iofunc_read_verify()

Verify a client's read access to a resource

Synopsis:

#include <sys/iofunc.h>

int iofunc_read_verify( resmgr_context_t* ctp,
                        io_read_t* msg,
                        iofunc_ocb_t* ocb,
                        int* nonblock );

Library:

libc

Description:

The iofunc_read_verify() function checks that the client that sent the _IO_READ message actually has read access to the resource, and, optionally (if nonblock isn't NULL), sets nonblock to O_NONBLOCK or 0).

The read permission check is done against ocb->ioflag.

Note that the io_read_t message has an override flag called msg->i.xtype. This flag allows the client to override the default blocking behavior for the resource on a per-request basis. This override flag is checked, and returned in the optional nonblock.

Note that if you're reading from a directory entry, you must return struct dirent structures in the read callout for your resource manager.

You'll also need to indicate how many bytes were read. You can do this with the macro:

_IO_SET_READ_NBYTES( resmgr_context_t *ctp,
                     int nbytes )

Returns:

EOK

The client has read access to this resource.

EBADF

The client doesn't have read access to this resource.

Classification:

QNX 6

See also:

iofunc_open(), iofunc_write_verify()