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-rw-r--r--kernel/bpf/lpm_trie.c748
1 files changed, 748 insertions, 0 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
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index 000000000..3c2d8722d
--- /dev/null
+++ b/kernel/bpf/lpm_trie.c
@@ -0,0 +1,748 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Longest prefix match list implementation
+ *
+ * Copyright (c) 2016,2017 Daniel Mack
+ * Copyright (c) 2016 David Herrmann
+ */
+
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <net/ipv6.h>
+#include <uapi/linux/btf.h>
+
+/* Intermediate node */
+#define LPM_TREE_NODE_FLAG_IM BIT(0)
+
+struct lpm_trie_node;
+
+struct lpm_trie_node {
+ struct rcu_head rcu;
+ struct lpm_trie_node __rcu *child[2];
+ u32 prefixlen;
+ u32 flags;
+ u8 data[];
+};
+
+struct lpm_trie {
+ struct bpf_map map;
+ struct lpm_trie_node __rcu *root;
+ size_t n_entries;
+ size_t max_prefixlen;
+ size_t data_size;
+ spinlock_t lock;
+};
+
+/* This trie implements a longest prefix match algorithm that can be used to
+ * match IP addresses to a stored set of ranges.
+ *
+ * Data stored in @data of struct bpf_lpm_key and struct lpm_trie_node is
+ * interpreted as big endian, so data[0] stores the most significant byte.
+ *
+ * Match ranges are internally stored in instances of struct lpm_trie_node
+ * which each contain their prefix length as well as two pointers that may
+ * lead to more nodes containing more specific matches. Each node also stores
+ * a value that is defined by and returned to userspace via the update_elem
+ * and lookup functions.
+ *
+ * For instance, let's start with a trie that was created with a prefix length
+ * of 32, so it can be used for IPv4 addresses, and one single element that
+ * matches 192.168.0.0/16. The data array would hence contain
+ * [0xc0, 0xa8, 0x00, 0x00] in big-endian notation. This documentation will
+ * stick to IP-address notation for readability though.
+ *
+ * As the trie is empty initially, the new node (1) will be places as root
+ * node, denoted as (R) in the example below. As there are no other node, both
+ * child pointers are %NULL.
+ *
+ * +----------------+
+ * | (1) (R) |
+ * | 192.168.0.0/16 |
+ * | value: 1 |
+ * | [0] [1] |
+ * +----------------+
+ *
+ * Next, let's add a new node (2) matching 192.168.0.0/24. As there is already
+ * a node with the same data and a smaller prefix (ie, a less specific one),
+ * node (2) will become a child of (1). In child index depends on the next bit
+ * that is outside of what (1) matches, and that bit is 0, so (2) will be
+ * child[0] of (1):
+ *
+ * +----------------+
+ * | (1) (R) |
+ * | 192.168.0.0/16 |
+ * | value: 1 |
+ * | [0] [1] |
+ * +----------------+
+ * |
+ * +----------------+
+ * | (2) |
+ * | 192.168.0.0/24 |
+ * | value: 2 |
+ * | [0] [1] |
+ * +----------------+
+ *
+ * The child[1] slot of (1) could be filled with another node which has bit #17
+ * (the next bit after the ones that (1) matches on) set to 1. For instance,
+ * 192.168.128.0/24:
+ *
+ * +----------------+
+ * | (1) (R) |
+ * | 192.168.0.0/16 |
+ * | value: 1 |
+ * | [0] [1] |
+ * +----------------+
+ * | |
+ * +----------------+ +------------------+
+ * | (2) | | (3) |
+ * | 192.168.0.0/24 | | 192.168.128.0/24 |
+ * | value: 2 | | value: 3 |
+ * | [0] [1] | | [0] [1] |
+ * +----------------+ +------------------+
+ *
+ * Let's add another node (4) to the game for 192.168.1.0/24. In order to place
+ * it, node (1) is looked at first, and because (4) of the semantics laid out
+ * above (bit #17 is 0), it would normally be attached to (1) as child[0].
+ * However, that slot is already allocated, so a new node is needed in between.
