NameResolutionPal.Unix enabled async name resolution

src/installer/corehost/cli/apphost/static/configure.cmake

@@ -1,4 +1,5 @@
 include(CheckIncludeFiles)
+include(CMakePushCheckState)
 
 check_include_files(
     GSS/GSS.h
@@ -10,3 +11,16 @@ if (HeimdalGssApi)
        gssapi/gssapi.h
        HAVE_HEIMDAL_HEADERS)
 endif()
+
+if (CLR_CMAKE_TARGET_LINUX)
+    cmake_push_check_state(RESET)
+    set (CMAKE_REQUIRED_DEFINITIONS "-D_GNU_SOURCE")
+    set (CMAKE_REQUIRED_LIBRARIES "-lanl")
+
+    check_symbol_exists(
+        getaddrinfo_a
+        netdb.h
+        HAVE_GETADDRINFO_A)
+
+    cmake_pop_check_state()
+endif ()

src/libraries/Common/src/Interop/Unix/System.Native/Interop.HostEntry.cs

@@ -1,7 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
+using System.Net.Sockets;
 using System.Runtime.InteropServices;
 
 internal static partial class Interop
@@ -32,8 +32,18 @@ internal unsafe struct HostEntry
             internal int IPAddressCount;       // Number of IP addresses in the list
         }
 
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_PlatformSupportsGetAddrInfoAsync")]
+        internal static extern bool PlatformSupportsGetAddrInfoAsync();
+
         [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetHostEntryForName")]
-        internal static extern unsafe int GetHostEntryForName(string address, System.Net.Sockets.AddressFamily family, HostEntry* entry);
+        internal static extern unsafe int GetHostEntryForName(string address, AddressFamily family, HostEntry* entry);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetHostEntryForNameAsync")]
+        internal static extern unsafe int GetHostEntryForNameAsync(
+            string address,
+            AddressFamily family,
+            HostEntry* entry,
+            delegate* unmanaged<HostEntry*, int, void> callback);
 
         [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_FreeHostEntry")]
         internal static extern unsafe void FreeHostEntry(HostEntry* entry);

src/libraries/Native/Unix/Common/pal_config.h.in

@@ -10,6 +10,7 @@
 #cmakedefine01 HAVE_F_FULLFSYNC
 #cmakedefine01 HAVE_O_CLOEXEC
 #cmakedefine01 HAVE_GETIFADDRS
+#cmakedefine01 HAVE_GETADDRINFO_A
 #cmakedefine01 HAVE_UTSNAME_DOMAINNAME
 #cmakedefine01 HAVE_STAT64
 #cmakedefine01 HAVE_FORK

src/libraries/Native/Unix/System.Native/entrypoints.c

@@ -115,7 +115,9 @@ static const Entry s_sysNative[] =
     DllImportEntry(SystemNative_ReadEvents)
     DllImportEntry(SystemNative_CreateNetworkChangeListenerSocket)
     DllImportEntry(SystemNative_CloseNetworkChangeListenerSocket)
+    DllImportEntry(SystemNative_PlatformSupportsGetAddrInfoAsync)
     DllImportEntry(SystemNative_GetHostEntryForName)
+    DllImportEntry(SystemNative_GetHostEntryForNameAsync)
     DllImportEntry(SystemNative_FreeHostEntry)
     DllImportEntry(SystemNative_GetNameInfo)
     DllImportEntry(SystemNative_GetDomainName)

src/libraries/Native/Unix/System.Native/extra_libs.cmake

@@ -13,4 +13,8 @@ macro(append_extra_system_libs NativeLibsExtra)
     if (CLR_CMAKE_TARGET_IOS OR CLR_CMAKE_TARGET_TVOS)
         list(APPEND ${NativeLibsExtra} "-framework Foundation")
     endif ()
+
+    if (CLR_CMAKE_TARGET_LINUX AND HAVE_GETADDRINFO_A)
+        list(APPEND ${NativeLibsExtra} anl)
+    endif ()
 endmacro()

src/libraries/Native/Unix/System.Native/pal_networking.c

@@ -60,6 +60,10 @@
 #if HAVE_LINUX_CAN_H
 #include <linux/can.h>
 #endif
+#if HAVE_GETADDRINFO_A
+#include <signal.h>
+#include <stdatomic.h>
+#endif
 #if HAVE_SYS_FILIO_H
 #include <sys/filio.h>
 #endif
@@ -335,37 +339,14 @@ static int32_t CopySockAddrToIPAddress(sockaddr* addr, sa_family_t family, IPAdd
     return -1;
 }
 
-int32_t SystemNative_GetHostEntryForName(const uint8_t* address, int32_t addressFamily, HostEntry* entry)
+static int32_t GetHostEntries(const uint8_t* address, struct addrinfo* info, HostEntry* entry)
 {
-    if (address == NULL || entry == NULL)
-    {
-        return GetAddrInfoErrorFlags_EAI_BADARG;
-    }
-
     int32_t ret = GetAddrInfoErrorFlags_EAI_SUCCESS;
 
