// Copyright (c) 2012 VMware, Inc.
// +build freebsd linux
package gosigar
import (
"bufio"
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"os/user"
"path/filepath"
"strconv"
"strings"
"syscall"
)
var system struct {
ticks uint64
btime uint64
}
var Procd string
func getLinuxBootTime() {
// grab system boot time
readFile(Procd+"/stat", func(line string) bool {
if strings.HasPrefix(line, "btime") {
system.btime, _ = strtoull(line[6:])
return false // stop reading
}
return true
})
}
func (self *LoadAverage) Get() error {
line, err := ioutil.ReadFile(Procd + "/loadavg")
if err != nil {
return nil
}
fields := strings.Fields(string(line))
self.One, _ = strconv.ParseFloat(fields[0], 64)
self.Five, _ = strconv.ParseFloat(fields[1], 64)
self.Fifteen, _ = strconv.ParseFloat(fields[2], 64)
return nil
}
func (self *Mem) Get() error {
table, err := parseMeminfo()
if err != nil {
return err
}
self.Total, _ = table["MemTotal"]
self.Free, _ = table["MemFree"]
buffers, _ := table["Buffers"]
cached, _ := table["Cached"]
if available, ok := table["MemAvailable"]; ok {
// MemAvailable is in /proc/meminfo (kernel 3.14+)
self.ActualFree = available
} else {
self.ActualFree = self.Free + buffers + cached
}
self.Used = self.Total - self.Free
self.ActualUsed = self.Total - self.ActualFree
return nil
}
func (self *Swap) Get() error {
table, err := parseMeminfo()
if err != nil {
return err
}
self.Total, _ = table["SwapTotal"]
self.Free, _ = table["SwapFree"]
self.Used = self.Total - self.Free
return nil
}
func (self *Cpu) Get() error {
return readFile(Procd+"/stat", func(line string) bool {
if len(line) > 4 && line[0:4] == "cpu " {
parseCpuStat(self, line)
return false
}
return true
})
}
func (self *CpuList) Get() error {
capacity := len(self.List)
if capacity == 0 {
capacity = 4
}
list := make([]Cpu, 0, capacity)
err := readFile(Procd+"/stat", func(line string) bool {
if len(line) > 3 && line[0:3] == "cpu" && line[3] != ' ' {
cpu := Cpu{}
parseCpuStat(&cpu, line)
list = append(list, cpu)
}
return true
})
self.List = list
return err
}
func (self *FileSystemList) Get() error {
capacity := len(self.List)
if capacity == 0 {
capacity = 10
}
fslist := make([]FileSystem, 0, capacity)
err := readFile(getMountTableFileName(), func(line string) bool {
fields := strings.Fields(line)
fs := FileSystem{}
fs.DevName = fields[0]
fs.DirName = fields[1]
fs.SysTypeName = fields[2]
fs.Options = fields[3]
fslist = append(fslist, fs)
return true
})
self.List = fslist
return err
}
func (self *ProcList) Get() error {
dir, err := os.Open(Procd)
if err != nil {
return err
}
defer dir.Close()
const readAllDirnames = -1 // see os.File.Readdirnames doc
names, err := dir.Readdirnames(readAllDirnames)
if err != nil {
return err
}
capacity := len(names)
list := make([]int, 0, capacity)
for _, name := range names {
if name[0] < '0' || name[0] > '9' {
continue
}
pid, err := strconv.Atoi(name)
if err == nil {
list = append(list, pid)
}
}
self.List = list
return nil
}
func (self *ProcState) Get(pid int) error {
data, err := readProcFile(pid, "stat")
if err != nil {
return err
}
// Extract the comm value with is surrounded by parentheses.
lIdx := bytes.Index(data, []byte("("))
rIdx := bytes.LastIndex(data, []byte(")"))
if lIdx < 0 || rIdx < 0 || lIdx >= rIdx || rIdx+2 >= len(data) {
return fmt.Errorf("failed to extract comm for pid %d from '%v'", pid, string(data))
}
self.Name = string(data[lIdx+1 : rIdx])
// Extract the rest of the fields that we are interested in.
fields := bytes.Fields(data[rIdx+2:])
if len(fields) <= 36 {
return fmt.Errorf("expected more stat fields for pid %d from '%v'", pid, string(data))
}
interests := bytes.Join([][]byte{
fields[0], // state
fields[1], // ppid
fields[2], // pgrp
fields[4], // tty_nr
fields[15], // priority
fields[16], // nice
fields[36], // processor (last processor executed on)
}, []byte(" "))
var state string
_, err = fmt.Fscan(bytes.NewBuffer(interests),
&state,
&self.Ppid,
&self.Pgid,
&self.Tty,
&self.Priority,
&self.Nice,
&self.Processor,
)
if err != nil {
return fmt.Errorf("failed to parse stat fields for pid %d from '%v': %v", pid, string(data), err)
}
self.State = RunState(state[0])
// Read /proc/[pid]/status to get the uid, then lookup uid to get username.
