/mandos/trunk : revision 132

56

#include <argp.h> /* struct argp_option, struct

57

argp_state, struct argp,

58

argp_parse(), ARGP_ERR_UNKNOWN,

59

ARGP_KEY_END, ARGP_KEY_ARG, error_t */

59

ARGP_KEY_END, ARGP_KEY_ARG,

60

error_t */

60

61

#include <signal.h> /* struct sigaction, sigemptyset(),

61

62

sigaddset(), sigaction(),

62

63

sigprocmask(), SIG_BLOCK, SIGCHLD,

64

65

#include <errno.h> /* errno, EBADF */

65

66

67

#define BUFFER_SIZE 256

67

#define ARGFILE "/conf/conf.d/mandos/plugin-runner.conf"

68

69

#define PDIR "/lib/mandos/plugins.d"

70

#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"

68

71

69

72

const char *argp_program_version = "plugin-runner 1.0";

70

73

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

71

74

72

struct process;

73

74

typedef struct process{

75

pid_t pid;

76

int fd;

77

char *buffer;

78

size_t buffer_size;

79

size_t buffer_length;

80

bool eof;

81

bool completed;

82

int status;

83

struct process *next;

84

} process;

75

struct plugin;

85

76

86

77

typedef struct plugin{

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char *name; /* can be NULL or any plugin name */

90

81

char **environ;

91

82

int envc;

92

83

bool disabled;

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85

/* Variables used for running processes*/

86

pid_t pid;

87

int fd;

88

char *buffer;

89

size_t buffer_size;

90

size_t buffer_length;

91

bool eof;

92

volatile bool completed;

93

volatile int status;

93

94

struct plugin *next;

94

95

} plugin;

95

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static plugin *getplugin(char *name, plugin **plugin_list){

97

for (plugin *p = *plugin_list; p != NULL; p = p->next){

97

static plugin *plugin_list = NULL;

98

99

/* Gets a existing plugin based on name,

100

or if none is found, creates a new one */

101

static plugin *getplugin(char *name){

102

/* Check for exiting plugin with that name */

103

for (plugin *p = plugin_list; p != NULL; p = p->next){

98

104

if ((p->name == name)

99

105

or (p->name and name and (strcmp(p->name, name) == 0))){

100

106

return p;

112

118

return NULL;

113

119

}

114

120

}

115

121

116

122

*new_plugin = (plugin) { .name = copy_name,

117

123

.argc = 1,

118

.envc = 0,

119

124

.disabled = false,

120

.next = *plugin_list };

125

.next = plugin_list };

121

126

122

127

new_plugin->argv = malloc(sizeof(char *) * 2);

123

128

if (new_plugin->argv == NULL){

136

141

return NULL;

137

142

}

138

143

new_plugin->environ[0] = NULL;

144

139

145

/* Append the new plugin to the list */

140

*plugin_list = new_plugin;

146

plugin_list = new_plugin;

141

147

return new_plugin;

142

148

}

143

149

180

186

return add_to_char_array(def, &(p->environ), &(p->envc));

181

187

}

182

188

183

184

189

/*

185

190

* Based on the example in the GNU LibC manual chapter 13.13 "File

186

191

* Descriptor Flags".

197

202

return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);

198

203

}

199

204

200

process *process_list = NULL;

201

205

202

/* Mark a process as completed when it exits, and save its exit

206

/* Mark processes as completed when they exit, and save their exit

203

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status. */

204

208

void handle_sigchld(__attribute__((unused)) int sig){

205

process *proc = process_list;

206

int status;

207

pid_t pid = wait(&status);

208

if(pid == -1){

209

perror("wait");

210

return;

211

}

212

while(proc != NULL and proc->pid != pid){

213

proc = proc->next;

214

}

215

if(proc == NULL){

216

/* Process not found in process list */

217

return;

218

}

219

proc->status = status;

220

proc->completed = true;

209

while(true){

210

plugin *proc = plugin_list;

211

int status;

212

pid_t pid = waitpid(-1, &status, WNOHANG);

