/mandos/release : revision 24.1.67

65

#include <errno.h> /* errno, EBADF */

66

67

#define BUFFER_SIZE 256

68

69

#define PDIR "/lib/mandos/plugins.d"

70

#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"

68

#define ARGFILE "/conf/conf.d/mandos/plugin-runner.conf"

71

69

72

70

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

73

71

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

74

72

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*/

73

struct process;

74

75

typedef struct process{

86

76

pid_t pid;

87

77

int fd;

88

78

char *buffer;

91

81

bool eof;

92

82

volatile bool completed;

93

83

volatile int status;

84

struct process *next;

85

} process;

86

87

typedef struct plugin{

88

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

89

char **argv;

90

int argc;

91

char **environ;

92

int envc;

93

bool disabled;

94

struct plugin *next;

95

} plugin;

96

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){

97

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

98

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

104

99

if ((p->name == name)

105

100

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

106

101

return p;

118

113

return NULL;

119

114

}

120

115

}

121

116

122

117

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

123

118

.argc = 1,

119

.envc = 0,

124

120

.disabled = false,

125

.next = plugin_list };

121

.next = *plugin_list };

126

122

127

123

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

128

124

if (new_plugin->argv == NULL){

132

128

}

133

129

new_plugin->argv[0] = copy_name;

134

130

new_plugin->argv[1] = NULL;

135

131

136

132

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

137

133

if(new_plugin->environ == NULL){

138

134

free(copy_name);

141

137

return NULL;

142

138

}

143

139

new_plugin->environ[0] = NULL;

144

145

140

/* Append the new plugin to the list */

146

plugin_list = new_plugin;

141

*plugin_list = new_plugin;

147

142

return new_plugin;

148

143

}

149

144

183

178

if(p == NULL){

184

179

return false;

185

180

}

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

181

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

196

182

}

197

183

184

198

185

/*

199

186

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

200

187

* Descriptor Flags".

211

198

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

212

199

}

213

200

201

process *process_list = NULL;

214

202

215

203

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

216

204

status. */

217

205

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

218

206

while(true){

219

plugin *proc = plugin_list;

207

process *proc = process_list;

220

208

int status;

221

209

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

222

210

if(pid == 0){

244

232

}

245

233

}

246

234

247

/* Prints out a password to stdout */

248

235

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

249

236

ssize_t ret;

250

237

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

260

247

return true;

261

248

}

262

249

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);

250

static void free_plugin_list(plugin *plugin_list){

251

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

252

next = plugin_list->next;

253

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

254

free(*arg);

255

}

256

free(plugin_list->argv);

257

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

258

free(*env);

259

}

260

free(plugin_list->environ);

261

free(plugin_list);

296

262

}

297

263

}

298

264

299

265

int main(int argc, char *argv[]){

300

char *plugindir = NULL;

301

char *argfile = NULL;

266

const char *plugindir = "/lib/mandos/plugins.d";

267

const char *argfile = ARGFILE;

302

268

FILE *conffp;

303

269

size_t d_name_len;

304

270

DIR *dir = NULL;

336

302

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

337

303

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

338

304

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

339

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

305

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

340

306

.arg = "VAR=value",

341

307

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

342

308

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

343

309

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

344

310

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

345

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

311

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

346

312

.arg = "PLUGIN:ENV=value",

347

313

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

348

314

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

351

317

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

352

318

.arg = "DIRECTORY",

353

319

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

354

{ .name = "config-file", .key = 129,

355

.arg = "FILE",

356

.doc = "Specify a different configuration file", .group = 2 },

357

{ .name = "userid", .key = 130,

358

.arg = "ID", .flags = 0,

359

.doc = "User ID the plugins will run as", .group = 3 },

360

{ .name = "groupid", .key = 131,

361

.arg = "ID", .flags = 0,

362

.doc = "Group ID the plugins will run as", .group = 3 },

363

{ .name = "debug", .key = 132,

364

.doc = "Debug mode", .group = 4 },

320

{ .name = "userid", .key = 129,

321

.arg = "ID", .flags = 0,

322

.doc = "User ID the plugins will run as", .group = 2 },

323

{ .name = "groupid", .key = 130,

324

.arg = "ID", .flags = 0,

325

.doc = "Group ID the plugins will run as", .group = 2 },

326

{ .name = "debug", .key = 131,

327

.doc = "Debug mode", .group = 3 },

365

328

{ .name = NULL }

366

329

};

367

330

368

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

369

struct argp_state *state) {

331

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

370

332

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

371

333

pointer to our plugin list pointer. */

334

plugin **plugins = state->input;

372

335

switch (key) {

373

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

336

case 'g':

374

337

if (arg != NULL){

375

338

char *p;

376

339

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

377

340

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

378

341

continue;

379

342

}

380

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

343

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

381

344

perror("add_argument");

