[PATCH] Enable "split DNS" configurations for an interface
Stephen Larew
stephen at slarew.net
Thu Oct 28 07:16:38 UTC 2021
By adding a tilde prefix to a domain name entry in the DNS= line, the
domain is interpreted as a "matching domain" for DNS routing instead of
a "search domain." This corresponds to setting a non-empty
NEDNSSettings.matchDomains property for the network tunnel. Using tilde
as a prefix is borrowed from systemd-resolved's equivalent usage.
If one or more match domains are specified, then the specified DNS
resolvers are only used for those matching domains instead of acting as
the first resolver before the system's primary DNS resolvers.
Signed-off-by: Stephen Larew <stephen at slarew.net>
---
.../Shared/Model/TunnelConfiguration+WgQuickConfig.swift | 5 +++++
.../Tunnel/TunnelConfiguration+UapiConfig.swift | 1 +
Sources/WireGuardApp/UI/TunnelViewModel.swift | 7 ++++++-
Sources/WireGuardApp/UI/macOS/View/highlighter.c | 9 ++++++++-
Sources/WireGuardKit/InterfaceConfiguration.swift | 4 +++-
Sources/WireGuardKit/PacketTunnelSettingsGenerator.swift | 7 ++++++-
6 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/Sources/Shared/Model/TunnelConfiguration+WgQuickConfig.swift b/Sources/Shared/Model/TunnelConfiguration+WgQuickConfig.swift
index 5d5216c..87bc93f 100644
--- a/Sources/Shared/Model/TunnelConfiguration+WgQuickConfig.swift
+++ b/Sources/Shared/Model/TunnelConfiguration+WgQuickConfig.swift
@@ -136,6 +136,7 @@ extension TunnelConfiguration {
if !interface.dns.isEmpty || !interface.dnsSearch.isEmpty {
var dnsLine = interface.dns.map { $0.stringRepresentation }
dnsLine.append(contentsOf: interface.dnsSearch)
+ dnsLine.append(contentsOf: interface.dnsMatchDomains.map { "~" + $0 })
let dnsString = dnsLine.joined(separator: ", ")
output.append("DNS = \(dnsString)\n")
}
@@ -191,15 +192,19 @@ extension TunnelConfiguration {
if let dnsString = attributes["dns"] {
var dnsServers = [DNSServer]()
var dnsSearch = [String]()
+ var dnsMatchDomains = [String]()
for dnsServerString in dnsString.splitToArray(trimmingCharacters: .whitespacesAndNewlines) {
if let dnsServer = DNSServer(from: dnsServerString) {
dnsServers.append(dnsServer)
+ } else if dnsServerString.first == "~" && !dnsServerString.dropFirst().isEmpty {
+ dnsMatchDomains.append(String(dnsServerString.dropFirst()))
} else {
dnsSearch.append(dnsServerString)
}
}
interface.dns = dnsServers
interface.dnsSearch = dnsSearch
+ interface.dnsMatchDomains = dnsMatchDomains
}
if let mtuString = attributes["mtu"] {
guard let mtu = UInt16(mtuString) else {
diff --git a/Sources/WireGuardApp/Tunnel/TunnelConfiguration+UapiConfig.swift b/Sources/WireGuardApp/Tunnel/TunnelConfiguration+UapiConfig.swift
index cdc81ce..f2ff763 100644
--- a/Sources/WireGuardApp/Tunnel/TunnelConfiguration+UapiConfig.swift
+++ b/Sources/WireGuardApp/Tunnel/TunnelConfiguration+UapiConfig.swift
@@ -75,6 +75,7 @@ extension TunnelConfiguration {
interfaceConfiguration?.addresses = base?.interface.addresses ?? []
interfaceConfiguration?.dns = base?.interface.dns ?? []
interfaceConfiguration?.dnsSearch = base?.interface.dnsSearch ?? []
+ interfaceConfiguration?.dnsMatchDomains = base?.interface.dnsMatchDomains ?? []
interfaceConfiguration?.mtu = base?.interface.mtu
if let interfaceConfiguration = interfaceConfiguration {
diff --git a/Sources/WireGuardApp/UI/TunnelViewModel.swift b/Sources/WireGuardApp/UI/TunnelViewModel.swift
index b65c8cc..3b3fcda 100644
--- a/Sources/WireGuardApp/UI/TunnelViewModel.swift
+++ b/Sources/WireGuardApp/UI/TunnelViewModel.swift
@@ -139,9 +139,10 @@ class TunnelViewModel {
if let mtu = config.mtu {
scratchpad[.mtu] = String(mtu)
}
- if !config.dns.isEmpty || !config.dnsSearch.isEmpty {
+ if !config.dns.isEmpty || !config.dnsSearch.isEmpty || !config.dnsMatchDomains.isEmpty {
