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xfrm_policy.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* xfrm_policy.c
*
* Changes:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <[email protected]>
* IPv6 support
* Kazunori MIYAZAWA @USAGI
* YOSHIFUJI Hideaki
* Split up af-specific portion
* Derek Atkins <[email protected]> Add the post_input processor
*
*/
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/cache.h>
#include <linux/cpu.h>
#include <linux/audit.h>
#include <linux/rhashtable.h>
#include <linux/if_tunnel.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/xfrm.h>
#include <net/ip.h>
#if IS_ENABLED(CONFIG_IPV6_MIP6)
#include <net/mip6.h>
#endif
#ifdef CONFIG_XFRM_STATISTICS
#include <net/snmp.h>
#endif
#ifdef CONFIG_XFRM_ESPINTCP
#include <net/espintcp.h>
#endif
#include "xfrm_hash.h"
#define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
#define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
#define XFRM_MAX_QUEUE_LEN 100
struct xfrm_flo {
struct dst_entry *dst_orig;
u8 flags;
};
/* prefixes smaller than this are stored in lists, not trees. */
#define INEXACT_PREFIXLEN_IPV4 16
#define INEXACT_PREFIXLEN_IPV6 48
struct xfrm_pol_inexact_node {
struct rb_node node;
union {
xfrm_address_t addr;
struct rcu_head rcu;
};
u8 prefixlen;
struct rb_root root;
/* the policies matching this node, can be empty list */
struct hlist_head hhead;
};
/* xfrm inexact policy search tree:
* xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
* |
* +---- root_d: sorted by daddr:prefix
* | |
* | xfrm_pol_inexact_node
* | |
* | +- root: sorted by saddr/prefix
* | | |
* | | xfrm_pol_inexact_node
* | | |
* | | + root: unused
* | | |
* | | + hhead: saddr:daddr policies
* | |
* | +- coarse policies and all any:daddr policies
* |
* +---- root_s: sorted by saddr:prefix
* | |
* | xfrm_pol_inexact_node
* | |
* | + root: unused
* | |
* | + hhead: saddr:any policies
* |
* +---- coarse policies and all any:any policies
*
* Lookups return four candidate lists:
* 1. any:any list from top-level xfrm_pol_inexact_bin
* 2. any:daddr list from daddr tree
* 3. saddr:daddr list from 2nd level daddr tree
* 4. saddr:any list from saddr tree
*
* This result set then needs to be searched for the policy with
* the lowest priority. If two results have same prio, youngest one wins.
*/
struct xfrm_pol_inexact_key {
possible_net_t net;
u32 if_id;
u16 family;
u8 dir, type;
};
struct xfrm_pol_inexact_bin {
struct xfrm_pol_inexact_key k;
struct rhash_head head;
/* list containing '*:*' policies */
struct hlist_head hhead;
seqcount_spinlock_t count;
/* tree sorted by daddr/prefix */
struct rb_root root_d;
/* tree sorted by saddr/prefix */
struct rb_root root_s;
/* slow path below */
struct list_head inexact_bins;
struct rcu_head rcu;
};
enum xfrm_pol_inexact_candidate_type {
XFRM_POL_CAND_BOTH,
XFRM_POL_CAND_SADDR,
XFRM_POL_CAND_DADDR,
XFRM_POL_CAND_ANY,
XFRM_POL_CAND_MAX,
};
struct xfrm_pol_inexact_candidates {
struct hlist_head *res[XFRM_POL_CAND_MAX];
};
static DEFINE_SPINLOCK(xfrm_if_cb_lock);
static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
__read_mostly;
static struct kmem_cache *xfrm_dst_cache __ro_after_init;
static __read_mostly seqcount_mutex_t xfrm_policy_hash_generation;
static struct rhashtable xfrm_policy_inexact_table;
static const struct rhashtable_params xfrm_pol_inexact_params;
static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
static int stale_bundle(struct dst_entry *dst);
static int xfrm_bundle_ok(struct xfrm_dst *xdst);
static void xfrm_policy_queue_process(struct timer_list *t);
static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
int dir);
static struct xfrm_pol_inexact_bin *
xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
u32 if_id);
static struct xfrm_pol_inexact_bin *
xfrm_policy_inexact_lookup_rcu(struct net *net,
u8 type, u16 family, u8 dir, u32 if_id);
static struct xfrm_policy *
xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
bool excl);
static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
struct xfrm_policy *policy);
static bool
xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
struct xfrm_pol_inexact_bin *b,
const xfrm_address_t *saddr,
const xfrm_address_t *daddr);
static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
{
return refcount_inc_not_zero(&policy->refcnt);
}
static inline bool
__xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
{
const struct flowi4 *fl4 = &fl->u.ip4;
return addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
(fl4->flowi4_proto == sel->proto || !sel->proto) &&
(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
}
static inline bool
__xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
{
const struct flowi6 *fl6 = &fl->u.ip6;
return addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
(fl6->flowi6_proto == sel->proto || !sel->proto) &&
(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
}
bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
unsigned short family)
{
switch (family) {
case AF_INET:
return __xfrm4_selector_match(sel, fl);
case AF_INET6:
return __xfrm6_selector_match(sel, fl);
}
return false;
}
static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
{
const struct xfrm_policy_afinfo *afinfo;
if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
return NULL;
rcu_read_lock();
afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
if (unlikely(!afinfo))
rcu_read_unlock();
return afinfo;
}
/* Called with rcu_read_lock(). */
static const struct xfrm_if_cb *xfrm_if_get_cb(void)
{
return rcu_dereference(xfrm_if_cb);
}
struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
const xfrm_address_t *saddr,
const xfrm_address_t *daddr,
int family, u32 mark)
{
const struct xfrm_policy_afinfo *afinfo;
struct dst_entry *dst;
afinfo = xfrm_policy_get_afinfo(family);
if (unlikely(afinfo == NULL))
return ERR_PTR(-EAFNOSUPPORT);
dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
rcu_read_unlock();
return dst;
}
EXPORT_SYMBOL(__xfrm_dst_lookup);
static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
int tos, int oif,
xfrm_address_t *prev_saddr,
xfrm_address_t *prev_daddr,
int family, u32 mark)
{
struct net *net = xs_net(x);
xfrm_address_t *saddr = &x->props.saddr;
xfrm_address_t *daddr = &x->id.daddr;
struct dst_entry *dst;
if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
saddr = x->coaddr;
daddr = prev_daddr;
}
if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
saddr = prev_saddr;
daddr = x->coaddr;
}
dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
if (!IS_ERR(dst)) {
if (prev_saddr != saddr)
memcpy(prev_saddr, saddr, sizeof(*prev_saddr));
if (prev_daddr != daddr)
memcpy(prev_daddr, daddr, sizeof(*prev_daddr));
}
return dst;
}
static inline unsigned long make_jiffies(long secs)
{
if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
return MAX_SCHEDULE_TIMEOUT-1;
else
return secs*HZ;
}
static void xfrm_policy_timer(struct timer_list *t)
{
struct xfrm_policy *xp = from_timer(xp, t, timer);
time64_t now = ktime_get_real_seconds();
time64_t next = TIME64_MAX;
int warn = 0;
int dir;
read_lock(&xp->lock);
if (unlikely(xp->walk.dead))
goto out;
dir = xfrm_policy_id2dir(xp->index);
if (xp->lft.hard_add_expires_seconds) {
time64_t 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) {
time64_t 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) {
time64_t 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) {
time64_t 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 != TIME64_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(struct net *net, gfp_t gfp)
{
struct xfrm_policy *policy;
policy = kzalloc(sizeof(struct xfrm_policy), gfp);
if (policy) {
write_pnet(&policy->xp_net, net);
INIT_LIST_HEAD(&policy->walk.all);
INIT_HLIST_NODE(&policy->bydst_inexact_list);
INIT_HLIST_NODE(&policy->bydst);
INIT_HLIST_NODE(&policy->byidx);
rwlock_init(&policy->lock);
refcount_set(&policy->refcnt, 1);
skb_queue_head_init(&policy->polq.hold_queue);
timer_setup(&policy->timer, xfrm_policy_timer, 0);
timer_setup(&policy->polq.hold_timer,
xfrm_policy_queue_process, 0);
}
return policy;
}
EXPORT_SYMBOL(xfrm_policy_alloc);
static void xfrm_policy_destroy_rcu(struct rcu_head *head)
{
struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
security_xfrm_policy_free(policy->security);
kfree(policy);
}
/* Destroy xfrm_policy: descendant resources must be released to this moment. */
void xfrm_policy_destroy(struct xfrm_policy *policy)
{
BUG_ON(!policy->walk.dead);
if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
BUG();
call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
}
EXPORT_SYMBOL(xfrm_policy_destroy);
/* Rule must be locked. Release descendant resources, announce
* entry dead. The rule must be unlinked from lists to the moment.
