copyresp(D4DK) —

NAME

copyresp − STREAMS transparent ioctl copy response structure

SYNOPSIS

#include <sys/stream.h>

DESCRIPTION

The copyresp structure contains information in response to a prior copy request necessary to continue processing transparent ioctls. M_IOCDATA messages, generated by the stream head, contain the copyresp structure.

STRUCTURE MEMBERS

int	cp_cmd;	/∗ ioctl command ∗/
cred_t	∗cp_cr;	/∗ user credentials ∗/
uint_t	cp_id;	/∗ ioctl ID ∗/
caddr_t	cp_rval;	/∗ status of request ∗/
mblk_t	∗cp_private;	/∗ module private data ∗/

The cp_cmd field is the ioctl command, copied from the cq_cmd field of the copyreq structure.

The cp_cr field contains a pointer to the user credentials. It is copied from the cq_cr field of the copyreq structure.

The cp_id field is the ioctl ID, copied from the cq_id field of the copyreq structure. It is used to uniquely identify the ioctl request in the stream.

The cq_rval field contains the return value from the last copy request. If the request succeeded, it is set to 0. Otherwise, if it is non-zero, the request failed. On success, the module or driver should continue processing the ioctl. On failure, the module or driver should abort ioctl processing and free the message. No M_IOCNAK message need be generated.

The cp_private field is copied from the cq_private field of the copyreq structure. It is available so that the module or driver can regain enough state information to continue processing the ioctl request.

NOTES

If an M_IOCDATA message is reused, any unused fields in the new message should be cleared.

When the M_IOCDATA message is freed, any message that cp_private refers to is not freed by the STREAMS subsystem. It is the responsibility of the module or driver to free it.