usr.bin/netstat/if.c

   1 /*
   2  * Copyright (c) 1983, 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)if.c     8.3 (Berkeley) 4/28/95
  34  * $FreeBSD: src/usr.bin/netstat/if.c,v 1.32.2.9 2001/09/17 14:35:46 ru Exp $
  35  */
  36
  37 #define _KERNEL_STRUCTURES
  38 #include <sys/param.h>
  39 #include <sys/protosw.h>
  40 #include <sys/socket.h>
  41 #include <sys/sysctl.h>
  42 #include <sys/time.h>
  43
  44 #include <net/if.h>
  45 #include <net/if_var.h>
  46 #include <net/if_dl.h>
  47 #include <net/if_types.h>
  48 #include <net/ethernet.h>
  49 #include <netinet/in.h>
  50 #include <netinet/in_var.h>
  51 #include <netproto/ipx/ipx.h>
  52 #include <netproto/ipx/ipx_if.h>
  53 #ifdef ISO
  54 #include <netiso/iso.h>
  55 #include <netiso/iso_var.h>
  56 #endif
  57 #include <arpa/inet.h>
  58
  59 #include <signal.h>
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <string.h>
  63 #include <unistd.h>
  64
  65 #include "netstat.h"
  66
  67 #define YES     1
  68 #define NO      0
  69
  70 static void sidewaysintpr (u_int, u_long);
  71 static void catchalarm (int);
  72
  73 #ifdef INET6
  74 static char ntop_buf[INET6_ADDRSTRLEN];         /* for inet_ntop() */
  75 #endif
  76
  77
  78 /*
  79  * Display a formatted value, or a '-' in the same space.
  80  */
  81 static void
  82 show_stat(const char *fmt, int width, u_long value, short showvalue)
  83 {
  84         char newfmt[32];
  85
  86         /* Construct the format string */
  87         if (showvalue) {
  88                 sprintf(newfmt, "%%%d%s", width, fmt);
  89                 printf(newfmt, value);
  90         } else {
  91                 sprintf(newfmt, "%%%ds", width);
  92                 printf(newfmt, "-");
  93         }
  94 }
  95
  96
  97
  98 /*
  99  * Print a description of the network interfaces.
 100  */
 101 void
 102 intpr(int interval1, u_long ifnetaddr, void (*pfunc)(char *))
 103 {
 104         struct ifnet ifnet;
 105         struct ifaddr_container ifac;
 106         struct ifnethead ifnethead;
 107         union {
 108                 struct ifaddr ifa;
 109                 struct in_ifaddr in;
 110 #ifdef INET6
 111                 struct in6_ifaddr in6;
 112 #endif
 113                 struct ipx_ifaddr ipx;
 114 #ifdef ISO
 115                 struct iso_ifaddr iso;
 116 #endif
 117         } ifaddr;
 118         u_long ifaddraddr;
 119         u_long ifaddrcont_addr;
 120         u_long ifaddrfound;
 121         u_long opackets;
 122         u_long ipackets;
 123         u_long obytes;
 124         u_long ibytes;
 125         u_long oerrors;
 126         u_long ierrors;
 127         u_long collisions;
 128         short timer;
 129         int drops;
 130         struct sockaddr *sa = NULL;
 131         char name[IFNAMSIZ];
 132         short network_layer;
 133         short link_layer;
 134
 135         if (ifnetaddr == 0) {
 136                 printf("ifnet: symbol not defined\n");
 137                 return;
 138         }
 139         if (interval1) {
 140                 sidewaysintpr((unsigned)interval1, ifnetaddr);
 141                 return;
 142         }
 143         if (kread(ifnetaddr, (char *)&ifnethead, sizeof ifnethead))
 144                 return;
 145         ifnetaddr = (u_long)TAILQ_FIRST(&ifnethead);
 146         if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
 147                 return;
 148
 149         if (!pfunc) {
 150                 printf("%-7.7s %-5.5s %-13.13s %-15.15s %8.8s %5.5s",
 151                        "Name", "Mtu", "Network", "Address", "Ipkts", "Ierrs");
 152                 if (bflag)
 153                         printf(" %10.10s","Ibytes");
 154                 printf(" %8.8s %5.5s", "Opkts", "Oerrs");
 155                 if (bflag)
 156                         printf(" %10.10s","Obytes");
 157                 printf(" %5s", "Coll");
 158                 if (tflag)
 159                         printf(" %s", "Time");
 160                 if (dflag)
 161                         printf(" %s", "Drop");
 162                 putchar('\n');
 163         }
 164         ifaddraddr = 0;
 165         while (ifnetaddr || ifaddraddr) {
 166                 struct sockaddr_in *sin;
 167 #ifdef INET6
 168                 struct sockaddr_in6 *sin6;
 169 #endif
 170                 char *cp;
 171                 int n, m;
 172
 173                 network_layer = 0;
 174                 link_layer = 0;
 175
 176                 if (ifaddraddr == 0) {
