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  * $DragonFly: src/usr.bin/netstat/if.c,v 1.12 2008/03/07 11:34:21 sephe Exp $
  36  */
  37
  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 NS
  54 #include <netproto/ns/ns.h>
  55 #include <netproto/ns/ns_if.h>
  56 #endif
  57 #ifdef ISO
  58 #include <netiso/iso.h>
  59 #include <netiso/iso_var.h>
  60 #endif
  61 #include <arpa/inet.h>
  62
  63 #include <signal.h>
  64 #include <stdio.h>
  65 #include <stdlib.h>
  66 #include <string.h>
  67 #include <unistd.h>
  68
  69 #include "netstat.h"
  70
  71 #define YES     1
  72 #define NO      0
  73
  74 static void sidewaysintpr (u_int, u_long);
  75 static void catchalarm (int);
  76
  77 #ifdef INET6
  78 static char ntop_buf[INET6_ADDRSTRLEN];         /* for inet_ntop() */
  79 #endif
  80
  81
  82 /*
  83  * Display a formatted value, or a '-' in the same space.
  84  */
  85 static void
  86 show_stat(const char *fmt, int width, u_long value, short showvalue)
  87 {
  88         char newfmt[32];
  89
  90         /* Construct the format string */
  91         if (showvalue) {
  92                 sprintf(newfmt, "%%%d%s", width, fmt);
  93                 printf(newfmt, value);
  94         } else {
  95                 sprintf(newfmt, "%%%ds", width);
  96                 printf(newfmt, "-");
  97         }
  98 }
  99
 100
 101
 102 /*
 103  * Print a description of the network interfaces.
 104  */
 105 void
 106 intpr(int interval1, u_long ifnetaddr, void (*pfunc)(char *))
 107 {
 108         struct ifnet ifnet;
 109         struct ifaddr_container ifac;
 110         struct ifnethead ifnethead;
 111         union {
 112                 struct ifaddr ifa;
 113                 struct in_ifaddr in;
 114 #ifdef INET6
 115                 struct in6_ifaddr in6;
 116 #endif
 117                 struct ipx_ifaddr ipx;
 118 #ifdef NS
 119                 struct ns_ifaddr ns;
 120 #endif
 121 #ifdef ISO
 122                 struct iso_ifaddr iso;
 123 #endif
 124         } ifaddr;
 125         u_long ifaddraddr;
 126         u_long ifaddrcont_addr;
 127         u_long ifaddrfound;
 128         u_long ifnetfound;
 129         u_long opackets;
 130         u_long ipackets;
 131         u_long obytes;
 132         u_long ibytes;
 133         u_long oerrors;
 134         u_long ierrors;
 135         u_long collisions;
 136         short timer;
 137         int drops;
 138         struct sockaddr *sa = NULL;
 139         char name[IFNAMSIZ];
 140         short network_layer;
 141         short link_layer;
 142
 143         if (ifnetaddr == 0) {
 144                 printf("ifnet: symbol not defined\n");
 145                 return;
 146         }
 147         if (interval1) {
 148                 sidewaysintpr((unsigned)interval1, ifnetaddr);
 149                 return;
 150         }
 151         if (kread(ifnetaddr, (char *)&ifnethead, sizeof ifnethead))
 152                 return;
 153         ifnetaddr = (u_long)TAILQ_FIRST(&ifnethead);
 154         if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
 155                 return;
 156
 157         if (!pfunc) {
 158                 printf("%-7.7s %-5.5s %-13.13s %-15.15s %8.8s %5.5s",
 159                        "Name", "Mtu", "Network", "Address", "Ipkts", "Ierrs");
 160                 if (bflag)
 161                         printf(" %10.10s","Ibytes");
 162                 printf(" %8.8s %5.5s", "Opkts", "Oerrs");
 163                 if (bflag)
 164                         printf(" %10.10s","Obytes");
 165                 printf(" %5s", "Coll");
 166                 if (tflag)
 167                         printf(" %s", "Time");
 168                 if (dflag)
 169                         printf(" %s", "Drop");
 170                 putchar('\n');
 171         }
 172         ifaddraddr = 0;
 173         while (ifnetaddr || ifaddraddr) {
 174                 struct sockaddr_in *sin;
 175 #ifdef INET6
 176                 struct sockaddr_in6 *sin6;
 177 #endif
 178                 char *cp;
 179                 int n, m;
 180
 181                 network_layer = 0;
 182                 link_layer = 0;
 183
 184                 if (ifaddraddr == 0) {
 185                         struct ifaddrhead head;
 186
 187                         ifnetfound = ifnetaddr;
 188                         if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
