/mandos/trunk : 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){

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

186

181

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

187

182

}

188

183

184

189

185

/*

190

186

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

191

187

* Descriptor Flags".

202

198

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

203

199

}

204

200

201

process *process_list = NULL;

205

202

206

203

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

207

204

status. */

208

205

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

209

206

while(true){

210

plugin *proc = plugin_list;

207

process *proc = process_list;

211

208

int status;

212

209

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

213

210

if(pid == 0){

235

232

}

236

233

}

237

234

238

/* Prints out a password to stdout */

239

235

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

240

236

ssize_t ret;

241

237

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

251

247

return true;

252

248

}

253

249

254

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

255

static void free_plugin(plugin *plugin_node){

256

257

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

258

free(*arg);

259

}

260

free(plugin_node->argv);

261

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

262

free(*env);

263

}

264

free(plugin_node->environ);

265

free(plugin_node->buffer);

266

267

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

268

if(plugin_node == plugin_list){

269

/* First one - simple */

270

plugin_list = plugin_list->next;

271

} else {

272

/* Second one or later */

273

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

274

if(p->next == plugin_node){

275

p->next = plugin_node->next;

276

break;

277

}

278

}

279

}

280

281

free(plugin_node);

282

}

283

284

static void free_plugin_list(void){

285

while(plugin_list != NULL){

286

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);

287

262

}

288

263

}

289

264

290

265

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

291

char *plugindir = NULL;

292

char *argfile = NULL;

266

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

267

const char *argfile = ARGFILE;

293

268

FILE *conffp;

294

269

size_t d_name_len;

295

270

DIR *dir = NULL;

342

317

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

343

318

.arg = "DIRECTORY",

344

319

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

345

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

346

.arg = "FILE",

347

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

348

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

349

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

350

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

351

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

352

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

353

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

354

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

355

.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 },

356

328

{ .name = NULL }

357

329

};

358

330

359

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

331

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

360

332

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

361

333

pointer to our plugin list pointer. */

334

plugin **plugins = state->input;

362

335

switch (key) {

363

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

336

case 'g':

364

337

if (arg != NULL){

365

338

char *p;

366

339

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

367

340

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

368

341

continue;

369

342

}

370

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

343

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

371

344

perror("add_argument");

372

345

return ARGP_ERR_UNKNOWN;

373

346

}

374

347

}

375

348

}

376

349

break;

377

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

350

case 'e':

378

351

if(arg == NULL){

379

352

break;

380

353

}

383

356

if(envdef == NULL){

384

357

break;

385

358

}

386

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

359

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

387

360

perror("add_environment");

388

361

}

389

362

}

390

363

break;

391

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

364

case 'o':

392

365

if (arg != NULL){

393

366

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

394

367

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

404

377

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

405

378

continue;

406

379

}

407

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

380

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

408

381

perror("add_argument");

409

382

return ARGP_ERR_UNKNOWN;

410

383

}

412

385

}

413

386

}

414

387

break;

415

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

388

case 'f':

416

389

if(arg == NULL){

417

390

break;

418

391

}

426

399

break;

427

400

}

428

401

envdef++;

429

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

402

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

430

403

perror("add_environment");

431

404

}

432

405

}

433

406

break;

434

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

407

case 'd':

435

408

if (arg != NULL){

436

plugin *p = getplugin(arg);

409

plugin *p = getplugin(arg, plugins);

437

410

if(p == NULL){

438

411

return ARGP_ERR_UNKNOWN;

439

412

}

440

413

p->disabled = true;

441

414

}

442

415

break;

443

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

444

plugindir = strdup(arg);

445

if(plugindir == NULL){

446

perror("strdup");

447

}

416

case 128:

417

plugindir = arg;

448

418

break;

449

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

450

argfile = strdup(arg);

451

if(argfile == NULL){

452

perror("strdup");

453

}

454

break;

455

case 130: /* --userid */

419

case 129:

456

420

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

457

421

break;

458

case 131: /* --groupid */

422

case 130:

459

423

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

460

424

break;

461

case 132: /* --debug */

425

case 131:

462

426

debug = true;

463

427

break;

464

428

case ARGP_KEY_ARG:

472

436

return 0;

473

437

}

474

438

439

plugin *plugin_list = NULL;

440

475

441

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

476

442

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

477

443

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

478

444

479

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

445

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

480

446

if (ret == ARGP_ERR_UNKNOWN){

481

447

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

482

448

exitstatus = EXIT_FAILURE;

483

449

goto fallback;

484

450

}

485

451

486

/* Opens the configfile if aviable */

487

if (argfile == NULL){

488

conffp = fopen(AFILE, "r");

489

} else {

490

conffp = fopen(argfile, "r");

491

}

452

conffp = fopen(argfile, "r");

492

453

if(conffp != NULL){

493

454

char *org_line = NULL;

494

455

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

506

467

}

507

468

custom_argv[0] = argv[0];

508

469

custom_argv[1] = NULL;

509

510

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

470

511

471

while(true){

512

472

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

513

473

if(sret == -1){

521

481

continue;

522

482

}

523

483

new_arg = strdup(p);

524

if(new_arg == NULL){

525

perror("strdup");

526

exitstatus = EXIT_FAILURE;

527

free(org_line);

528

goto fallback;

529

}

530

484

531

485

custom_argc += 1;

532

486

custom_argv = realloc(custom_argv, sizeof(char *)

533

487

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

551

505

goto fallback;

552

506

}

553

507

}

554

/* If there was any arguments from configuration file,

555

pass them to parser as command arguments */

508

556

509

if(custom_argv != NULL){

557

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

510

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

558

511

if (ret == ARGP_ERR_UNKNOWN){

559

512

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

560

513

exitstatus = EXIT_FAILURE;

