From 8acfdbc07e82191871ec282d9633c1964c00f4e3 Mon Sep 17 00:00:00 2001
From: Jonni Liljamo <jonni@liljamo.com>
Date: Tue, 17 Oct 2023 00:17:42 +0300
Subject: [PATCH] feat: dns server to fetch a records from db

---
 internal/db/domains.go | 10 ++++++++++
 internal/dns/query.go  | 24 ++++++++++++++++--------
 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/internal/db/domains.go b/internal/db/domains.go
index cb62078..b03d168 100644
--- a/internal/db/domains.go
+++ b/internal/db/domains.go
@@ -70,3 +70,13 @@ func DeleteDomainsForUser(userId string) error {
 	}
 	return nil
 }
+
+func FetchDomainARecord(ddns_domain string) (string, error) {
+	var aRecord string
+	err := DBConn.QueryRow(`SELECT a_record FROM domains WHERE ddns_domain = $1`,
+		ddns_domain).Scan(&aRecord)
+	if err != nil {
+		return "", err
+	}
+	return aRecord, nil
+}
diff --git a/internal/dns/query.go b/internal/dns/query.go
index 3979390..0f4ddc8 100644
--- a/internal/dns/query.go
+++ b/internal/dns/query.go
@@ -8,7 +8,10 @@ package dns
 
 import (
 	"log"
+	"net"
+	"strings"
 
+	"git.src.quest/~skye/felu-ddns/internal/db"
 	"github.com/miekg/dns"
 )
 
@@ -24,12 +27,17 @@ func parseQuery(m *dns.Msg, r *dns.Msg) {
 func handleARecord(q *dns.Question, m *dns.Msg, r *dns.Msg) {
 	log.Printf("[felu/dns] Query for '%s'", q.Name)
 
-	// fetch from db here
-	// if found do this:
-	//m.Answer = append(m.Answer, &dns,A{
-  //	Hdr: dns.RR_Header{ Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60 },
-	//	A: net.ParseIP(THEIPGOTTENFROMDBLOLOLOLO)
-  //}
-	// else, do this:
-	m.SetRcode(r, dns.RcodeNameError)
+	if index := strings.IndexByte(q.Name, '.'); index >= 0 {
+		aRecord, err := db.FetchDomainARecord(q.Name[:index])
+		if err != nil {
+			m.SetRcode(r, dns.RcodeNameError)
+		} else {
+			m.Answer = append(m.Answer, &dns.A{
+				Hdr: dns.RR_Header{ Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60 },
+				A: net.ParseIP(aRecord),
+			})
+		}
+	} else {
+		m.SetRcode(r, dns.RcodeNameError)
+	}
 }
-- 
2.44.1