Large commit. Filenames are now converted from UTF-16LE and placed into a linked list. Parsers also exist for every entry in the XP3 format.

1 files changed, 134 insertions, 0 deletions

diff --git a/src/extract.c b/src/extract.c
new file mode 100644
index 0000000..8a1eec0
--- /dev/null
+++ b/src/extract.c
@@ -0,0 +1,134 @@
+/* This file is part of Nekopack.
+
+   Copyright (C) 2017 Jakob Tsar-Fox, All Rights Reserved.
+
+   Nekopack 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 3 of the License, or (at
+   your option) any later version.
+
+   Nekopack 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 Nekopack. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <inttypes.h> // Needed for debugging at this point.
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <iconv.h>
+#include <zlib.h>
+
+#include "defs.h"
+#include "decompress.h"
+#include "extract.h"
+#include "file.h"
+#include "write.h"
+
+#define ELIF_MAGIC 0x46696c65
+#define FILE_MAGIC 0x656c6946
+#define HNFN_MAGIC 0x6e666e68
+
+void read_stream(void *destination, Bytef **source, size_t size);
+void read_file_entry(memory_stream *data_stream, Bytef *section_end);
+node *read_elif_entry(memory_stream *data_stream);
+
+
+/* Handles decompression of the archive, as well as
+   parsing, decrypting and writing the table entries. */
+void extract(FILE *archive, uint64_t table_offset) {
+    /* Filenames are stored in a linked list as they're seen.
+       calloc is used to prevent the next pointer from being junk. */
+    node *root = calloc(sizeof(node), 1);
+
+    uint8_t compressed;
+    fseek(archive, table_offset, SEEK_SET);
+    fread(&compressed, sizeof(uint8_t), 1, archive);
+
+    int stream_ended = 0;
+    memory_stream data_stream;
+    if (compressed) {
+        data_stream = decompress_file(archive, ftell(archive));
+    } else {
+        fprintf(stderr, "This archive is not supported.\n");
+        exit(EXIT_FAILURE);
+    }
+
+    /* The header for every entry in the XP3 archive format contains
+       a magic number, followed by the size of the entry. */
+    uint32_t entry_magic;
+    uint64_t entry_size;
+    /* Implement "last filename" variable, which gets freed
+       and reallocated every time an elif entry is read. */
+    do {
+        read_stream(&entry_magic, &data_stream.data, sizeof(uint32_t));
+        read_stream(&entry_size, &data_stream.data, sizeof(uint64_t));
+        printf("entry at 0x%lx\n", data_stream.data - data_stream.start - 12);
+        printf("Magic: %" PRIx32 " Size: %" PRIx64 "\n", entry_magic, entry_size);
+
+        switch (entry_magic) {
+            /* hnfn and eliF entries are identical. The size given by
+               the entry header doesn't match the actual entry size,
+               so it isn't passed to the function. */
+            case HNFN_MAGIC:
+            case ELIF_MAGIC:
+                defer_node(read_elif_entry(&data_stream), root);
+                break;
+            case FILE_MAGIC:
+                read_file_entry(&data_stream, data_stream.data + entry_size);
+                break;
+            default:
+                printf("End of archive reached.\n");
+                stream_ended = 1;
+        }
+    } while (!stream_ended);
+
+    test_linked_list(root);
+    free_node(root);
+
+    free(data_stream.start);
+}
+
+
+/* Wrapper for memcpy which increments the source operand by
+   the amount of bytes read to simulate a file stream. */
+void read_stream(void *destination, Bytef **source, size_t size) {
+    memcpy(destination, *source, size);
+    *source += size;
+}
+
+
+/* Document */
+node *read_elif_entry(memory_stream *data_stream) {
+    uint16_t name_size;
+    uint32_t name_hash;
+    read_stream(&name_hash, &data_stream->data, sizeof(uint32_t));
+    read_stream(&name_size, &data_stream->data, sizeof(uint16_t));
+
+    /* Strings are terminated by null bytes, 
+       which aren't counted in the name size. */
+    char *input_buffer = malloc(name_size * 2 + 2);
+    char *file_name = malloc(name_size + 1);
+    read_stream(input_buffer, &data_stream->data, name_size * 2 + 2);
+
+    /* iconv is the non-portable glibc way of doing it. */
+    char *in_start = input_buffer, *out_start = file_name;
+    size_t in_size = name_size * 2 + 2, out_size = name_size + 1;
+    iconv_t conversion = iconv_open("UTF-8", "UTF-16LE");
+    iconv(conversion, &in_start, &in_size, &out_start, &out_size);
+    iconv_close(conversion);
+
+    node *current = malloc(sizeof(node));
+    current->key = name_hash;
+    current->file_name = file_name;
+    current->next = NULL;
+
+    free(input_buffer);
+
+    return current;
+}