 189                                 return;
 190                         strlcpy(name, ifnet.if_xname, sizeof(name));
 191                         ifnetaddr = (u_long)TAILQ_NEXT(&ifnet, if_link);
 192                         if (interface != 0 && (strcmp(name, interface) != 0))
 193                                 continue;
 194                         cp = strchr(name, '\0');
 195
 196                         if (pfunc) {
 197                                 (*pfunc)(name);
 198                                 continue;
 199                         }
 200
 201                         if ((ifnet.if_flags&IFF_UP) == 0)
 202                                 *cp++ = '*';
 203                         *cp = '\0';
 204
 205                         if (kread((u_long)ifnet.if_addrheads,
 206                                   (char *)&head, sizeof(head)))
 207                                 return;
 208
 209                         ifaddrcont_addr =
 210                                 (u_long)TAILQ_FIRST(&head);
 211                         if (ifaddrcont_addr == 0) {
 212                                 ifaddraddr = 0;
 213                         } else {
 214                                 if (kread(ifaddrcont_addr, (char *)&ifac,
 215                                           sizeof(ifac)))
 216                                         return;
 217                                 ifaddraddr = (u_long)ifac.ifa;
 218                         }
 219                 }
 220                 ifaddrfound = ifaddraddr;
 221
 222                 /*
 223                  * Get the interface stats.  These may get
 224                  * overriden below on a per-interface basis.
 225                  */
 226                 opackets = ifnet.if_opackets;
 227                 ipackets = ifnet.if_ipackets;
 228                 obytes = ifnet.if_obytes;
 229                 ibytes = ifnet.if_ibytes;
 230                 oerrors = ifnet.if_oerrors;
 231                 ierrors = ifnet.if_ierrors;
 232                 collisions = ifnet.if_collisions;
 233                 timer = ifnet.if_timer;
 234                 drops = ifnet.if_snd.ifq_drops;
 235
 236                 if (ifaddraddr == 0) {
 237                         printf("%-7.7s %-5lu ", name, ifnet.if_mtu);
 238                         printf("%-13.13s ", "none");
 239                         printf("%-15.15s ", "none");
 240                 } else {
 241                         if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
 242                                 ifaddraddr = 0;
 243                                 continue;
 244                         }
 245 #define CP(x) ((char *)(x))
 246                         cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
 247                                 CP(&ifaddr);
 248                         sa = (struct sockaddr *)cp;
 249                         if (af != AF_UNSPEC && sa->sa_family != af) {
 250                                 ifaddrcont_addr =
 251                                         (u_long)TAILQ_NEXT(&ifac, ifa_link);
 252                                 if (ifaddrcont_addr == 0) {
 253                                         ifaddraddr = 0;
 254                                 } else {
 255                                         if (kread(ifaddrcont_addr,
 256                                             (char *)&ifac, sizeof(ifac))) {
 257                                                 ifaddraddr = 0;
 258                                                 continue;
 259                                         }
 260                                         ifaddraddr = (u_long)ifac.ifa;
 261                                 }
 262                                 continue;
 263                         }
 264                         printf("%-7.7s %-5lu ", name, ifnet.if_mtu);
 265                         switch (sa->sa_family) {
 266                         case AF_UNSPEC:
 267                                 printf("%-13.13s ", "none");
 268                                 printf("%-15.15s ", "none");
 269                                 break;
 270                         case AF_INET:
 271                                 sin = (struct sockaddr_in *)sa;
 272 #ifdef notdef
 273                                 /* can't use inet_makeaddr because kernel
 274                                  * keeps nets unshifted.
