Implement User Directed Commissioning - Phase 1

examples/minimal-mdns/server.cpp

@@ -188,22 +188,27 @@ int main(int argc, char ** args)
     mdns::Minimal::Server<10 /* endpoints */> mdnsServer;
     mdns::Minimal::QueryResponder<16 /* maxRecords */> queryResponder;
 
-    mdns::Minimal::QNamePart tcpServiceName[]       = { kOperationalServiceName, kOperationalProtocol, kLocalDomain };
-    mdns::Minimal::QNamePart tcpServerServiceName[] = { gOptions.instanceName, kOperationalServiceName, kOperationalProtocol,
-                                                        kLocalDomain };
-    mdns::Minimal::QNamePart udpServiceName[]       = { kCommissionableServiceName, kCommissionProtocol, kLocalDomain };
-    mdns::Minimal::QNamePart udpServerServiceName[] = { gOptions.instanceName, kCommissionableServiceName, kCommissionProtocol,
-                                                        kLocalDomain };
+    mdns::Minimal::QNamePart tcpServiceName[]       = { chip::Mdns::kOperationalServiceName, chip::Mdns::kOperationalProtocol,
+                                                  chip::Mdns::kLocalDomain };
+    mdns::Minimal::QNamePart tcpServerServiceName[] = { gOptions.instanceName, chip::Mdns::kOperationalServiceName,
+                                                        chip::Mdns::kOperationalProtocol, chip::Mdns::kLocalDomain };
+    mdns::Minimal::QNamePart udpServiceName[]       = { chip::Mdns::kCommissionableServiceName, chip::Mdns::kCommissionProtocol,
+                                                  chip::Mdns::kLocalDomain };
+    mdns::Minimal::QNamePart udpServerServiceName[] = { gOptions.instanceName, chip::Mdns::kCommissionableServiceName,
+                                                        chip::Mdns::kCommissionProtocol, chip::Mdns::kLocalDomain };
 
     // several UDP versions for discriminators
-    mdns::Minimal::QNamePart udpDiscriminator1[] = { "S52", kSubtypeServiceNamePart, kCommissionableServiceName,
-                                                     kCommissionProtocol, kLocalDomain };
-    mdns::Minimal::QNamePart udpDiscriminator2[] = { "V123", kSubtypeServiceNamePart, kCommissionableServiceName,
-                                                     kCommissionProtocol, kLocalDomain };
-    mdns::Minimal::QNamePart udpDiscriminator3[] = { "L840", kSubtypeServiceNamePart, kCommissionableServiceName,
-                                                     kCommissionProtocol, kLocalDomain };
-
-    mdns::Minimal::QNamePart serverName[] = { gOptions.instanceName, kLocalDomain };
+    mdns::Minimal::QNamePart udpDiscriminator1[] = { "S52", chip::Mdns::kSubtypeServiceNamePart,
+                                                     chip::Mdns::kCommissionableServiceName, chip::Mdns::kCommissionProtocol,
+                                                     chip::Mdns::kLocalDomain };
+    mdns::Minimal::QNamePart udpDiscriminator2[] = { "V123", chip::Mdns::kSubtypeServiceNamePart,
+                                                     chip::Mdns::kCommissionableServiceName, chip::Mdns::kCommissionProtocol,
+                                                     chip::Mdns::kLocalDomain };
+    mdns::Minimal::QNamePart udpDiscriminator3[] = { "L840", chip::Mdns::kSubtypeServiceNamePart,
+                                                     chip::Mdns::kCommissionableServiceName, chip::Mdns::kCommissionProtocol,
+                                                     chip::Mdns::kLocalDomain };
+
+    mdns::Minimal::QNamePart serverName[] = { gOptions.instanceName, chip::Mdns::kLocalDomain };
 
     mdns::Minimal::IPv4Responder ipv4Responder(serverName);
     mdns::Minimal::IPv6Responder ipv6Responder(serverName);

src/app/server/Mdns.cpp

@@ -21,6 +21,7 @@
 
 #include <core/Optional.h>
 #include <mdns/Advertiser.h>
+#include <mdns/ServiceNaming.h>
 #include <messaging/ReliableMessageProtocolConfig.h>
 #if CONFIG_DEVICE_LAYER
 #include <platform/CHIPDeviceLayer.h>
@@ -87,6 +88,12 @@ chip::ByteSpan FillMAC(uint8_t (&mac)[8])
 
