You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
653 lines
20 KiB
653 lines
20 KiB
/* gzread.c -- zlib functions for reading gzip files
|
|
* Copyright (C) 2004, 2005, 2010 Mark Adler
|
|
* For conditions of distribution and use, see copyright notice in zlib.h
|
|
*/
|
|
|
|
#include "gzguts.h"
|
|
|
|
/* Local functions */
|
|
local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
|
|
local int gz_avail OF((gz_statep));
|
|
local int gz_next4 OF((gz_statep, unsigned long *));
|
|
local int gz_head OF((gz_statep));
|
|
local int gz_decomp OF((gz_statep));
|
|
local int gz_make OF((gz_statep));
|
|
local int gz_skip OF((gz_statep, z_off64_t));
|
|
|
|
/* Use read() to load a buffer -- return -1 on error, otherwise 0. Read from
|
|
state->fd, and update state->eof, state->err, and state->msg as appropriate.
|
|
This function needs to loop on read(), since read() is not guaranteed to
|
|
read the number of bytes requested, depending on the type of descriptor. */
|
|
local int gz_load(state, buf, len, have)
|
|
gz_statep state;
|
|
unsigned char *buf;
|
|
unsigned len;
|
|
unsigned *have;
|
|
{
|
|
int ret;
|
|
|
|
*have = 0;
|
|
do {
|
|
ret = read(state->fd, buf + *have, len - *have);
|
|
if (ret <= 0)
|
|
break;
|
|
*have += ret;
|
|
} while (*have < len);
|
|
if (ret < 0) {
|
|
gz_error(state, Z_ERRNO, zstrerror());
|
|
return -1;
|
|
}
|
|
if (ret == 0)
|
|
state->eof = 1;
|
|
return 0;
|
|
}
|
|
|
|
/* Load up input buffer and set eof flag if last data loaded -- return -1 on
|
|
error, 0 otherwise. Note that the eof flag is set when the end of the input
|
|
file is reached, even though there may be unused data in the buffer. Once
|
|
that data has been used, no more attempts will be made to read the file.
|
|
gz_avail() assumes that strm->avail_in == 0. */
|
|
local int gz_avail(state)
|
|
gz_statep state;
|
|
{
|
|
z_streamp strm = &(state->strm);
|
|
|
|
if (state->err != Z_OK)
|
|
return -1;
|
|
if (state->eof == 0) {
|
|
if (gz_load(state, state->in, state->size,
|
|
(unsigned *)&(strm->avail_in)) == -1)
|
|
return -1;
|
|
strm->next_in = state->in;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Get next byte from input, or -1 if end or error. */
|
|
#define NEXT() ((strm->avail_in == 0 && gz_avail(state) == -1) ? -1 : \
|
|
(strm->avail_in == 0 ? -1 : \
|
|
(strm->avail_in--, *(strm->next_in)++)))
|
|
|
|
/* Get a four-byte little-endian integer and return 0 on success and the value
|
|
in *ret. Otherwise -1 is returned and *ret is not modified. */
|
|
local int gz_next4(state, ret)
|
|
gz_statep state;
|
|
unsigned long *ret;
|
|
{
|
|
int ch;
|
|
unsigned long val;
|
|
z_streamp strm = &(state->strm);
|
|
|
|
val = NEXT();
|
|
val += (unsigned)NEXT() << 8;
|
|
val += (unsigned long)NEXT() << 16;
|
|
ch = NEXT();
|
|
if (ch == -1)
|
|
return -1;
|
|
val += (unsigned long)ch << 24;
|
|
*ret = val;
|
|
return 0;
|
|
}
|
|
|
|
/* Look for gzip header, set up for inflate or copy. state->have must be zero.
