| /* |
| * |
| * 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 |
| |
| #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 "absl/container/inlined_vector.h" |
| #include "absl/strings/str_cat.h" |
| #include "absl/strings/str_format.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/resolver/dns/c_ares/grpc_ares_ev_driver.h" |
| #include "src/core/lib/address_utils/parse_address.h" |
| #include "src/core/lib/address_utils/sockaddr_utils.h" |
| #include "src/core/lib/gpr/string.h" |
| #include "src/core/lib/gprpp/host_port.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/timer.h" |
| #include "src/core/lib/transport/authority_override.h" |
| |
| using grpc_core::ServerAddress; |
| using grpc_core::ServerAddressList; |
| |
| grpc_core::TraceFlag grpc_trace_cares_address_sorting(false, |
| "cares_address_sorting"); |
| |
| grpc_core::TraceFlag grpc_trace_cares_resolver(false, "cares_resolver"); |
| |
| typedef struct grpc_ares_ev_driver grpc_ares_ev_driver; |
| |
| 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 */ |
| std::unique_ptr<grpc_core::ServerAddressList>* addresses_out; |
| /** the pointer to receive the resolved balancer addresses */ |
| std::unique_ptr<grpc_core::ServerAddressList>* balancer_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; |
| |
| /** the errors explaining query failures, appended to in query callbacks */ |
| grpc_error_handle error; |
| }; |
| |
| typedef struct fd_node { |
| /** the owner of this fd node */ |
| grpc_ares_ev_driver* ev_driver; |
| /** a closure wrapping on_readable_locked, which should be |
| invoked when the grpc_fd in this node becomes readable. */ |
| grpc_closure read_closure; |
| /** a closure wrapping on_writable_locked, which should be |
| invoked when the grpc_fd in this node becomes writable. */ |
| grpc_closure write_closure; |
| /** next fd node in the list */ |
| struct fd_node* next; |
| |
| /** wrapped fd that's polled by grpc's poller for the current platform */ |
| grpc_core::GrpcPolledFd* grpc_polled_fd; |
| /** if the readable closure has been registered */ |
| bool readable_registered; |
| /** if the writable closure has been registered */ |
| bool writable_registered; |
| /** if the fd has been shutdown yet from grpc iomgr perspective */ |
| bool already_shutdown; |
| } fd_node; |
| |
| struct grpc_ares_ev_driver { |
| /** the ares_channel owned by this event driver */ |
| ares_channel channel; |
| /** pollset set for driving the IO events of the channel */ |
| grpc_pollset_set* pollset_set; |
| /** refcount of the event driver */ |
| gpr_refcount refs; |
| |
| /** work_serializer to synchronize c-ares and I/O callbacks on */ |
| std::shared_ptr<grpc_core::WorkSerializer> work_serializer; |
| /** a list of grpc_fd that this event driver is currently using. */ |
| fd_node* fds; |
| /** is this event driver being shut down */ |
| bool shutting_down; |
| /** request object that's using this ev driver */ |
| grpc_ares_request* request; |
| /** Owned by the ev_driver. Creates new GrpcPolledFd's */ |
| std::unique_ptr<grpc_core::GrpcPolledFdFactory> polled_fd_factory; |
| /** query timeout in milliseconds */ |
| int query_timeout_ms; |
| /** alarm to cancel active queries */ |
| grpc_timer query_timeout; |
| /** cancels queries on a timeout */ |
| grpc_closure on_timeout_locked; |
| /** alarm to poll ares_process on in case fd events don't happen */ |
| grpc_timer ares_backup_poll_alarm; |
| /** polls ares_process on a periodic timer */ |
| grpc_closure on_ares_backup_poll_alarm_locked; |
| }; |
| |
| // TODO(apolcyn): make grpc_ares_hostbyname_request a sub-class |
| // of GrpcAresQuery. |
| 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; |
| /** for logging and errors: the query type ("A" or "AAAA") */ |
| const char* qtype; |
| } grpc_ares_hostbyname_request; |
| |
| static void grpc_ares_request_ref_locked(grpc_ares_request* r); |
| static void grpc_ares_request_unref_locked(grpc_ares_request* r); |
| |
| // TODO(apolcyn): as a part of C++-ification, find a way to |
| // organize per-query and per-resolution information in such a way |
| // that doesn't involve allocating a number of different data |
| // structures. |
| class GrpcAresQuery { |
| public: |
| explicit GrpcAresQuery(grpc_ares_request* r, const std::string& name) |
| : r_(r), name_(name) { |
| grpc_ares_request_ref_locked(r_); |
| } |
| |
| ~GrpcAresQuery() { grpc_ares_request_unref_locked(r_); } |
| |
| grpc_ares_request* parent_request() { return r_; } |
| |
| const std::string& name() { return name_; } |
| |
| private: |
| /* the top level request instance */ |
| grpc_ares_request* r_; |
| /** for logging and errors */ |
