/mandos/trunk : revision 75

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() */

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,

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

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;

92

90

bool disabled;

93

91

struct plugin *next;

94

92

} plugin;

103

101

/* Create a new plugin */

104

102

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

105

103

if (new_plugin == NULL){

106

return NULL;

107

}

108

char *copy_name = strdup(name);

109

if(copy_name == NULL){

110

return NULL;

111

}

112

113

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

114

.argc = 1,

115

.envc = 0,

116

.disabled = false,

117

.next = *plugin_list };

118

104

perror("malloc");

105

exit(EXIT_FAILURE);

106

}

107

new_plugin->name = name;

119

108

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

120

109

if (new_plugin->argv == NULL){

121

free(new_plugin);

122

return NULL;

110

perror("malloc");

111

exit(EXIT_FAILURE);

123

112

}

124

new_plugin->argv[0] = copy_name;

113

new_plugin->argv[0] = name;

125

114

new_plugin->argv[1] = NULL;

126

127

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

128

if(new_plugin->environ == NULL){

129

free(new_plugin->argv);

130

free(new_plugin);

131

return NULL;

132

}

133

new_plugin->environ[0] = NULL;

115

new_plugin->argc = 1;

116

new_plugin->disabled = false;

117

new_plugin->next = *plugin_list;

134

118

/* Append the new plugin to the list */

135

119

*plugin_list = new_plugin;

136

120

return new_plugin;

137

121

}

138

122

139

/* Helper function for add_argument and add_environment */

140

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

141

int *len){

142

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

143

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

144

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

145

/* Malloc check */

146

if(*array == NULL){

147

return false;

148

}

149

/* Make a copy of the new string */

150

char *copy = strdup(new);

151

if(copy == NULL){

152

return false;

153

}

154

/* Insert the copy */

155

(*array)[*len] = copy;

156

(*len)++;

157

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

158

(*array)[*len] = NULL;

159

return true;

160

}

161

162

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

163

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

164

if(p == NULL){

165

return false;

166

}

167

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

168

}

169

170

/* Add to a plugin's environment */

171

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

172

if(p == NULL){

173

return false;

174

}

175

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

176

}

177

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

}

178

133

179

134

/*

180

135

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

230

185

return true;

231

186

}

232

187

233

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

234

if (argv == NULL){

235

*argc = 1;

236

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

237

if(argv == NULL){

238

return NULL;

239

}

240

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

241

argv[1] = NULL;

242

}

243

*argc += 1;

244

argv = realloc(argv, sizeof(char *)

245

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

246

if(argv == NULL){

247

return NULL;

248

}

249

argv[*argc-1] = arg;

250

argv[*argc] = NULL;

251

return argv;

252

}

253

254

static void free_plugin_list(plugin *plugin_list){

255

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

256

next = plugin_list->next;

257

free(plugin_list->name);

258

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

259

free(*arg);

260

}

261

free(plugin_list->argv);

262

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

263

free(*env);

264

}

265

free(plugin_list->environ);

266

free(plugin_list);

267

}

268

}

269

270

188

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

271

189

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

272

const char *argfile = ARGFILE;

273

FILE *conffp;

274

190

size_t d_name_len;

275

191

DIR *dir = NULL;

276

192

struct dirent *dirst;

284

200

struct sigaction old_sigchld_action;

285

201

struct sigaction sigchld_action = { .sa_handler = handle_sigchld,

286

202

.sa_flags = SA_NOCLDSTOP };

287

char **custom_argv = NULL;

288

int custom_argc = 0;

289

203

char *plus_options = NULL;

204

char **plus_argv = NULL;

205

290

206

/* Establish a signal handler */

291

207

sigemptyset(&sigchld_action.sa_mask);

292

208

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

293

if(ret == -1){

209

if(ret < 0){

294

210

perror("sigaddset");

295

exitstatus = EXIT_FAILURE;

296

goto fallback;

211

exit(EXIT_FAILURE);

297

212

}

298

213

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

299

if(ret == -1){

214

if(ret < 0){

300

215

perror("sigaction");

301

exitstatus = EXIT_FAILURE;

302

goto fallback;

216

exit(EXIT_FAILURE);

303

217

}

304

218

305

219

/* The options we understand. */

307

221

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

308

222

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

309

223

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

310

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

311

.arg = "VAR=value",

312

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

313

224

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

314

225

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

315

226

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

316

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

317

.arg = "PLUGIN:ENV=value",

318

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

319

227

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

320

228

.arg = "PLUGIN",

321

229

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

342

250

if (arg != NULL){

343

251

char *p;

344

252

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

345

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

253

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

346

254

continue;

347

255

}

348

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

349

perror("add_argument");

