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xfrm_state.c
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/*
* xfrm_state.c
*
* Changes:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
* IPv6 support
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific functions
* Derek Atkins <derek@ihtfp.com>
* Add UDP Encapsulation
*
*/
#include <linux/workqueue.h>
#include <net/xfrm.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/module.h>
#include <linux/cache.h>
#include <linux/audit.h>
#include <asm/uaccess.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include "xfrm_hash.h"
#define xfrm_state_deref_prot(table, net) \
rcu_dereference_protected((table), lockdep_is_held(&(net)->xfrm.xfrm_state_lock))
static void xfrm_state_gc_task(struct work_struct *work);
/* Each xfrm_state may be linked to two tables:
1. Hash table by (spi,daddr,ah/esp) to find SA by SPI. (input,ctl)
2. Hash table by (daddr,family,reqid) to find what SAs exist for given
destination/tunnel endpoint. (output)
*/
static unsigned int xfrm_state_hashmax __read_mostly = 1 * 1024 * 1024;
static __read_mostly seqcount_t xfrm_state_hash_generation = SEQCNT_ZERO(xfrm_state_hash_generation);
static DECLARE_WORK(xfrm_state_gc_work, xfrm_state_gc_task);
static HLIST_HEAD(xfrm_state_gc_list);
static inline bool xfrm_state_hold_rcu(struct xfrm_state __rcu *x)
{
return atomic_inc_not_zero(&x->refcnt);
}
static inline unsigned int xfrm_dst_hash(struct net *net,
const xfrm_address_t *daddr,
const xfrm_address_t *saddr,
u32 reqid,
unsigned short family)
{
return __xfrm_dst_hash(daddr, saddr, reqid, family, net->xfrm.state_hmask);
}
static inline unsigned int xfrm_src_hash(struct net *net,
const xfrm_address_t *daddr,
const xfrm_address_t *saddr,
unsigned short family)
{
return __xfrm_src_hash(daddr, saddr, family, net->xfrm.state_hmask);
}
static inline unsigned int
xfrm_spi_hash(struct net *net, const xfrm_address_t *daddr,
__be32 spi, u8 proto, unsigned short family)
{
return __xfrm_spi_hash(daddr, spi, proto, family, net->xfrm.state_hmask);
}
static void xfrm_hash_transfer(struct hlist_head *list,
struct hlist_head *ndsttable,
struct hlist_head *nsrctable,
struct hlist_head *nspitable,
unsigned int nhashmask)
{
struct hlist_node *tmp;
struct xfrm_state *x;
hlist_for_each_entry_safe(x, tmp, list, bydst) {
unsigned int h;
h = __xfrm_dst_hash(&x->id.daddr, &x->props.saddr,
x->props.reqid, x->props.family,
nhashmask);
hlist_add_head_rcu(&x->bydst, ndsttable + h);
h = __xfrm_src_hash(&x->id.daddr, &x->props.saddr,
x->props.family,
nhashmask);
hlist_add_head_rcu(&x->bysrc, nsrctable + h);
if (x->id.spi) {
h = __xfrm_spi_hash(&x->id.daddr, x->id.spi,
x->id.proto, x->props.family,
nhashmask);
hlist_add_head_rcu(&x->byspi, nspitable + h);
}
}
}
static unsigned long xfrm_hash_new_size(unsigned int state_hmask)
{
return ((state_hmask + 1) << 1) * sizeof(struct hlist_head);
}
static void xfrm_hash_resize(struct work_struct *work)
{
struct net *net = container_of(work, struct net, xfrm.state_hash_work);
struct hlist_head *ndst, *nsrc, *nspi, *odst, *osrc, *ospi;
unsigned long nsize, osize;
unsigned int nhashmask, ohashmask;
int i;
