README.md

@@ -1,5 +1,5 @@
 # probehost2
-a http endpoint to query network diagnosis tools from remote hosts
+an http endpoint to query network diagnosis tools from remote hosts
 
 - <a href="#probehost2">Overview</a>
 - <a href="#disclaimer">Disclaimer</a>
@@ -15,15 +15,14 @@ a http endpoint to query network diagnosis tools from remote hosts
         - <a href="#ping">Ping</a>
         - <a href="#mtr">MTR</a>
         - <a href="#traceroute">Traceroute</a>
-        - <a href="#nping">Nping</a>
 
 # Disclaimer
-Don't expect good or even mediocre code here. This is my first take at go and is mostly for myself to learn. Suggestions and improvements are welcome.
+Dont expect good or even mediocre code here. This is my first take at go and is mostly for myself to learn. Suggestions and improvements are welcome.
 
 Please note that this project does not include any kind of rate limiting or other protection. It is therefore heavily advised to only make it publicly reachable if a reverse proxy is in place. A sample config for <a href="caddyserver.com/">Caddy</a> can be found in the `caddy` subfolder. 
 
 # Installation
-The runtime dependencies are currently `iputils`, `traceroute`, `nping` (usually provided by nmap) and `mtr` (sometimes called `mtr-tiny`). `iputils` and `traceroute` can be substituted by `busybox`.
+The runtime dependencies are currently `iputils`, `traceroute` and `mtr` (sometimes called `mtr-tiny`). `iputils` and `traceroute` can be substituted by `busybox`.
 
 ## Building
 The app can be built with the latest Go toolchain.
@@ -49,7 +48,7 @@ docker build -f docker/Dockerfile . -t byreqz/probehost2:latest
 A compose file can also be found in `docker/docker-compose.yml`.
 
 ## Proxy
-It's recommended to only run this app together with a rate-limiting reverse-proxy. An example configuration for <a href="caddyserver.com/">Caddy</a> can be found in the `caddy` subfolder. 
+Its recommended to only run this app together with a rate-limiting reverse-proxy. An example configuration for <a href="caddyserver.com/">Caddy</a> can be found in the `caddy` subfolder. 
 
 # Usage
 ## Server
@@ -59,9 +58,9 @@ The app currently has 4 runtime flags:
 - `-x / --disable-x-forwarded-for` -- disables checking for the X-Forwarded-For header
 - `-l / --allow-private` -- allows lookups of private IP ranges
 
-All the Flags also have an accompanying environment value: `PROBEHOST_LOGPATH`, `PROBEHOST_ALLOW_PRIVATE`, `PROBEHOST_LISTEN_PORT` and `PROBEHOST_DISABLE_X_FORWARDED_FOR` but the options given via commandline have priority.
+All of the Flags also have an accompanying environment value: `PROBEHOST_LOGPATH`, `PROBEHOST_ALLOW_PRIVATE`, `PROBEHOST_LISTEN_PORT` and `PROBEHOST_DISABLE_X_FORWARDED_FOR` but the options given via commandline have priority.
 
-The app will log every request including the IP that's querying and show failed requests on stdout.
+The app will log every request including the IP thats querying and show failed requests on stdout.
 
 Requests that contain an X-Forwarded-For header (implying the app is behind a reverse proxy) will automatically log that address instead of the requesting IP (the proxy itself), this can be turned off with -x.
 
@@ -69,7 +68,7 @@ Requests that contain an X-Forwarded-For header (implying the app is behind a re
 ### General
 The app can be queried via HTTP/HTTPS with the following scheme:
 ```
-https://[address]/[command]/[host](_[port]),[host].../[options]
+https://[address]/[command]/[hosts]/[options]
 ```
 
 - [address] = the IP or domain serving the site
@@ -77,8 +76,7 @@ https://[address]/[command]/[host](_[port]),[host].../[options]
   - ping
   - mtr
   - traceroute
-- [host] = can be one or more hosts query, seperated by a comma
+- [hosts] = can be one or more hosts query, seperated by a comma
-- [port] = port to be queried, optional
 - [options] = options to run the command with, seperated by a comma
 
 All inputs are validated and invalid input is discarded. If the request contains no valid data, the server will return HTTP 500.
@@ -133,7 +131,7 @@ Available options are:
 - `c10` / `count10`: send 10 pings
 
