/* $NetBSD: cgd.c,v 1.34.8.1 2006/03/08 01:44:48 elad Exp $ */ /*- * Copyright (c) 2002 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Roland C. Dowdeswell. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 __KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.34.8.1 2006/03/08 01:44:48 elad Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Entry Point Functions */ void cgdattach(int); static dev_type_open(cgdopen); static dev_type_close(cgdclose); static dev_type_read(cgdread); static dev_type_write(cgdwrite); static dev_type_ioctl(cgdioctl); static dev_type_strategy(cgdstrategy); static dev_type_dump(cgddump); static dev_type_size(cgdsize); const struct bdevsw cgd_bdevsw = { cgdopen, cgdclose, cgdstrategy, cgdioctl, cgddump, cgdsize, D_DISK }; const struct cdevsw cgd_cdevsw = { cgdopen, cgdclose, cgdread, cgdwrite, cgdioctl, nostop, notty, nopoll, nommap, nokqfilter, D_DISK }; /* Internal Functions */ static int cgdstart(struct dk_softc *, struct buf *); static void cgdiodone(struct buf *); static int cgd_ioctl_set(struct cgd_softc *, void *, struct lwp *); static int cgd_ioctl_clr(struct cgd_softc *, void *, struct lwp *); static int cgdinit(struct cgd_softc *, const char *, struct vnode *, struct lwp *); static void cgd_cipher(struct cgd_softc *, caddr_t, caddr_t, size_t, daddr_t, size_t, int); /* Pseudo-disk Interface */ static struct dk_intf the_dkintf = { DTYPE_CGD, "cgd", cgdopen, cgdclose, cgdstrategy, cgdstart, }; static struct dk_intf *di = &the_dkintf; static struct dkdriver cgddkdriver = { .d_strategy = cgdstrategy, .d_minphys = minphys, }; /* DIAGNOSTIC and DEBUG definitions */ #if defined(CGDDEBUG) && !defined(DEBUG) #define DEBUG #endif #ifdef DEBUG int cgddebug = 0; #define CGDB_FOLLOW 0x1 #define CGDB_IO 0x2 #define CGDB_CRYPTO 0x4 #define IFDEBUG(x,y) if (cgddebug & (x)) y #define DPRINTF(x,y) IFDEBUG(x, printf y) #define DPRINTF_FOLLOW(y) DPRINTF(CGDB_FOLLOW, y) static void hexprint(const char *, void *, int); #else #define IFDEBUG(x,y) #define DPRINTF(x,y) #define DPRINTF_FOLLOW(y) #endif #ifdef DIAGNOSTIC #define DIAGPANIC(x) panic x #define DIAGCONDPANIC(x,y) if (x) panic y #else #define DIAGPANIC(x) #define DIAGCONDPANIC(x,y) #endif /* Global variables */ struct cgd_softc *cgd_softc; int numcgd = 0; /* Utility Functions */ #define CGDUNIT(x) DISKUNIT(x) #define GETCGD_SOFTC(_cs, x) if (!((_cs) = getcgd_softc(x))) return ENXIO static struct cgd_softc * getcgd_softc(dev_t dev) { int unit = CGDUNIT(dev); DPRINTF_FOLLOW(("getcgd_softc(0x%x): unit = %d\n", dev, unit)); if (unit >= numcgd) return NULL; return &cgd_softc[unit]; } /* The code */ static void cgdsoftc_init(struct cgd_softc *cs, int num) { char sbuf[DK_XNAME_SIZE]; memset(cs, 0x0, sizeof(*cs)); snprintf(sbuf, DK_XNAME_SIZE, "cgd%d", num); simple_lock_init(&cs->sc_slock); dk_sc_init(&cs->sc_dksc, cs, sbuf); cs->sc_dksc.sc_dkdev.dk_driver = &cgddkdriver; pseudo_disk_init(&cs->sc_dksc.sc_dkdev); } void cgdattach(int num) { int i; DPRINTF_FOLLOW(("cgdattach(%d)\n", num)); if (num <= 0) { DIAGPANIC(("cgdattach: count <= 0")); return; } cgd_softc = (void *)malloc(num * sizeof(*cgd_softc), M_DEVBUF, M_NOWAIT); if (!cgd_softc) { printf("WARNING: unable to malloc(9) memory for crypt disks\n"); DIAGPANIC(("cgdattach: cannot malloc(9) enough memory")); return; } numcgd = num; for (i=0; isc_dksc, dev, flags, fmt, l); } static