/mandos/trunk : revision 132

65

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

66

67

#define BUFFER_SIZE 256

68

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

68

69

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

70

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

69

71

70

72

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

71

73

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

72

74

73

struct process;

74

75

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*/

76

86

pid_t pid;

77

87

int fd;

78

88

char *buffer;

81

91

bool eof;

82

92

volatile bool completed;

83

93

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

98

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){

99

104

if ((p->name == name)

100

105

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

101

106

return p;

113

118

return NULL;

114

119

}

115

120

}

116

121

117

122

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

118

123

.argc = 1,

119

.envc = 0,

120

124

.disabled = false,

121

.next = *plugin_list };

125

.next = plugin_list };

122

126

123

127

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

124

128

if (new_plugin->argv == NULL){

137

141

return NULL;

138

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

190

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

187

191

* Descriptor Flags".

198

202

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

204

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;

208

211

int status;

209

212

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

210

213

if(pid == 0){

232

235

}

233

236

}

234

237

238

/* Prints out a password to stdout */

235

239

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

251

return true;

248

252

}

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

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

}

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

287

}

285

288

}

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;

290

293

FILE *conffp;

291

294

size_t d_name_len;

292

295

DIR *dir = NULL;

339

342

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

340

343

.arg = "DIRECTORY",

341

344

.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,

347

.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 },

350

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)) struct argp_state *state) {

354

360

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

355

361

pointer to our plugin list pointer. */

356

plugin **plugins = state->input;

357

362

switch (key) {

358

case 'g':

363

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

359

364

if (arg != NULL){

360

365

char *p;

361

366

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

362

367

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

363

368

continue;

364

369

}

365

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

370

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

366

371

perror("add_argument");

367

372

return ARGP_ERR_UNKNOWN;

368

373

}

369

374

}

370

375

}

371

376

break;

372

case 'e':

377

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

373

378

if(arg == NULL){

374

379

break;

375

380

}

378

383

if(envdef == NULL){

379

384

break;

380

385

}

381

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

386

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

382

387

perror("add_environment");

383

388

}

384

389

}

385

390

break;

386

case 'o':

391

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

387

392

if (arg != NULL){

388

393

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

389

394

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

399

404

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

400

405

continue;

401

406

}

402

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

407

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

403

408

perror("add_argument");

404

409

return ARGP_ERR_UNKNOWN;

405

410

}

407

412

}

408

413

}

409

414

break;

410

case 'f':

415

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

411

416

if(arg == NULL){

412

417

break;

413

418

}

421

426

break;

422

427

}

423

428

envdef++;

424

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

429

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

425

430

perror("add_environment");

426

431

}

427

432

}

428

433

break;

429

case 'd':

434

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

430

435

if (arg != NULL){

431

plugin *p = getplugin(arg, plugins);

436

plugin *p = getplugin(arg);

432

437

if(p == NULL){

433

438

return ARGP_ERR_UNKNOWN;

434

439

}

435

440

p->disabled = true;

436

441

}

437

442

break;

438

case 128:

439

plugindir = arg;

443

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

444

plugindir = strdup(arg);

445

if(plugindir == NULL){

446

perror("strdup");

447

}

440

448

break;

441

case 129:

449

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

450

argfile = strdup(arg);

451

if(argfile == NULL){

452

perror("strdup");

453

}

454

break;

455

case 130: /* --userid */

442

456

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

443

457

break;

444

case 130:

458

case 131: /* --groupid */

445

459

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

446

460

break;

447

case 131:

461

case 132: /* --debug */

448

462

debug = true;

449

463

break;

450

464

case ARGP_KEY_ARG:

458

472

return 0;

459

473

}

460

474

461

plugin *plugin_list = NULL;

462

463

475

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

464

476

.args_doc = "[+PLUS_SEPARATED_OPTIONS]",

465

477

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

466

478

467

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

479

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

468

480

if (ret == ARGP_ERR_UNKNOWN){

469

481

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

470

482

exitstatus = EXIT_FAILURE;

471

483

goto fallback;

472

484

}

473

485

474

conffp = fopen(argfile, "r");

486

/* Opens the configfile if aviable */

487

if (argfile == NULL){

488

conffp = fopen(AFILE, "r");

489

} else {

490

conffp = fopen(argfile, "r");

491

}

475

492

if(conffp != NULL){

476

493

char *org_line = NULL;

477

494

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

480

497

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

481

498

const char comment_delim[] = "#";

482

499

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 */

483

511

while(true){

484

512

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

485

513

if(sret == -1){

493

521

continue;

494

522

}

495

523

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

}

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;

502

542

}

503

543

}

504

544

free(org_line);

511

551

goto fallback;

512

552

}

513

553

}

514

554

/* If there was any arguments from configuration file,

555

pass them to parser as command arguments */

515

556

if(custom_argv != NULL){

516

custom_argv[0] = argv[0];

517

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

518

&plugin_list);

557

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

519

558

if (ret == ARGP_ERR_UNKNOWN){

520

559

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

521

560

exitstatus = EXIT_FAILURE;

536

575

}

537

576

}

538

577

}

539

578

579

/* Strip permissions down to nobody */

540

580

ret = setuid(uid);

541

581

if (ret == -1){

542

582

perror("setuid");

