/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2009 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
// Buffer overrun..
//---------------------------------------------------------------------------
#include "checkbufferoverrun.h"
#include "tokenize.h"
#include "errorlogger.h"
#include "mathlib.h"
#include <algorithm>
#include <sstream>
#include <list>
#include <cstring>
#include <cctype>
#include <cassert> // <- assert
#include <cstdlib> // <- strtoul
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
namespace
{
CheckBufferOverrun instance;
}
//---------------------------------------------------------------------------
void CheckBufferOverrun::arrayIndexOutOfBounds(const Token *tok, int size, int index)
{
if (!tok)
arrayIndexOutOfBounds(size, index);
else
{
_callStack.push_back(tok);
arrayIndexOutOfBounds(size, index);
_callStack.pop_back();
}
}
void CheckBufferOverrun::arrayIndexOutOfBounds(int size, int index)
{
Severity::e severity;
if (size <= 1 || _callStack.size() > 1)
{
severity = Severity::possibleError;
if (_settings->_showAll == false)
return;
}
else
{
severity = Severity::error;
}
if (_callStack.size() == 1)
{
std::ostringstream oss;
oss << "Array '" << (*_callStack.begin())->str() << "[" << size << "]' index " << index << " out of bounds";
reportError(_callStack, severity, "arrayIndexOutOfBounds", oss.str().c_str());
}
else
reportError(_callStack, severity, "arrayIndexOutOfBounds", "Array index out of bounds");
}
void CheckBufferOverrun::bufferOverrun(const Token *tok, const std::string &varnames)
{
Severity::e severity;
if (_callStack.size() > 0)
{
severity = Severity::possibleError;
if (_settings->_showAll == false)
return;
}
else
{
severity = Severity::error;
}
std::string v = varnames;
while (v.find(" ") != std::string::npos)
v.erase(v.find(" "), 1);
std::string errmsg("Buffer access out-of-bounds");
if (!v.empty())
errmsg += ": " + v;
reportError(tok, severity, "bufferAccessOutOfBounds", errmsg);
}
void CheckBufferOverrun::dangerousStdCin(const Token *tok)
{
if (_settings && _settings->_showAll == false)
return;
reportError(tok, Severity::possibleError, "dangerousStdCin", "Dangerous usage of std::cin, possible buffer overrun");
}
void CheckBufferOverrun::strncatUsage(const Token *tok)
{
if (_settings && _settings->_showAll == false)
return;
reportError(tok, Severity::possibleError, "strncatUsage", "Dangerous usage of strncat. Tip: the 3rd parameter means maximum number of characters to append");
}
void CheckBufferOverrun::outOfBounds(const Token *tok, const std::string &what)
{
reportError(tok, Severity::error, "outOfBounds", what + " is out of bounds");
}
void CheckBufferOverrun::sizeArgumentAsChar(const Token *tok)
{
if (_settings && _settings->_showAll == false)
return;
reportError(tok, Severity::possibleError, "sizeArgumentAsChar", "The size argument is given as a char constant");
}
void CheckBufferOverrun::terminateStrncpyError(const Token *tok)
{
reportError(tok, Severity::style, "terminateStrncpy", "After a strncpy() the buffer should be zero-terminated");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check array usage..
//---------------------------------------------------------------------------
void CheckBufferOverrun::checkScope(const Token *tok, const std::vector<std::string> &varname, const int size, const int total_size, unsigned int varid)
{
std::string varnames;
for (unsigned int i = 0; i < varname.size(); ++i)
varnames += (i == 0 ? "" : " . ") + varname[i];
unsigned int varc = varname.size();
if (varc == 0)
varc = 1;
varc = 2 * (varc - 1);
if (Token::Match(tok, "return"))
{
tok = tok->next();
if (!tok)
return;
}
// Array index..
if (varid > 0)
{
if (Token::Match(tok, "%varid% [ %num% ]", varid))
{
int index = MathLib::toLongNumber(tok->strAt(2));
if (index < 0 || index >= size)
{
arrayIndexOutOfBounds(tok, size, index);
}
}
}
else if (Token::Match(tok, (varnames + " [ %num% ]").c_str()))
{
int index = MathLib::toLongNumber(tok->strAt(2 + varc));
if (index < 0 || index >= size)
{
arrayIndexOutOfBounds(tok->tokAt(varc), size, index);
}
}
int indentlevel = 0;
for (; tok; tok = tok->next())
{
if (tok->str() == "{")
{
++indentlevel;
}
else if (tok->str() == "}")
{
--indentlevel;
if (indentlevel < 0)
return;
}
if (varid != 0 && Token::Match(tok, "%varid% = new|malloc|realloc", varid))
{
// Abort
break;
}
// Array index..
