/mandos/trunk : revision 105

65

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

66

67

#define BUFFER_SIZE 256

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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"

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69

72

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

73

71

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

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72

75

struct plugin;

76

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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;

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77

int fd;

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78

char *buffer;

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81

bool eof;

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volatile bool completed;

93

83

volatile int status;

84

struct process *next;

85

} process;

86

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typedef struct plugin{

88

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

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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

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/* 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){

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99

if ((p->name == name)

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100

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

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101

return p;

118

113

return NULL;

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}

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}

121

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

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118

.argc = 1,

119

.envc = 0,

124

120

.disabled = false,

125

.next = plugin_list };

121

.next = *plugin_list };

126

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127

123

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

128

124

if (new_plugin->argv == NULL){

141

137

return NULL;

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}

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;

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143

}

149

144

186

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

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182

}

188

183

184

189

185

/*

190

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

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* Descriptor Flags".

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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

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status. */

208

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

209

206

while(true){

210

plugin *proc = plugin_list;

207

process *proc = process_list;

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int status;

212

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

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210

if(pid == 0){

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}

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}

237

234

238

/* Prints out a password to stdout */

239

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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'){

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return true;

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}

253

249

254

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

255

static void free_plugin(plugin *plugin_node){

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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

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/* 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

}

250

char **add_to_argv(char **argv, int *argc, char *arg){

251

if (argv == NULL){

252

*argc = 1;

253

argv = malloc(sizeof(char*) * 2);

254

if(argv == NULL){

255

return NULL;

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256

}

279

}

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free(plugin_node);

257

argv[0] = NULL; /* Will be set to argv[0] in main before

258

parsing */

259

argv[1] = NULL;

260

}

261

*argc += 1;

262

argv = realloc(argv, sizeof(char *)

263

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

264

if(argv == NULL){

265

return NULL;

266

}

267

argv[*argc-1] = arg;

268

argv[*argc] = NULL;

269

return argv;

282

270

}

283

271

284

static void free_plugin_list(void){

285

while(plugin_list != NULL){

286

free_plugin(plugin_list);

272

static void free_plugin_list(plugin *plugin_list){

273

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

274

next = plugin_list->next;

275

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

276

free(*arg);

277

}

278

free(plugin_list->argv);

279

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

280

free(*env);

281

}

282

free(plugin_list->environ);

283

free(plugin_list);

287

284

}

288

285

}

289

286

290

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

291

char *plugindir = NULL;

292

char *argfile = NULL;

288

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

289

const char *argfile = ARGFILE;

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FILE *conffp;

294

291

size_t d_name_len;

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292

DIR *dir = NULL;

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

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.arg = "DIRECTORY",

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.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 },

342

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

343

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

344

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

345

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

346

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

347

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

348

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

349

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

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350

{ .name = NULL }

357

351

};

358

352

359

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

353

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

360

354

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

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pointer to our plugin list pointer. */

356

plugin **plugins = state->input;

362

357

switch (key) {

363

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

358

case 'g':

364

359

if (arg != NULL){

365

360

char *p;

366

361

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

367

362

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

368

363

continue;

369

364

}

370

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

365

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

371

366

perror("add_argument");

372

367

return ARGP_ERR_UNKNOWN;

373

368

}

374

369

}

375

370

}

376

371

break;

377

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

372

case 'e':

378

373

if(arg == NULL){

379

374

break;

380

375

}

383

378

if(envdef == NULL){

384

379

break;

385

380

}

386

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

381

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

387

382

perror("add_environment");

388

383

}

389

384

}

390

385

break;

391

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

386

case 'o':

392

387

if (arg != NULL){

393

388

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

394

389

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

404

399

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

405

400

continue;

406

401

}

407

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

402

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

408

403

perror("add_argument");

409

404

return ARGP_ERR_UNKNOWN;

410

405

}

412

407

}

413

408

}

414

409

break;

415

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

410

case 'f':

416

411

if(arg == NULL){

417

412

break;

418

413

}

426

421

break;

427

422

}

428

423

envdef++;

429

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

424

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

430

425

perror("add_environment");

431

426

}

432

427

}

433

428

break;

434

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

429

case 'd':

435

430

if (arg != NULL){

436

plugin *p = getplugin(arg);

431

plugin *p = getplugin(arg, plugins);

437

432

if(p == NULL){

438

433

return ARGP_ERR_UNKNOWN;

439

434

}

440

435

p->disabled = true;

441

436

}

442

437

break;

443

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

444

plugindir = strdup(arg);

445

if(plugindir == NULL){

446

perror("strdup");

