diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/xfrm/xfrm_policy.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/xfrm/xfrm_policy.c')
-rw-r--r-- | net/xfrm/xfrm_policy.c | 1367 |
1 files changed, 1367 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c new file mode 100644 index 0000000..8082807 --- /dev/null +++ b/net/xfrm/xfrm_policy.c @@ -0,0 +1,1367 @@ +/* + * 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 <asm/bug.h> +#include <linux/config.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/module.h> +#include <net/xfrm.h> +#include <net/ip.h> + +DECLARE_MUTEX(xfrm_cfg_sem); +EXPORT_SYMBOL(xfrm_cfg_sem); + +static DEFINE_RWLOCK(xfrm_policy_lock); + +struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2]; +EXPORT_SYMBOL(xfrm_policy_list); + +static DEFINE_RWLOCK(xfrm_policy_afinfo_lock); +static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO]; + +static kmem_cache_t *xfrm_dst_cache; + +static struct work_struct xfrm_policy_gc_work; +static struct list_head xfrm_policy_gc_list = + LIST_HEAD_INIT(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); + +int xfrm_register_type(struct xfrm_type *type, unsigned short family) +{ + struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); + struct xfrm_type_map *typemap; + int err = 0; + + if (unlikely(afinfo == NULL)) + return -EAFNOSUPPORT; + typemap = afinfo->type_map; + + write_lock(&typemap->lock); + if (likely(typemap->map[type->proto] == NULL)) + typemap->map[type->proto] = type; + else + err = -EEXIST; + write_unlock(&typemap->lock); + xfrm_policy_put_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_get_afinfo(family); + struct xfrm_type_map *typemap; + int err = 0; + + if (unlikely(afinfo == NULL)) + return -EAFNOSUPPORT; + typemap = afinfo->type_map; + + write_lock(&typemap->lock); + if (unlikely(typemap->map[type->proto] != type)) + err = -ENOENT; + else + typemap->map[type->proto] = NULL; + write_unlock(&typemap->lock); + xfrm_policy_put_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_map *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; + + read_lock(&typemap->lock); + type = typemap->map[proto]; + if (unlikely(type && !try_module_get(type->owner))) + type = NULL; + read_unlock(&typemap->lock); + 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; +} +EXPORT_SYMBOL(xfrm_get_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); +} + +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 = xp->index & 7; + + 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); + 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); + km_policy_expired(xp, dir, 1); + xfrm_policy_delete(xp, dir); + 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(int gfp) +{ + struct xfrm_policy *policy; + + policy = kmalloc(sizeof(struct xfrm_policy), gfp); + + if (policy) { + memset(policy, 0, sizeof(struct xfrm_policy)); + atomic_set(&policy->refcnt, 1); + rwlock_init(&policy->lock); + 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) +{ + if (!policy->dead) + BUG(); + + if (policy->bundles) + BUG(); + + if (del_timer(&policy->timer)) + BUG(); + + 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 list_head *entry, *tmp; + struct list_head gc_list = LIST_HEAD_INIT(gc_list); + + spin_lock_bh(&xfrm_policy_gc_lock); + list_splice_init(&xfrm_policy_gc_list, &gc_list); + spin_unlock_bh(&xfrm_policy_gc_lock); + + list_for_each_safe(entry, tmp, &gc_list) { + policy = list_entry(entry, struct xfrm_policy, list); + 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); + list_add(&policy->list, &xfrm_policy_gc_list); + spin_unlock(&xfrm_policy_gc_lock); + + schedule_work(&xfrm_policy_gc_work); +} + +/* 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(int dir) +{ + u32 idx; + struct xfrm_policy *p; + static u32 idx_generator; + + for (;;) { + idx = (idx_generator | dir); + idx_generator += 8; + if (idx == 0) + idx = 8; + for (p = xfrm_policy_list[dir]; p; p = p->next) { + if (p->index == idx) + break; + } + if (!p) + return idx; + } +} + +int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) +{ + struct xfrm_policy *pol, **p; + struct xfrm_policy *delpol = NULL; + struct xfrm_policy **newpos = NULL; + + write_lock_bh(&xfrm_policy_lock); + for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) { + if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0) { + if (excl) { + write_unlock_bh(&xfrm_policy_lock); + return -EEXIST; + } + *p = pol->next; + delpol = pol; + if (policy->priority > pol->priority) + continue; + } else if (policy->priority >= pol->priority) { + p = &pol->next; + continue; + } + if (!newpos) + newpos = p; + if (delpol) + break; + p = &pol->next; + } + if (newpos) + p = newpos; + xfrm_pol_hold(policy); + policy->next = *p; + *p = policy; + atomic_inc(&flow_cache_genid); + policy->index = delpol ? delpol->index : xfrm_gen_index(dir); + 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); + } + return 0; +} +EXPORT_SYMBOL(xfrm_policy_insert); + +struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel, + int delete) +{ + struct xfrm_policy *pol, **p; + + write_lock_bh(&xfrm_policy_lock); + for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) { + if (memcmp(sel, &pol->selector, sizeof(*sel)) == 0) { + xfrm_pol_hold(pol); + if (delete) + *p = pol->next; + break; + } + } + write_unlock_bh(&xfrm_policy_lock); + + if (pol && delete) { + atomic_inc(&flow_cache_genid); + xfrm_policy_kill(pol); + } + return pol; +} +EXPORT_SYMBOL(xfrm_policy_bysel); + +struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete) +{ + struct xfrm_policy *pol, **p; + + write_lock_bh(&xfrm_policy_lock); + for (p = &xfrm_policy_list[id & 7]; (pol=*p)!=NULL; p = &pol->next) { + if (pol->index == id) { + xfrm_pol_hold(pol); + if (delete) + *p = pol->next; + break; + } + } + write_unlock_bh(&xfrm_policy_lock); + + if (pol && delete) { + atomic_inc(&flow_cache_genid); + xfrm_policy_kill(pol); + } + return pol; +} +EXPORT_SYMBOL(xfrm_policy_byid); + +void xfrm_policy_flush(void) +{ + struct xfrm_policy *xp; + int dir; + + write_lock_bh(&xfrm_policy_lock); + for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { + while ((xp = xfrm_policy_list[dir]) != NULL) { + xfrm_policy_list[dir] = xp->next; + write_unlock_bh(&xfrm_policy_lock); + + xfrm_policy_kill(xp); + + write_lock_bh(&xfrm_policy_lock); + } + } + atomic_inc(&flow_cache_genid); + write_unlock_bh(&xfrm_policy_lock); +} +EXPORT_SYMBOL(xfrm_policy_flush); + +int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*), + void *data) +{ + struct xfrm_policy *xp; + int dir; + int count = 0; + int error = 0; + + read_lock_bh(&xfrm_policy_lock); + for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) { + for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) + count++; + } + + if (count == 0) { + error = -ENOENT; + goto out; + } + + for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) { + for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) { + error = func(xp, dir%XFRM_POLICY_MAX, --count, data); + if (error) + goto out; + } + } + +out: + read_unlock_bh(&xfrm_policy_lock); + return error; +} +EXPORT_SYMBOL(xfrm_policy_walk); + +/* Find policy to apply to this flow. */ + +static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir, + void **objp, atomic_t **obj_refp) +{ + struct xfrm_policy *pol; + + read_lock_bh(&xfrm_policy_lock); + for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) { + struct xfrm_selector *sel = &pol->selector; + int match; + + if (pol->family != family) + continue; + + match = xfrm_selector_match(sel, fl, family); + if (match) { + xfrm_pol_hold(pol); + break; + } + } + read_unlock_bh(&xfrm_policy_lock); + if ((*objp = (void *) pol) != NULL) + *obj_refp = &pol->refcnt; +} + +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); + if (match) + xfrm_pol_hold(pol); + else + pol = NULL; + } + read_unlock_bh(&xfrm_policy_lock); + return pol; +} + +static void __xfrm_policy_link(struct xfrm_policy *pol, int dir) +{ + pol->next = xfrm_policy_list[dir]; + xfrm_policy_list[dir] = pol; + xfrm_pol_hold(pol); +} + +static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, + int dir) +{ + struct xfrm_policy **polp; + + for (polp = &xfrm_policy_list[dir]; + *polp != NULL; polp = &(*polp)->next) { + if (*polp == pol) { + *polp = pol->next; + return pol; + } + } + return NULL; +} + +void 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); + } +} + +int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol) +{ + struct xfrm_policy *old_pol; + + 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(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; + 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; + memcpy(newp->xfrm_vec, old->xfrm_vec, + newp->xfrm_nr*sizeof(struct xfrm_tmpl)); + write_lock_bh(&xfrm_policy_lock); + __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir); + write_unlock_bh(&xfrm_policy_lock); + xfrm_pol_put(newp); + } + return newp; +} + +int __xfrm_sk_clone_policy(struct sock *sk) +{ + struct xfrm_policy *p0 = sk->sk_policy[0], + *p1 = sk->sk_policy[1]; + + sk->sk_policy[0] = sk->sk_policy[1] = NULL; + if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL) + return -ENOMEM; + if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL) + return -ENOMEM; + return 0; +} + +/* Resolve list of templates for the flow, given policy. */ + +static int +xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl, + struct xfrm_state **xfrm, + unsigned short family) +{ + int nx; + int i, error; + xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family); + xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family); + + for (nx=0, i = 0; i < policy->xfrm_nr; i++) { + struct xfrm_state *x; + xfrm_address_t *remote = daddr; + xfrm_address_t *local = saddr; + struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i]; + + if (tmpl->mode) { + remote = &tmpl->id.daddr; + local = &tmpl->saddr; + } + + x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family); + + if (x && x->km.state == XFRM_STATE_VALID) { + xfrm[nx++] = x; + daddr = remote; + saddr = local; + continue; + } + if (x) { + error = (x->km.state == XFRM_STATE_ERROR ? + -EINVAL : -EAGAIN); + xfrm_state_put(x); + } + + if (!tmpl->optional) + goto fail; + } + return nx; + +fail: + for (nx--; nx>=0; nx--) + xfrm_state_put(xfrm[nx]); + return error; +} + +/* 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 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 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_state *xfrm[XFRM_MAX_DEPTH]; + struct dst_entry *dst, *dst_orig = *dst_p; + int nx = 0; + int err; + u32 genid; + u16 family = dst_orig->ops->family; +restart: + genid = atomic_read(&flow_cache_genid); + policy = NULL; + if (sk && sk->sk_policy[1]) + policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl); + + if (!policy) { + /* To accelerate a bit... */ + if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT]) + return 0; + + policy = flow_cache_lookup(fl, family, + policy_to_flow_dir(XFRM_POLICY_OUT), + xfrm_policy_lookup); + } + + if (!policy) + return 0; + + policy->curlft.use_time = (unsigned long)xtime.tv_sec; + + switch (policy->action) { + case XFRM_POLICY_BLOCK: + /* Prohibit the flow */ + xfrm_pol_put(policy); + return -EPERM; + + case XFRM_POLICY_ALLOW: + if (policy->xfrm_nr == 0) { + /* Flow passes not transformed. */ + xfrm_pol_put(policy); + return 0; + } + + /* 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)) { + xfrm_pol_put(policy); + return PTR_ERR(dst); + } + + if (dst) + break; + + nx = xfrm_tmpl_resolve(policy, 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(policy, fl, xfrm, family); + + if (nx == -EAGAIN && signal_pending(current)) { + err = -ERESTART; + goto error; + } + if (nx == -EAGAIN || + genid != atomic_read(&flow_cache_genid)) { + xfrm_pol_put(policy); + goto restart; + } + err = nx; + } + if (err < 