|
|
If this is the first time in, allocate required memory. state->how will be
|
|
left unchanged if there is no more input data available, will be set to COPY
|
|
if there is no gzip header and direct copying will be performed, or it will
|
|
be set to GZIP for decompression, and the gzip header will be skipped so
|
|
that the next available input data is the raw deflate stream. If direct
|
|
copying, then leftover input data from the input buffer will be copied to
|
|
the output buffer. In that case, all further file reads will be directly to
|
|
either the output buffer or a user buffer. If decompressing, the inflate
|
|
state and the check value will be initialized. gz_head() will return 0 on
|
|
success or -1 on failure. Failures may include read errors or gzip header
|
|
errors. */
|
|
local int gz_head(state)
|
|
gz_statep state;
|
|
{
|
|
z_streamp strm = &(state->strm);
|
|
int flags;
|
|
unsigned len;
|
|
|
|
/* allocate read buffers and inflate memory */
|
|
if (state->size == 0) {
|
|
/* allocate buffers */
|
|
state->in = malloc(state->want);
|
|
state->out = malloc(state->want << 1);
|
|
if (state->in == NULL || state->out == NULL) {
|
|
if (state->out != NULL)
|
|
free(state->out);
|
|
if (state->in != NULL)
|
|
free(state->in);
|
|
gz_error(state, Z_MEM_ERROR, "out of memory");
|
|
return -1;
|
|
}
|
|
state->size = state->want;
|
|
|
|
/* allocate inflate memory */
|
|
state->strm.zalloc = Z_NULL;
|
|
state->strm.zfree = Z_NULL;
|
|
state->strm.opaque = Z_NULL;
|
|
state->strm.avail_in = 0;
|
|
state->strm.next_in = Z_NULL;
|
|
if (inflateInit2(&(state->strm), -15) != Z_OK) { /* raw inflate */
|
|
free(state->out);
|
|
free(state->in);
|
|
state->size = 0;
|
|
gz_error(state, Z_MEM_ERROR, "out of memory");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* get some data in the input buffer */
|
|
if (strm->avail_in == 0) {
|
|
if (gz_avail(state) == -1)
|
|
return -1;
|
|
if (strm->avail_in == 0)
|
|
return 0;
|
|
}
|
|
|
|
/* look for the gzip magic header bytes 31 and 139 */
|
|
if (strm->next_in[0] == 31) {
|
|
strm->avail_in--;
|
|
strm->next_in++;
|
|
if (strm->avail_in == 0 && gz_avail(state) == -1)
|
|
return -1;
|
|
if (strm->avail_in && strm->next_in[0] == 139) {
|
|
/* we have a gzip header, woo hoo! */
|
|
strm->avail_in--;
|
|
strm->next_in++;
|
|
|
|
/* skip rest of header */
|
|
if (NEXT() != 8) { /* compression method */
|
|
gz_error(state, Z_DATA_ERROR, "unknown compression method");
|
|
return -1;
|
|
}
|
|
flags = NEXT();
|
|
if (flags & 0xe0) { /* reserved flag bits */
|
|
gz_error(state, Z_DATA_ERROR, "unknown header flags set");
|
|
return -1;
|
|
}
|
|
NEXT(); /* modification time */
|
|
NEXT();
|
|
NEXT();
|
|
NEXT();
|
|
NEXT(); /* extra flags */
|
|
NEXT(); /* operating system */
|
|
if (flags & 4) { /* extra field */
|
|
len = (unsigned)NEXT();
|
|
len += (unsigned)NEXT() << 8;
|
|
while (len--)
|
|
if (NEXT() < 0)
|
|
break;
|
|
}
|
|
if (flags & 8) /* file name */
|
|
while (NEXT() > 0)
|
|
;
|
|
if (flags & 16) /* comment */
|
|
while (NEXT() > 0)
|
|
;
|
|
if (flags & 2) { /* header crc */
|
|
NEXT();
|
|
NEXT();
|
|
}
|
|
/* an unexpected end of file is not checked for here -- it will be
|
|
noticed on the first request for uncompressed data */
|
|
|
|
/* set up for decompression */
|
|
inflateReset(strm);
|
|
strm->adler = crc32(0L, Z_NULL, 0);
|
|
state->how = GZIP;
|
|
state->direct = 0;
|
|
return 0;
|
|
}
|
|
else {
|
|
/* not a gzip file -- save first byte (31) and fall to raw i/o */
|
|
state->out[0] = 31;
|
|
state->have = 1;
|
|
}
|
|
}
|
|
|
|
/* doing raw i/o, save start of raw data for seeking, copy any leftover
|
|
input to output -- this assumes that the output buffer is larger than
|
|
the input buffer, which also assures space for gzungetc() */
|
|
state->raw = state->pos;
|
|
state->next = state->out;
|
|
if (strm->avail_in) {
|
|
memcpy(state->next + state->have, strm->next_in, strm->avail_in);
|
|
state->have += strm->avail_in;
|
|
strm->avail_in = 0;
|
|
}
|
|
state->how = COPY;
|
|
state->direct = 1;
|
|
return 0;
|
|
}
|
|
|
|
/* Decompress from input to the provided next_out and avail_out in the state.
