misc/ifstat.c

   1 /*
   2  * ifstat.c     handy utility to read net interface statistics
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <fcntl.h>
  16 #include <string.h>
  17 #include <errno.h>
  18 #include <time.h>
  19 #include <sys/time.h>
  20 #include <fnmatch.h>
  21 #include <sys/file.h>
  22 #include <sys/socket.h>
  23 #include <sys/un.h>
  24 #include <sys/poll.h>
  25 #include <sys/wait.h>
  26 #include <sys/stat.h>
  27 #include <signal.h>
  28 #include <math.h>
  29
  30 #include <libnetlink.h>
  31 #include <linux/netdevice.h>
  32
  33 #include <SNAPSHOT.h>
  34
  35 int dump_zeros = 0;
  36 int reset_history = 0;
  37 int ignore_history = 0;
  38 int no_output = 0;
  39 int no_update = 0;
  40 int scan_interval = 0;
  41 int time_constant = 0;
  42 int show_errors = 0;
  43 double W;
  44 char **patterns;
  45 int npatterns;
  46
  47 char info_source[128];
  48 int source_mismatch;
  49
  50 #define MAXS (sizeof(struct net_device_stats)/sizeof(unsigned long))
  51
  52 struct ifstat_ent
  53 {
  54         struct ifstat_ent       *next;
  55         char                    *name;
  56         int                     ifindex;
  57         unsigned long long      val[MAXS];
  58         double                  rate[MAXS];
  59         unsigned long           ival[MAXS];
  60 };
  61
  62 struct ifstat_ent *kern_db;
  63 struct ifstat_ent *hist_db;
  64
  65 int match(char *id)
  66 {
  67         int i;
  68
  69         if (npatterns == 0)
  70                 return 1;
  71
  72         for (i=0; i<npatterns; i++) {
  73                 if (!fnmatch(patterns[i], id, 0))
  74                         return 1;
  75         }
  76         return 0;
  77 }
  78
  79 int get_nlmsg(struct sockaddr_nl *who, struct nlmsghdr *m, void *arg)
  80 {
  81         struct ifinfomsg *ifi = NLMSG_DATA(m);
  82         struct rtattr * tb[IFLA_MAX+1];
  83         int len = m->nlmsg_len;
  84         struct ifstat_ent *n;
  85         int i;
  86
  87         if (m->nlmsg_type != RTM_NEWLINK)
  88                 return 0;
  89
  90         len -= NLMSG_LENGTH(sizeof(*ifi));
  91         if (len < 0)
  92                 return -1;
  93
  94         if (!(ifi->ifi_flags&IFF_UP))
  95                 return 0;
  96
  97         memset(tb, 0, sizeof(tb));
  98         parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), len);
  99         if (tb[IFLA_IFNAME] == NULL || tb[IFLA_STATS] == NULL)
 100                 return 0;
 101
 102         n = malloc(sizeof(*n));
 103         if (!n)
 104                 abort();
 105         n->ifindex = ifi->ifi_index;
 106         n->name = strdup(RTA_DATA(tb[IFLA_IFNAME]));
 107         memcpy(&n->ival, RTA_DATA(tb[IFLA_STATS]), sizeof(n->ival));
 108         memset(&n->rate, 0, sizeof(n->rate));
 109         for (i=0; i<MAXS; i++)
 110                 n->val[i] = n->ival[i];
 111         n->next = kern_db;
 112         kern_db = n;
 113         return 0;
 114 }
 115
 116 void load_info(void)
 117 {
 118         struct ifstat_ent *db, *n;
 119         struct rtnl_handle rth;
 120
 121         if (rtnl_open(&rth, 0) < 0)
 122                 exit(1);
 123
 124         if (rtnl_wilddump_request(&rth, AF_INET, RTM_GETLINK) < 0) {
 125                 perror("Cannot send dump request");
 126                 exit(1);
 127         }
 128
 129         if (rtnl_dump_filter(&rth, get_nlmsg, NULL, NULL, NULL) < 0) {
 130                 fprintf(stderr, "Dump terminated\n");
 131                 exit(1);
 132         }
 133
 134         rtnl_close(&rth);
 135
 136         db = kern_db;
 137         kern_db = NULL;
 138
 139         while (db) {
 140                 n = db;
 141                 db = db->next;
 142                 n->next = kern_db;
 143                 kern_db = n;
 144         }
 145 }
 146
 147 void load_raw_table(FILE *fp)
 148 {
 149         char buf[4096];
 150         struct ifstat_ent *db = NULL;
 151         struct ifstat_ent *n;
 152
 153         while (fgets(buf, sizeof(buf), fp) != NULL) {
 154                 char *p;
 155                 char *next;
 156                 int i;
 157
 158                 if (buf[0] == '#') {
 159                         buf[strlen(buf)-1] = 0;
 160                         if (info_source[0] && strcmp(info_source, buf+1))
 161                                 source_mismatch = 1;
 162                         strncpy(info_source, buf+1, sizeof(info_source)-1);
 163                         continue;
 164                 }
 165                 if ((n = malloc(sizeof(*n))) == NULL)
