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

258 lines
5.9 KiB
Go
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// Copyright 2018 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"
"fmt"
"io"
"os"
"strconv"
"strings"
)
// For the proc file format details,
// see https://elixir.bootlin.com/linux/v4.17/source/net/unix/af_unix.c#L2815
// and https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/net.h#L48.
// Constants for the various /proc/net/unix enumerations.
// TODO: match against x/sys/unix or similar?
const (
netUnixTypeStream = 1
netUnixTypeDgram = 2
netUnixTypeSeqpacket = 5
netUnixFlagDefault = 0
netUnixFlagListen = 1 << 16
netUnixStateUnconnected = 1
netUnixStateConnecting = 2
netUnixStateConnected = 3
netUnixStateDisconnected = 4
)
// NetUNIXType is the type of the type field.
type NetUNIXType uint64
// NetUNIXFlags is the type of the flags field.
type NetUNIXFlags uint64
// NetUNIXState is the type of the state field.
type NetUNIXState uint64
// NetUNIXLine represents a line of /proc/net/unix.
type NetUNIXLine struct {
KernelPtr string
RefCount uint64
Protocol uint64
Flags NetUNIXFlags
Type NetUNIXType
State NetUNIXState
Inode uint64
Path string
}
// NetUNIX holds the data read from /proc/net/unix.
type NetUNIX struct {
Rows []*NetUNIXLine
}
// NetUNIX returns data read from /proc/net/unix.
func (fs FS) NetUNIX() (*NetUNIX, error) {
return readNetUNIX(fs.proc.Path("net/unix"))
}
// readNetUNIX reads data in /proc/net/unix format from the specified file.
func readNetUNIX(file string) (*NetUNIX, error) {
// This file could be quite large and a streaming read is desirable versus
// reading the entire contents at once.
f, err := os.Open(file)
if err != nil {
return nil, err
}
defer f.Close()
return parseNetUNIX(f)
}
// parseNetUNIX creates a NetUnix structure from the incoming stream.
func parseNetUNIX(r io.Reader) (*NetUNIX, error) {
// Begin scanning by checking for the existence of Inode.
s := bufio.NewScanner(r)
s.Scan()
// From the man page of proc(5), it does not contain an Inode field,
// but in actually it exists. This code works for both cases.
hasInode := strings.Contains(s.Text(), "Inode")
// Expect a minimum number of fields, but Inode and Path are optional:
// Num RefCount Protocol Flags Type St Inode Path
minFields := 6
if hasInode {
minFields++
}
var nu NetUNIX
for s.Scan() {
line := s.Text()
item, err := nu.parseLine(line, hasInode, minFields)
if err != nil {
return nil, fmt.Errorf("failed to parse /proc/net/unix data %q: %w", line, err)
}
nu.Rows = append(nu.Rows, item)
}
if err := s.Err(); err != nil {
return nil, fmt.Errorf("failed to scan /proc/net/unix data: %w", err)
}
return &nu, nil
}
func (u *NetUNIX) parseLine(line string, hasInode bool, min int) (*NetUNIXLine, error) {
fields := strings.Fields(line)
l := len(fields)
if l < min {
return nil, fmt.Errorf("expected at least %d fields but got %d", min, l)
}
// Field offsets are as follows:
// Num RefCount Protocol Flags Type St Inode Path
kernelPtr := strings.TrimSuffix(fields[0], ":")
users, err := u.parseUsers(fields[1])
if err != nil {
return nil, fmt.Errorf("failed to parse ref count %q: %w", fields[1], err)
}
flags, err := u.parseFlags(fields[3])
if err != nil {
return nil, fmt.Errorf("failed to parse flags %q: %w", fields[3], err)
}
typ, err := u.parseType(fields[4])
if err != nil {
return nil, fmt.Errorf("failed to parse type %q: %w", fields[4], err)
}
state, err := u.parseState(fields[5])
if err != nil {
return nil, fmt.Errorf("failed to parse state %q: %w", fields[5], err)
}
var inode uint64
if hasInode {
inode, err = u.parseInode(fields[6])
if err != nil {
return nil, fmt.Errorf("failed to parse inode %q: %w", fields[6], err)
}
}
n := &NetUNIXLine{
KernelPtr: kernelPtr,
RefCount: users,
Type: typ,
Flags: flags,
State: state,
Inode: inode,
}
// Path field is optional.
if l > min {
// Path occurs at either index 6 or 7 depending on whether inode is
// already present.
pathIdx := 7
if !hasInode {
pathIdx--
}
n.Path = fields[pathIdx]
}
return n, nil
}
func (u NetUNIX) parseUsers(s string) (uint64, error) {
return strconv.ParseUint(s, 16, 32)
}
func (u NetUNIX) parseType(s string) (NetUNIXType, error) {
typ, err := strconv.ParseUint(s, 16, 16)
if err != nil {
return 0, err
}
return NetUNIXType(typ), nil
}
func (u NetUNIX) parseFlags(s string) (NetUNIXFlags, error) {
flags, err := strconv.ParseUint(s, 16, 32)
if err != nil {
return 0, err
}
return NetUNIXFlags(flags), nil
}
func (u NetUNIX) parseState(s string) (NetUNIXState, error) {
st, err := strconv.ParseInt(s, 16, 8)
if err != nil {
return 0, err
}
return NetUNIXState(st), nil
}
func (u NetUNIX) parseInode(s string) (uint64, error) {
return strconv.ParseUint(s, 10, 64)
}
func (t NetUNIXType) String() string {
switch t {
case netUnixTypeStream:
return "stream"
case netUnixTypeDgram:
return "dgram"
case netUnixTypeSeqpacket:
return "seqpacket"
}
return "unknown"
}
func (f NetUNIXFlags) String() string {
switch f {
case netUnixFlagListen:
return "listen"
default:
return "default"
}
}
func (s NetUNIXState) String() string {
switch s {
case netUnixStateUnconnected:
return "unconnected"
case netUnixStateConnecting:
return "connecting"
case netUnixStateConnected:
return "connected"
case netUnixStateDisconnected:
return "disconnected"
}
return "unknown"
}