/mandos/trunk : revision 101

21

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

22

*/

23

24

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */

25

24

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

25

asprintf() */

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(), strcpy(),

55

strcat() */

54

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

56

55

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

57

56

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

58

57

argp_state, struct argp,

65

64

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

66

65

67

66

#define BUFFER_SIZE 256

67

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

68

69

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

70

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

87

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

88

char **argv;

89

int argc;

90

char **environ;

91

int envc;

90

92

bool disabled;

91

93

struct plugin *next;

92

94

} plugin;

101

103

/* Create a new plugin */

102

104

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

103

105

if (new_plugin == NULL){

104

perror("malloc");

105

exit(EXIT_FAILURE);

106

}

107

new_plugin->name = name;

106

return NULL;

107

}

108

char *copy_name = NULL;

109

if(name != NULL){

110

copy_name = strdup(name);

111

if(copy_name == NULL){

112

return NULL;

113

}

114

}

115

116

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

117

.argc = 1,

118

.envc = 0,

119

.disabled = false,

120

.next = *plugin_list };

121

108

122

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

109

123

if (new_plugin->argv == NULL){

110

perror("malloc");

111

exit(EXIT_FAILURE);

124

free(copy_name);

125

free(new_plugin);

126

return NULL;

112

127

}

113

new_plugin->argv[0] = name;

128

new_plugin->argv[0] = copy_name;

114

129

new_plugin->argv[1] = NULL;

115

new_plugin->argc = 1;

116

new_plugin->disabled = false;

117

new_plugin->next = *plugin_list;

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;

118

139

/* Append the new plugin to the list */

119

140

*plugin_list = new_plugin;

120

141

return new_plugin;

121

142

}

122

143

123

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

124

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

125

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

126

if (p->argv == NULL){

127

perror("malloc");

128

exit(EXIT_FAILURE);

129

}

130

p->argc++;

131

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

132

}

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

133

183

134

184

/*

135

185

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

185

235

return true;

186

236

}

187

237

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;

244

}

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;

257

}

258

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);

271

}

272

}

273

188

274

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

189

275

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

276

const char *argfile = ARGFILE;

277

FILE *conffp;

190

278

size_t d_name_len;

191

279

DIR *dir = NULL;

192

280

struct dirent *dirst;

200

288

struct sigaction old_sigchld_action;

201

289

struct sigaction sigchld_action = { .sa_handler = handle_sigchld,

202

290

.sa_flags = SA_NOCLDSTOP };

203

char *plus_options = NULL;

204

char **plus_argv = NULL;

205

291

char **custom_argv = NULL;

292

int custom_argc = 0;

293

206

294

/* Establish a signal handler */

207

295

sigemptyset(&sigchld_action.sa_mask);

208

296

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

209

if(ret < 0){

297

if(ret == -1){

210

298

perror("sigaddset");

211

exit(EXIT_FAILURE);

299

exitstatus = EXIT_FAILURE;

300

goto fallback;

212

301

}

213

302

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

214

if(ret < 0){

303

if(ret == -1){

215

304

perror("sigaction");

216

exit(EXIT_FAILURE);

305

exitstatus = EXIT_FAILURE;

306

goto fallback;

217

307

}

218

308

219

309

/* The options we understand. */

221

311

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

222

312

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

223

313

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

314

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

315

.arg = "VAR=value",

316

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

224

317

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

225

318

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

226

319

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

320

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

321

.arg = "PLUGIN:ENV=value",

322

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

227

323

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

228

324

.arg = "PLUGIN",

229

325

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

250

346

if (arg != NULL){

251

347

char *p;

252

348

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

253

if(strcmp(p, "") == 0){

349

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

254

350

continue;

255

351

}

256

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

352

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

353

perror("add_argument");

354

return ARGP_ERR_UNKNOWN;

355

}

356

}

357

}

358

break;

359

case 'e':

360

if(arg == NULL){

361

break;

362

}

363

{

364

char *envdef = strdup(arg);

365

if(envdef == NULL){

366

break;

367

}

368

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

369

perror("add_environment");

257

370

}

258

371

}

259

372

break;

260

373

case 'o':

261

374

if (arg != NULL){

262

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

263

if(strcmp(name, "") == 0){

375

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

376

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

264

377

break;

265

378

}

266

379

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

267

if(strcmp(opt, "") == 0){

380

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

268

381

break;

269

382

}

270

383

if(opt != NULL){

271

384

char *p;

272

385

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

273

if(strcmp(p, "") == 0){

386

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

274

387

continue;

275

388

}

276

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

389

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

390

perror("add_argument");

391

return ARGP_ERR_UNKNOWN;

392

}

277

393

}

278

394

}

279

395

}

280

396

break;

