/mandos/trunk : revision 134

65

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

66

67

#define BUFFER_SIZE 256

68

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

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69

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

70

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

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71

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72

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

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73

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

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74

73

struct process;

74

75

typedef struct process{

75

struct plugin;

76

77

typedef struct plugin{

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

79

char **argv;

80

int argc;

81

char **environ;

82

int envc;

83

bool disabled;

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85

/* Variables used for running processes*/

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86

pid_t pid;

77

87

int fd;

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char *buffer;

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91

bool eof;

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92

volatile bool completed;

83

93

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 */

89

char **argv;

90

int argc;

91

char **environ;

92

int envc;

93

bool disabled;

94

struct plugin *next;

95

} plugin;

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

98

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

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){

99

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if ((p->name == name)

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

101

106

return p;

113

118

return NULL;

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}

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}

116

121

117

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

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123

.argc = 1,

119

.envc = 0,

120

124

.disabled = false,

121

.next = *plugin_list };

125

.next = plugin_list };

122

126

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

124

128

if (new_plugin->argv == NULL){

137

141

return NULL;

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142

}

139

143

new_plugin->environ[0] = NULL;

144

140

145

/* Append the new plugin to the list */

141

*plugin_list = new_plugin;

146

plugin_list = new_plugin;

142

147

return new_plugin;

143

148

}

144

149

181

186

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

182

187

}

183

188

184

185

189

/*

186

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

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191

* Descriptor Flags".

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

199

203

}

200

204

201

process *process_list = NULL;

202

205

203

206

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

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207

status. */

205

208

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

206

209

while(true){

207

process *proc = process_list;

210

plugin *proc = plugin_list;

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211

int status;

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

210

213

if(pid == 0){

232

235

}

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236

}

234

237

238

/* Prints out a password to stdout */

235

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

236

240

ssize_t ret;

237

241

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

247

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return true;

248

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}

249

253

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;

254

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

255

static void free_plugin(plugin *plugin_node){

256

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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

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

}

256

278

}

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;

279

}

280

281

free(plugin_node);

270

282

}

271

283

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);

284

static void free_plugin_list(void){

285

while(plugin_list != NULL){

286

free_plugin(plugin_list);

284

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}

285

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}

286

289

287

290

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

288

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

289

const char *argfile = ARGFILE;

291

char *plugindir = NULL;

292

char *argfile = NULL;

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FILE *conffp;

291

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size_t d_name_len;

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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 },

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,

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

348

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

349

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

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 },

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356

{ .name = NULL }

351

357

};

352

358

353

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

359

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

360

struct argp_state *state) {

354

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

355

362

pointer to our plugin list pointer. */

356

plugin **plugins = state->input;

357

363

switch (key) {

358

case 'g':

364

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

359

365

if (arg != NULL){

360

366

char *p;

361

367

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

362

368

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

363

369

continue;

364

370

}

365

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

371

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

366

372

perror("add_argument");

367

373

return ARGP_ERR_UNKNOWN;

368

374

}

369

375

}

370

376

}

371

377

break;

372

case 'e':

378

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

373

379

if(arg == NULL){

374

380

break;

375

381

}

378

384

if(envdef == NULL){

379

385

break;

380

386

}

381

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

387

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

382

388

perror("add_environment");

383

389

}

384

390

}

385

391

break;

386

case 'o':

392

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

387

393

if (arg != NULL){

388

394

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

389

395

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

399

405

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

400

406

continue;

401

407

}

402

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

408

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

403

409

perror("add_argument");

404

410

return ARGP_ERR_UNKNOWN;

405

411

}

407

413

}

408

414

}

409

415

break;

410

case 'f':

416

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

411

417

if(arg == NULL){

412

418

break;

413

419

}

421

427

break;

422

428

}

423

429

envdef++;

424

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

430

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

425

431

perror("add_environment");

426

432

}

427

433

}

428

434

break;

429

case 'd':

435

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

430

436

if (arg != NULL){

431

plugin *p = getplugin(arg, plugins);

437

plugin *p = getplugin(arg);

432

438

if(p == NULL){

433

439

return ARGP_ERR_UNKNOWN;

434

440

}

435

441

p->disabled = true;

436

442

}

437

443

break;

438

case 128:

439

plugindir = arg;

444

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

445

plugindir = strdup(arg);

