tools/syz-aflow: add command line tool for agentic workflows

syz-aflow tool can be used to invoke any agentic workflow registered with pkg/aflow.
For example, to run the patching workflow use:
  go run ./tools/syz-aflow -input=input.json -download-bug=d8fd35fa6177afa8c92b
  go run ./tools/syz-aflow -input=input.json -workflow=patching-baseline -workdir=workdir

Author: dvyukov

tools/syz-aflow/aflow.go

@@ -0,0 +1,132 @@
+// Copyright 2025 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// syz-aflow tool can be used to invoke any agentic workflow registered with pkg/aflow.
+// For example, to run the patching workflow use:
+//
+//	go run ./tools/syz-aflow -input=input.json -download-bug=d8fd35fa6177afa8c92b
+//	go run ./tools/syz-aflow -input=input.json -workflow=patching -workdir=workdir
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+
+	"github.com/google/syzkaller/pkg/aflow"
+	_ "github.com/google/syzkaller/pkg/aflow/flow"
+	"github.com/google/syzkaller/pkg/aflow/trajectory"
+	"github.com/google/syzkaller/pkg/osutil"
+	"github.com/google/syzkaller/pkg/tool"
+)
+
+func main() {
+	var (
+		flagFlow        = flag.String("workflow", "", "workflow to execute")
+		flagInput       = flag.String("input", "", "input json file with workflow arguments")
+		flagWorkdir     = flag.String("workdir", "", "directory for kernel checkout, kernel builds, etc")
+		flagModel       = flag.String("model", aflow.DefaultModel, "use this LLM model")
+		flagDownloadBug = flag.String("download-bug", "", "extid of a bug to download from the dashboard"+
+			" and save into -input file")
+	)
+	defer tool.Init()()
+	if *flagDownloadBug != "" {
+		if err := downloadBug(*flagDownloadBug, *flagInput); err != nil {
+			tool.Fail(err)
+		}
+		return
+	}
+	if *flagFlow == "" {
+		fmt.Fprintf(os.Stderr, "syz-aflow usage:\n")
+		flag.PrintDefaults()
+		fmt.Fprintf(os.Stderr, "available workflows:\n")
+		for _, flow := range aflow.Flows {
+			fmt.Fprintf(os.Stderr, "\t%v: %v\n", flow.Name, flow.Description)
+		}
+		return
+	}
+	if err := run(context.Background(), *flagModel, *flagFlow, *flagInput, *flagWorkdir); err != nil {
+		tool.Fail(err)
+	}
+}
+
+func run(ctx context.Context, model, flowName, inputFile, workdir string) error {
+	flow := aflow.Flows[flowName]
+	if flow == nil {
+		return fmt.Errorf("workflow %q is not found", flowName)
+	}
+	inputData, err := os.ReadFile(inputFile)
+	if err != nil {
+		return fmt.Errorf("failed to open -input file: %w", err)
+	}
+	var inputs map[string]any
+	if err := json.Unmarshal(inputData, &inputs); err != nil {
+		return err
+	}
+	cache, err := aflow.NewCache(filepath.Join(workdir, "cache"), 0)
+	if err != nil {
+		return err
+	}
+	_, err = flow.Execute(ctx, model, workdir, inputs, cache, onEvent)
+	return err
+}
+
+func onEvent(span *trajectory.Span) error {
+	log.Printf("%v", span)
+	return nil
+}
+
+func downloadBug(extID, inputFile string) error {
+	if inputFile == "" {
+		return fmt.Errorf("-download-bug requires -input flag")
+	}
+	resp, err := get(fmt.Sprintf("/bug?extid=%v&json=1", extID))
+	if err != nil {
+		return err
+	}
+	var info map[string]any
+	if err := json.Unmarshal([]byte(resp), &info); err != nil {
+		return err
+	}
+	crash := info["crashes"].([]any)[0].(map[string]any)
+	inputs := map[string]any{
+		"SyzkallerCommit": crash["syzkaller-commit"],
+	}
+	inputs["ReproSyz"], err = get(crash["syz-reproducer"].(string))
+	if err != nil {
+		return err
+	}
+	inputs["ReproC"], err = get(crash["c-reproducer"].(string))
+	if err != nil {
+		return err
+	}
+	inputs["KernelConfig"], err = get(crash["kernel-config"].(string))
+	if err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(inputs, "", "\t")
+	if err != nil {
+		return err
+	}
+	return osutil.WriteFile(inputFile, data)
+}
+
+func get(path string) (string, error) {
+	if path == "" {
+		return "", nil
+	}
+	const host = "https://syzbot.org"
+	resp, err := http.Get(fmt.Sprintf("%v%v", host, path))
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	body, err := io.ReadAll(resp.Body)
+	return string(body), err
+}