 275                                  */
 276                                 in = inet_makeaddr(ifaddr.in.ia_subnet,
 277                                         INADDR_ANY);
 278                                 printf("%-13.13s ", netname(in.s_addr,
 279                                     ifaddr.in.ia_subnetmask));
 280 #else
 281                                 printf("%-13.13s ",
 282                                     netname(htonl(ifaddr.in.ia_subnet),
 283                                     ifaddr.in.ia_subnetmask));
 284 #endif
 285                                 printf("%-15.15s ",
 286                                     routename(sin->sin_addr.s_addr));
 287
 288                                 network_layer = 1;
 289                                 break;
 290 #ifdef INET6
 291                         case AF_INET6:
 292                                 sin6 = (struct sockaddr_in6 *)sa;
 293                                 printf("%-11.11s ",
 294                                        netname6(&ifaddr.in6.ia_addr,
 295                                                 &ifaddr.in6.ia_prefixmask.sin6_addr));
 296                                 printf("%-17.17s ",
 297                                     inet_ntop(AF_INET6,
 298                                         &sin6->sin6_addr,
 299                                         ntop_buf, sizeof(ntop_buf)));
 300
 301                                 network_layer = 1;
 302                                 break;
 303 #endif /*INET6*/
 304                         case AF_IPX:
 305                                 {
 306                                 struct sockaddr_ipx *sipx =
 307                                         (struct sockaddr_ipx *)sa;
 308                                 u_long net;
 309                                 char netnum[10];
 310
 311                                 *(union ipx_net *) &net = sipx->sipx_addr.x_net;
 312                                 sprintf(netnum, "%lx", (u_long)ntohl(net));
 313                                 printf("ipx:%-8s  ", netnum);
 314 /*                              printf("ipx:%-8s ", netname(net, 0L)); */
 315                                 printf("%-15s ",
 316                                     ipx_phost((struct sockaddr *)sipx));
 317                                 }
 318                                 break;
 319
 320                         case AF_APPLETALK:
 321                                 printf("atalk:%-12.12s ",atalk_print(sa,0x10) );
 322                                 printf("%-9.9s  ",atalk_print(sa,0x0b) );
 323                                 break;
 324 #ifdef NS
 325                         case AF_NS:
 326                                 {
 327                                 struct sockaddr_ns *sns =
 328                                         (struct sockaddr_ns *)sa;
 329                                 u_long net;
 330                                 char netnum[10];
 331
 332                                 *(union ns_net *) &net = sns->sns_addr.x_net;
 333                                 sprintf(netnum, "%lxH", ntohl(net));
 334                                 upHex(netnum);
 335                                 printf("ns:%-8s ", netnum);
 336                                 printf("%-15s ",
 337                                     ns_phost((struct sockaddr *)sns));
 338                                 }
 339                                 break;
 340 #endif
 341                         case AF_LINK:
 342                                 {
 343                                 struct sockaddr_dl *sdl =
 344                                         (struct sockaddr_dl *)sa;
 345                                 char linknum[10];
 346                                 cp = (char *)LLADDR(sdl);
 347                                 n = sdl->sdl_alen;
 348                                 sprintf(linknum, "<Link#%d>", sdl->sdl_index);
 349                                 m = printf("%-11.11s ", linknum);
 350                                 }
 351                                 goto hexprint;
 352                         default:
 353                                 m = printf("(%d)", sa->sa_family);
 354                                 for (cp = sa->sa_len + (char *)sa;
 355                                         --cp > sa->sa_data && (*cp == 0);) {}
 356                                 n = cp - sa->sa_data + 1;
 357                                 cp = sa->sa_data;
 358                         hexprint:
 359                                 while (--n >= 0)
 360                                         m += printf("%02x%c", *cp++ & 0xff,
 361                                                     n > 0 ? ':' : ' ');
 362                                 m = 30 - m;
 363                                 while (m-- > 0)
 364                                         putchar(' ');
 365
 366                                 link_layer = 1;
 367                                 break;
 368                         }
 369
 370                         /*
 371                          * Fixup the statistics for interfaces that
 372                          * update stats for their network addresses
 373                          */
 374                         if (network_layer) {
 375                                 opackets = ifaddr.in.ia_ifa.if_opackets;
 376                                 ipackets = ifaddr.in.ia_ifa.if_ipackets;
 377                                 obytes = ifaddr.in.ia_ifa.if_obytes;
 378                                 ibytes = ifaddr.in.ia_ifa.if_ibytes;
 379                         }
 380
 381                         ifaddrcont_addr =
 382                                 (u_long)TAILQ_NEXT(&ifac, ifa_link);
