mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-12-02 10:42:45 +00:00
524 lines
15 KiB
C
524 lines
15 KiB
C
/* gzio.c -- IO on .gz files
|
|
* Copyright (C) 1995-1996 Jean-loup Gailly.
|
|
* For conditions of distribution and use, see copyright notice in zlib.h
|
|
*/
|
|
|
|
/* $Id: gzio.c,v 1.14 1996/07/24 13:41:01 me Exp $ */
|
|
|
|
#include <stdio.h>
|
|
|
|
#include "zutil.h"
|
|
|
|
struct internal_state {int dummy;}; /* for buggy compilers */
|
|
|
|
#define Z_BUFSIZE 4096
|
|
|
|
#define ALLOC(size) malloc(size)
|
|
#define TRYFREE(p) {if (p) free(p);}
|
|
|
|
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 */
|
|
FILE *file; /* .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' */
|
|
} gz_stream;
|
|
|
|
|
|
local gzFile gz_open OF((const char *path, const char *mode, int fd));
|
|
local int get_byte OF((gz_stream *s));
|
|
local void check_header OF((gz_stream *s));
|
|
local int destroy OF((gz_stream *s));
|
|
local void putLong OF((FILE *file, uLong x));
|
|
local uLong getLong OF((gz_stream *s));
|
|
|
|
/* ===========================================================================
|
|
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).
|
|
*/
|
|
local gzFile gz_open (path, mode, fd)
|
|
const char *path;
|
|
const char *mode;
|
|
int fd;
|
|
{
|
|
int err;
|
|
int level = Z_DEFAULT_COMPRESSION; /* compression level */
|
|
char *p = (char*)mode;
|
|
gz_stream *s;
|
|
char fmode[80]; /* copy of mode, without the compression level */
|
|
char *m = fmode;
|
|
|
|
if (!path || !mode) return Z_NULL;
|
|
|
|
s = (gz_stream *)ALLOC(sizeof(gz_stream));
|
|
if (!s) return Z_NULL;
|
|
|
|
s->stream.zalloc = (alloc_func)0;
|
|
s->stream.zfree = (free_func)0;
|
|
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 = crc32(0L, Z_NULL, 0);
|
|
s->msg = NULL;
|
|
s->transparent = 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 {
|
|
*m++ = *p; /* copy the mode */
|
|
}
|
|
} while (*p++ && m != fmode + sizeof(fmode));
|
|
if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL;
|
|
|
|
if (s->mode == 'w') {
|
|
err = deflateInit2(&(s->stream), level,
|
|
Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, 0);
|
|
/* 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;
|
|
}
|
|
} else {
|
|
err = inflateInit2(&(s->stream), -MAX_WBITS);
|
|
s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
|
|
|
|
if (err != Z_OK || s->inbuf == Z_NULL) {
|
|
return destroy(s), (gzFile)Z_NULL;
|
|
}
|
|
}
|
|
s->stream.avail_out = Z_BUFSIZE;
|
|
|
|
errno = 0;
|
|
s->file = fd < 0 ? FOPEN(path, fmode) : (FILE*)fdopen(fd, fmode);
|
|
|
|
if (s->file == NULL) {
|
|
return destroy(s), (gzFile)Z_NULL;
|
|
}
|
|
if (s->mode == 'w') {
|
|
/* Write a very simple .gz header:
|
|
*/
|
|
fprintf(s->file, "%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);
|
|
} else {
|
|
check_header(s); /* skip the .gz header */
|
|
}
|
|
return (gzFile)s;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Opens a gzip (.gz) file for reading or writing.
|
|
*/
|
|
gzFile gzopen (path, mode)
|
|
const char *path;
|
|
const char *mode;
|
|
{
|
|
return gz_open (path, mode, -1);
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Associate a gzFile with the file descriptor fd. fd is not dup'ed here
|
|
to mimic the behavio(u)r of fdopen.
