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xfrm_policy.c
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/*
* xfrm_policy.c
*
* Changes:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <[email protected]>
* IPv6 support
* Kazunori MIYAZAWA @USAGI
* YOSHIFUJI Hideaki
* Split up af-specific portion
* Derek Atkins <[email protected]> Add the post_input processor
*
*/
#include <linux/err.h>
#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 <linux/audit.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/ip.h>
#ifdef CONFIG_XFRM_STATISTICS
#include <net/snmp.h>
#endif
#include "xfrm_hash.h"
DEFINE_MUTEX(xfrm_cfg_mutex);
EXPORT_SYMBOL(xfrm_cfg_mutex);
static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
static struct dst_entry *xfrm_policy_sk_bundles;
static DEFINE_RWLOCK(xfrm_policy_lock);
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 xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
static void xfrm_init_pmtu(struct dst_entry *dst);
static int stale_bundle(struct dst_entry *dst);
static int xfrm_bundle_ok(struct xfrm_dst *xdst);
static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
int dir);
static inline int
__xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
{
const struct flowi4 *fl4 = &fl->u.ip4;
return addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
(fl4->flowi4_proto == sel->proto || !sel->proto) &&
(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
}
static inline int
__xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
{
const struct flowi6 *fl6 = &fl->u.ip6;
return addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
(fl6->flowi6_proto == sel->proto || !sel->proto) &&
(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
}
int xfrm_selector_match(const struct xfrm_selector *sel, const 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;
}
static inline struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos,
const xfrm_address_t *saddr,
const xfrm_address_t *daddr,
int family)
{
struct xfrm_policy_afinfo *afinfo;
struct dst_entry *dst;
afinfo = xfrm_policy_get_afinfo(family);
if (unlikely(afinfo == NULL))
return ERR_PTR(-EAFNOSUPPORT);
dst = afinfo->dst_lookup(net, tos, saddr, daddr);
xfrm_policy_put_afinfo(afinfo);
return dst;
}
static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, int tos,
xfrm_address_t *prev_saddr,
xfrm_address_t *prev_daddr,
int family)
{
struct net *net = xs_net(x);
xfrm_address_t *saddr = &x->props.saddr;
xfrm_address_t *daddr = &x->id.daddr;
struct dst_entry *dst;
if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
saddr = x->coaddr;
daddr = prev_daddr;
}
if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
saddr = prev_saddr;
daddr = x->coaddr;
}
dst = __xfrm_dst_lookup(net, tos, saddr, daddr, family);
if (!IS_ERR(dst)) {
if (prev_saddr != saddr)
memcpy(prev_saddr, saddr, sizeof(*prev_saddr));
if (prev_daddr != daddr)
memcpy(prev_daddr, daddr, sizeof(*prev_daddr));
}
return dst;
}
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 (unlikely(xp->walk.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);
}
static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
{
struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
if (unlikely(pol->walk.dead))
flo = NULL;
else
xfrm_pol_hold(pol);
return flo;
}
static int xfrm_policy_flo_check(struct flow_cache_object *flo)
{
struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
return !pol->walk.dead;
}
static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
{
xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
}
static const struct flow_cache_ops xfrm_policy_fc_ops = {
.get = xfrm_policy_flo_get,
.check = xfrm_policy_flo_check,
.delete = xfrm_policy_flo_delete,
};
/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
* SPD calls.
*/
struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
{
struct xfrm_policy *policy;
policy = kzalloc(sizeof(struct xfrm_policy), gfp);
if (policy) {
write_pnet(&policy->xp_net, net);
INIT_LIST_HEAD(&policy->walk.all);
INIT_HLIST_NODE(&policy->bydst);
INIT_HLIST_NODE(&policy->byidx);
rwlock_init(&policy->lock);
atomic_set(&policy->refcnt, 1);
setup_timer(&policy->timer, xfrm_policy_timer,
(unsigned long)policy);
policy->flo.ops = &xfrm_policy_fc_ops;
}
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->walk.dead);
if (del_timer(&policy->timer))
BUG();
security_xfrm_policy_free(policy->security);
kfree(policy);
}
EXPORT_SYMBOL(xfrm_policy_destroy);
/* 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)
{
policy->walk.dead = 1;
atomic_inc(&policy->genid);
if (del_timer(&policy->timer))
xfrm_pol_put(policy);
xfrm_pol_put(policy);
}
static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
static inline unsigned int idx_hash(struct net *net, u32 index)
{
return __idx_hash(index, net->xfrm.policy_idx_hmask);
}
static struct hlist_head *policy_hash_bysel(struct net *net,
const struct xfrm_selector *sel,
unsigned short family, int dir)
{
unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
unsigned int hash = __sel_hash(sel, family, hmask);
return (hash == hmask + 1 ?