if (varid > 0)
{
if (!tok->isName() && !Token::Match(tok, "[.&]") && Token::Match(tok->next(), "%varid% [ %num% ]", varid))
{
int index = MathLib::toLongNumber(tok->strAt(3));
if (index < 0 || index >= size)
{
if (index > size || !Token::Match(tok->previous(), "& ("))
{
arrayIndexOutOfBounds(tok->next(), size, index);
}
}
}
}
else if (!tok->isName() && !Token::Match(tok, "[.&]") && Token::Match(tok->next(), (varnames + " [ %num% ]").c_str()))
{
int index = MathLib::toLongNumber(tok->strAt(3 + varc));
if (index < 0 || index >= size)
{
arrayIndexOutOfBounds(tok->tokAt(1 + varc), size, index);
}
tok = tok->tokAt(4);
continue;
}
// memset, memcmp, memcpy, strncpy, fgets..
if (varid > 0)
{
if (_settings->_checkCodingStyle)
{
// check for strncpy which is not terminated
if (Token::Match(tok, "strncpy ( %varid% , %any% , %any% )", varid))
{
const Token *tokSz = tok->tokAt(6);
if (tokSz->isNumber())
{
// strncpy takes entire variable length as input size
const std::string num = tok->strAt(6);
if (MathLib::toLongNumber(num) == total_size)
{
const Token *tok2 = tok->next()->link()->next()->next();
for (; tok2; tok2 = tok2->next())
{
if (Token::Match(tok2, "%varid%", tok->tokAt(2)->varId()))
{
if (!Token::Match(tok2, "%varid% [ %any% ] = 0 ;", tok->tokAt(2)->varId()))
{
terminateStrncpyError(tok);
}
else
{
break;
}
}
}
}
}
}
}
if (Token::Match(tok, "memset|memcpy|memmove|memcmp|strncpy|fgets ( %varid% , %any% , %any% )", varid) ||
Token::Match(tok, "memset|memcpy|memmove|memcmp|fgets ( %var% , %varid% , %any% )", varid))
{
const Token *tokSz = tok->tokAt(6);
if (tokSz->str()[0] == '\'')
sizeArgumentAsChar(tok);
else if (tokSz->isNumber())
{
const std::string num = tok->strAt(6);
if (MathLib::toLongNumber(num) < 0 || MathLib::toLongNumber(num) > total_size)
{
bufferOverrun(tok, varnames);
}
}
}
}
else if (Token::Match(tok, ("memset|memcpy|memmove|memcmp|strncpy|fgets ( " + varnames + " , %num% , %num% )").c_str()) ||
Token::Match(tok, ("memcpy|memcmp ( %var% , " + varnames + " , %num% )").c_str()))
{
const std::string num = tok->strAt(varc + 6);
if (MathLib::toLongNumber(num) < 0 || MathLib::toLongNumber(num) > total_size)
{
bufferOverrun(tok, varnames);
}
continue;
}
// Loop..
if (Token::simpleMatch(tok, "for ("))
{
const Token *tok2 = tok->tokAt(2);
unsigned int counter_varid = 0;
std::string min_counter_value;
std::string max_counter_value;
// for - setup..
