diff options
Diffstat (limited to 'src/core/ext/filters/client_channel/resolver_result_parsing.cc')
-rw-r--r-- | src/core/ext/filters/client_channel/resolver_result_parsing.cc | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/src/core/ext/filters/client_channel/resolver_result_parsing.cc b/src/core/ext/filters/client_channel/resolver_result_parsing.cc new file mode 100644 index 0000000000..82a26ace63 --- /dev/null +++ b/src/core/ext/filters/client_channel/resolver_result_parsing.cc @@ -0,0 +1,384 @@ +/* + * + * Copyright 2018 gRPC authors. + * + * 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 <grpc/support/port_platform.h> + +#include "src/core/ext/filters/client_channel/resolver_result_parsing.h" + +#include <ctype.h> +#include <stdio.h> +#include <string.h> + +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> +#include <grpc/support/string_util.h> + +#include "src/core/ext/filters/client_channel/client_channel.h" +#include "src/core/ext/filters/client_channel/lb_policy_registry.h" +#include "src/core/lib/channel/status_util.h" +#include "src/core/lib/gpr/string.h" +#include "src/core/lib/gprpp/memory.h" + +// As per the retry design, we do not allow more than 5 retry attempts. +#define MAX_MAX_RETRY_ATTEMPTS 5 + +namespace grpc_core { +namespace internal { + +namespace { + +// Converts string format from JSON to proto. +grpc_core::UniquePtr<char> ConvertCamelToSnake(const char* camel) { + const size_t size = strlen(camel); + char* snake = static_cast<char*>(gpr_malloc(size * 2)); + size_t j = 0; + for (size_t i = 0; i < size; ++i) { + if (isupper(camel[i])) { + snake[j++] = '_'; + snake[j++] = tolower(camel[i]); + } else { + snake[j++] = camel[i]; + } + } + snake[j] = '\0'; + return grpc_core::UniquePtr<char>(snake); +} + +} // namespace + +ProcessedResolverResult::ProcessedResolverResult( + const grpc_channel_args* resolver_result, bool parse_retry) { + ProcessServiceConfig(resolver_result, parse_retry); + // If no LB config was found above, just find the LB policy name then. + if (lb_policy_config_ == nullptr) ProcessLbPolicyName(resolver_result); +} + +void ProcessedResolverResult::ProcessServiceConfig( + const grpc_channel_args* resolver_result, bool parse_retry) { + const grpc_arg* channel_arg = + grpc_channel_args_find(resolver_result, GRPC_ARG_SERVICE_CONFIG); + const char* service_config_json = grpc_channel_arg_get_string(channel_arg); + if (service_config_json != nullptr) { + service_config_json_.reset(gpr_strdup(service_config_json)); + service_config_ = grpc_core::ServiceConfig::Create(service_config_json); + if (service_config_ != nullptr) { + if (parse_retry) { + channel_arg = + grpc_channel_args_find(resolver_result, GRPC_ARG_SERVER_URI); + const char* server_uri = grpc_channel_arg_get_string(channel_arg); + GPR_ASSERT(server_uri != nullptr); + grpc_uri* uri = grpc_uri_parse(server_uri, true); + GPR_ASSERT(uri->path[0] != '\0'); + server_name_ = uri->path[0] == '/' ? uri->path + 1 : uri->path; + service_config_->ParseGlobalParams(ParseServiceConfig, this); + grpc_uri_destroy(uri); + } else { + service_config_->ParseGlobalParams(ParseServiceConfig, this); + } + method_params_table_ = service_config_->CreateMethodConfigTable( + ClientChannelMethodParams::CreateFromJson); + } + } +} + +void ProcessedResolverResult::ProcessLbPolicyName( + const grpc_channel_args* resolver_result) { + const char* lb_policy_name = nullptr; + // Prefer the LB policy name found in the service config. Note that this is + // checking the deprecated loadBalancingPolicy field, rather than the new + // loadBalancingConfig field. + if (service_config_ != nullptr) { + lb_policy_name = service_config_->GetLoadBalancingPolicyName(); + } + // Otherwise, find the LB policy name set by the client API. + if (lb_policy_name == nullptr) { + const grpc_arg* channel_arg = + grpc_channel_args_find(resolver_result, GRPC_ARG_LB_POLICY_NAME); + lb_policy_name = grpc_channel_arg_get_string(channel_arg); + } + // Special case: If at least one balancer address is present, we use + // the grpclb policy, regardless of what the resolver has returned. + const grpc_arg* channel_arg = + grpc_channel_args_find(resolver_result, GRPC_ARG_LB_ADDRESSES); + if (channel_arg != nullptr && channel_arg->type == GRPC_ARG_POINTER) { + grpc_lb_addresses* addresses = + static_cast<grpc_lb_addresses*>(channel_arg->value.pointer.p); + if (grpc_lb_addresses_contains_balancer_address(*addresses)) { + if (lb_policy_name != nullptr && + gpr_stricmp(lb_policy_name, "grpclb") != 0) { + gpr_log(GPR_INFO, + "resolver requested LB policy %s but provided at least one " + "balancer address -- forcing use of grpclb LB policy", + lb_policy_name); + } + lb_policy_name = "grpclb"; + } + } + // Use pick_first if nothing was specified and we didn't select grpclb + // above. + if (lb_policy_name == nullptr) lb_policy_name = "pick_first"; + lb_policy_name_.reset(gpr_strdup(lb_policy_name)); +} + +void ProcessedResolverResult::ParseServiceConfig( + const grpc_json* field, ProcessedResolverResult* parsing_state) { + parsing_state->ParseLbConfigFromServiceConfig(field); + if (parsing_state->server_name_ != nullptr) { + parsing_state->ParseRetryThrottleParamsFromServiceConfig(field); + } +} + +void ProcessedResolverResult::ParseLbConfigFromServiceConfig( + const grpc_json* field) { + if (lb_policy_config_ != nullptr) return; // Already found. + // Find the LB config global parameter. + if (field->key == nullptr || strcmp(field->key, "loadBalancingConfig") != 0 || + field->type != GRPC_JSON_ARRAY) { + return; // Not valid lb config array. + } + // Find the first LB policy that this client supports. + for (grpc_json* lb_config = field->child; lb_config != nullptr; + lb_config = lb_config->next) { + if (lb_config->type != GRPC_JSON_OBJECT) return; + // Find the policy object. + grpc_json* policy = nullptr; + for (grpc_json* field = lb_config->child; field != nullptr; + field = field->next) { + if (field->key == nullptr || strcmp(field->key, "policy") != 0 || + field->type != GRPC_JSON_OBJECT) { + return; + } + if (policy != nullptr) return; // Duplicate. + policy = field; + } + // Find the specific policy content since the policy object is of type + // "oneof". + grpc_json* policy_content = nullptr; + for (grpc_json* field = policy->child; field != nullptr; + field = field->next) { + if (field->key == nullptr || field->type != GRPC_JSON_OBJECT) return; + if (policy_content != nullptr) return; // Violate "oneof" type. + policy_content = field; + } + grpc_core::UniquePtr<char> lb_policy_name = + ConvertCamelToSnake(policy_content->key); + if (!grpc_core::LoadBalancingPolicyRegistry::LoadBalancingPolicyExists( + lb_policy_name.get())) { + continue; + } + lb_policy_name_ = std::move(lb_policy_name); + lb_policy_config_ = policy_content->child; + return; + } +} + +void ProcessedResolverResult::ParseRetryThrottleParamsFromServiceConfig( + const grpc_json* field) { + if (strcmp(field->key, "retryThrottling") == 0) { + if (retry_throttle_data_ != nullptr) return; // Duplicate. + if (field->type != GRPC_JSON_OBJECT) return; + int max_milli_tokens = 0; + int milli_token_ratio = 0; + for (grpc_json* sub_field = field->child; sub_field != nullptr; + sub_field = sub_field->next) { + if (sub_field->key == nullptr) return; + if (strcmp(sub_field->key, "maxTokens") == 0) { + if (max_milli_tokens != 0) return; // Duplicate. + if (sub_field->type != GRPC_JSON_NUMBER) return; + max_milli_tokens = gpr_parse_nonnegative_int(sub_field->value); + if (max_milli_tokens == -1) return; + max_milli_tokens *= 1000; + } else if (strcmp(sub_field->key, "tokenRatio") == 0) { + if (milli_token_ratio != 0) return; // Duplicate. + if (sub_field->type != GRPC_JSON_NUMBER) return; + // We support up to 3 decimal digits. + size_t whole_len = strlen(sub_field->value); + uint32_t multiplier = 1; + uint32_t decimal_value = 0; + const char* decimal_point = strchr(sub_field->value, '.'); + if (decimal_point != nullptr) { + whole_len = static_cast<size_t>(decimal_point - sub_field->value); + multiplier = 1000; + size_t decimal_len = strlen(decimal_point + 1); + if (decimal_len > 3) decimal_len = 3; + if (!gpr_parse_bytes_to_uint32(decimal_point + 1, decimal_len, + &decimal_value)) { + return; + } + uint32_t decimal_multiplier = 1; + for (size_t i = 0; i < (3 - decimal_len); ++i) { + decimal_multiplier *= 10; + } + decimal_value *= decimal_multiplier; + } + uint32_t whole_value; + if (!gpr_parse_bytes_to_uint32(sub_field->value, whole_len, + &whole_value)) { + return; + } + milli_token_ratio = + static_cast<int>((whole_value * multiplier) + decimal_value); + if (milli_token_ratio <= 0) return; + } + } + retry_throttle_data_ = + grpc_core::internal::ServerRetryThrottleMap::GetDataForServer( + server_name_, max_milli_tokens, milli_token_ratio); + } +} + +namespace { + +bool ParseWaitForReady( + grpc_json* field, ClientChannelMethodParams::WaitForReady* wait_for_ready) { + if (field->type != GRPC_JSON_TRUE && field->type != GRPC_JSON_FALSE) { + return false; + } + *wait_for_ready = field->type == GRPC_JSON_TRUE + ? ClientChannelMethodParams::WAIT_FOR_READY_TRUE + : ClientChannelMethodParams::WAIT_FOR_READY_FALSE; + return true; +} + +// Parses a JSON field of the form generated for a google.proto.Duration +// proto message, as per: +// https://developers.google.com/protocol-buffers/docs/proto3#json +bool ParseDuration(grpc_json* field, grpc_millis* duration) { + if (field->type != GRPC_JSON_STRING) return false; + size_t len = strlen(field->value); + if (field->value[len - 1] != 's') return false; + UniquePtr<char> buf(gpr_strdup(field->value)); + *(buf.get() + len - 1) = '\0'; // Remove trailing 's'. + char* decimal_point = strchr(buf.get(), '.'); + int nanos = 0; + if (decimal_point != nullptr) { + *decimal_point = '\0'; + nanos = gpr_parse_nonnegative_int(decimal_point + 1); + if (nanos == -1) { + return false; + } + int num_digits = static_cast<int>(strlen(decimal_point + 1)); + if (num_digits > 9) { // We don't accept greater precision than nanos. + return false; + } + for (int i = 0; i < (9 - num_digits); ++i) { + nanos *= 10; + } + } + int seconds = + decimal_point == buf.get() ? 0 : gpr_parse_nonnegative_int(buf.get()); + if (seconds == -1) return false; + *duration = seconds * GPR_MS_PER_SEC + nanos / GPR_NS_PER_MS; + return true; +} + +UniquePtr<ClientChannelMethodParams::RetryPolicy> ParseRetryPolicy( + grpc_json* field) { + auto retry_policy = MakeUnique<ClientChannelMethodParams::RetryPolicy>(); + if (field->type != GRPC_JSON_OBJECT) return nullptr; + for (grpc_json* sub_field = field->child; sub_field != nullptr; + sub_field = sub_field->next) { + if (sub_field->key == nullptr) return nullptr; + if (strcmp(sub_field->key, "maxAttempts") == 0) { + if (retry_policy->max_attempts != 0) return nullptr; // Duplicate. + if (sub_field->type != GRPC_JSON_NUMBER) return nullptr; + retry_policy->max_attempts = gpr_parse_nonnegative_int(sub_field->value); + if (retry_policy->max_attempts <= 1) return nullptr; + if (retry_policy->max_attempts > MAX_MAX_RETRY_ATTEMPTS) { + gpr_log(GPR_ERROR, + "service config: clamped retryPolicy.maxAttempts at %d", + MAX_MAX_RETRY_ATTEMPTS); + retry_policy->max_attempts = MAX_MAX_RETRY_ATTEMPTS; + } + } else if (strcmp(sub_field->key, "initialBackoff") == 0) { + if (retry_policy->initial_backoff > 0) return nullptr; // Duplicate. + if (!ParseDuration(sub_field, &retry_policy->initial_backoff)) { + return nullptr; + } + if (retry_policy->initial_backoff == 0) return nullptr; + } else if (strcmp(sub_field->key, "maxBackoff") == 0) { + if (retry_policy->max_backoff > 0) return nullptr; // Duplicate. + if (!ParseDuration(sub_field, &retry_policy->max_backoff)) { + return nullptr; + } + if (retry_policy->max_backoff == 0) return nullptr; + } else if (strcmp(sub_field->key, "backoffMultiplier") == 0) { + if (retry_policy->backoff_multiplier != 0) return nullptr; // Duplicate. + if (sub_field->type != GRPC_JSON_NUMBER) return nullptr; + if (sscanf(sub_field->value, "%f", &retry_policy->backoff_multiplier) != + 1) { + return nullptr; + } + if (retry_policy->backoff_multiplier <= 0) return nullptr; + } else if (strcmp(sub_field->key, "retryableStatusCodes") == 0) { + if (!retry_policy->retryable_status_codes.Empty()) { + return nullptr; // Duplicate. + } + if (sub_field->type != GRPC_JSON_ARRAY) return nullptr; + for (grpc_json* element = sub_field->child; element != nullptr; + element = element->next) { + if (element->type != GRPC_JSON_STRING) return nullptr; + grpc_status_code status; + if (!grpc_status_code_from_string(element->value, &status)) { + return nullptr; + } + retry_policy->retryable_status_codes.Add(status); + } + if (retry_policy->retryable_status_codes.Empty()) return nullptr; + } + } + // Make sure required fields are set. + if (retry_policy->max_attempts == 0 || retry_policy->initial_backoff == 0 || + retry_policy->max_backoff == 0 || retry_policy->backoff_multiplier == 0 || + retry_policy->retryable_status_codes.Empty()) { + return nullptr; + } + return retry_policy; +} + +} // namespace + +RefCountedPtr<ClientChannelMethodParams> +ClientChannelMethodParams::CreateFromJson(const grpc_json* json) { + RefCountedPtr<ClientChannelMethodParams> method_params = + MakeRefCounted<ClientChannelMethodParams>(); + for (grpc_json* field = json->child; field != nullptr; field = field->next) { + if (field->key == nullptr) continue; + if (strcmp(field->key, "waitForReady") == 0) { + if (method_params->wait_for_ready_ != WAIT_FOR_READY_UNSET) { + return nullptr; // Duplicate. + } + if (!ParseWaitForReady(field, &method_params->wait_for_ready_)) { + return nullptr; + } + } else if (strcmp(field->key, "timeout") == 0) { + if (method_params->timeout_ > 0) return nullptr; // Duplicate. + if (!ParseDuration(field, &method_params->timeout_)) return nullptr; + } else if (strcmp(field->key, "retryPolicy") == 0) { + if (method_params->retry_policy_ != nullptr) { + return nullptr; // Duplicate. + } + method_params->retry_policy_ = ParseRetryPolicy(field); + if (method_params->retry_policy_ == nullptr) return nullptr; + } + } + return method_params; +} + +} // namespace internal +} // namespace grpc_core |