cubefs

1
// Copyright 2019 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

14
package procfs
15

16
import (
17
	"bufio"
18
	"bytes"
19
	"fmt"
20
	"io"
21
	"strconv"
22
	"strings"
23

24
	"github.com/prometheus/procfs/internal/util"
25
)
26

27
// For the proc file format details,
28
// See:
29
// * Linux 2.6.23 https://elixir.bootlin.com/linux/v2.6.23/source/net/core/dev.c#L2343
30
// * Linux 4.17 https://elixir.bootlin.com/linux/v4.17/source/net/core/net-procfs.c#L162
31
// and https://elixir.bootlin.com/linux/v4.17/source/include/linux/netdevice.h#L2810.
32

33
// SoftnetStat contains a single row of data from /proc/net/softnet_stat.
34
type SoftnetStat struct {
35
	// Number of processed packets.
36
	Processed uint32
37
	// Number of dropped packets.
38
	Dropped uint32
39
	// Number of times processing packets ran out of quota.
40
	TimeSqueezed uint32
41
}
42

43
var softNetProcFile = "net/softnet_stat"
44

45
// NetSoftnetStat reads data from /proc/net/softnet_stat.
46
func (fs FS) NetSoftnetStat() ([]SoftnetStat, error) {
47
	b, err := util.ReadFileNoStat(fs.proc.Path(softNetProcFile))
48
	if err != nil {
49
		return nil, err
50
	}
51

52
	entries, err := parseSoftnet(bytes.NewReader(b))
53
	if err != nil {
54
		return nil, fmt.Errorf("failed to parse /proc/net/softnet_stat: %w", err)
55
	}
56

57
	return entries, nil
58
}
59

60
func parseSoftnet(r io.Reader) ([]SoftnetStat, error) {
61
	const minColumns = 9
62

63
	s := bufio.NewScanner(r)
64

65
	var stats []SoftnetStat
66
	for s.Scan() {
67
		columns := strings.Fields(s.Text())
68
		width := len(columns)
69

70
		if width < minColumns {
71
			return nil, fmt.Errorf("%d columns were detected, but at least %d were expected", width, minColumns)
72
		}
73

74
		// We only parse the first three columns at the moment.
75
		us, err := parseHexUint32s(columns[0:3])
76
		if err != nil {
77
			return nil, err
78
		}
79

80
		stats = append(stats, SoftnetStat{
81
			Processed:    us[0],
82
			Dropped:      us[1],
83
			TimeSqueezed: us[2],
84
		})
85
	}
86

87
	return stats, nil
88
}
89

90
func parseHexUint32s(ss []string) ([]uint32, error) {
91
	us := make([]uint32, 0, len(ss))
92
	for _, s := range ss {
93
		u, err := strconv.ParseUint(s, 16, 32)
94
		if err != nil {
95
			return nil, err
96
		}
97

98
		us = append(us, uint32(u))
99
	}
100

101
	return us, nil
102
}
103