3 * Copyright 2016 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #include <grpc/support/port_platform.h>
20 #include "src/core/lib/iomgr/port.h"
21 #if GRPC_ARES == 1 && defined(GRPC_WINDOWS_SOCKET_ARES_EV_DRIVER)
25 #include <grpc/support/alloc.h>
26 #include <grpc/support/log.h>
27 #include <grpc/support/log_windows.h>
28 #include <grpc/support/string_util.h>
29 #include <grpc/support/time.h>
31 #include "src/core/lib/gpr/string.h"
32 #include "src/core/lib/gprpp/memory.h"
33 #include "src/core/lib/iomgr/combiner.h"
34 #include "src/core/lib/iomgr/iocp_windows.h"
35 #include "src/core/lib/iomgr/sockaddr_utils.h"
36 #include "src/core/lib/iomgr/sockaddr_windows.h"
37 #include "src/core/lib/iomgr/socket_windows.h"
38 #include "src/core/lib/iomgr/tcp_windows.h"
39 #include "src/core/lib/slice/slice_internal.h"
41 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
42 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
44 /* TODO(apolcyn): remove this hack after fixing upstream.
45 * Our grpc/c-ares code on Windows uses the ares_set_socket_functions API,
46 * which uses "struct iovec" type, which on Windows is defined inside of
47 * a c-ares header that is not public.
48 * See https://github.com/c-ares/c-ares/issues/206. */
56 /* c-ares reads and takes action on the error codes of the
57 * "virtual socket operations" in this file, via the WSAGetLastError
58 * APIs. If code in this file wants to set a specific WSA error that
59 * c-ares should read, it must do so by calling SetWSAError() on the
60 * WSAErrorContext instance passed to it. A WSAErrorContext must only be
61 * instantiated at the top of the virtual socket function callstack. */
62 class WSAErrorContext {
64 explicit WSAErrorContext(){};
68 WSASetLastError(error_);
72 /* Disallow copy and assignment operators */
73 WSAErrorContext(const WSAErrorContext&) = delete;
74 WSAErrorContext& operator=(const WSAErrorContext&) = delete;
76 void SetWSAError(int error) { error_ = error; }
82 /* c-ares creates its own sockets and is meant to read them when readable and
83 * write them when writeable. To fit this socket usage model into the grpc
84 * windows poller (which gives notifications when attempted reads and writes are
85 * actually fulfilled rather than possible), this GrpcPolledFdWindows class
86 * takes advantage of the ares_set_socket_functions API and acts as a virtual
87 * socket. It holds its own read and write buffers which are written to and read
88 * from c-ares and are used with the grpc windows poller, and it, e.g.,
89 * manufactures virtual socket error codes when it e.g. needs to tell the c-ares
90 * library to wait for an async read. */
91 class GrpcPolledFdWindows : public GrpcPolledFd {
97 WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY,
100 GrpcPolledFdWindows(ares_socket_t as, grpc_combiner* combiner,
101 int address_family, int socket_type)
102 : read_buf_(grpc_empty_slice()),
103 write_buf_(grpc_empty_slice()),
104 tcp_write_state_(WRITE_IDLE),
105 gotten_into_driver_list_(false),
106 address_family_(address_family),
107 socket_type_(socket_type) {
108 gpr_asprintf(&name_, "c-ares socket: %" PRIdPTR, as);
109 winsocket_ = grpc_winsocket_create(as, name_);
110 combiner_ = GRPC_COMBINER_REF(combiner, name_);
111 GRPC_CLOSURE_INIT(&outer_read_closure_,
112 &GrpcPolledFdWindows::OnIocpReadable, this,
113 grpc_combiner_scheduler(combiner_));
114 GRPC_CLOSURE_INIT(&outer_write_closure_,
115 &GrpcPolledFdWindows::OnIocpWriteable, this,
116 grpc_combiner_scheduler(combiner_));
117 GRPC_CLOSURE_INIT(&on_tcp_connect_locked_,
118 &GrpcPolledFdWindows::OnTcpConnectLocked, this,
