| /* |
| * |
| * Copyright 2016 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> |
| |
| #if GRPC_ARES == 1 && !defined(GRPC_UV) |
| |
| #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h" |
| #include "src/core/lib/iomgr/sockaddr.h" |
| |
| #include <string.h> |
| #include <sys/types.h> |
| |
| #include <ares.h> |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/string_util.h> |
| #include <grpc/support/time.h> |
| |
| #include <address_sorting/address_sorting.h> |
| #include "src/core/ext/filters/client_channel/parse_address.h" |
| #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h" |
| #include "src/core/lib/gpr/host_port.h" |
| #include "src/core/lib/gpr/string.h" |
| #include "src/core/lib/iomgr/combiner.h" |
| #include "src/core/lib/iomgr/error.h" |
| #include "src/core/lib/iomgr/executor.h" |
| #include "src/core/lib/iomgr/iomgr_internal.h" |
| #include "src/core/lib/iomgr/nameser.h" |
| #include "src/core/lib/iomgr/sockaddr_utils.h" |
| |
| using grpc_core::ServerAddress; |
| using grpc_core::ServerAddressList; |
| |
| static gpr_once g_basic_init = GPR_ONCE_INIT; |
| static gpr_mu g_init_mu; |
| |
| grpc_core::TraceFlag grpc_trace_cares_address_sorting(false, |
| "cares_address_sorting"); |
| |
| grpc_core::TraceFlag grpc_trace_cares_resolver(false, "cares_resolver"); |
| |
| struct grpc_ares_request { |
| /** indicates the DNS server to use, if specified */ |
| struct ares_addr_port_node dns_server_addr; |
| /** following members are set in grpc_resolve_address_ares_impl */ |
| /** closure to call when the request completes */ |
| grpc_closure* on_done; |
| /** the pointer to receive the resolved addresses */ |
| grpc_core::UniquePtr<grpc_core::ServerAddressList>* addresses_out; |
| /** the pointer to receive the service config in JSON */ |
| char** service_config_json_out; |
| /** the evernt driver used by this request */ |
| grpc_ares_ev_driver* ev_driver; |
| /** number of ongoing queries */ |
| size_t pending_queries; |
| |
| /** is there at least one successful query, set in on_done_cb */ |
| bool success; |
| /** the errors explaining the request failure, set in on_done_cb */ |
| grpc_error* error; |
| }; |
| |
| typedef struct grpc_ares_hostbyname_request { |
| /** following members are set in create_hostbyname_request_locked |
| */ |
| /** the top-level request instance */ |
| grpc_ares_request* parent_request; |
| /** host to resolve, parsed from the name to resolve */ |
| char* host; |
| /** port to fill in sockaddr_in, parsed from the name to resolve */ |
| uint16_t port; |
| /** is it a grpclb address */ |
| bool is_balancer; |
| } grpc_ares_hostbyname_request; |
| |
| static void do_basic_init(void) { gpr_mu_init(&g_init_mu); } |
| |
| static void log_address_sorting_list(const ServerAddressList& addresses, |
| const char* input_output_str) { |
| for (size_t i = 0; i < addresses.size(); i++) { |
| char* addr_str; |
| if (grpc_sockaddr_to_string(&addr_str, &addresses[i].address(), true)) { |
| gpr_log(GPR_INFO, "c-ares address sorting: %s[%" PRIuPTR "]=%s", |
| input_output_str, i, addr_str); |
| gpr_free(addr_str); |
| } else { |
| gpr_log(GPR_INFO, |
| "c-ares address sorting: %s[%" PRIuPTR "]=<unprintable>", |
| input_output_str, i); |
| } |
| } |
| } |
