| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "chpp/clients/discovery.h" |
| |
| #include <inttypes.h> |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <string.h> |
| |
| #include "chpp/app.h" |
| #include "chpp/common/discovery.h" |
| #include "chpp/macros.h" |
| #include "chpp/memory.h" |
| #include "chpp/platform/log.h" |
| #include "chpp/transport.h" |
| |
| /************************************************ |
| * Prototypes |
| ***********************************************/ |
| |
| static inline bool chppIsClientCompatibleWithService( |
| const struct ChppClientDescriptor *client, |
| const struct ChppServiceDescriptor *service); |
| static uint8_t chppFindMatchingClient( |
| struct ChppAppState *context, const struct ChppServiceDescriptor *service); |
| static void chppDiscoveryProcessDiscoverAll(struct ChppAppState *context, |
| const uint8_t *buf, size_t len); |
| |
| /************************************************ |
| * Private Functions |
| ***********************************************/ |
| |
| /** |
| * Determines if a client is compatible with a service. Compatibility |
| * requirements are: |
| * 1. UUIDs must match |
| * 2. Major version numbers must match |
| * |
| * @param client ChppClientDescriptor of client. |
| * @param service ChppServiceDescriptor of service. |
| * |
| * @param return True if compatible. |
| */ |
| static inline bool chppIsClientCompatibleWithService( |
| const struct ChppClientDescriptor *client, |
| const struct ChppServiceDescriptor *service) { |
| return (memcmp(client->uuid, service->uuid, CHPP_SERVICE_UUID_LEN) == 0 && |
| client->version.major == service->version.major); |
| } |
| |
| /** |
| * Attempts to match a registered client to a (discovered) service, responding |
| * with either the client index or CHPP_CLIENT_INDEX_NONE if it fails. |
| * |
| * @param context Maintains status for each app layer instance. |
| * @param service ChppServiceDescriptor of service. |
| * |
| * @param return Index of client matching the service, or CHPP_CLIENT_INDEX_NONE |
| * if there is none. |
| */ |
| static uint8_t chppFindMatchingClient( |
| struct ChppAppState *context, const struct ChppServiceDescriptor *service) { |
| uint8_t result = CHPP_CLIENT_INDEX_NONE; |
| |
| for (size_t i = 0; i < context->registeredClientCount; i++) { |
| if (chppIsClientCompatibleWithService( |
| &context->registeredClients[i]->descriptor, service)) { |
| result = i; |
| break; |
| } |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Processes the Discover All Services response |
| * (CHPP_DISCOVERY_COMMAND_DISCOVER_ALL). |
| * |
| * @param context Maintains status for each app layer instance. |
| * @param buf Input (request) datagram. Cannot be null. |
| * @param len Length of input data in bytes. |
| */ |
| static void chppDiscoveryProcessDiscoverAll(struct ChppAppState *context, |
| const uint8_t *buf, size_t len) { |
| CHPP_DEBUG_ASSERT(len >= sizeof(struct ChppAppHeader)); |
| |
| const struct ChppDiscoveryResponse *response = |
| (struct ChppDiscoveryResponse *)buf; |
| size_t servicesLen = len - sizeof(struct ChppAppHeader); |
| uint8_t serviceCount = servicesLen / sizeof(struct ChppServiceDescriptor); |
| |
| if (servicesLen != serviceCount * sizeof(struct ChppServiceDescriptor)) { |
| // Incomplete service list |
| CHPP_LOGE("Service descriptors length length=%" PRIuSIZE |
| " is invalid for a service count = %" PRIu8 |
| " and descriptor length = %" PRIuSIZE, |
| servicesLen, serviceCount, sizeof(struct ChppServiceDescriptor)); |
| CHPP_DEBUG_ASSERT(false); |
| } |
| |
| if (serviceCount >= CHPP_MAX_DISCOVERED_SERVICES) { |
| CHPP_LOGE("Discovered service count = %" PRIu8 |
| " larger than CHPP_MAX_DISCOVERED_SERVICES = %d", |
| serviceCount, CHPP_MAX_DISCOVERED_SERVICES); |
| CHPP_DEBUG_ASSERT(false); |
| } |
| |
| CHPP_LOGI("Attempting to match %" PRIu8 " registered clients and %" PRIu8 |
| " discovered services", |