nsize = xfrm_hash_new_size(net->xfrm.state_hmask);
ndst = xfrm_hash_alloc(nsize);
if (!ndst)
return;
nsrc = xfrm_hash_alloc(nsize);
if (!nsrc) {
xfrm_hash_free(ndst, nsize);
return;
}
nspi = xfrm_hash_alloc(nsize);
if (!nspi) {
xfrm_hash_free(ndst, nsize);
xfrm_hash_free(nsrc, nsize);
return;
}
spin_lock_bh(&net->xfrm.xfrm_state_lock);
write_seqcount_begin(&xfrm_state_hash_generation);
nhashmask = (nsize / sizeof(struct hlist_head)) - 1U;
odst = xfrm_state_deref_prot(net->xfrm.state_bydst, net);
for (i = net->xfrm.state_hmask; i >= 0; i--)
xfrm_hash_transfer(odst + i, ndst, nsrc, nspi, nhashmask);
osrc = xfrm_state_deref_prot(net->xfrm.state_bysrc, net);
ospi = xfrm_state_deref_prot(net->xfrm.state_byspi, net);
ohashmask = net->xfrm.state_hmask;
rcu_assign_pointer(net->xfrm.state_bydst, ndst);
rcu_assign_pointer(net->xfrm.state_bysrc, nsrc);
rcu_assign_pointer(net->xfrm.state_byspi, nspi);
net->xfrm.state_hmask = nhashmask;
write_seqcount_end(&xfrm_state_hash_generation);
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
osize = (ohashmask + 1) * sizeof(struct hlist_head);
synchronize_rcu();
xfrm_hash_free(odst, osize);
xfrm_hash_free(osrc, osize);
xfrm_hash_free(ospi, osize);
}
static DEFINE_SPINLOCK(xfrm_state_afinfo_lock);
static struct xfrm_state_afinfo __rcu *xfrm_state_afinfo[NPROTO];
static DEFINE_SPINLOCK(xfrm_state_gc_lock);
int __xfrm_state_delete(struct xfrm_state *x);
int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
bool km_is_alive(const struct km_event *c);
void km_state_expired(struct xfrm_state *x, int hard, u32 portid);
static DEFINE_SPINLOCK(xfrm_type_lock);
int xfrm_register_type(const struct xfrm_type *type, unsigned short family)
{
struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
const struct xfrm_type **typemap;
int err = 0;
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
typemap = afinfo->type_map;
spin_lock_bh(&xfrm_type_lock);
if (likely(typemap[type->proto] == NULL))
typemap[type->proto] = type;
else
err = -EEXIST;
spin_unlock_bh(&xfrm_type_lock);
xfrm_state_put_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_register_type);
int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family)
{
struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
const struct xfrm_type **typemap;
int err = 0;
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
typemap = afinfo->type_map;
spin_lock_bh(&xfrm_type_lock);
if (unlikely(typemap[type->proto] != type))
err = -ENOENT;
else
typemap[type->proto] = NULL;
spin_unlock_bh(&xfrm_type_lock);
xfrm_state_put_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_unregister_type);
static const struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
{
struct xfrm_state_afinfo *afinfo;
const struct xfrm_type **typemap;
const struct xfrm_type *type;
int modload_attempted = 0;
retry:
afinfo = xfrm_state_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_state_put_afinfo(afinfo);
request_module("xfrm-type-%d-%d", family, proto);
modload_attempted = 1;
goto retry;
}
xfrm_state_put_afinfo(afinfo);
return type;
}
static void xfrm_put_type(const struct xfrm_type *type)
{
module_put(type->owner);
}
static DEFINE_SPINLOCK(xfrm_mode_lock);
