Milestone 5: deliver embedded RDP sessions and lifecycle hardening

third_party/FreeRDP/libfreerdp/utils/signal.c

@@ -0,0 +1,123 @@
+/**
+ * FreeRDP: A Remote Desktop Protocol Implementation
+ * Signal handling
+ *
+ * Copyright 2011 Shea Levy <shea@shealevy.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <freerdp/config.h>
+
+#include <string.h>
+
+#include <winpr/crt.h>
+#include <winpr/debug.h>
+
+#include <freerdp/utils/signal.h>
+#include <freerdp/log.h>
+
+#include "platform_signal.h"
+
+#define TAG FREERDP_TAG("utils.signal")
+
+#if defined(_WIN32)
+const char* strsignal(int signum);
+#endif
+
+BOOL fsig_handlers_registered = FALSE;
+
+typedef struct
+{
+	void* context;
+	freerdp_signal_handler_t handler;
+} cleanup_handler_t;
+
+static size_t cleanup_handler_count = 0;
+static cleanup_handler_t cleanup_handlers[20] = WINPR_C_ARRAY_INIT;
+
+void fsig_term_handler(int signum)
+{
+	static BOOL recursive = FALSE;
+
+	if (!recursive)
+	{
+		recursive = TRUE;
+		// NOLINTNEXTLINE(concurrency-mt-unsafe)
+		WLog_ERR(TAG, "Caught signal '%s' [%d]", strsignal(signum), signum);
+	}
+
+	fsig_lock();
+	for (size_t x = 0; x < cleanup_handler_count; x++)
+	{
+		const cleanup_handler_t empty = WINPR_C_ARRAY_INIT;
+		cleanup_handler_t* cur = &cleanup_handlers[x];
+		if (cur->handler)
+		{
+			// NOLINTNEXTLINE(concurrency-mt-unsafe)
+			cur->handler(signum, strsignal(signum), cur->context);
+		}
+		*cur = empty;
+	}
+	cleanup_handler_count = 0;
+	fsig_unlock();
+}
+
+BOOL freerdp_add_signal_cleanup_handler(void* context, freerdp_signal_handler_t handler)
+{
+	BOOL rc = FALSE;
+	fsig_lock();
+	if (fsig_handlers_registered)
+	{
+		if (cleanup_handler_count < ARRAYSIZE(cleanup_handlers))
+		{
+			cleanup_handler_t* cur = &cleanup_handlers[cleanup_handler_count++];
+			cur->context = context;
+			cur->handler = handler;
+		}
+		else
+			WLog_WARN(TAG, "Failed to register cleanup handler, only %" PRIuz " handlers supported",
+			          ARRAYSIZE(cleanup_handlers));
+	}
+	rc = TRUE;
+	fsig_unlock();
+	return rc;
+}
+
+BOOL freerdp_del_signal_cleanup_handler(void* context, freerdp_signal_handler_t handler)
+{
+	BOOL rc = FALSE;
+	fsig_lock();
+	if (fsig_handlers_registered)
+	{
+		for (size_t x = 0; x < cleanup_handler_count; x++)
+		{
+			cleanup_handler_t* cur = &cleanup_handlers[x];
+			if ((cur->context == context) && (cur->handler == handler))
+			{
+				const cleanup_handler_t empty = WINPR_C_ARRAY_INIT;
+				for (size_t y = x + 1; y < cleanup_handler_count - 1; y++)
+				{
+					*cur++ = cleanup_handlers[y];
+				}
+
+				*cur = empty;
+				cleanup_handler_count--;
+				break;
+			}
+		}
+	}
+	rc = TRUE;
+	fsig_unlock();
+	return rc;
+}