119 grpc_combiner_scheduler(combiner_));
120 GRPC_CLOSURE_INIT(&continue_register_for_on_readable_locked_,
121 &GrpcPolledFdWindows::ContinueRegisterForOnReadableLocked,
122 this, grpc_combiner_scheduler(combiner_));
124 &continue_register_for_on_writeable_locked_,
125 &GrpcPolledFdWindows::ContinueRegisterForOnWriteableLocked, this,
126 grpc_combiner_scheduler(combiner_));
129 ~GrpcPolledFdWindows() {
130 GRPC_COMBINER_UNREF(combiner_, name_);
131 grpc_slice_unref_internal(read_buf_);
132 grpc_slice_unref_internal(write_buf_);
133 GPR_ASSERT(read_closure_ == nullptr);
134 GPR_ASSERT(write_closure_ == nullptr);
135 grpc_winsocket_destroy(winsocket_);
139 void ScheduleAndNullReadClosure(grpc_error* error) {
140 GRPC_CLOSURE_SCHED(read_closure_, error);
141 read_closure_ = nullptr;
144 void ScheduleAndNullWriteClosure(grpc_error* error) {
145 GRPC_CLOSURE_SCHED(write_closure_, error);
146 write_closure_ = nullptr;
149 void RegisterForOnReadableLocked(grpc_closure* read_closure) override {
150 GPR_ASSERT(read_closure_ == nullptr);
151 read_closure_ = read_closure;
152 GPR_ASSERT(GRPC_SLICE_LENGTH(read_buf_) == 0);
153 grpc_slice_unref_internal(read_buf_);
154 GPR_ASSERT(!read_buf_has_data_);
155 read_buf_ = GRPC_SLICE_MALLOC(4192);
157 GRPC_CLOSURE_SCHED(&continue_register_for_on_readable_locked_,
160 GPR_ASSERT(pending_continue_register_for_on_readable_locked_ == nullptr);
161 pending_continue_register_for_on_readable_locked_ =
162 &continue_register_for_on_readable_locked_;
166 static void ContinueRegisterForOnReadableLocked(void* arg,
167 grpc_error* unused_error) {
168 GrpcPolledFdWindows* grpc_polled_fd =
169 static_cast<GrpcPolledFdWindows*>(arg);
170 grpc_polled_fd->InnerContinueRegisterForOnReadableLocked(GRPC_ERROR_NONE);
173 void InnerContinueRegisterForOnReadableLocked(grpc_error* unused_error) {
174 GRPC_CARES_TRACE_LOG(
175 "fd:|%s| InnerContinueRegisterForOnReadableLocked "
176 "wsa_connect_error_:%d",
177 GetName(), wsa_connect_error_);
178 GPR_ASSERT(connect_done_);
179 if (wsa_connect_error_ != 0) {
180 ScheduleAndNullReadClosure(GRPC_WSA_ERROR(wsa_connect_error_, "connect"));
184 buffer.buf = (char*)GRPC_SLICE_START_PTR(read_buf_);
185 buffer.len = GRPC_SLICE_LENGTH(read_buf_);
186 memset(&winsocket_->read_info.overlapped, 0, sizeof(OVERLAPPED));
187 recv_from_source_addr_len_ = sizeof(recv_from_source_addr_);
189 if (WSARecvFrom(grpc_winsocket_wrapped_socket(winsocket_), &buffer, 1,
190 nullptr, &flags, (sockaddr*)recv_from_source_addr_,
191 &recv_from_source_addr_len_,
192 &winsocket_->read_info.overlapped, nullptr)) {
193 int wsa_last_error = WSAGetLastError();
194 char* msg = gpr_format_message(wsa_last_error);
195 GRPC_CARES_TRACE_LOG(
196 "fd:|%s| RegisterForOnReadableLocked WSARecvFrom error code:|%d| "
198 GetName(), wsa_last_error, msg);
200 if (wsa_last_error != WSA_IO_PENDING) {
201 ScheduleAndNullReadClosure(
202 GRPC_WSA_ERROR(wsa_last_error, "WSARecvFrom"));
206 grpc_socket_notify_on_read(winsocket_, &outer_read_closure_);
209 void RegisterForOnWriteableLocked(grpc_closure* write_closure) override {
210 if (socket_type_ == SOCK_DGRAM) {
211 GRPC_CARES_TRACE_LOG("fd:|%s| RegisterForOnWriteableLocked called",
214 GPR_ASSERT(socket_type_ == SOCK_STREAM);
215 GRPC_CARES_TRACE_LOG(
216 "fd:|%s| RegisterForOnWriteableLocked called tcp_write_state_: %d",
217 GetName(), tcp_write_state_);
219 GPR_ASSERT(write_closure_ == nullptr);
220 write_closure_ = write_closure;
222 GRPC_CLOSURE_SCHED(&continue_register_for_on_writeable_locked_,
225 GPR_ASSERT(pending_continue_register_for_on_writeable_locked_ == nullptr);
