                                 */
                                xfrm_pol_put(policy);
                                return -EREMOTE;
                        }
                        if (err == -EAGAIN && flags) {
                                DECLARE_WAITQUEUE(wait, current);
 
                                add_wait_queue(&km_waitq, &wait);
                                set_current_state(TASK_INTERRUPTIBLE);
                                schedule();
                                set_current_state(TASK_RUNNING);
                                remove_wait_queue(&km_waitq, &wait);
 
                                nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
 
                                if (nx == -EAGAIN && signal_pending(current)) {
                                        err = -ERESTART;
                                        goto error;
                                }
                                if (nx == -EAGAIN ||
                                    genid != atomic_read(&flow_cache_genid)) {
                                        xfrm_pols_put(pols, npols);
                                        goto restart;
                                }
                                err = nx;
                        }
                        if (err < 0)
                                goto error;
                }
                if (nx == 0) {
                        /* Flow passes not transformed. */
                        xfrm_pols_put(pols, npols);
                        return 0;
                }
 
                dst = dst_orig;
                err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
 
                if (unlikely(err)) {
                        int i;
                        for (i=0; i<nx; i++)
                                xfrm_state_put(xfrm[i]);
                        goto error;
                }
 
                for (pi = 0; pi < npols; pi++) {
                        read_lock_bh(&pols[pi]->lock);
                        pol_dead |= pols[pi]->dead;
                        read_unlock_bh(&pols[pi]->lock);
                }
 
                write_lock_bh(&policy->lock);
                if (unlikely(pol_dead || stale_bundle(dst))) {
                        /* Wow! While we worked on resolving, this
                         * policy has gone. Retry. It is not paranoia,
                         * we just cannot enlist new bundle to dead object.
                         * We can't enlist stable bundles either.
                         */
                        write_unlock_bh(&policy->lock);
                        if (dst)
                                dst_free(dst);
 
                        err = -EHOSTUNREACH;
                        goto error;
                }
 
                if (npols > 1)
                        err = xfrm_dst_update_parent(dst, &pols[1]->selector);
                else
                        err = xfrm_dst_update_origin(dst, fl);
                if (unlikely(err)) {
                        write_unlock_bh(&policy->lock);
                        if (dst)
                                dst_free(dst);
                        goto error;
                }
 
                dst->next = policy->bundles;
                policy->bundles = dst;
                dst_hold(dst);
                write_unlock_bh(&policy->lock);
        }
        *dst_p = dst;
        dst_release(dst_orig);
        xfrm_pols_put(pols, npols);
        return 0;
 
error:
        xfrm_pols_put(pols, npols);
dropdst:
        dst_release(dst_orig);
        *dst_p = NULL;
        return err;
}
EXPORT_SYMBOL(__xfrm_lookup);
 
int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
                struct sock *sk, int flags)
{
        int err = __xfrm_lookup(dst_p, fl, sk, flags);
 
        if (err == -EREMOTE) {
                dst_release(*dst_p);
                *dst_p = NULL;
                err = -EAGAIN;
        }
 
        return err;
}
EXPORT_SYMBOL(xfrm_lookup);
 
static inline int
xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
{
        struct xfrm_state *x;
 
        if (!skb->sp || idx < 0 || idx >= skb->sp->len)
                return 0;
        x = skb->sp->xvec[idx];
        if (!x->type->reject)
                return 0;
        return x->type->reject(x, skb, fl);
}
 
/* When skb is transformed back to its "native" form, we have to
 * check policy restrictions. At the moment we make this in maximally
 * stupid way. Shame on me. :-) Of course, connected sockets must
 * have policy cached at them.
 */
 
static inline int
xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
              unsigned short family)
{
        if (xfrm_state_kern(x))
                return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
        return  x->id.proto == tmpl->id.proto &&
                (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
                (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
                x->props.mode == tmpl->mode &&
                ((tmpl->aalgos & (1<<x->props.aalgo)) ||
                 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
                !(x->props.mode != XFRM_MODE_TRANSPORT &&
                  xfrm_state_addr_cmp(tmpl, x, family));
}
 