+ * That node does not have a value attached to it and it will never be
+ * returned to users as result of a lookup. It is only there to differentiate
+ * the traversal further. It will get a prefix as wide as necessary to
+ * distinguish its two children:
+ *
+ * +----------------+
+ * | (1) (R) |
+ * | 192.168.0.0/16 |
+ * | value: 1 |
+ * | [0] [1] |
+ * +----------------+
+ * | |
+ * +----------------+ +------------------+
+ * | (4) (I) | | (3) |
+ * | 192.168.0.0/23 | | 192.168.128.0/24 |
+ * | value: --- | | value: 3 |
+ * | [0] [1] | | [0] [1] |
+ * +----------------+ +------------------+
+ * | |
+ * +----------------+ +----------------+
+ * | (2) | | (5) |
+ * | 192.168.0.0/24 | | 192.168.1.0/24 |
+ * | value: 2 | | value: 5 |
+ * | [0] [1] | | [0] [1] |
+ * +----------------+ +----------------+
+ *
+ * 192.168.1.1/32 would be a child of (5) etc.
+ *
+ * An intermediate node will be turned into a 'real' node on demand. In the
+ * example above, (4) would be re-used if 192.168.0.0/23 is added to the trie.
+ *
+ * A fully populated trie would have a height of 32 nodes, as the trie was
+ * created with a prefix length of 32.
+ *
+ * The lookup starts at the root node. If the current node matches and if there
+ * is a child that can be used to become more specific, the trie is traversed
+ * downwards. The last node in the traversal that is a non-intermediate one is
+ * returned.
+ */
+
+static inline int extract_bit(const u8 *data, size_t index)
+{
+ return !!(data[index / 8] & (1 << (7 - (index % 8))));
+}
+
+/**
+ * longest_prefix_match() - determine the longest prefix
+ * @trie: The trie to get internal sizes from
+ * @node: The node to operate on
+ * @key: The key to compare to @node
+ *
+ * Determine the longest prefix of @node that matches the bits in @key.
+ */
+static size_t longest_prefix_match(const struct lpm_trie *trie,
+ const struct lpm_trie_node *node,
+ const struct bpf_lpm_trie_key *key)
+{
+ u32 limit = min(node->prefixlen, key->prefixlen);
+ u32 prefixlen = 0, i = 0;
+
+ BUILD_BUG_ON(offsetof(struct lpm_trie_node, data) % sizeof(u32));
+ BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key, data) % sizeof(u32));
+
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(CONFIG_64BIT)
+
+ /* data_size >= 16 has very small probability.
+ * We do not use a loop for optimal code generation.
+ */
+ if (trie->data_size >= 8) {
+ u64 diff = be64_to_cpu(*(__be64 *)node->data ^
+ *(__be64 *)key->data);
+
+ prefixlen = 64 - fls64(diff);
+ if (prefixlen >= limit)
+ return limit;
+ if (diff)
+ return prefixlen;
+ i = 8;
+ }
+#endif
+
+ while (trie->data_size >= i + 4) {
+ u32 diff = be32_to_cpu(*(__be32 *)&node->data[i] ^
+ *(__be32 *)&key->data[i]);
+
+ prefixlen += 32 - fls(diff);
+ if (prefixlen >= limit)
+ return limit;
+ if (diff)
+ return prefixlen;
+ i += 4;
+ }
+
+ if (trie->data_size >= i + 2) {
+ u16 diff = be16_to_cpu(*(__be16 *)&node->data[i] ^
+ *(__be16 *)&key->data[i]);
+
+ prefixlen += 16 - fls(diff);
+ if (prefixlen >= limit)
+ return limit;
+ if (diff)
+ return prefixlen;
+ i += 2;
+ }
+
+ if (trie->data_size >= i + 1) {
+ prefixlen += 8 - fls(node->data[i] ^ key->data[i]);
+
+ if (prefixlen >= limit)
+ return limit;
+ }
+
+ return prefixlen;
+}
+
+/* Called from syscall or from eBPF program */
+static void *trie_lookup_elem(struct bpf_map *map, void *_key)
+{
+ struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+ struct lpm_trie_node *node, *found = NULL;
+ struct bpf_lpm_trie_key *key = _key;
+
+ if (key->prefixlen > trie->max_prefixlen)
+ return NULL;
+
+ /* Start walking the trie from the root node ... */
+
+ for (node = rcu_dereference(trie->root); node;) {
+ unsigned int next_bit;
+ size_t matchlen;
+
+ /* Determine the longest prefix of @node that matches @key.
