bash.go

  1package tools
  2
  3import (
  4	"bytes"
  5	"cmp"
  6	"context"
  7	_ "embed"
  8	"fmt"
  9	"html/template"
 10	"os"
 11	"path/filepath"
 12	"runtime"
 13	"strings"
 14	"time"
 15
 16	"charm.land/fantasy"
 17	"git.secluded.site/crush/internal/config"
 18	"git.secluded.site/crush/internal/permission"
 19	"git.secluded.site/crush/internal/shell"
 20)
 21
 22type BashParams struct {
 23	Description     string `json:"description" description:"A brief description of what the command does, try to keep it under 30 characters or so"`
 24	Command         string `json:"command" description:"The command to execute"`
 25	WorkingDir      string `json:"working_dir,omitempty" description:"The working directory to execute the command in (defaults to current directory)"`
 26	RunInBackground bool   `json:"run_in_background,omitempty" description:"Set to true (boolean) to run this command in the background. Use job_output to read the output later."`
 27}
 28
 29type BashPermissionsParams struct {
 30	Description     string `json:"description"`
 31	Command         string `json:"command"`
 32	WorkingDir      string `json:"working_dir"`
 33	RunInBackground bool   `json:"run_in_background"`
 34}
 35
 36type BashResponseMetadata struct {
 37	StartTime        int64  `json:"start_time"`
 38	EndTime          int64  `json:"end_time"`
 39	Output           string `json:"output"`
 40	Description      string `json:"description"`
 41	WorkingDirectory string `json:"working_directory"`
 42	Background       bool   `json:"background,omitempty"`
 43	ShellID          string `json:"shell_id,omitempty"`
 44}
 45
 46const (
 47	BashToolName = "bash"
 48
 49	AutoBackgroundThreshold = 1 * time.Minute // Commands taking longer automatically become background jobs
 50	MaxOutputLength         = 30000
 51	BashNoOutput            = "no output"
 52)
 53
 54//go:embed bash.tpl
 55var bashDescriptionTmpl []byte
 56
 57var bashDescriptionTpl = template.Must(
 58	template.New("bashDescription").
 59		Parse(string(bashDescriptionTmpl)),
 60)
 61
 62type bashDescriptionData struct {
 63	BannedCommands  string
 64	MaxOutputLength int
 65	Attribution     config.Attribution
 66	ModelName       string
 67}
 68
 69var bannedCommands = []string{
 70	// Network/Download tools
 71	"alias",
 72	"aria2c",
 73	"axel",
 74	"chrome",
 75	"curl",
 76	"curlie",
 77	"firefox",
 78	"http-prompt",
 79	"httpie",
 80	"links",
 81	"lynx",
 82	"nc",
 83	"safari",
 84	"scp",
 85	"ssh",
 86	"telnet",
 87	"w3m",
 88	"wget",
 89	"xh",
 90
 91	// System administration
 92	"doas",
 93	"su",
 94	"sudo",
 95
 96	// Package managers
 97	"apk",
 98	"apt",
 99	"apt-cache",
100	"apt-get",
101	"dnf",
102	"dpkg",
103	"emerge",
104	"home-manager",
105	"makepkg",
106	"opkg",
107	"pacman",
108	"paru",
109	"pkg",
110	"pkg_add",
111	"pkg_delete",
112	"portage",
113	"rpm",
114	"yay",
115	"yum",
116	"zypper",
117
118	// System modification
119	"at",
120	"batch",
121	"chkconfig",
122	"crontab",
123	"fdisk",
124	"mkfs",
125	"mount",
126	"parted",
127	"service",
128	"systemctl",
129	"umount",
130
131	// Network configuration
132	"firewall-cmd",
133	"ifconfig",
134	"ip",
135	"iptables",
136	"netstat",
137	"pfctl",
138	"route",
139	"ufw",
140}
141
142func bashDescription(attribution *config.Attribution, modelName string) string {
143	bannedCommandsStr := strings.Join(bannedCommands, ", ")
144	var out bytes.Buffer
145	if err := bashDescriptionTpl.Execute(&out, bashDescriptionData{
146		BannedCommands:  bannedCommandsStr,
147		MaxOutputLength: MaxOutputLength,
148		Attribution:     *attribution,
149		ModelName:       modelName,
150	}); err != nil {
151		// this should never happen.