|
|
*/
|
|
gzFile gzdopen (fd, mode)
|
|
int fd;
|
|
const char *mode;
|
|
{
|
|
char name[20];
|
|
|
|
if (fd < 0) return (gzFile)Z_NULL;
|
|
sprintf(name, "<fd:%d>", fd); /* for debugging */
|
|
|
|
return gz_open (name, mode, fd);
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Read a byte from a gz_stream; update next_in and avail_in. Return EOF
|
|
for end of file.
|
|
IN assertion: the stream s has been sucessfully opened for reading.
|
|
*/
|
|
local int get_byte(s)
|
|
gz_stream *s;
|
|
{
|
|
if (s->z_eof) return EOF;
|
|
if (s->stream.avail_in == 0) {
|
|
errno = 0;
|
|
s->stream.avail_in = fread(s->inbuf, 1, Z_BUFSIZE, s->file);
|
|
if (s->stream.avail_in == 0) {
|
|
s->z_eof = 1;
|
|
if (ferror(s->file)) s->z_err = Z_ERRNO;
|
|
return EOF;
|
|
}
|
|
s->stream.next_in = s->inbuf;
|
|
}
|
|
s->stream.avail_in--;
|
|
return *(s->stream.next_in)++;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Check the gzip header of a gz_stream opened for reading. Set the stream
|
|
mode to transparent if the gzip magic header is not present; set s->err
|
|
to Z_DATA_ERROR if the magic header is present but the rest of the header
|
|
is incorrect.
|
|
IN assertion: the stream s has already been created sucessfully;
|
|
s->stream.avail_in is zero for the first time, but may be non-zero
|
|
for concatenated .gz files.
|
|
*/
|
|
local void check_header(s)
|
|
gz_stream *s;
|
|
{
|
|
int method; /* method byte */
|
|
int flags; /* flags byte */
|
|
uInt len;
|
|
int c;
|
|
|
|
/* Check the gzip magic header */
|
|
for (len = 0; len < 2; len++) {
|
|
c = get_byte(s);
|
|
if (c != gz_magic[len]) {
|
|
s->transparent = 1;
|
|
if (c != EOF) s->stream.avail_in++, s->stream.next_in--;
|
|
s->z_err = s->stream.avail_in != 0 ? Z_OK : Z_STREAM_END;
|
|
return;
|
|
}
|
|
}
|
|
method = get_byte(s);
|
|
flags = get_byte(s);
|
|
if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
|
|
s->z_err = Z_DATA_ERROR;
|
|
return;
|
|
}
|
|
|
|
/* Discard time, xflags and OS code: */
|
|
for (len = 0; len < 6; len++) (void)get_byte(s);
|
|
|
|
if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
|
|
len = (uInt)get_byte(s);
|
|
len += ((uInt)get_byte(s))<<8;
|
|
/* len is garbage if EOF but the loop below will quit anyway */
|
|
while (len-- != 0 && get_byte(s) != EOF) ;
|
|
}
|
|
if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
|
|
while ((c = get_byte(s)) != 0 && c != EOF) ;
|
|
}
|
|
if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
|
|
while ((c = get_byte(s)) != 0 && c != EOF) ;
|
|
}
|
|
if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
|
|
for (len = 0; len < 2; len++) (void)get_byte(s);
|
|
}
|
|
s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
* 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));
|
|
} else if (s->mode == 'r') {
|
|
err = inflateEnd(&(s->stream));
|
|
}
|
|
}
|
|
if (s->file != NULL && fclose(s->file)) {
|
|
err = Z_ERRNO;
|
|
}
|
|
if (s->z_err < 0) err = s->z_err;
|
|
|
|
TRYFREE(s->inbuf);
|
|
TRYFREE(s->outbuf);
|
|
TRYFREE(s->path);
|
|
TRYFREE(s);
|
|
return err;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Reads the given number of uncompressed bytes from the compressed file.
|
|
gzread returns the number of bytes actually read (0 for end of file).
