aplhidev_msghdr
struct aplhidev_msghdr hdr;
struct aplhidev_msghdr hdr;
struct aplhidev_msghdr hdr;
msg->hdr.cmdlen = sizeof(*msg) - sizeof(struct aplhidev_msghdr) - 2;
msg->hdr.cmdlen = sizeof(*msg) - sizeof(struct aplhidev_msghdr) - 2;
struct aplhidev_msghdr *hdr = (struct aplhidev_msghdr *)&packet.data[0];