src/odhcp6c.c

   1 /**
   2  * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License v2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #include <time.h>
  16 #include <errno.h>
  17 #include <ctype.h>
  18 #include <fcntl.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23 #include <syslog.h>
  24 #include <signal.h>
  25 #include <string.h>
  26 #include <strings.h>
  27 #include <stdbool.h>
  28
  29 #include <net/if.h>
  30 #include <sys/wait.h>
  31 #include <sys/syscall.h>
  32 #include <arpa/inet.h>
  33 #include <linux/if_addr.h>
  34
  35 #include "odhcp6c.h"
  36 #include "ra.h"
  37
  38 #ifdef EXT_BFD_PING
  39 #include "bfd.h"
  40 #endif
  41
  42 #ifndef IN6_IS_ADDR_UNIQUELOCAL
  43 #define IN6_IS_ADDR_UNIQUELOCAL(a) \
  44         ((((__const uint32_t *) (a))[0] & htonl (0xfe000000)) \
  45          == htonl (0xfc000000))
  46 #endif
  47
  48 static void sighandler(int signal);
  49 static int usage(void);
  50
  51 static uint8_t *state_data[_STATE_MAX] = {NULL};
  52 static size_t state_len[_STATE_MAX] = {0};
  53
  54 static volatile int do_signal = 0;
  55 static int urandom_fd = -1, allow_slaac_only = 0;
  56 static bool bound = false, release = true;
  57 static time_t last_update = 0;
  58 static char *ifname = NULL;
  59
  60 int main(_unused int argc, char* const argv[])
  61 {
  62         // Allocate ressources
  63         const char *pidfile = NULL;
  64         const char *script = "/usr/sbin/odhcp6c-update";
  65         ssize_t l;
  66         uint8_t buf[134];
  67         char *optpos;
  68         uint16_t opttype;
  69         enum odhcp6c_ia_mode ia_na_mode = IA_MODE_TRY;
  70         enum odhcp6c_ia_mode ia_pd_mode = IA_MODE_TRY;
  71         static struct in6_addr ifid = IN6ADDR_ANY_INIT;
  72         int sol_timeout = 120;
  73
  74 #ifdef EXT_BFD_PING
  75         int bfd_interval = 0, bfd_loss = 3;
  76 #endif
  77
  78         bool help = false, daemonize = false;
  79         int logopt = LOG_PID;
  80         int c, request_pd = 0;
  81         while ((c = getopt(argc, argv, "S::N:P:FB:c:i:r:s:kt:hedp:")) != -1) {
  82                 switch (c) {
  83                 case 'S':
  84                         allow_slaac_only = (optarg) ? atoi(optarg) : -1;
  85                         break;
  86
  87                 case 'N':
  88                         if (!strcmp(optarg, "force")) {
  89                                 ia_na_mode = IA_MODE_FORCE;
  90                                 allow_slaac_only = -1;
  91                         } else if (!strcmp(optarg, "none")) {
  92                                 ia_na_mode = IA_MODE_NONE;
  93                         } else if (!strcmp(optarg, "try")) {
  94                                 ia_na_mode = IA_MODE_TRY;
  95                         } else{
  96                                 help = true;
  97                         }
  98                         break;
  99
 100                 case 'P':
 101                         if (allow_slaac_only >= 0 && allow_slaac_only < 10)
 102                                 allow_slaac_only = 10;
 103
 104                         request_pd = strtoul(optarg, NULL, 10);
 105                         if (request_pd == 0)
 106                                 request_pd = -1;
 107
 108                         break;
 109
 110                 case 'F':
 111                         allow_slaac_only = -1;
 112                         ia_pd_mode = IA_MODE_FORCE;
 113                         break;
 114
 115 #ifdef EXT_BFD_PING
 116                 case 'B':
 117                         bfd_interval = atoi(optarg);
 118                         break;
 119 #endif
 120
 121                 case 'c':
 122                         l = script_unhexlify(&buf[4], sizeof(buf) - 4, optarg);
 123                         if (l > 0) {
 124                                 buf[0] = 0;
 125                                 buf[1] = DHCPV6_OPT_CLIENTID;
 126                                 buf[2] = 0;
 127                                 buf[3] = l;
 128                                 odhcp6c_add_state(STATE_CLIENT_ID, buf, l + 4);
 129                         } else {
 130                                 help = true;
 131                         }
 132                         break;
 133
 134                 case 'i':
 135                         if (inet_pton(AF_INET6, optarg, &ifid) != 1)
 136                                 help = true;
 137                         break;
 138
 139                 case 'r':
 140                         optpos = optarg;
 141                         while (optpos[0]) {
 142                                 opttype = htons(strtoul(optarg, &optpos, 10));
 143                                 if (optpos == optarg)
 144                                         break;
 145                                 else if (optpos[0])
 146                                         optarg = &optpos[1];
 147                                 odhcp6c_add_state(STATE_ORO, &opttype, 2);
 148                         }
 149                         break;
 150
 151                 case 's':
 152                         script = optarg;
 153                         break;
 154
 155                 case 'k':
 156                         release = false;