447

}

438

case 128:

439

plugindir = arg;

448

440

break;

449

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

450

argfile = strdup(arg);

451

if(argfile == NULL){

452

perror("strdup");

453

}

454

break;

455

case 130: /* --userid */

441

case 129:

456

442

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

457

443

break;

458

case 131: /* --groupid */

444

case 130:

459

445

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

460

446

break;

461

case 132: /* --debug */

447

case 131:

462

448

debug = true;

463

449

break;

464

450

case ARGP_KEY_ARG:

472

458

return 0;

473

459

}

474

460

461

plugin *plugin_list = NULL;

462

475

463

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

476

464

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

477

465

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

478

466

479

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

467

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

480

468

if (ret == ARGP_ERR_UNKNOWN){

481

469

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

482

470

exitstatus = EXIT_FAILURE;

483

471

goto fallback;

484

472

}

485

473

486

/* Opens the configfile if aviable */

487

if (argfile == NULL){

488

conffp = fopen(AFILE, "r");

489

} else {

490

conffp = fopen(argfile, "r");

491

}

474

conffp = fopen(argfile, "r");

492

475

if(conffp != NULL){

493

476

char *org_line = NULL;

494

477

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

497

480

const char whitespace_delims[] = " \r\t\f\v\n";

498

481

const char comment_delim[] = "#";

499

482

500

custom_argc = 1;

501

custom_argv = malloc(sizeof(char*) * 2);

502

if(custom_argv == NULL){

503

perror("malloc");

504

exitstatus = EXIT_FAILURE;

505

goto fallback;

506

}

507

custom_argv[0] = argv[0];

508

custom_argv[1] = NULL;

509

510

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

511

483

while(true){

512

484

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

513

485

if(sret == -1){

521

493

continue;

522

494

}

523

495

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

531

custom_argc += 1;

532

custom_argv = realloc(custom_argv, sizeof(char *)

533

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

534

if(custom_argv == NULL){

535

perror("realloc");

536

exitstatus = EXIT_FAILURE;

537

free(org_line);

538

goto fallback;

539

}

540

custom_argv[custom_argc-1] = new_arg;

541

custom_argv[custom_argc] = NULL;

496

custom_argv = add_to_argv(custom_argv, &custom_argc, new_arg);

497

if (custom_argv == NULL){

498

perror("add_to_argv");

499

exitstatus = EXIT_FAILURE;

500

goto fallback;

501

}

542

502

}

543

503

}

544

504

free(org_line);

551

511

goto fallback;

552

512

}

553

513

}

554

/* If there was any arguments from configuration file,

555

pass them to parser as command arguments */

514

556

515

if(custom_argv != NULL){

557

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

516

custom_argv[0] = argv[0];

517

ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0,

518

&plugin_list);

558

519

if (ret == ARGP_ERR_UNKNOWN){

559

520

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

560

521

exitstatus = EXIT_FAILURE;

575

536

}

576

537

}

577

538

}

578

579

/* Strip permissions down to nobody */

539

580

540

ret = setuid(uid);

581

541

if (ret == -1){

582

542

perror("setuid");

583

}

543

}

544

584

545

setgid(gid);

585

546

if (ret == -1){

586

547

perror("setgid");

587

548

}

588

589

if (plugindir == NULL){

590

dir = opendir(PDIR);

591

} else {

592

dir = opendir(plugindir);

593

}

594

549

550

dir = opendir(plugindir);

595

551

if(dir == NULL){

596

552

perror("Could not open plugin dir");

597

553

exitstatus = EXIT_FAILURE;

612

568

}

613

569

614

570

FD_ZERO(&rfds_all);

615

616

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

571

617

572

while(true){

618

573

dirst = readdir(dir);

619

574

650

605

break;

651

606

}

652

607

}

608

653

609

if(bad_name){

654

610

continue;

655

611

}

612

656

613

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

657

614

size_t suf_len = strlen(*suf);

658

615

if((d_name_len >= suf_len)

685

642

free(filename);

686

643

continue;

687

644

}

688

689

/* Ignore non-executable files */

645

690

646

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

691

647

if(debug){

692

648

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

695

651

free(filename);

696

652

continue;

697

653

}

698

699

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

654

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

700

655

if(p == NULL){

701

656

perror("getplugin");

702

657

free(filename);

712

667

}

713

668

{

714

669

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

715

plugin *g = getplugin(NULL);

670

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

716

671

if(g != NULL){

717

672

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

718

673

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

750

705

exitstatus = EXIT_FAILURE;

751

706

goto fallback;

