safe.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]>
 *
 * Copyright (c) 2003 Sam Leffler, Errno Consulting
 * Copyright (c) 2003 Global Technology Associates, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#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/pci.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/random.h>
#include <asm/io.h>

/*
 * some support for older kernels
 */

#ifndef IRQ_NONE
#define IRQ_NONE
#define IRQ_HANDLED
#define irqreturn_t void
#endif

/*
 * SafeNet SafeXcel-1141 hardware crypto accelerator
 */

#include <cryptodev.h>
#include <uio.h>
#include <safe/safereg.h>
#include <safe/safevar.h>

#define bswap32(x)  /* seems the code using this below is buggy */

#define read_random(p,l) get_random_bytes(p,l)

#define KASSERT(c,p)	if (!c) { printk p ; } else

#if 1
#define	DPRINTF(a...)	if (debug) { printk("safe: " a); } else
#else
#define	DPRINTF(a...)
#endif

#define DELAY(x)	udelay(x)

#define bcopy(s,d,l)			memcpy(d,s,l)
#define bzero(p,l)				memset(p,0,l)

#define	READ_REG(sc,r)			readl((sc)->sc_base_addr + (r))
#define WRITE_REG(sc,r,val)		writel((val), (sc)->sc_base_addr + (r))

/* add proc entry for this */
struct safe_stats safestats;

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

#ifndef SAFE_NO_RNG
static	int safe_rnginterval = 1;		/* poll once a second */
MODULE_PARM(safe_rnginterval, "i");
MODULE_PARM_DESC(safe_rnginterval, "RNG polling interval (secs)");
static	int safe_rngbufsize = 16;		/* 64 bytes each poll  */
MODULE_PARM(safe_rngbufsize, "i");
MODULE_PARM_DESC(safe_rngbufsize, "RNG polling buffer size (32-bit words)");
static	int safe_rngmaxalarm = 8;		/* max alarms before reset */
MODULE_PARM(safe_rngmaxalarm, "i");
MODULE_PARM_DESC(safe_rngmaxalarm, "RNG max alarms before reset");
#endif /* SAFE_NO_RNG */


static void safe_callback(struct safe_softc *sc, struct safe_ringentry *re);
static void safe_totalreset(struct safe_softc *sc);
static int safe_dmamap_aligned(const struct safe_operand *op);
static int safe_dmamap_uniform(const struct safe_operand *op);
static int safe_free_entry(struct safe_softc *sc, struct safe_ringentry *re);

/*
 * map in a given buffer (great on some arches :-)
 */

static int
pci_map_uio(struct safe_softc *sc, struct safe_operand *buf, struct uio *uio)
{
	struct iovec *iov = uio->uio_iov;

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

	buf->mapsize = 0;
	for (buf->nsegs = 0; buf->nsegs < uio->uio_iovcnt; ) {
		buf->segs[buf->nsegs].ds_addr = pci_map_single(sc->sc_dev,
				iov->iov_base, iov->iov_len,
				PCI_DMA_BIDIRECTIONAL);
		buf->segs[buf->nsegs].ds_len = iov->iov_len;
		buf->mapsize += iov->iov_len;
		iov++;
		buf->nsegs++;
	}
	/* identify this buffer by the first segment */
	buf->map = (void *) buf->segs[0].ds_addr;
	return(0);
}

static void
pci_sync_iov(struct safe_softc *sc, struct safe_operand *buf)
{
	int i;

	DPRINTF("%s()\n", __FUNCTION__);
	for (i = 0; i < buf->nsegs; i++)
		pci_dma_sync_single(sc->sc_dev, buf->segs[i].ds_addr,
				buf->segs[i].ds_len, PCI_DMA_BIDIRECTIONAL);
}

static void
pci_unmap_iov(struct safe_softc *sc, struct safe_operand *buf)
{
	int i;
	DPRINTF("%s()\n", __FUNCTION__);
	for (i = 0; i < buf->nsegs; i++) {
		pci_unmap_single(sc->sc_dev, buf->segs[i].ds_addr,
				buf->segs[i].ds_len, PCI_DMA_BIDIRECTIONAL);
		buf->segs[i].ds_addr = 0;
		buf->segs[i].ds_len = 0;
	}
	buf->nsegs = 0;
	buf->mapsize = 0;
	buf->map = 0;
}


/*
 * SafeXcel Interrupt routine
 */
static irqreturn_t
safe_intr(int irq, void *arg, struct pt_regs *regs)
{
	struct safe_softc *sc = arg;
	int stat, flags;

	stat = READ_REG(sc, SAFE_HM_STAT);

	DPRINTF("%s(stat=0x%x)\n", __FUNCTION__, stat);

	if (stat == 0)		/* shared irq, not for us */
		return IRQ_NONE;

	WRITE_REG(sc, SAFE_HI_CLR, stat);	/* IACK */

	if ((stat & SAFE_INT_PE_DDONE)) {
		/*
		 * Descriptor(s) done; scan the ring and
		 * process completed operations.
		 */
		spin_lock_irqsave(&sc->sc_ringmtx, flags);
		while (sc->sc_back != sc->sc_front) {
			struct safe_ringentry *re = sc->sc_back;

