// 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) |
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* | 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;
|
|
/* 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;
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|
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;
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|
node = kmalloc_node(size, GFP_ATOMIC | __GFP_NOWARN,
|
trie->map.numa_node);
|
if (!node)
|
return NULL;
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|
node->flags = 0;
|
|
if (value)
|
memcpy(node->data + trie->data_size, value,
|
trie->map.value_size);
|
|
return node;
|
}
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|
/* 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,
|
};
|
