/mandos/trunk : revision 142

72

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

73

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

74

75

struct process;

76

77

typedef struct process{

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*/

78

86

pid_t pid;

79

87

int fd;

80

88

char *buffer;

83

91

bool eof;

84

92

volatile bool completed;

85

93

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;

96

94

struct plugin *next;

97

95

} plugin;

98

96

99

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

100

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

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){

101

104

if ((p->name == name)

102

105

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

103

106

return p;

115

118

return NULL;

116

119

}

117

120

}

118

121

119

122

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

120

123

.argc = 1,

121

.envc = 0,

122

124

.disabled = false,

123

.next = *plugin_list };

125

.next = plugin_list };

124

126

125

127

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

126

128

if (new_plugin->argv == NULL){

130

132

}

131

133

new_plugin->argv[0] = copy_name;

132

134

new_plugin->argv[1] = NULL;

133

135

134

136

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

135

137

if(new_plugin->environ == NULL){

136

138

free(copy_name);

139

141

return NULL;

140

142

}

141

143

new_plugin->environ[0] = NULL;

144

142

145

/* Append the new plugin to the list */

143

*plugin_list = new_plugin;

146

plugin_list = new_plugin;

144

147

return new_plugin;

145

148

}

146

149

176

179

}

177

180

178

181

/* Add to a plugin's environment */

179

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

182

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

180

183

if(p == NULL){

181

184

return false;

182

185

}

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

}

183

203

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

184

204

}

185

205

186

187

206

/*

188

207

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

189

208

* Descriptor Flags".

200

219

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

201

220

}

202

221

203

process *process_list = NULL;

204

222

205

223

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

206

224

status. */

207

225

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

208

226

while(true){

209

process *proc = process_list;

227

plugin *proc = plugin_list;

210

228

int status;

211

229

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

212

230

if(pid == 0){

234

252

}

235

253

}

236

254

255

/* Prints out a password to stdout */

237

256

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

238

257

ssize_t ret;

239

258

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

249

268

return true;

250

269

}

251

270

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);

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);

264

304

}

265

305

}

266

306

304

344

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

305

345

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

306

346

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

307

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

347

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

308

348

.arg = "VAR=value",

309

349

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

310

350

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

311

351

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

312

352

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

313

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

353

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

314

354

.arg = "PLUGIN:ENV=value",

315

355

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

316

356

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

317

357

.arg = "PLUGIN",

318

358

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

359

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

360

.arg = "PLUGIN",

361

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

319

362

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

320

363

.arg = "DIRECTORY",

321

364

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

333

376

{ .name = NULL }

334

377

};

335

378

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;

379

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

380

struct argp_state *state) {

340

381

switch (key) {

341

case 'g':

382

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

342

383

if (arg != NULL){

343

384

char *p;

344

385

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

345

386

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

346

387

continue;

347

388

}

348

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

389

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

349

390

perror("add_argument");

350

391

return ARGP_ERR_UNKNOWN;

351

392

}

352

393

}

353

394

}

354

395

break;

355

case 'e':

396

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

356

397

if(arg == NULL){

357

398

break;

358

399

}

361

402

if(envdef == NULL){

362

403

break;

363

404

}

364

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

405

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

365

406

perror("add_environment");

366

407

}

367

408

}

368

409

break;

369

case 'o':

410

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

370

411

if (arg != NULL){

371

412

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

372

413

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

382

423

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

383

424

continue;

384

425

}

385

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

426

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

386

427

perror("add_argument");

387

428

return ARGP_ERR_UNKNOWN;

388

429

}

390

431

}

391

432

}

392

433

break;

393

case 'f':

434

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

394

435

if(arg == NULL){

395

436

break;

396

437

}

404

445

break;

405

446

}

406

447

envdef++;

407

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

448

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

408

449

perror("add_environment");

409

450

}

410

451

}

411

452

break;

412

case 'd':

453

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

413

454

if (arg != NULL){

414

plugin *p = getplugin(arg, plugins);

455

plugin *p = getplugin(arg);

415

456

if(p == NULL){

416

457

return ARGP_ERR_UNKNOWN;

417

458

}

418

459

p->disabled = true;

419

460

}

420

461

break;

421

case 128:

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 */

422

472

plugindir = strdup(arg);