 } // namespace
 
+CHIP_ERROR GetCommissionableInstanceName(char * buffer, size_t bufferLen)
+{
+    auto & mdnsAdvertiser = chip::Mdns::ServiceAdvertiser::Instance();
+    return mdnsAdvertiser.GetCommissionableInstanceName(buffer, bufferLen);
+}
+
 /// Set MDNS operational advertisement
 CHIP_ERROR AdvertiseOperational()
 {

src/app/server/Mdns.h

@@ -42,6 +42,9 @@ void StartServer();
 
 CHIP_ERROR GenerateRotatingDeviceId(char rotatingDeviceIdHexBuffer[], size_t rotatingDeviceIdHexBufferSize);
 
+/// Generates the (random) instance name that a CHIP device is to use for pre-commissioning DNS-SD
+CHIP_ERROR GetCommissionableInstanceName(char * buffer, size_t bufferLen);
+
 } // namespace Mdns
 } // namespace app
 } // namespace chip

src/controller/python/ChipDeviceController-ScriptBinding.cpp

@@ -252,7 +252,7 @@ CHIP_ERROR pychip_DeviceController_ConnectIP(chip::Controller::DeviceCommissione
 
 CHIP_ERROR pychip_DeviceController_DiscoverAllCommissionableNodes(chip::Controller::DeviceCommissioner * devCtrl)
 {
-    Mdns::DiscoveryFilter filter(Mdns::DiscoveryFilterType::kNone, 0);
+    Mdns::DiscoveryFilter filter(Mdns::DiscoveryFilterType::kNone, (uint16_t) 0);
     return devCtrl->DiscoverCommissionableNodes(filter);
 }
 

src/lib/mdns/Advertiser.h

@@ -25,6 +25,7 @@
 #include <core/PeerId.h>
 #include <inet/InetLayer.h>
 #include <lib/support/Span.h>
+#include <support/CHIPMemString.h>
 
 namespace chip {
 namespace Mdns {
@@ -179,34 +180,55 @@ class CommissionAdvertisingParameters : public BaseAdvertisingParams<CommissionA
     {
         if (deviceName.HasValue())
         {
-            strncpy(sDeviceName, deviceName.Value(), min(strlen(deviceName.Value()) + 1, sizeof(sDeviceName)));
-            mDeviceName = Optional<const char *>::Value(static_cast<const char *>(sDeviceName));
+            chip::Platform::CopyString(mDeviceName, sizeof(mDeviceName), deviceName.Value());
+            mDeviceNameHasValue = true;
+        }
+        else
+        {
+            mDeviceNameHasValue = false;
         }
         return *this;
     }
-    Optional<const char *> GetDeviceName() const { return mDeviceName; }
+    Optional<const char *> GetDeviceName() const
+    {
+        return mDeviceNameHasValue ? Optional<const char *>::Value(mDeviceName) : Optional<const char *>::Missing();
+    }
 
     CommissionAdvertisingParameters & SetRotatingId(Optional<const char *> rotatingId)
     {
         if (rotatingId.HasValue())
         {
-            strncpy(sRotatingId, rotatingId.Value(), min(strlen(rotatingId.Value()) + 1, sizeof(sRotatingId)));
-            mRotatingId = Optional<const char *>::Value(static_cast<const char *>(sRotatingId));
+            chip::Platform::CopyString(mRotatingId, sizeof(mRotatingId), rotatingId.Value());
+            mRotatingIdHasValue = true;
+        }
+        else
+        {
+            mRotatingIdHasValue = false;
         }
         return *this;
     }
-    Optional<const char *> GetRotatingId() const { return mRotatingId; }
+    Optional<const char *> GetRotatingId() const
+    {
+        return mRotatingIdHasValue ? Optional<const char *>::Value(mRotatingId) : Optional<const char *>::Missing();
+    }
 
     CommissionAdvertisingParameters & SetPairingInstr(Optional<const char *> pairingInstr)
     {
         if (pairingInstr.HasValue())
         {
-            strncpy(sPairingInstr, pairingInstr.Value(), min(strlen(pairingInstr.Value()) + 1, sizeof(sPairingInstr)));
-            mPairingInstr = Optional<const char *>::Value(static_cast<const char *>(sPairingInstr));
+            chip::Platform::CopyString(mPairingInstr, sizeof(mPairingInstr), pairingInstr.Value());
+            mPairingInstrHasValue = true;
+        }
+        else
+        {
+            mPairingInstrHasValue = false;
         }
         return *this;
     }
-    Optional<const char *> GetPairingInstr() const { return mPairingInstr; }
+    Optional<const char *> GetPairingInstr() const
+    {
+        return mPairingInstrHasValue ? Optional<const char *>::Value(mPairingInstr) : Optional<const char *>::Missing();
+    }
 
