https-dns-proxy: fix deleting server items, configurable dnsmasq settings change

Signed-off-by: Stan Grishin <stangri@melmac.net>

net/https-dns-proxy/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=https-dns-proxy
 PKG_VERSION:=2019-12-03
-PKG_RELEASE=2
+PKG_RELEASE=3
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/aarond10/https_dns_proxy

net/https-dns-proxy/files/README.md

@@ -0,0 +1,94 @@
+# DNS Over HTTPS Proxy (https-dns-proxy)
+
+A lean RFC8484-compatible (no JSON API support) DNS-over-HTTPS (DoH) proxy service which supports DoH servers ran by AdGuard, CleanBrowsing, Cloudflare, Google, ODVR (nic.cz) and Quad9. Please see the [README](https://github.com/stangri/openwrt_packages/blob/master/https-dns-proxy/files/README.md) for further information. Based on [@aarond10](https://github.com/aarond10)'s [https-dns-proxy](https://github.com/aarond10/https_dns_proxy).
+
+## Features
+
+- [RFC8484](https://tools.ietf.org/html/rfc8484)-compatible DoH Proxy.
+- Compact size.
+- Web UI (```luci-app-https-dns-proxy```) available.
+- (By default) automatically updates DNSMASQ settings to use DoH proxy when it's started and reverts to old DNSMASQ resolvers when DoH proxy is stopped.
+
+## Screenshots (luci-app-https-dns-proxy)
+
+![screenshot](https://raw.githubusercontent.com/stangri/openwrt_packages/master/screenshots/https-dns-proxy/screenshot01.png "https-dns-proxy screenshot")
+
+## Requirements
+
+This proxy requires the following packages to be installed on your router: ```libc```, ```libcares```, ```libcurl```, ```libev```, ```ca-bundle```. They will be automatically installed when you're installing ```https-dns-proxy```.
+
+## Unmet Dependencies
+
+If you are running a development (trunk/snapshot) build of OpenWrt/LEDE Project on your router and your build is outdated (meaning that packages of the same revision/commit hash are no longer available and when you try to satisfy the [requirements](#requirements) you get errors), please flash either current LEDE release image or current development/snapshot image.
+
+## How To Install
+
+Install ```https-dns-proxy``` and ```luci-app-https-dns-proxy``` packages from Web UI or run the following in the command line:
+
+```sh
+opkg update; opkg install https-dns-proxy luci-app-https-dns-proxy;
+```
+
+## Default Settings
+
+Default configuration has service enabled and starts the service with Google and Cloudflare DoH servers. In most configurations, you will keep the default ```DNSMASQ``` service installed to handle requests from devices in your local network and point ```DNSMASQ``` to use ```https-dns-proxy``` for name resolution.
+
+By default, the service will intelligently override existing ```DNSMASQ``` servers settings on start to use the DoH servers and restores original ```DNSMASQ``` servers on stop. See the [Configuration Settings](#configuration-settings) section below for more information and how to disable this behavior.
+
+## Configuration Settings
+
+Configuration contains the (named) "main" config section where you can configure which ```DNSMASQ``` settings the service will automatically affect and the typed (unnamed) https-dns-proxy instance settings. The original config file is included below:
+
+```text
+config main 'config'
+  option update_dnsmasq_config '*'
+
+config https-dns-proxy
+  option bootstrap_dns '8.8.8.8,8.8.4.4'
+  option resolver_url 'https://dns.google/dns-query'
+  option listen_addr '127.0.0.1'
+  option listen_port '5053'
+  option user 'nobody'
+  option group 'nogroup'
+
+config https-dns-proxy
+  option bootstrap_dns '1.1.1.1,1.0.0.1'
+  option resolver_url 'https://cloudflare-dns.com/dns-query'
+  option listen_addr '127.0.0.1'
+  option listen_port '5054'
+  option user 'nobody'
+  option group 'nogroup'```
+```
+
+The ```update_dnsmasq_config``` option can be set to dash (set to ```'-'``` to not change ```DNSMASQ``` server settings on start/stop), can be set to ```'*'``` to affect all ```DNSMASQ``` instance server settings or have a space-separated list of ```DNSMASQ``` instances to affect (like ```'0 4 5'```). If this option is omitted, the default setting is ```'*'```.
+
+Starting with ```https-dns-proxy``` version ```2019-12-03-3``` and higher, when the service is set to update the DNSMASQ servers setting on start/stop, it does not override entries which contain either ```#``` or ```/```, so the entries like listed below will be kept in use:
+
+```test
+  list server '/onion/127.0.0.1#65453'
+  list server '/openwrt.org/8.8.8.8'
+  list server '/pool.ntp.org/8.8.8.8'
+  list server '127.0.0.1#15353'
+  list server '127.0.0.1#55353'
+  list server '127.0.0.1#65353'
+```
+
+The https-dns-proxy instance settings are:
+
+|Parameter|Type|Default|Description|
+| --- | --- | --- | --- |
+|bootstrap_dns|IP Address||The non-encrypted DNS servers to be used to resolve the DoH server name on start.|
+|edns_subnet|Subnet||EDNS Subnet address can be supplied to supported DoH servers to provide local resolution results.|
+|listen_addr|IP Address|127.0.0.1|The local IP address to listen to requests.|
+|listen_port|port|5053 and up|If this setting is omitted, the service will start the first https-dns-proxy instance on port 5053, second on 5054 and so on.|
+|logfile|Full filepath||Full filepath to the file to log the instance events to.|
+|resolver_url|URL||The https URL to the RFC8484-compatible resolver.|
+|proxy_server|URL||Local proxy server to use when accessing resolvers.|
+|user|String|nobody|Local user to run instance under.|
+|group|String|nogroup|Local group to run instance under.|
+|use_http1|Boolean|0|If set to 1, use HTTP/1 on installations with broken/outdated ```curl``` package. Included for posterity reasons, you will most likely not ever need it on OpenWrt.|
+|verbosity|Integer||Use setting between 1 to 4 to control the logging verbosity level.|String
+
+## Thanks
+
+This OpenWrt package wouldn't have been possible without [@aarond10](https://github.com/aarond10)'s [https-dns-proxy](https://github.com/aarond10/https_dns_proxy) and his active participation in the OpenWrt package itself. Special thanks to [@jow-](https://github.com/jow-) for general package/luci guidance.

