decompress_inflate.c 3.48 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
#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"
22
#include <linux/slab.h>
23 24 25 26 27

#endif /* STATIC */

#include <linux/decompress/mm.h>

28
#define GZIP_IOBUF_SIZE (16*1024)
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

/* 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_fn)(char *x)) {
	u8 *zbuf;
	struct z_stream_s *strm;
	int rc;
	size_t out_len;

	set_error_fn(error_fn);
	rc = -1;
	if (flush) {
45
		out_len = 0x8000; /* 32 K */
46 47 48 49 50 51 52 53 54 55 56 57
		out_buf = malloc(out_len);
	} else {
		out_len = 0x7fffffff; /* no limit */
	}
	if (!out_buf) {
		error("Out of memory while allocating output buffer");
		goto gunzip_nomem1;
	}

	if (buf)
		zbuf = buf;
	else {
58
		zbuf = malloc(GZIP_IOBUF_SIZE);
59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79
		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 (len == 0)
80
		len = fill(zbuf, GZIP_IOBUF_SIZE);
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

	/* 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;
	/* skip over asciz filename */
	if (zbuf[3] & 0x8) {
		while (strm->next_in[0])
			strm->next_in++;
		strm->next_in++;
	}
101
	strm->avail_in = len - (strm->next_in - zbuf);
102 103 104 105 106 107 108 109 110 111 112 113 114 115

	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 */
116
			len = fill(zbuf, GZIP_IOBUF_SIZE);
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168
			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