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|
package ps
import (
"fmt"
"io/ioutil"
"os"
"os/user"
"runtime"
"strconv"
"strings"
"sync"
"time"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
// DefaultFormat is the `ps -ef` compatible default format.
const DefaultFormat = "user,pid,ppid,pcpu,etime,tty,time,comm"
var (
// ErrUnkownDescriptor is returned when an unknown descriptor is parsed.
ErrUnkownDescriptor = errors.New("unknown descriptor")
// errNoSuchPID is returned when `/proc/PID` does not exist (anymore).
errNoSuchPID = errors.New("PID does not exist in /proc")
// bootTime holds the host's boot time. Singleton to safe some time and
// energy.
bootTime int64
// clockTicks is the value of sysconf(SC_CLK_TCK)
clockTicks = getClockTicks()
// ttyDevices is a slice of ttys. Singledton to safe some time and
// energy.
ttyDevices []*tty
descriptors = []aixFormatDescriptor{
{
code: "%C",
normal: "pcpu",
header: "%CPU",
procFn: processPCPU,
},
{
code: "%G",
normal: "group",
header: "GROUP",
procFn: processGROUP,
},
{
code: "%P",
normal: "ppid",
header: "PPID",
procFn: processPPID,
},
{
code: "%U",
normal: "user",
header: "USER",
procFn: processUSER,
},
{
code: "%a",
normal: "args",
header: "COMMAND",
procFn: processARGS,
},
{
code: "%c",
normal: "comm",
header: "COMMAND",
procFn: processCOMM,
},
{
code: "%g",
normal: "rgroup",
header: "RGROUP",
procFn: processRGROUP,
},
{
code: "%n",
normal: "nice",
header: "NI",
procFn: processNICE,
},
{
code: "%p",
normal: "pid",
header: "PID",
procFn: processPID,
},
{
code: "%r",
normal: "pgid",
header: "PGID",
procFn: processPGID,
},
{
code: "%t",
normal: "etime",
header: "ELAPSED",
procFn: processETIME,
},
{
code: "%u",
normal: "ruser",
header: "RUSER",
procFn: processRUSER,
},
{
code: "%x",
normal: "time",
header: "TIME",
procFn: processTIME,
},
{
code: "%y",
normal: "tty",
header: "TTY",
procFn: processTTY,
},
{
code: "%z",
normal: "vsz",
header: "VSZ",
procFn: processVSZ,
},
{
normal: "capinh",
header: "CAPABILITIES",
procFn: processCAPINH,
},
{
normal: "capprm",
header: "CAPABILITIES",
procFn: processCAPPRM,
},
{
normal: "capeff",
header: "CAPABILITIES",
procFn: processCAPEFF,
},
{
normal: "capbnd",
header: "CAPABILITIES",
procFn: processCAPBND,
},
{
normal: "seccomp",
header: "SECCOMP",
procFn: processSECCOMP,
},
{
normal: "label",
header: "LABEL",
procFn: processLABEL,
},
}
)
// process includes a process ID and the corresponding data from /proc/pid/stat,
// /proc/pid/status and from /prod/pid/cmdline.
type process struct {
pid int
pstat *stat
pstatus *status
cmdline []string
}
// elapsedTime returns the time.Duration since process p was created.
func (p *process) elapsedTime() (time.Duration, error) {
sinceBoot, err := strconv.ParseInt(p.pstat.starttime, 10, 64)
if err != nil {
return 0, err
}
sinceBoot = sinceBoot / clockTicks
if bootTime == 0 {
bootTime, err = getBootTime()
if err != nil {
return 0, err
}
}
created := time.Unix(sinceBoot+bootTime, 0)
return (time.Now()).Sub(created), nil
}
// cpuTime returns the cumlative CPU time of process p as a time.Duration.
func (p *process) cpuTime() (time.Duration, error) {
user, err := strconv.ParseInt(p.pstat.utime, 10, 64)
if err != nil {
return 0, err
}
system, err := strconv.ParseInt(p.pstat.stime, 10, 64)
if err != nil {
return 0, err
}
secs := (user + system) / clockTicks
cpu := time.Unix(secs, 0)
return cpu.Sub(time.Unix(0, 0)), nil
}
// processes returns a process slice of processes mentioned in /proc.