213

if(pid == 0){

214

/* Only still running child processes */

215

break;

216

}

217

if(pid == -1){

218

if (errno != ECHILD){

219

perror("waitpid");

220

}

221

/* No child processes */

222

break;

223

}

224

225

/* A child exited, find it in process_list */

226

while(proc != NULL and proc->pid != pid){

227

proc = proc->next;

228

}

229

if(proc == NULL){

230

/* Process not found in process list */

231

continue;

232

}

233

proc->status = status;

234

proc->completed = true;

235

}

221

236

}

222

237

238

/* Prints out a password to stdout */

223

239

bool print_out_password(const char *buffer, size_t length){

224

240

ssize_t ret;

225

241

if(length>0 and buffer[length-1] == '\n'){

235

251

return true;

236

252

}

237

253

238

char **add_to_argv(char **argv, int *argc, char *arg){

239

if (argv == NULL){

240

*argc = 1;

241

argv = malloc(sizeof(char*) * 2);

242

if(argv == NULL){

243

return NULL;

254

/* Removes and free a plugin from the plugin list */

255

static void free_plugin(plugin *plugin_node){

256

257

for(char **arg = plugin_node->argv; *arg != NULL; arg++){

258

free(*arg);

259

}

260

free(plugin_node->argv);

261

for(char **env = plugin_node->environ; *env != NULL; env++){

262

free(*env);

263

}

264

free(plugin_node->environ);

265

free(plugin_node->buffer);

266

267

/* Removes the plugin from the singly-linked list */

268

if(plugin_node == plugin_list){

269

/* First one - simple */

270

plugin_list = plugin_list->next;

271

} else {

272

/* Second one or later */

273

for(plugin *p = plugin_list; p != NULL; p = p->next){

274

if(p->next == plugin_node){

275

p->next = plugin_node->next;

276

break;

277

}

244

278

}

245

argv[0] = NULL; /* Will be set to argv[0] in main before parsing */

246

argv[1] = NULL;

247

}

248

*argc += 1;

249

argv = realloc(argv, sizeof(char *)

250

* ((unsigned int) *argc + 1));

251

if(argv == NULL){

252

return NULL;

253

}

254

argv[*argc-1] = arg;

255

argv[*argc] = NULL;

256

return argv;

279

}

280

281

free(plugin_node);

257

282

}

258

283

259

static void free_plugin_list(plugin *plugin_list){

260

for(plugin *next; plugin_list != NULL; plugin_list = next){

261

next = plugin_list->next;

262

for(char **arg = plugin_list->argv; *arg != NULL; arg++){

263

free(*arg);

264

}

265

free(plugin_list->argv);

266

for(char **env = plugin_list->environ; *env != NULL; env++){

267

free(*env);

268

}

269

free(plugin_list->environ);

270

free(plugin_list);

284

static void free_plugin_list(void){

285

while(plugin_list != NULL){

286

free_plugin(plugin_list);

271

287

}

272

288

}

273

289

274

290

int main(int argc, char *argv[]){

275

const char *plugindir = "/lib/mandos/plugins.d";

276

const char *argfile = ARGFILE;

291

char *plugindir = NULL;

292

char *argfile = NULL;

277

293

FILE *conffp;

278

294

size_t d_name_len;

279

295

DIR *dir = NULL;

326

342

{ .name = "plugin-dir", .key = 128,

327

343

.arg = "DIRECTORY",

328

344

.doc = "Specify a different plugin directory", .group = 2 },

329

{ .name = "userid", .key = 129,

330

.arg = "ID", .flags = 0,

331

.doc = "User ID the plugins will run as", .group = 2 },

332

{ .name = "groupid", .key = 130,

333

.arg = "ID", .flags = 0,

334

.doc = "Group ID the plugins will run as", .group = 2 },

335

{ .name = "debug", .key = 131,

336

.doc = "Debug mode", .group = 3 },

345

{ .name = "config-file", .key = 129,

346

.arg = "FILE",

347

.doc = "Specify a different configuration file", .group = 2 },

348

{ .name = "userid", .key = 130,

349

.arg = "ID", .flags = 0,

350

.doc = "User ID the plugins will run as", .group = 3 },

351

{ .name = "groupid", .key = 131,

352

.arg = "ID", .flags = 0,

353

.doc = "Group ID the plugins will run as", .group = 3 },

354

{ .name = "debug", .key = 132,

355

.doc = "Debug mode", .group = 4 },

337

356

{ .name = NULL }

338

357

};

