Minimal debugging information about the stream is printed.

1 files changed, 264 insertions, 0 deletions

diff --git a/src/parse.c b/src/parse.c
new file mode 100644
index 0000000..c53a627
--- /dev/null
+++ b/src/parse.c
@@ -0,0 +1,264 @@
+/* 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"
+
+#define ELIF_MAGIC 0x46696c65
+#define FILE_MAGIC 0x656c6946
+#define ADLR_MAGIC 0x726c6461
+#define SEGM_MAGIC 0x6d676573
+#define INFO_MAGIC 0x6f666e69
+#define TIME_MAGIC 0x656d6974
+
+/* A pointer to the start of the memory region
+   has to be kept for freeing purposes. */
+typedef struct {
+    uint64_t stream_length;
+    Bytef *start;
+    Bytef *data;
+} memory_stream;
+
+/* typedef struct { */
+/*     uint64_t timestamp; */
+/*     uint32_t hash_key; */
+/* } file_entry; */
+
+memory_stream decompress_stream(FILE *archive, uint64_t sizes_offset);
+void read_stream(void *destination, Bytef **source, size_t size);
+void read_file_entry(memory_stream *data_stream, Bytef *section_end);
+void read_elif_entry(memory_stream *data_stream);
+void read_info_chunk(memory_stream *data_stream);
+
+
+/* Parses and extracts entries from the archive. */
+void extract(FILE *archive, uint64_t table_offset) {
+    /* An 8-bit unsigned integers at the table offset indicates
+       whether or not the archive has to be decompressed. */
+    uint8_t compressed;
+    fseek(archive, table_offset, SEEK_SET);
+    fread(&compressed, sizeof(uint8_t), 1, archive);
+
+    memory_stream data_stream;
+    if (compressed) {
+        data_stream = decompress_stream(archive, ftell(archive));
+    } else {
+        fprintf(stderr, "Uncompressed archives not yet 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;
+    for (;;) {
+        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); // Debug.
+
+        switch (entry_magic) {
+            case ELIF_MAGIC:
+                /* The size given by the entry header doesn't match the
+                   actual entry size, so it isn't passed to the function. */
+                read_elif_entry(&data_stream);
+                break;
+            case FILE_MAGIC:
+                // printf("[File entry]\n");
+                // data_stream.data += entry_size;
+                read_file_entry(&data_stream, data_stream.data + entry_size);
+                break;
+            default: // Debug.
+                printf("Unknown magic: %x\n", entry_magic);
+                exit(EXIT_FAILURE);
+        }
+    }
+
+    free(data_stream.start);
+}
+
+
+/* Inflates the file pointer and returns a struct containing the
+   size and a pointer to the decompressed data in memory. */
+memory_stream decompress_stream(FILE *archive, uint64_t sizes_offset) {
+    uint64_t compressed_size, decompressed_size;
+    fseek(archive, sizes_offset, SEEK_SET);
+    fread(&compressed_size, sizeof(uint64_t), 1, archive);
+    fread(&decompressed_size, sizeof(uint64_t), 1, archive);
+
+    /* Decompression is done in memory because it's $CURRENT_YEAR. */
+    Bytef *compressed_data = malloc(compressed_size);
+    Bytef *decompressed_data = malloc(decompressed_size);
+
+    /* This is a pretty shitty way of handling it, though. */
+    if (compressed_data == NULL || decompressed_data == NULL) {
+        if (compressed_data != NULL)
+            free(compressed_data);
+        fprintf(stderr, "Insufficient memory to decompress archive.\n");
+        fclose(archive);
+        exit(EXIT_FAILURE);
+    }
+
+    z_stream data_stream;
+    data_stream.zalloc = Z_NULL;
+    data_stream.zfree = Z_NULL;
+    data_stream.opaque = Z_NULL;
+    data_stream.avail_in = 0;
+    data_stream.next_in = Z_NULL;
+
+    if (inflateInit(&data_stream) != Z_OK) {
+        fprintf(stderr, "Could not initialize zlib.\n");
+        free(compressed_data);
+        free(decompressed_data);
+        fclose(archive);
+        exit(EXIT_FAILURE);
+    }
+
+    int status_code;
+    do {
+        fread(compressed_data, compressed_size, 1, archive);
+        data_stream.avail_in = compressed_size;
+
+        /* This really shouldn't happen. */
+        if (ferror(archive)) {
+            fprintf(stderr, "File corrupt.\n");
+            inflateEnd(&data_stream);
+            free(compressed_data);
+            free(decompressed_data);
+            exit(EXIT_FAILURE);
+        }
+
+        if (data_stream.avail_in == 0)
+            break;
+        data_stream.next_in = compressed_data;
+        // Flushing probably isn't required here.