 166                         abort();
 167
 168                 if (!(p = strchr(buf, ' ')))
 169                         abort();
 170                 *p++ = 0;
 171
 172                 if (sscanf(buf, "%d", &n->ifindex) != 1)
 173                         abort();
 174                 if (!(next = strchr(p, ' ')))
 175                         abort();
 176                 *next++ = 0;
 177
 178                 n->name = strdup(p);
 179                 p = next;
 180
 181                 for (i=0; i<MAXS; i++) {
 182                         unsigned rate;
 183                         if (!(next = strchr(p, ' ')))
 184                                 abort();
 185                         *next++ = 0;
 186                         if (sscanf(p, "%llu", n->val+i) != 1)
 187                                 abort();
 188                         n->ival[i] = (unsigned long)n->val[i];
 189                         p = next;
 190                         if (!(next = strchr(p, ' ')))
 191                                 abort();
 192                         *next++ = 0;
 193                         if (sscanf(p, "%u", &rate) != 1)
 194                                 abort();
 195                         n->rate[i] = rate;
 196                         p = next;
 197                 }
 198                 n->next = db;
 199                 db = n;
 200         }
 201
 202         while (db) {
 203                 n = db;
 204                 db = db->next;
 205                 n->next = kern_db;
 206                 kern_db = n;
 207         }
 208 }
 209
 210 void dump_raw_db(FILE *fp, int to_hist)
 211 {
 212         struct ifstat_ent *n, *h;
 213         h = hist_db;
 214         fprintf(fp, "#%s\n", info_source);
 215
 216         for (n=kern_db; n; n=n->next) {
 217                 int i;
 218                 unsigned long long *vals = n->val;
 219                 double *rates = n->rate;
 220                 if (!match(n->name)) {
 221                         struct ifstat_ent *h1;
 222                         if (!to_hist)
 223                                 continue;
 224                         for (h1 = h; h1; h1 = h1->next) {
 225                                 if (h1->ifindex == n->ifindex) {
 226                                         vals = h1->val;
 227                                         rates = h1->rate;
 228                                         h = h1->next;
 229                                         break;
 230                                 }
 231                         }
 232                 }
 233                 fprintf(fp, "%d %s ", n->ifindex, n->name);
 234                 for (i=0; i<MAXS; i++)
 235                         fprintf(fp, "%llu %u ", vals[i], (unsigned)rates[i]);
 236                 fprintf(fp, "\n");
 237         }
 238 }
 239
 240
 241 void format_rate(FILE *fp, unsigned long long *vals, double *rates, int i)
 242 {
 243         char temp[64];
 244         if (vals[i] > 1024*1024*1024)
 245                 fprintf(fp, "%7lluM ", vals[i]/(1024*1024));
 246         else if (vals[i] > 1024*1024)
 247                 fprintf(fp, "%7lluK ", vals[i]/1024);
 248         else
 249                 fprintf(fp, "%8llu ", vals[i]);
 250
 251         if (rates[i] > 1024*1024) {
 252                 sprintf(temp, "%uM", (unsigned)(rates[i]/(1024*1024)));
 253                 fprintf(fp, "%-6s ", temp);
 254         } else if (rates[i] > 1024) {
 255                 sprintf(temp, "%uK", (unsigned)(rates[i]/1024));
 256                 fprintf(fp, "%-6s ", temp);
 257         } else
 258                 fprintf(fp, "%-6u ", (unsigned)rates[i]);
 259 }
 260
 261 void format_pair(FILE *fp, unsigned long long *vals, int i, int k)
 262 {
 263         char temp[64];
 264         if (vals[i] > 1024*1024*1024)
 265                 fprintf(fp, "%7lluM ", vals[i]/(1024*1024));
 266         else if (vals[i] > 1024*1024)
 267                 fprintf(fp, "%7lluK ", vals[i]/1024);
 268         else
 269                 fprintf(fp, "%8llu ", vals[i]);
 270
 271         if (vals[k] > 1024*1024*1024) {
 272                 sprintf(temp, "%uM", (unsigned)(vals[k]/(1024*1024)));
 273                 fprintf(fp, "%-6s ", temp);
 274         } else if (vals[k] > 1024*1024) {
 275                 sprintf(temp, "%uK", (unsigned)(vals[k]/1024));
 276                 fprintf(fp, "%-6s ", temp);
 277         } else
 278                 fprintf(fp, "%-6u ", (unsigned)vals[k]);
 279 }
 280
 281 void print_head(FILE *fp)
 282 {
 283         fprintf(fp, "#%s\n", info_source);
 284         fprintf(fp, "%-15s ", "Interface");