 177                         struct ifaddrhead head;
 178
 179                         if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
 180                                 return;
 181                         strlcpy(name, ifnet.if_xname, sizeof(name));
 182                         ifnetaddr = (u_long)TAILQ_NEXT(&ifnet, if_link);
 183                         if (interface != 0 && (strcmp(name, interface) != 0))
 184                                 continue;
 185                         cp = strchr(name, '\0');
 186
 187                         if (pfunc) {
 188                                 (*pfunc)(name);
 189                                 continue;
 190                         }
 191
 192                         if ((ifnet.if_flags&IFF_UP) == 0)
 193                                 *cp++ = '*';
 194                         *cp = '\0';
 195
 196                         if (kread((u_long)ifnet.if_addrheads,
 197                                   (char *)&head, sizeof(head)))
 198                                 return;
 199
 200                         ifaddrcont_addr =
 201                                 (u_long)TAILQ_FIRST(&head);
 202                         if (ifaddrcont_addr == 0) {
 203                                 ifaddraddr = 0;
 204                         } else {
 205                                 if (kread(ifaddrcont_addr, (char *)&ifac,
 206                                           sizeof(ifac)))
 207                                         return;
 208                                 ifaddraddr = (u_long)ifac.ifa;
 209                         }
 210                 }
 211                 ifaddrfound = ifaddraddr;
 212
 213                 /*
 214                  * Get the interface stats.  These may get
 215                  * overriden below on a per-interface basis.
 216                  */
 217                 opackets = ifnet.if_opackets;
 218                 ipackets = ifnet.if_ipackets;
 219                 obytes = ifnet.if_obytes;
 220                 ibytes = ifnet.if_ibytes;
 221                 oerrors = ifnet.if_oerrors;
 222                 ierrors = ifnet.if_ierrors;
 223                 collisions = ifnet.if_collisions;
 224                 timer = ifnet.if_timer;
 225                 drops = ifnet.if_snd.ifq_drops;
 226
 227                 if (ifaddraddr == 0) {
 228                         printf("%-7.7s %-5lu ", name, ifnet.if_mtu);
 229                         printf("%-13.13s ", "none");
 230                         printf("%-15.15s ", "none");
 231                 } else {
 232                         if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
 233                                 ifaddraddr = 0;
 234                                 continue;
 235                         }
 236 #define CP(x) ((char *)(x))
 237                         cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
 238                                 CP(&ifaddr);
 239                         sa = (struct sockaddr *)cp;
 240                         if (af != AF_UNSPEC && sa->sa_family != af) {
 241                                 ifaddrcont_addr =
 242                                         (u_long)TAILQ_NEXT(&ifac, ifa_link);
 243                                 if (ifaddrcont_addr == 0) {
 244                                         ifaddraddr = 0;
 245                                 } else {
 246                                         if (kread(ifaddrcont_addr,
 247                                             (char *)&ifac, sizeof(ifac))) {
 248                                                 ifaddraddr = 0;
 249                                                 continue;
 250                                         }
 251                                         ifaddraddr = (u_long)ifac.ifa;
 252                                 }
 253                                 continue;
 254                         }
 255                         printf("%-7.7s %-5lu ", name, ifnet.if_mtu);
 256                         switch (sa->sa_family) {
 257                         case AF_UNSPEC:
 258                                 printf("%-13.13s ", "none");
 259                                 printf("%-15.15s ", "none");
 260                                 break;
 261                         case AF_INET:
 262                                 sin = (struct sockaddr_in *)sa;
 263 #ifdef notdef
 264                                 /* can't use inet_makeaddr because kernel
 265                                  * keeps nets unshifted.