/*
 * 0 or more than 0 is returned when validation is succeeded (either bypass
 * because of optional transport mode, or next index of the mathced secpath
 * state with the template.
 * -1 is returned when no matching template is found.
 * Otherwise "-2 - errored_index" is returned.
 */
static inline int
xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
               unsigned short family)
{
        int idx = start;
 
        if (tmpl->optional) {
                if (tmpl->mode == XFRM_MODE_TRANSPORT)
                        return start;
        } else
                start = -1;
        for (; idx < sp->len; idx++) {
                if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
                        return ++idx;
                if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
                        if (start == -1)
                                start = -2-idx;
                        break;
                }
        }
        return start;
}
 
int
xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
{
        struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
        int err;
 
        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;
 
        afinfo->decode_session(skb, fl);
        err = security_xfrm_decode_session(skb, &fl->secid);
        xfrm_policy_put_afinfo(afinfo);
        return err;
}
EXPORT_SYMBOL(xfrm_decode_session);
 
static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
{
        for (; k < sp->len; k++) {
                if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
                        *idxp = k;
                        return 1;
                }
        }
 
        return 0;
}
 
int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
                        unsigned short family)
{
        struct xfrm_policy *pol;
        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
        int npols = 0;
        int xfrm_nr;
        int pi;
        struct flowi fl;
        u8 fl_dir = policy_to_flow_dir(dir);
        int xerr_idx = -1;
 
        if (xfrm_decode_session(skb, &fl, family) < 0)
                return 0;
        nf_nat_decode_session(skb, &fl, family);
 
        /* First, check used SA against their selectors. */
        if (skb->sp) {
                int i;
 
                for (i=skb->sp->len-1; i>=0; i--) {
                        struct xfrm_state *x = skb->sp->xvec[i];
                        if (!xfrm_selector_match(&x->sel, &fl, family))
                                return 0;
                }
        }
 
        pol = NULL;
        if (sk && sk->sk_policy[dir]) {
                pol = xfrm_sk_policy_lookup(sk, dir, &fl);
                if (IS_ERR(pol))
                        return 0;
        }
 
        if (!pol)
                pol = flow_cache_lookup(&fl, family, fl_dir,
                                        xfrm_policy_lookup);
 
        if (IS_ERR(pol))
                return 0;
 
        if (!pol) {
                if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
                        xfrm_secpath_reject(xerr_idx, skb, &fl);
                        return 0;
                }
                return 1;
        }
 
        pol->curlft.use_time = get_seconds();
 
        pols[0] = pol;
        npols ++;
#ifdef CONFIG_XFRM_SUB_POLICY
        if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
                pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
                                                    &fl, family,
                                                    XFRM_POLICY_IN);
                if (pols[1]) {
                        if (IS_ERR(pols[1]))
                                return 0;
                        pols[1]->curlft.use_time = get_seconds();
                        npols ++;
                }
        }
#endif
 
        if (pol->action == XFRM_POLICY_ALLOW) {
                struct sec_path *sp;
                static struct sec_path dummy;
                struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
                struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
                struct xfrm_tmpl **tpp = tp;
                int ti = 0;
                int i, k;
 
                if ((sp = skb->sp) == NULL)
                        sp = &dummy;
 
                for (pi = 0; pi < npols; pi++) {
                        if (pols[pi] != pol &&
                            pols[pi]->action != XFRM_POLICY_ALLOW)
                                goto reject;
                        if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH)
                                goto reject_error;
                        for (i = 0; i < pols[pi]->xfrm_nr; i++)
                                tpp[ti++] = &pols[pi]->xfrm_vec[i];
                }
                xfrm_nr = ti;
                if (npols > 1) {
                        xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
                        tpp = stp;
                }
 