| |
| void grpc_cares_wrapper_address_sorting_sort(ServerAddressList* addresses) { |
| if (grpc_trace_cares_address_sorting.enabled()) { |
| log_address_sorting_list(*addresses, "input"); |
| } |
| address_sorting_sortable* sortables = (address_sorting_sortable*)gpr_zalloc( |
| sizeof(address_sorting_sortable) * addresses->size()); |
| for (size_t i = 0; i < addresses->size(); ++i) { |
| sortables[i].user_data = &(*addresses)[i]; |
| memcpy(&sortables[i].dest_addr.addr, &(*addresses)[i].address().addr, |
| (*addresses)[i].address().len); |
| sortables[i].dest_addr.len = (*addresses)[i].address().len; |
| } |
| address_sorting_rfc_6724_sort(sortables, addresses->size()); |
| ServerAddressList sorted; |
| sorted.reserve(addresses->size()); |
| for (size_t i = 0; i < addresses->size(); ++i) { |
| sorted.emplace_back(*static_cast<ServerAddress*>(sortables[i].user_data)); |
| } |
| gpr_free(sortables); |
| *addresses = std::move(sorted); |
| if (grpc_trace_cares_address_sorting.enabled()) { |
| log_address_sorting_list(*addresses, "output"); |
| } |
| } |
| |
| static void grpc_ares_request_ref_locked(grpc_ares_request* r) { |
| r->pending_queries++; |
| } |
| |
| static void grpc_ares_request_unref_locked(grpc_ares_request* r) { |
| r->pending_queries--; |
| if (r->pending_queries == 0u) { |
| grpc_ares_ev_driver_on_queries_complete_locked(r->ev_driver); |
| } |
| } |
| |
| void grpc_ares_complete_request_locked(grpc_ares_request* r) { |
| /* Invoke on_done callback and destroy the |
| request */ |
| r->ev_driver = nullptr; |
| ServerAddressList* addresses = r->addresses_out->get(); |
| if (addresses != nullptr) { |
| grpc_cares_wrapper_address_sorting_sort(addresses); |
| } |
| GRPC_CLOSURE_SCHED(r->on_done, r->error); |
| } |
| |
| static grpc_ares_hostbyname_request* create_hostbyname_request_locked( |
| grpc_ares_request* parent_request, char* host, uint16_t port, |
| bool is_balancer) { |
| grpc_ares_hostbyname_request* hr = static_cast<grpc_ares_hostbyname_request*>( |
| gpr_zalloc(sizeof(grpc_ares_hostbyname_request))); |
| hr->parent_request = parent_request; |
| hr->host = gpr_strdup(host); |
| hr->port = port; |
| hr->is_balancer = is_balancer; |
| grpc_ares_request_ref_locked(parent_request); |
| return hr; |
| } |
| |
| static void destroy_hostbyname_request_locked( |
| grpc_ares_hostbyname_request* hr) { |
| grpc_ares_request_unref_locked(hr->parent_request); |
| gpr_free(hr->host); |
| gpr_free(hr); |
| } |
| |
| static void on_hostbyname_done_locked(void* arg, int status, int timeouts, |
| struct hostent* hostent) { |
| grpc_ares_hostbyname_request* hr = |
| static_cast<grpc_ares_hostbyname_request*>(arg); |
| grpc_ares_request* r = hr->parent_request; |
| if (status == ARES_SUCCESS) { |
| GRPC_ERROR_UNREF(r->error); |
| r->error = GRPC_ERROR_NONE; |
| r->success = true; |
| if (*r->addresses_out == nullptr) { |
| *r->addresses_out = grpc_core::MakeUnique<ServerAddressList>(); |
| } |
| ServerAddressList& addresses = **r->addresses_out; |
| for (size_t i = 0; hostent->h_addr_list[i] != nullptr; ++i) { |
| grpc_core::InlinedVector<grpc_arg, 2> args_to_add; |
| if (hr->is_balancer) { |
| args_to_add.emplace_back(grpc_channel_arg_integer_create( |
| const_cast<char*>(GRPC_ARG_ADDRESS_IS_BALANCER), 1)); |