 266                                  */
 267                                 in = inet_makeaddr(ifaddr.in.ia_subnet,
 268                                         INADDR_ANY);
 269                                 printf("%-13.13s ", netname(in.s_addr,
 270                                     ifaddr.in.ia_subnetmask));
 271 #else
 272                                 printf("%-13.13s ",
 273                                     netname(htonl(ifaddr.in.ia_subnet),
 274                                     ifaddr.in.ia_subnetmask));
 275 #endif
 276                                 printf("%-15.15s ",
 277                                     routename(sin->sin_addr.s_addr));
 278
 279                                 network_layer = 1;
 280                                 break;
 281 #ifdef INET6
 282                         case AF_INET6:
 283                                 sin6 = (struct sockaddr_in6 *)sa;
 284                                 printf("%-11.11s ",
 285                                        netname6(&ifaddr.in6.ia_addr,
 286                                                 &ifaddr.in6.ia_prefixmask.sin6_addr));
 287                                 printf("%-17.17s ",
 288                                     inet_ntop(AF_INET6,
 289                                         &sin6->sin6_addr,
 290                                         ntop_buf, sizeof(ntop_buf)));
 291
 292                                 network_layer = 1;
 293                                 break;
 294 #endif /*INET6*/
 295                         case AF_IPX:
 296                                 {
 297                                 struct sockaddr_ipx *sipx =
 298                                         (struct sockaddr_ipx *)sa;
 299                                 u_long net;
 300                                 char netnum[10];
 301
 302                                 *(union ipx_net *) &net = sipx->sipx_addr.x_net;
 303                                 sprintf(netnum, "%lx", (u_long)ntohl(net));
 304                                 printf("ipx:%-8s  ", netnum);
 305 /*                              printf("ipx:%-8s ", netname(net, 0L)); */
 306                                 printf("%-15s ",
 307                                     ipx_phost((struct sockaddr *)sipx));
 308                                 }
 309                                 break;
 310
 311                         case AF_LINK:
 312                                 {
 313                                 struct sockaddr_dl *sdl =
 314                                         (struct sockaddr_dl *)sa;
 315                                 char linknum[10];
 316                                 cp = (char *)LLADDR(sdl);
 317                                 n = sdl->sdl_alen;
 318                                 sprintf(linknum, "<Link#%d>", sdl->sdl_index);
 319                                 m = printf("%-11.11s ", linknum);
 320                                 }
 321                                 goto hexprint;
 322                         default:
 323                                 m = printf("(%d)", sa->sa_family);
 324                                 for (cp = sa->sa_len + (char *)sa;
 325                                         --cp > sa->sa_data && (*cp == 0);) {}
 326                                 n = cp - sa->sa_data + 1;
 327                                 cp = sa->sa_data;
 328                         hexprint:
 329                                 while (--n >= 0)
 330                                         m += printf("%02x%c", *cp++ & 0xff,
 331                                                     n > 0 ? ':' : ' ');
 332                                 m = 30 - m;
 333                                 while (m-- > 0)
 334                                         putchar(' ');
 335
 336                                 link_layer = 1;
 337                                 break;
 338                         }
 339
 340                         /*
 341                          * Fixup the statistics for interfaces that
 342                          * update stats for their network addresses
 343                          */
 344                         if (network_layer) {
 345                                 opackets = ifaddr.in.ia_ifa.if_opackets;
 346                                 ipackets = ifaddr.in.ia_ifa.if_ipackets;
 347                                 obytes = ifaddr.in.ia_ifa.if_obytes;
 348                                 ibytes = ifaddr.in.ia_ifa.if_ibytes;
 349                         }
 350
 351                         ifaddrcont_addr =
 352                                 (u_long)TAILQ_NEXT(&ifac, ifa_link);
 353                         if (ifaddrcont_addr == 0) {
 354                                 ifaddraddr = 0;
 355                         } else {
 356                                 if (kread(ifaddrcont_addr,
 357                                     (char *)&ifac, sizeof(ifac))) {
 358                                         ifaddraddr = 0;
 359                                 } else {
 360                                         ifaddraddr = (u_long)ifac.ifa;
 361                                 }
 362                         }
