1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
  23  *
  24  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
  25  * Copyright (c) 2016 Andrey Sokolov
  26  */
  27 
  28 /*
  29  * lofi (loopback file) driver - allows you to attach a file to a device,
  30  * which can then be accessed through that device. The simple model is that
  31  * you tell lofi to open a file, and then use the block device you get as
  32  * you would any block device. lofi translates access to the block device
  33  * into I/O on the underlying file. This is mostly useful for
  34  * mounting images of filesystems.
  35  *
  36  * lofi is controlled through /dev/lofictl - this is the only device exported
  37  * during attach, and is minor number 0. lofiadm communicates with lofi through
  38  * ioctls on this device. When a file is attached to lofi, block and character
  39  * devices are exported in /dev/lofi and /dev/rlofi. Currently, these devices
  40  * are identified by their minor number, and the minor number is also used
  41  * as the name in /dev/lofi. If we ever decide to support virtual disks,
  42  * we'll have to divide the minor number space to identify fdisk partitions
  43  * and slices, and the name will then be the minor number shifted down a
  44  * few bits. Minor devices are tracked with state structures handled with
  45  * ddi_soft_state(9F) for simplicity.
  46  *
  47  * A file attached to lofi is opened when attached and not closed until
  48  * explicitly detached from lofi. This seems more sensible than deferring
  49  * the open until the /dev/lofi device is opened, for a number of reasons.
  50  * One is that any failure is likely to be noticed by the person (or script)
  51  * running lofiadm. Another is that it would be a security problem if the
  52  * file was replaced by another one after being added but before being opened.
  53  *
  54  * The only hard part about lofi is the ioctls. In order to support things
  55  * like 'newfs' on a lofi device, it needs to support certain disk ioctls.
  56  * So it has to fake disk geometry and partition information. More may need
  57  * to be faked if your favorite utility doesn't work and you think it should
  58  * (fdformat doesn't work because it really wants to know the type of floppy
  59  * controller to talk to, and that didn't seem easy to fake. Or possibly even
  60  * necessary, since we have mkfs_pcfs now).
  61  *
  62  * Normally, a lofi device cannot be detached if it is open (i.e. busy).  To
  63  * support simulation of hotplug events, an optional force flag is provided.
  64  * If a lofi device is open when a force detach is requested, then the
  65  * underlying file is closed and any subsequent operations return EIO.  When the
  66  * device is closed for the last time, it will be cleaned up at that time.  In
  67  * addition, the DKIOCSTATE ioctl will return DKIO_DEV_GONE when the device is
  68  * detached but not removed.
  69  *
  70  * Known problems:
  71  *
  72  *      UFS logging. Mounting a UFS filesystem image "logging"
  73  *      works for basic copy testing but wedges during a build of ON through
  74  *      that image. Some deadlock in lufs holding the log mutex and then
  75  *      getting stuck on a buf. So for now, don't do that.
  76  *
  77  *      Direct I/O. Since the filesystem data is being cached in the buffer
  78  *      cache, _and_ again in the underlying filesystem, it's tempting to
  79  *      enable direct I/O on the underlying file. Don't, because that deadlocks.
  80  *      I think to fix the cache-twice problem we might need filesystem support.
  81  *
  82  * Interesting things to do:
  83  *
  84  *      Allow multiple files for each device. A poor-man's metadisk, basically.
  85  *
  86  *      Pass-through ioctls on block devices. You can (though it's not
  87  *      documented), give lofi a block device as a file name. Then we shouldn't
  88  *      need to fake a geometry, however, it may be relevant if you're replacing
  89  *      metadisk, or using lofi to get crypto.
  90  *      It makes sense to do lofiadm -c aes -a /dev/dsk/c0t0d0s4 /dev/lofi/1
  91  *      and then in /etc/vfstab have an entry for /dev/lofi/1 as /export/home.
  92  *      In fact this even makes sense if you have lofi "above" metadisk.
  93  *
  94  * Encryption:
  95  *      Each lofi device can have its own symmetric key and cipher.
  96  *      They are passed to us by lofiadm(1m) in the correct format for use
  97  *      with the misc/kcf crypto_* routines.
  98  *
  99  *      Each block has its own IV, that is calculated in lofi_blk_mech(), based
 100  *      on the "master" key held in the lsp and the block number of the buffer.
 101  */
 102 
 103 #include <sys/types.h>
 104 #include <netinet/in.h>
 105 #include <sys/sysmacros.h>
 106 #include <sys/uio.h>
 107 #include <sys/kmem.h>
 108 #include <sys/cred.h>
 109 #include <sys/mman.h>
 110 #include <sys/errno.h>
 111 #include <sys/aio_req.h>
 112 #include <sys/stat.h>
 113 #include <sys/file.h>
 114 #include <sys/modctl.h>
 115 #include <sys/conf.h>
 116 #include <sys/debug.h>
 117 #include <sys/vnode.h>
 118 #include <sys/lofi.h>
 119 #include <sys/fcntl.h>
 120 #include <sys/pathname.h>
 121 #include <sys/filio.h>
 122 #include <sys/fdio.h>
 123 #include <sys/open.h>
 124 #include <sys/disp.h>
 125 #include <vm/seg_map.h>
 126 #include <sys/ddi.h>
 127 #include <sys/sunddi.h>
 128 #include <sys/zmod.h>
 129 #include <sys/id_space.h>
 130 #include <sys/mkdev.h>
 131 #include <sys/crypto/common.h>
 132 #include <sys/crypto/api.h>
 133 #include <sys/rctl.h>
 134 #include <LzmaDec.h>
 135 
 136 #define NBLOCKS_PROP_NAME       "Nblocks"
 137 #define SIZE_PROP_NAME          "Size"
 138 #define ZONE_PROP_NAME          "zone"
 139 
 140 #define SETUP_C_DATA(cd, buf, len)              \
 141         (cd).cd_format = CRYPTO_DATA_RAW;       \
 142         (cd).cd_offset = 0;                     \
 143         (cd).cd_miscdata = NULL;                \
 144         (cd).cd_length = (len);                 \
 145         (cd).cd_raw.iov_base = (buf);           \
 146         (cd).cd_raw.iov_len = (len);
 147 
 148 #define UIO_CHECK(uio)  \
 149         if (((uio)->uio_loffset % DEV_BSIZE) != 0 || \
 150             ((uio)->uio_resid % DEV_BSIZE) != 0) { \
 151                 return (EINVAL); \
 152         }
 153 
 154 static dev_info_t *lofi_dip = NULL;
 155 static void *lofi_statep = NULL;
 156 static kmutex_t lofi_lock;              /* state lock */
 157 static id_space_t *lofi_minor_id;
 158 static list_t lofi_list;
 159 static zone_key_t lofi_zone_key;
 160 
 161 /*
 162  * Because lofi_taskq_nthreads limits the actual swamping of the device, the
 163  * maxalloc parameter (lofi_taskq_maxalloc) should be tuned conservatively
 164  * high.  If we want to be assured that the underlying device is always busy,
 165  * we must be sure that the number of bytes enqueued when the number of
 166  * enqueued tasks exceeds maxalloc is sufficient to keep the device busy for
 167  * the duration of the sleep time in taskq_ent_alloc().  That is, lofi should
 168  * set maxalloc to be the maximum throughput (in bytes per second) of the
 169  * underlying device divided by the minimum I/O size.  We assume a realistic
 170  * maximum throughput of one hundred megabytes per second; we set maxalloc on
 171  * the lofi task queue to be 104857600 divided by DEV_BSIZE.
 172  */
 173 static int lofi_taskq_maxalloc = 104857600 / DEV_BSIZE;
 174 static int lofi_taskq_nthreads = 4;     /* # of taskq threads per device */
 175 
 176 const char lofi_crypto_magic[6] = LOFI_CRYPTO_MAGIC;
 177 
 178 /*
 179  * To avoid decompressing data in a compressed segment multiple times
 180  * when accessing small parts of a segment's data, we cache and reuse
 181  * the uncompressed segment's data.
 182  *
 183  * A single cached segment is sufficient to avoid lots of duplicate
 184  * segment decompress operations. A small cache size also reduces the
 185  * memory footprint.
 186  *
 187  * lofi_max_comp_cache is the maximum number of decompressed data segments
 188  * cached for each compressed lofi image. It can be set to 0 to disable
 189  * caching.
 190  */
 191 
 192 uint32_t lofi_max_comp_cache = 1;
 193 
 194 static int gzip_decompress(void *src, size_t srclen, void *dst,
 195         size_t *destlen, int level);
 196 
 197 static int lzma_decompress(void *src, size_t srclen, void *dst,
 198         size_t *dstlen, int level);
 199 
 200 lofi_compress_info_t lofi_compress_table[LOFI_COMPRESS_FUNCTIONS] = {
 201         {gzip_decompress,       NULL,   6,      "gzip"}, /* default */
 202         {gzip_decompress,       NULL,   6,      "gzip-6"},
 203         {gzip_decompress,       NULL,   9,      "gzip-9"},
 204         {lzma_decompress,       NULL,   0,      "lzma"}
 205 };
 206 
 207 /*ARGSUSED*/
 208 static void
 209 *SzAlloc(void *p, size_t size)
 210 {
 211         return (kmem_alloc(size, KM_SLEEP));
 212 }
 213 
 214 /*ARGSUSED*/
 215 static void
 216 SzFree(void *p, void *address, size_t size)
 217 {
 218         kmem_free(address, size);
 219 }
 220 
 221 static ISzAlloc g_Alloc = { SzAlloc, SzFree };
 222 
 223 /*
 224  * Free data referenced by the linked list of cached uncompressed
 225  * segments.
 226  */
 227 static void
 228 lofi_free_comp_cache(struct lofi_state *lsp)
 229 {
 230         struct lofi_comp_cache *lc;
 231 
 232         while ((lc = list_remove_head(&lsp->ls_comp_cache)) != NULL) {
 233                 kmem_free(lc->lc_data, lsp->ls_uncomp_seg_sz);
 234                 kmem_free(lc, sizeof (struct lofi_comp_cache));
 235                 lsp->ls_comp_cache_count--;
 236         }
 237         ASSERT(lsp->ls_comp_cache_count == 0);
 238 }
 239 
 240 static int
 241 is_opened(struct lofi_state *lsp)
 242 {
 243         ASSERT(MUTEX_HELD(&lofi_lock));
 244         return (lsp->ls_chr_open || lsp->ls_blk_open || lsp->ls_lyr_open_count);
 245 }
 246 
 247 static int
 248 mark_opened(struct lofi_state *lsp, int otyp)
 249 {
 250         ASSERT(MUTEX_HELD(&lofi_lock));
 251         switch (otyp) {
 252         case OTYP_CHR:
 253                 lsp->ls_chr_open = 1;
 254                 break;
 255         case OTYP_BLK:
 256                 lsp->ls_blk_open = 1;
 257                 break;
 258         case OTYP_LYR:
 259                 lsp->ls_lyr_open_count++;
 260                 break;
 261         default:
 262                 return (-1);
 263         }
 264         return (0);
 265 }
 266 
 267 static void
 268 mark_closed(struct lofi_state *lsp, int otyp)
 269 {
 270         ASSERT(MUTEX_HELD(&lofi_lock));
 271         switch (otyp) {
 272         case OTYP_CHR:
 273                 lsp->ls_chr_open = 0;
 274                 break;
 275         case OTYP_BLK:
 276                 lsp->ls_blk_open = 0;
 277                 break;
 278         case OTYP_LYR:
 279                 lsp->ls_lyr_open_count--;
 280                 break;
 281         default:
 282                 break;
 283         }
 284 }
 285 
 286 static void
 287 lofi_free_crypto(struct lofi_state *lsp)
 288 {
 289         ASSERT(MUTEX_HELD(&lofi_lock));
 290 
 291         if (lsp->ls_crypto_enabled) {
 292                 /*
 293                  * Clean up the crypto state so that it doesn't hang around
 294                  * in memory after we are done with it.
