/mandos/trunk : revision 109

72

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

73

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

74

75

struct plugin;

76

77

typedef struct plugin{

78

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

79

char **argv;

80

int argc;

81

char **environ;

82

int envc;

83

bool disabled;

84

85

/* Variables used for running processes*/

75

struct process;

76

77

typedef struct process{

86

78

pid_t pid;

87

79

int fd;

88

80

char *buffer;

91

83

bool eof;

92

84

volatile bool completed;

93

85

volatile int status;

86

struct process *next;

87

} process;

88

89

typedef struct plugin{

90

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

91

char **argv;

92

int argc;

93

char **environ;

94

int envc;

95

bool disabled;

94

96

struct plugin *next;

95

97

} plugin;

96

98

97

static plugin *plugin_list = NULL;

98

99

/* Gets a existing plugin based on name,

100

or if none is found, creates a new one */

101

static plugin *getplugin(char *name){

102

/* Check for exiting plugin with that name */

103

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

99

static plugin *getplugin(char *name, plugin **plugin_list){

100

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

104

101

if ((p->name == name)

105

102

or (p->name and name and (strcmp(p->name, name) == 0))){

106

103

return p;

118

115

return NULL;

119

116

}

120

117

}

121

118

122

119

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

123

120

.argc = 1,

121

.envc = 0,

124

122

.disabled = false,

125

.next = plugin_list };

123

.next = *plugin_list };

126

124

127

125

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

128

126

if (new_plugin->argv == NULL){

132

130

}

133

131

new_plugin->argv[0] = copy_name;

134

132

new_plugin->argv[1] = NULL;

135

133

136

134

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

137

135

if(new_plugin->environ == NULL){

138

136

free(copy_name);

141

139

return NULL;

142

140

}

143

141

new_plugin->environ[0] = NULL;

144

145

142

/* Append the new plugin to the list */

146

plugin_list = new_plugin;

143

*plugin_list = new_plugin;

147

144

return new_plugin;

148

145

}

149

146

179

176

}

180

177

181

178

/* Add to a plugin's environment */

182

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

179

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

183

180

if(p == NULL){

184

181

return false;

185

182

}

186

/* namelen = length of name of environment variable */

187

size_t namelen = (size_t)(strchrnul(def, '=') - def);

188

/* Search for this environment variable */

189

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

190

if(strncmp(*e, def, namelen+1) == 0){

191

/* It already exists */

192

if(replace){

193

char *new = realloc(*e, strlen(def));

194

if(new == NULL){

195

return false;

196

}

197

*e = new;

198

strcpy(*e, def);

199

}

200

return true;

201

}

202

}

203

183

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

204

184

}

205

185

186

206

187

/*

207

188

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

208

189

* Descriptor Flags".

219

200

return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);

220

201

}

221

202

203

process *process_list = NULL;

222

204

223

205

/* Mark processes as completed when they exit, and save their exit

224

206

status. */

225

207

void handle_sigchld(__attribute__((unused)) int sig){

226

208

while(true){

227

plugin *proc = plugin_list;

209

process *proc = process_list;

228

210

int status;

229

211

pid_t pid = waitpid(-1, &status, WNOHANG);

230

212

if(pid == 0){

252

234

}

253

235

}

254

236

255

/* Prints out a password to stdout */

256

237

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

257

238

ssize_t ret;

258

239

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

268

249

return true;

269

250

}

270

251

271

/* Removes and free a plugin from the plugin list */

272

static void free_plugin(plugin *plugin_node){

273

274

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

275

free(*arg);

276

}

277

free(plugin_node->argv);

278

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

279

free(*env);

280

}

281

free(plugin_node->environ);

282

free(plugin_node->buffer);

283

284

/* Removes the plugin from the singly-linked list */

285

if(plugin_node == plugin_list){

286

/* First one - simple */

287

plugin_list = plugin_list->next;

288

} else {

289

/* Second one or later */

290

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

291

if(p->next == plugin_node){

292

p->next = plugin_node->next;

293

break;

294

}

295

}

296

}

297

298

free(plugin_node);

