control/controlclient, version/distro, wgengine: recognize OpenWrt

And help out with missing packages.

Thanks to @willangley for tips.

Updates #724

control/controlclient/hostinfo_linux.go

@@ -26,8 +26,11 @@ func init() {
 func osVersionLinux() string {
 	dist := distro.Get()
 	propFile := "/etc/os-release"
-	if dist == distro.Synology {
+	switch dist {
+	case distro.Synology:
 		propFile = "/etc.defaults/VERSION"
+	case distro.OpenWrt:
+		propFile = "/etc/openwrt_release"
 	}
 
 	m := map[string]string{}
@@ -36,7 +39,7 @@ func osVersionLinux() string {
 		if eq == -1 {
 			return nil
 		}
-		k, v := string(line[:eq]), strings.Trim(string(line[eq+1:]), `"`)
+		k, v := string(line[:eq]), strings.Trim(string(line[eq+1:]), `"'`)
 		m[k] = v
 		return nil
 	})
@@ -78,8 +81,11 @@ func osVersionLinux() string {
 			return fmt.Sprintf("%s%s", v, attr)
 		}
 	}
-	if dist == distro.Synology {
+	switch dist {
+	case distro.Synology:
 		return fmt.Sprintf("Synology %s%s", m["productversion"], attr)
+	case distro.OpenWrt:
+		return fmt.Sprintf("OpenWrt %s%s", m["DISTRIB_RELEASE"], attr)
 	}
 	return fmt.Sprintf("Other%s", attr)
 }

version/distro/distro.go

@@ -16,6 +16,7 @@ const (
 	Debian   = Distro("debian")
 	Arch     = Distro("arch")
 	Synology = Distro("synology")
+	OpenWrt  = Distro("openwrt")
 )
 
 // Get returns the current distro, or the empty string if unknown.
@@ -36,5 +37,8 @@ func linuxDistro() Distro {
 	if _, err := os.Stat("/etc/arch-release"); err == nil {
 		return Arch
 	}
+	if _, err := os.Stat("/etc/openwrt_version"); err == nil {
+		return OpenWrt
+	}
 	return ""
 }

wgengine/userspace.go

@@ -1272,5 +1272,16 @@ func diagnoseLinuxTUNFailure(logf logger.Logf) {
 		if !bytes.Contains(findOut, kernel) {
 			logf("kernel/drivers/net/tun.ko found on disk, but not for current kernel; are you in middle of a system update and haven't rebooted? found: %s", findOut)
 		}
+	case distro.OpenWrt:
+		out, err := exec.Command("opkg", "list-installed").CombinedOutput()
+		if err != nil {
+			logf("error querying OpenWrt installed packages: %s", out)
+			return
+		}
+		for _, pkg := range []string{"kmod-tun", "ca-bundle"} {
+			if !bytes.Contains(out, []byte(pkg+" - ")) {
+				logf("Missing required package %s; run: opkg install %s", pkg, pkg)
+			}
+		}
 	}
 }