339

358

340

error_t parse_opt (int key, char *arg, struct argp_state *state) {

359

error_t parse_opt (int key, char *arg, __attribute__((unused)) struct argp_state *state) {

341

360

/* Get the INPUT argument from `argp_parse', which we know is a

342

361

pointer to our plugin list pointer. */

343

plugin **plugins = state->input;

344

362

switch (key) {

345

case 'g':

363

case 'g': /* --global-options */

346

364

if (arg != NULL){

347

365

char *p;

348

366

while((p = strsep(&arg, ",")) != NULL){

349

367

if(p[0] == '\0'){

350

368

continue;

351

369

}

352

if(not add_argument(getplugin(NULL, plugins), p)){

370

if(not add_argument(getplugin(NULL), p)){

353

371

perror("add_argument");

354

372

return ARGP_ERR_UNKNOWN;

355

373

}

356

374

}

357

375

}

358

376

break;

359

case 'e':

377

case 'e': /* --global-envs */

360

378

if(arg == NULL){

361

379

break;

362

380

}

365

383

if(envdef == NULL){

366

384

break;

367

385

}

368

if(not add_environment(getplugin(NULL, plugins), envdef)){

386

if(not add_environment(getplugin(NULL), envdef)){

369

387

perror("add_environment");

370

388

}

371

389

}

372

390

break;

373

case 'o':

391

case 'o': /* --options-for */

374

392

if (arg != NULL){

375

393

char *p_name = strsep(&arg, ":");

376

394

if(p_name[0] == '\0'){

386

404

if(p[0] == '\0'){

387

405

continue;

388

406

}

389

if(not add_argument(getplugin(p_name, plugins), p)){

407

if(not add_argument(getplugin(p_name), p)){

390

408

perror("add_argument");

391

409

return ARGP_ERR_UNKNOWN;

392

410

}

394

412

}

395

413

}

396

414

break;

397

case 'f':

415

case 'f': /* --envs-for */

398

416

if(arg == NULL){

399

417

break;

400

418

}

408

426

break;

409

427

}

410

428

envdef++;

411

if(not add_environment(getplugin(p_name, plugins), envdef)){

429

if(not add_environment(getplugin(p_name), envdef)){

412

430

perror("add_environment");

413

431

}

414

432

}

415

433

break;

416

case 'd':

434

case 'd': /* --disable */

417

435

if (arg != NULL){

418

plugin *p = getplugin(arg, plugins);

436

plugin *p = getplugin(arg);

419

437

if(p == NULL){

420

438

return ARGP_ERR_UNKNOWN;

421

439

}

422

440

p->disabled = true;

423

441

}

424

442

break;

425

case 128:

426

plugindir = arg;

443

case 128: /* --plugin-dir */

444

plugindir = strdup(arg);

445

if(plugindir == NULL){

446

perror("strdup");

447

}

427

448

break;

428

case 129:

449

case 129: /* --config-file */

450

argfile = strdup(arg);

451

if(argfile == NULL){

452

perror("strdup");

453

}

454

break;

455

case 130: /* --userid */

429

456

uid = (uid_t)strtol(arg, NULL, 10);

430

457

break;

431

case 130:

458

case 131: /* --groupid */

432

459

gid = (gid_t)strtol(arg, NULL, 10);

433

460

break;

434

case 131:

461

case 132: /* --debug */

435

462

debug = true;

436

463

break;

437

464

case ARGP_KEY_ARG:

445

472

return 0;

446

473

}

447

474

448

plugin *plugin_list = NULL;

449

450

475

struct argp argp = { .options = options, .parser = parse_opt,

451

476

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

452

477

.doc = "Mandos plugin runner -- Run plugins" };

