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tdelibs/kdesu/su.cpp

343 lines
9.0 KiB

/* vi: ts=8 sts=4 sw=4
*
* $Id$
*
* This file is part of the KDE project, module kdesu.
* Copyright (C) 1999,2000 Geert Jansen <jansen@kde.org>
*
* Sudo support added by Jonathan Riddell <jriddell@ ubuntu.com>
* Copyright (C) 2005 Canonical Ltd
*
* This is free software; you can use this library under the GNU Library
* General Public License, version 2. See the file "COPYING.LIB" for the
* exact licensing terms.
*
* su.cpp: Execute a program as another user with "class SuProcess".
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <tqglobal.h>
#include <tqcstring.h>
#include <tqfile.h>
#include <kconfig.h>
#include <kdebug.h>
#include <klocale.h>
#include <kstandarddirs.h>
#include "su.h"
#include "kcookie.h"
#ifndef __PATH_SU
#define __PATH_SU "false"
#endif
#ifndef __PATH_SUDO
#define __PATH_SUDO "false"
#endif
SuProcess::SuProcess(const TQCString &user, const TQCString &command)
{
m_User = user;
m_Command = command;
KConfig* config = KGlobal::config();
config->setGroup("super-user-command");
superUserCommand = config->readEntry("super-user-command", DEFAULT_SUPER_USER_COMMAND);
if ( superUserCommand != "sudo" && superUserCommand != "su" ) {
kdWarning() << "unknown super user command" << endl;
superUserCommand = "su";
}
}
SuProcess::~SuProcess()
{
}
int SuProcess::checkInstall(const char *password)
{
return exec(password, Install);
}
int SuProcess::checkNeedPassword()
{
return exec(0L, NeedPassword);
}
/*
* Execute a command with su(1).
*/
int SuProcess::exec(const char *password, int check)
{
if (check)
setTerminal(true);
// since user may change after constructor (due to setUser())
// we need to override sudo with su for non-root here
if (m_User != "root") {
superUserCommand = "su";
}
QCStringList args;
if (superUserCommand == "sudo") {
args += "-u";
}
#ifdef Q_OS_DARWIN
args += "-c";
args += "staff";
#endif
if ((m_Scheduler != SchedNormal) || (m_Priority > 50))
args += "root";
else
args += m_User;
if (superUserCommand == "su") {
args += "-c";
}
args += TQCString(__KDE_BINDIR) + "/kdesu_stub";
#ifndef Q_OS_DARWIN
args += "-";
#endif
/// TQCString command = __PATH_SU;
/// if (::access(__PATH_SU, X_OK) != 0)
TQCString command;
if (superUserCommand == "sudo") {
command = __PATH_SUDO;
} else {
command = __PATH_SU;
}
if (::access(command, X_OK) != 0)
{
/// command = TQFile::encodeName(KGlobal::dirs()->findExe("su"));
command = TQFile::encodeName( KGlobal::dirs()->findExe(superUserCommand.ascii()) );
if (command.isEmpty())
return check ? SuNotFound : -1;
}
// kdDebug(900) << k_lineinfo << "Call StubProcess::exec()" << endl;
if (StubProcess::exec(command, args) < 0)
{
return check ? SuNotFound : -1;
}
// kdDebug(900) << k_lineinfo << "Done StubProcess::exec()" << endl;
SuErrors ret = (SuErrors) ConverseSU(password);
// kdDebug(900) << k_lineinfo << "Conversation returned " << ret << endl;
if (ret == error)
{
if (!check)
kdError(900) << k_lineinfo << "Conversation with " << superUserCommand << " failed\n";
return ret;
}
if (check == NeedPassword)
{
if (ret == killme)
{
/// if (kill(m_Pid, SIGKILL) < 0)
/// {
/// ret=error;
/// }
if ( superUserCommand == "sudo" ) {
// sudo can not be killed, just return
return ret;
}
if (kill(m_Pid, SIGKILL) < 0) {
kdDebug() << k_funcinfo << "kill < 0" << endl;
//FIXME SIGKILL doesn't work for sudo,
//why is this different from su?