543

}

544

583

}

545

584

setgid(gid);

546

585

if (ret == -1){

547

586

perror("setgid");

548

587

}

588

589

if (plugindir == NULL){

590

dir = opendir(PDIR);

591

} else {

592

dir = opendir(plugindir);

593

}

549

594

550

dir = opendir(plugindir);

551

595

if(dir == NULL){

552

596

perror("Could not open plugin dir");

553

597

exitstatus = EXIT_FAILURE;

568

612

}

569

613

570

614

FD_ZERO(&rfds_all);

571

615

616

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

572

617

while(true){

573

618

dirst = readdir(dir);

574

619

605

650

break;

606

651

}

607

652

}

608

609

653

if(bad_name){

610

654

continue;

611

655

}

612

613

656

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

614

657

size_t suf_len = strlen(*suf);

615

658

if((d_name_len >= suf_len)

642

685

free(filename);

643

686

continue;

644

687

}

645

688

689

/* Ignore non-executable files */

646

690

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

647

691

if(debug){

648

692

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

651

695

free(filename);

652

696

continue;

653

697

}

654

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

698

699

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

655

700

if(p == NULL){

656

701

perror("getplugin");

657

702

free(filename);

667

712

}

668

713

{

669

714

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

670

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

715

plugin *g = getplugin(NULL);

671

716

if(g != NULL){

672

717

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

673

718

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

705

750

exitstatus = EXIT_FAILURE;

706

751

goto fallback;

707

752

}

753

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

708

754

ret = set_cloexec_flag(pipefd[0]);

709

755

if(ret < 0){

710

756

perror("set_cloexec_flag");

768

814

}

769

815

/* no return */

770

816

}

771

/* parent process */

817

/* Parent process */

818

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

772

819

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");

820

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

821

if (new_plugin == NULL){

822

perror("getplugin");

777

823

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

778

824

if(ret < 0){

779

perror("sigprocmask");

825

perror("sigprocmask");

780

826

}

781

827

exitstatus = EXIT_FAILURE;

782

828

goto fallback;

783

829

}

784

830

785

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

786

.fd = pipefd[0],

787

.next = process_list };

788

// List handling

789

process_list = new_process;

831

new_plugin->pid = pid;

832

new_plugin->fd = pipefd[0];

833

790

834

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

791

835

has already completed */

792

836

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

796

840

goto fallback;

797

841

}

798

842

799

FD_SET(new_process->fd, &rfds_all);

843

FD_SET(new_plugin->fd, &rfds_all);

800

844

801

if (maxfd < new_process->fd){

802

maxfd = new_process->fd;

845

if (maxfd < new_plugin->fd){

846

maxfd = new_plugin->fd;

803

847

}

804

848

805

849

}

806

850

807

free_plugin_list(plugin_list);

808

plugin_list = NULL;

809

810

851

closedir(dir);

811

852

dir = NULL;

812

813

if (process_list == NULL){

814

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

815

" directory?\n");

816

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

}

817

863

}

818

while(process_list){

864

865

/* Main loop while running plugins exist */

866

while(plugin_list){

819

867

fd_set rfds = rfds_all;

820

868

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

821

869

if (select_ret == -1){

825

873

}

826

874

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

827

875

from one of them */

828

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

876

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

829

877

/* Is this process completely done? */

830

878

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

831

879

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

832

880

if(not WIFEXITED(proc->status)

833

881

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

834

882

/* Bad exit by plugin */

883

835

884

if(debug){

836

885

if(WIFEXITED(proc->status)){

837

886

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

846

895

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

847

896

}

848

897

}

898

849

899

/* Remove the plugin */

850

900

FD_CLR(proc->fd, &rfds_all);

901

851

902

/* Block signal while modifying process_list */

852

903

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

853

904

if(ret < 0){

855

906

exitstatus = EXIT_FAILURE;

856

907

goto fallback;

857

908

}

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

}

909

free_plugin(proc);

871

910

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

872

911

ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,

873

912

NULL);

874

913

if(ret < 0){

875

914

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;

915

exitstatus = EXIT_FAILURE;

916

goto fallback;

917

}

918

919

if(plugin_list == NULL){

920

break;

921

}

922

continue;

883

923

}

924

884

925

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

885

926

886

927

bool bret = print_out_password(proc->buffer,

891

932

}

892

933

goto fallback;

893

934

}

935

894

936

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

895

937

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

896

938

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

926

968

927

969

fallback:

928

970

929

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

971

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

930

972

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

931

973

occured */

932

974

bool bret;

947

989

}

948

990

949

991

if(custom_argv != NULL){

950

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

992

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

951

993

free(*arg);

952

994

}

953

995

free(custom_argv);

954

996

}

955

free_plugin_list(plugin_list);

956

997

957

998

if(dir != NULL){

958

999

closedir(dir);

959

1000

}

960

1001

961

1002

/* 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");

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

}

969

1011

}

970

free(process_list->buffer);

971

free(process_list);

972

1012

}

973

1013

974

1014

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

978

1018

if(errno != ECHILD){

979

1019

perror("wait");

980

1020

}

1021

1022

free_plugin_list();

1023

1024

free(plugindir);

1025

free(argfile);

981

1026

982

1027

return exitstatus;

983

1028

}