397

case 'f':

398

if(arg == NULL){

399

break;

400

}

401

{

402

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

403

if(envdef == NULL){

404

break;

405

}

406

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

407

if(p_name == NULL){

408

break;

409

}

410

envdef++;

411

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

412

perror("add_environment");

413

}

414

}

415

break;

281

416

case 'd':

282

417

if (arg != NULL){

283

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

418

plugin *p = getplugin(arg, plugins);

419

if(p == NULL){

420

return ARGP_ERR_UNKNOWN;

421

}

422

p->disabled = true;

284

423

}

285

424

break;

286

425

case 128:

296

435

debug = true;

297

436

break;

298

437

case ARGP_KEY_ARG:

299

if(plus_options != NULL or arg == NULL or arg[0] != '+'){

300

argp_usage (state);

301

}

302

plus_options = arg;

438

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

303

439

break;

304

440

case ARGP_KEY_END:

305

441

break;

319

455

if (ret == ARGP_ERR_UNKNOWN){

320

456

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

321

457

exitstatus = EXIT_FAILURE;

322

goto end;

458

goto fallback;

323

459

}

324

325

if(plus_options){

326

/* This is a mangled argument in the form of

327

"+--option+--other-option=parameter+--yet-another-option", etc */

328

/* Make new argc and argv vars, and call argp_parse() again. */

329

plus_options++; /* skip the first '+' character */

330

const char delims[] = "+";

331

char *arg;

332

int new_argc = 1;

333

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

334

if(plus_argv == NULL){

335

perror("malloc");

460

461

conffp = fopen(argfile, "r");

462

if(conffp != NULL){

463

char *org_line = NULL;

464

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

465

size_t size = 0;

466

ssize_t sret;

467

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

468

const char comment_delim[] = "#";

469

470

while(true){

471

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

472

if(sret == -1){

473

break;

474

}

475

476

line = org_line;

477

arg = strsep(&line, comment_delim);

478

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

479

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

480

continue;

481

}

482

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

}

489

}

490

}

491

free(org_line);

492

} else{

493

/* Check for harmful errors and go to fallback. Other errors might

494

not affect opening plugins */

495

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

496

perror("fopen");

336

497

exitstatus = EXIT_FAILURE;

337

goto end;

498

goto fallback;

338

499

}

339

plus_argv[0] = argv[0];

340

plus_argv[1] = NULL;

500

}

341

501

342

while((arg = strsep(&plus_options, delims)) != NULL){

343

new_argc++;

344

plus_argv = realloc(plus_argv, sizeof(char *)

345

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

346

if(plus_argv == NULL){

347

perror("realloc");

348

exitstatus = EXIT_FAILURE;

349

goto end;

350

}

351

plus_argv[new_argc-1] = arg;

352

plus_argv[new_argc] = NULL;

353

}

354

355

ret = argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);

502

if(custom_argv != NULL){

503

custom_argv[0] = argv[0];

504

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

356

505

if (ret == ARGP_ERR_UNKNOWN){

357

506

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

358

507

exitstatus = EXIT_FAILURE;

359

goto end;

508

goto fallback;

360

509

}

361

510

}

362

511

367

516

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

368

517

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

369

518

}

519

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

520

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

521

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

522

}

370

523

}

371

524

}

372

525

384

537

if(dir == NULL){

385

538

perror("Could not open plugin dir");

386

539

exitstatus = EXIT_FAILURE;

387

goto end;

540

goto fallback;

388

541

}

389

542

390

543

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

395

548

if(ret < 0){

396

549

perror("set_cloexec_flag");

397

550

exitstatus = EXIT_FAILURE;

398

goto end;

551

goto fallback;

399

552

}

400

553

}

401

554

}

410

563

if (errno == EBADF){

411

564

perror("readdir");

412

565

exitstatus = EXIT_FAILURE;

413

goto end;

566

goto fallback;

414

567

}

415

568

break;

416

569

}

461

614

continue;

462

615

}

463

616

}

464

465

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

466

if (filename == NULL){

467

perror("malloc");

617

618

char *filename;

619

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

620

if(ret < 0){

621

perror("asprintf");

468

622

continue;

469

623

}

470

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

471

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

472

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

473

624

474

625

ret = stat(filename, &st);

475

626

if (ret == -1){

486

637

free(filename);

487

638

continue;

488

639

}

489

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

640

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

641

if(p == NULL){

642

perror("getplugin");

643

free(filename);

644

continue;

645

}

646

if(p->disabled){

490

647

if(debug){

491

648

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

492

649

dirst->d_name);

494

651

free(filename);

495

652

continue;

496

653

}

497

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

498

654

{

499

655

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

500

656

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

501

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

502

addargument(p, *a);

