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loader: completely rewrite.

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This commit is contained in:
Michael Scire 2019-06-26 15:46:19 -07:00
parent 9217e4c5f9
commit 61fcf5e0f4
49 changed files with 2523 additions and 5817 deletions
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172
stratosphere/loader/source/ldr_patcher.cpp
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@ -14,174 +14,30 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <cstdlib>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <dirent.h>
#include <ctype.h>
#include <stratosphere/patcher.hpp>
#include <stratosphere/ro.hpp>
#include <switch.h>
#include "ldr_patcher.hpp"
/* IPS Patching adapted from Luma3DS (https://github.com/AuroraWright/Luma3DS/blob/master/sysmodules/loader/source/patcher.c) */
namespace sts::ldr {
#define IPS_MAGIC "PATCH"
#define IPS_TAIL "EOF"
namespace {
#define IPS32_MAGIC "IPS32"
#define IPS32_TAIL "EEOF"
constexpr const char *NsoPatchesDirectory = "exefs_patches";
static inline u8 HexNybbleToU8(const char nybble) {
if ('0' <= nybble && nybble <= '9') {
return nybble - '0';
} else if ('a' <= nybble && nybble <= 'f') {
return nybble - 'a' + 0xa;
} else {
return nybble - 'A' + 0xA;
}
}
/* Exefs patches want to prevent modification of header, */
/* and also want to adjust offset relative to mapped location. */
constexpr size_t NsoPatchesProtectedSize = sizeof(NsoHeader);
constexpr size_t NsoPatchesProtectedOffset = sizeof(NsoHeader);
static bool MatchesBuildId(const char *name, size_t name_len, const u8 *build_id) {
/* Validate name is hex build id. */
for (unsigned int i = 0; i < name_len - 4; i++) {
if (isxdigit(name[i]) == 0) {
return false;
}
}
/* Read build id from name. */
u8 build_id_from_name[0x20] = {0};
for (unsigned int name_ofs = 0, id_ofs = 0; name_ofs < name_len - 4; id_ofs++) {
build_id_from_name[id_ofs] |= HexNybbleToU8(name[name_ofs++]) << 4;
build_id_from_name[id_ofs] |= HexNybbleToU8(name[name_ofs++]);
/* Apply IPS patches. */
void LocateAndApplyIpsPatchesToModule(const u8 *build_id, uintptr_t mapped_nso, size_t mapped_size) {
ro::ModuleId module_id;
std::memcpy(&module_id.build_id, build_id, sizeof(module_id.build_id));
sts::patcher::LocateAndApplyIpsPatchesToModule(NsoPatchesDirectory, NsoPatchesProtectedSize, NsoPatchesProtectedOffset, &module_id, reinterpret_cast<u8 *>(mapped_nso), mapped_size);
}
return memcmp(build_id, build_id_from_name, sizeof(build_id_from_name)) == 0;
}
static void ApplyIpsPatch(u8 *mapped_nso, size_t mapped_size, bool is_ips32, FILE *f_ips) {
u8 buffer[4];
while (fread(buffer, is_ips32 ? 4 : 3, 1, f_ips) == 1) {
if (is_ips32 && memcmp(buffer, IPS32_TAIL, 4) == 0) {
break;
} else if (!is_ips32 && memcmp(buffer, IPS_TAIL, 3) == 0) {
break;
}
/* Offset of patch. */
u32 patch_offset;
if (is_ips32) {
patch_offset = (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
} else {
patch_offset = (buffer[0] << 16) | (buffer[1] << 8) | (buffer[2]);
}
/* Size of patch. */
if (fread(buffer, 2, 1, f_ips) != 1) {
break;
}