int xfrm_register_mode(struct xfrm_mode *mode, int family)
{
struct xfrm_state_afinfo *afinfo;
struct xfrm_mode **modemap;
int err;
if (unlikely(mode->encap >= XFRM_MODE_MAX))
return -EINVAL;
afinfo = xfrm_state_get_afinfo(family);
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
err = -EEXIST;
modemap = afinfo->mode_map;
spin_lock_bh(&xfrm_mode_lock);
if (modemap[mode->encap])
goto out;
err = -ENOENT;
if (!try_module_get(afinfo->owner))
goto out;
mode->afinfo = afinfo;
modemap[mode->encap] = mode;
err = 0;
out:
spin_unlock_bh(&xfrm_mode_lock);
xfrm_state_put_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_register_mode);
int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
{
struct xfrm_state_afinfo *afinfo;
struct xfrm_mode **modemap;
int err;
if (unlikely(mode->encap >= XFRM_MODE_MAX))
return -EINVAL;
afinfo = xfrm_state_get_afinfo(family);
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
err = -ENOENT;
modemap = afinfo->mode_map;
spin_lock_bh(&xfrm_mode_lock);
if (likely(modemap[mode->encap] == mode)) {
modemap[mode->encap] = NULL;
module_put(mode->afinfo->owner);
err = 0;
}
spin_unlock_bh(&xfrm_mode_lock);
xfrm_state_put_afinfo(afinfo);
return err;
}
EXPORT_SYMBOL(xfrm_unregister_mode);
static struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
{
struct xfrm_state_afinfo *afinfo;
struct xfrm_mode *mode;
int modload_attempted = 0;
if (unlikely(encap >= XFRM_MODE_MAX))
return NULL;
retry:
afinfo = xfrm_state_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_state_put_afinfo(afinfo);
request_module("xfrm-mode-%d-%d", family, encap);
modload_attempted = 1;
goto retry;
}
xfrm_state_put_afinfo(afinfo);
return mode;
}
static void xfrm_put_mode(struct xfrm_mode *mode)
{
module_put(mode->owner);
}
static void xfrm_state_gc_destroy(struct xfrm_state *x)
{
tasklet_hrtimer_cancel(&x->mtimer);
del_timer_sync(&x->rtimer);
kfree(x->aead);
kfree(x->aalg);
kfree(x->ealg);
kfree(x->calg);
kfree(x->encap);
kfree(x->coaddr);
kfree(x->replay_esn);
kfree(x->preplay_esn);
if (x->inner_mode)
xfrm_put_mode(x->inner_mode);
if (x->inner_mode_iaf)
xfrm_put_mode(x->inner_mode_iaf);
if (x->outer_mode)
xfrm_put_mode(x->outer_mode);
if (x->type) {
x->type->destructor(x);
xfrm_put_type(x->type);
}
security_xfrm_state_free(x);
kfree(x);
}
static void xfrm_state_gc_task(struct work_struct *work)
{
struct xfrm_state *x;
struct hlist_node *tmp;
struct hlist_head gc_list;
spin_lock_bh(&xfrm_state_gc_lock);
hlist_move_list(&xfrm_state_gc_list, &gc_list);
spin_unlock_bh(&xfrm_state_gc_lock);
synchronize_rcu();
hlist_for_each_entry_safe(x, tmp, &gc_list, gclist)
xfrm_state_gc_destroy(x);
}
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 enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
{
struct tasklet_hrtimer *thr = container_of(me, struct tasklet_hrtimer, timer);
struct xfrm_state *x = container_of(thr, struct xfrm_state, mtimer);
unsigned long now = get_seconds();
long next = LONG_MAX;
int warn = 0;
int err = 0;
spin_lock(&x->lock);
if (x->km.state == XFRM_STATE_DEAD)
goto out;
if (x->km.state == XFRM_STATE_EXPIRED)
goto expired;
if (x->lft.hard_add_expires_seconds) {
long tmo = x->lft.hard_add_expires_seconds +
x->curlft.add_time - now;
