Loader: Add Nso Header loading, loadset validation in CreateProcess

stratosphere/loader/source/ldr_nso.cpp

@@ -0,0 +1,87 @@
+#include <switch.h>
+#include <algorithm>
+#include <cstdio>
+#include "ldr_nso.hpp"
+
+static NsoUtils::NsoHeader g_nso_headers[NSO_NUM_MAX] = {0};
+static bool g_nso_present[NSO_NUM_MAX] = {0};
+
+void NsoUtils::GetNsoCodePath(char *content_path, unsigned int index) {
+    std::fill(content_path, content_path + FS_MAX_PATH, 0);
+    snprintf(content_path, FS_MAX_PATH, "code:/%s", NsoUtils::GetNsoFileName(index));
+}
+
+void NsoUtils::GetNsoSdPath(char *content_path, u64 title_id, unsigned int index) {  
+    std::fill(content_path, content_path + FS_MAX_PATH, 0);
+    snprintf(content_path, FS_MAX_PATH, "sdmc:/atmosphere/titles/%016lx/exefs/%s", title_id, NsoUtils::GetNsoFileName(index));
+}
+
+bool NsoUtils::IsNsoPresent(unsigned int index) {
+    return g_nso_present[index];
+}
+
+Result NsoUtils::LoadNsoHeaders(u64 title_id) {
+    char nso_path[FS_MAX_PATH] = {0};
+    FILE *f_nso;
+    
+    /* Zero out the cache. */
+    std::fill(g_nso_present, g_nso_present + NSO_NUM_MAX, false);
+    std::fill(g_nso_headers, g_nso_headers + NSO_NUM_MAX, (const NsoUtils::NsoHeader &){0});
+    
+    for (unsigned int i = 0; i < NSO_NUM_MAX; i++) {
+        GetNsoSdPath(nso_path, title_id, i);
+        if ((f_nso = fopen(nso_path, "rb")) != NULL) {
+            if (fread(&g_nso_headers[i], sizeof(NsoUtils::NsoHeader), 1, f_nso) != sizeof(NsoUtils::NsoHeader)) {
+                return 0xA09;
+            }
+            g_nso_present[i] = true;
+            fclose(f_nso);
+            continue;
+        }
+        GetNsoCodePath(nso_path, i);
+        if ((f_nso = fopen(nso_path, "rb")) != NULL) {
+            if (fread(&g_nso_headers[i], sizeof(NsoUtils::NsoHeader), 1, f_nso) != sizeof(NsoUtils::NsoHeader)) {
+                return 0xA09;
+            }
+            g_nso_present[i] = true;
+            fclose(f_nso);
+            continue;
+        }
+        if (1 < i && i < 12) {
+            /* If we failed to open a subsdk, there are no more subsdks. */
+            i = 12;
+        }
+    }
+    
+    return 0x0;
+}
+
+Result NsoUtils::ValidateNsoLoadSet() {
+    /* We *must* have a "main" NSO. */
+    if (!g_nso_present[1]) {
+        return 0xA09;
+    }
+    
+    /* Behavior switches depending on whether we have an rtld. */
+    if (g_nso_present[0]) {
+         /* If we have an rtld, dst offset for .text must be 0 for all other NSOs. */
+        for (unsigned int i = 0; i < NSO_NUM_MAX; i++) {
+            if (g_nso_present[i] && g_nso_headers[i].segments[0].dst_offset != 0) {
+                return 0xA09;
+            }
+        }
+    } else {
+        /* If we don't have an rtld, we must ONLY have a main. */
+        for (unsigned int i = 2; i < NSO_NUM_MAX; i++) {
+            if (g_nso_present[i]) {
+                return 0xA09;
+            }
+        }
+        /* That main's .text must be at dst_offset 0. */
+        if (g_nso_headers[1].segments[0].dst_offset != 0) {
+            return 0xA09;
+        }
+    }
+    
+    return 0x0;
+}