u32 patch_size = (buffer[0] << 8) | (buffer[1]);
/* Check for RLE encoding. */
if (patch_size == 0) {
/* Size of RLE. */
if (fread(buffer, 2, 1, f_ips) != 1) {
break;
}
u32 rle_size = (buffer[0] << 8) | (buffer[1]);
/* Value for RLE. */
if (fread(buffer, 1, 1, f_ips) != 1) {
break;
}
if (patch_offset < sizeof(NsoUtils::NsoHeader)) {
if (patch_offset + rle_size > sizeof(NsoUtils::NsoHeader)) {
u32 diff = sizeof(NsoUtils::NsoHeader) - patch_offset;
patch_offset += diff;
rle_size -= diff;
goto IPS_RLE_PATCH_OFFSET_WITHIN_BOUNDS;
}
} else {
IPS_RLE_PATCH_OFFSET_WITHIN_BOUNDS:
patch_offset -= sizeof(NsoUtils::NsoHeader);
if (patch_offset + rle_size > mapped_size) {
rle_size = mapped_size - patch_offset;
}
memset(mapped_nso + patch_offset, buffer[0], rle_size);
}
} else {
if (patch_offset < sizeof(NsoUtils::NsoHeader)) {
if (patch_offset + patch_size > sizeof(NsoUtils::NsoHeader)) {
u32 diff = sizeof(NsoUtils::NsoHeader) - patch_offset;
patch_offset += diff;
patch_size -= diff;
fseek(f_ips, diff, SEEK_CUR);
goto IPS_DATA_PATCH_OFFSET_WITHIN_BOUNDS;
} else {
fseek(f_ips, patch_size, SEEK_CUR);
}
} else {
IPS_DATA_PATCH_OFFSET_WITHIN_BOUNDS:
patch_offset -= sizeof(NsoUtils::NsoHeader);
u32 read_size = patch_size;
if (patch_offset + read_size > mapped_size) {
read_size = mapped_size - patch_offset;
}
if (fread(mapped_nso + patch_offset, read_size, 1, f_ips) != 1) {
break;
}
if (patch_size > read_size) {
fseek(f_ips, patch_size - read_size, SEEK_CUR);
}
}
}
}
}
void PatchUtils::ApplyPatches(const NsoUtils::NsoHeader *header, u8 *mapped_nso, size_t mapped_size) {
/* Inspect all patches from /atmosphere/exefs_patches/<*>/<*>.ips */
char path[FS_MAX_PATH+1] = {0};
snprintf(path, sizeof(path) - 1, "sdmc:/atmosphere/exefs_patches");
DIR *patches_dir = opendir(path);
struct dirent *pdir_ent;
if (patches_dir != NULL) {
/* Iterate over the patches directory to find patch subdirectories. */
while ((pdir_ent = readdir(patches_dir)) != NULL) {
if (strcmp(pdir_ent->d_name, ".") == 0 || strcmp(pdir_ent->d_name, "..") == 0) {
continue;
}
snprintf(path, sizeof(path) - 1, "sdmc:/atmosphere/exefs_patches/%s", pdir_ent->d_name);
DIR *patch_dir = opendir(path);
struct dirent *ent;
if (patch_dir != NULL) {
/* Iterate over the patch subdirectory to find .ips patches. */
while ((ent = readdir(patch_dir)) != NULL) {
if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) {
continue;
}
size_t name_len = strlen(ent->d_name);
if ((4 < name_len && name_len <= 0x44) && ((name_len & 1) == 0) && strcmp(ent->d_name + name_len - 4, ".ips") == 0 && MatchesBuildId(ent->d_name, name_len, header->build_id)) {
snprintf(path, sizeof(path) - 1, "sdmc:/atmosphere/exefs_patches/%s/%s", pdir_ent->d_name, ent->d_name);
FILE *f_ips = fopen(path, "rb");
if (f_ips != NULL) {
u8 header[5];
if (fread(header, 5, 1, f_ips) == 1) {
if (memcmp(header, IPS_MAGIC, 5) == 0) {
ApplyIpsPatch(mapped_nso, mapped_size, false, f_ips);
} else if (memcmp(header, IPS32_MAGIC, 5) == 0) {
ApplyIpsPatch(mapped_nso, mapped_size, true, f_ips);
}
}
fclose(f_ips);
}
}
}
closedir(patch_dir);
}
}
closedir(patches_dir);
}
}