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fail2ban-ui/internal/fail2ban/connector_ssh.go

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package fail2ban
import (
"bufio"
"bytes"
"context"
"encoding/base64"
"errors"
"fmt"
"os"
"os/exec"
"path/filepath"
"sort"
"strconv"
"strings"
"sync"
"syscall"
"time"
"github.com/swissmakers/fail2ban-ui/internal/config"
)
const sshEnsureActionScript = `python3 - <<'PY'
import base64
import pathlib
import sys
try:
action_dir = pathlib.Path("/etc/fail2ban/action.d")
action_dir.mkdir(parents=True, exist_ok=True)
action_cfg = base64.b64decode("__PAYLOAD__").decode("utf-8")
(action_dir / "ui-custom-action.conf").write_text(action_cfg)
jail_file = pathlib.Path("/etc/fail2ban/jail.local")
if not jail_file.exists():
jail_file.write_text("[DEFAULT]\n")
lines = jail_file.read_text().splitlines()
already = any("Custom Fail2Ban action applied by fail2ban-ui" in line for line in lines)
if not already:
new_lines = []
inserted = False
for line in lines:
stripped = line.strip()
if stripped.startswith("action") and "ui-custom-action" not in stripped and not inserted:
if not stripped.startswith("#"):
new_lines.append("# " + line)
else:
new_lines.append(line)
new_lines.append("# Custom Fail2Ban action applied by fail2ban-ui")
new_lines.append("action = %(action_mwlg)s")
inserted = True
continue
new_lines.append(line)
if not inserted:
insert_at = None
for idx, value in enumerate(new_lines):
if value.strip().startswith("[DEFAULT]"):
insert_at = idx + 1
break
if insert_at is None:
new_lines.append("[DEFAULT]")
insert_at = len(new_lines)
new_lines.insert(insert_at, "# Custom Fail2Ban action applied by fail2ban-ui")
new_lines.insert(insert_at + 1, "action = %(action_mwlg)s")
jail_file.write_text("\n".join(new_lines) + "\n")
except Exception as e:
sys.stderr.write(f"Error: {e}\n")
sys.exit(1)
PY`
// SSHConnector connects to a remote Fail2ban instance over SSH.
type SSHConnector struct {
server config.Fail2banServer
fail2banPath string // Cache the fail2ban path
pathCached bool // Track if path is cached
pathMutex sync.RWMutex
}
// NewSSHConnector creates a new SSH connector.
func NewSSHConnector(server config.Fail2banServer) (Connector, error) {
if server.Host == "" {
return nil, fmt.Errorf("host is required for ssh connector")
}
if server.SSHUser == "" {
return nil, fmt.Errorf("sshUser is required for ssh connector")
}
conn := &SSHConnector{server: server}
// Use a timeout context to prevent hanging if SSH server isn't ready yet
// The action file can be ensured later when actually needed
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
if err := conn.ensureAction(ctx); err != nil {
// Log warning but don't fail connector creation - action can be ensured later
config.DebugLog("warning: failed to ensure remote fail2ban action for %s during startup (server may not be ready): %v", server.Name, err)
// Don't return error - allow connector to be created even if action setup fails
// The action will be ensured later when UpdateActionFiles is called
}
return conn, nil
}
func (sc *SSHConnector) ID() string {
return sc.server.ID
}
func (sc *SSHConnector) Server() config.Fail2banServer {
return sc.server
}
func (sc *SSHConnector) GetJailInfos(ctx context.Context) ([]JailInfo, error) {
jails, err := sc.getJails(ctx)
if err != nil {
return nil, err
}
// Use parallel execution for better performance
type jailResult struct {
jail JailInfo
err error
}
results := make(chan jailResult, len(jails))
var wg sync.WaitGroup
for _, jail := range jails {
wg.Add(1)
go func(j string) {
defer wg.Done()
ips, err := sc.GetBannedIPs(ctx, j)
if err != nil {
results <- jailResult{err: err}
return
}
results <- jailResult{
jail: JailInfo{
JailName: j,
TotalBanned: len(ips),
NewInLastHour: 0,
BannedIPs: ips,
Enabled: true,
},
}
}(jail)
}
go func() {
wg.Wait()
close(results)
}()
var infos []JailInfo
for result := range results {
if result.err != nil {
continue
}
infos = append(infos, result.jail)
}
sort.SliceStable(infos, func(i, j int) bool {
return infos[i].JailName < infos[j].JailName
})
return infos, nil
}
func (sc *SSHConnector) GetBannedIPs(ctx context.Context, jail string) ([]string, error) {
out, err := sc.runFail2banCommand(ctx, "status", jail)
if err != nil {
return nil, err
}
var bannedIPs []string
lines := strings.Split(out, "\n")
for _, line := range lines {
if strings.Contains(line, "IP list:") {
// Use SplitN to only split on the first colon, preserving IPv6 addresses
parts := strings.SplitN(line, ":", 2)
if len(parts) > 1 {
ips := strings.Fields(strings.TrimSpace(parts[1]))
bannedIPs = append(bannedIPs, ips...)
}
break
}
}
return bannedIPs, nil
}
func (sc *SSHConnector) UnbanIP(ctx context.Context, jail, ip string) error {
_, err := sc.runFail2banCommand(ctx, "set", jail, "unbanip", ip)
return err
}
func (sc *SSHConnector) BanIP(ctx context.Context, jail, ip string) error {
_, err := sc.runFail2banCommand(ctx, "set", jail, "banip", ip)
return err
}
func (sc *SSHConnector) Reload(ctx context.Context) error {
_, err := sc.runFail2banCommand(ctx, "reload")
return err
}
// RestartWithMode restarts (or reloads) the remote Fail2ban instance over SSH
// and returns a mode string describing what happened:
// - "restart": systemd service was restarted and health check passed
// - "reload": configuration was reloaded via fail2ban-client and pong check passed
func (sc *SSHConnector) Restart(ctx context.Context) error {
_, err := sc.RestartWithMode(ctx)
return err
}
// RestartWithMode implements the detailed restart logic for SSH connectors.
func (sc *SSHConnector) RestartWithMode(ctx context.Context) (string, error) {
// First, we try systemd restart on the remote host
out, err := sc.runRemoteCommand(ctx, []string{"systemctl", "restart", "fail2ban"})
if err == nil {
if err := sc.checkFail2banHealthyRemote(ctx); err != nil {
return "restart", fmt.Errorf("remote fail2ban health check after systemd restart failed: %w", err)
}
return "restart", nil
}
// Then, if systemd is not available, we fall back to fail2ban-client.
if sc.isSystemctlUnavailable(out, err) {
reloadOut, reloadErr := sc.runFail2banCommand(ctx, "reload")
if reloadErr != nil {
return "reload", fmt.Errorf("failed to reload fail2ban via fail2ban-client on remote: %w (output: %s)",
reloadErr, strings.TrimSpace(reloadOut))
}
if err := sc.checkFail2banHealthyRemote(ctx); err != nil {
return "reload", fmt.Errorf("remote fail2ban health check after reload failed: %w", err)
}
return "reload", nil
}
// systemctl exists but restart failed for some other reason, we surface it.
return "restart", fmt.Errorf("failed to restart fail2ban via systemd on remote: %w (output: %s)", err, out)
}
func (sc *SSHConnector) GetFilterConfig(ctx context.Context, filterName string) (string, string, error) {
// Validate filter name
filterName = strings.TrimSpace(filterName)
if filterName == "" {
return "", "", fmt.Errorf("filter name cannot be empty")
}
fail2banPath := sc.getFail2banPath(ctx)
// Try .local first, then fallback to .conf
localPath := filepath.Join(fail2banPath, "filter.d", filterName+".local")
confPath := filepath.Join(fail2banPath, "filter.d", filterName+".conf")
content, err := sc.readRemoteFile(ctx, localPath)
if err == nil {
return content, localPath, nil
}
// Fallback to .conf
content, err = sc.readRemoteFile(ctx, confPath)
if err != nil {
return "", "", fmt.Errorf("failed to read remote filter config (tried .local and .conf): %w", err)
}
return content, confPath, nil
}
func (sc *SSHConnector) SetFilterConfig(ctx context.Context, filterName, content string) error {
// Validate filter name
filterName = strings.TrimSpace(filterName)
if filterName == "" {
return fmt.Errorf("filter name cannot be empty")
}
fail2banPath := sc.getFail2banPath(ctx)
filterDPath := filepath.Join(fail2banPath, "filter.d")
// Ensure directory exists
_, err := sc.runRemoteCommand(ctx, []string{"mkdir", "-p", filterDPath})
if err != nil {
return fmt.Errorf("failed to create filter.d directory: %w", err)
}
// Ensure .local file exists (copy from .conf if needed)
if err := sc.ensureRemoteLocalFile(ctx, filterDPath, filterName); err != nil {
return fmt.Errorf("failed to ensure filter .local file: %w", err)
}
// Write to .local file
localPath := filepath.Join(filterDPath, filterName+".local")
if err := sc.writeRemoteFile(ctx, localPath, content); err != nil {
return fmt.Errorf("failed to write filter config: %w", err)
}
return nil
}
func (sc *SSHConnector) FetchBanEvents(ctx context.Context, limit int) ([]BanEvent, error) {
// Not available over SSH without copying logs; return empty slice.
