Implemented header offsets for XP3 version 2.

1 files changed, 51 insertions, 41 deletions

diff --git a/src/main.c b/src/main.c
index b81d58b..7f42ea8 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,10 +1,6 @@
-/* main.c
+/* This file is part of Nekopack.
 
-   The entry point to Nekopack.
-
-   Copyright (C) 2013 Jakob Tsar-Fox, All Rights Reserved.
-
-   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
@@ -19,35 +15,38 @@
    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>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#include <zlib.h>
+
+#include "cli.h"
+
 #define XP3_MAGIC "XP3\x0d\x0a\x20\x0a\x1a\x8b\x67\x01"
 #define XP3_VERSION_1_TABLE_OFFSET 11
 #define XP3_VERSION_OFFSET 19
 
+#define EXIT_SUCCESS 0
+#define EXIT_FAILURE 1
+
 int is_xp3_archive(FILE *archive);
 int get_archive_version(FILE *archive);
-int get_table_offset(FILE *archive, uint8_t archive_version);
-int table_is_compressed(FILE *archive, uint8_t table_offset);
+uint8_t table_is_compressed(FILE *archive, uint8_t table_offset);
+uint64_t get_table_offset(FILE *archive, uint8_t archive_version);
 
 
 int main(int argc, char *argv[]) {
-    if (argc != 2) {
-        fprintf(stderr, "Usage: %s (PATH TO ARCHIVE)\n", argv[0]);
-        exit(1);
-    }
-    uint8_t archive_version;
+    struct configuration arguments = parse_args(argc, argv);
+
     FILE *archive = fopen(argv[1], "rb");
     if (!is_xp3_archive(archive)) {
         fprintf(stderr, "File is not an XP3 archive.\n");
         fclose(archive);
-        exit(1);
+        exit(EXIT_FAILURE);
     }
-    archive_version = get_archive_version(archive);
     /* After the table_is_compressed byte is 8 bytes containing the
        compressed size followed by 8 bytes containing the original size
        (if the archive is compressed). Use zlib's inflate function to
@@ -67,50 +66,61 @@ int main(int argc, char *argv[]) {
 }
 
 
-/* Returns whether or not the stream represents an XP3 archive. */
+/* Very simple check of the archive's magic number to decide
+   whether or not it really is a valid XP3 archive. */
 int is_xp3_archive(FILE *archive) {
-    char *magic_buffer = malloc(12);
-    if (magic_buffer == NULL) {
-        perror("calloc");
-        fclose(archive);
-        exit(1);
-    }
+    char magic_buffer[12] = {0};
     rewind(archive);
-    fread(magic_buffer, 11, 1, archive);
-    if (strcmp(magic_buffer, XP3_MAGIC)) {
-        printf("Not an XP3 archive\n");
+    fread(magic_buffer, sizeof(magic_buffer) - 1, 1, archive);
+    if (strcmp(magic_buffer, XP3_MAGIC))
         return 0;
-    }
     return 1;
 }
 
 
-/* Returns the version of (???) used to pack the archive. */
+/* Returns the version of XP3 used to pack the archive. */
 int get_archive_version(FILE *archive) {
-    uint8_t archive_version;
+    uint32_t version_word;
     fseek(archive, XP3_VERSION_OFFSET, SEEK_SET);
-    fread(&archive_version, 1, 1, archive);
-    return archive_version;
+    fread(&version_word, sizeof(uint32_t), 1, archive);
+    return version_word == 1 ? 2 : 1;
 }
 
 
-/* Returns the table offset for the archive. */
-int get_table_offset(FILE *archive, uint8_t archive_version) {
+/* Subroutine for finding the archive's table offset. If the
+   minor_version is invalid, the program will exit.  */
+uint64_t get_table_offset(FILE *archive, uint8_t archive_version) {
+    fseek(archive, XP3_VERSION_1_TABLE_OFFSET, SEEK_SET);
     if (archive_version == 1) {
-        uint8_t table_offset;
-        fseek(archive, XP3_VERSION_1_TABLE_OFFSET, SEEK_SET);
-        fread(&table_offset, 1, 1, archive);
+        uint64_t table_offset;
+        fread(&table_offset, sizeof(uint64_t), 1, archive);
         return table_offset;
     }
-    fprintf(stderr, "Not implemented.\n");
-    exit(1);
+    uint64_t additional_header_offset, table_offset;
+    uint32_t minor_version;
+    fread(&additional_header_offset, sizeof(uint64_t), 1, archive);
+    fread(&minor_version, sizeof(uint32_t), 1, archive);
+    if (minor_version != 1) {
+        fprintf(stderr, "Version not implemented.\n");
+        exit(EXIT_FAILURE);
+    }
+    fseek(archive, additional_header_offset, SEEK_CUR);
+    fseek(archive, sizeof(uint8_t) + sizeof(uint64_t), SEEK_CUR);
+    fread(&table_offset, sizeof(uint64_t), 1, archive);
+    return table_offset;
 }
 
 
-/* Returns whether or not the archive is compressed. */
-int table_is_compressed(FILE *archive, uint8_t table_offset) {
+/* Function that returns the byte representing
+   whether or not the archive was compressed. */
+uint8_t table_is_compressed(FILE *archive, uint8_t table_offset) {
     uint8_t is_compressed;
     fseek(archive, table_offset, SEEK_SET);
-    fread(&is_compressed, 1, 1, archive);
+    fread(&is_compressed, sizeof(uint8_t), 1, archive);
     return is_compressed;
 }
+
+
+void *inflate_table(FILE *archive, uint8_t table_offset) {
+    return 0x0;
+}