From 6346bad069be47f1d25c04af74ce0cd3b2c3457d Mon Sep 17 00:00:00 2001
From: Jeroen Leenarts <jeroen.leenarts@gmail.com>
Date: Wed, 3 Oct 2018 21:34:51 +0200
Subject: [PATCH] Better handling of CIDR values.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 Shared/Validators.swift                       | 43 ++++++++++++++-----
 ...nnelConfigurationTableViewController.swift |  8 ++++
 2 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/Shared/Validators.swift b/Shared/Validators.swift
index a73f329..cf20326 100644
--- a/Shared/Validators.swift
+++ b/Shared/Validators.swift
@@ -122,25 +122,42 @@ struct CIDRAddress {
     var addressType: AddressType
 
     init?(stringRepresentation: String) throws {
-        guard let range = stringRepresentation.range(of: "/", options: .backwards, range: nil, locale: nil) else {
-            throw CIDRAddressValidationError.noIpAndSubnet(stringRepresentation)
+        let subnetString: String.SubSequence
+        if let range = stringRepresentation.range(of: "/", options: .backwards, range: nil, locale: nil) {
+            let ipString = stringRepresentation[..<range.lowerBound].replacingOccurrences(of: "[", with: "").replacingOccurrences(of: "]", with: "")
+            ipAddress = String(ipString)
+            subnetString = stringRepresentation[range.upperBound...]
+        } else {
+            let ipString = stringRepresentation
+            ipAddress = String(ipString)
+            subnetString = ""
         }
 
-        let ipString = stringRepresentation[..<range.lowerBound].replacingOccurrences(of: "[", with: "").replacingOccurrences(of: "]", with: "")
-        let subnetString = stringRepresentation[range.upperBound...]
-
-        guard let subnet = Int32(subnetString) else {
-            throw CIDRAddressValidationError.invalidSubnet(String(subnetString))
-        }
-
-        ipAddress = String(ipString)
         let addressType = validateIpAddress(ipToValidate: ipAddress)
         guard addressType == .IPv4 || addressType == .IPv6 else {
             throw CIDRAddressValidationError.invalidIP(ipAddress)
         }
         self.addressType = addressType
 
-        self.subnet = subnet
+        if let subnet = Int32(subnetString) {
+            switch addressType {
+            case .IPv6:
+                self.subnet = subnet > 128 ? 128 : subnet
+            case .IPv4:
+                self.subnet = subnet > 32 ? 32 : subnet
+            case .other:
+                self.subnet = subnet
+            }
+        } else {
+            switch addressType {
+            case .IPv4:
+                subnet = 32
+            case .IPv6:
+                subnet = 128
+            case .other:
+                throw CIDRAddressValidationError.invalidSubnet(String(subnetString))
+            }
+        }
     }
 
     var subnetString: String {
@@ -156,4 +173,8 @@ struct CIDRAddress {
 
         return "\(first).\(second).\(third).\(fourth)"
     }
+
+    var stringRepresentation: String {
+        return "\(ipAddress)/\(subnet)"
+    }
 }
diff --git a/WireGuard/ViewControllers/TunnelConfigurationTableViewController.swift b/WireGuard/ViewControllers/TunnelConfigurationTableViewController.swift
index 0d2fe2f..65679c7 100644
--- a/WireGuard/ViewControllers/TunnelConfigurationTableViewController.swift
+++ b/WireGuard/ViewControllers/TunnelConfigurationTableViewController.swift
@@ -224,6 +224,14 @@ extension InterfaceTableViewCell: UITextFieldDelegate {
             }
         }
     }
+
+    func textFieldDidEndEditing(_ textField: UITextField) {
+        if textField == addressesField {
+            if let addresses = model.addresses?.commaSeparatedToArray() {
+                textField.text = addresses.compactMap { try? CIDRAddress(stringRepresentation: $0 ) }.compactMap { $0?.stringRepresentation }.joined(separator: ", ")
+            }
+        }
+    }
 }
 
 protocol PeerTableViewCellDelegate: class {