Function crypto_newsession

freebsd/opencrypto/crypto.c:909–963

* Create a new session. The crid argument specifies a crypto * driver to use or constraints on a driver to select (hardware * only, software only, either). Whatever driver is selected * must be capable of the requested crypto algorithms. */

 * must be capable of the requested crypto algorithms.
 */
int
crypto_newsession(crypto_session_t *cses,
    const struct crypto_session_params *csp, int crid)
{
	static uint64_t sessid = 0;
	crypto_session_t res;
	struct cryptocap *cap;
	int err;

	if (!check_csp(csp))
		return (EINVAL);

	res = NULL;

	CRYPTO_DRIVER_LOCK();
	if ((crid & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
		/*
		 * Use specified driver; verify it is capable.
		 */
		cap = crypto_checkdriver(crid);
		if (cap != NULL && CRYPTODEV_PROBESESSION(cap->cc_dev, csp) > 0)
			cap = NULL;
	} else {
		/*
		 * No requested driver; select based on crid flags.
		 */
		cap = crypto_select_driver(csp, crid);
	}
	if (cap == NULL) {
		CRYPTO_DRIVER_UNLOCK();
		CRYPTDEB("no driver");
		return (EOPNOTSUPP);
	}
	cap_ref(cap);
	cap->cc_sessions++;
	CRYPTO_DRIVER_UNLOCK();

	/* Allocate a single block for the generic session and driver softc. */
	res = malloc(sizeof(*res) + cap->cc_session_size, M_CRYPTO_DATA,
	    M_WAITOK | M_ZERO);
	res->cap = cap;
	res->csp = *csp;
	res->id = atomic_fetchadd_64(&sessid, 1);

	/* Call the driver initialization routine. */
	err = CRYPTODEV_NEWSESSION(cap->cc_dev, res, csp);
	if (err != 0) {
		CRYPTDEB("dev newsession failed: %d", err);
		crypto_deletesession(res);
		return (err);
	}

	*cses = res;
	return (0);
}

/*
 * Delete an existing session (or a reserved session on an unregistered