feat(mk8): Override DLC matchmaking from ini file (for modpacks)

Makefile

@@ -21,9 +21,9 @@ WUMS_ROOT := $(DEVKITPRO)/wums
 #-------------------------------------------------------------------------------
 TARGET		:=	Inkay-pretendo
 BUILD		:=	build
-SOURCES		:=	src src/patches src/utils
+SOURCES		:=	src src/patches src/utils src/ext/inih
 DATA		:=	data
-INCLUDES	:=	src
+INCLUDES	:=	src src/ext/inih
 
 #-------------------------------------------------------------------------------
 # options for code generation

src/ext/inih/LICENSE.txt

@@ -0,0 +1,27 @@
+
+The "inih" library is distributed under the New BSD license:
+
+Copyright (c) 2009, Ben Hoyt
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of Ben Hoyt nor the names of its contributors
+      may be used to endorse or promote products derived from this software
+      without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY BEN HOYT ''AS IS'' AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL BEN HOYT BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

src/ext/inih/ini.c

@@ -0,0 +1,304 @@
+/* inih -- simple .INI file parser
+
+SPDX-License-Identifier: BSD-3-Clause
+
+Copyright (C) 2009-2020, Ben Hoyt
+
+inih is released under the New BSD license (see LICENSE.txt). Go to the project
+home page for more info:
+
+https://github.com/benhoyt/inih
+
+*/
+
+#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+
+#include "ini.h"
+
+#if !INI_USE_STACK
+#if INI_CUSTOM_ALLOCATOR
+#include <stddef.h>
+void* ini_malloc(size_t size);
+void ini_free(void* ptr);
+void* ini_realloc(void* ptr, size_t size);
+#else
+#include <stdlib.h>
+#define ini_malloc malloc
+#define ini_free free
+#define ini_realloc realloc
+#endif
+#endif
+
+#define MAX_SECTION 50
+#define MAX_NAME 50
+
+/* Used by ini_parse_string() to keep track of string parsing state. */
+typedef struct {
+    const char* ptr;
+    size_t num_left;
+} ini_parse_string_ctx;
+
+/* Strip whitespace chars off end of given string, in place. Return s. */
+static char* rstrip(char* s)
+{
+    char* p = s + strlen(s);
+    while (p > s && isspace((unsigned char)(*--p)))
+        *p = '\0';
+    return s;
+}
+
+/* Return pointer to first non-whitespace char in given string. */
+static char* lskip(const char* s)
+{
+    while (*s && isspace((unsigned char)(*s)))
+        s++;
+    return (char*)s;
+}
+
+/* Return pointer to first char (of chars) or inline comment in given string,
+   or pointer to NUL at end of string if neither found. Inline comment must
+   be prefixed by a whitespace character to register as a comment. */
+static char* find_chars_or_comment(const char* s, const char* chars)
+{
+#if INI_ALLOW_INLINE_COMMENTS
+    int was_space = 0;
+    while (*s && (!chars || !strchr(chars, *s)) &&
+           !(was_space && strchr(INI_INLINE_COMMENT_PREFIXES, *s))) {
+        was_space = isspace((unsigned char)(*s));
+        s++;
+    }
+#else
+    while (*s && (!chars || !strchr(chars, *s))) {
+        s++;
+    }
+#endif
+    return (char*)s;
+}
+
+/* Similar to strncpy, but ensures dest (size bytes) is
+   NUL-terminated, and doesn't pad with NULs. */
+static char* strncpy0(char* dest, const char* src, size_t size)
+{
+    /* Could use strncpy internally, but it causes gcc warnings (see issue #91) */
+    size_t i;
+    for (i = 0; i < size - 1 && src[i]; i++)
+        dest[i] = src[i];
+    dest[i] = '\0';
+    return dest;
+}
+
+/* See documentation in header file. */
+int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
+                     void* user)
+{
+    /* Uses a fair bit of stack (use heap instead if you need to) */
+#if INI_USE_STACK
+    char line[INI_MAX_LINE];
+    size_t max_line = INI_MAX_LINE;
+#else
+    char* line;
+    size_t max_line = INI_INITIAL_ALLOC;
+#endif
+#if INI_ALLOW_REALLOC && !INI_USE_STACK
+    char* new_line;
+    size_t offset;
+#endif
+    char section[MAX_SECTION] = "";
+    char prev_name[MAX_NAME] = "";
+
+    char* start;
+    char* end;
+    char* name;
+    char* value;
+    int lineno = 0;
+    int error = 0;
+
+#if !INI_USE_STACK
+    line = (char*)ini_malloc(INI_INITIAL_ALLOC);
+    if (!line) {
+        return -2;
+    }
+#endif
+
+#if INI_HANDLER_LINENO
+#define HANDLER(u, s, n, v) handler(u, s, n, v, lineno)
+#else
+#define HANDLER(u, s, n, v) handler(u, s, n, v)
+#endif
+
+    /* Scan through stream line by line */
+    while (reader(line, (int)max_line, stream) != NULL) {
+#if INI_ALLOW_REALLOC && !INI_USE_STACK
+        offset = strlen(line);
+        while (offset == max_line - 1 && line[offset - 1] != '\n') {
+            max_line *= 2;
+            if (max_line > INI_MAX_LINE)
+                max_line = INI_MAX_LINE;
+            new_line = ini_realloc(line, max_line);
+            if (!new_line) {
