foundationdb/flow/XmlTraceLogFormatter.cpp

144 lines
4.4 KiB
C++

/*
* XmlTraceLogFormatter.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "flow/flow.h"
#include "flow/ScopeExit.h"
#include "flow/UnitTest.h"
#include "XmlTraceLogFormatter.h"
void XmlTraceLogFormatter::addref() {
ReferenceCounted<XmlTraceLogFormatter>::addref();
}
void XmlTraceLogFormatter::delref() {
ReferenceCounted<XmlTraceLogFormatter>::delref();
}
const char* XmlTraceLogFormatter::getExtension() const {
return "xml";
}
const char* XmlTraceLogFormatter::getHeader() const {
return "<?xml version=\"1.0\"?>\r\n<Trace>\r\n";
}
const char* XmlTraceLogFormatter::getFooter() const {
return "</Trace>\r\n";
}
static Severity xmlIllegalCharSeverity = SevWarnAlways;
void XmlTraceLogFormatter::escape(std::ostringstream& oss, std::string source) const {
for (;;) {
int index = source.find_first_of(std::string({ '&', '"', '<', '>', '\r', '\n', '\0' }));
if (index == source.npos) {
break;
}
oss << source.substr(0, index);
if (source[index] == '&') {
oss << "&amp;";
} else if (source[index] == '"') {
oss << "&quot;";
} else if (source[index] == '<') {
oss << "&lt;";
} else if (source[index] == '>') {
oss << "&gt;";
} else if (source[index] == '\n' || source[index] == '\r') {
oss << " ";
} else if (source[index] == '\0') {
oss << " ";
TraceEvent(xmlIllegalCharSeverity, "StrippedIllegalCharacterFromTraceEvent")
.detail("Source", StringRef(source).printable())
.detail("Character", StringRef(source.substr(index, 1)).printable());
} else {
ASSERT(false);
}
source = source.substr(index + 1);
}
oss << source;
}
std::string XmlTraceLogFormatter::formatEvent(const TraceEventFields& fields) const {
std::ostringstream oss;
oss << "<Event ";
for (const auto& itr : fields) {
escape(oss, itr.first);
oss << "=\"";
escape(oss, itr.second);
oss << "\" ";
}
oss << "/>\n";
return std::move(oss).str();
}
// Test case to ensure that TraceEvent details with XML junk get escaped.
//
// This doesn't attempt to ensure that whatever we log is valid XML.
// We might be logging a response from a remote server which may or
// may not be 100% well formed. In this situation we want to know
// exactly what it is telling us, so we escape meta characters but log
// the string regardless of its parseability.
TEST_CASE("/flow/XmlTraceEscape") {
std::string garbage_input = "<root attr=\"value&weird\">\n"
" <child>Some <b>bold</b> & \"quoted\" text</child>\n"
" <child2><![CDATA[<not>really</not> xml]]></child2>\n"
" <empty/>\n"
" <<<mismatched>>>>>>><<\n"
" <weird attr='><&\"'><inner>><<&&\"\"</inner></weird>\n"
" <!-- comment with <tags> & stuff -->\n"
" <deep>\n"
" <level1>\n"
" <level2>\n"
" <level3 attr=\"a&b<c>d\">text & more text</level3>\n"
" </level2>\n"
" </level1>\n"
" </deep>\n"
"</root>"
"more junk\n"
"<<even more>\n";
auto defaultSeverity = xmlIllegalCharSeverity;
ScopeExit cleanup([&]() { xmlIllegalCharSeverity = defaultSeverity; });
xmlIllegalCharSeverity = SevInfo;
TraceEvent event("TestEvent");
event.detail("Garbage", garbage_input);
XmlTraceLogFormatter formatter;
std::ostringstream output;
for (const auto& f : event.getFields()) {
formatter.escape(output, f.first);
formatter.escape(output, f.second);
}
std::string str = output.str();
for (const char ch : str) {
ASSERT(ch != '<' && ch != '>');
}
return Void();
}