Files
SingularityViewer/indra/llmessage/llmime.cpp
2012-07-22 11:26:36 +02:00

630 lines
14 KiB
C++

/**
* @file llmime.cpp
* @author Phoenix
* @date 2006-12-20
* @brief Implementation of mime tools.
*
* $LicenseInfo:firstyear=2006&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#include "linden_common.h"
#include "llmime.h"
#include <vector>
#include "llmemorystream.h"
/**
* Useful constants.
*/
// Headers specified in rfc-2045 will be canonicalized below.
static const std::string CONTENT_LENGTH("Content-Length");
static const std::string CONTENT_TYPE("Content-Type");
static const S32 KNOWN_HEADER_COUNT = 6;
static const std::string KNOWN_HEADER[KNOWN_HEADER_COUNT] =
{
CONTENT_LENGTH,
CONTENT_TYPE,
std::string("MIME-Version"),
std::string("Content-Transfer-Encoding"),
std::string("Content-ID"),
std::string("Content-Description"),
};
// parser helpers
static const std::string MULTIPART("multipart");
static const std::string BOUNDARY("boundary");
static const std::string END_OF_CONTENT_PARAMETER("\r\n ;\t");
static const std::string SEPARATOR_PREFIX("--");
//static const std::string SEPARATOR_SUFFIX("\r\n");
/*
Content-Type: multipart/mixed; boundary="segment"
Content-Length: 24832
--segment
Content-Type: image/j2c
Content-Length: 23715
<data>
--segment
Content-Type: text/xml; charset=UTF-8
<meta data>
EOF
*/
/**
* LLMimeIndex
*/
/**
* @class LLMimeIndex::Impl
* @brief Implementation details of the mime index class.
* @see LLMimeIndex
*/
class LLMimeIndex::Impl
{
public:
Impl() : mOffset(-1), mUseCount(1)
{}
Impl(LLSD headers, S32 offset) :
mHeaders(headers), mOffset(offset), mUseCount(1)
{}
public:
LLSD mHeaders;
S32 mOffset;
S32 mUseCount;
typedef std::vector<LLMimeIndex> sub_part_t;
sub_part_t mAttachments;
};
LLSD LLMimeIndex::headers() const
{
return mImpl->mHeaders;
}
S32 LLMimeIndex::offset() const
{
return mImpl->mOffset;
}
S32 LLMimeIndex::contentLength() const
{
// Find the content length in the headers.
S32 length = -1;
LLSD content_length = mImpl->mHeaders[CONTENT_LENGTH];
if(content_length.isDefined())
{
length = content_length.asInteger();
}
return length;
}
std::string LLMimeIndex::contentType() const
{
std::string type;
LLSD content_type = mImpl->mHeaders[CONTENT_TYPE];
if(content_type.isDefined())
{
type = content_type.asString();
}
return type;
}
bool LLMimeIndex::isMultipart() const
{
bool multipart = false;
LLSD content_type = mImpl->mHeaders[CONTENT_TYPE];
if(content_type.isDefined())
{
std::string type = content_type.asString();
int comp = type.compare(0, MULTIPART.size(), MULTIPART);
if(0 == comp)
{
multipart = true;
}
}
return multipart;
}
S32 LLMimeIndex::subPartCount() const
{
return mImpl->mAttachments.size();
}
LLMimeIndex LLMimeIndex::subPart(S32 index) const
{
LLMimeIndex part;
if((index >= 0) && (index < (S32)mImpl->mAttachments.size()))
{
part = mImpl->mAttachments[index];
}
return part;
}
LLMimeIndex::LLMimeIndex() : mImpl(new LLMimeIndex::Impl)
{
}
LLMimeIndex::LLMimeIndex(LLSD headers, S32 content_offset) :
mImpl(new LLMimeIndex::Impl(headers, content_offset))
{
}
LLMimeIndex::LLMimeIndex(const LLMimeIndex& mime) :
mImpl(mime.mImpl)
{
++mImpl->mUseCount;
}
LLMimeIndex::~LLMimeIndex()
{
if(0 == --mImpl->mUseCount)
{
delete mImpl;
}
}
LLMimeIndex& LLMimeIndex::operator=(const LLMimeIndex& mime)
{
// Increment use count first so that we handle self assignment
// automatically.
++mime.mImpl->mUseCount;
if(0 == --mImpl->mUseCount)
{
delete mImpl;
}
mImpl = mime.mImpl;
return *this;
}
bool LLMimeIndex::attachSubPart(LLMimeIndex sub_part)
{
// *FIX: Should we check for multi-part?
if(mImpl->mAttachments.size() < S32_MAX)
{
mImpl->mAttachments.push_back(sub_part);
return true;
}
return false;
}
/**
* LLMimeParser
*/
/**
* @class LLMimeParser::Impl
* @brief Implementation details of the mime parser class.
* @see LLMimeParser
*/
class LLMimeParser::Impl
{
public:
// @brief Constructor.