*/
static void xfrm_policy_kill(struct xfrm_policy *policy)
{
write_lock_bh(&policy->lock);
policy->walk.dead = 1;
write_unlock_bh(&policy->lock);
atomic_inc(&policy->genid);
if (del_timer(&policy->polq.hold_timer))
xfrm_pol_put(policy);
skb_queue_purge(&policy->polq.hold_queue);
if (del_timer(&policy->timer))
xfrm_pol_put(policy);
xfrm_pol_put(policy);
}
static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
static inline unsigned int idx_hash(struct net *net, u32 index)
{
return __idx_hash(index, net->xfrm.policy_idx_hmask);
}
/* calculate policy hash thresholds */
static void __get_hash_thresh(struct net *net,
unsigned short family, int dir,
u8 *dbits, u8 *sbits)
{
switch (family) {
case AF_INET:
*dbits = net->xfrm.policy_bydst[dir].dbits4;
*sbits = net->xfrm.policy_bydst[dir].sbits4;
break;
case AF_INET6:
*dbits = net->xfrm.policy_bydst[dir].dbits6;
*sbits = net->xfrm.policy_bydst[dir].sbits6;
break;
default:
*dbits = 0;
*sbits = 0;
}
}
static struct hlist_head *policy_hash_bysel(struct net *net,
const struct xfrm_selector *sel,
unsigned short family, int dir)
{
unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
unsigned int hash;
u8 dbits;
u8 sbits;
__get_hash_thresh(net, family, dir, &dbits, &sbits);
hash = __sel_hash(sel, family, hmask, dbits, sbits);
if (hash == hmask + 1)
return NULL;
return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
}
static struct hlist_head *policy_hash_direct(struct net *net,
const xfrm_address_t *daddr,
const xfrm_address_t *saddr,
unsigned short family, int dir)
{
unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
unsigned int hash;
u8 dbits;
u8 sbits;
__get_hash_thresh(net, family, dir, &dbits, &sbits);
hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
}
static void xfrm_dst_hash_transfer(struct net *net,
struct hlist_head *list,
struct hlist_head *ndsttable,
unsigned int nhashmask,
int dir)
{
struct hlist_node *tmp, *entry0 = NULL;
struct xfrm_policy *pol;
unsigned int h0 = 0;
u8 dbits;
u8 sbits;
redo:
hlist_for_each_entry_safe(pol, tmp, list, bydst) {
unsigned int h;
__get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
pol->family, nhashmask, dbits, sbits);
if (!entry0) {
hlist_del_rcu(&pol->bydst);
hlist_add_head_rcu(&pol->bydst, ndsttable + h);
h0 = h;
} else {
if (h != h0)
continue;
hlist_del_rcu(&pol->bydst);
hlist_add_behind_rcu(&pol->bydst, entry0);
}
entry0 = &pol->bydst;
}
if (!hlist_empty(list)) {
entry0 = NULL;
goto redo;
}
}
static void xfrm_idx_hash_transfer(struct hlist_head *list,
struct hlist_head *nidxtable,
unsigned int nhashmask)
{
struct hlist_node *tmp;
struct xfrm_policy *pol;
hlist_for_each_entry_safe(pol, tmp, list, byidx) {
unsigned int h;
h = __idx_hash(pol->index, nhashmask);
hlist_add_head(&pol->byidx, nidxtable+h);
}
}
static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
{
return ((old_hmask + 1) << 1) - 1;
}
static void xfrm_bydst_resize(struct net *net, int dir)
{
unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
unsigned int nhashmask = xfrm_new_hash_mask(hmask);
unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
struct hlist_head *ndst = xfrm_hash_alloc(nsize);
struct hlist_head *odst;
int i;
if (!ndst)
return;
spin_lock_bh(&net->xfrm.xfrm_policy_lock);
write_seqcount_begin(&xfrm_policy_hash_generation);
odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
lockdep_is_held(&net->xfrm.xfrm_policy_lock));
for (i = hmask; i >= 0; i--)
xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
net->xfrm.policy_bydst[dir].hmask = nhashmask;
write_seqcount_end(&xfrm_policy_hash_generation);
spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
synchronize_rcu();
xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
}
static void xfrm_byidx_resize(struct net *net, int total)
{
unsigned int hmask = net->xfrm.policy_idx_hmask;
unsigned int nhashmask = xfrm_new_hash_mask(hmask);
unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
struct hlist_head *oidx = net->xfrm.policy_byidx;
struct hlist_head *nidx = xfrm_hash_alloc(nsize);
int i;
if (!nidx)
return;
spin_lock_bh(&net->xfrm.xfrm_policy_lock);
for (i = hmask; i >= 0; i--)
xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
net->xfrm.policy_byidx = nidx;
net->xfrm.policy_idx_hmask = nhashmask;
spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
}
static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
{
unsigned int cnt = net->xfrm.policy_count[dir];
unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
if (total)
*total += cnt;
if ((hmask + 1) < xfrm_policy_hashmax &&
cnt > hmask)
return 1;
return 0;
}
