/* Keyring handling
*
- * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
#include <linux/seq_file.h>
#include <linux/err.h>
#include <keys/keyring-type.h>
+#include <keys/user-type.h>
+#include <linux/assoc_array_priv.h>
#include <linux/uaccess.h>
#include "internal.h"
-#define rcu_dereference_locked_keyring(keyring) \
- (rcu_dereference_protected( \
- (keyring)->payload.subscriptions, \
- rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem)))
-
-#define rcu_deref_link_locked(klist, index, keyring) \
- (rcu_dereference_protected( \
- (klist)->keys[index], \
- rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem)))
-
-#define MAX_KEYRING_LINKS \
- min_t(size_t, USHRT_MAX - 1, \
- ((PAGE_SIZE - sizeof(struct keyring_list)) / sizeof(struct key *)))
-
-#define KEY_LINK_FIXQUOTA 1UL
-
/*
* When plumbing the depths of the key tree, this sets a hard limit
* set on how deep we're willing to go.
*/
#define KEYRING_NAME_HASH_SIZE (1 << 5)
+/*
+ * We mark pointers we pass to the associative array with bit 1 set if
+ * they're keyrings and clear otherwise.
+ */
+#define KEYRING_PTR_SUBTYPE 0x2UL
+
+static inline bool keyring_ptr_is_keyring(const struct assoc_array_ptr *x)
+{
+ return (unsigned long)x & KEYRING_PTR_SUBTYPE;
+}
+static inline struct key *keyring_ptr_to_key(const struct assoc_array_ptr *x)
+{
+ void *object = assoc_array_ptr_to_leaf(x);
+ return (struct key *)((unsigned long)object & ~KEYRING_PTR_SUBTYPE);
+}
+static inline void *keyring_key_to_ptr(struct key *key)
+{
+ if (key->type == &key_type_keyring)
+ return (void *)((unsigned long)key | KEYRING_PTR_SUBTYPE);
+ return key;
+}
+
static struct list_head keyring_name_hash[KEYRING_NAME_HASH_SIZE];
static DEFINE_RWLOCK(keyring_name_lock);
*/
static int keyring_instantiate(struct key *keyring,
struct key_preparsed_payload *prep);
-static int keyring_match(const struct key *keyring, const void *criterion);
static void keyring_revoke(struct key *keyring);
static void keyring_destroy(struct key *keyring);
static void keyring_describe(const struct key *keyring, struct seq_file *m);
struct key_type key_type_keyring = {
.name = "keyring",
- .def_datalen = sizeof(struct keyring_list),
+ .def_datalen = 0,
.instantiate = keyring_instantiate,
- .match = keyring_match,
+ .match = user_match,
.revoke = keyring_revoke,
.destroy = keyring_destroy,
.describe = keyring_describe,
ret = -EINVAL;
if (prep->datalen == 0) {
+ assoc_array_init(&keyring->keys);
/* make the keyring available by name if it has one */
keyring_publish_name(keyring);
ret = 0;
}
/*
- * Match keyrings on their name
+ * Multiply 64-bits by 32-bits to 96-bits and fold back to 64-bit. Ideally we'd
+ * fold the carry back too, but that requires inline asm.
+ */
+static u64 mult_64x32_and_fold(u64 x, u32 y)
+{
+ u64 hi = (u64)(u32)(x >> 32) * y;
+ u64 lo = (u64)(u32)(x) * y;
+ return lo + ((u64)(u32)hi << 32) + (u32)(hi >> 32);
+}
+
+/*
+ * Hash a key type and description.
*/
-static int keyring_match(const struct key *keyring, const void *description)
+static unsigned long hash_key_type_and_desc(const struct keyring_index_key *index_key)
{
- return keyring->description &&
- strcmp(keyring->description, description) == 0;
+ const unsigned level_shift = ASSOC_ARRAY_LEVEL_STEP;
+ const unsigned long level_mask = ASSOC_ARRAY_LEVEL_STEP_MASK;
+ const char *description = index_key->description;
+ unsigned long hash, type;
+ u32 piece;
+ u64 acc;
+ int n, desc_len = index_key->desc_len;
+
+ type = (unsigned long)index_key->type;
+
+ acc = mult_64x32_and_fold(type, desc_len + 13);
+ acc = mult_64x32_and_fold(acc, 9207);
+ for (;;) {
+ n = desc_len;
+ if (n <= 0)
+ break;
+ if (n > 4)
+ n = 4;
+ piece = 0;
+ memcpy(&piece, description, n);
+ description += n;
+ desc_len -= n;
+ acc = mult_64x32_and_fold(acc, piece);
+ acc = mult_64x32_and_fold(acc, 9207);
+ }
+
+ /* Fold the hash down to 32 bits if need be. */
+ hash = acc;
+ if (ASSOC_ARRAY_KEY_CHUNK_SIZE == 32)
+ hash ^= acc >> 32;
+
+ /* Squidge all the keyrings into a separate part of the tree to
+ * ordinary keys by making sure the lowest level segment in the hash is
+ * zero for keyrings and non-zero otherwise.
+ */
+ if (index_key->type != &key_type_keyring && (hash & level_mask) == 0)
+ return hash | (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1;
+ if (index_key->type == &key_type_keyring && (hash & level_mask) != 0)
+ return (hash + (hash << level_shift)) & ~level_mask;
+ return hash;
}
+/*
+ * Build the next index key chunk.
+ *
+ * On 32-bit systems the index key is laid out as:
+ *
+ * 0 4 5 9...
+ * hash desclen typeptr desc[]
+ *
+ * On 64-bit systems:
+ *
+ * 0 8 9 17...
+ * hash desclen typeptr desc[]
+ *
+ * We return it one word-sized chunk at a time.
+ */
+static unsigned long keyring_get_key_chunk(const void *data, int level)
+{
+ const struct keyring_index_key *index_key = data;
+ unsigned long chunk = 0;
+ long offset = 0;
+ int desc_len = index_key->desc_len, n = sizeof(chunk);
+
+ level /= ASSOC_ARRAY_KEY_CHUNK_SIZE;
+ switch (level) {
+ case 0:
+ return hash_key_type_and_desc(index_key);
+ case 1:
+ return ((unsigned long)index_key->type << 8) | desc_len;
+ case 2:
+ if (desc_len == 0)
+ return (u8)((unsigned long)index_key->type >>
+ (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8));
+ n--;
+ offset = 1;
+ default:
+ offset += sizeof(chunk) - 1;
+ offset += (level - 3) * sizeof(chunk);
+ if (offset >= desc_len)
+ return 0;
+ desc_len -= offset;
+ if (desc_len > n)
+ desc_len = n;
+ offset += desc_len;
+ do {
+ chunk <<= 8;
+ chunk |= ((u8*)index_key->description)[--offset];
+ } while (--desc_len > 0);
+
+ if (level == 2) {
+ chunk <<= 8;
+ chunk |= (u8)((unsigned long)index_key->type >>
+ (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8));
+ }
+ return chunk;
+ }
+}
+
+static unsigned long keyring_get_object_key_chunk(const void *object, int level)
+{
+ const struct key *key = keyring_ptr_to_key(object);
+ return keyring_get_key_chunk(&key->index_key, level);
+}
+
+static bool keyring_compare_object(const void *object, const void *data)
+{
+ const struct keyring_index_key *index_key = data;
+ const struct key *key = keyring_ptr_to_key(object);
+
+ return key->index_key.type == index_key->type &&
+ key->index_key.desc_len == index_key->desc_len &&
+ memcmp(key->index_key.description, index_key->description,
+ index_key->desc_len) == 0;
+}
+
+/*
+ * Compare the index keys of a pair of objects and determine the bit position
+ * at which they differ - if they differ.