     CommissionAdvertisingParameters & SetPairingHint(Optional<uint16_t> pairingHint)
     {
@@ -233,14 +255,14 @@ class CommissionAdvertisingParameters : public BaseAdvertisingParams<CommissionA
     chip::Optional<uint16_t> mDeviceType;
     chip::Optional<uint16_t> mPairingHint;
 
-    char sDeviceName[kKeyDeviceNameMaxLength + 1];
-    chip::Optional<const char *> mDeviceName;
+    char mDeviceName[kKeyDeviceNameMaxLength + 1];
+    bool mDeviceNameHasValue = false;
 
-    char sRotatingId[kKeyRotatingIdMaxLength + 1];
-    chip::Optional<const char *> mRotatingId;
+    char mRotatingId[kKeyRotatingIdMaxLength + 1];
+    bool mRotatingIdHasValue = false;
 
-    char sPairingInstr[kKeyPairingInstructionMaxLength + 1];
-    chip::Optional<const char *> mPairingInstr;
+    char mPairingInstr[kKeyPairingInstructionMaxLength + 1];
+    bool mPairingInstrHasValue = false;
 };
 
 /// Handles advertising of CHIP nodes
@@ -264,6 +286,9 @@ class ServiceAdvertiser
 
     /// Provides the system-wide implementation of the service advertiser
     static ServiceAdvertiser & Instance();
+
+    /// Returns DNS-SD instance name formatted as hex string
+    virtual CHIP_ERROR GetCommissionableInstanceName(char * instanceName, size_t maxLength) = 0;
 };
 
 } // namespace Mdns

src/lib/mdns/Advertiser_ImplMinimalMdns.cpp

@@ -116,6 +116,7 @@ class AdvertiserMinMdns : public ServiceAdvertiser,
     CHIP_ERROR Advertise(const OperationalAdvertisingParameters & params) override;
     CHIP_ERROR Advertise(const CommissionAdvertisingParameters & params) override;
     CHIP_ERROR StopPublishDevice() override;
+    CHIP_ERROR GetCommissionableInstanceName(char * instanceName, size_t maxLength) override;
 
     // MdnsPacketDelegate
     void OnMdnsPacketData(const BytesRange & data, const chip::Inet::IPPacketInfo * info) override;
@@ -146,6 +147,8 @@ class AdvertiserMinMdns : public ServiceAdvertiser,
     QueryResponderAllocator<kMaxCommissionRecords> mQueryResponderAllocatorCommissioner;
 
     ResponseSender mResponseSender;
+    uint32_t mCommissionInstanceName1;
+    uint32_t mCommissionInstanceName2;
 
     // current request handling
     const chip::Inet::IPPacketInfo * mCurrentSource = nullptr;
@@ -191,6 +194,9 @@ CHIP_ERROR AdvertiserMinMdns::Start(chip::Inet::InetLayer * inetLayer, uint16_t
 {
     GlobalMinimalMdnsServer::Server().Shutdown();
 
+    mCommissionInstanceName1 = GetRandU32();
+    mCommissionInstanceName2 = GetRandU32();
+
     ReturnErrorOnFailure(GlobalMinimalMdnsServer::Instance().StartServer(inetLayer, port));
 
     ChipLogProgress(Discovery, "CHIP minimal mDNS started advertising.");
@@ -277,8 +283,23 @@ CHIP_ERROR AdvertiserMinMdns::Advertise(const OperationalAdvertisingParameters &
     return CHIP_NO_ERROR;
 }
 
+CHIP_ERROR AdvertiserMinMdns::GetCommissionableInstanceName(char * instanceName, size_t maxLength)
+{
+    if (maxLength < (kMaxInstanceNameSize + 1))
+    {
+        return CHIP_ERROR_NO_MEMORY;
+    }
+    size_t len = snprintf(instanceName, maxLength, ChipLogFormatX64, mCommissionInstanceName1, mCommissionInstanceName2);
+    if (len >= maxLength)
+    {
+        return CHIP_ERROR_NO_MEMORY;
+    }
+    return CHIP_NO_ERROR;
+}
+
 CHIP_ERROR AdvertiserMinMdns::Advertise(const CommissionAdvertisingParameters & params)
 {
+
     // TODO: When multi-admin is enabled, operational does not need to be cleared here.
     if (params.GetCommissionAdvertiseMode() == CommssionAdvertiseMode::kCommissionableNode)
     {
@@ -291,11 +312,8 @@ CHIP_ERROR AdvertiserMinMdns::Advertise(const CommissionAdvertisingParameters &
 