 295                  */
 296                 if (lsp->ls_key.ck_data != NULL) {
 297                         bzero(lsp->ls_key.ck_data,
 298                             CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
 299                         kmem_free(lsp->ls_key.ck_data,
 300                             CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
 301                         lsp->ls_key.ck_data = NULL;
 302                         lsp->ls_key.ck_length = 0;
 303                 }
 304 
 305                 if (lsp->ls_mech.cm_param != NULL) {
 306                         kmem_free(lsp->ls_mech.cm_param,
 307                             lsp->ls_mech.cm_param_len);
 308                         lsp->ls_mech.cm_param = NULL;
 309                         lsp->ls_mech.cm_param_len = 0;
 310                 }
 311 
 312                 if (lsp->ls_iv_mech.cm_param != NULL) {
 313                         kmem_free(lsp->ls_iv_mech.cm_param,
 314                             lsp->ls_iv_mech.cm_param_len);
 315                         lsp->ls_iv_mech.cm_param = NULL;
 316                         lsp->ls_iv_mech.cm_param_len = 0;
 317                 }
 318 
 319                 mutex_destroy(&lsp->ls_crypto_lock);
 320         }
 321 }
 322 
 323 static void
 324 lofi_destroy(struct lofi_state *lsp, cred_t *credp)
 325 {
 326         minor_t minor = getminor(lsp->ls_dev);
 327         int i;
 328 
 329         ASSERT(MUTEX_HELD(&lofi_lock));
 330 
 331         list_remove(&lofi_list, lsp);
 332 
 333         lofi_free_crypto(lsp);
 334 
 335         /*
 336          * Free pre-allocated compressed buffers
 337          */
 338         if (lsp->ls_comp_bufs != NULL) {
 339                 for (i = 0; i < lofi_taskq_nthreads; i++) {
 340                         if (lsp->ls_comp_bufs[i].bufsize > 0)
 341                                 kmem_free(lsp->ls_comp_bufs[i].buf,
 342                                     lsp->ls_comp_bufs[i].bufsize);
 343                 }
 344                 kmem_free(lsp->ls_comp_bufs,
 345                     sizeof (struct compbuf) * lofi_taskq_nthreads);
 346         }
 347 
 348         (void) VOP_CLOSE(lsp->ls_vp, lsp->ls_openflag,
 349             1, 0, credp, NULL);
 350         VN_RELE(lsp->ls_vp);
 351         if (lsp->ls_stacked_vp != lsp->ls_vp)
 352                 VN_RELE(lsp->ls_stacked_vp);
 353 
 354         taskq_destroy(lsp->ls_taskq);
 355 
 356         if (lsp->ls_kstat != NULL)
 357                 kstat_delete(lsp->ls_kstat);
 358 
 359         /*
 360          * Free cached decompressed segment data
 361          */
 362         lofi_free_comp_cache(lsp);
 363         list_destroy(&lsp->ls_comp_cache);
 364 
 365         if (lsp->ls_uncomp_seg_sz > 0) {
 366                 kmem_free(lsp->ls_comp_index_data, lsp->ls_comp_index_data_sz);
 367                 lsp->ls_uncomp_seg_sz = 0;
 368         }
 369 
 370         rctl_decr_lofi(lsp->ls_zone.zref_zone, 1);
 371         zone_rele_ref(&lsp->ls_zone, ZONE_REF_LOFI);
 372 
 373         mutex_destroy(&lsp->ls_comp_cache_lock);
 374         mutex_destroy(&lsp->ls_comp_bufs_lock);
 375         mutex_destroy(&lsp->ls_kstat_lock);
 376         mutex_destroy(&lsp->ls_vp_lock);
 377 
 378         ASSERT(ddi_get_soft_state(lofi_statep, minor) == lsp);
 379         ddi_soft_state_free(lofi_statep, minor);
 380         id_free(lofi_minor_id, minor);
 381 }
 382 
 383 static void
 384 lofi_free_dev(dev_t dev)
 385 {
 386         minor_t minor = getminor(dev);
 387         char namebuf[50];
 388 
 389         ASSERT(MUTEX_HELD(&lofi_lock));
 390 
 391         (void) ddi_prop_remove(dev, lofi_dip, ZONE_PROP_NAME);
 392         (void) ddi_prop_remove(dev, lofi_dip, SIZE_PROP_NAME);
 393         (void) ddi_prop_remove(dev, lofi_dip, NBLOCKS_PROP_NAME);
 394 
 395         (void) snprintf(namebuf, sizeof (namebuf), "%d", minor);
 396         ddi_remove_minor_node(lofi_dip, namebuf);
 397         (void) snprintf(namebuf, sizeof (namebuf), "%d,raw", minor);
 398         ddi_remove_minor_node(lofi_dip, namebuf);
 399 }
 400 
 401 /*ARGSUSED*/
 402 static void
 403 lofi_zone_shutdown(zoneid_t zoneid, void *arg)
 404 {
 405         struct lofi_state *lsp;
 406         struct lofi_state *next;
 407 
 408         mutex_enter(&lofi_lock);
 409 
 410         for (lsp = list_head(&lofi_list); lsp != NULL; lsp = next) {
 411 
 412                 /* lofi_destroy() frees lsp */
 413                 next = list_next(&lofi_list, lsp);
 414 
 415                 if (lsp->ls_zone.zref_zone->zone_id != zoneid)
 416                         continue;
 417 
 418                 /*
 419                  * No in-zone processes are running, but something has this
 420                  * open.  It's either a global zone process, or a lofi
 421                  * mount.  In either case we set ls_cleanup so the last
 422                  * user destroys the device.
 423                  */
 424                 if (is_opened(lsp)) {
 425                         lsp->ls_cleanup = 1;
 426                 } else {
 427                         lofi_free_dev(lsp->ls_dev);
 428                         lofi_destroy(lsp, kcred);
 429                 }
 430         }
 431 
 432         mutex_exit(&lofi_lock);
 433 }
 434 
 435 /*ARGSUSED*/
 436 static int
 437 lofi_open(dev_t *devp, int flag, int otyp, struct cred *credp)
 438 {
 439         minor_t minor;
 440         struct lofi_state *lsp;
 441 
 442         /*
 443          * lofiadm -a /dev/lofi/1 gets us here.
 444          */
 445         if (mutex_owner(&lofi_lock) == curthread)
 446                 return (EINVAL);
 447 
 448         mutex_enter(&lofi_lock);
 449 
 450         minor = getminor(*devp);
 451 
 452         /* master control device */
 453         if (minor == 0) {
 454                 mutex_exit(&lofi_lock);
 455                 return (0);
 456         }
 457 
 458         /* otherwise, the mapping should already exist */
 459         lsp = ddi_get_soft_state(lofi_statep, minor);
 460         if (lsp == NULL) {
 461                 mutex_exit(&lofi_lock);
 462                 return (EINVAL);
 463         }
 464 
 465         if (lsp->ls_vp == NULL) {
 466                 mutex_exit(&lofi_lock);
 467                 return (ENXIO);
 468         }
 469 
 470         if (lsp->ls_readonly && (flag & FWRITE)) {
 471                 mutex_exit(&lofi_lock);
 472                 return (EROFS);
 473         }
 474 
 475         if (mark_opened(lsp, otyp) == -1) {
 476                 mutex_exit(&lofi_lock);
 477                 return (EINVAL);
 478         }
 479 
 480         mutex_exit(&lofi_lock);
 481         return (0);
 482 }
 483 
 484 /*ARGSUSED*/
 485 static int
 486 lofi_close(dev_t dev, int flag, int otyp, struct cred *credp)
 487 {
 488         minor_t minor;
 489         struct lofi_state *lsp;
 490 
 491         mutex_enter(&lofi_lock);
 492         minor = getminor(dev);
 493         lsp = ddi_get_soft_state(lofi_statep, minor);
 494         if (lsp == NULL) {
 495                 mutex_exit(&lofi_lock);
 496                 return (EINVAL);
 497         }
 498 
 499         if (minor == 0) {
 500                 mutex_exit(&lofi_lock);
 501                 return (0);
 502         }
 503 
 504         mark_closed(lsp, otyp);
 505 
 506         /*
 507          * If we forcibly closed the underlying device (li_force), or
 508          * asked for cleanup (li_cleanup), finish up if we're the last
 509          * out of the door.
 510          */
 511         if (!is_opened(lsp) && (lsp->ls_cleanup || lsp->ls_vp == NULL)) {
 512                 lofi_free_dev(lsp->ls_dev);
 513                 lofi_destroy(lsp, credp);
 514         }
 515 
 516         mutex_exit(&lofi_lock);
 517         return (0);
 518 }
 519 
 520 /*
 521  * Sets the mechanism's initialization vector (IV) if one is needed.
 522  * The IV is computed from the data block number.  lsp->ls_mech is
 523  * altered so that:
 524  *      lsp->ls_mech.cm_param_len is set to the IV len.
 525  *      lsp->ls_mech.cm_param is set to the IV.
 526  */
 527 static int
 528 lofi_blk_mech(struct lofi_state *lsp, longlong_t lblkno)
 529 {
 530         int     ret;
 531         crypto_data_t cdata;
 532         char    *iv;
 533         size_t  iv_len;
 534         size_t  min;
 535         void    *data;
 536         size_t  datasz;
 537 
 538         ASSERT(MUTEX_HELD(&lsp->ls_crypto_lock));
 539 
 540         if (lsp == NULL)
 541                 return (CRYPTO_DEVICE_ERROR);
 542 
 543         /* lsp->ls_mech.cm_param{_len} has already been set for static iv */
 544         if (lsp->ls_iv_type == IVM_NONE) {
 545                 return (CRYPTO_SUCCESS);
 546         }
 547 
 548         /*
 549          * if kmem already alloced from previous call and it's the same size
 550          * we need now, just recycle it; allocate new kmem only if we have to
 551          */
 552         if (lsp->ls_mech.cm_param == NULL ||
 553             lsp->ls_mech.cm_param_len != lsp->ls_iv_len) {
 554                 iv_len = lsp->ls_iv_len;
 555                 iv = kmem_zalloc(iv_len, KM_SLEEP);
 556         } else {
 557                 iv_len = lsp->ls_mech.cm_param_len;
 558                 iv = lsp->ls_mech.cm_param;
 559                 bzero(iv, iv_len);
 560         }
 561 
 562         switch (lsp->ls_iv_type) {
 563         case IVM_ENC_BLKNO:
 564                 /* iv is not static, lblkno changes each time */
 565                 data = &lblkno;
 566                 datasz = sizeof (lblkno);
 567                 break;
 568         default:
 569                 data = 0;
 570                 datasz = 0;
 571                 break;
 572         }
 573 
 574         /*
 575          * write blkno into the iv buffer padded on the left in case
 576          * blkno ever grows bigger than its current longlong_t size
 577          * or a variation other than blkno is used for the iv data
 578          */
 579         min = MIN(datasz, iv_len);
 580         bcopy(data, iv + (iv_len - min), min);
 581 
 582         /* encrypt the data in-place to get the IV */
 583         SETUP_C_DATA(cdata, iv, iv_len);
 584 
 585         ret = crypto_encrypt(&lsp->ls_iv_mech, &cdata, &lsp->ls_key,
 586             NULL, NULL, NULL);
 587         if (ret != CRYPTO_SUCCESS) {
 588                 cmn_err(CE_WARN, "failed to create iv for block %lld: (0x%x)",
 589                     lblkno, ret);
 590                 if (lsp->ls_mech.cm_param != iv)
 591                         kmem_free(iv, iv_len);
 592 
 593                 return (ret);
 594         }
 595 
 596         /* clean up the iv from the last computation */
 597         if (lsp->ls_mech.cm_param != NULL && lsp->ls_mech.cm_param != iv)
 598                 kmem_free(lsp->ls_mech.cm_param, lsp->ls_mech.cm_param_len);
 599 
 600         lsp->ls_mech.cm_param_len = iv_len;
 601         lsp->ls_mech.cm_param = iv;
 602 
 603         return (CRYPTO_SUCCESS);
 604 }
 605 
 606 /*
 607  * Performs encryption and decryption of a chunk of data of size "len",
 608  * one DEV_BSIZE block at a time.  "len" is assumed to be a multiple of
 609  * DEV_BSIZE.
 610  */
 611 static int
 612 lofi_crypto(struct lofi_state *lsp, struct buf *bp, caddr_t plaintext,
 613     caddr_t ciphertext, size_t len, boolean_t op_encrypt)
 614 {
 615         crypto_data_t cdata;
 616         crypto_data_t wdata;
 617         int ret;
 618         longlong_t lblkno = bp->b_lblkno;
 619 
 620         mutex_enter(&lsp->ls_crypto_lock);
 621 
 622         /*
 623          * though we could encrypt/decrypt entire "len" chunk of data, we need
 624          * to break it into DEV_BSIZE pieces to capture blkno incrementing
 625          */
 626         SETUP_C_DATA(cdata, plaintext, len);
 627         cdata.cd_length = DEV_BSIZE;
 628         if (ciphertext != NULL) {               /* not in-place crypto */
 629                 SETUP_C_DATA(wdata, ciphertext, len);
 630                 wdata.cd_length = DEV_BSIZE;
 631         }
 632 
 633         do {
 634                 ret = lofi_blk_mech(lsp, lblkno);
 635                 if (ret != CRYPTO_SUCCESS)
 636                         continue;
 637 
 638                 if (op_encrypt) {
 639                         ret = crypto_encrypt(&lsp->ls_mech, &cdata,
 640                             &lsp->ls_key, NULL,
 641                             ((ciphertext != NULL) ? &wdata : NULL), NULL);
 642                 } else {
 643                         ret = crypto_decrypt(&lsp->ls_mech, &cdata,
 644                             &lsp->ls_key, NULL,
 645                             ((ciphertext != NULL) ? &wdata : NULL), NULL);
 646                 }
 647 
 648                 cdata.cd_offset += DEV_BSIZE;
 649                 if (ciphertext != NULL)
 650                         wdata.cd_offset += DEV_BSIZE;
 651                 lblkno++;
 652         } while (ret == CRYPTO_SUCCESS && cdata.cd_offset < len);
 653 
 654         mutex_exit(&lsp->ls_crypto_lock);
 655 
 656         if (ret != CRYPTO_SUCCESS) {
 657                 cmn_err(CE_WARN, "%s failed for block %lld:  (0x%x)",
 658                     op_encrypt ? "crypto_encrypt()" : "crypto_decrypt()",
 659                     lblkno, ret);
 660         }
 661 
 662         return (ret);
 663 }
 664 
 665 #define RDWR_RAW        1
 666 #define RDWR_BCOPY      2
 667 
 668 static int
 669 lofi_rdwr(caddr_t bufaddr, offset_t offset, struct buf *bp,
 670     struct lofi_state *lsp, size_t len, int method, caddr_t bcopy_locn)
 671 {
 672         ssize_t resid;
 673         int isread;
 674         int error;
 675 
 676         /*
 677          * Handles reads/writes for both plain and encrypted lofi
 678          * Note:  offset is already shifted by lsp->ls_crypto_offset
 679          * when it gets here.
