sys/kern/subr_compressor.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2014, 2017 Mark Johnston <markj@FreeBSD.org>
   5  * Copyright (c) 2017 Conrad Meyer <cem@FreeBSD.org>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are
   9  * met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Subroutines used for writing compressed user process and kernel core dumps.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include "opt_gzio.h"
  38 #include "opt_zstdio.h"
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42
  43 #include <sys/compressor.h>
  44 #include <sys/kernel.h>
  45 #include <sys/linker_set.h>
  46 #include <sys/malloc.h>
  47
  48 MALLOC_DEFINE(M_COMPRESS, "compressor", "kernel compression subroutines");
  49
  50 struct compressor_methods {
  51         int format;
  52         void *(* const init)(size_t, int);
  53         void (* const reset)(void *);
  54         int (* const write)(void *, void *, size_t, compressor_cb_t, void *);
  55         void (* const fini)(void *);
  56 };
  57
  58 struct compressor {
  59         const struct compressor_methods *methods;
  60         compressor_cb_t cb;
  61         void *priv;
  62         void *arg;
  63 };
  64
  65 SET_DECLARE(compressors, struct compressor_methods);
  66
  67 #ifdef GZIO
  68
  69 #include <contrib/zlib/zutil.h>
  70
  71 struct gz_stream {
  72         uint8_t         *gz_buffer;     /* output buffer */
  73         size_t          gz_bufsz;       /* output buffer size */
  74         off_t           gz_off;         /* offset into the output stream */
  75         uint32_t        gz_crc;         /* stream CRC32 */
  76         z_stream        gz_stream;      /* zlib state */
  77 };
  78
  79 static void     *gz_init(size_t maxiosize, int level);
  80 static void     gz_reset(void *stream);
  81 static int      gz_write(void *stream, void *data, size_t len, compressor_cb_t,
  82                     void *);
  83 static void     gz_fini(void *stream);
  84
  85 static void *
  86 gz_alloc(void *arg __unused, u_int n, u_int sz)
  87 {
  88
  89         /*
  90          * Memory for zlib state is allocated using M_NODUMP since it may be
  91          * used to compress a kernel dump, and we don't want zlib to attempt to
  92          * compress its own state.
  93          */
  94         return (malloc(n * sz, M_COMPRESS, M_WAITOK | M_ZERO | M_NODUMP));
  95 }
  96
  97 static void
  98 gz_free(void *arg __unused, void *ptr)
  99 {
 100
 101         free(ptr, M_COMPRESS);
 102 }
 103
 104 static void *
 105 gz_init(size_t maxiosize, int level)
 106 {
 107         struct gz_stream *s;
 108         int error;
 109
 110         s = gz_alloc(NULL, 1, roundup2(sizeof(*s), PAGE_SIZE));
 111         s->gz_buffer = gz_alloc(NULL, 1, maxiosize);
 112         s->gz_bufsz = maxiosize;
 113
 114         s->gz_stream.zalloc = gz_alloc;
 115         s->gz_stream.zfree = gz_free;
 116         s->gz_stream.opaque = NULL;
 117         s->gz_stream.next_in = Z_NULL;
 118         s->gz_stream.avail_in = 0;
 119
 120         if (level != Z_DEFAULT_COMPRESSION) {
 121                 if (level < Z_BEST_SPEED)
 122                         level = Z_BEST_SPEED;
 123                 else if (level > Z_BEST_COMPRESSION)
 124                         level = Z_BEST_COMPRESSION;
 125         }
 126
 127         error = deflateInit2(&s->gz_stream, level, Z_DEFLATED, -MAX_WBITS,
 128             DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
 129         if (error != 0)
 130                 goto fail;
 131
 132         gz_reset(s);
 133
 134         return (s);
 135
 136 fail:
 137         gz_free(NULL, s);
 138         return (NULL);
 139 }
 140
 141 static void
 142 gz_reset(void *stream)
 143 {
 144         struct gz_stream *s;
 145         uint8_t *hdr;
 146         const size_t hdrlen = 10;
 147
 148         s = stream;
 149         s->gz_off = 0;
 150         s->gz_crc = crc32(0L, Z_NULL, 0);
 151
 152         (void)deflateReset(&s->gz_stream);
 153         s->gz_stream.avail_out = s->gz_bufsz;
 154         s->gz_stream.next_out = s->gz_buffer;
 155
 156         /* Write the gzip header to the output buffer. */
 157         hdr = s->gz_buffer;
 158         memset(hdr, 0, hdrlen);
 159         hdr[0] = 0x1f;
 160         hdr[1] = 0x8b;
 161         hdr[2] = Z_DEFLATED;
 162         hdr[9] = OS_CODE;
 163         s->gz_stream.next_out += hdrlen;
 164         s->gz_stream.avail_out -= hdrlen;
 165 }
 166
 167 static int
 168 gz_write(void *stream, void *data, size_t len, compressor_cb_t cb,
 169     void *arg)
 170 {
 171         struct gz_stream *s;
 172         uint8_t trailer[8];
 173         size_t room;
 174         int error, zerror, zflag;
 175
 176         s = stream;
 177         zflag = data == NULL ? Z_FINISH : Z_NO_FLUSH;
 178
 179         if (len > 0) {
 180                 s->gz_stream.avail_in = len;
 181                 s->gz_stream.next_in = data;
 182                 s->gz_crc = crc32(s->gz_crc, data, len);
 183         }
 184
 185         error = 0;
 186         do {
 187                 zerror = deflate(&s->gz_stream, zflag);
 188                 if (zerror != Z_OK && zerror != Z_STREAM_END) {
 189                         error = EIO;
 190                         break;
 191                 }
 192
 193                 if (s->gz_stream.avail_out == 0 || zerror == Z_STREAM_END) {
 194                         /*
 195                          * Our output buffer is full or there's nothing left
 196                          * to produce, so we're flushing the buffer.