if (tmo <= 0) {
if (x->xflags & XFRM_SOFT_EXPIRE) {
/* enter hard expire without soft expire first?!
* setting a new date could trigger this.
* workarbound: fix x->curflt.add_time by below:
*/
x->curlft.add_time = now - x->saved_tmo - 1;
tmo = x->lft.hard_add_expires_seconds - x->saved_tmo;
} else
goto expired;
}
if (tmo < next)
next = tmo;
}
if (x->lft.hard_use_expires_seconds) {
long tmo = x->lft.hard_use_expires_seconds +
(x->curlft.use_time ? : now) - now;
if (tmo <= 0)
goto expired;
if (tmo < next)
next = tmo;
}
if (x->km.dying)
goto resched;
if (x->lft.soft_add_expires_seconds) {
long tmo = x->lft.soft_add_expires_seconds +
x->curlft.add_time - now;
if (tmo <= 0) {
warn = 1;
x->xflags &= ~XFRM_SOFT_EXPIRE;
} else if (tmo < next) {
next = tmo;
x->xflags |= XFRM_SOFT_EXPIRE;
x->saved_tmo = tmo;
}
}
if (x->lft.soft_use_expires_seconds) {
long tmo = x->lft.soft_use_expires_seconds +
(x->curlft.use_time ? : now) - now;
if (tmo <= 0)
warn = 1;
else if (tmo < next)
next = tmo;
}
x->km.dying = warn;
if (warn)
km_state_expired(x, 0, 0);
resched:
if (next != LONG_MAX) {
tasklet_hrtimer_start(&x->mtimer, ktime_set(next, 0), HRTIMER_MODE_REL);
}
goto out;
expired:
if (x->km.state == XFRM_STATE_ACQ && x->id.spi == 0)
x->km.state = XFRM_STATE_EXPIRED;
err = __xfrm_state_delete(x);
if (!err)
km_state_expired(x, 1, 0);
xfrm_audit_state_delete(x, err ? 0 : 1, true);
out:
spin_unlock(&x->lock);
return HRTIMER_NORESTART;
}
static void xfrm_replay_timer_handler(unsigned long data);
struct xfrm_state *xfrm_state_alloc(struct net *net)
{
struct xfrm_state *x;
x = kzalloc(sizeof(struct xfrm_state), GFP_ATOMIC);
if (x) {
write_pnet(&x->xs_net, net);
atomic_set(&x->refcnt, 1);
atomic_set(&x->tunnel_users, 0);
INIT_LIST_HEAD(&x->km.all);
INIT_HLIST_NODE(&x->bydst);
INIT_HLIST_NODE(&x->bysrc);
INIT_HLIST_NODE(&x->byspi);
tasklet_hrtimer_init(&x->mtimer, xfrm_timer_handler,
CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
setup_timer(&x->rtimer, xfrm_replay_timer_handler,
(unsigned long)x);
x->curlft.add_time = get_seconds();
x->lft.soft_byte_limit = XFRM_INF;
x->lft.soft_packet_limit = XFRM_INF;
x->lft.hard_byte_limit = XFRM_INF;
x->lft.hard_packet_limit = XFRM_INF;
x->replay_maxage = 0;
x->replay_maxdiff = 0;
x->inner_mode = NULL;
x->inner_mode_iaf = NULL;
spin_lock_init(&x->lock);
}
return x;
}
EXPORT_SYMBOL(xfrm_state_alloc);
void __xfrm_state_destroy(struct xfrm_state *x)
{
WARN_ON(x->km.state != XFRM_STATE_DEAD);
spin_lock_bh(&xfrm_state_gc_lock);
hlist_add_head(&x->gclist, &xfrm_state_gc_list);
spin_unlock_bh(&xfrm_state_gc_lock);
schedule_work(&xfrm_state_gc_work);
}
EXPORT_SYMBOL(__xfrm_state_destroy);
int __xfrm_state_delete(struct xfrm_state *x)
{
struct net *net = xs_net(x);
int err = -ESRCH;
if (x->km.state != XFRM_STATE_DEAD) {
x->km.state = XFRM_STATE_DEAD;
spin_lock(&net->xfrm.xfrm_state_lock);
list_del(&x->km.all);
hlist_del_rcu(&x->bydst);
hlist_del_rcu(&x->bysrc);
if (x->id.spi)
hlist_del_rcu(&x->byspi);
net->xfrm.state_num--;
spin_unlock(&net->xfrm.xfrm_state_lock);
/* All xfrm_state objects are created by xfrm_state_alloc.
* The xfrm_state_alloc call gives a reference, and that
* is what we are dropping here.
