/* * Copyright (C) 2001  Hakan Tandogan (hakan@gurkensalat.com) * * 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 2 * 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, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */#include "common/setup_before.h"#ifdef HAVE_STDDEF_H# include <stddef.h>#else# ifndef NULL#  define NULL ((void *)0)# endif#endif#ifdef STDC_HEADERS# include <stdlib.h>#endif#ifdef HAVE_SYS_TYPES_H# include <sys/types.h>#endif#ifdef HAVE_UNISTD_H# include <unistd.h>#endif#ifdef HAVE_PWD_H# include <pwd.h>#endif#ifdef HAVE_GRP_H# include <grp.h>#endif#ifdef HAVE_STRING_H# include <string.h>#endif#include <errno.h>#include "compat/strerror.h"#include "common/eventlog.h"#include "common/give_up_root_privileges.h"#include "common/setup_after.h"#define ILLEGAL_ID -1static int gurp_gname2id(const char *name);static int gurp_uname2id(const char *name);extern int give_up_root_privileges(char const * user_name, char const * group_name){    int user_id  = 0;    int group_id = 0;        eventlog(eventlog_level_debug,__FUNCTION__,"about to give up root privileges");        if (user_name)    {	if ((user_id = gurp_uname2id(user_name))==ILLEGAL_ID)	  { return -1; }        else	  { eventlog(eventlog_level_debug,__FUNCTION__,"should change to user = '%s' (%d)", user_name, user_id); }    }    if (group_name)    {	if ((group_id = gurp_gname2id(group_name))==ILLEGAL_ID)	  { return -1; }        else	  { eventlog(eventlog_level_debug,__FUNCTION__,"should change to group = '%s' (%d)", group_name, group_id); }    }        /*  Change first the group ID, later we might not be able to anymore     *  We can use setgid safely because we don't want to return to root     *  privileges anymore     */    #ifdef HAVE_SETGID    if (group_name)    {        if (-1 == setgid(group_id))        {            eventlog(eventlog_level_fatal,__FUNCTION__,"could not set gid to %d (setgid: %s)", group_id, pstrerror(errno));            return -1;        }    # ifdef HAVE_GETUID        eventlog(eventlog_level_info,__FUNCTION__,"Changed privileges to gid = %d", getgid());# endif    }#endif    #ifdef HAVE_SETUID    if (user_name)    {        if (-1 == setuid(user_id))        {            eventlog(eventlog_level_fatal,__FUNCTION__,"could not set uid to %d (setuid: %s)", user_id, pstrerror(errno));            return -1;        }    # ifdef HAVE_GETGID        eventlog(eventlog_level_info,__FUNCTION__,"Changed privileges to uid = %d", getuid());# endif    }#endif        return 0;}static int gurp_uname2id(const char *name){    int id = ILLEGAL_ID;        if (name != NULL)    {        if (name[0] == '#')        {            id = atoi(&name[1]);        }        else        {#ifdef HAVE_GETPWNAM            struct passwd * ent;                        eventlog(eventlog_level_debug,__FUNCTION__,"about to getpwnam(%s)", name);                        if (!(ent = getpwnam(name)))            {                eventlog(eventlog_level_fatal,__FUNCTION__,"cannot get password file entry for '%s' (getpwnam: %s)", name, pstrerror(errno));                return id;            }            id = ent->pw_uid;#else            return id;#endif        }    }    return id;}static int gurp_gname2id(const char *name){    int id = ILLEGAL_ID;        if (name != NULL)    {        if (name[0] == '#')        {            id = atoi(&name[1]);        }        else        {#ifdef HAVE_GETGRNAM            struct group * ent;                        eventlog(eventlog_level_debug,__FUNCTION__,"about to getgrnam(%s)", name);                        if (!(ent = getgrnam(name)))            {                eventlog(eventlog_level_fatal,__FUNCTION__,"cannot get group file entry for '%s' (getgrnam: %s)", name, pstrerror(errno));                return id;            }            id = ent->gr_gid;#else            return id;#endif        }    }    return id;}