+ */
+static int keyring_diff_objects(const void *_a, const void *_b)
+{
+ const struct key *key_a = keyring_ptr_to_key(_a);
+ const struct key *key_b = keyring_ptr_to_key(_b);
+ const struct keyring_index_key *a = &key_a->index_key;
+ const struct keyring_index_key *b = &key_b->index_key;
+ unsigned long seg_a, seg_b;
+ int level, i;
+
+ level = 0;
+ seg_a = hash_key_type_and_desc(a);
+ seg_b = hash_key_type_and_desc(b);
+ if ((seg_a ^ seg_b) != 0)
+ goto differ;
+
+ /* The number of bits contributed by the hash is controlled by a
+ * constant in the assoc_array headers. Everything else thereafter we
+ * can deal with as being machine word-size dependent.
+ */
+ level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8;
+ seg_a = a->desc_len;
+ seg_b = b->desc_len;
+ if ((seg_a ^ seg_b) != 0)
+ goto differ;
+
+ /* The next bit may not work on big endian */
+ level++;
+ seg_a = (unsigned long)a->type;
+ seg_b = (unsigned long)b->type;
+ if ((seg_a ^ seg_b) != 0)
+ goto differ;
+
+ level += sizeof(unsigned long);
+ if (a->desc_len == 0)
+ goto same;
+
+ i = 0;
+ if (((unsigned long)a->description | (unsigned long)b->description) &
+ (sizeof(unsigned long) - 1)) {
+ do {
+ seg_a = *(unsigned long *)(a->description + i);
+ seg_b = *(unsigned long *)(b->description + i);
+ if ((seg_a ^ seg_b) != 0)
+ goto differ_plus_i;
+ i += sizeof(unsigned long);
+ } while (i < (a->desc_len & (sizeof(unsigned long) - 1)));
+ }
+
+ for (; i < a->desc_len; i++) {
+ seg_a = *(unsigned char *)(a->description + i);
+ seg_b = *(unsigned char *)(b->description + i);
+ if ((seg_a ^ seg_b) != 0)
+ goto differ_plus_i;
+ }
+
+same:
+ return -1;
+
+differ_plus_i:
+ level += i;
+differ:
+ i = level * 8 + __ffs(seg_a ^ seg_b);
+ return i;
+}
+
+/*
+ * Free an object after stripping the keyring flag off of the pointer.
+ */
+static void keyring_free_object(void *object)
+{
+ key_put(keyring_ptr_to_key(object));
+}
+
+/*
+ * Operations for keyring management by the index-tree routines.
+ */
+static const struct assoc_array_ops keyring_assoc_array_ops = {
+ .get_key_chunk = keyring_get_key_chunk,
+ .get_object_key_chunk = keyring_get_object_key_chunk,
+ .compare_object = keyring_compare_object,
+ .diff_objects = keyring_diff_objects,
+ .free_object = keyring_free_object,
+};
+
/*
* Clean up a keyring when it is destroyed. Unpublish its name if it had one
* and dispose of its data.
*/
static void keyring_destroy(struct key *keyring)
{
- struct keyring_list *klist;
- int loop;
-
if (keyring->description) {
write_lock(&keyring_name_lock);
write_unlock(&keyring_name_lock);
}
- klist = rcu_access_pointer(keyring->payload.subscriptions);
- if (klist) {
- for (loop = klist->nkeys - 1; loop >= 0; loop--)
- key_put(rcu_access_pointer(klist->keys[loop]));
- kfree(klist);
- }
+ assoc_array_destroy(&keyring->keys, &keyring_assoc_array_ops);
}
/*
*/
static void keyring_describe(const struct key *keyring, struct seq_file *m)
{
- struct keyring_list *klist;
-
if (keyring->description)
seq_puts(m, keyring->description);
else
seq_puts(m, "[anon]");
if (key_is_instantiated(keyring)) {
- rcu_read_lock();
- klist = rcu_dereference(keyring->payload.subscriptions);
- if (klist)
- seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys);
+ if (keyring->keys.nr_leaves_on_tree != 0)
+ seq_printf(m, ": %lu", keyring->keys.nr_leaves_on_tree);
else
seq_puts(m, ": empty");
- rcu_read_unlock();
}
}
+struct keyring_read_iterator_context {
+ size_t qty;
+ size_t count;
+ key_serial_t __user *buffer;
+};
+
+static int keyring_read_iterator(const void *object, void *data)
+{
+ struct keyring_read_iterator_context *ctx = data;
+ const struct key *key = keyring_ptr_to_key(object);
+ int ret;
+
+ kenter("{%s,%d},,{%zu/%zu}",
+ key->type->name, key->serial, ctx->count, ctx->qty);
+
+ if (ctx->count >= ctx->qty)
+ return 1;
+
+ ret = put_user(key->serial, ctx->buffer);
+ if (ret < 0)
+ return ret;
+ ctx->buffer++;
+ ctx->count += sizeof(key->serial);
+ return 0;
+}
+
/*
* Read a list of key IDs from the keyring's contents in binary form
*
- * The keyring's semaphore is read-locked by the caller.
+ * The keyring's semaphore is read-locked by the caller. This prevents someone
+ * from modifying it under us - which could cause us to read key IDs multiple
+ * times.
*/
static long keyring_read(const struct key *keyring,
char __user *buffer, size_t buflen)
{
- struct keyring_list *klist;
- struct key *key;
- size_t qty, tmp;
- int loop, ret;
+ struct keyring_read_iterator_context ctx;
+ unsigned long nr_keys;
+ int ret;
- ret = 0;
- klist = rcu_dereference_locked_keyring(keyring);
- if (klist) {
- /* calculate how much data we could return */
- qty = klist->nkeys * sizeof(key_serial_t);
-
- if (buffer && buflen > 0) {
- if (buflen > qty)
- buflen = qty;
-
- /* copy the IDs of the subscribed keys into the
- * buffer */
- ret = -EFAULT;
-
- for (loop = 0; loop < klist->nkeys; loop++) {
- key = rcu_deref_link_locked(klist, loop,
- keyring);
-
- tmp = sizeof(key_serial_t);
- if (tmp > buflen)
- tmp = buflen;
-
- if (copy_to_user(buffer,
- &key->serial,
- tmp) != 0)
- goto error;
-
- buflen -= tmp;
- if (buflen == 0)
- break;
- buffer += tmp;
- }
- }
+ kenter("{%d},,%zu", key_serial(keyring), buflen);
- ret = qty;
+ if (buflen & (sizeof(key_serial_t) - 1))
+ return -EINVAL;
+
+ nr_keys = keyring->keys.nr_leaves_on_tree;
+ if (nr_keys == 0)
+ return 0;
+
+ /* Calculate how much data we could return */
+ ctx.qty = nr_keys * sizeof(key_serial_t);
+
+ if (!buffer || !buflen)
+ return ctx.qty;
+
+ if (buflen > ctx.qty)
+ ctx.qty = buflen;
+
+ /* Copy the IDs of the subscribed keys into the buffer */
+ ctx.buffer = (key_serial_t __user *)buffer;
+ ctx.count = 0;
+ ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx);
+ if (ret < 0) {
+ kleave(" = %d [iterate]", ret);
+ return ret;
}
-error:
- return ret;
+ kleave(" = %zu [ok]", ctx.count);
+ return ctx.count;
}
/*
}
EXPORT_SYMBOL(keyring_alloc);
-/**
- * keyring_search_aux - Search a keyring tree for a key matching some criteria
- * @keyring_ref: A pointer to the keyring with possession indicator.
