decompress_inflate.c
3.74 KB
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#ifdef STATIC
/* Pre-boot environment: included */
/* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
* errors about console_printk etc... on ARM */
#define _LINUX_KERNEL_H
#include "zlib_inflate/inftrees.c"
#include "zlib_inflate/inffast.c"
#include "zlib_inflate/inflate.c"
#else /* STATIC */
/* initramfs et al: linked */
#include <linux/zutil.h>
#include "zlib_inflate/inftrees.h"
#include "zlib_inflate/inffast.h"
#include "zlib_inflate/inflate.h"
#include "zlib_inflate/infutil.h"
#endif /* STATIC */
#include <linux/decompress/mm.h>
#define GZIP_IOBUF_SIZE (16*1024)
static int INIT nofill(void *buffer, unsigned int len)
{
return -1;
}
/* Included from initramfs et al code */
STATIC int INIT gunzip(unsigned char *buf, int len,
int(*fill)(void*, unsigned int),
int(*flush)(void*, unsigned int),
unsigned char *out_buf,
int *pos,
void(*error)(char *x)) {
u8 *zbuf;
struct z_stream_s *strm;
int rc;
size_t out_len;
rc = -1;
if (flush) {
out_len = 0x8000; /* 32 K */
out_buf = malloc(out_len);
} else {
out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
}
if (!out_buf) {
error("Out of memory while allocating output buffer");
goto gunzip_nomem1;
}
if (buf)
zbuf = buf;
else {
zbuf = malloc(GZIP_IOBUF_SIZE);
len = 0;
}
if (!zbuf) {
error("Out of memory while allocating input buffer");
goto gunzip_nomem2;
}
strm = malloc(sizeof(*strm));
if (strm == NULL) {
error("Out of memory while allocating z_stream");
goto gunzip_nomem3;
}
strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
sizeof(struct inflate_state));
if (strm->workspace == NULL) {
error("Out of memory while allocating workspace");
goto gunzip_nomem4;
}
if (!fill)
fill = nofill;
if (len == 0)
len = fill(zbuf, GZIP_IOBUF_SIZE);
/* verify the gzip header */
if (len < 10 ||
zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
if (pos)
*pos = 0;
error("Not a gzip file");
goto gunzip_5;
}
/* skip over gzip header (1f,8b,08... 10 bytes total +
* possible asciz filename)
*/
strm->next_in = zbuf + 10;
strm->avail_in = len - 10;
/* skip over asciz filename */
if (zbuf[3] & 0x8) {
do {
/*
* If the filename doesn't fit into the buffer,
* the file is very probably corrupt. Don't try
* to read more data.
*/
if (strm->avail_in == 0) {
error("header error");
goto gunzip_5;
}
--strm->avail_in;
} while (*strm->next_in++);
}
strm->next_out = out_buf;
strm->avail_out = out_len;
rc = zlib_inflateInit2(strm, -MAX_WBITS);
if (!flush) {
WS(strm)->inflate_state.wsize = 0;
WS(strm)->inflate_state.window = NULL;
}
while (rc == Z_OK) {
if (strm->avail_in == 0) {
/* TODO: handle case where both pos and fill are set */
len = fill(zbuf, GZIP_IOBUF_SIZE);
if (len < 0) {
rc = -1;
error("read error");
break;
}
strm->next_in = zbuf;
strm->avail_in = len;
}
rc = zlib_inflate(strm, 0);
/* Write any data generated */
if (flush && strm->next_out > out_buf) {
int l = strm->next_out - out_buf;
if (l != flush(out_buf, l)) {
rc = -1;
error("write error");
break;
}
strm->next_out = out_buf;
strm->avail_out = out_len;
}
/* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
if (rc == Z_STREAM_END) {
rc = 0;
break;
} else if (rc != Z_OK) {
error("uncompression error");
rc = -1;
}
}
zlib_inflateEnd(strm);
if (pos)
/* add + 8 to skip over trailer */
*pos = strm->next_in - zbuf+8;
gunzip_5:
free(strm->workspace);
gunzip_nomem4:
free(strm);
gunzip_nomem3:
if (!buf)
free(zbuf);
gunzip_nomem2:
if (flush)
free(out_buf);
gunzip_nomem1:
return rc; /* returns Z_OK (0) if successful */
}
#define decompress gunzip