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authorGlenn L McGrath2002-01-02 13:52:26 +0000
committerGlenn L McGrath2002-01-02 13:52:26 +0000
commit87ac7028e01cdc4f504ea558a6ae3d086ed1bf2b (patch)
tree4f406c877f88a013c4e1dc650ac312640a95cb00 /archival/libunarchive/get_header_zip.c
parent438803311b67c6337ea97476e97336e027ef9a3a (diff)
downloadbusybox-87ac7028e01cdc4f504ea558a6ae3d086ed1bf2b.zip
busybox-87ac7028e01cdc4f504ea558a6ae3d086ed1bf2b.tar.gz
unzip applet by Laurence Anderson
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Diffstat (limited to 'archival/libunarchive/get_header_zip.c')
-rw-r--r--archival/libunarchive/get_header_zip.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/archival/libunarchive/get_header_zip.c b/archival/libunarchive/get_header_zip.c
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+++ b/archival/libunarchive/get_header_zip.c
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+/* vi: set sw=4 ts=4: */
+/*
+ * get_header_zip for busybox
+ *
+ * Copyright (C) 2001 by Laurence Anderson
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "unarchive.h"
+#include "libbb.h"
+
+#define ZIP_FILEHEADER_MAGIC 0x04034b50
+#define ZIP_CDS_MAGIC 0x02014b50
+#define ZIP_CDS_END_MAGIC 0x06054b50
+#define ZIP_DD_MAGIC 0x8074b50
+
+file_header_t *get_header_zip(FILE *zip_stream)
+{
+ struct {
+ short version __attribute__ ((packed));
+ short flags __attribute__ ((packed));
+ short method __attribute__ ((packed));
+ short modtime __attribute__ ((packed));
+ short moddate __attribute__ ((packed));
+ int crc32 __attribute__ ((packed));
+ int cmpsize __attribute__ ((packed));
+ int ucmpsize __attribute__ ((packed));
+ short filename_len __attribute__ ((packed));
+ short extra_len __attribute__ ((packed));
+ } zip_header;
+ file_header_t *zip_entry = NULL;
+ int magic;
+ static int dd_ahead = 0; // If this is true, the we didn't know how long the last extraced file was
+
+ fread (&magic, 4, 1, zip_stream);
+ archive_offset += 4;
+
+ if (feof(zip_stream)) return(NULL);
+checkmagic:
+ switch (magic) {
+ case ZIP_FILEHEADER_MAGIC:
+ zip_entry = xcalloc(1, sizeof(file_header_t));
+ fread (&zip_header, sizeof(zip_header), 1, zip_stream);
+ archive_offset += sizeof(zip_header);
+ if (!(zip_header.method == 8 || zip_header.method == 0)) { printf("Unsupported compression method %d\n", zip_header.method); return(NULL); }
+ zip_entry->name = calloc(zip_header.filename_len + 1, sizeof(char));
+ fread (zip_entry->name, sizeof(char), zip_header.filename_len, zip_stream);
+ archive_offset += zip_header.filename_len;
+ seek_sub_file(zip_stream, zip_header.extra_len);
+ zip_entry->size = zip_header.cmpsize;
+ if (zip_header.method == 8) zip_entry->extract_func = &inflate;
+ zip_entry->mode = S_IFREG | 0777;
+ // Time/Date?
+ if (*(zip_entry->name + strlen(zip_entry->name) - 1) == '/') { // Files that end in a / are directories
+ zip_entry->mode ^= S_IFREG;
+ zip_entry->mode |= S_IFDIR;
+ *(zip_entry->name + strlen(zip_entry->name) - 1) = '\0'; // Remove trailing / so unarchive doesn't get confused
+ }
+ //printf("cmpsize: %d, ucmpsize: %d, method: %d\n", zip_header.cmpsize, zip_header.ucmpsize, zip_header.method);
+ if (zip_header.flags & 0x8) { // crc32, and sizes are in the data description _after_ the file
+ if (zip_header.cmpsize == 0) dd_ahead = 1; // As we don't know how long this file it is difficult to skip! but it is compressed, so normally its ok
+ if (zip_header.ucmpsize != 0) dd_ahead = 2; // Humm... we would otherwise skip this twice - not good!
+ }
+ break;
+ case ZIP_CDS_MAGIC: /* FALLTHRU */
+ case ZIP_CDS_END_MAGIC:
+ return(NULL);
+ break;
+ case ZIP_DD_MAGIC: {
+ int cmpsize;
+ seek_sub_file(zip_stream, 4); // Skip crc32
+ fread(&cmpsize, 4, 1, zip_stream);
+ archive_offset += 4;
+ if (dd_ahead == 1) archive_offset += cmpsize;
+ seek_sub_file(zip_stream, 4); // Skip uncompressed size
+ dd_ahead = 0;
+ return (get_header_zip(zip_stream));
+ break; }
+ default:
+ if (!dd_ahead) error_msg("Invalid magic (%#x): Trying to skip junk", magic);
+ dd_ahead = 0;
+ while (!feof(zip_stream)) {
+ int tmpmagic;
+ tmpmagic = fgetc(zip_stream);
+ archive_offset++;
+ magic = ((magic >> 8) & 0x00ffffff) | ((tmpmagic << 24) & 0xff000000);
+ if (magic == ZIP_FILEHEADER_MAGIC || magic == ZIP_CDS_MAGIC || magic == ZIP_CDS_END_MAGIC) goto checkmagic;
+ }
+ error_msg("End of archive reached: Bad archive");
+ return(NULL);
+ }
+ //if (archive_offset != ftell(zip_stream)) printf("Archive offset out of sync (%d,%d)\n", (int) archive_offset, (int) ftell(zip_stream));
+ return(zip_entry);
+}