 Example query:
-```sh
+```
 $ curl http://localhost:8000/mtr/localhost/c1,z
 Start: 2022-01-02T00:06:56+0100
 HOST: xxx                 Loss%   Snt   Last   Avg  Best  Wrst StDev
@@ -157,37 +155,9 @@ Available options are:
 - `b` / `back`: Guess the number of hops in the backward path and print if it differs
 
 Example query:
-```sh
+```
 $ curl http://localhost:8000/tracert/localhost/i 
 traceroute to localhost (127.0.0.1), 30 hops max, 60 byte packets
  1  localhost (127.0.0.1)  0.063 ms  0.008 ms  0.006 ms
-```
+
-### Nping
-The default options are:
-- `c3`: send 3 pings
-
-Available options are:
-- `4` / `force4`: force IPv4
-- `6` / `force6`: force IPv6
-- `u` / `udp`: use UDP
-- `t` / `tcp`: use TCP
-- `v` / `verbose`: be verbose
-- `c1` / `count1`: send 1 ping
-- `c3` / `count3`: send 3 pings
-- `c5` / `count5`: send 5 pings
-
-Example query:
-```sh
-$ curl localhost:8000/nping/localhost_22
-Starting Nping 0.7.92 ( https://nmap.org/nping ) at 2022-05-29 15:28 CEST
-SENT (0.0022s) Starting TCP Handshake > localhost:22 (127.0.0.1:22)
-RCVD (0.0133s) Handshake with localhost:22 (127.0.0.1:22) completed
-SENT (1.0041s) Starting TCP Handshake > localhost:22 (127.0.0.1:22)
-RCVD (1.0089s) Handshake with localhost:22 (127.0.0.1:22) completed
-SENT (2.0071s) Starting TCP Handshake > localhost:22 (127.0.0.1:22)
-RCVD (2.0090s) Handshake with localhost:22 (127.0.0.1:22) completed
- 
-Max rtt: 11.130ms | Min rtt: 1.945ms | Avg rtt: 5.965ms
-TCP connection attempts: 3 | Successful connections: 3 | Failed: 0 (0.00%)
-Nping done: 1 IP address pinged in 2.01 seconds
 ```

docker/Dockerfile

@@ -6,7 +6,7 @@ RUN CGO_ENABLED=0 go build -o probehost2
 
 FROM alpine:latest
 RUN apk update
-RUN apk add mtr iputils nmap-nping
+RUN apk add mtr iputils
 COPY --from=builder /build/probehost2 /
 RUN touch /probehost2.log
 CMD ["/probehost2"]

main.go

@@ -1,16 +1,16 @@
 package main
-
 import (
-	"fmt"
+  "fmt"
-	"net"
+  "os"
-	"net/http"
+  "os/exec"
-	"os"
+  "strings"
-	"os/exec"
+  "net/http"
-	"strconv"
+  "net"
-	"strings"
+  "strconv"
+
+  log "github.com/sirupsen/logrus"
+  flag "github.com/spf13/pflag"
 
-	log "github.com/sirupsen/logrus"
-	flag "github.com/spf13/pflag"
 )
 
 var logstdout = log.New()
@@ -21,219 +21,181 @@ var disablexforwardedfor bool
 var allowprivate bool
 
 func init() {
-	logstdout.SetFormatter(&log.TextFormatter{
+  logstdout.SetFormatter(&log.TextFormatter{
-		FullTimestamp: true})
+    FullTimestamp: true})
-	logstdout.SetOutput(os.Stdout)
+  logstdout.SetOutput(os.Stdout)
-	logstdout.SetLevel(log.InfoLevel)
+  logstdout.SetLevel(log.InfoLevel)
-	var logfilepath string
+  var logfilepath string
 
-	if _, exists := os.LookupEnv("PROBEHOST_LOGPATH"); exists == true {
+  if _, exists := os.LookupEnv("PROBEHOST_LOGPATH"); exists == true {
-		logfilepath, _ = os.LookupEnv("PROBEHOST_LOGPATH")
+    logfilepath, _ = os.LookupEnv("PROBEHOST_LOGPATH")
-	} else {
+  } else {
-		logfilepath = "probehost2.log"
+    logfilepath = "probehost2.log"
-	}
+  }
-	if exists, _ := os.LookupEnv("PROBEHOST_ALLOW_PRIVATE"); exists == "true" {
+  if exists, _ := os.LookupEnv("PROBEHOST_ALLOW_PRIVATE"); exists == "true" {
-		allowprivate = true
+    allowprivate = true
-	} else {
+  } else {
-		allowprivate = false
+    allowprivate = false
