Add Darwin API for starting multiple controllers on the same fabric.

Fixes project-chip#27394

src/darwin/Framework/CHIP/MTRDeviceController.mm

@@ -374,6 +374,7 @@ - (BOOL)startup:(MTRDeviceControllerStartupParamsInternal *)startupParams
         // bring-up.
         commissionerParams.removeFromFabricTableOnShutdown = false;
         commissionerParams.deviceAttestationVerifier = _factory.deviceAttestationVerifier;
+        commissionerParams.permitMultiControllerFabrics = startupParams.isAdditionalController;
 
         auto & factory = chip::Controller::DeviceControllerFactory::GetInstance();
 

src/darwin/Framework/CHIP/MTRDeviceControllerFactory.h

@@ -149,6 +149,22 @@ API_AVAILABLE(ios(16.4), macos(13.3), watchos(9.4), tvos(16.4))
 - (MTRDeviceController * _Nullable)createControllerOnExistingFabric:(MTRDeviceControllerStartupParams *)startupParams
                                                               error:(NSError * __autoreleasing *)error;
 
+/**
+ * Create a an additional MTRDeviceController on an existing fabric.  Returns nil on failure.
+ *
+ * The fabric is identified by the root public key and fabric id in
+ * the startupParams.
+ *
+ * This method will fail if there is no such fabric.
+ *
+ * This method will fail if the MTRDeviceControllerStartupParams don't follow
+ * the rules for creating a controller on a new fabric.  In particular, the
+ * vendor ID must not be nil.
+ */
+- (MTRDeviceController * _Nullable)createAdditionalControllerOnExistingFabric:(MTRDeviceControllerStartupParams *)startupParams
+                                                                        error:(NSError * __autoreleasing *)error
+    MTR_NEWLY_AVAILABLE;
+
 /**
  * Create a MTRDeviceController on a new fabric.  Returns nil on failure.
  *

src/darwin/Framework/CHIP/MTRDeviceControllerFactory.mm

@@ -555,6 +555,19 @@ - (void)stopControllerFactory
 
 - (MTRDeviceController * _Nullable)createControllerOnExistingFabric:(MTRDeviceControllerStartupParams *)startupParams
                                                               error:(NSError * __autoreleasing *)error
+{
+    return [self _createControllerOnExistingFabric:startupParams isAdditional:NO error:error];
+}
+
+- (MTRDeviceController * _Nullable)createAdditionalControllerOnExistingFabric:(MTRDeviceControllerStartupParams *)startupParams
+                                                                        error:(NSError * __autoreleasing *)error
+{
+    return [self _createControllerOnExistingFabric:startupParams isAdditional:YES error:error];
+}
+
+- (MTRDeviceController * _Nullable)_createControllerOnExistingFabric:(MTRDeviceControllerStartupParams *)startupParams
+                                                        isAdditional:(BOOL)isAdditional
+                                                               error:(NSError * __autoreleasing *)error
 {
     [self _assertCurrentQueueIsNotMatterQueue];
 
@@ -594,27 +607,36 @@ - (MTRDeviceController * _Nullable)createControllerOnExistingFabric:(MTRDeviceCo
             return;
         }
 
-        for (MTRDeviceController * existing in _controllers) {
-            BOOL isRunning = YES; // assume the worst
-            if ([existing isRunningOnFabric:fabricTable fabricIndex:fabric->GetFabricIndex() isRunning:&isRunning]
-                != CHIP_NO_ERROR) {
-                MTR_LOG_ERROR("Can't tell what fabric a controller is running on.  Not safe to start.");
-                fabricError = CHIP_ERROR_INTERNAL;
-                return;
-            }
+        if (!isAdditional) {
+            for (MTRDeviceController * existing in _controllers) {
+                BOOL isRunning = YES; // assume the worst
+                if ([existing isRunningOnFabric:fabricTable fabricIndex:fabric->GetFabricIndex() isRunning:&isRunning]
+                    != CHIP_NO_ERROR) {
+                    MTR_LOG_ERROR("Can't tell what fabric a controller is running on.  Not safe to start.");
+                    fabricError = CHIP_ERROR_INTERNAL;
+                    return;
+                }
 
-            if (isRunning) {
-                MTR_LOG_ERROR("Can't start on existing fabric: another controller is running on it");
-                fabricError = CHIP_ERROR_INCORRECT_STATE;
-                return;
+                if (isRunning) {
+                    MTR_LOG_ERROR("Can't start on existing fabric: another controller is running on it");
+                    fabricError = CHIP_ERROR_INCORRECT_STATE;
+                    return;
+                }
             }
+
+            params = [[MTRDeviceControllerStartupParamsInternal alloc] _initForExistingFabricEntry:fabricTable
+                                                                                       fabricIndex:fabric->GetFabricIndex()
+                                                                                          keystore:_keystore
+                                                                              advertiseOperational:self.advertiseOperational
+                                                                                            params:startupParams];
+        } else {
+            params = [[MTRDeviceControllerStartupParamsInternal alloc] _initForNewFabricEntry:fabricTable
+                                                                                     keystore:_keystore
+                                                                         advertiseOperational:self.advertiseOperational
+                                                                                       params:startupParams
+                                                                       isAdditionalController:YES];
         }
 