226 pending_continue_register_for_on_writeable_locked_ =
227 &continue_register_for_on_writeable_locked_;
231 static void ContinueRegisterForOnWriteableLocked(void* arg,
232 grpc_error* unused_error) {
233 GrpcPolledFdWindows* grpc_polled_fd =
234 static_cast<GrpcPolledFdWindows*>(arg);
235 grpc_polled_fd->InnerContinueRegisterForOnWriteableLocked(GRPC_ERROR_NONE);
238 void InnerContinueRegisterForOnWriteableLocked(grpc_error* unused_error) {
239 GRPC_CARES_TRACE_LOG(
240 "fd:|%s| InnerContinueRegisterForOnWriteableLocked "
241 "wsa_connect_error_:%d",
242 GetName(), wsa_connect_error_);
243 GPR_ASSERT(connect_done_);
244 if (wsa_connect_error_ != 0) {
245 ScheduleAndNullWriteClosure(
246 GRPC_WSA_ERROR(wsa_connect_error_, "connect"));
249 if (socket_type_ == SOCK_DGRAM) {
250 ScheduleAndNullWriteClosure(GRPC_ERROR_NONE);
252 GPR_ASSERT(socket_type_ == SOCK_STREAM);
253 int wsa_error_code = 0;
254 switch (tcp_write_state_) {
256 ScheduleAndNullWriteClosure(GRPC_ERROR_NONE);
258 case WRITE_REQUESTED:
259 tcp_write_state_ = WRITE_PENDING;
260 if (SendWriteBuf(nullptr, &winsocket_->write_info.overlapped,
261 &wsa_error_code) != 0) {
262 ScheduleAndNullWriteClosure(
263 GRPC_WSA_ERROR(wsa_error_code, "WSASend (overlapped)"));
265 grpc_socket_notify_on_write(winsocket_, &outer_write_closure_);
269 case WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY:
275 bool IsFdStillReadableLocked() override {
276 return GRPC_SLICE_LENGTH(read_buf_) > 0;
279 void ShutdownLocked(grpc_error* error) override {
280 grpc_winsocket_shutdown(winsocket_);
283 ares_socket_t GetWrappedAresSocketLocked() override {
284 return grpc_winsocket_wrapped_socket(winsocket_);
287 const char* GetName() override { return name_; }
289 ares_ssize_t RecvFrom(WSAErrorContext* wsa_error_ctx, void* data,
290 ares_socket_t data_len, int flags,
291 struct sockaddr* from, ares_socklen_t* from_len) {
292 GRPC_CARES_TRACE_LOG(
293 "fd:|%s| RecvFrom called read_buf_has_data:%d Current read buf "
295 GetName(), read_buf_has_data_, GRPC_SLICE_LENGTH(read_buf_));
296 if (!read_buf_has_data_) {
297 wsa_error_ctx->SetWSAError(WSAEWOULDBLOCK);
300 ares_ssize_t bytes_read = 0;
301 for (size_t i = 0; i < GRPC_SLICE_LENGTH(read_buf_) && i < data_len; i++) {
302 ((char*)data)[i] = GRPC_SLICE_START_PTR(read_buf_)[i];
305 read_buf_ = grpc_slice_sub_no_ref(read_buf_, bytes_read,
306 GRPC_SLICE_LENGTH(read_buf_));
307 if (GRPC_SLICE_LENGTH(read_buf_) == 0) {
308 read_buf_has_data_ = false;
310 /* c-ares overloads this recv_from virtual socket function to receive
311 * data on both UDP and TCP sockets, and from is nullptr for TCP. */
312 if (from != nullptr) {
313 GPR_ASSERT(*from_len <= recv_from_source_addr_len_);
314 memcpy(from, &recv_from_source_addr_, recv_from_source_addr_len_);
315 *from_len = recv_from_source_addr_len_;
320 grpc_slice FlattenIovec(const struct iovec* iov, int iov_count) {
322 for (int i = 0; i < iov_count; i++) {
323 total += iov[i].iov_len;
325 grpc_slice out = GRPC_SLICE_MALLOC(total);
327 for (int i = 0; i < iov_count; i++) {
328 for (int k = 0; k < iov[i].iov_len; k++) {
329 GRPC_SLICE_START_PTR(out)[cur++] = ((char*)iov[i].iov_base)[k];
335 int SendWriteBuf(LPDWORD bytes_sent_ptr, LPWSAOVERLAPPED overlapped,
336 int* wsa_error_code) {
338 buf.len = GRPC_SLICE_LENGTH(write_buf_);
339 buf.buf = (char*)GRPC_SLICE_START_PTR(write_buf_);
341 int out = WSASend(grpc_winsocket_wrapped_socket(winsocket_), &buf, 1,
342 bytes_sent_ptr, flags, overlapped, nullptr);
343 *wsa_error_code = WSAGetLastError();
344 GRPC_CARES_TRACE_LOG(
345 "fd:|%s| SendWriteBuf WSASend buf.len:%d *bytes_sent_ptr:%d "
