servers/vfs/stadir.c

   1 /* This file contains the code for performing four system calls relating to
   2  * status and directories.
   3  *
   4  * The entry points into this file are
   5  *   do_chdir:  perform the CHDIR system call
   6  *   do_chroot: perform the CHROOT system call
   7  *   do_lstat:  perform the LSTAT system call
   8  *   do_stat:   perform the STAT system call
   9  *   do_fstat:  perform the FSTAT system call
  10  *   do_fstatfs: perform the FSTATFS system call
  11  */
  12
  13 #include "fs.h"
  14 #include <sys/stat.h>
  15 #include <sys/statfs.h>
  16 #include <minix/com.h>
  17 #include <minix/u64.h>
  18 #include <string.h>
  19 #include "file.h"
  20 #include "fproc.h"
  21 #include "param.h"
  22 #include <minix/vfsif.h>
  23 #include "vnode.h"
  24 #include "vmnt.h"
  25
  26 FORWARD _PROTOTYPE( int change, (struct vnode **iip, char *name_ptr, int len));
  27 FORWARD _PROTOTYPE( int change_into, (struct vnode **iip, struct vnode *vp));
  28
  29
  30 /*===========================================================================*
  31  *                              do_fchdir                                    *
  32  *===========================================================================*/
  33 PUBLIC int do_fchdir()
  34 {
  35   /* Change directory on already-opened fd. */
  36   struct filp *rfilp;
  37
  38   /* Is the file descriptor valid? */
  39   if ((rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code);
  40   dup_vnode(rfilp->filp_vno);   /* Change into expects a reference. */
  41   return change_into(&fp->fp_wd, rfilp->filp_vno);
  42 }
  43
  44
  45 /*===========================================================================*
  46  *                              do_chdir                                     *
  47  *===========================================================================*/
  48 PUBLIC int do_chdir()
  49 {
  50 /* Perform the chdir(name) system call. */
  51
  52   return change(&fp->fp_wd, m_in.name, m_in.name_length);
  53 }
  54
  55
  56 /*===========================================================================*
  57  *                              do_chroot                                    *
  58  *===========================================================================*/
  59 PUBLIC int do_chroot()
  60 {
  61 /* Perform the chroot(name) system call. */
  62
  63   if (!super_user) return(EPERM);       /* only su may chroot() */
  64   return change(&fp->fp_rd, m_in.name, m_in.name_length);
  65 }
  66
  67
  68 /*===========================================================================*
  69  *                              change                                       *
  70  *===========================================================================*/
  71 PRIVATE int change(iip, name_ptr, len)
  72 struct vnode **iip;             /* pointer to the inode pointer for the dir */
  73 char *name_ptr;                 /* pointer to the directory name to change to */
  74 int len;                        /* length of the directory name string */
  75 {
  76 /* Do the actual work for chdir() and chroot(). */
  77   struct vnode *vp;
  78   int r;
  79
  80   /* Try to open the directory */
  81   if (fetch_name(name_ptr, len, M3) != OK) return(err_code);
  82   if ((vp = eat_path(PATH_NOFLAGS)) == NIL_VNODE) return(err_code);
  83   return change_into(iip, vp);
  84 }
  85
  86
  87 /*===========================================================================*
  88  *                              change_into                                  *
  89  *===========================================================================*/
  90 PRIVATE int change_into(iip, vp)
  91 struct vnode **iip;             /* pointer to the inode pointer for the dir */
  92 struct vnode *vp;               /* this is what the inode has to become */
  93 {
  94   int r;
  95
  96   /* It must be a directory and also be searchable */
  97   if ((vp->v_mode & I_TYPE) != I_DIRECTORY)
  98         r = ENOTDIR;
  99   else
 100         r = forbidden(vp, X_BIT);       /* Check if dir is searchable*/
 101
 102   /* If error, return vnode */
 103   if (r != OK) {
 104         put_vnode(vp);
 105         return(r);
 106   }
 107
 108   /* Everything is OK.  Make the change. */
 109   put_vnode(*iip);              /* release the old directory */
 110   *iip = vp;                    /* acquire the new one */
 111   return(OK);
 112 }
 113
 114
 115 /*===========================================================================*
 116  *                              do_stat                                      *
 117  *===========================================================================*/
 118 PUBLIC int do_stat()
 119 {
 120 /* Perform the stat(name, buf) system call. */
 121   int r;
 122   struct vnode *vp;
 123
 124   if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
 125   if ((vp = eat_path(PATH_NOFLAGS)) == NIL_VNODE) return(err_code);
 126   r = req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0);
 127
 128   put_vnode(vp);
 129   return r;
 130 }
 131
 132
 133 /*===========================================================================*
 134  *                              do_fstat                                     *
 135  *===========================================================================*/
 136 PUBLIC int do_fstat()
 137 {
 138 /* Perform the fstat(fd, buf) system call. */
 139   register struct filp *rfilp;
 140   int pipe_pos = 0;
 141
 142   /* Is the file descriptor valid? */
 143   if ((rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code);
 144
 145   /* If we read from a pipe, send position too */
 146   if (rfilp->filp_vno->v_pipe == I_PIPE) {
 147         if (rfilp->filp_mode & R_BIT)
 148                 if (ex64hi(rfilp->filp_pos) != 0) {
 149                         panic("do_fstat: bad position in pipe");
 150                 }
 151         pipe_pos = ex64lo(rfilp->filp_pos);
 152   }
 153
 154   return req_stat(rfilp->filp_vno->v_fs_e, rfilp->filp_vno->v_inode_nr,
 155                   who_e, m_in.buffer, pipe_pos);
 156 }
 157
 158
 159 /*===========================================================================*
 160  *                              do_fstatfs                                   *
 161  *===========================================================================*/
 162 PUBLIC int do_fstatfs()
 163 {
 164 /* Perform the fstatfs(fd, buf) system call. */
 165   struct filp *rfilp;
 166
 167   /* Is the file descriptor valid? */
 168   if( (rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code);
 169
 170   return req_fstatfs(rfilp->filp_vno->v_fs_e, who_e, m_in.buffer);
 171 }
 172
 173
 174 /*===========================================================================*
 175  *                             do_lstat                                      *
 176  *===========================================================================*/
 177 PUBLIC int do_lstat()
 178 {
 179 /* Perform the lstat(name, buf) system call. */
 180   struct vnode *vp;
 181   int r;
 182
 183   if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code);
 184   if ((vp = eat_path(PATH_RET_SYMLINK)) == NIL_VNODE) return(err_code);
 185   r = req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0);
 186
 187   put_vnode(vp);
 188   return(r);
 189 }
 190
 191