| const std::string name_; |
| }; |
| |
| static grpc_ares_ev_driver* grpc_ares_ev_driver_ref( |
| grpc_ares_ev_driver* ev_driver) { |
| GRPC_CARES_TRACE_LOG("request:%p Ref ev_driver %p", ev_driver->request, |
| ev_driver); |
| gpr_ref(&ev_driver->refs); |
| return ev_driver; |
| } |
| |
| static void grpc_ares_ev_driver_unref(grpc_ares_ev_driver* ev_driver) { |
| GRPC_CARES_TRACE_LOG("request:%p Unref ev_driver %p", ev_driver->request, |
| ev_driver); |
| if (gpr_unref(&ev_driver->refs)) { |
| GRPC_CARES_TRACE_LOG("request:%p destroy ev_driver %p", ev_driver->request, |
| ev_driver); |
| GPR_ASSERT(ev_driver->fds == nullptr); |
| ares_destroy(ev_driver->channel); |
| grpc_ares_complete_request_locked(ev_driver->request); |
| delete ev_driver; |
| } |
| } |
| |
| static void fd_node_destroy_locked(fd_node* fdn) { |
| GRPC_CARES_TRACE_LOG("request:%p delete fd: %s", fdn->ev_driver->request, |
| fdn->grpc_polled_fd->GetName()); |
| GPR_ASSERT(!fdn->readable_registered); |
| GPR_ASSERT(!fdn->writable_registered); |
| GPR_ASSERT(fdn->already_shutdown); |
| delete fdn->grpc_polled_fd; |
| gpr_free(fdn); |
| } |
| |
| static void fd_node_shutdown_locked(fd_node* fdn, const char* reason) { |
| if (!fdn->already_shutdown) { |
| fdn->already_shutdown = true; |
| fdn->grpc_polled_fd->ShutdownLocked( |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING(reason)); |
| } |
| } |
| |
| void grpc_ares_ev_driver_on_queries_complete_locked( |
| grpc_ares_ev_driver* ev_driver) { |
| // We mark the event driver as being shut down. |
| // grpc_ares_notify_on_event_locked will shut down any remaining |
| // fds. |
| ev_driver->shutting_down = true; |
| grpc_timer_cancel(&ev_driver->query_timeout); |
| grpc_timer_cancel(&ev_driver->ares_backup_poll_alarm); |
| grpc_ares_ev_driver_unref(ev_driver); |
| } |
| |
| void grpc_ares_ev_driver_shutdown_locked(grpc_ares_ev_driver* ev_driver) { |
| ev_driver->shutting_down = true; |
| fd_node* fn = ev_driver->fds; |
| while (fn != nullptr) { |
| fd_node_shutdown_locked(fn, "grpc_ares_ev_driver_shutdown"); |
| fn = fn->next; |
| } |
| } |
| |
| // Search fd in the fd_node list head. This is an O(n) search, the max possible |
| // value of n is ARES_GETSOCK_MAXNUM (16). n is typically 1 - 2 in our tests. |
| static fd_node* pop_fd_node_locked(fd_node** head, ares_socket_t as) { |
| fd_node phony_head; |
| phony_head.next = *head; |
| fd_node* node = &phony_head; |
| while (node->next != nullptr) { |
| if (node->next->grpc_polled_fd->GetWrappedAresSocketLocked() == as) { |
| fd_node* ret = node->next; |
| node->next = node->next->next; |
| *head = phony_head.next; |
| return ret; |
| } |
| node = node->next; |
| } |
| return nullptr; |
| } |
| |
| static grpc_millis calculate_next_ares_backup_poll_alarm_ms( |
| grpc_ares_ev_driver* driver) { |
| // An alternative here could be to use ares_timeout to try to be more |
| // accurate, but that would require using "struct timeval"'s, which just makes |
| // things a bit more complicated. So just poll every second, as suggested |
| // by the c-ares code comments. |
| grpc_millis ms_until_next_ares_backup_poll_alarm = 1000; |
| GRPC_CARES_TRACE_LOG( |
| "request:%p ev_driver=%p. next ares process poll time in " |
| "%" PRId64 " ms", |
| driver->request, driver, ms_until_next_ares_backup_poll_alarm); |
| return ms_until_next_ares_backup_poll_alarm + |
| grpc_core::ExecCtx::Get()->Now(); |
| } |
| |
| static void on_timeout_locked(grpc_ares_ev_driver* driver, |
| grpc_error_handle error) { |
| GRPC_CARES_TRACE_LOG( |
| "request:%p ev_driver=%p on_timeout_locked. driver->shutting_down=%d. " |
| "err=%s", |
| driver->request, driver, driver->shutting_down, |
| grpc_error_std_string(error).c_str()); |
| if (!driver->shutting_down && error == GRPC_ERROR_NONE) { |
| grpc_ares_ev_driver_shutdown_locked(driver); |
| } |
| grpc_ares_ev_driver_unref(driver); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void on_timeout(void* arg, grpc_error_handle error) { |
| grpc_ares_ev_driver* driver = static_cast<grpc_ares_ev_driver*>(arg); |
| GRPC_ERROR_REF(error); // ref owned by lambda |
| driver->work_serializer->Run( |
| [driver, error]() { on_timeout_locked(driver, error); }, DEBUG_LOCATION); |
| } |
| |
| static void grpc_ares_notify_on_event_locked(grpc_ares_ev_driver* ev_driver); |
| |
| static void on_ares_backup_poll_alarm_locked(grpc_ares_ev_driver* driver, |
| grpc_error_handle error); |
| |
| static void on_ares_backup_poll_alarm(void* arg, grpc_error_handle error) { |
| grpc_ares_ev_driver* driver = static_cast<grpc_ares_ev_driver*>(arg); |
| GRPC_ERROR_REF(error); |
| driver->work_serializer->Run( |
