usr.bin/netstat/if.c

   1 /*-
   2  * Copyright (c) 2013 Gleb Smirnoff <glebius@FreeBSD.org>
   3  * Copyright (c) 1983, 1988, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 4. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #if 0
  32 #ifndef lint
  33 static char sccsid[] = "@(#)if.c        8.3 (Berkeley) 4/28/95";
  34 #endif /* not lint */
  35 #endif
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/protosw.h>
  42 #include <sys/socket.h>
  43 #include <sys/socketvar.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/time.h>
  46
  47 #define _IFI_OQDROPS
  48 #include <net/if.h>
  49 #include <net/if_var.h>
  50 #include <net/if_dl.h>
  51 #include <net/if_types.h>
  52 #include <net/ethernet.h>
  53 #include <netinet/in.h>
  54 #include <netinet/in_var.h>
  55 #include <netipx/ipx.h>
  56 #include <netipx/ipx_if.h>
  57 #include <arpa/inet.h>
  58 #ifdef PF
  59 #include <net/pfvar.h>
  60 #include <net/if_pfsync.h>
  61 #endif
  62
  63 #include <err.h>
  64 #include <errno.h>
  65 #include <ifaddrs.h>
  66 #include <libutil.h>
  67 #ifdef INET6
  68 #include <netdb.h>
  69 #endif
  70 #include <signal.h>
  71 #include <stdbool.h>
  72 #include <stdint.h>
  73 #include <stdio.h>
  74 #include <stdlib.h>
  75 #include <string.h>
  76 #include <sysexits.h>
  77 #include <unistd.h>
  78
  79 #include "netstat.h"
  80
  81 static void sidewaysintpr(int);
  82
  83 #ifdef INET6
  84 static char addr_buf[NI_MAXHOST];               /* for getnameinfo() */
  85 #endif
  86
  87 #ifdef PF
  88 static const char* pfsyncacts[] = {
  89         /* PFSYNC_ACT_CLR */            "clear all request",
  90         /* PFSYNC_ACT_INS */            "state insert",
  91         /* PFSYNC_ACT_INS_ACK */        "state inserted ack",
  92         /* PFSYNC_ACT_UPD */            "state update",
  93         /* PFSYNC_ACT_UPD_C */          "compressed state update",
  94         /* PFSYNC_ACT_UPD_REQ */        "uncompressed state request",
  95         /* PFSYNC_ACT_DEL */            "state delete",
  96         /* PFSYNC_ACT_DEL_C */          "compressed state delete",
  97         /* PFSYNC_ACT_INS_F */          "fragment insert",
  98         /* PFSYNC_ACT_DEL_F */          "fragment delete",
  99         /* PFSYNC_ACT_BUS */            "bulk update mark",
 100         /* PFSYNC_ACT_TDB */            "TDB replay counter update",
 101         /* PFSYNC_ACT_EOF */            "end of frame mark",
 102 };
 103
 104 static void
 105 pfsync_acts_stats(const char *fmt, uint64_t *a)
 106 {
 107         int i;
 108
 109         for (i = 0; i < PFSYNC_ACT_MAX; i++, a++)
 110                 if (*a || sflag <= 1)
 111                         printf(fmt, *a, pfsyncacts[i], plural(*a));
 112 }
 113
 114 /*
 115  * Dump pfsync statistics structure.