func processes() ([]*process, error) {
pids, err := getPIDs()
if err != nil {
panic(err)
}
processes := []*process{}
for _, pid := range pids {
var (
err error
p process
)
p.pid = pid
p.pstat, err = parseStat(fmt.Sprintf("/proc/%d/stat", pid))
if err != nil {
if err == errNoSuchPID {
continue
}
return nil, err
}
p.pstatus, err = parseStatus(fmt.Sprintf("/proc/%d/status", pid))
if err != nil {
if err == errNoSuchPID {
continue
}
return nil, err
}
p.cmdline, err = parseCmdline(fmt.Sprintf("/proc/%d/cmdline", pid))
if err != nil {
if err == errNoSuchPID {
continue
}
return nil, err
}
processes = append(processes, &p)
}
return processes, nil
}
// getPIDs extracts and returns all PIDs from /proc.
func getPIDs() ([]int, error) {
procDir, err := os.Open("/proc/")
if err != nil {
return nil, err
}
defer procDir.Close()
// extract string slice of all directories in procDir
pidDirs, err := procDir.Readdirnames(0)
if err != nil {
return nil, err
}
// convert pidDirs to int
pids := []int{}
for _, pidDir := range pidDirs {
pid, err := strconv.Atoi(pidDir)
if err != nil {
// skip non-numerical entries (e.g., `/proc/softirqs`)
continue
}
pids = append(pids, pid)
}
return pids, nil
}
// processFunc is used to map a given aixFormatDescriptor to a corresponding
// function extracting the desired data from a process.
type processFunc func(*process) (string, error)
// aixFormatDescriptor as mentioned in the ps(1) manpage. A given descriptor
// can either be specified via its code (e.g., "%C") or its normal representation
// (e.g., "pcpu") and will be printed under its corresponding header (e.g, "%CPU").
type aixFormatDescriptor struct {
code string
normal string
header string
procFn processFunc
}
// processDescriptors calls each `procFn` of all formatDescriptors on each
// process and returns an array of tab-separated strings.
func processDescriptors(formatDescriptors []aixFormatDescriptor, processes []*process) ([]string, error) {
data := []string{}
// create header
headerArr := []string{}
for _, desc := range formatDescriptors {
headerArr = append(headerArr, desc.header)
}
data = append(data, strings.Join(headerArr, "\t"))
// dispatch all descriptor functions on each process
for _, proc := range processes {
pData := []string{}
for _, desc := range formatDescriptors {
dataStr, err := desc.procFn(proc)
if err != nil {
return nil, err
}
pData = append(pData, dataStr)
}
data = append(data, strings.Join(pData, "\t"))
}
return data, nil
}
// ListDescriptors returns a string slice of all supported AIX format
// descriptors in the normal form.
func ListDescriptors() (list []string) {
for _, d := range descriptors {
list = append(list, d.normal)
}
return
}
// JoinNamespaceAndProcessInfo has the same semantics as ProcessInfo but joins
// the mount namespace of the specified pid before extracting data from `/proc`.
func JoinNamespaceAndProcessInfo(pid, format string) ([]string, error) {
var (
data []string
dataErr error
wg sync.WaitGroup
)
wg.Add(1)
go func() {
defer wg.Done()
runtime.LockOSThread()
fd, err := os.Open(fmt.Sprintf("/proc/%s/ns/mnt", pid))
if err != nil {
dataErr = err
return
}
defer fd.Close()
// create a new mountns on the current thread
if err = unix.Unshare(unix.CLONE_NEWNS); err != nil {
dataErr = err
return
}
unix.Setns(int(fd.Fd()), unix.CLONE_NEWNS)
data, dataErr = ProcessInfo(format)
}()
wg.Wait()
return data, dataErr
}
// ProcessInfo returns the process information of all processes in the current
// mount namespace. The input format must be a comma-separated list of
// supported AIX format descriptors. If the input string is empty, the
// DefaultFormat is used.