503

}

504

}

505

int pipefd[2];

657

if(g != NULL){

658

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

659

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

660

perror("add_argument");

661

}

662

}

663

/* Add global environment variables */

664

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

665

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

666

perror("add_environment");

667

}

668

}

669

}

670

}

671

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

672

using execve and need to duplicate the environment from this

673

process, too. */

674

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

675

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

676

char *copy = strdup(*e);

677

if(copy == NULL){

678

perror("strdup");

679

continue;

680

}

681

if(not add_environment(p, copy)){

682

perror("add_environment");

683

}

684

}

685

}

686

687

int pipefd[2];

506

688

ret = pipe(pipefd);

507

689

if (ret == -1){

508

690

perror("pipe");

509

691

exitstatus = EXIT_FAILURE;

510

goto end;

692

goto fallback;

511

693

}

512

694

ret = set_cloexec_flag(pipefd[0]);

513

695

if(ret < 0){

514

696

perror("set_cloexec_flag");

515

697

exitstatus = EXIT_FAILURE;

516

goto end;

698

goto fallback;

517

699

}

518

700

ret = set_cloexec_flag(pipefd[1]);

519

701

if(ret < 0){

520

702

perror("set_cloexec_flag");

521

703

exitstatus = EXIT_FAILURE;

522

goto end;

704

goto fallback;

523

705

}

524

706

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

525

707

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

526

708

if(ret < 0){

527

709

perror("sigprocmask");

528

710

exitstatus = EXIT_FAILURE;

529

goto end;

711

goto fallback;

530

712

}

531

713

// Starting a new process to be watched

532

714

pid_t pid = fork();

533

715

if(pid == -1){

534

716

perror("fork");

535

717

exitstatus = EXIT_FAILURE;

536

goto end;

718

goto fallback;

537

719

}

538

720

if(pid == 0){

539

721

/* this is the child process */

559

741

above and must now close it manually here. */

560

742

closedir(dir);

561

743

}

562

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

563

perror("execv");

564

_exit(EXIT_FAILURE);

744

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

745

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

746

perror("execv");

747

_exit(EXIT_FAILURE);

748

}

749

} else {

750

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

751

perror("execve");

752

_exit(EXIT_FAILURE);

753

}

565

754

}

566

755

/* no return */

567

756

}

576

765

perror("sigprocmask");

577

766

}

578

767

exitstatus = EXIT_FAILURE;

579

goto end;

768

goto fallback;

580

769

}

581

770

582

771

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

590

779

if(ret < 0){

591

780

perror("sigprocmask");

592

781

exitstatus = EXIT_FAILURE;

593

goto end;

782

goto fallback;

594

783

}

595

784

596

785

FD_SET(new_process->fd, &rfds_all);

601

790

602

791

}

603

792

604

/* Free the plugin list */

605

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

606

next = plugin_list->next;

607

free(plugin_list->argv);

608

free(plugin_list);

609

}

793

free_plugin_list(plugin_list);

794

plugin_list = NULL;

610

795

611

796

closedir(dir);

612

797

dir = NULL;

622

807

if (select_ret == -1){

623

808

perror("select");

624

809

exitstatus = EXIT_FAILURE;

625

goto end;

810

goto fallback;

626

811

}

627

812

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

628

813

from one of them */

654

839

if(ret < 0){

655

840

perror("sigprocmask");

656

841

exitstatus = EXIT_FAILURE;

657

goto end;

842

goto fallback;

658

843

}

659

844

/* Delete this process entry from the list */

660

845

if(process_list == proc){

689

874

perror("print_out_password");

690

875

exitstatus = EXIT_FAILURE;

691

876

}

692

goto end;

877

goto fallback;

693

878

}

694

879

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

695

880

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

703

888

if (proc->buffer == NULL){

704

889

perror("malloc");

705

890

exitstatus = EXIT_FAILURE;

706

goto end;

891

goto fallback;

707

892

}

708

893

proc->buffer_size += BUFFER_SIZE;

709

894

}

724

909

}

725

910

726

911

727

end:

912

fallback:

728

913

729

914

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

730

915

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

735

920

if(not bret){

736

921

perror("print_out_password");

737

922

exitstatus = EXIT_FAILURE;

738

goto end;

739

923

}

740

924

}

741

925

742

926

/* Restore old signal handler */

743

sigaction(SIGCHLD, &old_sigchld_action, NULL);

744

745

free(plus_argv);

746

747

/* Free the plugin list */

748

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

749

next = plugin_list->next;

750

free(plugin_list->argv);

751

free(plugin_list);

752

}

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);

753

940

754

941

if(dir != NULL){

755

942

closedir(dir);