453

478

454

ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);

479

ret = argp_parse (&argp, argc, argv, 0, 0, NULL);

455

480

if (ret == ARGP_ERR_UNKNOWN){

456

481

fprintf(stderr, "Unknown error while parsing arguments\n");

457

482

exitstatus = EXIT_FAILURE;

458

483

goto fallback;

459

484

}

460

485

461

conffp = fopen(argfile, "r");

486

/* Opens the configfile if aviable */

487

if (argfile == NULL){

488

conffp = fopen(AFILE, "r");

489

} else {

490

conffp = fopen(argfile, "r");

491

}

462

492

if(conffp != NULL){

463

493

char *org_line = NULL;

464

494

char *p, *arg, *new_arg, *line;

467

497

const char whitespace_delims[] = " \r\t\f\v\n";

468

498

const char comment_delim[] = "#";

469

499

500

custom_argc = 1;

501

custom_argv = malloc(sizeof(char*) * 2);

502

if(custom_argv == NULL){

503

perror("malloc");

504

exitstatus = EXIT_FAILURE;

505

goto fallback;

506

}

507

custom_argv[0] = argv[0];

508

custom_argv[1] = NULL;

509

510

/* for each line in the config file, strip whitespace and ignore commented text */

470

511

while(true){

471

512

sret = getline(&org_line, &size, conffp);

472

513

if(sret == -1){

480

521

continue;

481

522

}

482

523

new_arg = strdup(p);

483

custom_argv = add_to_argv(custom_argv, &custom_argc, new_arg);

484

if (custom_argv == NULL){

485

perror("add_to_argv");

486

exitstatus = EXIT_FAILURE;

487

goto fallback;

488

}

524

if(new_arg == NULL){

525

perror("strdup");

526

exitstatus = EXIT_FAILURE;

527

free(org_line);

528

goto fallback;

529

}

530

531

custom_argc += 1;

532

custom_argv = realloc(custom_argv, sizeof(char *)

533

* ((unsigned int) custom_argc + 1));

534

if(custom_argv == NULL){

535

perror("realloc");

536

exitstatus = EXIT_FAILURE;

537

free(org_line);

538

goto fallback;

539

}

540

custom_argv[custom_argc-1] = new_arg;

541

custom_argv[custom_argc] = NULL;

489

542

}

490

543

}

491

544

free(org_line);

498

551

goto fallback;

499

552

}

500

553

}

501

554

/* If there was any arguments from configuration file,

555

pass them to parser as command arguments */

502

556

if(custom_argv != NULL){

503

custom_argv[0] = argv[0];

504

ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);

557

ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, NULL);

505

558

if (ret == ARGP_ERR_UNKNOWN){

506

559

fprintf(stderr, "Unknown error while parsing arguments\n");

507

560

exitstatus = EXIT_FAILURE;

522

575

}

523

576

}

524

577

}

525

578

579

/* Strip permissions down to nobody */

526

580

ret = setuid(uid);

527

581

if (ret == -1){

528

582

perror("setuid");

529

}

530

583

}

531

584

setgid(gid);

532

585

if (ret == -1){

533

586

perror("setgid");

534

587

}

588

589

if (plugindir == NULL){

590

dir = opendir(PDIR);

591

} else {

592

dir = opendir(plugindir);

593

}

535

594

536

dir = opendir(plugindir);

537

595

if(dir == NULL){

538

596

perror("Could not open plugin dir");

539

597

exitstatus = EXIT_FAILURE;

554

612

}

555

613

556

614

FD_ZERO(&rfds_all);

557

615

616

/* Read and execute any executable in the plugin directory*/

558

617

while(true){

559

618

dirst = readdir(dir);

560

619

591

650

break;

592

651

}

593

652

}

594

595

653

if(bad_name){

596

654

continue;

597

655

}

598

599

656

for(const char **suf = bad_suffixes; *suf != NULL; suf++){

600

657

size_t suf_len = strlen(*suf);

601

658

if((d_name_len >= suf_len)

628

685

free(filename);

629

686

continue;