int cgdclose(dev_t dev, int flags, int fmt, struct lwp *l) { struct cgd_softc *cs; DPRINTF_FOLLOW(("cgdclose(%d, %d)\n", dev, flags)); GETCGD_SOFTC(cs, dev); return dk_close(di, &cs->sc_dksc, dev, flags, fmt, l); } static void cgdstrategy(struct buf *bp) { struct cgd_softc *cs = getcgd_softc(bp->b_dev); DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp, (long)bp->b_bcount)); /* XXXrcd: Should we test for (cs != NULL)? */ dk_strategy(di, &cs->sc_dksc, bp); return; } static int cgdsize(dev_t dev) { struct cgd_softc *cs = getcgd_softc(dev); DPRINTF_FOLLOW(("cgdsize(%d)\n", dev)); if (!cs) return -1; return dk_size(di, &cs->sc_dksc, dev); } /* * cgd_{get,put}data are functions that deal with getting a buffer * for the new encrypted data. We have a buffer per device so that * we can ensure that we can always have a transaction in flight. * We use this buffer first so that we have one less piece of * malloc'ed data at any given point. */ static void * cgd_getdata(struct dk_softc *dksc, unsigned long size) { struct cgd_softc *cs =dksc->sc_osc; caddr_t data = NULL; simple_lock(&cs->sc_slock); if (cs->sc_data_used == 0) { cs->sc_data_used = 1; data = cs->sc_data; } simple_unlock(&cs->sc_slock); if (data) return data; return malloc(size, M_DEVBUF, M_NOWAIT); } static void cgd_putdata(struct dk_softc *dksc, caddr_t data) { struct cgd_softc *cs =dksc->sc_osc; if (data == cs->sc_data) { simple_lock(&cs->sc_slock); cs->sc_data_used = 0; simple_unlock(&cs->sc_slock); } else { free(data, M_DEVBUF); } } static int cgdstart(struct dk_softc *dksc, struct buf *bp) { struct cgd_softc *cs = dksc->sc_osc; struct buf *nbp; caddr_t addr; caddr_t newaddr; daddr_t bn; DPRINTF_FOLLOW(("cgdstart(%p, %p)\n", dksc, bp)); disk_busy(&dksc->sc_dkdev); /* XXX: put in dksubr.c */ bn = bp->b_rawblkno; /* * We attempt to allocate all of our resources up front, so that * we can fail quickly if they are unavailable. */ nbp = getiobuf_nowait(); if (nbp == NULL) { disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ)); return -1; } /* * If we are writing, then we need to encrypt the outgoing * block into a new block of memory. If we fail, then we * return an error and let the dksubr framework deal with it. */ newaddr = addr = bp->b_data; if ((bp->b_flags & B_READ) == 0) { newaddr = cgd_getdata(dksc, bp->b_bcount); if (!newaddr) { putiobuf(nbp); disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ)); return -1; } cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn, DEV_BSIZE, CGD_CIPHER_ENCRYPT); } nbp->b_data = newaddr; nbp->b_flags = bp->b_flags | B_CALL; nbp->b_iodone = cgdiodone; nbp->b_proc = bp->b_proc; nbp->b_blkno = bn; nbp->b_vp = cs->sc_tvn; nbp->b_bcount = bp->b_bcount; nbp->b_private = bp; BIO_COPYPRIO(nbp, bp); if ((nbp->b_flags & B_READ) == 0) { V_INCR_NUMOUTPUT(nbp->b_vp); } VOP_STRATEGY(cs->sc_tvn, nbp); return 0; } /* expected to be called at splbio() */ static void cgdiodone(struct buf *nbp) { struct buf *obp = nbp->b_private; struct cgd_softc *cs = getcgd_softc(obp->b_dev); struct dk_softc *dksc = &cs->sc_dksc; KDASSERT(cs); DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp)); DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n", obp, obp->b_bcount, obp->b_resid)); DPRINTF(CGDB_IO, (" dev 0x%x, nbp %p bn %" PRId64 " addr %p bcnt %d\n", nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data, nbp->b_bcount)); if (nbp->b_flags & B_ERROR) { obp->b_flags |= B_ERROR; obp->b_error = nbp->b_error ? nbp->b_error : EIO; printf("%s: error %d\n", dksc->sc_xname, obp->b_error); } /* Perform the decryption if we are reading. * * Note: use the blocknumber from nbp, since it is what * we used to encrypt the blocks. */ if (nbp->b_flags & B_READ) cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount, nbp->b_blkno, DEV_BSIZE, CGD_CIPHER_DECRYPT); /* If we allocated memory, free it now... */ if (nbp->b_data != obp->b_data) cgd_putdata(dksc, nbp->b_data); putiobuf(nbp); /* Request is complete for whatever reason */ obp->b_resid = 0; if (obp->b_flags & B_ERROR) obp->b_resid = obp->b_bcount; disk_unbusy(&dksc->sc_dkdev, obp->b_bcount - obp->b_resid, (obp->b_flags & B_READ)); biodone(obp); dk_iodone(di, dksc); } /* XXX: we should probably put these into dksubr.c, mostly */ static int cgdread(dev_t dev, struct uio *uio, int flags) { struct cgd_softc *cs; struct dk_softc *dksc; DPRINTF_FOLLOW(("cgdread(%d, %p, %d)\n", dev, uio, flags)); GETCGD_SOFTC(cs, dev); dksc = &cs->sc_dksc; if ((dksc->sc_flags & DKF_INITED) == 0) return ENXIO; return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio); } /* XXX: we should probably put these into dksubr.c, mostly */ static int cgdwrite(dev_t dev, struct uio *uio, int flags) { struct cgd_softc *cs; struct dk_softc *dksc; DPRINTF_FOLLOW(("cgdwrite(%d, %p, %d)\n", dev, uio, flags)); GETCGD_SOFTC(cs, dev); dksc = &cs->sc_dksc; if ((dksc->sc_flags & DKF_INITED) == 0) return ENXIO; return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio); } static int cgdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l) { struct cgd_softc *cs; struct dk_softc *dksc; struct disk *dk; int ret; int part = DISKPART(dev); int pmask = 1 << part; DPRINTF_FOLLOW(("cgdioctl(%d, %ld, %p, %d, %p)\n", dev, cmd, data, flag, l)); GETCGD_SOFTC(cs, dev); dksc = &cs->sc_dksc; dk = &dksc->sc_dkdev; switch (cmd) { case CGDIOCSET: case CGDIOCCLR: if ((flag & FWRITE) == 0) return EBADF; } switch (cmd) { case CGDIOCSET: if (dksc->sc_flags & DKF_INITED) ret = EBUSY; else ret = cgd_ioctl_set(cs, data, l); break; case CGDIOCCLR: if (!(dksc->sc_flags & DKF_INITED)) { ret = ENXIO; break; } if (DK_BUSY(&cs->sc_dksc, pmask)) { ret = EBUSY; break; } ret = cgd_ioctl_clr(cs, data, l); break; default: ret = dk_ioctl(di, dksc, dev, cmd, data, flag, l); break; } return ret; } static int cgddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size) { struct cgd_softc *cs; DPRINTF_FOLLOW(("cgddump(%d, %" PRId64 ", %p, %lu)\n", dev, blkno, va, (unsigned long)size)); GETCGD_SOFTC(cs, dev); return dk_dump(di, &cs->sc_dksc, dev, blkno, va, size); } /* * XXXrcd: * for now we hardcode the maximum key length. */ #define MAX_KEYSIZE 1024 /* ARGSUSED */ static int cgd_ioctl_set(struct cgd_softc *cs, void *data, struct lwp *l) { struct cgd_ioctl *ci = data; struct vnode *vp; int ret; int keybytes; /* key length in bytes */ const char *cp; char inbuf[MAX_KEYSIZE]; cp = ci->ci_disk; if ((ret = dk_lookup(cp, l, &vp)) != 0) return ret; if ((ret = cgdinit(cs, cp, vp, l)) != 0) goto bail; memset(inbuf, 0x0, sizeof(inbuf)); ret = copyinstr(ci->ci_alg, inbuf, 256, NULL); if (ret) goto bail; cs->sc_cfuncs = cryptfuncs_find(inbuf); if (!cs->sc_cfuncs) { ret = EINVAL; goto bail; } /* right now we only support encblkno, so