return []BanEvent{}, nil
}
func (sc *SSHConnector) ensureAction(ctx context.Context) error {
callbackURL := config.GetCallbackURL()
settings := config.GetSettings()
actionConfig := config.BuildFail2banActionConfig(callbackURL, sc.server.ID, settings.CallbackSecret)
payload := base64.StdEncoding.EncodeToString([]byte(actionConfig))
script := strings.ReplaceAll(sshEnsureActionScript, "__PAYLOAD__", payload)
// Base64 encode the entire script to avoid shell escaping issues
scriptB64 := base64.StdEncoding.EncodeToString([]byte(script))
// Use sh -s to read commands from stdin, then pass the base64 string via stdin
// This is the most reliable way to pass data via SSH
args := sc.buildSSHArgs([]string{"sh", "-s"})
cmd := exec.CommandContext(ctx, "ssh", args...)
// Set process group to ensure all child processes (including SSH control master) are killed
// when the context is cancelled. This prevents zombie processes.
cmd.SysProcAttr = &syscall.SysProcAttr{
Setpgid: true,
Pgid: 0,
}
// Create a script that reads the base64 string from stdin and pipes it through base64 -d | bash
// We use a here-document to pass the base64 string
scriptContent := fmt.Sprintf("cat <<'ENDBASE64' | base64 -d | bash\n%s\nENDBASE64\n", scriptB64)
cmd.Stdin = strings.NewReader(scriptContent)
settingSnapshot := config.GetSettings()
if settingSnapshot.Debug {
config.DebugLog("SSH ensureAction command [%s]: ssh %s (with here-doc via stdin)", sc.server.Name, strings.Join(args, " "))
}
// Capture stdout and stderr
var stdout, stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
// Start the command
if err := cmd.Start(); err != nil {
return fmt.Errorf("failed to start ssh command: %w", err)
}
// Monitor context cancellation and command completion
done := make(chan error, 1)
go func() {
done <- cmd.Wait()
}()
var err error
select {
case err = <-done:
// Command completed normally
case <-ctx.Done():
// Context cancelled - kill the entire process group to prevent zombies
if cmd.Process != nil && cmd.Process.Pid > 0 {
// Kill the entire process group (negative PID kills the process group)
_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGTERM)
// Give it a moment to exit gracefully
time.Sleep(100 * time.Millisecond)
// Force kill if still running
_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
// Wait for the process to exit to prevent zombies
_, _ = cmd.Process.Wait()
}
return ctx.Err()
}
combinedOutput := append(stdout.Bytes(), stderr.Bytes()...)
output := strings.TrimSpace(string(combinedOutput))
if err != nil {
config.DebugLog("Failed to ensure action file for server %s: %v (output: %s)", sc.server.Name, err, output)
return fmt.Errorf("failed to ensure action file on remote server %s: %w (remote output: %s)", sc.server.Name, err, output)
}
if output != "" {
config.DebugLog("Successfully ensured action file for server %s (output: %s)", sc.server.Name, output)
} else {
config.DebugLog("Successfully ensured action file for server %s (no output)", sc.server.Name)
}
return nil
}
func (sc *SSHConnector) getJails(ctx context.Context) ([]string, error) {
out, err := sc.runFail2banCommand(ctx, "status")
if err != nil {
return nil, err
}
var jails []string
lines := strings.Split(out, "\n")
for _, line := range lines {
if strings.Contains(line, "Jail list:") {
// Use SplitN to only split on the first colon
parts := strings.SplitN(line, ":", 2)
if len(parts) > 1 {
raw := strings.TrimSpace(parts[1])
jails = strings.Split(raw, ",")
for i := range jails {
jails[i] = strings.TrimSpace(jails[i])
}
}
}
}
return jails, nil
}
func (sc *SSHConnector) runFail2banCommand(ctx context.Context, args ...string) (string, error) {
fail2banArgs := sc.buildFail2banArgs(args...)
cmdArgs := append([]string{"sudo", "fail2ban-client"}, fail2banArgs...)
return sc.runRemoteCommand(ctx, cmdArgs)
}
// isSystemctlUnavailable tries to detect “no systemd” situations on the remote host.
func (sc *SSHConnector) isSystemctlUnavailable(output string, err error) bool {
msg := strings.ToLower(output + " " + err.Error())
return strings.Contains(msg, "command not found") ||
strings.Contains(msg, "system has not been booted with systemd") ||
strings.Contains(msg, "failed to connect to bus")
}
// checkFail2banHealthyRemote runs `sudo fail2ban-client ping` on the remote host
// and expects a successful pong reply.
func (sc *SSHConnector) checkFail2banHealthyRemote(ctx context.Context) error {
out, err := sc.runFail2banCommand(ctx, "ping")
trimmed := strings.TrimSpace(out)
if err != nil {
return fmt.Errorf("remote fail2ban ping error: %w (output: %s)", err, trimmed)
}
// Typical output is e.g. "Server replied: pong" accept anything that
// contains "pong" case-insensitively.
if !strings.Contains(strings.ToLower(trimmed), "pong") {
return fmt.Errorf("unexpected remote fail2ban ping output: %s", trimmed)
}
return nil
}
func (sc *SSHConnector) buildFail2banArgs(args ...string) []string {
if sc.server.SocketPath == "" {
return args
}
base := []string{"-s", sc.server.SocketPath}
return append(base, args...)
}
func (sc *SSHConnector) runRemoteCommand(ctx context.Context, command []string) (string, error) {
args := sc.buildSSHArgs(command)
cmd := exec.Command("ssh", args...)
// Set process group to ensure all child processes (including SSH control master) are killed
// when we need to terminate. This prevents zombie processes.
cmd.SysProcAttr = &syscall.SysProcAttr{
Setpgid: true,
Pgid: 0,
}
settingSnapshot := config.GetSettings()
if settingSnapshot.Debug {
config.DebugLog("SSH command [%s]: ssh %s", sc.server.Name, strings.Join(args, " "))
}
// Capture stdout and stderr
var stdout, stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
// Start the command
if err := cmd.Start(); err != nil {
return "", fmt.Errorf("failed to start ssh command: %w", err)
}
// Monitor context cancellation and command completion
done := make(chan error, 1)
go func() {
done <- cmd.Wait()
}()
select {
case err := <-done:
// Command completed
combinedOutput := append(stdout.Bytes(), stderr.Bytes()...)
output := strings.TrimSpace(string(combinedOutput))
if err != nil {
if settingSnapshot.Debug {
config.DebugLog("SSH command error [%s]: %v | output: %s", sc.server.Name, err, output)
}
return output, fmt.Errorf("ssh command failed: %w (output: %s)", err, output)
}
if settingSnapshot.Debug {
config.DebugLog("SSH command output [%s]: %s", sc.server.Name, output)
}
return output, nil
case <-ctx.Done():
// Context cancelled - kill the entire process group to prevent zombies
if cmd.Process != nil && cmd.Process.Pid > 0 {
// Kill the entire process group (negative PID kills the process group)
_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGTERM)
// Give it a moment to exit gracefully
time.Sleep(100 * time.Millisecond)
// Force kill if still running
_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
// Wait for the process to exit to prevent zombies
_, _ = cmd.Process.Wait()
}
return "", ctx.Err()
}
}
func (sc *SSHConnector) buildSSHArgs(command []string) []string {
args := []string{"-o", "BatchMode=yes"}
// Add connection timeout to prevent hanging
args = append(args,
"-o", "ConnectTimeout=10",
"-o", "ServerAliveInterval=5",
"-o", "ServerAliveCountMax=2",
)
// In containerized environments, disable strict host key checking
if _, container := os.LookupEnv("CONTAINER"); container {
args = append(args,
"-o", "StrictHostKeyChecking=no",
"-o", "UserKnownHostsFile=/dev/null",
"-o", "LogLevel=ERROR",
)
}
// Enable SSH connection multiplexing for faster connections
// Use a control socket based on server ID for connection reuse
controlPath := fmt.Sprintf("/tmp/ssh_control_%s_%s", sc.server.ID, strings.ReplaceAll(sc.server.Host, ".", "_"))
args = append(args,
"-o", "ControlMaster=auto",
"-o", fmt.Sprintf("ControlPath=%s", controlPath),
"-o", "ControlPersist=300", // Keep connection alive for 5 minutes
)
if sc.server.SSHKeyPath != "" {
args = append(args, "-i", sc.server.SSHKeyPath)
}
if sc.server.Port > 0 {
args = append(args, "-p", strconv.Itoa(sc.server.Port))
}
target := sc.server.Host
if sc.server.SSHUser != "" {
target = fmt.Sprintf("%s@%s", sc.server.SSHUser, target)
}
args = append(args, target)
args = append(args, command...)
return args
}
// listRemoteFiles lists files in a remote directory matching a pattern.
