1// Copyright 2020 The Prometheus Authors 2// Licensed under the Apache License, Version 2.0 (the "License"); 3// you may not use this file except in compliance with the License. 4// You may obtain a copy of the License at 5// 6// http://www.apache.org/licenses/LICENSE-2.0 7// 8// Unless required by applicable law or agreed to in writing, software 9// distributed under the License is distributed on an "AS IS" BASIS, 10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 11// See the License for the specific language governing permissions and 12// limitations under the License. 13 14package procfs 15 16import ( 17 "bufio" 18 "bytes" 19 "fmt" 20 "io" 21 "strconv" 22 "strings" 23 24 "github.com/prometheus/procfs/internal/util" 25) 26 27// A ConntrackStatEntry represents one line from net/stat/nf_conntrack 28// and contains netfilter conntrack statistics at one CPU core 29type ConntrackStatEntry struct { 30 Entries uint64 31 Found uint64 32 Invalid uint64 33 Ignore uint64 34 Insert uint64 35 InsertFailed uint64 36 Drop uint64 37 EarlyDrop uint64 38 SearchRestart uint64 39} 40 41// ConntrackStat retrieves netfilter's conntrack statistics, split by CPU cores 42func (fs FS) ConntrackStat() ([]ConntrackStatEntry, error) { 43 return readConntrackStat(fs.proc.Path("net", "stat", "nf_conntrack")) 44} 45 46// Parses a slice of ConntrackStatEntries from the given filepath 47func readConntrackStat(path string) ([]ConntrackStatEntry, error) { 48 // This file is small and can be read with one syscall. 49 b, err := util.ReadFileNoStat(path) 50 if err != nil { 51 // Do not wrap this error so the caller can detect os.IsNotExist and 52 // similar conditions. 53 return nil, err 54 } 55 56 stat, err := parseConntrackStat(bytes.NewReader(b)) 57 if err != nil { 58 return nil, fmt.Errorf("failed to read conntrack stats from %q: %w", path, err) 59 } 60 61 return stat, nil 62} 63 64// Reads the contents of a conntrack statistics file and parses a slice of ConntrackStatEntries 65func parseConntrackStat(r io.Reader) ([]ConntrackStatEntry, error) { 66 var entries []ConntrackStatEntry 67 68 scanner := bufio.NewScanner(r) 69 scanner.Scan() 70 for scanner.Scan() { 71 fields := strings.Fields(scanner.Text()) 72 conntrackEntry, err := parseConntrackStatEntry(fields) 73 if err != nil { 74 return nil, err 75 } 76 entries = append(entries, *conntrackEntry) 77 } 78 79 return entries, nil 80} 81 82// Parses a ConntrackStatEntry from given array of fields 83func parseConntrackStatEntry(fields []string) (*ConntrackStatEntry, error) { 84 if len(fields) != 17 { 85 return nil, fmt.Errorf("invalid conntrackstat entry, missing fields") 86 } 87 entry := &ConntrackStatEntry{} 88 89 entries, err := parseConntrackStatField(fields[0]) 90 if err != nil { 91 return nil, err 92 } 93 entry.Entries = entries 94 95 found, err := parseConntrackStatField(fields[2]) 96 if err != nil { 97 return nil, err 98 } 99 entry.Found = found 100 101 invalid, err := parseConntrackStatField(fields[4]) 102 if err != nil { 103 return nil, err 104 } 105 entry.Invalid = invalid 106 107 ignore, err := parseConntrackStatField(fields[5]) 108 if err != nil { 109 return nil, err 110 } 111 entry.Ignore = ignore 112 113 insert, err := parseConntrackStatField(fields[8]) 114 if err != nil { 115 return nil, err 116 } 117 entry.Insert = insert 118 119 insertFailed, err := parseConntrackStatField(fields[9]) 120 if err != nil { 121 return nil, err 122 } 123 entry.InsertFailed = insertFailed 124 125 drop, err := parseConntrackStatField(fields[10]) 126 if err != nil { 127 return nil, err 128 } 129 entry.Drop = drop 130 131 earlyDrop, err := parseConntrackStatField(fields[11]) 132 if err != nil { 133 return nil, err 134 } 135 entry.EarlyDrop = earlyDrop 136 137 searchRestart, err := parseConntrackStatField(fields[16]) 138 if err != nil { 139 return nil, err 140 } 141 entry.SearchRestart = searchRestart 142 143 return entry, nil 144} 145 146// Parses a uint64 from given hex in string 147func parseConntrackStatField(field string) (uint64, error) { 148 val, err := strconv.ParseUint(field, 16, 64) 149 if err != nil { 150 return 0, fmt.Errorf("couldn't parse %q field: %w", field, err) 151 } 152 return val, err 153} 154