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 <sys/gsb_crc32.h>
  70 #include <sys/zutil.h>
  71
  72 struct gz_stream {
  73         uint8_t         *gz_buffer;     /* output buffer */
  74         size_t          gz_bufsz;       /* output buffer size */
  75         off_t           gz_off;         /* offset into the output stream */
  76         uint32_t        gz_crc;         /* stream CRC32 */
  77         z_stream        gz_stream;      /* zlib state */
  78 };
  79
  80 static void     *gz_init(size_t maxiosize, int level);
  81 static void     gz_reset(void *stream);
  82 static int      gz_write(void *stream, void *data, size_t len, compressor_cb_t,
  83                     void *);
  84 static void     gz_fini(void *stream);
  85
  86 static void *
  87 gz_alloc(void *arg __unused, u_int n, u_int sz)
  88 {
  89
  90         /*
  91          * Memory for zlib state is allocated using M_NODUMP since it may be
  92          * used to compress a kernel dump, and we don't want zlib to attempt to
  93          * compress its own state.
  94          */
  95         return (malloc(n * sz, M_COMPRESS, M_WAITOK | M_ZERO | M_NODUMP));
  96 }
  97
  98 static void
  99 gz_free(void *arg __unused, void *ptr)
 100 {
 101
 102         free(ptr, M_COMPRESS);
 103 }
 104
 105 static void *
 106 gz_init(size_t maxiosize, int level)
 107 {
 108         struct gz_stream *s;
 109         int error;
 110
 111         s = gz_alloc(NULL, 1, roundup2(sizeof(*s), PAGE_SIZE));
 112         s->gz_buffer = gz_alloc(NULL, 1, maxiosize);
 113         s->gz_bufsz = maxiosize;
 114
 115         s->gz_stream.zalloc = gz_alloc;
 116         s->gz_stream.zfree = gz_free;
 117         s->gz_stream.opaque = NULL;
 118         s->gz_stream.next_in = Z_NULL;
 119         s->gz_stream.avail_in = 0;
 120
 121         error = deflateInit2(&s->gz_stream, level, Z_DEFLATED, -MAX_WBITS,
 122             DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
 123         if (error != 0)
 124                 goto fail;
 125
 126         gz_reset(s);
 127
 128         return (s);
 129
 130 fail:
 131         gz_free(NULL, s);
 132         return (NULL);
 133 }
 134
 135 static void
 136 gz_reset(void *stream)
 137 {
 138         struct gz_stream *s;
 139         uint8_t *hdr;
 140         const size_t hdrlen = 10;
 141
 142         s = stream;
 143         s->gz_off = 0;
 144         s->gz_crc = ~0U;
 145
 146         (void)deflateReset(&s->gz_stream);
 147         s->gz_stream.avail_out = s->gz_bufsz;
 148         s->gz_stream.next_out = s->gz_buffer;
 149
 150         /* Write the gzip header to the output buffer. */
 151         hdr = s->gz_buffer;
 152         memset(hdr, 0, hdrlen);
 153         hdr[0] = 0x1f;
 154         hdr[1] = 0x8b;
 155         hdr[2] = Z_DEFLATED;
 156         hdr[9] = OS_CODE;
 157         s->gz_stream.next_out += hdrlen;
 158         s->gz_stream.avail_out -= hdrlen;
 159 }
 160
 161 static int
 162 gz_write(void *stream, void *data, size_t len, compressor_cb_t cb,
 163     void *arg)
 164 {
 165         struct gz_stream *s;
 166         uint8_t trailer[8];
 167         size_t room;
 168         int error, zerror, zflag;
 169
 170         s = stream;
 171         zflag = data == NULL ? Z_FINISH : Z_NO_FLUSH;
 172
 173         if (len > 0) {
 174                 s->gz_stream.avail_in = len;
 175                 s->gz_stream.next_in = data;
 176                 s->gz_crc = crc32_raw(data, len, s->gz_crc);
 177         } else
 178                 s->gz_crc ^= ~0U;
 179
 180         error = 0;
 181         do {
 182                 zerror = deflate(&s->gz_stream, zflag);
 183                 if (zerror != Z_OK && zerror != Z_STREAM_END) {
 184                         error = EIO;
 185                         break;
 186                 }
 187
 188                 if (s->gz_stream.avail_out == 0 || zerror == Z_STREAM_END) {
 189                         /*
 190                          * Our output buffer is full or there's nothing left
 191                          * to produce, so we're flushing the buffer.
