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|
package goprocnet
import (
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"regexp"
"strconv"
"strings"
)
const (
PROC_NET_TCP = "/proc/net/tcp"
PROC_NET_UDP = "/proc/net/udp"
)
var STATE = map[string]string{
"01": "ESTABLISHED",
"02": "SYN_SENT",
"03": "SYN_RECV",
"04": "FIN_WAIT1",
"05": "FIN_WAIT2",
"06": "TIME_WAIT",
"07": "CLOSE",
"08": "CLOSE_WAIT",
"09": "LAST_ACK",
"0A": "LISTEN",
"0B": "CLOSING",
}
var Version string
type Socket struct {
PID string
UID string
Bin string
Name string
State string
LocalIP string
LocalPort int32
RemoteIP string
RemotePort int32
}
func (s Socket) String() string {
return fmt.Sprintf("%s\t%s\t%s\t%s\t%s:%d\t%s:%d",
s.PID,
s.UID,
s.Bin,
s.State,
s.LocalIP,
s.LocalPort,
s.RemoteIP,
s.RemotePort)
}
func GetTCPSockets() []Socket {
sockets, err := netstat("tcp")
if err != nil {
log.Panic(err)
}
return sockets
}
func GetUDPSockets() []Socket {
sockets, err := netstat("udp")
if err != nil {
log.Panic(err)
}
return sockets
}
func getFilename(t string) string {
switch {
case t == "tcp":
return PROC_NET_TCP
case t == "udp":
return PROC_NET_UDP
}
return ""
}
func readFile(t string) ([]string, error) {
filename := getFilename(t)
if filename == "" {
}
data, err := ioutil.ReadFile(filename)
if err != nil {
log.Println("Unable to read file", err)
return nil, err
}
lines := strings.Split(string(data), "\n")
// return lines without header or tailing blank line
return lines[1 : len(lines)-1], nil
}
func convertHexToDec(hex string) int64 {
d, err := strconv.ParseInt(hex, 16, 64)
if err != nil {
log.Panic("Unable to convert hex to dec", err)
}
return d
}
func getIP(hexip string) string {
// we are going to assume IPv4 addresses for now...
// We are also assuming address is in little endian
return fmt.Sprintf("%v.%v.%v.%v",
convertHexToDec(hexip[6:8]),
convertHexToDec(hexip[4:6]),
convertHexToDec(hexip[2:4]),
convertHexToDec(hexip[0:2]))
}
func getPort(hex string) string {
return fmt.Sprintf("%v", convertHexToDec(hex))
}
func removeInnerSpace(values []string) []string {
var newValues []string
for _, value := range values {
if value != "" {
newValues = append(newValues, value)
}
}
return newValues
}
func netstat(t string) ([]Socket, error) {
lines, err := readFile(t)
if err != nil {
log.Println("Failed to retrieve proc data", err)
return nil, err
}
var sockets []Socket
mustParse := func(p string) int32 {
i, err := strconv.ParseInt(p, 10, 32)
if err != nil {
log.Panic(err)
}
return int32(i)
}
for _, line := range lines {
values := removeInnerSpace(strings.Split(strings.TrimSpace(line), " "))
ipPort := strings.Split(values[1], ":")
localIP := getIP(ipPort[0])
localPort := mustParse(getPort(ipPort[1]))
remIpPort := strings.Split(values[2], ":")
remoteIP := getIP(remIpPort[0])
remotePort := mustParse(getPort(remIpPort[1]))
state := STATE[values[3]]
uid := values[7]
pid := getProcessID(values[9])
exe := getProcessExecutable(pid)
name := getProcessName(exe)
s := Socket{pid, uid, exe, name, state, localIP, localPort, remoteIP, remotePort}
sockets = append(sockets, s)
}
return sockets, nil
}
func getProcessID(inode string) string {
// Loop over the fd directories under /proc/pid for the right inode
pid := "-"
procDirs, err := filepath.Glob("/proc/[0-9]*/fd/[0-9]*")
if err != nil {
log.Panic(err)
}
re := regexp.MustCompile(inode)
for _, item := range procDirs {
path, _ := os.Readlink(item)
out := re.FindString(path)
if len(out) != 0 {
pid = strings.Split(item, "/")[2]
}
}
return pid
}
func getProcessExecutable(pid string) string {
path, _ := os.Readlink(fmt.Sprintf("/proc/%s/exe", pid))
return path
}
func getProcessName(exe string) string {
n := strings.Split(exe, "/")
name := n[len(n)-1]
return strings.Title(name)
}
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