| args_to_add.emplace_back(grpc_channel_arg_string_create( |
| const_cast<char*>(GRPC_ARG_ADDRESS_BALANCER_NAME), hr->host)); |
| } |
| grpc_channel_args* args = grpc_channel_args_copy_and_add( |
| nullptr, args_to_add.data(), args_to_add.size()); |
| switch (hostent->h_addrtype) { |
| case AF_INET6: { |
| size_t addr_len = sizeof(struct sockaddr_in6); |
| struct sockaddr_in6 addr; |
| memset(&addr, 0, addr_len); |
| memcpy(&addr.sin6_addr, hostent->h_addr_list[i], |
| sizeof(struct in6_addr)); |
| addr.sin6_family = static_cast<unsigned char>(hostent->h_addrtype); |
| addr.sin6_port = hr->port; |
| addresses.emplace_back(&addr, addr_len, args); |
| char output[INET6_ADDRSTRLEN]; |
| ares_inet_ntop(AF_INET6, &addr.sin6_addr, output, INET6_ADDRSTRLEN); |
| GRPC_CARES_TRACE_LOG( |
| "request:%p c-ares resolver gets a AF_INET6 result: \n" |
| " addr: %s\n port: %d\n sin6_scope_id: %d\n", |
| r, output, ntohs(hr->port), addr.sin6_scope_id); |
| break; |
| } |
| case AF_INET: { |
| size_t addr_len = sizeof(struct sockaddr_in); |
| struct sockaddr_in addr; |
| memset(&addr, 0, addr_len); |
| memcpy(&addr.sin_addr, hostent->h_addr_list[i], |
| sizeof(struct in_addr)); |
| addr.sin_family = static_cast<unsigned char>(hostent->h_addrtype); |
| addr.sin_port = hr->port; |
| addresses.emplace_back(&addr, addr_len, args); |
| char output[INET_ADDRSTRLEN]; |
| ares_inet_ntop(AF_INET, &addr.sin_addr, output, INET_ADDRSTRLEN); |
| GRPC_CARES_TRACE_LOG( |
| "request:%p c-ares resolver gets a AF_INET result: \n" |
| " addr: %s\n port: %d\n", |
| r, output, ntohs(hr->port)); |
| break; |
| } |
| } |
| } |
| } else if (!r->success) { |
| char* error_msg; |
| gpr_asprintf(&error_msg, "C-ares status is not ARES_SUCCESS: %s", |
| ares_strerror(status)); |
| grpc_error* error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg); |
| gpr_free(error_msg); |
| if (r->error == GRPC_ERROR_NONE) { |
| r->error = error; |
| } else { |
| r->error = grpc_error_add_child(error, r->error); |
| } |
| } |
| destroy_hostbyname_request_locked(hr); |
| } |
| |
| static void on_srv_query_done_locked(void* arg, int status, int timeouts, |
| unsigned char* abuf, int alen) { |
| grpc_ares_request* r = static_cast<grpc_ares_request*>(arg); |
| GRPC_CARES_TRACE_LOG("request:%p on_query_srv_done_locked", r); |
| if (status == ARES_SUCCESS) { |
| GRPC_CARES_TRACE_LOG("request:%p on_query_srv_done_locked ARES_SUCCESS", r); |
| struct ares_srv_reply* reply; |
| const int parse_status = ares_parse_srv_reply(abuf, alen, &reply); |
| if (parse_status == ARES_SUCCESS) { |
| ares_channel* channel = |
| grpc_ares_ev_driver_get_channel_locked(r->ev_driver); |
| for (struct ares_srv_reply* srv_it = reply; srv_it != nullptr; |
| srv_it = srv_it->next) { |
| if (grpc_ares_query_ipv6()) { |
| grpc_ares_hostbyname_request* hr = create_hostbyname_request_locked( |
| r, srv_it->host, htons(srv_it->port), true /* is_balancer */); |
| ares_gethostbyname(*channel, hr->host, AF_INET6, |
| on_hostbyname_done_locked, hr); |
| } |
| grpc_ares_hostbyname_request* hr = create_hostbyname_request_locked( |
| r, srv_it->host, htons(srv_it->port), true /* is_balancer */); |
| ares_gethostbyname(*channel, hr->host, AF_INET, |
| on_hostbyname_done_locked, hr); |