| [driver, error]() { on_ares_backup_poll_alarm_locked(driver, error); }, |
| DEBUG_LOCATION); |
| } |
| |
| /* In case of non-responsive DNS servers, dropped packets, etc., c-ares has |
| * intelligent timeout and retry logic, which we can take advantage of by |
| * polling ares_process_fd on time intervals. Overall, the c-ares library is |
| * meant to be called into and given a chance to proceed name resolution: |
| * a) when fd events happen |
| * b) when some time has passed without fd events having happened |
| * For the latter, we use this backup poller. Also see |
| * https://github.com/grpc/grpc/pull/17688 description for more details. */ |
| static void on_ares_backup_poll_alarm_locked(grpc_ares_ev_driver* driver, |
| grpc_error_handle error) { |
| GRPC_CARES_TRACE_LOG( |
| "request:%p ev_driver=%p on_ares_backup_poll_alarm_locked. " |
| "driver->shutting_down=%d. " |
| "err=%s", |
| driver->request, driver, driver->shutting_down, |
| grpc_error_std_string(error).c_str()); |
| if (!driver->shutting_down && error == GRPC_ERROR_NONE) { |
| fd_node* fdn = driver->fds; |
| while (fdn != nullptr) { |
| if (!fdn->already_shutdown) { |
| GRPC_CARES_TRACE_LOG( |
| "request:%p ev_driver=%p on_ares_backup_poll_alarm_locked; " |
| "ares_process_fd. fd=%s", |
| driver->request, driver, fdn->grpc_polled_fd->GetName()); |
| ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked(); |
| ares_process_fd(driver->channel, as, as); |
| } |
| fdn = fdn->next; |
| } |
| if (!driver->shutting_down) { |
| // InvalidateNow to avoid getting stuck re-initializing this timer |
| // in a loop while draining the currently-held WorkSerializer. |
| // Also see https://github.com/grpc/grpc/issues/26079. |
| grpc_core::ExecCtx::Get()->InvalidateNow(); |
| grpc_millis next_ares_backup_poll_alarm = |
| calculate_next_ares_backup_poll_alarm_ms(driver); |
| grpc_ares_ev_driver_ref(driver); |
| GRPC_CLOSURE_INIT(&driver->on_ares_backup_poll_alarm_locked, |
| on_ares_backup_poll_alarm, driver, |
| grpc_schedule_on_exec_ctx); |
| grpc_timer_init(&driver->ares_backup_poll_alarm, |
| next_ares_backup_poll_alarm, |
| &driver->on_ares_backup_poll_alarm_locked); |
| } |
| grpc_ares_notify_on_event_locked(driver); |
| } |
| grpc_ares_ev_driver_unref(driver); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void on_readable_locked(fd_node* fdn, grpc_error_handle error) { |
| GPR_ASSERT(fdn->readable_registered); |
| grpc_ares_ev_driver* ev_driver = fdn->ev_driver; |
| const ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked(); |
| fdn->readable_registered = false; |
| GRPC_CARES_TRACE_LOG("request:%p readable on %s", fdn->ev_driver->request, |
| fdn->grpc_polled_fd->GetName()); |
| if (error == GRPC_ERROR_NONE) { |
| do { |
| ares_process_fd(ev_driver->channel, as, ARES_SOCKET_BAD); |
| } while (fdn->grpc_polled_fd->IsFdStillReadableLocked()); |
| } else { |
| // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or |
| // timed out. The pending lookups made on this ev_driver will be cancelled |
| // by the following ares_cancel() and the on_done callbacks will be invoked |
| // with a status of ARES_ECANCELLED. The remaining file descriptors in this |
| // ev_driver will be cleaned up in the follwing |
| // grpc_ares_notify_on_event_locked(). |
| ares_cancel(ev_driver->channel); |
| } |
| grpc_ares_notify_on_event_locked(ev_driver); |
| grpc_ares_ev_driver_unref(ev_driver); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void on_readable(void* arg, grpc_error_handle error) { |
| fd_node* fdn = static_cast<fd_node*>(arg); |
| GRPC_ERROR_REF(error); /* ref owned by lambda */ |
| fdn->ev_driver->work_serializer->Run( |
| [fdn, error]() { on_readable_locked(fdn, error); }, DEBUG_LOCATION); |
| } |
| |
| static void on_writable_locked(fd_node* fdn, grpc_error_handle error) { |
| GPR_ASSERT(fdn->writable_registered); |
| grpc_ares_ev_driver* ev_driver = fdn->ev_driver; |
| const ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked(); |
| fdn->writable_registered = false; |
| GRPC_CARES_TRACE_LOG("request:%p writable on %s", ev_driver->request, |
| fdn->grpc_polled_fd->GetName()); |
| if (error == GRPC_ERROR_NONE) { |
| ares_process_fd(ev_driver->channel, ARES_SOCKET_BAD, as); |
| } else { |
| // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or |
| // timed out. The pending lookups made on this ev_driver will be cancelled |
| // by the following ares_cancel() and the on_done callbacks will be invoked |
| // with a status of ARES_ECANCELLED. The remaining file descriptors in this |
| // ev_driver will be cleaned up in the follwing |
| // grpc_ares_notify_on_event_locked(). |
| ares_cancel(ev_driver->channel); |