- * @cred: The credentials to use for permissions checks.
- * @type: The type of key to search for.
- * @description: Parameter for @match.
- * @match: Function to rule on whether or not a key is the one required.
- * @no_state_check: Don't check if a matching key is bad
- *
- * Search the supplied keyring tree for a key that matches the criteria given.
- * The root keyring and any linked keyrings must grant Search permission to the
- * caller to be searchable and keys can only be found if they too grant Search
- * to the caller. The possession flag on the root keyring pointer controls use
- * of the possessor bits in permissions checking of the entire tree. In
- * addition, the LSM gets to forbid keyring searches and key matches.
- *
- * The search is performed as a breadth-then-depth search up to the prescribed
- * limit (KEYRING_SEARCH_MAX_DEPTH).
- *
- * Keys are matched to the type provided and are then filtered by the match
- * function, which is given the description to use in any way it sees fit. The
- * match function may use any attributes of a key that it wishes to to
- * determine the match. Normally the match function from the key type would be
- * used.
- *
- * RCU is used to prevent the keyring key lists from disappearing without the
- * need to take lots of locks.
- *
- * Returns a pointer to the found key and increments the key usage count if
- * successful; -EAGAIN if no matching keys were found, or if expired or revoked
- * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the
- * specified keyring wasn't a keyring.
- *
- * In the case of a successful return, the possession attribute from
- * @keyring_ref is propagated to the returned key reference.
+/*
+ * Iteration function to consider each key found.
*/
-key_ref_t keyring_search_aux(key_ref_t keyring_ref,
- const struct cred *cred,
- struct key_type *type,
- const void *description,
- key_match_func_t match,
- bool no_state_check)
+static int keyring_search_iterator(const void *object, void *iterator_data)
{
- struct {
- /* Need a separate keylist pointer for RCU purposes */
- struct key *keyring;
- struct keyring_list *keylist;
- int kix;
- } stack[KEYRING_SEARCH_MAX_DEPTH];
+ struct keyring_search_context *ctx = iterator_data;
+ const struct key *key = keyring_ptr_to_key(object);
+ unsigned long kflags = key->flags;
- struct keyring_list *keylist;
- struct timespec now;
- unsigned long possessed, kflags;
- struct key *keyring, *key;
- key_ref_t key_ref;
- long err;
- int sp, nkeys, kix;
-
- keyring = key_ref_to_ptr(keyring_ref);
- possessed = is_key_possessed(keyring_ref);
- key_check(keyring);
+ kenter("{%d}", key->serial);
- /* top keyring must have search permission to begin the search */
- err = key_task_permission(keyring_ref, cred, KEY_SEARCH);
- if (err < 0) {
- key_ref = ERR_PTR(err);
- goto error;
+ /* ignore keys not of this type */
+ if (key->type != ctx->index_key.type) {
+ kleave(" = 0 [!type]");
+ return 0;
}
- key_ref = ERR_PTR(-ENOTDIR);
- if (keyring->type != &key_type_keyring)
- goto error;
+ /* skip invalidated, revoked and expired keys */
+ if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) {
+ if (kflags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED))) {
+ ctx->result = ERR_PTR(-EKEYREVOKED);
+ kleave(" = %d [invrev]", ctx->skipped_ret);
+ goto skipped;
+ }
- rcu_read_lock();
+ if (key->expiry && ctx->now.tv_sec >= key->expiry) {
+ ctx->result = ERR_PTR(-EKEYEXPIRED);
+ kleave(" = %d [expire]", ctx->skipped_ret);
+ goto skipped;
+ }
+ }
- now = current_kernel_time();
- err = -EAGAIN;
- sp = 0;
-
- /* firstly we should check to see if this top-level keyring is what we
- * are looking for */
- key_ref = ERR_PTR(-EAGAIN);
- kflags = keyring->flags;
- if (keyring->type == type && match(keyring, description)) {
- key = keyring;
- if (no_state_check)
- goto found;
+ /* keys that don't match */
+ if (!ctx->match(key, ctx->match_data)) {
+ kleave(" = 0 [!match]");
+ return 0;
+ }
- /* check it isn't negative and hasn't expired or been
- * revoked */
- if (kflags & (1 << KEY_FLAG_REVOKED))
- goto error_2;
- if (key->expiry && now.tv_sec >= key->expiry)
- goto error_2;
- key_ref = ERR_PTR(key->type_data.reject_error);
- if (kflags & (1 << KEY_FLAG_NEGATIVE))
- goto error_2;
- goto found;
+ /* key must have search permissions */
+ if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) &&
+ key_task_permission(make_key_ref(key, ctx->possessed),
+ ctx->cred, KEY_SEARCH) < 0) {
+ ctx->result = ERR_PTR(-EACCES);
+ kleave(" = %d [!perm]", ctx->skipped_ret);
+ goto skipped;
}
- /* otherwise, the top keyring must not be revoked, expired, or
- * negatively instantiated if we are to search it */
- key_ref = ERR_PTR(-EAGAIN);
- if (kflags & ((1 << KEY_FLAG_INVALIDATED) |
- (1 << KEY_FLAG_REVOKED) |
- (1 << KEY_FLAG_NEGATIVE)) ||
- (keyring->expiry && now.tv_sec >= keyring->expiry))
- goto error_2;
-
- /* start processing a new keyring */
-descend:
- kflags = keyring->flags;
- if (kflags & ((1 << KEY_FLAG_INVALIDATED) |
- (1 << KEY_FLAG_REVOKED)))
- goto not_this_keyring;
+ if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) {
+ /* we set a different error code if we pass a negative key */
+ if (kflags & (1 << KEY_FLAG_NEGATIVE)) {
+ ctx->result = ERR_PTR(key->type_data.reject_error);
+ kleave(" = %d [neg]", ctx->skipped_ret);
+ goto skipped;
+ }
+ }
- keylist = rcu_dereference(keyring->payload.subscriptions);
- if (!keylist)
- goto not_this_keyring;
+ /* Found */
+ ctx->result = make_key_ref(key, ctx->possessed);
+ kleave(" = 1 [found]");
+ return 1;
- /* iterate through the keys in this keyring first */
- nkeys = keylist->nkeys;
- smp_rmb();
- for (kix = 0; kix < nkeys; kix++) {
- key = rcu_dereference(keylist->keys[kix]);
- kflags = key->flags;
+skipped:
+ return ctx->skipped_ret;
+}
- /* ignore keys not of this type */
- if (key->type != type)
- continue;
+/*
+ * Search inside a keyring for a key. We can search by walking to it
+ * directly based on its index-key or we can iterate over the entire
+ * tree looking for it, based on the match function.
