117 lines
2.3 KiB
Go
117 lines
2.3 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package portlist
|
|
|
|
import (
|
|
"fmt"
|
|
"sort"
|
|
"strings"
|
|
|
|
"tailscale.com/envknob"
|
|
)
|
|
|
|
// Port is a listening port on the machine.
|
|
type Port struct {
|
|
Proto string // "tcp" or "udp"
|
|
Port uint16 // port number
|
|
Process string // optional process name, if found
|
|
|
|
inode string // OS-specific; "socket:[165614651]" on Linux
|
|
}
|
|
|
|
// List is a list of Ports.
|
|
type List []Port
|
|
|
|
func (a *Port) lessThan(b *Port) bool {
|
|
if a.Port < b.Port {
|
|
return true
|
|
} else if a.Port > b.Port {
|
|
return false
|
|
}
|
|
|
|
if a.Proto < b.Proto {
|
|
return true
|
|
} else if a.Proto > b.Proto {
|
|
return false
|
|
}
|
|
|
|
if a.inode < b.inode {
|
|
return true
|
|
} else if a.inode > b.inode {
|
|
return false
|
|
}
|
|
|
|
if a.Process < b.Process {
|
|
return true
|
|
} else if a.Process > b.Process {
|
|
return false
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (a List) sameInodes(b List) bool {
|
|
if a == nil || b == nil || len(a) != len(b) {
|
|
return false
|
|
}
|
|
for i := range a {
|
|
if a[i].Proto != b[i].Proto ||
|
|
a[i].Port != b[i].Port ||
|
|
a[i].inode != b[i].inode {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (pl List) String() string {
|
|
var sb strings.Builder
|
|
for _, v := range pl {
|
|
fmt.Fprintf(&sb, "%-3s %5d %-17s %#v\n",
|
|
v.Proto, v.Port, v.inode, v.Process)
|
|
}
|
|
return strings.TrimRight(sb.String(), "\n")
|
|
}
|
|
|
|
var debugDisablePortlist = envknob.Bool("TS_DEBUG_DISABLE_PORTLIST")
|
|
|
|
func GetList(prev List) (List, error) {
|
|
if debugDisablePortlist {
|
|
return nil, nil
|
|
}
|
|
pl, err := listPorts()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("listPorts: %s", err)
|
|
}
|
|
pl = sortAndDedup(pl)
|
|
if pl.sameInodes(prev) {
|
|
// Nothing changed, skip inode lookup
|
|
return prev, nil
|
|
}
|
|
pl, err = addProcesses(pl)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("addProcesses: %s", err)
|
|
}
|
|
return pl, nil
|
|
}
|
|
|
|
// sortAndDedup sorts ps in place (by Port.lessThan) and then returns
|
|
// a subset of it with duplicate (Proto, Port) removed.
|
|
func sortAndDedup(ps List) List {
|
|
sort.Slice(ps, func(i, j int) bool {
|
|
return (&ps[i]).lessThan(&ps[j])
|
|
})
|
|
out := ps[:0]
|
|
var last Port
|
|
for _, p := range ps {
|
|
protoPort := Port{Proto: p.Proto, Port: p.Port}
|
|
if last == protoPort {
|
|
continue
|
|
}
|
|
out = append(out, p)
|
|
last = protoPort
|
|
}
|
|
return out
|
|
}
|