-    struct addrinfo* info = NULL;
 #if HAVE_GETIFADDRS
     struct ifaddrs* addrs = NULL;
 #endif
 
-    sa_family_t platformFamily;
-    if (!TryConvertAddressFamilyPalToPlatform(addressFamily, &platformFamily))
-    {
-        return GetAddrInfoErrorFlags_EAI_FAMILY;
-    }
-
-    struct addrinfo hint;
-    memset(&hint, 0, sizeof(struct addrinfo));
-    hint.ai_flags = AI_CANONNAME;
-    hint.ai_family = platformFamily;
-
-    int result = getaddrinfo((const char*)address, NULL, &hint, &info);
-    if (result != 0)
-    {
-        return ConvertGetAddrInfoAndGetNameInfoErrorsToPal(result);
-    }
-
     entry->CanonicalName = NULL;
     entry->Aliases = NULL;
     entry->IPAddressList = NULL;
@@ -393,7 +374,8 @@ int32_t SystemNative_GetHostEntryForName(const uint8_t* address, int32_t address
 
 #if HAVE_GETIFADDRS
     char name[_POSIX_HOST_NAME_MAX];
-    result = gethostname((char*)name, _POSIX_HOST_NAME_MAX);
+
+    int result = gethostname((char*)name, _POSIX_HOST_NAME_MAX);
 
     bool includeIPv4Loopback = true;
     bool includeIPv6Loopback = true;
@@ -443,6 +425,8 @@ int32_t SystemNative_GetHostEntryForName(const uint8_t* address, int32_t address
             }
         }
     }
+#else
+    (void)address;
 #endif
 
     if (entry->IPAddressCount > 0)
@@ -519,6 +503,166 @@ int32_t SystemNative_GetHostEntryForName(const uint8_t* address, int32_t address
     return ret;
 }
 
+#if HAVE_GETADDRINFO_A
+struct GetAddrInfoAsyncState
+{
+    struct gaicb gai_request;
+    struct gaicb* gai_requests;
+    struct sigevent sigevent;
+
+    struct addrinfo hint;
+    HostEntry* entry;
+    GetHostEntryForNameCallback callback;
+    char address[];
+};
+
+static void GetHostEntryForNameAsyncComplete(sigval_t context)
+{
+    struct GetAddrInfoAsyncState* state = (struct GetAddrInfoAsyncState*)context.sival_ptr;
+
+    atomic_thread_fence(memory_order_acquire);
+
+    GetHostEntryForNameCallback callback = state->callback;
+
+    int ret = ConvertGetAddrInfoAndGetNameInfoErrorsToPal(gai_error(&state->gai_request));
+
+    if (ret == 0)
+    {
+        const uint8_t* address = (const uint8_t*)state->address;
+        struct addrinfo* info = state->gai_request.ar_result;
+
+        ret = GetHostEntries(address, info, state->entry);
+    }
+
+    assert(callback != NULL);
+    callback(state->entry, ret);
+
+    free(state);
+}
+#endif
+
+static bool TrySetAddressFamily(int32_t addressFamily, struct addrinfo* hint)
+{
+    sa_family_t platformFamily;
+    if (!TryConvertAddressFamilyPalToPlatform(addressFamily, &platformFamily))
+    {
+        return false;
+    }
+
+    memset(hint, 0, sizeof(struct addrinfo));
+
+    hint->ai_flags = AI_CANONNAME;
+    hint->ai_family = platformFamily;
+
+    return true;
+}
+
+int32_t SystemNative_PlatformSupportsGetAddrInfoAsync()
+{
+    return HAVE_GETADDRINFO_A;
+}
+
+int32_t SystemNative_GetHostEntryForName(const uint8_t* address, int32_t addressFamily, HostEntry* entry)
+{
+    if (address == NULL || entry == NULL)
+    {
+        return GetAddrInfoErrorFlags_EAI_BADARG;
+    }
+
+    struct addrinfo hint;
+    if (!TrySetAddressFamily(addressFamily, &hint))
+    {
+        return GetAddrInfoErrorFlags_EAI_FAMILY;
+    }
+
+    struct addrinfo* info = NULL;
+
+    int result = getaddrinfo((const char*)address, NULL, &hint, &info);
+    if (result != 0)
+    {
+        return ConvertGetAddrInfoAndGetNameInfoErrorsToPal(result);
+    }
+
+    return GetHostEntries(address, info, entry);
+}
+
+int32_t SystemNative_GetHostEntryForNameAsync(const uint8_t* address, int32_t addressFamily, HostEntry* entry, GetHostEntryForNameCallback callback)
+{
+#if HAVE_GETADDRINFO_A
+    if (address == NULL || entry == NULL)
+    {
+        return GetAddrInfoErrorFlags_EAI_BADARG;
+    }
+
+    size_t addrlen = strlen((const char*)address);
+
+    if (addrlen > _POSIX_HOST_NAME_MAX)
+    {
+        return GetAddrInfoErrorFlags_EAI_BADARG;
+    }
+
+    sa_family_t platformFamily;
+    if (!TryConvertAddressFamilyPalToPlatform(addressFamily, &platformFamily))
+    {
+        return GetAddrInfoErrorFlags_EAI_FAMILY;
+    }
+
+    struct GetAddrInfoAsyncState* state = malloc(sizeof(*state) + addrlen + 1);
+
+    if (state == NULL)
+    {
+        return GetAddrInfoErrorFlags_EAI_MEMORY;
+    }
+
+    if (!TrySetAddressFamily(addressFamily, &state->hint))
+    {
+        free(state);
+        return GetAddrInfoErrorFlags_EAI_FAMILY;
+    }
+
+    memcpy(state->address, address, addrlen + 1);
+
+    *state = (struct GetAddrInfoAsyncState) {
+        .gai_request = {
+            .ar_name = state->address,
+            .ar_service = NULL,
+            .ar_request = &state->hint,
+            .ar_result = NULL
+        },
+        .gai_requests = &state->gai_request,
+        .sigevent = {
+            .sigev_notify = SIGEV_THREAD,
+            .sigev_value = {
+                .sival_ptr = state
+            },
+            .sigev_notify_function = GetHostEntryForNameAsyncComplete
+        },
+        .entry = entry,
+        .callback = callback
+    };
+
+    atomic_thread_fence(memory_order_release);
+
+    int32_t result = getaddrinfo_a(GAI_NOWAIT, &state->gai_requests, 1, &state->sigevent);
+
+    if (result != 0)
+    {
+        free(state);
+        return ConvertGetAddrInfoAndGetNameInfoErrorsToPal(result);
+    }
+
+    return result;
+#else
+    (void)address;
+    (void)addressFamily;
+    (void)entry;
+    (void)callback;
+
+    // GetHostEntryForNameAsync is not supported on this platform.
+    return -1;
+#endif
+}
+
 void SystemNative_FreeHostEntry(HostEntry* entry)
 {
     if (entry != NULL)
@@ -555,13 +699,13 @@ static inline NativeFlagsType ConvertGetNameInfoFlagsToNative(int32_t flags)
 }
 
