static const struct cred *root_cred;
-static void
-shrink_idmap_tree(struct rb_root *root, int nr_to_scan, int *nr_rem,
- int *nr_del)
-{
- struct rb_node *node;
- struct rb_node *tmp;
- struct cifs_sid_id *psidid;
-
- node = rb_first(root);
- while (node) {
- tmp = node;
- node = rb_next(tmp);
- psidid = rb_entry(tmp, struct cifs_sid_id, rbnode);
- if (nr_to_scan == 0 || *nr_del == nr_to_scan)
- ++(*nr_rem);
- else {
- if (time_after(jiffies, psidid->time + SID_MAP_EXPIRE)
- && psidid->refcount == 0) {
- rb_erase(tmp, root);
- ++(*nr_del);
- } else
- ++(*nr_rem);
- }
- }
-}
-
-/*
- * Run idmap cache shrinker.
- */
-static int
-cifs_idmap_shrinker(struct shrinker *shrink, struct shrink_control *sc)
-{
- int nr_to_scan = sc->nr_to_scan;
- int nr_del = 0;
- int nr_rem = 0;
- struct rb_root *root;
-
- root = &uidtree;
- spin_lock(&siduidlock);
- shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
- spin_unlock(&siduidlock);
-
- root = &gidtree;
- spin_lock(&sidgidlock);
- shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
- spin_unlock(&sidgidlock);
-
- root = &siduidtree;
- spin_lock(&uidsidlock);
- shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
- spin_unlock(&uidsidlock);
-
- root = &sidgidtree;
- spin_lock(&gidsidlock);
- shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
- spin_unlock(&gidsidlock);
-
- return nr_rem;
-}
-
-static void
-sid_rb_insert(struct rb_root *root, unsigned long cid,
- struct cifs_sid_id **psidid, char *typestr)
-{
- char *strptr;
- struct rb_node *node = root->rb_node;
- struct rb_node *parent = NULL;
- struct rb_node **linkto = &(root->rb_node);
- struct cifs_sid_id *lsidid;
-
- while (node) {
- lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
- parent = node;
- if (cid > lsidid->id) {
- linkto = &(node->rb_left);
- node = node->rb_left;
- }
- if (cid < lsidid->id) {
- linkto = &(node->rb_right);
- node = node->rb_right;
- }
- }
-
- (*psidid)->id = cid;
- (*psidid)->time = jiffies - (SID_MAP_RETRY + 1);
- (*psidid)->refcount = 0;
-
- sprintf((*psidid)->sidstr, "%s", typestr);
- strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr);
- sprintf(strptr, "%ld", cid);
-
- clear_bit(SID_ID_PENDING, &(*psidid)->state);
- clear_bit(SID_ID_MAPPED, &(*psidid)->state);
-
- rb_link_node(&(*psidid)->rbnode, parent, linkto);
- rb_insert_color(&(*psidid)->rbnode, root);
-}
-
-static struct cifs_sid_id *
-sid_rb_search(struct rb_root *root, unsigned long cid)
-{
- struct rb_node *node = root->rb_node;
- struct cifs_sid_id *lsidid;
-
- while (node) {
- lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
- if (cid > lsidid->id)
- node = node->rb_left;
- else if (cid < lsidid->id)
- node = node->rb_right;
- else /* node found */
- return lsidid;
- }
-
- return NULL;
-}
-
-static struct shrinker cifs_shrinker = {
- .shrink = cifs_idmap_shrinker,
- .seeks = DEFAULT_SEEKS,
-};
-
static int
cifs_idmap_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
{
.match = user_match,
};
-static void
-sid_to_str(struct cifs_sid *sidptr, char *sidstr)
+static char *
+sid_to_key_str(struct cifs_sid *sidptr, unsigned int type)
{
- int i;
+ int i, len;
unsigned int saval;
- char *strptr;
+ char *sidstr, *strptr;
- strptr = sidstr;
+ /* 3 bytes for prefix */
+ sidstr = kmalloc(3 + SID_STRING_BASE_SIZE +
+ (SID_STRING_SUBAUTH_SIZE * sidptr->num_subauth),
+ GFP_KERNEL);
+ if (!sidstr)
