path: root/indra/llmessage/llmessagetemplateparser.cpp

/**
 * @file llmessagetemplateparser.cpp
 * @brief LLMessageTemplateParser implementation
 *
 * $LicenseInfo:firstyear=2007&license=viewerlgpl$
 * 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 "llmessagetemplateparser.h"
#include <boost/tokenizer.hpp>


// What follows is a bunch of C functions to do validation.

// Lets support a small subset of regular expressions here
// Syntax is a string made up of:
//  a   - checks against alphanumeric               ([A-Za-z0-9])
//  c   - checks against character                  ([A-Za-z])
//  f   - checks against first variable character   ([A-Za-z_])
//  v   - checks against variable                   ([A-Za-z0-9_])
//  s   - checks against sign of integer            ([-0-9])
//  d   - checks against integer digit              ([0-9])
//  *   - repeat last check

// checks 'a'
BOOL    b_return_alphanumeric_ok(char c)
{
    if (  (  (c < 'A')
           ||(c > 'Z'))
        &&(  (c < 'a')
           ||(c > 'z'))
        &&(  (c < '0')
           ||(c > '9')))
    {
        return FALSE;
    }
    return TRUE;
}

// checks 'c'
BOOL    b_return_character_ok(char c)
{
    if (  (  (c < 'A')
           ||(c > 'Z'))
        &&(  (c < 'a')
           ||(c > 'z')))
    {
        return FALSE;
    }
    return TRUE;
}

// checks 'f'
BOOL    b_return_first_variable_ok(char c)
{
    if (  (  (c < 'A')
           ||(c > 'Z'))
        &&(  (c < 'a')
           ||(c > 'z'))
        &&(c != '_'))
    {
        return FALSE;
    }
    return TRUE;
}

// checks 'v'
BOOL    b_return_variable_ok(char c)
{
    if (  (  (c < 'A')
           ||(c > 'Z'))
        &&(  (c < 'a')
           ||(c > 'z'))
        &&(  (c < '0')
           ||(c > '9'))
        &&(c != '_'))
    {
        return FALSE;
    }
    return TRUE;
}

// checks 's'
BOOL    b_return_signed_integer_ok(char c)
{
    if (  (  (c < '0')
           ||(c > '9'))
        &&(c != '-'))
    {
        return FALSE;
    }
    return TRUE;
}

// checks 'd'
BOOL    b_return_integer_ok(char c)
{
    if (  (c < '0')
        ||(c > '9'))
    {
        return FALSE;
    }
    return TRUE;
}

BOOL    (*gParseCheckCharacters[])(char c) =
{
    b_return_alphanumeric_ok,
    b_return_character_ok,
    b_return_first_variable_ok,
    b_return_variable_ok,
    b_return_signed_integer_ok,
    b_return_integer_ok
};

S32 get_checker_number(char checker)
{
    switch(checker)
    {
    case 'a':
        return 0;
    case 'c':
        return 1;
    case 'f':
        return 2;
    case 'v':
        return 3;
    case 's':
        return 4;
    case 'd':
        return 5;
    case '*':
        return 9999;
    default:
        return -1;
    }
}

// check token based on passed simplified regular expression
BOOL    b_check_token(const char *token, const char *regexp)
{
    S32 tptr, rptr = 0;
    S32 current_checker, next_checker = 0;

    current_checker = get_checker_number(regexp[rptr++]);

    if (current_checker == -1)
    {
        LL_ERRS() << "Invalid regular expression value!" << LL_ENDL;
        return FALSE;
    }

    if (current_checker == 9999)
    {
        LL_ERRS() << "Regular expression can't start with *!" << LL_ENDL;
        return FALSE;
    }

    for (tptr = 0; token[tptr]; tptr++)
    {
        if (current_checker == -1)
        {
            LL_ERRS() << "Input exceeds regular expression!\nDid you forget a *?" << LL_ENDL;
            return FALSE;
        }

        if (!gParseCheckCharacters[current_checker](token[tptr]))
        {
            return FALSE;
        }
        if (next_checker != 9999)
        {
            next_checker = get_checker_number(regexp[rptr++]);
            if (next_checker != 9999)
            {
                current_checker = next_checker;
            }
        }
    }
    return TRUE;
}

// C variable can be made up of upper or lower case letters, underscores, or numbers, but can't start with a number
BOOL    b_variable_ok(const char *token)
{
    if (!b_check_token(token, "fv*"))
    {
        LL_WARNS() << "Token '" << token << "' isn't a variable!" << LL_ENDL;
        return FALSE;
    }
    return TRUE;
}