-        params = [[MTRDeviceControllerStartupParamsInternal alloc] initForExistingFabric:fabricTable
-                                                                             fabricIndex:fabric->GetFabricIndex()
-                                                                                keystore:_keystore
-                                                                    advertiseOperational:self.advertiseOperational
-                                                                                  params:startupParams];
         if (params == nil) {
             fabricError = CHIP_ERROR_NO_MEMORY;
         }
@@ -656,16 +678,6 @@ - (MTRDeviceController * _Nullable)createControllerOnNewFabric:(MTRDeviceControl
         return nil;
     }
 
-    if (startupParams.vendorID == nil) {
-        MTR_LOG_ERROR("Must provide vendor id when starting controller on new fabric");
-        return nil;
-    }
-
-    if (startupParams.intermediateCertificate != nil && startupParams.rootCertificate == nil) {
-        MTR_LOG_ERROR("Must provide a root certificate when using an intermediate certificate");
-        return nil;
-    }
-
     // Create the controller, so we start the event loop, since we plan to do
     // our fabric table operations there.
     auto * controller = [self createController];
@@ -697,10 +709,11 @@ - (MTRDeviceController * _Nullable)createControllerOnNewFabric:(MTRDeviceControl
             return;
         }
 
-        params = [[MTRDeviceControllerStartupParamsInternal alloc] initForNewFabric:fabricTable
-                                                                           keystore:_keystore
-                                                               advertiseOperational:self.advertiseOperational
-                                                                             params:startupParams];
+        params = [[MTRDeviceControllerStartupParamsInternal alloc] _initForNewFabricEntry:fabricTable
+                                                                                 keystore:_keystore
+                                                                     advertiseOperational:self.advertiseOperational
+                                                                                   params:startupParams
+                                                                   isAdditionalController:NO];
         if (params == nil) {
             fabricError = CHIP_ERROR_NO_MEMORY;
         }

src/darwin/Framework/CHIP/MTRDeviceControllerStartupParams.mm

@@ -211,15 +211,26 @@ - (instancetype)initWithParams:(MTRDeviceControllerStartupParams *)params
     return self;
 }
 
-- (instancetype)initForNewFabric:(chip::FabricTable *)fabricTable
-                        keystore:(chip::Crypto::OperationalKeystore *)keystore
-            advertiseOperational:(BOOL)advertiseOperational
-                          params:(MTRDeviceControllerStartupParams *)params
+- (instancetype)_initForNewFabricEntry:(chip::FabricTable *)fabricTable
+                              keystore:(chip::Crypto::OperationalKeystore *)keystore
+                  advertiseOperational:(BOOL)advertiseOperational
+                                params:(MTRDeviceControllerStartupParams *)params
+                isAdditionalController:(BOOL)isAdditionalController
 {
     if (!(self = [self initWithParams:params])) {
         return nil;
     }
 
+    if (self.vendorID == nil) {
+        MTR_LOG_ERROR("Must provide vendor id when starting controller on new fabric");
+        return nil;
+    }
+
+    if (self.intermediateCertificate != nil && self.rootCertificate == nil) {
+        MTR_LOG_ERROR("Must provide a root certificate when using an intermediate certificate");
+        return nil;
+    }
+
     if (self.nocSigner == nil && self.operationalCertificate == nil) {
         MTR_LOG_ERROR("No way to get an operational certificate: nocSigner and operationalCertificate are both nil");
         return nil;
@@ -248,15 +259,16 @@ - (instancetype)initForNewFabric:(chip::FabricTable *)fabricTable
     _fabricTable = fabricTable;
     _keystore = keystore;
     _advertiseOperational = advertiseOperational;
+    _isAdditionalController = isAdditionalController;
 