347 "return:%d *wsa_error_code:%d",
348 GetName(), buf.len, bytes_sent_ptr != nullptr ? *bytes_sent_ptr : 0,
349 overlapped, out, *wsa_error_code);
353 ares_ssize_t SendV(WSAErrorContext* wsa_error_ctx, const struct iovec* iov,
355 GRPC_CARES_TRACE_LOG(
356 "fd:|%s| SendV called connect_done_:%d wsa_connect_error_:%d",
357 GetName(), connect_done_, wsa_connect_error_);
358 if (!connect_done_) {
359 wsa_error_ctx->SetWSAError(WSAEWOULDBLOCK);
362 if (wsa_connect_error_ != 0) {
363 wsa_error_ctx->SetWSAError(wsa_connect_error_);
366 switch (socket_type_) {
368 return SendVUDP(wsa_error_ctx, iov, iov_count);
370 return SendVTCP(wsa_error_ctx, iov, iov_count);
376 ares_ssize_t SendVUDP(WSAErrorContext* wsa_error_ctx, const struct iovec* iov,
378 // c-ares doesn't handle retryable errors on writes of UDP sockets.
379 // Therefore, the sendv handler for UDP sockets must only attempt
380 // to write everything inline.
381 GRPC_CARES_TRACE_LOG("fd:|%s| SendVUDP called", GetName());
382 GPR_ASSERT(GRPC_SLICE_LENGTH(write_buf_) == 0);
383 grpc_slice_unref_internal(write_buf_);
384 write_buf_ = FlattenIovec(iov, iov_count);
385 DWORD bytes_sent = 0;
386 int wsa_error_code = 0;
387 if (SendWriteBuf(&bytes_sent, nullptr, &wsa_error_code) != 0) {
388 wsa_error_ctx->SetWSAError(wsa_error_code);
389 char* msg = gpr_format_message(wsa_error_code);
390 GRPC_CARES_TRACE_LOG(
391 "fd:|%s| SendVUDP SendWriteBuf error code:%d msg:|%s|", GetName(),
392 wsa_error_code, msg);
396 write_buf_ = grpc_slice_sub_no_ref(write_buf_, bytes_sent,
397 GRPC_SLICE_LENGTH(write_buf_));
401 ares_ssize_t SendVTCP(WSAErrorContext* wsa_error_ctx, const struct iovec* iov,
403 // The "sendv" handler on TCP sockets buffers up write
404 // requests and returns an artifical WSAEWOULDBLOCK. Writing that buffer out
405 // in the background, and making further send progress in general, will
406 // happen as long as c-ares continues to show interest in writeability on
408 GRPC_CARES_TRACE_LOG("fd:|%s| SendVTCP called tcp_write_state_:%d",
409 GetName(), tcp_write_state_);
410 switch (tcp_write_state_) {
412 tcp_write_state_ = WRITE_REQUESTED;
413 GPR_ASSERT(GRPC_SLICE_LENGTH(write_buf_) == 0);
414 grpc_slice_unref_internal(write_buf_);
415 write_buf_ = FlattenIovec(iov, iov_count);
416 wsa_error_ctx->SetWSAError(WSAEWOULDBLOCK);
418 case WRITE_REQUESTED:
420 wsa_error_ctx->SetWSAError(WSAEWOULDBLOCK);
422 case WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY:
423 // c-ares is retrying a send on data that we previously returned
424 // WSAEWOULDBLOCK for, but then subsequently wrote out in the
425 // background. Right now, we assume that c-ares is retrying the same
426 // send again. If c-ares still needs to send even more data, we'll get
428 grpc_slice currently_attempted = FlattenIovec(iov, iov_count);
429 GPR_ASSERT(GRPC_SLICE_LENGTH(currently_attempted) >=
430 GRPC_SLICE_LENGTH(write_buf_));
431 ares_ssize_t total_sent = 0;
432 for (size_t i = 0; i < GRPC_SLICE_LENGTH(write_buf_); i++) {
433 GPR_ASSERT(GRPC_SLICE_START_PTR(currently_attempted)[i] ==
434 GRPC_SLICE_START_PTR(write_buf_)[i]);
437 grpc_slice_unref_internal(currently_attempted);
438 tcp_write_state_ = WRITE_IDLE;
444 static void OnTcpConnectLocked(void* arg, grpc_error* error) {
445 GrpcPolledFdWindows* grpc_polled_fd =
446 static_cast<GrpcPolledFdWindows*>(arg);
447 grpc_polled_fd->InnerOnTcpConnectLocked(error);
450 void InnerOnTcpConnectLocked(grpc_error* error) {
451 GRPC_CARES_TRACE_LOG(
452 "fd:%s InnerOnTcpConnectLocked error:|%s| "
453 "pending_register_for_readable:%" PRIdPTR
