From daae040f9cb2e9dbcbfd03e31d4e899fce2049c0 Mon Sep 17 00:00:00 2001
From: Eugene Bujak <hmage@hmage.net>
Date: Fri, 1 Feb 2019 19:25:04 +0300
Subject: [PATCH] Check if IP:port combinations are possible before returning
OK on /install/configure
---
app.go | 16 +++++++++-------
control.go | 17 ++++++++++++++---
helpers.go | 14 ++++++++++++--
3 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/app.go b/app.go
index 6fa8ef34..71f3ee82 100644
--- a/app.go
+++ b/app.go
@@ -116,14 +116,16 @@ func run(args options) {
log.Fatal(err)
}
- err = startDNSServer()
- if err != nil {
- log.Fatal(err)
- }
+ if !config.firstRun {
+ err = startDNSServer()
+ if err != nil {
+ log.Fatal(err)
+ }
- err = startDHCPServer()
- if err != nil {
- log.Fatal(err)
+ err = startDHCPServer()
+ if err != nil {
+ log.Fatal(err)
+ }
}
// Update filters we've just loaded right away, don't wait for periodic update timer
diff --git a/control.go b/control.go
index 38464a90..1f64ae6c 100644
--- a/control.go
+++ b/control.go
@@ -723,7 +723,7 @@ func handleInstallGetAddresses(w http.ResponseWriter, r *http.Request) {
// fill out the fields
// find out if port 80 is available -- if not, fall back to 3000
- if checkPortAvailable(80) {
+ if checkPortAvailable("", 80) {
data.Web.Port = 80
} else {
data.Web.Port = 3000
@@ -731,7 +731,7 @@ func handleInstallGetAddresses(w http.ResponseWriter, r *http.Request) {
// find out if port 53 is available -- if not, show a big warning
data.DNS.Port = 53
- if !checkPortAvailable(53) {
+ if !checkPacketPortAvailable("", 53) {
data.DNS.Warning = "Port 53 is not available for binding -- this will make DNS clients unable to contact AdGuard Home."
}
@@ -764,7 +764,18 @@ func handleInstallConfigure(w http.ResponseWriter, r *http.Request) {
}
spew.Dump(newSettings)
- // TODO: validate that hosts and ports are bindable
+ // validate that hosts and ports are bindable
+
+ if !checkPortAvailable(newSettings.Web.IP, newSettings.Web.Port) {
+ httpError(w, http.StatusBadRequest, "Impossible to listen on IP:port %s:%d", newSettings.Web.IP, newSettings.Web.Port)
+ return
+ }
+
+ if !checkPacketPortAvailable(newSettings.DNS.IP, newSettings.DNS.Port) {
+ httpError(w, http.StatusBadRequest, "Impossible to listen on IP:port %s:%d", newSettings.DNS.IP, newSettings.DNS.Port)
+ return
+ }
+
config.firstRun = false
config.BindHost = newSettings.Web.IP
config.BindPort = newSettings.Web.Port
diff --git a/helpers.go b/helpers.go
index f83b9821..9dbd59b7 100644
--- a/helpers.go
+++ b/helpers.go
@@ -12,6 +12,7 @@ import (
"path"
"path/filepath"
"runtime"
+ "strconv"
"strings"
"github.com/hmage/golibs/log"
@@ -259,8 +260,17 @@ func findIPv4IfaceAddr(ifaces []netInterface) string {
}
// checkPortAvailable is not a cheap test to see if the port is bindable, because it's actually doing the bind momentarily
-func checkPortAvailable(port int) bool {
- ln, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
+func checkPortAvailable(host string, port int) bool {
+ ln, err := net.Listen("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
+ if err != nil {
+ return false
+ }
+ ln.Close()
+ return true
+}
+
+func checkPacketPortAvailable(host string, port int) bool {
+ ln, err := net.ListenPacket("udp", net.JoinHostPort(host, strconv.Itoa(port)))
if err != nil {
return false
}