/mandos/trunk : revision 88

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 = 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

108

119

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

109

120

if (new_plugin->argv == NULL){

110

perror("malloc");

111

exit(EXIT_FAILURE);

121

free(new_plugin);

122

return NULL;

112

123

}

113

new_plugin->argv[0] = name;

124

new_plugin->argv[0] = copy_name;

114

125

new_plugin->argv[1] = NULL;

115

new_plugin->argc = 1;

116

new_plugin->disabled = false;

117

new_plugin->next = *plugin_list;

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;

118

134

/* Append the new plugin to the list */

119

135

*plugin_list = new_plugin;

120

136

return new_plugin;

121

137

}

122

138

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

}

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

133

178

134

179

/*

135

180

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

185

230

return true;

186

231

}

187

232

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

188

270

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

189

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

271

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

272

const char *argfile = ARGFILE;

273

FILE *conffp;

190

274

size_t d_name_len;

191

275

DIR *dir = NULL;

192

276

struct dirent *dirst;

200

284

struct sigaction old_sigchld_action;

201

285

struct sigaction sigchld_action = { .sa_handler = handle_sigchld,

202

286

.sa_flags = SA_NOCLDSTOP };

203

char *plus_options = NULL;

204

char **plus_argv = NULL;

205

287

char **custom_argv = NULL;

288

int custom_argc = 0;

289

206

290

/* Establish a signal handler */

207

291

sigemptyset(&sigchld_action.sa_mask);

208

292

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

209

if(ret < 0){

293

if(ret == -1){

210

294

perror("sigaddset");

211

exit(EXIT_FAILURE);

295

exitstatus = EXIT_FAILURE;

296

goto fallback;

212

297

}

213

298

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

214

if(ret < 0){

299

if(ret == -1){

215

300

perror("sigaction");

216

exit(EXIT_FAILURE);

301

exitstatus = EXIT_FAILURE;

302

goto fallback;

217

303

}

218

304

219

305

/* The options we understand. */

221

307

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

222

308

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

223

309

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

310

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

311

.arg = "VAR=value",

312

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

224

313

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

225

314

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

226

315

.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" },

227

319

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

228

320

.arg = "PLUGIN",

229

321

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

248

340

switch (key) {

249

341

case 'g':

250

342

if (arg != NULL){

251

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

252

do{

253

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

254

p = strtok(NULL, ",");

255

} while (p != NULL);

343

char *p;

344

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

345

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

346

continue;

347

}

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");

366

}

256

367

}

257

368

break;

258

369

case 'o':

259

370

if (arg != NULL){

260

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

261

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

262

if(p != NULL){

263

p = strtok(p, ",");

264

do{

265

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

266

p = strtok(NULL, ",");

267

} while (p != NULL);

371

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

372

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

373

break;

374

}

375

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

376

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

377

break;

378

}

379

if(opt != NULL){

380

char *p;

381

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

382

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

383

continue;

384

}

385

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

386

perror("add_argument");

387

return ARGP_ERR_UNKNOWN;

388

}

389

}

390

}

391

}

392

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");

268

409

}

269

410

}

270

411

break;

271

412

case 'd':

272

413

if (arg != NULL){

273

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

414

plugin *p = getplugin(arg, plugins);

415

if(p == NULL){

416

return ARGP_ERR_UNKNOWN;

417

}

418

p->disabled = true;

274

419

}

275

420

break;

276

421

case 128:

286

431

debug = true;

287

432

break;

288

433

case ARGP_KEY_ARG:

289

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

290

argp_usage (state);

291

}

292

plus_options = arg;

434

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

293

435

break;

294

436

case ARGP_KEY_END:

295

437

break;

309

451

if (ret == ARGP_ERR_UNKNOWN){

310

452

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

311

453

exitstatus = EXIT_FAILURE;

312

goto end;

454

goto fallback;

313

455

}

314

315

if(plus_options){

316

/* This is a mangled argument in the form of

317

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

318

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

319

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

320

const char delims[] = "+";

321

char *arg;

322

int new_argc = 1;

323

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

324

if(plus_argv == NULL){

325

perror("malloc");

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");

326

493

exitstatus = EXIT_FAILURE;

327

goto end;

328

}

329

plus_argv[0] = argv[0];

330

plus_argv[1] = NULL;

331

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

332

while(arg != NULL){

333

new_argc++;

334

plus_argv = realloc(plus_argv, sizeof(char *)

335

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

336

if(plus_argv == NULL){

337

perror("realloc");

338

exitstatus = EXIT_FAILURE;

339

goto end;

340

}

341

plus_argv[new_argc-1] = arg;

342

plus_argv[new_argc] = NULL;

343

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

344

}

345

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

494

goto fallback;

495

}

496

}

497

498

if(custom_argv != NULL){

499

custom_argv[0] = argv[0];

500

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

346

501

if (ret == ARGP_ERR_UNKNOWN){

347

502

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

348

503

exitstatus = EXIT_FAILURE;

349

goto end;

504

goto fallback;

350

505

}

351

506

}

352

507

357

512

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

358

513

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

359

514

}

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

}

360

519

}

361

520

}

362

521

374

533

if(dir == NULL){

375

534

perror("Could not open plugin dir");

