/mandos/release : revision 24.1.75

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

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

/* Refuse to add an existing variable */

192

return true;

193

}

194

}

195

183

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

196

184

}

197

185

186

198

187

/*

199

188

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

200

189

* Descriptor Flags".

211

200

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

212

201

}

213

202

203

process *process_list = NULL;

214

204

215

205

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

216

206

status. */

217

207

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

218

208

while(true){

219

plugin *proc = plugin_list;

209

process *proc = process_list;

220

210

int status;

221

211

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

222

212

if(pid == 0){

244

234

}

245

235

}

246

236

247

/* Prints out a password to stdout */

248

237

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

249

238

ssize_t ret;

250

239

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

260

249

return true;

261

250

}

262

251

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);

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);

296

264

}

297

265

}

298

266

336

304

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

337

305

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

338

306

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

339

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

307

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

340

308

.arg = "VAR=value",

341

309

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

342

310

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

343

311

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

344

312

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

345

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

313

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

346

314

.arg = "PLUGIN:ENV=value",

347

315

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

348

316

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

365

333

{ .name = NULL }

366

334

};

367

335

368

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

369

struct argp_state *state) {

336

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

370

337

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

371

338

pointer to our plugin list pointer. */

339

plugin **plugins = state->input;

372

340

switch (key) {

373

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

341

case 'g':

374

342

if (arg != NULL){

375

343

char *p;

376

344

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

377

345

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

378

346

continue;

379

347

}

380

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

348

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

381

349

perror("add_argument");

382

350

return ARGP_ERR_UNKNOWN;

383

351

}

384

352

}

385

353

}

386

354

break;

387

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

355

case 'e':

388

356

if(arg == NULL){

389

357

break;

390

358

}

393

361

if(envdef == NULL){

394

362

break;

395

363

}

396

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

364

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

397

365

perror("add_environment");

398

366

}

399

367

}

400

368

break;

401

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

369

case 'o':

402

370

if (arg != NULL){

403

371

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

404

372

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

414

382

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

415

383

continue;

416

384

}

417

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

385

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

418

386

perror("add_argument");

419

387

return ARGP_ERR_UNKNOWN;

420

388

}

422

390

}

423

391

}

424

392

break;

425

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

393

case 'f':

426

394

if(arg == NULL){

427

395

break;

428

396

}

436

404

break;

437

405

}

438

406

envdef++;

439

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

407

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

440

408

perror("add_environment");

441

409

}

442

410

}

443

411

break;

444

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

412

case 'd':

445

413

if (arg != NULL){

446

plugin *p = getplugin(arg);

414

plugin *p = getplugin(arg, plugins);

447

415

if(p == NULL){

448

416

return ARGP_ERR_UNKNOWN;

449

417

}

450

418

p->disabled = true;

451

419

}

452

420

break;

453

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

421

case 128:

454

422

plugindir = strdup(arg);

455

423

if(plugindir == NULL){

456

424

perror("strdup");

457

425

}

458

426

break;

459

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

427

case 129:

460

428

argfile = strdup(arg);

461

429

if(argfile == NULL){

462

430

perror("strdup");

463

431

}

464

432

break;

465

case 130: /* --userid */

433

case 130:

466

434

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

467

435

break;

468

case 131: /* --groupid */

436

case 131:

469

437

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

470

438

break;

471

case 132: /* --debug */

439

case 132:

472

440

debug = true;

473

441

break;

474

442

case ARGP_KEY_ARG:

482

450

return 0;

483

451

}

484

452

453

plugin *plugin_list = NULL;

454

485

455

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

486

456

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

487

457

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

488

458

489

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

459

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

490

460

if (ret == ARGP_ERR_UNKNOWN){

491

461

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

492

462

exitstatus = EXIT_FAILURE;

493

463

goto fallback;

494

464

}

495

465

496

/* Opens the configfile if aviable */

497

466

if (argfile == NULL){

498

467

conffp = fopen(AFILE, "r");

499

468

} else {

500

469

conffp = fopen(argfile, "r");

501

}

470

}

471

502

472

if(conffp != NULL){

503

473

char *org_line = NULL;

504

474

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

516

486

}

517

487

custom_argv[0] = argv[0];

518

488

custom_argv[1] = NULL;

519

520

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

521

commented text */

489

522

490

while(true){

523

491

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

524

492

if(sret == -1){

562

530

goto fallback;

563

531

}

564

532

}

565

/* If there was any arguments from configuration file,

566

pass them to parser as command arguments */

533

567

534

if(custom_argv != NULL){

568

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

535

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

569

536

if (ret == ARGP_ERR_UNKNOWN){

570

537

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

571

538

exitstatus = EXIT_FAILURE;

586

553

}

587

554

}

588

555

}

589

590

/* Strip permissions down to nobody */

556

591

557

ret = setuid(uid);

