1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
// SPDX-License-Identifier: MIT
// Copyright © 2018 WireGuard LLC. All Rights Reserved.
import Network
import Foundation
class DNSResolver {
static func isAllEndpointsAlreadyResolved(endpoints: [Endpoint?]) -> Bool {
for endpoint in endpoints {
guard let endpoint = endpoint else { continue }
if !endpoint.hasHostAsIPAddress() {
return false
}
}
return true
}
static func resolveSync(endpoints: [Endpoint?]) -> [Endpoint?]? {
let dispatchGroup = DispatchGroup()
if isAllEndpointsAlreadyResolved(endpoints: endpoints) {
return endpoints
}
var resolvedEndpoints: [Endpoint?] = Array(repeating: nil, count: endpoints.count)
for (index, endpoint) in endpoints.enumerated() {
guard let endpoint = endpoint else { continue }
if endpoint.hasHostAsIPAddress() {
resolvedEndpoints[index] = endpoint
} else {
let workItem = DispatchWorkItem {
resolvedEndpoints[index] = DNSResolver.resolveSync(endpoint: endpoint)
}
DispatchQueue.global(qos: .userInitiated).async(group: dispatchGroup, execute: workItem)
}
}
dispatchGroup.wait() // TODO: Timeout?
var hostnamesWithDnsResolutionFailure = [String]()
assert(endpoints.count == resolvedEndpoints.count)
for tuple in zip(endpoints, resolvedEndpoints) {
let endpoint = tuple.0
let resolvedEndpoint = tuple.1
if let endpoint = endpoint {
if resolvedEndpoint == nil {
// DNS resolution failed
guard let hostname = endpoint.hostname() else { fatalError() }
hostnamesWithDnsResolutionFailure.append(hostname)
}
}
}
if !hostnamesWithDnsResolutionFailure.isEmpty {
wg_log(.error, message: "DNS resolution failed for the following hostnames: \(hostnamesWithDnsResolutionFailure.joined(separator: ", "))")
return nil
}
return resolvedEndpoints
}
}
extension DNSResolver {
// Based on DNS resolution code by Jason Donenfeld <jason@zx2c4.com>
// in parse_endpoint() in src/tools/config.c in the WireGuard codebase
//swiftlint:disable:next cyclomatic_complexity
private static func resolveSync(endpoint: Endpoint) -> Endpoint? {
switch endpoint.host {
case .name(let name, _):
var resultPointer = UnsafeMutablePointer<addrinfo>(OpaquePointer(bitPattern: 0))
// The endpoint is a hostname and needs DNS resolution
if addressInfo(for: name, port: endpoint.port, resultPointer: &resultPointer) == 0 {
// getaddrinfo succeeded
let ipv4Buffer = UnsafeMutablePointer<Int8>.allocate(capacity: Int(INET_ADDRSTRLEN))
let ipv6Buffer = UnsafeMutablePointer<Int8>.allocate(capacity: Int(INET6_ADDRSTRLEN))
var ipv4AddressString: String?
var ipv6AddressString: String?
while resultPointer != nil {
let result = resultPointer!.pointee
resultPointer = result.ai_next
if result.ai_family == AF_INET && result.ai_addrlen == MemoryLayout<sockaddr_in>.size {
var sa4 = UnsafeRawPointer(result.ai_addr)!.assumingMemoryBound(to: sockaddr_in.self).pointee
if inet_ntop(result.ai_family, &sa4.sin_addr, ipv4Buffer, socklen_t(INET_ADDRSTRLEN)) != nil {
ipv4AddressString = String(cString: ipv4Buffer)
// If we found an IPv4 address, we can stop
break
}
} else if result.ai_family == AF_INET6 && result.ai_addrlen == MemoryLayout<sockaddr_in6>.size {
if ipv6AddressString != nil {
// If we already have an IPv6 address, we can skip this one
continue
}
var sa6 = UnsafeRawPointer(result.ai_addr)!.assumingMemoryBound(to: sockaddr_in6.self).pointee
if inet_ntop(result.ai_family, &sa6.sin6_addr, ipv6Buffer, socklen_t(INET6_ADDRSTRLEN)) != nil {
ipv6AddressString = String(cString: ipv6Buffer)
}
}
}
ipv4Buffer.deallocate()
ipv6Buffer.deallocate()
// We prefer an IPv4 address over an IPv6 address
if let ipv4AddressString = ipv4AddressString, let ipv4Address = IPv4Address(ipv4AddressString) {
return Endpoint(host: .ipv4(ipv4Address), port: endpoint.port)
} else if let ipv6AddressString = ipv6AddressString, let ipv6Address = IPv6Address(ipv6AddressString) {
return Endpoint(host: .ipv6(ipv6Address), port: endpoint.port)
} else {
return nil
}
} else {
// getaddrinfo failed
return nil
}
default:
// The endpoint is already resolved
return endpoint
}
}
private static func addressInfo(for name: String, port: NWEndpoint.Port, resultPointer: inout UnsafeMutablePointer<addrinfo>?) -> Int32 {
var hints = addrinfo(
ai_flags: 0,
ai_family: AF_UNSPEC,
ai_socktype: SOCK_DGRAM, // WireGuard is UDP-only
ai_protocol: IPPROTO_UDP, // WireGuard is UDP-only
ai_addrlen: 0,
ai_canonname: nil,
ai_addr: nil,
ai_next: nil)
return getaddrinfo(
name.cString(using: .utf8), // Hostname
"\(port)".cString(using: .utf8), // Port
&hints,
&resultPointer)
}
}
|
