crypto.c

linux下基于加密芯片的加密设备

/*
 * The linux port of this code done by David McCullough <[e-mail]>
 * The license and original author are listed below.
 * Copyright (C) 2004 David McCullough <[e-mail]>
 *
 * The author of this code is Angelos D. Keromytis ([e-mail])
 *
 * This code was written by Angelos D. Keromytis in Athens, Greece, in
 * February 2000. Network Security Technologies Inc. (NSTI) kindly
 * supported the development of this code.
 *
 * Copyright (c) 2000, 2001 Angelos D. Keromytis
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all source code copies of any software which is or includes a copy or
 * modification of this software.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <cryptodev.h>

/*
 * keep track of whether or not we have been initialised, a big
 * issue if we are linked into the kernel and a driver gets started before
 * us
 */
static int crypto_initted = 0;

/*
 * Crypto drivers register themselves by allocating a slot in the
 * crypto_drivers table with crypto_get_driverid() and then registering
 * each algorithm they support with crypto_register() and crypto_kregister().
 */

static spinlock_t crypto_drivers_lock;		/* lock on driver table */
#define	CRYPTO_DRIVER_LOCK() \
			({ \
				spin_lock_irqsave(&crypto_drivers_lock, d_flags); \
				dprintk("%s,%d: DRIVER_LOCK()\n", __FILE__, __LINE__); \
			 })
#define	CRYPTO_DRIVER_UNLOCK() \
			({ \
			 	dprintk("%s,%d: DRIVER_UNLOCK()\n", __FILE__, __LINE__); \
				spin_unlock_irqrestore(&crypto_drivers_lock, d_flags); \
			 })
static struct cryptocap *crypto_drivers = NULL;
static int crypto_drivers_num = 0;

/*
 * There are two queues for crypto requests; one for symmetric (e.g.
 * cipher) operations and one for asymmetric (e.g. MOD)operations.
 * A single mutex is used to lock access to both queues.  We could
 * have one per-queue but having one simplifies handling of block/unblock
 * operations.
 */
static LIST_HEAD(crp_q);		/* request queues */
static LIST_HEAD(crp_kq);

static int crypto_q_locked = 0;	/* on !SMP systems, spin locks do nothing :-( */
static spinlock_t crypto_q_lock;
#define	CRYPTO_Q_LOCK() \
			({ \
				spin_lock_irqsave(&crypto_q_lock, q_flags); \
			 	dprintk("%s,%d: Q_LOCK()\n", __FILE__, __LINE__); \
				crypto_q_locked++; \
			 })
#define	CRYPTO_Q_UNLOCK() \
			({ \
			 	dprintk("%s,%d: Q_UNLOCK()\n", __FILE__, __LINE__); \
				crypto_q_locked--; \
				spin_unlock_irqrestore(&crypto_q_lock, q_flags); \
			 })

/*
 * There are two queues for processing completed crypto requests; one
 * for the symmetric and one for the asymmetric ops.  We only need one
 * but have two to avoid type futzing (cryptop vs. cryptkop).  A single
 * mutex is used to lock access to both queues.  Note that this lock
 * must be separate from the lock on request queues to insure driver
 * callbacks don't generate lock order reversals.
 */
static LIST_HEAD(crp_ret_q);		/* callback queues */
static LIST_HEAD(crp_ret_kq);

static spinlock_t crypto_ret_q_lock;
#define	CRYPTO_RETQ_LOCK() \
			({ \
				spin_lock_irqsave(&crypto_ret_q_lock, r_flags); \
				dprintk("%s,%d: RETQ_LOCK\n", __FILE__, __LINE__); \
			 })
#define	CRYPTO_RETQ_UNLOCK() \
			({ \
			 	dprintk("%s,%d: RETQ_UNLOCK\n", __FILE__, __LINE__); \
				spin_unlock_irqrestore(&crypto_ret_q_lock, r_flags); \
			 })

static kmem_cache_t *cryptop_zone;
static kmem_cache_t *cryptodesc_zone;

static int debug = 0;
MODULE_PARM(debug, "i");
MODULE_PARM_DESC(debug,
	   "Enable debug");

static int crypto_verbose = 0;
MODULE_PARM(crypto_verbose, "i");
MODULE_PARM_DESC(crypto_verbose,
	   "Enable verbose crypto startup");

static int	crypto_userasymcrypto = 1;	/* userland may do asym crypto reqs */
MODULE_PARM(crypto_userasymcrypto, "i");
MODULE_PARM_DESC(crypto_userasymcrypto,
	   "Enable/disable user-mode access to asymmetric crypto support");

