sys/kern/subr_compressor.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   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 #include "opt_gzio.h"
  36 #include "opt_zstdio.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40
  41 #include <sys/compressor.h>
  42 #include <sys/endian.h>
  43 #include <sys/kernel.h>
  44 #include <sys/linker_set.h>
  45 #include <sys/malloc.h>
  46
  47 MALLOC_DEFINE(M_COMPRESS, "compressor", "kernel compression subroutines");
  48
  49 struct compressor_methods {
  50         int format;
  51         void *(* const init)(size_t, int);
  52         void (* const reset)(void *);
  53         int (* const write)(void *, void *, size_t, compressor_cb_t, void *);
  54         void (* const fini)(void *);
  55 };
  56
  57 struct compressor {
  58         const struct compressor_methods *methods;
  59         compressor_cb_t cb;
  60         void *priv;
  61         void *arg;
  62 };
  63
  64 SET_DECLARE(compressors, struct compressor_methods);
  65
  66 #ifdef GZIO
  67
  68 #include <contrib/zlib/zutil.h>
  69
  70 struct gz_stream {
  71         uint8_t         *gz_buffer;     /* output buffer */
  72         size_t          gz_bufsz;       /* output buffer size */
  73         off_t           gz_off;         /* offset into the output stream */
  74         uint32_t        gz_crc;         /* stream CRC32 */
  75         z_stream        gz_stream;      /* zlib state */
  76 };
  77
  78 static void     *gz_init(size_t maxiosize, int level);
  79 static void     gz_reset(void *stream);
  80 static int      gz_write(void *stream, void *data, size_t len, compressor_cb_t,
  81                     void *);
  82 static void     gz_fini(void *stream);
  83
  84 static void *
  85 gz_alloc(void *arg __unused, u_int n, u_int sz)
  86 {
  87
  88         /*
  89          * Memory for zlib state is allocated using M_NODUMP since it may be
  90          * used to compress a kernel dump, and we don't want zlib to attempt to
  91          * compress its own state.
  92          */
  93         return (malloc(n * sz, M_COMPRESS, M_WAITOK | M_ZERO | M_NODUMP));
  94 }
  95
  96 static void
  97 gz_free(void *arg __unused, void *ptr)
  98 {
  99
 100         free(ptr, M_COMPRESS);
 101 }
 102
 103 static void *
 104 gz_init(size_t maxiosize, int level)
 105 {
 106         struct gz_stream *s;
 107         int error;
 108
 109         s = gz_alloc(NULL, 1, roundup2(sizeof(*s), PAGE_SIZE));
 110         s->gz_buffer = gz_alloc(NULL, 1, maxiosize);
 111         s->gz_bufsz = maxiosize;
 112
 113         s->gz_stream.zalloc = gz_alloc;
 114         s->gz_stream.zfree = gz_free;
 115         s->gz_stream.opaque = NULL;
 116         s->gz_stream.next_in = Z_NULL;
 117         s->gz_stream.avail_in = 0;
 118
 119         if (level != Z_DEFAULT_COMPRESSION) {
 120                 if (level < Z_BEST_SPEED)
 121                         level = Z_BEST_SPEED;
 122                 else if (level > Z_BEST_COMPRESSION)
 123                         level = Z_BEST_COMPRESSION;
 124         }
 125
 126         error = deflateInit2(&s->gz_stream, level, Z_DEFLATED, -MAX_WBITS,
 127             DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
 128         if (error != 0)
 129                 goto fail;
 130
 131         gz_reset(s);
 132
 133         return (s);
 134
 135 fail:
 136         gz_free(NULL, s);
 137         return (NULL);
 138 }
 139
 140 static void
 141 gz_reset(void *stream)
 142 {
 143         struct gz_stream *s;
 144         uint8_t *hdr;
 145         const size_t hdrlen = 10;
 146
 147         s = stream;
 148         s->gz_off = 0;
 149         s->gz_crc = crc32(0L, Z_NULL, 0);
 150
 151         (void)deflateReset(&s->gz_stream);
 152         s->gz_stream.avail_out = s->gz_bufsz;
 153         s->gz_stream.next_out = s->gz_buffer;
 154
 155         /* Write the gzip header to the output buffer. */
 156         hdr = s->gz_buffer;
 157         memset(hdr, 0, hdrlen);
 158         hdr[0] = 0x1f;
 159         hdr[1] = 0x8b;
 160         hdr[2] = Z_DEFLATED;
 161         hdr[9] = OS_CODE;
 162         s->gz_stream.next_out += hdrlen;
 163         s->gz_stream.avail_out -= hdrlen;
 164 }
 165
 166 static int
 167 gz_write(void *stream, void *data, size_t len, compressor_cb_t cb,
 168     void *arg)
 169 {
 170         struct gz_stream *s;
 171         uint8_t trailer[8];
 172         size_t room;
 173         int error, zerror, zflag;
 174
 175         s = stream;
 176         zflag = data == NULL ? Z_FINISH : Z_NO_FLUSH;
 177
 178         if (len > 0) {
 179                 s->gz_stream.avail_in = len;
 180                 s->gz_stream.next_in = data;
 181                 s->gz_crc = crc32(s->gz_crc, data, len);
 182         }
 183
 184         error = 0;
 185         do {
 186                 zerror = deflate(&s->gz_stream, zflag);
 187                 if (zerror != Z_OK && zerror != Z_STREAM_END) {
 188                         error = EIO;
 189                         break;
 190                 }
 191
 192                 if (s->gz_stream.avail_out == 0 || zerror == Z_STREAM_END) {
 193                         /*
 194                          * Our output buffer is full or there's nothing left
 195                          * to produce, so we're flushing the buffer.
