freebsd-dev/sys/kern/subr_compressor.c

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2014, 2017 Mark Johnston <markj@FreeBSD.org>
* Copyright (c) 2017 Conrad Meyer <cem@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Subroutines used for writing compressed user process and kernel core dumps.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_gzio.h"
#include "opt_zstdio.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/compressor.h>
#include <sys/kernel.h>
#include <sys/linker_set.h>
#include <sys/malloc.h>
MALLOC_DEFINE(M_COMPRESS, "compressor", "kernel compression subroutines");
struct compressor_methods {
int format;
void *(* const init)(size_t, int);
void (* const reset)(void *);
int (* const write)(void *, void *, size_t, compressor_cb_t, void *);
void (* const fini)(void *);
};
struct compressor {
const struct compressor_methods *methods;
compressor_cb_t cb;
void *priv;
void *arg;
};
SET_DECLARE(compressors, struct compressor_methods);
#ifdef GZIO
#include <sys/zutil.h>
struct gz_stream {
uint8_t *gz_buffer; /* output buffer */
size_t gz_bufsz; /* output buffer size */
off_t gz_off; /* offset into the output stream */
uint32_t gz_crc; /* stream CRC32 */
z_stream gz_stream; /* zlib state */
};
static void *gz_init(size_t maxiosize, int level);
static void gz_reset(void *stream);
static int gz_write(void *stream, void *data, size_t len, compressor_cb_t,
void *);
static void gz_fini(void *stream);
static void *
gz_alloc(void *arg __unused, u_int n, u_int sz)
{
/*
* Memory for zlib state is allocated using M_NODUMP since it may be
* used to compress a kernel dump, and we don't want zlib to attempt to
* compress its own state.
*/
return (malloc(n * sz, M_COMPRESS, M_WAITOK | M_ZERO | M_NODUMP));
}
static void
gz_free(void *arg __unused, void *ptr)
{
free(ptr, M_COMPRESS);
}
static void *
gz_init(size_t maxiosize, int level)
{
struct gz_stream *s;
int error;
s = gz_alloc(NULL, 1, roundup2(sizeof(*s), PAGE_SIZE));
s->gz_buffer = gz_alloc(NULL, 1, maxiosize);
s->gz_bufsz = maxiosize;
s->gz_stream.zalloc = gz_alloc;
s->gz_stream.zfree = gz_free;
s->gz_stream.opaque = NULL;
s->gz_stream.next_in = Z_NULL;
s->gz_stream.avail_in = 0;
error = deflateInit2(&s->gz_stream, level, Z_DEFLATED, -MAX_WBITS,
DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
if (error != 0)
goto fail;
gz_reset(s);
return (s);
fail:
gz_free(NULL, s);
return (NULL);
}
static void
gz_reset(void *stream)
{
struct gz_stream *s;
uint8_t *hdr;
const size_t hdrlen = 10;
s = stream;
s->gz_off = 0;
s->gz_crc = ~0U;
(void)deflateReset(&s->gz_stream);
s->gz_stream.avail_out = s->gz_bufsz;
s->gz_stream.next_out = s->gz_buffer;
/* Write the gzip header to the output buffer. */
hdr = s->gz_buffer;
memset(hdr, 0, hdrlen);
hdr[0] = 0x1f;
hdr[1] = 0x8b;
hdr[2] = Z_DEFLATED;
hdr[9] = OS_CODE;
s->gz_stream.next_out += hdrlen;
s->gz_stream.avail_out -= hdrlen;
}
static int
gz_write(void *stream, void *data, size_t len, compressor_cb_t cb,
void *arg)
{
struct gz_stream *s;
uint8_t trailer[8];
size_t room;
int error, zerror, zflag;
s = stream;
zflag = data == NULL ? Z_FINISH : Z_NO_FLUSH;
if (len > 0) {
s->gz_stream.avail_in = len;
s->gz_stream.next_in = data;
s->gz_crc = crc32_raw(data, len, s->gz_crc);
} else
s->gz_crc ^= ~0U;
error = 0;
do {
zerror = deflate(&s->gz_stream, zflag);
if (zerror != Z_OK && zerror != Z_STREAM_END) {
error = EIO;
break;
}
if (s->gz_stream.avail_out == 0 || zerror == Z_STREAM_END) {
/*
* Our output buffer is full or there's nothing left
* to produce, so we're flushing the buffer.
*/
len = s->gz_bufsz - s->gz_stream.avail_out;
if (zerror == Z_STREAM_END) {
/*
* Try to pack as much of the trailer into the
* output buffer as we can.