 285
 286         fprintf(fp, "%8s/%-6s ", "RX Pkts", "Rate");
 287         fprintf(fp, "%8s/%-6s ", "TX Pkts", "Rate");
 288         fprintf(fp, "%8s/%-6s ", "RX Data", "Rate");
 289         fprintf(fp, "%8s/%-6s\n","TX Data", "Rate");
 290
 291         if (!show_errors) {
 292                 fprintf(fp, "%-15s ", "");
 293                 fprintf(fp, "%8s/%-6s ", "RX Errs", "Drop");
 294                 fprintf(fp, "%8s/%-6s ", "TX Errs", "Drop");
 295                 fprintf(fp, "%8s/%-6s ", "RX Over", "Rate");
 296                 fprintf(fp, "%8s/%-6s\n","TX Coll", "Rate");
 297         } else {
 298                 fprintf(fp, "%-15s ", "");
 299                 fprintf(fp, "%8s/%-6s ", "RX Errs", "Rate");
 300                 fprintf(fp, "%8s/%-6s ", "RX Drop", "Rate");
 301                 fprintf(fp, "%8s/%-6s ", "RX Over", "Rate");
 302                 fprintf(fp, "%8s/%-6s\n","RX Leng", "Rate");
 303
 304                 fprintf(fp, "%-15s ", "");
 305                 fprintf(fp, "%8s/%-6s ", "RX Crc", "Rate");
 306                 fprintf(fp, "%8s/%-6s ", "RX Frm", "Rate");
 307                 fprintf(fp, "%8s/%-6s ", "RX Fifo", "Rate");
 308                 fprintf(fp, "%8s/%-6s\n","RX Miss", "Rate");
 309
 310                 fprintf(fp, "%-15s ", "");
 311                 fprintf(fp, "%8s/%-6s ", "TX Errs", "Rate");
 312                 fprintf(fp, "%8s/%-6s ", "TX Drop", "Rate");
 313                 fprintf(fp, "%8s/%-6s ", "TX Coll", "Rate");
 314                 fprintf(fp, "%8s/%-6s\n","TX Carr", "Rate");
 315
 316                 fprintf(fp, "%-15s ", "");
 317                 fprintf(fp, "%8s/%-6s ", "TX Abrt", "Rate");
 318                 fprintf(fp, "%8s/%-6s ", "TX Fifo", "Rate");
 319                 fprintf(fp, "%8s/%-6s ", "TX Hear", "Rate");
 320                 fprintf(fp, "%8s/%-6s\n","TX Wind", "Rate");
 321         }
 322 }
 323
 324 void print_one_if(FILE *fp, struct ifstat_ent *n, unsigned long long *vals)
 325 {
 326         int i;
 327         fprintf(fp, "%-15s ", n->name);
 328         for (i=0; i<4; i++)
 329                 format_rate(fp, vals, n->rate, i);
 330         fprintf(fp, "\n");
 331
 332         if (!show_errors) {
 333                 fprintf(fp, "%-15s ", "");
 334                 format_pair(fp, vals, 4, 6);
 335                 format_pair(fp, vals, 5, 7);
 336                 format_rate(fp, vals, n->rate, 11);
 337                 format_rate(fp, vals, n->rate, 9);
 338                 fprintf(fp, "\n");
 339         } else {
 340                 fprintf(fp, "%-15s ", "");
 341                 format_rate(fp, vals, n->rate, 4);
 342                 format_rate(fp, vals, n->rate, 6);
 343                 format_rate(fp, vals, n->rate, 11);
 344                 format_rate(fp, vals, n->rate, 10);
 345                 fprintf(fp, "\n");
 346
 347                 fprintf(fp, "%-15s ", "");
 348                 format_rate(fp, vals, n->rate, 12);
 349                 format_rate(fp, vals, n->rate, 13);
 350                 format_rate(fp, vals, n->rate, 14);
 351                 format_rate(fp, vals, n->rate, 15);
 352                 fprintf(fp, "\n");
 353
 354                 fprintf(fp, "%-15s ", "");
 355                 format_rate(fp, vals, n->rate, 5);
 356                 format_rate(fp, vals, n->rate, 7);
 357                 format_rate(fp, vals, n->rate, 9);
 358                 format_rate(fp, vals, n->rate, 17);
 359                 fprintf(fp, "\n");
 360
 361                 fprintf(fp, "%-15s ", "");
 362                 format_rate(fp, vals, n->rate, 16);
 363                 format_rate(fp, vals, n->rate, 18);
 364                 format_rate(fp, vals, n->rate, 19);
 365                 format_rate(fp, vals, n->rate, 20);
 366                 fprintf(fp, "\n");
 367         }
 368 }
 369
 370
 371 void dump_kern_db(FILE *fp)
 372 {
 373         struct ifstat_ent *n, *h;
 374         h = hist_db;
 375
 376         print_head(fp);
 377
 378         for (n=kern_db; n; n=n->next) {
 379                 if (!match(n->name))
 380                         continue;
 381                 print_one_if(fp, n, n->val);
 382         }
 383 }
 384
 385
 386 void dump_incr_db(FILE *fp)
 387 {
 388         struct ifstat_ent *n, *h;
 389         h = hist_db;
 390
 391         print_head(fp);
 392
 393         for (n=kern_db; n; n=n->next) {
 394                 int i;
 395                 unsigned long long vals[MAXS];
 396                 struct ifstat_ent *h1;
 397
 398                 memcpy(vals, n->val, sizeof(vals));