+ return sidstr;
- sprintf(strptr, "S-%hhu", sidptr->revision);
- strptr = sidstr + strlen(sidstr);
+ strptr = sidstr;
+ len = sprintf(strptr, "%cs:S-%hhu", type == SIDOWNER ? 'o' : 'g',
+ sidptr->revision);
+ strptr += len;
for (i = 0; i < NUM_AUTHS; ++i) {
if (sidptr->authority[i]) {
- sprintf(strptr, "-%hhu", sidptr->authority[i]);
- strptr = sidstr + strlen(sidstr);
+ len = sprintf(strptr, "-%hhu", sidptr->authority[i]);
+ strptr += len;
}
}
for (i = 0; i < sidptr->num_subauth; ++i) {
saval = le32_to_cpu(sidptr->sub_auth[i]);
- sprintf(strptr, "-%u", saval);
- strptr = sidstr + strlen(sidstr);
+ len = sprintf(strptr, "-%u", saval);
+ strptr += len;
}
+
+ return sidstr;
}
/*
dst->sub_auth[i] = src->sub_auth[i];
}
-static void
-id_rb_insert(struct rb_root *root, struct cifs_sid *sidptr,
- struct cifs_sid_id **psidid, char *typestr)
-{
- int rc;
- char *strptr;
- struct rb_node *node = root->rb_node;
- struct rb_node *parent = NULL;
- struct rb_node **linkto = &(root->rb_node);
- struct cifs_sid_id *lsidid;
-
- while (node) {
- lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
- parent = node;
- rc = compare_sids(sidptr, &((lsidid)->sid));
- if (rc > 0) {
- linkto = &(node->rb_left);
- node = node->rb_left;
- } else if (rc < 0) {
- linkto = &(node->rb_right);
- node = node->rb_right;
- }
- }
-
- cifs_copy_sid(&(*psidid)->sid, sidptr);
- (*psidid)->time = jiffies - (SID_MAP_RETRY + 1);
- (*psidid)->refcount = 0;
-
- sprintf((*psidid)->sidstr, "%s", typestr);
- strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr);
- sid_to_str(&(*psidid)->sid, strptr);
-
- clear_bit(SID_ID_PENDING, &(*psidid)->state);
- clear_bit(SID_ID_MAPPED, &(*psidid)->state);
-
- rb_link_node(&(*psidid)->rbnode, parent, linkto);
- rb_insert_color(&(*psidid)->rbnode, root);
-}
-
-static struct cifs_sid_id *
-id_rb_search(struct rb_root *root, struct cifs_sid *sidptr)
-{
- int rc;
- struct rb_node *node = root->rb_node;
- struct cifs_sid_id *lsidid;
-
- while (node) {
- lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
- rc = compare_sids(sidptr, &((lsidid)->sid));
- if (rc > 0) {
- node = node->rb_left;
- } else if (rc < 0) {
- node = node->rb_right;
- } else /* node found */
- return lsidid;
- }
-
- return NULL;
-}
-
-static int
-sidid_pending_wait(void *unused)
-{
- schedule();
- return signal_pending(current) ? -ERESTARTSYS : 0;
-}
-
static int
-id_to_sid(unsigned long cid, uint sidtype, struct cifs_sid *ssid)
+id_to_sid(unsigned int cid, uint sidtype, struct cifs_sid *ssid)
{
- int rc = 0;
+ int rc;
struct key *sidkey;
+ char desc[3 + 10 + 1]; /* 3 byte prefix + 10 bytes for value + NULL */
const struct cred *saved_cred;
- struct cifs_sid *lsid;
- struct cifs_sid_id *psidid, *npsidid;
- struct rb_root *cidtree;
- spinlock_t *cidlock;
-
- if (sidtype == SIDOWNER) {
- cidlock = &siduidlock;
- cidtree = &uidtree;
- } else if (sidtype == SIDGROUP) {
- cidlock = &sidgidlock;
- cidtree = &gidtree;
- } else
- return -EINVAL;
-
- spin_lock(cidlock);
- psidid = sid_rb_search(cidtree, cid);
-
- if (!psidid) { /* node does not exist, allocate one & attempt adding */
- spin_unlock(cidlock);
- npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL);
- if (!npsidid)
- return -ENOMEM;
-
- npsidid->sidstr = kmalloc(SID_STRING_MAX, GFP_KERNEL);
- if (!npsidid->sidstr) {
- kfree(npsidid);
- return -ENOMEM;
- }
-
- spin_lock(cidlock);