*/
((uint32_t *)trailer)[0] = s->gz_crc;
((uint32_t *)trailer)[1] =
s->gz_stream.total_in;
room = MIN(sizeof(trailer),
s->gz_bufsz - len);
memcpy(s->gz_buffer + len, trailer, room);
len += room;
}
error = cb(s->gz_buffer, len, s->gz_off, arg);
if (error != 0)
break;
s->gz_off += len;
s->gz_stream.next_out = s->gz_buffer;
s->gz_stream.avail_out = s->gz_bufsz;
/*
* If we couldn't pack the trailer into the output
* buffer, write it out now.
*/
if (zerror == Z_STREAM_END && room < sizeof(trailer))
error = cb(trailer + room,
sizeof(trailer) - room, s->gz_off, arg);
}
} while (zerror != Z_STREAM_END &&
(zflag == Z_FINISH || s->gz_stream.avail_in > 0));
return (error);
}
static void
gz_fini(void *stream)
{
struct gz_stream *s;
s = stream;
(void)deflateEnd(&s->gz_stream);
gz_free(NULL, s->gz_buffer);
gz_free(NULL, s);
}
struct compressor_methods gzip_methods = {
.format = COMPRESS_GZIP,
.init = gz_init,
.reset = gz_reset,
.write = gz_write,
.fini = gz_fini,
};
DATA_SET(compressors, gzip_methods);
#endif /* GZIO */
#ifdef ZSTDIO
#define ZSTD_STATIC_LINKING_ONLY
#include <contrib/zstd/lib/zstd.h>
struct zstdio_stream {
ZSTD_CCtx *zst_stream;
ZSTD_inBuffer zst_inbuffer;
ZSTD_outBuffer zst_outbuffer;
uint8_t * zst_buffer; /* output buffer */
size_t zst_maxiosz; /* Max output IO size */
off_t zst_off; /* offset into the output stream */
void * zst_static_wkspc;
};
static void *zstdio_init(size_t maxiosize, int level);
static void zstdio_reset(void *stream);
static int zstdio_write(void *stream, void *data, size_t len,
compressor_cb_t, void *);
static void zstdio_fini(void *stream);
static void *
zstdio_init(size_t maxiosize, int level)
{
ZSTD_CCtx *dump_compressor;
struct zstdio_stream *s;
void *wkspc, *owkspc, *buffer;
size_t wkspc_size, buf_size;
wkspc_size = ZSTD_estimateCStreamSize(level);
owkspc = wkspc = malloc(wkspc_size + 8, M_COMPRESS,
M_WAITOK | M_NODUMP);
/* Zstd API requires 8-byte alignment. */
if ((uintptr_t)wkspc % 8 != 0)
wkspc = (void *)roundup2((uintptr_t)wkspc, 8);
dump_compressor = ZSTD_initStaticCCtx(wkspc, wkspc_size);
if (dump_compressor == NULL) {
free(owkspc, M_COMPRESS);
printf("%s: workspace too small.\n", __func__);
return (NULL);
}
(void)ZSTD_CCtx_setParameter(dump_compressor, ZSTD_p_checksumFlag, 1);
buf_size = ZSTD_CStreamOutSize() * 2;
buffer = malloc(buf_size, M_COMPRESS, M_WAITOK | M_NODUMP);
s = malloc(sizeof(*s), M_COMPRESS, M_NODUMP | M_WAITOK);
s->zst_buffer = buffer;
s->zst_outbuffer.dst = buffer;
s->zst_outbuffer.size = buf_size;
s->zst_maxiosz = maxiosize;
s->zst_stream = dump_compressor;
s->zst_static_wkspc = owkspc;
zstdio_reset(s);
return (s);
}
static void
zstdio_reset(void *stream)
{
struct zstdio_stream *s;
size_t res;
s = stream;
res = ZSTD_resetCStream(s->zst_stream, 0);
if (ZSTD_isError(res))
panic("%s: could not reset stream %p: %s\n", __func__, s,
ZSTD_getErrorName(res));
s->zst_off = 0;
s->zst_inbuffer.src = NULL;
s->zst_inbuffer.size = 0;
s->zst_inbuffer.pos = 0;
s->zst_outbuffer.pos = 0;
}
static int
zst_flush_intermediate(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
{
size_t bytes_to_dump;
int error;
/* Flush as many full output blocks as possible. */
/* XXX: 4096 is arbitrary safe HDD block size for kernel dumps */
while (s->zst_outbuffer.pos >= 4096) {
bytes_to_dump = rounddown(s->zst_outbuffer.pos, 4096);
if (bytes_to_dump > s->zst_maxiosz)
bytes_to_dump = s->zst_maxiosz;
error = cb(s->zst_buffer, bytes_to_dump, s->zst_off, arg);
if (error != 0)
return (error);
/*
* Shift any non-full blocks up to the front of the output
* buffer.