hard-code it */ memset(inbuf, 0x0, sizeof(inbuf)); ret = copyinstr(ci->ci_ivmethod, inbuf, sizeof(inbuf), NULL); if (ret) goto bail; if (strcmp("encblkno", inbuf)) { ret = EINVAL; goto bail; } keybytes = ci->ci_keylen / 8 + 1; if (keybytes > MAX_KEYSIZE) { ret = EINVAL; goto bail; } memset(inbuf, 0x0, sizeof(inbuf)); ret = copyin(ci->ci_key, inbuf, keybytes); if (ret) goto bail; cs->sc_cdata.cf_blocksize = ci->ci_blocksize; cs->sc_cdata.cf_mode = CGD_CIPHER_CBC_ENCBLKNO; cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf, &cs->sc_cdata.cf_blocksize); memset(inbuf, 0x0, sizeof(inbuf)); if (!cs->sc_cdata.cf_priv) { printf("cgd: unable to initialize cipher\n"); ret = EINVAL; /* XXX is this the right error? */ goto bail; } bufq_alloc(&cs->sc_dksc.sc_bufq, "fcfs", 0); cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK); cs->sc_data_used = 0; cs->sc_dksc.sc_flags |= DKF_INITED; /* Attach the disk. */ pseudo_disk_attach(&cs->sc_dksc.sc_dkdev); /* Try and read the disklabel. */ dk_getdisklabel(di, &cs->sc_dksc, 0 /* XXX ? */); /* Discover wedges on this disk. */ dkwedge_discover(&cs->sc_dksc.sc_dkdev); return 0; bail: (void)vn_close(vp, FREAD|FWRITE, l->l_proc->p_cred, l); return ret; } /* ARGSUSED */ static int cgd_ioctl_clr(struct cgd_softc *cs, void *data, struct lwp *l) { int s; /* Delete all of our wedges. */ dkwedge_delall(&cs->sc_dksc.sc_dkdev); /* Kill off any queued buffers. */ s = splbio(); bufq_drain(cs->sc_dksc.sc_bufq); splx(s); bufq_free(cs->sc_dksc.sc_bufq); (void)vn_close(cs->sc_tvn, FREAD|FWRITE, l->l_proc->p_cred, l); cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv); free(cs->sc_tpath, M_DEVBUF); free(cs->sc_data, M_DEVBUF); cs->sc_data_used = 0; cs->sc_dksc.sc_flags &= ~DKF_INITED; pseudo_disk_detach(&cs->sc_dksc.sc_dkdev); return 0; } static int cgdinit(struct cgd_softc *cs, const char *cpath, struct vnode *vp, struct lwp *l) { struct dk_geom *pdg; struct partinfo dpart; struct vattr va; size_t size; int maxsecsize = 0; int ret; char tmppath[MAXPATHLEN]; cs->sc_dksc.sc_size = 0; cs->sc_tvn = vp; memset(tmppath, 0x0, sizeof(tmppath)); ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen); if (ret) goto bail; cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK); memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen); if ((ret = VOP_GETATTR(vp, &va, l->l_proc->p_cred, l)) != 0) goto bail; cs->sc_tdev = va.va_rdev; ret = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, l->l_proc->p_cred, l); if (ret) goto bail; maxsecsize = ((dpart.disklab->d_secsize > maxsecsize) ? dpart.disklab->d_secsize : maxsecsize); size = dpart.part->p_size; if (!size) { ret = ENODEV; goto bail; } cs->sc_dksc.sc_size = size; /* * XXX here we should probe the underlying device. If we * are accessing a partition of type RAW_PART, then * we should populate our initial geometry with the * geometry that we discover from the device. */ pdg = &cs->sc_dksc.sc_geom; pdg->pdg_secsize = DEV_BSIZE; pdg->pdg_ntracks = 1; pdg->pdg_nsectors = 1024 * (1024 / pdg->pdg_secsize); pdg->pdg_ncylinders = cs->sc_dksc.sc_size / pdg->pdg_nsectors; bail: if (ret && cs->sc_tpath) free(cs->sc_tpath, M_DEVBUF); return ret; } /* * Our generic cipher entry point. This takes care of the * IV mode and passes off the work to the specific cipher. * We implement here the IV method ``encrypted block * number''. * * For the