| grpc_ares_ev_driver_start_locked(r->ev_driver); |
| } |
| } |
| if (reply != nullptr) { |
| ares_free_data(reply); |
| } |
| } else if (!r->success) { |
| char* error_msg; |
| gpr_asprintf(&error_msg, "C-ares status is not ARES_SUCCESS: %s", |
| ares_strerror(status)); |
| grpc_error* error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg); |
| gpr_free(error_msg); |
| if (r->error == GRPC_ERROR_NONE) { |
| r->error = error; |
| } else { |
| r->error = grpc_error_add_child(error, r->error); |
| } |
| } |
| grpc_ares_request_unref_locked(r); |
| } |
| |
| static const char g_service_config_attribute_prefix[] = "grpc_config="; |
| |
| static void on_txt_done_locked(void* arg, int status, int timeouts, |
| unsigned char* buf, int len) { |
| char* error_msg; |
| grpc_ares_request* r = static_cast<grpc_ares_request*>(arg); |
| GRPC_CARES_TRACE_LOG("request:%p on_txt_done_locked", r); |
| const size_t prefix_len = sizeof(g_service_config_attribute_prefix) - 1; |
| struct ares_txt_ext* result = nullptr; |
| struct ares_txt_ext* reply = nullptr; |
| grpc_error* error = GRPC_ERROR_NONE; |
| if (status != ARES_SUCCESS) goto fail; |
| status = ares_parse_txt_reply_ext(buf, len, &reply); |
| if (status != ARES_SUCCESS) goto fail; |
| // Find service config in TXT record. |
| for (result = reply; result != nullptr; result = result->next) { |
| if (result->record_start && |
| memcmp(result->txt, g_service_config_attribute_prefix, prefix_len) == |
| 0) { |
| break; |
| } |
| } |
| // Found a service config record. |
| if (result != nullptr) { |
| size_t service_config_len = result->length - prefix_len; |
| *r->service_config_json_out = |
| static_cast<char*>(gpr_malloc(service_config_len + 1)); |
| memcpy(*r->service_config_json_out, result->txt + prefix_len, |
| service_config_len); |
| for (result = result->next; result != nullptr && !result->record_start; |
| result = result->next) { |
| *r->service_config_json_out = static_cast<char*>( |
| gpr_realloc(*r->service_config_json_out, |
| service_config_len + result->length + 1)); |
| memcpy(*r->service_config_json_out + service_config_len, result->txt, |
| result->length); |
| service_config_len += result->length; |
| } |
| (*r->service_config_json_out)[service_config_len] = '\0'; |
| GRPC_CARES_TRACE_LOG("request:%p found service config: %s", r, |
| *r->service_config_json_out); |
| } |
| // Clean up. |
| ares_free_data(reply); |
| goto done; |
| fail: |
| gpr_asprintf(&error_msg, "C-ares TXT lookup status is not ARES_SUCCESS: %s", |
| ares_strerror(status)); |
| error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg); |
| gpr_free(error_msg); |
| if (r->error == GRPC_ERROR_NONE) { |
| r->error = error; |
| } else { |
| r->error = grpc_error_add_child(error, r->error); |
| } |
| done: |
| grpc_ares_request_unref_locked(r); |
| } |
| |
| void grpc_dns_lookup_ares_continue_after_check_localhost_and_ip_literals_locked( |
| grpc_ares_request* r, const char* dns_server, const char* name, |
| const char* default_port, grpc_pollset_set* interested_parties, |
| bool check_grpclb, int query_timeout_ms, grpc_combiner* combiner) { |
| grpc_error* error = GRPC_ERROR_NONE; |
| grpc_ares_hostbyname_request* hr = nullptr; |
| ares_channel* channel = nullptr; |
