bottom part of serial port support on Unix

src/Common/src/Interop/Unix/System.Native/Interop.OpenFlags.cs

@@ -22,6 +22,8 @@ internal enum OpenFlags
             O_EXCL    = 0x0040,
             O_TRUNC   = 0x0080,
             O_SYNC    = 0x0100,
+            O_NOCTTY  = 0x0200,
+            O_NONBLOCK = 0x0400,
         }
     }
 }

src/Common/src/Interop/Unix/System.Native/Interop.Terminal.cs

@@ -0,0 +1,55 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.IO.Ports;
+using System.Runtime.InteropServices;
+using Microsoft.Win32.SafeHandles;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosReset", SetLastError = true)]
+        internal static extern int TerminalReset(SafeFileHandle fd, int speed, int data, StopBits stop, Parity parity, Handshake flow);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosGetDcd", SetLastError = true)]
+        internal static extern int TerminalGetCd(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosGetCts", SetLastError = true)]
+        internal static extern int TerminalGetCts(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosGetRts", SetLastError = true)]
+        internal static extern int TerminalGetRts(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosGetDsr", SetLastError = true)]
+        internal static extern int TerminalGetDsr(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosGetDtr", SetLastError = true)]
+        internal static extern int TerminalGetDtr(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosSetDtr", SetLastError = true)]
+        internal static extern int TerminalSetDtr(SafeFileHandle fd, int value);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosSetRts", SetLastError = true)]
+        internal static extern int TerminalSetRts(SafeFileHandle fd, int value);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosSetSpeed", SetLastError = true)]
+        internal static extern int TerminalSetSpeed(SafeFileHandle fd, int speed);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosGetSpeed", SetLastError = true)]
+        internal static extern int TerminalGetSpeed(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosAvailableBytes", SetLastError = true)]
+        internal static extern int TerminalGetAvailableBytes(SafeFileHandle fd, int input);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosDiscard", SetLastError = true)]
+        internal static extern int TerminalDiscard(SafeFileHandle fd, int input);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosDrain", SetLastError = true)]
+        internal static extern int TerminalDrain(SafeFileHandle fd);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_TermiosSendBreak", SetLastError = true)]
+        internal static extern int TerminalSendBreak(SafeFileHandle fd, int duration);
+    }
+}

src/Native/Unix/System.Native/CMakeLists.txt

@@ -21,6 +21,7 @@ set(NATIVE_SOURCES
     pal_uid.cpp
     pal_datetime.cpp
     pal_sysctl.cpp
+    pal_termios.cpp
 )
 
 if (CMAKE_SYSTEM_NAME STREQUAL Linux)

src/Native/Unix/System.Native/pal_io.c

@@ -233,7 +233,7 @@ static int32_t ConvertOpenFlags(int32_t flags)
             return -1;
     }
 
-    if (flags & ~(PAL_O_ACCESS_MODE_MASK | PAL_O_CLOEXEC | PAL_O_CREAT | PAL_O_EXCL | PAL_O_TRUNC | PAL_O_SYNC))
+    if (flags & ~(PAL_O_ACCESS_MODE_MASK | PAL_O_CLOEXEC | PAL_O_CREAT | PAL_O_EXCL | PAL_O_TRUNC | PAL_O_SYNC | PAL_O_NOCTTY | PAL_O_NONBLOCK))
     {
         assert_msg(false, "Unknown Open flag", (int)flags);
         return -1;
@@ -249,6 +249,10 @@ static int32_t ConvertOpenFlags(int32_t flags)
         ret |= O_TRUNC;
     if (flags & PAL_O_SYNC)
         ret |= O_SYNC;
+    if (flags & PAL_O_NOCTTY)
+        ret |= O_NOCTTY;
+    if (flags & PAL_O_NONBLOCK)
+        ret |= O_NONBLOCK;
 
     assert(ret != -1);
     return ret;

src/Native/Unix/System.Native/pal_io.h

@@ -142,6 +142,8 @@ enum
     PAL_O_EXCL = 0x0040,    // When combined with CREAT, fails if file already exists
     PAL_O_TRUNC = 0x0080,   // Truncate file to length 0 if it already exists
     PAL_O_SYNC = 0x0100,    // Block writes call will block until physically written
+    PAL_O_NOCTTY = 0x0200,  //  Will not allocate controlling terminal when opening TTY device.
+    PAL_O_NONBLOCK = 0x0400, // Open file in non-blocking mode.
 };
 
 /**