static inline int xfrm_byidx_should_resize(struct net *net, int total)
{
unsigned int hmask = net->xfrm.policy_idx_hmask;
if ((hmask + 1) < xfrm_policy_hashmax &&
total > hmask)
return 1;
return 0;
}
void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
{
si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
si->spdhcnt = net->xfrm.policy_idx_hmask;
si->spdhmcnt = xfrm_policy_hashmax;
}
EXPORT_SYMBOL(xfrm_spd_getinfo);
static DEFINE_MUTEX(hash_resize_mutex);
static void xfrm_hash_resize(struct work_struct *work)
{
struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
int dir, total;
mutex_lock(&hash_resize_mutex);
total = 0;
for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
if (xfrm_bydst_should_resize(net, dir, &total))
xfrm_bydst_resize(net, dir);
}
if (xfrm_byidx_should_resize(net, total))
xfrm_byidx_resize(net, total);
mutex_unlock(&hash_resize_mutex);
}
/* Make sure *pol can be inserted into fastbin.
* Useful to check that later insert requests will be sucessful
* (provided xfrm_policy_lock is held throughout).
*/
static struct xfrm_pol_inexact_bin *
xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
{
struct xfrm_pol_inexact_bin *bin, *prev;
struct xfrm_pol_inexact_key k = {
.family = pol->family,
.type = pol->type,
.dir = dir,
.if_id = pol->if_id,
};
struct net *net = xp_net(pol);
lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
write_pnet(&k.net, net);
bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
xfrm_pol_inexact_params);
if (bin)
return bin;
bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
if (!bin)
return NULL;
bin->k = k;
INIT_HLIST_HEAD(&bin->hhead);
bin->root_d = RB_ROOT;
bin->root_s = RB_ROOT;
seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock);
prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
&bin->k, &bin->head,
xfrm_pol_inexact_params);
if (!prev) {
list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
return bin;
}
kfree(bin);
return IS_ERR(prev) ? NULL : prev;
}
static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
int family, u8 prefixlen)
{
if (xfrm_addr_any(addr, family))
return true;
if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
return true;
if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
return true;
return false;
}
static bool
xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
{
const xfrm_address_t *addr;
bool saddr_any, daddr_any;
u8 prefixlen;
addr = &policy->selector.saddr;
prefixlen = policy->selector.prefixlen_s;
saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
policy->family,
prefixlen);
addr = &policy->selector.daddr;
prefixlen = policy->selector.prefixlen_d;
daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
policy->family,
prefixlen);
return saddr_any && daddr_any;
}
static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
const xfrm_address_t *addr, u8 prefixlen)
{
node->addr = *addr;
node->prefixlen = prefixlen;
}
static struct xfrm_pol_inexact_node *
xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
{
struct xfrm_pol_inexact_node *node;
node = kzalloc(sizeof(*node), GFP_ATOMIC);
if (node)
xfrm_pol_inexact_node_init(node, addr, prefixlen);
return node;
}
static int xfrm_policy_addr_delta(const xfrm_address_t *a,
const xfrm_address_t *b,
u8 prefixlen, u16 family)
{
unsigned int pdw, pbi;
int delta = 0;
switch (family) {
case AF_INET:
if (sizeof(long) == 4 && prefixlen == 0)
return ntohl(a->a4) - ntohl(b->a4);
return (ntohl(a->a4) & ((~0UL << (32 - prefixlen)))) -
(ntohl(b->a4) & ((~0UL << (32 - prefixlen))));
case AF_INET6:
pdw = prefixlen >> 5;
pbi = prefixlen & 0x1f;
if (pdw) {
delta = memcmp(a->a6, b->a6, pdw << 2);
if (delta)
return delta;
}
if (pbi) {
u32 mask = ~0u << (32 - pbi);
delta = (ntohl(a->a6[pdw]) & mask) -
(ntohl(b->a6[pdw]) & mask);
}
break;
default:
break;
}
return delta;
}
static void xfrm_policy_inexact_list_reinsert(struct net *net,
struct xfrm_pol_inexact_node *n,
u16 family)
{
unsigned int matched_s, matched_d;
struct xfrm_policy *policy, *p;
matched_s = 0;
matched_d = 0;
list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
struct hlist_node *newpos = NULL;
bool matches_s, matches_d;
if (!policy->bydst_reinsert)
continue;
WARN_ON_ONCE(policy->family != family);
policy->bydst_reinsert = false;
hlist_for_each_entry(p, &n->hhead, bydst) {
if (policy->priority > p->priority)
newpos = &p->bydst;
else if (policy->priority == p->priority &&
policy->pos > p->pos)
newpos = &p->bydst;
else
break;
}
if (newpos)
hlist_add_behind_rcu(&policy->bydst, newpos);
else
hlist_add_head_rcu(&policy->bydst, &n->hhead);
/* paranoia checks follow.
