implement device probe in C

It's an attempt to build auto-completion for the dive-computers
based on unpublished code inside libdivecomputer[1]

[1] -
http://git.libdivecomputer.org/?p=libdivecomputer.git;a=commitdiff;h=d44053a99435fb9fc1f408fb3f1629a54c938afc

Signed-off-by: Danilo Cesar Lemes de Paula <danilo.eu@gmail.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/windows.c b/windows.c
index d6cb531ae..de2ef9a45 100644
--- a/windows.c
+++ b/windows.c
@@ -333,3 +333,56 @@ gboolean subsurface_os_feature_available(os_feature_t f)
 		return TRUE;
 	}
 }
+
+int enumerate_devices (device_callback_t callback, void *userdata)
+{
+	// Open the registry key.
+	HKEY hKey;
+	int index = -1;
+	LONG rc = RegOpenKeyEx (HKEY_LOCAL_MACHINE, "HARDWARE\\DEVICEMAP\\SERIALCOMM", 0, KEY_QUERY_VALUE, &hKey);
+	if (rc != ERROR_SUCCESS) {
+		return -1;
+	}
+
+	// Get the number of values.
+	DWORD count = 0;
+	rc = RegQueryInfoKey (hKey, NULL, NULL, NULL, NULL, NULL, NULL, &count, NULL, NULL, NULL, NULL);
+	if (rc != ERROR_SUCCESS) {
+		RegCloseKey(hKey);
+		return -1;
+	}
+
+	for (DWORD i = 0; i < count; ++i) {
+		// Get the value name, data and type.
+		char name[512], data[512];
+		DWORD name_len = sizeof (name);
+		DWORD data_len = sizeof (data);
+		DWORD type = 0;
+		rc = RegEnumValue (hKey, i, name, &name_len, NULL, &type, (LPBYTE) data, &data_len);
+		if (rc != ERROR_SUCCESS) {
+			RegCloseKey(hKey);
+			return -1;
+		}
+
+		// Ignore non-string values.
+		if (type != REG_SZ)
+			continue;
+
+		// Prevent a possible buffer overflow.
+		if (data_len >= sizeof (data)) {
+			RegCloseKey(hKey);
+			return -1;
+		}
+
+		// Null terminate the string.
+		data[data_len] = 0;
+
+		callback (data, userdata);
+		index++;
+		if (is_default_dive_computer_device(filename))
+			index = i;
+	}
+
+	RegCloseKey(hKey);
+	return index;
+}