// The return value is an array of tab-separated strings, to easily use the
// output for column-based formatting (e.g., with the `text/tabwriter` package).
func ProcessInfo(format string) ([]string, error) {
if len(format) == 0 {
format = DefaultFormat
}
formatDescriptors, err := parseDescriptors(format)
if err != nil {
return nil, err
}
processes, err := processes()
if err != nil {
return nil, err
}
return processDescriptors(formatDescriptors, processes)
}
// parseDescriptors parses the input string and returns a correspodning array
// of aixFormatDescriptors, which are expected to be separated by commas.
// The input format is "desc1, desc2, ..., desN" where a given descriptor can be
// specified both, in the code and in the normal form. A concrete example is
// "pid, %C, nice, %a".
func parseDescriptors(input string) ([]aixFormatDescriptor, error) {
formatDescriptors := []aixFormatDescriptor{}
for _, s := range strings.Split(input, ",") {
s = strings.TrimSpace(s)
found := false
for _, d := range descriptors {
if s == d.code || s == d.normal {
formatDescriptors = append(formatDescriptors, d)
found = true
}
}
if !found {
return nil, errors.Wrapf(ErrUnkownDescriptor, "'%s'", s)
}
}
return formatDescriptors, nil
}
// lookupGID returns the textual group ID, if it can be optained, or the
// decimal input representation otherwise.
func lookupGID(gid string) (string, error) {
if gid == "0" {
return "root", nil
}
g, err := user.LookupGroupId(gid)
if err != nil {
switch err.(type) {
case user.UnknownGroupIdError:
return gid, nil
default:
return "", err
}
}
return g.Name, nil
}
// processGROUP returns the effective group ID of the process. This will be
// the textual group ID, if it can be optained, or a decimal representation
// otherwise.
func processGROUP(p *process) (string, error) {
return lookupGID(p.pstatus.gids[1])
}
// processRGROUP returns the real group ID of the process. This will be
// the textual group ID, if it can be optained, or a decimal representation
// otherwise.
func processRGROUP(p *process) (string, error) {
return lookupGID(p.pstatus.gids[0])
}
// processPPID returns the parent process ID of process p.
func processPPID(p *process) (string, error) {
return p.pstatus.pPid, nil
}
// lookupUID return the textual user ID, if it can be optained, or the decimal
// input representation otherwise.
func lookupUID(uid string) (string, error) {
if uid == "0" {
return "root", nil
}
u, err := user.LookupId(uid)
if err != nil {
switch err.(type) {
case user.UnknownUserError:
return uid, nil
default:
return "", err
}
}
return u.Username, nil
}
// processUSER returns the effective user name of the process. This will be
// the textual group ID, if it can be optained, or a decimal representation
// otherwise.
func processUSER(p *process) (string, error) {
return lookupUID(p.pstatus.uids[1])
}
// processRUSER returns the effective user name of the process. This will be
// the textual group ID, if it can be optained, or a decimal representation
// otherwise.
func processRUSER(p *process) (string, error) {
return lookupUID(p.pstatus.uids[0])
}
// processName returns the name of process p in the format "[$name]".
func processName(p *process) (string, error) {
return fmt.Sprintf("[%s]", p.pstatus.name), nil
}
// processARGS returns the command of p with all its arguments.
func processARGS(p *process) (string, error) {
args := p.cmdline
// ps (1) returns "[$name]" if command/args are empty
if len(args) == 0 {
return processName(p)
}
return strings.Join(args, " "), nil
}
// processCOMM returns the command name (i.e., executable name) of process p.
func processCOMM(p *process) (string, error) {
args := p.cmdline
// ps (1) returns "[$name]" if command/args are empty
if len(args) == 0 {
return processName(p)
}
spl := strings.Split(args[0], "/")
return spl[len(spl)-1], nil
}
// processNICE returns the nice value of process p.
func processNICE(p *process) (string, error) {
return p.pstat.nice, nil
}
// processPID returns the process ID of process p.
func processPID(p *process) (string, error) {
return p.pstatus.pid, nil
}
// processPGID returns the process group ID of process p.
func processPGID(p *process) (string, error) {
return p.pstat.pgrp, nil
}
// processPCPU returns how many percent of the CPU time process p uses as
// a three digit float as string.
