bpf: add a longest prefix match trie map implementation

This trie implements a longest prefix match algorithm that can be used to match IP addresses to a stored set of ranges. Internally, data is stored in an unbalanced trie of nodes that has a maximum height of n, where n is the prefixlen the trie was created with. Tries may be created with prefix lengths that are multiples of 8, in the range from 8 to 2048. The key used for lookup and update operations is a struct bpf_lpm_trie_key, and the value is a uint64_t. The code carries more information about the internal implementation.

Daniel Mack committed 9 years ago

Commit b95a5c41 parent 10eeb5e3 files · +511 −1Browse files

Showing the changes to include/uapi/linux (1 of 3 files). Show all

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include/uapi/linux/bpf.h+7−0

@@ -63,6 +63,12 @@ struct bpf_insn { · 62 unmodified lines
63	63	__s32 imm; /* signed immediate constant */
64	64	};
65	65
	66	+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
	67	+struct bpf_lpm_trie_key {
	68	+ __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
	69	+ __u8 data[0]; /* Arbitrary size */
	70	+};
	71	+
66	72	/* BPF syscall commands, see bpf(2) man-page for details. */
67	73	enum bpf_cmd {
68	74	BPF_MAP_CREATE,
@@ -89,6 +95,7 @@ enum bpf_map_type { · 20 unmodified lines
89	95	BPF_MAP_TYPE_CGROUP_ARRAY,
90	96	BPF_MAP_TYPE_LRU_HASH,
91	97	BPF_MAP_TYPE_LRU_PERCPU_HASH,
	98	+ BPF_MAP_TYPE_LPM_TRIE,
92	99	};
93	100
94	101	enum bpf_prog_type {