iofunc_mknod()

Verify a client's ability to make a new filesystem entry point

Synopsis:

#include <sys/iofunc.h>

int iofunc_mknod( resmgr_context_t *ctp,
                  io_mknod_t *msg,
                  iofunc_attr_t *attr,
                  iofunc_attr_t *dattr,
                  struct _client_info *info );

Arguments:

ctp

A pointer to a resmgr_context_t structure that the resource-manager library uses to pass context information between functions.

msg

A pointer to the io_mknod_t structure that contains the message that the resource manager received; see below.

attr

NULL, or a pointer to the iofunc_attr_t structure that describes the characteristics of the resource.

dattr

A pointer to the iofunc_attr_t structure that you must set. The iofunc_attr_t structure describes the attributes of the parent directory.

info

NULL, or a pointer to a _client_info structure that contains information about the client. For information about this structure, see ConnectClientInfo().

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The iofunc_mknod() helper function supports mknod() requests by verifying that the client can make a new filesystem entry point. It's similar to iofunc_open().

The iofunc_mknod() function checks to see if the client (described by the optional info structure) has access to open the resource (name passed in the msg structure). The attr structure describes the resource's attributes, and the optional dattr structure defines the attributes of the parent directory (i.e. if dattr isn't NULL, it implies that the resource identified by attr is being created within the directory specified by dattr).

The info argument can be passed as NULL, in which case iofunc_mknod() obtains the client information itself via a call to iofunc_client_info(). It is, of course, more efficient to get the client info once, rather than calling this function with NULL every time.

If an error occurs, the function returns information about a client's connection in info and a constant.

io_mknod_t structure

The io_mknod_t structure holds the _IO_CONNECT message received by the resource manager:

typedef union {
    struct _io_connect                  connect;
    struct _io_connect_link_reply       link_reply;
    struct _io_connect_ftype_reply      ftype_reply;
} io_mknod_t;

This message structure is a union of an input message (coming to the resource manager), _io_connect, and two possible output or reply messages (going back to the client):

• _io_connect_link_reply if the reply is redirecting the client to another resource

  Or:

• _io_connect_ftype_reply if the reply consists of a status and a file type.

Returns:

EOK

Success.

EBADFSYS

NULL was passed in dattr.

EFAULT

A fault occurred when the kernel tried to access the info buffer.

EINVAL

The client process is no longer valid.

ENOSYS

NULL was passed in info.

EPERM

The group ID or owner ID didn't match.

Classification:

QNX Neutrino

See also:

_io_connect, _io_connect_link_reply, _io_connect_ftype_reply, iofunc_client_info(), iofunc_open(), mknod()

Writing a Resource Manager

Resource Managers chapter of Getting Started with QNX Neutrino