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;
+}

stratosphere/loader/source/ldr_nso.hpp

@@ -0,0 +1,73 @@
+#pragma once
+#include <switch.h>
+
+#define MAGIC_NSO0 0x304F534E
+#define NSO_NUM_MAX 13
+
+class NsoUtils {
+    public:
+        struct NsoSegment {
+            u32 file_offset;
+            u32 dst_offset;
+            u32 decomp_size;
+            u32 align_or_total_size;
+        };
+        
+        struct NsoHeader {
+            u32 magic;
+            u32 _0x4;
+            u32 _0x8;
+            u32 flags;
+            NsoSegment segments[3];
+            u8 build_id[0x20];
+            u32 compressed_sizes[3];
+            u8 _0x6C[0x24];
+            u64 dynstr_extents;
+            u64 dynsym_extents;
+            u8 section_hashes[3][0x20];
+        };
+        
+        
+        static_assert(sizeof(NsoHeader) == 0x100, "Incorrectly defined NsoHeader!");
+        
+        static const char *GetNsoFileName(unsigned int index) {
+            switch (index) {
+                case 0:
+                    return "rtld";
+                case 1:
+                    return "main";
+                case 2:
+                    return "subsdk0";
+                case 3:
+                    return "subsdk1";
+                case 4:
+                    return "subsdk2";
+                case 5:
+                    return "subsdk3";
+                case 6:
+                    return "subsdk4";
+                case 7:
+                    return "subsdk5";
+                case 8:
+                    return "subsdk6";
+                case 9:
+                    return "subsdk7";
+                case 10:
+                    return "subsdk8";
+                case 11:
+                    return "subsdk9";
+                case 12:
+                    return "sdk";
+                default:
+                    /* TODO: Panic. */
+                    return "?";
+            }
+        }
+        
+        static void GetNsoCodePath(char *content_path, unsigned int index);
+        static void GetNsoSdPath(char *content_path, u64 title_id, unsigned int index);
+        
+        static bool IsNsoPresent(unsigned int index);
+        static Result LoadNsoHeaders(u64 title_id);
+        static Result ValidateNsoLoadSet();
+};

stratosphere/loader/source/ldr_process_creation.cpp

@@ -5,40 +5,54 @@
 #include "ldr_launch_queue.hpp"
 #include "ldr_content_management.hpp"
 #include "ldr_npdm.hpp"
+#include "ldr_nso.hpp"
 
 Result ProcessCreation::CreateProcess(Handle *out_process_h, u64 index, char *nca_path, LaunchQueue::LaunchItem *launch_item, u64 flags, Handle reslimit_h) {
     NpdmUtils::NpdmInfo info;
     Registration::Process *target_process;
     Result rc;
     
+    /* Get the process from the registration queue. */
     target_process = Registration::get_process(index);
     if (target_process == NULL) {
         return 0x1009;
     }
     
+    /* Mount the title's exefs. */
     rc = ContentManagement::MountCodeForTidSid(&target_process->tid_sid);  
     if (R_FAILED(rc)) {
         return rc;
     }
     
+    /* Load the process's NPDM. */
     rc = NpdmUtils::LoadNpdmFromCache(target_process->tid_sid.title_id, &info);
     if (R_FAILED(rc)) {
         goto CREATE_PROCESS_END;
     }
     
+    /* Validate the title we're loading is what we expect. */
     if (info.aci0->title_id < info.acid->title_id_range_min || info.aci0->title_id > info.acid->title_id_range_max) {
         rc = 0x1209;
         goto CREATE_PROCESS_END;
     }
     
+    /* Validate that the ACI0 Kernel Capabilities are valid and restricted by the ACID Kernel Capabilities. */
     rc = NpdmUtils::ValidateCapabilities((u32 *)info.acid_kac, info.acid->kac_size/sizeof(u32), (u32 *)info.aci0_kac, info.aci0->kac_size/sizeof(u32));
     if (R_FAILED(rc)) {
         goto CREATE_PROCESS_END;
     }
     
-    /* TODO: Read in all NSO headers, see what NSOs are present. */
+    /* Read in all NSO headers, see what NSOs are present. */
+    rc = NsoUtils::LoadNsoHeaders(info.aci0->title_id);
+    if (R_FAILED(rc)) {
+        goto CREATE_PROCESS_END;
+    }
     
-    /* TODO: Validate that the set of NSOs to be loaded is correct. */
+    /* Validate that the set of NSOs to be loaded is correct. */
+    rc = NsoUtils::ValidateNsoLoadSet();
+    if (R_FAILED(rc)) {
+        goto CREATE_PROCESS_END;
+    }
     
     /* TODO: Create the CreateProcessInfo. */