minix/servers/vfs/protect.c

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/* This file deals with protection in the file system. It contains the code
* for four system calls that relate to protection.
*
* The entry points into this file are
* do_chmod: perform the CHMOD and FCHMOD system calls
* do_chown: perform the CHOWN and FCHOWN system calls
* do_umask: perform the UMASK system call
* do_access: perform the ACCESS system call
*
* Changes for VFS:
* Jul 2006 (Balazs Gerofi)
*/
#include "fs.h"
#include <unistd.h>
#include <minix/callnr.h>
#include "file.h"
#include "fproc.h"
#include "param.h"
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"
/*===========================================================================*
* do_chmod *
*===========================================================================*/
PUBLIC int do_chmod()
{
struct filp *flp;
struct chmod_req req;
struct lookup_req lookup_req;
struct node_details res;
int r;
if (call_nr == CHMOD) {
/* Perform the chmod(name, mode) system call. */
if (fetch_name(m_in.name, m_in.name_length, M3) != OK) return(err_code);
/* Fill in lookup request fields */
lookup_req.path = user_fullpath;
lookup_req.lastc = NULL;
lookup_req.flags = EAT_PATH;
/* Request lookup */
if ((r = lookup(&lookup_req, &res)) != OK) return r;
req.inode_nr = res.inode_nr;
req.fs_e = res.fs_e;
}
else if (call_nr == FCHMOD) {
if (!(flp = get_filp(m_in.m3_i1))) return err_code;
req.inode_nr = flp->filp_vno->v_inode_nr;
req.fs_e = flp->filp_vno->v_fs_e;
}
else panic(__FILE__, "do_chmod called with strange call_nr", call_nr);
/* Fill in request message fields.*/
req.uid = fp->fp_effuid;
req.gid = fp->fp_effgid;
req.rmode = m_in.mode;
/* Issue request */
return req_chmod(&req);
}
/*===========================================================================*
* do_chown *
*===========================================================================*/
PUBLIC int do_chown()
{
int inode_nr;
int fs_e;
struct filp *flp;
struct chown_req req;
struct lookup_req lookup_req;
struct node_details res;
int r;
if (call_nr == CHOWN) {
/* Perform the chmod(name, mode) system call. */
if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
/* Fill in lookup request fields */
lookup_req.path = user_fullpath;
lookup_req.lastc = NULL;
lookup_req.flags = EAT_PATH;
/* Request lookup */
if ((r = lookup(&lookup_req, &res)) != OK) return r;
req.inode_nr = res.inode_nr;
req.fs_e = res.fs_e;
}
else if (call_nr == FCHOWN) {
if (!(flp = get_filp(m_in.m1_i1))) return err_code;
req.inode_nr = flp->filp_vno->v_inode_nr;
req.fs_e = flp->filp_vno->v_fs_e;
}
else panic(__FILE__, "do_chmod called with strange call_nr", call_nr);
/* Fill in request message fields.*/
req.uid = fp->fp_effuid;
req.gid = fp->fp_effgid;
req.newuid = m_in.owner;
req.newgid = m_in.group;
/* Issue request */
return req_chown(&req);
}
/*===========================================================================*
* do_umask *
*===========================================================================*/
PUBLIC int do_umask()
{
/* Perform the umask(co_mode) system call. */
register mode_t r;
r = ~fp->fp_umask; /* set 'r' to complement of old mask */
fp->fp_umask = ~(m_in.co_mode & RWX_MODES);
return(r); /* return complement of old mask */
}
/*===========================================================================*
* do_access *
*===========================================================================*/
PUBLIC int do_access()
{
/* Perform the access(name, mode) system call. */
struct access_req req;
struct lookup_req lookup_req;
struct node_details res;
int r;
/* First check to see if the mode is correct. */
if ( (m_in.mode & ~(R_OK | W_OK | X_OK)) != 0 && m_in.mode != F_OK)
return(EINVAL);
if (fetch_name(m_in.name, m_in.name_length, M3) != OK) return(err_code);
/* Fill in lookup request fields */
lookup_req.path = user_fullpath;
lookup_req.lastc = NULL;
lookup_req.flags = EAT_PATH;
/* Request lookup */
if ((r = lookup(&lookup_req, &res)) != OK) return r;
/* Fill in request fields */
req.fs_e = res.fs_e;
req.amode = m_in.mode;
req.inode_nr = res.inode_nr;
req.uid = fp->fp_realuid; /* real user and group id */
req.gid = fp->fp_realgid;
/* Issue request */
return req_access(&req);
}