 int32_t SystemNative_GetNameInfo(const uint8_t* address,
-                               int32_t addressLength,
-                               int8_t isIPv6,
-                               uint8_t* host,
-                               int32_t hostLength,
-                               uint8_t* service,
-                               int32_t serviceLength,
-                               int32_t flags)
+                                 int32_t addressLength,
+                                 int8_t isIPv6,
+                                 uint8_t* host,
+                                 int32_t hostLength,
+                                 uint8_t* service,
+                                 int32_t serviceLength,
+                                 int32_t flags)
 {
     assert(address != NULL);
     assert(addressLength > 0);

src/libraries/Native/Unix/System.Native/pal_networking.h

@@ -301,8 +301,16 @@ typedef struct
     uint32_t Padding;    // Pad out to 8-byte alignment
 } SocketEvent;
 
+PALEXPORT int32_t SystemNative_PlatformSupportsGetAddrInfoAsync(void);
+
 PALEXPORT int32_t SystemNative_GetHostEntryForName(const uint8_t* address, int32_t addressFamily, HostEntry* entry);
 
+typedef void (*GetHostEntryForNameCallback)(HostEntry* entry, int status);
+PALEXPORT int32_t SystemNative_GetHostEntryForNameAsync(const uint8_t* address,
+                                                        int32_t addressFamily,
+                                                        HostEntry* entry,
+                                                        GetHostEntryForNameCallback callback);
+
 PALEXPORT void SystemNative_FreeHostEntry(HostEntry* entry);
 
 

src/libraries/Native/Unix/configure.cmake

@@ -6,6 +6,7 @@ include(CheckPrototypeDefinition)
 include(CheckStructHasMember)
 include(CheckSymbolExists)
 include(CheckTypeSize)
+include(CMakePushCheckState)
 
 # CMP0075 Include file check macros honor CMAKE_REQUIRED_LIBRARIES.
 if(POLICY CMP0075)
@@ -900,6 +901,19 @@ check_symbol_exists(
     HAVE_INOTIFY_RM_WATCH)
 set (CMAKE_REQUIRED_LIBRARIES ${PREVIOUS_CMAKE_REQUIRED_LIBRARIES})
 
+if (CLR_CMAKE_TARGET_LINUX)
+    cmake_push_check_state(RESET)
+    set (CMAKE_REQUIRED_DEFINITIONS "-D_GNU_SOURCE")
+    set (CMAKE_REQUIRED_LIBRARIES "-lanl")
+
+    check_symbol_exists(
+        getaddrinfo_a
+        netdb.h
+        HAVE_GETADDRINFO_A)
+
+    cmake_pop_check_state()
+endif ()
+
 set (HAVE_INOTIFY 0)
 if (HAVE_INOTIFY_INIT AND HAVE_INOTIFY_ADD_WATCH AND HAVE_INOTIFY_RM_WATCH)
     set (HAVE_INOTIFY 1)