// An integer is made up of the digits 0-9 and may be preceded by a '-'
BOOL    b_integer_ok(const char *token)
{
    if (!b_check_token(token, "sd*"))
    {
        LL_WARNS() << "Token isn't an integer!" << LL_ENDL;
        return FALSE;
    }
    return TRUE;
}

// An integer is made up of the digits 0-9
BOOL    b_positive_integer_ok(const char *token)
{
    if (!b_check_token(token, "d*"))
    {
        LL_WARNS() << "Token isn't an integer!" << LL_ENDL;
        return FALSE;
    }
    return TRUE;
}


// Done with C functions, here's the tokenizer.

typedef boost::tokenizer< boost::char_separator<char> > tokenizer;

LLTemplateTokenizer::LLTemplateTokenizer(const std::string & contents) : mStarted(false), mTokens()
{
    boost::char_separator<char> newline("\r\n", "", boost::keep_empty_tokens);
    boost::char_separator<char> spaces(" \t");
    U32 line_counter = 1;

    tokenizer line_tokens(contents, newline);
    for(tokenizer::iterator line_iter = line_tokens.begin();
        line_iter != line_tokens.end();
        ++line_iter, ++line_counter)
    {
        tokenizer word_tokens(*line_iter, spaces);
        for(tokenizer::iterator word_iter = word_tokens.begin();
            word_iter != word_tokens.end();
            ++word_iter)
        {
            if((*word_iter)[0] == '/')
            {
                break;   // skip to end of line on comments
            }
            positioned_token pt;// = new positioned_token();
            pt.str = std::string(*word_iter);
            pt.line = line_counter;
            mTokens.push_back(pt);
        }
    }
    mCurrent = mTokens.begin();
}
void LLTemplateTokenizer::inc()
{
    if(atEOF())
    {
        error("trying to increment token of EOF");
    }
    else if(mStarted)
    {
        ++mCurrent;
    }
    else
    {
        mStarted = true;
        mCurrent = mTokens.begin();
    }
}
void LLTemplateTokenizer::dec()
{
    if(mCurrent == mTokens.begin())
    {
        if(mStarted)
        {
            mStarted = false;
        }
        else
        {
            error("trying to decrement past beginning of file");
        }
    }
    else
    {
        mCurrent--;
    }
}

std::string LLTemplateTokenizer::get() const
{
    if(atEOF())
    {
        error("trying to get EOF");
    }
    return mCurrent->str;
}

U32 LLTemplateTokenizer::line() const
{
    if(atEOF())
    {
        return 0;
    }
    return mCurrent->line;
}

bool LLTemplateTokenizer::atEOF() const
{
    return mCurrent == mTokens.end();
}

std::string LLTemplateTokenizer::next()
{
    inc();
    return get();
}

bool LLTemplateTokenizer::want(const std::string & token)
{
    if(atEOF()) return false;
    inc();
    if(atEOF()) return false;
    if(get() != token)
    {
        dec(); // back up a step
        return false;
    }
    return true;
}

bool LLTemplateTokenizer::wantEOF()
{
    // see if the next token is EOF
    if(atEOF()) return true;
    inc();
    if(!atEOF())
    {
        dec(); // back up a step
        return false;
    }
    return true;
}

void LLTemplateTokenizer::error(std::string message) const
{
    if(atEOF())
    {
        LL_ERRS() << "Unexpected end of file: " << message << LL_ENDL;
    }
    else
    {
        LL_ERRS() << "Problem parsing message template at line "
               << line() << ", with token '" << get() << "' : "
               << message << LL_ENDL;
    }
}


// Done with tokenizer, next is the parser.

LLTemplateParser::LLTemplateParser(LLTemplateTokenizer & tokens):
    mVersion(0.f),
    mMessages()
{
    // the version number should be the first thing in the file
    if (tokens.want("version"))
    {
        // version number
        std::string vers_string = tokens.next();
        mVersion = (F32)atof(vers_string.c_str());

        LL_INFOS() << "### Message template version " << mVersion << "  ###" << LL_ENDL;
    }
    else
    {
        LL_ERRS() << "Version must be first in the message template, found "
               << tokens.next() << LL_ENDL;
    }

    while(LLMessageTemplate * templatep = parseMessage(tokens))
    {
        if (templatep->getDeprecation() != MD_DEPRECATED)
        {
            mMessages.push_back(templatep);
        }
        else
        {
            delete templatep;
        }
    }

    if(!tokens.wantEOF())
    {
        LL_ERRS() << "Expected end of template or a message, instead found: "
               << tokens.next() << " at " << tokens.line() << LL_ENDL;
    }
}