     return self;
 }
 
-- (instancetype)initForExistingFabric:(FabricTable *)fabricTable
-                          fabricIndex:(FabricIndex)fabricIndex
-                             keystore:(chip::Crypto::OperationalKeystore *)keystore
-                 advertiseOperational:(BOOL)advertiseOperational
-                               params:(MTRDeviceControllerStartupParams *)params
+- (instancetype)_initForExistingFabricEntry:(FabricTable *)fabricTable
+                                fabricIndex:(FabricIndex)fabricIndex
+                                   keystore:(chip::Crypto::OperationalKeystore *)keystore
+                       advertiseOperational:(BOOL)advertiseOperational
+                                     params:(MTRDeviceControllerStartupParams *)params
 {
     if (!(self = [self initWithParams:params])) {
         return nil;
@@ -384,6 +396,7 @@ - (instancetype)initForExistingFabric:(FabricTable *)fabricTable
     _fabricIndex.Emplace(fabricIndex);
     _keystore = keystore;
     _advertiseOperational = advertiseOperational;
+    _isAdditionalController = NO;
 
     return self;
 }

src/darwin/Framework/CHIP/MTRDeviceControllerStartupParams_Internal.h

@@ -58,6 +58,8 @@ MTR_HIDDEN
 
 @property (nonatomic, assign, readonly) BOOL advertiseOperational;
 
+@property (nonatomic, assign, readonly) BOOL isAdditionalController;
+
 /**
  * Helper method that checks that our keypairs match our certificates.
  * Specifically:
@@ -73,21 +75,24 @@ MTR_HIDDEN
 - (BOOL)keypairsMatchCertificates;
 
 /**
- * Initialize for controller bringup on a new fabric.
+ * Initialize for controller bringup on a new fabric entry (which might be a new
+ * fabric or an additional controller on an existing fabric).
  */
-- (instancetype)initForNewFabric:(chip::FabricTable *)fabricTable
-                        keystore:(chip::Crypto::OperationalKeystore *)keystore
-            advertiseOperational:(BOOL)advertiseOperational
-                          params:(MTRDeviceControllerStartupParams *)params;
+- (instancetype)_initForNewFabricEntry:(chip::FabricTable *)fabricTable
+                              keystore:(chip::Crypto::OperationalKeystore *)keystore
+                  advertiseOperational:(BOOL)advertiseOperational
+                                params:(MTRDeviceControllerStartupParams *)params
+                isAdditionalController:(BOOL)isAdditionalController;
 
 /**
- * Initialize for controller bringup on an existing fabric.
+ * Initialize for controller bringup on an existing fabric entry, identified by
+ * the provided fabricIndex.
  */
-- (instancetype)initForExistingFabric:(chip::FabricTable *)fabricTable
-                          fabricIndex:(chip::FabricIndex)fabricIndex
-                             keystore:(chip::Crypto::OperationalKeystore *)keystore
-                 advertiseOperational:(BOOL)advertiseOperational
-                               params:(MTRDeviceControllerStartupParams *)params;
+- (instancetype)_initForExistingFabricEntry:(chip::FabricTable *)fabricTable
+                                fabricIndex:(chip::FabricIndex)fabricIndex
+                                   keystore:(chip::Crypto::OperationalKeystore *)keystore
+                       advertiseOperational:(BOOL)advertiseOperational
+                                     params:(MTRDeviceControllerStartupParams *)params;
 
 /**
  * Should use initForExistingFabric or initForNewFabric to initialize

src/darwin/Framework/CHIPTests/MTRControllerTests.m

@@ -23,6 +23,7 @@
 // system dependencies
 #import <XCTest/XCTest.h>
 
+#import "MTRFabricInfoChecker.h"
 #import "MTRTestKeys.h"
 #import "MTRTestOTAProvider.h"
 #import "MTRTestStorage.h"
@@ -1524,8 +1525,6 @@ - (void)testControllerCATs
     [controller shutdown];
     XCTAssertFalse([controller isRunning]);
 
-    fprintf(stderr, "DOING TOO LONG TEST\n");
-
     //
     // Trying to bring up the same fabric with too-long CATs should fail, if we
     // are taking the provided CATs into account.
@@ -1536,21 +1535,122 @@ - (void)testControllerCATs
     controller = [factory createControllerOnExistingFabric:params error:nil];
     XCTAssertNil(controller);
 
-    fprintf(stderr, "DOING INVALID TEST\n");
-
     //
     // Trying to bring up the same fabric with invalid CATs should fail, if we
     // are taking the provided CATs into account.
     //
     params.nodeID = @(17);
     params.operationalKeypair = operationalKeys;
     params.caseAuthenticatedTags = invalidCATs;
-    fprintf(stderr, "BRINGING UP CONTROLLER\n");
     controller = [factory createControllerOnExistingFabric:params error:nil];
-    fprintf(stderr, "CONTROLLER SHOULD BE NIL\n");
     XCTAssertNil(controller);
 
