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Remove stack size limit feature

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It is not very useful for iterative parsing as the worst case of heap
size is O(n) where n is number of character in JSON, for the worst
synthetic cases. This is reasonable and should not create stack overflow
security problem as in recursive parsing.
This commit is contained in:
Milo Yip 2014-07-26 21:40:11 +08:00
parent 89865cb919
commit e3e8fea0f3
4 changed files with 20 additions and 63 deletions
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45
include/rapidjson/document.h
View File

@ -1221,13 +1221,12 @@ public:
\tparam SourceEncoding Encoding of input stream
\tparam InputStream Type of input stream, implementing Stream concept
\param is Input stream to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\return The document itself for fluent API.
*/
template <unsigned parseFlags, typename SourceEncoding, typename InputStream>
GenericDocument& ParseStream(InputStream& is, size_t limit = 0) {
GenericDocument& ParseStream(InputStream& is) {
ValueType::SetNull(); // Remove existing root if exist
GenericReader<SourceEncoding, Encoding, Allocator> reader(limit, &GetAllocator());
GenericReader<SourceEncoding, Encoding, Allocator> reader(&GetAllocator());
ClearStackOnExit scope(*this);
parseResult_ = reader.template Parse<parseFlags>(is, *this);
if (parseResult_) {
@ -1241,23 +1240,21 @@ public:
/*! \tparam parseFlags Combination of \ref ParseFlag.
\tparam InputStream Type of input stream, implementing Stream concept
\param is Input stream to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\return The document itself for fluent API.
*/
template <unsigned parseFlags, typename InputStream>
GenericDocument& ParseStream(InputStream& is, size_t limit = 0) {
return ParseStream<parseFlags,Encoding,InputStream>(is, limit);
GenericDocument& ParseStream(InputStream& is) {
return ParseStream<parseFlags,Encoding,InputStream>(is);
}
//! Parse JSON text from an input stream (with \ref kParseDefaultFlags)
/*! \tparam InputStream Type of input stream, implementing Stream concept
\param is Input stream to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\return The document itself for fluent API.
*/
template <typename InputStream>
GenericDocument& ParseStream(InputStream& is, size_t limit = 0) {
return ParseStream<kParseDefaultFlags, Encoding, InputStream>(is, limit);
GenericDocument& ParseStream(InputStream& is) {
return ParseStream<kParseDefaultFlags, Encoding, InputStream>(is);
}
//!@}
@ -1268,33 +1265,30 @@ public:
/*! \tparam parseFlags Combination of \ref ParseFlag.
\tparam SourceEncoding Transcoding from input Encoding
\param str Mutable zero-terminated string to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\return The document itself for fluent API.
*/
template <unsigned parseFlags, typename SourceEncoding>
GenericDocument& ParseInsitu(Ch* str, size_t limit = 0) {
GenericDocument& ParseInsitu(Ch* str) {
GenericInsituStringStream<Encoding> s(str);
return ParseStream<parseFlags | kParseInsituFlag, SourceEncoding>(s, limit);
return ParseStream<parseFlags | kParseInsituFlag, SourceEncoding>(s);
}
//! Parse JSON text from a mutable string
/*! \tparam parseFlags Combination of \ref ParseFlag.
\param str Mutable zero-terminated string to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\return The document itself for fluent API.
*/
template <unsigned parseFlags>
GenericDocument& ParseInsitu(Ch* str, size_t limit = 0) {
return ParseInsitu<parseFlags, Encoding>(str, limit);
GenericDocument& ParseInsitu(Ch* str) {
return ParseInsitu<parseFlags, Encoding>(str);
}
//! Parse JSON text from a mutable string (with \ref kParseDefaultFlags)
/*! \param str Mutable zero-terminated string to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\return The document itself for fluent API.
*/
GenericDocument& ParseInsitu(Ch* str, size_t limit = 0) {
return ParseInsitu<kParseDefaultFlags, Encoding>(str, limit);
GenericDocument& ParseInsitu(Ch* str) {
return ParseInsitu<kParseDefaultFlags, Encoding>(str);
}
//!@}
@ -1305,31 +1299,28 @@ public:
/*! \tparam parseFlags Combination of \ref ParseFlag (must not contain \ref kParseInsituFlag).
\tparam SourceEncoding Transcoding from input Encoding
\param str Read-only zero-terminated string to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
*/
template <unsigned parseFlags, typename SourceEncoding>
GenericDocument& Parse(const Ch* str, size_t limit = 0) {
GenericDocument& Parse(const Ch* str) {
RAPIDJSON_ASSERT(!(parseFlags & kParseInsituFlag));
GenericStringStream<SourceEncoding> s(str);
return ParseStream<parseFlags, SourceEncoding>(s, limit);
return ParseStream<parseFlags, SourceEncoding>(s);
}
//! Parse JSON text from a read-only string
/*! \tparam parseFlags Combination of \ref ParseFlag (must not contain \ref kParseInsituFlag).
\param str Read-only zero-terminated string to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
*/
template <unsigned parseFlags>
GenericDocument& Parse(const Ch* str, size_t limit = 0) {
return Parse<parseFlags, Encoding>(str, limit);
GenericDocument& Parse(const Ch* str) {
return Parse<parseFlags, Encoding>(str);
}
//! Parse JSON text from a read-only string (with \ref kParseDefaultFlags)
/*! \param str Read-only zero-terminated string to be parsed.
\param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
*/
GenericDocument& Parse(const Ch* str, size_t limit = 0) {
return Parse<kParseDefaultFlags>(str, limit);
GenericDocument& Parse(const Ch* str) {
return Parse<kParseDefaultFlags>(str);
}
//!@}