     // TODO: need to detect colisions here
     char nameBuffer[64] = "";
-    size_t len          = snprintf(nameBuffer, sizeof(nameBuffer), ChipLogFormatX64, GetRandU32(), GetRandU32());
-    if (len >= sizeof(nameBuffer))
-    {
-        return CHIP_ERROR_NO_MEMORY;
-    }
+    ReturnErrorOnFailure(GetCommissionableInstanceName(nameBuffer, sizeof(nameBuffer)));
+
     QueryResponderAllocator<kMaxCommissionRecords> * allocator =
         params.GetCommissionAdvertiseMode() == CommssionAdvertiseMode::kCommissionableNode ? &mQueryResponderAllocatorCommissionable
                                                                                            : &mQueryResponderAllocatorCommissioner;
@@ -486,26 +504,26 @@ FullQName AdvertiserMinMdns::GetCommisioningTextEntries(const CommissionAdvertis
     char txtVidPid[chip::Mdns::kKeyVendorProductMaxLength + 4];
     if (params.GetProductId().HasValue() && params.GetVendorId().HasValue())
     {
-        sprintf(txtVidPid, "VP=%d+%d", params.GetVendorId().Value(), params.GetProductId().Value());
+        snprintf(txtVidPid, sizeof(txtVidPid), "VP=%d+%d", params.GetVendorId().Value(), params.GetProductId().Value());
         txtFields[numTxtFields++] = txtVidPid;
     }
     else if (params.GetVendorId().HasValue())
     {
-        sprintf(txtVidPid, "VP=%d", params.GetVendorId().Value());
+        snprintf(txtVidPid, sizeof(txtVidPid), "VP=%d", params.GetVendorId().Value());
         txtFields[numTxtFields++] = txtVidPid;
     }
 
     char txtDeviceType[chip::Mdns::kKeyDeviceTypeMaxLength + 4];
     if (params.GetDeviceType().HasValue())
     {
-        sprintf(txtDeviceType, "DT=%d", params.GetDeviceType().Value());
+        snprintf(txtDeviceType, sizeof(txtDeviceType), "DT=%d", params.GetDeviceType().Value());
         txtFields[numTxtFields++] = txtDeviceType;
     }
 
     char txtDeviceName[chip::Mdns::kKeyDeviceNameMaxLength + 4];
     if (params.GetDeviceName().HasValue())
     {
-        sprintf(txtDeviceName, "DN=%s", params.GetDeviceName().Value());
+        snprintf(txtDeviceName, sizeof(txtDeviceName), "DN=%s", params.GetDeviceName().Value());
         txtFields[numTxtFields++] = txtDeviceName;
     }
 
@@ -514,7 +532,7 @@ FullQName AdvertiserMinMdns::GetCommisioningTextEntries(const CommissionAdvertis
     {
         // a discriminator always exists
         char txtDiscriminator[chip::Mdns::kKeyDiscriminatorMaxLength + 3];
-        sprintf(txtDiscriminator, "D=%d", params.GetLongDiscriminator());
+        snprintf(txtDiscriminator, sizeof(txtDiscriminator), "D=%d", params.GetLongDiscriminator());
         txtFields[numTxtFields++] = txtDiscriminator;
 
         if (!params.GetVendorId().HasValue())
@@ -523,34 +541,34 @@ FullQName AdvertiserMinMdns::GetCommisioningTextEntries(const CommissionAdvertis
         }
 
         char txtCommissioningMode[chip::Mdns::kKeyCommissioningModeMaxLength + 4];
-        sprintf(txtCommissioningMode, "CM=%d", params.GetCommissioningMode() ? 1 : 0);
+        snprintf(txtCommissioningMode, sizeof(txtCommissioningMode), "CM=%d", params.GetCommissioningMode() ? 1 : 0);
         txtFields[numTxtFields++] = txtCommissioningMode;
 
         char txtOpenWindowCommissioningMode[chip::Mdns::kKeyAdditionalPairingMaxLength + 4];
         if (params.GetCommissioningMode() && params.GetOpenWindowCommissioningMode())
         {
-            sprintf(txtOpenWindowCommissioningMode, "AP=1");
+            snprintf(txtOpenWindowCommissioningMode, sizeof(txtOpenWindowCommissioningMode), "AP=1");
             txtFields[numTxtFields++] = txtOpenWindowCommissioningMode;
         }
 