|
|
*/
|
|
int gzread (file, buf, len)
|
|
gzFile file;
|
|
voidp buf;
|
|
unsigned len;
|
|
{
|
|
gz_stream *s = (gz_stream*)file;
|
|
Bytef *start = buf; /* starting point for crc computation */
|
|
Byte *next_out; /* == stream.next_out but not forced far (for MSDOS) */
|
|
|
|
if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;
|
|
|
|
if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
|
|
if (s->z_err == Z_STREAM_END) return 0; /* EOF */
|
|
|
|
s->stream.next_out = next_out = buf;
|
|
s->stream.avail_out = len;
|
|
|
|
while (s->stream.avail_out != 0) {
|
|
|
|
if (s->transparent) {
|
|
/* Copy first the lookahead bytes: */
|
|
uInt n = s->stream.avail_in;
|
|
if (n > s->stream.avail_out) n = s->stream.avail_out;
|
|
if (n > 0) {
|
|
zmemcpy(s->stream.next_out, s->stream.next_in, n);
|
|
next_out += n;
|
|
s->stream.next_out = next_out;
|
|
s->stream.next_in += n;
|
|
s->stream.avail_out -= n;
|
|
s->stream.avail_in -= n;
|
|
}
|
|
if (s->stream.avail_out > 0) {
|
|
s->stream.avail_out -= fread(next_out, 1, s->stream.avail_out,
|
|
s->file);
|
|
}
|
|
return (int)(len - s->stream.avail_out);
|
|
}
|
|
if (s->stream.avail_in == 0 && !s->z_eof) {
|
|
|
|
errno = 0;
|
|
s->stream.avail_in = fread(s->inbuf, 1, Z_BUFSIZE, s->file);
|
|
if (s->stream.avail_in == 0) {
|
|
s->z_eof = 1;
|
|
if (ferror(s->file)) {
|
|
s->z_err = Z_ERRNO;
|
|
break;
|
|
}
|
|
}
|
|
s->stream.next_in = s->inbuf;
|
|
}
|
|
s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
|
|
|
|
if (s->z_err == Z_STREAM_END) {
|
|
/* Check CRC and original size */
|
|
s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
|
|
start = s->stream.next_out;
|
|
|
|
if (getLong(s) != s->crc || getLong(s) != s->stream.total_out) {
|
|
s->z_err = Z_DATA_ERROR;
|
|
} else {
|
|
/* Check for concatenated .gz files: */
|
|
check_header(s);
|
|
if (s->z_err == Z_OK) {
|
|
inflateReset(&(s->stream));
|
|
s->crc = crc32(0L, Z_NULL, 0);
|
|
}
|
|
}
|
|
}
|
|
if (s->z_err != Z_OK || s->z_eof) break;
|
|
}
|
|
s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
|
|
|
|
return (int)(len - s->stream.avail_out);
|
|
}
|
|
|
|
/* ===========================================================================
|
|
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 gzwrite (file, buf, len)
|
|
gzFile file;
|
|
const voidp buf;
|
|
unsigned len;
|
|
{
|
|
gz_stream *s = (gz_stream*)file;
|
|
|
|
if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
|
|
|
|
s->stream.next_in = buf;
|
|
s->stream.avail_in = len;
|
|
|
|
while (s->stream.avail_in != 0) {
|
|
|
|
if (s->stream.avail_out == 0) {
|
|
|
|
s->stream.next_out = s->outbuf;
|
|
if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
|
|
s->z_err = Z_ERRNO;
|
|
break;
|
|
}
|
|
s->stream.avail_out = Z_BUFSIZE;
|
|
}
|
|
s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
|
|
if (s->z_err != Z_OK) break;
|
|
}
|
|
s->crc = crc32(s->crc, buf, len);
|
|
|
|
return (int)(len - s->stream.avail_in);
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Flushes all pending output into the compressed file. The parameter
|
|
flush is as in the deflate() function.