0) + goto error; + } + if (nx == 0) { + /* Flow passes not transformed. */ + xfrm_pol_put(policy); + 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; + } + + write_lock_bh(&policy->lock); + if (unlikely(policy->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); + + xfrm_pol_put(policy); + if (dst) + dst_free(dst); + goto restart; + } + dst->next = policy->bundles; + policy->bundles = dst; + dst_hold(dst); + write_unlock_bh(&policy->lock); + } + *dst_p = dst; + dst_release(dst_orig); + xfrm_pol_put(policy); + return 0; + +error: + dst_release(dst_orig); + xfrm_pol_put(policy); + *dst_p = NULL; + return err; +} +EXPORT_SYMBOL(xfrm_lookup); + +/* 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)) && + !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family)); +} + +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) + return start; + } else + start = -1; + for (; idx < sp->len; idx++) { + if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family)) + return ++idx; + if (sp->x[idx].xvec->props.mode) + break; + } + return start; +} + +static int +_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family) +{ + struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); + + if (unlikely(afinfo == NULL)) + return -EAFNOSUPPORT; + + afinfo->decode_session(skb, fl); + xfrm_policy_put_afinfo(afinfo); + return 0; +} + +static inline int secpath_has_tunnel(struct sec_path *sp, int k) +{ + for (; k < sp->len; k++) { + if (sp->x[k].xvec->props.mode) + 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 flowi fl; + + if (_decode_session(skb, &fl, family) < 0) + return 0; + + /* First, check used SA against their selectors. */ + if (skb->sp) { + int i; + + for (i=skb->sp->len-1; i>=0; i--) { + struct sec_decap_state *xvec = &(skb->sp->x[i]); + if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family)) + return 0; + + /* If there is a post_input processor, try running it */ + if (xvec->xvec->type->post_input && + (xvec->xvec->type->post_input)(xvec->xvec, + &(xvec->decap), + skb) != 0) + return 0; + } + } + + pol = NULL; + if (sk && sk->sk_policy[dir]) + pol = xfrm_sk_policy_lookup(sk, dir, &fl); + + if (!pol) + pol = flow_cache_lookup(&fl, family, + policy_to_flow_dir(dir), + xfrm_policy_lookup); + + if (!pol) + return !skb->sp || !secpath_has_tunnel(skb->sp, 0); + + pol->curlft.use_time = (unsigned long)xtime.tv_sec; + + if (pol->action == XFRM_POLICY_ALLOW) { + struct sec_path *sp; + static struct sec_path dummy; + int i, k; + + if ((sp = skb->sp) == NULL) + sp = &dummy; + + /* 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 = pol->xfrm_nr-1, k = 0; i >= 0; i--) { + k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family); + if (k < 0) + goto reject; + } + + if (secpath_has_tunnel(sp, k)) + goto reject; + + xfrm_pol_put(pol); + return 1; + } + +reject: + xfrm_pol_put(pol); + return 0; +} +EXPORT_SYMBOL(__xfrm_policy_check); + +int __xfrm_route_forward(struct sk_buff *skb, unsigned short family) +{ + struct flowi fl; + + if (_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) +{ + if (!stale_bundle(dst)) + return dst; + + return NULL; +} + +static int stale_bundle(struct dst_entry *dst) +{ + return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC); +} + +static void xfrm_dst_destroy(struct dst_entry *dst) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + + dst_release(xdst->route); + + if (!dst->xfrm) + return; + xfrm_state_put(dst->xfrm); + dst->xfrm = NULL; +} + +static void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev, + int unregister) +{ + if (!unregister) + return; + + while ((dst = dst->child) && dst->xfrm && dst->dev == dev) { + dst->dev = &loopback_dev; + dev_hold(&loopback_dev); + dev_put(dev); + } +} + +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 xfrm_prune_bundles(int (*func)(struct dst_entry *)) +{ + int i; + struct xfrm_policy *pol; + struct dst_entry *dst, **dstp, *gc_list = NULL; + + read_lock_bh(&xfrm_policy_lock); + for (i=0; i<2*XFRM_POLICY_MAX; i++) { + for (pol = xfrm_policy_list[i]; pol; pol = pol->next) { + write_lock(&pol->lock); + dstp = &pol->bundles; + while ((dst=*dstp) != NULL) { + if (func(dst)) { + *dstp = dst->next; + dst->next = gc_list; + gc_list = dst; + } else { + dstp = &dst->next; + } + } + write_unlock(&pol->lock); + } + } + read_unlock_bh(&xfrm_policy_lock); + + while (gc_list) { + 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); +} + +int xfrm_flush_bundles(void) +{ + xfrm_prune_bundles(stale_bundle); + return 0; +} + +void xfrm_init_pmtu(struct dst_entry *dst) +{ + do { + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + u32 pmtu, route_mtu_cached; + + pmtu = dst_mtu(dst->child); + xdst->child_mtu_cached = pmtu; + + pmtu = xfrm_state_mtu(dst->xfrm, pmtu); + + route_mtu_cached = dst_mtu(xdst->route); + xdst->route_mtu_cached = route_mtu_cached; + + if (pmtu > route_mtu_cached) + pmtu = route_mtu_cached; + + dst->metrics[RTAX_MTU-1] = pmtu; + } while ((dst = dst->next)); +} + +EXPORT_SYMBOL(xfrm_init_pmtu); + +/* Check that the bundle accepts the flow and its components are + * still valid. + */ + +int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family) +{ + struct dst_entry *dst = &first->u.dst; + struct xfrm_dst *last; + u32 mtu; + + if (!dst_check(dst->path, 0) || + (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 (dst->xfrm->km.state != XFRM_STATE_VALID) + 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, 0)) + 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); + +/* Well... that's _TASK_. We need to scan through transformation + * list and figure out what mss tcp should generate in order to + * final datagram fit to mtu. Mama mia... :-) + * + * Apparently, some easy way exists, but we used to choose the most + * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta. + * + * Consider this function as something like dark humour. :-) + */ +static int xfrm_get_mss(struct dst_entry *dst, u32 mtu) +{ + int res = mtu - dst->header_len; + + for (;;) { + struct dst_entry *d = dst; + int m = res; + + do { + struct xfrm_state *x = d->xfrm; + if (x) { + spin_lock_bh(&x->lock); + if (x->km.state == XFRM_STATE_VALID && + x->type && x->type->get_max_size) + m = x->type->get_max_size(d->xfrm, m); + else + m += x->props.header_len; + spin_unlock_bh(&x->lock); + } + } while ((d = d->child) != NULL); + + if (m <= mtu) + break; + res -= (m - mtu); + if (res < 88) + return mtu; + } + + return res + dst->header_len; +} + +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(&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->destroy == NULL)) + dst_ops->destroy = xfrm_dst_destroy; + if (likely(dst_ops->ifdown == NULL)) + dst_ops->ifdown = xfrm_dst_ifdown; + 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(dst_ops->get_mss == NULL)) + dst_ops->get_mss = xfrm_get_mss; + if (likely(afinfo->garbage_collect == NULL)) + afinfo->garbage_collect = __xfrm_garbage_collect; + xfrm_policy_afinfo[afinfo->family] = afinfo; + } + write_unlock(&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(&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->destroy = NULL; + dst_ops->ifdown = NULL; + dst_ops->negative_advice = NULL; + dst_ops->link_failure = NULL; + dst_ops->get_mss = NULL; + afinfo->garbage_collect = NULL; + } + } + write_unlock(&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 (likely(afinfo != NULL)) + read_lock(&afinfo->lock); + read_unlock(&xfrm_policy_afinfo_lock); + return afinfo; +} + +static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo) +{ + if (unlikely(afinfo == NULL)) + return; + read_unlock(&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) +{ + xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache", + sizeof(struct xfrm_dst), + 0, SLAB_HWCACHE_ALIGN, + NULL, NULL); + if (!xfrm_dst_cache) + panic("XFRM: failed to allocate xfrm_dst_cache\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(); +} + |