                /* For each tunnel xfrm, find the first matching tmpl.
                 * For each tmpl before that, find corresponding xfrm.
                 * Order is _important_. Later we will implement
                 * some barriers, but at the moment barriers
                 * are implied between each two transformations.
                 */
                for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
                        k = xfrm_policy_ok(tpp[i], sp, k, family);
                        if (k < 0) {
                                if (k < -1)
                                        /* "-2 - errored_index" returned */
                                        xerr_idx = -(2+k);
                                goto reject;
                        }
                }
 
                if (secpath_has_nontransport(sp, k, &xerr_idx))
                        goto reject;
 
                xfrm_pols_put(pols, npols);
                return 1;
        }
 
reject:
        xfrm_secpath_reject(xerr_idx, skb, &fl);
reject_error:
        xfrm_pols_put(pols, npols);
        return 0;
}
EXPORT_SYMBOL(__xfrm_policy_check);
 
int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
{
        struct flowi fl;
 
        if (xfrm_decode_session(skb, &fl, family) < 0)
                return 0;
 
        return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
}
EXPORT_SYMBOL(__xfrm_route_forward);
 
/* Optimize later using cookies and generation ids. */
 
static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
{
        /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
         * to "-1" to force all XFRM destinations to get validated by
         * dst_ops->check on every use.  We do this because when a
         * normal route referenced by an XFRM dst is obsoleted we do
         * not go looking around for all parent referencing XFRM dsts
         * so that we can invalidate them.  It is just too much work.
         * Instead we make the checks here on every use.  For example:
         *
         *      XFRM dst A --> IPv4 dst X
         *
         * X is the "xdst->route" of A (X is also the "dst->path" of A
         * in this example).  If X is marked obsolete, "A" will not
         * notice.  That's what we are validating here via the
         * stale_bundle() check.
         *
         * When a policy's bundle is pruned, we dst_free() the XFRM
         * dst which causes it's ->obsolete field to be set to a
         * positive non-zero integer.  If an XFRM dst has been pruned
         * like this, we want to force a new route lookup.
         */
        if (dst->obsolete < 0 && !stale_bundle(dst))
                return dst;
 
        return NULL;
}
 
static int stale_bundle(struct dst_entry *dst)
{
        return !xfrm_bundle_ok(NULL, (struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
}
 
void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
{
        while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
                dst->dev = init_net.loopback_dev;
                dev_hold(dst->dev);
                dev_put(dev);
        }
}
EXPORT_SYMBOL(xfrm_dst_ifdown);
 
static void xfrm_link_failure(struct sk_buff *skb)
{
        /* Impossible. Such dst must be popped before reaches point of failure. */
        return;
}
 
static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
{
        if (dst) {
                if (dst->obsolete) {
                        dst_release(dst);
                        dst = NULL;
                }
        }
        return dst;
}
 
static void prune_one_bundle(struct xfrm_policy *pol, int (*func)(struct dst_entry *), struct dst_entry **gc_list_p)
{
        struct dst_entry *dst, **dstp;
 
        write_lock(&pol->lock);
        dstp = &pol->bundles;
        while ((dst=*dstp) != NULL) {
                if (func(dst)) {
                        *dstp = dst->next;
                        dst->next = *gc_list_p;
                        *gc_list_p = dst;
                } else {
                        dstp = &dst->next;
                }
        }
        write_unlock(&pol->lock);
}
 
static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
{
        struct dst_entry *gc_list = NULL;
        int dir;
 
        read_lock_bh(&xfrm_policy_lock);
        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
                struct xfrm_policy *pol;
                struct hlist_node *entry;
                struct hlist_head *table;
                int i;
 
                hlist_for_each_entry(pol, entry,
                                     &xfrm_policy_inexact[dir], bydst)
                        prune_one_bundle(pol, func, &gc_list);
 
                table = xfrm_policy_bydst[dir].table;
                for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
                        hlist_for_each_entry(pol, entry, table + i, bydst)
                                prune_one_bundle(pol, func, &gc_list);
                }
        }
        read_unlock_bh(&xfrm_policy_lock);
 
        while (gc_list) {
                struct dst_entry *dst = gc_list;
                gc_list = dst->next;
                dst_free(dst);
        }
}
 
static int unused_bundle(struct dst_entry *dst)
{
        return !atomic_read(&dst->__refcnt);
}
 
static void __xfrm_garbage_collect(void)
{
        xfrm_prune_bundles(unused_bundle);
}
 
static int xfrm_flush_bundles(void)
{
        xfrm_prune_bundles(stale_bundle);
        return 0;
}
 
void xfrm_init_pmtu(struct dst_entry *dst)
{
        do {
                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
                u32 pmtu, route_mtu_cached;
 
                pmtu = dst_mtu(dst->child);
                xdst->child_mtu_cached = pmtu;
 
                pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
 
                route_mtu_cached = dst_mtu(xdst->route);
                xdst->route_mtu_cached = route_mtu_cached;
 
                if (pmtu > route_mtu_cached)
                        pmtu = route_mtu_cached;
 
                dst->metrics[RTAX_MTU-1] = pmtu;
        } while ((dst = dst->next));
}
 
EXPORT_SYMBOL(xfrm_init_pmtu);
 
