VPN: Bring up the tunnel

The app figures out all settings and passes them in the
'options' parameter of startTunnel().

The network extension just takes them as is and just plugs the supplied
values into the right places.

Signed-off-by: Roopesh Chander <roop@roopc.net>
This commit is contained in:
Roopesh Chander
2018-10-27 19:07:16 +05:30
parent a08e08fe2e
commit 793bf63989
5 changed files with 306 additions and 71 deletions
@@ -0,0 +1,180 @@
// SPDX-License-Identifier: MIT
// Copyright © 2018 WireGuard LLC. All rights reserved.
import Foundation
import Network
class PacketTunnelOptionsGenerator {
static func generateOptions(from tc: TunnelConfiguration,
withResolvedEndpoints resolvedEndpoints: [Endpoint?]) -> [String:NSObject] {
var options: [String:NSObject] = [:]
// Interface name
options[.interfaceName] = tc.interface.name as NSObject
// WireGuard settings
var wgSettings = ""
let privateKey = tc.interface.privateKey.hexEncodedString()
wgSettings.append("private_key=\(privateKey)\n")
if let listenPort = tc.interface.listenPort {
wgSettings.append("listen_port=\(listenPort)\n")
}
if (tc.peers.count > 0) {
wgSettings.append("replace_peers=true\n")
}
assert(tc.peers.count == resolvedEndpoints.count)
for (i, peer) in tc.peers.enumerated() {
wgSettings.append("public_key=\(peer.publicKey.hexEncodedString())\n")
if let preSharedKey = peer.preSharedKey {
wgSettings.append("preshared_key=\(preSharedKey.hexEncodedString())\n")
}
if let endpoint = resolvedEndpoints[i] {
if case .name(_, _) = endpoint.host { assert(false, "Endpoint is not resolved") }
wgSettings.append("endpoint=\(endpoint.stringRepresentation())\n")
}
let persistentKeepAlive = peer.persistentKeepAlive ?? 0
wgSettings.append("persistent_keepalive_interval=\(persistentKeepAlive)\n")
if (!peer.allowedIPs.isEmpty) {
wgSettings.append("replace_allowed_ips=true\n")
for ip in peer.allowedIPs {
wgSettings.append("allowed_ip=\(ip.stringRepresentation())\n")
}
}
}
options[.wireguardSettings] = wgSettings as NSObject
// Remote address
let remoteAddress: String
if let firstEndpoint = resolvedEndpoints.compactMap({ $0 }).first {
switch (firstEndpoint.host) {
case .ipv4(let address):
remoteAddress = "\(address)"
case .ipv6(let address):
remoteAddress = "\(address)"
default:
fatalError("Endpoint must be resolved")
}
} else {
// We don't have any peer with an endpoint
remoteAddress = ""
}
options[.remoteAddress] = remoteAddress as NSObject
// DNS
options[.dnsServers] = tc.interface.dns.map { $0.stringRepresentation() } as NSObject
// MTU
options[.mtu] = NSNumber(value: tc.interface.mtu ?? 0) // 0 implies auto-MTU
// Addresses from interface addresses
var ipv4Addresses: [String] = []
var ipv4SubnetMasks: [String] = []
var ipv6Addresses: [String] = []
var ipv6NetworkPrefixLengths: [NSNumber] = []
for addressRange in tc.interface.addresses {
if (addressRange.address is IPv4Address) {
ipv4Addresses.append("\(addressRange.address)")
ipv4SubnetMasks.append(ipv4SubnetMaskString(of: addressRange))
} else if (addressRange.address is IPv6Address) {
ipv6Addresses.append("\(addressRange.address)")
ipv6NetworkPrefixLengths.append(NSNumber(value: addressRange.networkPrefixLength))
}
}
options[.ipv4Addresses] = ipv4Addresses as NSObject
options[.ipv4SubnetMasks] = ipv4SubnetMasks as NSObject
