127 lines
4.8 KiB
C

#include "romfs.h"
#include "utf.h"
// get lvl datablock offset from IVC (zero for total size)
// see: https://github.com/profi200/Project_CTR/blob/046bb359ee95423938886dbf477d00690aaecd3e/ctrtool/ivfc.c#L88-L111
u64 GetRomFsLvOffset(RomFsIvfcHeader* ivfc, u32 lvl) {
// regardless of lvl given, we calculate them all
u64 offset[4];
// lvl1/2/3 offset and size
offset[3] = align(sizeof(RomFsIvfcHeader) + ivfc->size_masterhash, 1 << ivfc->log_lvl3);
offset[1] = offset[3] + align(ivfc->size_lvl3, 1 << ivfc->log_lvl3);
offset[2] = offset[1] + align(ivfc->size_lvl1, 1 << ivfc->log_lvl1);
offset[0] = offset[2] + align(ivfc->size_lvl2, 1 << ivfc->log_lvl2); // (min) size
return (lvl <= 3) ? offset[lvl] : 0;
}
// validate IVFC header by checking offsets and hash sizes
u32 ValidateRomFsHeader(RomFsIvfcHeader* ivfc, u32 max_size) {
u8 magic[] = { ROMFS_MAGIC };
// check magic number
if (memcmp(magic, ivfc->magic, sizeof(magic)) != 0)
return 1;
// check hash block sizes vs data block sizes
if ((((ivfc->size_masterhash / 0x20) << ivfc->log_lvl1) < ivfc->size_lvl1) || // lvl1
(((ivfc->size_lvl1 / 0x20) << ivfc->log_lvl2) < ivfc->size_lvl2) || // lvl2
(((ivfc->size_lvl2 / 0x20) << ivfc->log_lvl3) < ivfc->size_lvl3)) // lvl3
return 1;
// check size if given
if (max_size && (max_size < GetRomFsLvOffset(ivfc, 0)))
return 1;
return 0;
}
// validate lvl3 header by checking offsets and sizes
u32 ValidateLv3Header(RomFsLv3Header* lv3, u32 max_size) {
return ((lv3->size_header == 0x28) &&
(lv3->offset_dirhash >= lv3->size_header) &&
(lv3->offset_dirmeta >= lv3->offset_dirhash + lv3->size_dirhash) &&
(lv3->offset_filehash >= lv3->offset_dirmeta + lv3->size_dirmeta) &&
(lv3->offset_filemeta >= lv3->offset_filehash + lv3->size_filehash) &&
(lv3->offset_filedata >= lv3->offset_filemeta + lv3->size_filemeta) &&
(!max_size || (lv3->offset_filedata <= max_size))) ? 0 : 1;
}
// build index of RomFS lvl3
u32 BuildLv3Index(RomFsLv3Index* index, u8* lv3) {
RomFsLv3Header* hdr = (void*)lv3;
index->header = hdr;
index->dirhash = (u32*) (void*) (lv3 + hdr->offset_dirhash);
index->dirmeta = lv3 + hdr->offset_dirmeta;
index->filehash = (u32*) (void*) (lv3 + hdr->offset_filehash);
index->filemeta = lv3 + hdr->offset_filemeta;
index->filedata = NULL;
index->mod_dir = (hdr->size_dirhash / sizeof(u32));
index->mod_file = (hdr->size_filehash / sizeof(u32));
index->size_dirmeta = hdr->size_dirmeta;
index->size_filemeta = hdr->size_filemeta;
return 0;
}
// hash lvl3 path - this is used to find the first offset in the file / dir hash table
u32 HashLv3Path(u16* wname, u32 name_len, u32 offset_parent) {
u32 hash = offset_parent ^ 123456789;
for (u32 i = 0; i < name_len; i++)
hash = ((hash>>5) | (hash<<27)) ^ wname[i];
return hash;
}
RomFsLv3DirMeta* GetLv3DirMeta(const char* name, u32 offset_parent, RomFsLv3Index* index) {
RomFsLv3DirMeta* meta;
// wide (UTF-16) name
u16 wname[256];
int name_len = utf8_to_utf16(wname, (u8*) name, 255, 255);
if (name_len <= 0) return NULL;
wname[name_len] = 0;
// hashing, first offset
u32 hash = HashLv3Path(wname, name_len, offset_parent);
u32 offset = index->dirhash[hash % index->mod_dir];
// process the hashbucket (make sure we got the correct data)
// slim chance of endless loop with broken lvl3 here
for (; offset < index->size_dirmeta; offset = meta->offset_samehash) {
meta = (void*)(index->dirmeta + offset);
if ((offset_parent == meta->offset_parent) &&
((u32) name_len == meta->name_len / 2) &&
(memcmp(wname, meta->wname, name_len * 2) == 0))
break;
}
return (offset >= index->size_dirmeta) ? NULL : meta;
}
RomFsLv3FileMeta* GetLv3FileMeta(const char* name, u32 offset_parent, RomFsLv3Index* index) {
RomFsLv3FileMeta* meta;
// wide (UTF-16) name
u16 wname[256];
int name_len = utf8_to_utf16(wname, (u8*) name, 255, 255);
if (name_len <= 0) return NULL;
wname[name_len] = 0;
// hashing, first offset
u32 hash = HashLv3Path(wname, name_len, offset_parent);
u32 offset = index->filehash[hash % index->mod_file];
// process the hashbucket (make sure we got the correct data)
// slim chance of endless loop with broken lvl3 here
for (; offset < index->size_filemeta; offset = meta->offset_samehash) {
meta = (void*)(index->filemeta + offset);
if ((offset_parent == meta->offset_parent) &&
((u32) name_len == meta->name_len / 2) &&
(memcmp(wname, meta->wname, name_len * 2) == 0))
break;
}
return (offset >= index->size_filemeta) ? NULL : meta;
}