minix/servers/vfs/stadir.c
2007-08-17 11:20:59 +00:00

262 lines
7.1 KiB
C

/* This file contains the code for performing four system calls relating to
* status and directories.
*
* The entry points into this file are
* do_chdir: perform the CHDIR system call
* do_chroot: perform the CHROOT system call
* do_stat: perform the STAT system call
* do_fstat: perform the FSTAT system call
* do_fstatfs: perform the FSTATFS system call
* do_lstat: perform the LSTAT system call
*
* Changes for VFS:
* Jul 2006 (Balazs Gerofi)
*/
#include "fs.h"
#include <sys/stat.h>
#include <sys/statfs.h>
#include <minix/com.h>
#include <minix/u64.h>
#include <string.h>
#include "file.h"
#include "fproc.h"
#include "param.h"
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"
FORWARD _PROTOTYPE( int change, (struct vnode **iip, char *name_ptr, int len));
FORWARD _PROTOTYPE( int change_into, (struct vnode **iip, struct vnode *vp));
/*===========================================================================*
* do_fchdir *
*===========================================================================*/
PUBLIC int do_fchdir()
{
/* Change directory on already-opened fd. */
struct filp *rfilp;
int r;
/* Is the file descriptor valid? */
if ( (rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code);
/* Is it a dir? */
if ((rfilp->filp_vno->v_mode & I_TYPE) != I_DIRECTORY)
return ENOTDIR;
/* Issue request and handle error */
r = forbidden(rfilp->filp_vno, X_BIT, 0 /*!use_realuid*/);
if (r != OK) return r;
rfilp->filp_vno->v_ref_count++; /* change_into expects a reference */
return change_into(&fp->fp_wd, rfilp->filp_vno);
}
/*===========================================================================*
* do_chdir *
*===========================================================================*/
PUBLIC int do_chdir()
{
/* Change directory. This function is also called by MM to simulate a chdir
* in order to do EXEC, etc. It also changes the root directory, the uids and
* gids, and the umask.
*/
int r;
register struct fproc *rfp;
if (who_e == PM_PROC_NR) {
int slot;
if(isokendpt(m_in.endpt1, &slot) != OK)
return EINVAL;
rfp = &fproc[slot];
put_vnode(fp->fp_rd);
dup_vnode(fp->fp_rd = rfp->fp_rd);
put_vnode(fp->fp_wd);
dup_vnode(fp->fp_wd = rfp->fp_wd);
/* MM uses access() to check permissions. To make this work, pretend
* that the user's real ids are the same as the user's effective ids.
* FS calls other than access() do not use the real ids, so are not
* affected.
*/
fp->fp_realuid =
fp->fp_effuid = rfp->fp_effuid;
fp->fp_realgid =
fp->fp_effgid = rfp->fp_effgid;
fp->fp_umask = rfp->fp_umask;
return(OK);
}
/* Perform the chdir(name) system call. */
r = change(&fp->fp_wd, m_in.name, m_in.name_length);
return(r);
}
/*===========================================================================*
* do_chroot *
*===========================================================================*/
PUBLIC int do_chroot()
{
/* Perform the chroot(name) system call. */
register int r;
if (!super_user) return(EPERM); /* only su may chroot() */
r = change(&fp->fp_rd, m_in.name, m_in.name_length);
return(r);
}
/*===========================================================================*
* change *
*===========================================================================*/
PRIVATE int change(iip, name_ptr, len)
struct vnode **iip; /* pointer to the inode pointer for the dir */
char *name_ptr; /* pointer to the directory name to change to */
int len; /* length of the directory name string */
{
/* Do the actual work for chdir() and chroot(). */
struct vnode *vp;
int r;
if (fetch_name(name_ptr, len, M3) != OK) return(err_code);
/* Request lookup */
if ((r = lookup_vp(0 /*flags*/, 0 /*!use_realuid*/, &vp)) != OK) return r;
/* Is it a dir? */
if ((vp->v_mode & I_TYPE) != I_DIRECTORY)
{
put_vnode(vp);
return ENOTDIR;
}
/* Access check */
r = forbidden(vp, X_BIT, 0 /*!use_realuid*/);
if (r != OK) {
put_vnode(vp);
return r;
}
return change_into(iip, vp);
}
/*===========================================================================*
* change_into *
*===========================================================================*/
PRIVATE int change_into(iip, vp)
struct vnode **iip; /* pointer to the inode pointer for the dir */
struct vnode *vp; /* this is what the inode has to become */
{
/* Everything is OK. Make the change. */
put_vnode(*iip); /* release the old directory */
*iip = vp; /* acquire the new one */
return(OK);
}
/*===========================================================================*
* do_stat *
*===========================================================================*/
PUBLIC int do_stat()
{
/* Perform the stat(name, buf) system call. */
int r;
struct vnode *vp;
if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
/* Request lookup */
if ((r = lookup_vp(0 /*flags*/, 0 /*!use_realuid*/, &vp)) != OK)
return r;
/* Issue request */
r= req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0);
put_vnode(vp);
return r;
}
/*===========================================================================*
* do_fstat *
*===========================================================================*/
PUBLIC int do_fstat()
{
/* Perform the fstat(fd, buf) system call. */
register struct filp *rfilp;
int pipe_pos = 0;
/* Is the file descriptor valid? */
if ( (rfilp = get_filp(m_in.fd)) == NIL_FILP) {
return(err_code);
}
/* If we read from a pipe, send position too */
pipe_pos= 0;
if (rfilp->filp_vno->v_pipe == I_PIPE) {
if (rfilp->filp_mode & R_BIT)
if (ex64hi(rfilp->filp_pos) != 0)
{
panic(__FILE__, "do_fstat: bad position in pipe",
NO_NUM);
}
pipe_pos = ex64lo(rfilp->filp_pos);
}
/* Issue request */
return req_stat(rfilp->filp_vno->v_fs_e, rfilp->filp_vno->v_inode_nr,
who_e, m_in.buffer, pipe_pos);
}
/*===========================================================================*
* do_fstatfs *
*===========================================================================*/
PUBLIC int do_fstatfs()
{
/* Perform the fstatfs(fd, buf) system call. */
register struct filp *rfilp;
/* Is the file descriptor valid? */
if ( (rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code);
/* Issue request */
return req_fstatfs(rfilp->filp_vno->v_fs_e, who_e, m_in.buffer);
}
/*===========================================================================*
* do_lstat *
*===========================================================================*/
PUBLIC int do_lstat()
{
/* Perform the lstat(name, buf) system call. */
struct vnode *vp;
int r;
if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
/* Request lookup */
if ((r = lookup_vp(PATH_RET_SYMLINK, 0 /*!use_realuid*/, &vp)) != OK)
return r;
/* Issue request */
r= req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0);
put_vnode(vp);
return r;
}