var dns = config.dns.map { $0.stringRepresentation }
dns.append(contentsOf: config.dnsSearch)
+ dns.append(contentsOf: config.dnsMatchDomains.map { "~" + $0 })
scratchpad[.dns] = dns.joined(separator: ", ")
}
return scratchpad
@@ -197,15 +198,19 @@ class TunnelViewModel {
if let dnsString = scratchpad[.dns] {
var dnsServers = [DNSServer]()
var dnsSearch = [String]()
+ var dnsMatchDomains = [String]()
for dnsServerString in dnsString.splitToArray(trimmingCharacters: .whitespacesAndNewlines) {
if let dnsServer = DNSServer(from: dnsServerString) {
dnsServers.append(dnsServer)
+ } else if dnsServerString.first == "~" && !dnsServerString.dropFirst().isEmpty {
+ dnsMatchDomains.append(String(dnsServerString.dropFirst()))
} else {
dnsSearch.append(dnsServerString)
}
}
config.dns = dnsServers
config.dnsSearch = dnsSearch
+ config.dnsMatchDomains = dnsMatchDomains
}
guard errorMessages.isEmpty else { return .error(errorMessages.first!) }
diff --git a/Sources/WireGuardApp/UI/macOS/View/highlighter.c b/Sources/WireGuardApp/UI/macOS/View/highlighter.c
index d89feda..e005377 100644
--- a/Sources/WireGuardApp/UI/macOS/View/highlighter.c
+++ b/Sources/WireGuardApp/UI/macOS/View/highlighter.c
@@ -121,6 +121,13 @@ static bool is_valid_hostname(string_span_t s)
return num_digit != num_entity;
}
+static bool is_valid_dns_match_hostname(string_span_t s)
+{
+ if (!s.len || s.s[0] != '~')
+ return false;
+ return is_valid_hostname((string_span_t){ s.s + 1, s.len - 1});
+}
+
static bool is_valid_ipv4(string_span_t s)
{
for (size_t j, i = 0, pos = 0; i < 4 && pos < s.len; ++i) {
@@ -448,7 +455,7 @@ static void highlight_multivalue_value(struct highlight_span_array *ret, const s
case DNS:
if (is_valid_ipv4(s) || is_valid_ipv6(s))
append_highlight_span(ret, parent.s, s, HighlightIP);
- else if (is_valid_hostname(s))
+ else if (is_valid_hostname(s) || is_valid_dns_match_hostname(s))
append_highlight_span(ret, parent.s, s, HighlightHost);
else
append_highlight_span(ret, parent.s, s, HighlightError);
diff --git a/Sources/WireGuardKit/InterfaceConfiguration.swift b/Sources/WireGuardKit/InterfaceConfiguration.swift
index 4fb8f1b..521d4b8 100644
--- a/Sources/WireGuardKit/InterfaceConfiguration.swift
+++ b/Sources/WireGuardKit/InterfaceConfiguration.swift
@@ -11,6 +11,7 @@ public struct InterfaceConfiguration {
public var mtu: UInt16?
public var dns = [DNSServer]()
public var dnsSearch = [String]()
+ public var dnsMatchDomains = [String]()
public init(privateKey: PrivateKey) {
self.privateKey = privateKey
@@ -27,6 +28,7 @@ extension InterfaceConfiguration: Equatable {
lhs.listenPort == rhs.listenPort &&
lhs.mtu == rhs.mtu &&
lhs.dns == rhs.dns &&
- lhs.dnsSearch == rhs.dnsSearch
+ lhs.dnsSearch == rhs.dnsSearch &&
+ lhs.dnsMatchDomains == rhs.dnsMatchDomains
}
}
diff --git a/Sources/WireGuardKit/PacketTunnelSettingsGenerator.swift b/Sources/WireGuardKit/PacketTunnelSettingsGenerator.swift
index c53a82c..dac7648 100644
--- a/Sources/WireGuardKit/PacketTunnelSettingsGenerator.swift
+++ b/Sources/WireGuardKit/PacketTunnelSettingsGenerator.swift
@@ -88,7 +88,12 @@ class PacketTunnelSettingsGenerator {
let dnsSettings = NEDNSSettings(servers: dnsServerStrings)
dnsSettings.searchDomains = tunnelConfiguration.interface.dnsSearch
if !tunnelConfiguration.interface.dns.isEmpty {
- dnsSettings.matchDomains = [""] // All DNS queries must first go through the tunnel's DNS
+ if tunnelConfiguration.interface.dnsMatchDomains.isEmpty {
+ // All DNS queries must first go through the tunnel's DNS
+ dnsSettings.matchDomains = [""]
+ } else {
+ dnsSettings.matchDomains = tunnelConfiguration.interface.dnsMatchDomains
+ }
}
networkSettings.dnsSettings = dnsSettings
}
--
2.30.1 (Apple Git-130)
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