 116  */
 117 void
 118 pfsync_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 119 {
 120         struct pfsyncstats pfsyncstat, zerostat;
 121         size_t len = sizeof(struct pfsyncstats);
 122
 123         if (live) {
 124                 if (zflag)
 125                         memset(&zerostat, 0, len);
 126                 if (sysctlbyname("net.pfsync.stats", &pfsyncstat, &len,
 127                     zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
 128                         if (errno != ENOENT)
 129                                 warn("sysctl: net.pfsync.stats");
 130                         return;
 131                 }
 132         } else
 133                 kread(off, &pfsyncstat, len);
 134
 135         printf("%s:\n", name);
 136
 137 #define p(f, m) if (pfsyncstat.f || sflag <= 1) \
 138         printf(m, (uintmax_t)pfsyncstat.f, plural(pfsyncstat.f))
 139
 140         p(pfsyncs_ipackets, "\t%ju packet%s received (IPv4)\n");
 141         p(pfsyncs_ipackets6, "\t%ju packet%s received (IPv6)\n");
 142         pfsync_acts_stats("\t    %ju %s%s received\n",
 143             &pfsyncstat.pfsyncs_iacts[0]);
 144         p(pfsyncs_badif, "\t\t%ju packet%s discarded for bad interface\n");
 145         p(pfsyncs_badttl, "\t\t%ju packet%s discarded for bad ttl\n");
 146         p(pfsyncs_hdrops, "\t\t%ju packet%s shorter than header\n");
 147         p(pfsyncs_badver, "\t\t%ju packet%s discarded for bad version\n");
 148         p(pfsyncs_badauth, "\t\t%ju packet%s discarded for bad HMAC\n");
 149         p(pfsyncs_badact,"\t\t%ju packet%s discarded for bad action\n");
 150         p(pfsyncs_badlen, "\t\t%ju packet%s discarded for short packet\n");
 151         p(pfsyncs_badval, "\t\t%ju state%s discarded for bad values\n");
 152         p(pfsyncs_stale, "\t\t%ju stale state%s\n");
 153         p(pfsyncs_badstate, "\t\t%ju failed state lookup/insert%s\n");
 154         p(pfsyncs_opackets, "\t%ju packet%s sent (IPv4)\n");
 155         p(pfsyncs_opackets6, "\t%ju packet%s sent (IPv6)\n");
 156         pfsync_acts_stats("\t    %ju %s%s sent\n",
 157             &pfsyncstat.pfsyncs_oacts[0]);
 158         p(pfsyncs_onomem, "\t\t%ju failure%s due to mbuf memory error\n");
 159         p(pfsyncs_oerrors, "\t\t%ju send error%s\n");
 160 #undef p
 161 }
 162 #endif /* PF */
 163
 164 /*
 165  * Display a formatted value, or a '-' in the same space.
 166  */
 167 static void
 168 show_stat(const char *fmt, int width, u_long value, short showvalue,
 169     int div1000)
 170 {
 171         const char *lsep, *rsep;
 172         char newfmt[32];
 173
 174         lsep = "";
 175         if (strncmp(fmt, "LS", 2) == 0) {
 176                 lsep = " ";
 177                 fmt += 2;
 178         }
 179         rsep = " ";
 180         if (strncmp(fmt, "NRS", 3) == 0) {
 181                 rsep = "";
 182                 fmt += 3;
 183         }
 184         if (showvalue == 0) {
 185                 /* Print just dash. */
 186                 sprintf(newfmt, "%s%%%ds%s", lsep, width, rsep);
 187                 printf(newfmt, "-");
 188                 return;
 189         }
 190
 191         if (hflag) {
 192                 char buf[5];
 193
 194                 /* Format in human readable form. */
 195                 humanize_number(buf, sizeof(buf), (int64_t)value, "",
 196                     HN_AUTOSCALE, HN_NOSPACE | HN_DECIMAL | \
 197                     ((div1000) ? HN_DIVISOR_1000 : 0));
 198                 sprintf(newfmt, "%s%%%ds%s", lsep, width, rsep);
 199                 printf(newfmt, buf);
 200         } else {
 201                 /* Construct the format string. */
 202                 sprintf(newfmt, "%s%%%d%s%s", lsep, width, fmt, rsep);
 203                 printf(newfmt, value);
 204         }
 205 }
 206
 207 /*
 208  * Find next multiaddr for a given interface name.
