13ef7f1f38
file descriptor passing, PFS does some back calls to VFS. For example, to verify the validity of a path provided by a process and to tell VFS it must copy file descriptors from one process to another.
224 lines
6.8 KiB
C
224 lines
6.8 KiB
C
/* This file contains the code for performing four system calls relating to
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* status and directories.
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*
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* The entry points into this file are
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* do_chdir: perform the CHDIR system call
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* do_chroot: perform the CHROOT system call
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* do_lstat: perform the LSTAT system call
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* do_stat: perform the STAT system call
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* do_fstat: perform the FSTAT system call
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* do_fstatfs: perform the FSTATFS system call
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* do_statvfs: perform the STATVFS system call
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* do_fstatvfs: perform the FSTATVFS system call
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*/
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#include "fs.h"
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#include <sys/stat.h>
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#include <sys/statfs.h>
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#include <minix/com.h>
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#include <minix/u64.h>
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#include <string.h>
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#include "file.h"
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#include "fproc.h"
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#include "param.h"
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#include <minix/vfsif.h>
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#include "vnode.h"
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#include "vmnt.h"
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FORWARD _PROTOTYPE( int change, (struct vnode **iip, char *name_ptr, int len));
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FORWARD _PROTOTYPE( int change_into, (struct vnode **iip, struct vnode *vp));
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/*===========================================================================*
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* do_fchdir *
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*===========================================================================*/
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PUBLIC int do_fchdir()
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{
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/* Change directory on already-opened fd. */
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struct filp *rfilp;
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/* Is the file descriptor valid? */
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if ((rfilp = get_filp(m_in.fd)) == NULL) return(err_code);
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dup_vnode(rfilp->filp_vno); /* Change into expects a reference. */
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return change_into(&fp->fp_wd, rfilp->filp_vno);
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}
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/*===========================================================================*
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* do_chdir *
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*===========================================================================*/
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PUBLIC int do_chdir()
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{
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/* Perform the chdir(name) system call. */
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return change(&fp->fp_wd, m_in.name, m_in.name_length);
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}
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/*===========================================================================*
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* do_chroot *
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*===========================================================================*/
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PUBLIC int do_chroot()
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{
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/* Perform the chroot(name) system call. */
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if (!super_user) return(EPERM); /* only su may chroot() */
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return change(&fp->fp_rd, m_in.name, m_in.name_length);
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}
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/*===========================================================================*
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* change *
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*===========================================================================*/
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PRIVATE int change(iip, name_ptr, len)
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struct vnode **iip; /* pointer to the inode pointer for the dir */
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char *name_ptr; /* pointer to the directory name to change to */
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int len; /* length of the directory name string */
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{
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/* Do the actual work for chdir() and chroot(). */
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struct vnode *vp;
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/* Try to open the directory */
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if (fetch_name(name_ptr, len, M3) != OK) return(err_code);
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if ((vp = eat_path(PATH_NOFLAGS, fp)) == NULL) return(err_code);
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return change_into(iip, vp);
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}
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/*===========================================================================*
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* change_into *
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*===========================================================================*/
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PRIVATE int change_into(iip, vp)
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struct vnode **iip; /* pointer to the inode pointer for the dir */
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struct vnode *vp; /* this is what the inode has to become */
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{
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int r;
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/* It must be a directory and also be searchable */
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if ((vp->v_mode & I_TYPE) != I_DIRECTORY)
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r = ENOTDIR;
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else
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r = forbidden(vp, X_BIT); /* Check if dir is searchable*/
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/* If error, return vnode */
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if (r != OK) {
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put_vnode(vp);
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return(r);
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}
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/* Everything is OK. Make the change. */
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put_vnode(*iip); /* release the old directory */
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*iip = vp; /* acquire the new one */
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return(OK);
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}
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/*===========================================================================*
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* do_stat *
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*===========================================================================*/
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PUBLIC int do_stat()
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{
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/* Perform the stat(name, buf) system call. */
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int r;
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struct vnode *vp;
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if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
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if ((vp = eat_path(PATH_NOFLAGS, fp)) == NULL) return(err_code);
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r = req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0);
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put_vnode(vp);
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return r;
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}
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/*===========================================================================*
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* do_fstat *
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*===========================================================================*/
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PUBLIC int do_fstat()
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{
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/* Perform the fstat(fd, buf) system call. */
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register struct filp *rfilp;
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int pipe_pos = 0;
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/* Is the file descriptor valid? */
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if ((rfilp = get_filp(m_in.fd)) == NULL) return(err_code);
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/* If we read from a pipe, send position too */
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if (rfilp->filp_vno->v_pipe == I_PIPE) {
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if (rfilp->filp_mode & R_BIT)
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if (ex64hi(rfilp->filp_pos) != 0) {
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panic("do_fstat: bad position in pipe");
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}
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pipe_pos = ex64lo(rfilp->filp_pos);
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}
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return req_stat(rfilp->filp_vno->v_fs_e, rfilp->filp_vno->v_inode_nr,
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who_e, m_in.buffer, pipe_pos);
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}
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/*===========================================================================*
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* do_fstatfs *
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*===========================================================================*/
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PUBLIC int do_fstatfs()
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{
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/* Perform the fstatfs(fd, buf) system call. */
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struct filp *rfilp;
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/* Is the file descriptor valid? */
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if( (rfilp = get_filp(m_in.fd)) == NULL) return(err_code);
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return req_fstatfs(rfilp->filp_vno->v_fs_e, who_e, m_in.buffer);
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}
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/*===========================================================================*
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* do_statvfs *
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*===========================================================================*/
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PUBLIC int do_statvfs()
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{
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/* Perform the stat(name, buf) system call. */
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int r;
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struct vnode *vp;
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if (fetch_name(m_in.STATVFS_NAME, m_in.STATVFS_LEN, M1) != OK) return(err_code);
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if ((vp = eat_path(PATH_NOFLAGS, fp)) == NULL) return(err_code);
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r = req_statvfs(vp->v_fs_e, who_e, m_in.STATVFS_BUF);
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put_vnode(vp);
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return r;
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}
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/*===========================================================================*
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* do_fstatvfs *
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*===========================================================================*/
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PUBLIC int do_fstatvfs()
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{
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/* Perform the fstat(fd, buf) system call. */
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register struct filp *rfilp;
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/* Is the file descriptor valid? */
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if ((rfilp = get_filp(m_in.FSTATVFS_FD)) == NULL) return(err_code);
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return req_statvfs(rfilp->filp_vno->v_fs_e, who_e, m_in.FSTATVFS_BUF);
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}
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/*===========================================================================*
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* do_lstat *
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*===========================================================================*/
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PUBLIC int do_lstat()
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{
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/* Perform the lstat(name, buf) system call. */
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struct vnode *vp;
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int r;
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if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
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if ((vp = eat_path(PATH_RET_SYMLINK, fp)) == NULL) return(err_code);
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r = req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0);
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put_vnode(vp);
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return(r);
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}
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