status, err := getProcStatus(pid)
if err != nil {
return fmt.Errorf("failed to read process status for pid %d: %v", pid, err)
}
uids, err := getUIDs(status)
if err != nil {
return fmt.Errorf("failed to read process status for pid %d: %v", pid, err)
}
user, err := user.LookupId(uids[0])
if err == nil {
self.Username = user.Username
} else {
self.Username = uids[0]
}
return nil
}
func (self *ProcMem) Get(pid int) error {
contents, err := readProcFile(pid, "statm")
if err != nil {
return err
}
fields := strings.Fields(string(contents))
size, _ := strtoull(fields[0])
self.Size = size << 12
rss, _ := strtoull(fields[1])
self.Resident = rss << 12
share, _ := strtoull(fields[2])
self.Share = share << 12
contents, err = readProcFile(pid, "stat")
if err != nil {
return err
}
fields = strings.Fields(string(contents))
self.MinorFaults, _ = strtoull(fields[10])
self.MajorFaults, _ = strtoull(fields[12])
self.PageFaults = self.MinorFaults + self.MajorFaults
return nil
}
func (self *ProcTime) Get(pid int) error {
contents, err := readProcFile(pid, "stat")
if err != nil {
return err
}
fields := strings.Fields(string(contents))
user, _ := strtoull(fields[13])
sys, _ := strtoull(fields[14])
// convert to millis
self.User = user * (1000 / system.ticks)
self.Sys = sys * (1000 / system.ticks)
self.Total = self.User + self.Sys
// convert to millis
self.StartTime, _ = strtoull(fields[21])
self.StartTime /= system.ticks
self.StartTime += system.btime
self.StartTime *= 1000
return nil
}
func (self *ProcArgs) Get(pid int) error {
contents, err := readProcFile(pid, "cmdline")
if err != nil {
return err
}
bbuf := bytes.NewBuffer(contents)
var args []string
for {
arg, err := bbuf.ReadBytes(0)
if err == io.EOF {
break
}
args = append(args, string(chop(arg)))
}
self.List = args
return nil
}
func (self *ProcEnv) Get(pid int) error {
contents, err := readProcFile(pid, "environ")
if err != nil {
return err
}
if self.Vars == nil {
self.Vars = map[string]string{}
}
pairs := bytes.Split(contents, []byte{0})
for _, kv := range pairs {
parts := bytes.SplitN(kv, []byte{'='}, 2)
if len(parts) != 2 {
continue
}
key := string(bytes.TrimSpace(parts[0]))
if key == "" {
continue
}
self.Vars[key] = string(bytes.TrimSpace(parts[1]))
}
return nil
}
func (self *ProcExe) Get(pid int) error {
fields := map[string]*string{
"exe": &self.Name,
"cwd": &self.Cwd,
"root": &self.Root,
}
for name, field := range fields {
val, err := os.Readlink(procFileName(pid, name))
if err != nil {
return err
}
*field = val
}
return nil
}
func parseMeminfo() (map[string]uint64, error) {
table := map[string]uint64{}
err := readFile(Procd+"/meminfo", func(line string) bool {
fields := strings.Split(line, ":")
if len(fields) != 2 {
return true // skip on errors
}
valueUnit := strings.Fields(fields[1])
value, err := strtoull(valueUnit[0])
if err != nil {
return true // skip on errors
}
if len(valueUnit) > 1 && valueUnit[1] == "kB" {
value *= 1024
}
table[fields[0]] = value
return true
})
return table, err
}
func readFile(file string, handler func(string) bool) error {
contents, err := ioutil.ReadFile(file)
if err != nil {
return err
}
reader := bufio.NewReader(bytes.NewBuffer(contents))
for {
line, _, err := reader.ReadLine()
if err == io.EOF {
break
}
if !handler(string(line)) {
break
}
}
return nil
}
func strtoull(val string) (uint64, error) {
return strconv.ParseUint(val, 10, 64)
}
func procFileName(pid int, name string) string {
return Procd + "/" + strconv.Itoa(pid) + "/" + name
}
func readProcFile(pid int, name string) (content []byte, err error) {
path := procFileName(pid, name)
// Panics have been reported when reading proc files, let's recover and
// report the path if this happens
// See https://github.com/elastic/beats/issues/6692
defer func() {
if r := recover(); r != nil {
content = nil
err = fmt.Errorf("recovered panic when reading proc file '%s': %v", path, r)
}
}()
contents, err := ioutil.ReadFile(path)
if err != nil {
if perr, ok := err.(*os.PathError); ok {
if perr.Err == syscall.ENOENT {
return nil, syscall.ESRCH
}
}
}
return contents, err
}
// getProcStatus reads /proc/[pid]/status which contains process status
// information in human readable form.
func getProcStatus(pid int) (map[string]string, error) {
status := make(map[string]string, 42)
path := filepath.Join(Procd, strconv.Itoa(pid), "status")
err := readFile(path, func(line string) bool {
fields := strings.SplitN(line, ":", 2)
if len(fields) == 2 {
status[fields[0]] = strings.TrimSpace(fields[1])
}
return true
})
return status, err
}
// getUIDs reads the "Uid" value from status and splits it into four values --
// real, effective, saved set, and file system UIDs.
func getUIDs(status map[string]string) ([]string, error) {
uidLine, ok := status["Uid"]
if !ok {
return nil, fmt.Errorf("Uid not found in proc status")
}
uidStrs := strings.Fields(uidLine)
if len(uidStrs) != 4 {
return nil, fmt.Errorf("Uid line ('%s') did not contain four values", uidLine)
}
return uidStrs, nil
}
