Process abstraction layer for NaCl

src/trusted/platform/win/nacl_process.c

+/*
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "native_client/src/trusted/platform/nacl_process.h"
+
+#include <fcntl.h>
+#include <io.h>
+#include <windows.h>
+#include <userenv.h>
+#include <psapi.h>
+
+#include "native_client/src/include/portability.h"
+#include "native_client/src/include/portability_string.h"
+
+#include "native_client/src/shared/platform/nacl_check.h"
+#include "native_client/src/shared/platform/nacl_log.h"
+#include "native_client/src/shared/platform/nacl_sync.h"
+#include "native_client/src/shared/platform/nacl_sync_checked.h"
+
+#ifndef STATUS_SUCCESS

[Mark Seaborn, 2012/08/24 00:22:42]

Aren't these defined by the Windows headers?  If so, you don't need definitions
of them here.

+#define STATUS_SUCCESS            ((NTSTATUS) 0)
+#endif
+#ifndef STATUS_WAIT_1
+#define STATUS_WAIT_1             ((NTSTATUS) 0x00000001)
+#endif
+#ifndef STATUS_DEBUGGER_INACTIVE
+#define STATUS_DEBUGGER_INACTIVE  ((NTSTATUS) 0xC0000354)
+#endif
+#ifndef STATUS_CONTROL_C_EXIT
+#define STATUS_CONTROL_C_EXIT     ((NTSTATUS) 0xC000013A)
+#endif
+#ifndef DBG_TERMINATE_PROCESS
+#define DBG_TERMINATE_PROCESS     ((NTSTATUS) 0x40010004)
+#endif
+
+static char *NaClEscapeShellArg(const char *str) {

[Mark Seaborn, 2012/08/24 00:22:42]

I don't know whether this properly implements Windows' strange quoting rules. 
Can you link to some documentation that explains Windows' quoting rules?  Also,
you should add some tests for it.

However: do we really need to pass arbitrary strings to a process via argv?  Can
we get away with passing any arguments via IPC instead?

+  const char *p;
+  char *esc;
+  char *q;
+
+  esc = calloc(2 * strlen(str) + 1, sizeof *esc);
+  for (p = str, q = esc; 0 != *p; ++p) {
+    if (*p == '"') {
+      *q++ = '\\';
+    } else if (*p == '\\' && *(p + 1) == '"') {
+      *q++ = '\\';
+    }
+    *q++ = *p;
+  }
+
+  return esc;
+}
+
+int NaClProcessLaunch(struct NaClProcess *npp,
+                      char *const *argv,
+                      char *const *envp,
+                      int flags) {
+  char                  cmd[MAX_PATH];
+  char const *const     *p;
+  size_t                off;
+  STARTUPINFO           startup_info;
+  PROCESS_INFORMATION   process_info;
+  DWORD                 creation_flags = CREATE_UNICODE_ENVIRONMENT;
+  BOOL                  inherit;
+
+  NaClLog(2,
+          ("NaClProcessLaunch(0x%08"NACL_PRIxPTR", 0x%08"NACL_PRIxPTR
+           ", 0x%08"NACL_PRIxPTR", 0x%x)\n"),
+          (uintptr_t) npp, (uintptr_t) argv, (uintptr_t) envp, flags);
+
+  CHECK(npp != NULL);
+
+  ZeroMemory(&startup_info, sizeof startup_info);

[Mark Seaborn, 2012/08/24 00:22:42]

Using memset() is more usual, since it's a better-known standard function.