630

687

}

631

688

689

/* Ignore non-executable files */

632

690

if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){

633

691

if(debug){

634

692

fprintf(stderr, "Ignoring plugin dir entry \"%s\""

637

695

free(filename);

638

696

continue;

639

697

}

640

plugin *p = getplugin(dirst->d_name, &plugin_list);

698

699

plugin *p = getplugin(dirst->d_name);

641

700

if(p == NULL){

642

701

perror("getplugin");

643

702

free(filename);

653

712

}

654

713

{

655

714

/* Add global arguments to argument list for this plugin */

656

plugin *g = getplugin(NULL, &plugin_list);

715

plugin *g = getplugin(NULL);

657

716

if(g != NULL){

658

717

for(char **a = g->argv + 1; *a != NULL; a++){

659

718

if(not add_argument(p, *a)){

691

750

exitstatus = EXIT_FAILURE;

692

751

goto fallback;

693

752

}

753

/* Ask OS to automatic close the pipe on exec */

694

754

ret = set_cloexec_flag(pipefd[0]);

695

755

if(ret < 0){

696

756

perror("set_cloexec_flag");

754

814

}

755

815

/* no return */

756

816

}

757

/* parent process */

817

/* Parent process */

818

close(pipefd[1]); /* Close unused write end of pipe */

758

819

free(filename);

759

close(pipefd[1]); /* close unused write end of pipe */

760

process *new_process = malloc(sizeof(process));

761

if (new_process == NULL){

762

perror("malloc");

820

plugin *new_plugin = getplugin(dirst->d_name);

821

if (new_plugin == NULL){

822

perror("getplugin");

763

823

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);

764

824

if(ret < 0){

765

perror("sigprocmask");

825

perror("sigprocmask");

766

826

}

767

827

exitstatus = EXIT_FAILURE;

768

828

goto fallback;

769

829

}

770

830

771

*new_process = (struct process){ .pid = pid,

772

.fd = pipefd[0],

773

.next = process_list };

774

// List handling

775

process_list = new_process;

831

new_plugin->pid = pid;

832

new_plugin->fd = pipefd[0];

833

776

834

/* Unblock SIGCHLD so signal handler can be run if this process

777

835

has already completed */

778

836

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);

782

840

goto fallback;

783

841

}

784

842

785

FD_SET(new_process->fd, &rfds_all);

843

FD_SET(new_plugin->fd, &rfds_all);

786

844

787

if (maxfd < new_process->fd){

788

maxfd = new_process->fd;

845

if (maxfd < new_plugin->fd){

846

maxfd = new_plugin->fd;

789

847

}

790

848

791

849

}

792

850

793

free_plugin_list(plugin_list);

794

plugin_list = NULL;

795

796

851

closedir(dir);

797

852

dir = NULL;

798

799

if (process_list == NULL){

800

fprintf(stderr, "No plugin processes started. Incorrect plugin"

801

" directory?\n");

802

process_list = NULL;

853

854

for(plugin *p = plugin_list; p != NULL; p = p->next){

855

if(p->pid != 0){

856

break;

857

}

858

if(p->next == NULL){

859

fprintf(stderr, "No plugin processes started. Incorrect plugin"

860

" directory?\n");

861

free_plugin_list();

862

}

803

863

}

804

while(process_list){

864

865

/* Main loop while running plugins exist */

866

while(plugin_list){

805

867

fd_set rfds = rfds_all;

806

868

int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);

807

869

if (select_ret == -1){

811

873

}

812

874

/* OK, now either a process completed, or something can be read

813

875

from one of them */

814

for(process *proc = process_list; proc ; proc = proc->next){

876

for(plugin *proc = plugin_list; proc != NULL; proc = proc->next){

815

877

/* Is this process completely done? */

816

878

if(proc->eof and proc->completed){

817

879

/* Only accept the plugin output if it exited cleanly */

818

880

if(not WIFEXITED(proc->status)

