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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/kern/kern_gzio.c |
/*
* $Id: kern_gzio.c,v 1.6 2008-10-18 22:54:45 lbazinet Exp $
*
* core_gzip.c -- gzip routines used in compressing user process cores
*
* This file is derived from src/lib/libz/gzio.c in FreeBSD.
*/
/* gzio.c -- IO on .gz files
* Copyright (C) 1995-1998 Jean-loup Gailly.
* For conditions of distribution and use, see copyright notice in zlib.h
*
*/
/* @(#) $FreeBSD: release/9.1.0/sys/kern/kern_gzio.c 233353 2012-03-23 11:26:54Z kib $ */
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/endian.h>
#include <net/zutil.h>
#include <sys/libkern.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#define GZ_HEADER_LEN 10
#ifndef Z_BUFSIZE
# ifdef MAXSEG_64K
# define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */
# else
# define Z_BUFSIZE 16384
# endif
#endif
#ifndef Z_PRINTF_BUFSIZE
# define Z_PRINTF_BUFSIZE 4096
#endif
#define ALLOC(size) malloc(size, M_TEMP, M_WAITOK | M_ZERO)
#define TRYFREE(p) {if (p) free(p, M_TEMP);}
static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define COMMENT 0x10 /* bit 4 set: file comment present */
#define RESERVED 0xE0 /* bits 5..7: reserved */
typedef struct gz_stream {
z_stream stream;
int z_err; /* error code for last stream operation */
int z_eof; /* set if end of input file */
struct vnode *file; /* vnode pointer of .gz file */
Byte *inbuf; /* input buffer */
Byte *outbuf; /* output buffer */
uLong crc; /* crc32 of uncompressed data */
char *msg; /* error message */
char *path; /* path name for debugging only */
int transparent; /* 1 if input file is not a .gz file */
char mode; /* 'w' or 'r' */
long startpos; /* start of compressed data in file (header skipped) */
off_t outoff; /* current offset in output file */
int flags;
} gz_stream;
local int do_flush OF((gzFile file, int flush));
local int destroy OF((gz_stream *s));
local void putU32 OF((gz_stream *file, uint32_t x));
local void *gz_alloc OF((void *notused, u_int items, u_int size));
local void gz_free OF((void *notused, void *ptr));
/* ===========================================================================
Opens a gzip (.gz) file for reading or writing. The mode parameter
is as in fopen ("rb" or "wb"). The file is given either by file descriptor
or path name (if fd == -1).
gz_open return NULL if the file could not be opened or if there was
insufficient memory to allocate the (de)compression state; errno
can be checked to distinguish the two cases (if errno is zero, the
zlib error is Z_MEM_ERROR).
*/
gzFile gz_open (path, mode, vp)
const char *path;
const char *mode;
struct vnode *vp;
{
int err;
int level = Z_DEFAULT_COMPRESSION; /* compression level */
int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */
const char *p = mode;
gz_stream *s;
char fmode[80]; /* copy of mode, without the compression level */
char *m = fmode;
ssize_t resid;
int error;
char buf[GZ_HEADER_LEN + 1];
if (!path || !mode) return Z_NULL;
s = (gz_stream *)ALLOC(sizeof(gz_stream));
if (!s) return Z_NULL;
s->stream.zalloc = (alloc_func)gz_alloc;
s->stream.zfree = (free_func)gz_free;
s->stream.opaque = (voidpf)0;
s->stream.next_in = s->inbuf = Z_NULL;
s->stream.next_out = s->outbuf = Z_NULL;
s->stream.avail_in = s->stream.avail_out = 0;
s->file = NULL;
s->z_err = Z_OK;
s->z_eof = 0;
s->crc = 0;
s->msg = NULL;
s->transparent = 0;
s->outoff = 0;
s->flags = 0;
s->path = (char*)ALLOC(strlen(path)+1);
if (s->path == NULL) {
return destroy(s), (gzFile)Z_NULL;
}
strcpy(s->path, path); /* do this early for debugging */
s->mode = '\0';
do {
if (*p == 'r') s->mode = 'r';
if (*p == 'w' || *p == 'a') s->mode = 'w';
if (*p >= '0' && *p <= '9') {
level = *p - '0';
} else if (*p == 'f') {
strategy = Z_FILTERED;
} else if (*p == 'h') {
strategy = Z_HUFFMAN_ONLY;
} else {
*m++ = *p; /* copy the mode */
}
} while (*p++ && m != fmode + sizeof(fmode));
if (s->mode != 'w') {
log(LOG_ERR, "gz_open: mode is not w (%c)\n", s->mode);
return destroy(s), (gzFile)Z_NULL;
}
err = deflateInit2(&(s->stream), level,
Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy);
/* windowBits is passed < 0 to suppress zlib header */
s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
if (err != Z_OK || s->outbuf == Z_NULL) {
return destroy(s), (gzFile)Z_NULL;
}
s->stream.avail_out = Z_BUFSIZE;
s->file = vp;
/* Write a very simple .gz header:
*/
snprintf(buf, sizeof(buf), "%c%c%c%c%c%c%c%c%c%c", gz_magic[0],
gz_magic[1], Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/,
0 /*xflags*/, OS_CODE);
if ((error = vn_rdwr(UIO_WRITE, s->file, buf, GZ_HEADER_LEN, s->outoff,
UIO_SYSSPACE, IO_UNIT, curproc->p_ucred,
NOCRED, &resid, curthread))) {
s->outoff += GZ_HEADER_LEN - resid;
return destroy(s), (gzFile)Z_NULL;
}
s->outoff += GZ_HEADER_LEN;
s->startpos = 10L;
return (gzFile)s;
}
/* ===========================================================================
* Cleanup then free the given gz_stream. Return a zlib error code.
Try freeing in the reverse order of allocations.
