1 files changed, 77 insertions, 0 deletions
diff --git a/security/sandbox/linux/SandboxOpenedFiles.cpp b/security/sandbox/linux/SandboxOpenedFiles.cpp
new file mode 100644
index 0000000000..8c26f7f206
--- /dev/null
+++ b/security/sandbox/linux/SandboxOpenedFiles.cpp
@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SandboxOpenedFiles.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <utility>
+
+#include "SandboxLogging.h"
+
+namespace mozilla {
+
+// The default move constructor almost works, but Atomic isn't
+// move-constructable and the fd needs some special handling.
+SandboxOpenedFile::SandboxOpenedFile(SandboxOpenedFile&& aMoved)
+    : mPath(std::move(aMoved.mPath)),
+      mMaybeFd(aMoved.TakeDesc()),
+      mDup(aMoved.mDup),
+      mExpectError(aMoved.mExpectError) {}
+
+SandboxOpenedFile::SandboxOpenedFile(const char* aPath, Dup aDup)
+    : mPath(aPath), mDup(aDup == Dup::YES), mExpectError(false) {
+  MOZ_ASSERT(aPath[0] == '/', "path should be absolute");
+
+  int fd = open(aPath, O_RDONLY | O_CLOEXEC);
+  if (fd < 0) {
+    mExpectError = true;
+  }
+  mMaybeFd = fd;
+}
+
+SandboxOpenedFile::SandboxOpenedFile(const char* aPath, Error)
+    : mPath(aPath), mMaybeFd(-1), mDup(false), mExpectError(true) {}
+
+int SandboxOpenedFile::GetDesc() const {
+  int fd;
+  if (mDup) {
+    fd = mMaybeFd;
+    if (fd >= 0) {
+      fd = dup(fd);
+      if (fd < 0) {
+        SANDBOX_LOG_ERRNO("dup");
+      }
+    }
+  } else {
+    fd = TakeDesc();
+  }
+  if (fd < 0 && !mExpectError) {
+    SANDBOX_LOG("unexpected multiple open of file %s", Path());
+  }
+  return fd;
+}
+
+SandboxOpenedFile::~SandboxOpenedFile() {
+  int fd = TakeDesc();
+  if (fd >= 0) {
+    close(fd);
+  }
+}
+
+int SandboxOpenedFiles::GetDesc(const char* aPath) const {
+  for (const auto& file : mFiles) {
+    if (strcmp(file.Path(), aPath) == 0) {
+      return file.GetDesc();
+    }
+  }
+  SANDBOX_LOG("attempt to open unexpected file %s", aPath);
+  return -1;
+}
+
+}  // namespace mozilla