+ */
+static int search_keyring(struct key *keyring, struct keyring_search_context *ctx)
+{
+ if ((ctx->flags & KEYRING_SEARCH_LOOKUP_TYPE) ==
+ KEYRING_SEARCH_LOOKUP_DIRECT) {
+ const void *object;
+
+ object = assoc_array_find(&keyring->keys,
+ &keyring_assoc_array_ops,
+ &ctx->index_key);
+ return object ? ctx->iterator(object, ctx) : 0;
+ }
+ return assoc_array_iterate(&keyring->keys, ctx->iterator, ctx);
+}
- /* skip invalidated, revoked and expired keys */
- if (!no_state_check) {
- if (kflags & ((1 << KEY_FLAG_INVALIDATED) |
- (1 << KEY_FLAG_REVOKED)))
- continue;
+/*
+ * Search a tree of keyrings that point to other keyrings up to the maximum
+ * depth.
+ */
+static bool search_nested_keyrings(struct key *keyring,
+ struct keyring_search_context *ctx)
+{
+ struct {
+ struct key *keyring;
+ struct assoc_array_node *node;
+ int slot;
+ } stack[KEYRING_SEARCH_MAX_DEPTH];
- if (key->expiry && now.tv_sec >= key->expiry)
- continue;
- }
+ struct assoc_array_shortcut *shortcut;
+ struct assoc_array_node *node;
+ struct assoc_array_ptr *ptr;
+ struct key *key;
+ int sp = 0, slot;
- /* keys that don't match */
- if (!match(key, description))
- continue;
+ kenter("{%d},{%s,%s}",
+ keyring->serial,
+ ctx->index_key.type->name,
+ ctx->index_key.description);
- /* key must have search permissions */
- if (key_task_permission(make_key_ref(key, possessed),
- cred, KEY_SEARCH) < 0)
- continue;
+ if (ctx->index_key.description)
+ ctx->index_key.desc_len = strlen(ctx->index_key.description);
- if (no_state_check)
+ /* Check to see if this top-level keyring is what we are looking for
+ * and whether it is valid or not.
+ */
+ if (ctx->flags & KEYRING_SEARCH_LOOKUP_ITERATE ||
+ keyring_compare_object(keyring, &ctx->index_key)) {
+ ctx->skipped_ret = 2;
+ ctx->flags |= KEYRING_SEARCH_DO_STATE_CHECK;
+ switch (ctx->iterator(keyring_key_to_ptr(keyring), ctx)) {
+ case 1:
goto found;
-
- /* we set a different error code if we pass a negative key */
- if (kflags & (1 << KEY_FLAG_NEGATIVE)) {
- err = key->type_data.reject_error;
- continue;
+ case 2:
+ return false;
+ default:
+ break;
}
+ }
+ ctx->skipped_ret = 0;
+ if (ctx->flags & KEYRING_SEARCH_NO_STATE_CHECK)
+ ctx->flags &= ~KEYRING_SEARCH_DO_STATE_CHECK;
+
+ /* Start processing a new keyring */
+descend_to_keyring:
+ kdebug("descend to %d", keyring->serial);
+ if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED)))
+ goto not_this_keyring;
+
+ /* Search through the keys in this keyring before its searching its
+ * subtrees.
+ */
+ if (search_keyring(keyring, ctx))
goto found;
- }
- /* search through the keyrings nested in this one */
- kix = 0;
-ascend:
- nkeys = keylist->nkeys;
- smp_rmb();
- for (; kix < nkeys; kix++) {
- key = rcu_dereference(keylist->keys[kix]);
- if (key->type != &key_type_keyring)
- continue;
+ /* Then manually iterate through the keyrings nested in this one.
+ *
+ * Start from the root node of the index tree. Because of the way the
+ * hash function has been set up, keyrings cluster on the leftmost
+ * branch of the root node (root slot 0) or in the root node itself.
+ * Non-keyrings avoid the leftmost branch of the root entirely (root
+ * slots 1-15).
+ */
+ ptr = ACCESS_ONCE(keyring->keys.root);
+ if (!ptr)
+ goto not_this_keyring;
- /* recursively search nested keyrings
- * - only search keyrings for which we have search permission
+ if (assoc_array_ptr_is_shortcut(ptr)) {
+ /* If the root is a shortcut, either the keyring only contains
+ * keyring pointers (everything clusters behind root slot 0) or
+ * doesn't contain any keyring pointers.
*/
- if (sp >= KEYRING_SEARCH_MAX_DEPTH)
+ shortcut = assoc_array_ptr_to_shortcut(ptr);
+ smp_read_barrier_depends();
+ if ((shortcut->index_key[0] & ASSOC_ARRAY_FAN_MASK) != 0)
+ goto not_this_keyring;
+
+ ptr = ACCESS_ONCE(shortcut->next_node);
+ node = assoc_array_ptr_to_node(ptr);
+ goto begin_node;
+ }
+
+ node = assoc_array_ptr_to_node(ptr);
+ smp_read_barrier_depends();
+
+ ptr = node->slots[0];
+ if (!assoc_array_ptr_is_meta(ptr))
+ goto begin_node;
+
+descend_to_node:
+ /* Descend to a more distal node in this keyring's content tree and go
+ * through that.
+ */
+ kdebug("descend");
+ if (assoc_array_ptr_is_shortcut(ptr)) {
+ shortcut = assoc_array_ptr_to_shortcut(ptr);
+ smp_read_barrier_depends();
+ ptr = ACCESS_ONCE(shortcut->next_node);
+ BUG_ON(!assoc_array_ptr_is_node(ptr));
+ node = assoc_array_ptr_to_node(ptr);
+ }
+
+begin_node:
+ kdebug("begin_node");
+ smp_read_barrier_depends();
+ slot = 0;
+ascend_to_node:
+ /* Go through the slots in a node */
+ for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) {
+ ptr = ACCESS_ONCE(node->slots[slot]);
+
+ if (assoc_array_ptr_is_meta(ptr) && node->back_pointer)
+ goto descend_to_node;
+
+ if (!keyring_ptr_is_keyring(ptr))
continue;
- if (key_task_permission(make_key_ref(key, possessed),
- cred, KEY_SEARCH) < 0)
+ key = keyring_ptr_to_key(ptr);
+
+ if (sp >= KEYRING_SEARCH_MAX_DEPTH) {
+ if (ctx->flags & KEYRING_SEARCH_DETECT_TOO_DEEP) {
+ ctx->result = ERR_PTR(-ELOOP);
+ return false;
+ }
+ goto not_this_keyring;
+ }
+
+ /* Search a nested keyring */
+ if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) &&
+ key_task_permission(make_key_ref(key, ctx->possessed),
+ ctx->cred, KEY_SEARCH) < 0)
continue;
/* stack the current position */
stack[sp].keyring = keyring;
- stack[sp].keylist = keylist;
- stack[sp].kix = kix;
+ stack[sp].node = node;
+ stack[sp].slot = slot;
sp++;
/* begin again with the new keyring */
keyring = key;
- goto descend;
+ goto descend_to_keyring;
+ }
+
+ /* We've dealt with all the slots in the current node, so now we need
+ * to ascend to the parent and continue processing there.