446

if(plugindir == NULL){

447

perror("strdup");

448

}

440

449

break;

441

case 129:

450

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

451

argfile = strdup(arg);

452

if(argfile == NULL){

453

perror("strdup");

454

}

455

break;

456

case 130: /* --userid */

442

457

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

443

458

break;

444

case 130:

459

case 131: /* --groupid */

445

460

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

446

461

break;

447

case 131:

462

case 132: /* --debug */

448

463

debug = true;

449

464

break;

450

465

case ARGP_KEY_ARG:

458

473

return 0;

459

474

}

460

475

461

plugin *plugin_list = NULL;

462

463

476

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

464

477

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

465

478

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

466

479

467

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

480

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

468

481

if (ret == ARGP_ERR_UNKNOWN){

469

482

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

470

483

exitstatus = EXIT_FAILURE;

471

484

goto fallback;

472

485

}

473

486

474

conffp = fopen(argfile, "r");

487

/* Opens the configfile if aviable */

488

if (argfile == NULL){

489

conffp = fopen(AFILE, "r");

490

} else {

491

conffp = fopen(argfile, "r");

492

}

475

493

if(conffp != NULL){

476

494

char *org_line = NULL;

477

495

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

480

498

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

481

499

const char comment_delim[] = "#";

482

500

501

custom_argc = 1;

502

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

503

if(custom_argv == NULL){

504

perror("malloc");

505

exitstatus = EXIT_FAILURE;

506

goto fallback;

507

}

508

custom_argv[0] = argv[0];

509

custom_argv[1] = NULL;

510

511

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

512

commented text */

483

513

while(true){

484

514

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

485

515

if(sret == -1){

493

523

continue;

494

524

}

495

525

new_arg = strdup(p);

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

}

526

if(new_arg == NULL){

527

perror("strdup");

528

exitstatus = EXIT_FAILURE;

529

free(org_line);

530

goto fallback;

531

}

532

533

custom_argc += 1;

534

custom_argv = realloc(custom_argv, sizeof(char *)

535

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

536

if(custom_argv == NULL){

537

perror("realloc");

538

exitstatus = EXIT_FAILURE;

539

free(org_line);

540

goto fallback;

541

}

542

custom_argv[custom_argc-1] = new_arg;

543

custom_argv[custom_argc] = NULL;

502

544

}

503

545

}

504

546

free(org_line);

511

553

goto fallback;

512

554

}

513

555

}

514

556

/* If there was any arguments from configuration file,

557

pass them to parser as command arguments */

515

558

if(custom_argv != NULL){

516

custom_argv[0] = argv[0];

517

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

518

&plugin_list);

559

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

519

560

if (ret == ARGP_ERR_UNKNOWN){

520

561

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

521

562

exitstatus = EXIT_FAILURE;

536

577

}

537

578

}

538

579

}

539

580

581

/* Strip permissions down to nobody */

540

582

ret = setuid(uid);

541

583

if (ret == -1){

542

584

perror("setuid");

543

}

544

585

}

545

586

setgid(gid);

546

587

if (ret == -1){

547

588

perror("setgid");

548

589

}

590

591

if (plugindir == NULL){

592

dir = opendir(PDIR);

593

} else {

594

dir = opendir(plugindir);

595

}

549

596

550

dir = opendir(plugindir);

551

597

if(dir == NULL){

552

598

perror("Could not open plugin dir");

553

599

exitstatus = EXIT_FAILURE;

568

614

}

569

615

570

616

FD_ZERO(&rfds_all);

571

617

618

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

572

619

while(true){

573

620

dirst = readdir(dir);

574

621

605

652

break;

606

653

}

607

654

}

608

609

655

if(bad_name){

610

656

continue;

611

657

}

612

613

658

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

614

659

size_t suf_len = strlen(*suf);

615

660

if((d_name_len >= suf_len)

642

687

free(filename);

643

688

continue;

644

689

}

645

690

691

/* Ignore non-executable files */

646

692

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

647

693

if(debug){

648

694

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

651

697

free(filename);

652

698

continue;

653

699

}

654

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

700

701

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

655

702

if(p == NULL){

656

703

perror("getplugin");

657

704

free(filename);

667

714

}

668

715

{

669

716

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

670

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

717

plugin *g = getplugin(NULL);