+ * If it's the maximum possible prefix for this trie, we have
+ * an exact match and can return it directly.
+ */
+ matchlen = longest_prefix_match(trie, node, key);
+ if (matchlen == trie->max_prefixlen) {
+ found = node;
+ break;
+ }
+
+ /* If the number of bits that match is smaller than the prefix
+ * length of @node, bail out and return the node we have seen
+ * last in the traversal (ie, the parent).
+ */
+ if (matchlen < node->prefixlen)
+ break;
+
+ /* Consider this node as return candidate unless it is an
+ * artificially added intermediate one.
+ */
+ if (!(node->flags & LPM_TREE_NODE_FLAG_IM))
+ found = node;
+
+ /* If the node match is fully satisfied, let's see if we can
+ * become more specific. Determine the next bit in the key and
+ * traverse down.
+ */
+ next_bit = extract_bit(key->data, node->prefixlen);
+ node = rcu_dereference(node->child[next_bit]);
+ }
+
+ if (!found)
+ return NULL;
+
+ return found->data + trie->data_size;
+}
+
+static struct lpm_trie_node *lpm_trie_node_alloc(const struct lpm_trie *trie,
+ const void *value)
+{
+ struct lpm_trie_node *node;
+ size_t size = sizeof(struct lpm_trie_node) + trie->data_size;
+
+ if (value)
+ size += trie->map.value_size;
+
+ node = kmalloc_node(size, GFP_ATOMIC | __GFP_NOWARN,
+ trie->map.numa_node);
+ if (!node)
+ return NULL;
+
+ node->flags = 0;
+
+ if (value)
+ memcpy(node->data + trie->data_size, value,
+ trie->map.value_size);
+
+ return node;
+}
+
+/* Called from syscall or from eBPF program */
+static int trie_update_elem(struct bpf_map *map,
+ void *_key, void *value, u64 flags)
+{
+ struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+ struct lpm_trie_node *node, *im_node = NULL, *new_node = NULL;
+ struct lpm_trie_node __rcu **slot;
+ struct bpf_lpm_trie_key *key = _key;
+ unsigned long irq_flags;
+ unsigned int next_bit;
+ size_t matchlen = 0;
+ int ret = 0;
+
+ if (unlikely(flags > BPF_EXIST))
+ return -EINVAL;
+
+ if (key->prefixlen > trie->max_prefixlen)
+ return -EINVAL;
+
+ spin_lock_irqsave(&trie->lock, irq_flags);
+
+ /* Allocate and fill a new node */
+
+ if (trie->n_entries == trie->map.max_entries) {
+ ret = -ENOSPC;
+ goto out;
+ }
+
+ new_node = lpm_trie_node_alloc(trie, value);
+ if (!new_node) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ trie->n_entries++;
+
+ new_node->prefixlen = key->prefixlen;
+ RCU_INIT_POINTER(new_node->child[0], NULL);
+ RCU_INIT_POINTER(new_node->child[1], NULL);
+ memcpy(new_node->data, key->data, trie->data_size);
+
+ /* Now find a slot to attach the new node. To do that, walk the tree
+ * from the root and match as many bits as possible for each node until
+ * we either find an empty slot or a slot that needs to be replaced by
+ * an intermediate node.
+ */
+ slot = &trie->root;
+
+ while ((node = rcu_dereference_protected(*slot,
+ lockdep_is_held(&trie->lock)))) {
+ matchlen = longest_prefix_match(trie, node, key);
+
+ if (node->prefixlen != matchlen ||
+ node->prefixlen == key->prefixlen ||
+ node->prefixlen == trie->max_prefixlen)
+ break;
+
+ next_bit = extract_bit(key->data, node->prefixlen);
+ slot = &node->child[next_bit];
+ }
+
+ /* If the slot is empty (a free child pointer or an empty root),
+ * simply assign the @new_node to that slot and be done.
+ */
+ if (!node) {
+ rcu_assign_pointer(*slot, new_node);
+ goto out;
+ }
+
+ /* If the slot we picked already exists, replace it with @new_node
+ * which already has the correct data array set.
