/mandos/trunk : revision 132

72

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

73

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

74

75

struct process;

76

77

typedef struct process{

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*/

78

86

pid_t pid;

79

87

int fd;

80

88

char *buffer;

83

91

bool eof;

84

92

volatile bool completed;

85

93

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;

96

94

struct plugin *next;

97

95

} plugin;

98

96

99

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

100

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

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){

101

104

if ((p->name == name)

102

105

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

103

106

return p;

115

118

return NULL;

116

119

}

117

120

}

118

121

119

122

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

120

123

.argc = 1,

121

.envc = 0,

122

124

.disabled = false,

123

.next = *plugin_list };

125

.next = plugin_list };

124

126

125

127

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

126

128

if (new_plugin->argv == NULL){

139

141

return NULL;

140

142

}

141

143

new_plugin->environ[0] = NULL;

144

142

145

/* Append the new plugin to the list */

143

*plugin_list = new_plugin;

146

plugin_list = new_plugin;

144

147

return new_plugin;

145

148

}

146

149

183

186

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

184

187

}

185

188

186

187

189

/*

188

190

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

189

191

* Descriptor Flags".

200

202

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

201

203

}

202

204

203

process *process_list = NULL;

204

205

206

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

206

207

status. */

207

208

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

208

209

while(true){

209

process *proc = process_list;

210

plugin *proc = plugin_list;

210

211

int status;

211

212

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

212

213

if(pid == 0){

234

235

}

235

236

}

236

237

238

/* Prints out a password to stdout */

237

239

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

238

240

ssize_t ret;

239

241

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

249

251

return true;

250

252

}

251

253

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);

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);

264

287

}

265

288

}

266

289

333

356

{ .name = NULL }

334

357

};

335

358

336

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

359

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

337

360

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

338

361

pointer to our plugin list pointer. */

339

plugin **plugins = state->input;

340

362

switch (key) {

341

case 'g':

363

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

342

364

if (arg != NULL){

343

365

char *p;

344

366

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

345

367

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

346

368

continue;

347

369

}

348

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

370

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

349

371

perror("add_argument");

350

372

return ARGP_ERR_UNKNOWN;

351

373

}

352

374

}

353

375

}

354

376

break;

355

case 'e':

377

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

356

378

if(arg == NULL){

357

379

break;

358

380

}

361

383

if(envdef == NULL){

362

384

break;

363

385

}

364

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

386

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

365

387

perror("add_environment");

366

388

}

367

389

}

368

390

break;

369

case 'o':

391

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

370

392

if (arg != NULL){

371

393

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

372

394

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

382

404

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

383

405

continue;

384

406

}

385

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

407

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

386

408

perror("add_argument");

387

409

return ARGP_ERR_UNKNOWN;

388

410

}

390

412

}

391

413

}

392

414

break;

393

case 'f':

415

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

394

416

if(arg == NULL){

395

417

break;

396

418

}

404

426

break;

405

427

}

406

428

envdef++;

407

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

429

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

408

430

perror("add_environment");

409

431

}

410

432

}

411

433

break;

412

case 'd':

434

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

413

435

if (arg != NULL){

414

plugin *p = getplugin(arg, plugins);

436

plugin *p = getplugin(arg);

415

437

if(p == NULL){

416

438

return ARGP_ERR_UNKNOWN;

417

439

}

418

440

p->disabled = true;

419

441

}

420

442

break;

421

case 128:

443

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

422

444

plugindir = strdup(arg);

423

445

if(plugindir == NULL){

424

446

perror("strdup");

425

447

}

426

448

break;

427

case 129:

449

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

428

450

argfile = strdup(arg);

429

451

if(argfile == NULL){

430

452

perror("strdup");

431

453

}

432

454

break;

433

case 130:

455

case 130: /* --userid */

434

456

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

435

457

break;

436

case 131:

458

case 131: /* --groupid */

437

459

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

438

460

break;

439

case 132:

461

case 132: /* --debug */

440

462

debug = true;

441

463

break;

442

464

case ARGP_KEY_ARG:

450

472

return 0;

451

473

}

452

474

453

plugin *plugin_list = NULL;

454

455

475

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

456

476

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

457

477

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

458

478

459

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

479

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

460

480

if (ret == ARGP_ERR_UNKNOWN){

461

481

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

462

482

exitstatus = EXIT_FAILURE;

463

483

goto fallback;

464

484

}

465

485

486

/* Opens the configfile if aviable */

466

487

if (argfile == NULL){

467

488

conffp = fopen(AFILE, "r");

468

489

} else {

469

490

conffp = fopen(argfile, "r");

470

}

471

491

}

472

492

if(conffp != NULL){

473

493

char *org_line = NULL;

474

494

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

486

506

}

487

507

custom_argv[0] = argv[0];

488

508

custom_argv[1] = NULL;

489

509

510

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

490

511

while(true){

491

512

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

492

513

if(sret == -1){

530

551

goto fallback;

531

552

}

532

553

}

533

554

/* If there was any arguments from configuration file,

555

pass them to parser as command arguments */

534

556

if(custom_argv != NULL){

535

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

557

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

536

558

if (ret == ARGP_ERR_UNKNOWN){

537

559

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

538

560

exitstatus = EXIT_FAILURE;