/* Check that the bundle accepts the flow and its components are
 * still valid.
 */
 
int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
                struct flowi *fl, int family, int strict)
{
        struct dst_entry *dst = &first->u.dst;
        struct xfrm_dst *last;
        u32 mtu;
 
        if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
            (dst->dev && !netif_running(dst->dev)))
                return 0;
#ifdef CONFIG_XFRM_SUB_POLICY
        if (fl) {
                if (first->origin && !flow_cache_uli_match(first->origin, fl))
                        return 0;
                if (first->partner &&
                    !xfrm_selector_match(first->partner, fl, family))
                        return 0;
        }
#endif
 
        last = NULL;
 
        do {
                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
 
                if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
                        return 0;
                if (fl && pol &&
                    !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
                        return 0;
                if (dst->xfrm->km.state != XFRM_STATE_VALID)
                        return 0;
                if (xdst->genid != dst->xfrm->genid)
                        return 0;
 
                if (strict && fl &&
                    !(dst->xfrm->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
                    !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
                        return 0;
 
                mtu = dst_mtu(dst->child);
                if (xdst->child_mtu_cached != mtu) {
                        last = xdst;
                        xdst->child_mtu_cached = mtu;
                }
 
                if (!dst_check(xdst->route, xdst->route_cookie))
                        return 0;
                mtu = dst_mtu(xdst->route);
                if (xdst->route_mtu_cached != mtu) {
                        last = xdst;
                        xdst->route_mtu_cached = mtu;
                }
 
                dst = dst->child;
        } while (dst->xfrm);
 
        if (likely(!last))
                return 1;
 
        mtu = last->child_mtu_cached;
        for (;;) {
                dst = &last->u.dst;
 
                mtu = xfrm_state_mtu(dst->xfrm, mtu);
                if (mtu > last->route_mtu_cached)
                        mtu = last->route_mtu_cached;
                dst->metrics[RTAX_MTU-1] = mtu;
 
                if (last == first)
                        break;
 
                last = (struct xfrm_dst *)last->u.dst.next;
                last->child_mtu_cached = mtu;
        }
 
        return 1;
}
 
EXPORT_SYMBOL(xfrm_bundle_ok);
 
int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
{
        int err = 0;
        if (unlikely(afinfo == NULL))
                return -EINVAL;
        if (unlikely(afinfo->family >= NPROTO))
                return -EAFNOSUPPORT;
        write_lock_bh(&xfrm_policy_afinfo_lock);
        if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
                err = -ENOBUFS;
        else {
                struct dst_ops *dst_ops = afinfo->dst_ops;
                if (likely(dst_ops->kmem_cachep == NULL))
                        dst_ops->kmem_cachep = xfrm_dst_cache;
                if (likely(dst_ops->check == NULL))
                        dst_ops->check = xfrm_dst_check;
                if (likely(dst_ops->negative_advice == NULL))
                        dst_ops->negative_advice = xfrm_negative_advice;
                if (likely(dst_ops->link_failure == NULL))
                        dst_ops->link_failure = xfrm_link_failure;
                if (likely(afinfo->garbage_collect == NULL))
                        afinfo->garbage_collect = __xfrm_garbage_collect;
                xfrm_policy_afinfo[afinfo->family] = afinfo;
        }
        write_unlock_bh(&xfrm_policy_afinfo_lock);
        return err;
}
EXPORT_SYMBOL(xfrm_policy_register_afinfo);
 
