service: sfdnsres: Implement DNS address resolution

src/core/hle/service/sockets/sfdnsres.cpp

@@ -2,8 +2,24 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <string_view>
+#include <utility>
+#include <vector>
+
+#include "common/string_util.h"
+#include "common/swap.h"
+#include "core/core.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/service/sockets/sfdnsres.h"
+#include "core/memory.h"
+
+#ifdef _WIN32
+#include <ws2tcpip.h>
+#elif YUZU_UNIX
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#endif
 
 namespace Service::Sockets {
 
@@ -21,7 +37,7 @@ SFDNSRES::SFDNSRES(Core::System& system_) : ServiceFramework{system_, "sfdnsres"
         {9, nullptr, "CancelRequest"},
         {10, nullptr, "GetHostByNameRequestWithOptions"},
         {11, nullptr, "GetHostByAddrRequestWithOptions"},
-        {12, nullptr, "GetAddrInfoRequestWithOptions"},
+        {12, &SFDNSRES::GetAddrInfoRequestWithOptions, "GetAddrInfoRequestWithOptions"},
         {13, nullptr, "GetNameInfoRequestWithOptions"},
         {14, nullptr, "ResolverSetOptionRequest"},
         {15, nullptr, "ResolverGetOptionRequest"},
@@ -31,7 +47,142 @@ SFDNSRES::SFDNSRES(Core::System& system_) : ServiceFramework{system_, "sfdnsres"
 
 SFDNSRES::~SFDNSRES() = default;
 
-void SFDNSRES::GetAddrInfoRequest(Kernel::HLERequestContext& ctx) {
+enum class NetDbError : s32 {
+    Internal = -1,
+    Success = 0,
+    HostNotFound = 1,
+    TryAgain = 2,
+    NoRecovery = 3,
+    NoData = 4,
+};
+
+static NetDbError AddrInfoErrorToNetDbError(s32 result) {
+    // Best effort guess to map errors
+    switch (result) {
+    case 0:
+        return NetDbError::Success;
+    case EAI_AGAIN:
+        return NetDbError::TryAgain;
+    case EAI_NODATA:
+        return NetDbError::NoData;
+    default:
+        return NetDbError::HostNotFound;
+    }
+}
+
+static std::vector<u8> SerializeAddrInfo(const addrinfo* addrinfo, s32 result_code,
+                                         std::string_view host) {
+    // Adapted from
+    // https://github.com/switchbrew/libnx/blob/c5a9a909a91657a9818a3b7e18c9b91ff0cbb6e3/nx/source/runtime/resolver.c#L190
+    std::vector<u8> data;
+
+    auto* current = addrinfo;
+    while (current != nullptr) {
+        struct SerializedResponseHeader {
+            u32 magic;
+            s32 flags;
+            s32 family;
+            s32 socket_type;
+            s32 protocol;
+            u32 address_length;
+        };
+        static_assert(sizeof(SerializedResponseHeader) == 0x18,
+                      "Response header size must be 0x18 bytes");
+
+        constexpr auto header_size = sizeof(SerializedResponseHeader);
+        const auto addr_size =
+            current->ai_addr && current->ai_addrlen > 0 ? current->ai_addrlen : 4;
+        const auto canonname_size = current->ai_canonname ? strlen(current->ai_canonname) + 1 : 1;
+
+        const auto last_size = data.size();
+        data.resize(last_size + header_size + addr_size + canonname_size);
+
+        // Header in network byte order
+        SerializedResponseHeader header{};
+
+        constexpr auto HEADER_MAGIC = 0xBEEFCAFE;
+        header.magic = htonl(HEADER_MAGIC);
+        header.family = htonl(current->ai_family);
+        header.flags = htonl(current->ai_flags);
+        header.socket_type = htonl(current->ai_socktype);
+        header.protocol = htonl(current->ai_protocol);
+        header.address_length = current->ai_addr ? htonl((u32)current->ai_addrlen) : 0;
+
+        auto* header_ptr = data.data() + last_size;
+        std::memcpy(header_ptr, &header, header_size);
+
+        if (header.address_length == 0) {
+            std::memset(header_ptr + header_size, 0, 4);
+        } else {
+            switch (current->ai_family) {
+            case AF_INET: {
+                struct SockAddrIn {
+                    s16 sin_family;
+                    u16 sin_port;
+                    u32 sin_addr;
+                    u8 sin_zero[8];
+                };
+
+                SockAddrIn serialized_addr{};
+                const auto addr = *reinterpret_cast<sockaddr_in*>(current->ai_addr);
+                serialized_addr.sin_port = htons(addr.sin_port);
+                serialized_addr.sin_family = htons(addr.sin_family);
+                serialized_addr.sin_addr = htonl(addr.sin_addr.s_addr);
+                std::memcpy(header_ptr + header_size, &serialized_addr, sizeof(SockAddrIn));
+
+                char addr_string_buf[64]{};
+                inet_ntop(AF_INET, &addr.sin_addr, addr_string_buf, std::size(addr_string_buf));
+                LOG_INFO(Service, "Resolved host '{}' to IPv4 address {}", host, addr_string_buf);
+                break;
+            }
+            case AF_INET6: {
+                struct SockAddrIn6 {
+                    s16 sin6_family;
+                    u16 sin6_port;
+                    u32 sin6_flowinfo;
+                    u8 sin6_addr[16];
+                    u32 sin6_scope_id;
+                };
+
+                SockAddrIn6 serialized_addr{};
+                const auto addr = *reinterpret_cast<sockaddr_in6*>(current->ai_addr);
+                serialized_addr.sin6_family = htons(addr.sin6_family);
+                serialized_addr.sin6_port = htons(addr.sin6_port);
+                serialized_addr.sin6_flowinfo = htonl(addr.sin6_flowinfo);
+                serialized_addr.sin6_scope_id = htonl(addr.sin6_scope_id);
+                std::memcpy(serialized_addr.sin6_addr, &addr.sin6_addr,
+                            sizeof(SockAddrIn6::sin6_addr));
+                std::memcpy(header_ptr + header_size, &serialized_addr, sizeof(SockAddrIn6));
+
+                char addr_string_buf[64]{};
+                inet_ntop(AF_INET6, &addr.sin6_addr, addr_string_buf, std::size(addr_string_buf));
+                LOG_INFO(Service, "Resolved host '{}' to IPv6 address {}", host, addr_string_buf);
+                break;
+            }
+            default:
+                std::memcpy(header_ptr + header_size, current->ai_addr, addr_size);
+                break;
+            }
+        }
+        if (current->ai_canonname) {
+            std::memcpy(header_ptr + addr_size, current->ai_canonname, canonname_size);
+        } else {
+            *(header_ptr + header_size + addr_size) = 0;
+        }
+
+        current = current->ai_next;
+    }
+
+    // 4-byte sentinel value
+    data.push_back(0);
+    data.push_back(0);
+    data.push_back(0);
+    data.push_back(0);
+
+    return data;
+}
+
+static std::pair<u32, s32> GetAddrInfoRequestImpl(Kernel::HLERequestContext& ctx) {
     struct Parameters {
         u8 use_nsd_resolve;
         u32 unknown;
@@ -42,11 +193,51 @@ void SFDNSRES::GetAddrInfoRequest(Kernel::HLERequestContext& ctx) {
     const auto parameters = rp.PopRaw<Parameters>();
 
