From 620b51e3ea1bfdd712f24873acf5cde57837b720 Mon Sep 17 00:00:00 2001
From: Eugene Burkov <e.burkov@adguard.com>
Date: Fri, 21 Apr 2023 18:57:53 +0300
Subject: [PATCH] Pull request 1840: 5752-unspec-ipv6

Merge in DNS/adguard-home from 5752-unspec-ipv6 to master

Closes #5752.

Squashed commit of the following:

commit 654b808d17c6d2374b6be919515113b361fc5ff7
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Apr 21 18:11:34 2023 +0300

    home: imp docs

commit 28b4c36df790f1eaa05b11a1f0a7b986894d37dc
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Apr 21 16:50:16 2023 +0300

    all: fix empty bind host
---
 CHANGELOG.md             |  6 ++++++
 docker/dns-bind.awk      |  2 +-
 internal/home/config.go  | 23 +++++++++++++++++++++++
 internal/home/upgrade.go |  3 ++-
 4 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51ac99b1..314a4646 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,11 @@ NOTE: Add new changes BELOW THIS COMMENT.
 
 ### Fixed
 
+- Unquoted IPv6 bind hosts with trailing colons erroneously considered
+  unspecified addresses are now properly validated ([#5752]).
+
+  **NOTE:** the Docker healthcheck script now also doesn't interpret the `""`
+  value as unspecified address.
 - Incorrect `Content-Type` header value in `POST /control/version.json` and `GET
   /control/dhcp/interfaces` HTTP APIs ([#5716]).
 - Provided bootstrap servers are now used to resolve the hostnames of plain
@@ -64,6 +69,7 @@ See also the [v0.107.29 GitHub milestone][ms-v0.107.29].
 [#5712]: https://github.com/AdguardTeam/AdGuardHome/issues/5712
 [#5721]: https://github.com/AdguardTeam/AdGuardHome/issues/5721
 [#5725]: https://github.com/AdguardTeam/AdGuardHome/issues/5725
+[#5752]: https://github.com/AdguardTeam/AdGuardHome/issues/5752
 
 [ms-v0.107.29]: https://github.com/AdguardTeam/AdGuardHome/milestone/65?closed=1
 
diff --git a/docker/dns-bind.awk b/docker/dns-bind.awk
index 778ebec0..abb5747c 100644
--- a/docker/dns-bind.awk
+++ b/docker/dns-bind.awk
@@ -7,7 +7,7 @@
         addrs[$2] = true
         prev_line = FNR
 
-        if ($2 == "0.0.0.0" || $2 == "\"\"" || $2 == "'::'") {
+        if ($2 == "0.0.0.0" || $2 == "'::'") {
             # Drop all the other addresses.
             delete addrs
             addrs[""] = true
diff --git a/internal/home/config.go b/internal/home/config.go
index c97e671c..bd3d7e49 100644
--- a/internal/home/config.go
+++ b/internal/home/config.go
@@ -414,6 +414,22 @@ func getLogSettings() logSettings {
 	return l
 }
 
+// validateBindHosts returns error if any of binding hosts from configuration is
+// not a valid IP address.
+func validateBindHosts(conf *configuration) (err error) {
+	if !conf.BindHost.IsValid() {
+		return errors.Error("bind_host is not a valid ip address")
+	}
+
+	for i, addr := range conf.DNS.BindHosts {
+		if !addr.IsValid() {
+			return fmt.Errorf("dns.bind_hosts at index %d is not a valid ip address", i)
+		}
+	}
+
+	return nil
+}
+
 // parseConfig loads configuration from the YAML file
 func parseConfig() (err error) {
 	var fileData []byte
@@ -425,6 +441,13 @@ func parseConfig() (err error) {
 	config.fileData = nil
 	err = yaml.Unmarshal(fileData, &config)
 	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	err = validateBindHosts(config)
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
 		return err
 	}
 
diff --git a/internal/home/upgrade.go b/internal/home/upgrade.go
index a97386a7..81168561 100644
--- a/internal/home/upgrade.go
+++ b/internal/home/upgrade.go
@@ -41,7 +41,8 @@ func upgradeConfig() error {
 
 	err = yaml.Unmarshal(body, &diskConf)
 	if err != nil {
-		log.Printf("Couldn't parse config file: %s", err)
+		log.Printf("parsing config file for upgrade: %s", err)
+
 		return err
 	}