Merge remote-tracking branch 'torvalds/master' into perf/core
[linux-2.6-microblaze.git] / drivers / net / wireguard / allowedips.c
index 3725e9c..b7197e8 100644 (file)
@@ -6,6 +6,8 @@
 #include "allowedips.h"
 #include "peer.h"
 
+static struct kmem_cache *node_cache;
+
 static void swap_endian(u8 *dst, const u8 *src, u8 bits)
 {
        if (bits == 32) {
@@ -28,8 +30,11 @@ static void copy_and_assign_cidr(struct allowedips_node *node, const u8 *src,
        node->bitlen = bits;
        memcpy(node->bits, src, bits / 8U);
 }
-#define CHOOSE_NODE(parent, key) \
-       parent->bit[(key[parent->bit_at_a] >> parent->bit_at_b) & 1]
+
+static inline u8 choose(struct allowedips_node *node, const u8 *key)
+{
+       return (key[node->bit_at_a] >> node->bit_at_b) & 1;
+}
 
 static void push_rcu(struct allowedips_node **stack,
                     struct allowedips_node __rcu *p, unsigned int *len)
@@ -40,6 +45,11 @@ static void push_rcu(struct allowedips_node **stack,
        }
 }
 
+static void node_free_rcu(struct rcu_head *rcu)
+{
+       kmem_cache_free(node_cache, container_of(rcu, struct allowedips_node, rcu));
+}
+
 static void root_free_rcu(struct rcu_head *rcu)
 {
        struct allowedips_node *node, *stack[128] = {
@@ -49,7 +59,7 @@ static void root_free_rcu(struct rcu_head *rcu)
        while (len > 0 && (node = stack[--len])) {
                push_rcu(stack, node->bit[0], &len);
                push_rcu(stack, node->bit[1], &len);
-               kfree(node);
+               kmem_cache_free(node_cache, node);
        }
 }
 
@@ -66,60 +76,6 @@ static void root_remove_peer_lists(struct allowedips_node *root)
        }
 }
 
-static void walk_remove_by_peer(struct allowedips_node __rcu **top,
-                               struct wg_peer *peer, struct mutex *lock)
-{
-#define REF(p) rcu_access_pointer(p)
-#define DEREF(p) rcu_dereference_protected(*(p), lockdep_is_held(lock))
-#define PUSH(p) ({                                                             \
-               WARN_ON(IS_ENABLED(DEBUG) && len >= 128);                      \
-               stack[len++] = p;                                              \
-       })
-
-       struct allowedips_node __rcu **stack[128], **nptr;
-       struct allowedips_node *node, *prev;
-       unsigned int len;
-
-       if (unlikely(!peer || !REF(*top)))
-               return;
-
-       for (prev = NULL, len = 0, PUSH(top); len > 0; prev = node) {
-               nptr = stack[len - 1];
-               node = DEREF(nptr);
-               if (!node) {
-                       --len;
-                       continue;
-               }
-               if (!prev || REF(prev->bit[0]) == node ||
-                   REF(prev->bit[1]) == node) {
-                       if (REF(node->bit[0]))
-                               PUSH(&node->bit[0]);
-                       else if (REF(node->bit[1]))
-                               PUSH(&node->bit[1]);
-               } else if (REF(node->bit[0]) == prev) {
-                       if (REF(node->bit[1]))
-                               PUSH(&node->bit[1]);
-               } else {
-                       if (rcu_dereference_protected(node->peer,
-                               lockdep_is_held(lock)) == peer) {
-                               RCU_INIT_POINTER(node->peer, NULL);
-                               list_del_init(&node->peer_list);
-                               if (!node->bit[0] || !node->bit[1]) {
-                                       rcu_assign_pointer(*nptr, DEREF(
-                                              &node->bit[!REF(node->bit[0])]));
-                                       kfree_rcu(node, rcu);
-                                       node = DEREF(nptr);
-                               }
-                       }
-                       --len;
-               }
-       }
-
-#undef REF
-#undef DEREF
-#undef PUSH
-}
-
 static unsigned int fls128(u64 a, u64 b)
 {
        return a ? fls64(a) + 64U : fls64(b);
@@ -159,7 +115,7 @@ static struct allowedips_node *find_node(struct allowedips_node *trie, u8 bits,
                        found = node;
                if (node->cidr == bits)
                        break;
-               node = rcu_dereference_bh(CHOOSE_NODE(node, key));
+               node = rcu_dereference_bh(node->bit[choose(node, key)]);
        }
        return found;
 }
@@ -191,8 +147,7 @@ static bool node_placement(struct allowedips_node __rcu *trie, const u8 *key,
                           u8 cidr, u8 bits, struct allowedips_node **rnode,
                           struct mutex *lock)
 {
-       struct allowedips_node *node = rcu_dereference_protected(trie,
-                                               lockdep_is_held(lock));
+       struct allowedips_node *node = rcu_dereference_protected(trie, lockdep_is_held(lock));
        struct allowedips_node *parent = NULL;
        bool exact = false;
 