if (Token::Match(tok2, "%var% = %any% ;"))
{
if (tok2->tokAt(2)->isNumber())
{
min_counter_value = tok2->strAt(2);
}
counter_varid = tok2->varId();
tok2 = tok2->tokAt(4);
}
else if (Token::Match(tok2, "%type% %var% = %any% ;"))
{
if (tok2->tokAt(3)->isNumber())
{
min_counter_value = tok2->strAt(3);
}
counter_varid = tok2->next()->varId();
tok2 = tok2->tokAt(5);
}
else if (Token::Match(tok2, "%type% %type% %var% = %any% ;"))
{
if (tok->tokAt(4)->isNumber())
{
min_counter_value = tok2->strAt(4);
}
counter_varid = tok2->tokAt(2)->varId();
tok2 = tok2->tokAt(6);
}
else
continue;
int value = 0;
if (counter_varid == 0)
continue;
const Token *strindextoken = 0;
if (Token::Match(tok2, "%varid% < %num% ;", counter_varid))
{
value = MathLib::toLongNumber(tok2->strAt(2));
max_counter_value = MathLib::toString<long>(value - 1);
strindextoken = tok2;
}
else if (Token::Match(tok2, "%varid% <= %num% ;", counter_varid))
{
value = MathLib::toLongNumber(tok2->strAt(2)) + 1;
max_counter_value = tok2->strAt(2);
strindextoken = tok2;
}
else if (Token::Match(tok2, " %num% < %varid% ;", counter_varid))
{
max_counter_value = min_counter_value;
min_counter_value = MathLib::toString<long>(value + 1);
value = MathLib::toLongNumber(max_counter_value);
strindextoken = tok2->tokAt(2);
}
else if (Token::Match(tok2, "%num% <= %varid% ;", counter_varid))
{
max_counter_value = min_counter_value;
min_counter_value = tok2->str();
value = MathLib::toLongNumber(max_counter_value);
strindextoken = tok2->tokAt(2);
}
else
{
continue;
}
// Get index variable and stopsize.
const std::string strindex = strindextoken->str();
bool condition_out_of_bounds = true;
if (value <= size)
condition_out_of_bounds = false;
const Token *tok3 = tok2->tokAt(4);
assert(tok3 != NULL);
if (Token::Match(tok3, "%varid% += %num% )", counter_varid) ||
Token::Match(tok3, "%varid% = %num% + %varid% )", counter_varid))
{
if (!MathLib::isInt(tok3->strAt(2)))
continue;
const int num = MathLib::toLongNumber(tok3->strAt(2));
// We have for example code: "for(i=2;i<22;i+=6)
// We can calculate that max value for i is 20, not 21
// 21-2 = 19
// 19/6 = 3
// 6*3+2 = 20
long max = MathLib::toLongNumber(max_counter_value);
long min = MathLib::toLongNumber(min_counter_value);
max = ((max - min) / num) * num + min;
max_counter_value = MathLib::toString<long>(max);
if (max <= size)
condition_out_of_bounds = false;
}
else if (Token::Match(tok3, "%varid% = %varid% + %num% )", counter_varid))
{
if (!MathLib::isInt(tok3->strAt(4)))
continue;
const int num = MathLib::toLongNumber(tok3->strAt(4));
long max = MathLib::toLongNumber(max_counter_value);
long min = MathLib::toLongNumber(min_counter_value);
max = ((max - min) / num) * num + min;
max_counter_value = MathLib::toString<long>(max);
if (max <= size)
condition_out_of_bounds = false;
}
else if (Token::Match(tok3, "%varid% -= %num% )", counter_varid) ||
Token::Match(tok3, "%varid% = %num% - %varid% )", counter_varid))
{
if (!MathLib::isInt(tok3->strAt(2)))
continue;
const int num = MathLib::toLongNumber(tok3->strAt(2));
long max = MathLib::toLongNumber(max_counter_value);
long min = MathLib::toLongNumber(min_counter_value);
max = ((max - min) / num) * num + min;
max_counter_value = MathLib::toString<long>(max);
if (max <= size)
condition_out_of_bounds = false;
}
else if (Token::Match(tok3, "%varid% = %varid% - %num% )", counter_varid))
{
if (!MathLib::isInt(tok3->strAt(4)))
continue;
const int num = MathLib::toLongNumber(tok3->strAt(4));
long max = MathLib::toLongNumber(max_counter_value);
long min = MathLib::toLongNumber(min_counter_value);
max = ((max - min) / num) * num + min;
max_counter_value = MathLib::toString<long>(max);
if (max <= size)
condition_out_of_bounds = false;
}
else if (! Token::Match(tok3, "++|--| %varid% ++|--| )", counter_varid))
{
continue;
}
// Goto the end paranthesis of the for-statement: "for (x; y; z)" ..