 157                         break;
 158
 159                 case 't':
 160                         sol_timeout = atoi(optarg);
 161                         break;
 162
 163                 case 'e':
 164                         logopt |= LOG_PERROR;
 165                         break;
 166
 167                 case 'd':
 168                         daemonize = true;
 169                         break;
 170
 171                 case 'p':
 172                         pidfile = optarg;
 173                         break;
 174
 175                 default:
 176                         help = true;
 177                         break;
 178                 }
 179         }
 180
 181         openlog("odhcp6c", logopt, LOG_DAEMON);
 182         ifname = argv[optind];
 183
 184         if (help || !ifname)
 185                 return usage();
 186
 187         signal(SIGIO, sighandler);
 188         signal(SIGHUP, sighandler);
 189         signal(SIGINT, sighandler);
 190         signal(SIGCHLD, sighandler);
 191         signal(SIGTERM, sighandler);
 192         signal(SIGUSR1, sighandler);
 193         signal(SIGUSR2, sighandler);
 194
 195         if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
 196                         init_dhcpv6(ifname, request_pd, sol_timeout) ||
 197                         ra_init(ifname, &ifid) || script_init(script, ifname)) {
 198                 syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
 199                 return 3;
 200         }
 201
 202         if (daemonize) {
 203                 openlog("odhcp6c", LOG_PID, LOG_DAEMON); // Disable LOG_PERROR
 204                 if (daemon(0, 0)) {
 205                         syslog(LOG_ERR, "Failed to daemonize: %s",
 206                                         strerror(errno));
 207                         return 4;
 208                 }
 209
 210                 char pidbuf[128];
 211                 if (!pidfile) {
 212                         snprintf(pidbuf, sizeof(pidbuf),
 213                                         "/var/run/odhcp6c.%s.pid", ifname);
 214                         pidfile = pidbuf;
 215                 }
 216
 217                 int fd = open(pidfile, O_WRONLY | O_CREAT);
 218                 if (fd >= 0) {
 219                         char buf[8];
 220                         int len = snprintf(buf, sizeof(buf), "%i\n", getpid());
 221                         write(fd, buf, len);
 222                         close(fd);
 223                 }
 224         }
 225
 226         script_call("started");
 227
 228         while (do_signal != SIGTERM) { // Main logic
 229                 odhcp6c_clear_state(STATE_SERVER_ID);
 230                 odhcp6c_clear_state(STATE_IA_NA);
 231                 odhcp6c_clear_state(STATE_IA_PD);
 232                 odhcp6c_clear_state(STATE_SNTP_IP);
 233                 odhcp6c_clear_state(STATE_SNTP_FQDN);
 234                 odhcp6c_clear_state(STATE_SIP_IP);
 235                 odhcp6c_clear_state(STATE_SIP_FQDN);
 236                 dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode);
 237                 bound = false;
 238
 239                 // Server candidates need deep-delete
 240                 size_t cand_len;
 241                 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
 242                 for (size_t i = 0; i < cand_len / sizeof(*cand); ++i) {
 243                         free(cand[i].ia_na);
 244                         free(cand[i].ia_pd);
 245                 }
 246                 odhcp6c_clear_state(STATE_SERVER_CAND);
 247
 248                 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
 249
 250                 do_signal = 0;
 251                 int res = dhcpv6_request(DHCPV6_MSG_SOLICIT);
 252                 odhcp6c_signal_process();
 253
 254                 if (res <= 0) {
 255                         continue; // Might happen if we got a signal
 256                 } else if (res == DHCPV6_STATELESS) { // Stateless mode
 257                         while (do_signal == 0 || do_signal == SIGUSR1) {
 258                                 do_signal = 0;
 259
 260                                 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
 261                                 odhcp6c_signal_process();
 262                                 if (do_signal == SIGUSR1)
 263                                         continue;
 264                                 else if (res < 0)
 265                                         break;
 266                                 else if (res > 0)
 267                                         script_call("informed");
 268
 269                                 bound = true;
 270                                 syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
 271
 272                                 if (dhcpv6_poll_reconfigure() > 0)
 273                                         script_call("informed");
 274                         }
 275
 276                         continue;
 277                 }
 278
 279                 // Stateful mode
 280                 if (dhcpv6_request(DHCPV6_MSG_REQUEST) <= 0)
 281                         continue;
 282
 283                 odhcp6c_signal_process();
 284                 script_call("bound");
 285                 bound = true;
