| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package l2topology |
| 4 | |
| 5 | import ( |
| 6 | _ "embed" |
| 7 | "sort" |
| 8 | "strings" |
| 9 | "sync" |
| 10 | ) |
| 11 | |
| 12 | //go:embed mac_oui_vendors.tsv |
| 13 | var macOUIVendorsTSV string |
| 14 | |
| 15 | type topologyOUIVendorIndex struct { |
| 16 | byPrefixLen map[int]map[string]string |
| 17 | prefixLens []int |
| 18 | } |
| 19 | |
| 20 | var ( |
| 21 | topologyOUIVendorsOnce sync.Once |
| 22 | topologyOUIVendorsIndex topologyOUIVendorIndex |
| 23 | ) |
| 24 | |
| 25 | func loadTopologyOUIVendorsIndex() topologyOUIVendorIndex { |
| 26 | topologyOUIVendorsOnce.Do(func() { |
| 27 | topologyOUIVendorsIndex = buildTopologyOUIVendorIndex(macOUIVendorsTSV) |
| 28 | }) |
| 29 | return topologyOUIVendorsIndex |
| 30 | } |
| 31 | |
| 32 | func buildTopologyOUIVendorIndex(tsv string) topologyOUIVendorIndex { |
| 33 | byPrefixLen := make(map[int]map[string]string) |
| 34 | for line := range strings.SplitSeq(tsv, "\n") { |
| 35 | line = strings.TrimSpace(line) |
| 36 | if line == "" || strings.HasPrefix(line, "#") { |
| 37 | continue |
| 38 | } |
| 39 | prefix, vendor, ok := strings.Cut(line, "\t") |
| 40 | if !ok { |
| 41 | continue |
| 42 | } |
| 43 | prefix = strings.ToUpper(strings.TrimSpace(prefix)) |
| 44 | vendor = strings.TrimSpace(vendor) |
| 45 | if prefix == "" || vendor == "" { |
| 46 | continue |
| 47 | } |
| 48 | if len(prefix) < 6 || len(prefix) > 12 { |
| 49 | continue |
| 50 | } |
| 51 | if !isHexToken(prefix) { |
| 52 | continue |
| 53 | } |
| 54 | if byPrefixLen[len(prefix)] == nil { |
| 55 | byPrefixLen[len(prefix)] = make(map[string]string) |
| 56 | } |
| 57 | if _, exists := byPrefixLen[len(prefix)][prefix]; exists { |
| 58 | continue |
| 59 | } |
| 60 | byPrefixLen[len(prefix)][prefix] = vendor |
| 61 | } |
| 62 | |
| 63 | prefixLens := make([]int, 0, len(byPrefixLen)) |
| 64 | for prefixLen := range byPrefixLen { |
| 65 | prefixLens = append(prefixLens, prefixLen) |
| 66 | } |
| 67 | sort.Slice(prefixLens, func(i, j int) bool { |
| 68 | return prefixLens[i] > prefixLens[j] |
| 69 | }) |
| 70 | return topologyOUIVendorIndex{ |
| 71 | byPrefixLen: byPrefixLen, |
| 72 | prefixLens: prefixLens, |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | func isHexToken(value string) bool { |
| 77 | if value == "" { |
| 78 | return false |
| 79 | } |
| 80 | for _, r := range value { |
| 81 | if (r >= '0' && r <= '9') || (r >= 'A' && r <= 'F') || (r >= 'a' && r <= 'f') { |
| 82 | continue |
| 83 | } |
| 84 | return false |
| 85 | } |
| 86 | return true |
| 87 | } |
| 88 | |
| 89 | func lookupTopologyVendorByMAC(mac string) (vendor string, prefix string) { |
| 90 | return lookupTopologyVendorByMACInIndex(loadTopologyOUIVendorsIndex(), mac) |
| 91 | } |
| 92 | |
| 93 | func lookupTopologyVendorByMACInIndex(index topologyOUIVendorIndex, mac string) (vendor string, prefix string) { |
| 94 | mac = normalizeMAC(mac) |
| 95 | if mac == "" { |
| 96 | return "", "" |
| 97 | } |
| 98 | hex := strings.ToUpper(strings.ReplaceAll(mac, ":", "")) |
| 99 | if hex == "" { |
| 100 | return "", "" |
| 101 | } |
| 102 | |
| 103 | for _, prefixLen := range index.prefixLens { |
| 104 | if len(hex) < prefixLen { |
| 105 | continue |
| 106 | } |
| 107 | candidatePrefix := hex[:prefixLen] |
| 108 | candidateVendor, ok := index.byPrefixLen[prefixLen][candidatePrefix] |
| 109 | if !ok { |
| 110 | continue |
| 111 | } |
| 112 | return candidateVendor, candidatePrefix |
| 113 | } |
| 114 | return "", "" |
| 115 | } |
| 116 | |
| 117 | func inferTopologyVendorFromMatch(match Match) (vendor string, prefix string) { |
| 118 | candidates := make(map[string]struct{}, len(match.MacAddresses)+len(match.ChassisIDs)) |
| 119 | for _, value := range match.MacAddresses { |
| 120 | if mac := normalizeMAC(value); mac != "" { |
| 121 | candidates[mac] = struct{}{} |
| 122 | } |
| 123 | } |
| 124 | for _, value := range match.ChassisIDs { |
| 125 | if mac := normalizeMAC(value); mac != "" { |
| 126 | candidates[mac] = struct{}{} |
| 127 | } |
| 128 | } |
| 129 | if len(candidates) == 0 { |
| 130 | return "", "" |
| 131 | } |
| 132 | |
| 133 | macs := make([]string, 0, len(candidates)) |
| 134 | for mac := range candidates { |
| 135 | macs = append(macs, mac) |
| 136 | } |
| 137 | sort.Strings(macs) |
| 138 | for _, mac := range macs { |
| 139 | if vendor, prefix := lookupTopologyVendorByMAC(mac); vendor != "" { |
| 140 | return vendor, prefix |
| 141 | } |
| 142 | } |
| 143 | return "", "" |
| 144 | } |