152		panic("failed to execute bash description template: " + err.Error())
153	}
154	return out.String()
155}
156
157func blockFuncs() []shell.BlockFunc {
158	return []shell.BlockFunc{
159		shell.CommandsBlocker(bannedCommands),
160
161		// System package managers
162		shell.ArgumentsBlocker("apk", []string{"add"}, nil),
163		shell.ArgumentsBlocker("apt", []string{"install"}, nil),
164		shell.ArgumentsBlocker("apt-get", []string{"install"}, nil),
165		shell.ArgumentsBlocker("dnf", []string{"install"}, nil),
166		shell.ArgumentsBlocker("pacman", nil, []string{"-S"}),
167		shell.ArgumentsBlocker("pkg", []string{"install"}, nil),
168		shell.ArgumentsBlocker("yum", []string{"install"}, nil),
169		shell.ArgumentsBlocker("zypper", []string{"install"}, nil),
170
171		// Language-specific package managers
172		shell.ArgumentsBlocker("brew", []string{"install"}, nil),
173		shell.ArgumentsBlocker("cargo", []string{"install"}, nil),
174		shell.ArgumentsBlocker("gem", []string{"install"}, nil),
175		shell.ArgumentsBlocker("go", []string{"install"}, nil),
176		shell.ArgumentsBlocker("npm", []string{"install"}, []string{"--global"}),
177		shell.ArgumentsBlocker("npm", []string{"install"}, []string{"-g"}),
178		shell.ArgumentsBlocker("pip", []string{"install"}, []string{"--user"}),
179		shell.ArgumentsBlocker("pip3", []string{"install"}, []string{"--user"}),
180		shell.ArgumentsBlocker("pnpm", []string{"add"}, []string{"--global"}),
181		shell.ArgumentsBlocker("pnpm", []string{"add"}, []string{"-g"}),
182		shell.ArgumentsBlocker("yarn", []string{"global", "add"}, nil),
183
184		// `go test -exec` can run arbitrary commands
185		shell.ArgumentsBlocker("go", []string{"test"}, []string{"-exec"}),
186	}
187}
188
189func NewBashTool(permissions permission.Service, workingDir string, attribution *config.Attribution, modelName string) fantasy.AgentTool {
190	return fantasy.NewAgentTool(
191		BashToolName,
192		string(bashDescription(attribution, modelName)),
193		func(ctx context.Context, params BashParams, call fantasy.ToolCall) (fantasy.ToolResponse, error) {
194			if params.Command == "" {
195				return fantasy.NewTextErrorResponse("missing command"), nil
196			}
197
198			// Determine working directory
199			execWorkingDir := cmp.Or(params.WorkingDir, workingDir)
200
201			isSafeReadOnly := false
202			cmdLower := strings.ToLower(params.Command)
203
204			for _, safe := range safeCommands {
205				if strings.HasPrefix(cmdLower, safe) {
206					if len(cmdLower) == len(safe) || cmdLower[len(safe)] == ' ' || cmdLower[len(safe)] == '-' {
207						isSafeReadOnly = true
208						break
209					}
210				}
211			}
212
213			sessionID := GetSessionFromContext(ctx)
214			if sessionID == "" {
215				return fantasy.ToolResponse{}, fmt.Errorf("session ID is required for executing shell command")
216			}
217			if !isSafeReadOnly {
218				p := permissions.Request(
219					permission.CreatePermissionRequest{
220						SessionID:   sessionID,
221						Path:        execWorkingDir,
222						ToolCallID:  call.ID,
223						ToolName:    BashToolName,
224						Action:      "execute",
225						Description: fmt.Sprintf("Execute command: %s", params.Command),
226						Params:      BashPermissionsParams(params),
227					},
228				)
229				if !p {
230					return fantasy.ToolResponse{}, permission.ErrorPermissionDenied
231				}
232			}
233
234			// If explicitly requested as background, start immediately with detached context
235			if params.RunInBackground {
236				startTime := time.Now()
237				bgManager := shell.GetBackgroundShellManager()
238				bgManager.Cleanup()
239				// Use background context so it continues after tool returns
240				bgShell, err := bgManager.Start(context.Background(), execWorkingDir, blockFuncs(), params.Command, params.Description)
241				if err != nil {
242					return fantasy.ToolResponse{}, fmt.Errorf("error starting background shell: %w", err)
243				}
244
245				// Wait a short time to detect fast failures (blocked commands, syntax errors, etc.)
