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Diffstat (limited to '')
-rw-r--r-- | security/sandbox/chromium/base/strings/stringprintf.cc | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/strings/stringprintf.cc b/security/sandbox/chromium/base/strings/stringprintf.cc new file mode 100644 index 0000000000..738cc63bbe --- /dev/null +++ b/security/sandbox/chromium/base/strings/stringprintf.cc @@ -0,0 +1,225 @@ +// Copyright 2013 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 "base/strings/stringprintf.h" + +#include <errno.h> +#include <stddef.h> + +#include <vector> + +#include "base/scoped_clear_last_error.h" +#include "base/stl_util.h" +#include "base/strings/string_util.h" +#include "base/strings/utf_string_conversions.h" +#include "build/build_config.h" + +namespace base { + +namespace { + +// Overloaded wrappers around vsnprintf and vswprintf. The buf_size parameter +// is the size of the buffer. These return the number of characters in the +// formatted string excluding the NUL terminator. If the buffer is not +// large enough to accommodate the formatted string without truncation, they +// return the number of characters that would be in the fully-formatted string +// (vsnprintf, and vswprintf on Windows), or -1 (vswprintf on POSIX platforms). +inline int vsnprintfT(char* buffer, + size_t buf_size, + const char* format, + va_list argptr) { + return base::vsnprintf(buffer, buf_size, format, argptr); +} + +#if defined(OS_WIN) +inline int vsnprintfT(wchar_t* buffer, + size_t buf_size, + const wchar_t* format, + va_list argptr) { + return base::vswprintf(buffer, buf_size, format, argptr); +} +inline int vsnprintfT(char16_t* buffer, + size_t buf_size, + const char16_t* format, + va_list argptr) { + return base::vswprintf(reinterpret_cast<wchar_t*>(buffer), buf_size, + reinterpret_cast<const wchar_t*>(format), argptr); +} +#endif + +// Templatized backend for StringPrintF/StringAppendF. This does not finalize +// the va_list, the caller is expected to do that. +template <class CharT> +static void StringAppendVT(std::basic_string<CharT>* dst, + const CharT* format, + va_list ap) { + // First try with a small fixed size buffer. + // This buffer size should be kept in sync with StringUtilTest.GrowBoundary + // and StringUtilTest.StringPrintfBounds. + CharT stack_buf[1024]; + + va_list ap_copy; + va_copy(ap_copy, ap); + + base::internal::ScopedClearLastError last_error; + int result = vsnprintfT(stack_buf, base::size(stack_buf), format, ap_copy); + va_end(ap_copy); + + if (result >= 0 && result < static_cast<int>(base::size(stack_buf))) { + // It fit. + dst->append(stack_buf, result); + return; + } + + // Repeatedly increase buffer size until it fits. + int mem_length = base::size(stack_buf); + while (true) { + if (result < 0) { +#if defined(OS_WIN) + // On Windows, vsnprintfT always returns the number of characters in a + // fully-formatted string, so if we reach this point, something else is + // wrong and no amount of buffer-doubling is going to fix it. + return; +#else + if (errno != 0 && errno != EOVERFLOW) + return; + // Try doubling the buffer size. + mem_length *= 2; +#endif + } else { + // We need exactly "result + 1" characters. + mem_length = result + 1; + } + + if (mem_length > 32 * 1024 * 1024) { + // That should be plenty, don't try anything larger. This protects + // against huge allocations when using vsnprintfT implementations that + // return -1 for reasons other than overflow without setting errno. + DLOG(WARNING) << "Unable to printf the requested string due to size."; + return; + } + + std::vector<CharT> mem_buf(mem_length); + + // NOTE: You can only use a va_list once. Since we're in a while loop, we + // need to make a new copy each time so we don't use up the original. + va_copy(ap_copy, ap); + result = vsnprintfT(&mem_buf[0], mem_length, format, ap_copy); + va_end(ap_copy); + + if ((result >= 0) && (result < mem_length)) { + // It fit. + dst->append(&mem_buf[0], result); + return; + } + } +} + +} // namespace + +std::string StringPrintf(const char* format, ...) { + va_list ap; + va_start(ap, format); + std::string result; + StringAppendV(&result, format, ap); + va_end(ap); + return result; +} + +#if defined(OS_WIN) +std::wstring StringPrintf(const wchar_t* format, ...) { + va_list ap; + va_start(ap, format); + std::wstring result; + StringAppendV(&result, format, ap); + va_end(ap); + return result; +} + +std::u16string StringPrintf(const char16_t* format, ...) { + va_list ap; + va_start(ap, format); + std::u16string result; + StringAppendV(&result, format, ap); + va_end(ap); + return result; +} +#endif + +std::string StringPrintV(const char* format, va_list ap) { + std::string result; + StringAppendV(&result, format, ap); + return result; +} + +const std::string& SStringPrintf(std::string* dst, const char* format, ...) { + va_list ap; + va_start(ap, format); + dst->clear(); + StringAppendV(dst, format, ap); + va_end(ap); + return *dst; +} + +#if defined(OS_WIN) +const std::wstring& SStringPrintf(std::wstring* dst, + const wchar_t* format, ...) { + va_list ap; + va_start(ap, format); + dst->clear(); + StringAppendV(dst, format, ap); + va_end(ap); + return *dst; +} + +const std::u16string& SStringPrintf(std::u16string* dst, + const char16_t* format, + ...) { + va_list ap; + va_start(ap, format); + dst->clear(); + StringAppendV(dst, format, ap); + va_end(ap); + return *dst; +} +#endif + +void StringAppendF(std::string* dst, const char* format, ...) { + va_list ap; + va_start(ap, format); + StringAppendV(dst, format, ap); + va_end(ap); +} + +#if defined(OS_WIN) +void StringAppendF(std::wstring* dst, const wchar_t* format, ...) { + va_list ap; + va_start(ap, format); + StringAppendV(dst, format, ap); + va_end(ap); +} + +void StringAppendF(std::u16string* dst, const char16_t* format, ...) { + va_list ap; + va_start(ap, format); + StringAppendV(dst, format, ap); + va_end(ap); +} +#endif + +void StringAppendV(std::string* dst, const char* format, va_list ap) { + StringAppendVT(dst, format, ap); +} + +#if defined(OS_WIN) +void StringAppendV(std::wstring* dst, const wchar_t* format, va_list ap) { + StringAppendVT(dst, format, ap); +} + +void StringAppendV(std::u16string* dst, const char16_t* format, va_list ap) { + StringAppendVT(dst, format, ap); +} +#endif + +} // namespace base |