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Code Issues Releases Activity

Store everything in uint64 to avoid overflow

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This commit is contained in:
Romein van Buren
2025-06-12 11:52:09 +02:00
parent 8562e1147b
commit d715fe6e64
5 changed files with 55 additions and 60 deletions
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68
fmp/fmp_chunk.go
View File

@ -1,9 +1,5 @@
package fmp
import (
"encoding/binary"
)
func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
// Simple data
@ -34,7 +30,7 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_DATA,
Value: payload[1 : 1+length],
Length: 1 + uint32(length),
Length: 1 + uint64(length),
}, nil
}
if 0x12 <= payload[0] && payload[0] <= 0x15 {
@ -42,7 +38,7 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_DATA,
Value: payload[1 : 1+length],
Length: 1 + uint32(length),
Length: 1 + uint64(length),
}, nil
}
if 0x1A <= payload[0] && payload[0] <= 0x1D {
@ -50,7 +46,7 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_DATA,
Value: payload[1 : 1+length],
Length: 1 + uint32(length),
Length: 1 + uint64(length),
}, nil
}
@ -59,7 +55,7 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
if payload[0] == 0x01 {
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_KEY_VALUE,
Key: uint32(payload[1]),
Key: uint64(payload[1]),
Value: payload[2 : 2+1],
Length: 3,
}, nil
@ -68,24 +64,24 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
length := 2 * (payload[0] - 1)
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_KEY_VALUE,
Key: uint32(payload[1]),
Key: uint64(payload[1]),
Value: payload[2 : 2+length],
Length: 2 + uint32(length),
Length: 2 + uint64(length),
}, nil
}
if payload[0] == 0x06 {
length := payload[2]
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_KEY_VALUE,
Key: uint32(payload[1]),
Key: uint64(payload[1]),
Value: payload[3 : 3+length], // docs say offset 2?
Length: 3 + uint32(length),
Length: 3 + uint64(length),
}, nil
}
if payload[0] == 0x09 {
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_KEY_VALUE,
Key: uint32(binary.BigEndian.Uint16(payload[1:3])),
Key: parseVarUint64(payload[1:3]),
Value: payload[3 : 3+1], // docs say offset 2?
Length: 4,
}, nil
@ -94,18 +90,18 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
length := 2 * (payload[0] - 9)
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_KEY_VALUE,
Key: uint32(binary.BigEndian.Uint16(payload[1:3])),
Key: parseVarUint64(payload[1:3]),
Value: payload[3 : 3+length], // docs say offset 2?
Length: 2 + uint32(length),
Length: 2 + uint64(length),
}, nil
}
if payload[0] == 0x0E {
length := payload[2]
return &FmpChunk{
Type: FMP_CHUNK_SIMPLE_KEY_VALUE,
Key: uint32(binary.BigEndian.Uint16(payload[1:3])),
Key: parseVarUint64(payload[1:3]),
Value: payload[4 : 4+length], // docs say offset 2?
Length: 4 + uint32(length),
Length: 4 + uint64(length),
}, nil
}
@ -115,18 +111,18 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
length := payload[4]
return &FmpChunk{
Type: FMP_CHUNK_LONG_KEY_VALUE,
Key: parseVarUint32(payload[1 : 1+3]),
Key: parseVarUint64(payload[1 : 1+3]),
Value: payload[5 : 5+length],
Length: 5 + uint32(length),
Length: 5 + uint64(length),
}, nil
}
if payload[0] == 0x17 {
length := uint32(binary.BigEndian.Uint16(payload[4 : 4+2]))
length := parseVarUint64(payload[4 : 4+2])
return &FmpChunk{
Type: FMP_CHUNK_LONG_KEY_VALUE,
Key: uint32(binary.BigEndian.Uint16(payload[1 : 1+2])),
Key: parseVarUint64(payload[1 : 1+2]),
Value: payload[6 : 6+length],
Length: 6 + uint32(length),
Length: 6 + uint64(length),
}, nil
}
if payload[0] == 0x1E {
@ -134,40 +130,40 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
valueLength := payload[2+keyLength]
return &FmpChunk{
Type: FMP_CHUNK_LONG_KEY_VALUE,
Key: parseVarUint32(payload[2 : 2+keyLength]),
Key: parseVarUint64(payload[2 : 2+keyLength]),
Value: payload[2+keyLength+1 : 2+keyLength+1+valueLength],
Length: 3 + uint32(keyLength) + uint32(valueLength),
Length: 3 + uint64(keyLength) + uint64(valueLength),
}, nil
}
if payload[0] == 0x1F {
keyLength := uint32(payload[1])
valueLength := parseVarUint32(payload[2+keyLength : 2+keyLength+2+1])
keyLength := uint64(payload[1])
valueLength := parseVarUint64(payload[2+keyLength : 2+keyLength+2+1])
return &FmpChunk{
Type: FMP_CHUNK_LONG_KEY_VALUE,
Key: parseVarUint32(payload[2 : 2+keyLength]),
Key: parseVarUint64(payload[2 : 2+keyLength]),
Value: payload[2+keyLength+2 : 2+keyLength+2+valueLength],
Length: 4 + uint32(keyLength) + uint32(valueLength),
Length: 4 + uint64(keyLength) + uint64(valueLength),
}, nil
}
// Segmented data
if payload[0] == 0x07 {
length := binary.BigEndian.Uint16(payload[2 : 2+2])
payloadLimit := min(4+length, uint16(len(payload)))
length := parseVarUint64(payload[2 : 2+2])
payloadLimit := min(4+length, uint64(len(payload)))
return &FmpChunk{
Type: FMP_CHUNK_SEGMENTED_DATA,
Index: uint32(payload[1]),
Index: uint64(payload[1]),
Value: payload[4:payloadLimit],
Length: 4 + uint32(length),
Length: 4 + uint64(length),
}, nil
}
if payload[0] == 0x0F {
length := uint32(binary.BigEndian.Uint16(payload[3 : 3+2]))
payloadLimit := min(5+length, uint32(len(payload)))
length := parseVarUint64(payload[3 : 3+2])
payloadLimit := min(5+length, uint64(len(payload)))
return &FmpChunk{
Type: FMP_CHUNK_SEGMENTED_DATA,
Index: uint32(binary.BigEndian.Uint16(payload[1 : 1+2])),
Index: parseVarUint64(payload[1 : 1+2]),
Value: payload[5:payloadLimit],
Length: 5 + length,
}, nil
@ -208,7 +204,7 @@ func (ctx *FmpFile) readChunk(payload []byte) (*FmpChunk, error) {
return &FmpChunk{
Type: FMP_CHUNK_PATH_PUSH,
Value: payload[2 : 2+length],
Length: 2 + uint32(length),
Length: 2 + uint64(length),
}, nil
}