int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
{
        int err = 0;
        if (unlikely(afinfo == NULL))
                return -EINVAL;
        if (unlikely(afinfo->family >= NPROTO))
                return -EAFNOSUPPORT;
        write_lock_bh(&xfrm_policy_afinfo_lock);
        if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
                if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
                        err = -EINVAL;
                else {
                        struct dst_ops *dst_ops = afinfo->dst_ops;
                        xfrm_policy_afinfo[afinfo->family] = NULL;
                        dst_ops->kmem_cachep = NULL;
                        dst_ops->check = NULL;
                        dst_ops->negative_advice = NULL;
                        dst_ops->link_failure = NULL;
                        afinfo->garbage_collect = NULL;
                }
        }
        write_unlock_bh(&xfrm_policy_afinfo_lock);
        return err;
}
EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
 
static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
{
        struct xfrm_policy_afinfo *afinfo;
        if (unlikely(family >= NPROTO))
                return NULL;
        read_lock(&xfrm_policy_afinfo_lock);
        afinfo = xfrm_policy_afinfo[family];
        if (unlikely(!afinfo))
                read_unlock(&xfrm_policy_afinfo_lock);
        return afinfo;
}
 
static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
{
        read_unlock(&xfrm_policy_afinfo_lock);
}
 
static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
        struct net_device *dev = ptr;
 
        if (dev->nd_net != &init_net)
                return NOTIFY_DONE;
 
        switch (event) {
        case NETDEV_DOWN:
                xfrm_flush_bundles();
        }
        return NOTIFY_DONE;
}
 
static struct notifier_block xfrm_dev_notifier = {
        xfrm_dev_event,
        NULL,
 
};
 
static void __init xfrm_policy_init(void)
{
        unsigned int hmask, sz;
        int dir;
 
        xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
                                           sizeof(struct xfrm_dst),
                                           0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
                                           NULL);
 
        hmask = 8 - 1;
        sz = (hmask+1) * sizeof(struct hlist_head);
 
        xfrm_policy_byidx = xfrm_hash_alloc(sz);
        xfrm_idx_hmask = hmask;
        if (!xfrm_policy_byidx)
                panic("XFRM: failed to allocate byidx hash\n");
 
        for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
                struct xfrm_policy_hash *htab;
 
                INIT_HLIST_HEAD(&xfrm_policy_inexact[dir]);
 
                htab = &xfrm_policy_bydst[dir];
                htab->table = xfrm_hash_alloc(sz);
                htab->hmask = hmask;
                if (!htab->table)
                        panic("XFRM: failed to allocate bydst hash\n");
        }
 
        INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task);
        register_netdevice_notifier(&xfrm_dev_notifier);
}
 
void __init xfrm_init(void)
{
        xfrm_state_init();
        xfrm_policy_init();
        xfrm_input_init();
}
 
#ifdef CONFIG_AUDITSYSCALL
static inline void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
                                                struct audit_buffer *audit_buf)
{
        if (xp->security)
                audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
                                 xp->security->ctx_alg, xp->security->ctx_doi,
                                 xp->security->ctx_str);
 
        switch(xp->selector.family) {
        case AF_INET:
                audit_log_format(audit_buf, " src=%u.%u.%u.%u dst=%u.%u.%u.%u",
                                 NIPQUAD(xp->selector.saddr.a4),
                                 NIPQUAD(xp->selector.daddr.a4));
                break;
        case AF_INET6:
                {
                        struct in6_addr saddr6, daddr6;
 
                        memcpy(&saddr6, xp->selector.saddr.a6,
                                sizeof(struct in6_addr));
                        memcpy(&daddr6, xp->selector.daddr.a6,
                                sizeof(struct in6_addr));
                        audit_log_format(audit_buf,
                                " src=" NIP6_FMT " dst=" NIP6_FMT,
                                NIP6(saddr6), NIP6(daddr6));
                }
                break;
        }
}
 
void
xfrm_audit_policy_add(struct xfrm_policy *xp, int result, u32 auid, u32 sid)
{
        struct audit_buffer *audit_buf;
        extern int audit_enabled;
 
        if (audit_enabled == 0)
                return;
        audit_buf = xfrm_audit_start(auid, sid);
        if (audit_buf == NULL)
                return;
        audit_log_format(audit_buf, " op=SPD-add res=%u", result);
        xfrm_audit_common_policyinfo(xp, audit_buf);
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
 
void
xfrm_audit_policy_delete(struct xfrm_policy *xp, int result, u32 auid, u32 sid)
{
        struct audit_buffer *audit_buf;
        extern int audit_enabled;
 
        if (audit_enabled == 0)
                return;
        audit_buf = xfrm_audit_start(auid, sid);
        if (audit_buf == NULL)
                return;
        audit_log_format(audit_buf, " op=SPD-delete res=%u", result);
        xfrm_audit_common_policyinfo(xp, audit_buf);
        audit_log_end(audit_buf);
}
EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
#endif
 
