/mandos/release : revision 77

21

* Contact the authors at <mandos@fukt.bsnet.se>.

22

*/

23

24

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),

25

asprintf() */

24

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline() */

25

26

#include <stddef.h> /* size_t, NULL */

27

#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,

28

EXIT_SUCCESS, realloc() */

51

close() */

52

#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,

53

FD_CLOEXEC */

54

#include <string.h> /* strsep, strlen(), asprintf() */

54

#include <string.h> /* strsep, strlen(), strcpy(),

55

strcat() */

55

56

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

56

57

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

57

58

argp_state, struct argp,

87

88

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

88

89

char **argv;

89

90

int argc;

90

char **environ;

91

int envc;

92

91

bool disabled;

93

92

struct plugin *next;

94

93

} plugin;

103

102

/* Create a new plugin */

104

103

plugin *new_plugin = malloc(sizeof(plugin));

105

104

if (new_plugin == NULL){

106

return NULL;

107

}

108

char *copy_name = NULL;

109

if(name != NULL){

110

copy_name = strdup(name);

111

}

112

if(copy_name == NULL){

113

return NULL;

114

}

115

116

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

117

.argc = 1,

118

.envc = 0,

119

.disabled = false,

120

.next = *plugin_list };

121

105

perror("malloc");

106

exit(EXIT_FAILURE);

107

}

108

new_plugin->name = name;

122

109

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

123

110

if (new_plugin->argv == NULL){

124

free(copy_name);

125

free(new_plugin);

126

return NULL;

111

perror("malloc");

112

exit(EXIT_FAILURE);

127

113

}

128

new_plugin->argv[0] = copy_name;

114

new_plugin->argv[0] = name;

129

115

new_plugin->argv[1] = NULL;

130

131

new_plugin->environ = malloc(sizeof(char *));

132

if(new_plugin->environ == NULL){

133

free(copy_name);

134

free(new_plugin->argv);

135

free(new_plugin);

136

return NULL;

137

}

138

new_plugin->environ[0] = NULL;

116

new_plugin->argc = 1;

117

new_plugin->disabled = false;

118

new_plugin->next = *plugin_list;

139

119

/* Append the new plugin to the list */

140

120

*plugin_list = new_plugin;

141

121

return new_plugin;

142

122

}

143

123

144

/* Helper function for add_argument and add_environment */

145

static bool add_to_char_array(const char *new, char ***array,

146

int *len){

147

/* Resize the pointed-to array to hold one more pointer */

148

*array = realloc(*array, sizeof(char *)

149

* (size_t) ((*len) + 2));

150

/* Malloc check */

151

if(*array == NULL){

152

return false;

153

}

154

/* Make a copy of the new string */

155

char *copy = strdup(new);

156

if(copy == NULL){

157

return false;

158

}

159

/* Insert the copy */

160

(*array)[*len] = copy;

161

(*len)++;

162

/* Add a new terminating NULL pointer to the last element */

163

(*array)[*len] = NULL;

164

return true;

165

}

166

167

/* Add to a plugin's argument vector */

168

static bool add_argument(plugin *p, const char *arg){

169

if(p == NULL){

170

return false;

171

}

172

return add_to_char_array(arg, &(p->argv), &(p->argc));

173

}

174

175

/* Add to a plugin's environment */

176

static bool add_environment(plugin *p, const char *def){

177

if(p == NULL){

178

return false;

179

}

180

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

181

}

182

124

static void addargument(plugin *p, char *arg){

125

p->argv[p->argc] = arg;

126

p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));

127

if (p->argv == NULL){

128

perror("malloc");

129

exit(EXIT_FAILURE);

130

}

131

p->argc++;

132

p->argv[p->argc] = NULL;

133

}

183

134

184

135

/*

185

136

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

235

186

return true;

236

187

}

237

188

238

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

189

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

190

239

191

if (argv == NULL){

240

192

*argc = 1;

241

193

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

256

208

return argv;

257

209

}

258

210

259

static void free_plugin_list(plugin *plugin_list){

260

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

261

next = plugin_list->next;

262

free(plugin_list->name);