         char txtRotatingDeviceId[chip::Mdns::kKeyRotatingIdMaxLength + 4];
         if (params.GetRotatingId().HasValue())
         {
-            sprintf(txtRotatingDeviceId, "RI=%s", params.GetRotatingId().Value());
+            snprintf(txtRotatingDeviceId, sizeof(txtRotatingDeviceId), "RI=%s", params.GetRotatingId().Value());
             txtFields[numTxtFields++] = txtRotatingDeviceId;
         }
 
         char txtPairingHint[chip::Mdns::kKeyPairingInstructionMaxLength + 4];
         if (params.GetPairingHint().HasValue())
         {
-            sprintf(txtPairingHint, "PH=%d", params.GetPairingHint().Value());
+            snprintf(txtPairingHint, sizeof(txtPairingHint), "PH=%d", params.GetPairingHint().Value());
             txtFields[numTxtFields++] = txtPairingHint;
         }
 
         char txtPairingInstr[chip::Mdns::kKeyPairingInstructionMaxLength + 4];
         if (params.GetPairingInstr().HasValue())
         {
-            sprintf(txtPairingInstr, "PI=%s", params.GetPairingInstr().Value());
+            snprintf(txtPairingInstr, sizeof(txtPairingInstr), "PI=%s", params.GetPairingInstr().Value());
             txtFields[numTxtFields++] = txtPairingInstr;
         }
     }

src/lib/mdns/Advertiser_ImplNone.cpp

@@ -50,6 +50,12 @@ class NoneAdvertiser : public ServiceAdvertiser
         ChipLogError(Discovery, "mDNS advertising not available. mDNS stop not available.");
         return CHIP_ERROR_NOT_IMPLEMENTED;
     }
+
+    CHIP_ERROR GetCommissionableInstanceName(char * instanceName, size_t maxLength) override
+    {
+        ChipLogError(Discovery, "mDNS advertising not available. mDNS GetCommissionableInstanceName not available.");
+        return CHIP_ERROR_NOT_IMPLEMENTED;
+    }
 };
 
 NoneAdvertiser gAdvertiser;

src/lib/mdns/Discovery_ImplPlatform.cpp

@@ -103,6 +103,21 @@ void DiscoveryImplPlatform::HandleMdnsError(void * context, CHIP_ERROR error)
     }
 }
 
+CHIP_ERROR DiscoveryImplPlatform::GetCommissionableInstanceName(char * instanceName, size_t maxLength)
+{
+    if (maxLength < (chip::Mdns::kMaxInstanceNameSize + 1))
+    {
+        return CHIP_ERROR_NO_MEMORY;
+    }
+    size_t len = snprintf(instanceName, maxLength, "%08" PRIX32 "%08" PRIX32, static_cast<uint32_t>(mCommissionInstanceName >> 32),
+                          static_cast<uint32_t>(mCommissionInstanceName));
+    if (len >= maxLength)
+    {
+        return CHIP_ERROR_NO_MEMORY;
+    }
+    return CHIP_NO_ERROR;
+}
+
 CHIP_ERROR DiscoveryImplPlatform::Advertise(const CommissionAdvertisingParameters & params)
 {
     CHIP_ERROR error = CHIP_NO_ERROR;
@@ -143,8 +158,8 @@ CHIP_ERROR DiscoveryImplPlatform::Advertise(const CommissionAdvertisingParameter
         return error;
     }
 
-    snprintf(service.mName, sizeof(service.mName), "%08" PRIX32 "%08" PRIX32, static_cast<uint32_t>(mCommissionInstanceName >> 32),
-             static_cast<uint32_t>(mCommissionInstanceName));
+    ReturnErrorOnFailure(GetCommissionableInstanceName(service.mName, sizeof(service.mName)));
+
     if (params.GetCommissionAdvertiseMode() == CommssionAdvertiseMode::kCommissionableNode)
     {
         strncpy(service.mType, kCommissionableServiceName, sizeof(service.mType));

src/lib/mdns/Discovery_ImplPlatform.h

@@ -48,6 +48,9 @@ class DiscoveryImplPlatform : public ServiceAdvertiser, public Resolver
     /// This function stops publishing the device on mDNS.
     CHIP_ERROR StopPublishDevice() override;
 
+    /// Returns DNS-SD instance name formatted as hex string
+    CHIP_ERROR GetCommissionableInstanceName(char * instanceName, size_t maxLength) override;
+
     /// Registers a resolver delegate if none has been registered before
     CHIP_ERROR SetResolverDelegate(ResolverDelegate * delegate) override;