 383                         if (ifaddrcont_addr == 0) {
 384                                 ifaddraddr = 0;
 385                         } else {
 386                                 if (kread(ifaddrcont_addr,
 387                                     (char *)&ifac, sizeof(ifac))) {
 388                                         ifaddraddr = 0;
 389                                 } else {
 390                                         ifaddraddr = (u_long)ifac.ifa;
 391                                 }
 392                         }
 393                 }
 394
 395                 show_stat("lu", 8, ipackets, link_layer|network_layer);
 396                 printf(" ");
 397                 show_stat("lu", 5, ierrors, link_layer);
 398                 printf(" ");
 399                 if (bflag) {
 400                         show_stat("lu", 10, ibytes, link_layer|network_layer);
 401                         printf(" ");
 402                 }
 403                 show_stat("lu", 8, opackets, link_layer|network_layer);
 404                 printf(" ");
 405                 show_stat("lu", 5, oerrors, link_layer);
 406                 printf(" ");
 407                 if (bflag) {
 408                         show_stat("lu", 10, obytes, link_layer|network_layer);
 409                         printf(" ");
 410                 }
 411                 show_stat("lu", 5, collisions, link_layer);
 412                 if (tflag) {
 413                         printf(" ");
 414                         show_stat("d", 3, timer, link_layer);
 415                 }
 416                 if (dflag) {
 417                         printf(" ");
 418                         show_stat("d", 3, drops, link_layer);
 419                 }
 420                 putchar('\n');
 421                 if (aflag && ifaddrfound) {
 422                         /*
 423                          * Print family's multicast addresses
 424                          */
 425                         u_long multiaddr;
 426                         struct ifmultiaddr ifma;
 427                         union {
 428                                 struct sockaddr sa;
 429                                 struct sockaddr_in in;
 430 #ifdef INET6
 431                                 struct sockaddr_in6 in6;
 432 #endif /* INET6 */
 433                                 struct sockaddr_dl dl;
 434                         } msa;
 435                         const char *fmt;
 436
 437                         for(multiaddr = (u_long)ifnet.if_multiaddrs.lh_first;
 438                             multiaddr;
 439                             multiaddr = (u_long)ifma.ifma_link.le_next) {
 440                                 if (kread(multiaddr, (char *)&ifma,
 441                                           sizeof ifma))
 442                                         break;
 443                                 if (kread((u_long)ifma.ifma_addr, (char *)&msa,
 444                                           sizeof msa))
 445                                         break;
 446                                 if (msa.sa.sa_family != sa->sa_family)
 447                                         continue;
 448
 449                                 fmt = 0;
 450                                 switch (msa.sa.sa_family) {
 451                                 case AF_INET:
 452                                         fmt = routename(msa.in.sin_addr.s_addr);
 453                                         break;
 454 #ifdef INET6
 455                                 case AF_INET6:
 456                                         printf("%23s %-19.19s(refs: %d)\n", "",
 457                                                inet_ntop(AF_INET6,
 458                                                          &msa.in6.sin6_addr,
 459                                                          ntop_buf,
 460                                                          sizeof(ntop_buf)),
 461                                                ifma.ifma_refcount);
 462                                         break;
 463 #endif /* INET6 */
 464                                 case AF_LINK:
 465                                         switch (msa.dl.sdl_type) {
 466                                         case IFT_ETHER:
 467                                         case IFT_FDDI:
 468                                                 fmt = ether_ntoa(
 469                                                         (struct ether_addr *)
 470                                                         LLADDR(&msa.dl));
 471                                                 break;
 472                                         }
 473                                         break;
 474                                 }
 475                                 if (fmt)
 476                                         printf("%23s %s\n", "", fmt);
 477                         }
 478                 }
 479         }
 480 }
 481
 482 struct  iftot {
 483         SLIST_ENTRY(iftot) chain;
 484         char    ift_name[IFNAMSIZ];     /* interface name */
 485         u_long  ift_ip;                 /* input packets */
 486         u_long  ift_ie;                 /* input errors */
 487         u_long  ift_op;                 /* output packets */
 488         u_long  ift_oe;                 /* output errors */
 489         u_long  ift_co;                 /* collisions */
 490         u_int   ift_dr;                 /* drops */
 491         u_long  ift_ib;                 /* input bytes */
 492         u_long  ift_ob;                 /* output bytes */
 493 };
 494
 495 u_char  signalled;                      /* set if alarm goes off "early" */
 496
 497 /*
 498  * Print a running summary of interface statistics.
