/* $NetBSD: cgd.c,v 1.12 2003/06/29 22:29:58 fvdl 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 1.12 2003/06/29 22:29:58 fvdl Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Entry Point Functions */ void cgdattach(int); dev_type_open(cgdopen); dev_type_close(cgdclose); dev_type_read(cgdread); dev_type_write(cgdwrite); dev_type_ioctl(cgdioctl); dev_type_strategy(cgdstrategy); dev_type_dump(cgddump); 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 void cgdstart(struct dk_softc *, struct buf *); static void cgdiodone(struct buf *); static int cgd_ioctl_set(struct cgd_softc *, void *, struct proc *); static int cgd_ioctl_clr(struct cgd_softc *, void *, struct proc *); static int cgdinit(struct cgd_softc *, char *, struct vnode *, struct proc *); 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; /* 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(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 /* Component Buffer Pool structures and macros */ struct cgdbuf { struct buf cb_buf; /* new I/O buf */ struct buf *cb_obp; /* ptr. to original I/O buf */ struct cgd_softc *cb_sc; /* pointer to cgd softc */ }; struct pool cgd_cbufpool; #define CGD_GETBUF() pool_get(&cgd_cbufpool, PR_NOWAIT) #define CGD_PUTBUF(cbp) pool_put(&cgd_cbufpool, cbp) /* 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 buf[DK_XNAME_SIZE]; memset(cs, 0x0, sizeof(*cs)); snprintf(buf, DK_XNAME_SIZE, "cgd%d", num); dk_sc_init(&cs->sc_dksc, cs, buf); } 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, p); } int cgdclose(dev_t dev, int flags, int fmt, struct proc *p) { 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, p); } 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; } 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); } static void cgdstart(struct dk_softc *dksc, struct buf *bp) { struct cgd_softc *cs = dksc->sc_osc; struct cgdbuf *cbp; struct partition *pp; 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 */ /* XXXrcd: * Translate partition relative blocks to absolute blocks, * this probably belongs (somehow) in dksubr.c, since it * is independant of the underlying code... This will require * that the interface be expanded slightly, though. */ bn = bp->b_blkno; if (DISKPART(bp->b_dev) != RAW_PART) { pp = &cs->sc_dksc.sc_dkdev.dk_label->d_partitions[DISKPART(bp->b_dev)]; bn += pp->p_offset; } /* * If we are writing, then we need to encrypt the outgoing * block. In the best case scenario, we are able to allocate * enough memory to encrypt the data in a new block, otherwise * we encrypt it in place (noting we'll have to decrypt it after * the write.) */ newaddr = addr = bp->b_data; if ((bp->b_flags & B_READ) == 0) { newaddr = malloc(bp->b_bcount, M_DEVBUF, 0); if (!newaddr) newaddr = addr; cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn, DEV_BSIZE, CGD_CIPHER_ENCRYPT); } cbp = CGD_GETBUF(); if (cbp == NULL) { bp->b_error = ENOMEM; bp->b_flags |= B_ERROR; if (newaddr != addr) free(newaddr, M_DEVBUF); biodone(bp); disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ)); return; } BUF_INIT(&cbp->cb_buf); cbp->cb_buf.b_data = newaddr; cbp->cb_buf.b_flags = bp->b_flags | B_CALL; cbp->cb_buf.b_iodone = cgdiodone; cbp->cb_buf.b_proc = bp->b_proc; cbp->cb_buf.b_dev = cs->sc_tdev; cbp->cb_buf.b_blkno = bn; cbp->cb_buf.b_vp = cs->sc_tvn; cbp->cb_buf.b_bcount = bp->b_bcount; /* context for cgdiodone */ cbp->cb_obp = bp; cbp->cb_sc = cs; if ((cbp->cb_buf.b_flags & B_READ) == 0) cbp->cb_buf.b_vp->v_numoutput++; VOP_STRATEGY(&cbp->cb_buf); } void cgdiodone(struct buf *vbp) { struct cgdbuf *cbp = (struct cgdbuf *)vbp; struct buf *obp = cbp->cb_obp; struct buf *nbp = &cbp->cb_buf; struct cgd_softc *cs = cbp->cb_sc; struct dk_softc *dksc = &cs->sc_dksc; int