static int	crypto_devallowsoft = 0;	/* only use hardware crypto for asym */
MODULE_PARM(crypto_devallowsoft, "i");
MODULE_PARM_DESC(crypto_devallowsoft,
	   "Enable/disable use of software asym crypto support");

static pid_t	cryptoproc = (pid_t) -1;
static struct	completion cryptoproc_exited;
static DECLARE_WAIT_QUEUE_HEAD(cryptoproc_wait);
static pid_t	cryptoretproc = (pid_t) -1;
static struct	completion cryptoretproc_exited;
static DECLARE_WAIT_QUEUE_HEAD(cryptoretproc_wait);

static	int crypto_proc(void *arg);
static	int crypto_ret_proc(void *arg);
static	int crypto_invoke(struct cryptop *crp, int hint);
static	int crypto_kinvoke(struct cryptkop *krp, int hint);
static	void crypto_exit(void);
static  int crypto_init(void);

static	struct cryptostats cryptostats;


/*
 * Create a new session.
 */
int
crypto_newsession(u_int64_t *sid, struct cryptoini *cri, int hard)
{
	struct cryptoini *cr;
	u_int32_t hid, lid;
	int err = EINVAL, d_flags;

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

	if (crypto_drivers == NULL) {
		dprintk("%s,%d: %s - no drivers\n", __FILE__, __LINE__, __FUNCTION__);
		goto done;
	}

	/*
	 * The algorithm we use here is pretty stupid; just use the
	 * first driver that supports all the algorithms we need.
	 *
	 * XXX We need more smarts here (in real life too, but that's
	 * XXX another story altogether).
	 */

	for (hid = 0; hid < crypto_drivers_num; hid++) {
		struct cryptocap *cap = &crypto_drivers[hid];
		/*
		 * If it's not initialized or has remaining sessions
		 * referencing it, skip.
		 */
		if (cap->cc_newsession == NULL ||
				(cap->cc_flags & CRYPTOCAP_F_CLEANUP)) {
			dprintk("%s,%d: %s skip1\n", __FILE__, __LINE__, __FUNCTION__);
			continue;
		}

		/* Hardware required -- ignore software drivers. */
		if (hard > 0 && (cap->cc_flags & CRYPTOCAP_F_SOFTWARE)) {
			dprintk("%s,%d: %s skip not HW\n",__FILE__,__LINE__,__FUNCTION__);
			continue;
		}
		/* Software required -- ignore hardware drivers. */
		if (hard < 0 && (cap->cc_flags & CRYPTOCAP_F_SOFTWARE) == 0) {
			dprintk("%s,%d: %s skip not SW\n",__FILE__,__LINE__,__FUNCTION__);
			continue;
		}

		/* See if all the algorithms are supported. */
		for (cr = cri; cr; cr = cr->cri_next)
			if (cap->cc_alg[cr->cri_alg] == 0)
				break;

		if (cr == NULL) {
			/* Ok, all algorithms are supported. */

			/*
			 * Can't do everything in one session.
			 *
			 * XXX Fix this. We need to inject a "virtual" session layer right
			 * XXX about here.
			 */

			/* Call the driver initialization routine. */
			lid = hid;		/* Pass the driver ID. */
			err = (*cap->cc_newsession)(cap->cc_arg, &lid, cri);
			if (err == 0) {
				/* XXX assert (hid &~ 0xffffff) == 0 */
				/* XXX assert (cap->cc_flags &~ 0xff) == 0 */
				(*sid) = ((cap->cc_flags & 0xff) << 24) | hid;
				(*sid) <<= 32;
				(*sid) |= (lid & 0xffffffff);
				cap->cc_sessions++;
			} else
				dprintk("%s,%d: %s - newsession returned %d\n",
						__FILE__, __LINE__, __FUNCTION__, err);
			break;
		}
	}
done:
	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Delete an existing session (or a reserved session on an unregistered
 * driver).
 */
int
crypto_freesession(u_int64_t sid)
{
	u_int32_t hid;
	int err, d_flags;

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

	if (crypto_drivers == NULL) {
		err = EINVAL;
		goto done;
	}

	/* Determine two IDs. */
	hid = CRYPTO_SESID2HID(sid);

	if (hid >= crypto_drivers_num) {
		err = ENOENT;
		goto done;
	}

	if (crypto_drivers[hid].cc_sessions)
		crypto_drivers[hid].cc_sessions--;