+ */
+ if (node->prefixlen == matchlen) {
+ new_node->child[0] = node->child[0];
+ new_node->child[1] = node->child[1];
+
+ if (!(node->flags & LPM_TREE_NODE_FLAG_IM))
+ trie->n_entries--;
+
+ rcu_assign_pointer(*slot, new_node);
+ kfree_rcu(node, rcu);
+
+ goto out;
+ }
+
+ /* If the new node matches the prefix completely, it must be inserted
+ * as an ancestor. Simply insert it between @node and *@slot.
+ */
+ if (matchlen == key->prefixlen) {
+ next_bit = extract_bit(node->data, matchlen);
+ rcu_assign_pointer(new_node->child[next_bit], node);
+ rcu_assign_pointer(*slot, new_node);
+ goto out;
+ }
+
+ im_node = lpm_trie_node_alloc(trie, NULL);
+ if (!im_node) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ im_node->prefixlen = matchlen;
+ im_node->flags |= LPM_TREE_NODE_FLAG_IM;
+ memcpy(im_node->data, node->data, trie->data_size);
+
+ /* Now determine which child to install in which slot */
+ if (extract_bit(key->data, matchlen)) {
+ rcu_assign_pointer(im_node->child[0], node);
+ rcu_assign_pointer(im_node->child[1], new_node);
+ } else {
+ rcu_assign_pointer(im_node->child[0], new_node);
+ rcu_assign_pointer(im_node->child[1], node);
+ }
+
+ /* Finally, assign the intermediate node to the determined spot */
+ rcu_assign_pointer(*slot, im_node);
+
+out:
+ if (ret) {
+ if (new_node)
+ trie->n_entries--;
+
+ kfree(new_node);
+ kfree(im_node);
+ }
+
+ spin_unlock_irqrestore(&trie->lock, irq_flags);
+
+ return ret;
+}
+
+/* Called from syscall or from eBPF program */
+static int trie_delete_elem(struct bpf_map *map, void *_key)
+{
+ struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+ struct bpf_lpm_trie_key *key = _key;
+ struct lpm_trie_node __rcu **trim, **trim2;
+ struct lpm_trie_node *node, *parent;
+ unsigned long irq_flags;
+ unsigned int next_bit;
+ size_t matchlen = 0;
+ int ret = 0;
+
+ if (key->prefixlen > trie->max_prefixlen)
+ return -EINVAL;
+
+ spin_lock_irqsave(&trie->lock, irq_flags);
+
+ /* Walk the tree looking for an exact key/length match and keeping
+ * track of the path we traverse. We will need to know the node
+ * we wish to delete, and the slot that points to the node we want
+ * to delete. We may also need to know the nodes parent and the
+ * slot that contains it.
+ */
+ trim = &trie->root;
+ trim2 = trim;
+ parent = NULL;
+ while ((node = rcu_dereference_protected(
+ *trim, lockdep_is_held(&trie->lock)))) {
+ matchlen = longest_prefix_match(trie, node, key);
+
+ if (node->prefixlen != matchlen ||
+ node->prefixlen == key->prefixlen)
+ break;
+
+ parent = node;
+ trim2 = trim;
+ next_bit = extract_bit(key->data, node->prefixlen);
+ trim = &node->child[next_bit];
+ }
+
+ if (!node || node->prefixlen != key->prefixlen ||
+ node->prefixlen != matchlen ||
+ (node->flags & LPM_TREE_NODE_FLAG_IM)) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ trie->n_entries--;
+
+ /* If the node we are removing has two children, simply mark it
+ * as intermediate and we are done.
+ */
+ if (rcu_access_pointer(node->child[0]) &&
+ rcu_access_pointer(node->child[1])) {
+ node->flags |= LPM_TREE_NODE_FLAG_IM;
+ goto out;
+ }
+
+ /* If the parent of the node we are about to delete is an intermediate
+ * node, and the deleted node doesn't have any children, we can delete
+ * the intermediate parent as well and promote its other child
+ * up the tree. Doing this maintains the invariant that all
+ * intermediate nodes have exactly 2 children and that there are no
+ * unnecessary intermediate nodes in the tree.