| /* parse name, splitting it into host and port parts */ |
| char* host; |
| char* port; |
| gpr_split_host_port(name, &host, &port); |
| if (host == nullptr) { |
| error = grpc_error_set_str( |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("unparseable host:port"), |
| GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name)); |
| goto error_cleanup; |
| } else if (port == nullptr) { |
| if (default_port == nullptr) { |
| error = grpc_error_set_str( |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("no port in name"), |
| GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name)); |
| goto error_cleanup; |
| } |
| port = gpr_strdup(default_port); |
| } |
| error = grpc_ares_ev_driver_create_locked(&r->ev_driver, interested_parties, |
| query_timeout_ms, combiner, r); |
| if (error != GRPC_ERROR_NONE) goto error_cleanup; |
| channel = grpc_ares_ev_driver_get_channel_locked(r->ev_driver); |
| // If dns_server is specified, use it. |
| if (dns_server != nullptr) { |
| GRPC_CARES_TRACE_LOG("request:%p Using DNS server %s", r, dns_server); |
| grpc_resolved_address addr; |
| if (grpc_parse_ipv4_hostport(dns_server, &addr, false /* log_errors */)) { |
| r->dns_server_addr.family = AF_INET; |
| struct sockaddr_in* in = reinterpret_cast<struct sockaddr_in*>(addr.addr); |
| memcpy(&r->dns_server_addr.addr.addr4, &in->sin_addr, |
| sizeof(struct in_addr)); |
| r->dns_server_addr.tcp_port = grpc_sockaddr_get_port(&addr); |
| r->dns_server_addr.udp_port = grpc_sockaddr_get_port(&addr); |
| } else if (grpc_parse_ipv6_hostport(dns_server, &addr, |
| false /* log_errors */)) { |
| r->dns_server_addr.family = AF_INET6; |
| struct sockaddr_in6* in6 = |
| reinterpret_cast<struct sockaddr_in6*>(addr.addr); |
| memcpy(&r->dns_server_addr.addr.addr6, &in6->sin6_addr, |
| sizeof(struct in6_addr)); |
| r->dns_server_addr.tcp_port = grpc_sockaddr_get_port(&addr); |
| r->dns_server_addr.udp_port = grpc_sockaddr_get_port(&addr); |
| } else { |
| error = grpc_error_set_str( |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("cannot parse authority"), |
| GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name)); |
| goto error_cleanup; |
| } |
| int status = ares_set_servers_ports(*channel, &r->dns_server_addr); |
| if (status != ARES_SUCCESS) { |
| char* error_msg; |
| gpr_asprintf(&error_msg, "C-ares status is not ARES_SUCCESS: %s", |
| ares_strerror(status)); |
| error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg); |
| gpr_free(error_msg); |
| goto error_cleanup; |
| } |
| } |
| r->pending_queries = 1; |
| if (grpc_ares_query_ipv6()) { |
| hr = create_hostbyname_request_locked(r, host, grpc_strhtons(port), |
| false /* is_balancer */); |
| ares_gethostbyname(*channel, hr->host, AF_INET6, on_hostbyname_done_locked, |
| hr); |
| } |
| hr = create_hostbyname_request_locked(r, host, grpc_strhtons(port), |
| false /* is_balancer */); |
| ares_gethostbyname(*channel, hr->host, AF_INET, on_hostbyname_done_locked, |
| hr); |
| if (check_grpclb) { |
| /* Query the SRV record */ |
| grpc_ares_request_ref_locked(r); |
| char* service_name; |
| gpr_asprintf(&service_name, "_grpclb._tcp.%s", host); |
| ares_query(*channel, service_name, ns_c_in, ns_t_srv, |
| on_srv_query_done_locked, r); |