376

535

exitstatus = EXIT_FAILURE;

377

goto end;

536

goto fallback;

378

537

}

379

538

380

539

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

385

544

if(ret < 0){

386

545

perror("set_cloexec_flag");

387

546

exitstatus = EXIT_FAILURE;

388

goto end;

547

goto fallback;

389

548

}

390

549

}

391

550

}

400

559

if (errno == EBADF){

401

560

perror("readdir");

402

561

exitstatus = EXIT_FAILURE;

403

goto end;

562

goto fallback;

404

563

}

405

564

break;

406

565

}

451

610

continue;

452

611

}

453

612

}

454

455

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

456

if (filename == NULL){

457

perror("malloc");

458

exitstatus = EXIT_FAILURE;

459

goto end;

613

614

char *filename;

615

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

616

if(ret < 0){

617

perror("asprintf");

618

continue;

460

619

}

461

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

462

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

463

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

464

620

465

621

ret = stat(filename, &st);

466

622

if (ret == -1){

467

623

perror("stat");

468

exitstatus = EXIT_FAILURE;

469

goto end;

624

free(filename);

625

continue;

470

626

}

471

627

472

628

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

477

633

free(filename);

478

634

continue;

479

635

}

480

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

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){

481

643

if(debug){

482

644

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

483

645

dirst->d_name);

485

647

free(filename);

486

648

continue;

487

649

}

488

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

489

650

{

490

651

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

491

652

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

492

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

493

addargument(p, *a);

494

}

495

}

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

496

683

int pipefd[2];

497

684

ret = pipe(pipefd);

498

685

if (ret == -1){

499

686

perror("pipe");

500

687

exitstatus = EXIT_FAILURE;

501

goto end;

688

goto fallback;

502

689

}

503

690

ret = set_cloexec_flag(pipefd[0]);

504

691

if(ret < 0){

505

692

perror("set_cloexec_flag");

506

693

exitstatus = EXIT_FAILURE;

507

goto end;

694

goto fallback;

508

695

}

509

696

ret = set_cloexec_flag(pipefd[1]);

510

697

if(ret < 0){

511

698

perror("set_cloexec_flag");

512

699

exitstatus = EXIT_FAILURE;

513

goto end;

700

goto fallback;

514

701

}

515

702

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

516

703

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

517

704

if(ret < 0){

518

705

perror("sigprocmask");

519

706

exitstatus = EXIT_FAILURE;

520

goto end;

707

goto fallback;

521

708

}

522

709

// Starting a new process to be watched

523

710

pid_t pid = fork();

711

if(pid == -1){

712

perror("fork");

713

exitstatus = EXIT_FAILURE;

714

goto fallback;

715

}

524

716

if(pid == 0){

525

717

/* this is the child process */

526

718

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

545

737

above and must now close it manually here. */

546

738

closedir(dir);

547

739

}

548

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

549

perror("execv");

550

_exit(EXIT_FAILURE);

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

}

551

750

}

552

751

/* no return */

553

752

}

562

761

perror("sigprocmask");

563

762

}

564

763

exitstatus = EXIT_FAILURE;

565

goto end;

764

goto fallback;

566

765

}

567

766

568

767

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

576

775

if(ret < 0){

577

776

perror("sigprocmask");

578

777

exitstatus = EXIT_FAILURE;

579

goto end;

778

goto fallback;

580

779

}

581

780

582

781

FD_SET(new_process->fd, &rfds_all);

587

786

588

787

}

589

788

590

/* Free the plugin list */

591

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

592

next = plugin_list->next;

593

free(plugin_list->argv);

594

free(plugin_list);

595

}

789

free_plugin_list(plugin_list);

596

790

597

791

closedir(dir);

598

792

dir = NULL;

608

802

if (select_ret == -1){

609

803

perror("select");

610

804

exitstatus = EXIT_FAILURE;

611

goto end;

805

goto fallback;

612

806

}

613

807

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

614

808

from one of them */

640

834

if(ret < 0){

641

835

perror("sigprocmask");

642

836

exitstatus = EXIT_FAILURE;

643

goto end;

837

goto fallback;

644

838

}

645

839

/* Delete this process entry from the list */

646

840

if(process_list == proc){

675

869

perror("print_out_password");

676

870

exitstatus = EXIT_FAILURE;

677

871

}

678

goto end;

872

goto fallback;

679

873

}

680

874

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

681

875

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

689

883

if (proc->buffer == NULL){

690

884

perror("malloc");

691

885

exitstatus = EXIT_FAILURE;

692

goto end;

886

goto fallback;

693

887

}

694

888

proc->buffer_size += BUFFER_SIZE;

695

889

}

710

904

}

711

905

712

906

713

end:

907

fallback:

714

908

715

909

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

716

/* Fallback if all plugins failed or an error occured */

910

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

717

911

bool bret;

718

912

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

719

913

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

721

915

if(not bret){

722

916

perror("print_out_password");

723

917

exitstatus = EXIT_FAILURE;

724

goto end;

725

918

}

726

919

}

727

920

728

921

/* 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

}

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);

739

935

740

936

if(dir != NULL){

741

937

closedir(dir);