-	}
+  }
-	if envvalue, exists := os.LookupEnv("PROBEHOST_LISTEN_PORT"); exists == true {
+  if envvalue, exists := os.LookupEnv("PROBEHOST_LISTEN_PORT"); exists == true {
-		var err error
+    var err error
-		listenport, err = strconv.Atoi(envvalue)
+    listenport, err = strconv.Atoi(envvalue)
-		if err != nil {
+    if err != nil {
-			logstdout.Fatal("Failed to read PROBEHOST_LISTEN_PORT: ", err.Error())
+      logstdout.Fatal("Failed to read PROBEHOST_LISTEN_PORT: ", err.Error())
-		}
+    }
-	} else {
+  } else {
-		listenport = 8000
+    listenport = 8000
-	}
+  }
-	if exists, _ := os.LookupEnv("PROBEHOST_DISABLE_X_FORWARDED_FOR"); exists == "true" {
+  if exists, _ := os.LookupEnv("PROBEHOST_DISABLE_X_FORWARDED_FOR"); exists == "true" {
-		disablexforwardedfor = true
+    disablexforwardedfor = true
-	} else {
+  } else {
-		disablexforwardedfor = false
+    disablexforwardedfor = false
-	}
+  }
-	flag.StringVarP(&logfilepath, "logfilepath", "o", logfilepath, "sets the output file for the log")
+  flag.StringVarP(&logfilepath, "logfilepath", "o", logfilepath, "sets the output file for the log")
-	flag.IntVarP(&listenport, "port", "p", listenport, "sets the port to listen on")
+  flag.IntVarP(&listenport, "port", "p", listenport, "sets the port to listen on")
-	flag.BoolVarP(&disablexforwardedfor, "disable-x-forwarded-for", "x", disablexforwardedfor, "whether to show x-forwarded-for or the requesting IP")
+  flag.BoolVarP(&disablexforwardedfor, "disable-x-forwarded-for", "x", disablexforwardedfor, "whether to show x-forwarded-for or the requesting IP")
-	flag.BoolVarP(&allowprivate, "allow-private", "l", allowprivate, "whether to show lookups of private IP ranges")
+  flag.BoolVarP(&allowprivate, "allow-private", "l", allowprivate, "whether to show lookups of private IP ranges")
-	flag.Parse()
+  flag.Parse()
 
-	logpath, err := os.OpenFile(logfilepath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0660)
+  logpath, err := os.OpenFile(logfilepath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0660)
-	if err != nil {
+  if err != nil {
-		logstdout.Fatal("Failed to initialize the logfile: ", err.Error())
+    logstdout.Fatal("Failed to initialize the logfile: ", err.Error())
-	}
+  }
-	logfile.SetLevel(log.InfoLevel)
+  logfile.SetLevel(log.InfoLevel)
-	logfile.SetOutput(logpath)
+  logfile.SetOutput(logpath)
-	logfile.Info("probehost2 initialized")
+  logfile.Info("probehost2 initialized")
 }
 
-func runner(remoteip string, command string, args ...string) string {
+func runner(remoteip string, command string, args... string) string{
-	logfile.WithFields(log.Fields{
+  logfile.WithFields(log.Fields{
-		"remote_ip": remoteip,
+    "remote_ip": remoteip,
-		"command":   fmt.Sprint(command, args),
+    "command": fmt.Sprint(command, args),
-	}).Info("request initiated:")
+  }).Info("request initiated:")
-	cmd, err := exec.Command(command, args...).Output()
+  cmd, err := exec.Command(command, args...).Output()
-	if err != nil {
+  if err != nil {
-		logstdout.WithFields(log.Fields{
+    logstdout.WithFields(log.Fields{
-			"remote_ip": remoteip,
+      "remote_ip": remoteip,
-			"command":   fmt.Sprint(command, args),
+      "command": fmt.Sprint(command, args),
-			"error":     err.Error(),
+      "error": err.Error(),