 209  */
 210 static struct ifmaddrs *
 211 next_ifma(struct ifmaddrs *ifma, const char *name, const sa_family_t family)
 212 {
 213
 214         for(; ifma != NULL; ifma = ifma->ifma_next) {
 215                 struct sockaddr_dl *sdl;
 216
 217                 sdl = (struct sockaddr_dl *)ifma->ifma_name;
 218                 if (ifma->ifma_addr->sa_family == family &&
 219                     strcmp(sdl->sdl_data, name) == 0)
 220                         break;
 221         }
 222
 223         return (ifma);
 224 }
 225
 226 /*
 227  * Print a description of the network interfaces.
 228  */
 229 void
 230 intpr(int interval, void (*pfunc)(char *), int af)
 231 {
 232         struct ifaddrs *ifap, *ifa;
 233         struct ifmaddrs *ifmap, *ifma;
 234         u_int ifn_len_max = 5;
 235
 236         if (interval)
 237                 return sidewaysintpr(interval);
 238
 239         if (getifaddrs(&ifap) != 0)
 240                 err(EX_OSERR, "getifaddrs");
 241         if (aflag && getifmaddrs(&ifmap) != 0)
 242                 err(EX_OSERR, "getifmaddrs");
 243
 244         if (Wflag) {
 245                 for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 246                         if (interface != NULL &&
 247                             strcmp(ifa->ifa_name, interface) != 0)
 248                                 continue;
 249                         if (af != AF_UNSPEC && ifa->ifa_addr->sa_family != af)
 250                                 continue;
 251                         ifn_len_max = MAX(ifn_len_max, strlen(ifa->ifa_name));
 252                 }
 253         }
 254
 255         if (!pfunc) {
 256                 printf("%-*.*s", ifn_len_max, ifn_len_max, "Name");
 257                 printf(" %5.5s %-13.13s %-17.17s %8.8s %5.5s %5.5s",
 258                     "Mtu", "Network", "Address", "Ipkts", "Ierrs", "Idrop");
 259                 if (bflag)
 260                         printf(" %10.10s","Ibytes");
 261                 printf(" %8.8s %5.5s", "Opkts", "Oerrs");
 262                 if (bflag)
 263                         printf(" %10.10s","Obytes");
 264                 printf(" %5s", "Coll");
 265                 if (dflag)
 266                         printf("  %s", "Drop");
 267                 putchar('\n');
 268         }
 269
 270         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 271                 bool network = false, link = false;
 272
 273                 if (interface != NULL && strcmp(ifa->ifa_name, interface) != 0)
 274                         continue;
 275
 276                 if (pfunc) {
 277                         char *name;
 278
 279                         name = ifa->ifa_name;
 280                         (*pfunc)(name);
 281
 282                         /*
 283                          * Skip all ifaddrs belonging to same interface.
 284                          */
 285                         while(ifa->ifa_next != NULL &&
 286                             (strcmp(ifa->ifa_next->ifa_name, name) == 0)) {
 287                                 ifa = ifa->ifa_next;
 288                         }
 289                         continue;
 290                 }
 291
 292                 if (af != AF_UNSPEC && ifa->ifa_addr->sa_family != af)
 293                         continue;
 294
 295                 printf("%-*.*s", ifn_len_max, ifn_len_max, ifa->ifa_name);
 296
 297 #define IFA_MTU(ifa)    (((struct if_data *)(ifa)->ifa_data)->ifi_mtu)
 298                 show_stat("lu", 6, IFA_MTU(ifa), IFA_MTU(ifa), 0);
 299 #undef IFA_MTU
 300
 301                 switch (ifa->ifa_addr->sa_family) {
 302                 case AF_UNSPEC:
 303                         printf("%-13.13s ", "none");
 304                         printf("%-15.15s ", "none");
 305                         break;
 306                 case AF_INET:
 307                     {
 308                         struct sockaddr_in *sin, *mask;
 309
 310                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 311                         mask = (struct sockaddr_in *)ifa->ifa_netmask;
 312                         printf("%-13.13s ", netname(sin->sin_addr.s_addr,