1
include/rapidjson/error/error.h
View File

@ -60,7 +60,6 @@ enum ParseErrorCode {
kParseErrorTermination, //!< Parsing was terminated.
kParseErrorUnspecificSyntaxError, //!< Unspecific syntax error.
kParseErrorStackSizeLimitExceeded //!< Parsing stack size limit is exceeded.
};
//! Result of parsing (wraps ParseErrorCode)

25
include/rapidjson/reader.h
View File

@ -273,11 +273,10 @@ public:
typedef typename SourceEncoding::Ch Ch; //!< SourceEncoding character type
//! Constructor.
/*! \param limit Parsing stack size limit(in bytes). Pass 0 means no limit.
\param allocator Optional allocator for allocating stack memory. (Only use for non-destructive parsing)
/*! \param allocator Optional allocator for allocating stack memory. (Only use for non-destructive parsing)
\param stackCapacity stack capacity in bytes for storing a single decoded string. (Only use for non-destructive parsing)
*/
GenericReader(size_t limit = 0, Allocator* allocator = 0, size_t stackCapacity = kDefaultStackCapacity) : stack_(allocator, stackCapacity), kStackSizeLimit_(limit), parseResult_() {}
GenericReader(Allocator* allocator = 0, size_t stackCapacity = kDefaultStackCapacity) : stack_(allocator, stackCapacity), parseResult_() {}
//! Parse JSON text.
/*! \tparam parseFlags Combination of \ref ParseFlag.
@ -572,11 +571,6 @@ private:
is.Take();
Ch e = is.Take();
if ((sizeof(Ch) == 1 || unsigned(e) < 256) && escape[(unsigned char)e]) {
if (!(parseFlags & kParseInsituFlag)) {
if (!CheckStackSpaceQuota(sizeof(Ch))) {
RAPIDJSON_PARSE_ERROR(kParseErrorStackSizeLimitExceeded, is.Tell() - 1);
}
}
os.Put(escape[(unsigned char)e]);
}
else if (e == 'u') { // Unicode
@ -597,11 +591,6 @@ private:
}
else if (c == '"') { // Closing double quote
is.Take();
if (!(parseFlags & kParseInsituFlag)) {
if (!CheckStackSpaceQuota(sizeof(Ch))) {
RAPIDJSON_PARSE_ERROR(kParseErrorStackSizeLimitExceeded, is.Tell() - 1);
}
}
os.Put('\0'); // null-terminate the string
return;
}
@ -1059,11 +1048,6 @@ private:
n = IterativeParsingElementState;
else if (src == IterativeParsingKeyValueDelimiterState)
n = IterativeParsingMemberValueState;
// Check stack space limit.
if (!CheckStackSpaceQuota(sizeof(IterativeParsingState) + sizeof(int))) {
RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorStackSizeLimitExceeded, is.Tell());
return IterativeParsingErrorState;
}
// Push current state.
*stack_.template Push<IterativeParsingState>(1) = n;
// Initialize and push the member/element count.
@ -1235,13 +1219,8 @@ private:
return parseResult_;
}
bool CheckStackSpaceQuota(size_t size) const {
return kStackSizeLimit_ == 0 || (stack_.GetSize() + size <= kStackSizeLimit_);
}
static const size_t kDefaultStackCapacity = 256; //!< Default stack capacity in bytes for storing a single decoded string.
internal::Stack<Allocator> stack_; //!< A stack for storing decoded string temporarily during non-destructive parsing.
const size_t kStackSizeLimit_; //!< Stack size limit(in bytes). A value of 0 means no limit.
ParseResult parseResult_;
}; // class GenericReader

12
test/unittest/readertest.cpp
View File

@ -932,18 +932,6 @@ TEST(Reader, IterativeParsing_ShortCircuit) {
}
}
TEST(Reader, IterativeParsing_LimitStackSize) {
BaseReaderHandler<> handler;
Reader reader(20);
StringStream is("[[[]]]");
ParseResult r = reader.Parse<kParseIterativeFlag>(is, handler);
EXPECT_TRUE(reader.HasParseError());
EXPECT_EQ(kParseErrorStackSizeLimitExceeded, r.Code());
EXPECT_EQ(2u, r.Offset());
}
#ifdef __GNUC__
RAPIDJSON_DIAG_POP
#endif