Honeyd/hsniff.c at dhcpWork · newdominic/Honeyd

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

#include <sys/param.h>

#include <sys/types.h>

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#ifdef HAVE_SYS_TIME_H

#include <sys/time.h>

#endif

#ifdef HAVE_SYS_IOCCOM_H

#include <sys/ioccom.h>

#endif

#include <sys/resource.h>

#include <sys/stat.h>

#include <sys/tree.h>

#include <sys/wait.h>

#include <sys/queue.h>

#include <pcap.h>

#include <err.h>

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <syslog.h>

#include <signal.h>

#ifdef HAVE_TIME_H

#include <time.h>

#endif

#include <unistd.h>

#include <grp.h>

#include <getopt.h>

#include <dnet.h>

#undef timeout_pending

#undef timeout_initialized

#include <event.h>

#include "honeyd.h"

#include "osfp.h"

#include "hsniff.h"

#include "hooks.h"

#include "interface.h"

#include "tagging.h"

#include "stats.h"

#include "debug.h"

int honeyd_debug;

static int hsniff_show_version;

static int hsniff_show_usage;

static int hsniff_useudp;

static uid_t hsniff_uid = 32767;

static gid_t hsniff_gid = 32767;

static struct option hsniff_long_opts[] = {

{"version", 0, &hsniff_show_version, 1},

{"help", 0, &hsniff_show_usage, 1},

{0, 0, 0, 0}

};

struct tree tcpcons;

SPLAY_PROTOTYPE(tree, tuple, node, conhdr_compare);

SPLAY_GENERATE(tree, tuple, node, conhdr_compare);

void

usage(void)

{

fprintf(stderr,

"Usage: hsniff [OPTIONS] [net ...]\n\n"

"where options include:\n"

" -d Do not daemonize, be verbose.\n"

" -V, --version Print program version and exit.\n"

" -h, --help Print this message and exit.\n"

);

exit(1);

}

void

hsniff_settcp(struct tcp_track *con, struct ip_hdr *ip, struct tcp_hdr *tcp,

int local)

{

struct tuple *hdr = &con->conhdr;

memset(hdr, 0, sizeof(struct tuple));

hdr->ip_src = ip->ip_src;

hdr->ip_dst = ip->ip_dst;

hdr->sport = ntohs(tcp->th_sport);

hdr->dport = ntohs(tcp->th_dport);

hdr->type = SOCK_STREAM;

hdr->local = local;

TAILQ_INIT(&con->segments);

}

void

hsniff_setudp(struct udp_con *con, struct ip_hdr *ip, struct udp_hdr *udp,

int local)

{

struct tuple *hdr = &con->conhdr;

memset(hdr, 0, sizeof(struct tuple));

hdr->ip_src = ip->ip_src;

hdr->ip_dst = ip->ip_dst;

hdr->sport = ntohs(udp->uh_sport);

hdr->dport = ntohs(udp->uh_dport);

hdr->type = SOCK_DGRAM;

hdr->local = local;

con->softerrors = 0;

con->cmd.pfd = -1;

con->cmd.perrfd = -1;

TAILQ_INIT(&con->incoming);

}

static void

syslog_init(int argc, char *argv[])

{

int options, i;

char buf[MAXPATHLEN];

#ifdef LOG_PERROR

options = LOG_PERROR|LOG_PID|LOG_CONS;

#else

options = LOG_PID|LOG_CONS;

#endif

openlog("hsniff", options, LOG_DAEMON);

/* Create a string containing all the command line

* arguments and pass it to syslog:

buf[0] = '\0';

for (i = 1; i < argc; i++) {

if (i > 1 && strlcat(buf, " ", sizeof(buf)) >= sizeof(buf))

break;

if (strlcat(buf, argv[i], sizeof(buf)) >= sizeof(buf))

break;

}

syslog(LOG_NOTICE, "started with %s", buf);

}

void

hsniff_init(void)

{

/* Initalize ongoing connection state */

SPLAY_INIT(&tcpcons);

}

void

hsniff_exit(int status)

{

interface_close_all();

closelog();

exit(status);

}

void

generic_timeout(struct event *ev, int seconds)

