1 files changed, 119 insertions, 0 deletions
diff --git a/sandbox/linux/services/proc_util.cc b/sandbox/linux/services/proc_util.cc
new file mode 100644
index 0000000000..d3f755f9a1
--- /dev/null
+++ b/sandbox/linux/services/proc_util.cc
@@ -0,0 +1,119 @@
+// Copyright 2014 The Chromium 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 "sandbox/linux/services/proc_util.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/strings/string_number_conversions.h"
+
+namespace sandbox {
+namespace {
+
+struct DIRCloser {
+  void operator()(DIR* d) const {
+    DCHECK(d);
+    PCHECK(0 == closedir(d));
+  }
+};
+
+typedef scoped_ptr<DIR, DIRCloser> ScopedDIR;
+
+base::ScopedFD OpenDirectory(const char* path) {
+  DCHECK(path);
+  base::ScopedFD directory_fd(
+      HANDLE_EINTR(open(path, O_RDONLY | O_DIRECTORY | O_CLOEXEC)));
+  PCHECK(directory_fd.is_valid());
+  return directory_fd.Pass();
+}
+
+}  // namespace
+
+int ProcUtil::CountOpenFds(int proc_fd) {
+  DCHECK_LE(0, proc_fd);
+  int proc_self_fd = HANDLE_EINTR(
+      openat(proc_fd, "self/fd/", O_DIRECTORY | O_RDONLY | O_CLOEXEC));
+  PCHECK(0 <= proc_self_fd);
+
+  // Ownership of proc_self_fd is transferred here, it must not be closed
+  // or modified afterwards except via dir.
+  ScopedDIR dir(fdopendir(proc_self_fd));
+  CHECK(dir);
+
+  int count = 0;
+  struct dirent e;
+  struct dirent* de;
+  while (!readdir_r(dir.get(), &e, &de) && de) {
+    if (strcmp(e.d_name, ".") == 0 || strcmp(e.d_name, "..") == 0) {
+      continue;
+    }
+
+    int fd_num;
+    CHECK(base::StringToInt(e.d_name, &fd_num));
+    if (fd_num == proc_fd || fd_num == proc_self_fd) {
+      continue;
+    }
+
+    ++count;
+  }
+  return count;
+}
+
+bool ProcUtil::HasOpenDirectory(int proc_fd) {
+  DCHECK_LE(0, proc_fd);
+  int proc_self_fd =
+      openat(proc_fd, "self/fd/", O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+
+  PCHECK(0 <= proc_self_fd);
+
+  // Ownership of proc_self_fd is transferred here, it must not be closed
+  // or modified afterwards except via dir.
+  ScopedDIR dir(fdopendir(proc_self_fd));
+  CHECK(dir);
+
+  struct dirent e;
+  struct dirent* de;
+  while (!readdir_r(dir.get(), &e, &de) && de) {
+    if (strcmp(e.d_name, ".") == 0 || strcmp(e.d_name, "..") == 0) {
+      continue;
+    }
+
+    int fd_num;
+    CHECK(base::StringToInt(e.d_name, &fd_num));
+    if (fd_num == proc_fd || fd_num == proc_self_fd) {
+      continue;
+    }
+
+    struct stat s;
+    // It's OK to use proc_self_fd here, fstatat won't modify it.
+    CHECK(fstatat(proc_self_fd, e.d_name, &s, 0) == 0);
+    if (S_ISDIR(s.st_mode)) {
+      return true;
+    }
+  }
+
+  // No open unmanaged directories found.
+  return false;
+}
+
+bool ProcUtil::HasOpenDirectory() {
+  base::ScopedFD proc_fd(
+      HANDLE_EINTR(open("/proc/", O_DIRECTORY | O_RDONLY | O_CLOEXEC)));
+  return HasOpenDirectory(proc_fd.get());
+}
+
+//static
+base::ScopedFD ProcUtil::OpenProc() {
+  return OpenDirectory("/proc/");
+}
+
+}  // namespace sandbox