Impl();
// @brief Reset this for a new parse.
void reset();
/**
* @brief Parse a mime entity to find the index information.
*
* This method will scan the istr until a single complete mime
* entity is read, an EOF, or limit bytes have been scanned. The
* istr will be modified by this parsing, so pass in a temporary
* stream or rewind/reset the stream after this call.
* @param istr An istream which contains a mime entity.
* @param limit The maximum number of bytes to scan.
* @param separator The multipart separator if it is known.
* @param is_subpart Set true if parsing a multipart sub part.
* @param index[out] The parsed output.
* @return Returns true if an index was parsed and no errors occurred.
*/
bool parseIndex(
std::istream& istr,
S32 limit,
const std::string& separator,
bool is_subpart,
LLMimeIndex& index);
protected:
/**
* @brief parse the headers.
*
* At the end of a successful parse, mScanCount will be at the
* start of the content.
* @param istr The input stream.
* @param limit maximum number of bytes to process
* @param headers[out] A map of the headers found.
* @return Returns true if the parse was successful.
*/
bool parseHeaders(std::istream& istr, S32 limit, LLSD& headers);
/**
* @brief Figure out the separator string from a content type header.
*
* @param multipart_content_type The content type value from the headers.
* @return Returns the separator string.
*/
std::string findSeparator(std::string multipart_content_type);
/**
* @brief Scan through istr past the separator.
*
* @param istr The input stream.
* @param limit Maximum number of bytes to scan.
* @param separator The multipart separator.
*/
void scanPastSeparator(
std::istream& istr,
S32 limit,
const std::string& separator);
/**
* @brief Scan through istr past the content of the current mime part.
*
* @param istr The input stream.
* @param limit Maximum number of bytes to scan.
* @param headers The headers for this mime part.
* @param separator The multipart separator if known.
*/
void scanPastContent(
std::istream& istr,
S32 limit,
LLSD headers,
const std::string separator);
/**
* @brief Eat CRLF.
*
* This method has no concept of the limit, so ensure you have at
* least 2 characters left to eat before hitting the limit. This
* method will increment mScanCount as it goes.
* @param istr The input stream.
* @return Returns true if CRLF was found and consumed off of istr.
*/
bool eatCRLF(std::istream& istr);
// @brief Returns true if parsing should continue.
bool continueParse() const { return (!mError && mContinue); }
// @brief anonymous enumeration for parse buffer size.
enum
{
LINE_BUFFER_LENGTH = 1024
};
protected:
S32 mScanCount;
bool mContinue;
bool mError;
char mBuffer[LINE_BUFFER_LENGTH];
};
LLMimeParser::Impl::Impl()
{
reset();
}
void LLMimeParser::Impl::reset()
{
mScanCount = 0;
mContinue = true;
mError = false;
mBuffer[0] = '\0';
}
bool LLMimeParser::Impl::parseIndex(
std::istream& istr,
S32 limit,
const std::string& separator,
bool is_subpart,
LLMimeIndex& index)
{
LLSD headers;
bool parsed_something = false;
if(parseHeaders(istr, limit, headers))
{
parsed_something = true;
LLMimeIndex mime(headers, mScanCount);
index = mime;
if(index.isMultipart())
{
// Figure out the separator, scan past it, and recurse.
std::string ct = headers[CONTENT_TYPE].asString();
std::string sep = findSeparator(ct);
scanPastSeparator(istr, limit, sep);
while(continueParse() && parseIndex(istr, limit, sep, true, mime))
{
index.attachSubPart(mime);
}
}
else
{
// Scan to the end of content.
scanPastContent(istr, limit, headers, separator);
if(is_subpart)
{
scanPastSeparator(istr, limit, separator);
}
}
}
if(mError) return false;
return parsed_something;
}
bool LLMimeParser::Impl::parseHeaders(
std::istream& istr,
S32 limit,
LLSD& headers)
{
while(continueParse())
{
// Get the next line.
// We subtract 1 from the limit so that we make sure
// not to read past limit when we get() the newline.
S32 max_get = llmin((S32)LINE_BUFFER_LENGTH, limit - mScanCount - 1);
istr.getline(mBuffer, max_get, '\r');
mScanCount += (S32)istr.gcount();
int c = istr.get();
if(EOF == c)
{
mContinue = false;
return false;
}
++mScanCount;
if(c != '\n')
{
mError = true;
return false;
}
if(mScanCount >= limit)
{
mContinue = false;
}
// Check if that's the end of headers.
if('\0' == mBuffer[0])
{
break;
}
// Split out the name and value.
// *NOTE: The use of strchr() here is safe since mBuffer is
// guaranteed to be NULL terminated from the call to getline()
// above.
char* colon = strchr(mBuffer, ':');
if(!colon)
{
mError = true;
return false;
}
// Cononicalize the name part, and store the name: value in
// the headers structure. We do this by iterating through
// 'known' headers and replacing the value found with the
// correct one.