#ifdef CONFIG_XFRM_MIGRATE
static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
                                       struct xfrm_selector *sel_tgt)
{
        if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
                if (sel_tgt->family == sel_cmp->family &&
                    xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
                                  sel_cmp->family) == 0 &&
                    xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
                                  sel_cmp->family) == 0 &&
                    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
                    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
                        return 1;
                }
        } else {
                if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
                        return 1;
                }
        }
        return 0;
}
 
static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
                                                     u8 dir, u8 type)
{
        struct xfrm_policy *pol, *ret = NULL;
        struct hlist_node *entry;
        struct hlist_head *chain;
        u32 priority = ~0U;
 
        read_lock_bh(&xfrm_policy_lock);
        chain = policy_hash_direct(&sel->daddr, &sel->saddr, sel->family, dir);
        hlist_for_each_entry(pol, entry, chain, bydst) {
                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
                    pol->type == type) {
                        ret = pol;
                        priority = ret->priority;
                        break;
                }
        }
        chain = &xfrm_policy_inexact[dir];
        hlist_for_each_entry(pol, entry, chain, bydst) {
                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
                    pol->type == type &&
                    pol->priority < priority) {
                        ret = pol;
                        break;
                }
        }
 
        if (ret)
                xfrm_pol_hold(ret);
 
        read_unlock_bh(&xfrm_policy_lock);
 
        return ret;
}
 
static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
{
        int match = 0;
 
        if (t->mode == m->mode && t->id.proto == m->proto &&
            (m->reqid == 0 || t->reqid == m->reqid)) {
                switch (t->mode) {
                case XFRM_MODE_TUNNEL:
                case XFRM_MODE_BEET:
                        if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
                                          m->old_family) == 0 &&
                            xfrm_addr_cmp(&t->saddr, &m->old_saddr,
                                          m->old_family) == 0) {
                                match = 1;
                        }
                        break;
                case XFRM_MODE_TRANSPORT:
                        /* in case of transport mode, template does not store
                           any IP addresses, hence we just compare mode and
                           protocol */
                        match = 1;
                        break;
                default:
                        break;
                }
        }
        return match;
}
 
/* update endpoint address(es) of template(s) */
static int xfrm_policy_migrate(struct xfrm_policy *pol,
                               struct xfrm_migrate *m, int num_migrate)
{
        struct xfrm_migrate *mp;
        struct dst_entry *dst;
        int i, j, n = 0;
 
        write_lock_bh(&pol->lock);
        if (unlikely(pol->dead)) {
                /* target policy has been deleted */
                write_unlock_bh(&pol->lock);
                return -ENOENT;
        }
 
        for (i = 0; i < pol->xfrm_nr; i++) {
                for (j = 0, mp = m; j < num_migrate; j++, mp++) {
                        if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
                                continue;
                        n++;
                        if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
                            pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
                                continue;
                        /* update endpoints */
                        memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
                               sizeof(pol->xfrm_vec[i].id.daddr));
                        memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
                               sizeof(pol->xfrm_vec[i].saddr));
                        pol->xfrm_vec[i].encap_family = mp->new_family;
                        /* flush bundles */
                        while ((dst = pol->bundles) != NULL) {
                                pol->bundles = dst->next;
                                dst_free(dst);
                        }
                }
        }
 
        write_unlock_bh(&pol->lock);
 
        if (!n)
                return -ENODATA;
 
        return 0;
}
 
static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
{
        int i, j;
 
        if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
                return -EINVAL;
 
        for (i = 0; i < num_migrate; i++) {
                if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
                                   m[i].old_family) == 0) &&
                    (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
                                   m[i].old_family) == 0))
                        return -EINVAL;
                if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
                    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
                        return -EINVAL;
 