+ */
+ ptr = ACCESS_ONCE(node->back_pointer);
+ slot = node->parent_slot;
+
+ if (ptr && assoc_array_ptr_is_shortcut(ptr)) {
+ shortcut = assoc_array_ptr_to_shortcut(ptr);
+ smp_read_barrier_depends();
+ ptr = ACCESS_ONCE(shortcut->back_pointer);
+ slot = shortcut->parent_slot;
+ }
+ if (!ptr)
+ goto not_this_keyring;
+ node = assoc_array_ptr_to_node(ptr);
+ smp_read_barrier_depends();
+ slot++;
+
+ /* If we've ascended to the root (zero backpointer), we must have just
+ * finished processing the leftmost branch rather than the root slots -
+ * so there can't be any more keyrings for us to find.
+ */
+ if (node->back_pointer) {
+ kdebug("ascend %d", slot);
+ goto ascend_to_node;
}
- /* the keyring we're looking at was disqualified or didn't contain a
- * matching key */
+ /* The keyring we're looking at was disqualified or didn't contain a
+ * matching key.
+ */
not_this_keyring:
- if (sp > 0) {
- /* resume the processing of a keyring higher up in the tree */
- sp--;
- keyring = stack[sp].keyring;
- keylist = stack[sp].keylist;
- kix = stack[sp].kix + 1;
- goto ascend;
+ kdebug("not_this_keyring %d", sp);
+ if (sp <= 0) {
+ kleave(" = false");
+ return false;
}
- key_ref = ERR_PTR(err);
- goto error_2;
+ /* Resume the processing of a keyring higher up in the tree */
+ sp--;
+ keyring = stack[sp].keyring;
+ node = stack[sp].node;
+ slot = stack[sp].slot + 1;
+ kdebug("ascend to %d [%d]", keyring->serial, slot);
+ goto ascend_to_node;
- /* we found a viable match */
+ /* We found a viable match */
found:
- atomic_inc(&key->usage);
- key->last_used_at = now.tv_sec;
- keyring->last_used_at = now.tv_sec;
- while (sp > 0)
- stack[--sp].keyring->last_used_at = now.tv_sec;
+ key = key_ref_to_ptr(ctx->result);
key_check(key);
- key_ref = make_key_ref(key, possessed);
-error_2:
+ if (!(ctx->flags & KEYRING_SEARCH_NO_UPDATE_TIME)) {
+ key->last_used_at = ctx->now.tv_sec;
+ keyring->last_used_at = ctx->now.tv_sec;
+ while (sp > 0)
+ stack[--sp].keyring->last_used_at = ctx->now.tv_sec;
+ }
+ kleave(" = true");
+ return true;
+}
+
+/**
+ * keyring_search_aux - Search a keyring tree for a key matching some criteria
+ * @keyring_ref: A pointer to the keyring with possession indicator.
+ * @ctx: The keyring search context.
+ *
+ * Search the supplied keyring tree for a key that matches the criteria given.
+ * The root keyring and any linked keyrings must grant Search permission to the
+ * caller to be searchable and keys can only be found if they too grant Search
+ * to the caller. The possession flag on the root keyring pointer controls use
+ * of the possessor bits in permissions checking of the entire tree. In
+ * addition, the LSM gets to forbid keyring searches and key matches.
+ *
+ * The search is performed as a breadth-then-depth search up to the prescribed
+ * limit (KEYRING_SEARCH_MAX_DEPTH).
+ *
+ * Keys are matched to the type provided and are then filtered by the match
+ * function, which is given the description to use in any way it sees fit. The
+ * match function may use any attributes of a key that it wishes to to
+ * determine the match. Normally the match function from the key type would be
+ * used.
+ *
+ * RCU can be used to prevent the keyring key lists from disappearing without
+ * the need to take lots of locks.
+ *
+ * Returns a pointer to the found key and increments the key usage count if
+ * successful; -EAGAIN if no matching keys were found, or if expired or revoked
+ * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the
+ * specified keyring wasn't a keyring.
+ *
+ * In the case of a successful return, the possession attribute from
+ * @keyring_ref is propagated to the returned key reference.
+ */
+key_ref_t keyring_search_aux(key_ref_t keyring_ref,
+ struct keyring_search_context *ctx)
+{
+ struct key *keyring;
+ long err;
+
+ ctx->iterator = keyring_search_iterator;
+ ctx->possessed = is_key_possessed(keyring_ref);
+ ctx->result = ERR_PTR(-EAGAIN);
+
+ keyring = key_ref_to_ptr(keyring_ref);
+ key_check(keyring);
+
+ if (keyring->type != &key_type_keyring)
+ return ERR_PTR(-ENOTDIR);
+
+ if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM)) {
+ err = key_task_permission(keyring_ref, ctx->cred, KEY_SEARCH);
+ if (err < 0)
+ return ERR_PTR(err);
+ }
+
+ rcu_read_lock();
+ ctx->now = current_kernel_time();
+ if (search_nested_keyrings(keyring, ctx))
+ __key_get(key_ref_to_ptr(ctx->result));
rcu_read_unlock();
-error:
- return key_ref;
+ return ctx->result;
}
/**
* @description: The name of the keyring we want to find.
*
* As keyring_search_aux() above, but using the current task's credentials and
- * type's default matching function.
+ * type's default matching function and preferred search method.
*/
key_ref_t keyring_search(key_ref_t keyring,
struct key_type *type,
const char *description)
{
- if (!type->match)
+ struct keyring_search_context ctx = {
+ .index_key.type = type,
+ .index_key.description = description,
+ .cred = current_cred(),
+ .match = type->match,
+ .match_data = description,
+ .flags = (type->def_lookup_type |
+ KEYRING_SEARCH_DO_STATE_CHECK),
+ };
+
+ if (!ctx.match)
return ERR_PTR(-ENOKEY);
- return keyring_search_aux(keyring, current->cred,
- type, description, type->match, false);
+ return keyring_search_aux(keyring, &ctx);
}
EXPORT_SYMBOL(keyring_search);
/*
- * Search the given keyring only (no recursion).
+ * Search the given keyring for a key that might be updated.
*
* The caller must guarantee that the keyring is a keyring and that the
- * permission is granted to search the keyring as no check is made here.
- *
- * RCU is used to make it unnecessary to lock the keyring key list here.
+ * permission is granted to modify the keyring as no check is made here. The
+ * caller must also hold a lock on the keyring semaphore.
*
* Returns a pointer to the found key with usage count incremented if
- * successful and returns -ENOKEY if not found. Revoked keys and keys not
- * providing the requested permission are skipped over.
+ * successful and returns NULL if not found. Revoked and invalidated keys are
+ * skipped over.
*
* If successful, the possession indicator is propagated from the keyring ref
* to the returned key reference.