s; DPRINTF_FOLLOW(("cgdiodone(%p)\n", vbp)); DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %ld resid %ld\n", obp, obp->b_bcount, obp->b_resid)); DPRINTF(CGDB_IO, (" dev 0x%x, cbp %p bn %" PRId64 " addr %p bcnt %ld\n", cbp->cb_buf.b_dev, cbp, cbp->cb_buf.b_blkno, cbp->cb_buf.b_data, cbp->cb_buf.b_bcount)); s = splbio(); 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 need to: * o if we are reading, or * o we wrote and couldn't allocate memory. * * Note: use the blocknumber from nbp, since it is what * we used to encrypt the blocks. */ if (nbp->b_flags & B_READ || nbp->b_data == obp->b_data) cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount, nbp->b_blkno, DEV_BSIZE, CGD_CIPHER_DECRYPT); /* If we managed to allocate memory, free it now... */ if (nbp->b_data != obp->b_data) free(nbp->b_data, M_DEVBUF); CGD_PUTBUF(cbp); /* 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); splx(s); } /* XXX: we should probably put these into dksubr.c, mostly */ 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; /* XXX see the comments about minphys in ccd.c */ return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio); } /* XXX: we should probably put these into dksubr.c, mostly */ 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; /* XXX see the comments about minphys in ccd.c */ return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio); } int cgdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p) { struct cgd_softc *cs; struct dk_softc *dksc; int ret; int part = DISKPART(dev); int pmask = 1 << part; DPRINTF_FOLLOW(("cgdioctl(%d, %ld, %p, %d, %p)\n", dev, cmd, data, flag, p)); GETCGD_SOFTC(cs, dev); dksc = &cs->sc_dksc; switch (cmd) { case CGDIOCSET: case CGDIOCCLR: if ((flag & FWRITE) == 0) return EBADF; } if ((ret = lockmgr(&dksc->sc_lock, LK_EXCLUSIVE, NULL)) != 0) return ret; switch (cmd) { case CGDIOCSET: if (dksc->sc_flags & DKF_INITED) ret = EBUSY; else ret = cgd_ioctl_set(cs, data, p); 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, p); break; default: ret = dk_ioctl(di, dksc, dev, cmd, data, flag, p); break; } lockmgr(&dksc->sc_lock, LK_RELEASE, NULL); return ret; } 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 proc *p) { struct cgd_ioctl *ci = data; struct vnode *vp; int ret; char *cp; char inbuf[MAX_KEYSIZE]; cp = ci->ci_disk; if ((ret = dk_lookup(cp, p, &vp)) != 0) return ret; if ((ret = cgdinit(cs, cp, vp, p)) != 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; } if (ci->ci_keylen > MAX_KEYSIZE) { ret = EINVAL; goto bail; } memset(inbuf, 0x0, sizeof(inbuf)); ret = copyin(ci->ci_key, inbuf, ci->ci_keylen); 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; } cs->sc_dksc.sc_flags |= DKF_INITED; /* Attach the disk. */ disk_attach(&cs->sc_dksc.sc_dkdev); /* Try and read the disklabel. */ dk_getdisklabel(di, &cs->sc_dksc, 0 /* XXX ? */); return 0; bail: (void)vn_close(vp, FREAD|FWRITE, p->p_ucred, p); return ret; } /* ARGSUSED */ static int cgd_ioctl_clr(struct cgd_softc *cs, void *data, struct proc *p) { (void)vn_close(cs->sc_tvn, FREAD|FWRITE, p->p_ucred, p); cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv); free(cs->sc_tpath, M_DEVBUF); cs->sc_dksc.sc_flags &= ~DKF_INITED; disk_detach(&cs->sc_dksc.sc_dkdev); return 0; } static int cgdinit(struct cgd_softc *cs, char *cpath, struct vnode *vp, struct proc *p) { 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, p->p_ucred, p)) != 0) goto bail; cs->sc_tdev = va.va_rdev; ret = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, p->p_ucred, p); 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 *buf, 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++) { *buf++ = 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(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