592

558

if (ret == -1){

593

559

perror("setuid");

594

}

560

}

561

595

562

setgid(gid);

596

563

if (ret == -1){

597

564

perror("setgid");

623

590

}

624

591

625

592

FD_ZERO(&rfds_all);

626

627

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

593

628

594

while(true){

629

595

dirst = readdir(dir);

630

596

661

627

break;

662

628

}

663

629

}

630

664

631

if(bad_name){

665

632

continue;

666

633

}

634

667

635

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

668

636

size_t suf_len = strlen(*suf);

669

637

if((d_name_len >= suf_len)

696

664

free(filename);

697

665

continue;

698

666

}

699

700

/* Ignore non-executable files */

667

701

668

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

702

669

if(debug){

703

670

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

706

673

free(filename);

707

674

continue;

708

675

}

709

710

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

676

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

711

677

if(p == NULL){

712

678

perror("getplugin");

713

679

free(filename);

723

689

}

724

690

{

725

691

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

726

plugin *g = getplugin(NULL);

692

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

727

693

if(g != NULL){

728

694

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

729

695

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

761

727

exitstatus = EXIT_FAILURE;

762

728

goto fallback;

763

729

}

764

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

765

730

ret = set_cloexec_flag(pipefd[0]);

766

731

if(ret < 0){

767

732

perror("set_cloexec_flag");

825

790

}

826

791

/* no return */

827

792

}

828

/* Parent process */

829

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

793

/* parent process */

830

794

free(filename);

831

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

832

if (new_plugin == NULL){

833

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");

834

799

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

835

800

if(ret < 0){

836

perror("sigprocmask");

801

perror("sigprocmask");

837

802

}

838

803

exitstatus = EXIT_FAILURE;

839

804

goto fallback;

840

805

}

841

806

842

new_plugin->pid = pid;

843

new_plugin->fd = pipefd[0];

844

807

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

808

.fd = pipefd[0],

809

.next = process_list };

810

// List handling

811

process_list = new_process;

845

812

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

846

813

has already completed */

847

814

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

851

818

goto fallback;

852

819

}

853

820

854

FD_SET(new_plugin->fd, &rfds_all);

821

FD_SET(new_process->fd, &rfds_all);

855

822

856

if (maxfd < new_plugin->fd){

857

maxfd = new_plugin->fd;

823

if (maxfd < new_process->fd){

824

maxfd = new_process->fd;

858

825

}

859

826

860

827

}

828

829

free_plugin_list(plugin_list);

830

plugin_list = NULL;

861

831

862

832

closedir(dir);

863

833

dir = 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

}

834

835

if (process_list == NULL){

836

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

837

" directory?\n");

838

process_list = NULL;

874

839

}

875

876

/* Main loop while running plugins exist */

877

while(plugin_list){

840

while(process_list){

878

841

fd_set rfds = rfds_all;

879

842

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

880

843

if (select_ret == -1){

884

847

}

885

848

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

886

849

from one of them */

887

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

850

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

888

851

/* Is this process completely done? */

889

852

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

890

853

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

891

854

if(not WIFEXITED(proc->status)

892

855

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

893

856

/* Bad exit by plugin */

894

895

857

if(debug){

896

858

if(WIFEXITED(proc->status)){

897

859

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

906

868

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

907

869

}

908

870

}

909

910

871

/* Remove the plugin */

911

872

FD_CLR(proc->fd, &rfds_all);

912

913

873

/* Block signal while modifying process_list */

914

874

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

915

875

if(ret < 0){

917

877

exitstatus = EXIT_FAILURE;

918

878

goto fallback;

919

879

}

920

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

}

921

893

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

922

894

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

923

895

NULL);

924

896

if(ret < 0){

925

897

perror("sigprocmask");

926

exitstatus = EXIT_FAILURE;

927

goto fallback;

928

}

929

930

if(plugin_list == NULL){

931

break;

932

}

933

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;

934

905

}

935

936

906

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

937

907

938

908

bool bret = print_out_password(proc->buffer,

943

913

}

944

914

goto fallback;

945

915

}

946

947

916

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

948

917

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

949

918

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

979

948

980

949

fallback:

981

950

982

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

951

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

983

952

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

984

953

occured */

985

954

bool bret;

1005

974

}

1006

975

free(custom_argv);

1007

976

}

977

free_plugin_list(plugin_list);

1008

978

1009

979

if(dir != NULL){

1010

980

closedir(dir);

1011

981

}

1012

982

1013

983

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

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

}

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");

1022

991

}

992

free(process_list->buffer);

993

free(process_list);

1023

994

}

1024

995

1025

996

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

1030

1001

perror("wait");

1031

1002

}

1032

1003

1033

free_plugin_list();

1034

1035

1004

free(plugindir);

1036

1005

free(argfile);

1037

1006