tor-browser

The Tor Browser
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SandboxOpenedFiles.cpp (1981B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
      5 * You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "SandboxOpenedFiles.h"
      8 
      9 #include <errno.h>
     10 #include <fcntl.h>
     11 #include <unistd.h>
     12 
     13 #include <utility>
     14 
     15 #include "SandboxLogging.h"
     16 
     17 namespace mozilla {
     18 
     19 // The default move constructor almost works, but Atomic isn't
     20 // move-constructable and the fd needs some special handling.
     21 SandboxOpenedFile::SandboxOpenedFile(SandboxOpenedFile&& aMoved)
     22    : mPath(std::move(aMoved.mPath)),
     23      mMaybeFd(aMoved.TakeDesc()),
     24      mDup(aMoved.mDup),
     25      mExpectError(aMoved.mExpectError) {}
     26 
     27 SandboxOpenedFile::SandboxOpenedFile(const char* aPath, Dup aDup)
     28    : mPath(aPath), mDup(aDup == Dup::YES), mExpectError(false) {
     29  MOZ_ASSERT(aPath[0] == '/', "path should be absolute");
     30 
     31  int fd = open(aPath, O_RDONLY | O_CLOEXEC);
     32  if (fd < 0) {
     33    mExpectError = true;
     34  }
     35  mMaybeFd = fd;
     36 }
     37 
     38 SandboxOpenedFile::SandboxOpenedFile(const char* aPath, Error)
     39    : mPath(aPath), mMaybeFd(-1), mDup(false), mExpectError(true) {}
     40 
     41 int SandboxOpenedFile::GetDesc() const {
     42  int fd;
     43  if (mDup) {
     44    fd = mMaybeFd;
     45    if (fd >= 0) {
     46      fd = dup(fd);
     47      if (fd < 0) {
     48        SANDBOX_LOG_ERRNO("dup");
     49      }
     50    }
     51  } else {
     52    fd = TakeDesc();
     53  }
     54  if (fd < 0 && !mExpectError) {
     55    SANDBOX_LOG("unexpected multiple open of file %s", Path());
     56  }
     57  return fd;
     58 }
     59 
     60 SandboxOpenedFile::~SandboxOpenedFile() {
     61  int fd = TakeDesc();
     62  if (fd >= 0) {
     63    close(fd);
     64  }
     65 }
     66 
     67 int SandboxOpenedFiles::GetDesc(const char* aPath) const {
     68  for (const auto& file : mFiles) {
     69    if (strcmp(file.Path(), aPath) == 0) {
     70      return file.GetDesc();
     71    }
     72  }
     73  SANDBOX_LOG("attempt to open unexpected file %s", aPath);
     74  return -1;
     75 }
     76 
     77 }  // namespace mozilla