 196                          */
 197                         len = s->gz_bufsz - s->gz_stream.avail_out;
 198                         if (zerror == Z_STREAM_END) {
 199                                 /*
 200                                  * Try to pack as much of the trailer into the
 201                                  * output buffer as we can.
 202                                  */
 203                                 ((uint32_t *)trailer)[0] = htole32(s->gz_crc);
 204                                 ((uint32_t *)trailer)[1] =
 205                                     htole32(s->gz_stream.total_in);
 206                                 room = MIN(sizeof(trailer),
 207                                     s->gz_bufsz - len);
 208                                 memcpy(s->gz_buffer + len, trailer, room);
 209                                 len += room;
 210                         }
 211
 212                         error = cb(s->gz_buffer, len, s->gz_off, arg);
 213                         if (error != 0)
 214                                 break;
 215
 216                         s->gz_off += len;
 217                         s->gz_stream.next_out = s->gz_buffer;
 218                         s->gz_stream.avail_out = s->gz_bufsz;
 219
 220                         /*
 221                          * If we couldn't pack the trailer into the output
 222                          * buffer, write it out now.
 223                          */
 224                         if (zerror == Z_STREAM_END && room < sizeof(trailer))
 225                                 error = cb(trailer + room,
 226                                     sizeof(trailer) - room, s->gz_off, arg);
 227                 }
 228         } while (zerror != Z_STREAM_END &&
 229             (zflag == Z_FINISH || s->gz_stream.avail_in > 0));
 230
 231         return (error);
 232 }
 233
 234 static void
 235 gz_fini(void *stream)
 236 {
 237         struct gz_stream *s;
 238
 239         s = stream;
 240         (void)deflateEnd(&s->gz_stream);
 241         gz_free(NULL, s->gz_buffer);
 242         gz_free(NULL, s);
 243 }
 244
 245 struct compressor_methods gzip_methods = {
 246         .format = COMPRESS_GZIP,
 247         .init = gz_init,
 248         .reset = gz_reset,
 249         .write = gz_write,
 250         .fini = gz_fini,
 251 };
 252 DATA_SET(compressors, gzip_methods);
 253
 254 #endif /* GZIO */
 255
 256 #ifdef ZSTDIO
 257
 258 #define ZSTD_STATIC_LINKING_ONLY
 259 #include <contrib/zstd/lib/zstd.h>
 260
 261 struct zstdio_stream {
 262         ZSTD_CCtx       *zst_stream;
 263         ZSTD_inBuffer   zst_inbuffer;
 264         ZSTD_outBuffer  zst_outbuffer;
 265         uint8_t *       zst_buffer;     /* output buffer */
 266         size_t          zst_maxiosz;    /* Max output IO size */
 267         off_t           zst_off;        /* offset into the output stream */
 268         void *          zst_static_wkspc;
 269 };
 270
 271 static void     *zstdio_init(size_t maxiosize, int level);
 272 static void     zstdio_reset(void *stream);
 273 static int      zstdio_write(void *stream, void *data, size_t len,
 274                     compressor_cb_t, void *);
 275 static void     zstdio_fini(void *stream);
 276
 277 static void *
 278 zstdio_init(size_t maxiosize, int level)
 279 {
 280         ZSTD_CCtx *dump_compressor;
 281         struct zstdio_stream *s;
 282         void *wkspc, *owkspc, *buffer;
 283         size_t wkspc_size, buf_size, rc;
 284
 285         s = NULL;
 286         wkspc_size = ZSTD_estimateCStreamSize(level);
 287         owkspc = wkspc = malloc(wkspc_size + 8, M_COMPRESS,
 288             M_WAITOK | M_NODUMP);
 289         /* Zstd API requires 8-byte alignment. */
 290         if ((uintptr_t)wkspc % 8 != 0)
 291                 wkspc = (void *)roundup2((uintptr_t)wkspc, 8);
 292
 293         dump_compressor = ZSTD_initStaticCCtx(wkspc, wkspc_size);
 294         if (dump_compressor == NULL) {
 295                 printf("%s: workspace too small.\n", __func__);
 296                 goto out;
 297         }
 298
 299         rc = ZSTD_CCtx_setParameter(dump_compressor, ZSTD_c_checksumFlag, 1);
 300         if (ZSTD_isError(rc)) {
 301                 printf("%s: error setting checksumFlag: %s\n", __func__,