 399
 400                 for (h1 = h; h1; h1 = h1->next) {
 401                         if (h1->ifindex == n->ifindex) {
 402                                 for (i = 0; i < MAXS; i++)
 403                                         vals[i] -= h1->val[i];
 404                                 h = h1->next;
 405                                 break;
 406                         }
 407                 }
 408                 if (!match(n->name))
 409                         continue;
 410                 print_one_if(fp, n, vals);
 411         }
 412 }
 413
 414
 415 static int children;
 416
 417 void sigchild(int signo)
 418 {
 419 }
 420
 421 void update_db(int interval)
 422 {
 423         struct ifstat_ent *n, *h;
 424
 425         n = kern_db;
 426         kern_db = NULL;
 427
 428         load_info();
 429
 430         h = kern_db;
 431         kern_db = n;
 432
 433         for (n = kern_db; n; n = n->next) {
 434                 struct ifstat_ent *h1;
 435                 for (h1 = h; h1; h1 = h1->next) {
 436                         if (h1->ifindex == n->ifindex) {
 437                                 int i;
 438                                 for (i = 0; i < MAXS; i++) {
 439                                         if ((long)(h1->ival[i] - n->ival[i]) < 0) {
 440                                                 memset(n->ival, 0, sizeof(n->ival));
 441                                                 break;
 442                                         }
 443                                 }
 444                                 for (i = 0; i < MAXS; i++) {
 445                                         double sample;
 446                                         unsigned long incr = h1->ival[i] - n->ival[i];
 447                                         n->val[i] += incr;
 448                                         n->ival[i] = h1->ival[i];
 449                                         sample = (double)(incr*1000)/interval;
 450                                         if (interval >= scan_interval) {
 451                                                 n->rate[i] += W*(sample-n->rate[i]);
 452                                         } else if (interval >= 1000) {
 453                                                 if (interval >= time_constant) {
 454                                                         n->rate[i] = sample;
 455                                                 } else {
 456                                                         double w = W*(double)interval/scan_interval;
 457                                                         n->rate[i] += w*(sample-n->rate[i]);
 458                                                 }
 459                                         }
 460                                 }
 461
 462                                 while (h != h1) {
 463                                         struct ifstat_ent *tmp = h;
 464                                         h = h->next;
 465                                         free(tmp->name);
 466                                         free(tmp);
 467                                 };
 468                                 h = h1->next;
 469                                 free(h1->name);
 470                                 free(h1);
 471                                 break;
 472                         }
 473                 }
 474         }
 475 }
 476
 477 #define T_DIFF(a,b) (((a).tv_sec-(b).tv_sec)*1000 + ((a).tv_usec-(b).tv_usec)/1000)
 478
 479
 480 void server_loop(int fd)
 481 {
 482         struct timeval snaptime;
 483         struct pollfd p;
 484         p.fd = fd;
 485         p.events = p.revents = POLLIN;
 486
 487         sprintf(info_source, "%d.%lu sampling_interval=%d time_const=%d",
 488                 getpid(), (unsigned long)random(), scan_interval/1000, time_constant/1000);
 489
 490         load_info();
 491
 492         for (;;) {
 493                 int status;
 494                 int tdiff;
 495                 struct timeval now;
 496                 gettimeofday(&now, NULL);
 497                 tdiff = T_DIFF(now, snaptime);
 498                 if (tdiff >= scan_interval) {
 499                         update_db(tdiff);
 500                         snaptime = now;
 501                         tdiff = 0;
 502                 }
 503                 if (poll(&p, 1, tdiff + scan_interval) > 0
 504                     && (p.revents&POLLIN)) {
 505                         int clnt = accept(fd, NULL, NULL);
 506                         if (clnt >= 0) {