&net->xfrm.policy_inexact[dir] :
net->xfrm.policy_bydst[dir].table + hash);
}
static struct hlist_head *policy_hash_direct(struct net *net,
const xfrm_address_t *daddr,
const xfrm_address_t *saddr,
unsigned short family, int dir)
{
unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
return net->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, *entry0 = NULL;
struct xfrm_policy *pol;
unsigned int h0 = 0;
redo:
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);
if (!entry0) {
hlist_del(entry);
hlist_add_head(&pol->bydst, ndsttable+h);
h0 = h;
} else {
if (h != h0)
continue;
hlist_del(entry);
hlist_add_after(entry0, &pol->bydst);
}
entry0 = entry;
}
if (!hlist_empty(list)) {
entry0 = NULL;
goto redo;
}
}
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(struct net *net, int dir)
{
unsigned int hmask = net->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 = net->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);
net->xfrm.policy_bydst[dir].table = ndst;
net->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(struct net *net, int total)
{
unsigned int hmask = net->xfrm.policy_idx_hmask;
unsigned int nhashmask = xfrm_new_hash_mask(hmask);
unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
struct hlist_head *oidx = net->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);
net->xfrm.policy_byidx = nidx;
net->xfrm.policy_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(struct net *net, int dir, int *total)
{
unsigned int cnt = net->xfrm.policy_count[dir];
unsigned int hmask = net->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(struct net *net, int total)
{
unsigned int hmask = net->xfrm.policy_idx_hmask;
if ((hmask + 1) < xfrm_policy_hashmax &&
total > hmask)
return 1;
return 0;
}
void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
{
read_lock_bh(&xfrm_policy_lock);
si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
si->spdhcnt = net->xfrm.policy_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 *work)
{
struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
int dir, total;
mutex_lock(&hash_resize_mutex);
total = 0;
for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
if (xfrm_bydst_should_resize(net, dir, &total))
xfrm_bydst_resize(net, dir);
}
if (xfrm_byidx_should_resize(net, total))
xfrm_byidx_resize(net, total);
mutex_unlock(&hash_resize_mutex);
}
/* 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(struct net *net, 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 = net->xfrm.policy_byidx + idx_hash(net, 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 net *net = xp_net(policy);
struct xfrm_policy *pol;
struct xfrm_policy *delpol;
struct hlist_head *chain;
struct hlist_node *entry, *newpos;
u32 mark = policy->mark.v & policy->mark.m;
write_lock_bh(&xfrm_policy_lock);
chain = policy_hash_bysel(net, &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) &&
(mark & pol->mark.m) == pol->mark.v &&
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);
net->xfrm.policy_count[dir]++;
atomic_inc(&flow_cache_genid);
if (delpol)
__xfrm_policy_unlink(delpol, dir);
policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
policy->curlft.add_time = get_seconds();
policy->curlft.use_time = 0;
if (!mod_timer(&policy->timer, jiffies + HZ))
xfrm_pol_hold(policy);
list_add(&policy->walk.all, &net->xfrm.policy_all);
write_unlock_bh(&xfrm_policy_lock);
if (delpol)
xfrm_policy_kill(delpol);
else if (xfrm_bydst_should_resize(net, dir, NULL))
schedule_work(&net->xfrm.policy_hash_work);
return 0;
}
EXPORT_SYMBOL(xfrm_policy_insert);
struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, 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(net, sel, sel->family, dir);
ret = NULL;
hlist_for_each_entry(pol, entry, chain, bydst) {
if (pol->type == type &&
(mark & pol->mark.m) == pol->mark.v &&
!selector_cmp(sel, &pol->selector) &&
xfrm_sec_ctx_match(ctx, pol->security)) {
xfrm_pol_hold(pol);
if (delete) {
*err = security_xfrm_policy_delete(
pol->security);
if (*err) {
write_unlock_bh(&xfrm_policy_lock);
return pol;
}
__xfrm_policy_unlink(pol, dir);
}
ret = pol;
break;
}
}
write_unlock_bh(&xfrm_policy_lock);
if (ret && delete)
xfrm_policy_kill(ret);
return ret;
}
EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, 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 = net->xfrm.policy_byidx + idx_hash(net, id);
ret = NULL;
hlist_for_each_entry(pol, entry, chain, byidx) {
if (pol->type == type && pol->index == id &&
(mark & pol->mark.m) == pol->mark.v) {
xfrm_pol_hold(pol);
if (delete) {
*err = security_xfrm_policy_delete(
pol->security);
if (*err) {
write_unlock_bh(&xfrm_policy_lock);
return pol;
}
__xfrm_policy_unlink(pol, dir);
}
ret = pol;
break;
}
}
write_unlock_bh(&xfrm_policy_lock);
if (ret && delete)
xfrm_policy_kill(ret);
return ret;
}
EXPORT_SYMBOL(xfrm_policy_byid);
#ifdef CONFIG_SECURITY_NETWORK_XFRM
static inline int
xfrm_policy_flush_secctx_check(struct net *net, 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,