382

345

return ARGP_ERR_UNKNOWN;

383

346

}

384

347

}

385

348

}

386

349

break;

387

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

350

case 'e':

388

351

if(arg == NULL){

389

352

break;

390

353

}

393

356

if(envdef == NULL){

394

357

break;

395

358

}

396

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

359

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

397

360

perror("add_environment");

398

361

}

399

362

}

400

363

break;

401

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

364

case 'o':

402

365

if (arg != NULL){

403

366

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

404

367

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

414

377

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

415

378

continue;

416

379

}

417

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

380

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

418

381

perror("add_argument");

419

382

return ARGP_ERR_UNKNOWN;

420

383

}

422

385

}

423

386

}

424

387

break;

425

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

388

case 'f':

426

389

if(arg == NULL){

427

390

break;

428

391

}

436

399

break;

437

400

}

438

401

envdef++;

439

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

402

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

440

403

perror("add_environment");

441

404

}

442

405

}

443

406

break;

444

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

407

case 'd':

445

408

if (arg != NULL){

446

plugin *p = getplugin(arg);

409

plugin *p = getplugin(arg, plugins);

447

410

if(p == NULL){

448

411

return ARGP_ERR_UNKNOWN;

449

412

}

450

413

p->disabled = true;

451

414

}

452

415

break;

453

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

454

plugindir = strdup(arg);

455

if(plugindir == NULL){

456

perror("strdup");

457

}

416

case 128:

417

plugindir = arg;

458

418

break;

459

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

460

argfile = strdup(arg);

461

if(argfile == NULL){

462

perror("strdup");

463

}

464

break;

465

case 130: /* --userid */

419

case 129:

466

420

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

467

421

break;

468

case 131: /* --groupid */

422

case 130:

469

423

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

470

424

break;

471

case 132: /* --debug */

425

case 131:

472

426

debug = true;

473

427

break;

474

428

case ARGP_KEY_ARG:

482

436

return 0;

483

437

}

484

438

439

plugin *plugin_list = NULL;

440

485

441

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

486

442

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

487

443

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

488

444

489

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

445

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

490

446

if (ret == ARGP_ERR_UNKNOWN){

491

447

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

492

448

exitstatus = EXIT_FAILURE;

493

449

goto fallback;

494

450

}

495

451

496

/* Opens the configfile if aviable */

497

if (argfile == NULL){

498

conffp = fopen(AFILE, "r");

499

} else {

500

conffp = fopen(argfile, "r");

501

}

452

conffp = fopen(argfile, "r");

502

453

if(conffp != NULL){

503

454

char *org_line = NULL;

504

455

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

516

467

}

517

468

custom_argv[0] = argv[0];

518

469

custom_argv[1] = NULL;

519

520

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

521

commented text */

470

522

471

while(true){

523

472

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

524

473

if(sret == -1){

532

481

continue;

533

482

}

534

483

new_arg = strdup(p);

535

if(new_arg == NULL){

536

perror("strdup");

537

exitstatus = EXIT_FAILURE;

538

free(org_line);

539

goto fallback;

540

}

541

484

542

485

custom_argc += 1;

543

486

custom_argv = realloc(custom_argv, sizeof(char *)

544

487

* ((unsigned int) custom_argc + 1));

562

505

goto fallback;

563

506

}

564

507

}

565

/* If there was any arguments from configuration file,

566

pass them to parser as command arguments */

508

567

509

if(custom_argv != NULL){

568

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

510

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

569

511

if (ret == ARGP_ERR_UNKNOWN){

570

512

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

571

513

exitstatus = EXIT_FAILURE;

586

528

}

587

529

}

588

530

}

589

590

/* Strip permissions down to nobody */

531

591

532

ret = setuid(uid);

592

533

if (ret == -1){

593

534

perror("setuid");

594

}

535

}

536

595

537

setgid(gid);

596

538

if (ret == -1){

597

539

perror("setgid");

598

540

}

599

600

if (plugindir == NULL){

601

dir = opendir(PDIR);

602

} else {

603

dir = opendir(plugindir);

604

}

605

541

542

dir = opendir(plugindir);

606

543

if(dir == NULL){

607

544

perror("Could not open plugin dir");

608

545

exitstatus = EXIT_FAILURE;

623

560

}

624

561

625

562

FD_ZERO(&rfds_all);

626

627

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

563

628

564

while(true){

629

565

dirst = readdir(dir);

630

566

661

597

break;

662

598

}

663

599

}

600

664

601

if(bad_name){

665

602

continue;

666

603

}

604

667

605

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

668

606

size_t suf_len = strlen(*suf);

669

607

if((d_name_len >= suf_len)

696

634

free(filename);

697

635

continue;