{

struct timeval tv;

timerclear(&tv);

tv.tv_sec = seconds;

evtimer_add(ev, &tv);

}

struct tcp_track *

tcp_track_new(struct ip_hdr *ip, struct tcp_hdr *tcp, int local)

{

struct tcp_track *con;

if ((con = calloc(1, sizeof(struct tcp_track))) == NULL) {

syslog(LOG_WARNING, "calloc: %m");

return (NULL);

}

hsniff_settcp(con, ip, tcp, local);

con->timeout = evtimer_new(libevent_base, hsniff_tcp_timeout, con);

SPLAY_INSERT(tree, &tcpcons, &con->conhdr);

TAILQ_INIT(&con->segments);

return (con);

}

void

tcp_track_free(struct tcp_track *con)

{

struct tcp_segment *seg;

SPLAY_REMOVE(tree, &tcpcons, &con->conhdr);

while ((seg = TAILQ_FIRST(&con->segments)) != NULL) {

TAILQ_REMOVE(&con->segments, seg, next);

free(seg);

}

hooks_dispatch(IP_PROTO_TCP, HD_INCOMING_STREAM, &con->conhdr,

NULL, 0);

evtimer_del(con->timeout);

free(con);

}

void

hsniff_tcp_timeout(int fd, short event, void *arg)

{

struct tcp_track *con = arg;

syslog(LOG_DEBUG, "Expiring TCP %s (%p)",

honeyd_contoa(&con->conhdr), con);

tcp_track_free(con);

}

void

tcp_insert(struct tcp_track *con, uint32_t th_seq, void *data, size_t dlen)

{

struct tcp_segment *seg, *newseg;

TAILQ_FOREACH(seg, &con->segments, next) {

/* New packet before data that we have seen so far */

if (TCP_SEQ_LEQ(th_seq + dlen, seg->seq)) {

newseg = calloc(1, sizeof(struct tcp_segment));

if (newseg == NULL)

{

syslog(LOG_ERR, "%s: calloc", __func__);

exit(EXIT_FAILURE);

}

TAILQ_INSERT_BEFORE(seg, newseg, next);

return;

}

/* Packet is a total duplicate */

if (TCP_SEQ_LEQ(th_seq + dlen, seg->seq + seg->len))

return;

/* There is some overlap */

if (TCP_SEQ_LT(th_seq, seg->seq + seg->len)) {

uint32_t off;

off = seg->seq + seg->len - th_seq;

th_seq += off;

data += off;

dlen -= off;

}

void

tcp_drop_subsumed(struct tcp_track *con)

{

struct tcp_segment *seg;

uint32_t off;

while ((seg = TAILQ_FIRST(&con->segments)) != NULL) {

/* This segment is still in the future */

if (TCP_SEQ_GT(seg->seq, con->snd_una))

break;

/* For all other segments, we can do some work */

TAILQ_REMOVE(&con->segments, seg, next);

/* The old segment is completely covered, so we can drop it */

if (TCP_SEQ_LEQ(seg->seq + seg->len, con->snd_una)) {

free(seg);

continue;

}

if (seg->seq != con->snd_una) {

/* The data overlaps */

off = con->snd_una - seg->seq;

seg->seq += off;

seg->len -= off;

}

* We are matching up a previously stored segment,

* so we can stream its content out.

syslog(LOG_NOTICE, "Streaming: %s %u: %zd",

honeyd_contoa(&con->conhdr), con->snd_una, seg->len);

hooks_dispatch(IP_PROTO_TCP, HD_INCOMING_STREAM,

&con->conhdr, seg->data, seg->len);

con->snd_una += seg->len;

free(seg);

}

void

tcp_recv_cb(u_char *pkt, u_short pktlen)

{

struct ip_hdr *ip;

struct tcp_hdr *tcp;

struct tcp_track *con, tmp;

uint32_t th_seq;

uint16_t th_sum;

size_t dlen;

u_char *data;

uint8_t tiflags;

ip = (struct ip_hdr *)pkt;

tcp = (struct tcp_hdr *)(pkt + (ip->ip_hl << 2));

data = (u_char *)(pkt + (ip->ip_hl*4) + (tcp->th_off*4));

if (pktlen < (ip->ip_hl << 2) + TCP_HDR_LEN)

return;