F32 LLTemplateParser::getVersion() const
{
    return mVersion;
}

LLTemplateParser::message_iterator LLTemplateParser::getMessagesBegin() const
{
    return mMessages.begin();
}

LLTemplateParser::message_iterator LLTemplateParser::getMessagesEnd() const
{
    return mMessages.end();
}


// static
LLMessageTemplate * LLTemplateParser::parseMessage(LLTemplateTokenizer & tokens)
{
    LLMessageTemplate   *templatep = NULL;
    if(!tokens.want("{"))
    {
        return NULL;
    }

    // name first
    std::string template_name = tokens.next();

    // is name a legit C variable name
    if (!b_variable_ok(template_name.c_str()))
    {
        LL_ERRS() << "Not legit variable name: " << template_name << " at " << tokens.line() << LL_ENDL;
    }

    // ok, now get Frequency ("High", "Medium", or "Low")
    EMsgFrequency frequency = MFT_LOW;
    std::string freq_string = tokens.next();
    if (freq_string == "High")
    {
        frequency = MFT_HIGH;
    }
    else if (freq_string == "Medium")
    {
        frequency = MFT_MEDIUM;
    }
    else if (freq_string == "Low" || freq_string == "Fixed")
    {
        frequency = MFT_LOW;
    }
    else
    {
        LL_ERRS() << "Expected frequency, got " << freq_string << " at " << tokens.line() << LL_ENDL;
    }

    // TODO more explicit checking here pls
    U32 message_number = strtoul(tokens.next().c_str(),NULL,0);

    switch (frequency) {
    case MFT_HIGH:
        break;
    case MFT_MEDIUM:
        message_number = (255 << 8) | message_number;
        break;
    case MFT_LOW:
        message_number = (255 << 24) | (255 << 16) | message_number;
        break;
    default:
        LL_ERRS() << "Unknown frequency enum: " << frequency << LL_ENDL;
    }

    templatep = new LLMessageTemplate(
        template_name.c_str(),
        message_number,
        frequency);

    // Now get trust ("Trusted", "NotTrusted")
    std::string trust = tokens.next();
    if (trust == "Trusted")
    {
        templatep->setTrust(MT_TRUST);
    }
    else if (trust == "NotTrusted")
    {
        templatep->setTrust(MT_NOTRUST);
    }
    else
    {
        LL_ERRS() << "Bad trust " << trust << " at " << tokens.line() << LL_ENDL;
    }

    // get encoding
    std::string encoding = tokens.next();
    if(encoding == "Unencoded")
    {
        templatep->setEncoding(ME_UNENCODED);
    }
    else if(encoding == "Zerocoded")
    {
        templatep->setEncoding(ME_ZEROCODED);
    }
    else
    {
        LL_ERRS() << "Bad encoding " << encoding << " at " << tokens.line() << LL_ENDL;
    }

    // get deprecation
    if(tokens.want("Deprecated"))
    {
        templatep->setDeprecation(MD_DEPRECATED);
    }
    else if (tokens.want("UDPDeprecated"))
    {
        templatep->setDeprecation(MD_UDPDEPRECATED);
    }
    else if (tokens.want("UDPBlackListed"))
    {
        templatep->setDeprecation(MD_UDPBLACKLISTED);
    }
    else if (tokens.want("NotDeprecated"))
    {
        // this is the default value, but it can't hurt to set it twice
        templatep->setDeprecation(MD_NOTDEPRECATED);
    }
    else {
        // It's probably a brace, let's just start block processing
    }

    while(LLMessageBlock * blockp = parseBlock(tokens))
    {
        templatep->addBlock(blockp);
    }

    if(!tokens.want("}"))
    {
        LL_ERRS() << "Expecting closing } for message " << template_name
               << " at " << tokens.line() << LL_ENDL;
    }
    return templatep;
}

// static
LLMessageBlock * LLTemplateParser::parseBlock(LLTemplateTokenizer & tokens)
{
    LLMessageBlock * blockp = NULL;

    if(!tokens.want("{"))
    {
        return NULL;
    }

    // name first
    std::string block_name = tokens.next();

    // is name a legit C variable name
    if (!b_variable_ok(block_name.c_str()))
    {
        LL_ERRS() << "not a legal block name: " << block_name
               << " at " << tokens.line() << LL_ENDL;
    }

