From 5ef54acb69cfa821d6b754201f82340382742a7b Mon Sep 17 00:00:00 2001
From: dovholuknf <46322585+dovholuknf@users.noreply.github.com>
Date: Fri, 10 Jan 2025 10:13:54 -0500
Subject: [PATCH] write a minidump if ziti-edge-tunnel crashes on windows
 (#1084)

* write a minidump if ziti-edge-tunnel crashes on windows

* windows only, just use MAX_PATH which is what we define PATH_MAX to when needed
---
 programs/ziti-edge-tunnel/CMakeLists.txt      |  5 ++-
 programs/ziti-edge-tunnel/windows/log_utils.c |  2 +-
 programs/ziti-edge-tunnel/windows/minidump.c  | 40 +++++++++++++++++++
 programs/ziti-edge-tunnel/windows/minidump.h  | 23 +++++++++++
 programs/ziti-edge-tunnel/ziti-edge-tunnel.c  |  6 +++
 5 files changed, 74 insertions(+), 2 deletions(-)
 create mode 100644 programs/ziti-edge-tunnel/windows/minidump.c
 create mode 100644 programs/ziti-edge-tunnel/windows/minidump.h

diff --git a/programs/ziti-edge-tunnel/CMakeLists.txt b/programs/ziti-edge-tunnel/CMakeLists.txt
index 0c1fb70c..6a597d09 100644
--- a/programs/ziti-edge-tunnel/CMakeLists.txt
+++ b/programs/ziti-edge-tunnel/CMakeLists.txt
@@ -40,7 +40,10 @@ if (WIN32)
             include/windows/windows-scripts.h
             windows-scripts.c
             windows/log_utils.c
-            include/service-utils.h)
+            include/service-utils.h
+            windows/minidump.c
+            windows/minidump.h
+    )
 endif ()
 if (LINUX)
     set(ZITI_INSTANCE_OS linux/diverter.c include/linux/diverter.h)
diff --git a/programs/ziti-edge-tunnel/windows/log_utils.c b/programs/ziti-edge-tunnel/windows/log_utils.c
index 2833cd7f..2defbbfe 100644
--- a/programs/ziti-edge-tunnel/windows/log_utils.c
+++ b/programs/ziti-edge-tunnel/windows/log_utils.c
@@ -67,7 +67,7 @@ static uint8_t mkdir_p(const char *path) {
     return mkdir(cur_path, NULL);
 }
 
-static char* get_log_path() {
+char* get_log_path() {
     char process_dir[PATH_MAX]; //create string buffer to hold path
     char process_full_path[PATH_MAX];
     char drive[_MAX_DRIVE];
diff --git a/programs/ziti-edge-tunnel/windows/minidump.c b/programs/ziti-edge-tunnel/windows/minidump.c
new file mode 100644
index 00000000..e84db98c
--- /dev/null
+++ b/programs/ziti-edge-tunnel/windows/minidump.c
@@ -0,0 +1,40 @@
+/*
+ Copyright NetFoundry Inc.
+
+ 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
+
+ https://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 <windows.h>
+#include <dbghelp.h>
+#include <stdio.h>
+
+extern char* get_log_path();
+LONG WINAPI CrashFilter(EXCEPTION_POINTERS *pExceptionInfo) {
+    char* mini_dump_path = calloc(MAX_PATH, sizeof(char));
+    snprintf(mini_dump_path, MAX_PATH, "%s%cziti-edge-tunnel.crash.dmp", get_log_path(), PATH_SEP);
+
+    printf("minidump created at: %s", mini_dump_path);
+    HANDLE hFile = CreateFile(mini_dump_path, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
+    if (hFile && hFile != INVALID_HANDLE_VALUE) {
+        MINIDUMP_EXCEPTION_INFORMATION mei = {
+                GetCurrentThreadId(),
+                pExceptionInfo,
+                TRUE
+        };
+        MiniDumpWriteDump(GetCurrentProcess(), GetCurrentProcessId(), hFile, MiniDumpWithThreadInfo, &mei, NULL, NULL);
+        CloseHandle(hFile);
+    }
+    free(mini_dump_path);
+    mini_dump_path = NULL;
+    return EXCEPTION_EXECUTE_HANDLER;
+}
\ No newline at end of file
diff --git a/programs/ziti-edge-tunnel/windows/minidump.h b/programs/ziti-edge-tunnel/windows/minidump.h
new file mode 100644
index 00000000..93dea238
--- /dev/null
+++ b/programs/ziti-edge-tunnel/windows/minidump.h
@@ -0,0 +1,23 @@
+/*
+ Copyright NetFoundry Inc.
+
+ 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
+
+ https://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.
+ */
+
+#ifndef ZITI_TUNNEL_SDK_C_MINIDUMP_H
+#define ZITI_TUNNEL_SDK_C_MINIDUMP_H
+
+#include <windows.h>
+LONG WINAPI CrashFilter(EXCEPTION_POINTERS *exceptionPointers);
+
+#endif //ZITI_TUNNEL_SDK_C_MINIDUMP_H
diff --git a/programs/ziti-edge-tunnel/ziti-edge-tunnel.c b/programs/ziti-edge-tunnel/ziti-edge-tunnel.c
index a5ea487a..b2996210 100644
--- a/programs/ziti-edge-tunnel/ziti-edge-tunnel.c
+++ b/programs/ziti-edge-tunnel/ziti-edge-tunnel.c
@@ -41,6 +41,7 @@
 #include "netif_driver/windows/tun.h"
 #include "windows/windows-service.h"
 #include "windows/windows-scripts.h"
+#include "windows/minidump.h"
 
 #endif
 
@@ -2749,6 +2750,11 @@ static bool is_host_only() {
 }
 
 int main(int argc, char *argv[]) {
+#if _WIN32
+    //register a crash handler for Windows
+    SetUnhandledExceptionFilter(CrashFilter);
+#endif
+
     const char *name = strrchr(argv[0], '/');
     if (name == NULL) {
         name = argv[0];