*/
xfrm_state_put(x);
err = 0;
}
return err;
}
EXPORT_SYMBOL(__xfrm_state_delete);
int xfrm_state_delete(struct xfrm_state *x)
{
int err;
spin_lock_bh(&x->lock);
err = __xfrm_state_delete(x);
spin_unlock_bh(&x->lock);
return err;
}
EXPORT_SYMBOL(xfrm_state_delete);
#ifdef CONFIG_SECURITY_NETWORK_XFRM
static inline int
xfrm_state_flush_secctx_check(struct net *net, u8 proto, bool task_valid)
{
int i, err = 0;
for (i = 0; i <= net->xfrm.state_hmask; i++) {
struct xfrm_state *x;
hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
if (xfrm_id_proto_match(x->id.proto, proto) &&
(err = security_xfrm_state_delete(x)) != 0) {
xfrm_audit_state_delete(x, 0, task_valid);
return err;
}
}
}
return err;
}
#else
static inline int
xfrm_state_flush_secctx_check(struct net *net, u8 proto, bool task_valid)
{
return 0;
}
#endif
int xfrm_state_flush(struct net *net, u8 proto, bool task_valid)
{
int i, err = 0, cnt = 0;
spin_lock_bh(&net->xfrm.xfrm_state_lock);
err = xfrm_state_flush_secctx_check(net, proto, task_valid);
if (err)
goto out;
err = -ESRCH;
for (i = 0; i <= net->xfrm.state_hmask; i++) {
struct xfrm_state *x;
restart:
hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
if (!xfrm_state_kern(x) &&
xfrm_id_proto_match(x->id.proto, proto)) {
xfrm_state_hold(x);
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
err = xfrm_state_delete(x);
xfrm_audit_state_delete(x, err ? 0 : 1,
task_valid);
xfrm_state_put(x);
if (!err)
cnt++;
spin_lock_bh(&net->xfrm.xfrm_state_lock);
goto restart;
}
}
}
if (cnt)
err = 0;
out:
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
return err;
}
EXPORT_SYMBOL(xfrm_state_flush);
void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si)
{
spin_lock_bh(&net->xfrm.xfrm_state_lock);
si->sadcnt = net->xfrm.state_num;
si->sadhcnt = net->xfrm.state_hmask;
si->sadhmcnt = xfrm_state_hashmax;
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
}
EXPORT_SYMBOL(xfrm_sad_getinfo);
static int
xfrm_init_tempstate(struct xfrm_state *x, const struct flowi *fl,
const struct xfrm_tmpl *tmpl,
const xfrm_address_t *daddr, const xfrm_address_t *saddr,
unsigned short family)
{
struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
if (!afinfo)
return -1;
afinfo->init_tempsel(&x->sel, fl);
if (family != tmpl->encap_family) {
xfrm_state_put_afinfo(afinfo);
afinfo = xfrm_state_get_afinfo(tmpl->encap_family);
if (!afinfo)
return -1;
}
afinfo->init_temprop(x, tmpl, daddr, saddr);
xfrm_state_put_afinfo(afinfo);
return 0;
}
static struct xfrm_state *__xfrm_state_lookup(struct net *net, u32 mark,
const xfrm_address_t *daddr,
__be32 spi, u8 proto,
unsigned short family)
{
unsigned int h = xfrm_spi_hash(net, daddr, spi, proto, family);
struct xfrm_state *x;
hlist_for_each_entry_rcu(x, net->xfrm.state_byspi + h, byspi) {
if (x->props.family != family ||
x->id.spi != spi ||
x->id.proto != proto ||
!xfrm_addr_equal(&x->id.daddr, daddr, family))
continue;
if ((mark & x->mark.m) != x->mark.v)
continue;
if (!xfrm_state_hold_rcu(x))
continue;
return x;
}
return NULL;
}
static struct xfrm_state *__xfrm_state_lookup_byaddr(struct net *net, u32 mark,
const xfrm_address_t *daddr,
const xfrm_address_t *saddr,
u8 proto, unsigned short family)
{
unsigned int h = xfrm_src_hash(net, daddr, saddr, family);
struct xfrm_state *x;
hlist_for_each_entry_rcu(x, net->xfrm.state_bysrc + h, bysrc) {
if (x->props.family != family ||
x->id.proto != proto ||
!xfrm_addr_equal(&x->id.daddr, daddr, family) ||
!xfrm_addr_equal(&x->props.saddr, saddr, family))
continue;
if ((mark & x->mark.m) != x->mark.v)
continue;
if (!xfrm_state_hold_rcu(x))
continue;
return x;
}
return NULL;
}
static inline struct xfrm_state *
__xfrm_state_locate(struct xfrm_state *x, int use_spi, int family)
{
struct net *net = xs_net(x);
u32 mark = x->mark.v & x->mark.m;
if (use_spi)
return __xfrm_state_lookup(net, mark, &x->id.daddr,
x->id.spi, x->id.proto, family);
else
return __xfrm_state_lookup_byaddr(net, mark,
&x->id.daddr,
&x->props.saddr,
x->id.proto, family);
}
static void xfrm_hash_grow_check(struct net *net, int have_hash_collision)
{
if (have_hash_collision &&
(net->xfrm.state_hmask + 1) < xfrm_state_hashmax &&
net->xfrm.state_num > net->xfrm.state_hmask)
schedule_work(&net->xfrm.state_hash_work);
}
static void xfrm_state_look_at(struct xfrm_policy *pol, struct xfrm_state *x,
const struct flowi *fl, unsigned short family,
struct xfrm_state **best, int *acq_in_progress,
int *error)
{
/* Resolution logic:
* 1. There is a valid state with matching selector. Done.