+                ini_free(line);
+                return -2;
+            }
+            line = new_line;
+            if (reader(line + offset, (int)(max_line - offset), stream) == NULL)
+                break;
+            if (max_line >= INI_MAX_LINE)
+                break;
+            offset += strlen(line + offset);
+        }
+#endif
+
+        lineno++;
+
+        start = line;
+#if INI_ALLOW_BOM
+        if (lineno == 1 && (unsigned char)start[0] == 0xEF &&
+                           (unsigned char)start[1] == 0xBB &&
+                           (unsigned char)start[2] == 0xBF) {
+            start += 3;
+        }
+#endif
+        start = lskip(rstrip(start));
+
+        if (strchr(INI_START_COMMENT_PREFIXES, *start)) {
+            /* Start-of-line comment */
+        }
+#if INI_ALLOW_MULTILINE
+            else if (*prev_name && *start && start > line) {
+#if INI_ALLOW_INLINE_COMMENTS
+            end = find_chars_or_comment(start, NULL);
+            if (*end)
+                *end = '\0';
+            rstrip(start);
+#endif
+            /* Non-blank line with leading whitespace, treat as continuation
+               of previous name's value (as per Python configparser). */
+            if (!HANDLER(user, section, prev_name, start) && !error)
+                error = lineno;
+        }
+#endif
+        else if (*start == '[') {
+            /* A "[section]" line */
+            end = find_chars_or_comment(start + 1, "]");
+            if (*end == ']') {
+                *end = '\0';
+                strncpy0(section, start + 1, sizeof(section));
+                *prev_name = '\0';
+#if INI_CALL_HANDLER_ON_NEW_SECTION
+                if (!HANDLER(user, section, NULL, NULL) && !error)
+                    error = lineno;
+#endif
+            }
+            else if (!error) {
+                /* No ']' found on section line */
+                error = lineno;
+            }
+        }
+        else if (*start) {
+            /* Not a comment, must be a name[=:]value pair */
+            end = find_chars_or_comment(start, "=:");
+            if (*end == '=' || *end == ':') {
+                *end = '\0';
+                name = rstrip(start);
+                value = end + 1;
+#if INI_ALLOW_INLINE_COMMENTS
+                end = find_chars_or_comment(value, NULL);
+                if (*end)
+                    *end = '\0';
+#endif
+                value = lskip(value);
+                rstrip(value);
+
+                /* Valid name[=:]value pair found, call handler */
+                strncpy0(prev_name, name, sizeof(prev_name));
+                if (!HANDLER(user, section, name, value) && !error)
+                    error = lineno;
+            }
+            else if (!error) {
+                /* No '=' or ':' found on name[=:]value line */
+#if INI_ALLOW_NO_VALUE
+                *end = '\0';
+                name = rstrip(start);
+                if (!HANDLER(user, section, name, NULL) && !error)
+                    error = lineno;
+#else
+                error = lineno;
+#endif
+            }
+        }
+
+#if INI_STOP_ON_FIRST_ERROR
+        if (error)
+            break;
+#endif
+    }
+
+#if !INI_USE_STACK
+    ini_free(line);
+#endif
+
+    return error;
+}
+
+/* See documentation in header file. */
+int ini_parse_file(FILE* file, ini_handler handler, void* user)
+{
+    return ini_parse_stream((ini_reader)fgets, file, handler, user);
+}
+
+/* See documentation in header file. */
+int ini_parse(const char* filename, ini_handler handler, void* user)
+{
+    FILE* file;
+    int error;
+
+    file = fopen(filename, "r");
+    if (!file)
+        return -1;
+    error = ini_parse_file(file, handler, user);
+    fclose(file);
+    return error;
+}
+
+/* An ini_reader function to read the next line from a string buffer. This
+   is the fgets() equivalent used by ini_parse_string(). */
+static char* ini_reader_string(char* str, int num, void* stream) {
+    ini_parse_string_ctx* ctx = (ini_parse_string_ctx*)stream;
+    const char* ctx_ptr = ctx->ptr;
+    size_t ctx_num_left = ctx->num_left;
+    char* strp = str;
+    char c;
+
+    if (ctx_num_left == 0 || num < 2)
+        return NULL;
+
+    while (num > 1 && ctx_num_left != 0) {
+        c = *ctx_ptr++;
+        ctx_num_left--;
+        *strp++ = c;
+        if (c == '\n')
+            break;
+        num--;
+    }
+
+    *strp = '\0';
+    ctx->ptr = ctx_ptr;
+    ctx->num_left = ctx_num_left;
+    return str;
+}
+
+/* See documentation in header file. */
+int ini_parse_string(const char* string, ini_handler handler, void* user) {
+    ini_parse_string_ctx ctx;
+
+    ctx.ptr = string;
+    ctx.num_left = strlen(string);
+    return ini_parse_stream((ini_reader)ini_reader_string, &ctx, handler,
+                            user);
+}