| context->registeredClientCount, serviceCount); |
| |
| uint8_t matchedClients = 0; |
| for (uint8_t i = 0; i < MIN(serviceCount, CHPP_MAX_DISCOVERED_SERVICES); |
| i++) { |
| // Update lookup table |
| context->clientIndexOfServiceIndex[i] = |
| chppFindMatchingClient(context, &response->services[i]); |
| |
| char uuidText[CHPP_SERVICE_UUID_STRING_LEN]; |
| chppUuidToStr(response->services[i].uuid, uuidText); |
| |
| if (context->clientIndexOfServiceIndex[i] == CHPP_CLIENT_INDEX_NONE) { |
| CHPP_LOGI( |
| "No matching client found for service on handle %d" |
| " with name=%s, UUID=%s, version=%" PRIu8 ".%" PRIu8 ".%" PRIu16, |
| CHPP_SERVICE_HANDLE_OF_INDEX(i), response->services[i].name, uuidText, |
| response->services[i].version.major, |
| response->services[i].version.minor, |
| response->services[i].version.patch); |
| |
| } else { |
| CHPP_LOGI( |
| "Client # %" PRIu8 |
| " matched to service on handle %d" |
| " with name=%s, UUID=%s. " |
| "client version=%" PRIu8 ".%" PRIu8 ".%" PRIu16 |
| ", service version=%" PRIu8 ".%" PRIu8 ".%" PRIu16, |
| context->clientIndexOfServiceIndex[i], |
| CHPP_SERVICE_HANDLE_OF_INDEX(i), response->services[i].name, uuidText, |
| context->registeredClients[context->clientIndexOfServiceIndex[i]] |
| ->descriptor.version.major, |
| context->registeredClients[context->clientIndexOfServiceIndex[i]] |
| ->descriptor.version.minor, |
| context->registeredClients[context->clientIndexOfServiceIndex[i]] |
| ->descriptor.version.patch, |
| response->services[i].version.major, |
| response->services[i].version.minor, |
| response->services[i].version.patch); |
| |
| // Initialize client |
| uint8_t idx = context->clientIndexOfServiceIndex[i]; |
| if (context->registeredClients[idx]->initFunctionPtr( |
| context->registeredClientContexts[idx], |
| CHPP_SERVICE_HANDLE_OF_INDEX(i), |
| response->services[i].version) == false) { |
| CHPP_LOGE( |
| "Client rejected initialization (maybe due to incompatible " |
| "versions?) client version=%" PRIu8 ".%" PRIu8 ".%" PRIu16 |
| ", service version=%" PRIu8 ".%" PRIu8 ".%" PRIu16, |
| context->registeredClients[context->clientIndexOfServiceIndex[i]] |
| ->descriptor.version.major, |
| context->registeredClients[context->clientIndexOfServiceIndex[i]] |
| ->descriptor.version.minor, |
| context->registeredClients[context->clientIndexOfServiceIndex[i]] |
| ->descriptor.version.patch, |
| response->services[i].version.major, |
| response->services[i].version.minor, |
| response->services[i].version.patch); |
| } else { |
| matchedClients++; |
| } |
| } |
| } |
| |
| CHPP_LOGI("Successfully matched %" PRIu8 |
| " clients with services, out of a total of %" PRIu8 |
| " registered clients and %" PRIu8 " discovered services", |
| matchedClients, context->registeredClientCount, serviceCount); |
| } |
| |
| /************************************************ |
| * Public Functions |
| ***********************************************/ |
| |
| bool chppDispatchDiscoveryServiceResponse(struct ChppAppState *context, |
| const uint8_t *buf, size_t len) { |
| struct ChppAppHeader *rxHeader = (struct ChppAppHeader *)buf; |
| bool success = true; |
| |
| switch (rxHeader->command) { |
| case CHPP_DISCOVERY_COMMAND_DISCOVER_ALL: { |
| chppDiscoveryProcessDiscoverAll(context, buf, len); |
| break; |
| } |
| default: { |
| success = false; |
| break; |
| } |
| } |
| return success; |
| } |
| |
| void chppInitiateDiscovery(struct ChppAppState *context) { |
| for (uint8_t i = 0; i < CHPP_MAX_DISCOVERED_SERVICES; i++) { |
| context->clientIndexOfServiceIndex[i] = CHPP_CLIENT_INDEX_NONE; |
| } |
| |
| struct ChppAppHeader *request = chppMalloc(sizeof(struct ChppAppHeader)); |
| request->handle = CHPP_HANDLE_DISCOVERY; |
| request->type = CHPP_MESSAGE_TYPE_CLIENT_REQUEST; |
| request->command = CHPP_DISCOVERY_COMMAND_DISCOVER_ALL; |
| |
| chppEnqueueTxDatagramOrFail(context->transportContext, request, |
| sizeof(struct ChppAppHeader)); |
| } |
