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gitea/vendor/github.com/prometheus/procfs/net_conntrackstat.go
2021-02-28 18:08:33 -05:00

154 lines
3.8 KiB
Go
Vendored

// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package procfs
import (
"bufio"
"bytes"
"fmt"
"io"
"strconv"
"strings"
"github.com/prometheus/procfs/internal/util"
)
// A ConntrackStatEntry represents one line from net/stat/nf_conntrack
// and contains netfilter conntrack statistics at one CPU core
type ConntrackStatEntry struct {
Entries uint64
Found uint64
Invalid uint64
Ignore uint64
Insert uint64
InsertFailed uint64
Drop uint64
EarlyDrop uint64
SearchRestart uint64
}
// ConntrackStat retrieves netfilter's conntrack statistics, split by CPU cores
func (fs FS) ConntrackStat() ([]ConntrackStatEntry, error) {
return readConntrackStat(fs.proc.Path("net", "stat", "nf_conntrack"))
}
// Parses a slice of ConntrackStatEntries from the given filepath
func readConntrackStat(path string) ([]ConntrackStatEntry, error) {
// This file is small and can be read with one syscall.
b, err := util.ReadFileNoStat(path)
if err != nil {
// Do not wrap this error so the caller can detect os.IsNotExist and
// similar conditions.
return nil, err
}
stat, err := parseConntrackStat(bytes.NewReader(b))
if err != nil {
return nil, fmt.Errorf("failed to read conntrack stats from %q: %w", path, err)
}
return stat, nil
}
// Reads the contents of a conntrack statistics file and parses a slice of ConntrackStatEntries
func parseConntrackStat(r io.Reader) ([]ConntrackStatEntry, error) {
var entries []ConntrackStatEntry
scanner := bufio.NewScanner(r)
scanner.Scan()
for scanner.Scan() {
fields := strings.Fields(scanner.Text())
conntrackEntry, err := parseConntrackStatEntry(fields)
if err != nil {
return nil, err
}
entries = append(entries, *conntrackEntry)
}
return entries, nil
}
// Parses a ConntrackStatEntry from given array of fields
func parseConntrackStatEntry(fields []string) (*ConntrackStatEntry, error) {
if len(fields) != 17 {
return nil, fmt.Errorf("invalid conntrackstat entry, missing fields")
}
entry := &ConntrackStatEntry{}
entries, err := parseConntrackStatField(fields[0])
if err != nil {
return nil, err
}
entry.Entries = entries
found, err := parseConntrackStatField(fields[2])
if err != nil {
return nil, err
}
entry.Found = found
invalid, err := parseConntrackStatField(fields[4])
if err != nil {
return nil, err
}
entry.Invalid = invalid
ignore, err := parseConntrackStatField(fields[5])
if err != nil {
return nil, err
}
entry.Ignore = ignore
insert, err := parseConntrackStatField(fields[8])
if err != nil {
return nil, err
}
entry.Insert = insert
insertFailed, err := parseConntrackStatField(fields[9])
if err != nil {
return nil, err
}
entry.InsertFailed = insertFailed
drop, err := parseConntrackStatField(fields[10])
if err != nil {
return nil, err
}
entry.Drop = drop
earlyDrop, err := parseConntrackStatField(fields[11])
if err != nil {
return nil, err
}
entry.EarlyDrop = earlyDrop
searchRestart, err := parseConntrackStatField(fields[16])
if err != nil {
return nil, err
}
entry.SearchRestart = searchRestart
return entry, nil
}
// Parses a uint64 from given hex in string
func parseConntrackStatField(field string) (uint64, error) {
val, err := strconv.ParseUint(field, 16, 64)
if err != nil {
return 0, fmt.Errorf("couldn't parse %q field: %w", field, err)
}
return val, err
}