/* Check the checksum the brutal way, until libdnet supports */

th_sum = tcp->th_sum;

ip_checksum(ip, pktlen);

if (th_sum != tcp->th_sum)

return;

th_seq = ntohl(tcp->th_seq);

tiflags = tcp->th_flags;

hsniff_settcp(&tmp, ip, tcp, 0);

con = (struct tcp_track *)SPLAY_FIND(tree, &tcpcons, &tmp.conhdr);

if (con == NULL) {

/* Only create new connections upon seeing a SYN packet */

if (!(tiflags & TH_SYN) || (tiflags & (TH_ACK|TH_RST)))

return;

/* Need to create new tcp connection tracker */

if ((con = tcp_track_new(ip, tcp, 0)) == NULL)

return;

con->snd_una = th_seq + 1;

}

* We need to hear back from this connection every so often,

* or we are going to time it out.

generic_timeout(con->timeout, HSNIFF_CON_EXPIRE);

hooks_dispatch(ip->ip_p, HD_INCOMING, &tmp.conhdr, pkt, pktlen);

dlen = ntohs(ip->ip_len) - (ip->ip_hl << 2) - (tcp->th_off << 2);

* This is responsible for ignoring the initial syn packet,

* so checking for SYN further below is safe.

if (TCP_SEQ_LEQ(th_seq + dlen, con->snd_una))

return;

/* There is some overlap */

if (TCP_SEQ_LT(th_seq, con->snd_una)) {

uint32_t off;

off = con->snd_una - th_seq;

th_seq += off;

data += off;

dlen -= off;

}

if (th_seq == con->snd_una) {

/* Inform our listener about the new data */

syslog(LOG_NOTICE, "Streaming: %s %u: %zd",

honeyd_contoa(&con->conhdr), con->snd_una, dlen);

hooks_dispatch(IP_PROTO_TCP, HD_INCOMING_STREAM, &con->conhdr,

data, dlen);

con->snd_una = th_seq + dlen;

tcp_drop_subsumed(con);

} else {

if (TCP_SEQ_GEQ(th_seq, con->snd_una + TCP_WIN_MAX) &&

TCP_SEQ_LEQ(th_seq, con->snd_una + TCP_WIN_MAX * 2)) {

* We probably lost some packets that are not going

* to be retransmitted.

con->snd_una = th_seq - TCP_WIN_MAX;

tcp_drop_subsumed(con);

}

/* Only insert data that is at most one window away */

if (TCP_SEQ_LEQ(th_seq, con->snd_una + TCP_WIN_MAX))

tcp_insert(con, th_seq, data, dlen);

}

if (tiflags & (TH_RST|TH_FIN|TH_SYN)) {

* Check if the conditions for closing this connection,

* have been met.

if (TCP_SEQ_GEQ(th_seq, con->snd_una) &&

TCP_SEQ_LEQ(th_seq, con->snd_una + TCP_WIN_MAX)) {

tcp_track_free(con);

return;

}

void

udp_recv_cb(u_char *pkt, u_short pktlen)

{

struct ip_hdr *ip = NULL;

struct udp_hdr *udp;

struct udp_con tmp;

uint16_t uh_sum;

u_char *data;

u_int dlen;

ip = (struct ip_hdr *)pkt;

udp = (struct udp_hdr *)(pkt + (ip->ip_hl << 2));

if (pktlen < (ip->ip_hl << 2) + UDP_HDR_LEN)

return;

hsniff_setudp(&tmp, ip, udp, 0);

hooks_dispatch(ip->ip_p, HD_INCOMING, &tmp.conhdr, pkt, pktlen);

data = (u_char *)(pkt + (ip->ip_hl*4) + UDP_HDR_LEN);

dlen = ntohs(ip->ip_len) - (ip->ip_hl << 2) - UDP_HDR_LEN;

if (dlen != (ntohs(udp->uh_ulen) - UDP_HDR_LEN))

return;

uh_sum = udp->uh_sum;

if (uh_sum) {

ip_checksum(ip, pktlen);

if (uh_sum != udp->uh_sum)

return;