-		}).Warn("request failed:")
+    }).Warn("request failed:")
-		logfile.WithFields(log.Fields{
+    logfile.WithFields(log.Fields{
-			"remote_ip": remoteip,
+      "remote_ip": remoteip,
-			"command":   fmt.Sprint(command, args),
+      "command": fmt.Sprint(command, args),
-			"error":     err.Error(),
+      "error": err.Error(),
-		}).Warn("request failed:")
+    }).Warn("request failed:")
-	} else {
+  } else {
-		logfile.WithFields(log.Fields{
+    logfile.WithFields(log.Fields{
-			"remote_ip": remoteip,
+      "remote_ip": remoteip,
-			"command":   fmt.Sprint(command, args),
+      "command": fmt.Sprint(command, args),
-		}).Info("request succeeded:")
+    }).Info("request succeeded:")
-	}
+  }
-	return string(cmd)
+  return string(cmd)
 }
 
-func validatehosts(hosts []string) ([]string, []string) {
+func validatehosts(hosts []string) []string{
-	var validhosts []string
+  var valid []string
-	var validports []string
+  for _, host := range hosts {
-	for _, host := range hosts {
+    if hostparse := net.ParseIP(host); hostparse != nil {
-		split := strings.Split(host, "_")
+      if (net.IP.IsPrivate(hostparse) || net.IP.IsLoopback(hostparse)) && allowprivate {
-		host = split[0]
+        valid = append(valid, host)
-		if hostparse := net.ParseIP(host); hostparse != nil {
+      } else if ! (net.IP.IsPrivate(hostparse) || net.IP.IsLoopback(hostparse)) {
-			if (net.IP.IsPrivate(hostparse) || net.IP.IsLoopback(hostparse)) && allowprivate {
+        valid = append(valid, host)
-				validhosts = append(validhosts, host)
+      }
-			} else if !(net.IP.IsPrivate(hostparse) || net.IP.IsLoopback(hostparse)) {
+    } else if _, err := net.LookupIP(host); err == nil {
-				validhosts = append(validhosts, host)
+      valid = append(valid, host)
-			}
+    }
-		} else if _, err := net.LookupIP(host); err == nil {
+  }
-			validhosts = append(validhosts, host)
+  return valid
-		} else {
-			continue
-		}
-
-		var port string
-		if len(split) > 1 {
-			port = split[1]
-			_, err := strconv.Atoi(port) // validate if port is just an int
-			if err == nil {
-				validports = append(validports, port)
-			} else {
-				validports = append(validports, "0")
-			}
-		} else {
-			validports = append(validports, "0")
-		}
-	}
-	return validhosts, validports
 }
 
-func parseopts(options []string, cmdopts map[string]string) []string {
+func parseopts(options []string, cmdopts map[string]string) []string{
-	var opts []string
+  var opts []string
-	for _, opt := range options {
+  for _, opt := range options {
-		opts = append(opts, cmdopts[opt])
+    opts = append(opts, cmdopts[opt])
-	}
+  }
-	return opts
+  return opts
 }
 
-func prerunner(req *http.Request, cmd string, cmdopts map[string]string, defaultopts []string) string {
+func prerunner(req *http.Request, cmd string, cmdopts map[string]string, defaultopts []string) string{
-	geturl := strings.Split(req.URL.String(), "/")
+  geturl := strings.Split(req.URL.String(), "/")
-	targets := strings.Split(geturl[2], ",")
+  targets := strings.Split(geturl[2], ",")
-	hosts, ports := validatehosts(targets)
+  hosts := validatehosts(targets)
-	var opts []string
+  var opts []string
-	opts = append(opts, defaultopts...)
+  opts = append(opts, defaultopts...)
-	if len(geturl) > 3 && len(geturl[3]) > 0 {
