main/pmos-base-ui: use dnsane for DNS

Fixes #1430 by basically filtering DNS queries to remove any with addresses
that might cause traffic to go over a lower priority interface. See that issue
for a more detailed explanation of the problem.

It does this by:
        1) configuring NetworkManager to send DNS config to resolvconf, instead
           of writing to resolv.conf directly. In my (limited) testing, this
           seems to be necessary to get NM to trigger resolvconf which is
           needed for...
        2) configuring resolvconf to ignore any DNS it receives and use
           localhost, when writing resolv.conf

openresolv is used because the alternative of modifying resolv.conf
manually gets messy, specifically with apk where it may not replace
/etc/resolv.conf if the user / something else has modified it...

Note that there's still some possibilities for apps that have hardcoded DNS
nameservers to bypass dnsane. It's not trivial to catch this. The most straight
forward way is to use a firewall rule to redirect all outbound DNS to dnsane.
But this would break mmsd and any other apps that actually need to query
specific nameservers to function properly.

I used a SIM that had a mobile data connection, but traffic was dropped by the
carrier outside of the phone. In other words, my phone was often in the exact
situation described in #1430. When connected to wifi, I could very easily
notice when traffic was being routed incorrectly because anything destined for
mobile data would fail (pages stopped loading, etc). After some amount of
casual testing while using the phone "normally", I haven't noticed any failures
yet from that problem.

main/postmarketos-base-ui/APKBUILD

@@ -1,7 +1,7 @@
 # Maintainer: Clayton Craft <clayton@craftyguy.net>
 pkgname=postmarketos-base-ui
-pkgver=6
-pkgrel=2
+pkgver=7
+pkgrel=0
 pkgdesc="Meta package for minimal postmarketOS UI base"
 url="https://postmarketos.org"
 arch="noarch"
@@ -37,11 +37,13 @@ replaces_priority=100  # leave plenty for alpine
 
 _source644="
 	etc/NetworkManager/conf.d/hostname-mode.conf
+	etc/NetworkManager/conf.d/00-resolvconf.conf
 	etc/chrony/chrony.conf
 	etc/conf.d/tinydm
 	etc/conf.d/wpa_supplicant
 	etc/elogind/logind.conf
 	etc/pulse/default.pa.d/postmarketos.pa
+	etc/resolvconf.conf
 	etc/skel/.profile
 	etc/sleep-inhibitor.conf
 	etc/X11/Xwrapper.config
@@ -119,22 +121,31 @@ _obexd() {
 
 networkmanager() {
 	depends="
+		dnsane
+		openresolv
 		networkmanager
 		networkmanager-cli
 		networkmanager-openrc
 		networkmanager-tui
 		networkmanager-wifi
 		networkmanager-wwan"
+	replaces="openresolv"
+	install="$subpkgname.post-install $subpkgname.post-upgrade"
+
 	amove etc/NetworkManager/conf.d/hostname-mode.conf
+	amove etc/NetworkManager/conf.d/00-resolvconf.conf
+	amove etc/resolvconf.conf
 }
 
 sha512sums="
 3c9ae7415f4891bee8595166ed6a42cb577a837f741c6b5409d193558626348b41516888a01d0c4895282c5f4e9a1ff838c19712888750b2ef68429bb4b42ee3  rootfs-etc-NetworkManager-conf.d-hostname-mode.conf
+c5ecb3583f60938ccbf896458d9abe98439b80b0876c84b77bbb6454af83909d398c0d7b23c077fbeaf6298ef5aa8f48bfdbbe63052af106097e33e495576575  rootfs-etc-NetworkManager-conf.d-00-resolvconf.conf
 e5d049db1d82c510bab9246208b51b8ec2711d008d67792fc10d4c0b65ed4dece7b5ae3c3dd28a8539d177b6849c1f921cb9fef3d2c7bee0355451f7b4757ec6  rootfs-etc-chrony-chrony.conf
 44e4283c6f77de83915977dd3bc2d8e2d96b3ed6cc68d3cc156304359ae649b5a8b0bac843e517ec6faa2066dd43ba85e313899b1eda04862f864fb9eb508aa0  rootfs-etc-conf.d-tinydm
 fe0651904c1f40ffa67d83daca190af199f63247e53642a59a1e1147cd06776fcf20b7b2fcc5373783d50b8bd6ce8d1354c8e5f4d582d319727b9ceefd1e8e16  rootfs-etc-conf.d-wpa_supplicant
 8d2c54fe3ca62c62f8337fb6be28479d0e02ea63f32abae81907f2768631e65c9e17485f8bc0854a013377f729b06dd1873e2b75f86f657ece866d00aecbbdb4  rootfs-etc-elogind-logind.conf
 6c516635a61fbaa93102f02301a75070a91de837456b07a50e24a9e0ee5dac785087d4a8f78906807719ebf6f0124127383441cccf00475d9a91d3dbaf9d4d81  rootfs-etc-pulse-default.pa.d-postmarketos.pa
+0b0bd22b209b580c9dd178c68f328839ad5685c64c31c1dedde48c61c0e6ee4f873972bbe1ffa7965fad26a23ee8ed5c1a50405e35faadf0cd02a919122480d4  rootfs-etc-resolvconf.conf
 90b30cbea660ef6cd4c0461b6935de0cd63a84a1a40edb24348a83044c97935b974bd8bafda9cd558e92d3eb69e22c5ccf55483b80f839e24f0eb57ae2df6fe3  rootfs-etc-skel-.profile
 6b9c7bb73213187eb9ca8a94109b2b816f50c1158c90fec2e92b373864280d67741589e5bfbab8810945f031d2f4b535aad78a72e46e52ea50be5b85324da381  rootfs-etc-sleep-inhibitor.conf
 cac604e25c46e695dd30bd5a10cfd2d69595fcc3bc290096ac94b76b10834d591ea6576afb79c46b5da492a1dbf8660cf87b6110cd39937e15237bc74fa7a5c6  rootfs-etc-X11-Xwrapper.config

main/postmarketos-base-ui/postmarketos-base-ui-networkmanager.post-install

@@ -0,0 +1,3 @@
+#!/bin/sh -e
+
+rc-update -q add dnsane default

main/postmarketos-base-ui/postmarketos-base-ui-networkmanager.post-upgrade

@@ -0,0 +1 @@
+postmarketos-base-ui-networkmanager.post-install

main/postmarketos-base-ui/rootfs-etc-NetworkManager-conf.d-00-resolvconf.conf

@@ -0,0 +1,2 @@
+[main]
+rc-manager=resolvconf

main/postmarketos-base-ui/rootfs-etc-resolvconf.conf

@@ -0,0 +1,5 @@
+# NOTE: Config provided by postmarketos-base-ui
+
+name_servers=127.0.0.1
+resolv_conf=/etc/resolv.conf
+resolv_conf_local_only=YES