tok2 = tok->next()->link();
if (!tok2 || !tok2->tokAt(5))
break;
// Check is the counter variable increased elsewhere inside the loop or used
// for anything else except reading
bool bailOut = false;
for (Token *loopTok = tok2->next(); loopTok && loopTok != tok2->next()->link(); loopTok = loopTok->next())
{
if (loopTok->varId() == counter_varid)
{
// Counter variable used inside loop
if (Token::Match(loopTok->next(), "+=|-=|++|--|=") ||
Token::Match(loopTok->previous(), "++|--"))
{
bailOut = true;
break;
}
}
}
if (bailOut)
{
break;
}
std::ostringstream pattern;
if (varid > 0)
pattern << "%varid% [ " << strindex << " ]";
else
pattern << varnames << " [ " << strindex << " ]";
int indentlevel2 = 0;
while ((tok2 = tok2->next()) != 0)
{
if (tok2->str() == ";" && indentlevel2 == 0)
break;
if (tok2->str() == "{")
++indentlevel2;
if (tok2->str() == "}")
{
--indentlevel2;
if (indentlevel2 <= 0)
break;
}
if (Token::Match(tok2, "if|switch"))
{
// Bailout
break;
}
if (condition_out_of_bounds && Token::Match(tok2, pattern.str().c_str(), varid))
{
bufferOverrun(tok2, varid > 0 ? "" : varnames.c_str());
break;
}
else if (varid > 0 && counter_varid > 0 && !min_counter_value.empty() && !max_counter_value.empty())
{
int min_index = 0;
int max_index = 0;
if (Token::Match(tok2, "%varid% [ %var% +|-|*|/ %num% ]", varid) &&
tok2->tokAt(2)->varId() == counter_varid)
{
const char action = tok2->strAt(3)[0];
const std::string &second(tok2->tokAt(4)->str());
//printf("min_index: %s %c %s\n", min_counter_value.c_str(), action, second.c_str());
//printf("max_index: %s %c %s\n", max_counter_value.c_str(), action, second.c_str());
min_index = std::atoi(MathLib::calculate(min_counter_value, second, action).c_str());
max_index = std::atoi(MathLib::calculate(max_counter_value, second, action).c_str());
}
else if (Token::Match(tok2, "%varid% [ %num% +|-|*|/ %var% ]", varid) &&
tok2->tokAt(4)->varId() == counter_varid)
{
const char action = tok2->strAt(3)[0];
const std::string &first(tok2->tokAt(2)->str());
//printf("min_index: %s %c %s\n", first.c_str(), action, min_counter_value.c_str());
//printf("max_index: %s %c %s\n", first.c_str(), action, max_counter_value.c_str());
min_index = std::atoi(MathLib::calculate(first, min_counter_value, action).c_str());
max_index = std::atoi(MathLib::calculate(first, max_counter_value, action).c_str());
}
//printf("min_index = %d, max_index = %d, size = %d\n", min_index, max_index, size);
if (min_index >= size || max_index >= size)
{
arrayIndexOutOfBounds(tok2, size, min_index > max_index ? min_index : max_index);
}
}
}
continue;
}
// Writing data into array..
if ((varid > 0 && Token::Match(tok, "strcpy|strcat ( %varid% , %str% )", varid)) ||
(varid == 0 && Token::Match(tok, ("strcpy|strcat ( " + varnames + " , %str% )").c_str())))
{
size_t len = Token::getStrLength(tok->tokAt(varc + 4));
if (len >= static_cast<size_t>(total_size))
{
bufferOverrun(tok, varid > 0 ? "" : varnames.c_str());
continue;
}
}
// Writing data into array..
if (varid > 0 &&
Token::Match(tok, "read|write ( %any% , %varid% , %num% )", varid) &&
MathLib::isInt(tok->strAt(6)))
{
size_t len = MathLib::toLongNumber(tok->strAt(6));
if (len > static_cast<size_t>(total_size))
{
bufferOverrun(tok);
continue;
}
}
// Writing data into array..
if (varid > 0 &&
Token::Match(tok, "fgets ( %varid% , %num% , %any% )", varid) &&
MathLib::isInt(tok->strAt(4)))
{
size_t len = MathLib::toLongNumber(tok->strAt(4));
if (len > static_cast<size_t>(total_size))
{
bufferOverrun(tok);
continue;
}
}
// Dangerous usage of strncat..
if (varid > 0 && Token::Match(tok, "strncat ( %varid% , %any% , %num% )", varid))
{
int n = MathLib::toLongNumber(tok->strAt(6));
if (n >= total_size)
strncatUsage(tok);
}
// Dangerous usage of strncpy + strncat..