 302                     ZSTD_getErrorName(rc));
 303                 goto out;
 304         }
 305         rc = ZSTD_CCtx_setParameter(dump_compressor, ZSTD_c_compressionLevel,
 306             level);
 307         if (ZSTD_isError(rc)) {
 308                 printf("%s: error setting compressLevel: %s\n", __func__,
 309                     ZSTD_getErrorName(rc));
 310                 goto out;
 311         }
 312
 313         buf_size = ZSTD_CStreamOutSize() * 2;
 314         buffer = malloc(buf_size, M_COMPRESS, M_WAITOK | M_NODUMP);
 315
 316         s = malloc(sizeof(*s), M_COMPRESS, M_NODUMP | M_WAITOK);
 317         s->zst_buffer = buffer;
 318         s->zst_outbuffer.dst = buffer;
 319         s->zst_outbuffer.size = buf_size;
 320         s->zst_maxiosz = maxiosize;
 321         s->zst_stream = dump_compressor;
 322         s->zst_static_wkspc = owkspc;
 323
 324         zstdio_reset(s);
 325
 326 out:
 327         if (s == NULL)
 328                 free(owkspc, M_COMPRESS);
 329         return (s);
 330 }
 331
 332 static void
 333 zstdio_reset(void *stream)
 334 {
 335         struct zstdio_stream *s;
 336         size_t res;
 337
 338         s = stream;
 339         res = ZSTD_resetCStream(s->zst_stream, 0);
 340         if (ZSTD_isError(res))
 341                 panic("%s: could not reset stream %p: %s\n", __func__, s,
 342                     ZSTD_getErrorName(res));
 343
 344         s->zst_off = 0;
 345         s->zst_inbuffer.src = NULL;
 346         s->zst_inbuffer.size = 0;
 347         s->zst_inbuffer.pos = 0;
 348         s->zst_outbuffer.pos = 0;
 349 }
 350
 351 static int
 352 zst_flush_intermediate(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
 353 {
 354         size_t bytes_to_dump;
 355         int error;
 356
 357         /* Flush as many full output blocks as possible. */
 358         /* XXX: 4096 is arbitrary safe HDD block size for kernel dumps */
 359         while (s->zst_outbuffer.pos >= 4096) {
 360                 bytes_to_dump = rounddown(s->zst_outbuffer.pos, 4096);
 361
 362                 if (bytes_to_dump > s->zst_maxiosz)
 363                         bytes_to_dump = s->zst_maxiosz;
 364
 365                 error = cb(s->zst_buffer, bytes_to_dump, s->zst_off, arg);
 366                 if (error != 0)
 367                         return (error);
 368
 369                 /*
 370                  * Shift any non-full blocks up to the front of the output
 371                  * buffer.
 372                  */
 373                 s->zst_outbuffer.pos -= bytes_to_dump;
 374                 memmove(s->zst_outbuffer.dst,
 375                     (char *)s->zst_outbuffer.dst + bytes_to_dump,
 376                     s->zst_outbuffer.pos);
 377                 s->zst_off += bytes_to_dump;
 378         }
 379         return (0);
 380 }
 381
 382 static int
 383 zstdio_flush(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
 384 {
 385         size_t rc, lastpos;
 386         int error;
 387
 388         /*
 389          * Positive return indicates unflushed data remaining; need to call
 390          * endStream again after clearing out room in output buffer.
 391          */
 392         rc = 1;
 393         lastpos = s->zst_outbuffer.pos;
 394         while (rc > 0) {
 395                 rc = ZSTD_endStream(s->zst_stream, &s->zst_outbuffer);
 396                 if (ZSTD_isError(rc)) {
 397                         printf("%s: ZSTD_endStream failed (%s)\n", __func__,
 398                             ZSTD_getErrorName(rc));
 399                         return (EIO);
 400                 }
 401                 if (lastpos == s->zst_outbuffer.pos) {
 402                         printf("%s: did not make forward progress endStream %zu\n",
 403                             __func__, lastpos);
 404                         return (EIO);
 405                 }
 406
 407                 error = zst_flush_intermediate(s, cb, arg);
 408                 if (error != 0)
 409                         return (error);
 410
 411                 lastpos = s->zst_outbuffer.pos;
 412         }
 413
 414         /*
 415          * We've already done an intermediate flush, so all full blocks have
 416          * been written.  Only a partial block remains.  Padding happens in a
 417          * higher layer.