-    fprintf(stderr, "STOPPING FACTORY\n");
+    [factory stopControllerFactory];
+    XCTAssertFalse([factory isRunning]);
+}
+
+- (void)testAdditionalController
+{
+    __auto_type * factory = [MTRDeviceControllerFactory sharedInstance];
+    XCTAssertNotNil(factory);
+
+    __auto_type * storage = [[MTRTestStorage alloc] init];
+    __auto_type * factoryParams = [[MTRDeviceControllerFactoryParams alloc] initWithStorage:storage];
+    XCTAssertTrue([factory startControllerFactory:factoryParams error:nil]);
+    XCTAssertTrue([factory isRunning]);
+
+    __auto_type * rootKeys = [[MTRTestKeys alloc] init];
+    XCTAssertNotNil(rootKeys);
+
+    __auto_type * params1 = [[MTRDeviceControllerStartupParams alloc] initWithIPK:rootKeys.ipk fabricID:@(1) nocSigner:rootKeys];
+    XCTAssertNotNil(params1);
+
+    params1.vendorID = @(kTestVendorId);
+
+    NSError * error;
+
+    // Start a main controller with node id 0x10001.
+    NSNumber * nodeID1 = @(0x10001);
+    params1.nodeID = nodeID1;
+    MTRDeviceController * controller1 = [factory createControllerOnNewFabric:params1 error:&error];
+    XCTAssertNil(error);
+    XCTAssertNotNil(controller1);
+    XCTAssertTrue([controller1 isRunning]);
+    XCTAssertEqualObjects(controller1.controllerNodeID, nodeID1);
+
+    // Start an additional controller with node id 0x10002.
+    NSNumber * nodeID2 = @(0x10002);
+    params1.nodeID = nodeID2;
+    MTRDeviceController * controller2 = [factory createAdditionalControllerOnExistingFabric:params1 error:&error];
+    XCTAssertNil(error);
+    XCTAssertNotNil(controller2);
+    XCTAssertTrue([controller2 isRunning]);
+    XCTAssertEqualObjects(controller2.controllerNodeID, nodeID2);
+
+    // Start an additional controller with node id 0x10003, using explicit
+    // certificates.
+    NSNumber * nodeID3 = @(0x10003);
+    __auto_type * root = [MTRCertificates createRootCertificate:rootKeys issuerID:nil fabricID:nil error:&error];
+    XCTAssertNil(error);
+    XCTAssertNotNil(root);
+
+    __auto_type * operationalKeys = [[MTRTestKeys alloc] init];
+    XCTAssertNotNil(operationalKeys);
+
+    __auto_type * operational = [MTRCertificates createOperationalCertificate:rootKeys
+                                                           signingCertificate:root
+                                                         operationalPublicKey:operationalKeys.publicKey
+                                                                     fabricID:@(1)
+                                                                       nodeID:nodeID3
+                                                        caseAuthenticatedTags:nil
+                                                                        error:&error];
+    XCTAssertNil(error);
+    XCTAssertNotNil(operational);
+
+    __auto_type * params2 = [[MTRDeviceControllerStartupParams alloc] initWithIPK:rootKeys.ipk
+                                                               operationalKeypair:operationalKeys
+                                                           operationalCertificate:operational
+                                                          intermediateCertificate:nil
+                                                                  rootCertificate:root];
+    params2.vendorID = @(kTestVendorId);
+
+    MTRDeviceController * controller3 = [factory createAdditionalControllerOnExistingFabric:params2 error:&error];
+    XCTAssertNil(error);
+    XCTAssertNotNil(controller3);
+    XCTAssertTrue([controller3 isRunning]);
+    XCTAssertEqualObjects(controller3.controllerNodeID, nodeID3);
+
+    __auto_type fabrics = factory.knownFabrics;
+    CheckFabricInfo(fabrics, [NSMutableSet setWithArray:@[
+        @{
+            @"rootPublicKey" : [rootKeys publicKeyData],
+            @"vendorID" : @(kTestVendorId),
+            @"fabricID" : @(1),
+            @"nodeID" : nodeID1,
+            @"label" : @"",
+            @"hasIntermediateCertificate" : @(NO),
+            @"fabricIndex" : @(1)
+        },
+        @{
+            @"rootPublicKey" : [rootKeys publicKeyData],
+            @"vendorID" : @(kTestVendorId),
+            @"fabricID" : @(1),
+            @"nodeID" : nodeID2,
+            @"label" : @"",
+            @"hasIntermediateCertificate" : @(NO),
+            @"fabricIndex" : @(2)
+        },
+        @{
+            @"rootPublicKey" : [rootKeys publicKeyData],
+            @"vendorID" : @(kTestVendorId),
+            @"fabricID" : @(1),
+            @"nodeID" : nodeID3,
+            @"label" : @"",
+            @"hasIntermediateCertificate" : @(NO),
+            @"fabricIndex" : @(3)
+        }
+    ]]);
+
     [factory stopControllerFactory];
     XCTAssertFalse([factory isRunning]);
 }