| gpr_free(service_name); |
| } |
| if (r->service_config_json_out != nullptr) { |
| grpc_ares_request_ref_locked(r); |
| char* config_name; |
| gpr_asprintf(&config_name, "_grpc_config.%s", host); |
| ares_search(*channel, config_name, ns_c_in, ns_t_txt, on_txt_done_locked, |
| r); |
| gpr_free(config_name); |
| } |
| grpc_ares_ev_driver_start_locked(r->ev_driver); |
| grpc_ares_request_unref_locked(r); |
| gpr_free(host); |
| gpr_free(port); |
| return; |
| |
| error_cleanup: |
| GRPC_CLOSURE_SCHED(r->on_done, error); |
| gpr_free(host); |
| gpr_free(port); |
| } |
| |
| static bool inner_resolve_as_ip_literal_locked( |
| const char* name, const char* default_port, |
| grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, char** host, |
| char** port, char** hostport) { |
| gpr_split_host_port(name, host, port); |
| if (*host == nullptr) { |
| gpr_log(GPR_ERROR, |
| "Failed to parse %s to host:port while attempting to resolve as ip " |
| "literal.", |
| name); |
| return false; |
| } |
| if (*port == nullptr) { |
| if (default_port == nullptr) { |
| gpr_log(GPR_ERROR, |
| "No port or default port for %s while attempting to resolve as " |
| "ip literal.", |
| name); |
| return false; |
| } |
| *port = gpr_strdup(default_port); |
| } |
| grpc_resolved_address addr; |
| GPR_ASSERT(gpr_join_host_port(hostport, *host, atoi(*port))); |
| if (grpc_parse_ipv4_hostport(*hostport, &addr, false /* log errors */) || |
| grpc_parse_ipv6_hostport(*hostport, &addr, false /* log errors */)) { |
| GPR_ASSERT(*addrs == nullptr); |
| *addrs = grpc_core::MakeUnique<ServerAddressList>(); |
| (*addrs)->emplace_back(addr.addr, addr.len, nullptr /* args */); |
| return true; |
| } |
| return false; |
| } |
| |
| static bool resolve_as_ip_literal_locked( |
| const char* name, const char* default_port, |
| grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs) { |
| char* host = nullptr; |
| char* port = nullptr; |
| char* hostport = nullptr; |
| bool out = inner_resolve_as_ip_literal_locked(name, default_port, addrs, |
| &host, &port, &hostport); |
| gpr_free(host); |
| gpr_free(port); |
| gpr_free(hostport); |
| return out; |
| } |
| |
| static bool target_matches_localhost_inner(const char* name, char** host, |
| char** port) { |
| if (!gpr_split_host_port(name, host, port)) { |
| gpr_log(GPR_ERROR, "Unable to split host and port for name: %s", name); |
| return false; |
| } |
| if (gpr_stricmp(*host, "localhost") == 0) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| static bool target_matches_localhost(const char* name) { |
| char* host = nullptr; |
| char* port = nullptr; |
| bool out = target_matches_localhost_inner(name, &host, &port); |
| gpr_free(host); |
| gpr_free(port); |
| return out; |
| } |
| |
| static grpc_ares_request* grpc_dns_lookup_ares_locked_impl( |
| const char* dns_server, const char* name, const char* default_port, |
| grpc_pollset_set* interested_parties, grpc_closure* on_done, |
| grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, |
| bool check_grpclb, char** service_config_json, int query_timeout_ms, |
| grpc_combiner* combiner) { |
| grpc_ares_request* r = |
| static_cast<grpc_ares_request*>(gpr_zalloc(sizeof(grpc_ares_request))); |
| r->ev_driver = nullptr; |
| r->on_done = on_done; |