671

718

if(g != NULL){

672

719

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

673

720

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

705

752

exitstatus = EXIT_FAILURE;

706

753

goto fallback;

707

754

}

755

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

708

756

ret = set_cloexec_flag(pipefd[0]);

709

757

if(ret < 0){

710

758

perror("set_cloexec_flag");

768

816

}

769

817

/* no return */

770

818

}

771

/* parent process */

819

/* Parent process */

820

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

772

821

free(filename);

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");

822

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

823

if (new_plugin == NULL){

824

perror("getplugin");

777

825

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

778

826

if(ret < 0){

779

perror("sigprocmask");

827

perror("sigprocmask");

780

828

}

781

829

exitstatus = EXIT_FAILURE;

782

830

goto fallback;

783

831

}

784

832

785

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

786

.fd = pipefd[0],

787

.next = process_list };

788

// List handling

789

process_list = new_process;

833

new_plugin->pid = pid;

834

new_plugin->fd = pipefd[0];

835

790

836

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

791

837

has already completed */

792

838

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

796

842

goto fallback;

797

843

}

798

844

799

FD_SET(new_process->fd, &rfds_all);

845

FD_SET(new_plugin->fd, &rfds_all);

800

846

801

if (maxfd < new_process->fd){

802

maxfd = new_process->fd;

847

if (maxfd < new_plugin->fd){

848

maxfd = new_plugin->fd;

803

849

}

804

850

805

851

}

806

852

807

free_plugin_list(plugin_list);

808

plugin_list = NULL;

809

810

853

closedir(dir);

811

854

dir = NULL;

812

813

if (process_list == NULL){

814

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

815

" directory?\n");

816

process_list = NULL;

855

856

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

857

if(p->pid != 0){

858

break;

859

}

860

if(p->next == NULL){

861

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

862

" directory?\n");

863

free_plugin_list();

864

}

817

865

}

818

while(process_list){

866

867

/* Main loop while running plugins exist */

868

while(plugin_list){

819

869

fd_set rfds = rfds_all;

820

870

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

821

871

if (select_ret == -1){

825

875

}

826

876

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

827

877

from one of them */

828

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

878

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

829

879

/* Is this process completely done? */

830

880

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

831

881

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

832

882

if(not WIFEXITED(proc->status)

833

883

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

834

884

/* Bad exit by plugin */

885

835

886

if(debug){

836

887

if(WIFEXITED(proc->status)){

837

888

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

846

897

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

847

898

}

848

899

}

900

849

901

/* Remove the plugin */

850

902

FD_CLR(proc->fd, &rfds_all);

903

851

904

/* Block signal while modifying process_list */

852

905

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

853

906

if(ret < 0){

855

908

exitstatus = EXIT_FAILURE;

856

909

goto fallback;

857

910

}

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

}

911

free_plugin(proc);

871

912

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

872

913

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

873

914

NULL);

874

915

if(ret < 0){

875

916

perror("sigprocmask");

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;

917

exitstatus = EXIT_FAILURE;

918

goto fallback;

919

}

920

921

if(plugin_list == NULL){

922

break;

923

}

924

continue;

883

925

}

926

884

927

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

885

928

886

929

bool bret = print_out_password(proc->buffer,

891

934

}

892

935

goto fallback;

893

936

}

937

894

938

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

895

939

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

896

940

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

926

970

927

971

fallback:

928

972

929

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

973

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

930

974

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

931

975

occured */

932

976

bool bret;

947

991

}

948

992

949

993

if(custom_argv != NULL){

950

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

994

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

951

995

free(*arg);

952

996

}

953

997

free(custom_argv);

954

998

}

955

free_plugin_list(plugin_list);

956

999

957

1000

if(dir != NULL){

958

1001

closedir(dir);

959

1002

}

960

1003

961

1004

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

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");

1005

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

1006

if(p->pid != 0){

1007

close(p->fd);

1008

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

1009

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

1010

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

1011

perror("kill");

1012

}

969

1013

}

970

free(process_list->buffer);

971

free(process_list);

972

1014

}

973

1015

974

1016

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

978

1020

if(errno != ECHILD){

979

1021

perror("wait");

980

1022

}

1023

1024

free_plugin_list();

1025

1026

free(plugindir);

1027

free(argfile);

981

1028

982

1029

return exitstatus;

983

1030

}