if (varid > 0 && Token::Match(tok, "strncpy|strncat ( %varid% , %any% , %num% ) ; strncat ( %varid% , %any% , %num% )", varid))
{
int n = MathLib::toLongNumber(tok->strAt(6)) + MathLib::toLongNumber(tok->strAt(15));
if (n > total_size)
strncatUsage(tok->tokAt(9));
}
// Detect few strcat() calls
if (varid > 0 && Token::Match(tok, "strcat ( %varid% , %str% ) ;", varid))
{
size_t charactersAppend = 0;
const Token *tok2 = tok;
while (tok2 && Token::Match(tok2, "strcat ( %varid% , %str% ) ;", varid))
{
charactersAppend += Token::getStrLength(tok2->tokAt(4));
if (charactersAppend >= static_cast<size_t>(total_size))
{
bufferOverrun(tok2);
break;
}
tok2 = tok2->tokAt(7);
}
}
// sprintf..
if (varid > 0 && Token::Match(tok, "sprintf ( %varid% , %str% [,)]", varid))
{
checkSprintfCall(tok, total_size);
}
// snprintf..
if (varid > 0 && Token::Match(tok, "snprintf ( %varid% , %num% ,", varid))
{
int n = MathLib::toLongNumber(tok->strAt(4));
if (n > total_size)
outOfBounds(tok->tokAt(4), "snprintf size");
}
// cin..
if (varid > 0 && Token::Match(tok, "cin >> %varid% ;", varid))
{
dangerousStdCin(tok);
}
// Function call..
// It's not interesting to check what happens when the whole struct is
// sent as the parameter, that is checked separately anyway.
if (Token::Match(tok, "%var% ("))
{
// Only perform this checking if showAll setting is enabled..
if (!_settings->_showAll)
continue;
unsigned int parlevel = 0, par = 0;
const Token * tok1 = tok;
for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
{
++parlevel;
}
else if (tok2->str() == ")")
{
--parlevel;
if (parlevel < 1)
{
par = 0;
break;
}
}
else if (parlevel == 1 && (tok2->str() == ","))
{
++par;
}
if (parlevel == 1)
{
if (varid > 0 && Token::Match(tok2, "[(,] %varid% [,)]", varid))
{
++par;
tok1 = tok2->next();
break;
}
else if (varid == 0 && Token::Match(tok2, ("[(,] " + varnames + " [,)]").c_str()))
{
++par;
tok1 = tok2->tokAt(varc + 1);
break;
}
}
}
if (par == 0)
continue;
// Find function..
const Token *ftok = _tokenizer->getFunctionTokenByName(tok->str().c_str());
if (!ftok)
continue;
// Parse head of function..
ftok = ftok->tokAt(2);
parlevel = 1;
while (ftok && parlevel == 1 && par >= 1)
{
if (ftok->str() == "(")
++parlevel;
else if (ftok->str() == ")")
--parlevel;
else if (ftok->str() == ",")
--par;
else if (par == 1 && parlevel == 1 && Token::Match(ftok, "%var% [,)]"))
{
// Parameter name..
std::vector<std::string> parname;
parname.push_back(ftok->str());
const unsigned int parId = ftok->varId();
// Goto function body..
while (ftok && (ftok->str() != "{"))
ftok = ftok->next();
ftok = ftok ? ftok->next() : 0;
// Don't make recursive checking..
if (std::find(_callStack.begin(), _callStack.end(), tok1) != _callStack.end())
continue;
// Check variable usage in the function..
_callStack.push_back(tok1);
checkScope(ftok, parname, size, total_size, parId);
_callStack.pop_back();
// break out..