 507                                 pid_t pid;
 508                                 if (children >= 5) {
 509                                         close(clnt);
 510                                 } else if ((pid = fork()) != 0) {
 511                                         if (pid>0)
 512                                                 children++;
 513                                         close(clnt);
 514                                 } else {
 515                                         FILE *fp = fdopen(clnt, "w");
 516                                         if (fp) {
 517                                                 if (tdiff > 0)
 518                                                         update_db(tdiff);
 519                                                 dump_raw_db(fp, 0);
 520                                         }
 521                                         exit(0);
 522                                 }
 523                         }
 524                 }
 525                 while (children && waitpid(-1, &status, WNOHANG) > 0)
 526                         children--;
 527         }
 528 }
 529
 530 int verify_forging(int fd)
 531 {
 532         struct ucred cred;
 533         int olen = sizeof(cred);
 534         if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, (void*)&cred, &olen) ||
 535             olen < sizeof(cred))
 536                 return -1;
 537         if (cred.uid == getuid() || cred.uid == 0)
 538                 return 0;
 539         return -1;
 540 }
 541
 542 static void usage(void) __attribute__((noreturn));
 543
 544 static void usage(void)
 545 {
 546         fprintf(stderr,
 547 "Usage: ifstat [ -h?vVzrnasd:t: ] [ PATTERN [ PATTERN ] ]\n"
 548                 );
 549         exit(-1);
 550 }
 551
 552
 553 int main(int argc, char *argv[])
 554 {
 555         char hist_name[128];
 556         struct sockaddr_un sun;
 557         FILE *hist_fp = NULL;
 558         int ch;
 559         int fd;
 560
 561         while ((ch = getopt(argc, argv, "h?vVzrnasd:t:e")) != EOF) {
 562                 switch(ch) {
 563                 case 'z':
 564                         dump_zeros = 1;
 565                         break;
 566                 case 'r':
 567                         reset_history = 1;
 568                         break;
 569                 case 'a':
 570                         ignore_history = 1;
 571                         break;
 572                 case 's':
 573                         no_update = 1;
 574                         break;
 575                 case 'n':
 576                         no_output = 1;
 577                         break;
 578                 case 'e':
 579                         show_errors = 1;
 580                         break;
 581                 case 'd':
 582                         scan_interval = 1000*atoi(optarg);
 583                         break;
 584                 case 't':
 585                         if (sscanf(optarg, "%d", &time_constant) != 1 ||
 586                             time_constant <= 0) {
 587                                 fprintf(stderr, "ifstat: invalid time constant divisor\n");
 588                                 exit(-1);
 589                         }
 590                         break;
 591                 case 'v':
 592                 case 'V':
 593                         printf("ifstat utility, iproute2-ss%s\n", SNAPSHOT);
 594                         exit(0);
 595                 case 'h':
 596                 case '?':
 597                 default:
 598                         usage();
 599                 }
 600         }
 601
 602         argc -= optind;
 603         argv += optind;
 604
 605         sun.sun_family = AF_UNIX;
 606         sun.sun_path[0] = 0;
 607         sprintf(sun.sun_path+1, "ifstat%d", getuid());
 608
 609         if (scan_interval > 0) {
 610                 if (time_constant == 0)
 611                         time_constant = 60;
 612                 time_constant *= 1000;
 613                 W = 1 - 1/exp(log(10)*(double)scan_interval/time_constant);
 614                 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
 615                         perror("ifstat: socket");
 616                         exit(-1);
 617                 }
 618                 if (bind(fd, (struct sockaddr*)&sun, 2+1+strlen(sun.sun_path+1)) < 0) {
 619                         perror("ifstat: bind");
 620                         exit(-1);
 621                 }
 622                 if (listen(fd, 5) < 0) {
 623                         perror("ifstat: listen");