423

473

if(plugindir == NULL){

424

474

perror("strdup");

425

475

}

426

476

break;

427

case 129:

428

argfile = strdup(arg);

429

if(argfile == NULL){

430

perror("strdup");

431

}

432

break;

433

case 130:

477

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

478

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

479

break;

480

case 130: /* --userid */

434

481

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

435

482

break;

436

case 131:

483

case 131: /* --groupid */

437

484

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

438

485

break;

439

case 132:

486

case 132: /* --debug */

440

487

debug = true;

441

488

break;

442

489

case ARGP_KEY_ARG:

450

497

return 0;

451

498

}

452

499

453

plugin *plugin_list = NULL;

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

}

454

531

455

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

456

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

532

struct argp argp = { .options = options,

533

.parser = parse_opt_config_file,

534

.args_doc = "",

457

535

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

458

536

459

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

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);

460

540

if (ret == ARGP_ERR_UNKNOWN){

461

541

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

462

542

exitstatus = EXIT_FAILURE;

463

543

goto fallback;

464

544

}

465

545

546

/* Reset to the normal argument parser */

547

argp.parser = parse_opt;

548

549

/* Open the configfile if available */

466

550

if (argfile == NULL){

467

551

conffp = fopen(AFILE, "r");

468

552

} else {

469

553

conffp = fopen(argfile, "r");

470

}

471

554

}

472

555

if(conffp != NULL){

473

556

char *org_line = NULL;

474

557

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

486

569

}

487

570

custom_argv[0] = argv[0];

488

571

custom_argv[1] = NULL;

489

572

573

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

574

commented text */

490

575

while(true){

491

576

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

492

577

if(sret == -1){

521

606

}

522

607

}

523

608

free(org_line);

524

} else{

609

} else {

525

610

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

526

611

not affect opening plugins */

527

612

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

530

615

goto fallback;

531

616

}

532

617

}

533

618

/* If there was any arguments from configuration file,

619

pass them to parser as command arguments */

534

620

if(custom_argv != NULL){

535

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

621

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

622

0, NULL);

536

623

if (ret == ARGP_ERR_UNKNOWN){

537

624

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

538

625

exitstatus = EXIT_FAILURE;

540

627

}

541

628

}

542

629

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

543

639

if(debug){

544

640

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

545

641

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

554

650

}

555

651

}

556

652

653

/* Strip permissions down to nobody */

557

654

ret = setuid(uid);

558

655

if (ret == -1){

559

656

perror("setuid");

560

}

561

657

}

562

658

setgid(gid);

563

659

if (ret == -1){

564

660

perror("setgid");

565

661

}

566

662

567

663

if (plugindir == NULL){

568

664

dir = opendir(PDIR);

569

665

} else {

591

687

592

688

FD_ZERO(&rfds_all);

593

689

690

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

594

691

while(true){

595

692

dirst = readdir(dir);

596

693

597

// All directory entries have been processed

694

/* All directory entries have been processed */

598

695

if(dirst == NULL){

599

696

if (errno == EBADF){

600

697

perror("readdir");

606

703

607

704

d_name_len = strlen(dirst->d_name);

608

705

609

// Ignore dotfiles, backup files and other junk

706

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

610

707

{

611

708

bool bad_name = false;

612

709

627

724

break;

628

725

}

629

726

}

630

631

727

if(bad_name){

632

728

continue;

633

729

}

634

635

730

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

636

731

size_t suf_len = strlen(*suf);

637

732

if((d_name_len >= suf_len)

664

759

free(filename);

665

760

continue;

666

761

}

667

762

763

/* Ignore non-executable files */

668

764

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

669

765

if(debug){

670

766

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

673

769

free(filename);

674

770

continue;

675

771

}

676

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

772

773

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

677

774

if(p == NULL){

678

775

perror("getplugin");

679

776

free(filename);

689

786

}

690

787

{

691

788

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

692

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

789

plugin *g = getplugin(NULL);

693

790

if(g != NULL){

694

791

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

695

792

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

698

795

}

699

796

/* Add global environment variables */

700

797

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

701

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

798

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

702

799

perror("add_environment");

703

800

}

704

801

}

709

806

process, too. */

710

807

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

711

808

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

712

char *copy = strdup(*e);