     LOG_WARNING(Service,
-                "(STUBBED) called. use_nsd_resolve={}, unknown=0x{:08X}, process_id=0x{:016X}",
+                "called with ignored parameters: use_nsd_resolve={}, unknown={}, process_id={}",
                 parameters.use_nsd_resolve, parameters.unknown, parameters.process_id);
 
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    const auto host_buffer = ctx.ReadBuffer(0);
+    const std::string host = Common::StringFromBuffer(host_buffer);
+
+    const auto service_buffer = ctx.ReadBuffer(1);
+    const std::string service = Common::StringFromBuffer(service_buffer);
+
+    addrinfo* addrinfo;
+    // Pass null for hints. Serialized hints are also passed in a buffer, but are ignored for now
+    s32 result_code = getaddrinfo(host.c_str(), service.c_str(), nullptr, &addrinfo);
+
+    u32 data_size = 0;
+    if (result_code == 0 && addrinfo != nullptr) {
+        const std::vector<u8>& data = SerializeAddrInfo(addrinfo, result_code, host);
+        data_size = static_cast<u32>(data.size());
+        freeaddrinfo(addrinfo);
+
+        ctx.WriteBuffer(data, 0);
+    }
+
+    return std::make_pair(data_size, result_code);
 }
 
-} // namespace Service::Sockets
+void SFDNSRES::GetAddrInfoRequest(Kernel::HLERequestContext& ctx) {
+    auto [data_size, result_code] = GetAddrInfoRequestImpl(ctx);
+
+    IPC::ResponseBuilder rb{ctx, 4};
+    rb.Push(ResultSuccess);
+    rb.Push(static_cast<s32>(AddrInfoErrorToNetDbError(result_code))); // NetDBErrorCode
+    rb.Push(result_code);                                              // errno
+    rb.Push(data_size);                                                // serialized size
+}
+
+void SFDNSRES::GetAddrInfoRequestWithOptions(Kernel::HLERequestContext& ctx) {
+    // Additional options are ignored
+    auto [data_size, result_code] = GetAddrInfoRequestImpl(ctx);
+
+    IPC::ResponseBuilder rb{ctx, 5};
+    rb.Push(ResultSuccess);
+    rb.Push(data_size);                                                // serialized size
+    rb.Push(result_code);                                              // errno
+    rb.Push(static_cast<s32>(AddrInfoErrorToNetDbError(result_code))); // NetDBErrorCode
+    rb.Push(0);
+}
+
+} // namespace Service::Sockets

src/core/hle/service/sockets/sfdnsres.h

@@ -19,6 +19,7 @@ public:
 
 private:
     void GetAddrInfoRequest(Kernel::HLERequestContext& ctx);
+    void GetAddrInfoRequestWithOptions(Kernel::HLERequestContext& ctx);
 };
 
 } // namespace Service::Sockets