From e8c6fcdd4eaf70a6d7c9ee3448ed1f7718d52f20 Mon Sep 17 00:00:00 2001
From: Jasmine Iwanek <jasmine@iwanek.co.uk>
Date: Thu, 19 Jun 2025 21:55:54 -0400
Subject: [PATCH] Add support for Client Named Pipe on Windows

---
 src/device/serial_passthrough.c |  2 --
 src/qt/win_serial_passthrough.c | 36 +++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/src/device/serial_passthrough.c b/src/device/serial_passthrough.c
index 479c1dc24..426bfbc7b 100644
--- a/src/device/serial_passthrough.c
+++ b/src/device/serial_passthrough.c
@@ -246,9 +246,7 @@ static const device_config_t serial_passthrough_config[] = {
         .selection      = {
 #ifdef _WIN32
             { .description = "Named Pipe (Server)",             .value = SERPT_MODE_NPIPE_SRV  },
-#if 0 /* TODO */
             { .description = "Named Pipe (Client)",             .value = SERPT_MODE_NPIPE_CLNT },
-#endif
 #else /* _WIN32 */
             { .description = "Pseudo Terminal/Virtual Console", .value = SERPT_MODE_VCON       },
 #endif /* _WIN32 */
diff --git a/src/qt/win_serial_passthrough.c b/src/qt/win_serial_passthrough.c
index e17d70f16..725dc096f 100644
--- a/src/qt/win_serial_passthrough.c
+++ b/src/qt/win_serial_passthrough.c
@@ -189,6 +189,38 @@ open_pseudo_terminal(serial_passthrough_t *dev)
     return 1;
 }
 
+static int
+connect_named_pipe_client(serial_passthrough_t *dev)
+{
+    char ascii_pipe_name[1024] = { 0 };
+    strncpy(ascii_pipe_name, dev->named_pipe, sizeof(ascii_pipe_name) - 1);
+
+    HANDLE hPipe = CreateFileA(
+        ascii_pipe_name,            // pipe name
+        GENERIC_READ | GENERIC_WRITE,
+        0,                          // no sharing
+        NULL,                       // default security attributes
+        OPEN_EXISTING,              // open existing pipe
+        0,                          // default attributes
+        NULL);                      // no template file
+
+    if (hPipe == INVALID_HANDLE_VALUE) {
+        DWORD error = GetLastError();
+        wchar_t errorMsg[1024] = { 0 };
+        wchar_t finalMsg[1024] = { 0 };
+        FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), errorMsg, 1024, NULL);
+        swprintf(finalMsg, 1024, L"Named Pipe (client, named_pipe=\"%hs\", port=COM%d): %ls\n", ascii_pipe_name, dev->port + 1, errorMsg);
+        ui_msgbox(MBX_ERROR | MBX_FATAL, finalMsg);
+        return 0;
+    }
+
+    DWORD mode = PIPE_READMODE_BYTE | PIPE_NOWAIT;
+    SetNamedPipeHandleState(hPipe, &mode, NULL, NULL);
+    dev->master_fd = (intptr_t) hPipe;
+    pclog("Named Pipe client connected to %s\n", ascii_pipe_name);
+    return 1;
+}
+
 static int
 open_host_serial_port(serial_passthrough_t *dev)
 {
@@ -228,6 +260,10 @@ plat_serpt_open_device(void *priv)
             if (open_pseudo_terminal(dev))
                 return 0;
             break;
+        case SERPT_MODE_NPIPE_CLNT:
+            if (connect_named_pipe_client(dev))
+                return 0;
+            break;
         case SERPT_MODE_HOSTSER:
             if (open_host_serial_port(dev))
                 return 0;