 197                          */
 198                         len = s->gz_bufsz - s->gz_stream.avail_out;
 199                         if (zerror == Z_STREAM_END) {
 200                                 /*
 201                                  * Try to pack as much of the trailer into the
 202                                  * output buffer as we can.
 203                                  */
 204                                 ((uint32_t *)trailer)[0] = s->gz_crc;
 205                                 ((uint32_t *)trailer)[1] =
 206                                     s->gz_stream.total_in;
 207                                 room = MIN(sizeof(trailer),
 208                                     s->gz_bufsz - len);
 209                                 memcpy(s->gz_buffer + len, trailer, room);
 210                                 len += room;
 211                         }
 212
 213                         error = cb(s->gz_buffer, len, s->gz_off, arg);
 214                         if (error != 0)
 215                                 break;
 216
 217                         s->gz_off += len;
 218                         s->gz_stream.next_out = s->gz_buffer;
 219                         s->gz_stream.avail_out = s->gz_bufsz;
 220
 221                         /*
 222                          * If we couldn't pack the trailer into the output
 223                          * buffer, write it out now.
 224                          */
 225                         if (zerror == Z_STREAM_END && room < sizeof(trailer))
 226                                 error = cb(trailer + room,
 227                                     sizeof(trailer) - room, s->gz_off, arg);
 228                 }
 229         } while (zerror != Z_STREAM_END &&
 230             (zflag == Z_FINISH || s->gz_stream.avail_in > 0));
 231
 232         return (error);
 233 }
 234
 235 static void
 236 gz_fini(void *stream)
 237 {
 238         struct gz_stream *s;
 239
 240         s = stream;
 241         (void)deflateEnd(&s->gz_stream);
 242         gz_free(NULL, s->gz_buffer);
 243         gz_free(NULL, s);
 244 }
 245
 246 struct compressor_methods gzip_methods = {
 247         .format = COMPRESS_GZIP,
 248         .init = gz_init,
 249         .reset = gz_reset,
 250         .write = gz_write,
 251         .fini = gz_fini,
 252 };
 253 DATA_SET(compressors, gzip_methods);
 254
 255 #endif /* GZIO */
 256
 257 #ifdef ZSTDIO
 258
 259 #define ZSTD_STATIC_LINKING_ONLY
 260 #include <contrib/zstd/lib/zstd.h>
 261
 262 struct zstdio_stream {
 263         ZSTD_CCtx       *zst_stream;
 264         ZSTD_inBuffer   zst_inbuffer;
 265         ZSTD_outBuffer  zst_outbuffer;
 266         uint8_t *       zst_buffer;     /* output buffer */
 267         size_t          zst_maxiosz;    /* Max output IO size */
 268         off_t           zst_off;        /* offset into the output stream */
 269         void *          zst_static_wkspc;
 270 };
 271
 272 static void     *zstdio_init(size_t maxiosize, int level);
 273 static void     zstdio_reset(void *stream);
 274 static int      zstdio_write(void *stream, void *data, size_t len,
 275                     compressor_cb_t, void *);
 276 static void     zstdio_fini(void *stream);
 277
 278 static void *
 279 zstdio_init(size_t maxiosize, int level)
 280 {
 281         ZSTD_CCtx *dump_compressor;
 282         struct zstdio_stream *s;
 283         void *wkspc, *owkspc, *buffer;
 284         size_t wkspc_size, buf_size, rc;
 285
 286         s = NULL;
 287         wkspc_size = ZSTD_estimateCStreamSize(level);
 288         owkspc = wkspc = malloc(wkspc_size + 8, M_COMPRESS,
 289             M_WAITOK | M_NODUMP);
 290         /* Zstd API requires 8-byte alignment. */
 291         if ((uintptr_t)wkspc % 8 != 0)
 292                 wkspc = (void *)roundup2((uintptr_t)wkspc, 8);
 293
 294         dump_compressor = ZSTD_initStaticCCtx(wkspc, wkspc_size);
 295         if (dump_compressor == NULL) {
 296                 printf("%s: workspace too small.\n", __func__);
 297                 goto out;
 298         }
 299
 300         rc = ZSTD_CCtx_setParameter(dump_compressor, ZSTD_c_checksumFlag, 1);
 301         if (ZSTD_isError(rc)) {
 302                 printf("%s: error setting checksumFlag: %s\n", __func__,