454 " pending_register_for_writeable:%" PRIdPTR,
455 GetName(), grpc_error_string(error),
456 pending_continue_register_for_on_readable_locked_,
457 pending_continue_register_for_on_writeable_locked_);
458 GPR_ASSERT(!connect_done_);
459 connect_done_ = true;
460 GPR_ASSERT(wsa_connect_error_ == 0);
461 if (error == GRPC_ERROR_NONE) {
462 DWORD transferred_bytes = 0;
465 WSAGetOverlappedResult(grpc_winsocket_wrapped_socket(winsocket_),
466 &winsocket_->write_info.overlapped,
467 &transferred_bytes, FALSE, &flags);
468 GPR_ASSERT(transferred_bytes == 0);
470 wsa_connect_error_ = WSAGetLastError();
471 char* msg = gpr_format_message(wsa_connect_error_);
472 GRPC_CARES_TRACE_LOG(
473 "fd:%s InnerOnTcpConnectLocked WSA overlapped result code:%d "
475 GetName(), wsa_connect_error_, msg);
479 // Spoof up an error code that will cause any future c-ares operations on
481 wsa_connect_error_ = WSA_OPERATION_ABORTED;
483 if (pending_continue_register_for_on_readable_locked_ != nullptr) {
484 GRPC_CLOSURE_SCHED(pending_continue_register_for_on_readable_locked_,
487 if (pending_continue_register_for_on_writeable_locked_ != nullptr) {
488 GRPC_CLOSURE_SCHED(pending_continue_register_for_on_writeable_locked_,
493 int Connect(WSAErrorContext* wsa_error_ctx, const struct sockaddr* target,
494 ares_socklen_t target_len) {
495 switch (socket_type_) {
497 return ConnectUDP(wsa_error_ctx, target, target_len);
499 return ConnectTCP(wsa_error_ctx, target, target_len);
505 int ConnectUDP(WSAErrorContext* wsa_error_ctx, const struct sockaddr* target,
506 ares_socklen_t target_len) {
507 GRPC_CARES_TRACE_LOG("fd:%s ConnectUDP", GetName());
508 GPR_ASSERT(!connect_done_);
509 GPR_ASSERT(wsa_connect_error_ == 0);
510 SOCKET s = grpc_winsocket_wrapped_socket(winsocket_);
512 WSAConnect(s, target, target_len, nullptr, nullptr, nullptr, nullptr);
513 wsa_connect_error_ = WSAGetLastError();
514 wsa_error_ctx->SetWSAError(wsa_connect_error_);
515 connect_done_ = true;
516 char* msg = gpr_format_message(wsa_connect_error_);
517 GRPC_CARES_TRACE_LOG("fd:%s WSAConnect error code:|%d| msg:|%s|", GetName(),
518 wsa_connect_error_, msg);
520 // c-ares expects a posix-style connect API
521 return out == 0 ? 0 : -1;
524 int ConnectTCP(WSAErrorContext* wsa_error_ctx, const struct sockaddr* target,
525 ares_socklen_t target_len) {
526 GRPC_CARES_TRACE_LOG("fd:%s ConnectTCP", GetName());
527 LPFN_CONNECTEX ConnectEx;
528 GUID guid = WSAID_CONNECTEX;
529 DWORD ioctl_num_bytes;
530 SOCKET s = grpc_winsocket_wrapped_socket(winsocket_);
531 if (WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER, &guid, sizeof(guid),
532 &ConnectEx, sizeof(ConnectEx), &ioctl_num_bytes, nullptr,
534 int wsa_last_error = WSAGetLastError();
535 wsa_error_ctx->SetWSAError(wsa_last_error);
536 char* msg = gpr_format_message(wsa_last_error);
537 GRPC_CARES_TRACE_LOG(
538 "fd:%s WSAIoctl(SIO_GET_EXTENSION_FUNCTION_POINTER) error code:%d "
540 GetName(), wsa_last_error, msg);
542 connect_done_ = true;
543 wsa_connect_error_ = wsa_last_error;
546 grpc_resolved_address wildcard4_addr;
547 grpc_resolved_address wildcard6_addr;
548 grpc_sockaddr_make_wildcards(0, &wildcard4_addr, &wildcard6_addr);
549 grpc_resolved_address* local_address = nullptr;
550 if (address_family_ == AF_INET) {
551 local_address = &wildcard4_addr;
553 local_address = &wildcard6_addr;
555 if (bind(s, (struct sockaddr*)local_address->addr,
556 (int)local_address->len) != 0) {
557 int wsa_last_error = WSAGetLastError();
558 wsa_error_ctx->SetWSAError(wsa_last_error);
559 char* msg = gpr_format_message(wsa_last_error);
560 GRPC_CARES_TRACE_LOG("fd:%s bind error code:%d msg:|%s|", GetName(),
