gotosocial/vendor/github.com/prometheus/procfs/proc_maps.go

212 lines
4.7 KiB
Go
Raw Normal View History

// 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.
//go:build (aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris) && !js
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
// +build !js
package procfs
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
"golang.org/x/sys/unix"
)
// ProcMapPermissions contains permission settings read from `/proc/[pid]/maps`.
type ProcMapPermissions struct {
// mapping has the [R]ead flag set
Read bool
// mapping has the [W]rite flag set
Write bool
// mapping has the [X]ecutable flag set
Execute bool
// mapping has the [S]hared flag set
Shared bool
// mapping is marked as [P]rivate (copy on write)
Private bool
}
// ProcMap contains the process memory-mappings of the process
// read from `/proc/[pid]/maps`.
type ProcMap struct {
// The start address of current mapping.
StartAddr uintptr
// The end address of the current mapping
EndAddr uintptr
// The permissions for this mapping
Perms *ProcMapPermissions
// The current offset into the file/fd (e.g., shared libs)
Offset int64
// Device owner of this mapping (major:minor) in Mkdev format.
Dev uint64
// The inode of the device above
Inode uint64
// The file or psuedofile (or empty==anonymous)
Pathname string
}
// parseDevice parses the device token of a line and converts it to a dev_t
// (mkdev) like structure.
func parseDevice(s string) (uint64, error) {
i := strings.Index(s, ":")
if i == -1 {
return 0, fmt.Errorf("%w: expected separator `:` in %s", ErrFileParse, s)
}
major, err := strconv.ParseUint(s[0:i], 16, 0)
if err != nil {
return 0, err
}
minor, err := strconv.ParseUint(s[i+1:], 16, 0)
if err != nil {
return 0, err
}
return unix.Mkdev(uint32(major), uint32(minor)), nil
}
// parseAddress converts a hex-string to a uintptr.
func parseAddress(s string) (uintptr, error) {
a, err := strconv.ParseUint(s, 16, 0)
if err != nil {
return 0, err
}
return uintptr(a), nil
}
// parseAddresses parses the start-end address.
func parseAddresses(s string) (uintptr, uintptr, error) {
idx := strings.Index(s, "-")
if idx == -1 {
return 0, 0, fmt.Errorf("%w: expected separator `-` in %s", ErrFileParse, s)
}
saddr, err := parseAddress(s[0:idx])
if err != nil {
return 0, 0, err
}
eaddr, err := parseAddress(s[idx+1:])
if err != nil {
return 0, 0, err
}
return saddr, eaddr, nil
}
// parsePermissions parses a token and returns any that are set.
func parsePermissions(s string) (*ProcMapPermissions, error) {
if len(s) < 4 {
return nil, fmt.Errorf("%w: invalid permissions token", ErrFileParse)
}
perms := ProcMapPermissions{}
for _, ch := range s {
switch ch {
case 'r':
perms.Read = true
case 'w':
perms.Write = true
case 'x':
perms.Execute = true
case 'p':
perms.Private = true
case 's':
perms.Shared = true
}
}
return &perms, nil
}
// parseProcMap will attempt to parse a single line within a proc/[pid]/maps
// buffer.
func parseProcMap(text string) (*ProcMap, error) {
fields := strings.Fields(text)
if len(fields) < 5 {
return nil, fmt.Errorf("%w: truncated procmap entry", ErrFileParse)
}
saddr, eaddr, err := parseAddresses(fields[0])
if err != nil {
return nil, err
}
perms, err := parsePermissions(fields[1])
if err != nil {
return nil, err
}
offset, err := strconv.ParseInt(fields[2], 16, 0)
if err != nil {
return nil, err
}
device, err := parseDevice(fields[3])
if err != nil {
return nil, err
}
inode, err := strconv.ParseUint(fields[4], 10, 0)
if err != nil {
return nil, err
}
pathname := ""
if len(fields) >= 5 {
pathname = strings.Join(fields[5:], " ")
}
return &ProcMap{
StartAddr: saddr,
EndAddr: eaddr,
Perms: perms,
Offset: offset,
Dev: device,
Inode: inode,
Pathname: pathname,
}, nil
}
// ProcMaps reads from /proc/[pid]/maps to get the memory-mappings of the
// process.
func (p Proc) ProcMaps() ([]*ProcMap, error) {
file, err := os.Open(p.path("maps"))
if err != nil {
return nil, err
}
defer file.Close()
maps := []*ProcMap{}
scan := bufio.NewScanner(file)
for scan.Scan() {
m, err := parseProcMap(scan.Text())
if err != nil {
return nil, err
}
maps = append(maps, m)
}
return maps, nil
}