// Uses find command which works reliably with FACL permissions.
func (sc *SSHConnector) listRemoteFiles(ctx context.Context, directory, pattern string) ([]string, error) {
// Use find command with absolute path - it will handle non-existent directories gracefully
// Find files ending with pattern, exclude hidden files, and ensure they're regular files
// Redirect stderr to /dev/null to suppress "No such file or directory" errors
// Pass the entire command as a single string to SSH (SSH executes through a shell by default)
cmd := fmt.Sprintf(`find "%s" -maxdepth 1 -type f -name "*%s" ! -name ".*" 2>/dev/null | sort`, directory, pattern)
out, err := sc.runRemoteCommand(ctx, []string{cmd})
if err != nil {
// If find fails (e.g., directory doesn't exist or permission denied), return empty list (not an error)
config.DebugLog("Find command failed for %s on server %s: %v, returning empty list", directory, sc.server.Name, err)
return []string{}, nil
}
// If find succeeds but directory doesn't exist, it will return empty output
// This is fine - we'll just return an empty list
var files []string
for _, line := range strings.Split(out, "\n") {
line = strings.TrimSpace(line)
// Skip empty lines, current directory marker, and relative paths
if line == "" || line == "." || strings.HasPrefix(line, "./") {
continue
}
// Only process files that match our pattern (end with .local or .conf)
// and are actually in the target directory
if strings.HasSuffix(line, pattern) {
// If it's already an absolute path starting with our directory, use it directly
if strings.HasPrefix(line, directory) {
files = append(files, line)
} else if !strings.HasPrefix(line, "/") {
// Relative path, join with directory
fullPath := filepath.Join(directory, line)
files = append(files, fullPath)
}
// Skip any other absolute paths that don't start with our directory
}
}
return files, nil
}
// readRemoteFile reads the content of a remote file via SSH.
func (sc *SSHConnector) readRemoteFile(ctx context.Context, filePath string) (string, error) {
content, err := sc.runRemoteCommand(ctx, []string{"cat", filePath})
if err != nil {
return "", fmt.Errorf("failed to read remote file %s: %w", filePath, err)
}
return content, nil
}
// writeRemoteFile writes content to a remote file via SSH using a heredoc.
func (sc *SSHConnector) writeRemoteFile(ctx context.Context, filePath, content string) error {
// Escape single quotes for safe use in a single-quoted heredoc
escaped := strings.ReplaceAll(content, "'", "'\"'\"'")
// Use heredoc to write file content
script := fmt.Sprintf(`cat > %s <<'REMOTEEOF'
%s
REMOTEEOF
`, filePath, escaped)
_, err := sc.runRemoteCommand(ctx, []string{script})
if err != nil {
return fmt.Errorf("failed to write remote file %s: %w", filePath, err)
}
return nil
}
// ensureRemoteLocalFile ensures that a .local file exists on the remote system.
// If .local doesn't exist, it copies from .conf if available, or creates an empty file.
func (sc *SSHConnector) ensureRemoteLocalFile(ctx context.Context, basePath, name string) error {
localPath := fmt.Sprintf("%s/%s.local", basePath, name)
confPath := fmt.Sprintf("%s/%s.conf", basePath, name)
// Check if .local exists, if not, copy from .conf or create empty file
script := fmt.Sprintf(`
if [ ! -f "%s" ]; then
if [ -f "%s" ]; then
cp "%s" "%s"
else
# Create empty .local file if neither exists
touch "%s"
fi
fi
`, localPath, confPath, confPath, localPath, localPath)
_, err := sc.runRemoteCommand(ctx, []string{script})
if err != nil {
return fmt.Errorf("failed to ensure remote .local file %s: %w", localPath, err)
}
return nil
}
// getFail2banPath detects the fail2ban configuration path on the remote system.
// Returns /config/fail2ban for linuxserver images, or /etc/fail2ban for standard installations.
// Uses caching to avoid repeated SSH calls.
func (sc *SSHConnector) getFail2banPath(ctx context.Context) string {
// Try to read from cache first
sc.pathMutex.RLock()
if sc.pathCached {
path := sc.fail2banPath
sc.pathMutex.RUnlock()
return path
}
sc.pathMutex.RUnlock()
// Acquire write lock to update cache
sc.pathMutex.Lock()
defer sc.pathMutex.Unlock()
// Double-check after acquiring write lock (another goroutine might have cached it)
if sc.pathCached {
return sc.fail2banPath
}
// Actually fetch the path
checkCmd := `test -d "/config/fail2ban" && echo "/config/fail2ban" || (test -d "/etc/fail2ban" && echo "/etc/fail2ban" || echo "/etc/fail2ban")`
out, err := sc.runRemoteCommand(ctx, []string{checkCmd})
if err == nil {
path := strings.TrimSpace(out)
if path != "" {
sc.fail2banPath = path
sc.pathCached = true
return path
}
}
// Default to /etc/fail2ban
sc.fail2banPath = "/etc/fail2ban"
sc.pathCached = true
return sc.fail2banPath
}
// GetAllJails implements Connector.
// Discovers all jails from filesystem (mirrors local connector behavior).
// Optimized to read all files in a single SSH command instead of individual reads.
func (sc *SSHConnector) GetAllJails(ctx context.Context) ([]JailInfo, error) {
fail2banPath := sc.getFail2banPath(ctx)
jailDPath := filepath.Join(fail2banPath, "jail.d")
var allJails []JailInfo
processedFiles := make(map[string]bool) // Track base names to avoid duplicates
processedJails := make(map[string]bool) // Track jail names to avoid duplicates
// Use a Python script to read all files in a single SSH command
// This is much more efficient than reading each file individually
readAllScript := fmt.Sprintf(`python3 << 'PYEOF'
import os
import sys
import json
jail_d_path = %q
files_data = {}
# Read all .local files first
local_files = []
if os.path.isdir(jail_d_path):
for filename in os.listdir(jail_d_path):
if filename.endswith('.local') and not filename.startswith('.'):
local_files.append(os.path.join(jail_d_path, filename))
# Process .local files
for filepath in sorted(local_files):
try:
filename = os.path.basename(filepath)
basename = filename[:-6] # Remove .local
if basename and basename not in files_data:
with open(filepath, 'r', encoding='utf-8', errors='ignore') as f:
content = f.read()
files_data[basename] = {'path': filepath, 'content': content, 'type': 'local'}
except Exception as e:
sys.stderr.write(f"Error reading {filepath}: {e}\n")
# Read all .conf files that don't have corresponding .local files
conf_files = []
if os.path.isdir(jail_d_path):
for filename in os.listdir(jail_d_path):
if filename.endswith('.conf') and not filename.startswith('.'):
basename = filename[:-5] # Remove .conf
if basename not in files_data:
conf_files.append(os.path.join(jail_d_path, filename))
# Process .conf files
for filepath in sorted(conf_files):
try:
filename = os.path.basename(filepath)
basename = filename[:-5] # Remove .conf
if basename:
with open(filepath, 'r', encoding='utf-8', errors='ignore') as f:
content = f.read()
files_data[basename] = {'path': filepath, 'content': content, 'type': 'conf'}
except Exception as e:
sys.stderr.write(f"Error reading {filepath}: {e}\n")
# Output files with a delimiter: FILE_START:path:type\ncontent\nFILE_END\n
for basename, data in sorted(files_data.items()):
print(f"FILE_START:{data['path']}:{data['type']}")
print(data['content'], end='')
print("FILE_END")
PYEOF`, jailDPath)
output, err := sc.runRemoteCommand(ctx, []string{readAllScript})
if err != nil {
// Fallback to individual file reads if the script fails
config.DebugLog("Failed to read all jail files at once on server %s, falling back to individual reads: %v", sc.server.Name, err)
return sc.getAllJailsFallback(ctx, jailDPath)
}
// Parse the output: files are separated by FILE_START:path:type\ncontent\nFILE_END\n
var currentFile string
var currentContent strings.Builder
var currentType string
inFile := false
lines := strings.Split(output, "\n")
for _, line := range lines {
if strings.HasPrefix(line, "FILE_START:") {
// Save previous file if any
if inFile && currentFile != "" {
content := currentContent.String()
jails := parseJailConfigContent(content)
for _, jail := range jails {
if jail.JailName != "" && jail.JailName != "DEFAULT" && !processedJails[jail.JailName] {
allJails = append(allJails, jail)
processedJails[jail.JailName] = true
}
}
}
// Parse new file header: FILE_START:path:type
parts := strings.SplitN(line, ":", 3)
if len(parts) == 3 {
currentFile = parts[1]
currentType = parts[2]
currentContent.Reset()
inFile = true
filename := filepath.Base(currentFile)
var baseName string
if currentType == "local" {
baseName = strings.TrimSuffix(filename, ".local")
} else {
baseName = strings.TrimSuffix(filename, ".conf")
}
if baseName != "" {
processedFiles[baseName] = true
}
}
} else if line == "FILE_END" {
// End of file, process it
if inFile && currentFile != "" {
content := currentContent.String()
jails := parseJailConfigContent(content)
for _, jail := range jails {
if jail.JailName != "" && jail.JailName != "DEFAULT" && !processedJails[jail.JailName] {
allJails = append(allJails, jail)
processedJails[jail.JailName] = true
}
}
}
inFile = false
currentFile = ""
currentContent.Reset()
} else if inFile {
// Content line
if currentContent.Len() > 0 {
currentContent.WriteString("\n")
}
currentContent.WriteString(line)
}
}
// Handle last file if output doesn't end with FILE_END
if inFile && currentFile != "" {
content := currentContent.String()
jails := parseJailConfigContent(content)
for _, jail := range jails {
if jail.JailName != "" && jail.JailName != "DEFAULT" && !processedJails[jail.JailName] {
allJails = append(allJails, jail)
processedJails[jail.JailName] = true
}
}
}
return allJails, nil
}
// getAllJailsFallback is the fallback method that reads files individually.