263

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

264

free(*arg);

265

}

266

free(plugin_list->argv);

267

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

268

free(*env);

269

}

270

free(plugin_list->environ);

271

free(plugin_list);

272

}

273

}

274

275

211

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

276

212

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

277

213

const char *argfile = ARGFILE;

295

231

/* Establish a signal handler */

296

232

sigemptyset(&sigchld_action.sa_mask);

297

233

ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);

298

if(ret == -1){

234

if(ret < 0){

299

235

perror("sigaddset");

300

exitstatus = EXIT_FAILURE;

301

goto fallback;

236

exit(EXIT_FAILURE);

302

237

}

303

238

ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);

304

if(ret == -1){

239

if(ret < 0){

305

240

perror("sigaction");

306

exitstatus = EXIT_FAILURE;

307

goto fallback;

241

exit(EXIT_FAILURE);

308

242

}

309

243

310

244

/* The options we understand. */

312

246

{ .name = "global-options", .key = 'g',

313

247

.arg = "OPTION[,OPTION[,...]]",

314

248

.doc = "Options passed to all plugins" },

315

{ .name = "global-envs", .key = 'e',

316

.arg = "VAR=value",

317

.doc = "Environment variable passed to all plugins" },

318

249

{ .name = "options-for", .key = 'o',

319

250

.arg = "PLUGIN:OPTION[,OPTION[,...]]",

320

251

.doc = "Options passed only to specified plugin" },

321

{ .name = "envs-for", .key = 'f',

322

.arg = "PLUGIN:ENV=value",

323

.doc = "Environment variable passed to specified plugin" },

324

252

{ .name = "disable", .key = 'd',

325

253

.arg = "PLUGIN",

326

254

.doc = "Disable a specific plugin", .group = 1 },

350

278

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

351

279

continue;

352

280

}

353

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

354

perror("add_argument");

355

return ARGP_ERR_UNKNOWN;

356

}

357

}

358

}

359

break;

360

case 'e':

361

if(arg == NULL){

362

break;

363

}

364

{

365

char *envdef = strdup(arg);

366

if(envdef == NULL){

367

break;

368

}

369

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

370

perror("add_environment");

281

addargument(getplugin(NULL, plugins), p);

371

282

}

372

283

}

373

284

break;

374

285

case 'o':

375

286

if (arg != NULL){

376

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

377

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

287

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

288

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

378

289

break;

379

290

}

380

291

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

387

298

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

388

299

continue;

389

300

}

390

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

391

perror("add_argument");

392

return ARGP_ERR_UNKNOWN;

393

}

301

addargument(getplugin(name, plugins), p);

394

302

}

395

303

}

396

304

}

397

305

break;

398

case 'f':

399

if(arg == NULL){

400

break;

401

}

402

{

403

char *envdef = strchr(arg, ':');

404

if(envdef == NULL){

405

break;

406

}

407

char *p_name = strndup(arg, (size_t) (envdef-arg));

408

if(p_name == NULL){

409

break;

410

}

411

envdef++;

412

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

413

perror("add_environment");

414

}

415

}

416

break;

417

306

case 'd':

418

307

if (arg != NULL){

419

plugin *p = getplugin(arg, plugins);

420

if(p == NULL){

421

return ARGP_ERR_UNKNOWN;

422

}

423

p->disabled = true;

308

getplugin(arg, plugins)->disabled = true;

424

309

}

425

310

break;

426

311

case 128:

436

321

debug = true;

437

322

break;

438

323

case ARGP_KEY_ARG:

439

fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);

324

fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);

440

325

break;

441

326

case ARGP_KEY_END:

442

327

break;

456

341

if (ret == ARGP_ERR_UNKNOWN){

457

342

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

458

343

exitstatus = EXIT_FAILURE;

459

goto fallback;

344

goto end;

460

345

}

461

346

462

347

conffp = fopen(argfile, "r");

463

348

if(conffp != NULL){

464

349

char *org_line = NULL;

465

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

466

350

size_t size = 0;

467

351

ssize_t sret;

352

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

468

353

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

469

354

const char comment_delim[] = "#";

470

355

481

366

continue;

