From: Christian Grothoff <christian@grothoff.org>
Date: Mon, 9 Jul 2012 11:17:55 +0000 (+0000)
Subject: -LRN: Our std handles are not created by us, and thus are inheritable by default.
X-Git-Tag: initial-import-from-subversion-38251~12580
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=078713080ee376ba8a490c70c474a1a2d22189c8;p=oweals%2Fgnunet.git

-LRN: Our std handles are not created by us, and thus are inheritable by default.
We don't want them to be passed to our child processes, because our parent
might be waiting for them to be closed, which would mean that our process
is dead.
---

diff --git a/src/util/os_priority.c b/src/util/os_priority.c
index c9174dee9..ca60f857e 100644
--- a/src/util/os_priority.c
+++ b/src/util/os_priority.c
@@ -961,6 +961,10 @@ start_process (int pipe_control,
   long lRet;
   HANDLE stdin_handle;
   HANDLE stdout_handle;
+  BOOL bresult;
+  DWORD error_code;
+  HANDLE stdih, stdoh, stdeh;
+  DWORD stdif, stdof, stdef;
 
   if (GNUNET_SYSERR == GNUNET_OS_check_helper_binary (filename))
     return NULL; /* not executable */
@@ -1083,8 +1087,7 @@ start_process (int pipe_control,
 
   memset (&start, 0, sizeof (start));
   start.cb = sizeof (start);
-  if ((pipe_stdin != NULL) || (pipe_stdout != NULL))
-    start.dwFlags |= STARTF_USESTDHANDLES;
+  start.dwFlags |= STARTF_USESTDHANDLES;
 
   if (pipe_stdin != NULL)
   {
@@ -1179,24 +1182,54 @@ start_process (int pipe_control,
     return NULL;
   }
 
-  if (!CreateProcessW (wpath, wcmd, NULL, NULL, TRUE,
-       DETACHED_PROCESS | CREATE_SUSPENDED, env_block, NULL, &start, &proc))
+  /* Prevents our std handles from being inherited by the child */
+  stdih = GetStdHandle (STD_INPUT_HANDLE);
+  stdoh = GetStdHandle (STD_OUTPUT_HANDLE);
+  stdeh = GetStdHandle (STD_ERROR_HANDLE);
+  if (stdih)
   {
-    SetErrnoFromWinError (GetLastError ());
+    GetHandleInformation (stdih, &stdif);
+    SetHandleInformation (stdih, HANDLE_FLAG_INHERIT, 0);
+  }
+  if (stdoh)
+  {
+    GetHandleInformation (stdoh, &stdof);
+    SetHandleInformation (stdoh, HANDLE_FLAG_INHERIT, 0);
+  }
+  if (stdeh)
+  {
+    GetHandleInformation (stdeh, &stdef);
+    SetHandleInformation (stdeh, HANDLE_FLAG_INHERIT, 0);
+  }
+
+  bresult = CreateProcessW (wpath, wcmd, NULL, NULL, TRUE,
+       DETACHED_PROCESS | CREATE_SUSPENDED, env_block, NULL, &start, &proc);
+  error_code = GetLastError ();
+
+  if (stdih)
+    SetHandleInformation (stdih, stdif, stdif);
+  if (stdoh)
+    SetHandleInformation (stdoh, stdof, stdof);
+  if (stdeh)
+    SetHandleInformation (stdeh, stdef, stdef);
+
+  GNUNET_free (env_block);
+  GNUNET_free (cmd);
+  free (wpath);
+  free (wcmd);
+
+  if (!bresult)
+  {
+    SetErrnoFromWinError (error_code);
     LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "CreateProcess");
+
     if (NULL != control_pipe)
       GNUNET_DISK_file_close (control_pipe);
     if (NULL != lsocks)
       GNUNET_DISK_pipe_close (lsocks_pipe);
-    GNUNET_free (env_block);
-    GNUNET_free (cmd);
-    free (wpath);
-    free (wcmd);
     return NULL;
   }
 
-  GNUNET_free (env_block);
-
   gnunet_proc = GNUNET_malloc (sizeof (struct GNUNET_OS_Process));
   gnunet_proc->pid = proc.dwProcessId;
   gnunet_proc->handle = proc.hProcess;
@@ -1206,9 +1239,6 @@ start_process (int pipe_control,
 
   ResumeThread (proc.hThread);
   CloseHandle (proc.hThread);
-  GNUNET_free (cmd);
-  free (wpath);
-  free (wcmd);
 
   if (lsocks == NULL || lsocks[0] == INVALID_SOCKET)
     return gnunet_proc;