| } |
| grpc_ares_notify_on_event_locked(ev_driver); |
| grpc_ares_ev_driver_unref(ev_driver); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void on_writable(void* arg, grpc_error_handle error) { |
| fd_node* fdn = static_cast<fd_node*>(arg); |
| GRPC_ERROR_REF(error); /* ref owned by lambda */ |
| fdn->ev_driver->work_serializer->Run( |
| [fdn, error]() { on_writable_locked(fdn, error); }, DEBUG_LOCATION); |
| } |
| |
| // Get the file descriptors used by the ev_driver's ares channel, register |
| // driver_closure with these filedescriptors. |
| static void grpc_ares_notify_on_event_locked(grpc_ares_ev_driver* ev_driver) { |
| fd_node* new_list = nullptr; |
| if (!ev_driver->shutting_down) { |
| ares_socket_t socks[ARES_GETSOCK_MAXNUM]; |
| int socks_bitmask = |
| ares_getsock(ev_driver->channel, socks, ARES_GETSOCK_MAXNUM); |
| for (size_t i = 0; i < ARES_GETSOCK_MAXNUM; i++) { |
| if (ARES_GETSOCK_READABLE(socks_bitmask, i) || |
| ARES_GETSOCK_WRITABLE(socks_bitmask, i)) { |
| fd_node* fdn = pop_fd_node_locked(&ev_driver->fds, socks[i]); |
| // Create a new fd_node if sock[i] is not in the fd_node list. |
| if (fdn == nullptr) { |
| fdn = static_cast<fd_node*>(gpr_malloc(sizeof(fd_node))); |
| fdn->grpc_polled_fd = |
| ev_driver->polled_fd_factory->NewGrpcPolledFdLocked( |
| socks[i], ev_driver->pollset_set, ev_driver->work_serializer); |
| GRPC_CARES_TRACE_LOG("request:%p new fd: %s", ev_driver->request, |
| fdn->grpc_polled_fd->GetName()); |
| fdn->ev_driver = ev_driver; |
| fdn->readable_registered = false; |
| fdn->writable_registered = false; |
| fdn->already_shutdown = false; |
| } |
| fdn->next = new_list; |
| new_list = fdn; |
| // Register read_closure if the socket is readable and read_closure has |
| // not been registered with this socket. |
| if (ARES_GETSOCK_READABLE(socks_bitmask, i) && |
| !fdn->readable_registered) { |
| grpc_ares_ev_driver_ref(ev_driver); |
| GRPC_CARES_TRACE_LOG("request:%p notify read on: %s", |
| ev_driver->request, |
| fdn->grpc_polled_fd->GetName()); |
| GRPC_CLOSURE_INIT(&fdn->read_closure, on_readable, fdn, |
| grpc_schedule_on_exec_ctx); |
| fdn->grpc_polled_fd->RegisterForOnReadableLocked(&fdn->read_closure); |
| fdn->readable_registered = true; |
| } |
| // Register write_closure if the socket is writable and write_closure |
| // has not been registered with this socket. |
| if (ARES_GETSOCK_WRITABLE(socks_bitmask, i) && |
| !fdn->writable_registered) { |
| GRPC_CARES_TRACE_LOG("request:%p notify write on: %s", |
| ev_driver->request, |
| fdn->grpc_polled_fd->GetName()); |
| grpc_ares_ev_driver_ref(ev_driver); |
| GRPC_CLOSURE_INIT(&fdn->write_closure, on_writable, fdn, |
| grpc_schedule_on_exec_ctx); |
| GRPC_CLOSURE_INIT(&fdn->write_closure, on_writable, fdn, |
| grpc_schedule_on_exec_ctx); |
| fdn->grpc_polled_fd->RegisterForOnWriteableLocked( |
| &fdn->write_closure); |
| fdn->writable_registered = true; |
| } |
| } |
| } |
| } |
| // Any remaining fds in ev_driver->fds were not returned by ares_getsock() and |
| // are therefore no longer in use, so they can be shut down and removed from |
| // the list. |
| while (ev_driver->fds != nullptr) { |
| fd_node* cur = ev_driver->fds; |
| ev_driver->fds = ev_driver->fds->next; |
| fd_node_shutdown_locked(cur, "c-ares fd shutdown"); |
| if (!cur->readable_registered && !cur->writable_registered) { |
| fd_node_destroy_locked(cur); |
| } else { |
| cur->next = new_list; |
| new_list = cur; |
| } |
| } |
| ev_driver->fds = new_list; |
| } |
| |
| void grpc_ares_ev_driver_start_locked(grpc_ares_ev_driver* ev_driver) { |
| grpc_ares_notify_on_event_locked(ev_driver); |
| // Initialize overall DNS resolution timeout alarm |
| grpc_millis timeout = |
| ev_driver->query_timeout_ms == 0 |
| ? GRPC_MILLIS_INF_FUTURE |
| : ev_driver->query_timeout_ms + grpc_core::ExecCtx::Get()->Now(); |
| GRPC_CARES_TRACE_LOG( |
| "request:%p ev_driver=%p grpc_ares_ev_driver_start_locked. timeout in " |
| "%" PRId64 " ms", |
| ev_driver->request, ev_driver, timeout); |
| grpc_ares_ev_driver_ref(ev_driver); |
| GRPC_CLOSURE_INIT(&ev_driver->on_timeout_locked, on_timeout, ev_driver, |
| grpc_schedule_on_exec_ctx); |
| grpc_timer_init(&ev_driver->query_timeout, timeout, |
| &ev_driver->on_timeout_locked); |
| // Initialize the backup poll alarm |
| grpc_millis next_ares_backup_poll_alarm = |
| calculate_next_ares_backup_poll_alarm_ms(ev_driver); |
| grpc_ares_ev_driver_ref(ev_driver); |
| GRPC_CLOSURE_INIT(&ev_driver->on_ares_backup_poll_alarm_locked, |
| on_ares_backup_poll_alarm, ev_driver, |
| grpc_schedule_on_exec_ctx); |
| grpc_timer_init(&ev_driver->ares_backup_poll_alarm, |