|
|
If the end of the compressed data is reached, then verify the gzip trailer
|
|
check value and length (modulo 2^32). state->have and state->next are set
|
|
to point to the just decompressed data, and the crc is updated. If the
|
|
trailer is verified, state->how is reset to LOOK to look for the next gzip
|
|
stream or raw data, once state->have is depleted. Returns 0 on success, -1
|
|
on failure. Failures may include invalid compressed data or a failed gzip
|
|
trailer verification. */
|
|
local int gz_decomp(state)
|
|
gz_statep state;
|
|
{
|
|
int ret;
|
|
unsigned had;
|
|
unsigned long crc, len;
|
|
z_streamp strm = &(state->strm);
|
|
|
|
/* fill output buffer up to end of deflate stream */
|
|
had = strm->avail_out;
|
|
do {
|
|
/* get more input for inflate() */
|
|
if (strm->avail_in == 0 && gz_avail(state) == -1)
|
|
return -1;
|
|
if (strm->avail_in == 0) {
|
|
gz_error(state, Z_DATA_ERROR, "unexpected end of file");
|
|
return -1;
|
|
}
|
|
|
|
/* decompress and handle errors */
|
|
ret = inflate(strm, Z_NO_FLUSH);
|
|
if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
|
|
gz_error(state, Z_STREAM_ERROR,
|
|
"internal error: inflate stream corrupt");
|
|
return -1;
|
|
}
|
|
if (ret == Z_MEM_ERROR) {
|
|
gz_error(state, Z_MEM_ERROR, "out of memory");
|
|
return -1;
|
|
}
|
|
if (ret == Z_DATA_ERROR) { /* deflate stream invalid */
|
|
gz_error(state, Z_DATA_ERROR,
|
|
strm->msg == NULL ? "compressed data error" : strm->msg);
|
|
return -1;
|
|
}
|
|
} while (strm->avail_out && ret != Z_STREAM_END);
|
|
|
|
/* update available output and crc check value */
|
|
state->have = had - strm->avail_out;
|
|
state->next = strm->next_out - state->have;
|
|
strm->adler = crc32(strm->adler, state->next, state->have);
|
|
|
|
/* check gzip trailer if at end of deflate stream */
|
|
if (ret == Z_STREAM_END) {
|
|
if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
|
|
gz_error(state, Z_DATA_ERROR, "unexpected end of file");
|
|
return -1;
|
|
}
|
|
if (crc != strm->adler) {
|
|
gz_error(state, Z_DATA_ERROR, "incorrect data check");
|
|
return -1;
|
|
}
|
|
if (len != (strm->total_out & 0xffffffffL)) {
|
|
gz_error(state, Z_DATA_ERROR, "incorrect length check");
|
|
return -1;
|
|
}
|
|
state->how = LOOK; /* ready for next stream, once have is 0 (leave
|
|
state->direct unchanged to remember how) */
|
|
}
|
|
|
|
/* good decompression */
|
|
return 0;
|
|
}
|
|
|
|
/* Make data and put in the output buffer. Assumes that state->have == 0.