net/https-dns-proxy/files/https-dns-proxy.config

@@ -1,3 +1,6 @@
+config main 'config'
+	option update_dnsmasq_config '*'
+
 config https-dns-proxy
 	option bootstrap_dns '8.8.8.8,8.8.4.4'
 	option resolver_url 'https://dns.google/dns-query'
@@ -5,8 +8,6 @@ config https-dns-proxy
 	option listen_port '5053'
 	option user 'nobody'
 	option group 'nogroup'
-	option ipv4_resolvers '1'
-	option verbosity '0' # fatal = 0, error = 1, warning = 2, info = 3, debug = 4
 
 config https-dns-proxy
 	option bootstrap_dns '1.1.1.1,1.0.0.1'
@@ -15,5 +16,3 @@ config https-dns-proxy
 	option listen_port '5054'
 	option user 'nobody'
 	option group 'nogroup'
-	option ipv4_resolvers '1'
-	option verbosity '0' # fatal = 0, error = 1, warning = 2, info = 3, debug = 4

net/https-dns-proxy/files/https-dns-proxy.init

@@ -5,6 +5,8 @@
 export START=80
 export USE_PROCD=1
 
+dnsmasqConfig=''
+
 PROG=/usr/sbin/https-dns-proxy
 
 xappend() { param="$param $1"; }
@@ -31,8 +33,18 @@ append_parm() {
 	xappend "$switch $_loctmp"
 }
 
+append_match() {
+	local section="$1"
+	local option="$2"
+	local value="$3"
+	local match="$4"
+	local _loctmp
+	config_get_bool _loctmp "$section" "$option"
+	[ "$_loctmp" = "$match" ] && xappend "$value"
+}
+
 start_instance() {
-	local cfg="$1" param listen_addr listen_port
+	local cfg="$1" param listen_addr listen_port i
 
 	append_parm "$cfg" 'listen_addr' '-a' '127.0.0.1'
 	append_parm "$cfg" 'listen_port' '-p' "$p"
@@ -44,37 +56,27 @@ start_instance() {
 	append_parm "$cfg" 'proxy_server' '-t'
 	append_parm "$cfg" 'logfile' '-l'
 	append_bool "$cfg" 'use_http1' '-x'
-	append_bool "$cfg" 'ipv4_resolvers' '-4'
-
-	config_get verbosity "$cfg" 'verbosity' "0"
-	for i in $(seq 1 $verbosity); do
-		xappend "-v"
-	done
+	append_match "$cfg" 'verbosity' '-v' '1'
+	append_match "$cfg" 'verbosity' '-vv' '2'
+	append_match "$cfg" 'verbosity' '-vvv' '3'
+	append_match "$cfg" 'verbosity' '-vvvv' '4'
 
 	procd_open_instance
 # shellcheck disable=SC2086
-	procd_set_param command ${PROG} ${param}
-	procd_set_param stderr 1
-	procd_set_param stdout 1
+	procd_set_param command ${PROG} -4 ${param}
 	procd_set_param respawn
 	procd_close_instance
 