 680          */
 681 
 682         isread = bp->b_flags & B_READ;
 683         if (isread) {
 684                 if (method == RDWR_BCOPY) {
 685                         /* DO NOT update bp->b_resid for bcopy */
 686                         bcopy(bcopy_locn, bufaddr, len);
 687                         error = 0;
 688                 } else {                /* RDWR_RAW */
 689                         error = vn_rdwr(UIO_READ, lsp->ls_vp, bufaddr, len,
 690                             offset, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred,
 691                             &resid);
 692                         bp->b_resid = resid;
 693                 }
 694                 if (lsp->ls_crypto_enabled && error == 0) {
 695                         if (lofi_crypto(lsp, bp, bufaddr, NULL, len,
 696                             B_FALSE) != CRYPTO_SUCCESS) {
 697                                 /*
 698                                  * XXX: original code didn't set residual
 699                                  * back to len because no error was expected
 700                                  * from bcopy() if encryption is not enabled
 701                                  */
 702                                 if (method != RDWR_BCOPY)
 703                                         bp->b_resid = len;
 704                                 error = EIO;
 705                         }
 706                 }
 707                 return (error);
 708         } else {
 709                 void *iobuf = bufaddr;
 710 
 711                 if (lsp->ls_crypto_enabled) {
 712                         /* don't do in-place crypto to keep bufaddr intact */
 713                         iobuf = kmem_alloc(len, KM_SLEEP);
 714                         if (lofi_crypto(lsp, bp, bufaddr, iobuf, len,
 715                             B_TRUE) != CRYPTO_SUCCESS) {
 716                                 kmem_free(iobuf, len);
 717                                 if (method != RDWR_BCOPY)
 718                                         bp->b_resid = len;
 719                                 return (EIO);
 720                         }
 721                 }
 722                 if (method == RDWR_BCOPY) {
 723                         /* DO NOT update bp->b_resid for bcopy */
 724                         bcopy(iobuf, bcopy_locn, len);
 725                         error = 0;
 726                 } else {                /* RDWR_RAW */
 727                         error = vn_rdwr(UIO_WRITE, lsp->ls_vp, iobuf, len,
 728                             offset, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred,
 729                             &resid);
 730                         bp->b_resid = resid;
 731                 }
 732                 if (lsp->ls_crypto_enabled) {
 733                         kmem_free(iobuf, len);
 734                 }
 735                 return (error);
 736         }
 737 }
 738 
 739 static int
 740 lofi_mapped_rdwr(caddr_t bufaddr, offset_t offset, struct buf *bp,
 741     struct lofi_state *lsp)
 742 {
 743         int error;
 744         offset_t alignedoffset, mapoffset;
 745         size_t  xfersize;
 746         int     isread;
 747         int     smflags;
 748         caddr_t mapaddr;
 749         size_t  len;
 750         enum seg_rw srw;
 751         int     save_error;
 752 
 753         /*
 754          * Note:  offset is already shifted by lsp->ls_crypto_offset
 755          * when it gets here.
 756          */
 757         if (lsp->ls_crypto_enabled)
 758                 ASSERT(lsp->ls_vp_comp_size == lsp->ls_vp_size);
 759 
 760         /*
 761          * segmap always gives us an 8K (MAXBSIZE) chunk, aligned on
 762          * an 8K boundary, but the buf transfer address may not be
 763          * aligned on more than a 512-byte boundary (we don't enforce
 764          * that even though we could). This matters since the initial
 765          * part of the transfer may not start at offset 0 within the
 766          * segmap'd chunk. So we have to compensate for that with
 767          * 'mapoffset'. Subsequent chunks always start off at the
 768          * beginning, and the last is capped by b_resid
 769          *
 770          * Visually, where "|" represents page map boundaries:
 771          *   alignedoffset (mapaddr begins at this segmap boundary)
 772          *    |   offset (from beginning of file)
 773          *    |    |       len
 774          *    v    v        v
 775          * ===|====X========|====...======|========X====|====
 776          *         /-------------...---------------/
 777          *              ^ bp->b_bcount/bp->b_resid at start
 778          *    /----/--------/----...------/--------/
 779          *      ^       ^       ^   ^           ^
 780          *      |       |       |   |           nth xfersize (<= MAXBSIZE)
 781          *      |       |       2nd thru n-1st xfersize (= MAXBSIZE)
 782          *      |       1st xfersize (<= MAXBSIZE)
 783          *    mapoffset (offset into 1st segmap, non-0 1st time, 0 thereafter)
 784          *
 785          * Notes: "alignedoffset" is "offset" rounded down to nearest
 786          * MAXBSIZE boundary.  "len" is next page boundary of size
 787          * PAGESIZE after "alignedoffset".
 788          */
 789         mapoffset = offset & MAXBOFFSET;
 790         alignedoffset = offset - mapoffset;
 791         bp->b_resid = bp->b_bcount;
 792         isread = bp->b_flags & B_READ;
 793         srw = isread ? S_READ : S_WRITE;
 794         do {
 795                 xfersize = MIN(lsp->ls_vp_comp_size - offset,
 796                     MIN(MAXBSIZE - mapoffset, bp->b_resid));
 797                 len = roundup(mapoffset + xfersize, PAGESIZE);
 798                 mapaddr = segmap_getmapflt(segkmap, lsp->ls_vp,
 799                     alignedoffset, MAXBSIZE, 1, srw);
 800                 /*
 801                  * Now fault in the pages. This lets us check
 802                  * for errors before we reference mapaddr and
 803                  * try to resolve the fault in bcopy (which would
 804                  * panic instead). And this can easily happen,
 805                  * particularly if you've lofi'd a file over NFS
 806                  * and someone deletes the file on the server.
 807                  */
 808                 error = segmap_fault(kas.a_hat, segkmap, mapaddr,
 809                     len, F_SOFTLOCK, srw);
 810                 if (error) {
 811                         (void) segmap_release(segkmap, mapaddr, 0);
 812                         if (FC_CODE(error) == FC_OBJERR)
 813                                 error = FC_ERRNO(error);
 814                         else
 815                                 error = EIO;
 816                         break;
 817                 }
 818                 /* error may be non-zero for encrypted lofi */
 819                 error = lofi_rdwr(bufaddr, 0, bp, lsp, xfersize,
 820                     RDWR_BCOPY, mapaddr + mapoffset);
 821                 if (error == 0) {
 822                         bp->b_resid -= xfersize;
 823                         bufaddr += xfersize;
 824                         offset += xfersize;
 825                 }
 826                 smflags = 0;
 827                 if (isread) {
 828                         smflags |= SM_FREE;
 829                         /*
 830                          * If we're reading an entire page starting
 831                          * at a page boundary, there's a good chance
 832                          * we won't need it again. Put it on the
 833                          * head of the freelist.
 834                          */
 835                         if (mapoffset == 0 && xfersize == MAXBSIZE)
 836                                 smflags |= SM_DONTNEED;
 837                 } else {
 838                         /*
 839                          * Write back good pages, it is okay to
 840                          * always release asynchronous here as we'll
 841                          * follow with VOP_FSYNC for B_SYNC buffers.
 842                          */
 843                         if (error == 0)
 844                                 smflags |= SM_WRITE | SM_ASYNC;
 845                 }
 846                 (void) segmap_fault(kas.a_hat, segkmap, mapaddr,
 847                     len, F_SOFTUNLOCK, srw);
 848                 save_error = segmap_release(segkmap, mapaddr, smflags);
 849                 if (error == 0)
 850                         error = save_error;
 851                 /* only the first map may start partial */
 852                 mapoffset = 0;
 853                 alignedoffset += MAXBSIZE;
 854         } while ((error == 0) && (bp->b_resid > 0) &&
 855             (offset < lsp->ls_vp_comp_size));
 856 
 857         return (error);
 858 }
 859 
 860 /*
 861  * Check if segment seg_index is present in the decompressed segment
 862  * data cache.
 863  *
 864  * Returns a pointer to the decompressed segment data cache entry if
 865  * found, and NULL when decompressed data for this segment is not yet
 866  * cached.
 867  */
 868 static struct lofi_comp_cache *
 869 lofi_find_comp_data(struct lofi_state *lsp, uint64_t seg_index)
 870 {
 871         struct lofi_comp_cache *lc;
 872 
 873         ASSERT(MUTEX_HELD(&lsp->ls_comp_cache_lock));
 874 
 875         for (lc = list_head(&lsp->ls_comp_cache); lc != NULL;
 876             lc = list_next(&lsp->ls_comp_cache, lc)) {
 877                 if (lc->lc_index == seg_index) {
 878                         /*
 879                          * Decompressed segment data was found in the
 880                          * cache.
 881                          *
 882                          * The cache uses an LRU replacement strategy;
 883                          * move the entry to head of list.
 884                          */
 885                         list_remove(&lsp->ls_comp_cache, lc);
 886                         list_insert_head(&lsp->ls_comp_cache, lc);
 887                         return (lc);
 888                 }
 889         }
 890         return (NULL);
 891 }
 892 
 893 /*
 894  * Add the data for a decompressed segment at segment index
 895  * seg_index to the cache of the decompressed segments.
 896  *
 897  * Returns a pointer to the cache element structure in case
 898  * the data was added to the cache; returns NULL when the data
 899  * wasn't cached.
 900  */
 901 static struct lofi_comp_cache *
 902 lofi_add_comp_data(struct lofi_state *lsp, uint64_t seg_index,
 903     uchar_t *data)
 904 {
 905         struct lofi_comp_cache *lc;
 906 
 907         ASSERT(MUTEX_HELD(&lsp->ls_comp_cache_lock));
 908 
 909         while (lsp->ls_comp_cache_count > lofi_max_comp_cache) {
 910                 lc = list_remove_tail(&lsp->ls_comp_cache);
 911                 ASSERT(lc != NULL);
 912                 kmem_free(lc->lc_data, lsp->ls_uncomp_seg_sz);
 913                 kmem_free(lc, sizeof (struct lofi_comp_cache));
 914                 lsp->ls_comp_cache_count--;
 915         }
 916 
 917         /*
 918          * Do not cache when disabled by tunable variable
 919          */
 920         if (lofi_max_comp_cache == 0)
 921                 return (NULL);
 922 
 923         /*
 924          * When the cache has not yet reached the maximum allowed
 925          * number of segments, allocate a new cache element.
 926          * Otherwise the cache is full; reuse the last list element
 927          * (LRU) for caching the decompressed segment data.
 928          *
 929          * The cache element for the new decompressed segment data is
 930          * added to the head of the list.
 931          */
 932         if (lsp->ls_comp_cache_count < lofi_max_comp_cache) {
 933                 lc = kmem_alloc(sizeof (struct lofi_comp_cache), KM_SLEEP);
 934                 lc->lc_data = NULL;
 935                 list_insert_head(&lsp->ls_comp_cache, lc);
 936                 lsp->ls_comp_cache_count++;
 937         } else {
 938                 lc = list_remove_tail(&lsp->ls_comp_cache);
 939                 if (lc == NULL)
 940                         return (NULL);
 941                 list_insert_head(&lsp->ls_comp_cache, lc);
 942         }
 943 
 944         /*
 945          * Free old uncompressed segment data when reusing a cache
 946          * entry.
 947          */
 948         if (lc->lc_data != NULL)
 949                 kmem_free(lc->lc_data, lsp->ls_uncomp_seg_sz);
 950 
 951         lc->lc_data = data;
 952         lc->lc_index = seg_index;
 953         return (lc);
 954 }
 955 
 956 
 957 /*ARGSUSED*/
 958 static int
 959 gzip_decompress(void *src, size_t srclen, void *dst,
 960     size_t *dstlen, int level)
 961 {
 962         ASSERT(*dstlen >= srclen);
 963 
 964         if (z_uncompress(dst, dstlen, src, srclen) != Z_OK)
 965                 return (-1);
 966         return (0);
 967 }
 968 
 969 #define LZMA_HEADER_SIZE        (LZMA_PROPS_SIZE + 8)
 970 /*ARGSUSED*/
 971 static int
 972 lzma_decompress(void *src, size_t srclen, void *dst,
 973         size_t *dstlen, int level)
 974 {
 975         size_t insizepure;
 976         void *actual_src;
 977         ELzmaStatus status;
 978 
 979         insizepure = srclen - LZMA_HEADER_SIZE;
 980         actual_src = (void *)((Byte *)src + LZMA_HEADER_SIZE);
 981 
 982         if (LzmaDecode((Byte *)dst, (size_t *)dstlen,
 983             (const Byte *)actual_src, &insizepure,
 984             (const Byte *)src, LZMA_PROPS_SIZE, LZMA_FINISH_ANY, &status,
 985             &g_Alloc) != SZ_OK) {
 986                 return (-1);
 987         }
 988         return (0);
 989 }
 990 
 991 /*
 992  * This is basically what strategy used to be before we found we
 993  * needed task queues.
 994  */
 995 static void
 996 lofi_strategy_task(void *arg)
 997 {
 998         struct buf *bp = (struct buf *)arg;
 999         int error;
1000         int syncflag = 0;
1001         struct lofi_state *lsp;
1002         offset_t offset;
1003         caddr_t bufaddr;
1004         size_t  len;
1005         size_t  xfersize;
1006         boolean_t bufinited = B_FALSE;
1007 
1008         lsp = ddi_get_soft_state(lofi_statep, getminor(bp->b_edev));
1009         if (lsp == NULL) {
1010                 error = ENXIO;
1011                 goto errout;
1012         }
1013         if (lsp->ls_kstat) {
1014                 mutex_enter(lsp->ls_kstat->ks_lock);
1015                 kstat_waitq_to_runq(KSTAT_IO_PTR(lsp->ls_kstat));
1016                 mutex_exit(lsp->ls_kstat->ks_lock);
1017         }
1018         bp_mapin(bp);
1019         bufaddr = bp->b_un.b_addr;
1020         offset = bp->b_lblkno * DEV_BSIZE;   /* offset within file */
1021         if (lsp->ls_crypto_enabled) {
1022                 /* encrypted data really begins after crypto header */
1023                 offset += lsp->ls_crypto_offset;
1024         }
1025         len = bp->b_bcount;
1026         bufinited = B_TRUE;
1027 
1028         if (lsp->ls_vp == NULL || lsp->ls_vp_closereq) {
1029                 error = EIO;
1030                 goto errout;
1031         }
1032 
1033         /*
1034          * If we're writing and the buffer was not B_ASYNC
1035          * we'll follow up with a VOP_FSYNC() to force any
1036          * asynchronous I/O to stable storage.
1037          */
1038         if (!(bp->b_flags & B_READ) && !(bp->b_flags & B_ASYNC))
1039                 syncflag = FSYNC;
1040 
1041         /*
1042          * We used to always use vn_rdwr here, but we cannot do that because
1043          * we might decide to read or write from the the underlying
1044          * file during this call, which would be a deadlock because
1045          * we have the rw_lock. So instead we page, unless it's not
1046          * mapable or it's a character device or it's an encrypted lofi.