246				time.Sleep(1 * time.Second)
247				stdout, stderr, done, execErr := bgShell.GetOutput()
248
249				if done {
250					// Command failed or completed very quickly
251					bgManager.Remove(bgShell.ID)
252
253					interrupted := shell.IsInterrupt(execErr)
254					exitCode := shell.ExitCode(execErr)
255					if exitCode == 0 && !interrupted && execErr != nil {
256						return fantasy.ToolResponse{}, fmt.Errorf("[Job %s] error executing command: %w", bgShell.ID, execErr)
257					}
258
259					stdout = formatOutput(stdout, stderr, execErr)
260
261					metadata := BashResponseMetadata{
262						StartTime:        startTime.UnixMilli(),
263						EndTime:          time.Now().UnixMilli(),
264						Output:           stdout,
265						Description:      params.Description,
266						Background:       params.RunInBackground,
267						WorkingDirectory: bgShell.WorkingDir,
268					}
269					if stdout == "" {
270						return fantasy.WithResponseMetadata(fantasy.NewTextResponse(BashNoOutput), metadata), nil
271					}
272					stdout += fmt.Sprintf("\n\n<cwd>%s</cwd>", normalizeWorkingDir(bgShell.WorkingDir))
273					return fantasy.WithResponseMetadata(fantasy.NewTextResponse(stdout), metadata), nil
274				}
275
276				// Still running after fast-failure check - return as background job
277				metadata := BashResponseMetadata{
278					StartTime:        startTime.UnixMilli(),
279					EndTime:          time.Now().UnixMilli(),
280					Description:      params.Description,
281					WorkingDirectory: bgShell.WorkingDir,
282					Background:       true,
283					ShellID:          bgShell.ID,
284				}
285				response := fmt.Sprintf("Background shell started with ID: %s\n\nUse job_output tool to view output or job_kill to terminate.", bgShell.ID)
286				return fantasy.WithResponseMetadata(fantasy.NewTextResponse(response), metadata), nil
287			}
288
289			// Start synchronous execution with auto-background support
290			startTime := time.Now()
291
292			// Start with detached context so it can survive if moved to background
293			bgManager := shell.GetBackgroundShellManager()
294			bgManager.Cleanup()
295			bgShell, err := bgManager.Start(context.Background(), execWorkingDir, blockFuncs(), params.Command, params.Description)
296			if err != nil {
297				return fantasy.ToolResponse{}, fmt.Errorf("error starting shell: %w", err)
298			}
299
300			// Wait for either completion, auto-background threshold, or context cancellation
301			ticker := time.NewTicker(100 * time.Millisecond)
302			defer ticker.Stop()
303			timeout := time.After(AutoBackgroundThreshold)
304
305			var stdout, stderr string
306			var done bool
307			var execErr error
308
309		waitLoop:
310			for {
311				select {
312				case <-ticker.C:
313					stdout, stderr, done, execErr = bgShell.GetOutput()
314					if done {
315						break waitLoop
316					}
317				case <-timeout:
318					stdout, stderr, done, execErr = bgShell.GetOutput()
319					break waitLoop
320				case <-ctx.Done():
321					// Incoming context was cancelled before we moved to background
322					// Kill the shell and return error
323					bgManager.Kill(bgShell.ID)
324					return fantasy.ToolResponse{}, ctx.Err()
325				}
326			}
327
328			if done {
329				// Command completed within threshold - return synchronously
330				// Remove from background manager since we're returning directly
331				// Don't call Kill() as it cancels the context and corrupts the exit code
332				bgManager.Remove(bgShell.ID)