 499  * Repeat display every interval1 seconds, showing statistics
 500  * collected over that interval.  Assumes that interval1 is non-zero.
 501  * First line printed at top of screen is always cumulative.
 502  * XXX - should be rewritten to use ifmib(4).
 503  */
 504 static void
 505 sidewaysintpr(unsigned interval1, u_long off)
 506 {
 507         struct ifnet ifnet;
 508         u_long firstifnet;
 509         struct ifnethead ifnethead;
 510         struct iftot *iftot, *ip, *ipn, *total, *sum, *interesting;
 511         int line;
 512         int oldmask, first;
 513         u_long interesting_off;
 514
 515         if (kread(off, (char *)&ifnethead, sizeof ifnethead))
 516                 return;
 517         firstifnet = (u_long)TAILQ_FIRST(&ifnethead);
 518
 519         if ((iftot = malloc(sizeof(struct iftot))) == NULL) {
 520                 printf("malloc failed\n");
 521                 exit(1);
 522         }
 523         memset(iftot, 0, sizeof(struct iftot));
 524
 525         interesting = NULL;
 526         interesting_off = 0;
 527         for (off = firstifnet, ip = iftot; off;) {
 528                 char name[IFNAMSIZ];
 529
 530                 if (kread(off, (char *)&ifnet, sizeof ifnet))
 531                         break;
 532                 strlcpy(name, ifnet.if_xname, sizeof(name));
 533                 if (interface && strcmp(name, interface) == 0) {
 534                         interesting = ip;
 535                         interesting_off = off;
 536                 }
 537                 snprintf(ip->ift_name, 16, "(%s)", name);
 538                 if ((ipn = malloc(sizeof(struct iftot))) == NULL) {
 539                         printf("malloc failed\n");
 540                         exit(1);
 541                 }
 542                 memset(ipn, 0, sizeof(struct iftot));
 543                 SLIST_NEXT(ip, chain) = ipn;
 544                 ip = ipn;
 545                 off = (u_long)TAILQ_NEXT(&ifnet, if_link);
 546         }
 547         if ((total = malloc(sizeof(struct iftot))) == NULL) {
 548                 printf("malloc failed\n");
 549                 exit(1);
 550         }
 551         memset(total, 0, sizeof(struct iftot));
 552         if ((sum = malloc(sizeof(struct iftot))) == NULL) {
 553                 printf("malloc failed\n");
 554                 exit(1);
 555         }
 556         memset(sum, 0, sizeof(struct iftot));
 557
 558
 559         (void)signal(SIGALRM, catchalarm);
 560         signalled = NO;
 561         (void)alarm(interval1);
 562         first = 1;
 563 banner:
 564         printf("%17s %14s %16s", "input",
 565             interesting ? interesting->ift_name : "(Total)", "output");
 566         putchar('\n');
 567         printf("%10s %5s %10s %10s %5s %10s %5s",
 568             "packets", "errs", "bytes", "packets", "errs", "bytes", "colls");
 569         if (dflag)
 570                 printf(" %5.5s", "drops");
 571         putchar('\n');
 572         fflush(stdout);
 573         line = 0;
 574 loop:
 575         if (interesting != NULL) {
 576                 ip = interesting;
 577                 if (kread(interesting_off, (char *)&ifnet, sizeof ifnet)) {
 578                         printf("???\n");
 579                         exit(1);
 580                 };
 581                 if (!first) {
 582                         printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
 583                                 ifnet.if_ipackets - ip->ift_ip,
 584                                 ifnet.if_ierrors - ip->ift_ie,
 585                                 ifnet.if_ibytes - ip->ift_ib,