 418          */
 419         if (s->zst_outbuffer.pos != 0) {
 420                 error = cb(s->zst_buffer, s->zst_outbuffer.pos, s->zst_off,
 421                     arg);
 422                 if (error != 0)
 423                         return (error);
 424         }
 425
 426         return (0);
 427 }
 428
 429 static int
 430 zstdio_write(void *stream, void *data, size_t len, compressor_cb_t cb,
 431     void *arg)
 432 {
 433         struct zstdio_stream *s;
 434         size_t lastpos, rc;
 435         int error;
 436
 437         s = stream;
 438         if (data == NULL)
 439                 return (zstdio_flush(s, cb, arg));
 440
 441         s->zst_inbuffer.src = data;
 442         s->zst_inbuffer.size = len;
 443         s->zst_inbuffer.pos = 0;
 444         lastpos = 0;
 445
 446         while (s->zst_inbuffer.pos < s->zst_inbuffer.size) {
 447                 rc = ZSTD_compressStream(s->zst_stream, &s->zst_outbuffer,
 448                     &s->zst_inbuffer);
 449                 if (ZSTD_isError(rc)) {
 450                         printf("%s: Compress failed on %p! (%s)\n",
 451                             __func__, data, ZSTD_getErrorName(rc));
 452                         return (EIO);
 453                 }
 454
 455                 if (lastpos == s->zst_inbuffer.pos) {
 456                         /*
 457                          * XXX: May need flushStream to make forward progress
 458                          */
 459                         printf("ZSTD: did not make forward progress @pos %zu\n",
 460                             lastpos);
 461                         return (EIO);
 462                 }
 463                 lastpos = s->zst_inbuffer.pos;
 464
 465                 error = zst_flush_intermediate(s, cb, arg);
 466                 if (error != 0)
 467                         return (error);
 468         }
 469         return (0);
 470 }
 471
 472 static void
 473 zstdio_fini(void *stream)
 474 {
 475         struct zstdio_stream *s;
 476
 477         s = stream;
 478         if (s->zst_static_wkspc != NULL)
 479                 free(s->zst_static_wkspc, M_COMPRESS);
 480         else
 481                 ZSTD_freeCCtx(s->zst_stream);
 482         free(s->zst_buffer, M_COMPRESS);
 483         free(s, M_COMPRESS);
 484 }
 485
 486 static struct compressor_methods zstd_methods = {
 487         .format = COMPRESS_ZSTD,
 488         .init = zstdio_init,
 489         .reset = zstdio_reset,
 490         .write = zstdio_write,
 491         .fini = zstdio_fini,
 492 };
 493 DATA_SET(compressors, zstd_methods);
 494
 495 #endif /* ZSTDIO */
 496
 497 bool
 498 compressor_avail(int format)
 499 {
 500         struct compressor_methods **iter;
 501
 502         SET_FOREACH(iter, compressors) {
 503                 if ((*iter)->format == format)
 504                         return (true);
 505         }
 506         return (false);
 507 }
 508
 509 struct compressor *
 510 compressor_init(compressor_cb_t cb, int format, size_t maxiosize, int level,
 511     void *arg)
 512 {
 513         struct compressor_methods **iter;
 514         struct compressor *s;
 515         void *priv;
 516
 517         SET_FOREACH(iter, compressors) {
 518                 if ((*iter)->format == format)
 519                         break;
 520         }
 521         if (iter == SET_LIMIT(compressors))
 522                 return (NULL);
 523
 524         priv = (*iter)->init(maxiosize, level);
 525         if (priv == NULL)
 526                 return (NULL);
 527
 528         s = malloc(sizeof(*s), M_COMPRESS, M_WAITOK | M_ZERO);
 529         s->methods = (*iter);
 530         s->priv = priv;
 531         s->cb = cb;
 532         s->arg = arg;
 533         return (s);
 534 }
 535
 536 void
 537 compressor_reset(struct compressor *stream)
 538 {
 539
 540         stream->methods->reset(stream->priv);
 541 }
 542
 543 int
 544 compressor_write(struct compressor *stream, void *data, size_t len)
 545 {
 546
 547         return (stream->methods->write(stream->priv, data, len, stream->cb,
 548             stream->arg));
 549 }
 550
 551 int
 552 compressor_flush(struct compressor *stream)
 553 {
 554
 555         return (stream->methods->write(stream->priv, NULL, 0, stream->cb,
 556             stream->arg));
 557 }
 558
 559 void
 560 compressor_fini(struct compressor *stream)
 561 {
 562
 563         stream->methods->fini(stream->priv);
 564 }