333
334				interrupted := shell.IsInterrupt(execErr)
335				exitCode := shell.ExitCode(execErr)
336				if exitCode == 0 && !interrupted && execErr != nil {
337					return fantasy.ToolResponse{}, fmt.Errorf("[Job %s] error executing command: %w", bgShell.ID, execErr)
338				}
339
340				stdout = formatOutput(stdout, stderr, execErr)
341
342				metadata := BashResponseMetadata{
343					StartTime:        startTime.UnixMilli(),
344					EndTime:          time.Now().UnixMilli(),
345					Output:           stdout,
346					Description:      params.Description,
347					Background:       params.RunInBackground,
348					WorkingDirectory: bgShell.WorkingDir,
349				}
350				if stdout == "" {
351					return fantasy.WithResponseMetadata(fantasy.NewTextResponse(BashNoOutput), metadata), nil
352				}
353				stdout += fmt.Sprintf("\n\n<cwd>%s</cwd>", normalizeWorkingDir(bgShell.WorkingDir))
354				return fantasy.WithResponseMetadata(fantasy.NewTextResponse(stdout), metadata), nil
355			}
356
357			// Still running - keep as background job
358			metadata := BashResponseMetadata{
359				StartTime:        startTime.UnixMilli(),
360				EndTime:          time.Now().UnixMilli(),
361				Description:      params.Description,
362				WorkingDirectory: bgShell.WorkingDir,
363				Background:       true,
364				ShellID:          bgShell.ID,
365			}
366			response := fmt.Sprintf("Command is taking longer than expected and has been moved to background.\n\nBackground shell ID: %s\n\nUse job_output tool to view output or job_kill to terminate.", bgShell.ID)
367			return fantasy.WithResponseMetadata(fantasy.NewTextResponse(response), metadata), nil
368		})
369}
370
371// formatOutput formats the output of a completed command with error handling
372func formatOutput(stdout, stderr string, execErr error) string {
373	interrupted := shell.IsInterrupt(execErr)
374	exitCode := shell.ExitCode(execErr)
375
376	stdout = truncateOutput(stdout)
377	stderr = truncateOutput(stderr)
378
379	errorMessage := stderr
380	if errorMessage == "" && execErr != nil {
381		errorMessage = execErr.Error()
382	}
383
384	if interrupted {
385		if errorMessage != "" {
386			errorMessage += "\n"
387		}
388		errorMessage += "Command was aborted before completion"
389	} else if exitCode != 0 {
390		if errorMessage != "" {
391			errorMessage += "\n"
392		}
393		errorMessage += fmt.Sprintf("Exit code %d", exitCode)
394	}
395
396	hasBothOutputs := stdout != "" && stderr != ""
397
398	if hasBothOutputs {
399		stdout += "\n"
400	}
401
402	if errorMessage != "" {
403		stdout += "\n" + errorMessage
404	}
405
406	return stdout
407}
408
409func truncateOutput(content string) string {
410	if len(content) <= MaxOutputLength {
411		return content
412	}
413
414	halfLength := MaxOutputLength / 2
415	start := content[:halfLength]
416	end := content[len(content)-halfLength:]
417
418	truncatedLinesCount := countLines(content[halfLength : len(content)-halfLength])
419	return fmt.Sprintf("%s\n\n... [%d lines truncated] ...\n\n%s", start, truncatedLinesCount, end)
420}
421
422func countLines(s string) int {
423	if s == "" {
424		return 0
425	}
426	return len(strings.Split(s, "\n"))
427}
428
429func normalizeWorkingDir(path string) string {
430	if runtime.GOOS == "windows" {
431		cwd, err := os.Getwd()
432		if err != nil {
433			cwd = "C:"
434		}
435		path = strings.ReplaceAll(path, filepath.VolumeName(cwd), "")
436	}
437
438	return filepath.ToSlash(path)
439}