 363                 }
 364
 365                 show_stat("lu", 8, ipackets, link_layer|network_layer);
 366                 printf(" ");
 367                 show_stat("lu", 5, ierrors, link_layer);
 368                 printf(" ");
 369                 if (bflag) {
 370                         show_stat("lu", 10, ibytes, link_layer|network_layer);
 371                         printf(" ");
 372                 }
 373                 show_stat("lu", 8, opackets, link_layer|network_layer);
 374                 printf(" ");
 375                 show_stat("lu", 5, oerrors, link_layer);
 376                 printf(" ");
 377                 if (bflag) {
 378                         show_stat("lu", 10, obytes, link_layer|network_layer);
 379                         printf(" ");
 380                 }
 381                 show_stat("lu", 5, collisions, link_layer);
 382                 if (tflag) {
 383                         printf(" ");
 384                         show_stat("d", 3, timer, link_layer);
 385                 }
 386                 if (dflag) {
 387                         printf(" ");
 388                         show_stat("d", 3, drops, link_layer);
 389                 }
 390                 putchar('\n');
 391                 if (aflag && ifaddrfound) {
 392                         /*
 393                          * Print family's multicast addresses
 394                          */
 395                         struct ifmultiaddr *multiaddr;
 396                         struct ifmultiaddr ifma;
 397                         union {
 398                                 struct sockaddr sa;
 399                                 struct sockaddr_in in;
 400 #ifdef INET6
 401                                 struct sockaddr_in6 in6;
 402 #endif /* INET6 */
 403                                 struct sockaddr_dl dl;
 404                         } msa;
 405                         const char *fmt;
 406
 407                         TAILQ_FOREACH(multiaddr, &ifnet.if_multiaddrs, ifma_link) {
 408                                 if (kread((u_long)multiaddr, (char *)&ifma,
 409                                           sizeof ifma))
 410                                         break;
 411                                 multiaddr = &ifma;
 412                                 if (kread((u_long)ifma.ifma_addr, (char *)&msa,
 413                                           sizeof msa))
 414                                         break;
 415                                 if (msa.sa.sa_family != sa->sa_family)
 416                                         continue;
 417
 418                                 fmt = NULL;
 419                                 switch (msa.sa.sa_family) {
 420                                 case AF_INET:
 421                                         fmt = routename(msa.in.sin_addr.s_addr);
 422                                         break;
 423 #ifdef INET6
 424                                 case AF_INET6:
 425                                         printf("%23s %-19.19s(refs: %d)\n", "",
 426                                                inet_ntop(AF_INET6,
 427                                                          &msa.in6.sin6_addr,
 428                                                          ntop_buf,
 429                                                          sizeof(ntop_buf)),
 430                                                ifma.ifma_refcount);
 431                                         break;
 432 #endif /* INET6 */
 433                                 case AF_LINK:
 434                                         switch (msa.dl.sdl_type) {
 435                                         case IFT_ETHER:
 436                                         case IFT_FDDI:
 437                                                 fmt = ether_ntoa(
 438                                                         (struct ether_addr *)
 439                                                         LLADDR(&msa.dl));
 440                                                 break;
 441                                         }
 442                                         break;
 443                                 }
 444                                 if (fmt)
 445                                         printf("%23s %s\n", "", fmt);
 446                         }
 447                 }
 448         }
 449 }
 450
 451 struct  iftot {
 452         SLIST_ENTRY(iftot) chain;
 453         char    ift_name[IFNAMSIZ];     /* interface name */
 454         u_long  ift_ip;                 /* input packets */
 455         u_long  ift_ie;                 /* input errors */
 456         u_long  ift_op;                 /* output packets */
 457         u_long  ift_oe;                 /* output errors */
 458         u_long  ift_co;                 /* collisions */
 459         u_int   ift_dr;                 /* drops */
 460         u_long  ift_ib;                 /* input bytes */
 461         u_long  ift_ob;                 /* output bytes */
 462 };
 463
 464 u_char  signalled;                      /* set if alarm goes off "early" */
 465
 466 /*
 467  * Print a running summary of interface statistics.