*/
-key_ref_t __keyring_search_one(key_ref_t keyring_ref,
- const struct key_type *ktype,
- const char *description,
- key_perm_t perm)
+key_ref_t find_key_to_update(key_ref_t keyring_ref,
+ const struct keyring_index_key *index_key)
{
- struct keyring_list *klist;
- unsigned long possessed;
struct key *keyring, *key;
- int nkeys, loop;
+ const void *object;
keyring = key_ref_to_ptr(keyring_ref);
- possessed = is_key_possessed(keyring_ref);
- rcu_read_lock();
+ kenter("{%d},{%s,%s}",
+ keyring->serial, index_key->type->name, index_key->description);
- klist = rcu_dereference(keyring->payload.subscriptions);
- if (klist) {
- nkeys = klist->nkeys;
- smp_rmb();
- for (loop = 0; loop < nkeys ; loop++) {
- key = rcu_dereference(klist->keys[loop]);
- if (key->type == ktype &&
- (!key->type->match ||
- key->type->match(key, description)) &&
- key_permission(make_key_ref(key, possessed),
- perm) == 0 &&
- !(key->flags & ((1 << KEY_FLAG_INVALIDATED) |
- (1 << KEY_FLAG_REVOKED)))
- )
- goto found;
- }
- }
+ object = assoc_array_find(&keyring->keys, &keyring_assoc_array_ops,
+ index_key);
- rcu_read_unlock();
- return ERR_PTR(-ENOKEY);
+ if (object)
+ goto found;
+
+ kleave(" = NULL");
+ return NULL;
found:
- atomic_inc(&key->usage);
- keyring->last_used_at = key->last_used_at =
- current_kernel_time().tv_sec;
- rcu_read_unlock();
- return make_key_ref(key, possessed);
+ key = keyring_ptr_to_key(object);
+ if (key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED))) {
+ kleave(" = NULL [x]");
+ return NULL;
+ }
+ __key_get(key);
+ kleave(" = {%d}", key->serial);
+ return make_key_ref(key, is_key_possessed(keyring_ref));
}
/*
return keyring;
}
+static int keyring_detect_cycle_iterator(const void *object,
+ void *iterator_data)
+{
+ struct keyring_search_context *ctx = iterator_data;
+ const struct key *key = keyring_ptr_to_key(object);
+
+ kenter("{%d}", key->serial);
+
+ BUG_ON(key != ctx->match_data);
+ ctx->result = ERR_PTR(-EDEADLK);
+ return 1;
+}
+
/*
* See if a cycle will will be created by inserting acyclic tree B in acyclic
* tree A at the topmost level (ie: as a direct child of A).
*/
static int keyring_detect_cycle(struct key *A, struct key *B)
{
- struct {
- struct keyring_list *keylist;
- int kix;
- } stack[KEYRING_SEARCH_MAX_DEPTH];
-
- struct keyring_list *keylist;
- struct key *subtree, *key;
- int sp, nkeys, kix, ret;
+ struct keyring_search_context ctx = {
+ .index_key = A->index_key,
+ .match_data = A,
+ .iterator = keyring_detect_cycle_iterator,
+ .flags = (KEYRING_SEARCH_LOOKUP_DIRECT |
+ KEYRING_SEARCH_NO_STATE_CHECK |
+ KEYRING_SEARCH_NO_UPDATE_TIME |
+ KEYRING_SEARCH_NO_CHECK_PERM |
+ KEYRING_SEARCH_DETECT_TOO_DEEP),
+ };
rcu_read_lock();
-
- ret = -EDEADLK;
- if (A == B)
- goto cycle_detected;
-
- subtree = B;
- sp = 0;
-
- /* start processing a new keyring */
-descend:
- if (test_bit(KEY_FLAG_REVOKED, &subtree->flags))
- goto not_this_keyring;
-
- keylist = rcu_dereference(subtree->payload.subscriptions);
- if (!keylist)
- goto not_this_keyring;
- kix = 0;
-
-ascend:
- /* iterate through the remaining keys in this keyring */
- nkeys = keylist->nkeys;
- smp_rmb();
- for (; kix < nkeys; kix++) {
- key = rcu_dereference(keylist->keys[kix]);
-
- if (key == A)
- goto cycle_detected;
-
- /* recursively check nested keyrings */
- if (key->type == &key_type_keyring) {
- if (sp >= KEYRING_SEARCH_MAX_DEPTH)
- goto too_deep;
-
- /* stack the current position */
- stack[sp].keylist = keylist;
- stack[sp].kix = kix;
- sp++;
-
- /* begin again with the new keyring */
- subtree = key;
- goto descend;
- }
- }
-
- /* the keyring we're looking at was disqualified or didn't contain a
- * matching key */
-not_this_keyring:
- if (sp > 0) {
- /* resume the checking of a keyring higher up in the tree */
- sp--;
- keylist = stack[sp].keylist;
- kix = stack[sp].kix + 1;
- goto ascend;
- }
-
- ret = 0; /* no cycles detected */
-
-error:
+ search_nested_keyrings(B, &ctx);
rcu_read_unlock();
- return ret;
-
-too_deep:
- ret = -ELOOP;
- goto error;
-
-cycle_detected:
- ret = -EDEADLK;
- goto error;
-}
-
-/*
- * Dispose of a keyring list after the RCU grace period, freeing the unlinked
- * key
- */
-static void keyring_unlink_rcu_disposal(struct rcu_head *rcu)
-{
- struct keyring_list *klist =
- container_of(rcu, struct keyring_list, rcu);
-
- if (klist->delkey != USHRT_MAX)
- key_put(rcu_access_pointer(klist->keys[klist->delkey]));
- kfree(klist);
+ return PTR_ERR(ctx.result) == -EAGAIN ? 0 : PTR_ERR(ctx.result);
}
/*
* Preallocate memory so that a key can be linked into to a keyring.
*/
-int __key_link_begin(struct key *keyring, const struct key_type *type,
- const char *description, unsigned long *_prealloc)
+int __key_link_begin(struct key *keyring,
+ const struct keyring_index_key *index_key,
+ struct assoc_array_edit **_edit)
__acquires(&keyring->sem)
__acquires(&keyring_serialise_link_sem)
{
- struct keyring_list *klist, *nklist;
- unsigned long prealloc;
- unsigned max;
- time_t lowest_lru;
- size_t size;
- int loop, lru, ret;
+ struct assoc_array_edit *edit;
+ int ret;
+
+ kenter("%d,%s,%s,",
+ keyring->serial, index_key->type->name, index_key->description);
- kenter("%d,%s,%s,", key_serial(keyring), type->name, description);
+ BUG_ON(index_key->desc_len == 0);
if (keyring->type != &key_type_keyring)
return -ENOTDIR;
/* serialise link/link calls to prevent parallel calls causing a cycle
* when linking two keyring in opposite orders */
- if (type == &key_type_keyring)
+ if (index_key->type == &key_type_keyring)
down_write(&keyring_serialise_link_sem);
- klist = rcu_dereference_locked_keyring(keyring);
-
- /* see if there's a matching key we can displace */
- lru = -1;
- if (klist && klist->nkeys > 0) {
- lowest_lru = TIME_T_MAX;
- for (loop = klist->nkeys - 1; loop >= 0; loop--) {
- struct key *key = rcu_deref_link_locked(klist, loop,
- keyring);
- if (key->type == type &&
- strcmp(key->description, description) == 0) {
- /* Found a match - we'll replace the link with
- * one to the new key. We record the slot
- * position.