15
fmp/fmp_file.go
View File

@ -2,7 +2,6 @@ package fmp
import (
"bytes"
"encoding/binary"
"io"
"os"
"time"
@ -39,7 +38,7 @@ func OpenFile(path string) (*FmpFile, error) {
ctx.NumSectors = ctx.FileSize / sectorSize
ctx.Sectors = make([]*FmpSector, ctx.NumSectors)
currentPath := make([]uint16, 0)
currentPath := make([]uint64, 0)
for i := uint(0); i < ctx.NumSectors; i++ {
sector, err := ctx.readSector()
@ -55,7 +54,7 @@ func OpenFile(path string) (*FmpFile, error) {
for _, chunk := range sector.Chunks {
switch chunk.Type {
case FMP_CHUNK_PATH_PUSH:
currentPath = append(currentPath, uint16(chunk.Value[0]))
currentPath = append(currentPath, uint64(chunk.Value[0]))
case FMP_CHUNK_PATH_POP:
if len(currentPath) > 0 {
@ -74,13 +73,13 @@ func OpenFile(path string) (*FmpFile, error) {
case FMP_CHUNK_SIMPLE_KEY_VALUE:
ctx.Dictionary.set(
append(currentPath, uint16(chunk.Key)),
append(currentPath, uint64(chunk.Key)),
chunk.Value,
)
case FMP_CHUNK_LONG_KEY_VALUE:
ctx.Dictionary.set(
append(currentPath, uint16(chunk.Key)), // todo: ??
append(currentPath, uint64(chunk.Key)), // todo: ??
chunk.Value,
)
@ -131,8 +130,8 @@ func (ctx *FmpFile) readSector() (*FmpSector, error) {
sector := &FmpSector{
Deleted: buf[0] != 0,
Level: uint8(buf[1]),
PrevSectorID: binary.BigEndian.Uint32(buf[2:6]),
NextSectorID: binary.BigEndian.Uint32(buf[6:10]),
PrevSectorID: parseVarUint64(buf[2:6]),
NextSectorID: parseVarUint64(buf[6:10]),
}
payload := make([]byte, sectorSize-sectorHeaderSize)
@ -160,7 +159,7 @@ func (ctx *FmpFile) readSector() (*FmpSector, error) {
panic("chunk length not set")
}
sector.Chunks = append(sector.Chunks, chunk)
payload = payload[min(chunk.Length, uint32(len(payload))):]
payload = payload[min(chunk.Length, uint64(len(payload))):]
if len(payload) == 0 || (len(payload) == 1 && payload[0] == 0x00) {
break
}