561 wsa_last_error, msg);
563 connect_done_ = true;
564 wsa_connect_error_ = wsa_last_error;
568 if (ConnectEx(s, target, target_len, nullptr, 0, nullptr,
569 &winsocket_->write_info.overlapped) == 0) {
571 int wsa_last_error = WSAGetLastError();
572 wsa_error_ctx->SetWSAError(wsa_last_error);
573 char* msg = gpr_format_message(wsa_last_error);
574 GRPC_CARES_TRACE_LOG("fd:%s ConnectEx error code:%d msg:|%s|", GetName(),
575 wsa_last_error, msg);
577 if (wsa_last_error == WSA_IO_PENDING) {
578 // c-ares only understands WSAEINPROGRESS and EWOULDBLOCK error codes on
579 // connect, but an async connect on IOCP socket will give
580 // WSA_IO_PENDING, so we need to convert.
581 wsa_error_ctx->SetWSAError(WSAEWOULDBLOCK);
583 // By returning a non-retryable error to c-ares at this point,
584 // we're aborting the possibility of any future operations on this fd.
585 connect_done_ = true;
586 wsa_connect_error_ = wsa_last_error;
590 grpc_socket_notify_on_write(winsocket_, &on_tcp_connect_locked_);
594 static void OnIocpReadable(void* arg, grpc_error* error) {
595 GrpcPolledFdWindows* polled_fd = static_cast<GrpcPolledFdWindows*>(arg);
596 polled_fd->OnIocpReadableInner(error);
599 // TODO(apolcyn): improve this error handling to be less conversative.
600 // An e.g. ECONNRESET error here should result in errors when
601 // c-ares reads from this socket later, but it shouldn't necessarily cancel
602 // the entire resolution attempt. Doing so will allow the "inject broken
603 // nameserver list" test to pass on Windows.
604 void OnIocpReadableInner(grpc_error* error) {
605 if (error == GRPC_ERROR_NONE) {
606 if (winsocket_->read_info.wsa_error != 0) {
607 /* WSAEMSGSIZE would be due to receiving more data
608 * than our read buffer's fixed capacity. Assume that
609 * the connection is TCP and read the leftovers
610 * in subsequent c-ares reads. */
611 if (winsocket_->read_info.wsa_error != WSAEMSGSIZE) {
612 GRPC_ERROR_UNREF(error);
613 error = GRPC_WSA_ERROR(winsocket_->read_info.wsa_error,
614 "OnIocpReadableInner");
615 GRPC_CARES_TRACE_LOG(
616 "fd:|%s| OnIocpReadableInner winsocket_->read_info.wsa_error "
617 "code:|%d| msg:|%s|",
618 GetName(), winsocket_->read_info.wsa_error,
619 grpc_error_string(error));
623 if (error == GRPC_ERROR_NONE) {
624 read_buf_ = grpc_slice_sub_no_ref(
625 read_buf_, 0, winsocket_->read_info.bytes_transferred);
626 read_buf_has_data_ = true;
628 grpc_slice_unref_internal(read_buf_);
629 read_buf_ = grpc_empty_slice();
631 GRPC_CARES_TRACE_LOG(
632 "fd:|%s| OnIocpReadable finishing. read buf length now:|%d|", GetName(),
633 GRPC_SLICE_LENGTH(read_buf_));
634 ScheduleAndNullReadClosure(error);
637 static void OnIocpWriteable(void* arg, grpc_error* error) {
638 GrpcPolledFdWindows* polled_fd = static_cast<GrpcPolledFdWindows*>(arg);
639 polled_fd->OnIocpWriteableInner(error);
642 void OnIocpWriteableInner(grpc_error* error) {
643 GRPC_CARES_TRACE_LOG("OnIocpWriteableInner. fd:|%s|", GetName());
644 GPR_ASSERT(socket_type_ == SOCK_STREAM);
645 if (error == GRPC_ERROR_NONE) {
646 if (winsocket_->write_info.wsa_error != 0) {
647 GRPC_ERROR_UNREF(error);
648 error = GRPC_WSA_ERROR(winsocket_->write_info.wsa_error,
649 "OnIocpWriteableInner");
650 GRPC_CARES_TRACE_LOG(
651 "fd:|%s| OnIocpWriteableInner. winsocket_->write_info.wsa_error "
652 "code:|%d| msg:|%s|",
653 GetName(), winsocket_->write_info.wsa_error,
654 grpc_error_string(error));
657 GPR_ASSERT(tcp_write_state_ == WRITE_PENDING);
658 if (error == GRPC_ERROR_NONE) {
659 tcp_write_state_ = WRITE_WAITING_FOR_VERIFICATION_UPON_RETRY;