 286                 syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
 287 #ifdef EXT_BFD_PING
 288                 if (bfd_interval > 0)
 289                         bfd_start(ifname, bfd_loss, bfd_interval);
 290 #endif
 291
 292                 while (do_signal == 0 || do_signal == SIGUSR1) {
 293                         // Renew Cycle
 294                         // Wait for T1 to expire or until we get a reconfigure
 295                         int res = dhcpv6_poll_reconfigure();
 296                         odhcp6c_signal_process();
 297                         if (res > 0) {
 298                                 script_call("updated");
 299                                 continue;
 300                         }
 301
 302                         // Handle signal, if necessary
 303                         if (do_signal == SIGUSR1)
 304                                 do_signal = 0; // Acknowledged
 305                         else if (do_signal > 0)
 306                                 break; // Other signal type
 307
 308                         size_t ia_pd_len, ia_na_len, ia_pd_new, ia_na_new;
 309                         odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 310                         odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 311
 312                         // If we have any IAs, send renew, otherwise request
 313                         int r;
 314                         if (ia_pd_len == 0 && ia_na_len == 0)
 315                                 r = dhcpv6_request(DHCPV6_MSG_REQUEST);
 316                         else
 317                                 r = dhcpv6_request(DHCPV6_MSG_RENEW);
 318                         odhcp6c_signal_process();
 319                         if (r > 0) { // Renew was succesfull
 320                                 // Publish updates
 321                                 script_call("updated");
 322                                 continue; // Renew was successful
 323                         }
 324
 325                         odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
 326
 327                         // If we have IAs, try rebind otherwise restart
 328                         res = dhcpv6_request(DHCPV6_MSG_REBIND);
 329                         odhcp6c_signal_process();
 330
 331                         odhcp6c_get_state(STATE_IA_PD, &ia_pd_new);
 332                         odhcp6c_get_state(STATE_IA_NA, &ia_na_new);
 333                         if (res <= 0 || (ia_pd_new == 0 && ia_pd_len) ||
 334                                         (ia_na_new == 0 && ia_na_len))
 335                                 break; // We lost all our IAs, restart
 336                         else if (res > 0)
 337                                 script_call("rebound");
 338                 }
 339
 340 #ifdef EXT_BFD_PING
 341                 bfd_stop();
 342 #endif
 343
 344
 345                 size_t ia_pd_len, ia_na_len, server_id_len;
 346                 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 347                 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 348                 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 349
 350                 // Add all prefixes to lost prefixes
 351                 bound = false;
 352                 script_call("unbound");
 353
 354                 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
 355                         dhcpv6_request(DHCPV6_MSG_RELEASE);
 356
 357                 odhcp6c_clear_state(STATE_IA_NA);
 358                 odhcp6c_clear_state(STATE_IA_PD);
 359         }
 360
 361         script_call("stopped");
 362         return 0;
 363 }
 364
 365
 366 static int usage(void)
 367 {
 368         const char buf[] =
 369         "Usage: odhcp6c [options] <interface>\n"
 370         "\nFeature options:\n"
 371         "       -S <time>       Wait at least <time> sec for a DHCP-server (0)\n"
 372         "       -N <mode>       Mode for requesting addresses [try|force|none]\n"
 373         "       -P <length>     Request IPv6-Prefix (0 = auto)\n"
 374         "       -F              Force IPv6-Prefix\n"
 375 #ifdef EXT_BFD_PING
 376         "       -B <interval>   Enable BFD ping check\n"
 377 #endif
 378         "       -c <clientid>   Override client-ID (base-16 encoded)\n"
 379         "       -i <iface-id>   Use a custom interface identifier for RA handling\n"
 380         "       -r <options>    Options to be requested (comma-separated)\n"
 381         "       -s <script>     Status update script (/usr/sbin/odhcp6c-update)\n"
 382         "       -k              Don't send a RELEASE when stopping\n"
 383         "       -t <seconds>    Maximum timeout for DHCPv6-SOLICIT (120)\n"
 384         "\nInvocation options:\n"
 385         "       -p <pidfile>    Set pidfile (/var/run/6relayd.pid)\n"
 386         "       -d              Daemonize\n"
 387         "       -e              Write logmessages to stderr\n"
 388         //"     -v              Increase logging verbosity\n"
 389         "       -h              Show this help\n\n";
 390         write(STDERR_FILENO, buf, sizeof(buf));
 391         return 1;
 392 }
 393
 394
 395 // Don't want to pull-in librt and libpthread just for a monotonic clock...