4
fmp/fmp_table.go
View File

@ -2,9 +2,9 @@ package fmp
func (ctx *FmpFile) Tables() []*FmpTable {
tables := make([]*FmpTable, 0)
metaDict := ctx.Dictionary.get([]uint16{4, 1, 7})
metaDict := ctx.Dictionary.get([]uint64{4, 1, 7})
for _, meta := range *metaDict.Children {
name := decodeByteSeq(meta.Children.get([]uint16{16}).Value)
name := decodeByteSeq(meta.Children.get([]uint64{16}).Value)
table := &FmpTable{Name: name}
tables = append(tables, table)
}

18
fmp/fmp_type.go
View File

@ -19,20 +19,20 @@ type FmpFile struct {
type FmpSector struct {
Deleted bool
Level uint8
PrevSectorID uint32
NextSectorID uint32
PrevSectorID uint64
NextSectorID uint64
Chunks []*FmpChunk
}
type FmpChunk struct {
Type FmpChunkType
Length uint32
Key uint32 // If Type == FMP_CHUNK_SHORT_KEY_VALUE or FMP_CHUNK_LONG_KEY_VALUE
Index uint32 // Segment index, if Type == FMP_CHUNK_SEGMENTED_DATA
Length uint64
Key uint64 // If Type == FMP_CHUNK_SHORT_KEY_VALUE or FMP_CHUNK_LONG_KEY_VALUE
Index uint64 // Segment index, if Type == FMP_CHUNK_SEGMENTED_DATA
Value []byte
}
type FmpDict map[uint16]*FmpDictEntry
type FmpDict map[uint64]*FmpDictEntry
type FmpDictEntry struct {
Value []byte
@ -43,7 +43,7 @@ type FmpTable struct {
Name string
}
func (dict *FmpDict) get(path []uint16) *FmpDictEntry {
func (dict *FmpDict) get(path []uint64) *FmpDictEntry {
for i, key := range path {
_, ok := (*dict)[key]
if !ok {
@ -59,7 +59,7 @@ func (dict *FmpDict) get(path []uint16) *FmpDictEntry {
return nil
}
func (dict *FmpDict) getValue(path []uint16) []byte {
func (dict *FmpDict) getValue(path []uint64) []byte {
ent := dict.get(path)
if ent != nil {
return ent.Value
@ -67,7 +67,7 @@ func (dict *FmpDict) getValue(path []uint16) []byte {
return nil
}
func (dict *FmpDict) set(path []uint16, value []byte) {
func (dict *FmpDict) set(path []uint64, value []byte) {
for i, key := range path {
_, ok := (*dict)[key]
if !ok {

10
fmp/fmp_util.go
View File

@ -1,14 +1,14 @@
package fmp
func parseVarUint32(payload []byte) uint32 {
var length uint32
func parseVarUint64(payload []byte) uint64 {
var length uint64
n := len(payload)
if n > 4 {
n = 4 // clamp to max uint32
if n > 8 {
n = 8 // clamp to max uint64
}
for i := range n {
length <<= 8
length |= uint32(payload[i])
length |= uint64(payload[i])
}
return length
}