#ifdef SAFE_DEBUG
			if (debug) {
				safe_dump_ringstate(sc, __func__);
				safe_dump_request(sc, __func__, re);
			}
#endif
			/*
			 * safe_process marks ring entries that were allocated
			 * but not used with a csr of zero.  This insures the
			 * ring front pointer never needs to be set backwards
			 * in the event that an entry is allocated but not used
			 * because of a setup error.
			 */
			DPRINTF("%s re->re_desc.d_csr=0x%x\n", __FUNCTION__, re->re_desc.d_csr);
			if (re->re_desc.d_csr != 0) {
				if (!SAFE_PE_CSR_IS_DONE(re->re_desc.d_csr)) {
					DPRINTF("%s !CSR_IS_DONE\n", __FUNCTION__);
					break;
				}
				if (!SAFE_PE_LEN_IS_DONE(re->re_desc.d_len)) {
					DPRINTF("%s !LEN_IS_DONE\n", __FUNCTION__);
					break;
				}
				sc->sc_nqchip--;
				safe_callback(sc, re);
			}
			if (++(sc->sc_back) == sc->sc_ringtop)
				sc->sc_back = sc->sc_ring;
		}
		spin_unlock_irqrestore(&sc->sc_ringmtx, flags);
	}

	/*
	 * Check to see if we got any DMA Error
	 */
	if (stat & SAFE_INT_PE_ERROR) {
		printk("safe: dmaerr dmastat %08x\n",
				(int)READ_REG(sc, SAFE_PE_DMASTAT));
		safestats.st_dmaerr++;
		safe_totalreset(sc);
#if 0
		safe_feed(sc);
#endif
	}

	if (sc->sc_needwakeup) {		/* XXX check high watermark */
		int wakeup = sc->sc_needwakeup & (CRYPTO_SYMQ|CRYPTO_ASYMQ);
		DPRINTF("%s: wakeup crypto %x\n", __func__,
			sc->sc_needwakeup);
		sc->sc_needwakeup &= ~wakeup;
		crypto_unblock(sc->sc_cid, wakeup);
	}
	
	return IRQ_HANDLED;
}

/*
 * safe_feed() - post a request to chip
 */
static void
safe_feed(struct safe_softc *sc, struct safe_ringentry *re)
{
	DPRINTF("%s()\n", __FUNCTION__);
#ifdef SAFE_DEBUG
	if (debug) {
		safe_dump_ringstate(sc, __func__);
		safe_dump_request(sc, __func__, re);
	}
#endif
	sc->sc_nqchip++;
	if (sc->sc_nqchip > safestats.st_maxqchip)
		safestats.st_maxqchip = sc->sc_nqchip;
	/* poke h/w to check descriptor ring, any value can be written */
	WRITE_REG(sc, SAFE_HI_RD_DESCR, 0);
}

/*
 * Allocate a new 'session' and return an encoded session id.  'sidp'
 * contains our registration id, and should contain an encoded session
 * id on successful allocation.
 */
static int
safe_newsession(void *arg, u_int32_t *sidp, struct cryptoini *cri)
{
#define	N(a)	(sizeof(a) / sizeof (a[0]))
	struct cryptoini *c, *encini = NULL, *macini = NULL;
	struct safe_softc *sc = arg;
	struct safe_session *ses = NULL;
#if NOTYET
	MD5_CTX md5ctx;
	SHA1_CTX sha1ctx;
#endif
	int i, sesn;

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

	if (sidp == NULL || cri == NULL || sc == NULL)
		return (EINVAL);

	for (c = cri; c != NULL; c = c->cri_next) {
		if (c->cri_alg == CRYPTO_MD5_HMAC ||
		    c->cri_alg == CRYPTO_SHA1_HMAC ||
		    c->cri_alg == CRYPTO_NULL_HMAC) {
			if (macini)
				return (EINVAL);
			macini = c;
		} else if (c->cri_alg == CRYPTO_DES_CBC ||
		    c->cri_alg == CRYPTO_3DES_CBC ||
		    c->cri_alg == CRYPTO_AES_CBC ||
		    c->cri_alg == CRYPTO_NULL_CBC) {
			if (encini)
				return (EINVAL);
			encini = c;
		} else
			return (EINVAL);
	}
	if (encini == NULL && macini == NULL)
		return (EINVAL);
	if (encini) {			/* validate key length */
		switch (encini->cri_alg) {
		case CRYPTO_DES_CBC:
			if (encini->cri_klen != 64)
				return (EINVAL);
			break;
		case CRYPTO_3DES_CBC:
			if (encini->cri_klen != 192)
				return (EINVAL);
			break;
		case CRYPTO_AES_CBC:
			if (encini->cri_klen != 128 &&
			    encini->cri_klen != 192 &&
			    encini->cri_klen != 256)
				return (EINVAL);
			break;
		}
	}