+  startup_info.cb = sizeof startup_info;
+  startup_info.dwFlags = STARTF_USESTDHANDLES;
+
+  /* Convert arguments to a single command string */
+  off = 0;
+  for (p = argv; NULL != *p; ++p) {
+    size_t len;
+    char *arg;
+    if (p != argv) {
+      cmd[off++] = ' ';
+    }
+    arg = NaClEscapeShellArg(*p);
+    len = _snprintf(cmd + off, MAX_PATH - off, "\"%s\"", arg);
+    free(arg);
+    if (MAX_PATH - off < len) {
+      break;
+    }
+    off += len;
+  }
+  cmd[off] = '\0';
+
+  if ((flags & NACL_PROCESS_LAUNCH_CLOSE_FDS) != 0) {
+    inherit = FALSE;
+  } else {
+    inherit = TRUE;
+  }
+
+  if (0 != (flags & NACL_PROCESS_LAUNCH_NEW_GROUP)) {
+    creation_flags |= CREATE_NEW_PROCESS_GROUP;
+  }
+
+  if (!CreateProcess(/* lpApplicationName= */ NULL,
+                     cmd,
+                     /* lpProcessAttributes= */ NULL,
+                     /* lpThreadAttributes= */ NULL,
+                     inherit,
+                     creation_flags,
+                     envp,
+                     /* lpCurrentDirectory= */NULL,
+                     &startup_info,
+                     &process_info)) {
+    NaClLog(LOG_ERROR,
+            "NaClProcessSpawn: CreateProcess failed, error %d\n",
+            GetLastError());
+    return 0;
+  }
+
+  /* TODO(phosek): might we ever need this handle? */
+  DCHECK(CloseHandle(process_info.hThread));
+
+  if (npp != NULL) {
+    npp->handle = process_info.hProcess;
+  }
+
+  return 1;
+}
+
+int NaClProcessKill(struct NaClProcess *npp, int exit_code, int wait) {
+  BOOL retval;
+
+  NaClLog(2,
+          "NaClProcessKill(0x%08"NACL_PRIxPTR", %d, %d)\n",
+          (uintptr_t) npp, exit_code, wait);
+
+  CHECK(npp != NULL);
+
+  retval = TerminateProcess(npp->handle, exit_code);
+  if (FALSE == retval) {
+    NaClLog(LOG_ERROR,
+            "NaClProcessKill: unable to terminate process, error %d\n",
+            GetLastError());
+    goto done;
+  }
+
+  if (wait != 0) {
+    /* The process may not end immediately due to pending I/O */
+    if (WAIT_OBJECT_0 != WaitForSingleObject(npp->handle, 60 * 1000)) {

[Mark Seaborn, 2012/08/24 00:22:42]

Why a hard-coded timeout?  What is the use case?

+      NaClLog(LOG_ERROR,
+              "NaClProcessKill: waiting for process failed, error %d\n",
+              GetLastError());
+    }
+  }
+
+ done:
+  return retval != FALSE;
+}
+
+int NaClProcessGetStatus(
+    struct NaClProcess  *npp,
+    int                 *status) {
+  DWORD exit_code = 0;
+
+  NaClLog(2,
+          ("NaClProcessGetStatus(0x%08"NACL_PRIxPTR
+           ", 0x%08"NACL_PRIxPTR")\n"),
+          (uintptr_t) npp, (uintptr_t) status);
+
+  CHECK(npp != NULL);
+
+  NaClLog(4,
+          "NaClProcessGetStatus: checking status of process %d\n",
+          (int) npp->handle);
+
+  if (!GetExitCodeProcess(npp->handle, &exit_code)) {
+    NaClLog(LOG_ERROR,
+            ("NaClProcessGetStatus: GetExitCodeProcess"
+             "returned error %d\n"),
+            GetLastError());
+    return 0;
+  }
+
+  if (STILL_ACTIVE == exit_code) {
+    DWORD wait_result = WaitForSingleObject(npp->handle, 0);
+    if (WAIT_TIMEOUT == wait_result) {
+      *status = NACL_PROCESS_STATUS_STILL_RUNNING;
+      return 1;
+    }
+
+    CHECK(WAIT_OBJECT_0 == wait_result);
+    /* The process used 0x103 (STILL_ACTIVE) as exit code. */
+    *status = NACL_PROCESS_STATUS_ABNORMAL_EXIT;
+    return 1;
+  }
+
+  switch (exit_code) {
+    case STATUS_SUCCESS:             /* Normal termination */
+      *status = NACL_PROCESS_STATUS_NORMAL_EXIT;
+      break;
+    case STATUS_DEBUGGER_INACTIVE:  /* Debugger inactive */
+    case STATUS_CONTROL_C_EXIT:     /* Keyboard interrupt */
+    case DBG_TERMINATE_PROCESS:     /* Debugger terminated */
+    case STATUS_WAIT_1:             /* Task manager killed */
+      *status = NACL_PROCESS_STATUS_KILLED;
+      break;
+    default:
+      /* All other exit codes indicate crashes */
+      *status = NACL_PROCESS_STATUS_CRASHED;
+      break;
+  }
+
+  return 1;
+}
+
+int NaClProcessWaitForExitCode(struct NaClProcess   *npp,
+                               int                  *exit_code) {
+  DWORD tmp_exit_code;
+
+  NaClLog(2,
+          ("NaClProcessWaitForExitCode(0x%08"NACL_PRIxPTR
+           ", 0x%08"NACL_PRIxPTR")\n"),
+          (uintptr_t) npp, (uintptr_t) exit_code);
+
+  CHECK(npp != NULL);
+
+  if (WAIT_OBJECT_0 != WaitForSingleObject(npp->handle, INFINITE)) {
+    return 0;
+  }
+
+  if (!GetExitCodeProcess(npp->handle, &tmp_exit_code)) {
+    return 0;
+  }
+
+  *exit_code = tmp_exit_code;
+  return 1;
+}