299

}

300

301

static void free_plugin_list(void){

302

while(plugin_list != NULL){

303

free_plugin(plugin_list);

252

static void free_plugin_list(plugin *plugin_list){

253

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

254

next = plugin_list->next;

255

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

256

free(*arg);

257

}

258

free(plugin_list->argv);

259

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

260

free(*env);

261

}

262

free(plugin_list->environ);

263

free(plugin_list);

304

264

}

305

265

}

306

266

344

304

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

345

305

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

346

306

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

347

{ .name = "global-env", .key = 'G',

307

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

348

308

.arg = "VAR=value",

349

309

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

350

310

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

351

311

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

352

312

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

353

{ .name = "env-for", .key = 'E',

313

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

354

314

.arg = "PLUGIN:ENV=value",

355

315

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

356

316

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

357

317

.arg = "PLUGIN",

358

318

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

359

{ .name = "enable", .key = 'e',

360

.arg = "PLUGIN",

361

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

362

319

{ .name = "plugin-dir", .key = 128,

363

320

.arg = "DIRECTORY",

364

321

.doc = "Specify a different plugin directory", .group = 2 },

376

333

{ .name = NULL }

377

334

};

378

335

379

error_t parse_opt (int key, char *arg, __attribute__((unused))

380

struct argp_state *state) {

336

error_t parse_opt (int key, char *arg, struct argp_state *state) {

337

/* Get the INPUT argument from `argp_parse', which we know is a

338

pointer to our plugin list pointer. */

339

plugin **plugins = state->input;

381

340

switch (key) {

382

case 'g': /* --global-options */

341

case 'g':

383

342

if (arg != NULL){

384

343

char *p;

385

344

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

386

345

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

387

346

continue;

388

347

}

389

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

348

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

390

349

perror("add_argument");

391

350

return ARGP_ERR_UNKNOWN;

392

351

}

393

352

}

394

353

}

395

354

break;

396

case 'G': /* --global-env */

355

case 'e':

397

356

if(arg == NULL){

398

357

break;

399

358

}

402

361

if(envdef == NULL){

403

362

break;

404

363

}

405

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

364

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

406

365

perror("add_environment");

407

366

}

408

367

}

409

368

break;

410

case 'o': /* --options-for */

369

case 'o':

411

370

if (arg != NULL){

412

371

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

413

372

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

423

382

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

424

383

continue;

425

384

}

426

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

385

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

427

386

perror("add_argument");

428

387

return ARGP_ERR_UNKNOWN;

429

388

}

431

390

}

432

391

}

433

392

break;

434

case 'E': /* --env-for */

393

case 'f':

435

394

if(arg == NULL){

436

395

break;

437

396

}

445

404

break;

446

405

}

447

406

envdef++;

448

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

407

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

449

408

perror("add_environment");

450

409

}

451

410

}

452

411

break;

453

case 'd': /* --disable */

412

case 'd':

454

413

if (arg != NULL){

455

plugin *p = getplugin(arg);

414

plugin *p = getplugin(arg, plugins);

456

415

if(p == NULL){

457

416

return ARGP_ERR_UNKNOWN;

458

417

}

459

418

p->disabled = true;

460

419

}

461

420

break;

462

case 'e': /* --enable */

463

if (arg != NULL){

464

plugin *p = getplugin(arg);

465

if(p == NULL){

466

return ARGP_ERR_UNKNOWN;

467

}

468

p->disabled = false;

469

}

470

break;

471

case 128: /* --plugin-dir */

421

case 128:

472

422

plugindir = strdup(arg);

473

423

if(plugindir == NULL){

474

424

perror("strdup");

475

425

}

476

426

break;

477

case 129: /* --config-file */

478

/* This is already done by parse_opt_config_file() */

479

break;

480

case 130: /* --userid */

427

case 129:

428

argfile = strdup(arg);

429

if(argfile == NULL){

430

perror("strdup");

431

}

432

break;

433

case 130:

481

434

uid = (uid_t)strtol(arg, NULL, 10);

482

435

break;

483

case 131: /* --groupid */

436

case 131:

484

437

gid = (gid_t)strtol(arg, NULL, 10);

485

438

break;

486

case 132: /* --debug */

439

case 132:

487

440

debug = true;

488

441

break;

489

442

case ARGP_KEY_ARG:

497

450

return 0;

498

451

}

499

452

500

/* This option parser is the same as parse_opt() above, except it

501

ignores everything but the --config-file option. */

502

error_t parse_opt_config_file (int key, char *arg,

503

__attribute__((unused))

504

struct argp_state *state) {

505

switch (key) {

506

case 'g': /* --global-options */

507

case 'G': /* --global-env */

508

case 'o': /* --options-for */

509

case 'E': /* --env-for */

510

case 'd': /* --disable */

511

case 'e': /* --enable */

512

case 128: /* --plugin-dir */

513

break;

514

case 129: /* --config-file */

515

argfile = strdup(arg);

516

if(argfile == NULL){

517

perror("strdup");

518

}

519

break;

520

case 130: /* --userid */

521

case 131: /* --groupid */

522

case 132: /* --debug */

523

case ARGP_KEY_ARG:

524

case ARGP_KEY_END:

525

break;

526

default:

527

return ARGP_ERR_UNKNOWN;

528

}

529

return 0;

530

}

453

plugin *plugin_list = NULL;

531

454

532

struct argp argp = { .options = options,

533

.parser = parse_opt_config_file,

534

.args_doc = "",

455

struct argp argp = { .options = options, .parser = parse_opt,

456

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

535

457

.doc = "Mandos plugin runner -- Run plugins" };

536

458

537

/* Parse using the parse_opt_config_file in order to get the custom

538

config file location, if any. */

539

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

459

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

540

460

if (ret == ARGP_ERR_UNKNOWN){

541

461

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

542

462

exitstatus = EXIT_FAILURE;

543

463

goto fallback;

544

464

}

545

546

/* Reset to the normal argument parser */

547

argp.parser = parse_opt;

548

549

/* Open the configfile if available */

465

550

466

if (argfile == NULL){

551

467

conffp = fopen(AFILE, "r");

552

468

} else {

553

469

conffp = fopen(argfile, "r");

554

}

470

}

471

555

472

if(conffp != NULL){

556

473

char *org_line = NULL;

557

474

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

569

486

}

570

487

custom_argv[0] = argv[0];

571

488

custom_argv[1] = NULL;

572

573

/* for each line in the config file, strip whitespace and ignore

574

commented text */

489

575

490

while(true){

576

491

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

577

492

if(sret == -1){

606

521

}

607

522

}

608

523

free(org_line);

609

} else {

524

} else{

610

525

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

611

526

not affect opening plugins */

612

527

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

615

530

goto fallback;

616

531

}

617

532

}

618

/* If there was any arguments from configuration file,

619

pass them to parser as command arguments */

533

620

534

if(custom_argv != NULL){

621

ret = argp_parse (&argp, custom_argc, custom_argv, ARGP_IN_ORDER,

622

0, NULL);

535

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

623

536

if (ret == ARGP_ERR_UNKNOWN){

624

537

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

625

538

exitstatus = EXIT_FAILURE;

627

540

}

628

541

}

629

542

630

/* Parse actual command line arguments, to let them override the

631

config file */

632

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

633

if (ret == ARGP_ERR_UNKNOWN){

634

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

635

exitstatus = EXIT_FAILURE;

636

goto fallback;

637

}

638

639

543

if(debug){

640

544

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

641

545

fprintf(stderr, "Plugin: %s has %d arguments\n",

650

554

}

651

555

}

652

556

653

/* Strip permissions down to nobody */

654

557

ret = setuid(uid);

655

558

if (ret == -1){

656

559

perror("setuid");

657

}

560

}

561

658

562

setgid(gid);

659

563

if (ret == -1){

660

564

perror("setgid");

661

565

}

662

566

663

567

if (plugindir == NULL){

664

568

dir = opendir(PDIR);

665

569

} else {

687

591

688

592

FD_ZERO(&rfds_all);

