iovec - data storage structure for I/O using uio
#include <sys/uio.h>
Architecture independent level 1 (DDI/DKI).
An iovec structure describes a data storage area for transfer in a uio(9S) structure. Conceptually, it can be thought of as a base address and length specification.
caddr_t iov_base; /* base address of the data storage area */
/* represented by the iovec structure */
int iov_len; /* size of the data storage area in bytes */