| next_ares_backup_poll_alarm, |
| &ev_driver->on_ares_backup_poll_alarm_locked); |
| } |
| |
| static void noop_inject_channel_config(ares_channel /*channel*/) {} |
| |
| void (*grpc_ares_test_only_inject_config)(ares_channel channel) = |
| noop_inject_channel_config; |
| |
| grpc_error_handle grpc_ares_ev_driver_create_locked( |
| grpc_ares_ev_driver** ev_driver, grpc_pollset_set* pollset_set, |
| int query_timeout_ms, |
| std::shared_ptr<grpc_core::WorkSerializer> work_serializer, |
| grpc_ares_request* request) { |
| *ev_driver = new grpc_ares_ev_driver(); |
| ares_options opts; |
| memset(&opts, 0, sizeof(opts)); |
| opts.flags |= ARES_FLAG_STAYOPEN; |
| int status = ares_init_options(&(*ev_driver)->channel, &opts, ARES_OPT_FLAGS); |
| grpc_ares_test_only_inject_config((*ev_driver)->channel); |
| GRPC_CARES_TRACE_LOG("request:%p grpc_ares_ev_driver_create_locked", request); |
| if (status != ARES_SUCCESS) { |
| grpc_error_handle err = GRPC_ERROR_CREATE_FROM_COPIED_STRING( |
| absl::StrCat("Failed to init ares channel. C-ares error: ", |
| ares_strerror(status)) |
| .c_str()); |
| gpr_free(*ev_driver); |
| return err; |
| } |
| (*ev_driver)->work_serializer = std::move(work_serializer); |
| gpr_ref_init(&(*ev_driver)->refs, 1); |
| (*ev_driver)->pollset_set = pollset_set; |
| (*ev_driver)->fds = nullptr; |
| (*ev_driver)->shutting_down = false; |
| (*ev_driver)->request = request; |
| (*ev_driver)->polled_fd_factory = |
| grpc_core::NewGrpcPolledFdFactory((*ev_driver)->work_serializer); |
| (*ev_driver) |
| ->polled_fd_factory->ConfigureAresChannelLocked((*ev_driver)->channel); |
| (*ev_driver)->query_timeout_ms = query_timeout_ms; |
| return GRPC_ERROR_NONE; |
| } |
| |
| static void log_address_sorting_list(const grpc_ares_request* r, |
| const ServerAddressList& addresses, |
| const char* input_output_str) { |
| for (size_t i = 0; i < addresses.size(); i++) { |
| std::string addr_str = |
| grpc_sockaddr_to_string(&addresses[i].address(), true); |
| gpr_log(GPR_INFO, |
| "(c-ares resolver) request:%p c-ares address sorting: %s[%" PRIuPTR |
| "]=%s", |
| r, input_output_str, i, addr_str.c_str()); |
| } |
| } |
| |
| void grpc_cares_wrapper_address_sorting_sort(const grpc_ares_request* r, |
| ServerAddressList* addresses) { |
| if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_cares_address_sorting)) { |
| log_address_sorting_list(r, *addresses, "input"); |
| } |
| address_sorting_sortable* sortables = static_cast<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_FLAG_ENABLED(grpc_trace_cares_address_sorting)) { |
| log_address_sorting_list(r, *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(r, addresses); |
| GRPC_ERROR_UNREF(r->error); |
| r->error = GRPC_ERROR_NONE; |
| // TODO(apolcyn): allow c-ares to return a service config |
| // with no addresses along side it |
| } |
| if (r->balancer_addresses_out != nullptr) { |
| ServerAddressList* balancer_addresses = r->balancer_addresses_out->get(); |
| if (balancer_addresses != nullptr) { |
| grpc_cares_wrapper_address_sorting_sort(r, balancer_addresses); |
| } |
| } |
| grpc_core::ExecCtx::Run(DEBUG_LOCATION, r->on_done, r->error); |
| } |
| |
| /* Note that the returned object takes a reference to qtype, so |
| * qtype must outlive it. */ |
| static grpc_ares_hostbyname_request* create_hostbyname_request_locked( |
| grpc_ares_request* parent_request, const char* host, uint16_t port, |
| bool is_balancer, const char* qtype) { |
| GRPC_CARES_TRACE_LOG( |
| "request:%p create_hostbyname_request_locked host:%s port:%d " |
| "is_balancer:%d qtype:%s", |
| parent_request, host, port, is_balancer, qtype); |
| grpc_ares_hostbyname_request* hr = new grpc_ares_hostbyname_request(); |
| hr->parent_request = parent_request; |
| hr->host = gpr_strdup(host); |
| hr->port = port; |
| hr->is_balancer = is_balancer; |
| hr->qtype = qtype; |
| 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); |
| delete 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_CARES_TRACE_LOG( |
| "request:%p on_hostbyname_done_locked qtype=%s host=%s ARES_SUCCESS", r, |
| hr->qtype, hr->host); |
| std::unique_ptr<ServerAddressList>* address_list_ptr = |
| hr->is_balancer ? r->balancer_addresses_out : r->addresses_out; |
| if (*address_list_ptr == nullptr) { |
| *address_list_ptr = absl::make_unique<ServerAddressList>(); |
| } |
| ServerAddressList& addresses = **address_list_ptr; |
| for (size_t i = 0; hostent->h_addr_list[i] != nullptr; ++i) { |
| absl::InlinedVector<grpc_arg, 1> args_to_add; |
| if (hr->is_balancer) { |
| args_to_add.emplace_back( |
| grpc_core::CreateAuthorityOverrideChannelArg(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 { |