|
|
Data is either copied from the input file or decompressed from the input
|
|
file depending on state->how. If state->how is LOOK, then a gzip header is
|
|
looked for (and skipped if found) to determine wither to copy or decompress.
|
|
Returns -1 on error, otherwise 0. gz_make() will leave state->have as COPY
|
|
or GZIP unless the end of the input file has been reached and all data has
|
|
been processed. */
|
|
local int gz_make(state)
|
|
gz_statep state;
|
|
{
|
|
z_streamp strm = &(state->strm);
|
|
|
|
if (state->how == LOOK) { /* look for gzip header */
|
|
if (gz_head(state) == -1)
|
|
return -1;
|
|
if (state->have) /* got some data from gz_head() */
|
|
return 0;
|
|
}
|
|
if (state->how == COPY) { /* straight copy */
|
|
if (gz_load(state, state->out, state->size << 1, &(state->have)) == -1)
|
|
return -1;
|
|
state->next = state->out;
|
|
}
|
|
else if (state->how == GZIP) { /* decompress */
|
|
strm->avail_out = state->size << 1;
|
|
strm->next_out = state->out;
|
|
if (gz_decomp(state) == -1)
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Skip len uncompressed bytes of output. Return -1 on error, 0 on success. */
|
|
local int gz_skip(state, len)
|
|
gz_statep state;
|
|
z_off64_t len;
|
|
{
|
|
unsigned n;
|
|
|
|
/* skip over len bytes or reach end-of-file, whichever comes first */
|
|
while (len)
|
|
/* skip over whatever is in output buffer */
|
|
if (state->have) {
|
|
n = GT_OFF(state->have) || (z_off64_t)state->have > len ?
|
|
(unsigned)len : state->have;
|
|
state->have -= n;
|
|
state->next += n;
|
|
state->pos += n;
|
|
len -= n;
|
|
}
|
|
|
|
/* output buffer empty -- return if we're at the end of the input */
|
|
else if (state->eof && state->strm.avail_in == 0)
|
|
break;
|
|
|
|
/* need more data to skip -- load up output buffer */
|
|
else {
|
|
/* get more output, looking for header if required */
|
|
if (gz_make(state) == -1)
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* -- see zlib.h -- */
|
|
int ZEXPORT gzread(file, buf, len)
|
|
gzFile file;
|
|
voidp buf;
|
|
unsigned len;
|
|
{
|
|
unsigned got, n;
|
|
gz_statep state;
|
|
z_streamp strm;
|
|
|
|
/* get internal structure */
|
|
if (file == NULL)
|
|
return -1;
|
|
state = (gz_statep)file;
|
|
strm = &(state->strm);
|
|
|
|
/* check that we're reading and that there's no error */
|
|
if (state->mode != GZ_READ || state->err != Z_OK)
|
|
return -1;
|
|
|
|
/* since an int is returned, make sure len fits in one, otherwise return
|
|
with an error (this avoids the flaw in the interface) */
|
|
if ((int)len < 0) {
|
|
gz_error(state, Z_BUF_ERROR, "requested length does not fit in int");
|
|
return -1;
|
|
}
|
|
|
|
/* if len is zero, avoid unnecessary operations */
|
|
if (len == 0)
|
|
return 0;
|
|
|
|
/* process a skip request */
|
|
if (state->seek) {
|
|
state->seek = 0;
|
|
if (gz_skip(state, state->skip) == -1)
|
|
return -1;
|
|
}
|
|
|
|
/* get len bytes to buf, or less than len if at the end */
|
|
got = 0;
|
|
do {
|
|
/* first just try copying data from the output buffer */
|
|
if (state->have) {
|
|
n = state->have > len ? len : state->have;
|
|
memcpy(buf, state->next, n);
|
|
state->next += n;
|
|