+  if len(geturl) > 3 && len(geturl[3]) > 0 { 
-		options := strings.Split(geturl[3], ",")
+    options := strings.Split(geturl[3], ",")
-		opts = append(opts, parseopts(options, cmdopts)...)
+    opts = append(opts, parseopts(options, cmdopts)...)
-	}
+  }
-	var res string
+  var res string
-	var args []string
+  var args []string
-	var remoteaddr string
+  var remoteaddr string
-	if req.Header.Get("X-Forwarded-For") != "" && disablexforwardedfor != true {
+  if req.Header.Get("X-Forwarded-For") != "" && disablexforwardedfor != true {
-		remoteaddr = req.Header.Get("X-Forwarded-For")
+    remoteaddr = req.Header.Get("X-Forwarded-For")
-	} else {
+  } else {
-		remoteaddr = req.RemoteAddr
+    remoteaddr = req.RemoteAddr
-	}
+  }
-	for i, host := range hosts {
+  for _, host := range hosts {
-		runargs := append(args, opts...)
+    args = append(args, opts...)
-		if ports[i] != "0" && cmd == "nping" {
+    args = append(args, host)
-			runargs = append(runargs, "-p"+ports[i])
+    res = fmt.Sprint(res, runner(remoteaddr, cmd, args...), "\n")
-		}
+  }
-		runargs = append(runargs, host)
+  return res
-		res = fmt.Sprint(res, runner(remoteaddr, cmd, runargs...), "\n")
-	}
-	return res
 }
 
 func ping(w http.ResponseWriter, req *http.Request) {
-	cmd := "ping"
+  cmd := "ping"
-	cmdopts := map[string]string{
+  cmdopts := map[string]string{
-		"4": "-4", "6": "-6", "d": "-D", "n": "-n", "v": "-v", "c1": "-c1", "c5": "-c5", "c10": "-c10",
+    "4": "-4", "6": "-6", "d": "-D", "n": "-n", "v": "-v", "c1": "-c1", "c5": "-c5", "c10": "-c10",
-		"force4": "-4", "force6": "-6", "timestamps": "-D", "nodns": "-n", "verbose": "-v", "count1": "-c1", "count5": "-c5", "count10": "-c10",
+    "force4": "-4", "force6": "-6", "timestamps": "-D", "nodns": "-n", "verbose": "-v", "count1": "-c1", "count5": "-c5", "count10": "-c10",
-	}
+  }
-	var defaultopts []string
+  var defaultopts []string
-	defaultopts = append(defaultopts, "-c10")
+  defaultopts = append(defaultopts, "-c10")
-	res := prerunner(req, cmd, cmdopts, defaultopts)
+  res := prerunner(req, cmd, cmdopts, defaultopts)
-	if strings.TrimSpace(res) == "" {
+  if strings.TrimSpace(res) == "" {
-		http.Error(w, "500: Internal Server Error", http.StatusInternalServerError)
+    fmt.Fprintln(w, http.StatusInternalServerError)
-	} else {
+  } else {
-		_, _ = fmt.Fprint(w, strings.TrimSpace(res), "\n")
+    fmt.Fprint(w, strings.TrimSpace(res), "\n")
-	}
+  }
 }
 
 func mtr(w http.ResponseWriter, req *http.Request) {
-	cmd := "mtr"
+  cmd := "mtr"
-	cmdopts := map[string]string{
+  cmdopts := map[string]string{
-		"4": "-4", "6": "-6", "u": "-u", "t": "-T", "e": "-e", "x": "-x", "n": "-n", "b": "-b", "z": "-z", "c1": "-c1", "c5": "-c5", "c10": "-c10",
+    "4": "-4", "6": "-6", "u": "-u", "t": "-T", "e": "-e", "x": "-x", "n": "-n", "b": "-b", "z": "-z", "c1": "-c1", "c5": "-c5", "c10": "-c10",
-		"force4": "-4", "force6": "-6", "udp": "-u", "tcp": "-T", "ext": "-e", "xml": "-x", "nodns": "-n", "cmb": "-b", "asn": "-z", "count1": "-c1", "count5": "-c5", "count10": "-c10",
+    "force4": "-4", "force6": "-6", "udp": "-u", "tcp": "-T", "ext": "-e", "xml": "-x", "nodns": "-n", "cmb": "-b", "asn": "-z", "count1": "-c1", "count5": "-c5", "count10": "-c10",
-	}
+  }
-	var defaultopts []string