// Used when the optimized batch read fails.
func (sc *SSHConnector) getAllJailsFallback(ctx context.Context, jailDPath string) ([]JailInfo, error) {
var allJails []JailInfo
processedFiles := make(map[string]bool)
processedJails := make(map[string]bool)
// List all .local files first
localFiles, err := sc.listRemoteFiles(ctx, jailDPath, ".local")
if err != nil {
config.DebugLog("Failed to list .local files in jail.d on server %s: %v", sc.server.Name, err)
} else {
for _, filePath := range localFiles {
filename := filepath.Base(filePath)
baseName := strings.TrimSuffix(filename, ".local")
if baseName == "" || processedFiles[baseName] {
continue
}
processedFiles[baseName] = true
content, err := sc.readRemoteFile(ctx, filePath)
if err != nil {
config.DebugLog("Failed to read jail file %s on server %s: %v", filePath, sc.server.Name, err)
continue
}
jails := parseJailConfigContent(content)
for _, jail := range jails {
if jail.JailName != "" && jail.JailName != "DEFAULT" && !processedJails[jail.JailName] {
allJails = append(allJails, jail)
processedJails[jail.JailName] = true
}
}
}
}
// List all .conf files that don't have corresponding .local files
confFiles, err := sc.listRemoteFiles(ctx, jailDPath, ".conf")
if err != nil {
config.DebugLog("Failed to list .conf files in jail.d on server %s: %v", sc.server.Name, err)
} else {
for _, filePath := range confFiles {
filename := filepath.Base(filePath)
baseName := strings.TrimSuffix(filename, ".conf")
if baseName == "" || processedFiles[baseName] {
continue
}
processedFiles[baseName] = true
content, err := sc.readRemoteFile(ctx, filePath)
if err != nil {
config.DebugLog("Failed to read jail file %s on server %s: %v", filePath, sc.server.Name, err)
continue
}
jails := parseJailConfigContent(content)
for _, jail := range jails {
if jail.JailName != "" && jail.JailName != "DEFAULT" && !processedJails[jail.JailName] {
allJails = append(allJails, jail)
processedJails[jail.JailName] = true
}
}
}
}
return allJails, nil
}
// UpdateJailEnabledStates implements Connector.
func (sc *SSHConnector) UpdateJailEnabledStates(ctx context.Context, updates map[string]bool) error {
fail2banPath := sc.getFail2banPath(ctx)
jailDPath := filepath.Join(fail2banPath, "jail.d")
// Update each jail in its own .local file
for jailName, enabled := range updates {
// Validate jail name - skip empty or invalid names
jailName = strings.TrimSpace(jailName)
if jailName == "" {
config.DebugLog("Skipping empty jail name in updates map")
continue
}
localPath := filepath.Join(jailDPath, jailName+".local")
confPath := filepath.Join(jailDPath, jailName+".conf")
// Combined script: ensure .local file exists AND read it in one SSH call
// This reduces SSH round-trips from 2 to 1 per jail
combinedScript := fmt.Sprintf(`
if [ ! -f "%s" ]; then
if [ -f "%s" ]; then
cp "%s" "%s"
else
echo "[%s]" > "%s"
fi
fi
cat "%s"
`, localPath, confPath, confPath, localPath, jailName, localPath, localPath)
content, err := sc.runRemoteCommand(ctx, []string{combinedScript})
if err != nil {
return fmt.Errorf("failed to ensure and read .local file for jail %s: %w", jailName, err)
}
// Update enabled state in existing file
lines := strings.Split(content, "\n")
var outputLines []string
var foundEnabled bool
var currentJail string
for _, line := range lines {
trimmed := strings.TrimSpace(line)
if strings.HasPrefix(trimmed, "[") && strings.HasSuffix(trimmed, "]") {
currentJail = strings.Trim(trimmed, "[]")
outputLines = append(outputLines, line)
} else if strings.HasPrefix(strings.ToLower(trimmed), "enabled") {
if currentJail == jailName {
outputLines = append(outputLines, fmt.Sprintf("enabled = %t", enabled))
foundEnabled = true
} else {
outputLines = append(outputLines, line)
}
} else {
outputLines = append(outputLines, line)
}
}
// If enabled line not found, add it after the jail section header
if !foundEnabled {
var newLines []string
for i, line := range outputLines {
newLines = append(newLines, line)
if strings.TrimSpace(line) == fmt.Sprintf("[%s]", jailName) {
newLines = append(newLines, fmt.Sprintf("enabled = %t", enabled))
if i+1 < len(outputLines) {
newLines = append(newLines, outputLines[i+1:]...)
}
break
}
}
if len(newLines) > len(outputLines) {
outputLines = newLines
} else {
outputLines = append(outputLines, fmt.Sprintf("enabled = %t", enabled))
}
}
// Write updated content to .local file
newContent := strings.Join(outputLines, "\n")
cmd := fmt.Sprintf("cat <<'EOF' | tee %s >/dev/null\n%s\nEOF", localPath, newContent)
if _, err := sc.runRemoteCommand(ctx, []string{cmd}); err != nil {
return fmt.Errorf("failed to write jail .local file %s: %w", localPath, err)
}
}
return nil
}
// GetFilters implements Connector.
// Discovers all filters from filesystem (mirrors local connector behavior).
