android_kernel_motorola_sm6225/net/xfrm/xfrm_policy.c
Alexey Dobriyan e5d679f339 [NET]: Use SLAB_PANIC
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 15:18:19 -07:00

2021 lines
46 KiB
C

/*
* 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"
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 kmem_cache_t *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 struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family);
static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo);
int xfrm_register_type(struct xfrm_type *type, unsigned short family)
{
struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
struct xfrm_type **typemap;
int err = 0;
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
typemap = afinfo->type_map;
if (likely(typemap[type->proto] == NULL))
typemap[type->proto] = type;
else
err = -EEXIST;
xfrm_policy_unlock_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_register_type);
int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
{
struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
struct xfrm_type **typemap;
int err = 0;
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
typemap = afinfo->type_map;
if (unlikely(typemap[type->proto] != type))
err = -ENOENT;
else
typemap[type->proto] = NULL;
xfrm_policy_unlock_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_unregister_type);
struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
{
struct xfrm_policy_afinfo *afinfo;
struct xfrm_type **typemap;
struct xfrm_type *type;
int modload_attempted = 0;
retry:
afinfo = xfrm_policy_get_afinfo(family);
if (unlikely(afinfo == NULL))
return NULL;
typemap = afinfo->type_map;
type = typemap[proto];
if (unlikely(type && !try_module_get(type->owner)))
type = NULL;
if (!type && !modload_attempted) {
xfrm_policy_put_afinfo(afinfo);
request_module("xfrm-type-%d-%d",
(int) family, (int) proto);
modload_attempted = 1;
goto retry;
}
xfrm_policy_put_afinfo(afinfo);
return type;
}
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);
void xfrm_put_type(struct xfrm_type *type)
{
module_put(type->owner);
}
int xfrm_register_mode(struct xfrm_mode *mode, int family)
{
struct xfrm_policy_afinfo *afinfo;
struct xfrm_mode **modemap;
int err;
if (unlikely(mode->encap >= XFRM_MODE_MAX))
return -EINVAL;
afinfo = xfrm_policy_lock_afinfo(family);
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
err = -EEXIST;
modemap = afinfo->mode_map;
if (likely(modemap[mode->encap] == NULL)) {
modemap[mode->encap] = mode;
err = 0;
}
xfrm_policy_unlock_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_register_mode);
int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
{
struct xfrm_policy_afinfo *afinfo;
struct xfrm_mode **modemap;
int err;
if (unlikely(mode->encap >= XFRM_MODE_MAX))
return -EINVAL;
afinfo = xfrm_policy_lock_afinfo(family);
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
err = -ENOENT;
modemap = afinfo->mode_map;
if (likely(modemap[mode->encap] == mode)) {
modemap[mode->encap] = NULL;
err = 0;
}
xfrm_policy_unlock_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_unregister_mode);
struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
{
struct xfrm_policy_afinfo *afinfo;
struct xfrm_mode *mode;
int modload_attempted = 0;
if (unlikely(encap >= XFRM_MODE_MAX))
return NULL;
retry:
afinfo = xfrm_policy_get_afinfo(family);
if (unlikely(afinfo == NULL))
return NULL;
mode = afinfo->mode_map[encap];
if (unlikely(mode && !try_module_get(mode->owner)))
mode = NULL;
if (!mode && !modload_attempted) {
xfrm_policy_put_afinfo(afinfo);
request_module("xfrm-mode-%d-%d", family, encap);
modload_attempted = 1;
goto retry;
}
xfrm_policy_put_afinfo(afinfo);
return mode;
}
void xfrm_put_mode(struct xfrm_mode *mode)
{
module_put(mode->owner);
}
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 = (unsigned long)xtime.tv_sec;
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(void *data)
{
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;
}
static DEFINE_MUTEX(hash_resize_mutex);
static void xfrm_hash_resize(void *__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, NULL);
/* 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, *last;
struct dst_entry *gc_list;
write_lock_bh(&xfrm_policy_lock);
chain = policy_hash_bysel(&policy->selector, policy->family, dir);
delpol = NULL;
newpos = NULL;
last = NULL;
hlist_for_each_entry(pol, entry, chain, bydst) {
if (!delpol &&
pol->type == policy->type &&
!selector_cmp(&pol->selector, &policy->selector) &&
xfrm_sec_ctx_match(pol->security, policy->security)) {
if (excl) {
write_unlock_bh(&xfrm_policy_lock);
return -EEXIST;
}
delpol = pol;
if (policy->priority > pol->priority)
continue;
} else if (policy->priority >= pol->priority) {
last = &pol->bydst;
continue;
}
if (!newpos)
newpos = &pol->bydst;
if (delpol)
break;
last = &pol->bydst;
}
if (!newpos)
newpos = last;
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 = (unsigned long)xtime.tv_sec;
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)
{
struct xfrm_policy *pol, *ret;
struct hlist_head *chain;
struct hlist_node *entry;
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) {
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)
{
struct xfrm_policy *pol, *ret;
struct hlist_head *chain;
struct hlist_node *entry;
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) {
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);
void xfrm_policy_flush(u8 type)
{
int dir;
write_lock_bh(&xfrm_policy_lock);
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,
&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_policy_kill(pol);
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_policy_kill(pol);
write_lock_bh(&xfrm_policy_lock);
goto again2;
}
}
