networking/udhcp/dhcpc.c

   1 /* vi: set sw=4 ts=4: */
   2 /* dhcpc.c
   3  *
   4  * udhcp DHCP client
   5  *
   6  * Russ Dill <Russ.Dill@asu.edu> July 2001
   7  *
   8  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
   9  */
  10
  11 #include <getopt.h>
  12 #include <syslog.h>
  13
  14 /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
  15 #define WANT_PIDFILE 1
  16 #include "common.h"
  17 #include "dhcpd.h"
  18 #include "dhcpc.h"
  19 #include "options.h"
  20
  21
  22 /* Something is definitely wrong here. IPv4 addresses
  23  * in variables of type long?? BTW, we use inet_ntoa()
  24  * in the code. Manpage says that struct in_addr has a member of type long (!)
  25  * which holds IPv4 address, and the struct is passed by value (!!)
  26  */
  27 static int timeout; /* = 0. Must be signed */
  28 static uint32_t requested_ip; /* = 0 */
  29 static uint32_t server_addr;
  30 static int packet_num; /* = 0 */
  31 static int sockfd = -1;
  32
  33 #define LISTEN_NONE 0
  34 #define LISTEN_KERNEL 1
  35 #define LISTEN_RAW 2
  36 static smallint listen_mode;
  37
  38 static smallint state;
  39
  40 /* struct client_config_t client_config is in bb_common_bufsiz1 */
  41
  42
  43 /* just a little helper */
  44 static void change_listen_mode(int new_mode)
  45 {
  46         DEBUG("entering %s listen mode",
  47                 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
  48         if (sockfd >= 0) {
  49                 close(sockfd);
  50                 sockfd = -1;
  51         }
  52         listen_mode = new_mode;
  53 }
  54
  55
  56 /* perform a renew */
  57 static void perform_renew(void)
  58 {
  59         bb_info_msg("Performing a DHCP renew");
  60         switch (state) {
  61         case BOUND:
  62                 change_listen_mode(LISTEN_KERNEL);
  63         case RENEWING:
  64         case REBINDING:
  65                 state = RENEW_REQUESTED;
  66                 break;
  67         case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
  68                 udhcp_run_script(NULL, "deconfig");
  69         case REQUESTING:
  70         case RELEASED:
  71                 change_listen_mode(LISTEN_RAW);
  72                 state = INIT_SELECTING;
  73                 break;
  74         case INIT_SELECTING:
  75                 break;
  76         }
  77
  78         /* start things over */
  79         packet_num = 0;
  80
  81         /* Kill any timeouts because the user wants this to hurry along */
  82         timeout = 0;
  83 }
  84
  85
  86 /* perform a release */
  87 static void perform_release(void)
  88 {
  89         char buffer[sizeof("255.255.255.255")];
  90         struct in_addr temp_addr;
  91
  92         /* send release packet */
  93         if (state == BOUND || state == RENEWING || state == REBINDING) {
  94                 temp_addr.s_addr = server_addr;
  95                 strcpy(buffer, inet_ntoa(temp_addr));
  96                 temp_addr.s_addr = requested_ip;
  97                 bb_info_msg("Unicasting a release of %s to %s",
  98                                 inet_ntoa(temp_addr), buffer);
  99                 send_release(server_addr, requested_ip); /* unicast */
 100                 udhcp_run_script(NULL, "deconfig");
 101         }
 102         bb_info_msg("Entering released state");
 103
 104         change_listen_mode(LISTEN_NONE);
 105         state = RELEASED;
 106         timeout = INT_MAX;
 107 }
 108
 109
 110 static void client_background(void)
 111 {
 112 #if !BB_MMU
 113         bb_error_msg("cannot background in uclinux (yet)");
 114 /* ... mainly because udhcpc calls client_background()
 115  * in _the _middle _of _udhcpc _run_, not at the start!
 116  * If that will be properly disabled for NOMMU, client_background()
 117  * will work on NOMMU too */
 118 #else
 119         bb_daemonize(0);
 120         logmode &= ~LOGMODE_STDIO;
 121         /* rewrite pidfile, as our pid is different now */
 122         write_pidfile(client_config.pidfile);
 123 #endif
 124         /* Do not fork again. */
 125         client_config.foreground = 1;
 126         client_config.background_if_no_lease = 0;
 127 }
 128
 129
 130 static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
 131 {
 132         uint8_t *storage;
 133         int len = strlen(str);
 134         if (len > 255) len = 255;
 135         storage = xzalloc(len + extra + OPT_DATA);
 136         storage[OPT_CODE] = code;
 137         storage[OPT_LEN] = len + extra;
 138         memcpy(storage + extra + OPT_DATA, str, len);
 139         return storage;
 140 }
 141
 142
 143 int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 144 int udhcpc_main(int argc, char **argv)
 145 {
 146         uint8_t *temp, *message;
 147         char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_A, *str_t;
 148 #if ENABLE_FEATURE_UDHCPC_ARPING
 149         char *str_W;
 150 #endif
 151         int tryagain_timeout = 20;
 152         int discover_timeout = 3;
 153         int discover_retries = 3;
 154         uint32_t xid = 0;
 155         uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
 156         unsigned t1 = 0, t2 = 0; /* what a wonderful names */
 157         unsigned timestamp_got_lease = 0; /* for gcc */
 158         unsigned opt;
 159         int max_fd;
 160         int retval;
 161         int len;
 162         struct timeval tv;
 163         struct in_addr temp_addr;
 164         struct dhcpMessage packet;
 165         fd_set rfds;
 166
 167         enum {
 168                 OPT_c = 1 << 0,
 169                 OPT_C = 1 << 1,
 170                 OPT_V = 1 << 2,
 171                 OPT_f = 1 << 3,
 172                 OPT_b = 1 << 4,
 173                 OPT_H = 1 << 5,
 174                 OPT_h = 1 << 6,
 175                 OPT_F = 1 << 7,
 176                 OPT_i = 1 << 8,
 177                 OPT_n = 1 << 9,
 178                 OPT_p = 1 << 10,
 179                 OPT_q = 1 << 11,
 180                 OPT_R = 1 << 12,
 181                 OPT_r = 1 << 13,
 182                 OPT_s = 1 << 14,
 183                 OPT_T = 1 << 15,
 184                 OPT_t = 1 << 16,
 185                 OPT_v = 1 << 17,
 186                 OPT_S = 1 << 18,
 187                 OPT_A = 1 << 19,
 188 #if ENABLE_FEATURE_UDHCPC_ARPING
 189                 OPT_a = 1 << 20,
 190                 OPT_W = 1 << 21,
 191 #endif
 192         };
 193 #if ENABLE_GETOPT_LONG
 194         static const char udhcpc_longopts[] ALIGN1 =
 195                 "clientid\0"      Required_argument "c"
 196                 "clientid-none\0" No_argument       "C"
 197                 "vendorclass\0"   Required_argument "V"
 198                 "foreground\0"    No_argument       "f"
 199                 "background\0"    No_argument       "b"
 200                 "hostname\0"      Required_argument "H"
 201                 "fqdn\0"          Required_argument "F"
 202                 "interface\0"     Required_argument "i"
 203                 "now\0"           No_argument       "n"
 204                 "pidfile\0"       Required_argument "p"
 205                 "quit\0"          No_argument       "q"
 206                 "release\0"       No_argument       "R"
 207                 "request\0"       Required_argument "r"
 208                 "script\0"        Required_argument "s"
 209                 "timeout\0"       Required_argument "T"
 210                 "version\0"       No_argument       "v"
 211                 "retries\0"       Required_argument "t"
 212                 "tryagain\0"      Required_argument "A"
 213                 "syslog\0"        No_argument       "S"
 214 #if ENABLE_FEATURE_UDHCPC_ARPING
 215                 "arping\0"        No_argument       "a"
 216 #endif
 217                 ;
 218 #endif
 219         /* Default options. */
 220         client_config.interface = "eth0";
 221         client_config.script = DEFAULT_SCRIPT;
 222
 223         /* Parse command line */
 224         opt_complementary = "c--C:C--c"; // mutually exclusive