break;
}
ftok = ftok->next();
}
}
}
}
//---------------------------------------------------------------------------
// Checking local variables in a scope
//---------------------------------------------------------------------------
void CheckBufferOverrun::checkGlobalAndLocalVariable()
{
int indentlevel = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->str() == "{")
++indentlevel;
else if (tok->str() == "}")
--indentlevel;
unsigned int size = 0;
std::string type;
unsigned int varid = 0;
int nextTok = 0;
// if the previous token exists, it must be either a variable name or "[;{}]"
if (tok->previous() && (!tok->previous()->isName() && !Token::Match(tok->previous(), "[;{}]")))
continue;
if (Token::Match(tok, "%type% *| %var% [ %num% ] [;=]"))
{
unsigned int varpos = 1;
if (tok->next()->str() == "*")
++varpos;
size = MathLib::toLongNumber(tok->strAt(varpos + 2));
type = tok->strAt(varpos - 1);
varid = tok->tokAt(varpos)->varId();
nextTok = varpos + 5;
}
else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = new %type% [ %num% ]"))
{
size = MathLib::toLongNumber(tok->strAt(6));
type = tok->strAt(4);
varid = tok->tokAt(1)->varId();
nextTok = 8;
}
else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = new %type% ( %num% )"))
{
size = 1;
type = tok->strAt(4);
varid = tok->tokAt(1)->varId();
nextTok = 8;
}
else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = malloc ( %num% ) ;"))
{
size = MathLib::toLongNumber(tok->strAt(5));
type = "char";
varid = tok->tokAt(1)->varId();
nextTok = 7;
// "int * x ; x = malloc (y);"
const Token *declTok = tok->tokAt(-3);
if (varid > 0 && declTok && Token::Match(declTok, "%type% * %varid% ;", varid))
{
type = declTok->strAt(0);
// malloc() gets count of bytes and not count of
// elements, so we should calculate count of elements
// manually
unsigned int sizeOfType = _tokenizer->sizeOfType(declTok);
if (sizeOfType > 0)
size /= sizeOfType;
}
}
else
{
continue;
}
if (varid == 0)
continue;
Token sizeTok(0);
sizeTok.str(type);
int total_size = size * _tokenizer->sizeOfType(&sizeTok);
if (total_size == 0)
continue;
// The callstack is empty
_callStack.clear();
std::vector<std::string> v;
checkScope(tok->tokAt(nextTok), v, size, total_size, varid);
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Checking member variables of structs..
//---------------------------------------------------------------------------
void CheckBufferOverrun::checkStructVariable()
{
const char declstruct[] = "struct|class %var% {";
for (const Token *tok = Token::findmatch(_tokenizer->tokens(), declstruct);
tok; tok = Token::findmatch(tok->next(), declstruct))
{
const std::string &structname = tok->next()->str();
// Found a struct declaration. Search for arrays..
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
{
if (tok2->str() == "}")
break;
int ivar = 0;
if (Token::Match(tok2->next(), "%type% %var% [ %num% ] ;"))
ivar = 2;
else if (Token::Match(tok2->next(), "%type% %type% %var% [ %num% ] ;"))
ivar = 3;
else if (Token::Match(tok2->next(), "%type% * %var% [ %num% ] ;"))
ivar = 3;
else if (Token::Match(tok2->next(), "%type% %type% * %var% [ %num% ] ;"))
ivar = 4;
else
continue;
std::vector<std::string> varname(2, "");
const unsigned int varId = tok2->tokAt(ivar)->varId();
varname[1] = tok2->strAt(ivar);
int arrsize = MathLib::toLongNumber(tok2->strAt(ivar + 2));
int total_size = arrsize * _tokenizer->sizeOfType(tok2->tokAt(1));
if (tok2->tokAt(2)->str() == "*")
total_size = arrsize * _tokenizer->sizeOfType(tok2->tokAt(2));
if (total_size == 0)
continue;
// Class member variable => Check functions
if (tok->str() == "class")
{
std::string func_pattern(structname + " :: %var% (");
const Token *tok3 = Token::findmatch(_tokenizer->tokens(), func_pattern.c_str());
while (tok3)
{
for (const Token *tok4 = tok3; tok4; tok4 = tok4->next())
{
if (Token::Match(tok4, "[;{}]"))
break;
if (Token::simpleMatch(tok4, ") {"))
{
std::vector<std::string> v;
checkScope(tok4->tokAt(2), v, arrsize, total_size, varId);
break;
}
}
tok3 = Token::findmatch(tok3->next(), func_pattern.c_str());
}
}
for (const Token *tok3 = _tokenizer->tokens(); tok3; tok3 = tok3->next())
{
if (tok3->str() != structname)
continue;
// Declare variable: Fred fred1;
if (Token::Match(tok3->next(), "%var% ;"))
varname[0] = tok3->strAt(1);
// Declare pointer: Fred *fred1
else if (Token::Match(tok3->next(), "* %var% [,);=]"))
varname[0] = tok3->strAt(2);
else
continue;
// Goto end of statement.
const Token *CheckTok = NULL;
while (tok3)
{
// End of statement.
if (tok3->str() == ";")
{
CheckTok = tok3;
break;
}
// End of function declaration..
if (Token::simpleMatch(tok3, ") ;"))
break;
// Function implementation..
