/mandos/release : 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 = 'e',

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 = 'f',

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',

373

333

{ .name = NULL }

374

334

};

375

335

376

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

377

struct argp_state *state) {

336

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

378

337

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

379

338

pointer to our plugin list pointer. */

339

plugin **plugins = state->input;

380

340

switch (key) {

381

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

341

case 'g':

382

342

if (arg != NULL){

383

343

char *p;

384

344

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

385

345

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

386

346

continue;

387

347

}

388

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

348

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

389

349

perror("add_argument");

390

350

return ARGP_ERR_UNKNOWN;

391

351

}

392

352

}

393

353

}

394

354

break;

395

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

355

case 'e':

396

356

if(arg == NULL){

397

357

break;

398

358

}

401

361

if(envdef == NULL){

402

362

break;

403

363

}

404

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

364

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

405

365

perror("add_environment");

406

366

}

407

367

}

408

368

break;

409

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

369

case 'o':

410

370

if (arg != NULL){

411

371

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

412

372

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

422

382

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

423

383

continue;

424

384

}

425

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

385

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

426

386

perror("add_argument");

427

387

return ARGP_ERR_UNKNOWN;

428

388

}

430

390

}

431

391

}

432

392

break;

433

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

393

case 'f':

434

394

if(arg == NULL){

435

395

break;

436

396

}

444

404

break;

445

405

}

446

406

envdef++;

447

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

407

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

448

408

perror("add_environment");

449

409

}

450

410

}

451

411

break;

452

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

412

case 'd':

453

413

if (arg != NULL){

454

plugin *p = getplugin(arg);

414

plugin *p = getplugin(arg, plugins);

455

415

if(p == NULL){

456

416

return ARGP_ERR_UNKNOWN;

457

417

}

458

418

p->disabled = true;

459

419

}

460

420

break;

461

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

421

case 128:

462

422

plugindir = strdup(arg);

463

423

if(plugindir == NULL){

464

424

perror("strdup");

465

425

}

466

426

break;

467

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

427

case 129:

468

428

argfile = strdup(arg);

469

429

if(argfile == NULL){

470

430

perror("strdup");

471

431

}

472

432

break;

473

case 130: /* --userid */

433

case 130:

474

434

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

475

435

break;

476

case 131: /* --groupid */

436

case 131:

477

437

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

478

438

break;

479

case 132: /* --debug */

439

case 132:

480

440

debug = true;

481

441

break;

482

442

case ARGP_KEY_ARG:

490

450

return 0;

491

451

}

492

452

453

plugin *plugin_list = NULL;

454

493

455

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

494

.args_doc = "",

456

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

495

457

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

496

458

497

/* Open the configfile if available */

459

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

460

if (ret == ARGP_ERR_UNKNOWN){

461

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

462

exitstatus = EXIT_FAILURE;

463

goto fallback;

464

}

465

498

466

if (argfile == NULL){

499

467

conffp = fopen(AFILE, "r");

500

468

} else {

501

469

conffp = fopen(argfile, "r");

502

}

470

}

471

503

472

if(conffp != NULL){

504

473

char *org_line = NULL;

505

474

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

517

486

}

518

487

custom_argv[0] = argv[0];

519

488

custom_argv[1] = NULL;

520

521

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

522

commented text */

489

523

490

while(true){

524

491

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

525

492

if(sret == -1){

554

521

}

555

522

}

556

523

free(org_line);

557

} else {

524

} else{

558

525

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

559

526

not affect opening plugins */

560

527

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

563

530

goto fallback;

564

531

}

565

532

}

566

/* If there was any arguments from configuration file,

567

pass them to parser as command arguments */

533

568

534

if(custom_argv != NULL){

569

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

570

0, NULL);

535

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

571

536

if (ret == ARGP_ERR_UNKNOWN){

572

537

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

573

538

exitstatus = EXIT_FAILURE;

575

540

}

576

541

}

577

542

578

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

579

config file */

580

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

581

if (ret == ARGP_ERR_UNKNOWN){

582

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

583

exitstatus = EXIT_FAILURE;

584

goto fallback;

585

}

586

587

543

if(debug){

588

544

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

589

545

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

598

554

}

599

555

}

600

556

601

/* Strip permissions down to nobody */

602

557

ret = setuid(uid);

603

558

if (ret == -1){

604

559

perror("setuid");

605

}

560

}

561

606

562

setgid(gid);

607

563

if (ret == -1){

608

564

perror("setgid");

609

565

}

610

566

611

567

if (plugindir == NULL){

612

568

dir = opendir(PDIR);

613

569

} else {

635

591

636

592

FD_ZERO(&rfds_all);

637

593

638

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

639

594

while(true){

640

595

dirst = readdir(dir);

641

596

642

/* All directory entries have been processed */

597

// All directory entries have been processed

643

598

if(dirst == NULL){

644

599

if (errno == EBADF){

645

600

perror("readdir");

651

606

652

607

d_name_len = strlen(dirst->d_name);

653

608

654

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

609

// Ignore dotfiles, backup files and other junk

655

610

{

656

611

bool bad_name = false;

657

612

672

627

break;

673

628

}

674

629

}

630

675

631

if(bad_name){

676

632

continue;