| std::string error_msg = absl::StrFormat( |
| "C-ares status is not ARES_SUCCESS qtype=%s name=%s is_balancer=%d: %s", |
| hr->qtype, hr->host, hr->is_balancer, ares_strerror(status)); |
| GRPC_CARES_TRACE_LOG("request:%p on_hostbyname_done_locked: %s", r, |
| error_msg.c_str()); |
| grpc_error_handle error = |
| GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg.c_str()); |
| 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) { |
| GrpcAresQuery* q = static_cast<GrpcAresQuery*>(arg); |
| grpc_ares_request* r = q->parent_request(); |
| if (status == ARES_SUCCESS) { |
| GRPC_CARES_TRACE_LOG( |
| "request:%p on_srv_query_done_locked name=%s ARES_SUCCESS", r, |
| q->name().c_str()); |
| struct ares_srv_reply* reply; |
| const int parse_status = ares_parse_srv_reply(abuf, alen, &reply); |
| GRPC_CARES_TRACE_LOG("request:%p ares_parse_srv_reply: %d", r, |
| parse_status); |
| if (parse_status == ARES_SUCCESS) { |
| 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 */, |
| "AAAA"); |
| ares_gethostbyname(r->ev_driver->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 */, "A"); |
| ares_gethostbyname(r->ev_driver->channel, hr->host, AF_INET, |
| on_hostbyname_done_locked, hr); |
| grpc_ares_notify_on_event_locked(r->ev_driver); |
| } |
| } |
| if (reply != nullptr) { |
| ares_free_data(reply); |
| } |
| } else { |
| std::string error_msg = absl::StrFormat( |
| "C-ares status is not ARES_SUCCESS qtype=SRV name=%s: %s", q->name(), |
| ares_strerror(status)); |
| GRPC_CARES_TRACE_LOG("request:%p on_srv_query_done_locked: %s", r, |
| error_msg.c_str()); |
| grpc_error_handle error = |
| GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg.c_str()); |
| r->error = grpc_error_add_child(error, r->error); |
| } |
| delete q; |
| } |
| |
| 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) { |
| GrpcAresQuery* q = static_cast<GrpcAresQuery*>(arg); |
| std::unique_ptr<GrpcAresQuery> query_deleter(q); |
| grpc_ares_request* r = q->parent_request(); |
| 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_handle error = GRPC_ERROR_NONE; |
| if (status != ARES_SUCCESS) goto fail; |
| GRPC_CARES_TRACE_LOG("request:%p on_txt_done_locked name=%s ARES_SUCCESS", r, |
| q->name().c_str()); |
| 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); |
| return; |
| fail: |
| std::string error_msg = |
| absl::StrFormat("C-ares status is not ARES_SUCCESS qtype=TXT name=%s: %s", |
| q->name(), ares_strerror(status)); |
| error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg.c_str()); |
| GRPC_CARES_TRACE_LOG("request:%p on_txt_done_locked %s", r, |
| error_msg.c_str()); |
| r->error = grpc_error_add_child(error, r->error); |
| } |
| |
| 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, |
| int query_timeout_ms, |
| std::shared_ptr<grpc_core::WorkSerializer> work_serializer) { |
| grpc_error_handle error = GRPC_ERROR_NONE; |
| grpc_ares_hostbyname_request* hr = nullptr; |
| /* parse name, splitting it into host and port parts */ |
| std::string host; |
| std::string port; |
| grpc_core::SplitHostPort(name, &host, &port); |
| if (host.empty()) { |
| 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.empty()) { |
| 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 = default_port; |
| } |
| error = grpc_ares_ev_driver_create_locked(&r->ev_driver, interested_parties, |
| query_timeout_ms, |
| std::move(work_serializer), r); |
| if (error != GRPC_ERROR_NONE) goto error_cleanup; |
| // If dns_server is specified, use it. |
| if (dns_server != nullptr && dns_server[0] != '\0') { |
| 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(r->ev_driver->channel, &r->dns_server_addr); |
| if (status != ARES_SUCCESS) { |
| error = GRPC_ERROR_CREATE_FROM_COPIED_STRING( |
| absl::StrCat("C-ares status is not ARES_SUCCESS: ", |
| ares_strerror(status)) |
| .c_str()); |
| goto error_cleanup; |
| } |
| } |
| r->pending_queries = 1; |
| if (grpc_ares_query_ipv6()) { |
| hr = create_hostbyname_request_locked(r, host.c_str(), |
| grpc_strhtons(port.c_str()), |
| /*is_balancer=*/false, "AAAA"); |
| ares_gethostbyname(r->ev_driver->channel, hr->host, AF_INET6, |
| on_hostbyname_done_locked, hr); |
| } |
| hr = create_hostbyname_request_locked(r, host.c_str(), |
| grpc_strhtons(port.c_str()), |
| /*is_balancer=*/false, "A"); |
| ares_gethostbyname(r->ev_driver->channel, hr->host, AF_INET, |
| on_hostbyname_done_locked, hr); |
| if (r->balancer_addresses_out != nullptr) { |
| /* Query the SRV record */ |
| std::string service_name = absl::StrCat("_grpclb._tcp.", host); |
| GrpcAresQuery* srv_query = new GrpcAresQuery(r, service_name); |
