From b3085eed7814aac702383e56a01323d23ff5734d Mon Sep 17 00:00:00 2001
From: Philippe Pittoli <karchnu@karchnu.fr>
Date: Tue, 29 Jul 2025 12:12:16 +0200
Subject: [PATCH] Delegation (WIP).

---
 src/storage.cr      | 27 +++++----------------------
 src/storage/zone.cr | 12 ++++++++++++
 src/util.cr         | 14 ++++++++++++++
 3 files changed, 31 insertions(+), 22 deletions(-)
 create mode 100644 src/util.cr

diff --git a/src/storage.cr b/src/storage.cr
index 425cd97..493a597 100644
--- a/src/storage.cr
+++ b/src/storage.cr
@@ -4,17 +4,9 @@ require "uuid/json"
 require "baguette-crystal-base"
 require "./service.cr"
 
+require "./util.cr"
 require "dodb"
 
-def safe_write(filename : String, &block)
-	filename_wip = "#{filename}.wip"
-	File.open(filename_wip, "w") do |file|
-		yield file
-	end
-	# Rename WIP filename to final file name.
-	File.rename filename_wip, filename
-end
-
 class DNSManager::Storage
 	getter domains                 : DODB::Storage::Common(Domain)
 	getter domains_by_name         : DODB::Trigger::IndexCached(Domain)
@@ -461,22 +453,13 @@ class DNSManager::Storage
 		return Response::InvalidDomainName.new unless Zone.is_domain_valid? nameserver1
 		return Response::InvalidDomainName.new unless Zone.is_domain_valid? nameserver2
 
-		# Wipes the domain from dnsmanager (generated zone file, tokens).
-		wipe_domain user_id, domain_name
-
-		remove_bind9_zonefile domain_name
+		# Wipes the zone from dnsmanager (zone db entry, generated zone file, tokens).
+		wipe_zone user_id, domain_name
 
 		# Creates the new zone.
 		zone = Zone.new domain_name
 		zone.delegation = Zone::Delegation.new nameserver1, nameserver2
-
-		filename = "#{@delegationdir}/#{domain_name}"
-		Baguette::Log.info "New delegation file: #{filename}"
-		safe_write filename do |file|
-			zone.to_delegation file
-		rescue e : NoDelegation
-			Baguette::Log.error "domain #{domain_name}: trying to delegate but doesn't have delegation parameters"
-		end
+		zone.update_delegation @delegationdir
 
 		# Once the new delegation file has been written, the script generating the (root) zone file must
 		# be informed by touching a file (named "delegation token file" in the source code).
@@ -561,7 +544,7 @@ class DNSManager::Storage
 		zone
 	end
 
-	# WARNING: this function removes a domain with all its related data (zone file, delegation file, indexes, etc.).
+	# WARNING: this function removes a zone with all its related data (zone file, delegation file, indexes, etc.).
 	#
 	# RATIONALE: wipe_zone can be used to renew to remove zone-related content (the entry in the zone db, tokens
 	#            and generated zone file) while preserving the entry in the domain db.
diff --git a/src/storage/zone.cr b/src/storage/zone.cr
index fa7f8dd..bc7a927 100644
--- a/src/storage/zone.cr
+++ b/src/storage/zone.cr
@@ -1,4 +1,5 @@
 require "ipaddress"
+require "../util.cr"
 
 # Domains cannot be parsed using regexes.
 # Yet, that will be good enough for now.
@@ -55,6 +56,17 @@ class DNSManager::Storage::Zone
 		def_clone
 	end
 
+	# Update the delegation file.
+	def update_delegation(delegation_directory : String)
+		filename = "#{delegation_directory}/#{@domain}"
+		Baguette::Log.info "New delegation file: #{filename}"
+		safe_write filename do |file|
+			to_delegation file
+		rescue e : NoDelegation
+			Baguette::Log.error "domain #{domain}: trying to delegate but doesn't have delegation parameters"
+		end
+	end
+
 	def to_delegation(io : IO)
 		if delegation = @delegation
 			io << "#{@domain}. 1800 IN NS #{delegation.nameserver1}\n"
diff --git a/src/util.cr b/src/util.cr
new file mode 100644
index 0000000..6d7f78c
--- /dev/null
+++ b/src/util.cr
@@ -0,0 +1,14 @@
+# Writes to a file "safely": a temporary file is generated then the file is moved.
+#
+# RATIONALE: several problems can occur while writing in a file.
+#            Using a temporary file prevents database corruption if a writting error occurs.
+#            Also, moving the temporary file to its final path enables to only read fully-written files
+#            (once the file is opened the content won't change).
+def safe_write(filename : String, &block)
+	filename_wip = "#{filename}.wip"
+	File.open(filename_wip, "w") do |file|
+		yield file
+	end
+	# Rename WIP filename to final file name.
+	File.rename filename_wip, filename
+end