+ */
+ if (parent && (parent->flags & LPM_TREE_NODE_FLAG_IM) &&
+ !node->child[0] && !node->child[1]) {
+ if (node == rcu_access_pointer(parent->child[0]))
+ rcu_assign_pointer(
+ *trim2, rcu_access_pointer(parent->child[1]));
+ else
+ rcu_assign_pointer(
+ *trim2, rcu_access_pointer(parent->child[0]));
+ kfree_rcu(parent, rcu);
+ kfree_rcu(node, rcu);
+ goto out;
+ }
+
+ /* The node we are removing has either zero or one child. If there
+ * is a child, move it into the removed node's slot then delete
+ * the node. Otherwise just clear the slot and delete the node.
+ */
+ if (node->child[0])
+ rcu_assign_pointer(*trim, rcu_access_pointer(node->child[0]));
+ else if (node->child[1])
+ rcu_assign_pointer(*trim, rcu_access_pointer(node->child[1]));
+ else
+ RCU_INIT_POINTER(*trim, NULL);
+ kfree_rcu(node, rcu);
+
+out:
+ spin_unlock_irqrestore(&trie->lock, irq_flags);
+
+ return ret;
+}
+
+#define LPM_DATA_SIZE_MAX 256
+#define LPM_DATA_SIZE_MIN 1
+
+#define LPM_VAL_SIZE_MAX (KMALLOC_MAX_SIZE - LPM_DATA_SIZE_MAX - \
+ sizeof(struct lpm_trie_node))
+#define LPM_VAL_SIZE_MIN 1
+
+#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key) + (X))
+#define LPM_KEY_SIZE_MAX LPM_KEY_SIZE(LPM_DATA_SIZE_MAX)
+#define LPM_KEY_SIZE_MIN LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
+
+#define LPM_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_NUMA_NODE | \
+ BPF_F_ACCESS_MASK)
+
+static struct bpf_map *trie_alloc(union bpf_attr *attr)
+{
+ struct lpm_trie *trie;
+ u64 cost = sizeof(*trie), cost_per_node;
+ int ret;
+
+ if (!bpf_capable())
+ return ERR_PTR(-EPERM);
+
+ /* check sanity of attributes */
+ if (attr->max_entries == 0 ||
+ !(attr->map_flags & BPF_F_NO_PREALLOC) ||
+ attr->map_flags & ~LPM_CREATE_FLAG_MASK ||
+ !bpf_map_flags_access_ok(attr->map_flags) ||
+ attr->key_size < LPM_KEY_SIZE_MIN ||
+ attr->key_size > LPM_KEY_SIZE_MAX ||
+ attr->value_size < LPM_VAL_SIZE_MIN ||
+ attr->value_size > LPM_VAL_SIZE_MAX)
+ return ERR_PTR(-EINVAL);
+
+ trie = kzalloc(sizeof(*trie), GFP_USER | __GFP_NOWARN);
+ if (!trie)
+ return ERR_PTR(-ENOMEM);
+
+ /* copy mandatory map attributes */
+ bpf_map_init_from_attr(&trie->map, attr);
+ trie->data_size = attr->key_size -
+ offsetof(struct bpf_lpm_trie_key, data);
+ trie->max_prefixlen = trie->data_size * 8;
+
+ cost_per_node = sizeof(struct lpm_trie_node) +
+ attr->value_size + trie->data_size;
+ cost += (u64) attr->max_entries * cost_per_node;
+
+ ret = bpf_map_charge_init(&trie->map.memory, cost);
+ if (ret)
+ goto out_err;
+
+ spin_lock_init(&trie->lock);
+
+ return &trie->map;
+out_err:
+ kfree(trie);
+ return ERR_PTR(ret);
+}
+
+static void trie_free(struct bpf_map *map)
+{
+ struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+ struct lpm_trie_node __rcu **slot;
+ struct lpm_trie_node *node;
+
+ /* Always start at the root and walk down to a node that has no
+ * children. Then free that node, nullify its reference in the parent
+ * and start over.