| r->addresses_out = addrs; |
| r->service_config_json_out = service_config_json; |
| r->success = false; |
| r->error = GRPC_ERROR_NONE; |
| r->pending_queries = 0; |
| GRPC_CARES_TRACE_LOG( |
| "request:%p c-ares grpc_dns_lookup_ares_locked_impl name=%s, " |
| "default_port=%s", |
| r, name, default_port); |
| // Early out if the target is an ipv4 or ipv6 literal. |
| if (resolve_as_ip_literal_locked(name, default_port, addrs)) { |
| GRPC_CLOSURE_SCHED(on_done, GRPC_ERROR_NONE); |
| return r; |
| } |
| // Early out if the target is localhost and we're on Windows. |
| if (grpc_ares_maybe_resolve_localhost_manually_locked(name, default_port, |
| addrs)) { |
| GRPC_CLOSURE_SCHED(on_done, GRPC_ERROR_NONE); |
| return r; |
| } |
| // Don't query for SRV and TXT records if the target is "localhost", so |
| // as to cut down on lookups over the network, especially in tests: |
| // https://github.com/grpc/proposal/pull/79 |
| if (target_matches_localhost(name)) { |
| check_grpclb = false; |
| r->service_config_json_out = nullptr; |
| } |
| // Look up name using c-ares lib. |
| grpc_dns_lookup_ares_continue_after_check_localhost_and_ip_literals_locked( |
| r, dns_server, name, default_port, interested_parties, check_grpclb, |
| query_timeout_ms, combiner); |
| return r; |
| } |
| |
| grpc_ares_request* (*grpc_dns_lookup_ares_locked)( |
| const char* dns_server, const char* name, const char* default_port, |
| grpc_pollset_set* interested_parties, grpc_closure* on_done, |
| grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, |
| bool check_grpclb, char** service_config_json, int query_timeout_ms, |
| grpc_combiner* combiner) = grpc_dns_lookup_ares_locked_impl; |
| |
| static void grpc_cancel_ares_request_locked_impl(grpc_ares_request* r) { |
| GPR_ASSERT(r != nullptr); |
| if (r->ev_driver != nullptr) { |
| grpc_ares_ev_driver_shutdown_locked(r->ev_driver); |
| } |
| } |
| |
| void (*grpc_cancel_ares_request_locked)(grpc_ares_request* r) = |
| grpc_cancel_ares_request_locked_impl; |
| |
| grpc_error* grpc_ares_init(void) { |
| gpr_once_init(&g_basic_init, do_basic_init); |
| gpr_mu_lock(&g_init_mu); |
| int status = ares_library_init(ARES_LIB_INIT_ALL); |
| gpr_mu_unlock(&g_init_mu); |
| |
| if (status != ARES_SUCCESS) { |
| char* error_msg; |
| gpr_asprintf(&error_msg, "ares_library_init failed: %s", |
| ares_strerror(status)); |
| grpc_error* error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg); |
| gpr_free(error_msg); |
| return error; |
| } |
| return GRPC_ERROR_NONE; |
| } |
| |
| void grpc_ares_cleanup(void) { |
| gpr_mu_lock(&g_init_mu); |
| ares_library_cleanup(); |
| gpr_mu_unlock(&g_init_mu); |
| } |
| |
| /* |
| * grpc_resolve_address_ares related structs and functions |
| */ |
| |
| typedef struct grpc_resolve_address_ares_request { |
| /* combiner that queries and related callbacks run under */ |
| grpc_combiner* combiner; |
| /** the pointer to receive the resolved addresses */ |
| grpc_resolved_addresses** addrs_out; |
| /** currently resolving addresses */ |
| grpc_core::UniquePtr<ServerAddressList> addresses; |
| /** closure to call when the resolve_address_ares request completes */ |
| grpc_closure* on_resolve_address_done; |
| /** a closure wrapping on_resolve_address_done, which should be invoked when |
