/* 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) {
      // This runs in a sandboxed process that can't exec, so the use
      // of dup instead of F_DUPFD_CLOEXEC doesn't matter.
      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