linux/net/xfrm/xfrm_policy.c
Venkat Yekkirala 3bccfbc7a7 IPsec: fix handling of errors for socket policies
This treats the security errors encountered in the case of
socket policy matching, the same as how these are treated in
the case of main/sub policies, which is to return a full lookup
failure.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>
2006-10-11 23:59:39 -07:00

2094 lines
48 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, 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_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_policy_kill(pol);
killed++;
write_lock_bh(&xfrm_policy_lock);
goto again2;
}
}
xfrm_policy_count[dir] -= killed;
}
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.
*
* 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 = (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;
}
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) {
remote = &tmpl->id.daddr;
local = &tmpl->saddr;
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 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 (IS_ERR(policy))
return PTR_ERR(policy);
}
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 (IS_ERR(policy))
return PTR_ERR(policy);
}
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 (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 && 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) {
*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 = (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]) {
if (IS_ERR(pols[1]))
return 0;
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)
/* "-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 = &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_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;
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, pol))
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();
}