 303                     ZSTD_getErrorName(rc));
 304                 goto out;
 305         }
 306         rc = ZSTD_CCtx_setParameter(dump_compressor, ZSTD_c_compressionLevel,
 307             level);
 308         if (ZSTD_isError(rc)) {
 309                 printf("%s: error setting compressLevel: %s\n", __func__,
 310                     ZSTD_getErrorName(rc));
 311                 goto out;
 312         }
 313
 314         buf_size = ZSTD_CStreamOutSize() * 2;
 315         buffer = malloc(buf_size, M_COMPRESS, M_WAITOK | M_NODUMP);
 316
 317         s = malloc(sizeof(*s), M_COMPRESS, M_NODUMP | M_WAITOK);
 318         s->zst_buffer = buffer;
 319         s->zst_outbuffer.dst = buffer;
 320         s->zst_outbuffer.size = buf_size;
 321         s->zst_maxiosz = maxiosize;
 322         s->zst_stream = dump_compressor;
 323         s->zst_static_wkspc = owkspc;
 324
 325         zstdio_reset(s);
 326
 327 out:
 328         if (s == NULL)
 329                 free(owkspc, M_COMPRESS);
 330         return (s);
 331 }
 332
 333 static void
 334 zstdio_reset(void *stream)
 335 {
 336         struct zstdio_stream *s;
 337         size_t res;
 338
 339         s = stream;
 340         res = ZSTD_resetCStream(s->zst_stream, 0);
 341         if (ZSTD_isError(res))
 342                 panic("%s: could not reset stream %p: %s\n", __func__, s,
 343                     ZSTD_getErrorName(res));
 344
 345         s->zst_off = 0;
 346         s->zst_inbuffer.src = NULL;
 347         s->zst_inbuffer.size = 0;
 348         s->zst_inbuffer.pos = 0;
 349         s->zst_outbuffer.pos = 0;
 350 }
 351
 352 static int
 353 zst_flush_intermediate(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
 354 {
 355         size_t bytes_to_dump;
 356         int error;
 357
 358         /* Flush as many full output blocks as possible. */
 359         /* XXX: 4096 is arbitrary safe HDD block size for kernel dumps */
 360         while (s->zst_outbuffer.pos >= 4096) {
 361                 bytes_to_dump = rounddown(s->zst_outbuffer.pos, 4096);
 362
 363                 if (bytes_to_dump > s->zst_maxiosz)
 364                         bytes_to_dump = s->zst_maxiosz;
 365
 366                 error = cb(s->zst_buffer, bytes_to_dump, s->zst_off, arg);
 367                 if (error != 0)
 368                         return (error);
 369
 370                 /*
 371                  * Shift any non-full blocks up to the front of the output
 372                  * buffer.
 373                  */
 374                 s->zst_outbuffer.pos -= bytes_to_dump;
 375                 memmove(s->zst_outbuffer.dst,
 376                     (char *)s->zst_outbuffer.dst + bytes_to_dump,
 377                     s->zst_outbuffer.pos);
 378                 s->zst_off += bytes_to_dump;
 379         }
 380         return (0);
 381 }
 382
 383 static int
 384 zstdio_flush(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
 385 {
 386         size_t rc, lastpos;
 387         int error;
 388
 389         /*
 390          * Positive return indicates unflushed data remaining; need to call
 391          * endStream again after clearing out room in output buffer.
 392          */
 393         rc = 1;
 394         lastpos = s->zst_outbuffer.pos;
 395         while (rc > 0) {
 396                 rc = ZSTD_endStream(s->zst_stream, &s->zst_outbuffer);
 397                 if (ZSTD_isError(rc)) {
 398                         printf("%s: ZSTD_endStream failed (%s)\n", __func__,
 399                             ZSTD_getErrorName(rc));
 400                         return (EIO);
 401                 }
 402                 if (lastpos == s->zst_outbuffer.pos) {
 403                         printf("%s: did not make forward progress endStream %zu\n",
 404                             __func__, lastpos);
 405                         return (EIO);
 406                 }
 407
 408                 error = zst_flush_intermediate(s, cb, arg);
 409                 if (error != 0)
 410                         return (error);
 411
 412                 lastpos = s->zst_outbuffer.pos;
 413         }
 414
 415         /*
 416          * We've already done an intermediate flush, so all full blocks have
 417          * been written.  Only a partial block remains.  Padding happens in a
 418          * higher layer.
