patch-pre2.0.8 linux/arch/ppc/boot/compressed/unzip.c

• Lines: 181
• Date: Mon May 27 12:00:57 1996
• Orig file: pre2.0.7/linux/arch/ppc/boot/compressed/unzip.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file pre2.0.7/linux/arch/ppc/boot/compressed/unzip.c linux/arch/ppc/boot/compressed/unzip.c
@@ -0,0 +1,180 @@
+/* unzip.c -- decompress files in gzip or pkzip format.
+ * Copyright (C) 1992-1993 Jean-loup Gailly
+ *
+ * Adapted for Linux booting by Hannu Savolainen 1993
+ *
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ *
+ * The code in this file is derived from the file funzip.c written
+ * and put in the public domain by Mark Adler.
+ */
+
+/*
+   This version can extract files in gzip or pkzip format.
+   For the latter, only the first entry is extracted, and it has to be
+   either deflated or stored.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: unzip.c,v 0.9 1993/02/10 16:07:22 jloup Exp $";
+#endif
+
+#include "gzip.h"
+#include "crypt.h"
+
+#include <stdio.h>
+
+/* PKZIP header definitions */
+#define LOCSIG 0x04034b50L      /* four-byte lead-in (lsb first) */
+#define LOCFLG 6                /* offset of bit flag */
+#define  CRPFLG 1               /*  bit for encrypted entry */
+#define  EXTFLG 8               /*  bit for extended local header */
+#define LOCHOW 8                /* offset of compression method */
+#define LOCTIM 10               /* file mod time (for decryption) */
+#define LOCCRC 14               /* offset of crc */
+#define LOCSIZ 18               /* offset of compressed size */
+#define LOCLEN 22               /* offset of uncompressed length */
+#define LOCFIL 26               /* offset of file name field length */
+#define LOCEXT 28               /* offset of extra field length */
+#define LOCHDR 30               /* size of local header, including sig */
+#define EXTHDR 16               /* size of extended local header, inc sig */
+
+
+/* Globals */
+
+int decrypt;      /* flag to turn on decryption */
+char *key;        /* not used--needed to link crypt.c */
+int pkzip = 0;    /* set for a pkzip file */
+int extended = 0; /* set if extended local header */
+
+/* ===========================================================================
+ * Check zip file and advance inptr to the start of the compressed data.
+ * Get ofname from the local header if necessary.
+ */
+int check_zipfile(in)
+    int in;   /* input file descriptors */
+{
+    uch *h = inbuf + inptr; /* first local header */
+
+    /* ifd = in; */
+
+    /* Check validity of local header, and skip name and extra fields */
+    inptr += LOCHDR + SH(h + LOCFIL) + SH(h + LOCEXT);
+
+    if (inptr > insize || LG(h) != LOCSIG) {
+	error("input not a zip");
+    }
+    method = h[LOCHOW];
+    if (method != STORED && method != DEFLATED) {
+	error("first entry not deflated or stored--can't extract");
+    }
+
+    /* If entry encrypted, decrypt and validate encryption header */
+    if ((decrypt = h[LOCFLG] & CRPFLG) != 0) {
+	error("encrypted file\n");
+	exit_code = ERROR;
+	return -1;
+    }
+
+    /* Save flags for unzip() */
+    extended = (h[LOCFLG] & EXTFLG) != 0;
+    pkzip = 1;
+
+    /* Get ofname and time stamp from local header (to be done) */
+    return 0;
+}
+
+/* ===========================================================================
+ * Unzip in to out.  This routine works on both gzip and pkzip files.
+ *
+ * IN assertions: the buffer inbuf contains already the beginning of
+ *   the compressed data, from offsets inptr to insize-1 included.
+ *   The magic header has already been checked. The output buffer is cleared.
+ */
+void unzip(in, out)
+    int in, out;   /* input and output file descriptors */
+{
+    ulg orig_crc = 0;       /* original crc */
+    ulg orig_len = 0;       /* original uncompressed length */
+    int n;
+    uch buf[EXTHDR];        /* extended local header */
+
+    /* ifd = in;
+    ofd = out; */
+
+    updcrc(NULL, 0);           /* initialize crc */
+
+    if (pkzip && !extended) {  /* crc and length at the end otherwise */
+	orig_crc = LG(inbuf + LOCCRC);
+	orig_len = LG(inbuf + LOCLEN);
+    }
+
+    /* Decompress */
+    if (method == DEFLATED)  {
+
+	int res = inflate();
+
+	if (res == 3) {
+	    error("out of memory");
+	} else if (res != 0) {
+	    error("invalid compressed format");
+	}
+
+    } else if (pkzip && method == STORED) {
+
+	register ulg n = LG(inbuf + LOCLEN);
+
+	if (n != LG(inbuf + LOCSIZ) - (decrypt ? RAND_HEAD_LEN : 0)) {
+
+	    error("length mismatch");
+	}
+	while (n--) {
+	    uch c = (uch)get_byte();
+#ifdef CRYPT
+	    if (decrypt) zdecode(c);
+#endif
+	    if (!test) put_char(c);
+	}
+    } else {
+	error("internal error, invalid method");
+    }
+
+    /* Get the crc and original length */
+    if (!pkzip) {
+        /* crc32  (see algorithm.doc)
+	 * uncompressed input size modulo 2^32
+         */
+	for (n = 0; n < 8; n++) {
+	    buf[n] = (uch)get_byte(); /* may cause an error if EOF */
+	}
+	orig_crc = LG(buf);
+	orig_len = LG(buf+4);
+
+    } else if (extended) {  /* If extended header, check it */
+	/* signature - 4bytes: 0x50 0x4b 0x07 0x08
+	 * CRC-32 value
+         * compressed size 4-bytes
+         * uncompressed size 4-bytes
+	 */
+	for (n = 0; n < EXTHDR; n++) {
+	    buf[n] = (uch)get_byte(); /* may cause an error if EOF */
+	}
+	orig_crc = LG(buf+4);
+	orig_len = LG(buf+12);
+    }
+
+    /* Validate decompression */
+    if (orig_crc != updcrc(outbuf, 0)) {
+	error("crc error");
+    }
+    if (orig_len != bytes_out) {
+	error("length error");
+    }
+
+    /* Check if there are more entries in a pkzip file */
+    if (pkzip && inptr + 4 < insize && LG(inbuf+inptr) == LOCSIG) {
+	    error("zip file has more than one entry");
+    }
+    extended = pkzip = 0; /* for next file */
+}