 468  * Repeat display every interval1 seconds, showing statistics
 469  * collected over that interval.  Assumes that interval1 is non-zero.
 470  * First line printed at top of screen is always cumulative.
 471  * XXX - should be rewritten to use ifmib(4).
 472  */
 473 static void
 474 sidewaysintpr(unsigned interval1, u_long off)
 475 {
 476         struct ifnet ifnet;
 477         u_long firstifnet;
 478         struct ifnethead ifnethead;
 479         struct iftot *iftot, *ip, *ipn, *total, *sum, *interesting;
 480         int line;
 481         int oldmask, first;
 482         u_long interesting_off;
 483
 484         if (kread(off, (char *)&ifnethead, sizeof ifnethead))
 485                 return;
 486         firstifnet = (u_long)TAILQ_FIRST(&ifnethead);
 487
 488         if ((iftot = malloc(sizeof(struct iftot))) == NULL) {
 489                 printf("malloc failed\n");
 490                 exit(1);
 491         }
 492         memset(iftot, 0, sizeof(struct iftot));
 493
 494         interesting = NULL;
 495         interesting_off = 0;
 496         for (off = firstifnet, ip = iftot; off;) {
 497                 char name[IFNAMSIZ];
 498
 499                 if (kread(off, (char *)&ifnet, sizeof ifnet))
 500                         break;
 501                 strlcpy(name, ifnet.if_xname, sizeof(name));
 502                 if (interface && strcmp(name, interface) == 0) {
 503                         interesting = ip;
 504                         interesting_off = off;
 505                 }
 506                 snprintf(ip->ift_name, 16, "(%s)", name);
 507                 if ((ipn = malloc(sizeof(struct iftot))) == NULL) {
 508                         printf("malloc failed\n");
 509                         exit(1);
 510                 }
 511                 memset(ipn, 0, sizeof(struct iftot));
 512                 SLIST_NEXT(ip, chain) = ipn;
 513                 ip = ipn;
 514                 off = (u_long)TAILQ_NEXT(&ifnet, if_link);
 515         }
 516         if ((total = malloc(sizeof(struct iftot))) == NULL) {
 517                 printf("malloc failed\n");
 518                 exit(1);
 519         }
 520         memset(total, 0, sizeof(struct iftot));
 521         if ((sum = malloc(sizeof(struct iftot))) == NULL) {
 522                 printf("malloc failed\n");
 523                 exit(1);
 524         }
 525         memset(sum, 0, sizeof(struct iftot));
 526
 527
 528         (void)signal(SIGALRM, catchalarm);
 529         signalled = NO;
 530         (void)alarm(interval1);
 531         first = 1;
 532 banner:
 533         printf("%17s %14s %16s", "input",
 534             interesting ? interesting->ift_name : "(Total)", "output");
 535         putchar('\n');
 536         printf("%10s %5s %10s %10s %5s %10s %5s",
 537             "packets", "errs", "bytes", "packets", "errs", "bytes", "colls");
 538         if (dflag)
 539                 printf(" %5.5s", "drops");
 540         putchar('\n');
 541         fflush(stdout);
 542         line = 0;
 543 loop:
 544         if (interesting != NULL) {
 545                 ip = interesting;
 546                 if (kread(interesting_off, (char *)&ifnet, sizeof ifnet)) {
 547                         printf("???\n");
 548                         exit(1);
 549                 }
 550                 if (!first) {
 551                         printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
 552                                 ifnet.if_ipackets - ip->ift_ip,
 553                                 ifnet.if_ierrors - ip->ift_ie,
 554                                 ifnet.if_ibytes - ip->ift_ib,