819

881

or WEXITSTATUS(proc->status) != 0){

820

882

/* Bad exit by plugin */

883

821

884

if(debug){

822

885

if(WIFEXITED(proc->status)){

823

886

fprintf(stderr, "Plugin %u exited with status %d\n",

832

895

(unsigned int) (proc->pid));

833

896

}

834

897

}

898

835

899

/* Remove the plugin */

836

900

FD_CLR(proc->fd, &rfds_all);

901

837

902

/* Block signal while modifying process_list */

838

ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);

903

ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);

839

904

if(ret < 0){

840

905

perror("sigprocmask");

841

906

exitstatus = EXIT_FAILURE;

842

907

goto fallback;

843

908

}

844

/* Delete this process entry from the list */

845

if(process_list == proc){

846

/* First one - simple */

847

process_list = proc->next;

848

} else {

849

/* Second one or later */

850

for(process *p = process_list; p != NULL; p = p->next){

851

if(p->next == proc){

852

p->next = proc->next;

853

break;

854

}

855

}

856

}

909

free_plugin(proc);

857

910

/* We are done modifying process list, so unblock signal */

858

911

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

859

912

NULL);

860

913

if(ret < 0){

861

914

perror("sigprocmask");

862

}

863

free(proc->buffer);

864

free(proc);

865

/* We deleted this process from the list, so we can't go

866

proc->next. Therefore, start over from the beginning of

867

the process list */

868

break;

915

exitstatus = EXIT_FAILURE;

916

goto fallback;

917

}

918

919

if(plugin_list == NULL){

920

break;

921

}

922

continue;

869

923

}

924

870

925

/* This process exited nicely, so print its buffer */

871

926

872

bool bret = print_out_password(proc->buffer, proc->buffer_length);

927

bool bret = print_out_password(proc->buffer,

928

proc->buffer_length);

873

929

if(not bret){

874

930

perror("print_out_password");

875

931

exitstatus = EXIT_FAILURE;

876

932

}

877

933

goto fallback;

878

934

}

935

879

936

/* This process has not completed. Does it have any output? */

880

937

if(proc->eof or not FD_ISSET(proc->fd, &rfds)){

881

938

/* This process had nothing to say at this time */

911

968

912

969

fallback:

913

970

914

if(process_list == NULL or exitstatus != EXIT_SUCCESS){

915

/* Fallback if all plugins failed, none are found or an error occured */

971

if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){

972

/* Fallback if all plugins failed, none are found or an error

973

occured */

916

974

bool bret;

917

975

fprintf(stderr, "Going to fallback mode using getpass(3)\n");

918

976

char *passwordbuffer = getpass("Password: ");

931

989

}

932

990

933

991

if(custom_argv != NULL){

934

for(char **arg = custom_argv; *arg != NULL; arg++){

992

for(char **arg = custom_argv+1; *arg != NULL; arg++){

935

993

free(*arg);

936

994

}

937

995

free(custom_argv);

938

996

}

939

free_plugin_list(plugin_list);

940

997

941

998

if(dir != NULL){

942

999

closedir(dir);

943

1000

}

944

1001

945

1002

/* Free the process list and kill the processes */

946

for(process *next; process_list != NULL; process_list = next){

947

next = process_list->next;

948

close(process_list->fd);

949

ret = kill(process_list->pid, SIGTERM);

950

if(ret == -1 and errno != ESRCH){

951

/* set-uid proccesses migth not get closed */

952

perror("kill");

1003

for(plugin *p = plugin_list; p != NULL; p = p->next){

1004

if(p->pid != 0){

1005

close(p->fd);

1006

ret = kill(p->pid, SIGTERM);

1007

if(ret == -1 and errno != ESRCH){

1008

/* Set-uid proccesses might not get closed */

1009

perror("kill");

1010

}

953

1011

}

954

free(process_list->buffer);

955

free(process_list);

956

1012

}

957

1013

958

1014

/* Wait for any remaining child processes to terminate */

962

1018

if(errno != ECHILD){

963

1019

perror("wait");

964

1020

}

1021

1022

free_plugin_list();

1023

1024

free(plugindir);

1025

free(argfile);

965

1026

966

1027

return exitstatus;

967

1028

}