From ad9ac6d07ce1819260c2b7f090fd4fe742c80d9f Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Sun, 10 Jul 2022 23:49:07 -0600
Subject: Fuzz btrfsitem, and by consequence improve binstruct errors

---
 lib/binstruct/binint/builtins.go | 38 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 22 deletions(-)

(limited to 'lib/binstruct/binint')

diff --git a/lib/binstruct/binint/builtins.go b/lib/binstruct/binint/builtins.go
index 5363dbe..01186bc 100644
--- a/lib/binstruct/binint/builtins.go
+++ b/lib/binstruct/binint/builtins.go
@@ -6,15 +6,9 @@ package binint
 
 import (
 	"encoding/binary"
-	"fmt"
-)
 
-func needNBytes(t interface{}, dat []byte, n int) error {
-	if len(dat) < n {
-		return fmt.Errorf("%T.UnmarshalBinary: need at least %v bytes, only have %v", t, n, len(dat))
-	}
-	return nil
-}
+	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct/binutil"
+)
 
 // unsigned
 
@@ -23,7 +17,7 @@ type U8 uint8
 func (U8) BinaryStaticSize() int            { return 1 }
 func (x U8) MarshalBinary() ([]byte, error) { return []byte{byte(x)}, nil }
 func (x *U8) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 1); err != nil {
+	if err := binutil.NeedNBytes(dat, 1); err != nil {
 		return 0, err
 	}
 	*x = U8(dat[0])
@@ -41,7 +35,7 @@ func (x U16le) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *U16le) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 2); err != nil {
+	if err := binutil.NeedNBytes(dat, 2); err != nil {
 		return 0, err
 	}
 	*x = U16le(binary.LittleEndian.Uint16(dat))
@@ -57,7 +51,7 @@ func (x U32le) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *U32le) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 4); err != nil {
+	if err := binutil.NeedNBytes(dat, 4); err != nil {
 		return 0, err
 	}
 	*x = U32le(binary.LittleEndian.Uint32(dat))
@@ -73,7 +67,7 @@ func (x U64le) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *U64le) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 8); err != nil {
+	if err := binutil.NeedNBytes(dat, 8); err != nil {
 		return 0, err
 	}
 	*x = U64le(binary.LittleEndian.Uint64(dat))
@@ -91,7 +85,7 @@ func (x U16be) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *U16be) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 2); err != nil {
+	if err := binutil.NeedNBytes(dat, 2); err != nil {
 		return 0, err
 	}
 	*x = U16be(binary.BigEndian.Uint16(dat))
@@ -107,7 +101,7 @@ func (x U32be) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *U32be) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 4); err != nil {
+	if err := binutil.NeedNBytes(dat, 4); err != nil {
 		return 0, err
 	}
 	*x = U32be(binary.BigEndian.Uint32(dat))
@@ -123,7 +117,7 @@ func (x U64be) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *U64be) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 8); err != nil {
+	if err := binutil.NeedNBytes(dat, 8); err != nil {
 		return 0, err
 	}
 	*x = U64be(binary.BigEndian.Uint64(dat))
@@ -137,7 +131,7 @@ type I8 int8
 func (I8) BinaryStaticSize() int            { return 1 }
 func (x I8) MarshalBinary() ([]byte, error) { return []byte{byte(x)}, nil }
 func (x *I8) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 1); err != nil {
+	if err := binutil.NeedNBytes(dat, 1); err != nil {
 		return 0, err
 	}
 	*x = I8(dat[0])
@@ -155,7 +149,7 @@ func (x I16le) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *I16le) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 2); err != nil {
+	if err := binutil.NeedNBytes(dat, 2); err != nil {
 		return 0, err
 	}
 	*x = I16le(binary.LittleEndian.Uint16(dat))
@@ -171,7 +165,7 @@ func (x I32le) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *I32le) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 4); err != nil {
+	if err := binutil.NeedNBytes(dat, 4); err != nil {
 		return 0, err
 	}
 	*x = I32le(binary.LittleEndian.Uint32(dat))
@@ -187,7 +181,7 @@ func (x I64le) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *I64le) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 8); err != nil {
+	if err := binutil.NeedNBytes(dat, 8); err != nil {
 		return 0, err
 	}
 	*x = I64le(binary.LittleEndian.Uint64(dat))
@@ -205,7 +199,7 @@ func (x I16be) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *I16be) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 2); err != nil {
+	if err := binutil.NeedNBytes(dat, 2); err != nil {
 		return 0, err
 	}
 	*x = I16be(binary.BigEndian.Uint16(dat))
@@ -221,7 +215,7 @@ func (x I32be) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *I32be) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 4); err != nil {
+	if err := binutil.NeedNBytes(dat, 4); err != nil {
 		return 0, err
 	}
 	*x = I32be(binary.BigEndian.Uint32(dat))
@@ -237,7 +231,7 @@ func (x I64be) MarshalBinary() ([]byte, error) {
 	return buf[:], nil
 }
 func (x *I64be) UnmarshalBinary(dat []byte) (int, error) {
-	if err := needNBytes(*x, dat, 8); err != nil {
+	if err := binutil.NeedNBytes(dat, 8); err != nil {
 		return 0, err
 	}
 	*x = I64be(binary.BigEndian.Uint64(dat))
-- 
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