350

return ARGP_ERR_UNKNOWN;

351

}

352

}

353

}

354

break;

355

case 'e':

356

if(arg == NULL){

357

break;

358

}

359

{

360

char *envdef = strdup(arg);

361

if(envdef == NULL){

362

break;

363

}

364

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

365

perror("add_environment");

256

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

366

257

}

367

258

}

368

259

break;

369

260

case 'o':

370

261

if (arg != NULL){

371

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

372

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

262

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

263

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

373

264

break;

374

265

}

375

266

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

376

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

267

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

377

268

break;

378

269

}

379

270

if(opt != NULL){

380

271

char *p;

381

272

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

382

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

273

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

383

274

continue;

384

275

}

385

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

386

perror("add_argument");

387

return ARGP_ERR_UNKNOWN;

388

}

276

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

389

277

}

390

278

}

391

279

}

392

280

break;

393

case 'f':

394

if(arg == NULL){

395

break;

396

}

397

{

398

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

399

if(envdef == NULL){

400

break;

401

}

402

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

403

if(p_name == NULL){

404

break;

405

}

406

envdef++;

407

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

408

perror("add_environment");

409

}

410

}

411

break;

412

281

case 'd':

413

282

if (arg != NULL){

414

plugin *p = getplugin(arg, plugins);

415

if(p == NULL){

416

return ARGP_ERR_UNKNOWN;

417

}

418

p->disabled = true;

283

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

419

284

}

420

285

break;

421

286

case 128:

431

296

debug = true;

432

297

break;

433

298

case ARGP_KEY_ARG:

434

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

299

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

300

argp_usage (state);

301

}

302

plus_options = arg;

435

303

break;

436

304

case ARGP_KEY_END:

437

305

break;

451

319

if (ret == ARGP_ERR_UNKNOWN){

452

320

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

453

321

exitstatus = EXIT_FAILURE;

454

goto fallback;

322

goto end;

455

323

}

456

457

conffp = fopen(argfile, "r");

458

if(conffp != NULL){

459

char *org_line = NULL;

460

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

461

size_t size = 0;

462

ssize_t sret;

463

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

464

const char comment_delim[] = "#";

465

466

while(true){

467

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

468

if(sret == -1){

469

break;

470

}

471

472

line = org_line;

473

arg = strsep(&line, comment_delim);

474

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

475

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

476

continue;

477

}

478

new_arg = strdup(p);

479

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

480

if (custom_argv == NULL){

481

perror("add_to_argv");

482

exitstatus = EXIT_FAILURE;

483

goto fallback;

484

}

485

}

486

}

487

free(org_line);

488

} else{

489

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

490

not affect opening plugins */

491

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

492

perror("fopen");

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");

493

336

exitstatus = EXIT_FAILURE;

494

goto fallback;

337

goto end;

495

338

}

496

}

339

plus_argv[0] = argv[0];

340

plus_argv[1] = NULL;

497

341

498

if(custom_argv != NULL){

499

custom_argv[0] = argv[0];

500

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

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);

501

356

if (ret == ARGP_ERR_UNKNOWN){

502

357

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

503

358

exitstatus = EXIT_FAILURE;

504

goto fallback;

359

goto end;

505

360

}

506

361

}

507

362

512

367

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

513

368

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

514

369

}

515

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

516

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

517

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

518

}

519

370

}

520

371

}

521

372

533

384

if(dir == NULL){

534

385

perror("Could not open plugin dir");

535

386

exitstatus = EXIT_FAILURE;

536

goto fallback;

387

goto end;

537

388

}

538

389

539

390

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

544

395

if(ret < 0){

545

396

perror("set_cloexec_flag");

546

397

exitstatus = EXIT_FAILURE;

547

goto fallback;

398

goto end;

548

399

}

549

400

}

550

401

}

559

410

if (errno == EBADF){

560

411

perror("readdir");

561

412

exitstatus = EXIT_FAILURE;

562

goto fallback;

413

goto end;

563

414

}

564

415

break;

565

416

}

610

461

continue;

611

462

}

612

463

}

613

614

char *filename;

615

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

616

if(ret < 0){

617

perror("asprintf");

464

465

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

466

if (filename == NULL){

467

perror("malloc");

618

468

continue;

619

469

}

470

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

471

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

472

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

620

473

621

474

ret = stat(filename, &st);

622

475

if (ret == -1){

633

486

free(filename);

634

487

continue;

635

488

}

636

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

637

if(p == NULL){

638

perror("getplugin");

639

free(filename);

640

continue;

641

}

642

if(p->disabled){

489

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

643

490

if(debug){

644

491

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

645

492

dirst->d_name);