*/
local int destroy (s)
gz_stream *s;
{
int err = Z_OK;
if (!s) return Z_STREAM_ERROR;
TRYFREE(s->msg);
if (s->stream.state != NULL) {
if (s->mode == 'w') {
err = deflateEnd(&(s->stream));
}
}
if (s->z_err < 0) err = s->z_err;
TRYFREE(s->inbuf);
TRYFREE(s->outbuf);
TRYFREE(s->path);
TRYFREE(s);
return err;
}
/* ===========================================================================
Writes the given number of uncompressed bytes into the compressed file.
gzwrite returns the number of bytes actually written (0 in case of error).
*/
int ZEXPORT gzwrite (file, buf, len)
gzFile file;
const voidp buf;
unsigned len;
{
gz_stream *s = (gz_stream*)file;
off_t curoff;
size_t resid;
int error;
int vfslocked;
if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
s->stream.next_in = (Bytef*)buf;
s->stream.avail_in = len;
curoff = s->outoff;
while (s->stream.avail_in != 0) {
if (s->stream.avail_out == 0) {
s->stream.next_out = s->outbuf;
vfslocked = VFS_LOCK_GIANT(s->file->v_mount);
error = vn_rdwr_inchunks(UIO_WRITE, s->file, s->outbuf, Z_BUFSIZE,
curoff, UIO_SYSSPACE, IO_UNIT,
curproc->p_ucred, NOCRED, &resid, curthread);
VFS_UNLOCK_GIANT(vfslocked);
if (error) {
log(LOG_ERR, "gzwrite: vn_rdwr return %d\n", error);
curoff += Z_BUFSIZE - resid;
s->z_err = Z_ERRNO;
break;
}
curoff += Z_BUFSIZE;
s->stream.avail_out = Z_BUFSIZE;
}
s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
if (s->z_err != Z_OK) {
log(LOG_ERR,
"gzwrite: deflate returned error %d\n", s->z_err);
break;
}
}
s->crc = ~crc32_raw(buf, len, ~s->crc);
s->outoff = curoff;
return (int)(len - s->stream.avail_in);
}
/* ===========================================================================
Flushes all pending output into the compressed file. The parameter
flush is as in the deflate() function.
*/
local int do_flush (file, flush)
gzFile file;
int flush;
{
uInt len;
int done = 0;
gz_stream *s = (gz_stream*)file;
off_t curoff = s->outoff;
size_t resid;
int vfslocked = 0;
int error;
if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
if (s->stream.avail_in) {
log(LOG_WARNING, "do_flush: avail_in non-zero on entry\n");
}
s->stream.avail_in = 0; /* should be zero already anyway */
for (;;) {
len = Z_BUFSIZE - s->stream.avail_out;
if (len != 0) {
vfslocked = VFS_LOCK_GIANT(s->file->v_mount);
error = vn_rdwr_inchunks(UIO_WRITE, s->file, s->outbuf, len, curoff,
UIO_SYSSPACE, IO_UNIT, curproc->p_ucred,
NOCRED, &resid, curthread);
VFS_UNLOCK_GIANT(vfslocked);
if (error) {
s->z_err = Z_ERRNO;
s->outoff = curoff + len - resid;
return Z_ERRNO;
}
s->stream.next_out = s->outbuf;
s->stream.avail_out = Z_BUFSIZE;
curoff += len;
}
if (done) break;
s->z_err = deflate(&(s->stream), flush);
/* Ignore the second of two consecutive flushes: */
if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK;
/* deflate has finished flushing only when it hasn't used up
* all the available space in the output buffer:
*/
done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
}
s->outoff = curoff;
return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
}
int ZEXPORT gzflush (file, flush)
gzFile file;
int flush;
{
gz_stream *s = (gz_stream*)file;
int err = do_flush (file, flush);
if (err) return err;
return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
}
/* ===========================================================================
Outputs a long in LSB order to the given file
*/
local void putU32 (s, x)
gz_stream *s;
uint32_t x;
{
uint32_t xx;
off_t curoff = s->outoff;
ssize_t resid;
#if BYTE_ORDER == BIG_ENDIAN
xx = bswap32(x);
#else
xx = x;
#endif
vn_rdwr(UIO_WRITE, s->file, (caddr_t)&xx, sizeof(xx), curoff,
UIO_SYSSPACE, IO_UNIT, curproc->p_ucred,
NOCRED, &resid, curthread);
s->outoff += sizeof(xx) - resid;
}
/* ===========================================================================
Flushes all pending output if necessary, closes the compressed file
and deallocates all the (de)compression state.
*/
int ZEXPORT gzclose (file)
gzFile file;
{
int err;
gz_stream *s = (gz_stream*)file;
if (s == NULL) return Z_STREAM_ERROR;
if (s->mode == 'w') {
err = do_flush (file, Z_FINISH);
if (err != Z_OK) {
log(LOG_ERR, "gzclose: do_flush failed (err %d)\n", err);
return destroy((gz_stream*)file);
}
#if 0
printf("gzclose: putting crc: %lld total: %lld\n",
(long long)s->crc, (long long)s->stream.total_in);
printf("sizeof uLong = %d\n", (int)sizeof(uLong));
#endif
putU32 (s, s->crc);
putU32 (s, (uint32_t) s->stream.total_in);
}
return destroy((gz_stream*)file);
}
/*
* Space allocation and freeing routines for use by zlib routines when called
* from gzip modules.
*/
static void *
gz_alloc(void *notused __unused, u_int items, u_int size)
{
void *ptr;
MALLOC(ptr, void *, items * size, M_TEMP, M_NOWAIT | M_ZERO);
return ptr;
}
static void
gz_free(void *opaque __unused, void *ptr)
{
FREE(ptr, M_TEMP);
}