| ares_query(r->ev_driver->channel, service_name.c_str(), ns_c_in, ns_t_srv, |
| on_srv_query_done_locked, srv_query); |
| } |
| if (r->service_config_json_out != nullptr) { |
| std::string config_name = absl::StrCat("_grpc_config.", host); |
| GrpcAresQuery* txt_query = new GrpcAresQuery(r, config_name); |
| ares_search(r->ev_driver->channel, config_name.c_str(), ns_c_in, ns_t_txt, |
| on_txt_done_locked, txt_query); |
| } |
| grpc_ares_ev_driver_start_locked(r->ev_driver); |
| grpc_ares_request_unref_locked(r); |
| return; |
| |
| error_cleanup: |
| grpc_core::ExecCtx::Run(DEBUG_LOCATION, r->on_done, error); |
| } |
| |
| static bool inner_resolve_as_ip_literal_locked( |
| const char* name, const char* default_port, |
| std::unique_ptr<grpc_core::ServerAddressList>* addrs, std::string* host, |
| std::string* port, std::string* hostport) { |
| if (!grpc_core::SplitHostPort(name, host, port)) { |
| gpr_log(GPR_ERROR, |
| "Failed to parse %s to host:port while attempting to resolve as ip " |
| "literal.", |
| name); |
| return false; |
| } |
| if (port->empty()) { |
| 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 = default_port; |
| } |
| grpc_resolved_address addr; |
| *hostport = grpc_core::JoinHostPort(*host, atoi(port->c_str())); |
| if (grpc_parse_ipv4_hostport(hostport->c_str(), &addr, |
| false /* log errors */) || |
| grpc_parse_ipv6_hostport(hostport->c_str(), &addr, |
| false /* log errors */)) { |
| GPR_ASSERT(*addrs == nullptr); |
| *addrs = absl::make_unique<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, |
| std::unique_ptr<grpc_core::ServerAddressList>* addrs) { |
| std::string host; |
| std::string port; |
| std::string hostport; |
| bool out = inner_resolve_as_ip_literal_locked(name, default_port, addrs, |
| &host, &port, &hostport); |
| return out; |
| } |
| |
| static bool target_matches_localhost_inner(const char* name, std::string* host, |
| std::string* port) { |
| if (!grpc_core::SplitHostPort(name, host, port)) { |
| gpr_log(GPR_ERROR, "Unable to split host and port for name: %s", name); |
| return false; |
| } |
| return gpr_stricmp(host->c_str(), "localhost") == 0; |
| } |
| |
| static bool target_matches_localhost(const char* name) { |
| std::string host; |
| std::string port; |
| return target_matches_localhost_inner(name, &host, &port); |
| } |
| |
| #ifdef GRPC_ARES_RESOLVE_LOCALHOST_MANUALLY |
| static bool inner_maybe_resolve_localhost_manually_locked( |
| const grpc_ares_request* r, const char* name, const char* default_port, |
| std::unique_ptr<grpc_core::ServerAddressList>* addrs, std::string* host, |
| std::string* port) { |
| grpc_core::SplitHostPort(name, host, port); |
| if (host->empty()) { |
| gpr_log(GPR_ERROR, |
| "Failed to parse %s into host:port during manual localhost " |
| "resolution check.", |
| name); |
| return false; |
| } |
| if (port->empty()) { |
| if (default_port == nullptr) { |
| gpr_log(GPR_ERROR, |
| "No port or default port for %s during manual localhost " |
| "resolution check.", |
| name); |
| return false; |
| } |
| *port = default_port; |
| } |
| if (gpr_stricmp(host->c_str(), "localhost") == 0) { |
| GPR_ASSERT(*addrs == nullptr); |
| *addrs = absl::make_unique<grpc_core::ServerAddressList>(); |
| uint16_t numeric_port = grpc_strhtons(port->c_str()); |
| // Append the ipv6 loopback address. |
| struct sockaddr_in6 ipv6_loopback_addr; |
| memset(&ipv6_loopback_addr, 0, sizeof(ipv6_loopback_addr)); |
| ((char*)&ipv6_loopback_addr.sin6_addr)[15] = 1; |
| ipv6_loopback_addr.sin6_family = AF_INET6; |
| ipv6_loopback_addr.sin6_port = numeric_port; |
| (*addrs)->emplace_back(&ipv6_loopback_addr, sizeof(ipv6_loopback_addr), |
| nullptr /* args */); |
| // Append the ipv4 loopback address. |
| struct sockaddr_in ipv4_loopback_addr; |
| memset(&ipv4_loopback_addr, 0, sizeof(ipv4_loopback_addr)); |
| ((char*)&ipv4_loopback_addr.sin_addr)[0] = 0x7f; |
| ((char*)&ipv4_loopback_addr.sin_addr)[3] = 0x01; |
| ipv4_loopback_addr.sin_family = AF_INET; |
| ipv4_loopback_addr.sin_port = numeric_port; |
| (*addrs)->emplace_back(&ipv4_loopback_addr, sizeof(ipv4_loopback_addr), |
| nullptr /* args */); |
| // Let the address sorter figure out which one should be tried first. |
| grpc_cares_wrapper_address_sorting_sort(r, addrs->get()); |
| return true; |
| } |
| return false; |
| } |
| |
| static bool grpc_ares_maybe_resolve_localhost_manually_locked( |
| const grpc_ares_request* r, const char* name, const char* default_port, |
| std::unique_ptr<grpc_core::ServerAddressList>* addrs) { |
| std::string host; |
| std::string port; |
| return inner_maybe_resolve_localhost_manually_locked(r, name, default_port, |
| addrs, &host, &port); |
| } |