- psidid = sid_rb_search(cidtree, cid);
- if (psidid) { /* node happened to get inserted meanwhile */
- ++psidid->refcount;
- spin_unlock(cidlock);
- kfree(npsidid->sidstr);
- kfree(npsidid);
- } else {
- psidid = npsidid;
- sid_rb_insert(cidtree, cid, &psidid,
- sidtype == SIDOWNER ? "oi:" : "gi:");
- ++psidid->refcount;
- spin_unlock(cidlock);
- }
- } else {
- ++psidid->refcount;
- spin_unlock(cidlock);
- }
- /*
- * If we are here, it is safe to access psidid and its fields
- * since a reference was taken earlier while holding the spinlock.
- * A reference on the node is put without holding the spinlock
- * and it is OK to do so in this case, shrinker will not erase
- * this node until all references are put and we do not access
- * any fields of the node after a reference is put .
- */
- if (test_bit(SID_ID_MAPPED, &psidid->state)) {
- cifs_copy_sid(ssid, &psidid->sid);
- psidid->time = jiffies; /* update ts for accessing */
- goto id_sid_out;
- }
+ rc = snprintf(desc, sizeof(desc), "%ci:%u",
+ sidtype == SIDOWNER ? 'o' : 'g', cid);
+ if (rc >= sizeof(desc))
+ return -EINVAL;
- if (time_after(psidid->time + SID_MAP_RETRY, jiffies)) {
+ rc = 0;
+ saved_cred = override_creds(root_cred);
+ sidkey = request_key(&cifs_idmap_key_type, desc, "");
+ if (IS_ERR(sidkey)) {
rc = -EINVAL;
- goto id_sid_out;
- }
-
- if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) {
- saved_cred = override_creds(root_cred);
- sidkey = request_key(&cifs_idmap_key_type, psidid->sidstr, "");
- if (IS_ERR(sidkey)) {
- rc = -EINVAL;
- cFYI(1, "%s: Can't map and id to a SID", __func__);
- } else if (sidkey->datalen < CIFS_SID_BASE_SIZE) {
- rc = -EIO;
- cFYI(1, "%s: Downcall contained malformed key "
- "(datalen=%hu)", __func__, sidkey->datalen);
- } else {
- lsid = (struct cifs_sid *)sidkey->payload.data;
- cifs_copy_sid(&psidid->sid, lsid);
- cifs_copy_sid(ssid, &psidid->sid);
- set_bit(SID_ID_MAPPED, &psidid->state);
- key_put(sidkey);
- kfree(psidid->sidstr);
- }
- psidid->time = jiffies; /* update ts for accessing */
- revert_creds(saved_cred);
- clear_bit(SID_ID_PENDING, &psidid->state);
- wake_up_bit(&psidid->state, SID_ID_PENDING);
- } else {
- rc = wait_on_bit(&psidid->state, SID_ID_PENDING,
- sidid_pending_wait, TASK_INTERRUPTIBLE);
- if (rc) {
- cFYI(1, "%s: sidid_pending_wait interrupted %d",
- __func__, rc);
- --psidid->refcount;
- return rc;
- }
- if (test_bit(SID_ID_MAPPED, &psidid->state))
- cifs_copy_sid(ssid, &psidid->sid);
- else
- rc = -EINVAL;
- }
-id_sid_out:
- --psidid->refcount;
+ cFYI(1, "%s: Can't map %cid %u to a SID", __func__,
+ sidtype == SIDOWNER ? 'u' : 'g', cid);
+ goto out_revert_creds;
+ } else if (sidkey->datalen < CIFS_SID_BASE_SIZE) {
+ rc = -EIO;
+ cFYI(1, "%s: Downcall contained malformed key "
+ "(datalen=%hu)", __func__, sidkey->datalen);
+ goto out_key_put;
+ }
+ cifs_copy_sid(ssid, (struct cifs_sid *)sidkey->payload.data);
+out_key_put:
+ key_put(sidkey);
+out_revert_creds:
+ revert_creds(saved_cred);
return rc;
}
struct cifs_fattr *fattr, uint sidtype)
{
int rc;
- unsigned long cid;
- struct key *idkey;
+ struct key *sidkey;
+ char *sidstr;
const struct cred *saved_cred;
- struct cifs_sid_id *psidid, *npsidid;
- struct rb_root *cidtree;
- spinlock_t *cidlock;
-
- if (sidtype == SIDOWNER) {
- cid = cifs_sb->mnt_uid; /* default uid, in case upcall fails */
- cidlock = &siduidlock;