647

494

free(filename);

648

495

continue;

649

496

}

497

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

650

498

{

651

499

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

652

500

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

653

if(g != NULL){

654

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

655

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

656

perror("add_argument");

657

}

658

}

659

/* Add global environment variables */

660

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

661

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

662

perror("add_environment");

663

}

664

}

665

}

666

}

667

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

668

using execve and need to duplicate the environment from this

669

process, too. */

670

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

671

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

672

char *copy = strdup(*e);

673

if(copy == NULL){

674

perror("strdup");

675

continue;

676

}

677

if(not add_environment(p, copy)){

678

perror("add_environment");

679

}

680

}

681

}

682

501

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

502

addargument(p, *a);

503

}

504

}

683

505

int pipefd[2];

684

506

ret = pipe(pipefd);

685

507

if (ret == -1){

686

508

perror("pipe");

687

509

exitstatus = EXIT_FAILURE;

688

goto fallback;

510

goto end;

689

511

}

690

512

ret = set_cloexec_flag(pipefd[0]);

691

513

if(ret < 0){

692

514

perror("set_cloexec_flag");

693

515

exitstatus = EXIT_FAILURE;

694

goto fallback;

516

goto end;

695

517

}

696

518

ret = set_cloexec_flag(pipefd[1]);

697

519

if(ret < 0){

698

520

perror("set_cloexec_flag");

699

521

exitstatus = EXIT_FAILURE;

700

goto fallback;

522

goto end;

701

523

}

702

524

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

703

525

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

704

526

if(ret < 0){

705

527

perror("sigprocmask");

706

528

exitstatus = EXIT_FAILURE;

707

goto fallback;

529

goto end;

708

530

}

709

531

// Starting a new process to be watched

710

532

pid_t pid = fork();

711

533

if(pid == -1){

712

534

perror("fork");

713

535

exitstatus = EXIT_FAILURE;

714

goto fallback;

536

goto end;

715

537

}

716

538

if(pid == 0){

717

539

/* this is the child process */

737

559

above and must now close it manually here. */

738

560

closedir(dir);

739

561

}

740

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

741

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

742

perror("execv");

743

_exit(EXIT_FAILURE);

744

}

745

} else {

746

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

747

perror("execve");

748

_exit(EXIT_FAILURE);

749

}

562

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

563

perror("execv");

564

_exit(EXIT_FAILURE);

750

565

}

751

566

/* no return */

752

567

}

761

576

perror("sigprocmask");

762

577

}

763

578

exitstatus = EXIT_FAILURE;

764

goto fallback;

579

goto end;

765

580

}

766

581

767

582

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

775

590

if(ret < 0){

776

591

perror("sigprocmask");

777

592

exitstatus = EXIT_FAILURE;

778

goto fallback;

593

goto end;

779

594

}

780

595

781

596

FD_SET(new_process->fd, &rfds_all);

786

601

787

602

}

788

603

789

free_plugin_list(plugin_list);

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

}

790

610

791

611

closedir(dir);

792

612

dir = NULL;

802

622

if (select_ret == -1){

803

623

perror("select");

804

624

exitstatus = EXIT_FAILURE;

805

goto fallback;

625

goto end;

806

626

}

807

627

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

808

628

from one of them */

834

654

if(ret < 0){

835

655

perror("sigprocmask");

836

656

exitstatus = EXIT_FAILURE;

837

goto fallback;

657

goto end;

838

658

}

839

659

/* Delete this process entry from the list */

840

660

if(process_list == proc){

869

689

perror("print_out_password");

870

690

exitstatus = EXIT_FAILURE;

871

691

}

872

goto fallback;

692

goto end;

873

693

}

874

694

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

875

695

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

883

703

if (proc->buffer == NULL){

884

704

perror("malloc");

885

705

exitstatus = EXIT_FAILURE;

886

goto fallback;

706

goto end;

887

707

}

888

708

proc->buffer_size += BUFFER_SIZE;

889

709

}

904

724

}

905

725

906

726

907

fallback:

727

end:

908

728

909

729

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

910

730

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

915

735

if(not bret){

916

736

perror("print_out_password");

917

737

exitstatus = EXIT_FAILURE;

738

goto end;

918

739

}

919

740

}

920

741

921

742

/* Restore old signal handler */

922

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

923

if(ret == -1){

924

perror("sigaction");

925

exitstatus = EXIT_FAILURE;

926

}

927

928

if(custom_argv != NULL){

929

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

930

free(*arg);

931

}

932

free(custom_argv);

933

}

934

free_plugin_list(plugin_list);

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

}

935

753

936

754

if(dir != NULL){

937

755

closedir(dir);