options[.ipv6Addresses] = ipv6Addresses as NSObject
options[.ipv6NetworkPrefixLengths] = ipv6NetworkPrefixLengths as NSObject
// Included routes from AllowedIPs
var ipv4IncludedRouteAddresses: [String] = []
var ipv4IncludedRouteSubnetMasks: [String] = []
var ipv6IncludedRouteAddresses: [String] = []
var ipv6IncludedRouteNetworkPrefixLengths: [NSNumber] = []
for peer in tc.peers {
for addressRange in peer.allowedIPs {
if (addressRange.address is IPv4Address) {
ipv4IncludedRouteAddresses.append("\(addressRange.address)")
ipv4IncludedRouteSubnetMasks.append(ipv4SubnetMaskString(of: addressRange))
} else if (addressRange.address is IPv6Address) {
ipv6IncludedRouteAddresses.append("\(addressRange.address)")
ipv6IncludedRouteNetworkPrefixLengths.append(NSNumber(value: addressRange.networkPrefixLength))
}
}
}
options[.ipv4IncludedRouteAddresses] = ipv4IncludedRouteAddresses as NSObject
options[.ipv4IncludedRouteSubnetMasks] = ipv4IncludedRouteSubnetMasks as NSObject
options[.ipv6IncludedRouteAddresses] = ipv6IncludedRouteAddresses as NSObject
options[.ipv6IncludedRouteNetworkPrefixLengths] = ipv6IncludedRouteNetworkPrefixLengths as NSObject
// Excluded routes from endpoints
var ipv4ExcludedRouteAddresses: [String] = []
var ipv4ExcludedRouteSubnetMasks: [String] = []
var ipv6ExcludedRouteAddresses: [String] = []
var ipv6ExcludedRouteNetworkPrefixLengths: [NSNumber] = []
for endpoint in resolvedEndpoints {
guard let endpoint = endpoint else { continue }
switch (endpoint.host) {
case .ipv4(let address):
ipv4ExcludedRouteAddresses.append("\(address)")
ipv4ExcludedRouteSubnetMasks.append("255.255.255.255") // A single IPv4 address
case .ipv6(let address):
ipv6ExcludedRouteAddresses.append("\(address)")
ipv6ExcludedRouteNetworkPrefixLengths.append(NSNumber(value: UInt8(128))) // A single IPv6 address
default:
fatalError()
}
}
options[.ipv4ExcludedRouteAddresses] = ipv4ExcludedRouteAddresses as NSObject
options[.ipv4ExcludedRouteSubnetMasks] = ipv4ExcludedRouteSubnetMasks as NSObject
options[.ipv6ExcludedRouteAddresses] = ipv6ExcludedRouteAddresses as NSObject
options[.ipv6ExcludedRouteNetworkPrefixLengths] = ipv6ExcludedRouteNetworkPrefixLengths as NSObject
return options
}
static func ipv4SubnetMaskString(of addressRange: IPAddressRange) -> String {
var n: UInt8 = addressRange.networkPrefixLength
assert(n <= 32)
var components: [UInt8] = []
while (n >= 8) {
components.append(255)
n = n - 8
}
if (n > 0) {
components.append(((1 << n) - 1) << (8 - n))
}
while (components.count < 4) {
components.append(0)
}
assert(components.count == 4)
return components.map { String($0) }.joined(separator: ".")
}
}
private extension Data {
func hexEncodedString() -> String {
return self.map { String(format: "%02x", $0) }.joined()
}
}
+3 -1
View File
@@ -277,7 +277,9 @@ class TunnelContainer: NSObject {
s.startObservingTunnelStatus()
let session = (s.tunnelProvider.connection as! NETunnelProviderSession)
do {
try session.startTunnel(options: [:]) // TODO: Provide options
let tunnelOptions = PacketTunnelOptionsGenerator.generateOptions(
from: tunnelConfiguration, withResolvedEndpoints: endpoints)
try session.startTunnel(options: tunnelOptions)
} catch (let error) {
os_log("Failed to activate tunnel: %{public}@", log: OSLog.default, type: .debug, "\(error)")
s.onActive = nil