encryption case, we accomplish this by setting * up a struct uio where the first iovec of the source is * the blocknumber and the first iovec of the dest is a * sink. We then call the cipher with an IV of zero, and * the right thing happens. * * For the decryption case, we use the same basic mechanism * for symmetry, but we encrypt the block number in the * first iovec. * * We mainly do this to avoid requiring the definition of * an ECB mode. * * XXXrcd: for now we rely on our own crypto framework defined * in dev/cgd_crypto.c. This will change when we * get a generic kernel crypto framework. */ static void blkno2blkno_buf(char *sbuf, daddr_t blkno) { int i; /* Set up the blkno in blkno_buf, here we do not care much * about the final layout of the information as long as we * can guarantee that each sector will have a different IV * and that the endianness of the machine will not affect * the representation that we have chosen. * * We choose this representation, because it does not rely * on the size of buf (which is the blocksize of the cipher), * but allows daddr_t to grow without breaking existing * disks. * * Note that blkno2blkno_buf does not take a size as input, * and hence must be called on a pre-zeroed buffer of length * greater than or equal to sizeof(daddr_t). */ for (i=0; i < sizeof(daddr_t); i++) { *sbuf++ = blkno & 0xff; blkno >>= 8; } } static void cgd_cipher(struct cgd_softc *cs, caddr_t dst, caddr_t src, size_t len, daddr_t blkno, size_t secsize, int dir) { cfunc_cipher *cipher = cs->sc_cfuncs->cf_cipher; struct uio dstuio; struct uio srcuio; struct iovec dstiov[2]; struct iovec srciov[2]; int blocksize = cs->sc_cdata.cf_blocksize; char sink[blocksize]; char zero_iv[blocksize]; char blkno_buf[blocksize]; DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir)); DIAGCONDPANIC(len % blocksize != 0, ("cgd_cipher: len %% blocksize != 0")); /* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */ DIAGCONDPANIC(sizeof(daddr_t) > blocksize, ("cgd_cipher: sizeof(daddr_t) > blocksize")); memset(zero_iv, 0x0, sizeof(zero_iv)); dstuio.uio_iov = dstiov; dstuio.uio_iovcnt = 2; srcuio.uio_iov = srciov; srcuio.uio_iovcnt = 2; dstiov[0].iov_base = sink; dstiov[0].iov_len = blocksize; srciov[0].iov_base = blkno_buf; srciov[0].iov_len = blocksize; dstiov[1].iov_len = secsize; srciov[1].iov_len = secsize; for (; len > 0; len -= secsize) { dstiov[1].iov_base = dst; srciov[1].iov_base = src; memset(blkno_buf, 0x0, sizeof(blkno_buf)); blkno2blkno_buf(blkno_buf, blkno); if (dir == CGD_CIPHER_DECRYPT) { dstuio.uio_iovcnt = 1; srcuio.uio_iovcnt = 1; IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf", blkno_buf, sizeof(blkno_buf))); cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, CGD_CIPHER_ENCRYPT); memcpy(blkno_buf, sink, blocksize); dstuio.uio_iovcnt = 2; srcuio.uio_iovcnt = 2; } IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf", blkno_buf, sizeof(blkno_buf))); cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir); IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink", sink, sizeof(sink))); dst += secsize; src += secsize; blkno++; } } #ifdef DEBUG static void hexprint(const char *start, void *buf, int len) { char *c = buf; DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0")); printf("%s: len=%06d 0x", start, len); while (len--) printf("%02x", (unsigned) *c++); } #endif