 313                             mask->sin_addr.s_addr));
 314                         printf("%-17.17s ",
 315                             routename(sin->sin_addr.s_addr));
 316
 317                         network = true;
 318                         break;
 319                     }
 320 #ifdef INET6
 321                 case AF_INET6:
 322                     {
 323                         struct sockaddr_in6 *sin6, *mask;
 324
 325                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 326                         mask = (struct sockaddr_in6 *)ifa->ifa_netmask;
 327
 328                         printf("%-13.13s ", netname6(sin6, &mask->sin6_addr));
 329                         getnameinfo(ifa->ifa_addr, ifa->ifa_addr->sa_len,
 330                             addr_buf, sizeof(addr_buf), 0, 0, NI_NUMERICHOST);
 331                         printf("%-17.17s ", addr_buf);
 332
 333                         network = 1;
 334                         break;
 335                     }
 336 #endif /* INET6 */
 337                 case AF_IPX:
 338                     {
 339                         struct sockaddr_ipx *sipx;
 340                         u_long net;
 341                         char netnum[10];
 342
 343                         sipx = (struct sockaddr_ipx *)ifa->ifa_addr;
 344                         *(union ipx_net *) &net = sipx->sipx_addr.x_net;
 345
 346                         sprintf(netnum, "%lx", (u_long)ntohl(net));
 347                         printf("ipx:%-8s  ", netnum);
 348                         printf("%-17s ", ipx_phost((struct sockaddr *)sipx));
 349
 350                         network = 1;
 351                         break;
 352                     }
 353                 case AF_APPLETALK:
 354                         printf("atalk:%-12.12s ",
 355                             atalk_print(ifa->ifa_addr, 0x10));
 356                         printf("%-11.11s  ",
 357                             atalk_print(ifa->ifa_addr, 0x0b));
 358                         break;
 359                 case AF_LINK:
 360                     {
 361                         struct sockaddr_dl *sdl;
 362                         char *cp, linknum[10];
 363                         int n, m;
 364
 365                         sdl = (struct sockaddr_dl *)ifa->ifa_addr;
 366                         cp = (char *)LLADDR(sdl);
 367                         n = sdl->sdl_alen;
 368                         sprintf(linknum, "<Link#%d>", sdl->sdl_index);
 369                         m = printf("%-13.13s ", linknum);
 370
 371                         while ((--n >= 0) && (m < 30))
 372                                 m += printf("%02x%c", *cp++ & 0xff,
 373                                             n > 0 ? ':' : ' ');
 374                         m = 32 - m;
 375                         while (m-- > 0)
 376                                 putchar(' ');
 377
 378                         link = 1;
 379                         break;
 380                     }
 381                 }
 382
 383 #define IFA_STAT(s)     (((struct if_data *)ifa->ifa_data)->ifi_ ## s)
 384                 show_stat("lu", 8, IFA_STAT(ipackets), link|network, 1);
 385                 show_stat("lu", 5, IFA_STAT(ierrors), link, 1);
 386                 show_stat("lu", 5, IFA_STAT(iqdrops), link, 1);
 387                 if (bflag)
 388                         show_stat("lu", 10, IFA_STAT(ibytes), link|network, 0);
 389                 show_stat("lu", 8, IFA_STAT(opackets), link|network, 1);
 390                 show_stat("lu", 5, IFA_STAT(oerrors), link, 1);
 391                 if (bflag)
 392                         show_stat("lu", 10, IFA_STAT(obytes), link|network, 0);
 393                 show_stat("NRSlu", 5, IFA_STAT(collisions), link, 1);
 394                 if (dflag)
 395                         show_stat("LSlu", 5, IFA_STAT(oqdrops), link, 1);
 396                 putchar('\n');
 397
 398                 if (!aflag)
 399                         continue;
 400
 401                 /*
 402                  * Print family's multicast addresses.
