mox/vendor/github.com/prometheus/procfs/net_conntrackstat.go

118 lines
3.3 KiB
Go

// 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"
"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
Searched uint64
Found uint64
New uint64
Invalid uint64
Ignore uint64
Delete uint64
DeleteList 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("%s: Cannot read file: %v: %w", ErrFileRead, 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) {
entries, err := util.ParseHexUint64s(fields)
if err != nil {
return nil, fmt.Errorf("%s: Cannot parse entry: %d: %w", ErrFileParse, entries, err)
}
numEntries := len(entries)
if numEntries < 16 || numEntries > 17 {
return nil,
fmt.Errorf("%w: invalid conntrackstat entry, invalid number of fields: %d", ErrFileParse, numEntries)
}
stats := &ConntrackStatEntry{
Entries: *entries[0],
Searched: *entries[1],
Found: *entries[2],
New: *entries[3],
Invalid: *entries[4],
Ignore: *entries[5],
Delete: *entries[6],
DeleteList: *entries[7],
Insert: *entries[8],
InsertFailed: *entries[9],
Drop: *entries[10],
EarlyDrop: *entries[11],
}
// Ignore missing search_restart on Linux < 2.6.35.
if numEntries == 17 {
stats.SearchRestart = *entries[16]
}
return stats, nil
}