| #else /* GRPC_ARES_RESOLVE_LOCALHOST_MANUALLY */ |
| static bool grpc_ares_maybe_resolve_localhost_manually_locked( |
| const grpc_ares_request* /*r*/, const char* /*name*/, |
| const char* /*default_port*/, |
| std::unique_ptr<grpc_core::ServerAddressList>* /*addrs*/) { |
| return false; |
| } |
| #endif /* GRPC_ARES_RESOLVE_LOCALHOST_MANUALLY */ |
| |
| 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, |
| std::unique_ptr<grpc_core::ServerAddressList>* addrs, |
| std::unique_ptr<grpc_core::ServerAddressList>* balancer_addrs, |
| char** service_config_json, int query_timeout_ms, |
| std::shared_ptr<grpc_core::WorkSerializer> work_serializer) { |
| 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->balancer_addresses_out = balancer_addrs; |
| r->service_config_json_out = service_config_json; |
| 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_ares_complete_request_locked(r); |
| return r; |
| } |
| // Early out if the target is localhost and we're on Windows. |
| if (grpc_ares_maybe_resolve_localhost_manually_locked(r, name, default_port, |
| addrs)) { |
| grpc_ares_complete_request_locked(r); |
| 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)) { |
| r->balancer_addresses_out = nullptr; |
| 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, query_timeout_ms, |
| std::move(work_serializer)); |
| 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, |
| std::unique_ptr<grpc_core::ServerAddressList>* addrs, |
| std::unique_ptr<grpc_core::ServerAddressList>* balancer_addrs, |
| char** service_config_json, int query_timeout_ms, |
| std::shared_ptr<grpc_core::WorkSerializer> work_serializer) = |
| 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; |
| |
| // ares_library_init and ares_library_cleanup are currently no-op except under |
| // Windows. Calling them may cause race conditions when other parts of the |
| // binary calls these functions concurrently. |
| #ifdef GPR_WINDOWS |
| grpc_error_handle grpc_ares_init(void) { |
| int status = ares_library_init(ARES_LIB_INIT_ALL); |
| if (status != ARES_SUCCESS) { |
| return GRPC_ERROR_CREATE_FROM_COPIED_STRING( |
| absl::StrCat("ares_library_init failed: ", ares_strerror(status)) |
| .c_str()); |
| } |
| return GRPC_ERROR_NONE; |
| } |
| |
| void grpc_ares_cleanup(void) { ares_library_cleanup(); } |
| #else |
| grpc_error_handle grpc_ares_init(void) { return GRPC_ERROR_NONE; } |
| void grpc_ares_cleanup(void) {} |
| #endif // GPR_WINDOWS |
| |
| /* |
| * grpc_resolve_address_ares related structs and functions |
| */ |
| |
| typedef struct grpc_resolve_address_ares_request { |
| /* work_serializer that queries and related callbacks run under */ |
| std::shared_ptr<grpc_core::WorkSerializer> work_serializer; |
| /** the pointer to receive the resolved addresses */ |
| grpc_resolved_addresses** addrs_out; |
| /** currently resolving addresses */ |
| std::unique_ptr<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(grpc_resolve_address_ares_request* r, |
| grpc_error_handle error) { |
| 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) { |
| memcpy(&(*resolved_addresses)->addrs[i], &(*r->addresses)[i].address(), |
| sizeof(grpc_resolved_address)); |
| } |
| } |
| grpc_core::ExecCtx::Run(DEBUG_LOCATION, r->on_resolve_address_done, error); |
| delete r; |
| } |
| |
| static void on_dns_lookup_done(void* arg, grpc_error_handle error) { |
| grpc_resolve_address_ares_request* r = |
| static_cast<grpc_resolve_address_ares_request*>(arg); |
| GRPC_ERROR_REF(error); // ref owned by lambda |
| r->work_serializer->Run([r, error]() { on_dns_lookup_done_locked(r, error); }, |
| DEBUG_LOCATION); |
| } |
| |
| static void grpc_resolve_address_invoke_dns_lookup_ares_locked(void* arg) { |
| grpc_resolve_address_ares_request* r = |
| static_cast<grpc_resolve_address_ares_request*>(arg); |
| GRPC_CLOSURE_INIT(&r->on_dns_lookup_done_locked, on_dns_lookup_done, r, |
| grpc_schedule_on_exec_ctx); |
| 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, |
| nullptr /* balancer_addresses */, nullptr /* service_config_json */, |
| GRPC_DNS_ARES_DEFAULT_QUERY_TIMEOUT_MS, r->work_serializer); |
| } |
| |
| 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 = |
| new grpc_resolve_address_ares_request(); |
| r->work_serializer = std::make_shared<grpc_core::WorkSerializer>(); |
| r->addrs_out = addrs; |
| r->on_resolve_address_done = on_done; |
| r->name = name; |
| r->default_port = default_port; |
| r->interested_parties = interested_parties; |
| r->work_serializer->Run( |
| [r]() { grpc_resolve_address_invoke_dns_lookup_ares_locked(r); }, |
| DEBUG_LOCATION); |
| } |
| |
| 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 */ |