 403                  */
 404                 for (ifma = next_ifma(ifmap, ifa->ifa_name,
 405                      ifa->ifa_addr->sa_family);
 406                      ifma != NULL;
 407                      ifma = next_ifma(ifma, ifa->ifa_name,
 408                      ifa->ifa_addr->sa_family)) {
 409                         const char *fmt = NULL;
 410
 411                         switch (ifma->ifma_addr->sa_family) {
 412                         case AF_INET:
 413                             {
 414                                 struct sockaddr_in *sin;
 415
 416                                 sin = (struct sockaddr_in *)ifma->ifma_addr;
 417                                 fmt = routename(sin->sin_addr.s_addr);
 418                                 break;
 419                             }
 420 #ifdef INET6
 421                         case AF_INET6:
 422
 423                                 /* in6_fillscopeid(&msa.in6); */
 424                                 getnameinfo(ifma->ifma_addr,
 425                                     ifma->ifma_addr->sa_len, addr_buf,
 426                                     sizeof(addr_buf), 0, 0, NI_NUMERICHOST);
 427                                 printf("%*s %s\n",
 428                                     Wflag ? 27 : 25, "", addr_buf);
 429                                 break;
 430 #endif /* INET6 */
 431                         case AF_LINK:
 432                             {
 433                                 struct sockaddr_dl *sdl;
 434
 435                                 sdl = (struct sockaddr_dl *)ifma->ifma_addr;
 436                                 switch (sdl->sdl_type) {
 437                                 case IFT_ETHER:
 438                                 case IFT_FDDI:
 439                                         fmt = ether_ntoa(
 440                                             (struct ether_addr *)LLADDR(sdl));
 441                                         break;
 442                                 }
 443                                 break;
 444                             }
 445                         }
 446
 447                         if (fmt) {
 448                                 printf("%*s %-17.17s",
 449                                     Wflag ? 27 : 25, "", fmt);
 450                                 if (ifma->ifma_addr->sa_family == AF_LINK) {
 451                                         printf(" %8lu", IFA_STAT(imcasts));
 452                                         printf("%*s", bflag ? 17 : 6, "");
 453                                         printf(" %8lu", IFA_STAT(omcasts));
 454                                 }
 455                                 putchar('\n');
 456                         }
 457
 458                         ifma = ifma->ifma_next;
 459                 }
 460         }
 461
 462         freeifaddrs(ifap);
 463         if (aflag)
 464                 freeifmaddrs(ifmap);
 465 }
 466
 467 struct iftot {
 468         u_long  ift_ip;                 /* input packets */
 469         u_long  ift_ie;                 /* input errors */
 470         u_long  ift_id;                 /* input drops */
 471         u_long  ift_op;                 /* output packets */
 472         u_long  ift_oe;                 /* output errors */
 473         u_long  ift_od;                 /* output drops */
 474         u_long  ift_co;                 /* collisions */
 475         u_long  ift_ib;                 /* input bytes */
 476         u_long  ift_ob;                 /* output bytes */
 477 };
 478
 479 /*
 480  * Obtain stats for interface(s).
 481  */
 482 static void
 483 fill_iftot(struct iftot *st)
 484 {
 485         struct ifaddrs *ifap, *ifa;
 486         bool found = false;
 487
 488         if (getifaddrs(&ifap) != 0)
 489                 err(EX_OSERR, "getifaddrs");
 490
 491         bzero(st, sizeof(*st));
 492
 493         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 494                 if (ifa->ifa_addr->sa_family != AF_LINK)
 495                         continue;
 496                 if (interface) {
 497                         if (strcmp(ifa->ifa_name, interface) == 0)
 498                                 found = true;
 499                         else
 500                                 continue;
 501                 }
 502
 503                 st->ift_ip += IFA_STAT(ipackets);
 504                 st->ift_ie += IFA_STAT(ierrors);
 505                 st->ift_id += IFA_STAT(iqdrops);
 506                 st->ift_ib += IFA_STAT(ibytes);
 507                 st->ift_op += IFA_STAT(opackets);
 508                 st->ift_oe += IFA_STAT(oerrors);
 509                 st->ift_od += IFA_STAT(oqdrops);
 510                 st->ift_ob += IFA_STAT(obytes);
 511                 st->ift_co += IFA_STAT(collisions);
 512         }
 513
 514         if (interface && found == false)
 515                 err(EX_DATAERR, "interface %s not found", interface);
 516
 517         freeifaddrs(ifap);
 518 }
 519
 520 /*
 521  * Set a flag to indicate that a signal from the periodic itimer has been
 522  * caught.