+ */
+
+ for (;;) {
+ slot = &trie->root;
+
+ for (;;) {
+ node = rcu_dereference_protected(*slot, 1);
+ if (!node)
+ goto out;
+
+ if (rcu_access_pointer(node->child[0])) {
+ slot = &node->child[0];
+ continue;
+ }
+
+ if (rcu_access_pointer(node->child[1])) {
+ slot = &node->child[1];
+ continue;
+ }
+
+ kfree(node);
+ RCU_INIT_POINTER(*slot, NULL);
+ break;
+ }
+ }
+
+out:
+ kfree(trie);
+}
+
+static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
+{
+ struct lpm_trie_node *node, *next_node = NULL, *parent, *search_root;
+ struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+ struct bpf_lpm_trie_key *key = _key, *next_key = _next_key;
+ struct lpm_trie_node **node_stack = NULL;
+ int err = 0, stack_ptr = -1;
+ unsigned int next_bit;
+ size_t matchlen;
+
+ /* The get_next_key follows postorder. For the 4 node example in
+ * the top of this file, the trie_get_next_key() returns the following
+ * one after another:
+ * 192.168.0.0/24
+ * 192.168.1.0/24
+ * 192.168.128.0/24
+ * 192.168.0.0/16
+ *
+ * The idea is to return more specific keys before less specific ones.
+ */
+
+ /* Empty trie */
+ search_root = rcu_dereference(trie->root);
+ if (!search_root)
+ return -ENOENT;
+
+ /* For invalid key, find the leftmost node in the trie */
+ if (!key || key->prefixlen > trie->max_prefixlen)
+ goto find_leftmost;
+
+ node_stack = kmalloc_array(trie->max_prefixlen,
+ sizeof(struct lpm_trie_node *),
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (!node_stack)
+ return -ENOMEM;
+
+ /* Try to find the exact node for the given key */
+ for (node = search_root; node;) {
+ node_stack[++stack_ptr] = node;
+ matchlen = longest_prefix_match(trie, node, key);
+ if (node->prefixlen != matchlen ||
+ node->prefixlen == key->prefixlen)
+ break;
+
+ next_bit = extract_bit(key->data, node->prefixlen);
+ node = rcu_dereference(node->child[next_bit]);
+ }
+ if (!node || node->prefixlen != key->prefixlen ||
+ (node->flags & LPM_TREE_NODE_FLAG_IM))
+ goto find_leftmost;
+
+ /* The node with the exactly-matching key has been found,
+ * find the first node in postorder after the matched node.
+ */
+ node = node_stack[stack_ptr];
+ while (stack_ptr > 0) {
+ parent = node_stack[stack_ptr - 1];
+ if (rcu_dereference(parent->child[0]) == node) {
+ search_root = rcu_dereference(parent->child[1]);
+ if (search_root)
+ goto find_leftmost;
+ }
+ if (!(parent->flags & LPM_TREE_NODE_FLAG_IM)) {
+ next_node = parent;
+ goto do_copy;
+ }
+
+ node = parent;
+ stack_ptr--;
+ }
+
+ /* did not find anything */
+ err = -ENOENT;
+ goto free_stack;
+
+find_leftmost:
+ /* Find the leftmost non-intermediate node, all intermediate nodes
+ * have exact two children, so this function will never return NULL.
+ */
+ for (node = search_root; node;) {
+ if (node->flags & LPM_TREE_NODE_FLAG_IM) {
+ node = rcu_dereference(node->child[0]);
+ } else {
+ next_node = node;
+ node = rcu_dereference(node->child[0]);
+ if (!node)
+ node = rcu_dereference(next_node->child[1]);
+ }
+ }
+do_copy:
+ next_key->prefixlen = next_node->prefixlen;
+ memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key, data),
+ next_node->data, trie->data_size);
+free_stack:
+ kfree(node_stack);
+ return err;
+}
+
+static int trie_check_btf(const struct bpf_map *map,
+ const struct btf *btf,
+ const struct btf_type *key_type,
+ const struct btf_type *value_type)
+{
+ /* Keys must have struct bpf_lpm_trie_key embedded. */
+ return BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ?
+ -EINVAL : 0;
+}
+
+static int trie_map_btf_id;
+const struct bpf_map_ops trie_map_ops = {
+ .map_meta_equal = bpf_map_meta_equal,
+ .map_alloc = trie_alloc,
+ .map_free = trie_free,
+ .map_get_next_key = trie_get_next_key,
+ .map_lookup_elem = trie_lookup_elem,
+ .map_update_elem = trie_update_elem,
+ .map_delete_elem = trie_delete_elem,
+ .map_check_btf = trie_check_btf,
+ .map_btf_name = "lpm_trie",
+ .map_btf_id = &trie_map_btf_id,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 09:09:59 +0000