src/ext/inih/ini.h

@@ -0,0 +1,178 @@
+/* inih -- simple .INI file parser
+
+SPDX-License-Identifier: BSD-3-Clause
+
+Copyright (C) 2009-2020, Ben Hoyt
+
+inih is released under the New BSD license (see LICENSE.txt). Go to the project
+home page for more info:
+
+https://github.com/benhoyt/inih
+
+*/
+
+#ifndef INI_H
+#define INI_H
+
+/* Make this header file easier to include in C++ code */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+
+/* Nonzero if ini_handler callback should accept lineno parameter. */
+#ifndef INI_HANDLER_LINENO
+#define INI_HANDLER_LINENO 0
+#endif
+
+/* Visibility symbols, required for Windows DLLs */
+#ifndef INI_API
+#if defined _WIN32 || defined __CYGWIN__
+#	ifdef INI_SHARED_LIB
+#		ifdef INI_SHARED_LIB_BUILDING
+#			define INI_API __declspec(dllexport)
+#		else
+#			define INI_API __declspec(dllimport)
+#		endif
+#	else
+#		define INI_API
+#	endif
+#else
+#	if defined(__GNUC__) && __GNUC__ >= 4
+#		define INI_API __attribute__ ((visibility ("default")))
+#	else
+#		define INI_API
+#	endif
+#endif
+#endif
+
+/* Typedef for prototype of handler function. */
+#if INI_HANDLER_LINENO
+typedef int (*ini_handler)(void* user, const char* section,
+                           const char* name, const char* value,
+                           int lineno);
+#else
+typedef int (*ini_handler)(void* user, const char* section,
+                           const char* name, const char* value);
+#endif
+
+/* Typedef for prototype of fgets-style reader function. */
+typedef char* (*ini_reader)(char* str, int num, void* stream);
+
+/* Parse given INI-style file. May have [section]s, name=value pairs
+   (whitespace stripped), and comments starting with ';' (semicolon). Section
+   is "" if name=value pair parsed before any section heading. name:value
+   pairs are also supported as a concession to Python's configparser.
+
+   For each name=value pair parsed, call handler function with given user
+   pointer as well as section, name, and value (data only valid for duration
+   of handler call). Handler should return nonzero on success, zero on error.
+
+   Returns 0 on success, line number of first error on parse error (doesn't
+   stop on first error), -1 on file open error, or -2 on memory allocation
+   error (only when INI_USE_STACK is zero).
+*/
+INI_API int ini_parse(const char* filename, ini_handler handler, void* user);
+
+/* Same as ini_parse(), but takes a FILE* instead of filename. This doesn't
+   close the file when it's finished -- the caller must do that. */
+INI_API int ini_parse_file(FILE* file, ini_handler handler, void* user);
+
+/* Same as ini_parse(), but takes an ini_reader function pointer instead of
+   filename. Used for implementing custom or string-based I/O (see also
+   ini_parse_string). */
+INI_API int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
+                             void* user);
+
+/* Same as ini_parse(), but takes a zero-terminated string with the INI data
+instead of a file. Useful for parsing INI data from a network socket or
+already in memory. */
