 ef7b484e5c
			
		
	
	
		ef7b484e5c
		
	
	
	
	
		
			
			This Shared Folders File System library (libsffs) now contains all the file system logic originally in HGFS. The actual HGFS server code is now a stub that passes on all the work to libsffs. The libhgfs library is changed accordingly.
		
			
				
	
	
		
			120 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			120 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* This file contains routines that verify inodes and paths against the host.
 | |
|  *
 | |
|  * The entry points into this file are:
 | |
|  *   verify_path	check whether a path,inode pair is still valid
 | |
|  *   verify_inode	construct a path for an inode and verify the inode
 | |
|  *   verify_dentry	check a directory inode and look for a directory entry
 | |
|  *
 | |
|  * Created:
 | |
|  *   April 2009 (D.C. van Moolenbroek)
 | |
|  */
 | |
| 
 | |
| #include "inc.h"
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				verify_path				     *
 | |
|  *===========================================================================*/
 | |
| int verify_path(path, ino, attr, stale)
 | |
| char path[PATH_MAX];
 | |
| struct inode *ino;
 | |
| struct sffs_attr *attr;
 | |
| int *stale;
 | |
| {
 | |
| /* Given a path, and the inode associated with that path, verify if the inode
 | |
|  * still matches the real world. Obtain the attributes of the file identified
 | |
|  * by the given path, and see if they match. If not, possibly mark the inode
 | |
|  * as deleted and return an error. Only upon success is the inode guaranteed
 | |
|  * to be usable.
 | |
|  *
 | |
|  * The caller must set the a_mask field of the passed attr struct.
 | |
|  * If 'stale' is not NULL, the value it points to must be initialized to 0,
 | |
|  * and will be set to 1 if the path was valid but the inode wasn't.
 | |
|  */
 | |
|   int r;
 | |
| 
 | |
|   attr->a_mask |= SFFS_ATTR_MODE;
 | |
| 
 | |
|   r = sffs_table->t_getattr(path, attr);
 | |
| 
 | |
|   dprintf(("%s: verify_path: getattr('%s') returned %d\n",
 | |
| 	sffs_name, path, r));
 | |
| 
 | |
|   if (r != OK) {
 | |
| 	/* If we are told that the path does not exist, delete the inode */
 | |
| 	if (r == ENOENT || r == ENOTDIR)
 | |
| 		del_dentry(ino);
 | |
| 
 | |
| 	return r; /* path isn't valid */
 | |
|   }
 | |
| 
 | |
|   /* If the file type (reg, dir) isn't what we thought, delete the inode */
 | |
|   if ((ino->i_flags & I_DIR) != MODE_TO_DIRFLAG(attr->a_mode)) {
 | |
| 	del_dentry(ino);
 | |
| 
 | |
| 	if (stale != NULL) *stale = 1;
 | |
| 	return ENOENT; /* path is valid, inode wasn't */
 | |
|   }
 | |
| 
 | |
|   return OK; /* path and inode are valid */
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				verify_inode				     *
 | |
|  *===========================================================================*/
 | |
| int verify_inode(ino, path, attr)
 | |
| struct inode *ino;		/* inode to verify */
 | |
| char path[PATH_MAX];		/* buffer in which to store the path */
 | |
| struct sffs_attr *attr;		/* buffer for attributes, or NULL */
 | |
| {
 | |
| /* Given an inode, construct a path identifying the inode, and check whether
 | |
|  * that path is still valid for that inode (as far as we can tell). As a side
 | |
|  * effect, store attributes in the given attribute structure if not NULL (its
 | |
|  * a_mask member must then be set).
 | |
|  */
 | |
|   struct sffs_attr attr2;
 | |
|   int r;
 | |
| 
 | |
|   if ((r = make_path(path, ino)) != OK) return r;
 | |
| 
 | |
|   if (attr == NULL) {
 | |
| 	attr2.a_mask = 0;
 | |
| 
 | |
| 	attr = &attr2;
 | |
|   }
 | |
| 
 | |
|   return verify_path(path, ino, attr, NULL);
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				verify_dentry				     *
 | |
|  *===========================================================================*/
 | |
| int verify_dentry(parent, name, path, res_ino)
 | |
| struct inode *parent;		/* parent inode: the inode to verify */
 | |
| char name[NAME_MAX+1];		/* the given directory entry path component */
 | |
| char path[PATH_MAX];		/* buffer to store the resulting path in */
 | |
| struct inode **res_ino;		/* pointer for addressed inode (or NULL) */
 | |
| {
 | |
| /* Given a directory inode and a name, construct a path identifying that
 | |
|  * directory entry, check whether the path to the parent is still valid, and
 | |
|  * check whether there is an inode pointed to by the full path. Upon success,
 | |
|  * res_ino will contain either the inode for the full path, with increased
 | |
|  * refcount, or NULL if no such inode exists.
 | |
|  */
 | |
|   int r;
 | |
| 
 | |
|   if ((r = verify_inode(parent, path, NULL)) != OK)
 | |
| 	return r;
 | |
| 
 | |
|   dprintf(("%s: verify_dentry: given path is '%s', name '%s'\n",
 | |
| 	sffs_name, path, name));
 | |
| 
 | |
|   if ((r = push_path(path, name)) != OK)
 | |
| 	return r;
 | |
| 
 | |
|   dprintf(("%s: verify_dentry: path now '%s'\n", sffs_name, path));
 | |
| 
 | |
|   *res_ino = lookup_dentry(parent, name);
 | |
| 
 | |
|   return OK;
 | |
| }
 |