feature: Caddy serves static web sites from folders on the router, defined in their own database, with files uploaded through the web service or WebDAV, and an optional PowerDNS name server answers for a zone of the sites.

debian-package/src/usr/share/vpn-router/sql/dns.sql

@@ -0,0 +1,87 @@
+-- The zone the router's name server (PowerDNS, gpgsql backend) answers for (vpnrouter_dns), in the vpn-router-dns
+-- database, whose domains and records tables are PowerDNS's own schema.
+-- The whole file runs as one transaction, serialized by an advisory lock, so that two processes can load it at once.
+
+SELECT pg_advisory_xact_lock(hashtext('vpn-router dns schema'));
+
+-- A record an administrator added to the zone, besides those of the zone itself and of the sites.
+CREATE TABLE IF NOT EXISTS dns_manual_records (
+    name text NOT NULL,
+    type text NOT NULL,
+    content text NOT NULL,
+    ttl integer NOT NULL,
+    PRIMARY KEY (name, type, content)
+);
+
+-- The digest of the records last written to the zone and the serial of its SOA.
+CREATE TABLE IF NOT EXISTS dns_state (
+    zone text PRIMARY KEY,
+    digest text NOT NULL,
+    serial bigint NOT NULL
+);
+
+CREATE OR REPLACE FUNCTION dns_manual_list()
+RETURNS TABLE (name text, type text, content text, ttl integer)
+LANGUAGE sql STABLE AS $$
+    SELECT name, type, content, ttl FROM dns_manual_records ORDER BY name, type, content;
+$$;
+
+-- Add the record, or set its TTL.
+CREATE OR REPLACE PROCEDURE dns_manual_put(p_name text, p_type text, p_content text, p_ttl integer)
+LANGUAGE sql AS $$
+    INSERT INTO dns_manual_records VALUES (p_name, p_type, p_content, p_ttl)
+    ON CONFLICT (name, type, content) DO UPDATE SET ttl = p_ttl;
+$$;
+
+-- Remove the records of the name and type, all of them without content.
+CREATE OR REPLACE PROCEDURE dns_manual_remove(p_name text, p_type text, p_content text)
+LANGUAGE sql AS $$
+    DELETE FROM dns_manual_records WHERE name = p_name AND type = p_type AND (p_content IS NULL OR content = p_content);
+$$;
+
+-- Make the zone the only one served and give it the records, its SOA first, whose content has {serial} for the serial.
+-- The serial grows, to at least the current Unix time, only when the records differ from those last written.
+CREATE OR REPLACE PROCEDURE dns_apply(p_zone text, p_soa text, p_ttl integer, p_names text[], p_types text[],
+                                      p_contents text[], p_ttls integer[])
+LANGUAGE plpgsql AS $$
+DECLARE
+    v_domain integer;
+    v_serial bigint;
+    v_digest text := md5(concat_ws('|', p_soa, p_ttl, array_to_string(p_names, ','), array_to_string(p_types, ','),
+                                   array_to_string(p_contents, ','), array_to_string(p_ttls, ',')));
+BEGIN
+    DELETE FROM domains WHERE name <> p_zone;
+    DELETE FROM dns_state WHERE zone <> p_zone;
+    SELECT id INTO v_domain FROM domains WHERE name = p_zone;
+    IF v_domain IS NULL THEN
+        INSERT INTO domains (name, type) VALUES (p_zone, 'NATIVE') RETURNING id INTO v_domain;
+    ELSIF EXISTS (SELECT 1 FROM dns_state WHERE zone = p_zone AND digest = v_digest) THEN
+        RETURN;
+    END IF;
+    SELECT greatest(coalesce(max(serial) + 1, 1), extract(epoch FROM now())::bigint) INTO v_serial
+    FROM dns_state WHERE zone = p_zone;
+    DELETE FROM records WHERE domain_id = v_domain;
+    INSERT INTO records (domain_id, name, type, content, ttl, prio, disabled, auth)
+    VALUES (v_domain, p_zone, 'SOA', replace(p_soa, '{serial}', v_serial::text), p_ttl, 0, false, true);
+    INSERT INTO records (domain_id, name, type, content, ttl, prio, disabled, auth)
+    SELECT v_domain, r.name, r.type, r.content, r.ttl, 0, false, true
+    FROM unnest(p_names, p_types, p_contents, p_ttls) AS r(name, type, content, ttl);
+    INSERT INTO dns_state VALUES (p_zone, v_digest, v_serial)
+    ON CONFLICT (zone) DO UPDATE SET digest = v_digest, serial = v_serial;
+END;
+$$;
+
+-- Serve no zone.
+CREATE OR REPLACE PROCEDURE dns_clear()
+LANGUAGE sql AS $$
+    DELETE FROM domains;
+    DELETE FROM dns_state;
+$$;
+
+-- The records of the zone as they are served.
+CREATE OR REPLACE FUNCTION dns_served(p_zone text)
+RETURNS TABLE (name text, type text, content text, ttl integer)
+LANGUAGE sql STABLE AS $$
+    SELECT r.name, r.type, r.content, r.ttl FROM records r JOIN domains d ON d.id = r.domain_id
+    WHERE d.name = p_zone ORDER BY r.type <> 'SOA', r.name, r.type, r.content;
+$$;