func (sc *SSHConnector) GetFilters(ctx context.Context) ([]string, error) {
fail2banPath := sc.getFail2banPath(ctx)
filterDPath := filepath.Join(fail2banPath, "filter.d")
filterMap := make(map[string]bool) // Track unique filter names
processedFiles := make(map[string]bool) // Track base names to avoid duplicates
// Helper function to check if file should be excluded
shouldExclude := func(filename string) bool {
if strings.HasSuffix(filename, ".bak") ||
strings.HasSuffix(filename, "~") ||
strings.HasSuffix(filename, ".old") ||
strings.HasSuffix(filename, ".rpmnew") ||
strings.HasSuffix(filename, ".rpmsave") ||
strings.Contains(filename, "README") {
return true
}
return false
}
// First pass: collect all .local files (these take precedence)
localFiles, err := sc.listRemoteFiles(ctx, filterDPath, ".local")
if err != nil {
config.DebugLog("Failed to list .local filters on server %s: %v", sc.server.Name, err)
} else {
for _, filePath := range localFiles {
filename := filepath.Base(filePath)
if shouldExclude(filename) {
continue
}
baseName := strings.TrimSuffix(filename, ".local")
if baseName == "" || processedFiles[baseName] {
continue
}
processedFiles[baseName] = true
filterMap[baseName] = true
}
}
// Second pass: collect .conf files that don't have corresponding .local files
confFiles, err := sc.listRemoteFiles(ctx, filterDPath, ".conf")
if err != nil {
config.DebugLog("Failed to list .conf filters on server %s: %v", sc.server.Name, err)
} else {
for _, filePath := range confFiles {
filename := filepath.Base(filePath)
if shouldExclude(filename) {
continue
}
baseName := strings.TrimSuffix(filename, ".conf")
if baseName == "" || processedFiles[baseName] {
continue
}
processedFiles[baseName] = true
filterMap[baseName] = true
}
}
// Convert map to sorted slice
var filters []string
for name := range filterMap {
filters = append(filters, name)
}
sort.Strings(filters)
return filters, nil
}
// resolveFilterIncludesRemote resolves filter includes by reading included files from remote server
// This is similar to resolveFilterIncludes but reads files via SSH instead of local filesystem
func (sc *SSHConnector) resolveFilterIncludesRemote(ctx context.Context, filterContent string, filterDPath string, currentFilterName string) (string, error) {
lines := strings.Split(filterContent, "\n")
var beforeFiles []string
var afterFiles []string
var inIncludesSection bool
var mainContent strings.Builder
// Parse the filter content to find [INCLUDES] section
for i, line := range lines {
trimmed := strings.TrimSpace(line)
// Check for [INCLUDES] section
if strings.HasPrefix(trimmed, "[INCLUDES]") {
inIncludesSection = true
continue
}
// Check for end of [INCLUDES] section (next section starts)
if inIncludesSection && strings.HasPrefix(trimmed, "[") {
inIncludesSection = false
}
// Parse before and after directives
if inIncludesSection {
if strings.HasPrefix(strings.ToLower(trimmed), "before") {
parts := strings.SplitN(trimmed, "=", 2)
if len(parts) == 2 {
file := strings.TrimSpace(parts[1])
if file != "" {
beforeFiles = append(beforeFiles, file)
}
}
continue
}
if strings.HasPrefix(strings.ToLower(trimmed), "after") {
parts := strings.SplitN(trimmed, "=", 2)
if len(parts) == 2 {
file := strings.TrimSpace(parts[1])
if file != "" {
afterFiles = append(afterFiles, file)
}
}
continue
}
}
// Collect main content (everything except [INCLUDES] section)
if !inIncludesSection {
if i > 0 {
mainContent.WriteString("\n")
}
mainContent.WriteString(line)
}
}
// Extract variables from main filter content first
mainContentStr := mainContent.String()
mainVariables := extractVariablesFromContent(mainContentStr)
// Build combined content: before files + main filter + after files
var combined strings.Builder
// Helper function to read remote file
readRemoteFilterFile := func(baseName string) (string, error) {
localPath := filepath.Join(filterDPath, baseName+".local")
confPath := filepath.Join(filterDPath, baseName+".conf")
// Try .local first
content, err := sc.readRemoteFile(ctx, localPath)
if err == nil {
config.DebugLog("Loading included filter file from .local: %s", localPath)
return content, nil
}
// Fallback to .conf
content, err = sc.readRemoteFile(ctx, confPath)
if err == nil {
config.DebugLog("Loading included filter file from .conf: %s", confPath)
return content, nil
}
return "", fmt.Errorf("could not load included filter file '%s' or '%s'", localPath, confPath)
}
// Load and append before files, removing duplicates that exist in main filter
for _, fileName := range beforeFiles {
// Remove any existing extension to get base name
baseName := fileName
if strings.HasSuffix(baseName, ".local") {
baseName = strings.TrimSuffix(baseName, ".local")
} else if strings.HasSuffix(baseName, ".conf") {
baseName = strings.TrimSuffix(baseName, ".conf")
}
// Skip if this is the same filter (avoid self-inclusion)
if baseName == currentFilterName {
config.DebugLog("Skipping self-inclusion of filter '%s' in before files", baseName)
continue
}
contentStr, err := readRemoteFilterFile(baseName)
if err != nil {
config.DebugLog("Warning: %v", err)
continue // Skip if file doesn't exist
}
// Remove variables from included file that are defined in main filter (main filter takes precedence)
cleanedContent := removeDuplicateVariables(contentStr, mainVariables)
combined.WriteString(cleanedContent)
if !strings.HasSuffix(cleanedContent, "\n") {
combined.WriteString("\n")
}
combined.WriteString("\n")
}
// Append main filter content (unchanged - this is what the user is editing)
combined.WriteString(mainContentStr)
if !strings.HasSuffix(mainContentStr, "\n") {
combined.WriteString("\n")
}
// Load and append after files, also removing duplicates that exist in main filter
for _, fileName := range afterFiles {
// Remove any existing extension to get base name
baseName := fileName
if strings.HasSuffix(baseName, ".local") {
baseName = strings.TrimSuffix(baseName, ".local")
} else if strings.HasSuffix(baseName, ".conf") {
baseName = strings.TrimSuffix(baseName, ".conf")
}
// Note: Self-inclusion in "after" directive is intentional in fail2ban
// (e.g., after = apache-common.local is standard pattern for .local files)
// So we always load it, even if it's the same filter name
contentStr, err := readRemoteFilterFile(baseName)
if err != nil {
config.DebugLog("Warning: %v", err)
continue // Skip if file doesn't exist
}
// Remove variables from included file that are defined in main filter (main filter takes precedence)
cleanedContent := removeDuplicateVariables(contentStr, mainVariables)
combined.WriteString("\n")
combined.WriteString(cleanedContent)
if !strings.HasSuffix(cleanedContent, "\n") {
combined.WriteString("\n")
}
}
return combined.String(), nil
}
// TestFilter implements Connector.
func (sc *SSHConnector) TestFilter(ctx context.Context, filterName string, logLines []string, filterContent string) (string, string, error) {
cleaned := normalizeLogLines(logLines)
if len(cleaned) == 0 {
return "No log lines provided.\n", "", nil
}
// Sanitize filter name to prevent path traversal
filterName = strings.TrimSpace(filterName)
if filterName == "" {
return "", "", fmt.Errorf("filter name cannot be empty")
}
// Remove any path components
filterName = strings.ReplaceAll(filterName, "/", "")
filterName = strings.ReplaceAll(filterName, "..", "")
// Get the fail2ban path dynamically
fail2banPath := sc.getFail2banPath(ctx)
// Try .local first, then fallback to .conf
localPath := filepath.Join(fail2banPath, "filter.d", filterName+".local")
confPath := filepath.Join(fail2banPath, "filter.d", filterName+".conf")
const heredocMarker = "F2B_FILTER_TEST_LOG"
const filterContentMarker = "F2B_FILTER_CONTENT"
logContent := strings.Join(cleaned, "\n")
var script string
if filterContent != "" {
// Resolve filter includes locally (same approach as local connector)
// This avoids complex Python scripts and heredoc issues
filterDPath := filepath.Join(fail2banPath, "filter.d")
// First, we need to create a remote-aware version of resolveFilterIncludes
// that can read included files from the remote server
resolvedContent, err := sc.resolveFilterIncludesRemote(ctx, filterContent, filterDPath, filterName)
if err != nil {
config.DebugLog("Warning: failed to resolve filter includes remotely, using original content: %v", err)
resolvedContent = filterContent
}
// Ensure it ends with a newline for proper parsing
if !strings.HasSuffix(resolvedContent, "\n") {
resolvedContent += "\n"
}
// Base64 encode resolved filter content to avoid any heredoc/escaping issues
resolvedContentB64 := base64.StdEncoding.EncodeToString([]byte(resolvedContent))
// Simple script: just write the resolved content to temp file and test
script = fmt.Sprintf(`
set -e
TMPFILTER=$(mktemp /tmp/fail2ban-filter-XXXXXX.conf)
trap 'rm -f "$TMPFILTER"' EXIT
# Write resolved filter content to temp file using base64 decode
echo '%[1]s' | base64 -d > "$TMPFILTER"
FILTER_PATH="$TMPFILTER"
echo "FILTER_PATH:$FILTER_PATH"
TMPFILE=$(mktemp /tmp/fail2ban-test-XXXXXX.log)
trap 'rm -f "$TMPFILE" "$TMPFILTER"' EXIT
cat <<'%[2]s' > "$TMPFILE"
%[3]s
%[2]s
fail2ban-regex "$TMPFILE" "$FILTER_PATH" || true
`, resolvedContentB64, heredocMarker, logContent)
} else {
// Use existing filter file
script = fmt.Sprintf(`
set -e
LOCAL_PATH=%[1]q
CONF_PATH=%[2]q
FILTER_PATH=""
if [ -f "$LOCAL_PATH" ]; then
FILTER_PATH="$LOCAL_PATH"
elif [ -f "$CONF_PATH" ]; then
FILTER_PATH="$CONF_PATH"
else
echo "Filter not found: checked both $LOCAL_PATH and $CONF_PATH" >&2
exit 1
fi
echo "FILTER_PATH:$FILTER_PATH"
TMPFILE=$(mktemp /tmp/fail2ban-test-XXXXXX.log)
trap 'rm -f "$TMPFILE"' EXIT
cat <<'%[3]s' > "$TMPFILE"
%[4]s
%[3]s
fail2ban-regex "$TMPFILE" "$FILTER_PATH" || true
`, localPath, confPath, heredocMarker, logContent)
}
out, err := sc.runRemoteCommand(ctx, []string{script})
if err != nil {
return "", "", err
}
// Extract filter path from output (it's on the first line with FILTER_PATH: prefix)
lines := strings.Split(out, "\n")
var filterPath string
var outputLines []string
foundPathMarker := false
for _, line := range lines {
if strings.HasPrefix(line, "FILTER_PATH:") {
filterPath = strings.TrimPrefix(line, "FILTER_PATH:")
filterPath = strings.TrimSpace(filterPath)
foundPathMarker = true
// Skip this line from the output
continue
}
outputLines = append(outputLines, line)
}
// If we didn't find FILTER_PATH marker, try to determine it
if !foundPathMarker || filterPath == "" {
// Check which file exists remotely
localOut, localErr := sc.runRemoteCommand(ctx, []string{"test", "-f", localPath, "&&", "echo", localPath, "||", "echo", ""})
if localErr == nil && strings.TrimSpace(localOut) != "" {
filterPath = strings.TrimSpace(localOut)
} else {
filterPath = confPath
}
}
output := strings.Join(outputLines, "\n")
return output, filterPath, nil
}
// GetJailConfig implements Connector.
