/mandos/release : revision 24.1.78

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

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

/* Refuse to add an existing variable */

192

return true;

193

}

194

}

183

195

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

184

196

}

185

197

186

187

198

/*

188

199

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

189

200

* Descriptor Flags".

200

211

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

201

212

}

202

213

203

process *process_list = NULL;

204

214

205

215

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

206

216

status. */

207

217

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

208

218

while(true){

209

process *proc = process_list;

219

plugin *proc = plugin_list;

210

220

int status;

211

221

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

212

222

if(pid == 0){

234

244

}

235

245

}

236

246

247

/* Prints out a password to stdout */

237

248

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

238

249

ssize_t ret;

239

250

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

249

260

return true;

250

261

}

251

262

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);

263

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

264

static void free_plugin(plugin *plugin_node){

265

266

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

267

free(*arg);

268

}

269

free(plugin_node->argv);

270

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

271

free(*env);

272

}

273

free(plugin_node->environ);

274

free(plugin_node->buffer);

275

276

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

277

if(plugin_node == plugin_list){

278

/* First one - simple */

279

plugin_list = plugin_list->next;

280

} else {

281

/* Second one or later */

282

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

283

if(p->next == plugin_node){

284

p->next = plugin_node->next;

285

break;

286

}

287

}

288

}

289

290

free(plugin_node);

291

}

292

293

static void free_plugin_list(void){

294

while(plugin_list != NULL){

295

free_plugin(plugin_list);

264

296

}

265

297

}

266

298

304

336

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

305

337

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

306

338

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

307

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

339

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

308

340

.arg = "VAR=value",

309

341

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

310

342

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

311

343

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

312

344

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

313

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

345

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

314

346

.arg = "PLUGIN:ENV=value",

315

347

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

316

348

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

333

365

{ .name = NULL }

334

366

};

335

367

336

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

368

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

369

struct argp_state *state) {

337

370

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

338

371

pointer to our plugin list pointer. */

339

plugin **plugins = state->input;

340

372

switch (key) {

341

case 'g':

373

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

342

374

if (arg != NULL){

343

375

char *p;

344

376

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

345

377

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

346

378

continue;

347

379

}

348

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

380

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

349

381

perror("add_argument");

350

382

return ARGP_ERR_UNKNOWN;

351

383

}

352

384

}

353

385

}

354

386

break;

355

case 'e':

387

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

356

388

if(arg == NULL){

357

389

break;

358

390

}

361

393

if(envdef == NULL){

362

394

break;

363

395

}

364

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

396

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

365

397

perror("add_environment");

366

398

}

367

399

}

368

400

break;

369

case 'o':

401

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

370

402

if (arg != NULL){

371

403

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

372

404

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

382

414

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

383

415

continue;

384

416

}

385

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

417

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

386

418

perror("add_argument");

387

419

return ARGP_ERR_UNKNOWN;

388

420

}

390

422

}

391

423

}

392

424

break;

393

case 'f':

425

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

394

426

if(arg == NULL){

395

427

break;

396

428

}

404

436

break;

405

437

}

406

438

envdef++;

407

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

439

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

408

440

perror("add_environment");

409

441

}

410

442

}

411

443

break;

412

case 'd':

444

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

413

445

if (arg != NULL){

414

plugin *p = getplugin(arg, plugins);

446

plugin *p = getplugin(arg);

415

447

if(p == NULL){

416

448

return ARGP_ERR_UNKNOWN;

417

449

}

418

450

p->disabled = true;

419

451

}

420

452

break;

421

case 128:

453

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

422

454

plugindir = strdup(arg);

423

455

if(plugindir == NULL){

424

456

perror("strdup");

425

457

}

426

458

break;

427

case 129:

459

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

428

460

argfile = strdup(arg);

429

461

if(argfile == NULL){

430

462

perror("strdup");

431

463

}

432

464

break;

433

case 130:

465

case 130: /* --userid */

434

466

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

435

467

break;

436

case 131:

468

case 131: /* --groupid */

437

469

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

438

470

break;

439

case 132:

471

case 132: /* --debug */

440

472

debug = true;

441

473

break;

442

474

case ARGP_KEY_ARG:

450

482

return 0;

451

483

}

452

484

453

plugin *plugin_list = NULL;

454

455

485

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

456

486

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

457

487

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

458

488

459

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

489

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

460

490

if (ret == ARGP_ERR_UNKNOWN){

461

491

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

462

492

exitstatus = EXIT_FAILURE;

463

493

goto fallback;

464

494

}

465

495

496

/* Opens the configfile if aviable */

466

497

if (argfile == NULL){

467

498

conffp = fopen(AFILE, "r");

468

499

} else {

469

500

conffp = fopen(argfile, "r");

470

}

471

501

}

472

502

if(conffp != NULL){

473

503

char *org_line = NULL;

474

504

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

486

516

}

487

517

custom_argv[0] = argv[0];

488

518

custom_argv[1] = NULL;

489

519

520

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

521

commented text */

490

522

while(true){

491

523

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

492

524

if(sret == -1){

530

562

goto fallback;

531

563

}

532

564

}

533

565

/* If there was any arguments from configuration file,

566

pass them to parser as command arguments */

534

567

if(custom_argv != NULL){

535

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

568

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

536

569

if (ret == ARGP_ERR_UNKNOWN){

537

570

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

538

571

exitstatus = EXIT_FAILURE;