	if (sc->sc_sessions == NULL) {
		ses = sc->sc_sessions = (struct safe_session *)
			kmalloc(sizeof(struct safe_session), GFP_ATOMIC);
		if (ses == NULL)
			return (ENOMEM);
		memset(ses, 0, sizeof(struct safe_session));
		sesn = 0;
		sc->sc_nsessions = 1;
	} else {
		for (sesn = 0; sesn < sc->sc_nsessions; sesn++) {
			if (sc->sc_sessions[sesn].ses_used == 0) {
				ses = &sc->sc_sessions[sesn];
				break;
			}
		}

		if (ses == NULL) {
			sesn = sc->sc_nsessions;
			ses = (struct safe_session *)
				kmalloc((sesn + 1) * sizeof(struct safe_session), GFP_ATOMIC);
			if (ses == NULL)
				return (ENOMEM);
			memset(ses, 0, (sesn + 1) * sizeof(struct safe_session));
			bcopy(sc->sc_sessions, ses, sesn *
			    sizeof(struct safe_session));
			bzero(sc->sc_sessions, sesn *
			    sizeof(struct safe_session));
			kfree(sc->sc_sessions);
			sc->sc_sessions = ses;
			ses = &sc->sc_sessions[sesn];
			sc->sc_nsessions++;
		}
	}

	bzero(ses, sizeof(struct safe_session));
	ses->ses_used = 1;

	if (encini) {
		/* get an IV */
		/* XXX may read fewer than requested */
		read_random(ses->ses_iv, sizeof(ses->ses_iv));

		ses->ses_klen = encini->cri_klen;
		bcopy(encini->cri_key, ses->ses_key, ses->ses_klen / 8);
		/* PE is little-endian, insure proper byte order */
		for (i = 0; i < N(ses->ses_key); i++)
			ses->ses_key[i] = cpu_to_le32(ses->ses_key[i]);
	}

	if (macini) {
#if NOTYET
		for (i = 0; i < macini->cri_klen / 8; i++)
			macini->cri_key[i] ^= HMAC_IPAD_VAL;

		if (macini->cri_alg == CRYPTO_MD5_HMAC) {
			MD5Init(&md5ctx);
			MD5Update(&md5ctx, macini->cri_key,
			    macini->cri_klen / 8);
			MD5Update(&md5ctx, hmac_ipad_buffer,
			    HMAC_BLOCK_LEN - (macini->cri_klen / 8));
			bcopy(md5ctx.state, ses->ses_hminner,
			    sizeof(md5ctx.state));
		} else {
			SHA1Init(&sha1ctx);
			SHA1Update(&sha1ctx, macini->cri_key,
			    macini->cri_klen / 8);
			SHA1Update(&sha1ctx, hmac_ipad_buffer,
			    HMAC_BLOCK_LEN - (macini->cri_klen / 8));
			bcopy(sha1ctx.h.b32, ses->ses_hminner,
			    sizeof(sha1ctx.h.b32));
		}

		for (i = 0; i < macini->cri_klen / 8; i++)
			macini->cri_key[i] ^= (HMAC_IPAD_VAL ^ HMAC_OPAD_VAL);

		if (macini->cri_alg == CRYPTO_MD5_HMAC) {
			MD5Init(&md5ctx);
			MD5Update(&md5ctx, macini->cri_key,
			    macini->cri_klen / 8);
			MD5Update(&md5ctx, hmac_opad_buffer,
			    HMAC_BLOCK_LEN - (macini->cri_klen / 8));
			bcopy(md5ctx.state, ses->ses_hmouter,
			    sizeof(md5ctx.state));
		} else {
			SHA1Init(&sha1ctx);
			SHA1Update(&sha1ctx, macini->cri_key,
			    macini->cri_klen / 8);
			SHA1Update(&sha1ctx, hmac_opad_buffer,
			    HMAC_BLOCK_LEN - (macini->cri_klen / 8));
			bcopy(sha1ctx.h.b32, ses->ses_hmouter,
			    sizeof(sha1ctx.h.b32));
		}

		for (i = 0; i < macini->cri_klen / 8; i++)
			macini->cri_key[i] ^= HMAC_OPAD_VAL;

		/* PE is little-endian, insure proper byte order */
		for (i = 0; i < N(ses->ses_hminner); i++) {
			ses->ses_hminner[i] = cpu_to_le32(ses->ses_hminner[i]);
			ses->ses_hmouter[i] = cpu_to_le32(ses->ses_hmouter[i]);
		}
#else
		printk("safe: no MD5 or SHA yet\n");
#endif
	}

	*sidp = SAFE_SID(sc->sc_num, sesn);
	return (0);
#undef N
}

/*
 * Deallocate a session.
 */
static int
safe_freesession(void *arg, u_int64_t tid)
{
	struct safe_softc *sc = arg;
	int session, ret;
	u_int32_t sid = ((u_int32_t) tid) & 0xffffffff;

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

	if (sc == NULL)
		return (EINVAL);

	session = SAFE_SESSION(sid);
	if (session < sc->sc_nsessions) {
		bzero(&sc->sc_sessions[session], sizeof(sc->sc_sessions[session]));
		ret = 0;