func (sc *SSHConnector) GetJailConfig(ctx context.Context, jail string) (string, string, error) {
// Validate jail name
jail = strings.TrimSpace(jail)
if jail == "" {
return "", "", fmt.Errorf("jail name cannot be empty")
}
fail2banPath := sc.getFail2banPath(ctx)
// Try .local first, then fallback to .conf
localPath := filepath.Join(fail2banPath, "jail.d", jail+".local")
confPath := filepath.Join(fail2banPath, "jail.d", jail+".conf")
content, err := sc.readRemoteFile(ctx, localPath)
if err == nil {
return content, localPath, nil
}
// Fallback to .conf
content, err = sc.readRemoteFile(ctx, confPath)
if err != nil {
// If neither exists, return empty jail section with .local path (will be created on save)
return fmt.Sprintf("[%s]\n", jail), localPath, nil
}
return content, confPath, nil
}
// SetJailConfig implements Connector.
func (sc *SSHConnector) SetJailConfig(ctx context.Context, jail, content string) error {
// Validate jail name
jail = strings.TrimSpace(jail)
if jail == "" {
return fmt.Errorf("jail name cannot be empty")
}
fail2banPath := sc.getFail2banPath(ctx)
jailDPath := filepath.Join(fail2banPath, "jail.d")
// Ensure jail.d directory exists
_, err := sc.runRemoteCommand(ctx, []string{"mkdir", "-p", jailDPath})
if err != nil {
return fmt.Errorf("failed to create jail.d directory: %w", err)
}
// Ensure .local file exists (copy from .conf if needed)
if err := sc.ensureRemoteLocalFile(ctx, jailDPath, jail); err != nil {
return fmt.Errorf("failed to ensure .local file for jail %s: %w", jail, err)
}
// Write to .local file
localPath := filepath.Join(jailDPath, jail+".local")
if err := sc.writeRemoteFile(ctx, localPath, content); err != nil {
return fmt.Errorf("failed to write jail config: %w", err)
}
return nil
}
// TestLogpath implements Connector.
func (sc *SSHConnector) TestLogpath(ctx context.Context, logpath string) ([]string, error) {
if logpath == "" {
return []string{}, nil
}
logpath = strings.TrimSpace(logpath)
hasWildcard := strings.ContainsAny(logpath, "*?[")
var script string
if hasWildcard {
// Use find with glob pattern
script = fmt.Sprintf(`
set -e
LOGPATH=%q
# Use find for glob patterns
find $(dirname "$LOGPATH") -maxdepth 1 -path "$LOGPATH" -type f 2>/dev/null | sort
`, logpath)
} else {
// Check if it's a directory or file
script = fmt.Sprintf(`
set -e
LOGPATH=%q
if [ -d "$LOGPATH" ]; then
find "$LOGPATH" -maxdepth 1 -type f 2>/dev/null | sort
elif [ -f "$LOGPATH" ]; then
echo "$LOGPATH"
fi
`, logpath)
}
out, err := sc.runRemoteCommand(ctx, []string{script})
if err != nil {
return []string{}, nil // Return empty on error
}
var matches []string
for _, line := range strings.Split(out, "\n") {
line = strings.TrimSpace(line)
if line != "" {
matches = append(matches, line)
}
}
return matches, nil
}
// TestLogpathWithResolution implements Connector.
// Resolves variables on remote system, then tests the resolved path.
func (sc *SSHConnector) TestLogpathWithResolution(ctx context.Context, logpath string) (originalPath, resolvedPath string, files []string, err error) {
originalPath = strings.TrimSpace(logpath)
if originalPath == "" {
return originalPath, "", []string{}, nil
}
// Create Python script to resolve variables on remote system
resolveScript := fmt.Sprintf(`python3 - <<'PYEOF'
import os
import re
import glob
from pathlib import Path
def extract_variables(s):
"""Extract all variable names from a string."""
pattern = r'%%\(([^)]+)\)s'
return re.findall(pattern, s)
def find_variable_definition(var_name, fail2ban_path="/etc/fail2ban"):
"""Search for variable definition in all .conf files."""
var_name_lower = var_name.lower()
for conf_file in Path(fail2ban_path).rglob("*.conf"):
try:
with open(conf_file, 'r') as f:
current_var = None
current_value = []
in_multiline = False
for line in f:
original_line = line
line = line.strip()
if not in_multiline:
if '=' in line and not line.startswith('#'):
parts = line.split('=', 1)
key = parts[0].strip()
value = parts[1].strip()
if key.lower() == var_name_lower:
current_var = key
current_value = [value]
in_multiline = True
continue
else:
# Check if continuation or new variable/section
if line.startswith('[') or (not line.startswith(' ') and '=' in line and not line.startswith('\t')):
# End of multi-line
return ' '.join(current_value)
else:
# Continuation
current_value.append(line)
if in_multiline and current_var:
return ' '.join(current_value)
except:
continue
return None
def resolve_variable_recursive(var_name, visited=None):
"""Resolve variable recursively."""
if visited is None:
visited = set()
if var_name in visited:
raise ValueError(f"Circular reference detected for variable '{var_name}'")
visited.add(var_name)
try:
value = find_variable_definition(var_name)
if value is None:
raise ValueError(f"Variable '{var_name}' not found")
# Check for nested variables
nested_vars = extract_variables(value)
if not nested_vars:
return value
# Resolve nested variables
resolved = value
for nested_var in nested_vars:
nested_value = resolve_variable_recursive(nested_var, visited.copy())
pattern = f'%%({re.escape(nested_var)})s'
resolved = re.sub(pattern, nested_value, resolved)
return resolved
finally:
visited.discard(var_name)
def resolve_logpath(logpath):
"""Resolve all variables in logpath."""
variables = extract_variables(logpath)
if not variables:
return logpath
resolved = logpath
for var_name in variables:
var_value = resolve_variable_recursive(var_name)
pattern = f'%%({re.escape(var_name)})s'
resolved = re.sub(pattern, var_value, resolved)
return resolved
# Main
logpath = %q
try:
resolved = resolve_logpath(logpath)
print(f"RESOLVED:{resolved}")
except Exception as e:
print(f"ERROR:{str(e)}")
exit(1)
PYEOF
`, originalPath)
// Run resolution script
resolveOut, err := sc.runRemoteCommand(ctx, []string{resolveScript})
if err != nil {
return originalPath, "", nil, fmt.Errorf("failed to resolve variables: %w", err)
}
resolveOut = strings.TrimSpace(resolveOut)
if strings.HasPrefix(resolveOut, "ERROR:") {
return originalPath, "", nil, errors.New(strings.TrimPrefix(resolveOut, "ERROR:"))
}
if strings.HasPrefix(resolveOut, "RESOLVED:") {
resolvedPath = strings.TrimPrefix(resolveOut, "RESOLVED:")
} else {
// Fallback: use original if resolution failed
resolvedPath = originalPath
}
// Test the resolved path
files, err = sc.TestLogpath(ctx, resolvedPath)
if err != nil {
return originalPath, resolvedPath, nil, fmt.Errorf("failed to test logpath: %w", err)
}
return originalPath, resolvedPath, files, nil
}
// UpdateDefaultSettings implements Connector.