 192                          */
 193                         len = s->gz_bufsz - s->gz_stream.avail_out;
 194                         if (zerror == Z_STREAM_END) {
 195                                 /*
 196                                  * Try to pack as much of the trailer into the
 197                                  * output buffer as we can.
 198                                  */
 199                                 ((uint32_t *)trailer)[0] = s->gz_crc;
 200                                 ((uint32_t *)trailer)[1] =
 201                                     s->gz_stream.total_in;
 202                                 room = MIN(sizeof(trailer),
 203                                     s->gz_bufsz - len);
 204                                 memcpy(s->gz_buffer + len, trailer, room);
 205                                 len += room;
 206                         }
 207
 208                         error = cb(s->gz_buffer, len, s->gz_off, arg);
 209                         if (error != 0)
 210                                 break;
 211
 212                         s->gz_off += len;
 213                         s->gz_stream.next_out = s->gz_buffer;
 214                         s->gz_stream.avail_out = s->gz_bufsz;
 215
 216                         /*
 217                          * If we couldn't pack the trailer into the output
 218                          * buffer, write it out now.
 219                          */
 220                         if (zerror == Z_STREAM_END && room < sizeof(trailer))
 221                                 error = cb(trailer + room,
 222                                     sizeof(trailer) - room, s->gz_off, arg);
 223                 }
 224         } while (zerror != Z_STREAM_END &&
 225             (zflag == Z_FINISH || s->gz_stream.avail_in > 0));
 226
 227         return (error);
 228 }
 229
 230 static void
 231 gz_fini(void *stream)
 232 {
 233         struct gz_stream *s;
 234
 235         s = stream;
 236         (void)deflateEnd(&s->gz_stream);
 237         gz_free(NULL, s->gz_buffer);
 238         gz_free(NULL, s);
 239 }
 240
 241 struct compressor_methods gzip_methods = {
 242         .format = COMPRESS_GZIP,
 243         .init = gz_init,
 244         .reset = gz_reset,
 245         .write = gz_write,
 246         .fini = gz_fini,
 247 };
 248 DATA_SET(compressors, gzip_methods);
 249
 250 #endif /* GZIO */
 251
 252 #ifdef ZSTDIO
 253
 254 #define ZSTD_STATIC_LINKING_ONLY
 255 #include <contrib/zstd/lib/zstd.h>
 256
 257 struct zstdio_stream {
 258         ZSTD_CCtx       *zst_stream;
 259         ZSTD_inBuffer   zst_inbuffer;
 260         ZSTD_outBuffer  zst_outbuffer;
 261         uint8_t *       zst_buffer;     /* output buffer */
 262         size_t          zst_maxiosz;    /* Max output IO size */
 263         off_t           zst_off;        /* offset into the output stream */
 264         void *          zst_static_wkspc;
 265 };
 266
 267 static void     *zstdio_init(size_t maxiosize, int level);
 268 static void     zstdio_reset(void *stream);
 269 static int      zstdio_write(void *stream, void *data, size_t len,
 270                     compressor_cb_t, void *);
 271 static void     zstdio_fini(void *stream);
 272
 273 static void *
 274 zstdio_init(size_t maxiosize, int level)
 275 {
 276         ZSTD_CCtx *dump_compressor;
 277         struct zstdio_stream *s;
 278         void *wkspc, *owkspc, *buffer;
 279         size_t wkspc_size, buf_size, rc;
 280
 281         s = NULL;
 282         wkspc_size = ZSTD_estimateCStreamSize(level);
 283         owkspc = wkspc = malloc(wkspc_size + 8, M_COMPRESS,
 284             M_WAITOK | M_NODUMP);
 285         /* Zstd API requires 8-byte alignment. */
 286         if ((uintptr_t)wkspc % 8 != 0)
 287                 wkspc = (void *)roundup2((uintptr_t)wkspc, 8);
 288
 289         dump_compressor = ZSTD_initStaticCCtx(wkspc, wkspc_size);
 290         if (dump_compressor == NULL) {
 291                 printf("%s: workspace too small.\n", __func__);
 292                 goto out;
 293         }
 294
 295         rc = ZSTD_CCtx_setParameter(dump_compressor, ZSTD_c_checksumFlag, 1);
 296         if (ZSTD_isError(rc)) {
 297                 printf("%s: error setting checksumFlag: %s\n", __func__,
