// Copyright 2018 syzkaller project authors. All rights reserved.
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// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
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// imagegen generates syz_mount_image/syz_read_part_table calls from disk images.
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package main
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import (
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"bytes"
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"encoding/hex"
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"flag"
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"fmt"
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"io/ioutil"
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"os"
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)
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type Segment struct {
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offset int
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data []byte
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}
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func main() {
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flagV := flag.Bool("v", false, "verbose output")
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flagImage := flag.String("image", "", "image file")
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flagSkip := flag.Int("skip", 32, "min zero bytes to skip")
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flagAlign := flag.Int("align", 32, "non-zero block alignment")
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flagFS := flag.String("fs", "", "filesystem")
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flag.Parse()
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data, err := ioutil.ReadFile(*flagImage)
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if err != nil {
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fmt.Fprintf(os.Stderr, "failed to read input file: %v\n", err)
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os.Exit(1)
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}
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data0 := data
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zeros := make([]byte, *flagAlign+*flagSkip)
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var segs []Segment
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offset := 0
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for len(data) != 0 {
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pos := bytes.Index(data, zeros)
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if pos == -1 {
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segs = append(segs, Segment{offset, data})
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break
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}
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pos = (pos + *flagAlign - 1) & ^(*flagAlign - 1)
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if pos != 0 {
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segs = append(segs, Segment{offset, data[:pos]})
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}
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for pos < len(data) && data[pos] == 0 {
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pos++
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}
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pos = pos & ^(*flagAlign - 1)
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offset += pos
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data = data[pos:]
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}
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totalData := 0
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for _, seg := range segs {
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totalData += len(seg.data)
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}
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fmt.Fprintf(os.Stderr, "image size: %v, segments: %v, data: %v\n",
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len(data0), len(segs), totalData)
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if *flagV {
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for i, seg := range segs {
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next := len(data0)
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if i != len(segs)-1 {
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next = segs[i+1].offset
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}
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skip := next - seg.offset - len(seg.data)
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fmt.Fprintf(os.Stderr, "segment: %8v-%8v [%8v] -%8v\n",
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seg.offset, seg.offset+len(seg.data), len(seg.data), skip)
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}
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}
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restored := make([]byte, len(data0))
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for _, seg := range segs {
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copy(restored[seg.offset:], seg.data)
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}
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if !bytes.Equal(data0, restored) {
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fmt.Fprintf(os.Stderr, "restored data differs!\n")
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os.Exit(1)
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}
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if *flagFS == "part" {
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fmt.Printf(`syz_read_part_table(0x%x, 0x%x, &(0x7f0000000200)=[`,
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len(data0), len(segs))
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addr := 0x7f0000010000
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for i, seg := range segs {
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if i != 0 {
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fmt.Printf(", ")
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}
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fmt.Printf(`{&(0x%x)="%v", 0x%x, 0x%x}`,
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addr, hex.EncodeToString(seg.data), len(seg.data), seg.offset)
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addr = (addr + len(seg.data) + 0xff) & ^0xff
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}
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fmt.Printf("])\n")
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} else {
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syscallSuffix := *flagFS
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if syscallSuffix == "ext2" || syscallSuffix == "ext3" {
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syscallSuffix = "ext4"
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}
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fmt.Printf(`syz_mount_image$%v(&(0x7f0000000000)='%v\x00', &(0x7f0000000100)='./file0\x00',`+
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` 0x%x, 0x%x, &(0x7f0000000200)=[`,
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syscallSuffix, *flagFS, len(data0), len(segs))
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addr := 0x7f0000010000
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for i, seg := range segs {
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if i != 0 {
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fmt.Printf(", ")
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}
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fmt.Printf(`{&(0x%x)="%v", 0x%x, 0x%x}`,
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addr, hex.EncodeToString(seg.data), len(seg.data), seg.offset)
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addr = (addr + len(seg.data) + 0xff) & ^0xff
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}
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fmt.Printf("], 0x0, &(0x%x))\n", addr)
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}
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}
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