1047          */
1048         if ((lsp->ls_vp->v_flag & VNOMAP) || (lsp->ls_vp->v_type == VCHR) ||
1049             lsp->ls_crypto_enabled) {
1050                 error = lofi_rdwr(bufaddr, offset, bp, lsp, len, RDWR_RAW,
1051                     NULL);
1052         } else if (lsp->ls_uncomp_seg_sz == 0) {
1053                 error = lofi_mapped_rdwr(bufaddr, offset, bp, lsp);
1054         } else {
1055                 uchar_t *compressed_seg = NULL, *cmpbuf;
1056                 uchar_t *uncompressed_seg = NULL;
1057                 lofi_compress_info_t *li;
1058                 size_t oblkcount;
1059                 ulong_t seglen;
1060                 uint64_t sblkno, eblkno, cmpbytes;
1061                 uint64_t uncompressed_seg_index;
1062                 struct lofi_comp_cache *lc;
1063                 offset_t sblkoff, eblkoff;
1064                 u_offset_t salign, ealign;
1065                 u_offset_t sdiff;
1066                 uint32_t comp_data_sz;
1067                 uint64_t i;
1068                 int j;
1069 
1070                 /*
1071                  * From here on we're dealing primarily with compressed files
1072                  */
1073                 ASSERT(!lsp->ls_crypto_enabled);
1074 
1075                 /*
1076                  * Compressed files can only be read from and
1077                  * not written to
1078                  */
1079                 if (!(bp->b_flags & B_READ)) {
1080                         bp->b_resid = bp->b_bcount;
1081                         error = EROFS;
1082                         goto done;
1083                 }
1084 
1085                 ASSERT(lsp->ls_comp_algorithm_index >= 0);
1086                 li = &lofi_compress_table[lsp->ls_comp_algorithm_index];
1087                 /*
1088                  * Compute starting and ending compressed segment numbers
1089                  * We use only bitwise operations avoiding division and
1090                  * modulus because we enforce the compression segment size
1091                  * to a power of 2
1092                  */
1093                 sblkno = offset >> lsp->ls_comp_seg_shift;
1094                 sblkoff = offset & (lsp->ls_uncomp_seg_sz - 1);
1095                 eblkno = (offset + bp->b_bcount) >> lsp->ls_comp_seg_shift;
1096                 eblkoff = (offset + bp->b_bcount) & (lsp->ls_uncomp_seg_sz - 1);
1097 
1098                 /*
1099                  * Check the decompressed segment cache.
1100                  *
1101                  * The cache is used only when the requested data
1102                  * is within a segment. Requests that cross
1103                  * segment boundaries bypass the cache.
1104                  */
1105                 if (sblkno == eblkno ||
1106                     (sblkno + 1 == eblkno && eblkoff == 0)) {
1107                         /*
1108                          * Request doesn't cross a segment boundary,
1109                          * now check the cache.
1110                          */
1111                         mutex_enter(&lsp->ls_comp_cache_lock);
1112                         lc = lofi_find_comp_data(lsp, sblkno);
1113                         if (lc != NULL) {
1114                                 /*
1115                                  * We've found the decompressed segment
1116                                  * data in the cache; reuse it.
1117                                  */
1118                                 bcopy(lc->lc_data + sblkoff, bufaddr,
1119                                     bp->b_bcount);
1120                                 mutex_exit(&lsp->ls_comp_cache_lock);
1121                                 bp->b_resid = 0;
1122                                 error = 0;
1123                                 goto done;
1124                         }
1125                         mutex_exit(&lsp->ls_comp_cache_lock);
1126                 }
1127 
1128                 /*
1129                  * Align start offset to block boundary for segmap
1130                  */
1131                 salign = lsp->ls_comp_seg_index[sblkno];
1132                 sdiff = salign & (DEV_BSIZE - 1);
1133                 salign -= sdiff;
1134                 if (eblkno >= (lsp->ls_comp_index_sz - 1)) {
1135                         /*
1136                          * We're dealing with the last segment of
1137                          * the compressed file -- the size of this
1138                          * segment *may not* be the same as the
1139                          * segment size for the file
1140                          */
1141                         eblkoff = (offset + bp->b_bcount) &
1142                             (lsp->ls_uncomp_last_seg_sz - 1);
1143                         ealign = lsp->ls_vp_comp_size;
1144                 } else {
1145                         ealign = lsp->ls_comp_seg_index[eblkno + 1];
1146                 }
1147 
1148                 /*
1149                  * Preserve original request paramaters
1150                  */
1151                 oblkcount = bp->b_bcount;
1152 
1153                 /*
1154                  * Assign the calculated parameters
1155                  */
1156                 comp_data_sz = ealign - salign;
1157                 bp->b_bcount = comp_data_sz;
1158 
1159                 /*
1160                  * Buffers to hold compressed segments are pre-allocated
1161                  * on a per-thread basis. Find a pre-allocated buffer
1162                  * that is not currently in use and mark it for use.
1163                  */
1164                 mutex_enter(&lsp->ls_comp_bufs_lock);
1165                 for (j = 0; j < lofi_taskq_nthreads; j++) {
1166                         if (lsp->ls_comp_bufs[j].inuse == 0) {
1167                                 lsp->ls_comp_bufs[j].inuse = 1;
1168                                 break;
1169                         }
1170                 }
1171 
1172                 mutex_exit(&lsp->ls_comp_bufs_lock);
1173                 ASSERT(j < lofi_taskq_nthreads);
1174 
1175                 /*
1176                  * If the pre-allocated buffer size does not match
1177                  * the size of the I/O request, re-allocate it with
1178                  * the appropriate size
1179                  */
1180                 if (lsp->ls_comp_bufs[j].bufsize < bp->b_bcount) {
1181                         if (lsp->ls_comp_bufs[j].bufsize > 0)
1182                                 kmem_free(lsp->ls_comp_bufs[j].buf,
1183                                     lsp->ls_comp_bufs[j].bufsize);
1184                         lsp->ls_comp_bufs[j].buf = kmem_alloc(bp->b_bcount,
1185                             KM_SLEEP);
1186                         lsp->ls_comp_bufs[j].bufsize = bp->b_bcount;
1187                 }
1188                 compressed_seg = lsp->ls_comp_bufs[j].buf;
1189 
1190                 /*
1191                  * Map in the calculated number of blocks
1192                  */
1193                 error = lofi_mapped_rdwr((caddr_t)compressed_seg, salign,
1194                     bp, lsp);
1195 
1196                 bp->b_bcount = oblkcount;
1197                 bp->b_resid = oblkcount;
1198                 if (error != 0)
1199                         goto done;
1200 
1201                 /*
1202                  * decompress compressed blocks start
1203                  */
1204                 cmpbuf = compressed_seg + sdiff;
1205                 for (i = sblkno; i <= eblkno; i++) {
1206                         ASSERT(i < lsp->ls_comp_index_sz - 1);
1207                         uchar_t *useg;
1208 
1209                         /*
1210                          * The last segment is special in that it is
1211                          * most likely not going to be the same
1212                          * (uncompressed) size as the other segments.
1213                          */
1214                         if (i == (lsp->ls_comp_index_sz - 2)) {
1215                                 seglen = lsp->ls_uncomp_last_seg_sz;
1216                         } else {
1217                                 seglen = lsp->ls_uncomp_seg_sz;
1218                         }
1219 
1220                         /*
1221                          * Each of the segment index entries contains
1222                          * the starting block number for that segment.
1223                          * The number of compressed bytes in a segment
1224                          * is thus the difference between the starting
1225                          * block number of this segment and the starting
1226                          * block number of the next segment.
1227                          */
1228                         cmpbytes = lsp->ls_comp_seg_index[i + 1] -
1229                             lsp->ls_comp_seg_index[i];
1230 
1231                         /*
1232                          * The first byte in a compressed segment is a flag
1233                          * that indicates whether this segment is compressed
1234                          * at all.
1235                          *
1236                          * The variable 'useg' is used (instead of
1237                          * uncompressed_seg) in this loop to keep a
1238                          * reference to the uncompressed segment.
1239                          *
1240                          * N.B. If 'useg' is replaced with uncompressed_seg,
1241                          * it leads to memory leaks and heap corruption in
1242                          * corner cases where compressed segments lie
1243                          * adjacent to uncompressed segments.
1244                          */
1245                         if (*cmpbuf == UNCOMPRESSED) {
1246                                 useg = cmpbuf + SEGHDR;
1247                         } else {
1248                                 if (uncompressed_seg == NULL)
1249                                         uncompressed_seg =
1250                                             kmem_alloc(lsp->ls_uncomp_seg_sz,
1251                                             KM_SLEEP);
1252                                 useg = uncompressed_seg;
1253                                 uncompressed_seg_index = i;
1254 
1255                                 if (li->l_decompress((cmpbuf + SEGHDR),
1256                                     (cmpbytes - SEGHDR), uncompressed_seg,
1257                                     &seglen, li->l_level) != 0) {
1258                                         error = EIO;
1259                                         goto done;
1260                                 }
1261                         }
1262 
1263                         /*
1264                          * Determine how much uncompressed data we
1265                          * have to copy and copy it
1266                          */
1267                         xfersize = lsp->ls_uncomp_seg_sz - sblkoff;
1268                         if (i == eblkno)
1269                                 xfersize -= (lsp->ls_uncomp_seg_sz - eblkoff);
1270 
1271                         bcopy((useg + sblkoff), bufaddr, xfersize);
1272 
1273                         cmpbuf += cmpbytes;
1274                         bufaddr += xfersize;
1275                         bp->b_resid -= xfersize;
1276                         sblkoff = 0;
1277 
1278                         if (bp->b_resid == 0)
1279                                 break;
1280                 } /* decompress compressed blocks ends */
1281 
1282                 /*
1283                  * Skip to done if there is no uncompressed data to cache
1284                  */
1285                 if (uncompressed_seg == NULL)
1286                         goto done;
1287 
1288                 /*
1289                  * Add the data for the last decompressed segment to
1290                  * the cache.
1291                  *
1292                  * In case the uncompressed segment data was added to (and
1293                  * is referenced by) the cache, make sure we don't free it
1294                  * here.
1295                  */
1296                 mutex_enter(&lsp->ls_comp_cache_lock);
1297                 if ((lc = lofi_add_comp_data(lsp, uncompressed_seg_index,
1298                     uncompressed_seg)) != NULL) {
1299                         uncompressed_seg = NULL;
1300                 }
1301                 mutex_exit(&lsp->ls_comp_cache_lock);
1302 
1303 done:
1304                 if (compressed_seg != NULL) {
1305                         mutex_enter(&lsp->ls_comp_bufs_lock);
1306                         lsp->ls_comp_bufs[j].inuse = 0;
1307                         mutex_exit(&lsp->ls_comp_bufs_lock);
1308                 }
1309                 if (uncompressed_seg != NULL)
1310                         kmem_free(uncompressed_seg, lsp->ls_uncomp_seg_sz);
1311         } /* end of handling compressed files */
1312 
1313         if ((error == 0) && (syncflag != 0))
1314                 error = VOP_FSYNC(lsp->ls_vp, syncflag, kcred, NULL);
1315 
1316 errout:
1317         if (bufinited && lsp->ls_kstat) {
1318                 size_t n_done = bp->b_bcount - bp->b_resid;
1319                 kstat_io_t *kioptr;
1320 
1321                 mutex_enter(lsp->ls_kstat->ks_lock);
1322                 kioptr = KSTAT_IO_PTR(lsp->ls_kstat);
1323                 if (bp->b_flags & B_READ) {
1324                         kioptr->nread += n_done;
1325                         kioptr->reads++;
1326                 } else {
1327                         kioptr->nwritten += n_done;
1328                         kioptr->writes++;
1329                 }
1330                 kstat_runq_exit(kioptr);
1331                 mutex_exit(lsp->ls_kstat->ks_lock);
1332         }
1333 
1334         mutex_enter(&lsp->ls_vp_lock);
1335         if (--lsp->ls_vp_iocount == 0)
1336                 cv_broadcast(&lsp->ls_vp_cv);
1337         mutex_exit(&lsp->ls_vp_lock);
1338 
1339         bioerror(bp, error);
1340         biodone(bp);
1341 }
1342 
1343 static int
1344 lofi_strategy(struct buf *bp)
1345 {
1346         struct lofi_state *lsp;
1347         offset_t        offset;
1348 
1349         /*
1350          * We cannot just do I/O here, because the current thread
1351          * _might_ end up back in here because the underlying filesystem
1352          * wants a buffer, which eventually gets into bio_recycle and
1353          * might call into lofi to write out a delayed-write buffer.
1354          * This is bad if the filesystem above lofi is the same as below.
1355          *
1356          * We could come up with a complex strategy using threads to
1357          * do the I/O asynchronously, or we could use task queues. task
1358          * queues were incredibly easy so they win.
