/mandos/release : 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> /* strtok, 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 = "mandos-client 1.0";

69

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

70

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

71

72

struct process;

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

171

221

}

172

222

173

223

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

174

size_t ret;

175

for(size_t written = 0; written < length; written += ret){

224

ssize_t ret;

225

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

226

length--;

227

}

228

for(size_t written = 0; written < length; written += (size_t)ret){

176

229

ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,

177

230

length - written));

178

231

if(ret < 0){

182

235

return true;

183

236

}

184

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

185

274

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

186

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

275

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

276

const char *argfile = ARGFILE;

277

FILE *conffp;

187

278

size_t d_name_len;

188

279

DIR *dir = NULL;

189

280

struct dirent *dirst;

197

288

struct sigaction old_sigchld_action;

198

289

struct sigaction sigchld_action = { .sa_handler = handle_sigchld,

199

290

.sa_flags = SA_NOCLDSTOP };

200

char *plus_options = NULL;

201

char **plus_argv = NULL;

291

char **custom_argv = NULL;

292

int custom_argc = 0;

202

293

203

294

/* Establish a signal handler */

204

295

sigemptyset(&sigchld_action.sa_mask);

205

296

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

206

if(ret < 0){

297

if(ret == -1){

207

298

perror("sigaddset");

208

exit(EXIT_FAILURE);

299

exitstatus = EXIT_FAILURE;

300

goto fallback;

209

301

}

210

302

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

211

if(ret < 0){

303

if(ret == -1){

212

304

perror("sigaction");

213

exit(EXIT_FAILURE);

305

exitstatus = EXIT_FAILURE;

306

goto fallback;

214

307

}

215

308

216

309

/* The options we understand. */

218

311

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

219

312

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

220

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" },

221

317

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

222

318

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

223

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" },

224

323

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

225

324

.arg = "PLUGIN",

226

325

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

245

344

switch (key) {

246

345

case 'g':

247

346

if (arg != NULL){

248

char *p = strtok(arg, ",");

249

do{

250

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

251

p = strtok(NULL, ",");

252

} while (p != NULL);

347

char *p;

348

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

349

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

350

continue;

351

}

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");

370

}

253

371

}

254

372

break;

255

373

case 'o':

256

374

if (arg != NULL){

257

char *name = strtok(arg, ":");

258

char *p = strtok(NULL, ":");

259

if(p != NULL){

260

p = strtok(p, ",");

261

do{

262

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

263

p = strtok(NULL, ",");

264

} while (p != NULL);

375

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

376

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

377

break;

378

}

379

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

380

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

381

break;

382

}

383

if(opt != NULL){

384

char *p;

385

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

386

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

387

continue;

388

}

389

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

390

perror("add_argument");

391

return ARGP_ERR_UNKNOWN;

392

}

393

}

394

}

395

}

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");

265

413

}

266

414

}

267

415

break;

268

416

case 'd':

269

417

if (arg != NULL){

270

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;

271

423

}

272

424

break;

273

425

case 128:

283

435

debug = true;

284

436

break;

285

437

case ARGP_KEY_ARG:

286

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

287

argp_usage (state);

288

}

289

plus_options = arg;

438

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

290

439

break;

291

440

case ARGP_KEY_END:

292

441

break;

304

453

305

454

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

306

455

if (ret == ARGP_ERR_UNKNOWN){

307

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

456

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

308

457

exitstatus = EXIT_FAILURE;

309

goto end;

458

goto fallback;

310

459

}

311

312

if(plus_options){

313

/* This is a mangled argument in the form of

314

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

315

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

316

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

317

const char delims[] = "+";

318

char *arg;

319

int new_argc = 1;

320

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

321

if(plus_argv == NULL){

322

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");

323

497

exitstatus = EXIT_FAILURE;

324

goto end;

325

}

326

plus_argv[0] = argv[0];

327

plus_argv[1] = NULL;

328

arg = strtok(plus_options, delims); /* Get first argument */

329

while(arg != NULL){

330

new_argc++;

331

plus_argv = realloc(plus_argv, sizeof(char *)

332

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

333

if(plus_argv == NULL){

334

perror("realloc");

335

exitstatus = EXIT_FAILURE;

336

goto end;

337

}

338

plus_argv[new_argc-1] = arg;

339

plus_argv[new_argc] = NULL;

340

arg = strtok(NULL, delims); /* Get next argument */

341

}

342

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

498

goto fallback;

499

}

500

}

501

502

if(custom_argv != NULL){

503

custom_argv[0] = argv[0];

504

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

343

505

if (ret == ARGP_ERR_UNKNOWN){

344

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

506

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

345

507

exitstatus = EXIT_FAILURE;

346

goto end;

508

goto fallback;

347

509

}

348

510

}

349

511

354

516

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

355

517

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

356

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

}

357

523

}

358

524

}

359

525

371

537

if(dir == NULL){

372

538

perror("Could not open plugin dir");

373

539

exitstatus = EXIT_FAILURE;

374

goto end;

540

goto fallback;

375

541

}

376

542

377

543

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

382

548

if(ret < 0){

383

549

perror("set_cloexec_flag");

384

550

exitstatus = EXIT_FAILURE;

385

goto end;

551

goto fallback;

