xref: /aosp_15_r20/external/grpc-grpc/src/core/lib/event_engine/windows/native_windows_dns_resolver.cc (revision cc02d7e222339f7a4f6ba5f422e6413f4bd931f2)
1 // Copyright 2024 The gRPC Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 #include <grpc/support/port_platform.h>
15 
16 #ifdef GPR_WINDOWS
17 #include <inttypes.h>
18 #include <string.h>
19 #include <sys/types.h>
20 
21 #include <string>
22 
23 #include "absl/strings/str_cat.h"
24 #include "absl/strings/str_format.h"
25 
26 #include <grpc/event_engine/event_engine.h>
27 
28 #include "src/core/lib/event_engine/windows/native_windows_dns_resolver.h"
29 #include "src/core/lib/gprpp/host_port.h"
30 #include "src/core/lib/gprpp/status_helper.h"
31 #include "src/core/lib/iomgr/error.h"
32 
33 namespace grpc_event_engine {
34 namespace experimental {
35 
36 namespace {
37 absl::StatusOr<std::vector<EventEngine::ResolvedAddress>>
LookupHostnameBlocking(absl::string_view name,absl::string_view default_port)38 LookupHostnameBlocking(absl::string_view name, absl::string_view default_port) {
39   std::vector<EventEngine::ResolvedAddress> addresses;
40   // parse name, splitting it into host and port parts
41   std::string host;
42   std::string port;
43   grpc_core::SplitHostPort(name, &host, &port);
44   if (host.empty()) {
45     return absl::InvalidArgumentError(absl::StrCat("Unparseable name: ", name));
46   }
47   if (port.empty()) {
48     if (default_port.empty()) {
49       return absl::InvalidArgumentError(
50           absl::StrFormat("No port in name %s or default_port argument", name));
51     }
52     port = std::string(default_port);
53   }
54   // Call getaddrinfo
55   struct addrinfo hints;
56   memset(&hints, 0, sizeof(hints));
57   hints.ai_family = AF_UNSPEC;      // ipv4 or ipv6
58   hints.ai_socktype = SOCK_STREAM;  // stream socket
59   hints.ai_flags = AI_PASSIVE;      // for wildcard IP address
60   struct addrinfo* result = nullptr;
61   int getaddrinfo_error =
62       getaddrinfo(host.c_str(), port.c_str(), &hints, &result);
63   if (getaddrinfo_error != 0) {
64     return absl::UnknownError(
65         absl::StrFormat("Address lookup failed for %s os_error: %s", name,
66                         grpc_core::StatusToString(
67                             GRPC_WSA_ERROR(WSAGetLastError(), "getaddrinfo"))
68                             .c_str()));
69   }
70   // Success path: collect and return all addresses
71   for (auto* resp = result; resp != nullptr; resp = resp->ai_next) {
72     addresses.emplace_back(resp->ai_addr, resp->ai_addrlen);
73   }
74   if (result) freeaddrinfo(result);
75   return addresses;
76 }
77 
78 }  // namespace
NativeWindowsDNSResolver(std::shared_ptr<EventEngine> event_engine)79 NativeWindowsDNSResolver::NativeWindowsDNSResolver(
80     std::shared_ptr<EventEngine> event_engine)
81     : event_engine_(std::move(event_engine)) {}
82 
LookupHostname(EventEngine::DNSResolver::LookupHostnameCallback on_resolved,absl::string_view name,absl::string_view default_port)83 void NativeWindowsDNSResolver::LookupHostname(
84     EventEngine::DNSResolver::LookupHostnameCallback on_resolved,
85     absl::string_view name, absl::string_view default_port) {
86   event_engine_->Run(
87       [name, default_port, on_resolved = std::move(on_resolved)]() mutable {
88         on_resolved(LookupHostnameBlocking(name, default_port));
89       });
90 }
91 
LookupSRV(EventEngine::DNSResolver::LookupSRVCallback on_resolved,absl::string_view)92 void NativeWindowsDNSResolver::LookupSRV(
93     EventEngine::DNSResolver::LookupSRVCallback on_resolved,
94     absl::string_view /* name */) {
95   // Not supported
96   event_engine_->Run([on_resolved = std::move(on_resolved)]() mutable {
97     on_resolved(absl::UnimplementedError(
98         "The Native resolver does not support looking up SRV records"));
99   });
100 }
101 
LookupTXT(EventEngine::DNSResolver::LookupTXTCallback on_resolved,absl::string_view)102 void NativeWindowsDNSResolver::LookupTXT(
103     EventEngine::DNSResolver::LookupTXTCallback on_resolved,
104     absl::string_view /* name */) {
105   // Not supported
106   event_engine_->Run([on_resolved = std::move(on_resolved)]() mutable {
107     on_resolved(absl::UnimplementedError(
108         "The Native resolver does not support looking up TXT records"));
109   });
110 }
111 
112 }  // namespace experimental
113 }  // namespace grpc_event_engine
114 
115 #endif  // GPR_WINDOWS
116