crypto.c

linux下基于加密芯片的加密设备

	    (CRYPTO_ALGORITHM_MIN <= alg && alg <= CRYPTO_ALGORITHM_MAX)) {
		/*
		 * XXX Do some performance testing to determine placing.
		 * XXX We probably need an auxiliary data structure that
		 * XXX describes relative performances.
		 */

		cap->cc_alg[alg] = flags | CRYPTO_ALG_FLAG_SUPPORTED;
		cap->cc_max_op_len[alg] = maxoplen;
		if (crypto_verbose)
			printk("crypto: driver %u registers alg %u flags %u maxoplen %u\n"
				, driverid
				, alg
				, flags
				, maxoplen
			);

		if (cap->cc_process == NULL) {
			cap->cc_arg = arg;
			cap->cc_newsession = newses;
			cap->cc_process = process;
			cap->cc_freesession = freeses;
			cap->cc_sessions = 0;		/* Unmark */
		}
		err = 0;
	} else
		err = EINVAL;

	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Unregister a crypto driver. If there are pending sessions using it,
 * leave enough information around so that subsequent calls using those
 * sessions will correctly detect the driver has been unregistered and
 * reroute requests.
 */
int
crypto_unregister(u_int32_t driverid, int alg)
{
	int i, err, d_flags;
	u_int32_t ses;
	struct cryptocap *cap;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_DRIVER_LOCK();

	cap = crypto_checkdriver(driverid);
	if (cap != NULL &&
	    (CRYPTO_ALGORITHM_MIN <= alg && alg <= CRYPTO_ALGORITHM_MAX) &&
	    cap->cc_alg[alg] != 0) {
		cap->cc_alg[alg] = 0;
		cap->cc_max_op_len[alg] = 0;

		/* Was this the last algorithm ? */
		for (i = 1; i <= CRYPTO_ALGORITHM_MAX; i++)
			if (cap->cc_alg[i] != 0)
				break;

		if (i == CRYPTO_ALGORITHM_MAX + 1) {
			ses = cap->cc_sessions;
			memset(cap, 0, sizeof(struct cryptocap));
			if (ses != 0) {
				/*
				 * If there are pending sessions, just mark as invalid.
				 */
				cap->cc_flags |= CRYPTOCAP_F_CLEANUP;
				cap->cc_sessions = ses;
			}
		}
		err = 0;
	} else
		err = EINVAL;

	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Unregister all algorithms associated with a crypto driver.
 * If there are pending sessions using it, leave enough information
 * around so that subsequent calls using those sessions will
 * correctly detect the driver has been unregistered and reroute
 * requests.
 */
int
crypto_unregister_all(u_int32_t driverid)
{
	int i, err, d_flags;
	u_int32_t ses;
	struct cryptocap *cap;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_DRIVER_LOCK();

	cap = crypto_checkdriver(driverid);
	if (cap != NULL) {
		for (i = CRYPTO_ALGORITHM_MIN; i <= CRYPTO_ALGORITHM_MAX; i++) {
			cap->cc_alg[i] = 0;
			cap->cc_max_op_len[i] = 0;
		}
		ses = cap->cc_sessions;
		memset(cap, 0, sizeof(struct cryptocap));
		if (ses != 0) {
			/*
			 * If there are pending sessions, just mark as invalid.
			 */
			cap->cc_flags |= CRYPTOCAP_F_CLEANUP;
			cap->cc_sessions = ses;
		}
		err = 0;
	} else
		err = EINVAL;

	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Clear blockage on a driver.  The what parameter indicates whether
 * the driver is now ready for cryptop's and/or cryptokop's.
 */
int
crypto_unblock(u_int32_t driverid, int what)
{
	struct cryptocap *cap;
	int needwakeup, err, q_flags;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_Q_LOCK();
	cap = crypto_checkdriver(driverid);
	if (cap != NULL) {
		needwakeup = 0;
		if (what & CRYPTO_SYMQ) {
			needwakeup |= cap->cc_qblocked;
			cap->cc_qblocked = 0;
		}
		if (what & CRYPTO_ASYMQ) {
			needwakeup |= cap->cc_kqblocked;
			cap->cc_kqblocked = 0;
		}
		if (needwakeup)
			wake_up_interruptible(&cryptoproc_wait);
		err = 0;
	} else
		err = EINVAL;
	CRYPTO_Q_UNLOCK();

