diff options
| author | Hou Tao <houtao1@huawei.com> | 2024-12-06 19:06:16 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-12-06 09:14:26 -0800 |
| commit | eae6a075e9537dd69891cf77ca5a88fa8a28b4a1 (patch) | |
| tree | 27fa885d13b42dac23fd4c265893fd8760784eca | |
| parent | 3d5611b4d7efbefb85a74fcdbc35c603847cc022 (diff) | |
| download | lwn-eae6a075e9537dd69891cf77ca5a88fa8a28b4a1.tar.gz lwn-eae6a075e9537dd69891cf77ca5a88fa8a28b4a1.zip | |
bpf: Handle BPF_EXIST and BPF_NOEXIST for LPM trie
Add the currently missing handling for the BPF_EXIST and BPF_NOEXIST
flags. These flags can be specified by users and are relevant since LPM
trie supports exact matches during update.
Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241206110622.1161752-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/lpm_trie.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index b5e281a55760..be5bf0389532 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -375,6 +375,10 @@ static long trie_update_elem(struct bpf_map *map, * simply assign the @new_node to that slot and be done. */ if (!node) { + if (flags == BPF_EXIST) { + ret = -ENOENT; + goto out; + } rcu_assign_pointer(*slot, new_node); goto out; } @@ -383,18 +387,31 @@ static long trie_update_elem(struct bpf_map *map, * which already has the correct data array set. */ if (node->prefixlen == matchlen) { + if (!(node->flags & LPM_TREE_NODE_FLAG_IM)) { + if (flags == BPF_NOEXIST) { + ret = -EEXIST; + goto out; + } + trie->n_entries--; + } else if (flags == BPF_EXIST) { + ret = -ENOENT; + goto out; + } + 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); free_node = node; goto out; } + if (flags == BPF_EXIST) { + ret = -ENOENT; + goto out; + } + /* If the new node matches the prefix completely, it must be inserted * as an ancestor. Simply insert it between @node and *@slot. */ |