386

552

}

387

553

}

388

554

}

397

563

if (errno == EBADF){

398

564

perror("readdir");

399

565

exitstatus = EXIT_FAILURE;

400

goto end;

566

goto fallback;

401

567

}

402

568

break;

403

569

}

448

614

continue;

449

615

}

450

616

}

451

452

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

453

if (filename == NULL){

454

perror("malloc");

455

exitstatus = EXIT_FAILURE;

456

goto end;

617

618

char *filename;

619

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

620

if(ret < 0){

621

perror("asprintf");

622

continue;

457

623

}

458

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

459

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

460

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

461

624

462

625

ret = stat(filename, &st);

463

626

if (ret == -1){

464

627

perror("stat");

465

exitstatus = EXIT_FAILURE;

466

goto end;

628

free(filename);

629

continue;

467

630

}

468

631

469

632

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

474

637

free(filename);

475

638

continue;

476

639

}

477

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){

478

647

if(debug){

479

648

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

480

649

dirst->d_name);

482

651

free(filename);

483

652

continue;

484

653

}

485

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

486

654

{

487

655

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

488

656

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

489

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

490

addargument(p, *a);

491

}

492

}

493

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];

494

688

ret = pipe(pipefd);

495

689

if (ret == -1){

496

690

perror("pipe");

497

691

exitstatus = EXIT_FAILURE;

498

goto end;

692

goto fallback;

499

693

}

500

694

ret = set_cloexec_flag(pipefd[0]);

501

695

if(ret < 0){

502

696

perror("set_cloexec_flag");

503

697

exitstatus = EXIT_FAILURE;

504

goto end;

698

goto fallback;

505

699

}

506

700

ret = set_cloexec_flag(pipefd[1]);

507

701

if(ret < 0){

508

702

perror("set_cloexec_flag");

509

703

exitstatus = EXIT_FAILURE;

510

goto end;

704

goto fallback;

511

705

}

512

706

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

513

707

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

514

708

if(ret < 0){

515

709

perror("sigprocmask");

516

710

exitstatus = EXIT_FAILURE;

517

goto end;

711

goto fallback;

518

712

}

519

713

// Starting a new process to be watched

520

714

pid_t pid = fork();

715

if(pid == -1){

716

perror("fork");

717

exitstatus = EXIT_FAILURE;

718

goto fallback;

719

}

521

720

if(pid == 0){

522

721

/* this is the child process */

523

722

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

542

741

above and must now close it manually here. */

543

742

closedir(dir);

544

743

}

545

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

546

perror("execv");

547

_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

}

548

754

}

549

755

/* no return */

550

756

}

559

765

perror("sigprocmask");

560

766

}

561

767

exitstatus = EXIT_FAILURE;

562

goto end;

768

goto fallback;

563

769

}

564

770

565

771

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

573

779

if(ret < 0){

574

780

perror("sigprocmask");

575

781

exitstatus = EXIT_FAILURE;

576

goto end;

782

goto fallback;

577

783

}

578

784

579

785

FD_SET(new_process->fd, &rfds_all);

584

790

585

791

}

586

792

587

/* Free the plugin list */

588

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

589

next = plugin_list->next;

590

free(plugin_list->argv);

591

free(plugin_list);

592

}

793

free_plugin_list(plugin_list);

794

plugin_list = NULL;

593

795

594

796

closedir(dir);

595

797

dir = NULL;

605

807

if (select_ret == -1){

606

808

perror("select");

607

809

exitstatus = EXIT_FAILURE;

608

goto end;

810

goto fallback;

609

811

}

610

812

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

611

813

from one of them */

637

839

if(ret < 0){

638

840

perror("sigprocmask");

639

841

exitstatus = EXIT_FAILURE;

640

goto end;

842

goto fallback;

641

843

}

642

844

/* Delete this process entry from the list */

643

845

if(process_list == proc){

672

874

perror("print_out_password");

673

875

exitstatus = EXIT_FAILURE;

674

876

}

675

goto end;

877

goto fallback;

676

878

}

677

879

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

678

880

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

686

888

if (proc->buffer == NULL){

687

889

perror("malloc");

688

890

exitstatus = EXIT_FAILURE;

689

goto end;

891

goto fallback;

690

892

}

691

893

proc->buffer_size += BUFFER_SIZE;

692

894

}

705

907

}

706

908

}

707

909

}

910

911

912

fallback:

708

913

709

if(process_list == NULL){

914

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

915

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

710

916

bool bret;

711

917

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

712

918

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

714

920

if(not bret){

715

921

perror("print_out_password");

716

922

exitstatus = EXIT_FAILURE;

717

goto end;

718

}

719

bret = print_out_password("\n", 1);

720

if(not bret){

721

perror("print_out_password");

722

exitstatus = EXIT_FAILURE;

723

923

}

724

924

}

725

726

end:

727

925

728

926

/* Restore old signal handler */

729

sigaction(SIGCHLD, &old_sigchld_action, NULL);

730

731

free(plus_argv);

732

733

/* Free the plugin list */

734

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

735

next = plugin_list->next;

736

free(plugin_list->argv);

737

free(plugin_list);

738

}

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);

739

940

740

941

if(dir != NULL){

741

942

closedir(dir);