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: releng/12.0/sys/kern/subr_compressor.c 329325 2018-02-15 17:35:40Z markj $");
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/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 error = deflateInit2(&s->gz_stream, level, Z_DEFLATED, -MAX_WBITS,
121 DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
122 if (error != 0)
123 goto fail;
124
125 gz_reset(s);
126
127 return (s);
128
129 fail:
130 gz_free(NULL, s);
131 return (NULL);
132 }
133
134 static void
135 gz_reset(void *stream)
136 {
137 struct gz_stream *s;
138 uint8_t *hdr;
139 const size_t hdrlen = 10;
140
141 s = stream;
142 s->gz_off = 0;
143 s->gz_crc = ~0U;
144
145 (void)deflateReset(&s->gz_stream);
146 s->gz_stream.avail_out = s->gz_bufsz;
147 s->gz_stream.next_out = s->gz_buffer;
148
149 /* Write the gzip header to the output buffer. */
150 hdr = s->gz_buffer;
151 memset(hdr, 0, hdrlen);
152 hdr[0] = 0x1f;
153 hdr[1] = 0x8b;
154 hdr[2] = Z_DEFLATED;
155 hdr[9] = OS_CODE;
156 s->gz_stream.next_out += hdrlen;
157 s->gz_stream.avail_out -= hdrlen;
158 }
159
160 static int
161 gz_write(void *stream, void *data, size_t len, compressor_cb_t cb,
162 void *arg)
163 {
164 struct gz_stream *s;
165 uint8_t trailer[8];
166 size_t room;
167 int error, zerror, zflag;
168
169 s = stream;
170 zflag = data == NULL ? Z_FINISH : Z_NO_FLUSH;
171
172 if (len > 0) {
173 s->gz_stream.avail_in = len;
174 s->gz_stream.next_in = data;
175 s->gz_crc = crc32_raw(data, len, s->gz_crc);
176 } else
177 s->gz_crc ^= ~0U;
178
179 error = 0;
180 do {
181 zerror = deflate(&s->gz_stream, zflag);
182 if (zerror != Z_OK && zerror != Z_STREAM_END) {
183 error = EIO;
184 break;
185 }
186
187 if (s->gz_stream.avail_out == 0 || zerror == Z_STREAM_END) {
188 /*
189 * Our output buffer is full or there's nothing left
190 * to produce, so we're flushing the buffer.
191 */
192 len = s->gz_bufsz - s->gz_stream.avail_out;
193 if (zerror == Z_STREAM_END) {
194 /*
195 * Try to pack as much of the trailer into the
196 * output buffer as we can.
197 */
198 ((uint32_t *)trailer)[0] = s->gz_crc;
199 ((uint32_t *)trailer)[1] =
200 s->gz_stream.total_in;
201 room = MIN(sizeof(trailer),
202 s->gz_bufsz - len);
203 memcpy(s->gz_buffer + len, trailer, room);
204 len += room;
205 }
206
207 error = cb(s->gz_buffer, len, s->gz_off, arg);
208 if (error != 0)
209 break;
210
211 s->gz_off += len;
212 s->gz_stream.next_out = s->gz_buffer;
213 s->gz_stream.avail_out = s->gz_bufsz;
214
215 /*
216 * If we couldn't pack the trailer into the output
217 * buffer, write it out now.