func (sc *SSHConnector) UpdateDefaultSettings(ctx context.Context, settings config.AppSettings) error {
jailLocalPath := "/etc/fail2ban/jail.local"
// Read existing file if it exists
existingContent, err := sc.runRemoteCommand(ctx, []string{"cat", jailLocalPath})
if err != nil {
// File doesn't exist, create new one
existingContent = ""
}
// Remove commented lines (lines starting with #) using sed
if existingContent != "" {
// Use sed to remove lines starting with # (but preserve empty lines)
removeCommentsCmd := fmt.Sprintf("sed '/^[[:space:]]*#/d' %s", jailLocalPath)
uncommentedContent, err := sc.runRemoteCommand(ctx, []string{removeCommentsCmd})
if err == nil {
existingContent = uncommentedContent
}
}
// Convert IgnoreIPs array to space-separated string
ignoreIPStr := strings.Join(settings.IgnoreIPs, " ")
if ignoreIPStr == "" {
ignoreIPStr = "127.0.0.1/8 ::1"
}
// Set default banaction values if not set
banactionVal := settings.Banaction
if banactionVal == "" {
banactionVal = "nftables-multiport"
}
banactionAllportsVal := settings.BanactionAllports
if banactionAllportsVal == "" {
banactionAllportsVal = "nftables-allports"
}
// Define the keys we want to update
keysToUpdate := map[string]string{
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"enabled": fmt.Sprintf("enabled = %t", settings.DefaultJailEnable),
"bantime.increment": fmt.Sprintf("bantime.increment = %t", settings.BantimeIncrement),
"ignoreip": fmt.Sprintf("ignoreip = %s", ignoreIPStr),
"bantime": fmt.Sprintf("bantime = %s", settings.Bantime),
"findtime": fmt.Sprintf("findtime = %s", settings.Findtime),
"maxretry": fmt.Sprintf("maxretry = %d", settings.Maxretry),
"banaction": fmt.Sprintf("banaction = %s", banactionVal),
"banaction_allports": fmt.Sprintf("banaction_allports = %s", banactionAllportsVal),
}
// Parse existing content and update only specific keys in DEFAULT section
if existingContent == "" {
// File doesn't exist, create new one with DEFAULT section
defaultLines := []string{"[DEFAULT]"}
for _, key := range []string{"enabled", "bantime.increment", "ignoreip", "bantime", "findtime", "maxretry", "banaction", "banaction_allports"} {
defaultLines = append(defaultLines, keysToUpdate[key])
}
defaultLines = append(defaultLines, "")
newContent := strings.Join(defaultLines, "\n")
cmd := fmt.Sprintf("cat <<'EOF' | tee %s >/dev/null\n%s\nEOF", jailLocalPath, newContent)
_, err = sc.runRemoteCommand(ctx, []string{cmd})
return err
}
// Use Python script to update only specific keys in DEFAULT section
// Preserves banner, action_mwlg, and action override sections
// Escape values for shell/Python
escapeForShell := func(s string) string {
// Escape single quotes for shell
return strings.ReplaceAll(s, "'", "'\"'\"'")
}
// Convert boolean values to Python boolean literals
defaultJailEnablePython := "False"
if settings.DefaultJailEnable {
defaultJailEnablePython = "True"
}
bantimeIncrementPython := "False"
if settings.BantimeIncrement {
bantimeIncrementPython = "True"
}
updateScript := fmt.Sprintf(`python3 <<'PY'
import re
jail_file = '%s'
ignore_ip_str = '%s'
banaction_val = '%s'
banaction_allports_val = '%s'
default_jail_enable_val = %s
bantime_increment_val = %s
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bantime_val = '%s'
findtime_val = '%s'
maxretry_val = %d
keys_to_update = {
'enabled': 'enabled = ' + str(default_jail_enable_val).lower(),
'bantime.increment': 'bantime.increment = ' + str(bantime_increment_val).lower(),
'ignoreip': 'ignoreip = ' + ignore_ip_str,
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'bantime': 'bantime = ' + bantime_val,
'findtime': 'findtime = ' + findtime_val,
'maxretry': 'maxretry = ' + str(maxretry_val),
'banaction': 'banaction = ' + banaction_val,
'banaction_allports': 'banaction_allports = ' + banaction_allports_val
}
try:
with open(jail_file, 'r') as f:
lines = f.readlines()
except FileNotFoundError:
lines = []
output_lines = []
in_default = False
default_section_found = False
keys_updated = set()
for line in lines:
stripped = line.strip()
# Preserve banner lines, action_mwlg lines, and action override lines
is_banner = 'Fail2Ban-UI' in line or 'fail2ban-ui' in line
is_action_mwlg = 'action_mwlg' in stripped
is_action_override = 'action = %%(action_mwlg)s' in stripped
if stripped.startswith('[') and stripped.endswith(']'):
section_name = stripped.strip('[]')
if section_name == "DEFAULT":
in_default = True
default_section_found = True
output_lines.append(line)
else:
in_default = False
output_lines.append(line)
elif in_default:
# Check if this line is a key we need to update
key_updated = False
for key, new_value in keys_to_update.items():
pattern = r'^\s*' + re.escape(key) + r'\s*='
if re.match(pattern, stripped):
output_lines.append(new_value + '\n')
keys_updated.add(key)
key_updated = True
break
if not key_updated:
# Keep the line as-is (might be action_mwlg or other DEFAULT settings)
output_lines.append(line)
else:
# Keep lines outside DEFAULT section (preserves banner, action_mwlg, action override)
output_lines.append(line)
# If DEFAULT section wasn't found, create it at the beginning
if not default_section_found:
default_lines = ["[DEFAULT]\n"]
for key in ["enabled", "bantime.increment", "ignoreip", "bantime", "findtime", "maxretry", "banaction", "banaction_allports"]:
default_lines.append(keys_to_update[key] + "\n")
default_lines.append("\n")
output_lines = default_lines + output_lines
else:
# Add any missing keys to the DEFAULT section
for key in ["enabled", "bantime.increment", "ignoreip", "bantime", "findtime", "maxretry", "banaction", "banaction_allports"]:
if key not in keys_updated:
# Find the DEFAULT section and insert after it
for i, line in enumerate(output_lines):
if line.strip() == "[DEFAULT]":
output_lines.insert(i + 1, keys_to_update[key] + "\n")
break
with open(jail_file, 'w') as f:
f.writelines(output_lines)
PY`, escapeForShell(jailLocalPath), escapeForShell(ignoreIPStr), escapeForShell(banactionVal), escapeForShell(banactionAllportsVal), defaultJailEnablePython, bantimeIncrementPython, escapeForShell(settings.Bantime), escapeForShell(settings.Findtime), settings.Maxretry)
_, err = sc.runRemoteCommand(ctx, []string{updateScript})
return err
}
// EnsureJailLocalStructure implements Connector.
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// For SSH connectors we:
// 1. Migrate any legacy jails out of jail.local into jail.d/*.local
// 2. Rebuild /etc/fail2ban/jail.local with a clean, managed structure
// (banner, [DEFAULT] section based on current settings, and action_mwlg/action override).
func (sc *SSHConnector) EnsureJailLocalStructure(ctx context.Context) error {
jailLocalPath := "/etc/fail2ban/jail.local"
settings := config.GetSettings()
// Convert IgnoreIPs array to space-separated string
ignoreIPStr := strings.Join(settings.IgnoreIPs, " ")
if ignoreIPStr == "" {
ignoreIPStr = "127.0.0.1/8 ::1"
}
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// Set default banaction values if not set
banactionVal := settings.Banaction
if banactionVal == "" {
banactionVal = "nftables-multiport"
}
banactionAllportsVal := settings.BanactionAllports
if banactionAllportsVal == "" {
banactionAllportsVal = "nftables-allports"
}
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// Build the new jail.local content in Go (mirrors local ensureJailLocalStructure)
banner := config.JailLocalBanner()
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defaultSection := fmt.Sprintf(`[DEFAULT]
enabled = %t
bantime.increment = %t
ignoreip = %s
bantime = %s
findtime = %s
maxretry = %d
banaction = %s
banaction_allports = %s
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`,
settings.DefaultJailEnable,
settings.BantimeIncrement,
ignoreIPStr,
settings.Bantime,
settings.Findtime,
settings.Maxretry,
banactionVal,
banactionAllportsVal,
)
actionMwlgConfig := `# Custom Fail2Ban action for UI callbacks
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action_mwlg = %(action_)s
ui-custom-action[logpath="%(logpath)s", chain="%(chain)s"]
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`
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actionOverride := `# Custom Fail2Ban action applied by fail2ban-ui
action = %(action_mwlg)s
`
content := banner + defaultSection + actionMwlgConfig + actionOverride
// Escape single quotes for safe use in a single-quoted heredoc
escaped := strings.ReplaceAll(content, "'", "'\"'\"'")
// IMPORTANT: Run migration FIRST before ensuring structure.
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// This is because EnsureJailLocalStructure may overwrite jail.local,
// which would destroy any jail sections that need to be migrated.