 396 uint64_t odhcp6c_get_milli_time(void)
 397 {
 398         struct timespec t = {0, 0};
 399         syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
 400         return t.tv_sec * 1000 + t.tv_nsec / 1000000;
 401 }
 402
 403
 404 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
 405 {
 406         if (len == 0)
 407                 return state_data[state] + state_len[state];
 408         else if (state_len[state] + len > 1024)
 409                 return NULL;
 410
 411         uint8_t *n = realloc(state_data[state], state_len[state] + len);
 412         if (n || state_len[state] + len == 0) {
 413                 state_data[state] = n;
 414                 n += state_len[state];
 415                 state_len[state] += len;
 416         }
 417         return n;
 418 }
 419
 420
 421 bool odhcp6c_signal_process(void)
 422 {
 423         if (do_signal == SIGIO) {
 424                 do_signal = 0;
 425                 bool ra_updated = ra_process();
 426
 427                 if (ra_link_up())
 428                         do_signal = SIGUSR2;
 429
 430                 if (ra_updated && (bound || allow_slaac_only == 0))
 431                         script_call("ra-updated"); // Immediate process urgent events
 432                 else if (ra_updated && !bound && allow_slaac_only > 0)
 433                         script_delay_call("ra-updated", allow_slaac_only);
 434
 435 #ifdef EXT_BFD_PING
 436                 bfd_receive();
 437 #endif
 438         }
 439
 440         return do_signal != 0;
 441 }
 442
 443
 444 void odhcp6c_clear_state(enum odhcp6c_state state)
 445 {
 446         state_len[state] = 0;
 447 }
 448
 449
 450 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
 451 {
 452         uint8_t *n = odhcp6c_resize_state(state, len);
 453         if (n)
 454                 memcpy(n, data, len);
 455 }
 456
 457
 458 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
 459 {
 460         uint8_t *data = state_data[state];
 461         ssize_t len_after = state_len[state] - (offset + len);
 462         if (len_after < 0)
 463                 return state_len[state];
 464
 465         memmove(data + offset, data + offset + len, len_after);
 466         return state_len[state] -= len;
 467 }
 468
 469
 470 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
 471 {
 472         *len = state_len[state];
 473         void *data = state_data[state];
 474
 475         state_len[state] = 0;
 476         state_data[state] = NULL;
 477
 478         return data;
 479 }
 480
 481
 482 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
 483 {
 484         *len = state_len[state];
 485         return state_data[state];
 486 }
 487
 488
 489 struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
 490 {
 491         size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + new->length / 8;
 492         struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
 493         struct odhcp6c_entry *x = NULL;
 494
 495         for (struct odhcp6c_entry *c = start; !x && c < &start[len/sizeof(*c)]; ++c)
 496                 if (!memcmp(c, new, cmplen))
 497                         return c;
 498
 499         return NULL;
 500 }
 501
 502
 503 bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
 504 {
 505         size_t len;
 506         struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
 507         struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
 508
 509         if (x && x->valid > new->valid && new->valid < safe)
 510                 new->valid = safe;
 511
 512         if (new->valid > 0) {
 513                 if (x) {
 514                         if (new->valid >= x->valid && new->valid - x->valid < 60 &&
 515                                         new->preferred >= x->preferred &&
 516                                         new->preferred - x->preferred < 60 &&
 517                                         x->class == new->class)
 518                                 return false;
 519                         x->valid = new->valid;
 520                         x->preferred = new->preferred;
 521                         x->t1 = new->t1;
 522                         x->t2 = new->t2;
 523                         x->class = new->class;
 524                 } else {
 525                         odhcp6c_add_state(state, new, sizeof(*new));
 526                 }
 527         } else if (x) {
 528                 odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
 529         }
 530         return true;
 531 }
 532
 533
 534 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
 535 {
 536         return odhcp6c_update_entry_safe(state, new, 0);