 225 #if ENABLE_GETOPT_LONG
 226         applet_long_options = udhcpc_longopts;
 227 #endif
 228         opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vSA:"
 229                 USE_FEATURE_UDHCPC_ARPING("aW:")
 230                 , &str_c, &str_V, &str_h, &str_h, &str_F,
 231                 &client_config.interface, &client_config.pidfile, &str_r,
 232                 &client_config.script, &str_T, &str_t, &str_A
 233                 USE_FEATURE_UDHCPC_ARPING(, &str_W)
 234                 );
 235
 236         if (opt & OPT_c)
 237                 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0);
 238         //if (opt & OPT_C)
 239         if (opt & OPT_V)
 240                 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
 241         if (opt & OPT_f)
 242                 client_config.foreground = 1;
 243         if (opt & OPT_b)
 244                 client_config.background_if_no_lease = 1;
 245         if (opt & (OPT_h|OPT_H))
 246                 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
 247         if (opt & OPT_F) {
 248                 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
 249                 /* Flags: 0000NEOS
 250                 S: 1 => Client requests Server to update A RR in DNS as well as PTR
 251                 O: 1 => Server indicates to client that DNS has been updated regardless
 252                 E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com"
 253                 N: 1 => Client requests Server to not update DNS
 254                 */
 255                 client_config.fqdn[OPT_DATA + 0] = 0x1;
 256                 /* client_config.fqdn[OPT_DATA + 1] = 0; - redundant */
 257                 /* client_config.fqdn[OPT_DATA + 2] = 0; - redundant */
 258         }
 259         // if (opt & OPT_i) client_config.interface = ...
 260         if (opt & OPT_n)
 261                 client_config.abort_if_no_lease = 1;
 262         // if (opt & OPT_p) client_config.pidfile = ...
 263         if (opt & OPT_q)
 264                 client_config.quit_after_lease = 1;
 265         if (opt & OPT_R)
 266                 client_config.release_on_quit = 1;
 267         if (opt & OPT_r)
 268                 requested_ip = inet_addr(str_r);
 269         // if (opt & OPT_s) client_config.script = ...
 270         if (opt & OPT_T)
 271                 discover_timeout = xatoi_u(str_T);
 272         if (opt & OPT_t)
 273                 discover_retries = xatoi_u(str_t);
 274         if (opt & OPT_A)
 275                 tryagain_timeout = xatoi_u(str_A);
 276         if (opt & OPT_v) {
 277                 puts("version "BB_VER);
 278                 return 0;
 279         }
 280
 281         if (opt & OPT_S) {
 282                 openlog(applet_name, LOG_PID, LOG_LOCAL0);
 283                 logmode |= LOGMODE_SYSLOG;
 284         }
 285
 286         if (read_interface(client_config.interface, &client_config.ifindex,
 287                            NULL, client_config.arp))
 288                 return 1;
 289
 290         /* Make sure fd 0,1,2 are open */
 291         bb_sanitize_stdio();
 292         /* Equivalent of doing a fflush after every \n */
 293         setlinebuf(stdout);
 294
 295         /* Create pidfile */
 296         write_pidfile(client_config.pidfile);
 297         /* if (!..) bb_perror_msg("cannot create pidfile %s", pidfile); */
 298
 299         /* Goes to stdout and possibly syslog */
 300         bb_info_msg("%s (v"BB_VER") started", applet_name);
 301
 302         /* if not set, and not suppressed, setup the default client ID */
 303         if (!client_config.clientid && !(opt & OPT_C)) {
 304                 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
 305                 client_config.clientid[OPT_DATA] = 1;
 306                 memcpy(client_config.clientid + OPT_DATA+1, client_config.arp, 6);
 307         }
 308
 309         if (!client_config.vendorclass)
 310                 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0);
 311
 312         /* setup the signal pipe */
 313         udhcp_sp_setup();
 314
 315         state = INIT_SELECTING;
 316         udhcp_run_script(NULL, "deconfig");
 317         change_listen_mode(LISTEN_RAW);
 318
 319         /* Main event loop. select() waits on signal pipe and possibly
 320          * on sockfd.