|
|
gzflush should be called only when strictly necessary because it can
|
|
degrade compression.
|
|
*/
|
|
int gzflush (file, flush)
|
|
gzFile file;
|
|
int flush;
|
|
{
|
|
uInt len;
|
|
int done = 0;
|
|
gz_stream *s = (gz_stream*)file;
|
|
|
|
if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
|
|
|
|
s->stream.avail_in = 0; /* should be zero already anyway */
|
|
|
|
for (;;) {
|
|
len = Z_BUFSIZE - s->stream.avail_out;
|
|
|
|
if (len != 0) {
|
|
if ((uInt)fwrite(s->outbuf, 1, len, s->file) != len) {
|
|
s->z_err = Z_ERRNO;
|
|
return Z_ERRNO;
|
|
}
|
|
s->stream.next_out = s->outbuf;
|
|
s->stream.avail_out = Z_BUFSIZE;
|
|
}
|
|
if (done) break;
|
|
s->z_err = deflate(&(s->stream), flush);
|
|
|
|
/* 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;
|
|
}
|
|
fflush(s->file);
|
|
return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Outputs a long in LSB order to the given file
|
|
*/
|
|
local void putLong (file, x)
|
|
FILE *file;
|
|
uLong x;
|
|
{
|
|
int n;
|
|
for (n = 0; n < 4; n++) {
|
|
fputc((int)(x & 0xff), file);
|
|
x >>= 8;
|
|
}
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Reads a long in LSB order from the given gz_stream. Sets
|
|
*/
|
|
local uLong getLong (s)
|
|
gz_stream *s;
|
|
{
|
|
uLong x = (uLong)get_byte(s);
|
|
int c;
|
|
|
|
x += ((uLong)get_byte(s))<<8;
|
|
x += ((uLong)get_byte(s))<<16;
|
|
c = get_byte(s);
|
|
if (c == EOF) s->z_err = Z_DATA_ERROR;
|
|
x += ((uLong)c)<<24;
|
|
return x;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Flushes all pending output if necessary, closes the compressed file
|
|
and deallocates all the (de)compression state.
|
|
*/
|
|
int gzclose (file)
|
|
gzFile file;
|
|
{
|
|
int err;
|
|
gz_stream *s = (gz_stream*)file;
|
|
|
|
if (s == NULL) return Z_STREAM_ERROR;
|
|
|
|
if (s->mode == 'w') {
|
|
err = gzflush (file, Z_FINISH);
|
|
if (err != Z_OK) return destroy(file);
|
|
|
|
putLong (s->file, s->crc);
|
|
putLong (s->file, s->stream.total_in);
|
|
|
|
}
|
|
return destroy(file);
|
|
}
|
|
|
|
/* ===========================================================================
|
|
Returns the error message for the last error which occured on the
|
|
given compressed file. errnum is set to zlib error number. If an
|
|
error occured in the file system and not in the compression library,
|
|
errnum is set to Z_ERRNO and the application may consult errno
|
|
to get the exact error code.
|
|
*/
|
|
const char* gzerror (file, errnum)
|
|
gzFile file;
|
|
int *errnum;
|
|
{
|
|
char *m;
|
|
gz_stream *s = (gz_stream*)file;
|
|
|
|
if (s == NULL) {
|
|
*errnum = Z_STREAM_ERROR;
|
|
return (const char*)ERR_MSG(Z_STREAM_ERROR);
|
|
}
|
|
*errnum = s->z_err;
|
|
if (*errnum == Z_OK) return (const char*)"";
|
|
|
|
m = (char*)(*errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg);
|
|
|
|
if (m == NULL || *m == '\0') m = (char*)ERR_MSG(s->z_err);
|
|
|
|
TRYFREE(s->msg);
|
|
s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3);
|
|
strcpy(s->msg, s->path);
|
|
strcat(s->msg, ": ");
|
|
strcat(s->msg, m);
|
|
return (const char*)s->msg;
|
|
}
|