@@ -202,13 +157,24 @@ static bool node_placement(struct allowedips_node __rcu *trie, const u8 *key,
                        exact = true;
                        break;
                }
-               node = rcu_dereference_protected(CHOOSE_NODE(parent, key),
-                                                lockdep_is_held(lock));
+               node = rcu_dereference_protected(parent->bit[choose(parent, key)], lockdep_is_held(lock));
        }
        *rnode = parent;
        return exact;
 }
 
+static inline void connect_node(struct allowedips_node **parent, u8 bit, struct allowedips_node *node)
+{
+       node->parent_bit_packed = (unsigned long)parent | bit;
+       rcu_assign_pointer(*parent, node);
+}
+
+static inline void choose_and_connect_node(struct allowedips_node *parent, struct allowedips_node *node)
+{
+       u8 bit = choose(parent, node->bits);
+       connect_node(&parent->bit[bit], bit, node);
+}
+
 static int add(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
               u8 cidr, struct wg_peer *peer, struct mutex *lock)
 {
@@ -218,13 +184,13 @@ static int add(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
                return -EINVAL;
 
        if (!rcu_access_pointer(*trie)) {
-               node = kzalloc(sizeof(*node), GFP_KERNEL);
+               node = kmem_cache_zalloc(node_cache, GFP_KERNEL);
                if (unlikely(!node))
                        return -ENOMEM;
                RCU_INIT_POINTER(node->peer, peer);
                list_add_tail(&node->peer_list, &peer->allowedips_list);
                copy_and_assign_cidr(node, key, cidr, bits);
-               rcu_assign_pointer(*trie, node);
+               connect_node(trie, 2, node);
                return 0;
        }
        if (node_placement(*trie, key, cidr, bits, &node, lock)) {
@@ -233,7 +199,7 @@ static int add(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
                return 0;
        }
 
-       newnode = kzalloc(sizeof(*newnode), GFP_KERNEL);
+       newnode = kmem_cache_zalloc(node_cache, GFP_KERNEL);
        if (unlikely(!newnode))
                return -ENOMEM;
        RCU_INIT_POINTER(newnode->peer, peer);
@@ -243,10 +209,10 @@ static int add(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
        if (!node) {
                down = rcu_dereference_protected(*trie, lockdep_is_held(lock));
        } else {
-               down = rcu_dereference_protected(CHOOSE_NODE(node, key),
-                                                lockdep_is_held(lock));
+               const u8 bit = choose(node, key);
+               down = rcu_dereference_protected(node->bit[bit], lockdep_is_held(lock));
                if (!down) {
-                       rcu_assign_pointer(CHOOSE_NODE(node, key), newnode);
+                       connect_node(&node->bit[bit], bit, newnode);
                        return 0;
                }
        }
@@ -254,30 +220,29 @@ static int add(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
        parent = node;
 
        if (newnode->cidr == cidr) {
-               rcu_assign_pointer(CHOOSE_NODE(newnode, down->bits), down);
+               choose_and_connect_node(newnode, down);
                if (!parent)
-                       rcu_assign_pointer(*trie, newnode);
+                       connect_node(trie, 2, newnode);
                else
-                       rcu_assign_pointer(CHOOSE_NODE(parent, newnode->bits),
-                                          newnode);
-       } else {
-               node = kzalloc(sizeof(*node), GFP_KERNEL);
-               if (unlikely(!node)) {
-                       list_del(&newnode->peer_list);
-                       kfree(newnode);
-                       return -ENOMEM;
-               }
-               INIT_LIST_HEAD(&node->peer_list);
-               copy_and_assign_cidr(node, newnode->bits, cidr, bits);
+                       choose_and_connect_node(parent, newnode);
+               return 0;
+       }
 