&net->xfrm.policy_inexact[dir], bydst) {
if (pol->type != type)
continue;
err = security_xfrm_policy_delete(pol->security);
if (err) {
xfrm_audit_policy_delete(pol, 0,
audit_info->loginuid,
audit_info->sessionid,
audit_info->secid);
return err;
}
}
for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
hlist_for_each_entry(pol, entry,
net->xfrm.policy_bydst[dir].table + i,
bydst) {
if (pol->type != type)
continue;
err = security_xfrm_policy_delete(
pol->security);
if (err) {
xfrm_audit_policy_delete(pol, 0,
audit_info->loginuid,
audit_info->sessionid,
audit_info->secid);
return err;
}
}
}
}
return err;
}
#else
static inline int
xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
{
return 0;
}
#endif
int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
{
int dir, err = 0, cnt = 0;
write_lock_bh(&xfrm_policy_lock);
err = xfrm_policy_flush_secctx_check(net, 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;
again1:
hlist_for_each_entry(pol, entry,
&net->xfrm.policy_inexact[dir], bydst) {
if (pol->type != type)
continue;
__xfrm_policy_unlink(pol, dir);
write_unlock_bh(&xfrm_policy_lock);
cnt++;
xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
audit_info->sessionid,
audit_info->secid);
xfrm_policy_kill(pol);
write_lock_bh(&xfrm_policy_lock);
goto again1;
}
for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
again2:
hlist_for_each_entry(pol, entry,
net->xfrm.policy_bydst[dir].table + i,
bydst) {
if (pol->type != type)
continue;
__xfrm_policy_unlink(pol, dir);
write_unlock_bh(&xfrm_policy_lock);
cnt++;
xfrm_audit_policy_delete(pol, 1,
audit_info->loginuid,
audit_info->sessionid,
audit_info->secid);
xfrm_policy_kill(pol);
write_lock_bh(&xfrm_policy_lock);
goto again2;
}
}
}
if (!cnt)
err = -ESRCH;
out:
write_unlock_bh(&xfrm_policy_lock);
return err;
}
EXPORT_SYMBOL(xfrm_policy_flush);
int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
int (*func)(struct xfrm_policy *, int, int, void*),
void *data)
{
struct xfrm_policy *pol;
struct xfrm_policy_walk_entry *x;
int error = 0;
if (walk->type >= XFRM_POLICY_TYPE_MAX &&
walk->type != XFRM_POLICY_TYPE_ANY)
return -EINVAL;
if (list_empty(&walk->walk.all) && walk->seq != 0)
return 0;
write_lock_bh(&xfrm_policy_lock);
if (list_empty(&walk->walk.all))
x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
else
x = list_entry(&walk->walk.all, struct xfrm_policy_walk_entry, all);
list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
if (x->dead)
continue;
pol = container_of(x, struct xfrm_policy, walk);
if (walk->type != XFRM_POLICY_TYPE_ANY &&
walk->type != pol->type)
continue;
error = func(pol, xfrm_policy_id2dir(pol->index),
walk->seq, data);
if (error) {
list_move_tail(&walk->walk.all, &x->all);
goto out;
}
walk->seq++;
}
if (walk->seq == 0) {
error = -ENOENT;
goto out;
}
list_del_init(&walk->walk.all);
out:
write_unlock_bh(&xfrm_policy_lock);
return error;
}
EXPORT_SYMBOL(xfrm_policy_walk);
void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
{
INIT_LIST_HEAD(&walk->walk.all);
walk->walk.dead = 1;
walk->type = type;
walk->seq = 0;
}
EXPORT_SYMBOL(xfrm_policy_walk_init);
void xfrm_policy_walk_done(struct xfrm_policy_walk *walk)
{
if (list_empty(&walk->walk.all))
return;
write_lock_bh(&xfrm_policy_lock);
list_del(&walk->walk.all);
write_unlock_bh(&xfrm_policy_lock);
}
EXPORT_SYMBOL(xfrm_policy_walk_done);
/*
* Find policy to apply to this flow.
*
* Returns 0 if policy found, else an -errno.
*/
static int xfrm_policy_match(const struct xfrm_policy *pol,
const struct flowi *fl,
u8 type, u16 family, int dir)
{
const struct xfrm_selector *sel = &pol->selector;
int match, ret = -ESRCH;
if (pol->family != family ||
(fl->flowi_mark & pol->mark.m) != pol->mark.v ||
pol->type != type)
return ret;
match = xfrm_selector_match(sel, fl, family);
if (match)
ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
dir);
return ret;
}
static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
const struct flowi *fl,
u16 family, u8 dir)
{
int err;
struct xfrm_policy *pol, *ret;
const 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(net, 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 = &net->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 struct xfrm_policy *
__xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
{
#ifdef CONFIG_XFRM_SUB_POLICY
struct xfrm_policy *pol;
pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
if (pol != NULL)
return pol;
#endif
return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
}
static struct flow_cache_object *
xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family,
u8 dir, struct flow_cache_object *old_obj, void *ctx)
{
struct xfrm_policy *pol;
if (old_obj)
xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
pol = __xfrm_policy_lookup(net, fl, family, dir);
if (IS_ERR_OR_NULL(pol))
return ERR_CAST(pol);
/* Resolver returns two references:
* one for cache and one for caller of flow_cache_lookup() */
xfrm_pol_hold(pol);
return &pol->flo;
}
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;
}
}