- */
- klist->delkey = loop;
- prealloc = 0;
- goto done;
- }
- if (key->last_used_at < lowest_lru) {
- lowest_lru = key->last_used_at;
- lru = loop;
- }
- }
- }
-
- /* If the keyring is full then do an LRU discard */
- if (klist &&
- klist->nkeys == klist->maxkeys &&
- klist->maxkeys >= MAX_KEYRING_LINKS) {
- kdebug("LRU discard %d\n", lru);
- klist->delkey = lru;
- prealloc = 0;
- goto done;
- }
-
/* check that we aren't going to overrun the user's quota */
ret = key_payload_reserve(keyring,
keyring->datalen + KEYQUOTA_LINK_BYTES);
if (ret < 0)
goto error_sem;
- if (klist && klist->nkeys < klist->maxkeys) {
- /* there's sufficient slack space to append directly */
- klist->delkey = klist->nkeys;
- prealloc = KEY_LINK_FIXQUOTA;
- } else {
- /* grow the key list */
- max = 4;
- if (klist) {
- max += klist->maxkeys;
- if (max > MAX_KEYRING_LINKS)
- max = MAX_KEYRING_LINKS;
- BUG_ON(max <= klist->maxkeys);
- }
-
- size = sizeof(*klist) + sizeof(struct key *) * max;
-
- ret = -ENOMEM;
- nklist = kmalloc(size, GFP_KERNEL);
- if (!nklist)
- goto error_quota;
-
- nklist->maxkeys = max;
- if (klist) {
- memcpy(nklist->keys, klist->keys,
- sizeof(struct key *) * klist->nkeys);
- nklist->delkey = klist->nkeys;
- nklist->nkeys = klist->nkeys + 1;
- klist->delkey = USHRT_MAX;
- } else {
- nklist->nkeys = 1;
- nklist->delkey = 0;
- }
-
- /* add the key into the new space */
- RCU_INIT_POINTER(nklist->keys[nklist->delkey], NULL);
- prealloc = (unsigned long)nklist | KEY_LINK_FIXQUOTA;
+ /* Create an edit script that will insert/replace the key in the
+ * keyring tree.
+ */
+ edit = assoc_array_insert(&keyring->keys,
+ &keyring_assoc_array_ops,
+ index_key,
+ NULL);
+ if (IS_ERR(edit)) {
+ ret = PTR_ERR(edit);
+ goto error_quota;
}
-done:
- *_prealloc = prealloc;
+ *_edit = edit;
kleave(" = 0");
return 0;
key_payload_reserve(keyring,
keyring->datalen - KEYQUOTA_LINK_BYTES);
error_sem:
- if (type == &key_type_keyring)
+ if (index_key->type == &key_type_keyring)
up_write(&keyring_serialise_link_sem);
error_krsem:
up_write(&keyring->sem);
* holds at most one link to any given key of a particular type+description
* combination.
*/
-void __key_link(struct key *keyring, struct key *key,
- unsigned long *_prealloc)
+void __key_link(struct key *key, struct assoc_array_edit **_edit)
{
- struct keyring_list *klist, *nklist;
- struct key *discard;
-
- nklist = (struct keyring_list *)(*_prealloc & ~KEY_LINK_FIXQUOTA);
- *_prealloc = 0;
-
- kenter("%d,%d,%p", keyring->serial, key->serial, nklist);
-
- klist = rcu_dereference_locked_keyring(keyring);
-
- atomic_inc(&key->usage);
- keyring->last_used_at = key->last_used_at =
- current_kernel_time().tv_sec;
-
- /* there's a matching key we can displace or an empty slot in a newly
- * allocated list we can fill */
- if (nklist) {
- kdebug("reissue %hu/%hu/%hu",
- nklist->delkey, nklist->nkeys, nklist->maxkeys);
-
- RCU_INIT_POINTER(nklist->keys[nklist->delkey], key);
-
- rcu_assign_pointer(keyring->payload.subscriptions, nklist);
-
- /* dispose of the old keyring list and, if there was one, the
- * displaced key */
- if (klist) {
- kdebug("dispose %hu/%hu/%hu",
- klist->delkey, klist->nkeys, klist->maxkeys);
- call_rcu(&klist->rcu, keyring_unlink_rcu_disposal);
- }
- } else if (klist->delkey < klist->nkeys) {
- kdebug("replace %hu/%hu/%hu",
- klist->delkey, klist->nkeys, klist->maxkeys);
-
- discard = rcu_dereference_protected(
- klist->keys[klist->delkey],
- rwsem_is_locked(&keyring->sem));
- rcu_assign_pointer(klist->keys[klist->delkey], key);
- /* The garbage collector will take care of RCU
- * synchronisation */
- key_put(discard);
- } else {
- /* there's sufficient slack space to append directly */
- kdebug("append %hu/%hu/%hu",
- klist->delkey, klist->nkeys, klist->maxkeys);
-
- RCU_INIT_POINTER(klist->keys[klist->delkey], key);
- smp_wmb();
- klist->nkeys++;
- }
+ __key_get(key);
+ assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key));
+ assoc_array_apply_edit(*_edit);
+ *_edit = NULL;
}
/*
*
* Must be called with __key_link_begin() having being called.
*/
-void __key_link_end(struct key *keyring, struct key_type *type,
- unsigned long prealloc)
+void __key_link_end(struct key *keyring,
+ const struct keyring_index_key *index_key,
+ struct assoc_array_edit *edit)
__releases(&keyring->sem)
__releases(&keyring_serialise_link_sem)
{
- BUG_ON(type == NULL);
- BUG_ON(type->name == NULL);
- kenter("%d,%s,%lx", keyring->serial, type->name, prealloc);
+ BUG_ON(index_key->type == NULL);
+ kenter("%d,%s,", keyring->serial, index_key->type->name);
- if (type == &key_type_keyring)
+ if (index_key->type == &key_type_keyring)
up_write(&keyring_serialise_link_sem);
- if (prealloc) {
- if (prealloc & KEY_LINK_FIXQUOTA)
- key_payload_reserve(keyring,
- keyring->datalen -
- KEYQUOTA_LINK_BYTES);
- kfree((struct keyring_list *)(prealloc & ~KEY_LINK_FIXQUOTA));
+ if (edit) {
+ key_payload_reserve(keyring,
+ keyring->datalen - KEYQUOTA_LINK_BYTES);
+ assoc_array_cancel_edit(edit);
}
up_write(&keyring->sem);
}
*/
int key_link(struct key *keyring, struct key *key)
{
- unsigned long prealloc;
+ struct assoc_array_edit *edit;
int ret;
+ kenter("{%d,%d}", keyring->serial, atomic_read(&keyring->usage));
+
key_check(keyring);
key_check(key);
- ret = __key_link_begin(keyring, key->type, key->description, &prealloc);
+ if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) &&
+ !test_bit(KEY_FLAG_TRUSTED, &key->flags))
+ return -EPERM;
+
+ ret = __key_link_begin(keyring, &key->index_key, &edit);
if (ret == 0) {
+ kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage));
ret = __key_link_check_live_key(keyring, key);
if (ret == 0)
- __key_link(keyring, key, &prealloc);
- __key_link_end(keyring, key->type, prealloc);
+ __key_link(key, &edit);
+ __key_link_end(keyring, &key->index_key, edit);
}
+ kleave(" = %d {%d,%d}", ret, keyring->serial, atomic_read(&keyring->usage));
return ret;
}
EXPORT_SYMBOL(key_link);
*/
int key_unlink(struct key *keyring, struct key *key)
{