482

367

}

483

368

new_arg = strdup(p);

484

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

369

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

485

370

if (custom_argv == NULL){

486

perror("add_to_argv");

371

perror("addcustomargument");

487

372

exitstatus = EXIT_FAILURE;

488

goto fallback;

373

goto end;

489

374

}

490

375

}

491

376

}

496

381

if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){

497

382

perror("fopen");

498

383

exitstatus = EXIT_FAILURE;

499

goto fallback;

384

goto end;

500

385

}

501

386

}

502

387

506

391

if (ret == ARGP_ERR_UNKNOWN){

507

392

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

508

393

exitstatus = EXIT_FAILURE;

509

goto fallback;

394

goto end;

510

395

}

511

396

}

512

397

517

402

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

518

403

fprintf(stderr, "\tArg: %s\n", *a);

519

404

}

520

fprintf(stderr, "...and %u environment variables\n", p->envc);

521

for(char **a = p->environ; *a != NULL; a++){

522

fprintf(stderr, "\t%s\n", *a);

523

}

524

405

}

525

406

}

526

407

538

419

if(dir == NULL){

539

420

perror("Could not open plugin dir");

540

421

exitstatus = EXIT_FAILURE;

541

goto fallback;

422

goto end;

542

423

}

543

424

544

425

/* Set the FD_CLOEXEC flag on the directory, if possible */

549

430

if(ret < 0){

550

431

perror("set_cloexec_flag");

551

432

exitstatus = EXIT_FAILURE;

552

goto fallback;

433

goto end;

553

434

}

554

435

}

555

436

}

564

445

if (errno == EBADF){

565

446

perror("readdir");

566

447

exitstatus = EXIT_FAILURE;

567

goto fallback;

448

goto end;

568

449

}

569

450

break;

570

451

}

615

496

continue;

616

497

}

617

498

}

618

619

char *filename;

620

ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);

621

if(ret < 0){

622

perror("asprintf");

499

500

char *filename = malloc(d_name_len + strlen(plugindir) + 2);

501

if (filename == NULL){

502

perror("malloc");

623

503

continue;

624

504

}

505

strcpy(filename, plugindir); /* Spurious warning */

506

strcat(filename, "/"); /* Spurious warning */

507

strcat(filename, dirst->d_name); /* Spurious warning */

625

508

626

509

ret = stat(filename, &st);

627

510

if (ret == -1){

638

521

free(filename);

639

522

continue;

640

523

}

641

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

642

if(p == NULL){

643

perror("getplugin");

644

free(filename);

645

continue;

646

}

647

if(p->disabled){

524

if(getplugin(dirst->d_name, &plugin_list)->disabled){

648

525

if(debug){

649

526

fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",

650

527

dirst->d_name);

652

529

free(filename);

653

530

continue;

654

531

}

532

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

655

533

{

656

534

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

657

535

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

658

if(g != NULL){

659

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

660

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

661

perror("add_argument");

662

}

663

}

664

/* Add global environment variables */

665

for(char **e = g->environ; *e != NULL; e++){

666

if(not add_environment(p, *e)){

667

perror("add_environment");

668

}

669

}

670

}

671

}

672

/* If this plugin has any environment variables, we will call

673

using execve and need to duplicate the environment from this

674

process, too. */

675

if(p->environ[0] != NULL){

676

for(char **e = environ; *e != NULL; e++){

677

char *copy = strdup(*e);

678

if(copy == NULL){

679

perror("strdup");

680

continue;

681

}

682

if(not add_environment(p, copy)){

683

perror("add_environment");

684

}

685

}

686

}

687

536

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

537

addargument(p, *a);

538

}

539

}

688

540

int pipefd[2];

689

541

ret = pipe(pipefd);

690

542

if (ret == -1){

691

543

perror("pipe");

692

544

exitstatus = EXIT_FAILURE;

693

goto fallback;

545

goto end;

694

546

}

695

547

ret = set_cloexec_flag(pipefd[0]);

696

548

if(ret < 0){

697

549

perror("set_cloexec_flag");

698

550

exitstatus = EXIT_FAILURE;