 321          * "continue" statements in code below jump to the top of the loop.
 322          */
 323         for (;;) {
 324                 tv.tv_sec = timeout;
 325                 tv.tv_usec = 0;
 326
 327                 if (listen_mode != LISTEN_NONE && sockfd < 0) {
 328                         if (listen_mode == LISTEN_KERNEL)
 329                                 sockfd = listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
 330                         else
 331                                 sockfd = raw_socket(client_config.ifindex);
 332                 }
 333                 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
 334
 335                 retval = 0; /* If we already timed out, fall through, else... */
 336                 if (tv.tv_sec > 0) {
 337                         DEBUG("Waiting on select...");
 338                         retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
 339                 }
 340
 341                 if (retval < 0) {
 342                         /* EINTR? signal was caught, don't panic */
 343                         if (errno != EINTR) {
 344                                 /* Else: an error occured, panic! */
 345                                 bb_perror_msg_and_die("select");
 346                         }
 347                         continue;
 348                 }
 349
 350                 /* If timeout dropped to zero, time to become active:
 351                  * resend discover/renew/whatever
 352                  */
 353                 if (retval == 0) {
 354                         switch (state) {
 355                         case INIT_SELECTING:
 356                                 if (packet_num < discover_retries) {
 357                                         if (packet_num == 0)
 358                                                 xid = random_xid();
 359
 360                                         /* send discover packet */
 361                                         send_discover(xid, requested_ip); /* broadcast */
 362
 363                                         timeout = discover_timeout;
 364                                         packet_num++;
 365                                         continue;
 366                                 }
 367                                 udhcp_run_script(NULL, "leasefail");
 368                                 if (client_config.background_if_no_lease) {
 369                                         bb_info_msg("No lease, forking to background");
 370                                         client_background();
 371                                 } else if (client_config.abort_if_no_lease) {
 372                                         bb_info_msg("No lease, failing");
 373                                         retval = 1;
 374                                         goto ret;
 375                                 }
 376                                 /* wait to try again */
 377                                 timeout = tryagain_timeout;
 378                                 packet_num = 0;
 379                                 continue;
 380                         case RENEW_REQUESTED:
 381                         case REQUESTING:
 382                                 if (packet_num < discover_retries) {
 383                                         /* send request packet */
 384                                         if (state == RENEW_REQUESTED)
 385                                                 send_renew(xid, server_addr, requested_ip); /* unicast */
 386                                         else send_selecting(xid, server_addr, requested_ip); /* broadcast */
 387
 388                                         timeout = ((packet_num == 2) ? 10 : 2);
 389                                         packet_num++;
 390                                         continue;
 391                                 }
 392                                 /* timed out, go back to init state */
 393                                 if (state == RENEW_REQUESTED)
 394                                         udhcp_run_script(NULL, "deconfig");
 395                                 change_listen_mode(LISTEN_RAW);
 396                                 state = INIT_SELECTING;
 397                                 timeout = 0;
 398                                 packet_num = 0;
 399                                 continue;
 400                         case BOUND:
 401                                 /* Lease is starting to run out, time to enter renewing state */
 402                                 change_listen_mode(LISTEN_KERNEL);
 403                                 DEBUG("Entering renew state");
 404                                 state = RENEWING;
 405                                 /* fall right through */
 406                         case RENEWING:
 407                                 /* Either set a new T1, or enter REBINDING state */
 408                                 if ((t2 - t1) > (lease_seconds / (4*60*60) + 1)) {
 409                                         /* send a request packet */
 410                                         send_renew(xid, server_addr, requested_ip); /* unicast */
 411                                         t1 += (t2 - t1) / 2;
 412                                         timeout = t1 - ((int)monotonic_sec() - timestamp_got_lease);
 413                                         continue;
 414                                 }
 415                                 /* Timed out, enter rebinding state */
 416                                 DEBUG("Entering rebinding state");
 417                                 state = REBINDING;
 418                                 timeout = (t2 - t1);