218 */
219 if (zerror == Z_STREAM_END && room < sizeof(trailer))
220 error = cb(trailer + room,
221 sizeof(trailer) - room, s->gz_off, arg);
222 }
223 } while (zerror != Z_STREAM_END &&
224 (zflag == Z_FINISH || s->gz_stream.avail_in > 0));
225
226 return (error);
227 }
228
229 static void
230 gz_fini(void *stream)
231 {
232 struct gz_stream *s;
233
234 s = stream;
235 (void)deflateEnd(&s->gz_stream);
236 gz_free(NULL, s->gz_buffer);
237 gz_free(NULL, s);
238 }
239
240 struct compressor_methods gzip_methods = {
241 .format = COMPRESS_GZIP,
242 .init = gz_init,
243 .reset = gz_reset,
244 .write = gz_write,
245 .fini = gz_fini,
246 };
247 DATA_SET(compressors, gzip_methods);
248
249 #endif /* GZIO */
250
251 #ifdef ZSTDIO
252
253 #define ZSTD_STATIC_LINKING_ONLY
254 #include <contrib/zstd/lib/zstd.h>
255
256 struct zstdio_stream {
257 ZSTD_CCtx *zst_stream;
258 ZSTD_inBuffer zst_inbuffer;
259 ZSTD_outBuffer zst_outbuffer;
260 uint8_t * zst_buffer; /* output buffer */
261 size_t zst_maxiosz; /* Max output IO size */
262 off_t zst_off; /* offset into the output stream */
263 void * zst_static_wkspc;
264 };
265
266 static void *zstdio_init(size_t maxiosize, int level);
267 static void zstdio_reset(void *stream);
268 static int zstdio_write(void *stream, void *data, size_t len,
269 compressor_cb_t, void *);
270 static void zstdio_fini(void *stream);
271
272 static void *
273 zstdio_init(size_t maxiosize, int level)
274 {
275 ZSTD_CCtx *dump_compressor;
276 struct zstdio_stream *s;
277 void *wkspc, *owkspc, *buffer;
278 size_t wkspc_size, buf_size;
279
280 wkspc_size = ZSTD_estimateCStreamSize(level);
281 owkspc = wkspc = malloc(wkspc_size + 8, M_COMPRESS,
282 M_WAITOK | M_NODUMP);
283 /* Zstd API requires 8-byte alignment. */
284 if ((uintptr_t)wkspc % 8 != 0)
285 wkspc = (void *)roundup2((uintptr_t)wkspc, 8);
286
287 dump_compressor = ZSTD_initStaticCCtx(wkspc, wkspc_size);
288 if (dump_compressor == NULL) {
289 free(owkspc, M_COMPRESS);
290 printf("%s: workspace too small.\n", __func__);
291 return (NULL);
292 }
293
294 (void)ZSTD_CCtx_setParameter(dump_compressor, ZSTD_p_checksumFlag, 1);
295
296 buf_size = ZSTD_CStreamOutSize() * 2;
297 buffer = malloc(buf_size, M_COMPRESS, M_WAITOK | M_NODUMP);
298
299 s = malloc(sizeof(*s), M_COMPRESS, M_NODUMP | M_WAITOK);
300 s->zst_buffer = buffer;
301 s->zst_outbuffer.dst = buffer;
302 s->zst_outbuffer.size = buf_size;
303 s->zst_maxiosz = maxiosize;
304 s->zst_stream = dump_compressor;
305 s->zst_static_wkspc = owkspc;
306
307 zstdio_reset(s);
308
309 return (s);
310 }
311
312 static void
313 zstdio_reset(void *stream)
314 {
315 struct zstdio_stream *s;
316 size_t res;
317
318 s = stream;
319 res = ZSTD_resetCStream(s->zst_stream, 0);
320 if (ZSTD_isError(res))
321 panic("%s: could not reset stream %p: %s\n", __func__, s,
322 ZSTD_getErrorName(res));
323
324 s->zst_off = 0;
325 s->zst_inbuffer.src = NULL;
326 s->zst_inbuffer.size = 0;
327 s->zst_inbuffer.pos = 0;
328 s->zst_outbuffer.pos = 0;
329 }
330
331 static int
332 zst_flush_intermediate(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
333 {
334 size_t bytes_to_dump;
335 int error;
336
337 /* Flush as many full output blocks as possible. */
338 /* XXX: 4096 is arbitrary safe HDD block size for kernel dumps */
339 while (s->zst_outbuffer.pos >= 4096) {
340 bytes_to_dump = rounddown(s->zst_outbuffer.pos, 4096);
341
342 if (bytes_to_dump > s->zst_maxiosz)
343 bytes_to_dump = s->zst_maxiosz;
344
345 error = cb(s->zst_buffer, bytes_to_dump, s->zst_off, arg);
346 if (error != 0)
347 return (error);
348
349 /*
350 * Shift any non-full blocks up to the front of the output
351 * buffer.
352 */
353 s->zst_outbuffer.pos -= bytes_to_dump;
354 memmove(s->zst_outbuffer.dst,
355 (char *)s->zst_outbuffer.dst + bytes_to_dump,
356 s->zst_outbuffer.pos);
357 s->zst_off += bytes_to_dump;
358 }
359 return (0);
360 }
361
362 static int
363 zstdio_flush(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
364 {
365 size_t rc, lastpos;
366 int error;
367
368 /*
369 * Positive return indicates unflushed data remaining; need to call
370 * endStream again after clearing out room in output buffer.