752

707

}

753

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

754

708

ret = set_cloexec_flag(pipefd[0]);

755

709

if(ret < 0){

756

710

perror("set_cloexec_flag");

814

768

}

815

769

/* no return */

816

770

}

817

/* Parent process */

818

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

771

/* parent process */

819

772

free(filename);

820

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

821

if (new_plugin == NULL){

822

perror("getplugin");

773

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

774

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

775

if (new_process == NULL){

776

perror("malloc");

823

777

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

824

778

if(ret < 0){

825

perror("sigprocmask");

779

perror("sigprocmask");

826

780

}

827

781

exitstatus = EXIT_FAILURE;

828

782

goto fallback;

829

783

}

830

784

831

new_plugin->pid = pid;

832

new_plugin->fd = pipefd[0];

833

785

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

786

.fd = pipefd[0],

787

.next = process_list };

788

// List handling

789

process_list = new_process;

834

790

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

835

791

has already completed */

836

792

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

840

796

goto fallback;

841

797

}

842

798

843

FD_SET(new_plugin->fd, &rfds_all);

799

FD_SET(new_process->fd, &rfds_all);

844

800

845

if (maxfd < new_plugin->fd){

846

maxfd = new_plugin->fd;

801

if (maxfd < new_process->fd){

802

maxfd = new_process->fd;

847

803

}

848

804

849

805

}

850

806

807

free_plugin_list(plugin_list);

808

plugin_list = NULL;

809

851

810

closedir(dir);

852

811

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

}

812

813

if (process_list == NULL){

814

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

815

" directory?\n");

816

process_list = NULL;

863

817

}

864

865

/* Main loop while running plugins exist */

866

while(plugin_list){

818

while(process_list){

867

819

fd_set rfds = rfds_all;

868

820

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

869

821

if (select_ret == -1){

873

825

}

874

826

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

875

827

from one of them */

876

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

828

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

877

829

/* Is this process completely done? */

878

830

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

879

831

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

880

832

if(not WIFEXITED(proc->status)

881

833

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

882

834

/* Bad exit by plugin */

883

884

835

if(debug){

885

836

if(WIFEXITED(proc->status)){

886

837

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

895

846

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

896

847

}

897

848

}

898

899

849

/* Remove the plugin */

900

850

FD_CLR(proc->fd, &rfds_all);

901

902

851

/* Block signal while modifying process_list */

903

852

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

904

853

if(ret < 0){

906

855

exitstatus = EXIT_FAILURE;

907

856

goto fallback;

908

857

}

909

free_plugin(proc);

858

/* Delete this process entry from the list */

859

if(process_list == proc){

860

/* First one - simple */

861

process_list = proc->next;

862

} else {

863

/* Second one or later */

864

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

865

if(p->next == proc){

866

p->next = proc->next;

867

break;

868

}

869

}

870

}

910

871

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

911

872

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

912

873

NULL);

913

874

if(ret < 0){

914

875

perror("sigprocmask");

915

exitstatus = EXIT_FAILURE;

916

goto fallback;

917

}

918

919

if(plugin_list == NULL){

920

break;

921

}

922

continue;

876

}

877

free(proc->buffer);

878

free(proc);

879

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

880

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

881

the process list */

882

break;

923

883

}

924

925

884

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

926

885

927

886

bool bret = print_out_password(proc->buffer,

932

891

}

933

892

goto fallback;

934

893

}

935

936

894

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

937

895

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

938

896

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

968

926

969

927

fallback:

970

928

971

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

929

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

972

930

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

973

931

occured */

974

932

bool bret;

989

947

}

990

948

991

949

if(custom_argv != NULL){

992

for(char **arg = custom_argv+1; *arg != NULL; arg++){

950

for(char **arg = custom_argv; *arg != NULL; arg++){

993

951

free(*arg);

994

952

}

995

953

free(custom_argv);

996

954

}

955

free_plugin_list(plugin_list);

997

956

998

957

if(dir != NULL){

999

958

closedir(dir);

1000

959

}

1001

960

1002

961

/* 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

}

962

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

963

next = process_list->next;

964

close(process_list->fd);

965

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

966

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

967

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

968

perror("kill");

1011

969

}

970

free(process_list->buffer);

971

free(process_list);

1012

972

}

1013

973

1014

974

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

1018

978

if(errno != ECHILD){

1019

979

perror("wait");

1020

980

}

1021

1022

free_plugin_list();

1023

1024

free(plugindir);

1025

free(argfile);

1026

981

1027

982

return exitstatus;

1028

983

}