	/* Call the driver cleanup routine, if available. */
	if (crypto_drivers[hid].cc_freesession)
		err = crypto_drivers[hid].cc_freesession(
				crypto_drivers[hid].cc_arg, sid);
	else
		err = 0;

	/*
	 * If this was the last session of a driver marked as invalid,
	 * make the entry available for reuse.
	 */
	if ((crypto_drivers[hid].cc_flags & CRYPTOCAP_F_CLEANUP) &&
	    crypto_drivers[hid].cc_sessions == 0)
		memset(&crypto_drivers[hid], 0, sizeof(struct cryptocap));

done:
	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Return an unused driver id.  Used by drivers prior to registering
 * support for the algorithms they handle.
 */
int32_t
crypto_get_driverid(u_int32_t flags)
{
	struct cryptocap *newdrv;
	int i, d_flags;

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

	if (!crypto_initted) {
		i = crypto_init();
		if (i) {
			printk("crypto: failed to init crypto!\n");
			return(-1);
		}
	}

	CRYPTO_DRIVER_LOCK();

	for (i = 0; i < crypto_drivers_num; i++)
		if (crypto_drivers[i].cc_process == NULL &&
		    (crypto_drivers[i].cc_flags & CRYPTOCAP_F_CLEANUP) == 0 &&
		    crypto_drivers[i].cc_sessions == 0)
			break;

	/* Out of entries, allocate some more. */
	if (i == crypto_drivers_num) {
		/* Be careful about wrap-around. */
		if (2 * crypto_drivers_num <= crypto_drivers_num) {
			CRYPTO_DRIVER_UNLOCK();
			printk("crypto: driver count wraparound!\n");
			return -1;
		}

		newdrv = kmalloc(2 * crypto_drivers_num * sizeof(struct cryptocap),
				GFP_KERNEL);
		if (newdrv == NULL) {
			CRYPTO_DRIVER_UNLOCK();
			printk("crypto: no space to expand driver table!\n");
			return -1;
		}

		memcpy(newdrv, crypto_drivers,
				crypto_drivers_num * sizeof(struct cryptocap));
		memset(&crypto_drivers[crypto_drivers_num], 0,
				2 * crypto_drivers_num * sizeof(struct cryptocap));

		crypto_drivers_num *= 2;

		kfree(crypto_drivers);
		crypto_drivers = newdrv;
	}

	/* NB: state is zero'd on free */
	crypto_drivers[i].cc_sessions = 1;	/* Mark */
	crypto_drivers[i].cc_flags = flags;
	if (crypto_verbose)
		printk("crypto: assign driver %u, flags %u\n", i, flags);

	CRYPTO_DRIVER_UNLOCK();

	return i;
}

static struct cryptocap *
crypto_checkdriver(u_int32_t hid)
{
	dprintk("%s()\n", __FUNCTION__);
	if (crypto_drivers == NULL) {
		dprintk("%s,%d: %s no drivers\n", __FILE__, __LINE__, __FUNCTION__);
		return NULL;
	}
	return (hid >= crypto_drivers_num ? NULL : &crypto_drivers[hid]);
}

/*
 * Register support for a key-related algorithm.  This routine
 * is called once for each algorithm supported a driver.
 */
int
crypto_kregister(u_int32_t driverid, int kalg, u_int32_t flags,
    int (*kprocess)(void*, struct cryptkop *, int),
    void *karg)
{
	struct cryptocap *cap;
	int err, d_flags;

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

	cap = crypto_checkdriver(driverid);
	if (cap != NULL &&
	    (CRK_ALGORITM_MIN <= kalg && kalg <= CRK_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_kalg[kalg] = flags | CRYPTO_ALG_FLAG_SUPPORTED;
		if (crypto_verbose)
			printk("crypto: driver %u registers key alg %u flags %u\n"
				, driverid
				, kalg
				, flags
			);

		if (cap->cc_kprocess == NULL) {
			cap->cc_karg = karg;
			cap->cc_kprocess = kprocess;
		}
		err = 0;
	} else
		err = EINVAL;

	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Register support for a non-key-related algorithm.  This routine
 * is called once for each such algorithm supported by a driver.
 */
int
crypto_register(u_int32_t driverid, int alg, u_int16_t maxoplen,
    u_int32_t flags,
    int (*newses)(void*, u_int32_t*, struct cryptoini*),
    int (*freeses)(void*, u_int64_t),
    int (*process)(void*, struct cryptop *, int),
    void *arg)
{
	struct cryptocap *cap;
	int err, d_flags;

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

	cap = crypto_checkdriver(driverid);
	/* NB: algorithms are in the range [1..max] */
	if (cap != NULL &&