677

633

}

634

678

635

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

679

636

size_t suf_len = strlen(*suf);

680

637

if((d_name_len >= suf_len)

707

664

free(filename);

708

665

continue;

709

666

}

710

711

/* Ignore non-executable files */

667

712

668

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

713

669

if(debug){

714

670

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

717

673

free(filename);

718

674

continue;

719

675

}

720

721

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

676

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

722

677

if(p == NULL){

723

678

perror("getplugin");

724

679

free(filename);

734

689

}

735

690

{

736

691

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

737

plugin *g = getplugin(NULL);

692

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

738

693

if(g != NULL){

739

694

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

740

695

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

743

698

}

744

699

/* Add global environment variables */

745

700

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

746

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

701

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

747

702

perror("add_environment");

748

703

}

749

704

}

754

709

process, too. */

755

710

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

756

711

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

757

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)){

758

718

perror("add_environment");

759

719

}

760

720

}

767

727

exitstatus = EXIT_FAILURE;

768

728

goto fallback;

769

729

}

770

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

771

730

ret = set_cloexec_flag(pipefd[0]);

772

731

if(ret < 0){

773

732

perror("set_cloexec_flag");

787

746

exitstatus = EXIT_FAILURE;

788

747

goto fallback;

789

748

}

790

/* Starting a new process to be watched */

749

// Starting a new process to be watched

791

750

pid_t pid = fork();

792

751

if(pid == -1){

793

752

perror("fork");

831

790

}

832

791

/* no return */

833

792

}

834

/* Parent process */

835

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

793

/* parent process */

836

794

free(filename);

837

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

838

if (new_plugin == NULL){

839

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");

840

799

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

841

800

if(ret < 0){

842

perror("sigprocmask");

801

perror("sigprocmask");

843

802

}

844

803

exitstatus = EXIT_FAILURE;

845

804

goto fallback;

846

805

}

847

806

848

new_plugin->pid = pid;

849

new_plugin->fd = pipefd[0];

850

807

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

808

.fd = pipefd[0],

809

.next = process_list };

810

// List handling

811

process_list = new_process;

851

812

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

852

813

has already completed */

853

814

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

857

818

goto fallback;

858

819

}

859

820

860

FD_SET(new_plugin->fd, &rfds_all);

821

FD_SET(new_process->fd, &rfds_all);

861

822

862

if (maxfd < new_plugin->fd){

863

maxfd = new_plugin->fd;

823

if (maxfd < new_process->fd){

824

maxfd = new_process->fd;

864

825

}

865

826

866

827

}

828

829

free_plugin_list(plugin_list);

830

plugin_list = NULL;

867

831

868

832

closedir(dir);

869

833

dir = NULL;

870

871

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

872

if(p->pid != 0){

873

break;

874

}

875

if(p->next == NULL){

876

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

877

" directory?\n");

878

free_plugin_list();

879

}

834

835

if (process_list == NULL){

836

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

837

" directory?\n");

838

process_list = NULL;

880

839

}

881

882

/* Main loop while running plugins exist */

883

while(plugin_list){

840

while(process_list){

884

841

fd_set rfds = rfds_all;

885

842

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

886

843

if (select_ret == -1){

890

847

}

891

848

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

892

849

from one of them */

893

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

850

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

894

851

/* Is this process completely done? */

895

852

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

896

853

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

897

854

if(not WIFEXITED(proc->status)

898

855

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

899

856

/* Bad exit by plugin */

900

901

857

if(debug){

902

858

if(WIFEXITED(proc->status)){

903

859

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

912

868

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

913

869

}

914

870

}

915

916

871

/* Remove the plugin */

917

872

FD_CLR(proc->fd, &rfds_all);

918

919

873

/* Block signal while modifying process_list */

920

874

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

921

875

if(ret < 0){

923

877

exitstatus = EXIT_FAILURE;

924

878

goto fallback;

925

879

}

926

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

}

927

893

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

928

894

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

929

895

NULL);

930

896

if(ret < 0){

931

897

perror("sigprocmask");

932

exitstatus = EXIT_FAILURE;

933

goto fallback;

934

}

935

936

if(plugin_list == NULL){

937

break;

938

}

939

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;

940

905

}

941

942

906

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

943

907

944

908

bool bret = print_out_password(proc->buffer,

949

913

}

950

914

goto fallback;

951

915

}

952

953

916

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

954

917

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

955

918

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

985

948

986

949

fallback:

987

950

988

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

951

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

989

952

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

990

953

occured */

991

954

bool bret;

1011

974

}

1012

975

free(custom_argv);

1013

976

}

977

free_plugin_list(plugin_list);

1014

978

1015

979

if(dir != NULL){

1016

980

closedir(dir);

1017

981

}

1018

982

1019

983

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

1020

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

1021

if(p->pid != 0){

1022

close(p->fd);

1023

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

1024

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

1025

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

1026

perror("kill");

1027

}

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");

1028

991

}

992

free(process_list->buffer);

993

free(process_list);

1029

994

}

1030

995

1031

996

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

1036

1001

perror("wait");

1037

1002

}

1038

1003

1039

free_plugin_list();

1040

1041

1004

free(plugindir);

1042

1005

free(argfile);

1043

1006