jehanne/sys/src/lib/c/9sys/access.c

73 lines
1.7 KiB
C

/*
* This file is part of Jehanne.
*
* Copyright (C) 2016-2017 Giacomo Tesio <giacomo@tesio.it>
*
* Jehanne 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, version 2 of the License.
*
* Jehanne 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 Jehanne. If not, see <http://www.gnu.org/licenses/>.
*/
#include <u.h>
#include <libc.h>
int
jehanne_access(const char *name, int mode)
{
int tmp, reqmode;
Dir *db;
char *user;
static char omode[] = {
OSTAT,
OEXEC,
OWRITE,
ORDWR,
OREAD,
OEXEC, /* 5=4+1 READ|EXEC, EXEC is enough */
ORDWR,
ORDWR /* 7=4+2+1 READ|WRITE|EXEC, ignore EXEC */
};
reqmode = omode[mode&AMASK];
tmp = open(name, reqmode);
if(tmp >= 0){
close(tmp);
return 0;
}
db = jehanne_dirstat(name);
if(db != nil){
if(db->mode & DMDIR){
/* check other first */
tmp = db->mode & reqmode;
if(tmp != reqmode){
/* TODO: make something better */
user = jehanne_getuser();
if(jehanne_strcmp(user, db->gid) == 0){
/* check group */
tmp |= (db->mode & (reqmode << 3)) >> 3;
if(tmp != reqmode && jehanne_strcmp(user, db->uid)== 0){
/* check user */
tmp |= (db->mode & (reqmode << 6)) >> 6;
}
} else if (jehanne_strcmp(user, db->uid)== 0){
/* check user */
tmp |= (db->mode & (reqmode << 6)) >> 6;
}
}
}
jehanne_free(db);
if(tmp == reqmode)
return 0;
}
return -1;
}