    // now, block type ("Single", "Multiple", or "Variable")
    std::string block_type = tokens.next();
    // which one is it?
    if (block_type == "Single")
    {
        // ok, we can create a block
        blockp = new LLMessageBlock(block_name.c_str(), MBT_SINGLE);
    }
    else if (block_type == "Multiple")
    {
        // need to get the number of repeats
        std::string repeats = tokens.next();

        // is it a legal integer
        if (!b_positive_integer_ok(repeats.c_str()))
        {
            LL_ERRS() << "not a legal integer for block multiple count: "
                   << repeats << " at " << tokens.line() << LL_ENDL;
        }

        // ok, we can create a block
        blockp = new LLMessageBlock(block_name.c_str(),
                                    MBT_MULTIPLE,
                                    atoi(repeats.c_str()));
    }
    else if (block_type == "Variable")
    {
        // ok, we can create a block
        blockp = new LLMessageBlock(block_name.c_str(), MBT_VARIABLE);
    }
    else
    {
        LL_ERRS() << "bad block type: " << block_type
               << " at " << tokens.line() << LL_ENDL;
    }


    while(LLMessageVariable * varp = parseVariable(tokens))
    {
        blockp->addVariable(varp->getName(),
                            varp->getType(),
                            varp->getSize());
        delete varp;
    }

    if(!tokens.want("}"))
    {
        LL_ERRS() << "Expecting closing } for block " << block_name
               << " at " << tokens.line() << LL_ENDL;
    }
    return blockp;

}

// static
LLMessageVariable * LLTemplateParser::parseVariable(LLTemplateTokenizer & tokens)
{
    LLMessageVariable * varp = NULL;
    if(!tokens.want("{"))
    {
        return NULL;
    }

    std::string var_name = tokens.next();

    if (!b_variable_ok(var_name.c_str()))
    {
        LL_ERRS() << "Not a legit variable name: " << var_name
               << " at " << tokens.line() << LL_ENDL;
    }

    std::string var_type = tokens.next();

    if (var_type == "U8")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_U8, 1);
    }
    else if (var_type == "U16")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_U16, 2);
    }
    else if (var_type == "U32")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_U32, 4);
    }
    else if (var_type == "U64")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_U64, 8);
    }
    else if (var_type == "S8")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_S8, 1);
    }
    else if (var_type == "S16")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_S16, 2);
    }
    else if (var_type == "S32")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_S32, 4);
    }
    else if (var_type == "S64")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_S64, 8);
    }
    else if (var_type == "F32")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_F32, 4);
    }
    else if (var_type == "F64")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_F64, 8);
    }
    else if (var_type == "LLVector3")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_LLVector3, 12);
    }
    else if (var_type == "LLVector3d")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_LLVector3d, 24);
    }
    else if (var_type == "LLVector4")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_LLVector4, 16);
    }
    else if (var_type == "LLQuaternion")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_LLQuaternion, 12);
    }
    else if (var_type == "LLUUID")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_LLUUID, 16);
    }
    else if (var_type == "BOOL")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_BOOL, 1);
    }
    else if (var_type == "IPADDR")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_IP_ADDR, 4);
    }
    else if (var_type == "IPPORT")
    {
        varp = new LLMessageVariable(var_name.c_str(), MVT_IP_PORT, 2);
    }
    else if (var_type == "Fixed" || var_type == "Variable")
    {
        std::string variable_size = tokens.next();

        if (!b_positive_integer_ok(variable_size.c_str()))
        {
            LL_ERRS() << "not a legal integer variable size: " << variable_size
                   << " at " << tokens.line() << LL_ENDL;
        }

        EMsgVariableType type_enum;
        if(var_type == "Variable")
        {
            type_enum = MVT_VARIABLE;
        }
        else if(var_type == "Fixed")
        {
            type_enum = MVT_FIXED;
        }
        else
        {
            type_enum = MVT_FIXED; // removes a warning
            LL_ERRS() << "bad variable type: " << var_type
                   << " at " << tokens.line() << LL_ENDL;
        }

        varp = new LLMessageVariable(
            var_name.c_str(),
            type_enum,
            atoi(variable_size.c_str()));
    }
    else
    {
        LL_ERRS() << "bad variable type:" << var_type
               << " at " << tokens.line() << LL_ENDL;
    }

    if(!tokens.want("}"))
    {
        LL_ERRS() << "Expecting closing } for variable " << var_name
               << " at " << tokens.line() << LL_ENDL;
    }
    return varp;
}