 586                                 ifnet.if_opackets - ip->ift_op,
 587                                 ifnet.if_oerrors - ip->ift_oe,
 588                                 ifnet.if_obytes - ip->ift_ob,
 589                                 ifnet.if_collisions - ip->ift_co);
 590                         if (dflag)
 591                                 printf(" %5u", ifnet.if_snd.ifq_drops - ip->ift_dr);
 592                 }
 593                 ip->ift_ip = ifnet.if_ipackets;
 594                 ip->ift_ie = ifnet.if_ierrors;
 595                 ip->ift_ib = ifnet.if_ibytes;
 596                 ip->ift_op = ifnet.if_opackets;
 597                 ip->ift_oe = ifnet.if_oerrors;
 598                 ip->ift_ob = ifnet.if_obytes;
 599                 ip->ift_co = ifnet.if_collisions;
 600                 ip->ift_dr = ifnet.if_snd.ifq_drops;
 601         } else {
 602                 sum->ift_ip = 0;
 603                 sum->ift_ie = 0;
 604                 sum->ift_ib = 0;
 605                 sum->ift_op = 0;
 606                 sum->ift_oe = 0;
 607                 sum->ift_ob = 0;
 608                 sum->ift_co = 0;
 609                 sum->ift_dr = 0;
 610                 for (off = firstifnet, ip = iftot;
 611                      off && SLIST_NEXT(ip, chain) != NULL;
 612                      ip = SLIST_NEXT(ip, chain)) {
 613                         if (kread(off, (char *)&ifnet, sizeof ifnet)) {
 614                                 off = 0;
 615                                 continue;
 616                         }
 617                         sum->ift_ip += ifnet.if_ipackets;
 618                         sum->ift_ie += ifnet.if_ierrors;
 619                         sum->ift_ib += ifnet.if_ibytes;
 620                         sum->ift_op += ifnet.if_opackets;
 621                         sum->ift_oe += ifnet.if_oerrors;
 622                         sum->ift_ob += ifnet.if_obytes;
 623                         sum->ift_co += ifnet.if_collisions;
 624                         sum->ift_dr += ifnet.if_snd.ifq_drops;
 625                         off = (u_long)TAILQ_NEXT(&ifnet, if_link);
 626                 }
 627                 if (!first) {
 628                         printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
 629                                 sum->ift_ip - total->ift_ip,
 630                                 sum->ift_ie - total->ift_ie,
 631                                 sum->ift_ib - total->ift_ib,
 632                                 sum->ift_op - total->ift_op,
 633                                 sum->ift_oe - total->ift_oe,
 634                                 sum->ift_ob - total->ift_ob,
 635                                 sum->ift_co - total->ift_co);
 636                         if (dflag)
 637                                 printf(" %5u", sum->ift_dr - total->ift_dr);
 638                 }
 639                 *total = *sum;
 640         }
 641         if (!first)
 642                 putchar('\n');
 643         fflush(stdout);
 644         oldmask = sigblock(sigmask(SIGALRM));
 645         if (! signalled) {
 646                 sigpause(0);
 647         }
 648         sigsetmask(oldmask);
 649         signalled = NO;
 650         (void)alarm(interval1);
 651         line++;
 652         first = 0;
 653         if (line == 21)
 654                 goto banner;
 655         else
 656                 goto loop;
 657         /*NOTREACHED*/
 658 }
 659
 660 /*
 661  * Called if an interval expires before sidewaysintpr has completed a loop.
 662  * Sets a flag to not wait for the alarm.
 663  */
 664 static void
 665 catchalarm(int signo __unused)
 666 {
 667         signalled = YES;
 668 }