553

586

}

554

587

}

555

588

}

556

589

590

/* Strip permissions down to nobody */

557

591

ret = setuid(uid);

558

592

if (ret == -1){

559

593

perror("setuid");

560

}

561

594

}

562

595

setgid(gid);

563

596

if (ret == -1){

564

597

perror("setgid");

590

623

}

591

624

592

625

FD_ZERO(&rfds_all);

593

626

627

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

594

628

while(true){

595

629

dirst = readdir(dir);

596

630

627

661

break;

628

662

}

629

663

}

630

631

664

if(bad_name){

632

665

continue;

633

666

}

634

635

667

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

636

668

size_t suf_len = strlen(*suf);

637

669

if((d_name_len >= suf_len)

664

696

free(filename);

665

697

continue;

666

698

}

667

699

700

/* Ignore non-executable files */

668

701

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

669

702

if(debug){

670

703

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

673

706

free(filename);

674

707

continue;

675

708

}

676

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

709

710

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

677

711

if(p == NULL){

678

712

perror("getplugin");

679

713

free(filename);

689

723

}

690

724

{

691

725

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

692

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

726

plugin *g = getplugin(NULL);

693

727

if(g != NULL){

694

728

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

695

729

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

727

761

exitstatus = EXIT_FAILURE;

728

762

goto fallback;

729

763

}

764

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

730

765

ret = set_cloexec_flag(pipefd[0]);

731

766

if(ret < 0){

732

767

perror("set_cloexec_flag");

790

825

}

791

826

/* no return */

792

827

}

793

/* parent process */

828

/* Parent process */

829

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

794

830

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");

831

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

832

if (new_plugin == NULL){

833

perror("getplugin");

799

834

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

800

835

if(ret < 0){

801

perror("sigprocmask");

836

perror("sigprocmask");

802

837

}

803

838

exitstatus = EXIT_FAILURE;

804

839

goto fallback;

805

840

}

806

841

807

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

808

.fd = pipefd[0],

809

.next = process_list };

810

// List handling

811

process_list = new_process;

842

new_plugin->pid = pid;

843

new_plugin->fd = pipefd[0];

844

812

845

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

813

846

has already completed */

814

847

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

818

851

goto fallback;

819

852

}

820

853

821

FD_SET(new_process->fd, &rfds_all);

854

FD_SET(new_plugin->fd, &rfds_all);

822

855

823

if (maxfd < new_process->fd){

824

maxfd = new_process->fd;

856

if (maxfd < new_plugin->fd){

857

maxfd = new_plugin->fd;

825

858

}

826

859

827

860

}

828

829

free_plugin_list(plugin_list);

830

plugin_list = NULL;

831

861

832

862

closedir(dir);

833

863

dir = NULL;

834

835

if (process_list == NULL){

836

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

837

" directory?\n");

838

process_list = NULL;

864

865

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

866

if(p->pid != 0){

867

break;

868

}

869

if(p->next == NULL){

870

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

871

" directory?\n");

872

free_plugin_list();

873

}

839

874

}

840

while(process_list){

875

876

/* Main loop while running plugins exist */

877

while(plugin_list){

841

878

fd_set rfds = rfds_all;

842

879

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

843

880

if (select_ret == -1){

847

884

}

848

885

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

849

886

from one of them */

850

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

887

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

851

888

/* Is this process completely done? */

852

889

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

853

890

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

854

891

if(not WIFEXITED(proc->status)

855

892

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

856

893

/* Bad exit by plugin */

894

857

895

if(debug){

858

896

if(WIFEXITED(proc->status)){

859

897

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

868

906

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

869

907

}

870

908

}

909

871

910

/* Remove the plugin */

872

911

FD_CLR(proc->fd, &rfds_all);

912

873

913

/* Block signal while modifying process_list */

874

914

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

875

915

if(ret < 0){

877

917

exitstatus = EXIT_FAILURE;

878

918

goto fallback;

879

919

}

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

}

920

free_plugin(proc);

893

921

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

894

922

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

895

923

NULL);

896

924

if(ret < 0){

897

925

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;

926

exitstatus = EXIT_FAILURE;

927

goto fallback;

928

}

929

930

if(plugin_list == NULL){

931

break;

932

}

933

continue;

905

934

}

935

906

936

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

907

937

908

938

bool bret = print_out_password(proc->buffer,

913

943

}

914

944

goto fallback;

915

945

}

946

916

947

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

917

948

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

918

949

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

948

979

949

980

fallback:

950

981

951

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

982

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

952

983

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

953

984

occured */

954

985

bool bret;

974

1005

}

975

1006

free(custom_argv);

976

1007

}

977

free_plugin_list(plugin_list);

978

1008

979

1009

if(dir != NULL){

980

1010

closedir(dir);

981

1011

}

982

1012

983

1013

/* 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");

1014

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

1015

if(p->pid != 0){

1016

close(p->fd);

1017

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

1018

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

1019

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

1020

perror("kill");

1021

}

991

1022

}

992

free(process_list->buffer);

993

free(process_list);

994

1023

}

995

1024

996

1025

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

1001

1030

perror("wait");

1002

1031

}

1003

1032

1033

free_plugin_list();

1034

1004

1035

free(plugindir);

1005

1036

free(argfile);

1006

1037