}

hooks_dispatch(ip->ip_p, HD_INCOMING_STREAM, &tmp.conhdr, data, dlen);

}

void

hsniff_recv_cb(u_char *ag, const struct pcap_pkthdr *pkthdr, const u_char *pkt)

{

const struct interface *inter = (const struct interface *)ag;

struct ip_hdr *ip;

u_short iplen;

/* Everything below assumes that the packet is IPv4 */

if (pkthdr->caplen < inter->if_dloff + IP_HDR_LEN)

return;

ip = (struct ip_hdr *)(pkt + inter->if_dloff);

iplen = ntohs(ip->ip_len);

if (pkthdr->caplen - inter->if_dloff < iplen)

return;

if (ip->ip_hl << 2 > iplen)

return;

if (ip->ip_hl << 2 < sizeof(struct ip_hdr))

return;

switch(ip->ip_p) {

case IP_PROTO_TCP:

tcp_recv_cb((u_char *)ip, iplen);

break;

case IP_PROTO_UDP:

if (hsniff_useudp)

udp_recv_cb((u_char *)ip, iplen);

break;

default:

return;

}

void

hsniff_signal(int fd, short what, void *arg)

{

syslog(LOG_NOTICE, "exiting on signal %d", fd);

hsniff_exit(0);

}

int

main(int argc, char *argv[])

{

extern int interface_dopoll;

char *dev[HSNIFF_MAX_INTERFACES];

char **orig_argv;

char *osfp = PATH_HONEYDDATA "/pf.os";

struct addr stats_dst;

u_short stats_port = 0;

char *stats_username = NULL;

char *stats_password = NULL;

char filter[2048], line[128];

int i, c, orig_argc, ninterfaces = 0;

FILE *fp;

orig_argc = argc;

orig_argv = argv;

while ((c = getopt_long(argc, argv, "VPUdc:i:u:g:f:0:h?",

hsniff_long_opts, NULL)) != -1) {

char *ep;

switch (c) {

case 'U':

hsniff_useudp = 1;

break;

case 'c': {

char line[1024], *p = line;

char *address;

char *strport;

char *name;

char *password;

strlcpy(line, optarg, sizeof(line));

if ((address = strsep(&p, ":")) == NULL)

usage();

if ((strport = strsep(&p, ":")) == NULL)

usage();

if ((name = strsep(&p, ":")) == NULL)

usage();

if ((password = strsep(&p, ":")) == NULL)

usage();

if (p != NULL && *p != '\0')

usage();

if (addr_pton(address, &stats_dst) == -1) {

fprintf(stderr, "Bad destination address %s\n",

address);

usage();

}

if ((stats_port = atoi(strport)) == 0) {

fprintf(stderr, "Bad destination port %s\n",

strport);

usage();

}

stats_username = strdup(name);

stats_password = strdup(password);

}

break;

case 'u':

hsniff_uid = strtoul(optarg, &ep, 10);

if (optarg[0] == '\0' || *ep != '\0') {

fprintf(stderr, "Bad uid %s\n", optarg);

usage();

}

break;

case 'g':

hsniff_gid = strtoul(optarg, &ep, 10);

if (optarg[0] == '\0' || *ep != '\0') {

fprintf(stderr, "Bad gid %s\n", optarg);

usage();

}

break;

case 'V':

hsniff_show_version = 1;

break;

case 'P':

interface_dopoll = 1;

break;

case 'd':

honeyd_debug++;

break;

case 'i':

if (ninterfaces >= HSNIFF_MAX_INTERFACES)

{

syslog(LOG_ERR, "Too many interfaces specified");

exit(EXIT_FAILURE);

}

dev[ninterfaces++] = optarg;

break;

case '0':

osfp = optarg;

break;

case 0:

/* long option handled -- skip this one. */

break;

default:

usage();

break;

}

if (hsniff_show_version) {

printf("Hsniff Version %s\n", VERSION);

exit(0);

}

if (hsniff_show_usage) {

usage();

/* not reached */

}

argc -= optind;

argv += optind;

filter[0] = '\0';

while (argc > 0) {

struct addr addr;

if (addr_pton(*argv, &addr) == -1)