 523  */
 524 static sig_atomic_t signalled;
 525 static void
 526 catchalarm(int signo __unused)
 527 {
 528         signalled = true;
 529 }
 530
 531 /*
 532  * Print a running summary of interface statistics.
 533  * Repeat display every interval seconds, showing statistics
 534  * collected over that interval.  Assumes that interval is non-zero.
 535  * First line printed at top of screen is always cumulative.
 536  */
 537 static void
 538 sidewaysintpr(int interval)
 539 {
 540         struct iftot ift[2], *new, *old;
 541         struct itimerval interval_it;
 542         int oldmask, line;
 543
 544         new = &ift[0];
 545         old = &ift[1];
 546         fill_iftot(old);
 547
 548         (void)signal(SIGALRM, catchalarm);
 549         signalled = false;
 550         interval_it.it_interval.tv_sec = interval;
 551         interval_it.it_interval.tv_usec = 0;
 552         interval_it.it_value = interval_it.it_interval;
 553         setitimer(ITIMER_REAL, &interval_it, NULL);
 554
 555 banner:
 556         printf("%17s %14s %16s", "input",
 557             interface != NULL ? interface : "(Total)", "output");
 558         putchar('\n');
 559         printf("%10s %5s %5s %10s %10s %5s %10s %5s",
 560             "packets", "errs", "idrops", "bytes", "packets", "errs", "bytes",
 561             "colls");
 562         if (dflag)
 563                 printf(" %5.5s", "drops");
 564         putchar('\n');
 565         fflush(stdout);
 566         line = 0;
 567
 568 loop:
 569         if ((noutputs != 0) && (--noutputs == 0))
 570                 exit(0);
 571         oldmask = sigblock(sigmask(SIGALRM));
 572         while (!signalled)
 573                 sigpause(0);
 574         signalled = false;
 575         sigsetmask(oldmask);
 576         line++;
 577
 578         fill_iftot(new);
 579
 580         show_stat("lu", 10, new->ift_ip - old->ift_ip, 1, 1);
 581         show_stat("lu", 5, new->ift_ie - old->ift_ie, 1, 1);
 582         show_stat("lu", 5, new->ift_id - old->ift_id, 1, 1);
 583         show_stat("lu", 10, new->ift_ib - old->ift_ib, 1, 0);
 584         show_stat("lu", 10, new->ift_op - old->ift_op, 1, 1);
 585         show_stat("lu", 5, new->ift_oe - old->ift_oe, 1, 1);
 586         show_stat("lu", 10, new->ift_ob - old->ift_ob, 1, 0);
 587         show_stat("NRSlu", 5, new->ift_co - old->ift_co, 1, 1);
 588         if (dflag)
 589                 show_stat("LSlu", 5, new->ift_od - old->ift_od, 1, 1);
 590         putchar('\n');
 591         fflush(stdout);
 592
 593         if (new == &ift[0]) {
 594                 new = &ift[1];
 595                 old = &ift[0];
 596         } else {
 597                 new = &ift[0];
 598                 old = &ift[1];
 599         }
 600
 601         if (line == 21)
 602                 goto banner;
 603         else
 604                 goto loop;
 605
 606         /* NOTREACHED */
 607 }