660 write_buf_ = grpc_slice_sub_no_ref(
661 write_buf_, 0, winsocket_->write_info.bytes_transferred);
662 GRPC_CARES_TRACE_LOG("fd:|%s| OnIocpWriteableInner. bytes transferred:%d",
663 GetName(), winsocket_->write_info.bytes_transferred);
665 grpc_slice_unref_internal(write_buf_);
666 write_buf_ = grpc_empty_slice();
668 ScheduleAndNullWriteClosure(error);
671 bool gotten_into_driver_list() const { return gotten_into_driver_list_; }
672 void set_gotten_into_driver_list() { gotten_into_driver_list_ = true; }
674 grpc_combiner* combiner_;
675 char recv_from_source_addr_[200];
676 ares_socklen_t recv_from_source_addr_len_;
677 grpc_slice read_buf_;
678 bool read_buf_has_data_ = false;
679 grpc_slice write_buf_;
680 grpc_closure* read_closure_ = nullptr;
681 grpc_closure* write_closure_ = nullptr;
682 grpc_closure outer_read_closure_;
683 grpc_closure outer_write_closure_;
684 grpc_winsocket* winsocket_;
685 // tcp_write_state_ is only used on TCP GrpcPolledFds
686 WriteState tcp_write_state_;
687 char* name_ = nullptr;
688 bool gotten_into_driver_list_;
691 grpc_closure on_tcp_connect_locked_;
692 bool connect_done_ = false;
693 int wsa_connect_error_ = 0;
694 // We don't run register_for_{readable,writeable} logic until
695 // a socket is connected. In the interim, we queue readable/writeable
696 // registrations with the following state.
697 grpc_closure continue_register_for_on_readable_locked_;
698 grpc_closure continue_register_for_on_writeable_locked_;
699 grpc_closure* pending_continue_register_for_on_readable_locked_ = nullptr;
700 grpc_closure* pending_continue_register_for_on_writeable_locked_ = nullptr;
703 struct SockToPolledFdEntry {
704 SockToPolledFdEntry(SOCKET s, GrpcPolledFdWindows* fd)
705 : socket(s), polled_fd(fd) {}
707 GrpcPolledFdWindows* polled_fd;
708 SockToPolledFdEntry* next = nullptr;
711 /* A SockToPolledFdMap can make ares_socket_t types (SOCKET's on windows)
712 * to GrpcPolledFdWindow's, and is used to find the appropriate
713 * GrpcPolledFdWindows to handle a virtual socket call when c-ares makes that
714 * socket call on the ares_socket_t type. Instances are owned by and one-to-one
715 * with a GrpcPolledFdWindows factory and event driver */
716 class SockToPolledFdMap {
718 SockToPolledFdMap(grpc_combiner* combiner) {
719 combiner_ = GRPC_COMBINER_REF(combiner, "sock to polled fd map");
722 ~SockToPolledFdMap() {
723 GPR_ASSERT(head_ == nullptr);
724 GRPC_COMBINER_UNREF(combiner_, "sock to polled fd map");
727 void AddNewSocket(SOCKET s, GrpcPolledFdWindows* polled_fd) {
728 SockToPolledFdEntry* new_node = New<SockToPolledFdEntry>(s, polled_fd);
729 new_node->next = head_;
733 GrpcPolledFdWindows* LookupPolledFd(SOCKET s) {
734 for (SockToPolledFdEntry* node = head_; node != nullptr;
736 if (node->socket == s) {
737 GPR_ASSERT(node->polled_fd != nullptr);
738 return node->polled_fd;
744 void RemoveEntry(SOCKET s) {
745 GPR_ASSERT(head_ != nullptr);
746 SockToPolledFdEntry** prev = &head_;
747 for (SockToPolledFdEntry* node = head_; node != nullptr;
749 if (node->socket == s) {
759 /* These virtual socket functions are called from within the c-ares
760 * library. These methods generally dispatch those socket calls to the
761 * appropriate methods. The virtual "socket" and "close" methods are
762 * special and instead create/add and remove/destroy GrpcPolledFdWindows
765 static ares_socket_t Socket(int af, int type, int protocol, void* user_data) {
766 if (type != SOCK_DGRAM && type != SOCK_STREAM) {
767 GRPC_CARES_TRACE_LOG("Socket called with invalid socket type:%d", type);
768 return INVALID_SOCKET;