-               rcu_assign_pointer(CHOOSE_NODE(node, down->bits), down);
-               rcu_assign_pointer(CHOOSE_NODE(node, newnode->bits), newnode);
-               if (!parent)
-                       rcu_assign_pointer(*trie, node);
-               else
-                       rcu_assign_pointer(CHOOSE_NODE(parent, node->bits),
-                                          node);
+       node = kmem_cache_zalloc(node_cache, GFP_KERNEL);
+       if (unlikely(!node)) {
+               list_del(&newnode->peer_list);
+               kmem_cache_free(node_cache, newnode);
+               return -ENOMEM;
        }
+       INIT_LIST_HEAD(&node->peer_list);
+       copy_and_assign_cidr(node, newnode->bits, cidr, bits);
+
+       choose_and_connect_node(node, down);
+       choose_and_connect_node(node, newnode);
+       if (!parent)
+               connect_node(trie, 2, node);
+       else
+               choose_and_connect_node(parent, node);
        return 0;
 }
 
@@ -335,9 +300,41 @@ int wg_allowedips_insert_v6(struct allowedips *table, const struct in6_addr *ip,
 void wg_allowedips_remove_by_peer(struct allowedips *table,
                                  struct wg_peer *peer, struct mutex *lock)
 {
+       struct allowedips_node *node, *child, **parent_bit, *parent, *tmp;
+       bool free_parent;
+
+       if (list_empty(&peer->allowedips_list))
+               return;
        ++table->seq;
-       walk_remove_by_peer(&table->root4, peer, lock);
-       walk_remove_by_peer(&table->root6, peer, lock);
+       list_for_each_entry_safe(node, tmp, &peer->allowedips_list, peer_list) {
+               list_del_init(&node->peer_list);
+               RCU_INIT_POINTER(node->peer, NULL);
+               if (node->bit[0] && node->bit[1])
+                       continue;
+               child = rcu_dereference_protected(node->bit[!rcu_access_pointer(node->bit[0])],
+                                                 lockdep_is_held(lock));
+               if (child)
+                       child->parent_bit_packed = node->parent_bit_packed;
+               parent_bit = (struct allowedips_node **)(node->parent_bit_packed & ~3UL);
+               *parent_bit = child;
+               parent = (void *)parent_bit -
+                        offsetof(struct allowedips_node, bit[node->parent_bit_packed & 1]);
+               free_parent = !rcu_access_pointer(node->bit[0]) &&
+                             !rcu_access_pointer(node->bit[1]) &&
+                             (node->parent_bit_packed & 3) <= 1 &&
+                             !rcu_access_pointer(parent->peer);
+               if (free_parent)
+                       child = rcu_dereference_protected(
+                                       parent->bit[!(node->parent_bit_packed & 1)],
+                                       lockdep_is_held(lock));
+               call_rcu(&node->rcu, node_free_rcu);
+               if (!free_parent)
+                       continue;
+               if (child)
+                       child->parent_bit_packed = parent->parent_bit_packed;
+               *(struct allowedips_node **)(parent->parent_bit_packed & ~3UL) = child;
+               call_rcu(&parent->rcu, node_free_rcu);
+       }
 }
 
 int wg_allowedips_read_node(struct allowedips_node *node, u8 ip[16], u8 *cidr)
@@ -374,4 +371,16 @@ struct wg_peer *wg_allowedips_lookup_src(struct allowedips *table,
        return NULL;
 }
 
+int __init wg_allowedips_slab_init(void)
+{
+       node_cache = KMEM_CACHE(allowedips_node, 0);
+       return node_cache ? 0 : -ENOMEM;
+}
+
+void wg_allowedips_slab_uninit(void)
+{
+       rcu_barrier();
+       kmem_cache_destroy(node_cache);
+}
+
 #include "selftest/allowedips.c"