*/
s->zst_outbuffer.pos -= bytes_to_dump;
memmove(s->zst_outbuffer.dst,
(char *)s->zst_outbuffer.dst + bytes_to_dump,
s->zst_outbuffer.pos);
s->zst_off += bytes_to_dump;
}
return (0);
}
static int
zstdio_flush(struct zstdio_stream *s, compressor_cb_t cb, void *arg)
{
size_t rc, lastpos;
int error;
/*
* Positive return indicates unflushed data remaining; need to call
* endStream again after clearing out room in output buffer.
*/
rc = 1;
lastpos = s->zst_outbuffer.pos;
while (rc > 0) {
rc = ZSTD_endStream(s->zst_stream, &s->zst_outbuffer);
if (ZSTD_isError(rc)) {
printf("%s: ZSTD_endStream failed (%s)\n", __func__,
ZSTD_getErrorName(rc));
return (EIO);
}
if (lastpos == s->zst_outbuffer.pos) {
printf("%s: did not make forward progress endStream %zu\n",
__func__, lastpos);
return (EIO);
}
error = zst_flush_intermediate(s, cb, arg);
if (error != 0)
return (error);
lastpos = s->zst_outbuffer.pos;
}
/*
* We've already done an intermediate flush, so all full blocks have
* been written. Only a partial block remains. Padding happens in a
* higher layer.
*/
if (s->zst_outbuffer.pos != 0) {
error = cb(s->zst_buffer, s->zst_outbuffer.pos, s->zst_off,
arg);
if (error != 0)
return (error);
}
return (0);
}
static int
zstdio_write(void *stream, void *data, size_t len, compressor_cb_t cb,
void *arg)
{
struct zstdio_stream *s;
size_t lastpos, rc;
int error;
s = stream;
if (data == NULL)
return (zstdio_flush(s, cb, arg));
s->zst_inbuffer.src = data;
s->zst_inbuffer.size = len;
s->zst_inbuffer.pos = 0;
lastpos = 0;
while (s->zst_inbuffer.pos < s->zst_inbuffer.size) {
rc = ZSTD_compressStream(s->zst_stream, &s->zst_outbuffer,
&s->zst_inbuffer);
if (ZSTD_isError(rc)) {
printf("%s: Compress failed on %p! (%s)\n",
__func__, data, ZSTD_getErrorName(rc));
return (EIO);
}
if (lastpos == s->zst_inbuffer.pos) {
/*
* XXX: May need flushStream to make forward progress
*/
printf("ZSTD: did not make forward progress @pos %zu\n",
lastpos);
return (EIO);
}
lastpos = s->zst_inbuffer.pos;
error = zst_flush_intermediate(s, cb, arg);
if (error != 0)
return (error);
}
return (0);
}
static void
zstdio_fini(void *stream)
{
struct zstdio_stream *s;
s = stream;
if (s->zst_static_wkspc != NULL)
free(s->zst_static_wkspc, M_COMPRESS);
else
ZSTD_freeCCtx(s->zst_stream);
free(s->zst_buffer, M_COMPRESS);
free(s, M_COMPRESS);
}
static struct compressor_methods zstd_methods = {
.format = COMPRESS_ZSTD,
.init = zstdio_init,
.reset = zstdio_reset,
.write = zstdio_write,
.fini = zstdio_fini,
};
DATA_SET(compressors, zstd_methods);
#endif /* ZSTDIO */
bool
compressor_avail(int format)
{
struct compressor_methods **iter;
SET_FOREACH(iter, compressors) {
if ((*iter)->format == format)
return (true);
}
return (false);
}
struct compressor *
compressor_init(compressor_cb_t cb, int format, size_t maxiosize, int level,
void *arg)
{
struct compressor_methods **iter;
struct compressor *s;
void *priv;
SET_FOREACH(iter, compressors) {
if ((*iter)->format == format)
break;
}
if (iter == SET_LIMIT(compressors))
return (NULL);
priv = (*iter)->init(maxiosize, level);
if (priv == NULL)
return (NULL);
s = malloc(sizeof(*s), M_COMPRESS, M_WAITOK | M_ZERO);
s->methods = (*iter);
s->priv = priv;
s->cb = cb;
s->arg = arg;
return (s);
}
void
compressor_reset(struct compressor *stream)
{
stream->methods->reset(stream->priv);
}
int
compressor_write(struct compressor *stream, void *data, size_t len)
{
return (stream->methods->write(stream->priv, data, len, stream->cb,
stream->arg));
}
int
compressor_flush(struct compressor *stream)
{
return (stream->methods->write(stream->priv, NULL, 0, stream->cb,
stream->arg));
}
void
compressor_fini(struct compressor *stream)
{
stream->methods->fini(stream->priv);
}