- cidtree = &uidtree;
- } else if (sidtype == SIDGROUP) {
- cid = cifs_sb->mnt_gid; /* default gid, in case upcall fails */
- cidlock = &sidgidlock;
- cidtree = &gidtree;
- } else
- return -ENOENT;
-
- spin_lock(cidlock);
- psidid = id_rb_search(cidtree, psid);
-
- if (!psidid) { /* node does not exist, allocate one & attempt adding */
- spin_unlock(cidlock);
- npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL);
- if (!npsidid)
- return -ENOMEM;
-
- npsidid->sidstr = kmalloc(SID_STRING_MAX, GFP_KERNEL);
- if (!npsidid->sidstr) {
- kfree(npsidid);
- return -ENOMEM;
- }
-
- spin_lock(cidlock);
- psidid = id_rb_search(cidtree, psid);
- if (psidid) { /* node happened to get inserted meanwhile */
- ++psidid->refcount;
- spin_unlock(cidlock);
- kfree(npsidid->sidstr);
- kfree(npsidid);
- } else {
- psidid = npsidid;
- id_rb_insert(cidtree, psid, &psidid,
- sidtype == SIDOWNER ? "os:" : "gs:");
- ++psidid->refcount;
- spin_unlock(cidlock);
- }
- } else {
- ++psidid->refcount;
- spin_unlock(cidlock);
- }
+ uid_t fuid = cifs_sb->mnt_uid;
+ gid_t fgid = cifs_sb->mnt_gid;
/*
- * If we are here, it is safe to access psidid and its fields
- * since a reference was taken earlier while holding the spinlock.
- * A reference on the node is put without holding the spinlock
- * and it is OK to do so in this case, shrinker will not erase
- * this node until all references are put and we do not access
- * any fields of the node after a reference is put .
+ * If we have too many subauthorities, then something is really wrong.
+ * Just return an error.
*/
- if (test_bit(SID_ID_MAPPED, &psidid->state)) {
- cid = psidid->id;
- psidid->time = jiffies; /* update ts for accessing */
- goto sid_to_id_out;
+ if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) {
+ cFYI(1, "%s: %u subauthorities is too many!", __func__,
+ psid->num_subauth);
+ return -EIO;
}
- if (time_after(psidid->time + SID_MAP_RETRY, jiffies))
- goto sid_to_id_out;
-
- if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) {
- saved_cred = override_creds(root_cred);
- idkey = request_key(&cifs_idmap_key_type, psidid->sidstr, "");
- if (IS_ERR(idkey))
- cFYI(1, "%s: Can't map SID to an id", __func__);
- else {
- cid = *(unsigned long *)idkey->payload.value;
- psidid->id = cid;
- set_bit(SID_ID_MAPPED, &psidid->state);
- key_put(idkey);
- kfree(psidid->sidstr);
- }
- revert_creds(saved_cred);
- psidid->time = jiffies; /* update ts for accessing */
- clear_bit(SID_ID_PENDING, &psidid->state);
- wake_up_bit(&psidid->state, SID_ID_PENDING);
- } else {
- rc = wait_on_bit(&psidid->state, SID_ID_PENDING,
- sidid_pending_wait, TASK_INTERRUPTIBLE);
- if (rc) {
- cFYI(1, "%s: sidid_pending_wait interrupted %d",
- __func__, rc);
- --psidid->refcount; /* decremented without spinlock */
- return rc;
- }
- if (test_bit(SID_ID_MAPPED, &psidid->state))
- cid = psidid->id;
+ sidstr = sid_to_key_str(psid, sidtype);
+ if (!sidstr)
+ return -ENOMEM;
+
+ saved_cred = override_creds(root_cred);
+ sidkey = request_key(&cifs_idmap_key_type, sidstr, "");
+ if (IS_ERR(sidkey)) {
+ rc = -EINVAL;
+ cFYI(1, "%s: Can't map SID %s to a %cid", __func__, sidstr,
+ sidtype == SIDOWNER ? 'u' : 'g');
+ goto out_revert_creds;
+ }
+
+ /*
+ * FIXME: Here we assume that uid_t and gid_t are same size. It's
+ * probably a safe assumption but might be better to check based on
+ * sidtype.
