cloudflared-mirror/vendor/github.com/prometheus/procfs/net_softnet.go

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// Copyright 2019 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"
)
// For the proc file format details,
// See:
// * Linux 2.6.23 https://elixir.bootlin.com/linux/v2.6.23/source/net/core/dev.c#L2343
// * Linux 2.6.39 https://elixir.bootlin.com/linux/v2.6.39/source/net/core/dev.c#L4086
// * Linux 4.18 https://elixir.bootlin.com/linux/v4.18/source/net/core/net-procfs.c#L162
// * Linux 5.14 https://elixir.bootlin.com/linux/v5.14/source/net/core/net-procfs.c#L169
// SoftnetStat contains a single row of data from /proc/net/softnet_stat.
type SoftnetStat struct {
// Number of processed packets.
Processed uint32
// Number of dropped packets.
Dropped uint32
// Number of times processing packets ran out of quota.
TimeSqueezed uint32
// Number of collision occur while obtaining device lock while transmitting.
CPUCollision uint32
// Number of times cpu woken up received_rps.
ReceivedRps uint32
// number of times flow limit has been reached.
FlowLimitCount uint32
// Softnet backlog status.
SoftnetBacklogLen uint32
// CPU id owning this softnet_data.
Index uint32
// softnet_data's Width.
Width int
}
var softNetProcFile = "net/softnet_stat"
// NetSoftnetStat reads data from /proc/net/softnet_stat.
func (fs FS) NetSoftnetStat() ([]SoftnetStat, error) {
b, err := util.ReadFileNoStat(fs.proc.Path(softNetProcFile))
if err != nil {
return nil, err
}
entries, err := parseSoftnet(bytes.NewReader(b))
if err != nil {
return nil, fmt.Errorf("%s: /proc/net/softnet_stat: %w", ErrFileParse, err)
}
return entries, nil
}
func parseSoftnet(r io.Reader) ([]SoftnetStat, error) {
const minColumns = 9
s := bufio.NewScanner(r)
var stats []SoftnetStat
cpuIndex := 0
for s.Scan() {
columns := strings.Fields(s.Text())
width := len(columns)
softnetStat := SoftnetStat{}
if width < minColumns {
return nil, fmt.Errorf("%w: detected %d columns, but expected at least %d", ErrFileParse, width, minColumns)
}
// Linux 2.6.23 https://elixir.bootlin.com/linux/v2.6.23/source/net/core/dev.c#L2347
if width >= minColumns {
us, err := parseHexUint32s(columns[0:9])
if err != nil {
return nil, err
}
softnetStat.Processed = us[0]
softnetStat.Dropped = us[1]
softnetStat.TimeSqueezed = us[2]
softnetStat.CPUCollision = us[8]
}
// Linux 2.6.39 https://elixir.bootlin.com/linux/v2.6.39/source/net/core/dev.c#L4086
if width >= 10 {
us, err := parseHexUint32s(columns[9:10])
if err != nil {
return nil, err
}
softnetStat.ReceivedRps = us[0]
}
// Linux 4.18 https://elixir.bootlin.com/linux/v4.18/source/net/core/net-procfs.c#L162
if width >= 11 {
us, err := parseHexUint32s(columns[10:11])
if err != nil {
return nil, err
}
softnetStat.FlowLimitCount = us[0]
}
// Linux 5.14 https://elixir.bootlin.com/linux/v5.14/source/net/core/net-procfs.c#L169
if width >= 13 {
us, err := parseHexUint32s(columns[11:13])
if err != nil {
return nil, err
}
softnetStat.SoftnetBacklogLen = us[0]
softnetStat.Index = us[1]
} else {
// For older kernels, create the Index based on the scan line number.
softnetStat.Index = uint32(cpuIndex)
}
softnetStat.Width = width
stats = append(stats, softnetStat)
cpuIndex++
}
return stats, nil
}
func parseHexUint32s(ss []string) ([]uint32, error) {
us := make([]uint32, 0, len(ss))
for _, s := range ss {
u, err := strconv.ParseUint(s, 16, 32)
if err != nil {
return nil, err
}
us = append(us, uint32(u))
}
return us, nil
}