{

syslog(LOG_ERR, "invalid address \"%s\"", *argv);

exit(EXIT_FAILURE);

}

if (strlen(filter) &&

strlcat(filter, " or ", sizeof(filter)) >= sizeof(filter))

{

syslog(LOG_ERR, "too many addresses; filter too big");

exit(EXIT_FAILURE);

}

if (addr.addr_bits == 32) {

snprintf(line, sizeof(line), "(not src %s and dst %s)",

addr_ntoa(&addr), addr_ntoa(&addr));

if (strlcat(filter, line, sizeof(filter)) >=

sizeof(filter))

{

syslog(LOG_ERR, "too many addresses; filter too big");

exit(EXIT_FAILURE);

}

} else {

snprintf(line, sizeof(line),

"(not src net %s and dst net %s)",

addr_ntoa(&addr), addr_ntoa(&addr));

if (strlcat(filter, line, sizeof(filter)) >=

sizeof(filter))

{

syslog(LOG_ERR, "too many addresses, filter too big");

exit(EXIT_FAILURE);

}

argv++;

argc--;

}

if (strlen(filter)) {

extern char *interface_filter;

interface_filter = filter;

} else {

fprintf(stderr, "no addresses specified\n");

usage();

/* NOTREACHED */

}

VERSION);

/* disabled event methods that don't work with bpf */

interface_prevent_init();

hsniff_libevent_base = event_base_new();

syslog_init(orig_argc, orig_argv);

/* Initialize Honeyd's callback hooks */

hooks_init();

interface_initialize(hsniff_recv_cb);

if (stats_username == NULL)

{

syslog(LOG_ERR, "no username specified for stats reporting");

exit(EXIT_FAILURE);

}

stats_init();

stats_init_collect(&stats_dst, stats_port,

stats_username, stats_password);

/* PF OS fingerprints */

if (honeyd_osfp_init(osfp) == -1)

{

syslog(LOG_ERR, "failed to read OS fingerprints");

exit(EXIT_FAILURE);

}

/* Initialize the specified interfaces */

if (ninterfaces == 0)

interface_init(NULL, argc, argc ? argv : NULL);

else {

for (i = 0; i < ninterfaces; i++)

interface_init(dev[i], argc, argc ? argv : NULL);

}

/* Create PID file, we might not be able to remove it */

unlink(HSNIFF_PIDFILE);

if ((fp = fopen(HSNIFF_PIDFILE, "w")) == NULL)

{

syslog(LOG_ERR, "fopen, failed to open file");

exit(EXIT_FAILURE);

}

/* Start Hsniff in the background if necessary */

if (!honeyd_debug) {

setlogmask(LOG_UPTO(LOG_INFO));

fprintf(stderr, "Hsniff starting as background process\n");

if (daemon(1, 0) < 0) {

unlink(HSNIFF_PIDFILE);

syslog(LOG_ERR, "daemon");

exit(EXIT_FAILURE);

}

fprintf(fp, "%d\n", getpid());

fclose(fp);

chmod(HSNIFF_PIDFILE, 0644);

/* Drop privileges if we do not need them */

droppriv(hsniff_uid, hsniff_gid);

syslog(LOG_NOTICE,

"Demoting process privileges to uid %u, gid %u",

hsniff_uid, hsniff_gid);

struct event *sigterm_ev, *sigint_ev;

sigterm_ev = evsignal_new(hsniff_libevent_base, SIGTERM, hsniff_signal, NULL);

sigint_ev = evsignal_new(hsniff_libevent_base, SIGINT, hsniff_signal, NULL);

event_add(sigterm_ev, NULL);

event_add(sigint_ev, NULL);

event_base_dispatch(hsniff_libevent_base);

syslog(LOG_ERR, "Kqueue does not recognize bpf filedescriptor.");

return (0);

}

/* Drop the privileges and verify that they got dropped */

#define SETERROR(x) do { \

snprintf x; \

strlcat(error, errline, sizeof(error)); \

} while (0)

void

droppriv(uid_t uid, gid_t gid)

{

static char error[1024];

static char errline[256];

error[0] = '\0';

/* Lower privileges */

#ifdef HAVE_SETGROUPS

if (setgroups(1, &gid) == -1)