1359          */
1360         lsp = ddi_get_soft_state(lofi_statep, getminor(bp->b_edev));
1361         if (lsp == NULL) {
1362                 bioerror(bp, ENXIO);
1363                 biodone(bp);
1364                 return (0);
1365         }
1366 
1367         mutex_enter(&lsp->ls_vp_lock);
1368         if (lsp->ls_vp == NULL || lsp->ls_vp_closereq) {
1369                 bioerror(bp, EIO);
1370                 biodone(bp);
1371                 mutex_exit(&lsp->ls_vp_lock);
1372                 return (0);
1373         }
1374 
1375         offset = bp->b_lblkno * DEV_BSIZE;   /* offset within file */
1376         if (lsp->ls_crypto_enabled) {
1377                 /* encrypted data really begins after crypto header */
1378                 offset += lsp->ls_crypto_offset;
1379         }
1380         if (offset == lsp->ls_vp_size) {
1381                 /* EOF */
1382                 if ((bp->b_flags & B_READ) != 0) {
1383                         bp->b_resid = bp->b_bcount;
1384                         bioerror(bp, 0);
1385                 } else {
1386                         /* writes should fail */
1387                         bioerror(bp, ENXIO);
1388                 }
1389                 biodone(bp);
1390                 mutex_exit(&lsp->ls_vp_lock);
1391                 return (0);
1392         }
1393         if (offset > lsp->ls_vp_size) {
1394                 bioerror(bp, ENXIO);
1395                 biodone(bp);
1396                 mutex_exit(&lsp->ls_vp_lock);
1397                 return (0);
1398         }
1399         lsp->ls_vp_iocount++;
1400         mutex_exit(&lsp->ls_vp_lock);
1401 
1402         if (lsp->ls_kstat) {
1403                 mutex_enter(lsp->ls_kstat->ks_lock);
1404                 kstat_waitq_enter(KSTAT_IO_PTR(lsp->ls_kstat));
1405                 mutex_exit(lsp->ls_kstat->ks_lock);
1406         }
1407         (void) taskq_dispatch(lsp->ls_taskq, lofi_strategy_task, bp, KM_SLEEP);
1408         return (0);
1409 }
1410 
1411 /*ARGSUSED2*/
1412 static int
1413 lofi_read(dev_t dev, struct uio *uio, struct cred *credp)
1414 {
1415         if (getminor(dev) == 0)
1416                 return (EINVAL);
1417         UIO_CHECK(uio);
1418         return (physio(lofi_strategy, NULL, dev, B_READ, minphys, uio));
1419 }
1420 
1421 /*ARGSUSED2*/
1422 static int
1423 lofi_write(dev_t dev, struct uio *uio, struct cred *credp)
1424 {
1425         if (getminor(dev) == 0)
1426                 return (EINVAL);
1427         UIO_CHECK(uio);
1428         return (physio(lofi_strategy, NULL, dev, B_WRITE, minphys, uio));
1429 }
1430 
1431 /*ARGSUSED2*/
1432 static int
1433 lofi_aread(dev_t dev, struct aio_req *aio, struct cred *credp)
1434 {
1435         if (getminor(dev) == 0)
1436                 return (EINVAL);
1437         UIO_CHECK(aio->aio_uio);
1438         return (aphysio(lofi_strategy, anocancel, dev, B_READ, minphys, aio));
1439 }
1440 
1441 /*ARGSUSED2*/
1442 static int
1443 lofi_awrite(dev_t dev, struct aio_req *aio, struct cred *credp)
1444 {
1445         if (getminor(dev) == 0)
1446                 return (EINVAL);
1447         UIO_CHECK(aio->aio_uio);
1448         return (aphysio(lofi_strategy, anocancel, dev, B_WRITE, minphys, aio));
1449 }
1450 
1451 /*ARGSUSED*/
1452 static int
1453 lofi_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
1454 {
1455         switch (infocmd) {
1456         case DDI_INFO_DEVT2DEVINFO:
1457                 *result = lofi_dip;
1458                 return (DDI_SUCCESS);
1459         case DDI_INFO_DEVT2INSTANCE:
1460                 *result = 0;
1461                 return (DDI_SUCCESS);
1462         }
1463         return (DDI_FAILURE);
1464 }
1465 
1466 static int
1467 lofi_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
1468 {
1469         int     error;
1470 
1471         if (cmd != DDI_ATTACH)
1472                 return (DDI_FAILURE);
1473 
1474         lofi_minor_id = id_space_create("lofi_minor_id", 1, L_MAXMIN32 + 1);
1475 
1476         if (!lofi_minor_id)
1477                 return (DDI_FAILURE);
1478 
1479         error = ddi_soft_state_zalloc(lofi_statep, 0);
1480         if (error == DDI_FAILURE) {
1481                 id_space_destroy(lofi_minor_id);
1482                 return (DDI_FAILURE);
1483         }
1484         error = ddi_create_minor_node(dip, LOFI_CTL_NODE, S_IFCHR, 0,
1485             DDI_PSEUDO, NULL);
1486         if (error == DDI_FAILURE) {
1487                 ddi_soft_state_free(lofi_statep, 0);
1488                 id_space_destroy(lofi_minor_id);
1489                 return (DDI_FAILURE);
1490         }
1491         /* driver handles kernel-issued IOCTLs */
1492         if (ddi_prop_create(DDI_DEV_T_NONE, dip, DDI_PROP_CANSLEEP,
1493             DDI_KERNEL_IOCTL, NULL, 0) != DDI_PROP_SUCCESS) {
1494                 ddi_remove_minor_node(dip, NULL);
1495                 ddi_soft_state_free(lofi_statep, 0);
1496                 id_space_destroy(lofi_minor_id);
1497                 return (DDI_FAILURE);
1498         }
1499 
1500         zone_key_create(&lofi_zone_key, NULL, lofi_zone_shutdown, NULL);
1501 
1502         lofi_dip = dip;
1503         ddi_report_dev(dip);
1504         return (DDI_SUCCESS);
1505 }
1506 
1507 static int
1508 lofi_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
1509 {
1510         if (cmd != DDI_DETACH)
1511                 return (DDI_FAILURE);
1512 
1513         mutex_enter(&lofi_lock);
1514 
1515         if (!list_is_empty(&lofi_list)) {
1516                 mutex_exit(&lofi_lock);
1517                 return (DDI_FAILURE);
1518         }
1519 
1520         lofi_dip = NULL;
1521         ddi_remove_minor_node(dip, NULL);
1522         ddi_prop_remove_all(dip);
1523 
1524         mutex_exit(&lofi_lock);
1525 
1526         if (zone_key_delete(lofi_zone_key) != 0)
1527                 cmn_err(CE_WARN, "failed to delete zone key");
1528 
1529         ddi_soft_state_free(lofi_statep, 0);
1530 
1531         id_space_destroy(lofi_minor_id);
1532 
1533         return (DDI_SUCCESS);
1534 }
1535 
1536 /*
1537  * With addition of encryption, be careful that encryption key is wiped before
1538  * kernel memory structures are freed, and also that key is not accidentally
1539  * passed out into userland structures.
1540  */
1541 static void
1542 free_lofi_ioctl(struct lofi_ioctl *klip)
1543 {
1544         /* Make sure this encryption key doesn't stick around */
1545         bzero(klip->li_key, sizeof (klip->li_key));
1546         kmem_free(klip, sizeof (struct lofi_ioctl));
1547 }
1548 
1549 /*
1550  * These two just simplify the rest of the ioctls that need to copyin/out
1551  * the lofi_ioctl structure.
1552  */
1553 int
1554 copy_in_lofi_ioctl(const struct lofi_ioctl *ulip, struct lofi_ioctl **klipp,
1555     int flag)
1556 {
1557         struct lofi_ioctl *klip;
1558         int     error;
1559 
1560         klip = *klipp = kmem_alloc(sizeof (struct lofi_ioctl), KM_SLEEP);
1561         error = ddi_copyin(ulip, klip, sizeof (struct lofi_ioctl), flag);
1562         if (error)
1563                 goto err;
1564 
1565         /* ensure NULL termination */
1566         klip->li_filename[MAXPATHLEN-1] = '\0';
1567         klip->li_algorithm[MAXALGLEN-1] = '\0';
1568         klip->li_cipher[CRYPTO_MAX_MECH_NAME-1] = '\0';
1569         klip->li_iv_cipher[CRYPTO_MAX_MECH_NAME-1] = '\0';
1570 
1571         if (klip->li_minor > L_MAXMIN32) {
1572                 error = EINVAL;
1573                 goto err;
1574         }
1575 
1576         return (0);
1577 
1578 err:
1579         free_lofi_ioctl(klip);
1580         return (error);
1581 }
1582 
1583 int
1584 copy_out_lofi_ioctl(const struct lofi_ioctl *klip, struct lofi_ioctl *ulip,
1585         int flag)
1586 {
1587         int     error;
1588 
1589         /*
1590          * NOTE: Do NOT copy the crypto_key_t "back" to userland.
1591          * This ensures that an attacker can't trivially find the
1592          * key for a mapping just by issuing the ioctl.
1593          *
1594          * It can still be found by poking around in kmem with mdb(1),
1595          * but there is no point in making it easy when the info isn't
1596          * of any use in this direction anyway.
1597          *
1598          * Either way we don't actually have the raw key stored in
1599          * a form that we can get it anyway, since we just used it
1600          * to create a ctx template and didn't keep "the original".
1601          */
1602         error = ddi_copyout(klip, ulip, sizeof (struct lofi_ioctl), flag);
1603         if (error)
1604                 return (EFAULT);
1605         return (0);
1606 }
1607 
1608 static int
1609 lofi_access(struct lofi_state *lsp)
1610 {
1611         ASSERT(MUTEX_HELD(&lofi_lock));
1612         if (INGLOBALZONE(curproc) || lsp->ls_zone.zref_zone == curzone)
1613                 return (0);
1614         return (EPERM);
1615 }
1616 
1617 /*
1618  * Find the lofi state for the given filename. We compare by vnode to
1619  * allow the global zone visibility into NGZ lofi nodes.
1620  */
1621 static int
1622 file_to_lofi_nocheck(char *filename, boolean_t readonly,
1623     struct lofi_state **lspp)
1624 {
1625         struct lofi_state *lsp;
1626         vnode_t *vp = NULL;
1627         int err = 0;
1628         int rdfiles = 0;
1629 
1630         ASSERT(MUTEX_HELD(&lofi_lock));
1631 
1632         if ((err = lookupname(filename, UIO_SYSSPACE, FOLLOW,
1633             NULLVPP, &vp)) != 0)
1634                 goto out;
1635 
1636         if (vp->v_type == VREG) {
1637                 vnode_t *realvp;
1638                 if (VOP_REALVP(vp, &realvp, NULL) == 0) {
1639                         VN_HOLD(realvp);
1640                         VN_RELE(vp);
1641                         vp = realvp;
1642                 }
1643         }
1644 
1645         for (lsp = list_head(&lofi_list); lsp != NULL;
1646             lsp = list_next(&lofi_list, lsp)) {
1647                 if (lsp->ls_vp == vp) {
1648                         if (lspp != NULL)
1649                                 *lspp = lsp;
1650                         if (lsp->ls_readonly) {
1651                                 rdfiles++;
1652                                 /* Skip if '-r' is specified */
1653                                 if (readonly)
1654                                         continue;
1655                         }
1656                         goto out;
1657                 }
1658         }
1659 
1660         err = ENOENT;
1661 
1662         /*
1663          * If a filename is given as an argument for lofi_unmap, we shouldn't
1664          * allow unmap if there are multiple read-only lofi devices associated
1665          * with this file.
1666          */
1667         if (lspp != NULL) {
1668                 if (rdfiles == 1)
1669                         err = 0;
1670                 else if (rdfiles > 1)
1671                         err = EBUSY;
1672         }
1673 
1674 out:
1675         if (vp != NULL)
1676                 VN_RELE(vp);
1677         return (err);
1678 }
1679 
1680 /*
1681  * Find the minor for the given filename, checking the zone can access
1682  * it.
1683  */
1684 static int
1685 file_to_lofi(char *filename, boolean_t readonly, struct lofi_state **lspp)
1686 {
1687         int err = 0;
1688 
1689         ASSERT(MUTEX_HELD(&lofi_lock));
1690 
1691         if ((err = file_to_lofi_nocheck(filename, readonly, lspp)) != 0)
1692                 return (err);
1693 
1694         if ((err = lofi_access(*lspp)) != 0)
1695                 return (err);
1696 
1697         return (0);
1698 }
1699 
1700 /*
1701  * Fakes up a disk geometry, and one big partition, based on the size
1702  * of the file. This is needed because we allow newfs'ing the device,
1703  * and newfs will do several disk ioctls to figure out the geometry and
1704  * partition information. It uses that information to determine the parameters
1705  * to pass to mkfs. Geometry is pretty much irrelevant these days, but we
1706  * have to support it.
1707  */
1708 static void
1709 fake_disk_geometry(struct lofi_state *lsp)
1710 {
1711         u_offset_t dsize = lsp->ls_vp_size - lsp->ls_crypto_offset;
1712 
1713         /* dk_geom - see dkio(7I) */
1714         /*
1715          * dkg_ncyl _could_ be set to one here (one big cylinder with gobs
1716          * of sectors), but that breaks programs like fdisk which want to
1717          * partition a disk by cylinder. With one cylinder, you can't create
1718          * an fdisk partition and put pcfs on it for testing (hard to pick
1719          * a number between one and one).
1720          *
1721          * The cheezy floppy test is an attempt to not have too few cylinders
1722          * for a small file, or so many on a big file that you waste space
1723          * for backup superblocks or cylinder group structures.
1724          */
1725         if (dsize < (2 * 1024 * 1024)) /* floppy? */
1726                 lsp->ls_dkg.dkg_ncyl = dsize / (100 * 1024);
1727         else
1728                 lsp->ls_dkg.dkg_ncyl = dsize / (300 * 1024);
1729         /* in case file file is < 100k */
1730         if (lsp->ls_dkg.dkg_ncyl == 0)
1731                 lsp->ls_dkg.dkg_ncyl = 1;
1732         lsp->ls_dkg.dkg_acyl = 0;
1733         lsp->ls_dkg.dkg_bcyl = 0;
1734         lsp->ls_dkg.dkg_nhead = 1;
1735         lsp->ls_dkg.dkg_obs1 = 0;
1736         lsp->ls_dkg.dkg_intrlv = 0;
1737         lsp->ls_dkg.dkg_obs2 = 0;
1738         lsp->ls_dkg.dkg_obs3 = 0;
1739         lsp->ls_dkg.dkg_apc = 0;
1740         lsp->ls_dkg.dkg_rpm = 7200;
1741         lsp->ls_dkg.dkg_pcyl = lsp->ls_dkg.dkg_ncyl + lsp->ls_dkg.dkg_acyl;
1742         lsp->ls_dkg.dkg_nsect = dsize / (DEV_BSIZE * lsp->ls_dkg.dkg_ncyl);
1743         lsp->ls_dkg.dkg_write_reinstruct = 0;
1744         lsp->ls_dkg.dkg_read_reinstruct = 0;
1745 
1746         /* vtoc - see dkio(7I) */
1747         bzero(&lsp->ls_vtoc, sizeof (struct vtoc));
1748         lsp->ls_vtoc.v_sanity = VTOC_SANE;
1749         lsp->ls_vtoc.v_version = V_VERSION;
1750         (void) strncpy(lsp->ls_vtoc.v_volume, LOFI_DRIVER_NAME,
1751             sizeof (lsp->ls_vtoc.v_volume));
1752         lsp->ls_vtoc.v_sectorsz = DEV_BSIZE;
1753         lsp->ls_vtoc.v_nparts = 1;
1754         lsp->ls_vtoc.v_part[0].p_tag = V_UNASSIGNED;
1755 
1756         /*
1757          * A compressed file is read-only, other files can
1758          * be read-write
1759          */
1760         if (lsp->ls_uncomp_seg_sz > 0) {
1761                 lsp->ls_vtoc.v_part[0].p_flag = V_UNMNT | V_RONLY;
1762         } else {
1763                 lsp->ls_vtoc.v_part[0].p_flag = V_UNMNT;
1764         }
1765         lsp->ls_vtoc.v_part[0].p_start = (daddr_t)0;
1766         /*
1767          * The partition size cannot just be the number of sectors, because
1768          * that might not end on a cylinder boundary. And if that's the case,
1769          * newfs/mkfs will print a scary warning. So just figure the size
1770          * based on the number of cylinders and sectors/cylinder.