* Check that the reinserted policy matches at least
* saddr or daddr for current node prefix.
*
* Matching both is fine, matching saddr in one policy
* (but not daddr) and then matching only daddr in another
* is a bug.
*/
matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
&n->addr,
n->prefixlen,
family) == 0;
matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
&n->addr,
n->prefixlen,
family) == 0;
if (matches_s && matches_d)
continue;
WARN_ON_ONCE(!matches_s && !matches_d);
if (matches_s)
matched_s++;
if (matches_d)
matched_d++;
WARN_ON_ONCE(matched_s && matched_d);
}
}
static void xfrm_policy_inexact_node_reinsert(struct net *net,
struct xfrm_pol_inexact_node *n,
struct rb_root *new,
u16 family)
{
struct xfrm_pol_inexact_node *node;
struct rb_node **p, *parent;
/* we should not have another subtree here */
WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
restart:
parent = NULL;
p = &new->rb_node;
while (*p) {
u8 prefixlen;
int delta;
parent = *p;
node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
prefixlen = min(node->prefixlen, n->prefixlen);
delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
prefixlen, family);
if (delta < 0) {
p = &parent->rb_left;
} else if (delta > 0) {
p = &parent->rb_right;
} else {
bool same_prefixlen = node->prefixlen == n->prefixlen;
struct xfrm_policy *tmp;
hlist_for_each_entry(tmp, &n->hhead, bydst) {
tmp->bydst_reinsert = true;
hlist_del_rcu(&tmp->bydst);
}
node->prefixlen = prefixlen;
xfrm_policy_inexact_list_reinsert(net, node, family);
if (same_prefixlen) {
kfree_rcu(n, rcu);
return;
}
rb_erase(*p, new);
kfree_rcu(n, rcu);
n = node;
goto restart;
}
}
rb_link_node_rcu(&n->node, parent, p);
rb_insert_color(&n->node, new);
}
/* merge nodes v and n */
static void xfrm_policy_inexact_node_merge(struct net *net,
struct xfrm_pol_inexact_node *v,
struct xfrm_pol_inexact_node *n,
u16 family)
{
struct xfrm_pol_inexact_node *node;
struct xfrm_policy *tmp;
struct rb_node *rnode;
/* To-be-merged node v has a subtree.
*
* Dismantle it and insert its nodes to n->root.
*/
while ((rnode = rb_first(&v->root)) != NULL) {
node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
rb_erase(&node->node, &v->root);
xfrm_policy_inexact_node_reinsert(net, node, &n->root,
family);
}
hlist_for_each_entry(tmp, &v->hhead, bydst) {
tmp->bydst_reinsert = true;
hlist_del_rcu(&tmp->bydst);
}
xfrm_policy_inexact_list_reinsert(net, n, family);
}
static struct xfrm_pol_inexact_node *
xfrm_policy_inexact_insert_node(struct net *net,
struct rb_root *root,
xfrm_address_t *addr,
u16 family, u8 prefixlen, u8 dir)
{
struct xfrm_pol_inexact_node *cached = NULL;
struct rb_node **p, *parent = NULL;
struct xfrm_pol_inexact_node *node;
p = &root->rb_node;
while (*p) {
int delta;
parent = *p;
node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
delta = xfrm_policy_addr_delta(addr, &node->addr,
node->prefixlen,
family);
if (delta == 0 && prefixlen >= node->prefixlen) {
WARN_ON_ONCE(cached); /* ipsec policies got lost */
return node;
}