From 10e56ffd473a2a388dbb690f074ce02e77a2b345 Mon Sep 17 00:00:00 2001
From: York Jasper Niebuhr <yjnworkstation@gmail.com>
Date: Sun, 26 Oct 2025 22:06:03 +0100
Subject: [PATCH] selfpatch instruction dispatcher

---
 selfpatch/src/selfpatch.c | 53 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 49 insertions(+), 4 deletions(-)

diff --git a/selfpatch/src/selfpatch.c b/selfpatch/src/selfpatch.c
index b5486ae..2aa307c 100644
--- a/selfpatch/src/selfpatch.c
+++ b/selfpatch/src/selfpatch.c
@@ -4,14 +4,59 @@
 
 #include <spslr_program.h>
 
+// TODO
+static int spslr_target(uint32_t uid, uint32_t size, uint32_t fieldcnt) { return 0; }
+static int spslr_field(uint32_t offset, uint32_t size, uint32_t flags) { return 0; }
+static int spslr_randomize(uint32_t target) { return 0; }
+static int spslr_mprot(void* base, uint32_t pagecnt, uint8_t perm) { return 0; }
+static int spslr_ipatch(void* ptr, uint32_t target, uint32_t field) { return 0; }
+static int spslr_dpatch(void* ptr, uint32_t target) { return 0; }
+
 /*
-To allow ASLR, all patcher addresses are relative to &__spslr_program
+Postprocessing tool patches the value of __spslr_program to point to the SPSLR program section.
+With ASLR, there are 2 options to make it function correctly:
+	1. Make sure __spslr_program is relocated with program image shift (preferred)
+	2. __spslr_program = spslr_ptr_absolute((uint64_t)__spslr_program) and postprocessor inserts relative value (kinda weird)
 */
-const uint8_t* __spslr_program = NULL;
+static const uint8_t* __spslr_program = NULL;
+
+static void* spslr_ptr_absolute(uint64_t relative) {
+	// To allow ASLR, all patcher addresses are relative to &__spslr_program
+	return ((uint8_t*)&__spslr_program) + relative;
+}
 
 static int spslr_do(const struct SPSLR_INST* inst) {
-	// TODO -> dispatch different instructions, make args/pointers absolute
-	return 0;
+	if (!inst)
+		return -1;
+
+	static uint32_t pending_fields = 0;
+
+	if (pending_fields) {
+		if (inst->opcode != SPSLR_FIELD) {
+			fprintf(stderr, "spslr_do encountered non field instruction where a field instruction was expected\n");
+			return -1;
+		}
+
+		pending_fields--;
+	}
+
+	switch (inst->opcode) {
+	case SPSLR_TARGET:
+		pending_fields = inst->op2.target_fieldcnt;
+		return spslr_target(inst->op0.target_uid, inst->op1.target_size, inst->op2.target_fieldcnt);
+	case SPSLR_FIELD:
+		return spslr_field(inst->op0.field_offset, inst->op1.field_size, inst->op2.field_flags);
+	case SPSLR_RANDOMIZE:
+		return spslr_randomize(inst->op0.randomize_target);
+	case SPSLR_MPROT:
+		return spslr_mprot(spslr_ptr_absolute(inst->op0.mprot_ptr), inst->op1.mprot_pagecnt, inst->op2.mprot_perm);
+	case SPSLR_IPATCH:
+		return spslr_ipatch(spslr_ptr_absolute(inst->op0.ipatch_ptr), inst->op1.ipatch_target, inst->op2.ipatch_field);
+	case SPSLR_DPATCH:
+		return spslr_dpatch(spslr_ptr_absolute(inst->op0.dpatch_ptr), inst->op1.dpatch_target);
+	default:
+		return -1;
+	}
 }
 
 void spslr_selfpatch() {