xfrm_policy_count[dir] = 0;
}
atomic_inc(&flow_cache_genid);
write_unlock_bh(&xfrm_policy_lock);
}
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;
struct hlist_node *entry;
int dir, 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)
count++;
}
for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
hlist_for_each_entry(pol, entry, table + i, bydst) {
if (pol->type == type)
count++;
}
}
}
if (count == 0) {
error = -ENOENT;
goto out;
}
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;
error = func(pol, dir % XFRM_POLICY_MAX, --count, data);
if (error)
goto out;
}
for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
hlist_for_each_entry(pol, entry, table + i, bydst) {
if (pol->type != type)
continue;
error = func(pol, dir % XFRM_POLICY_MAX, --count, data);
if (error)
goto out;
}
}
}
error = 0;
out:
read_unlock_bh(&xfrm_policy_lock);
return error;
}
EXPORT_SYMBOL(xfrm_policy_walk);
/* Find policy to apply to this flow. */
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;
if (pol->family != family ||
pol->type != type)
return 0;
match = xfrm_selector_match(sel, fl, family);
if (match) {
if (!security_xfrm_policy_lookup(pol, fl->secid, dir))
return 1;
}
return 0;
}
static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
u16 family, u8 dir)
{
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) {
if (xfrm_policy_match(pol, fl, type, family, dir)) {
ret = pol;
priority = ret->priority;
break;
}
}
chain = &xfrm_policy_inexact[dir];
hlist_for_each_entry(pol, entry, chain, bydst) {
if (xfrm_policy_match(pol, fl, type, family, dir) &&
pol->priority < priority) {
ret = pol;
break;
}
}
if (ret)
xfrm_pol_hold(ret);
read_unlock_bh(&xfrm_policy_lock);
return ret;
}
static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
void **objp, atomic_t **obj_refp)
{
struct xfrm_policy *pol;
#ifdef CONFIG_XFRM_SUB_POLICY
pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
if (pol)
goto end;
#endif
pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
#ifdef CONFIG_XFRM_SUB_POLICY
end:
#endif
if ((*objp = (void *) pol) != NULL)
*obj_refp = &pol->refcnt;
}
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 (match && !err)
xfrm_pol_hold(pol);
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 = (unsigned long)xtime.tv_sec;
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;
}
/* 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);
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) {
remote = &tmpl->id.daddr;
local = &tmpl->saddr;
}
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 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[1])
policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
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);
}
if (!policy)
return 0;
family = dst_orig->ops->family;
policy->curlft.use_time = (unsigned long)xtime.tv_sec;
pols[0] = policy;
npols ++;
xfrm_nr += pols[0]->xfrm_nr;
switch (policy->action) {
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 (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 && 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;
}
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:
dst_release(dst_orig);
xfrm_pols_put(pols, npols);
*dst_p = NULL;
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;
int err;
if (!skb->sp || idx < 0 || idx >= skb->sp->len)
return 0;
x = skb->sp->xvec[idx];
if (!x->type->reject)
return 0;
xfrm_state_hold(x);
err = x->type->reject(x, skb, fl);
xfrm_state_put(x);
return err;
}
/* 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, 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) {
if (idxp)
*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;
int *xerr_idxp = &xerr_idx;
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 (!pol)
pol = flow_cache_lookup(&fl, family, fl_dir,
xfrm_policy_lookup);
if (!pol) {
if (skb->sp && secpath_has_nontransport(skb->sp, 0, xerr_idxp)) {
xfrm_secpath_reject(xerr_idx, skb, &fl);
return 0;
}
return 1;
}
pol->curlft.use_time = (unsigned long)xtime.tv_sec;
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]) {
pols[1]->curlft.use_time = (unsigned long)xtime.tv_sec;
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 && xerr_idxp)
*xerr_idxp = -(2+k);
goto reject;
}
}
if (secpath_has_nontransport(sp, k, xerr_idxp))
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((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 = &loopback_dev;
dev_hold(&loopback_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_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;
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 && !security_xfrm_flow_state_match(fl, dst->xfrm))
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->props.mode != XFRM_MODE_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 = last->u.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 struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family)
{
struct xfrm_policy_afinfo *afinfo;
if (unlikely(family >= NPROTO))
return NULL;
write_lock_bh(&xfrm_policy_afinfo_lock);
afinfo = xfrm_policy_afinfo[family];
if (unlikely(!afinfo))
write_unlock_bh(&xfrm_policy_afinfo_lock);
return afinfo;
}
static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo)
{
write_unlock_bh(&xfrm_policy_afinfo_lock);
}
static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
switch (event) {
case NETDEV_DOWN:
xfrm_flush_bundles();
}
return NOTIFY_DONE;
}
static struct notifier_block xfrm_dev_notifier = {
xfrm_dev_event,
NULL,
0
};
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, 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, NULL);
register_netdevice_notifier(&xfrm_dev_notifier);
}
void __init xfrm_init(void)
{
xfrm_state_init();
xfrm_policy_init();
xfrm_input_init();
}