770 SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
771 SOCKET s = WSASocket(af, type, protocol, nullptr, 0,
772 grpc_get_default_wsa_socket_flags());
773 if (s == INVALID_SOCKET) {
774 GRPC_CARES_TRACE_LOG(
775 "WSASocket failed with params af:%d type:%d protocol:%d", af, type,
779 grpc_tcp_set_non_block(s);
780 GrpcPolledFdWindows* polled_fd =
781 New<GrpcPolledFdWindows>(s, map->combiner_, af, type);
782 GRPC_CARES_TRACE_LOG(
783 "fd:|%s| created with params af:%d type:%d protocol:%d",
784 polled_fd->GetName(), af, type, protocol);
785 map->AddNewSocket(s, polled_fd);
789 static int Connect(ares_socket_t as, const struct sockaddr* target,
790 ares_socklen_t target_len, void* user_data) {
791 WSAErrorContext wsa_error_ctx;
792 SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
793 GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(as);
794 return polled_fd->Connect(&wsa_error_ctx, target, target_len);
797 static ares_ssize_t SendV(ares_socket_t as, const struct iovec* iov,
798 int iovec_count, void* user_data) {
799 WSAErrorContext wsa_error_ctx;
800 SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
801 GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(as);
802 return polled_fd->SendV(&wsa_error_ctx, iov, iovec_count);
805 static ares_ssize_t RecvFrom(ares_socket_t as, void* data, size_t data_len,
806 int flags, struct sockaddr* from,
807 ares_socklen_t* from_len, void* user_data) {
808 WSAErrorContext wsa_error_ctx;
809 SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
810 GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(as);
811 return polled_fd->RecvFrom(&wsa_error_ctx, data, data_len, flags, from,
815 static int CloseSocket(SOCKET s, void* user_data) {
816 SockToPolledFdMap* map = static_cast<SockToPolledFdMap*>(user_data);
817 GrpcPolledFdWindows* polled_fd = map->LookupPolledFd(s);
819 // If a gRPC polled fd has not made it in to the driver's list yet, then
820 // the driver has not and will never see this socket.
821 if (!polled_fd->gotten_into_driver_list()) {
822 polled_fd->ShutdownLocked(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
823 "Shut down c-ares fd before without it ever having made it into the "
831 SockToPolledFdEntry* head_ = nullptr;
832 grpc_combiner* combiner_;
835 const struct ares_socket_functions custom_ares_sock_funcs = {
836 &SockToPolledFdMap::Socket /* socket */,
837 &SockToPolledFdMap::CloseSocket /* close */,
838 &SockToPolledFdMap::Connect /* connect */,
839 &SockToPolledFdMap::RecvFrom /* recvfrom */,
840 &SockToPolledFdMap::SendV /* sendv */,
843 class GrpcPolledFdFactoryWindows : public GrpcPolledFdFactory {
845 GrpcPolledFdFactoryWindows(grpc_combiner* combiner)
846 : sock_to_polled_fd_map_(combiner) {}
848 GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
849 grpc_pollset_set* driver_pollset_set,
850 grpc_combiner* combiner) override {
851 GrpcPolledFdWindows* polled_fd = sock_to_polled_fd_map_.LookupPolledFd(as);
852 // Set a flag so that the virtual socket "close" method knows it
853 // doesn't need to call ShutdownLocked, since now the driver will.
854 polled_fd->set_gotten_into_driver_list();
858 void ConfigureAresChannelLocked(ares_channel channel) override {
859 ares_set_socket_functions(channel, &custom_ares_sock_funcs,
860 &sock_to_polled_fd_map_);
864 SockToPolledFdMap sock_to_polled_fd_map_;
867 UniquePtr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(grpc_combiner* combiner) {
868 return UniquePtr<GrpcPolledFdFactory>(
869 New<GrpcPolledFdFactoryWindows>(combiner));
872 } // namespace grpc_core
874 #endif /* GRPC_ARES == 1 && defined(GPR_WINDOWS) */