	return err;
}

/*
 * Add a crypto request to a queue, to be processed by the kernel thread.
 */
int
crypto_dispatch(struct cryptop *crp)
{
	u_int32_t hid = CRYPTO_SESID2HID(crp->crp_sid);
	int result, q_flags;

	dprintk("%s()\n", __FUNCTION__);

	cryptostats.cs_ops++;
	CRYPTO_Q_LOCK();
	if ((crp->crp_flags & CRYPTO_F_BATCH) == 0) {
		struct cryptocap *cap;
		/*
		 * Caller marked the request to be processed
		 * immediately; dispatch it directly to the
		 * driver unless the driver is currently blocked.
		 */
		cap = crypto_checkdriver(hid);
		if (cap && !cap->cc_qblocked) {
			result = crypto_invoke(crp, 0);
			if (result == ERESTART) {
				/*
				 * The driver ran out of resources, mark the
				 * driver ``blocked'' for cryptop's and put
				 * the request on the queue.
				 *
				 * XXX ops are placed at the tail so their
				 * order is preserved but this can place them
				 * behind batch'd ops.
				 */
				crypto_drivers[hid].cc_qblocked = 1;
				list_add_tail(&crp->crp_list, &crp_q);
				cryptostats.cs_blocks++;
				result = 0;
			}
		} else {
			/*
			 * The driver is blocked, just queue the op until
			 * it unblocks and the kernel thread gets kicked.
			 */
			list_add_tail(&crp->crp_list, &crp_q);
			result = 0;
		}
	} else {
		int wasempty;
		/*
		 * Caller marked the request as ``ok to delay'';
		 * queue it for the dispatch thread.  This is desirable
		 * when the operation is low priority and/or suitable
		 * for batching.
		 */
		wasempty = list_empty(&crp_q);
		list_add_tail(&crp->crp_list, &crp_q);
		if (wasempty)
			wake_up_interruptible(&cryptoproc_wait);
		result = 0;
	}
	CRYPTO_Q_UNLOCK();

	return result;
}

/*
 * Add an asymetric crypto request to a queue,
 * to be processed by the kernel thread.
 */
int
crypto_kdispatch(struct cryptkop *krp)
{
	struct cryptocap *cap;
	int result, q_flags;

	dprintk("%s()\n", __FUNCTION__);
	cryptostats.cs_kops++;

	CRYPTO_Q_LOCK();
	cap = crypto_checkdriver(krp->krp_hid);
	if (cap && !cap->cc_kqblocked) {
		result = crypto_kinvoke(krp, 0);
		if (result == ERESTART) {
			/*
			 * The driver ran out of resources, mark the
			 * driver ``blocked'' for cryptkop's and put
			 * the request back in the queue.  It would
			 * best to put the request back where we got
			 * it but that's hard so for now we put it
			 * at the front.  This should be ok; putting
			 * it at the end does not work.
			 */
			crypto_drivers[krp->krp_hid].cc_kqblocked = 1;
			list_add_tail(&krp->krp_list, &crp_kq);
			cryptostats.cs_kblocks++;
		}
	} else {
		/*
		 * The driver is blocked, just queue the op until
		 * it unblocks and the kernel thread gets kicked.
		 */
		list_add_tail(&krp->krp_list, &crp_kq);
		result = 0;
	}
	CRYPTO_Q_UNLOCK();

	return result;
}

/*
 * Dispatch an assymetric crypto request to the appropriate crypto devices.
 */
static int
crypto_kinvoke(struct cryptkop *krp, int hint)
{
	u_int32_t hid;
	int error;

	dprintk("%s()\n", __FUNCTION__);
	if (!crypto_q_locked)
		printk("crypto: crypto_kinvoke called without lock!\n");