| the grpc_dns_lookup_ares_locked operation is done. */ |
| grpc_closure on_dns_lookup_done_locked; |
| /* target name */ |
| const char* name; |
| /* default port to use if none is specified */ |
| const char* default_port; |
| /* pollset_set to be driven by */ |
| grpc_pollset_set* interested_parties; |
| /* underlying ares_request that the query is performed on */ |
| grpc_ares_request* ares_request = nullptr; |
| } grpc_resolve_address_ares_request; |
| |
| static void on_dns_lookup_done_locked(void* arg, grpc_error* error) { |
| grpc_resolve_address_ares_request* r = |
| static_cast<grpc_resolve_address_ares_request*>(arg); |
| gpr_free(r->ares_request); |
| grpc_resolved_addresses** resolved_addresses = r->addrs_out; |
| if (r->addresses == nullptr || r->addresses->empty()) { |
| *resolved_addresses = nullptr; |
| } else { |
| *resolved_addresses = static_cast<grpc_resolved_addresses*>( |
| gpr_zalloc(sizeof(grpc_resolved_addresses))); |
| (*resolved_addresses)->naddrs = r->addresses->size(); |
| (*resolved_addresses)->addrs = |
| static_cast<grpc_resolved_address*>(gpr_zalloc( |
| sizeof(grpc_resolved_address) * (*resolved_addresses)->naddrs)); |
| for (size_t i = 0; i < (*resolved_addresses)->naddrs; ++i) { |
| GPR_ASSERT(!(*r->addresses)[i].IsBalancer()); |
| memcpy(&(*resolved_addresses)->addrs[i], &(*r->addresses)[i].address(), |
| sizeof(grpc_resolved_address)); |
| } |
| } |
| GRPC_CLOSURE_SCHED(r->on_resolve_address_done, GRPC_ERROR_REF(error)); |
| GRPC_COMBINER_UNREF(r->combiner, "on_dns_lookup_done_cb"); |
| grpc_core::Delete(r); |
| } |
| |
| static void grpc_resolve_address_invoke_dns_lookup_ares_locked( |
| void* arg, grpc_error* unused_error) { |
| grpc_resolve_address_ares_request* r = |
| static_cast<grpc_resolve_address_ares_request*>(arg); |
| r->ares_request = grpc_dns_lookup_ares_locked( |
| nullptr /* dns_server */, r->name, r->default_port, r->interested_parties, |
| &r->on_dns_lookup_done_locked, &r->addresses, false /* check_grpclb */, |
| nullptr /* service_config_json */, GRPC_DNS_ARES_DEFAULT_QUERY_TIMEOUT_MS, |
| r->combiner); |
| } |
| |
| static void grpc_resolve_address_ares_impl(const char* name, |
| const char* default_port, |
| grpc_pollset_set* interested_parties, |
| grpc_closure* on_done, |
| grpc_resolved_addresses** addrs) { |
| grpc_resolve_address_ares_request* r = |
| grpc_core::New<grpc_resolve_address_ares_request>(); |
| r->combiner = grpc_combiner_create(); |
| r->addrs_out = addrs; |
| r->on_resolve_address_done = on_done; |
| GRPC_CLOSURE_INIT(&r->on_dns_lookup_done_locked, on_dns_lookup_done_locked, r, |
| grpc_combiner_scheduler(r->combiner)); |
| r->name = name; |
| r->default_port = default_port; |
| r->interested_parties = interested_parties; |
| GRPC_CLOSURE_SCHED( |
| GRPC_CLOSURE_CREATE(grpc_resolve_address_invoke_dns_lookup_ares_locked, r, |
| grpc_combiner_scheduler(r->combiner)), |
| GRPC_ERROR_NONE); |
| } |
| |
| void (*grpc_resolve_address_ares)( |
| const char* name, const char* default_port, |
| grpc_pollset_set* interested_parties, grpc_closure* on_done, |
| grpc_resolved_addresses** addrs) = grpc_resolve_address_ares_impl; |
| |
| #endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */ |
