| /* |
| * |
| * Copyright 2015 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 "src/core/ext/filters/client_channel/resolver_registry.h" |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/string_util.h> |
| |
| #define MAX_RESOLVERS 10 |
| #define DEFAULT_RESOLVER_PREFIX_MAX_LENGTH 32 |
| |
| static grpc_resolver_factory* g_all_of_the_resolvers[MAX_RESOLVERS]; |
| static int g_number_of_resolvers = 0; |
| |
| static char g_default_resolver_prefix[DEFAULT_RESOLVER_PREFIX_MAX_LENGTH] = |
| "dns:///"; |
| |
| void grpc_resolver_registry_init() {} |
| |
| void grpc_resolver_registry_shutdown(void) { |
| for (int i = 0; i < g_number_of_resolvers; i++) { |
| grpc_resolver_factory_unref(g_all_of_the_resolvers[i]); |
| } |
| // FIXME(ctiller): this should live in grpc_resolver_registry_init, |
| // however that would have the client_channel plugin call this AFTER we start |
| // registering resolvers from third party plugins, and so they'd never show |
| // up. |
| // We likely need some kind of dependency system for plugins.... what form |
| // that takes is TBD. |
| g_number_of_resolvers = 0; |
| } |
| |
| void grpc_resolver_registry_set_default_prefix( |
| const char* default_resolver_prefix) { |
| const size_t len = strlen(default_resolver_prefix); |
| GPR_ASSERT(len < DEFAULT_RESOLVER_PREFIX_MAX_LENGTH && |
| "default resolver prefix too long"); |
| GPR_ASSERT(len > 0 && "default resolver prefix can't be empty"); |
| // By the previous assert, default_resolver_prefix is safe to be copied with a |
| // plain strcpy. |
| strcpy(g_default_resolver_prefix, default_resolver_prefix); |
| } |
| |
| void grpc_register_resolver_type(grpc_resolver_factory* factory) { |
| int i; |
| for (i = 0; i < g_number_of_resolvers; i++) { |
| GPR_ASSERT(0 != strcmp(factory->vtable->scheme, |
| g_all_of_the_resolvers[i]->vtable->scheme)); |
| } |
| GPR_ASSERT(g_number_of_resolvers != MAX_RESOLVERS); |
| grpc_resolver_factory_ref(factory); |
| g_all_of_the_resolvers[g_number_of_resolvers++] = factory; |
| } |
| |
| static grpc_resolver_factory* lookup_factory(const char* name) { |
| int i; |
| |
| for (i = 0; i < g_number_of_resolvers; i++) { |
| if (0 == strcmp(name, g_all_of_the_resolvers[i]->vtable->scheme)) { |
| return g_all_of_the_resolvers[i]; |
| } |
| } |
| return nullptr; |
| } |
| |
| grpc_resolver_factory* grpc_resolver_factory_lookup(const char* name) { |
| grpc_resolver_factory* f = lookup_factory(name); |
| if (f) grpc_resolver_factory_ref(f); |
| return f; |
| } |
| |
| static grpc_resolver_factory* lookup_factory_by_uri(grpc_uri* uri) { |
| if (!uri) return nullptr; |
| return lookup_factory(uri->scheme); |
| } |
| |
| static grpc_resolver_factory* resolve_factory(grpc_exec_ctx* exec_ctx, |
| const char* target, |
| grpc_uri** uri, |
| char** canonical_target) { |
| grpc_resolver_factory* factory = nullptr; |
| |
| GPR_ASSERT(uri != nullptr); |
| *uri = grpc_uri_parse(exec_ctx, target, 1); |
| factory = lookup_factory_by_uri(*uri); |
| if (factory == nullptr) { |
| grpc_uri_destroy(*uri); |
| gpr_asprintf(canonical_target, "%s%s", g_default_resolver_prefix, target); |
| *uri = grpc_uri_parse(exec_ctx, *canonical_target, 1); |
| factory = lookup_factory_by_uri(*uri); |
| if (factory == nullptr) { |
| grpc_uri_destroy(grpc_uri_parse(exec_ctx, target, 0)); |
| grpc_uri_destroy(grpc_uri_parse(exec_ctx, *canonical_target, 0)); |
| gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", target, |
| *canonical_target); |
| } |
| } |
| return factory; |
| } |
| |
| grpc_resolver* grpc_resolver_create(grpc_exec_ctx* exec_ctx, const char* target, |
| const grpc_channel_args* args, |
| grpc_pollset_set* pollset_set, |
| grpc_combiner* combiner) { |
| grpc_uri* uri = nullptr; |
| char* canonical_target = nullptr; |
| grpc_resolver_factory* factory = |
| resolve_factory(exec_ctx, target, &uri, &canonical_target); |
| grpc_resolver* resolver; |
| grpc_resolver_args resolver_args; |
| memset(&resolver_args, 0, sizeof(resolver_args)); |
| resolver_args.uri = uri; |
| resolver_args.args = args; |
| resolver_args.pollset_set = pollset_set; |
| resolver_args.combiner = combiner; |
| resolver = |
| grpc_resolver_factory_create_resolver(exec_ctx, factory, &resolver_args); |
| grpc_uri_destroy(uri); |
| gpr_free(canonical_target); |
| return resolver; |
| } |
| |
| char* grpc_get_default_authority(grpc_exec_ctx* exec_ctx, const char* target) { |
| grpc_uri* uri = nullptr; |
| char* canonical_target = nullptr; |
| grpc_resolver_factory* factory = |
| resolve_factory(exec_ctx, target, &uri, &canonical_target); |
| char* authority = grpc_resolver_factory_get_default_authority(factory, uri); |
| grpc_uri_destroy(uri); |
| gpr_free(canonical_target); |
| return authority; |
| } |
| |
| char* grpc_resolver_factory_add_default_prefix_if_needed( |
| grpc_exec_ctx* exec_ctx, const char* target) { |
| grpc_uri* uri = nullptr; |
| char* canonical_target = nullptr; |
| resolve_factory(exec_ctx, target, &uri, &canonical_target); |
| grpc_uri_destroy(uri); |
| return canonical_target == nullptr ? gpr_strdup(target) : canonical_target; |
| } |