 624                         exit(-1);
 625                 }
 626                 if (fork())
 627                         exit(0);
 628                 chdir("/");
 629                 close(0); close(1); close(2); setsid();
 630                 signal(SIGPIPE, SIG_IGN);
 631                 signal(SIGCHLD, sigchild);
 632                 server_loop(fd);
 633                 exit(0);
 634         }
 635
 636         patterns = argv;
 637         npatterns = argc;
 638
 639         if (getenv("IFSTAT_HISTORY"))
 640                 snprintf(hist_name, sizeof(hist_name), getenv("IFSTAT_HISTORY"));
 641         else
 642                 sprintf(hist_name, "/tmp/.ifstat.u%d", getuid());
 643
 644         if (reset_history)
 645                 unlink(hist_name);
 646
 647         if (!ignore_history || !no_update) {
 648                 struct stat stb;
 649
 650                 fd = open(hist_name, O_RDWR|O_CREAT|O_NOFOLLOW, 0600);
 651                 if (fd < 0) {
 652                         perror("ifstat: open history file");
 653                         exit(-1);
 654                 }
 655                 if ((hist_fp = fdopen(fd, "r+")) == NULL) {
 656                         perror("ifstat: fdopen history file");
 657                         exit(-1);
 658                 }
 659                 if (flock(fileno(hist_fp), LOCK_EX)) {
 660                         perror("ifstat: flock history file");
 661                         exit(-1);
 662                 }
 663                 if (fstat(fileno(hist_fp), &stb) != 0) {
 664                         perror("ifstat: fstat history file");
 665                         exit(-1);
 666                 }
 667                 if (stb.st_nlink != 1 || stb.st_uid != getuid()) {
 668                         fprintf(stderr, "ifstat: something is so wrong with history file, that I prefer not to proceed.\n");
 669                         exit(-1);
 670                 }
 671                 if (!ignore_history) {
 672                         FILE *tfp;
 673                         long uptime;
 674                         if ((tfp = fopen("/proc/uptime", "r")) != NULL) {
 675                                 if (fscanf(tfp, "%ld", &uptime) != 1)
 676                                         uptime = -1;
 677                                 fclose(tfp);
 678                         }
 679                         if (uptime >= 0 && time(NULL) >= stb.st_mtime+uptime) {
 680                                 fprintf(stderr, "ifstat: history is aged out, resetting\n");
 681                                 ftruncate(fileno(hist_fp), 0);
 682                         }
 683                 }
 684
 685                 load_raw_table(hist_fp);
 686
 687                 hist_db = kern_db;
 688                 kern_db = NULL;
 689         }
 690
 691         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0 &&
 692             (connect(fd, (struct sockaddr*)&sun, 2+1+strlen(sun.sun_path+1)) == 0
 693              || (strcpy(sun.sun_path+1, "ifstat0"),
 694                  connect(fd, (struct sockaddr*)&sun, 2+1+strlen(sun.sun_path+1)) == 0))
 695             && verify_forging(fd) == 0) {
 696                 FILE *sfp = fdopen(fd, "r");
 697                 load_raw_table(sfp);
 698                 if (hist_db && source_mismatch) {
 699                         fprintf(stderr, "ifstat: history is stale, ignoring it.\n");
 700                         hist_db = NULL;
 701                 }
 702                 fclose(sfp);
 703         } else {
 704                 if (fd >= 0)
 705                         close(fd);
 706                 if (hist_db && info_source[0] && strcmp(info_source, "kernel")) {
 707                         fprintf(stderr, "ifstat: history is stale, ignoring it.\n");
 708                         hist_db = NULL;
 709                         info_source[0] = 0;
 710                 }
 711                 load_info();
 712                 if (info_source[0] == 0)
 713                         strcpy(info_source, "kernel");
 714         }
 715
 716         if (!no_output) {
 717                 if (ignore_history || hist_db == NULL)
 718                         dump_kern_db(stdout);
 719                 else
 720                         dump_incr_db(stdout);
 721         }
 722         if (!no_update) {
 723                 ftruncate(fileno(hist_fp), 0);
 724                 rewind(hist_fp);
 725                 dump_raw_db(hist_fp, 1);
 726                 fflush(hist_fp);
 727         }
 728         exit(0);
 729 }