 298                     ZSTD_getErrorName(rc));
 299                 goto out;
 300         }
 301         rc = ZSTD_CCtx_setParameter(dump_compressor, ZSTD_c_compressionLevel,
 302             level);
 303         if (ZSTD_isError(rc)) {
 304                 printf("%s: error setting compressLevel: %s\n", __func__,
 305                     ZSTD_getErrorName(rc));
 306                 goto out;
 307         }
 308
 309         buf_size = ZSTD_CStreamOutSize() * 2;
 310         buffer = malloc(buf_size, M_COMPRESS, M_WAITOK | M_NODUMP);
 311
 312         s = malloc(sizeof(*s), M_COMPRESS, M_NODUMP | M_WAITOK);
 313         s->zst_buffer = buffer;
 314         s->zst_outbuffer.dst = buffer;
 315         s->zst_outbuffer.size = buf_size;
 316         s->zst_maxiosz = maxiosize;
 317         s->zst_stream = dump_compressor;
 318         s->zst_static_wkspc = owkspc;
 319
 320         zstdio_reset(s);
 321
 322 out:
 323         if (s == NULL)
 324                 free(owkspc, M_COMPRESS);
 325         return (s);
 326 }
 327
 328 static void
 329 zstdio_reset(void *stream)
 330 {
 331         struct zstdio_stream *s;
 332         size_t res;
 333
 334         s = stream;
 335         res = ZSTD_resetCStream(s->zst_stream, 0);
 336         if (ZSTD_isError(res))
 337                 panic("%s: could not reset stream %p: %s\n", __func__, s,
 338                     ZSTD_getErrorName(res));
 339
 340         s->zst_off = 0;
 341         s->zst_inbuffer.src = NULL;
 342         s->zst_inbuffer.size = 0;
 343         s->zst_inbuffer.pos = 0;
 344         s->zst_outbuffer.pos = 0;
 345 }
 346
 347 static int
 348 zst_flush_intermediate(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
 349 {
 350         size_t bytes_to_dump;
 351         int error;
 352
 353         /* Flush as many full output blocks as possible. */
 354         /* XXX: 4096 is arbitrary safe HDD block size for kernel dumps */
 355         while (s->zst_outbuffer.pos >= 4096) {
 356                 bytes_to_dump = rounddown(s->zst_outbuffer.pos, 4096);
 357
 358                 if (bytes_to_dump > s->zst_maxiosz)
 359                         bytes_to_dump = s->zst_maxiosz;
 360
 361                 error = cb(s->zst_buffer, bytes_to_dump, s->zst_off, arg);
 362                 if (error != 0)
 363                         return (error);
 364
 365                 /*
 366                  * Shift any non-full blocks up to the front of the output
 367                  * buffer.
 368                  */
 369                 s->zst_outbuffer.pos -= bytes_to_dump;
 370                 memmove(s->zst_outbuffer.dst,
 371                     (char *)s->zst_outbuffer.dst + bytes_to_dump,
 372                     s->zst_outbuffer.pos);
 373                 s->zst_off += bytes_to_dump;
 374         }
 375         return (0);
 376 }
 377
 378 static int
 379 zstdio_flush(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
 380 {
 381         size_t rc, lastpos;
 382         int error;
 383
 384         /*
 385          * Positive return indicates unflushed data remaining; need to call
 386          * endStream again after clearing out room in output buffer.
 387          */
 388         rc = 1;
 389         lastpos = s->zst_outbuffer.pos;
 390         while (rc > 0) {
 391                 rc = ZSTD_endStream(s->zst_stream, &s->zst_outbuffer);
 392                 if (ZSTD_isError(rc)) {
 393                         printf("%s: ZSTD_endStream failed (%s)\n", __func__,
 394                             ZSTD_getErrorName(rc));
 395                         return (EIO);
 396                 }
 397                 if (lastpos == s->zst_outbuffer.pos) {
 398                         printf("%s: did not make forward progress endStream %zu\n",
 399                             __func__, lastpos);
 400                         return (EIO);
 401                 }
 402
 403                 error = zst_flush_intermediate(s, cb, arg);
 404                 if (error != 0)
 405                         return (error);
 406
 407                 lastpos = s->zst_outbuffer.pos;
 408         }
 409
 410         /*
 411          * We've already done an intermediate flush, so all full blocks have
 412          * been written.  Only a partial block remains.  Padding happens in a
 413          * higher layer.