 419                                 continue;
 420                         case REBINDING:
 421                                 /* Lease is *really* about to run out,
 422                                  * try to find DHCP server using broadcast */
 423                                 if ((lease_seconds - t2) > (lease_seconds / (4*60*60) + 1)) {
 424                                         /* send a request packet */
 425                                         send_renew(xid, 0, requested_ip); /* broadcast */
 426                                         t2 += (lease_seconds - t2) / 2;
 427                                         timeout = t2 - ((int)monotonic_sec() - timestamp_got_lease);
 428                                         continue;
 429                                 }
 430                                 /* Timed out, enter init state */
 431                                 bb_info_msg("Lease lost, entering init state");
 432                                 udhcp_run_script(NULL, "deconfig");
 433                                 change_listen_mode(LISTEN_RAW);
 434                                 state = INIT_SELECTING;
 435                                 timeout = 0;
 436                                 packet_num = 0;
 437                                 continue;
 438                         /* case RELEASED: */
 439                         }
 440                         /* yah, I know, *you* say it would never happen */
 441                         timeout = INT_MAX;
 442                         continue; /* back to main loop */
 443                 }
 444
 445                 /* select() didn't timeout, something did happen. */
 446                 /* Is is a packet? */
 447                 if (listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) {
 448                         /* A packet is ready, read it */
 449
 450                         if (listen_mode == LISTEN_KERNEL)
 451                                 len = udhcp_get_packet(&packet, sockfd);
 452                         else len = get_raw_packet(&packet, sockfd);
 453
 454                         if (len == -1 && errno != EINTR) {
 455                                 DEBUG("error on read, %s, reopening socket", strerror(errno));
 456                                 change_listen_mode(listen_mode); /* just close and reopen */
 457                         }
 458                         if (len < 0) continue;
 459
 460                         if (packet.xid != xid) {
 461                                 DEBUG("Ignoring XID %x (our xid is %x)",
 462                                         (unsigned)packet.xid, (unsigned)xid);
 463                                 continue;
 464                         }
 465
 466                         /* Ignore packets that aren't for us */
 467                         if (memcmp(packet.chaddr, client_config.arp, 6)) {
 468                                 DEBUG("Packet does not have our chaddr - ignoring");
 469                                 continue;
 470                         }
 471
 472                         message = get_option(&packet, DHCP_MESSAGE_TYPE);
 473                         if (message == NULL) {
 474                                 bb_error_msg("cannot get message type from packet - ignoring");
 475                                 continue;
 476                         }
 477
 478                         switch (state) {
 479                         case INIT_SELECTING:
 480                                 /* Must be a DHCPOFFER to one of our xid's */
 481                                 if (*message == DHCPOFFER) {
 482                         /* TODO: why we don't just fetch server's IP from IP header? */
 483                                         temp = get_option(&packet, DHCP_SERVER_ID);
 484                                         if (!temp) {
 485                                                 bb_error_msg("no server ID in message");
 486                                                 continue;
 487                                                 /* still selecting - this server looks bad */
 488                                         }
 489                                         /* can be misaligned, thus memcpy */
 490                                         memcpy(&server_addr, temp, 4);
 491                                         xid = packet.xid;
 492                                         requested_ip = packet.yiaddr;
 493
 494                                         /* enter requesting state */
 495                                         state = REQUESTING;
 496                                         timeout = 0;
 497                                         packet_num = 0;
 498                                 }
 499                                 continue;
 500                         case RENEW_REQUESTED:
 501                         case REQUESTING:
 502                         case RENEWING:
 503                         case REBINDING:
 504                                 if (*message == DHCPACK) {
 505                                         temp = get_option(&packet, DHCP_LEASE_TIME);
 506                                         if (!temp) {
 507                                                 bb_error_msg("no lease time with ACK, using 1 hour lease");
 508                                                 lease_seconds = 60 * 60;
 509                                         } else {
 510                                                 /* can be misaligned, thus memcpy */
 511                                                 memcpy(&lease_seconds, temp, 4);
 512                                                 lease_seconds = ntohl(lease_seconds);
 513                                         }