 537 }
 538
 539
 540 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
 541 {
 542         size_t len;
 543         struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
 544         for (struct odhcp6c_entry *c = start; c < &start[len / sizeof(*c)]; ++c) {
 545                 if (c->t1 < elapsed)
 546                         c->t1 = 0;
 547                 else if (c->t1 != UINT32_MAX)
 548                         c->t1 -= elapsed;
 549
 550                 if (c->t2 < elapsed)
 551                         c->t2 = 0;
 552                 else if (c->t2 != UINT32_MAX)
 553                         c->t2 -= elapsed;
 554
 555                 if (c->preferred < elapsed)
 556                         c->preferred = 0;
 557                 else if (c->preferred != UINT32_MAX)
 558                         c->preferred -= elapsed;
 559
 560                 if (c->valid < elapsed)
 561                         c->valid = 0;
 562                 else if (c->valid != UINT32_MAX)
 563                         c->valid -= elapsed;
 564
 565                 if (!c->valid)
 566                         odhcp6c_remove_state(state, (c - start) * sizeof(*c), sizeof(*c));
 567         }
 568 }
 569
 570
 571 void odhcp6c_expire(void)
 572 {
 573         time_t now = odhcp6c_get_milli_time() / 1000;
 574         uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 575         last_update = now;
 576
 577         odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
 578         odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
 579         odhcp6c_expire_list(STATE_RA_DNS, elapsed);
 580         odhcp6c_expire_list(STATE_IA_NA, elapsed);
 581         odhcp6c_expire_list(STATE_IA_PD, elapsed);
 582 }
 583
 584
 585 uint32_t odhcp6c_elapsed(void)
 586 {
 587         return odhcp6c_get_milli_time() / 1000 - last_update;
 588 }
 589
 590
 591 void odhcp6c_random(void *buf, size_t len)
 592 {
 593         read(urandom_fd, buf, len);
 594 }
 595
 596
 597 bool odhcp6c_is_bound(void)
 598 {
 599         return bound;
 600 }
 601
 602
 603 bool odhcp6c_addr_in_scope(const struct in6_addr *addr)
 604 {
 605         FILE *fd = fopen("/proc/net/if_inet6", "r");
 606         int len;
 607         char buf[256];
 608
 609         if (fd == NULL)
 610                 return false;
 611
 612         while (fgets(buf, sizeof(buf), fd)) {
 613                 struct in6_addr inet6_addr;
 614                 uint32_t flags, dummy;
 615                 unsigned int i;
 616                 char name[8], addr_buf[32];
 617
 618                 len = strlen(buf);
 619
 620                 if ((len <= 0) || buf[len - 1] != '\n')
 621                         return false;
 622
 623                 buf[--len] = '\0';
 624
 625                 if (sscanf(buf, "%s %x %x %x %x %s",
 626                                 addr_buf, &dummy, &dummy, &dummy, &flags, name) != 6)
 627                         return false;
 628
 629                 if (strcmp(name, ifname) ||
 630                         (flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE | IFA_F_DEPRECATED)))
 631                         continue;
 632
 633                 for (i = 0; i < sizeof(addr_buf); i++) {
 634                         if (!isxdigit(addr_buf[i]) || isupper(addr_buf[i]))
 635                                 return false;
 636                 }
 637
 638                 memset(&inet6_addr, 0, sizeof(inet6_addr));
 639                 for (i = 0; i < (sizeof(addr_buf) / 2); i++) {
 640                         unsigned char byte;
 641                         static const char hex[] = "0123456789abcdef";
 642                         byte = ((index(hex, addr_buf[i * 2]) - hex) << 4) |
 643                                 (index(hex, addr_buf[i * 2 + 1]) - hex);
 644                         inet6_addr.s6_addr[i] = byte;
 645                 }
 646
 647                 if ((IN6_IS_ADDR_LINKLOCAL(&inet6_addr) == IN6_IS_ADDR_LINKLOCAL(addr)) &&
 648                         (IN6_IS_ADDR_UNIQUELOCAL(&inet6_addr) == IN6_IS_ADDR_UNIQUELOCAL(addr)))
 649                         return true;
 650         }
 651         return false;
 652 }
 653
 654 static void sighandler(int signal)
 655 {
 656         if (signal == SIGCHLD)
 657                 while (waitpid(-1, NULL, WNOHANG) > 0);
 658         else if (signal == SIGUSR1)
 659                 do_signal = SIGUSR1;
 660         else if (signal == SIGUSR2)
 661                 do_signal = SIGUSR2;
 662         else if (signal == SIGIO)
 663                 do_signal = SIGIO;
 664         else
 665                 do_signal = SIGTERM;
 666 }