 414          */
 415         if (s->zst_outbuffer.pos != 0) {
 416                 error = cb(s->zst_buffer, s->zst_outbuffer.pos, s->zst_off,
 417                     arg);
 418                 if (error != 0)
 419                         return (error);
 420         }
 421
 422         return (0);
 423 }
 424
 425 static int
 426 zstdio_write(void *stream, void *data, size_t len, compressor_cb_t cb,
 427     void *arg)
 428 {
 429         struct zstdio_stream *s;
 430         size_t lastpos, rc;
 431         int error;
 432
 433         s = stream;
 434         if (data == NULL)
 435                 return (zstdio_flush(s, cb, arg));
 436
 437         s->zst_inbuffer.src = data;
 438         s->zst_inbuffer.size = len;
 439         s->zst_inbuffer.pos = 0;
 440         lastpos = 0;
 441
 442         while (s->zst_inbuffer.pos < s->zst_inbuffer.size) {
 443                 rc = ZSTD_compressStream(s->zst_stream, &s->zst_outbuffer,
 444                     &s->zst_inbuffer);
 445                 if (ZSTD_isError(rc)) {
 446                         printf("%s: Compress failed on %p! (%s)\n",
 447                             __func__, data, ZSTD_getErrorName(rc));
 448                         return (EIO);
 449                 }
 450
 451                 if (lastpos == s->zst_inbuffer.pos) {
 452                         /*
 453                          * XXX: May need flushStream to make forward progress
 454                          */
 455                         printf("ZSTD: did not make forward progress @pos %zu\n",
 456                             lastpos);
 457                         return (EIO);
 458                 }
 459                 lastpos = s->zst_inbuffer.pos;
 460
 461                 error = zst_flush_intermediate(s, cb, arg);
 462                 if (error != 0)
 463                         return (error);
 464         }
 465         return (0);
 466 }
 467
 468 static void
 469 zstdio_fini(void *stream)
 470 {
 471         struct zstdio_stream *s;
 472
 473         s = stream;
 474         if (s->zst_static_wkspc != NULL)
 475                 free(s->zst_static_wkspc, M_COMPRESS);
 476         else
 477                 ZSTD_freeCCtx(s->zst_stream);
 478         free(s->zst_buffer, M_COMPRESS);
 479         free(s, M_COMPRESS);
 480 }
 481
 482 static struct compressor_methods zstd_methods = {
 483         .format = COMPRESS_ZSTD,
 484         .init = zstdio_init,
 485         .reset = zstdio_reset,
 486         .write = zstdio_write,
 487         .fini = zstdio_fini,
 488 };
 489 DATA_SET(compressors, zstd_methods);
 490
 491 #endif /* ZSTDIO */
 492
 493 bool
 494 compressor_avail(int format)
 495 {
 496         struct compressor_methods **iter;
 497
 498         SET_FOREACH(iter, compressors) {
 499                 if ((*iter)->format == format)
 500                         return (true);
 501         }
 502         return (false);
 503 }
 504
 505 struct compressor *
 506 compressor_init(compressor_cb_t cb, int format, size_t maxiosize, int level,
 507     void *arg)
 508 {
 509         struct compressor_methods **iter;
 510         struct compressor *s;
 511         void *priv;
 512
 513         SET_FOREACH(iter, compressors) {
 514                 if ((*iter)->format == format)
 515                         break;
 516         }
 517         if (iter == SET_LIMIT(compressors))
 518                 return (NULL);
 519
 520         priv = (*iter)->init(maxiosize, level);
 521         if (priv == NULL)
 522                 return (NULL);
 523
 524         s = malloc(sizeof(*s), M_COMPRESS, M_WAITOK | M_ZERO);
 525         s->methods = (*iter);
 526         s->priv = priv;
 527         s->cb = cb;
 528         s->arg = arg;
 529         return (s);
 530 }
 531
 532 void
 533 compressor_reset(struct compressor *stream)
 534 {
 535
 536         stream->methods->reset(stream->priv);
 537 }
 538
 539 int
 540 compressor_write(struct compressor *stream, void *data, size_t len)
 541 {
 542
 543         return (stream->methods->write(stream->priv, data, len, stream->cb,
 544             stream->arg));
 545 }
 546
 547 int
 548 compressor_flush(struct compressor *stream)
 549 {
 550
 551         return (stream->methods->write(stream->priv, NULL, 0, stream->cb,
 552             stream->arg));
 553 }
 554
 555 void
 556 compressor_fini(struct compressor *stream)
 557 {
 558
 559         stream->methods->fini(stream->priv);
 560 }