	/* Sanity checks. */
	if (krp == NULL) {
		dprintk("%s,%d: null krp\n", __FILE__, __LINE__);
		return EINVAL;
	}
	if (krp->krp_callback == NULL) {
		dprintk("%s,%d: null krp_callback\n", __FILE__, __LINE__);
		kfree(krp);		/* XXX allocated in cryptodev */
		return EINVAL;
	}

	for (hid = 0; hid < crypto_drivers_num; hid++) {
		if ((crypto_drivers[hid].cc_flags & CRYPTOCAP_F_SOFTWARE) &&
		    !crypto_devallowsoft)
			continue;
		if (crypto_drivers[hid].cc_kprocess == NULL)
			continue;
		if ((crypto_drivers[hid].cc_kalg[krp->krp_op] &
		    CRYPTO_ALG_FLAG_SUPPORTED) == 0)
			continue;
		break;
	}
	if (hid < crypto_drivers_num) {
		krp->krp_hid = hid;
		error = crypto_drivers[hid].cc_kprocess(
				crypto_drivers[hid].cc_karg, krp, hint);
	} else {
		dprintk("%s,%d: ENODEV\n", __FILE__, __LINE__);
		error = ENODEV;
	}

	if (error) {
		krp->krp_status = error;
		crypto_kdone(krp);
	}
	return 0;
}


/*
 * Dispatch a crypto request to the appropriate crypto devices.
 */
static int
crypto_invoke(struct cryptop *crp, int hint)
{
	u_int32_t hid;
	int (*process)(void*, struct cryptop *, int);

	dprintk("%s()\n", __FUNCTION__);

	if (crypto_q_locked == 0)
		printk("crypto: crypto_invoke called without lock!\n");

	/* Sanity checks. */
	if (crp == NULL)
		return EINVAL;
	if (crp->crp_callback == NULL) {
		crypto_freereq(crp);
		return EINVAL;
	}
	if (crp->crp_desc == NULL) {
		crp->crp_etype = EINVAL;
		crypto_done(crp);
		return 0;
	}

	hid = CRYPTO_SESID2HID(crp->crp_sid);
	if (hid < crypto_drivers_num) {
		if (crypto_drivers[hid].cc_flags & CRYPTOCAP_F_CLEANUP)
			crypto_freesession(crp->crp_sid);
		process = crypto_drivers[hid].cc_process;
	} else {
		process = NULL;
	}

	if (process == NULL) {
		struct cryptodesc *crd;
		u_int64_t nid;

		/*
		 * Driver has unregistered; migrate the session and return
		 * an error to the caller so they'll resubmit the op.
		 */
		for (crd = crp->crp_desc; crd->crd_next; crd = crd->crd_next)
			crd->CRD_INI.cri_next = &(crd->crd_next->CRD_INI);

		if (crypto_newsession(&nid, &(crp->crp_desc->CRD_INI), 0) == 0)
			crp->crp_sid = nid;

		crp->crp_etype = EAGAIN;
		crypto_done(crp);
		return 0;
	} else {
		/*
		 * Invoke the driver to process the request.
		 */
		return (*process)(crypto_drivers[hid].cc_arg, crp, hint);
	}
}

/*
 * Release a set of crypto descriptors.
 */
void
crypto_freereq(struct cryptop *crp)
{
	struct cryptodesc *crd;

	if (crp == NULL)
		return;

	while ((crd = crp->crp_desc) != NULL) {
		crp->crp_desc = crd->crd_next;
		kmem_cache_free(cryptodesc_zone, crd);
	}

	kmem_cache_free(cryptop_zone, crp);
}

/*
 * Acquire a set of crypto descriptors.
 */
struct cryptop *
crypto_getreq(int num)
{
	struct cryptodesc *crd;
	struct cryptop *crp;

	crp = kmem_cache_alloc(cryptop_zone, SLAB_ATOMIC);
	if (crp != NULL) {
		memset(crp, 0, sizeof(*crp));
		INIT_LIST_HEAD(&crp->crp_list);
		init_waitqueue_head(&crp->crp_waitq);
		while (num--) {
			crd = kmem_cache_alloc(cryptodesc_zone, SLAB_ATOMIC);
			if (crd == NULL) {
				crypto_freereq(crp);
				return NULL;
			}
			memset(crd, 0, sizeof(*crd));
			crd->crd_next = crp->crp_desc;
			crp->crp_desc = crd;
		}
	}
	return crp;
}

/*
 * Invoke the callback on behalf of the driver.
 */
void
crypto_done(struct cryptop *crp)
{