 555                                 ifnet.if_opackets - ip->ift_op,
 556                                 ifnet.if_oerrors - ip->ift_oe,
 557                                 ifnet.if_obytes - ip->ift_ob,
 558                                 ifnet.if_collisions - ip->ift_co);
 559                         if (dflag)
 560                                 printf(" %5u", ifnet.if_snd.ifq_drops - ip->ift_dr);
 561                 }
 562                 ip->ift_ip = ifnet.if_ipackets;
 563                 ip->ift_ie = ifnet.if_ierrors;
 564                 ip->ift_ib = ifnet.if_ibytes;
 565                 ip->ift_op = ifnet.if_opackets;
 566                 ip->ift_oe = ifnet.if_oerrors;
 567                 ip->ift_ob = ifnet.if_obytes;
 568                 ip->ift_co = ifnet.if_collisions;
 569                 ip->ift_dr = ifnet.if_snd.ifq_drops;
 570         } else {
 571                 sum->ift_ip = 0;
 572                 sum->ift_ie = 0;
 573                 sum->ift_ib = 0;
 574                 sum->ift_op = 0;
 575                 sum->ift_oe = 0;
 576                 sum->ift_ob = 0;
 577                 sum->ift_co = 0;
 578                 sum->ift_dr = 0;
 579                 for (off = firstifnet, ip = iftot;
 580                      off && SLIST_NEXT(ip, chain) != NULL;
 581                      ip = SLIST_NEXT(ip, chain)) {
 582                         if (kread(off, (char *)&ifnet, sizeof ifnet)) {
 583                                 off = 0;
 584                                 continue;
 585                         }
 586                         sum->ift_ip += ifnet.if_ipackets;
 587                         sum->ift_ie += ifnet.if_ierrors;
 588                         sum->ift_ib += ifnet.if_ibytes;
 589                         sum->ift_op += ifnet.if_opackets;
 590                         sum->ift_oe += ifnet.if_oerrors;
 591                         sum->ift_ob += ifnet.if_obytes;
 592                         sum->ift_co += ifnet.if_collisions;
 593                         sum->ift_dr += ifnet.if_snd.ifq_drops;
 594                         off = (u_long)TAILQ_NEXT(&ifnet, if_link);
 595                 }
 596                 if (!first) {
 597                         printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
 598                                 sum->ift_ip - total->ift_ip,
 599                                 sum->ift_ie - total->ift_ie,
 600                                 sum->ift_ib - total->ift_ib,
 601                                 sum->ift_op - total->ift_op,
 602                                 sum->ift_oe - total->ift_oe,
 603                                 sum->ift_ob - total->ift_ob,
 604                                 sum->ift_co - total->ift_co);
 605                         if (dflag)
 606                                 printf(" %5u", sum->ift_dr - total->ift_dr);
 607                 }
 608                 *total = *sum;
 609         }
 610         if (!first)
 611                 putchar('\n');
 612         fflush(stdout);
 613         oldmask = sigblock(sigmask(SIGALRM));
 614         if (! signalled) {
 615                 sigpause(0);
 616         }
 617         sigsetmask(oldmask);
 618         signalled = NO;
 619         (void)alarm(interval1);
 620         line++;
 621         first = 0;
 622         if (line == 21)
 623                 goto banner;
 624         else
 625                 goto loop;
 626         /*NOTREACHED*/
 627 }
 628
 629 /*
 630  * Called if an interval expires before sidewaysintpr has completed a loop.
 631  * Sets a flag to not wait for the alarm.
 632  */
 633 static void
 634 catchalarm(int signo __unused)
 635 {
 636         signalled = YES;
 637 }