Make it protocol aware

dns/example_usage.go

@@ -0,0 +1,53 @@
+package dns
+
+// Example usage of DNS record management (not compiled, just for reference)
+/*
+
+import (
+	"net"
+	"github.com/fosrl/olm/dns"
+)
+
+func exampleUsage() {
+	// Assuming you have a DNSProxy instance
+	var proxy *dns.DNSProxy
+
+	// Add an A record for example.com pointing to 192.168.1.100
+	ip := net.ParseIP("192.168.1.100")
+	err := proxy.AddDNSRecord("example.com", ip)
+	if err != nil {
+		// Handle error
+	}
+
+	// Add multiple A records for the same domain (round-robin)
+	proxy.AddDNSRecord("example.com", net.ParseIP("192.168.1.101"))
+	proxy.AddDNSRecord("example.com", net.ParseIP("192.168.1.102"))
+
+	// Add an AAAA record (IPv6)
+	ipv6 := net.ParseIP("2001:db8::1")
+	proxy.AddDNSRecord("example.com", ipv6)
+
+	// Query records
+	aRecords := proxy.GetDNSRecords("example.com", dns.RecordTypeA)
+	// Returns: [192.168.1.100, 192.168.1.101, 192.168.1.102]
+
+	aaaaRecords := proxy.GetDNSRecords("example.com", dns.RecordTypeAAAA)
+	// Returns: [2001:db8::1]
+
+	// Remove a specific record
+	proxy.RemoveDNSRecord("example.com", net.ParseIP("192.168.1.101"))
+
+	// Remove all records for a domain
+	proxy.RemoveDNSRecord("example.com", nil)
+
+	// Clear all DNS records
+	proxy.ClearDNSRecords()
+}
+
+// How it works:
+// 1. When a DNS query arrives, the proxy first checks its local record store
+// 2. If a matching A or AAAA record exists locally, it returns that immediately
+// 3. If no local record exists, it forwards the query to upstream DNS (8.8.8.8 or 8.8.4.4)
+// 4. All other DNS record types (MX, CNAME, TXT, etc.) are always forwarded upstream
+
+*/