1771          */
1772         lsp->ls_vtoc.v_part[0].p_size = lsp->ls_dkg.dkg_pcyl *
1773             lsp->ls_dkg.dkg_nsect * lsp->ls_dkg.dkg_nhead;
1774 
1775         /* dk_cinfo - see dkio(7I) */
1776         bzero(&lsp->ls_ci, sizeof (struct dk_cinfo));
1777         (void) strcpy(lsp->ls_ci.dki_cname, LOFI_DRIVER_NAME);
1778         lsp->ls_ci.dki_ctype = DKC_MD;
1779         lsp->ls_ci.dki_flags = 0;
1780         lsp->ls_ci.dki_cnum = 0;
1781         lsp->ls_ci.dki_addr = 0;
1782         lsp->ls_ci.dki_space = 0;
1783         lsp->ls_ci.dki_prio = 0;
1784         lsp->ls_ci.dki_vec = 0;
1785         (void) strcpy(lsp->ls_ci.dki_dname, LOFI_DRIVER_NAME);
1786         lsp->ls_ci.dki_unit = 0;
1787         lsp->ls_ci.dki_slave = 0;
1788         lsp->ls_ci.dki_partition = 0;
1789         /*
1790          * newfs uses this to set maxcontig. Must not be < 16, or it
1791          * will be 0 when newfs multiplies it by DEV_BSIZE and divides
1792          * it by the block size. Then tunefs doesn't work because
1793          * maxcontig is 0.
1794          */
1795         lsp->ls_ci.dki_maxtransfer = 16;
1796 }
1797 
1798 /*
1799  * map in a compressed file
1800  *
1801  * Read in the header and the index that follows.
1802  *
1803  * The header is as follows -
1804  *
1805  * Signature (name of the compression algorithm)
1806  * Compression segment size (a multiple of 512)
1807  * Number of index entries
1808  * Size of the last block
1809  * The array containing the index entries
1810  *
1811  * The header information is always stored in
1812  * network byte order on disk.
1813  */
1814 static int
1815 lofi_map_compressed_file(struct lofi_state *lsp, char *buf)
1816 {
1817         uint32_t index_sz, header_len, i;
1818         ssize_t resid;
1819         enum uio_rw rw;
1820         char *tbuf = buf;
1821         int error;
1822 
1823         /* The signature has already been read */
1824         tbuf += sizeof (lsp->ls_comp_algorithm);
1825         bcopy(tbuf, &(lsp->ls_uncomp_seg_sz), sizeof (lsp->ls_uncomp_seg_sz));
1826         lsp->ls_uncomp_seg_sz = ntohl(lsp->ls_uncomp_seg_sz);
1827 
1828         /*
1829          * The compressed segment size must be a power of 2
1830          */
1831         if (lsp->ls_uncomp_seg_sz < DEV_BSIZE ||
1832             !ISP2(lsp->ls_uncomp_seg_sz))
1833                 return (EINVAL);
1834 
1835         for (i = 0; !((lsp->ls_uncomp_seg_sz >> i) & 1); i++)
1836                 ;
1837 
1838         lsp->ls_comp_seg_shift = i;
1839 
1840         tbuf += sizeof (lsp->ls_uncomp_seg_sz);
1841         bcopy(tbuf, &(lsp->ls_comp_index_sz), sizeof (lsp->ls_comp_index_sz));
1842         lsp->ls_comp_index_sz = ntohl(lsp->ls_comp_index_sz);
1843 
1844         tbuf += sizeof (lsp->ls_comp_index_sz);
1845         bcopy(tbuf, &(lsp->ls_uncomp_last_seg_sz),
1846             sizeof (lsp->ls_uncomp_last_seg_sz));
1847         lsp->ls_uncomp_last_seg_sz = ntohl(lsp->ls_uncomp_last_seg_sz);
1848 
1849         /*
1850          * Compute the total size of the uncompressed data
1851          * for use in fake_disk_geometry and other calculations.
1852          * Disk geometry has to be faked with respect to the
1853          * actual uncompressed data size rather than the
1854          * compressed file size.
1855          */
1856         lsp->ls_vp_size =
1857             (u_offset_t)(lsp->ls_comp_index_sz - 2) * lsp->ls_uncomp_seg_sz
1858             + lsp->ls_uncomp_last_seg_sz;
1859 
1860         /*
1861          * Index size is rounded up to DEV_BSIZE for ease
1862          * of segmapping
1863          */
1864         index_sz = sizeof (*lsp->ls_comp_seg_index) * lsp->ls_comp_index_sz;
1865         header_len = sizeof (lsp->ls_comp_algorithm) +
1866             sizeof (lsp->ls_uncomp_seg_sz) +
1867             sizeof (lsp->ls_comp_index_sz) +
1868             sizeof (lsp->ls_uncomp_last_seg_sz);
1869         lsp->ls_comp_offbase = header_len + index_sz;
1870 
1871         index_sz += header_len;
1872         index_sz = roundup(index_sz, DEV_BSIZE);
1873 
1874         lsp->ls_comp_index_data = kmem_alloc(index_sz, KM_SLEEP);
1875         lsp->ls_comp_index_data_sz = index_sz;
1876 
1877         /*
1878          * Read in the index -- this has a side-effect
1879          * of reading in the header as well
1880          */
1881         rw = UIO_READ;
1882         error = vn_rdwr(rw, lsp->ls_vp, lsp->ls_comp_index_data, index_sz,
1883             0, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
1884 
1885         if (error != 0)
1886                 return (error);
1887 
1888         /* Skip the header, this is where the index really begins */
1889         lsp->ls_comp_seg_index =
1890             /*LINTED*/
1891             (uint64_t *)(lsp->ls_comp_index_data + header_len);
1892 
1893         /*
1894          * Now recompute offsets in the index to account for
1895          * the header length
1896          */
1897         for (i = 0; i < lsp->ls_comp_index_sz; i++) {
1898                 lsp->ls_comp_seg_index[i] = lsp->ls_comp_offbase +
1899                     BE_64(lsp->ls_comp_seg_index[i]);
1900         }
1901 
1902         return (error);
1903 }
1904 
1905 static int
1906 lofi_init_crypto(struct lofi_state *lsp, struct lofi_ioctl *klip)
1907 {
1908         struct crypto_meta chead;
1909         char buf[DEV_BSIZE];
1910         ssize_t resid;
1911         char *marker;
1912         int error;
1913         int ret;
1914         int i;
1915 
1916         if (!klip->li_crypto_enabled)
1917                 return (0);
1918 
1919         /*
1920          * All current algorithms have a max of 448 bits.
1921          */
1922         if (klip->li_iv_len > CRYPTO_BITS2BYTES(512))
1923                 return (EINVAL);
1924 
1925         if (CRYPTO_BITS2BYTES(klip->li_key_len) > sizeof (klip->li_key))
1926                 return (EINVAL);
1927 
1928         lsp->ls_crypto_enabled = klip->li_crypto_enabled;
1929 
1930         mutex_init(&lsp->ls_crypto_lock, NULL, MUTEX_DRIVER, NULL);
1931 
1932         lsp->ls_mech.cm_type = crypto_mech2id(klip->li_cipher);
1933         if (lsp->ls_mech.cm_type == CRYPTO_MECH_INVALID) {
1934                 cmn_err(CE_WARN, "invalid cipher %s requested for %s",
1935                     klip->li_cipher, klip->li_filename);
1936                 return (EINVAL);
1937         }
1938 
1939         /* this is just initialization here */
1940         lsp->ls_mech.cm_param = NULL;
1941         lsp->ls_mech.cm_param_len = 0;
1942 
1943         lsp->ls_iv_type = klip->li_iv_type;
1944         lsp->ls_iv_mech.cm_type = crypto_mech2id(klip->li_iv_cipher);
1945         if (lsp->ls_iv_mech.cm_type == CRYPTO_MECH_INVALID) {
1946                 cmn_err(CE_WARN, "invalid iv cipher %s requested"
1947                     " for %s", klip->li_iv_cipher, klip->li_filename);
1948                 return (EINVAL);
1949         }
1950 
1951         /* iv mech must itself take a null iv */
1952         lsp->ls_iv_mech.cm_param = NULL;
1953         lsp->ls_iv_mech.cm_param_len = 0;
1954         lsp->ls_iv_len = klip->li_iv_len;
1955 
1956         /*
1957          * Create ctx using li_cipher & the raw li_key after checking
1958          * that it isn't a weak key.
1959          */
1960         lsp->ls_key.ck_format = CRYPTO_KEY_RAW;
1961         lsp->ls_key.ck_length = klip->li_key_len;
1962         lsp->ls_key.ck_data = kmem_alloc(
1963             CRYPTO_BITS2BYTES(lsp->ls_key.ck_length), KM_SLEEP);
1964         bcopy(klip->li_key, lsp->ls_key.ck_data,
1965             CRYPTO_BITS2BYTES(lsp->ls_key.ck_length));
1966 
1967         ret = crypto_key_check(&lsp->ls_mech, &lsp->ls_key);
1968         if (ret != CRYPTO_SUCCESS) {
1969                 cmn_err(CE_WARN, "weak key check failed for cipher "
1970                     "%s on file %s (0x%x)", klip->li_cipher,
1971                     klip->li_filename, ret);
1972                 return (EINVAL);
1973         }
1974 
1975         error = vn_rdwr(UIO_READ, lsp->ls_vp, buf, DEV_BSIZE,
1976             CRYOFF, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
1977         if (error != 0)
1978                 return (error);
1979 
1980         /*
1981          * This is the case where the header in the lofi image is already
1982          * initialized to indicate it is encrypted.
1983          */
1984         if (strncmp(buf, lofi_crypto_magic, sizeof (lofi_crypto_magic)) == 0) {
1985                 /*
1986                  * The encryption header information is laid out this way:
1987                  *      6 bytes:        hex "CFLOFI"
1988                  *      2 bytes:        version = 0 ... for now
1989                  *      96 bytes:       reserved1 (not implemented yet)
1990                  *      4 bytes:        data_sector = 2 ... for now
1991                  *      more...         not implemented yet
1992                  */
1993 
1994                 marker = buf;
1995 
1996                 /* copy the magic */
1997                 bcopy(marker, lsp->ls_crypto.magic,
1998                     sizeof (lsp->ls_crypto.magic));
1999                 marker += sizeof (lsp->ls_crypto.magic);
2000 
2001                 /* read the encryption version number */
2002                 bcopy(marker, &(lsp->ls_crypto.version),
2003                     sizeof (lsp->ls_crypto.version));
2004                 lsp->ls_crypto.version = ntohs(lsp->ls_crypto.version);
2005                 marker += sizeof (lsp->ls_crypto.version);
2006 
2007                 /* read a chunk of reserved data */
2008                 bcopy(marker, lsp->ls_crypto.reserved1,
2009                     sizeof (lsp->ls_crypto.reserved1));
2010                 marker += sizeof (lsp->ls_crypto.reserved1);
2011 
2012                 /* read block number where encrypted data begins */
2013                 bcopy(marker, &(lsp->ls_crypto.data_sector),
2014                     sizeof (lsp->ls_crypto.data_sector));
2015                 lsp->ls_crypto.data_sector = ntohl(lsp->ls_crypto.data_sector);
2016                 marker += sizeof (lsp->ls_crypto.data_sector);
2017 
2018                 /* and ignore the rest until it is implemented */
2019 
2020                 lsp->ls_crypto_offset = lsp->ls_crypto.data_sector * DEV_BSIZE;
2021                 return (0);
2022         }
2023 
2024         /*
2025          * We've requested encryption, but no magic was found, so it must be
2026          * a new image.
2027          */
2028 
2029         for (i = 0; i < sizeof (struct crypto_meta); i++) {
2030                 if (buf[i] != '\0')
2031                         return (EINVAL);
2032         }
2033 
2034         marker = buf;
2035         bcopy(lofi_crypto_magic, marker, sizeof (lofi_crypto_magic));
2036         marker += sizeof (lofi_crypto_magic);
2037         chead.version = htons(LOFI_CRYPTO_VERSION);
2038         bcopy(&(chead.version), marker, sizeof (chead.version));
2039         marker += sizeof (chead.version);
2040         marker += sizeof (chead.reserved1);
2041         chead.data_sector = htonl(LOFI_CRYPTO_DATA_SECTOR);
2042         bcopy(&(chead.data_sector), marker, sizeof (chead.data_sector));
2043 
2044         /* write the header */
2045         error = vn_rdwr(UIO_WRITE, lsp->ls_vp, buf, DEV_BSIZE,
2046             CRYOFF, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
2047         if (error != 0)
2048                 return (error);
2049 
2050         /* fix things up so it looks like we read this info */
2051         bcopy(lofi_crypto_magic, lsp->ls_crypto.magic,
2052             sizeof (lofi_crypto_magic));
2053         lsp->ls_crypto.version = LOFI_CRYPTO_VERSION;
2054         lsp->ls_crypto.data_sector = LOFI_CRYPTO_DATA_SECTOR;
2055         lsp->ls_crypto_offset = lsp->ls_crypto.data_sector * DEV_BSIZE;
2056         return (0);
2057 }
2058 
2059 /*
2060  * Check to see if the passed in signature is a valid one.  If it is
2061  * valid, return the index into lofi_compress_table.