- struct keyring_list *klist, *nklist;
- int loop, ret;
+ struct assoc_array_edit *edit;
+ int ret;
key_check(keyring);
key_check(key);
- ret = -ENOTDIR;
if (keyring->type != &key_type_keyring)
- goto error;
+ return -ENOTDIR;
down_write(&keyring->sem);
- klist = rcu_dereference_locked_keyring(keyring);
- if (klist) {
- /* search the keyring for the key */
- for (loop = 0; loop < klist->nkeys; loop++)
- if (rcu_access_pointer(klist->keys[loop]) == key)
- goto key_is_present;
+ edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops,
+ &key->index_key);
+ if (IS_ERR(edit)) {
+ ret = PTR_ERR(edit);
+ goto error;
}
-
- up_write(&keyring->sem);
ret = -ENOENT;
- goto error;
-
-key_is_present:
- /* we need to copy the key list for RCU purposes */
- nklist = kmalloc(sizeof(*klist) +
- sizeof(struct key *) * klist->maxkeys,
- GFP_KERNEL);
- if (!nklist)
- goto nomem;
- nklist->maxkeys = klist->maxkeys;
- nklist->nkeys = klist->nkeys - 1;
-
- if (loop > 0)
- memcpy(&nklist->keys[0],
- &klist->keys[0],
- loop * sizeof(struct key *));
-
- if (loop < nklist->nkeys)
- memcpy(&nklist->keys[loop],
- &klist->keys[loop + 1],
- (nklist->nkeys - loop) * sizeof(struct key *));
-
- /* adjust the user's quota */
- key_payload_reserve(keyring,
- keyring->datalen - KEYQUOTA_LINK_BYTES);
-
- rcu_assign_pointer(keyring->payload.subscriptions, nklist);
-
- up_write(&keyring->sem);
-
- /* schedule for later cleanup */
- klist->delkey = loop;
- call_rcu(&klist->rcu, keyring_unlink_rcu_disposal);
+ if (edit == NULL)
+ goto error;
+ assoc_array_apply_edit(edit);
ret = 0;
error:
- return ret;
-nomem:
- ret = -ENOMEM;
up_write(&keyring->sem);
- goto error;
+ return ret;
}
EXPORT_SYMBOL(key_unlink);
-/*
- * Dispose of a keyring list after the RCU grace period, releasing the keys it
- * links to.
- */
-static void keyring_clear_rcu_disposal(struct rcu_head *rcu)
-{
- struct keyring_list *klist;
- int loop;
-
- klist = container_of(rcu, struct keyring_list, rcu);
-
- for (loop = klist->nkeys - 1; loop >= 0; loop--)
- key_put(rcu_access_pointer(klist->keys[loop]));
-
- kfree(klist);
-}
-
/**
* keyring_clear - Clear a keyring
* @keyring: The keyring to clear.
*/
int keyring_clear(struct key *keyring)
{
- struct keyring_list *klist;
+ struct assoc_array_edit *edit;
int ret;
- ret = -ENOTDIR;
- if (keyring->type == &key_type_keyring) {
- /* detach the pointer block with the locks held */
- down_write(&keyring->sem);
-
- klist = rcu_dereference_locked_keyring(keyring);
- if (klist) {
- /* adjust the quota */
- key_payload_reserve(keyring,
- sizeof(struct keyring_list));
-
- rcu_assign_pointer(keyring->payload.subscriptions,
- NULL);
- }
-
- up_write(&keyring->sem);
+ if (keyring->type != &key_type_keyring)
+ return -ENOTDIR;
- /* free the keys after the locks have been dropped */
- if (klist)
- call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
+ down_write(&keyring->sem);
+ edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops);
+ if (IS_ERR(edit)) {
+ ret = PTR_ERR(edit);
+ } else {
+ if (edit)
+ assoc_array_apply_edit(edit);
+ key_payload_reserve(keyring, 0);
ret = 0;
}
+ up_write(&keyring->sem);
return ret;
}
EXPORT_SYMBOL(keyring_clear);
*/
static void keyring_revoke(struct key *keyring)
{
- struct keyring_list *klist;
+ struct assoc_array_edit *edit;
- klist = rcu_dereference_locked_keyring(keyring);
+ edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops);
+ if (!IS_ERR(edit)) {
+ if (edit)
+ assoc_array_apply_edit(edit);
+ key_payload_reserve(keyring, 0);
+ }
+}
- /* adjust the quota */
- key_payload_reserve(keyring, 0);
+static bool gc_iterator(void *object, void *iterator_data)
+{
+ struct key *key = keyring_ptr_to_key(object);
+ time_t *limit = iterator_data;
- if (klist) {
- rcu_assign_pointer(keyring->payload.subscriptions, NULL);
- call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
- }
+ if (key_is_dead(key, *limit))
+ return false;
+ key_get(key);
+ return true;
}
/*
*/
void keyring_gc(struct key *keyring, time_t limit)
{
- struct keyring_list *klist, *new;
- struct key *key;
- int loop, keep, max;
-
kenter("{%x,%s}", key_serial(keyring), keyring->description);
down_write(&keyring->sem);
-
- klist = rcu_dereference_locked_keyring(keyring);
- if (!klist)
- goto no_klist;
-
- /* work out how many subscriptions we're keeping */
- keep = 0;
- for (loop = klist->nkeys - 1; loop >= 0; loop--)
- if (!key_is_dead(rcu_deref_link_locked(klist, loop, keyring),
- limit))
- keep++;
-
- if (keep == klist->nkeys)
- goto just_return;
-
- /* allocate a new keyring payload */
- max = roundup(keep, 4);
- new = kmalloc(sizeof(struct keyring_list) + max * sizeof(struct key *),
- GFP_KERNEL);
- if (!new)
- goto nomem;
- new->maxkeys = max;
- new->nkeys = 0;
- new->delkey = 0;
-
- /* install the live keys
- * - must take care as expired keys may be updated back to life
- */
- keep = 0;
- for (loop = klist->nkeys - 1; loop >= 0; loop--) {
- key = rcu_deref_link_locked(klist, loop, keyring);
- if (!key_is_dead(key, limit)) {
- if (keep >= max)
- goto discard_new;
- RCU_INIT_POINTER(new->keys[keep++], key_get(key));
- }
- }
- new->nkeys = keep;
-
- /* adjust the quota */
- key_payload_reserve(keyring,
- sizeof(struct keyring_list) +
- KEYQUOTA_LINK_BYTES * keep);
-
- if (keep == 0) {
- rcu_assign_pointer(keyring->payload.subscriptions, NULL);
- kfree(new);
- } else {
- rcu_assign_pointer(keyring->payload.subscriptions, new);
- }
-
- up_write(&keyring->sem);
-
- call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
- kleave(" [yes]");
- return;
-
-discard_new:
- new->nkeys = keep;
- keyring_clear_rcu_disposal(&new->rcu);
+ assoc_array_gc(&keyring->keys, &keyring_assoc_array_ops,
+ gc_iterator, &limit);
up_write(&keyring->sem);
- kleave(" [discard]");
- return;
-just_return:
- up_write(&keyring->sem);
- kleave(" [no dead]");
- return;
-
-no_klist:
- up_write(&keyring->sem);
- kleave(" [no_klist]");
- return;
-
-nomem:
- up_write(&keyring->sem);
- kleave(" [oom]");
+ kleave("");
}
projects / karo-tx-linux.git / blobdiff