* 2. Valid state with inappropriate selector. Skip.
*
* Entering area of "sysdeps".
*
* 3. If state is not valid, selector is temporary, it selects
* only session which triggered previous resolution. Key
* manager will do something to install a state with proper
* selector.
*/
if (x->km.state == XFRM_STATE_VALID) {
if ((x->sel.family &&
!xfrm_selector_match(&x->sel, fl, x->sel.family)) ||
!security_xfrm_state_pol_flow_match(x, pol, fl))
return;
if (!*best ||
(*best)->km.dying > x->km.dying ||
((*best)->km.dying == x->km.dying &&
(*best)->curlft.add_time < x->curlft.add_time))
*best = x;
} else if (x->km.state == XFRM_STATE_ACQ) {
*acq_in_progress = 1;
} else if (x->km.state == XFRM_STATE_ERROR ||
x->km.state == XFRM_STATE_EXPIRED) {
if (xfrm_selector_match(&x->sel, fl, x->sel.family) &&
security_xfrm_state_pol_flow_match(x, pol, fl))
*error = -ESRCH;
}
}
struct xfrm_state *
xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr,
const struct flowi *fl, struct xfrm_tmpl *tmpl,
struct xfrm_policy *pol, int *err,
unsigned short family)
{
static xfrm_address_t saddr_wildcard = { };
struct net *net = xp_net(pol);
unsigned int h, h_wildcard;
struct xfrm_state *x, *x0, *to_put;
int acquire_in_progress = 0;
int error = 0;
struct xfrm_state *best = NULL;
u32 mark = pol->mark.v & pol->mark.m;
unsigned short encap_family = tmpl->encap_family;
unsigned int sequence;
struct km_event c;
to_put = NULL;
sequence = read_seqcount_begin(&xfrm_state_hash_generation);
rcu_read_lock();
h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family);
hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {
if (x->props.family == encap_family &&
x->props.reqid == tmpl->reqid &&
(mark & x->mark.m) == x->mark.v &&
!(x->props.flags & XFRM_STATE_WILDRECV) &&
xfrm_state_addr_check(x, daddr, saddr, encap_family) &&
tmpl->mode == x->props.mode &&
tmpl->id.proto == x->id.proto &&
(tmpl->id.spi == x->id.spi || !tmpl->id.spi))
xfrm_state_look_at(pol, x, fl, encap_family,
&best, &acquire_in_progress, &error);
}
if (best || acquire_in_progress)
goto found;
h_wildcard = xfrm_dst_hash(net, daddr, &saddr_wildcard, tmpl->reqid, encap_family);
hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h_wildcard, bydst) {
if (x->props.family == encap_family &&
x->props.reqid == tmpl->reqid &&
(mark & x->mark.m) == x->mark.v &&
!(x->props.flags & XFRM_STATE_WILDRECV) &&
xfrm_addr_equal(&x->id.daddr, daddr, encap_family) &&
tmpl->mode == x->props.mode &&
tmpl->id.proto == x->id.proto &&
(tmpl->id.spi == x->id.spi || !tmpl->id.spi))
xfrm_state_look_at(pol, x, fl, encap_family,
&best, &acquire_in_progress, &error);
}
found:
x = best;
if (!x && !error && !acquire_in_progress) {
if (tmpl->id.spi &&
(x0 = __xfrm_state_lookup(net, mark, daddr, tmpl->id.spi,
tmpl->id.proto, encap_family)) != NULL) {
to_put = x0;
error = -EEXIST;
goto out;
}
c.net = net;
/* If the KMs have no listeners (yet...), avoid allocating an SA
* for each and every packet - garbage collection might not
* handle the flood.
*/
if (!km_is_alive(&c)) {
error = -ESRCH;
goto out;
}
x = xfrm_state_alloc(net);
if (x == NULL) {
error = -ENOMEM;
goto out;
}
/* Initialize temporary state matching only
* to current session. */
xfrm_init_tempstate(x, fl, tmpl, daddr, saddr, family);
memcpy(&x->mark, &pol->mark, sizeof(x->mark));
error = security_xfrm_state_alloc_acquire(x, pol->security, fl->flowi_secid);
if (error) {
x->km.state = XFRM_STATE_DEAD;
to_put = x;
x = NULL;
goto out;
}
if (km_query(x, tmpl, pol) == 0) {
spin_lock_bh(&net->xfrm.xfrm_state_lock);
x->km.state = XFRM_STATE_ACQ;
list_add(&x->km.all, &net->xfrm.state_all);
hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);
h = xfrm_src_hash(net, daddr, saddr, encap_family);
hlist_add_head_rcu(&x->bysrc, net->xfrm.state_bysrc + h);
if (x->id.spi) {
h = xfrm_spi_hash(net, &x->id.daddr, x->id.spi, x->id.proto, encap_family);
hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
}
x->lft.hard_add_expires_seconds = net->xfrm.sysctl_acq_expires;
tasklet_hrtimer_start(&x->mtimer, ktime_set(net->xfrm.sysctl_acq_expires, 0), HRTIMER_MODE_REL);
net->xfrm.state_num++;
xfrm_hash_grow_check(net, x->bydst.next != NULL);
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
} else {
x->km.state = XFRM_STATE_DEAD;
to_put = x;
x = NULL;
error = -ESRCH;
}
}
out:
if (x) {
if (!xfrm_state_hold_rcu(x)) {
*err = -EAGAIN;
x = NULL;
}
} else {
*err = acquire_in_progress ? -EAGAIN : error;
}
rcu_read_unlock();
if (to_put)
xfrm_state_put(to_put);
if (read_seqcount_retry(&xfrm_state_hash_generation, sequence)) {
*err = -EAGAIN;
if (x) {
xfrm_state_put(x);
x = NULL;
}
}
return x;
}
struct xfrm_state *
xfrm_stateonly_find(struct net *net, u32 mark,
xfrm_address_t *daddr, xfrm_address_t *saddr,
unsigned short family, u8 mode, u8 proto, u32 reqid)
{
unsigned int h;
struct xfrm_state *rx = NULL, *x = NULL;
spin_lock_bh(&net->xfrm.xfrm_state_lock);
h = xfrm_dst_hash(net, daddr, saddr, reqid, family);
hlist_for_each_entry(x, net->xfrm.state_bydst+h, bydst) {
if (x->props.family == family &&
x->props.reqid == reqid &&
(mark & x->mark.m) == x->mark.v &&
!(x->props.flags & XFRM_STATE_WILDRECV) &&
xfrm_state_addr_check(x, daddr, saddr, family) &&
mode == x->props.mode &&
proto == x->id.proto &&
x->km.state == XFRM_STATE_VALID) {
rx = x;
break;
}
}
if (rx)
xfrm_state_hold(rx);
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
return rx;
}
EXPORT_SYMBOL(xfrm_stateonly_find);
struct xfrm_state *xfrm_state_lookup_byspi(struct net *net, __be32 spi,
unsigned short family)
{
struct xfrm_state *x;
struct xfrm_state_walk *w;
spin_lock_bh(&net->xfrm.xfrm_state_lock);
list_for_each_entry(w, &net->xfrm.state_all, all) {
x = container_of(w, struct xfrm_state, km);
if (x->props.family != family ||
x->id.spi != spi)
continue;
xfrm_state_hold(x);
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
return x;
}
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
return NULL;
}
EXPORT_SYMBOL(xfrm_state_lookup_byspi);
static void __xfrm_state_insert(struct xfrm_state *x)
{
struct net *net = xs_net(x);
unsigned int h;
list_add(&x->km.all, &net->xfrm.state_all);
h = xfrm_dst_hash(net, &x->id.daddr, &x->props.saddr,
x->props.reqid, x->props.family);
hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);
h = xfrm_src_hash(net, &x->id.daddr, &x->props.saddr, x->props.family);
hlist_add_head_rcu(&x->bysrc, net->xfrm.state_bysrc + h);
if (x->id.spi) {
h = xfrm_spi_hash(net, &x->id.daddr, x->id.spi, x->id.proto,
x->props.family);
hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
}
tasklet_hrtimer_start(&x->mtimer, ktime_set(1, 0), HRTIMER_MODE_REL);
if (x->replay_maxage)
mod_timer(&x->rtimer, jiffies + x->replay_maxage);