699

goto fallback;

551

goto end;

700

552

}

701

553

ret = set_cloexec_flag(pipefd[1]);

702

554

if(ret < 0){

703

555

perror("set_cloexec_flag");

704

556

exitstatus = EXIT_FAILURE;

705

goto fallback;

557

goto end;

706

558

}

707

559

/* Block SIGCHLD until process is safely in process list */

708

560

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

709

561

if(ret < 0){

710

562

perror("sigprocmask");

711

563

exitstatus = EXIT_FAILURE;

712

goto fallback;

564

goto end;

713

565

}

714

566

// Starting a new process to be watched

715

567

pid_t pid = fork();

716

568

if(pid == -1){

717

569

perror("fork");

718

570

exitstatus = EXIT_FAILURE;

719

goto fallback;

571

goto end;

720

572

}

721

573

if(pid == 0){

722

574

/* this is the child process */

742

594

above and must now close it manually here. */

743

595

closedir(dir);

744

596

}

745

if(p->environ[0] == NULL){

746

if(execv(filename, p->argv) < 0){

747

perror("execv");

748

_exit(EXIT_FAILURE);

749

}

750

} else {

751

if(execve(filename, p->argv, p->environ) < 0){

752

perror("execve");

753

_exit(EXIT_FAILURE);

754

}

597

if(execv(filename, p->argv) < 0){

598

perror("execv");

599

_exit(EXIT_FAILURE);

755

600

}

756

601

/* no return */

757

602

}

766

611

perror("sigprocmask");

767

612

}

768

613

exitstatus = EXIT_FAILURE;

769

goto fallback;

614

goto end;

770

615

}

771

616

772

617

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

780

625

if(ret < 0){

781

626

perror("sigprocmask");

782

627

exitstatus = EXIT_FAILURE;

783

goto fallback;

628

goto end;

784

629

}

785

630

786

631

FD_SET(new_process->fd, &rfds_all);

791

636

792

637

}

793

638

794

free_plugin_list(plugin_list);

639

/* Free the plugin list */

640

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

641

next = plugin_list->next;

642

free(plugin_list->argv);

643

free(plugin_list);

644

}

795

645

796

646

closedir(dir);

797

647

dir = NULL;

807

657

if (select_ret == -1){

808

658

perror("select");

809

659

exitstatus = EXIT_FAILURE;

810

goto fallback;

660

goto end;

811

661

}

812

662

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

813

663

from one of them */

839

689

if(ret < 0){

840

690

perror("sigprocmask");

841

691

exitstatus = EXIT_FAILURE;

842

goto fallback;

692

goto end;

843

693

}

844

694

/* Delete this process entry from the list */

845

695

if(process_list == proc){

874

724

perror("print_out_password");

875

725

exitstatus = EXIT_FAILURE;

876

726

}

877

goto fallback;

727

goto end;

878

728

}

879

729

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

880

730

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

888

738

if (proc->buffer == NULL){

889

739

perror("malloc");

890

740

exitstatus = EXIT_FAILURE;

891

goto fallback;

741

goto end;

892

742

}

893

743

proc->buffer_size += BUFFER_SIZE;

894

744

}

909

759

}

910

760

911

761

912

fallback:

762

end:

913

763

914

764

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

915

765

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

920

770

if(not bret){

921

771

perror("print_out_password");

922

772

exitstatus = EXIT_FAILURE;

773

goto end;

923

774

}

924

775

}

925

776

926

777

/* Restore old signal handler */

927

ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);

928

if(ret == -1){

929

perror("sigaction");

930

exitstatus = EXIT_FAILURE;

931

}

932

933

if(custom_argv != NULL){

934

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

935

free(*arg);

936

}

937

free(custom_argv);

938

}

939

free_plugin_list(plugin_list);

778

sigaction(SIGCHLD, &old_sigchld_action, NULL);

779

780

free(custom_argv);

781

782

/* Free the plugin list */

783

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

784

next = plugin_list->next;

785

free(plugin_list->argv);

786

free(plugin_list);

787

}

940

788

941

789

if(dir != NULL){

942

790

closedir(dir);