713

if(copy == NULL){

714

perror("strdup");

715

continue;

716

}

717

if(not add_environment(p, copy)){

809

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

718

810

perror("add_environment");

719

811

}

720

812

}

727

819

exitstatus = EXIT_FAILURE;

728

820

goto fallback;

729

821

}

822

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

730

823

ret = set_cloexec_flag(pipefd[0]);

731

824

if(ret < 0){

732

825

perror("set_cloexec_flag");

746

839

exitstatus = EXIT_FAILURE;

747

840

goto fallback;

748

841

}

749

// Starting a new process to be watched

842

/* Starting a new process to be watched */

750

843

pid_t pid = fork();

751

844

if(pid == -1){

752

845

perror("fork");

790

883

}

791

884

/* no return */

792

885

}

793

/* parent process */

886

/* Parent process */

887

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

794

888

free(filename);

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");

889

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

890

if (new_plugin == NULL){

891

perror("getplugin");

799

892

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

800

893

if(ret < 0){

801

perror("sigprocmask");

894

perror("sigprocmask");

802

895

}

803

896

exitstatus = EXIT_FAILURE;

804

897

goto fallback;

805

898

}

806

899

807

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

808

.fd = pipefd[0],

809

.next = process_list };

810

// List handling

811

process_list = new_process;

900

new_plugin->pid = pid;

901

new_plugin->fd = pipefd[0];

902

812

903

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

813

904

has already completed */

814

905

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

818

909

goto fallback;

819

910

}

820

911

821

FD_SET(new_process->fd, &rfds_all);

912

FD_SET(new_plugin->fd, &rfds_all);

822

913

823

if (maxfd < new_process->fd){

824

maxfd = new_process->fd;

914

if (maxfd < new_plugin->fd){

915

maxfd = new_plugin->fd;

825

916

}

826

917

827

918

}

828

829

free_plugin_list(plugin_list);

830

plugin_list = NULL;

831

919

832

920

closedir(dir);

833

921

dir = NULL;

834

835

if (process_list == NULL){

836

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

837

" directory?\n");

838

process_list = 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

}

839

932

}

840

while(process_list){

933

934

/* Main loop while running plugins exist */

935

while(plugin_list){

841

936

fd_set rfds = rfds_all;

842

937

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

843

938

if (select_ret == -1){

847

942

}

848

943

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

849

944

from one of them */

850

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

945

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

851

946

/* Is this process completely done? */

852

947

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

853

948

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

854

949

if(not WIFEXITED(proc->status)

855

950

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

856

951

/* Bad exit by plugin */

952

857

953

if(debug){

858

954

if(WIFEXITED(proc->status)){

859

955

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

868

964

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

869

965

}

870

966

}

967

871

968

/* Remove the plugin */

872

969

FD_CLR(proc->fd, &rfds_all);

970

873

971

/* Block signal while modifying process_list */

874

972

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

875

973

if(ret < 0){

877

975

exitstatus = EXIT_FAILURE;

878

976

goto fallback;

879

977

}

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

}

978

free_plugin(proc);

893

979

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

894

980

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

895

981

NULL);

896

982

if(ret < 0){

897

983

perror("sigprocmask");

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;

984

exitstatus = EXIT_FAILURE;

985

goto fallback;

986

}

987

988

if(plugin_list == NULL){

989

break;

990

}

991

continue;

905

992

}

993

906

994

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

907

995

908

996

bool bret = print_out_password(proc->buffer,

913

1001

}

914

1002

goto fallback;

915

1003

}

1004

916

1005

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

917

1006

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

918

1007

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

948

1037

949

1038

fallback:

950

1039

951

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

1040

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

952

1041

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

953

1042

occured */

954

1043

bool bret;

974

1063

}

975

1064

free(custom_argv);

976

1065

}

977

free_plugin_list(plugin_list);

978

1066

979

1067

if(dir != NULL){

980

1068

closedir(dir);

981

1069

}

982

1070

983

1071

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

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");

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

}

991

1080

}

992

free(process_list->buffer);

993

free(process_list);

994

1081

}

995

1082

996

1083

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

1001

1088

perror("wait");

1002

1089

}

1003

1090

1091

free_plugin_list();

1092

1004

1093

free(plugindir);

1005

1094

free(argfile);

1006

1095