// *NOTE: Not so efficient, but iterating through a small
// subset should not be too much of an issue.
std::string name(mBuffer, colon++ - mBuffer);
while(isspace(*colon)) ++colon;
std::string value(colon);
for(S32 ii = 0; ii < KNOWN_HEADER_COUNT; ++ii)
{
if(0 == LLStringUtil::compareInsensitive(name, KNOWN_HEADER[ii]))
{
name = KNOWN_HEADER[ii];
break;
}
}
headers[name] = value;
}
if(headers.isUndefined()) return false;
return true;
}
std::string LLMimeParser::Impl::findSeparator(std::string header)
{
// 01234567890
//Content-Type: multipart/mixed; boundary="segment"
std::string separator;
std::string::size_type pos = header.find(BOUNDARY);
if(std::string::npos == pos) return separator;
pos += BOUNDARY.size() + 1;
std::string::size_type end;
if(header[pos] == '"')
{
// the boundary is quoted, find the end from pos, and take the
// substring.
end = header.find('"', ++pos);
if(std::string::npos == end)
{
// poorly formed boundary.
mError = true;
}
}
else
{
// otherwise, it's every character until a whitespace, end of
// line, or another parameter begins.
end = header.find_first_of(END_OF_CONTENT_PARAMETER, pos);
if(std::string::npos == end)
{
// it goes to the end of the string.
end = header.size();
}
}
if(!mError) separator = header.substr(pos, end - pos);
return separator;
}
void LLMimeParser::Impl::scanPastSeparator(
std::istream& istr,
S32 limit,
const std::string& sep)
{
std::ostringstream ostr;
ostr << SEPARATOR_PREFIX << sep;
std::string separator = ostr.str();
bool found_separator = false;
while(!found_separator && continueParse())
{
// Subtract 1 from the limit so that we make sure not to read
// past limit when we get() the newline.
S32 max_get = llmin((S32)LINE_BUFFER_LENGTH, limit - mScanCount - 1);
istr.getline(mBuffer, max_get, '\r');
mScanCount += (S32)istr.gcount();
if(istr.gcount() >= LINE_BUFFER_LENGTH - 1)
{
// that's way too long to be a separator, so ignore it.
continue;
}
int c = istr.get();
if(EOF == c)
{
mContinue = false;
return;
}
++mScanCount;
if(c != '\n')
{
mError = true;
return;
}
if(mScanCount >= limit)
{
mContinue = false;
}
if(0 == LLStringUtil::compareStrings(std::string(mBuffer), separator))
{
found_separator = true;
}
}
}
void LLMimeParser::Impl::scanPastContent(
std::istream& istr,
S32 limit,
LLSD headers,
const std::string separator)
{
if(headers.has(CONTENT_LENGTH))
{
S32 content_length = headers[CONTENT_LENGTH].asInteger();
// Subtract 2 here for the \r\n after the content.
S32 max_skip = llmin(content_length, limit - mScanCount - 2);
istr.ignore(max_skip);
mScanCount += max_skip;
// *NOTE: Check for hitting the limit and eof here before
// checking for the trailing EOF, because our mime parser has
// to gracefully handle incomplete mime entites.
if((mScanCount >= limit) || istr.eof())
{
mContinue = false;
}
else if(!eatCRLF(istr))
{
mError = true;
return;
}
}
}
bool LLMimeParser::Impl::eatCRLF(std::istream& istr)
{
int c = istr.get();
++mScanCount;
if(c != '\r')
{
return false;
}
c = istr.get();
++mScanCount;
if(c != '\n')
{
return false;
}
return true;
}
LLMimeParser::LLMimeParser() : mImpl(* new LLMimeParser::Impl)
{
}
LLMimeParser::~LLMimeParser()
{
delete & mImpl;
}
void LLMimeParser::reset()
{
mImpl.reset();
}
bool LLMimeParser::parseIndex(std::istream& istr, LLMimeIndex& index)
{
std::string separator;
return mImpl.parseIndex(istr, S32_MAX, separator, false, index);
}
bool LLMimeParser::parseIndex(
const std::vector<U8>& buffer,
LLMimeIndex& index)
{
LLMemoryStream mstr(&buffer[0], buffer.size());
return parseIndex(mstr, buffer.size() + 1, index);
}
bool LLMimeParser::parseIndex(
std::istream& istr,
S32 limit,
LLMimeIndex& index)
{
std::string separator;
return mImpl.parseIndex(istr, limit, separator, false, index);
}
bool LLMimeParser::parseIndex(const U8* buffer, S32 length, LLMimeIndex& index)
{
LLMemoryStream mstr(buffer, length);
return parseIndex(mstr, length + 1, index);
}
/*
bool LLMimeParser::verify(std::istream& isr, LLMimeIndex& index) const
{
return false;
}
bool LLMimeParser::verify(U8* buffer, S32 length, LLMimeIndex& index) const
{
LLMemoryStream mstr(buffer, length);
return verify(mstr, index);
}
*/