+INI_API int ini_parse_string(const char* string, ini_handler handler, void* user);
+
+/* Nonzero to allow multi-line value parsing, in the style of Python's
+   configparser. If allowed, ini_parse() will call the handler with the same
+   name for each subsequent line parsed. */
+#ifndef INI_ALLOW_MULTILINE
+#define INI_ALLOW_MULTILINE 1
+#endif
+
+/* Nonzero to allow a UTF-8 BOM sequence (0xEF 0xBB 0xBF) at the start of
+   the file. See https://github.com/benhoyt/inih/issues/21 */
+#ifndef INI_ALLOW_BOM
+#define INI_ALLOW_BOM 1
+#endif
+
+/* Chars that begin a start-of-line comment. Per Python configparser, allow
+   both ; and # comments at the start of a line by default. */
+#ifndef INI_START_COMMENT_PREFIXES
+#define INI_START_COMMENT_PREFIXES ";#"
+#endif
+
+/* Nonzero to allow inline comments (with valid inline comment characters
+   specified by INI_INLINE_COMMENT_PREFIXES). Set to 0 to turn off and match
+   Python 3.2+ configparser behaviour. */
+#ifndef INI_ALLOW_INLINE_COMMENTS
+#define INI_ALLOW_INLINE_COMMENTS 1
+#endif
+#ifndef INI_INLINE_COMMENT_PREFIXES
+#define INI_INLINE_COMMENT_PREFIXES ";"
+#endif
+
+/* Nonzero to use stack for line buffer, zero to use heap (malloc/free). */
+#ifndef INI_USE_STACK
+#define INI_USE_STACK 1
+#endif
+
+/* Maximum line length for any line in INI file (stack or heap). Note that
+   this must be 3 more than the longest line (due to '\r', '\n', and '\0'). */
+#ifndef INI_MAX_LINE
+#define INI_MAX_LINE 200
+#endif
+
+/* Nonzero to allow heap line buffer to grow via realloc(), zero for a
+   fixed-size buffer of INI_MAX_LINE bytes. Only applies if INI_USE_STACK is
+   zero. */
+#ifndef INI_ALLOW_REALLOC
+#define INI_ALLOW_REALLOC 0
+#endif
+
+/* Initial size in bytes for heap line buffer. Only applies if INI_USE_STACK
+   is zero. */
+#ifndef INI_INITIAL_ALLOC
+#define INI_INITIAL_ALLOC 200
+#endif
+
+/* Stop parsing on first error (default is to keep parsing). */
+#ifndef INI_STOP_ON_FIRST_ERROR
+#define INI_STOP_ON_FIRST_ERROR 0
+#endif
+
+/* Nonzero to call the handler at the start of each new section (with
+   name and value NULL). Default is to only call the handler on
+   each name=value pair. */
+#ifndef INI_CALL_HANDLER_ON_NEW_SECTION
+#define INI_CALL_HANDLER_ON_NEW_SECTION 0
+#endif
+
+/* Nonzero to allow a name without a value (no '=' or ':' on the line) and
+   call the handler with value NULL in this case. Default is to treat
+   no-value lines as an error. */
+#ifndef INI_ALLOW_NO_VALUE
+#define INI_ALLOW_NO_VALUE 0
+#endif
+
+/* Nonzero to use custom ini_malloc, ini_free, and ini_realloc memory
+   allocation functions (INI_USE_STACK must also be 0). These functions must
+   have the same signatures as malloc/free/realloc and behave in a similar
+   way. ini_realloc is only needed if INI_ALLOW_REALLOC is set. */
+#ifndef INI_CUSTOM_ALLOCATOR
+#define INI_CUSTOM_ALLOCATOR 0
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* INI_H */

src/main.cpp

@@ -54,6 +54,7 @@ WUPS_PLUGIN_AUTHOR("Pretendo contributors");
 WUPS_PLUGIN_LICENSE("ISC");
 
 WUPS_USE_STORAGE("inkay");
+WUPS_USE_WUT_DEVOPTAB();
 