+ */
+ if (sidkey->datalen < sizeof(uid_t)) {
+ rc = -EIO;
+ cFYI(1, "%s: Downcall contained malformed key "
+ "(datalen=%hu)", __func__, sidkey->datalen);
+ goto out_key_put;
}
-sid_to_id_out:
- --psidid->refcount; /* decremented without spinlock */
if (sidtype == SIDOWNER)
- fattr->cf_uid = cid;
+ fuid = *(uid_t *)sidkey->payload.value;
else
- fattr->cf_gid = cid;
+ fgid = *(gid_t *)sidkey->payload.value;
+out_key_put:
+ key_put(sidkey);
+out_revert_creds:
+ revert_creds(saved_cred);
+ kfree(sidstr);
+
+ /*
+ * Note that we return 0 here unconditionally. If the mapping
+ * fails then we just fall back to using the mnt_uid/mnt_gid.
+ */
+ if (sidtype == SIDOWNER)
+ fattr->cf_uid = fuid;
+ else
+ fattr->cf_gid = fgid;
return 0;
}
cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
root_cred = cred;
- spin_lock_init(&siduidlock);
- uidtree = RB_ROOT;
- spin_lock_init(&sidgidlock);
- gidtree = RB_ROOT;
-
- spin_lock_init(&uidsidlock);
- siduidtree = RB_ROOT;
- spin_lock_init(&gidsidlock);
- sidgidtree = RB_ROOT;
- register_shrinker(&cifs_shrinker);
-
cFYI(1, "cifs idmap keyring: %d", key_serial(keyring));
return 0;
key_revoke(root_cred->thread_keyring);
unregister_key_type(&cifs_idmap_key_type);
put_cred(root_cred);
- unregister_shrinker(&cifs_shrinker);
cFYI(1, "Unregistered %s key type", cifs_idmap_key_type.name);
}
-void
-cifs_destroy_idmaptrees(void)
-{
- struct rb_root *root;
- struct rb_node *node;
-
- root = &uidtree;
- spin_lock(&siduidlock);
- while ((node = rb_first(root)))
- rb_erase(node, root);
- spin_unlock(&siduidlock);
-
- root = &gidtree;
- spin_lock(&sidgidlock);
- while ((node = rb_first(root)))
- rb_erase(node, root);
- spin_unlock(&sidgidlock);
-
- root = &siduidtree;
- spin_lock(&uidsidlock);
- while ((node = rb_first(root)))
- rb_erase(node, root);
- spin_unlock(&uidsidlock);
-
- root = &sidgidtree;
- spin_lock(&gidsidlock);
- while ((node = rb_first(root)))
- rb_erase(node, root);
- spin_unlock(&gidsidlock);
-}
-
/* copy ntsd, owner sid, and group sid from a security descriptor to another */
static void copy_sec_desc(const struct cifs_ntsd *pntsd,
struct cifs_ntsd *pnntsd, __u32 sidsoffset)
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff