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server: Check sharing options when duplicating an fd object.

This commit is contained in:
Alexandre Julliard 2011-04-18 13:41:32 +02:00
parent 94fbcd7ce2
commit 35431ed0e7
1 changed files with 48 additions and 44 deletions
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92
server/fd.c
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@ -1471,6 +1471,48 @@ static void fd_destroy( struct object *obj )
}
}
/* check if the desired access is possible without violating */
/* the sharing mode of other opens of the same file */
static unsigned int check_sharing( struct fd *fd, unsigned int access, unsigned int sharing,
unsigned int open_flags, unsigned int options )
{
unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
unsigned int existing_access = 0;
struct list *ptr;
fd->access = access;
fd->sharing = sharing;
LIST_FOR_EACH( ptr, &fd->inode->open )
{
struct fd *fd_ptr = LIST_ENTRY( ptr, struct fd, inode_entry );
if (fd_ptr != fd)
{
/* if access mode is 0, sharing mode is ignored */
if (fd_ptr->access) existing_sharing &= fd_ptr->sharing;
existing_access |= fd_ptr->access;
}
}
if (((access & FILE_UNIX_READ_ACCESS) && !(existing_sharing & FILE_SHARE_READ)) ||
((access & FILE_UNIX_WRITE_ACCESS) && !(existing_sharing & FILE_SHARE_WRITE)) ||
((access & DELETE) && !(existing_sharing & FILE_SHARE_DELETE)))
return STATUS_SHARING_VIOLATION;
if (((existing_access & FILE_MAPPING_WRITE) && !(sharing & FILE_SHARE_WRITE)) ||
((existing_access & FILE_MAPPING_IMAGE) && (access & FILE_UNIX_WRITE_ACCESS)))
return STATUS_SHARING_VIOLATION;
if ((existing_access & FILE_MAPPING_IMAGE) && (options & FILE_DELETE_ON_CLOSE))
return STATUS_CANNOT_DELETE;
if ((existing_access & FILE_MAPPING_ACCESS) && (open_flags & O_TRUNC))
return STATUS_USER_MAPPED_FILE;
if (!access) return 0; /* if access mode is 0, sharing mode is ignored (except for mappings) */
if (((existing_access & FILE_UNIX_READ_ACCESS) && !(sharing & FILE_SHARE_READ)) ||
((existing_access & FILE_UNIX_WRITE_ACCESS) && !(sharing & FILE_SHARE_WRITE)) ||
((existing_access & DELETE) && !(sharing & FILE_SHARE_DELETE)))
return STATUS_SHARING_VIOLATION;
return 0;
}
/* set the events that select waits for on this fd */
void set_fd_events( struct fd *fd, int events )
{
@ -1581,13 +1623,12 @@ struct fd *alloc_pseudo_fd( const struct fd_ops *fd_user_ops, struct object *use
/* duplicate an fd object for a different user */
struct fd *dup_fd_object( struct fd *orig, unsigned int access, unsigned int sharing, unsigned int options )
{
unsigned int err;
struct fd *fd = alloc_fd_object();
if (!fd) return NULL;
fd->access = access;
fd->options = options;
fd->sharing = sharing;
fd->cacheable = orig->cacheable;
if (orig->unix_name)
@ -1611,6 +1652,11 @@ struct fd *dup_fd_object( struct fd *orig, unsigned int access, unsigned int sha
fd->closed = closed;
fd->inode = (struct inode *)grab_object( orig->inode );
list_add_head( &fd->inode->open, &fd->inode_entry );
if ((err = check_sharing( fd, access, sharing, 0, options )))
{
set_error( err );
goto failed;
}
}
else if ((fd->unix_fd = dup( orig->unix_fd )) == -1)
{
@ -1630,48 +1676,6 @@ void set_no_fd_status( struct fd *fd, unsigned int status )
fd->no_fd_status = status;
}
/* check if the desired access is possible without violating */
/* the sharing mode of other opens of the same file */
static unsigned int check_sharing( struct fd *fd, unsigned int access, unsigned int sharing,
unsigned int open_flags, unsigned int options )
{
unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
unsigned int existing_access = 0;
struct list *ptr;
fd->access = access;
fd->sharing = sharing;
LIST_FOR_EACH( ptr, &fd->inode->open )
{
struct fd *fd_ptr = LIST_ENTRY( ptr, struct fd, inode_entry );
if (fd_ptr != fd)
{
/* if access mode is 0, sharing mode is ignored */
if (fd_ptr->access) existing_sharing &= fd_ptr->sharing;
existing_access |= fd_ptr->access;
}
}
if (((access & FILE_UNIX_READ_ACCESS) && !(existing_sharing & FILE_SHARE_READ)) ||
((access & FILE_UNIX_WRITE_ACCESS) && !(existing_sharing & FILE_SHARE_WRITE)) ||
((access & DELETE) && !(existing_sharing & FILE_SHARE_DELETE)))
return STATUS_SHARING_VIOLATION;
if (((existing_access & FILE_MAPPING_WRITE) && !(sharing & FILE_SHARE_WRITE)) ||
((existing_access & FILE_MAPPING_IMAGE) && (access & FILE_SHARE_WRITE)))
return STATUS_SHARING_VIOLATION;
if ((existing_access & FILE_MAPPING_IMAGE) && (options & FILE_DELETE_ON_CLOSE))
return STATUS_CANNOT_DELETE;
if ((existing_access & FILE_MAPPING_ACCESS) && (open_flags & O_TRUNC))
return STATUS_USER_MAPPED_FILE;
if (!access) return 0; /* if access mode is 0, sharing mode is ignored (except for mappings) */
if (((existing_access & FILE_UNIX_READ_ACCESS) && !(sharing & FILE_SHARE_READ)) ||
((existing_access & FILE_UNIX_WRITE_ACCESS) && !(sharing & FILE_SHARE_WRITE)) ||
((existing_access & DELETE) && !(sharing & FILE_SHARE_DELETE)))
return STATUS_SHARING_VIOLATION;
return 0;
}
/* sets the user of an fd that previously had no user */
void set_fd_user( struct fd *fd, const struct fd_ops *user_ops, struct object *user )
{