ret=error;
}
else
{
int iret = waitForChild();
if (iret < 0) ret=error;
else /* nothing */ {} ;
}
}
return ret;
}
if (m_bErase && password)
{
char *ptr = const_cast<char *>(password);
const uint plen = strlen(password);
for (unsigned i=0; i < plen; i++)
ptr[i] = '\000';
}
if (ret == notauthorized)
{
kill(m_Pid, SIGKILL);
if (superUserCommand != "sudo") {
waitForChild();
}
return SuIncorrectPassword;
}
int iret = ConverseStub(check);
if (iret < 0)
{
if (!check)
kdError(900) << k_lineinfo << "Converstation with kdesu_stub failed\n";
return iret;
}
else if (iret == 1)
{
kill(m_Pid, SIGKILL);
waitForChild();
return SuIncorrectPassword;
}
if (check == Install)
{
waitForChild();
return 0;
}
iret = waitForChild();
return iret;
}
/*
* Conversation with su: feed the password.
* Return values: -1 = error, 0 = ok, 1 = kill me, 2 not authorized
*/
int SuProcess::ConverseSU(const char *password)
{
enum { WaitForPrompt, CheckStar, HandleStub } state = WaitForPrompt;
int colon;
unsigned i, j;
// kdDebug(900) << k_lineinfo << "ConverseSU starting." << endl;
TQCString line;
while (true)
{
line = readLine();
if (line.isNull())
return ( state == HandleStub ? notauthorized : error);
kdDebug(900) << k_lineinfo << "Read line <" << line << ">" << endl;
switch (state)
{
//////////////////////////////////////////////////////////////////////////
case WaitForPrompt:
{
// In case no password is needed.
if (line == "kdesu_stub")
{
unreadLine(line);
return ok;
}
while(waitMS(m_Fd,100)>0)
{
// There is more output available, so the previous line
// couldn't have been a password prompt (the definition
// of prompt being that there's a line of output followed
// by a colon, and then the process waits).
TQCString more = readLine();
if (more.isEmpty())
break;
line = more;
kdDebug(900) << k_lineinfo << "Read line <" << more << ">" << endl;
}
// Match "Password: " with the regex ^[^:]+:[\w]*$.
const uint len = line.length();
for (i=0,j=0,colon=0; i<len; i++)
{
if (line[i] == ':')
{
j = i; colon++;
continue;
}
if (!isspace(line[i]))
j++;
}
if ((colon == 1) && (line[j] == ':'))
{
if (password == 0L)
return killme;
if (!checkPid(m_Pid))
{
kdError(900) << superUserCommand << " has exited while waiting for pwd." << endl;
return error;
}
if ((WaitSlave() == 0) && checkPid(m_Pid))
{
write(m_Fd, password, strlen(password));
write(m_Fd, "\n", 1);
state=CheckStar;
}
else
{
return error;
}
}
break;
}
//////////////////////////////////////////////////////////////////////////
case CheckStar:
{
TQCString s = line.stripWhiteSpace();
if (s.isEmpty())
{
state=HandleStub;
break;
}
const uint len = line.length();
for (i=0; i< len; i++)
{
if (s[i] != '*')
return error;
}
state=HandleStub;
break;
}
//////////////////////////////////////////////////////////////////////////
case HandleStub:
// Read till we get "kdesu_stub"
if (line == "kdesu_stub")
{
unreadLine(line);
return ok;
} else if (superUserCommand == "sudo") {
// sudo gives a "sorry" line so reaches here
// with the wrong password
return notauthorized;
}
break;
//////////////////////////////////////////////////////////////////////////
} // end switch
} // end while (true)
return ok;
}
void SuProcess::virtual_hook( int id, void* data )
{ StubProcess::virtual_hook( id, data ); }