// If migration fails for any reason, we SHOULD NOT overwrite jail.local,
// otherwise legacy jails would be lost.
if err := sc.MigrateJailsFromJailLocalRemote(ctx); err != nil {
return fmt.Errorf("failed to migrate legacy jails from jail.local on remote server %s: %w", sc.server.Name, err)
}
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// Write the rebuilt content via heredoc over SSH
writeScript := fmt.Sprintf(`cat > %s <<'JAILLOCAL'
%s
JAILLOCAL
`, jailLocalPath, escaped)
_, err := sc.runRemoteCommand(ctx, []string{writeScript})
return err
}
// MigrateJailsFromJailLocalRemote migrates non-commented jail sections from jail.local to jail.d/*.local files on remote system.
func (sc *SSHConnector) MigrateJailsFromJailLocalRemote(ctx context.Context) error {
jailLocalPath := "/etc/fail2ban/jail.local"
jailDPath := "/etc/fail2ban/jail.d"
// Check if jail.local exists
checkScript := fmt.Sprintf("test -f %s && echo 'exists' || echo 'notfound'", jailLocalPath)
out, err := sc.runRemoteCommand(ctx, []string{checkScript})
if err != nil || strings.TrimSpace(out) != "exists" {
config.DebugLog("No jails to migrate from jail.local on server %s (file does not exist)", sc.server.Name)
return nil // Nothing to migrate
}
// Read jail.local content
content, err := sc.runRemoteCommand(ctx, []string{"cat", jailLocalPath})
if err != nil {
return fmt.Errorf("failed to read jail.local on server %s: %w", sc.server.Name, err)
}
// Parse content locally to extract non-commented sections
sections, defaultContent, err := parseJailSectionsUncommented(content)
if err != nil {
return fmt.Errorf("failed to parse jail.local on server %s: %w", sc.server.Name, err)
}
// If no non-commented, non-DEFAULT jails found, nothing to migrate
if len(sections) == 0 {
config.DebugLog("No jails to migrate from jail.local on remote system")
return nil
}
// Create backup
backupPath := jailLocalPath + ".backup." + fmt.Sprintf("%d", time.Now().Unix())
backupScript := fmt.Sprintf("cp %s %s", jailLocalPath, backupPath)
if _, err := sc.runRemoteCommand(ctx, []string{backupScript}); err != nil {
return fmt.Errorf("failed to create backup on server %s: %w", sc.server.Name, err)
}
config.DebugLog("Created backup of jail.local at %s on server %s", backupPath, sc.server.Name)
// Ensure jail.d directory exists
ensureDirScript := fmt.Sprintf("mkdir -p %s", jailDPath)
if _, err := sc.runRemoteCommand(ctx, []string{ensureDirScript}); err != nil {
return fmt.Errorf("failed to create jail.d directory on server %s: %w", sc.server.Name, err)
}
// Write each jail to its own .local file
migratedCount := 0
for jailName, jailContent := range sections {
if jailName == "" {
continue
}
jailFilePath := fmt.Sprintf("%s/%s.local", jailDPath, jailName)
// Check if .local file already exists
checkFileScript := fmt.Sprintf("test -f %s && echo 'exists' || echo 'notfound'", jailFilePath)
fileOut, err := sc.runRemoteCommand(ctx, []string{checkFileScript})
if err == nil && strings.TrimSpace(fileOut) == "exists" {
config.DebugLog("Skipping migration for jail %s on server %s: .local file already exists", jailName, sc.server.Name)
continue
}
// Write jail content to .local file using heredoc
// Escape single quotes in content for shell
escapedContent := strings.ReplaceAll(jailContent, "'", "'\"'\"'")
writeScript := fmt.Sprintf(`cat > %s <<'JAILEOF'
%s
JAILEOF
'`, jailFilePath, escapedContent)
if _, err := sc.runRemoteCommand(ctx, []string{writeScript}); err != nil {
return fmt.Errorf("failed to write jail file %s: %w", jailFilePath, err)
}
config.DebugLog("Migrated jail %s to %s on server %s", jailName, jailFilePath, sc.server.Name)
migratedCount++
}
// Only rewrite jail.local if we migrated something
if migratedCount > 0 {
// Rewrite jail.local with only DEFAULT section
// Escape single quotes in defaultContent for shell
escapedDefault := strings.ReplaceAll(defaultContent, "'", "'\"'\"'")
writeLocalScript := fmt.Sprintf(`cat > %s <<'LOCALEOF'
%s
LOCALEOF
'`, jailLocalPath, escapedDefault)
if _, err := sc.runRemoteCommand(ctx, []string{writeLocalScript}); err != nil {
return fmt.Errorf("failed to rewrite jail.local: %w", err)
}
config.DebugLog("Migration completed on server %s: moved %d jails to jail.d/", sc.server.Name, migratedCount)
}
return nil
}
// CreateJail implements Connector.
func (sc *SSHConnector) CreateJail(ctx context.Context, jailName, content string) error {
// Validate jail name
if err := ValidateJailName(jailName); err != nil {
return err
}
fail2banPath := sc.getFail2banPath(ctx)
jailDPath := filepath.Join(fail2banPath, "jail.d")
// Ensure jail.d directory exists
_, err := sc.runRemoteCommand(ctx, []string{"mkdir", "-p", jailDPath})
if err != nil {
return fmt.Errorf("failed to create jail.d directory: %w", err)
}
// Validate content starts with correct section header
trimmed := strings.TrimSpace(content)
expectedSection := fmt.Sprintf("[%s]", jailName)
if !strings.HasPrefix(trimmed, expectedSection) {
// Prepend the section header if missing
content = expectedSection + "\n" + content
}
// Write the file
localPath := filepath.Join(jailDPath, jailName+".local")
if err := sc.writeRemoteFile(ctx, localPath, content); err != nil {
return fmt.Errorf("failed to create jail file: %w", err)
}
return nil
}
// DeleteJail implements Connector.
func (sc *SSHConnector) DeleteJail(ctx context.Context, jailName string) error {
// Validate jail name
if err := ValidateJailName(jailName); err != nil {
return err
}
fail2banPath := sc.getFail2banPath(ctx)
localPath := filepath.Join(fail2banPath, "jail.d", jailName+".local")
confPath := filepath.Join(fail2banPath, "jail.d", jailName+".conf")
// Delete both .local and .conf files if they exist (rm -f doesn't error if file doesn't exist)
// Use a single command to delete both files
_, err := sc.runRemoteCommand(ctx, []string{"rm", "-f", localPath, confPath})
if err != nil {
return fmt.Errorf("failed to delete jail files %s or %s: %w", localPath, confPath, err)
}
return nil
}
// CreateFilter implements Connector.
func (sc *SSHConnector) CreateFilter(ctx context.Context, filterName, content string) error {
// Validate filter name
if err := ValidateFilterName(filterName); err != nil {
return err
}
fail2banPath := sc.getFail2banPath(ctx)
filterDPath := filepath.Join(fail2banPath, "filter.d")
// Ensure filter.d directory exists
_, err := sc.runRemoteCommand(ctx, []string{"mkdir", "-p", filterDPath})
if err != nil {
return fmt.Errorf("failed to create filter.d directory: %w", err)
}
// Write the file
localPath := filepath.Join(filterDPath, filterName+".local")
if err := sc.writeRemoteFile(ctx, localPath, content); err != nil {
return fmt.Errorf("failed to create filter file: %w", err)
}
return nil
}
// DeleteFilter implements Connector.
func (sc *SSHConnector) DeleteFilter(ctx context.Context, filterName string) error {
// Validate filter name
if err := ValidateFilterName(filterName); err != nil {
return err
}
fail2banPath := sc.getFail2banPath(ctx)
localPath := filepath.Join(fail2banPath, "filter.d", filterName+".local")
confPath := filepath.Join(fail2banPath, "filter.d", filterName+".conf")
// Delete both .local and .conf files if they exist (rm -f doesn't error if file doesn't exist)
// Use a single command to delete both files
_, err := sc.runRemoteCommand(ctx, []string{"rm", "-f", localPath, confPath})
if err != nil {
return fmt.Errorf("failed to delete filter files %s or %s: %w", localPath, confPath, err)
}
return nil
}
// parseJailConfigContent parses jail configuration content and returns JailInfo slice.
func parseJailConfigContent(content string) []JailInfo {
var jails []JailInfo
scanner := bufio.NewScanner(strings.NewReader(content))
var currentJail string
enabled := true
// Sections that should be ignored (not jails)
ignoredSections := map[string]bool{
"DEFAULT": true,
"INCLUDES": true,
}
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
if currentJail != "" && !ignoredSections[currentJail] {
jails = append(jails, JailInfo{
JailName: currentJail,
Enabled: enabled,
})
}
currentJail = strings.Trim(line, "[]")
enabled = true
} else if strings.HasPrefix(strings.ToLower(line), "enabled") {
parts := strings.Split(line, "=")
if len(parts) == 2 {
value := strings.TrimSpace(parts[1])
enabled = strings.EqualFold(value, "true")
}
}
}
if currentJail != "" && !ignoredSections[currentJail] {
jails = append(jails, JailInfo{
JailName: currentJail,
Enabled: enabled,
})
}
return jails
}