689

593

690

/* Read and execute any executable in the plugin directory*/

691

594

while(true){

692

595

dirst = readdir(dir);

693

596

694

/* All directory entries have been processed */

597

// All directory entries have been processed

695

598

if(dirst == NULL){

696

599

if (errno == EBADF){

697

600

perror("readdir");

703

606

704

607

d_name_len = strlen(dirst->d_name);

705

608

706

/* Ignore dotfiles, backup files and other junk */

609

// Ignore dotfiles, backup files and other junk

707

610

{

708

611

bool bad_name = false;

709

612

724

627

break;

725

628

}

726

629

}

630

727

631

if(bad_name){

728

632

continue;

729

633

}

634

730

635

for(const char **suf = bad_suffixes; *suf != NULL; suf++){

731

636

size_t suf_len = strlen(*suf);

732

637

if((d_name_len >= suf_len)

759

664

free(filename);

760

665

continue;

761

666

}

762

763

/* Ignore non-executable files */

667

764

668

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

765

669

if(debug){

766

670

fprintf(stderr, "Ignoring plugin dir entry \"%s\""

769

673

free(filename);

770

674

continue;

771

675

}

772

773

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

676

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

774

677

if(p == NULL){

775

678

perror("getplugin");

776

679

free(filename);

786

689

}

787

690

{

788

691

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

789

plugin *g = getplugin(NULL);

692

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

790

693

if(g != NULL){

791

694

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

792

695

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

795

698

}

796

699

/* Add global environment variables */

797

700

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

798

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

701

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

799

702

perror("add_environment");

800

703

}

801

704

}

806

709

process, too. */

807

710

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

808

711

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

809

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

712

char *copy = strdup(*e);

713

if(copy == NULL){

714

perror("strdup");

715

continue;

716

}

717

if(not add_environment(p, copy)){

810

718

perror("add_environment");

811

719

}

812

720

}

819

727

exitstatus = EXIT_FAILURE;

820

728

goto fallback;

821

729

}

822

/* Ask OS to automatic close the pipe on exec */

823

730

ret = set_cloexec_flag(pipefd[0]);

824

731

if(ret < 0){

825

732

perror("set_cloexec_flag");

839

746

exitstatus = EXIT_FAILURE;

840

747

goto fallback;

841

748

}

842

/* Starting a new process to be watched */

749

// Starting a new process to be watched

843

750

pid_t pid = fork();

844

751

if(pid == -1){

845

752

perror("fork");

883

790

}

884

791

/* no return */

885

792

}

886

/* Parent process */

887

close(pipefd[1]); /* Close unused write end of pipe */

793

/* parent process */

888

794

free(filename);

889

plugin *new_plugin = getplugin(dirst->d_name);

890

if (new_plugin == NULL){

891

perror("getplugin");

795

close(pipefd[1]); /* close unused write end of pipe */

796

process *new_process = malloc(sizeof(process));

797

if (new_process == NULL){

798

perror("malloc");

892

799

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

893

800

if(ret < 0){

894

perror("sigprocmask");

801

perror("sigprocmask");

895

802

}

896

803

exitstatus = EXIT_FAILURE;

897

804

goto fallback;

898

805

}

899

806

900

new_plugin->pid = pid;

901

new_plugin->fd = pipefd[0];

902

807

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

808

.fd = pipefd[0],

809

.next = process_list };

810

// List handling

811

process_list = new_process;

903

812

/* Unblock SIGCHLD so signal handler can be run if this process

904

813

has already completed */

905

814

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

909

818

goto fallback;

910

819

}

911

820

912

FD_SET(new_plugin->fd, &rfds_all);

821

FD_SET(new_process->fd, &rfds_all);

913

822

914

if (maxfd < new_plugin->fd){

915

maxfd = new_plugin->fd;

823

if (maxfd < new_process->fd){

824

maxfd = new_process->fd;

916

825

}

917

826

918

827

}

828

829

free_plugin_list(plugin_list);

830

plugin_list = NULL;

919

831

920

832

closedir(dir);

921

833

dir = NULL;

922

923

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

924

if(p->pid != 0){

925

break;