+  var defaultopts []string
-	defaultopts = append(defaultopts, "-r", "-w", "-c10")
+  defaultopts = append(defaultopts, "-r", "-w", "-c10")
-	res := prerunner(req, cmd, cmdopts, defaultopts)
+  res := prerunner(req, cmd, cmdopts, defaultopts)
-	if strings.TrimSpace(res) == "" {
+  if strings.TrimSpace(res) == "" {
-		http.Error(w, "500: Internal Server Error", http.StatusInternalServerError)
+    fmt.Fprintln(w, http.StatusInternalServerError)
-	} else {
+  } else {
-		_, _ = fmt.Fprint(w, strings.TrimSpace(res), "\n")
+    fmt.Fprint(w, strings.TrimSpace(res), "\n")
-	}
+  }
 }
 
 func traceroute(w http.ResponseWriter, req *http.Request) {
-	cmd := "traceroute"
+  cmd := "traceroute"
-	cmdopts := map[string]string{
+  cmdopts := map[string]string{
-		"4": "-4", "6": "-6", "f": "-F", "i": "-I", "t": "-T", "n": "-n", "u": "-U", "ul": "-UL", "d": "-D", "b": "--back",
+    "4": "-4", "6": "-6", "f": "-F", "i": "-I", "t": "-T", "n": "-n", "u": "-U", "ul": "-UL", "d": "-D", "b": "--back",
-		"force4": "-4", "force6": "-6", "dnf": "-F", "icmp": "-I", "tcp": "-T", "nodns": "-n", "udp": "-U", "udplite": "-UL", "dccp": "-D", "back": "--back",
+    "force4": "-4", "force6": "-6", "dnf": "-F", "icmp": "-I", "tcp": "-T", "nodns": "-n", "udp": "-U", "udplite": "-UL", "dccp": "-D", "back": "--back",
-	}
+  }
-	var defaultopts []string
+  var defaultopts []string
-	//defaultopts = append(defaultopts) // no default options for traceroute
+  //defaultopts = append(defaultopts) // no default options for traceroute
-	res := prerunner(req, cmd, cmdopts, defaultopts)
+  res := prerunner(req, cmd, cmdopts, defaultopts)
-	if strings.TrimSpace(res) == "" {
+  if strings.TrimSpace(res) == "" {
-		http.Error(w, "500: Internal Server Error", http.StatusInternalServerError)
+    fmt.Fprintln(w, http.StatusInternalServerError)
-	} else {
+  } else {
-		_, _ = fmt.Fprint(w, strings.TrimSpace(res), "\n")
+    fmt.Fprint(w, strings.TrimSpace(res), "\n")
-	}
+  }
-}
-
-func nping(w http.ResponseWriter, req *http.Request) {
-	cmd := "nping"
-	cmdopts := map[string]string{
-		"4": "-4", "6": "-6", "u": "--udp", "t": "--tcp-connect", "v": "-v", "c1": "-c1", "c3": "-c3", "c5": "-c5",
-		"force4": "-4", "force6": "-6", "udp": "--udp", "tcp": "--tcp-connect", "verbose": "-v", "count1": "-c1", "count3": "-c3", "count5": "-c5",
-	}
-	var defaultopts []string
-	defaultopts = append(defaultopts, "-c3")
-	res := prerunner(req, cmd, cmdopts, defaultopts)
-	if strings.TrimSpace(res) == "" {
-		http.Error(w, "500: Internal Server Error", http.StatusInternalServerError)
-	} else {
-		_, _ = fmt.Fprint(w, strings.TrimSpace(res), "\n")
-	}
 }
 
 func main() {
-	http.HandleFunc("/ping/", ping)
+  http.HandleFunc("/ping/", ping)
-	http.HandleFunc("/mtr/", mtr)
+  http.HandleFunc("/mtr/", mtr)
-	http.HandleFunc("/tracert/", traceroute)
+  http.HandleFunc("/tracert/", traceroute)
-	http.HandleFunc("/traceroute/", traceroute)
+  http.HandleFunc("/traceroute/", traceroute)
-	http.HandleFunc("/nping/", nping)
+  logstdout.Info("Serving on :", listenport)
-	logstdout.Info("Serving on :", listenport)
+  logfile.Info("Serving on :", listenport)
-	logfile.Info("Serving on :", listenport)
+  http.ListenAndServe(fmt.Sprint(":", listenport), nil)
-	_ = http.ListenAndServe(fmt.Sprint(":", listenport), nil)
 }