 514 #if ENABLE_FEATURE_UDHCPC_ARPING
 515                                         if (opt & OPT_a) {
 516                                                 if (!arpping(packet.yiaddr,
 517                                                             (uint32_t) 0,
 518                                                             client_config.arp,
 519                                                             client_config.interface)
 520                                                 ) {
 521                                                         bb_info_msg("offered address is in use "
 522                                                                 "(got ARP reply), declining");
 523                                                         send_decline(xid, server_addr);
 524
 525                                                         if (state != REQUESTING)
 526                                                                 udhcp_run_script(NULL, "deconfig");
 527                                                         change_listen_mode(LISTEN_RAW);
 528                                                         state = INIT_SELECTING;
 529                                                         requested_ip = 0;
 530                                                         timeout = tryagain_timeout;
 531                                                         packet_num = 0;
 532                                                         continue; /* back to main loop */
 533                                                 }
 534                                         }
 535 #endif
 536                                         /* enter bound state */
 537                                         t1 = lease_seconds / 2;
 538
 539                                         /* little fixed point for n * .875 */
 540                                         t2 = (lease_seconds * 7) >> 3;
 541                                         temp_addr.s_addr = packet.yiaddr;
 542                                         bb_info_msg("Lease of %s obtained, lease time %u",
 543                                                 inet_ntoa(temp_addr), (unsigned)lease_seconds);
 544                                         timestamp_got_lease = monotonic_sec();
 545                                         timeout = t1;
 546                                         requested_ip = packet.yiaddr;
 547                                         udhcp_run_script(&packet,
 548                                                    ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
 549
 550                                         state = BOUND;
 551                                         change_listen_mode(LISTEN_NONE);
 552                                         if (client_config.quit_after_lease) {
 553                                                 if (client_config.release_on_quit)
 554                                                         perform_release();
 555                                                 goto ret0;
 556                                         }
 557                                         if (!client_config.foreground)
 558                                                 client_background();
 559
 560                                         continue; /* back to main loop */
 561                                 }
 562                                 if (*message == DHCPNAK) {
 563                                         /* return to init state */
 564                                         bb_info_msg("Received DHCP NAK");
 565                                         udhcp_run_script(&packet, "nak");
 566                                         if (state != REQUESTING)
 567                                                 udhcp_run_script(NULL, "deconfig");
 568                                         change_listen_mode(LISTEN_RAW);
 569                                         sleep(3); /* avoid excessive network traffic */
 570                                         state = INIT_SELECTING;
 571                                         requested_ip = 0;
 572                                         timeout = 0;
 573                                         packet_num = 0;
 574                                 }
 575                                 continue;
 576                         /* case BOUND, RELEASED: - ignore all packets */
 577                         }
 578                         continue; /* back to main loop */
 579                 }
 580
 581                 /* select() didn't timeout, something did happen.
 582                  * But it wasn't a packet. It's a signal pipe then. */
 583                 {
 584                         int signo = udhcp_sp_read(&rfds);
 585                         switch (signo) {
 586                         case SIGUSR1:
 587                                 perform_renew();
 588                                 break;
 589                         case SIGUSR2:
 590                                 perform_release();
 591                                 break;
 592                         case SIGTERM:
 593                                 bb_info_msg("Received SIGTERM");
 594                                 if (client_config.release_on_quit)
 595                                         perform_release();
 596                                 goto ret0;
 597                         }
 598                 }
 599         } /* for (;;) - main loop ends */
 600
 601  ret0:
 602         retval = 0;
 603  ret:
 604         /*if (client_config.pidfile) - remove_pidfile has it's own check */
 605                 remove_pidfile(client_config.pidfile);
 606         return retval;
 607 }