if (Token::simpleMatch(tok3, ") {"))
{
CheckTok = tok3->tokAt(2);
break;
}
tok3 = tok3->next();
}
if (!tok3)
break;
if (!CheckTok)
continue;
// Check variable usage..
checkScope(CheckTok, varname, arrsize, total_size, 0);
}
}
}
}
//---------------------------------------------------------------------------
void CheckBufferOverrun::bufferOverrun()
{
checkGlobalAndLocalVariable();
checkStructVariable();
}
//---------------------------------------------------------------------------
int CheckBufferOverrun::countSprintfLength(const std::string &input_string, const std::list<const Token*> ¶meters)
{
bool percentCharFound = false;
int input_string_size = 1;
bool handleNextParameter = false;
std::string digits_string = "";
bool i_d_x_f_found = false;
std::list<const Token*>::const_iterator paramIter = parameters.begin();
unsigned int parameterLength = 0;
for (std::string::size_type i = 0; i < input_string.length(); ++i)
{
if (input_string[i] == '\\')
{
if (input_string[i+1] == '0')
break;
++input_string_size;
++i;
continue;
}
if (percentCharFound)
{
switch (input_string[i])
{
case 'f':
case 'x':
case 'X':
case 'i':
i_d_x_f_found = true;
case 'c':
case 'e':
case 'E':
case 'g':
case 'o':
case 'u':
case 'p':
case 'n':
handleNextParameter = true;
break;
case 'd':
i_d_x_f_found = true;
if (paramIter != parameters.end() && *paramIter && (*paramIter)->str()[0] != '"')
parameterLength = (*paramIter)->str().length();
handleNextParameter = true;
break;
case 's':
if (paramIter != parameters.end() && *paramIter && (*paramIter)->str()[0] == '"')
parameterLength = Token::getStrLength(*paramIter);
handleNextParameter = true;
break;
}
}
if (input_string[i] == '%')
percentCharFound = !percentCharFound;
else if (percentCharFound)
{
digits_string.append(1, input_string[i]);
}
if (!percentCharFound)
input_string_size++;
if (handleNextParameter)
{
unsigned int tempDigits = std::abs(std::atoi(digits_string.c_str()));
if (i_d_x_f_found)
tempDigits = std::max(static_cast<int>(tempDigits), 1);
if (digits_string.find('.') != std::string::npos)
{
const std::string endStr = digits_string.substr(digits_string.find('.') + 1);
unsigned int maxLen = std::max(std::abs(std::atoi(endStr.c_str())), 1);
if (input_string[i] == 's')
{
// For strings, the length after the dot "%.2s" will limit
// the length of the string.
if (parameterLength > maxLen)
parameterLength = maxLen;
}
else
{
// For integers, the length after the dot "%.2d" can
// increase required length
if (tempDigits < maxLen)
tempDigits = maxLen;
}
}
if (tempDigits < parameterLength)
input_string_size += parameterLength;
else
input_string_size += tempDigits;
parameterLength = 0;
digits_string = "";
i_d_x_f_found = false;
percentCharFound = false;
handleNextParameter = false;
if (paramIter != parameters.end())
++paramIter;
}
}
return input_string_size;
}
void CheckBufferOverrun::checkSprintfCall(const Token *tok, int size)
{
std::list<const Token*> parameters;
if (tok->tokAt(5)->str() == ",")
{
const Token *end = tok->next()->link();
for (const Token *tok2 = tok->tokAt(5); tok2 && tok2 != end; tok2 = tok2->next())
{
if (Token::Match(tok2, ", %any% [,)]"))
{
if (Token::Match(tok2->next(), "%str%"))
parameters.push_back(tok2->next());
else if (Token::Match(tok2->next(), "%num%"))
parameters.push_back(tok2->next());
// TODO, get value of the variable if possible and use that instead of 0
else
parameters.push_back(0);
}
else
{
// Parameter is more complex, than just a value or variable. Ignore it for now
// and skip to next token.
parameters.push_back(0);
int ind = 0;
for (const Token *tok3 = tok2->next(); tok3; tok3 = tok3->next())
{
if (tok3->str() == "(")
++ind;
else if (tok3->str() == ")")
{
--ind;
if (ind < 0)
break;
}
else if (ind == 0 && tok3->str() == ",")
{
tok2 = tok3->previous();
break;
}
}
if (ind < 0)
break;
}
}
}
int len = countSprintfLength(tok->tokAt(4)->strValue(), parameters);
if (len > size)
{
bufferOverrun(tok);
}
}