func processPCPU(p *process) (string, error) {
elapsed, err := p.elapsedTime()
if err != nil {
return "", err
}
cpu, err := p.cpuTime()
if err != nil {
return "", err
}
pcpu := 100 * cpu.Seconds() / elapsed.Seconds()
return strconv.FormatFloat(pcpu, 'f', 3, 64), nil
}
// processETIME returns the elapsed time since the process was started.
func processETIME(p *process) (string, error) {
elapsed, err := p.elapsedTime()
if err != nil {
return "", nil
}
return fmt.Sprintf("%v", elapsed), nil
}
// processTIME returns the cumulative CPU time of process p.
func processTIME(p *process) (string, error) {
cpu, err := p.cpuTime()
if err != nil {
return "", err
}
return fmt.Sprintf("%v", cpu), nil
}
// processTTY returns the controlling tty (terminal) of process p.
func processTTY(p *process) (string, error) {
ttyNr, err := strconv.ParseUint(p.pstat.ttyNr, 10, 64)
if err != nil {
return "", nil
}
maj, min := ttyNrToDev(ttyNr)
t, err := findTTY(maj, min)
if err != nil {
return "", err
}
ttyS := "?"
if t != nil {
ttyS = strings.TrimPrefix(t.device, "/dev/")
}
return ttyS, nil
}
// processVSZ returns the virtual memory size of process p in KiB (1024-byte
// units).
func processVSZ(p *process) (string, error) {
vmsize, err := strconv.Atoi(p.pstat.vsize)
if err != nil {
return "", err
}
return fmt.Sprintf("%d", vmsize/1024), nil
}
// parseCAP parses cap (a string bit mask) and returns the associated set of
// capabilities. If all capabilties are set, "full" is returned. If no
// capability is enabled, "none" is returned.
func parseCAP(cap string) (string, error) {
mask, err := strconv.ParseUint(cap, 16, 64)
if err != nil {
return "", err
}
if mask == fullCAPs {
return "full", nil
}
caps := maskToCaps(mask)
if len(caps) == 0 {
return "none", nil
}
return strings.Join(caps, ", "), nil
}
// processCAPINH returns the set of inheritable capabilties associated with
// process p. If all capabilties are set, "full" is returned. If no
// capability is enabled, "none" is returned.
func processCAPINH(p *process) (string, error) {
return parseCAP(p.pstatus.capInh)
}
// processCAPPRM returns the set of permitted capabilties associated with
// process p. If all capabilties are set, "full" is returned. If no
// capability is enabled, "none" is returned.
func processCAPPRM(p *process) (string, error) {
return parseCAP(p.pstatus.capPrm)
}
// processCAPEFF returns the set of effective capabilties associated with
// process p. If all capabilties are set, "full" is returned. If no
// capability is enabled, "none" is returned.
func processCAPEFF(p *process) (string, error) {
return parseCAP(p.pstatus.capEff)
}
// processCAPBND returns the set of bounding capabilties associated with
// process p. If all capabilties are set, "full" is returned. If no
// capability is enabled, "none" is returned.
func processCAPBND(p *process) (string, error) {
return parseCAP(p.pstatus.capBnd)
}
// processSECCOMP returns the seccomp mode of the process (i.e., disabled,
// strict or filter) or "?" if /proc/$pid/status.seccomp has a unknown value.
func processSECCOMP(p *process) (string, error) {
switch p.pstatus.seccomp {
case "0":
return "disabled", nil
case "1":
return "strict", nil
case "2":
return "filter", nil
default:
return "?", nil
}
}
// processLABEL returns the process label of process p.
func processLABEL(p *process) (string, error) {
data, err := ioutil.ReadFile(fmt.Sprintf("/proc/%d/attr/current", p.pid))
if err != nil {
if os.IsNotExist(err) {
// make sure the pid does not exist,
// could be system does not support labeling.
if _, err2 := os.Stat(fmt.Sprintf("/proc/%d", p.pid)); err2 != nil {
return "", errNoSuchPID
}
}
return "", err
}
return strings.Trim(string(data), "\x00"), nil
}
|