 	config_get listen_addr "$cfg" 'listen_addr' '127.0.0.1'
 	config_get listen_port "$cfg" 'listen_port' "$p"
-
-	# Don't add the any address to dnsmasq
-	case $listen_addr in
-		0.0.0.0|::ffff:0.0.0.0)
-			listen_addr='127.0.0.1'
-			;;
-		::)
-			listen_addr='::1'
-			;;
-	esac
-
-	config_load 'dhcp'
-# shellcheck disable=SC2154
-	config_foreach dnsmasq_add_doh_server 'dnsmasq' "${listen_addr}#${listen_port}"
+	if [ "$dnsmasqConfig" = "*" ]; then
+		config_load 'dhcp'
+		config_foreach dnsmasq_add_doh_server 'dnsmasq' "${listen_addr}#${listen_port}"
+	elif [ -n "$dnsmasqConfig" ]; then
+		for i in $dnsmasqConfig; do
+			dnsmasq_add_doh_server "@dnsmasq[${i}]" "${listen_addr}#${listen_port}"
+		done
+	fi
 	p="$((p+1))"
 }
 
@@ -84,12 +86,11 @@ service_triggers() {
 
 start_service() {
 	local p=5053
+	config_load 'https-dns-proxy'
+	config_get dnsmasqConfig	'config' 'update_dnsmasq_config' '*'
 	dhcp_backup 'create'
 	config_load 'https-dns-proxy'
 	config_foreach start_instance 'https-dns-proxy'
-	if [ -z "$(uci -q get dhcp.@dnsmasq[0].server)" ]; then
-		dhcp_backup 'restore'
-	fi
 	if [ -n "$(uci -q changes dhcp)" ]; then
 		uci -q commit dhcp
 		[ -x /etc/init.d/dnsmasq ] && /etc/init.d/dnsmasq restart >/dev/null 2>&1
@@ -97,6 +98,8 @@ start_service() {
 }
 
 stop_service() {
+	config_load 'https-dns-proxy'
+	config_get dnsmasqConfig	'config' 'update_dnsmasq_config' '*'
 	dhcp_backup 'restore'
 	if [ -n "$(uci -q changes dhcp)" ]; then
 		uci -q commit dhcp
@@ -110,35 +113,49 @@ service_triggers() {
 
 dnsmasq_add_doh_server() {
 	local cfg="$1" value="$2"
+	uci -q del_list dhcp."$cfg".server="$value"
 	uci -q add_list dhcp."$cfg".server="$value"
 }
 
 dnsmasq_create_server_backup() {
-	local cfg="$1" i
-	if ! uci -q get "dhcp.$cfg.doh_backup_server" >/dev/null; then
-		for i in $(uci -q get "dhcp.$cfg.server"); do
-			uci -q add_list dhcp."$cfg".doh_backup_server="$i"
-		done
-	fi
-	uci -q del "dhcp.$cfg.server"
+	local cfg="$1"
+	local i
+	uci -q get "dhcp.$cfg.doh_backup_server" >/dev/null && return 0
+	for i in $(uci -q get "dhcp.$cfg.server"); do
+		uci -q add_list dhcp."$cfg".doh_backup_server="$i"
+		if [ "$i" = "${i//127.0.0.1}" ] && [ "$i" = "$(echo "$i" | tr -d /)" ]; then
+			uci -q del_list dhcp."$cfg".server="$i"
+		fi
+	done
 }
 
 dnsmasq_restore_server_backup() {
-	local cfg="$1" i
+	local cfg="$1"
+	local i
 	if uci -q get "dhcp.$cfg.doh_backup_server" >/dev/null; then
 		uci -q del "dhcp.$cfg.server"
 		for i in $(uci -q get "dhcp.$cfg.doh_backup_server"); do
 			uci -q add_list dhcp."$cfg".server="$i"
 		done
+	uci -q del "dhcp.$cfg.doh_backup_server"
 	fi
 }
 
 dhcp_backup() {
+	local i
 	config_load 'dhcp'
 	case "$1" in
 		create)
-			config_foreach dnsmasq_create_server_backup 'dnsmasq';;
+			if [ "$dnsmasqConfig" = "*" ]; then
+				config_foreach dnsmasq_create_server_backup 'dnsmasq'
+			elif [ -n "$dnsmasqConfig" ]; then
+				for i in $dnsmasqConfig; do
+					dnsmasq_create_server_backup "@dnsmasq[${i}]"
+				done
+			fi
+			;;
 		restore)
-			config_foreach dnsmasq_restore_server_backup 'dnsmasq';;
+			config_foreach dnsmasq_restore_server_backup 'dnsmasq'
+			;;
 	esac
 }