+        do {
+            data_stream.avail_out = decompressed_size;
+            data_stream.next_out = decompressed_data;
+            status_code = inflate(&data_stream, Z_NO_FLUSH);
+        } while (data_stream.avail_out == 0);
+    } while (status_code != Z_STREAM_END);
+
+    /* The compressed data is irrelevant at this point. */
+    free(compressed_data);
+
+    return (memory_stream) {decompressed_size, decompressed_data,
+                            decompressed_data};
+}
+
+
+/* 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 */
+void read_file_entry(memory_stream *data_stream, Bytef *section_end) {
+    uint32_t entry_magic;
+    uint64_t entry_size;
+    while (data_stream->data < section_end) {
+        read_stream(&entry_magic, &data_stream->data, sizeof(uint32_t));
+        read_stream(&entry_size, &data_stream->data, sizeof(uint64_t));
+        switch (entry_magic) {
+            case ADLR_MAGIC:
+                printf("[ADLR found at 0x%lx]\n", data_stream->data - data_stream->start);
+                data_stream->data += entry_size;
+                break;
+            case SEGM_MAGIC:
+                printf("[SEGM found at 0x%lx]\n", data_stream->data - data_stream->start);
+                data_stream->data += entry_size;
+                break;
+            case INFO_MAGIC:
+                printf("[INFO found at 0x%lx]\n", data_stream->data - data_stream->start);
+                read_info_chunk(data_stream);
+                /* data_stream->data += entry_size; */
+                break;
+            case TIME_MAGIC:
+                printf("[TIME found at 0x%lx]\n", data_stream->data - data_stream->start);
+                data_stream->data += entry_size;
+                break;
+            default:
+                printf("New magic discovered: %" PRIx32 " size: %" PRIx64 "\n", entry_magic, entry_size);  // Debug.
+        }
+    }
+    printf("\n\n\n\n"); // Debug.
+}
+
+
+/* Document */
+void read_elif_entry(memory_stream *data_stream) {
+    uint16_t name_size;
+    /* The first part of an ELIF entry is a 32-bit file name hash. */
+    data_stream->data += sizeof(uint32_t);
+    read_stream(&name_size, &data_stream->data, sizeof(uint16_t));
+
+    char *input_buffer = malloc(name_size * 2);
+    char *file_name = malloc(name_size);
+    read_stream(input_buffer, &data_stream->data, name_size * 2);
+
+    /* There seems to be an extra UTF-16 byte at the end of the entry. */
+    data_stream->data += 2;
+
+    printf("Filename (ASCII): ");
+    for (int i = 0; i < name_size * 2; i++) {
+        if (input_buffer[i] >= 0x20 && input_buffer[i] < 0x7f)
+            printf("%c", input_buffer[i]);
+    }
+    printf("\n");
+
+    free(input_buffer);
+    free(file_name);
+}
+
+
+/* Document */
+void read_info_chunk(memory_stream *data_stream) {
+    uint32_t flags;
+    uint64_t decompressed_size, compressed_size;
+    uint16_t file_name_size;
+    read_stream(&flags, &data_stream->data, sizeof(uint32_t));
+    read_stream(&decompressed_size, &data_stream->data, sizeof(uint64_t));
+    read_stream(&compressed_size, &data_stream->data, sizeof(uint64_t));
+    read_stream(&file_name_size, &data_stream->data, sizeof(uint16_t));
+
+    char *file_name = malloc(file_name_size * 2);
+    read_stream(file_name, &data_stream->data, file_name_size * 2);
+    printf("\nINFO SEGMENT\n");
+    printf("------------\n");
+    printf("FLAGS: %" PRIx32 "\n", flags);
+    printf("DECOMPRESSED_SIZE: %" PRIx64 "\n", decompressed_size);
+    printf("COMPRESSED_SIZE: %" PRIx64 "\n", compressed_size);
+    printf("FILENAME (HASH?): ");
+    for (int i = 0; i < file_name_size * 2; i++) {
+        if (file_name[i] >= 0x20 && file_name[i] < 0x7f)
+            printf("%c", file_name[i]);
+    }
+    printf("\n");
+
+    data_stream->data += 2;
+}