575

528

}

576

529

}

577

530

}

578

579

/* Strip permissions down to nobody */

531

580

532

ret = setuid(uid);

581

533

if (ret == -1){

582

534

perror("setuid");

583

}

535

}

536

584

537

setgid(gid);

585

538

if (ret == -1){

586

539

perror("setgid");

587

540

}

588

589

if (plugindir == NULL){

590

dir = opendir(PDIR);

591

} else {

592

dir = opendir(plugindir);

593

}

594

541

542

dir = opendir(plugindir);

595

543

if(dir == NULL){

596

544

perror("Could not open plugin dir");

597

545

exitstatus = EXIT_FAILURE;

612

560

}

613

561

614

562

FD_ZERO(&rfds_all);

615

616

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

563

617

564

while(true){

618

565

dirst = readdir(dir);

619

566

650

597

break;

651

598

}

652

599

}

600

653

601

if(bad_name){

654

602

continue;

655

603

}

604

656

605

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

657

606

size_t suf_len = strlen(*suf);

658

607

if((d_name_len >= suf_len)

685

634

free(filename);

686

635

continue;

687

636

}

688

689

/* Ignore non-executable files */

637

690

638

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

691

639

if(debug){

692

640

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

695

643

free(filename);

696

644

continue;

697

645

}

698

699

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

646

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

700

647

if(p == NULL){

701

648

perror("getplugin");

702

649

free(filename);

712

659

}

713

660

{

714

661

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

715

plugin *g = getplugin(NULL);

662

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

716

663

if(g != NULL){

717

664

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

718

665

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

750

697

exitstatus = EXIT_FAILURE;

751

698

goto fallback;

752

699

}

753

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

754

700

ret = set_cloexec_flag(pipefd[0]);

755

701

if(ret < 0){

756

702

perror("set_cloexec_flag");

814

760

}

815

761

/* no return */

816

762

}

817

/* Parent process */

818

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

763

/* parent process */

819

764

free(filename);

820

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

821

if (new_plugin == NULL){

822

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");

823

769

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

824

770

if(ret < 0){

825

perror("sigprocmask");

771

perror("sigprocmask");

826

772

}

827

773

exitstatus = EXIT_FAILURE;

828

774

goto fallback;

829

775

}

830

776

831

new_plugin->pid = pid;

832

new_plugin->fd = pipefd[0];

833

777

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

778

.fd = pipefd[0],

779

.next = process_list };

780

// List handling

781

process_list = new_process;

834

782

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

835

783

has already completed */

836

784

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

840

788

goto fallback;

841

789

}

842

790

843

FD_SET(new_plugin->fd, &rfds_all);

791

FD_SET(new_process->fd, &rfds_all);

844

792

845

if (maxfd < new_plugin->fd){

846

maxfd = new_plugin->fd;

793

if (maxfd < new_process->fd){

794

maxfd = new_process->fd;

847

795

}

848

796

849

797

}

850

798

799

free_plugin_list(plugin_list);

800

plugin_list = NULL;

801

851

802

closedir(dir);

852

803

dir = NULL;

853

854

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

855

if(p->pid != 0){

856

break;

857

}

858

if(p->next == NULL){

859

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

860

" directory?\n");

861

free_plugin_list();

862

}

804

805

if (process_list == NULL){

806

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

807

" directory?\n");

808

process_list = NULL;

863

809

}

864

865

/* Main loop while running plugins exist */

866

while(plugin_list){

810

while(process_list){

867

811

fd_set rfds = rfds_all;

868

812

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

869

813

if (select_ret == -1){

873

817

}

874

818

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

875

819

from one of them */

876

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

820

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

877

821

/* Is this process completely done? */

878

822

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

879

823

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

880

824

if(not WIFEXITED(proc->status)

881

825

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

882

826

/* Bad exit by plugin */

883

884

827

if(debug){

885

828

if(WIFEXITED(proc->status)){

886

829

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

895

838

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

896

839

}

897

840

}

898

899

841

/* Remove the plugin */

900

842

FD_CLR(proc->fd, &rfds_all);

901

902

843

/* Block signal while modifying process_list */

903

844

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

904

845

if(ret < 0){

906

847

exitstatus = EXIT_FAILURE;

907

848

goto fallback;

908

849

}

909

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

}

910

863

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

911

864

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

912

865

NULL);

913

866

if(ret < 0){

914

867

perror("sigprocmask");

915

exitstatus = EXIT_FAILURE;

916

goto fallback;

917

}

918

919

if(plugin_list == NULL){

920

break;

921

}

922

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;

923

875

}

924

925

876

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

926

877

927

878

bool bret = print_out_password(proc->buffer,

932

883

}

933

884

goto fallback;

934

885

}

935

936

886

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

937

887

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

938

888

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

968

918

969

919

fallback:

970

920

971

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

921

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

972

922

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

973

923

occured */

974

924

bool bret;

994

944

}

995

945

free(custom_argv);

996

946

}

947

free_plugin_list(plugin_list);

997

948

998

949

if(dir != NULL){

999

950

closedir(dir);

1000

951

}

1001

952

1002

953

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

1003

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

1004

if(p->pid != 0){

1005

close(p->fd);

1006

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

1007

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

1008

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

1009

perror("kill");

1010

}

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");

1011

961

}

962

free(process_list->buffer);

963

free(process_list);

1012

964

}

1013

965

1014

966

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

1018

970

if(errno != ECHILD){

1019

971

perror("wait");

1020

972

}

1021

1022

free_plugin_list();

1023

1024

free(plugindir);

1025

free(argfile);

1026

973

1027

974

return exitstatus;

1028

975

}