371 */
372 rc = 1;
373 lastpos = s->zst_outbuffer.pos;
374 while (rc > 0) {
375 rc = ZSTD_endStream(s->zst_stream, &s->zst_outbuffer);
376 if (ZSTD_isError(rc)) {
377 printf("%s: ZSTD_endStream failed (%s)\n", __func__,
378 ZSTD_getErrorName(rc));
379 return (EIO);
380 }
381 if (lastpos == s->zst_outbuffer.pos) {
382 printf("%s: did not make forward progress endStream %zu\n",
383 __func__, lastpos);
384 return (EIO);
385 }
386
387 error = zst_flush_intermediate(s, cb, arg);
388 if (error != 0)
389 return (error);
390
391 lastpos = s->zst_outbuffer.pos;
392 }
393
394 /*
395 * We've already done an intermediate flush, so all full blocks have
396 * been written. Only a partial block remains. Padding happens in a
397 * higher layer.
398 */
399 if (s->zst_outbuffer.pos != 0) {
400 error = cb(s->zst_buffer, s->zst_outbuffer.pos, s->zst_off,
401 arg);
402 if (error != 0)
403 return (error);
404 }
405
406 return (0);
407 }
408
409 static int
410 zstdio_write(void *stream, void *data, size_t len, compressor_cb_t cb,
411 void *arg)
412 {
413 struct zstdio_stream *s;
414 size_t lastpos, rc;
415 int error;
416
417 s = stream;
418 if (data == NULL)
419 return (zstdio_flush(s, cb, arg));
420
421 s->zst_inbuffer.src = data;
422 s->zst_inbuffer.size = len;
423 s->zst_inbuffer.pos = 0;
424 lastpos = 0;
425
426 while (s->zst_inbuffer.pos < s->zst_inbuffer.size) {
427 rc = ZSTD_compressStream(s->zst_stream, &s->zst_outbuffer,
428 &s->zst_inbuffer);
429 if (ZSTD_isError(rc)) {
430 printf("%s: Compress failed on %p! (%s)\n",
431 __func__, data, ZSTD_getErrorName(rc));
432 return (EIO);
433 }
434
435 if (lastpos == s->zst_inbuffer.pos) {
436 /*
437 * XXX: May need flushStream to make forward progress
438 */
439 printf("ZSTD: did not make forward progress @pos %zu\n",
440 lastpos);
441 return (EIO);
442 }
443 lastpos = s->zst_inbuffer.pos;
444
445 error = zst_flush_intermediate(s, cb, arg);
446 if (error != 0)
447 return (error);
448 }
449 return (0);
450 }
451
452 static void
453 zstdio_fini(void *stream)
454 {
455 struct zstdio_stream *s;
456
457 s = stream;
458 if (s->zst_static_wkspc != NULL)
459 free(s->zst_static_wkspc, M_COMPRESS);
460 else
461 ZSTD_freeCCtx(s->zst_stream);
462 free(s->zst_buffer, M_COMPRESS);
463 free(s, M_COMPRESS);
464 }
465
466 static struct compressor_methods zstd_methods = {
467 .format = COMPRESS_ZSTD,
468 .init = zstdio_init,
469 .reset = zstdio_reset,
470 .write = zstdio_write,
471 .fini = zstdio_fini,
472 };
473 DATA_SET(compressors, zstd_methods);
474
475 #endif /* ZSTDIO */
476
477 bool
478 compressor_avail(int format)
479 {
480 struct compressor_methods **iter;
481
482 SET_FOREACH(iter, compressors) {
483 if ((*iter)->format == format)
484 return (true);
485 }
486 return (false);
487 }
488
489 struct compressor *
490 compressor_init(compressor_cb_t cb, int format, size_t maxiosize, int level,
491 void *arg)
492 {
493 struct compressor_methods **iter;
494 struct compressor *s;
495 void *priv;
496
497 SET_FOREACH(iter, compressors) {
498 if ((*iter)->format == format)
499 break;
500 }
501 if (iter == SET_LIMIT(compressors))
502 return (NULL);
503
504 priv = (*iter)->init(maxiosize, level);
505 if (priv == NULL)
506 return (NULL);
507
508 s = malloc(sizeof(*s), M_COMPRESS, M_WAITOK | M_ZERO);
509 s->methods = (*iter);
510 s->priv = priv;
511 s->cb = cb;
512 s->arg = arg;
513 return (s);
514 }
515
516 void
517 compressor_reset(struct compressor *stream)
518 {
519
520 stream->methods->reset(stream->priv);
521 }
522
523 int
524 compressor_write(struct compressor *stream, void *data, size_t len)
525 {
526
527 return (stream->methods->write(stream->priv, data, len, stream->cb,
528 stream->arg));
529 }
530
531 int
532 compressor_flush(struct compressor *stream)
533 {
534
535 return (stream->methods->write(stream->priv, NULL, 0, stream->cb,
536 stream->arg));
537 }
538
539 void
540 compressor_fini(struct compressor *stream)
541 {
542
543 stream->methods->fini(stream->priv);
544 }
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