553

575

}

554

576

}

555

577

}

556

578

579

/* Strip permissions down to nobody */

557

580

ret = setuid(uid);

558

581

if (ret == -1){

559

582

perror("setuid");

560

}

561

583

}

562

584

setgid(gid);

563

585

if (ret == -1){

564

586

perror("setgid");

590

612

}

591

613

592

614

FD_ZERO(&rfds_all);

593

615

616

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

594

617

while(true){

595

618

dirst = readdir(dir);

596

619

627

650

break;

628

651

}

629

652

}

630

631

653

if(bad_name){

632

654

continue;

633

655

}

634

635

656

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

636

657

size_t suf_len = strlen(*suf);

637

658

if((d_name_len >= suf_len)

664

685

free(filename);

665

686

continue;

666

687

}

667

688

689

/* Ignore non-executable files */

668

690

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

669

691

if(debug){

670

692

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

673

695

free(filename);

674

696

continue;

675

697

}

676

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

698

699

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

677

700

if(p == NULL){

678

701

perror("getplugin");

679

702

free(filename);

689

712

}

690

713

{

691

714

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

692

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

715

plugin *g = getplugin(NULL);

693

716

if(g != NULL){

694

717

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

695

718

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

727

750

exitstatus = EXIT_FAILURE;

728

751

goto fallback;

729

752

}

753

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

730

754

ret = set_cloexec_flag(pipefd[0]);

731

755

if(ret < 0){

732

756

perror("set_cloexec_flag");

790

814

}

791

815

/* no return */

792

816

}

793

/* parent process */

817

/* Parent process */

818

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

794

819

free(filename);

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");

820

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

821

if (new_plugin == NULL){

822

perror("getplugin");

799

823

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

800

824

if(ret < 0){

801

perror("sigprocmask");

825

perror("sigprocmask");

802

826

}

803

827

exitstatus = EXIT_FAILURE;

804

828

goto fallback;

805

829

}

806

830

807

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

808

.fd = pipefd[0],

809

.next = process_list };

810

// List handling

811

process_list = new_process;

831

new_plugin->pid = pid;

832

new_plugin->fd = pipefd[0];

833

812

834

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

813

835

has already completed */

814

836

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

818

840

goto fallback;

819

841

}

820

842

821

FD_SET(new_process->fd, &rfds_all);

843

FD_SET(new_plugin->fd, &rfds_all);

822

844

823

if (maxfd < new_process->fd){

824

maxfd = new_process->fd;

845

if (maxfd < new_plugin->fd){

846

maxfd = new_plugin->fd;

825

847

}

826

848

827

849

}

828

829

free_plugin_list(plugin_list);

830

plugin_list = NULL;

831

850

832

851

closedir(dir);

833

852

dir = NULL;

834

835

if (process_list == NULL){

836

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

837

" directory?\n");

838

process_list = 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

}

839

863

}

840

while(process_list){

864

865

/* Main loop while running plugins exist */

866

while(plugin_list){

841

867

fd_set rfds = rfds_all;

842

868

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

843

869

if (select_ret == -1){

847

873

}

848

874

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

849

875

from one of them */

850

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

876

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

851

877

/* Is this process completely done? */

852

878

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

853

879

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

854

880

if(not WIFEXITED(proc->status)

855

881

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

856

882

/* Bad exit by plugin */

883

857

884

if(debug){

858

885

if(WIFEXITED(proc->status)){

859

886

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

868

895

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

869

896

}

870

897

}

898

871

899

/* Remove the plugin */

872

900

FD_CLR(proc->fd, &rfds_all);

901

873

902

/* Block signal while modifying process_list */

874

903

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

875

904

if(ret < 0){

877

906

exitstatus = EXIT_FAILURE;

878

907

goto fallback;

879

908

}

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

}

909

free_plugin(proc);

893

910

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

894

911

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

895

912

NULL);

896

913

if(ret < 0){

897

914

perror("sigprocmask");

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;

915

exitstatus = EXIT_FAILURE;

916

goto fallback;

917

}

918

919

if(plugin_list == NULL){

920

break;

921

}

922

continue;

905

923

}

924

906

925

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

907

926

908

927

bool bret = print_out_password(proc->buffer,

913

932

}

914

933

goto fallback;

915

934

}

935

916

936

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

917

937

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

918

938

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

948

968

949

969

fallback:

950

970

951

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

971

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

952

972

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

953

973

occured */

954

974

bool bret;

974

994

}

975

995

free(custom_argv);

976

996

}

977

free_plugin_list(plugin_list);

978

997

979

998

if(dir != NULL){

980

999

closedir(dir);

981

1000

}

982

1001

983

1002

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

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");

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

}

991

1011

}

992

free(process_list->buffer);

993

free(process_list);

994

1012

}

995

1013

996

1014

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

1001

1019

perror("wait");

1002

1020

}

1003

1021

1022

free_plugin_list();

1023

1004

1024

free(plugindir);

1005

1025

free(argfile);

1006

1026