 #include <kernel/kernel.h>
 #include <mocha/mocha.h>
@@ -158,6 +159,7 @@ ON_APPLICATION_START() {
     DEBUG_FUNCTION_LINE("Inkay: hewwo!\n");
 
     setup_olv_libs();
+    matchmaking_notify_titleswitch();
 }
 
 ON_APPLICATION_ENDS() {

src/patches/game_matchmaking.cpp

@@ -15,7 +15,10 @@
 #include "game_matchmaking.h"
 #include "utils/logger.h"
 
+#include "ini.h"
 #include <array>
+#include <optional>
+#include <string>
 #include <vector>
 #include <cstdint>
 #include <function_patcher/function_patching.h>
@@ -27,21 +30,60 @@
 constexpr std::array<uint64_t, 3> mk8_tids = {MARIO_KART_8_TID_J, MARIO_KART_8_TID_U, MARIO_KART_8_TID_E};
 std::vector<PatchedFunctionHandle> matchmaking_patches;
 
+struct modpack {
+    std::string name = "Mario Kart 8";
+    int dlc_id = -1;
+};
+std::optional<modpack> dlc_modpack;
+
+static int handler(void* user, const char* section, const char* name, const char* value) {
+    auto* mod = (modpack*)user;
+    auto match = [section, name](const char* s, const char* n) -> bool {
+        return strcmp(section, s) == 0 && strcmp(name, n) == 0;
+    };
+
+    if (match("pretendo", "name")) {
+        mod->name = value;
+    } else if (match("pretendo", "dlc_id")) {
+        mod->dlc_id = std::strtol(value, nullptr, 16);
+    } else return 0;
+
+    return 1;
+}
+
+static void check_modpack() {
+    modpack mod;
+    if (ini_parse("fs:/vol/content/pretendo.ini", handler, &mod)) {
+        DEBUG_FUNCTION_LINE("Inkay/MK8: Doesn't look like a modpack");
+    }
+
+    DEBUG_FUNCTION_LINE("Inkay/MK8: Playing %s (%08x)", mod.name.c_str(), mod.dlc_id);
+    dlc_modpack = mod;
+}
+
 DECL_FUNCTION(void, mk8_MatchmakeSessionSearchCriteria_SetAttribute, void* _this, uint32_t attributeIndex, uint32_t attributeValue) {
-    const int new_dlc = 4; //todo
     if (attributeIndex == 4) {
-        DEBUG_FUNCTION_LINE("changed search DLC from %d to %d", attributeValue, new_dlc);
-        attributeValue = (attributeValue & ~0xFF) | new_dlc; // keep upper bits
+        if (!dlc_modpack) check_modpack();
+
+        const int dlc_id = dlc_modpack->dlc_id;
+        if (dlc_id != -1) {
+            DEBUG_FUNCTION_LINE("Inkay/MK8: Searching for %s session (%08x)", dlc_modpack->name.c_str(), dlc_id);
+            attributeValue = dlc_id;
+        }
     }
 
     real_mk8_MatchmakeSessionSearchCriteria_SetAttribute(_this, attributeIndex, attributeValue);
 }
 
 DECL_FUNCTION(void, mk8_MatchmakeSession_SetAttribute, void* _this, uint32_t attributeIndex, uint32_t attributeValue) {
-    const int new_dlc = 4; //todo
     if (attributeIndex == 4) {
-        DEBUG_FUNCTION_LINE("changed DLC from %d to %d", attributeValue, new_dlc);
-        attributeValue = (attributeValue & ~0xFF) | new_dlc; // keep upper bits
+        if (!dlc_modpack) check_modpack();
+
+        const int dlc_id = dlc_modpack->dlc_id;
+        if (dlc_id != -1) {
+            DEBUG_FUNCTION_LINE("Inkay/MK8: Creating %s session (%08x)", dlc_modpack->name.c_str(), dlc_id);
+            attributeValue = dlc_id;
+        }
     }
 
     real_mk8_MatchmakeSession_SetAttribute(_this, attributeIndex, attributeValue);
@@ -80,3 +122,7 @@ void remove_matchmaking_patches() {
     }
     matchmaking_patches.clear();
 }
+
+void matchmaking_notify_titleswitch() {
+    dlc_modpack.reset();
+}

src/patches/game_matchmaking.h

@@ -16,3 +16,4 @@
 
 void install_matchmaking_patches();
 void remove_matchmaking_patches();
+void matchmaking_notify_titleswitch();