                /* check if there is any duplicated entry */
                for (j = i + 1; j < num_migrate; j++) {
                        if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
                                    sizeof(m[i].old_daddr)) &&
                            !memcmp(&m[i].old_saddr, &m[j].old_saddr,
                                    sizeof(m[i].old_saddr)) &&
                            m[i].proto == m[j].proto &&
                            m[i].mode == m[j].mode &&
                            m[i].reqid == m[j].reqid &&
                            m[i].old_family == m[j].old_family)
                                return -EINVAL;
                }
        }
 
        return 0;
}
 
int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
                 struct xfrm_migrate *m, int num_migrate)
{
        int i, err, nx_cur = 0, nx_new = 0;
        struct xfrm_policy *pol = NULL;
        struct xfrm_state *x, *xc;
        struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
        struct xfrm_state *x_new[XFRM_MAX_DEPTH];
        struct xfrm_migrate *mp;
 
        if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
                goto out;
 
        /* Stage 1 - find policy */
        if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
                err = -ENOENT;
                goto out;
        }
 
        /* Stage 2 - find and update state(s) */
        for (i = 0, mp = m; i < num_migrate; i++, mp++) {
                if ((x = xfrm_migrate_state_find(mp))) {
                        x_cur[nx_cur] = x;
                        nx_cur++;
                        if ((xc = xfrm_state_migrate(x, mp))) {
                                x_new[nx_new] = xc;
                                nx_new++;
                        } else {
                                err = -ENODATA;
                                goto restore_state;
                        }
                }
        }
 
        /* Stage 3 - update policy */
        if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
                goto restore_state;
 
        /* Stage 4 - delete old state(s) */
        if (nx_cur) {
                xfrm_states_put(x_cur, nx_cur);
                xfrm_states_delete(x_cur, nx_cur);
        }
 
        /* Stage 5 - announce */
        km_migrate(sel, dir, type, m, num_migrate);
 
        xfrm_pol_put(pol);
 
        return 0;
out:
        return err;
 
restore_state:
        if (pol)
                xfrm_pol_put(pol);
        if (nx_cur)
                xfrm_states_put(x_cur, nx_cur);
        if (nx_new)
                xfrm_states_delete(x_new, nx_new);
 
        return err;
}
EXPORT_SYMBOL(xfrm_migrate);
#endif
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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [net/] [xfrm/] [xfrm_policy.c] - Blame information for rev 3

Line No.	Rev	Author	Line
1	3	xianfeng	`/*`
2			`* xfrm_policy.c`
3			`*`
4			`* Changes:`
5			`* Mitsuru KANDA @USAGI`
6			`* Kazunori MIYAZAWA @USAGI`
7			`* Kunihiro Ishiguro <kunihiro@ipinfusion.com>`
8			`* IPv6 support`
9			`* Kazunori MIYAZAWA @USAGI`
10			`* YOSHIFUJI Hideaki`
11			`* Split up af-specific portion`
12			`* Derek Atkins <derek@ihtfp.com> Add the post_input processor`
13			`*`
14			`*/`
15
16			`#include <linux/slab.h>`
17			`#include <linux/kmod.h>`
18			`#include <linux/list.h>`
19			`#include <linux/spinlock.h>`
20			`#include <linux/workqueue.h>`
21			`#include <linux/notifier.h>`
22			`#include <linux/netdevice.h>`
23			`#include <linux/netfilter.h>`
24			`#include <linux/module.h>`
25			`#include <linux/cache.h>`
26			`#include <net/xfrm.h>`
27			`#include <net/ip.h>`
28
29			`#include "xfrm_hash.h"`
30
31			`int sysctl_xfrm_larval_drop __read_mostly;`
32
33			`DEFINE_MUTEX(xfrm_cfg_mutex);`
34			`EXPORT_SYMBOL(xfrm_cfg_mutex);`
35
36			`static DEFINE_RWLOCK(xfrm_policy_lock);`
37
38			`unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];`
39			`EXPORT_SYMBOL(xfrm_policy_count);`
40