Refactored DNS provider data structures

internal/constants/dns.go

@@ -1,6 +1,8 @@
 package constants
 
 import (
+	"net"
+
 	"github.com/qdm12/private-internet-access-docker/internal/models"
 )
 
@@ -21,28 +23,46 @@ const (
 	LibreDNS models.DNSProvider = "libredns"
 )
 
-const (
-	CloudflareAddress1    models.DNSForwardAddress = "1.1.1.1@853#cloudflare-dns.com"
-	CloudflareAddress2    models.DNSForwardAddress = "1.0.0.1@853#cloudflare-dns.com"
-	GoogleAddress1        models.DNSForwardAddress = "8.8.8.8@853#dns.google"
-	GoogleAddress2        models.DNSForwardAddress = "8.8.4.4@853#dns.google"
-	Quad9Address1         models.DNSForwardAddress = "9.9.9.9@853#dns.quad9.net"
-	Quad9Address2         models.DNSForwardAddress = "149.112.112.112@853#dns.quad9.net"
-	QuadrantAddress       models.DNSForwardAddress = "12.159.2.159@853#dns-tls.qis.io"
-	CleanBrowsingAddress1 models.DNSForwardAddress = "185.228.168.9@853#security-filter-dns.cleanbrowsing.org"
-	CleanBrowsingAddress2 models.DNSForwardAddress = "185.228.169.9@853#security-filter-dns.cleanbrowsing.org"
-	SecureDNSAddress      models.DNSForwardAddress = "146.185.167.43@853#dot.securedns.eu"
-	LibreDNSAddress       models.DNSForwardAddress = "116.203.115.192@853#dot.libredns.gr"
-)
-
-var DNSAddressesMapping = map[models.DNSProvider][]models.DNSForwardAddress{
-	Cloudflare:    []models.DNSForwardAddress{CloudflareAddress1, CloudflareAddress2},
-	Google:        []models.DNSForwardAddress{GoogleAddress1, GoogleAddress2},
-	Quad9:         []models.DNSForwardAddress{Quad9Address1, Quad9Address2},
-	Quadrant:      []models.DNSForwardAddress{QuadrantAddress},
-	CleanBrowsing: []models.DNSForwardAddress{CleanBrowsingAddress1, CleanBrowsingAddress2},
-	SecureDNS:     []models.DNSForwardAddress{SecureDNSAddress},
-	LibreDNS:      []models.DNSForwardAddress{LibreDNSAddress},
+// DNSProviderMapping returns a constant mapping of dns provider name
+// to their data such as IP addresses or TLS host name.
+func DNSProviderMapping() map[models.DNSProvider]models.DNSProviderData {
+	return map[models.DNSProvider]models.DNSProviderData{
+		Cloudflare: models.DNSProviderData{
+			IPs:         []net.IP{{1, 1, 1, 1}, {1, 0, 0, 1}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("cloudflare-dns.com"),
+		},
+		Google: models.DNSProviderData{
+			IPs:         []net.IP{{8, 8, 8, 8}, {8, 8, 4, 4}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("dns.google"),
+		},
+		Quad9: models.DNSProviderData{
+			IPs:         []net.IP{{9, 9, 9, 9}, {149, 112, 112, 112}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("dns.quad9.net"),
+		},
+		Quadrant: models.DNSProviderData{
+			IPs:         []net.IP{{12, 159, 2, 159}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("dns-tls.qis.io"),
+		},
+		CleanBrowsing: models.DNSProviderData{
+			IPs:         []net.IP{{185, 228, 168, 9}, {185, 228, 169, 9}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("security-filter-dns.cleanbrowsing.org"),
+		},
+		SecureDNS: models.DNSProviderData{
+			IPs:         []net.IP{{146, 185, 167, 43}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("dot.securedns.eu"),
+		},
+		LibreDNS: models.DNSProviderData{
+			IPs:         []net.IP{{116, 203, 115, 192}},
+			SupportsTLS: true,
+			Host:        models.DNSHost("dot.libredns.gr"),
+		},
+	}
 }
 
 // Block lists URLs

internal/dns/conf.go

@@ -108,12 +108,15 @@ func generateUnboundConf(settings settings.DNS, client network.Client, logger lo
 		return forwardZoneLines[i] < forwardZoneLines[j]
 	})
 	for _, provider := range settings.Providers {
-		forwardAddresses, ok := constants.DNSAddressesMapping[provider]
-		if !ok || len(forwardAddresses) == 0 {
-			return nil, warnings, fmt.Errorf("DNS provider %q does not have any matching forward addresses", provider)
+		providerData, ok := constants.DNSProviderMapping()[provider]
+		if !ok {
+			return nil, warnings, fmt.Errorf("DNS provider %q does not have associated data", provider)
+		} else if !providerData.SupportsTLS {
+			return nil, warnings, fmt.Errorf("DNS provider %q does not support DNS over TLS", provider)
 		}
-		for _, forwardAddress := range forwardAddresses {
-			forwardZoneLines = append(forwardZoneLines, fmt.Sprintf("  forward-addr: %s", forwardAddress))
+		for _, IP := range providerData.IPs {
+			forwardZoneLines = append(forwardZoneLines,
+				fmt.Sprintf("  forward-addr: %s@853#%s", IP.String(), providerData.Host))
 		}
 	}
 	lines = append(lines, forwardZoneLines...)

internal/models/alias.go

@@ -5,8 +5,8 @@ type (
 	VPNDevice string
 	// DNSProvider is a DNS over TLS server provider name
 	DNSProvider string
-	// DNSForwardAddress is the Unbound formatted forward address
-	DNSForwardAddress string
+	// DNSHost is the DNS host to use for TLS validation
+	DNSHost string
 	// PIAEncryption defines the level of encryption for communication with PIA servers
 	PIAEncryption string
 	// PIARegion contains the list of regions available for PIA

internal/models/dns.go

@@ -0,0 +1,10 @@
+package models
+
+import "net"
+
+// DNSProviderData contains information for a DNS provider
+type DNSProviderData struct {
+	IPs         []net.IP
+	SupportsTLS bool
+	Host        DNSHost
+}