2062  *
2063  * Return -1 if it is invalid
2064  */
2065 static int
2066 lofi_compress_select(const char *signature)
2067 {
2068         int i;
2069 
2070         for (i = 0; i < LOFI_COMPRESS_FUNCTIONS; i++) {
2071                 if (strcmp(lofi_compress_table[i].l_name, signature) == 0)
2072                         return (i);
2073         }
2074 
2075         return (-1);
2076 }
2077 
2078 static int
2079 lofi_init_compress(struct lofi_state *lsp)
2080 {
2081         char buf[DEV_BSIZE];
2082         int compress_index;
2083         ssize_t resid;
2084         int error;
2085 
2086         error = vn_rdwr(UIO_READ, lsp->ls_vp, buf, DEV_BSIZE, 0, UIO_SYSSPACE,
2087             0, RLIM64_INFINITY, kcred, &resid);
2088 
2089         if (error != 0)
2090                 return (error);
2091 
2092         if ((compress_index = lofi_compress_select(buf)) == -1)
2093                 return (0);
2094 
2095         /* compression and encryption are mutually exclusive */
2096         if (lsp->ls_crypto_enabled)
2097                 return (ENOTSUP);
2098 
2099         /* initialize compression info for compressed lofi */
2100         lsp->ls_comp_algorithm_index = compress_index;
2101         (void) strlcpy(lsp->ls_comp_algorithm,
2102             lofi_compress_table[compress_index].l_name,
2103             sizeof (lsp->ls_comp_algorithm));
2104 
2105         /* Finally setup per-thread pre-allocated buffers */
2106         lsp->ls_comp_bufs = kmem_zalloc(lofi_taskq_nthreads *
2107             sizeof (struct compbuf), KM_SLEEP);
2108 
2109         return (lofi_map_compressed_file(lsp, buf));
2110 }
2111 
2112 /*
2113  * map a file to a minor number. Return the minor number.
2114  */
2115 static int
2116 lofi_map_file(dev_t dev, struct lofi_ioctl *ulip, int pickminor,
2117     int *rvalp, struct cred *credp, int ioctl_flag)
2118 {
2119         minor_t minor = (minor_t)-1;
2120         struct lofi_state *lsp = NULL;
2121         struct lofi_ioctl *klip;
2122         int     error;
2123         struct vnode *vp = NULL;
2124         vattr_t vattr;
2125         int     flag;
2126         dev_t   newdev;
2127         char    namebuf[50];
2128 
2129         error = copy_in_lofi_ioctl(ulip, &klip, ioctl_flag);
2130         if (error != 0)
2131                 return (error);
2132 
2133         mutex_enter(&lofi_lock);
2134 
2135         mutex_enter(&curproc->p_lock);
2136         if ((error = rctl_incr_lofi(curproc, curproc->p_zone, 1)) != 0) {
2137                 mutex_exit(&curproc->p_lock);
2138                 mutex_exit(&lofi_lock);
2139                 free_lofi_ioctl(klip);
2140                 return (error);
2141         }
2142         mutex_exit(&curproc->p_lock);
2143 
2144         if (file_to_lofi_nocheck(klip->li_filename, klip->li_readonly,
2145             NULL) == 0) {
2146                 error = EBUSY;
2147                 goto err;
2148         }
2149 
2150         if (pickminor) {
2151                 minor = (minor_t)id_allocff_nosleep(lofi_minor_id);
2152                 if (minor == (minor_t)-1) {
2153                         error = EAGAIN;
2154                         goto err;
2155                 }
2156         } else {
2157                 if (ddi_get_soft_state(lofi_statep, klip->li_minor) != NULL) {
2158                         error = EEXIST;
2159                         goto err;
2160                 }
2161 
2162                 minor = (minor_t)
2163                     id_alloc_specific_nosleep(lofi_minor_id, klip->li_minor);
2164                 ASSERT(minor != (minor_t)-1);
2165         }
2166 
2167         flag = FREAD | FWRITE | FOFFMAX | FEXCL;
2168         error = vn_open(klip->li_filename, UIO_SYSSPACE, flag, 0, &vp, 0, 0);
2169         if (error) {
2170                 /* try read-only */
2171                 flag &= ~FWRITE;
2172                 error = vn_open(klip->li_filename, UIO_SYSSPACE, flag, 0,
2173                     &vp, 0, 0);
2174                 if (error)
2175                         goto err;
2176         }
2177 
2178         if (!V_ISLOFIABLE(vp->v_type)) {
2179                 error = EINVAL;
2180                 goto err;
2181         }
2182 
2183         vattr.va_mask = AT_SIZE;
2184         error = VOP_GETATTR(vp, &vattr, 0, credp, NULL);
2185         if (error)
2186                 goto err;
2187 
2188         /* the file needs to be a multiple of the block size */
2189         if ((vattr.va_size % DEV_BSIZE) != 0) {
2190                 error = EINVAL;
2191                 goto err;
2192         }
2193 
2194         /* lsp alloc+init */
2195 
2196         error = ddi_soft_state_zalloc(lofi_statep, minor);
2197         if (error == DDI_FAILURE) {
2198                 error = ENOMEM;
2199                 goto err;
2200         }
2201 
2202         lsp = ddi_get_soft_state(lofi_statep, minor);
2203         list_insert_tail(&lofi_list, lsp);
2204 
2205         newdev = makedevice(getmajor(dev), minor);
2206         lsp->ls_dev = newdev;
2207         zone_init_ref(&lsp->ls_zone);
2208         zone_hold_ref(curzone, &lsp->ls_zone, ZONE_REF_LOFI);
2209         lsp->ls_uncomp_seg_sz = 0;
2210         lsp->ls_comp_algorithm[0] = '\0';
2211         lsp->ls_crypto_offset = 0;
2212 
2213         cv_init(&lsp->ls_vp_cv, NULL, CV_DRIVER, NULL);
2214         mutex_init(&lsp->ls_comp_cache_lock, NULL, MUTEX_DRIVER, NULL);
2215         mutex_init(&lsp->ls_comp_bufs_lock, NULL, MUTEX_DRIVER, NULL);
2216         mutex_init(&lsp->ls_kstat_lock, NULL, MUTEX_DRIVER, NULL);
2217         mutex_init(&lsp->ls_vp_lock, NULL, MUTEX_DRIVER, NULL);
2218 
2219         (void) snprintf(namebuf, sizeof (namebuf), "%s_taskq_%d",
2220             LOFI_DRIVER_NAME, minor);
2221         lsp->ls_taskq = taskq_create_proc(namebuf, lofi_taskq_nthreads,
2222             minclsyspri, 1, lofi_taskq_maxalloc, curzone->zone_zsched, 0);
2223 
2224         list_create(&lsp->ls_comp_cache, sizeof (struct lofi_comp_cache),
2225             offsetof(struct lofi_comp_cache, lc_list));
2226 
2227         /*
2228          * save open mode so file can be closed properly and vnode counts
2229          * updated correctly.
2230          */
2231         lsp->ls_openflag = flag;
2232 
2233         lsp->ls_vp = vp;
2234         lsp->ls_stacked_vp = vp;
2235         /*
2236          * Try to handle stacked lofs vnodes.
2237          */
2238         if (vp->v_type == VREG) {
2239                 vnode_t *realvp;
2240 
2241                 if (VOP_REALVP(vp, &realvp, NULL) == 0) {
2242                         /*
2243                          * We need to use the realvp for uniqueness
2244                          * checking, but keep the stacked vp for
2245                          * LOFI_GET_FILENAME display.
2246                          */
2247                         VN_HOLD(realvp);
2248                         lsp->ls_vp = realvp;
2249                 }
2250         }
2251 
2252         lsp->ls_vp_size = vattr.va_size;
2253         lsp->ls_vp_comp_size = lsp->ls_vp_size;
2254 
2255         lsp->ls_kstat = kstat_create_zone(LOFI_DRIVER_NAME, minor,
2256             NULL, "disk", KSTAT_TYPE_IO, 1, 0, getzoneid());
2257 
2258         if (lsp->ls_kstat == NULL) {
2259                 error = ENOMEM;
2260                 goto err;
2261         }
2262 
2263         lsp->ls_kstat->ks_lock = &lsp->ls_kstat_lock;
2264         kstat_zone_add(lsp->ls_kstat, GLOBAL_ZONEID);
2265 
2266         lsp->ls_readonly = klip->li_readonly;
2267 
2268         if ((error = lofi_init_crypto(lsp, klip)) != 0)
2269                 goto err;
2270 
2271         if ((error = lofi_init_compress(lsp)) != 0)
2272                 goto err;
2273 
2274         fake_disk_geometry(lsp);
2275 
2276         /* create minor nodes */
2277 
2278         (void) snprintf(namebuf, sizeof (namebuf), "%d", minor);
2279         error = ddi_create_minor_node(lofi_dip, namebuf, S_IFBLK, minor,
2280             DDI_PSEUDO, NULL);
2281         if (error != DDI_SUCCESS) {
2282                 error = ENXIO;
2283                 goto err;
2284         }
2285 
2286         (void) snprintf(namebuf, sizeof (namebuf), "%d,raw", minor);
2287         error = ddi_create_minor_node(lofi_dip, namebuf, S_IFCHR, minor,
2288             DDI_PSEUDO, NULL);
2289         if (error != DDI_SUCCESS) {
2290                 /* remove block node */
2291                 (void) snprintf(namebuf, sizeof (namebuf), "%d", minor);
2292                 ddi_remove_minor_node(lofi_dip, namebuf);
2293                 error = ENXIO;
2294                 goto err;
2295         }
2296 
2297         /* create DDI properties */
2298 
2299         if ((ddi_prop_update_int64(newdev, lofi_dip, SIZE_PROP_NAME,
2300             lsp->ls_vp_size - lsp->ls_crypto_offset)) != DDI_PROP_SUCCESS) {
2301                 error = EINVAL;
2302                 goto nodeerr;
2303         }
2304 
2305         if ((ddi_prop_update_int64(newdev, lofi_dip, NBLOCKS_PROP_NAME,
2306             (lsp->ls_vp_size - lsp->ls_crypto_offset) / DEV_BSIZE))
2307             != DDI_PROP_SUCCESS) {
2308                 error = EINVAL;
2309                 goto nodeerr;
2310         }
2311 
2312         if (ddi_prop_update_string(newdev, lofi_dip, ZONE_PROP_NAME,
2313             (char *)curproc->p_zone->zone_name) != DDI_PROP_SUCCESS) {
2314                 error = EINVAL;
2315                 goto nodeerr;
2316         }
2317 
2318         kstat_install(lsp->ls_kstat);
2319 
2320         mutex_exit(&lofi_lock);
2321 
2322         if (rvalp)
2323                 *rvalp = (int)minor;
2324         klip->li_minor = minor;
2325         (void) copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
2326         free_lofi_ioctl(klip);
2327         return (0);
2328 
2329 nodeerr:
2330         lofi_free_dev(newdev);
2331 err:
2332         if (lsp != NULL) {
2333                 lofi_destroy(lsp, credp);
2334         } else {
2335                 if (vp != NULL) {
2336                         (void) VOP_CLOSE(vp, flag, 1, 0, credp, NULL);
2337                         VN_RELE(vp);
2338                 }
2339 
2340                 if (minor != (minor_t)-1)
2341                         id_free(lofi_minor_id, minor);
2342 
2343                 rctl_decr_lofi(curproc->p_zone, 1);
2344         }
2345 
2346         mutex_exit(&lofi_lock);
2347         free_lofi_ioctl(klip);
2348         return (error);
2349 }
2350 
2351 /*
2352  * unmap a file.
2353  */
2354 static int
2355 lofi_unmap_file(struct lofi_ioctl *ulip, int byfilename,
2356     struct cred *credp, int ioctl_flag)
2357 {
2358         struct lofi_state *lsp;
2359         struct lofi_ioctl *klip;
2360         int err;
2361 
2362         err = copy_in_lofi_ioctl(ulip, &klip, ioctl_flag);
2363         if (err != 0)
2364                 return (err);
2365 
2366         mutex_enter(&lofi_lock);
2367         if (byfilename) {
2368                 if ((err = file_to_lofi(klip->li_filename, klip->li_readonly,
2369                     &lsp)) != 0) {
2370                         mutex_exit(&lofi_lock);
2371                         return (err);
2372                 }
2373         } else if (klip->li_minor == 0) {
2374                 mutex_exit(&lofi_lock);
2375                 free_lofi_ioctl(klip);
2376                 return (ENXIO);
2377         } else {
2378                 lsp = ddi_get_soft_state(lofi_statep, klip->li_minor);
2379         }
2380 
2381         if (lsp == NULL || lsp->ls_vp == NULL || lofi_access(lsp) != 0) {
2382                 mutex_exit(&lofi_lock);
2383                 free_lofi_ioctl(klip);
2384                 return (ENXIO);
2385         }
2386 
2387         klip->li_minor = getminor(lsp->ls_dev);
2388 
2389         /*
2390          * If it's still held open, we'll do one of three things:
2391          *
2392          * If no flag is set, just return EBUSY.
2393          *
2394          * If the 'cleanup' flag is set, unmap and remove the device when
2395          * the last user finishes.
2396          *
2397          * If the 'force' flag is set, then we forcibly close the underlying
2398          * file.  Subsequent operations will fail, and the DKIOCSTATE ioctl
2399          * will return DKIO_DEV_GONE.  When the device is last closed, the
2400          * device will be cleaned up appropriately.
2401          *
2402          * This is complicated by the fact that we may have outstanding
2403          * dispatched I/Os.  Rather than having a single mutex to serialize all
2404          * I/O, we keep a count of the number of outstanding I/O requests
2405          * (ls_vp_iocount), as well as a flag to indicate that no new I/Os
2406          * should be dispatched (ls_vp_closereq).
2407          *
2408          * We set the flag, wait for the number of outstanding I/Os to reach 0,
2409          * and then close the underlying vnode.
2410          */
2411         if (is_opened(lsp)) {
2412                 if (klip->li_force) {
2413                         mutex_enter(&lsp->ls_vp_lock);
2414                         lsp->ls_vp_closereq = B_TRUE;
2415                         /* wake up any threads waiting on dkiocstate */
2416                         cv_broadcast(&lsp->ls_vp_cv);
2417                         while (lsp->ls_vp_iocount > 0)
2418                                 cv_wait(&lsp->ls_vp_cv, &lsp->ls_vp_lock);
2419                         mutex_exit(&lsp->ls_vp_lock);
2420 
2421                         goto out;
2422                 } else if (klip->li_cleanup) {
2423                         lsp->ls_cleanup = 1;
2424                         mutex_exit(&lofi_lock);
2425                         free_lofi_ioctl(klip);
2426                         return (0);
2427                 }
2428 
2429                 mutex_exit(&lofi_lock);
2430                 free_lofi_ioctl(klip);
2431                 return (EBUSY);
2432         }
2433 
2434 out:
2435         lofi_free_dev(lsp->ls_dev);
2436         lofi_destroy(lsp, credp);
2437 
2438         mutex_exit(&lofi_lock);
2439         (void) copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
2440         free_lofi_ioctl(klip);
2441         return (0);
2442 }
2443 
2444 /*
2445  * get the filename given the minor number, or the minor number given
2446  * the name.