698

636

}

699

700

/* Ignore non-executable files */

637

701

638

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

702

639

if(debug){

703

640

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

706

643

free(filename);

707

644

continue;

708

645

}

709

710

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

646

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

711

647

if(p == NULL){

712

648

perror("getplugin");

713

649

free(filename);

723

659

}

724

660

{

725

661

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

726

plugin *g = getplugin(NULL);

662

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

727

663

if(g != NULL){

728

664

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

729

665

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

761

697

exitstatus = EXIT_FAILURE;

762

698

goto fallback;

763

699

}

764

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

765

700

ret = set_cloexec_flag(pipefd[0]);

766

701

if(ret < 0){

767

702

perror("set_cloexec_flag");

825

760

}

826

761

/* no return */

827

762

}

828

/* Parent process */

829

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

763

/* parent process */

830

764

free(filename);

831

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

832

if (new_plugin == NULL){

833

perror("getplugin");

765

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

766

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

767

if (new_process == NULL){

768

perror("malloc");

834

769

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

835

770

if(ret < 0){

836

perror("sigprocmask");

771

perror("sigprocmask");

837

772

}

838

773

exitstatus = EXIT_FAILURE;

839

774

goto fallback;

840

775

}

841

776

842

new_plugin->pid = pid;

843

new_plugin->fd = pipefd[0];

844

777

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

778

.fd = pipefd[0],

779

.next = process_list };

780

// List handling

781

process_list = new_process;

845

782

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

846

783

has already completed */

847

784

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

851

788

goto fallback;

852

789

}

853

790

854

FD_SET(new_plugin->fd, &rfds_all);

791

FD_SET(new_process->fd, &rfds_all);

855

792

856

if (maxfd < new_plugin->fd){

857

maxfd = new_plugin->fd;

793

if (maxfd < new_process->fd){

794

maxfd = new_process->fd;

858

795

}

859

796

860

797

}

861

798

799

free_plugin_list(plugin_list);

800

plugin_list = NULL;

801

862

802

closedir(dir);

863

803

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

}

804

805

if (process_list == NULL){

806

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

807

" directory?\n");

808

process_list = NULL;

874

809

}

875

876

/* Main loop while running plugins exist */

877

while(plugin_list){

810

while(process_list){

878

811

fd_set rfds = rfds_all;

879

812

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

880

813

if (select_ret == -1){

884

817

}

885

818

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

886

819

from one of them */

887

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

820

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

888

821

/* Is this process completely done? */

889

822

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

890

823

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

891

824

if(not WIFEXITED(proc->status)

892

825

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

893

826

/* Bad exit by plugin */

894

895

827

if(debug){

896

828

if(WIFEXITED(proc->status)){

897

829

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

906

838

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

907

839

}

908

840

}

909

910

841

/* Remove the plugin */

911

842

FD_CLR(proc->fd, &rfds_all);

912

913

843

/* Block signal while modifying process_list */

914

844

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

915

845

if(ret < 0){

917

847

exitstatus = EXIT_FAILURE;

918

848

goto fallback;

919

849

}

920

free_plugin(proc);

850

/* Delete this process entry from the list */

851

if(process_list == proc){

852

/* First one - simple */

853

process_list = proc->next;

854

} else {

855

/* Second one or later */

856

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

857

if(p->next == proc){

858

p->next = proc->next;

859

break;

860

}

861

}

862

}

921

863

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

922

864

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

923

865

NULL);

924

866

if(ret < 0){

925

867

perror("sigprocmask");

926

exitstatus = EXIT_FAILURE;

927

goto fallback;

928

}

929

930

if(plugin_list == NULL){

931

break;

932

}

933

continue;

868

}

869

free(proc->buffer);

870

free(proc);

871

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

872

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

873

the process list */

874

break;

934

875

}

935

936

876

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

937

877

938

878

bool bret = print_out_password(proc->buffer,

943

883

}

944

884

goto fallback;

945

885

}

946

947

886

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

948

887

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

949

888

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

979

918

980

919

fallback:

981

920

982

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

921

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

983

922

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

984

923

occured */

985

924

bool bret;

1005

944

}

1006

945

free(custom_argv);

1007

946

}

947

free_plugin_list(plugin_list);

1008

948

1009

949

if(dir != NULL){

1010

950

closedir(dir);

1011

951

}

1012

952

1013

953

/* 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

}

954

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

955

next = process_list->next;

956

close(process_list->fd);

957

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

958

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

959

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

960

perror("kill");

1022

961

}

962

free(process_list->buffer);

963

free(process_list);

1023

964

}

1024

965

1025

966

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

1029

970

if(errno != ECHILD){

1030

971

perror("wait");

1031

972

}

1032

1033

free_plugin_list();

1034

1035

free(plugindir);

1036

free(argfile);

1037

973

1038

974

return exitstatus;

1039

975

}