 419          */
 420         if (s->zst_outbuffer.pos != 0) {
 421                 error = cb(s->zst_buffer, s->zst_outbuffer.pos, s->zst_off,
 422                     arg);
 423                 if (error != 0)
 424                         return (error);
 425         }
 426
 427         return (0);
 428 }
 429
 430 static int
 431 zstdio_write(void *stream, void *data, size_t len, compressor_cb_t cb,
 432     void *arg)
 433 {
 434         struct zstdio_stream *s;
 435         size_t lastpos, rc;
 436         int error;
 437
 438         s = stream;
 439         if (data == NULL)
 440                 return (zstdio_flush(s, cb, arg));
 441
 442         s->zst_inbuffer.src = data;
 443         s->zst_inbuffer.size = len;
 444         s->zst_inbuffer.pos = 0;
 445         lastpos = 0;
 446
 447         while (s->zst_inbuffer.pos < s->zst_inbuffer.size) {
 448                 rc = ZSTD_compressStream(s->zst_stream, &s->zst_outbuffer,
 449                     &s->zst_inbuffer);
 450                 if (ZSTD_isError(rc)) {
 451                         printf("%s: Compress failed on %p! (%s)\n",
 452                             __func__, data, ZSTD_getErrorName(rc));
 453                         return (EIO);
 454                 }
 455
 456                 if (lastpos == s->zst_inbuffer.pos) {
 457                         /*
 458                          * XXX: May need flushStream to make forward progress
 459                          */
 460                         printf("ZSTD: did not make forward progress @pos %zu\n",
 461                             lastpos);
 462                         return (EIO);
 463                 }
 464                 lastpos = s->zst_inbuffer.pos;
 465
 466                 error = zst_flush_intermediate(s, cb, arg);
 467                 if (error != 0)
 468                         return (error);
 469         }
 470         return (0);
 471 }
 472
 473 static void
 474 zstdio_fini(void *stream)
 475 {
 476         struct zstdio_stream *s;
 477
 478         s = stream;
 479         if (s->zst_static_wkspc != NULL)
 480                 free(s->zst_static_wkspc, M_COMPRESS);
 481         else
 482                 ZSTD_freeCCtx(s->zst_stream);
 483         free(s->zst_buffer, M_COMPRESS);
 484         free(s, M_COMPRESS);
 485 }
 486
 487 static struct compressor_methods zstd_methods = {
 488         .format = COMPRESS_ZSTD,
 489         .init = zstdio_init,
 490         .reset = zstdio_reset,
 491         .write = zstdio_write,
 492         .fini = zstdio_fini,
 493 };
 494 DATA_SET(compressors, zstd_methods);
 495
 496 #endif /* ZSTDIO */
 497
 498 bool
 499 compressor_avail(int format)
 500 {
 501         struct compressor_methods **iter;
 502
 503         SET_FOREACH(iter, compressors) {
 504                 if ((*iter)->format == format)
 505                         return (true);
 506         }
 507         return (false);
 508 }
 509
 510 struct compressor *
 511 compressor_init(compressor_cb_t cb, int format, size_t maxiosize, int level,
 512     void *arg)
 513 {
 514         struct compressor_methods **iter;
 515         struct compressor *s;
 516         void *priv;
 517
 518         SET_FOREACH(iter, compressors) {
 519                 if ((*iter)->format == format)
 520                         break;
 521         }
 522         if (iter == SET_LIMIT(compressors))
 523                 return (NULL);
 524
 525         priv = (*iter)->init(maxiosize, level);
 526         if (priv == NULL)
 527                 return (NULL);
 528
 529         s = malloc(sizeof(*s), M_COMPRESS, M_WAITOK | M_ZERO);
 530         s->methods = (*iter);
 531         s->priv = priv;
 532         s->cb = cb;
 533         s->arg = arg;
 534         return (s);
 535 }
 536
 537 void
 538 compressor_reset(struct compressor *stream)
 539 {
 540
 541         stream->methods->reset(stream->priv);
 542 }
 543
 544 int
 545 compressor_write(struct compressor *stream, void *data, size_t len)
 546 {
 547
 548         return (stream->methods->write(stream->priv, data, len, stream->cb,
 549             stream->arg));
 550 }
 551
 552 int
 553 compressor_flush(struct compressor *stream)
 554 {
 555
 556         return (stream->methods->write(stream->priv, NULL, 0, stream->cb,
 557             stream->arg));
 558 }
 559
 560 void
 561 compressor_fini(struct compressor *stream)
 562 {
 563
 564         stream->methods->fini(stream->priv);
 565 }