state->have -= n;
|
|
}
|
|
|
|
/* output buffer empty -- return if we're at the end of the input */
|
|
else if (state->eof && strm->avail_in == 0)
|
|
break;
|
|
|
|
/* need output data -- for small len or new stream load up our output
|
|
buffer */
|
|
else if (state->how == LOOK || len < (state->size << 1)) {
|
|
/* get more output, looking for header if required */
|
|
if (gz_make(state) == -1)
|
|
return -1;
|
|
continue; /* no progress yet -- go back to memcpy() above */
|
|
/* the copy above assures that we will leave with space in the
|
|
output buffer, allowing at least one gzungetc() to succeed */
|
|
}
|
|
|
|
/* large len -- read directly into user buffer */
|
|
else if (state->how == COPY) { /* read directly */
|
|
if (gz_load(state, buf, len, &n) == -1)
|
|
return -1;
|
|
}
|
|
|
|
/* large len -- decompress directly into user buffer */
|
|
else { /* state->how == GZIP */
|
|
strm->avail_out = len;
|
|
strm->next_out = buf;
|
|
if (gz_decomp(state) == -1)
|
|
return -1;
|
|
n = state->have;
|
|
state->have = 0;
|
|
}
|
|
|
|
/* update progress */
|
|
len -= n;
|
|
buf = (char *)buf + n;
|
|
got += n;
|
|
state->pos += n;
|
|
} while (len);
|
|
|
|
/* return number of bytes read into user buffer (will fit in int) */
|
|
return (int)got;
|
|
}
|
|
|
|
/* -- see zlib.h -- */
|
|
int ZEXPORT gzgetc(file)
|
|
gzFile file;
|
|
{
|
|
int ret;
|
|
unsigned char buf[1];
|
|
gz_statep state;
|
|
|
|
/* get internal structure */
|
|
if (file == NULL)
|
|
return -1;
|
|
state = (gz_statep)file;
|
|
|
|
/* check that we're reading and that there's no error */
|
|
if (state->mode != GZ_READ || state->err != Z_OK)
|
|
return -1;
|
|
|
|
/* try output buffer (no need to check for skip request) */
|
|
if (state->have) {
|
|
state->have--;
|
|
state->pos++;
|
|
return *(state->next)++;
|
|
}
|
|
|
|
/* nothing there -- try gzread() */
|
|
ret = gzread(file, buf, 1);
|
|
return ret < 1 ? -1 : buf[0];
|
|
}
|
|
|
|
/* -- see zlib.h -- */
|
|
int ZEXPORT gzungetc(c, file)
|
|
int c;
|
|
gzFile file;
|
|
{
|
|
gz_statep state;
|
|
|
|
/* get internal structure */
|
|
if (file == NULL)
|
|
return -1;
|
|
state = (gz_statep)file;
|
|
|
|
/* check that we're reading and that there's no error */
|
|
if (state->mode != GZ_READ || state->err != Z_OK)
|
|
return -1;
|
|
|
|
/* process a skip request */
|
|
if (state->seek) {
|
|
state->seek = 0;
|
|
if (gz_skip(state, state->skip) == -1)
|
|
return -1;
|
|
}
|
|
|
|
/* can't push EOF */
|
|
if (c < 0)
|
|
return -1;
|
|
|
|
/* if output buffer empty, put byte at end (allows more pushing) */
|
|
if (state->have == 0) {
|
|
state->have = 1;
|
|
state->next = state->out + (state->size << 1) - 1;
|
|
state->next[0] = c;
|
|
state->pos--;
|
|
return c;
|
|
}
|
|
|
|
/* if no room, give up (must have already done a gzungetc()) */
|
|
if (state->have == (state->size << 1)) {
|
|
gz_error(state, Z_BUF_ERROR, "out of room to push characters");
|
|
return -1;
|
|
}
|
|
|
|
/* slide output data if needed and insert byte before existing data */
|
|
if (state->next == state->out) {
|
|
unsigned char *src = state->out + state->have;
|
|
unsigned char *dest = state->out + (state->size << 1);
|
|
