| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include "src/core/ext/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 NULL; |
| } |
| |
| 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 NULL; |
| 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 = NULL; |
| |
| GPR_ASSERT(uri != NULL); |
| *uri = grpc_uri_parse(exec_ctx, target, 1); |
| factory = lookup_factory_by_uri(*uri); |
| if (factory == NULL) { |
| 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 == NULL) { |
| 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 = NULL; |
| char *canonical_target = NULL; |
| 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 = NULL; |
| char *canonical_target = NULL; |
| 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 = NULL; |
| char *canonical_target = NULL; |
| resolve_factory(exec_ctx, target, &uri, &canonical_target); |
| grpc_uri_destroy(uri); |
| return canonical_target == NULL ? gpr_strdup(target) : canonical_target; |
| } |