[SDK-2470] Created branchVPNBlockingError method

Sources/BranchSDK/BNCServerInterface.m

@@ -124,6 +124,8 @@ - (void)genericHTTPRequest:(NSURLRequest *)request retryNumber:(NSInteger)retryN
                 if (status != 200) {
                     if ([NSError branchDNSBlockingError:underlyingError]) {
                         [[BranchLogger shared] logWarning:[NSString stringWithFormat:@"Possible DNS Ad Blocker. Giving up on request with HTTP status code %ld", (long)status] error:underlyingError];
+                    } else if ([NSError branchVPNBlockingError:underlyingError]) {
+                        [[BranchLogger shared] logWarning:[NSString stringWithFormat:@"Possible VPN Ad Blocker. Giving up on request with HTTP status code %ld", (long)status] error:underlyingError];
                     } else {
                         [[BranchLogger shared] logWarning: [NSString stringWithFormat:@"Giving up on request with HTTP status code %ld", (long)status] error:underlyingError];
                     }

Sources/BranchSDK/BNCURLFilter.m

@@ -133,6 +133,8 @@ - (BOOL)foundUpdatedURLList:(id<BNCNetworkOperationProtocol>)operation {
     } else if (statusCode != 200 || error != nil || jsonString == nil) {
         if ([NSError branchDNSBlockingError:error]) {
             [[BranchLogger shared] logWarning:@"Possible DNS Ad Blocker" error:error];
+        } else if ([NSError branchVPNBlockingError:error]) {
+            [[BranchLogger shared] logWarning:@"Possible VPN Ad Blocker" error:error];
         } else {
             [[BranchLogger shared] logWarning:@"Failed to update URL ignore list" error:operation.error];
         }

Sources/BranchSDK/BranchQRCode.m

@@ -145,6 +145,8 @@ - (void)callQRCodeAPI:(nullable NSDictionary *)params
         if (error) {
             if ([NSError branchDNSBlockingError:error]) {
                 [[BranchLogger shared] logWarning:@"Possible DNS Ad Blocker" error:error];
+            } else if ([NSError branchVPNBlockingError:error]) {
+                [[BranchLogger shared] logWarning:@"Possible VPN Ad Blocker" error:error];
             } else {
                 [[BranchLogger shared] logError:@"QR Code request failed" error:error];
                 completion(nil, error);

Sources/BranchSDK/NSError+Branch.m

@@ -115,4 +115,50 @@ + (BOOL)branchDNSBlockingError:(NSError *)error {
     return NO;
 }
 
++ (BOOL)branchVPNBlockingError:(NSError *)error {
+    if (error) {
+        NSError *underlyingError = error.userInfo[@"NSUnderlyingError"];
+        if (underlyingError) {
+
+            /**
+             `Domain=kCFErrorDomainCFNetwork Code=-1004` indicates that the connection failed because a connection can't be made to the host.
+             Reference: https://developer.apple.com/documentation/cfnetwork/cfnetworkerrors/kcfurlerrorcannotconnecttohost?language=objc
+
+             `_kCFStreamErrorCodeKey=61` indicates that the connection was refused.
+             Reference: https://opensource.apple.com/source/xnu/xnu-792/bsd/sys/errno.h.auto.html
+             */
+
+            BOOL isCouldntConnectErrorCode = [@(-1004) isEqual:@(underlyingError.code)];
+            BOOL isLocalHostErrorKey = [@(61) isEqual:error.userInfo[@"_kCFStreamErrorCodeKey"]];
+
+            if ([self isConnectedToVPN] && isCouldntConnectErrorCode && isLocalHostErrorKey) {
+                return YES;
+            }
+        }
+    }
+    return NO;
+}
+
+/**
+ Helper method to which checks the device's internet proxy settings for common VPN protocol and interface substrings to determine if a VPN enabled.
+ https://developer.apple.com/documentation/cfnetwork/cfnetworkcopysystemproxysettings()
+ */
++ (BOOL)isConnectedToVPN {
+    NSDictionary *proxySettings = (__bridge NSDictionary *)(CFNetworkCopySystemProxySettings());
+    if (proxySettings) {
+        NSDictionary *scopedSettings = proxySettings[@"__SCOPED__"];
+        if (scopedSettings) {
+            for (NSString *key in scopedSettings) {
+                if ([key containsString:@"tap"] ||
+                    [key containsString:@"tun"] ||
+                    [key containsString:@"ppp"] ||
+                    [key containsString:@"ipsec"]) {
+                    return YES;
+                }
+            }
+        }
+    }
+    return NO;
+}
+
 @end

Sources/BranchSDK/Private/NSError+Branch.h

@@ -46,6 +46,9 @@ typedef NS_ENUM(NSInteger, BNCErrorCode) {
 // Checks if an NSError looks like a DNS blocking error
 + (BOOL)branchDNSBlockingError:(NSError *)error;
 
+// Checks if an NSError looks like a VPN blocking error
++ (BOOL)branchVPNBlockingError:(NSError *)error;
+
 @end
 
 NS_ASSUME_NONNULL_END