926

}

927

if(p->next == NULL){

928

fprintf(stderr, "No plugin processes started. Incorrect plugin"

929

" directory?\n");

930

free_plugin_list();

931

}

834

835

if (process_list == NULL){

836

fprintf(stderr, "No plugin processes started. Incorrect plugin"

837

" directory?\n");

838

process_list = NULL;

932

839

}

933

934

/* Main loop while running plugins exist */

935

while(plugin_list){

840

while(process_list){

936

841

fd_set rfds = rfds_all;

937

842

int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);

938

843

if (select_ret == -1){

942

847

}

943

848

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

944

849

from one of them */

945

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

850

for(process *proc = process_list; proc ; proc = proc->next){

946

851

/* Is this process completely done? */

947

852

if(proc->eof and proc->completed){

948

853

/* Only accept the plugin output if it exited cleanly */

949

854

if(not WIFEXITED(proc->status)

950

855

or WEXITSTATUS(proc->status) != 0){

951

856

/* Bad exit by plugin */

952

953

857

if(debug){

954

858

if(WIFEXITED(proc->status)){

955

859

fprintf(stderr, "Plugin %u exited with status %d\n",

964

868

(unsigned int) (proc->pid));

965

869

}

966

870

}

967

968

871

/* Remove the plugin */

969

872

FD_CLR(proc->fd, &rfds_all);

970

971

873

/* Block signal while modifying process_list */

972

874

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

973

875

if(ret < 0){

975

877

exitstatus = EXIT_FAILURE;

976

878

goto fallback;

977

879

}

978

free_plugin(proc);

880

/* Delete this process entry from the list */

881

if(process_list == proc){

882

/* First one - simple */

883

process_list = proc->next;

884

} else {

885

/* Second one or later */

886

for(process *p = process_list; p != NULL; p = p->next){

887

if(p->next == proc){

888

p->next = proc->next;

889

break;

890

}

891

}

892

}

979

893

/* We are done modifying process list, so unblock signal */

980

894

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

981

895

NULL);

982

896

if(ret < 0){

983

897

perror("sigprocmask");

984

exitstatus = EXIT_FAILURE;

985

goto fallback;

986

}

987

988

if(plugin_list == NULL){

989

break;

990

}

991

continue;

898

}

899

free(proc->buffer);

900

free(proc);

901

/* We deleted this process from the list, so we can't go

902

proc->next. Therefore, start over from the beginning of

903

the process list */

904

break;

992

905

}

993

994

906

/* This process exited nicely, so print its buffer */

995

907

996

908

bool bret = print_out_password(proc->buffer,

1001

913

}

1002

914

goto fallback;

1003

915

}

1004

1005

916

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

1006

917

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

1007

918

/* This process had nothing to say at this time */

1037

948

1038

949

fallback:

1039

950

1040

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

951

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

1041

952

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

1042

953

occured */

1043

954

bool bret;

1063

974

}

1064

975

free(custom_argv);

1065

976

}

977

free_plugin_list(plugin_list);

1066

978

1067

979

if(dir != NULL){

1068

980

closedir(dir);

1069

981

}

1070

982

1071

983

/* Free the process list and kill the processes */

1072

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

1073

if(p->pid != 0){

1074

close(p->fd);

1075

ret = kill(p->pid, SIGTERM);

1076

if(ret == -1 and errno != ESRCH){

1077

/* Set-uid proccesses might not get closed */

1078

perror("kill");

1079

}

984

for(process *next; process_list != NULL; process_list = next){

985

next = process_list->next;

986

close(process_list->fd);

987

ret = kill(process_list->pid, SIGTERM);

988

if(ret == -1 and errno != ESRCH){

989

/* set-uid proccesses migth not get closed */

990

perror("kill");

1080

991

}

992

free(process_list->buffer);

993

free(process_list);

1081

994

}

1082

995

1083

996

/* Wait for any remaining child processes to terminate */

1088

1001

perror("wait");

1089

1002

}

1090

1003

1091

free_plugin_list();

1092

1093

1004

free(plugindir);

1094

1005

free(argfile);

1095

1006