2447  */
2448 /*ARGSUSED*/
2449 static int
2450 lofi_get_info(dev_t dev, struct lofi_ioctl *ulip, int which,
2451     struct cred *credp, int ioctl_flag)
2452 {
2453         struct lofi_ioctl *klip;
2454         struct lofi_state *lsp;
2455         int     error;
2456 
2457         error = copy_in_lofi_ioctl(ulip, &klip, ioctl_flag);
2458         if (error != 0)
2459                 return (error);
2460 
2461         switch (which) {
2462         case LOFI_GET_FILENAME:
2463                 if (klip->li_minor == 0) {
2464                         free_lofi_ioctl(klip);
2465                         return (EINVAL);
2466                 }
2467 
2468                 mutex_enter(&lofi_lock);
2469                 lsp = ddi_get_soft_state(lofi_statep, klip->li_minor);
2470                 if (lsp == NULL || lofi_access(lsp) != 0) {
2471                         mutex_exit(&lofi_lock);
2472                         free_lofi_ioctl(klip);
2473                         return (ENXIO);
2474                 }
2475 
2476                 /*
2477                  * This may fail if, for example, we're trying to look
2478                  * up a zoned NFS path from the global zone.
2479                  */
2480                 if (vnodetopath(NULL, lsp->ls_stacked_vp, klip->li_filename,
2481                     sizeof (klip->li_filename), CRED()) != 0) {
2482                         (void) strlcpy(klip->li_filename, "?",
2483                             sizeof (klip->li_filename));
2484                 }
2485 
2486                 klip->li_readonly = lsp->ls_readonly;
2487 
2488                 (void) strlcpy(klip->li_algorithm, lsp->ls_comp_algorithm,
2489                     sizeof (klip->li_algorithm));
2490                 klip->li_crypto_enabled = lsp->ls_crypto_enabled;
2491                 mutex_exit(&lofi_lock);
2492                 error = copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
2493                 free_lofi_ioctl(klip);
2494                 return (error);
2495         case LOFI_GET_MINOR:
2496                 mutex_enter(&lofi_lock);
2497                 error = file_to_lofi(klip->li_filename,
2498                     klip->li_readonly, &lsp);
2499                 if (error == 0)
2500                         klip->li_minor = getminor(lsp->ls_dev);
2501                 mutex_exit(&lofi_lock);
2502 
2503                 if (error == 0)
2504                         error = copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
2505 
2506                 free_lofi_ioctl(klip);
2507                 return (error);
2508         case LOFI_CHECK_COMPRESSED:
2509                 mutex_enter(&lofi_lock);
2510                 error = file_to_lofi(klip->li_filename,
2511                     klip->li_readonly, &lsp);
2512                 if (error != 0) {
2513                         mutex_exit(&lofi_lock);
2514                         free_lofi_ioctl(klip);
2515                         return (error);
2516                 }
2517 
2518                 klip->li_minor = getminor(lsp->ls_dev);
2519                 (void) strlcpy(klip->li_algorithm, lsp->ls_comp_algorithm,
2520                     sizeof (klip->li_algorithm));
2521 
2522                 mutex_exit(&lofi_lock);
2523                 error = copy_out_lofi_ioctl(klip, ulip, ioctl_flag);
2524                 free_lofi_ioctl(klip);
2525                 return (error);
2526         default:
2527                 free_lofi_ioctl(klip);
2528                 return (EINVAL);
2529         }
2530 }
2531 
2532 static int
2533 lofi_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *credp,
2534     int *rvalp)
2535 {
2536         int     error;
2537         enum dkio_state dkstate;
2538         struct lofi_state *lsp;
2539         minor_t minor;
2540 
2541         minor = getminor(dev);
2542         /* lofi ioctls only apply to the master device */
2543         if (minor == 0) {
2544                 struct lofi_ioctl *lip = (struct lofi_ioctl *)arg;
2545 
2546                 /*
2547                  * the query command only need read-access - i.e., normal
2548                  * users are allowed to do those on the ctl device as
2549                  * long as they can open it read-only.
2550                  */
2551                 switch (cmd) {
2552                 case LOFI_MAP_FILE:
2553                         if ((flag & FWRITE) == 0)
2554                                 return (EPERM);
2555                         return (lofi_map_file(dev, lip, 1, rvalp, credp, flag));
2556                 case LOFI_MAP_FILE_MINOR:
2557                         if ((flag & FWRITE) == 0)
2558                                 return (EPERM);
2559                         return (lofi_map_file(dev, lip, 0, rvalp, credp, flag));
2560                 case LOFI_UNMAP_FILE:
2561                         if ((flag & FWRITE) == 0)
2562                                 return (EPERM);
2563                         return (lofi_unmap_file(lip, 1, credp, flag));
2564                 case LOFI_UNMAP_FILE_MINOR:
2565                         if ((flag & FWRITE) == 0)
2566                                 return (EPERM);
2567                         return (lofi_unmap_file(lip, 0, credp, flag));
2568                 case LOFI_GET_FILENAME:
2569                         return (lofi_get_info(dev, lip, LOFI_GET_FILENAME,
2570                             credp, flag));
2571                 case LOFI_GET_MINOR:
2572                         return (lofi_get_info(dev, lip, LOFI_GET_MINOR,
2573                             credp, flag));
2574 
2575                 /*
2576                  * This API made limited sense when this value was fixed
2577                  * at LOFI_MAX_FILES.  However, its use to iterate
2578                  * across all possible devices in lofiadm means we don't
2579                  * want to return L_MAXMIN32, but the highest
2580                  * *allocated* minor.
2581                  */
2582                 case LOFI_GET_MAXMINOR:
2583                         minor = 0;
2584 
2585                         mutex_enter(&lofi_lock);
2586 
2587                         for (lsp = list_head(&lofi_list); lsp != NULL;
2588                             lsp = list_next(&lofi_list, lsp)) {
2589                                 if (lofi_access(lsp) != 0)
2590                                         continue;
2591 
2592                                 if (getminor(lsp->ls_dev) > minor)
2593                                         minor = getminor(lsp->ls_dev);
2594                         }
2595 
2596                         mutex_exit(&lofi_lock);
2597 
2598                         error = ddi_copyout(&minor, &lip->li_minor,
2599                             sizeof (minor), flag);
2600                         if (error)
2601                                 return (EFAULT);
2602                         return (0);
2603 
2604                 case LOFI_CHECK_COMPRESSED:
2605                         return (lofi_get_info(dev, lip, LOFI_CHECK_COMPRESSED,
2606                             credp, flag));
2607                 default:
2608                         return (EINVAL);
2609                 }
2610         }
2611 
2612         mutex_enter(&lofi_lock);
2613         lsp = ddi_get_soft_state(lofi_statep, minor);
2614         if (lsp == NULL || lsp->ls_vp_closereq) {
2615                 mutex_exit(&lofi_lock);
2616                 return (ENXIO);
2617         }
2618         mutex_exit(&lofi_lock);
2619 
2620         /*
2621          * We explicitly allow DKIOCSTATE, but all other ioctls should fail with
2622          * EIO as if the device was no longer present.
2623          */
2624         if (lsp->ls_vp == NULL && cmd != DKIOCSTATE)
2625                 return (EIO);
2626 
2627         /* these are for faking out utilities like newfs */
2628         switch (cmd) {
2629         case DKIOCGVTOC:
2630                 switch (ddi_model_convert_from(flag & FMODELS)) {
2631                 case DDI_MODEL_ILP32: {
2632                         struct vtoc32 vtoc32;
2633 
2634                         vtoctovtoc32(lsp->ls_vtoc, vtoc32);
2635                         if (ddi_copyout(&vtoc32, (void *)arg,
2636                             sizeof (struct vtoc32), flag))
2637                                 return (EFAULT);
2638                         break;
2639                         }
2640 
2641                 case DDI_MODEL_NONE:
2642                         if (ddi_copyout(&lsp->ls_vtoc, (void *)arg,
2643                             sizeof (struct vtoc), flag))
2644                                 return (EFAULT);
2645                         break;
2646                 }
2647                 return (0);
2648         case DKIOCINFO:
2649                 error = ddi_copyout(&lsp->ls_ci, (void *)arg,
2650                     sizeof (struct dk_cinfo), flag);
2651                 if (error)
2652                         return (EFAULT);
2653                 return (0);
2654         case DKIOCG_VIRTGEOM:
2655         case DKIOCG_PHYGEOM:
2656         case DKIOCGGEOM:
2657                 error = ddi_copyout(&lsp->ls_dkg, (void *)arg,
2658                     sizeof (struct dk_geom), flag);
2659                 if (error)
2660                         return (EFAULT);
2661                 return (0);
2662         case DKIOCSTATE:
2663                 /*
2664                  * Normally, lofi devices are always in the INSERTED state.  If
2665                  * a device is forcefully unmapped, then the device transitions
2666                  * to the DKIO_DEV_GONE state.
2667                  */
2668                 if (ddi_copyin((void *)arg, &dkstate, sizeof (dkstate),
2669                     flag) != 0)
2670                         return (EFAULT);
2671 
2672                 mutex_enter(&lsp->ls_vp_lock);
2673                 lsp->ls_vp_iocount++;
2674                 while (((dkstate == DKIO_INSERTED && lsp->ls_vp != NULL) ||
2675                     (dkstate == DKIO_DEV_GONE && lsp->ls_vp == NULL)) &&
2676                     !lsp->ls_vp_closereq) {
2677                         /*
2678                          * By virtue of having the device open, we know that
2679                          * 'lsp' will remain valid when we return.
2680                          */
2681                         if (!cv_wait_sig(&lsp->ls_vp_cv,
2682                             &lsp->ls_vp_lock)) {
2683                                 lsp->ls_vp_iocount--;
2684                                 cv_broadcast(&lsp->ls_vp_cv);
2685                                 mutex_exit(&lsp->ls_vp_lock);
2686                                 return (EINTR);
2687                         }
2688                 }
2689 
2690                 dkstate = (!lsp->ls_vp_closereq && lsp->ls_vp != NULL ?
2691                     DKIO_INSERTED : DKIO_DEV_GONE);
2692                 lsp->ls_vp_iocount--;
2693                 cv_broadcast(&lsp->ls_vp_cv);
2694                 mutex_exit(&lsp->ls_vp_lock);
2695 
2696                 if (ddi_copyout(&dkstate, (void *)arg,
2697                     sizeof (dkstate), flag) != 0)
2698                         return (EFAULT);
2699                 return (0);
2700         default:
2701                 return (ENOTTY);
2702         }
2703 }
2704 
2705 static struct cb_ops lofi_cb_ops = {
2706         lofi_open,              /* open */
2707         lofi_close,             /* close */
2708         lofi_strategy,          /* strategy */
2709         nodev,                  /* print */
2710         nodev,                  /* dump */
2711         lofi_read,              /* read */
2712         lofi_write,             /* write */
2713         lofi_ioctl,             /* ioctl */
2714         nodev,                  /* devmap */
2715         nodev,                  /* mmap */
2716         nodev,                  /* segmap */
2717         nochpoll,               /* poll */
2718         ddi_prop_op,            /* prop_op */
2719         0,                      /* streamtab  */
2720         D_64BIT | D_NEW | D_MP, /* Driver compatibility flag */
2721         CB_REV,
2722         lofi_aread,
2723         lofi_awrite
2724 };
2725 
2726 static struct dev_ops lofi_ops = {
2727         DEVO_REV,               /* devo_rev, */
2728         0,                      /* refcnt  */
2729         lofi_info,              /* info */
2730         nulldev,                /* identify */
2731         nulldev,                /* probe */
2732         lofi_attach,            /* attach */
2733         lofi_detach,            /* detach */
2734         nodev,                  /* reset */
2735         &lofi_cb_ops,               /* driver operations */
2736         NULL,                   /* no bus operations */
2737         NULL,                   /* power */
2738         ddi_quiesce_not_needed, /* quiesce */
2739 };
2740 
2741 static struct modldrv modldrv = {
2742         &mod_driverops,
2743         "loopback file driver",
2744         &lofi_ops,
2745 };
2746 
2747 static struct modlinkage modlinkage = {
2748         MODREV_1,
2749         &modldrv,
2750         NULL
2751 };
2752 
2753 int
2754 _init(void)
2755 {
2756         int error;
2757 
2758         list_create(&lofi_list, sizeof (struct lofi_state),
2759             offsetof(struct lofi_state, ls_list));
2760 
2761         error = ddi_soft_state_init(&lofi_statep,
2762             sizeof (struct lofi_state), 0);
2763         if (error)
2764                 return (error);
2765 
2766         mutex_init(&lofi_lock, NULL, MUTEX_DRIVER, NULL);
2767 
2768         error = mod_install(&modlinkage);
2769         if (error) {
2770                 mutex_destroy(&lofi_lock);
2771                 ddi_soft_state_fini(&lofi_statep);
2772                 list_destroy(&lofi_list);
2773         }
2774 
2775         return (error);
2776 }
2777 
2778 int
2779 _fini(void)
2780 {
2781         int     error;
2782 
2783         mutex_enter(&lofi_lock);
2784 
2785         if (!list_is_empty(&lofi_list)) {
2786                 mutex_exit(&lofi_lock);
2787                 return (EBUSY);
2788         }
2789 
2790         mutex_exit(&lofi_lock);
2791 
2792         error = mod_remove(&modlinkage);
2793         if (error)
2794                 return (error);
2795 
2796         mutex_destroy(&lofi_lock);
2797         ddi_soft_state_fini(&lofi_statep);
2798         list_destroy(&lofi_list);
2799 
2800         return (error);
2801 }
2802 
2803 int
2804 _info(struct modinfo *modinfop)
2805 {
2806         return (mod_info(&modlinkage, modinfop));
2807 }