while (src > state->out)
|
|
*--dest = *--src;
|
|
state->next = dest;
|
|
}
|
|
state->have++;
|
|
state->next--;
|
|
state->next[0] = c;
|
|
state->pos--;
|
|
return c;
|
|
}
|
|
|
|
/* -- see zlib.h -- */
|
|
char * ZEXPORT gzgets(file, buf, len)
|
|
gzFile file;
|
|
char *buf;
|
|
int len;
|
|
{
|
|
unsigned left, n;
|
|
char *str;
|
|
unsigned char *eol;
|
|
gz_statep state;
|
|
|
|
/* check parameters and get internal structure */
|
|
if (file == NULL || buf == NULL || len < 1)
|
|
return NULL;
|
|
state = (gz_statep)file;
|
|
|
|
/* check that we're reading and that there's no error */
|
|
if (state->mode != GZ_READ || state->err != Z_OK)
|
|
return NULL;
|
|
|
|
/* process a skip request */
|
|
if (state->seek) {
|
|
state->seek = 0;
|
|
if (gz_skip(state, state->skip) == -1)
|
|
return NULL;
|
|
}
|
|
|
|
/* copy output bytes up to new line or len - 1, whichever comes first --
|
|
append a terminating zero to the string (we don't check for a zero in
|
|
the contents, let the user worry about that) */
|
|
str = buf;
|
|
left = (unsigned)len - 1;
|
|
if (left) do {
|
|
/* assure that something is in the output buffer */
|
|
if (state->have == 0) {
|
|
if (gz_make(state) == -1)
|
|
return NULL; /* error */
|
|
if (state->have == 0) { /* end of file */
|
|
if (buf == str) /* got bupkus */
|
|
return NULL;
|
|
break; /* got something -- return it */
|
|
}
|
|
}
|
|
|
|
/* look for end-of-line in current output buffer */
|
|
n = state->have > left ? left : state->have;
|
|
eol = memchr(state->next, '\n', n);
|
|
if (eol != NULL)
|
|
n = (unsigned)(eol - state->next) + 1;
|
|
|
|
/* copy through end-of-line, or remainder if not found */
|
|
memcpy(buf, state->next, n);
|
|
state->have -= n;
|
|
state->next += n;
|
|
state->pos += n;
|
|
left -= n;
|
|
buf += n;
|
|
} while (left && eol == NULL);
|
|
|
|
/* found end-of-line or out of space -- terminate string and return it */
|
|
buf[0] = 0;
|
|
return str;
|
|
}
|
|
|
|
/* -- see zlib.h -- */
|
|
int ZEXPORT gzdirect(file)
|
|
gzFile file;
|
|
{
|
|
gz_statep state;
|
|
|
|
/* get internal structure */
|
|
if (file == NULL)
|
|
return 0;
|
|
state = (gz_statep)file;
|
|
|
|
/* check that we're reading */
|
|
if (state->mode != GZ_READ)
|
|
return 0;
|
|
|
|
/* if the state is not known, but we can find out, then do so (this is
|
|
mainly for right after a gzopen() or gzdopen()) */
|
|
if (state->how == LOOK && state->have == 0)
|
|
(void)gz_head(state);
|
|
|
|
/* return 1 if reading direct, 0 if decompressing a gzip stream */
|
|
return state->direct;
|
|
}
|
|
|
|
/* -- see zlib.h -- */
|
|
int ZEXPORT gzclose_r(file)
|
|
gzFile file;
|
|
{
|
|
int ret;
|
|
gz_statep state;
|
|
|
|
/* get internal structure */
|
|
if (file == NULL)
|
|
return Z_STREAM_ERROR;
|
|
state = (gz_statep)file;
|
|
|
|
/* check that we're reading */
|
|
if (state->mode != GZ_READ)
|
|
return Z_STREAM_ERROR;
|
|
|
|
/* free memory and close file */
|
|
if (state->size) {
|
|
inflateEnd(&(state->strm));
|
|
free(state->out);
|
|
free(state->in);
|
|
}
|
|
gz_error(state, Z_OK, NULL);
|
|
free(state->path);
|
|
ret = close(state->fd);
|
|
free(state);
|
|
return ret ? Z_ERRNO : Z_OK;
|
|
}
|
|
|