misc/nstat.c

   1 /*
   2  * nstat.c      handy utility to read counters /proc/net/netstat and snmp
   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 #include <getopt.h>
  30
  31 #include <json_writer.h>
  32 #include <SNAPSHOT.h>
  33 #include "utils.h"
  34
  35 int dump_zeros;
  36 int reset_history;
  37 int ignore_history;
  38 int no_output;
  39 int json_output;
  40 int no_update;
  41 int scan_interval;
  42 int time_constant;
  43 double W;
  44 char **patterns;
  45 int npatterns;
  46
  47 char info_source[128];
  48 int source_mismatch;
  49
  50 static int generic_proc_open(const char *env, char *name)
  51 {
  52         char store[128];
  53         char *p = getenv(env);
  54
  55         if (!p) {
  56                 p = getenv("PROC_ROOT") ? : "/proc";
  57                 snprintf(store, sizeof(store)-1, "%s/%s", p, name);
  58                 p = store;
  59         }
  60         return open(p, O_RDONLY);
  61 }
  62
  63 static int net_netstat_open(void)
  64 {
  65         return generic_proc_open("PROC_NET_NETSTAT", "net/netstat");
  66 }
  67
  68 static int net_snmp_open(void)
  69 {
  70         return generic_proc_open("PROC_NET_SNMP", "net/snmp");
  71 }
  72
  73 static int net_snmp6_open(void)
  74 {
  75         return generic_proc_open("PROC_NET_SNMP6", "net/snmp6");
  76 }
  77
  78 static int net_sctp_snmp_open(void)
  79 {
  80         return generic_proc_open("PROC_NET_SCTP_SNMP", "net/sctp/snmp");
  81 }
  82
  83 struct nstat_ent {
  84         struct nstat_ent *next;
  85         char             *id;
  86         unsigned long long val;
  87         double             rate;
  88 };
  89
  90 struct nstat_ent *kern_db;
  91 struct nstat_ent *hist_db;
  92
  93 static const char *useless_numbers[] = {
  94         "IpForwarding", "IpDefaultTTL",
  95         "TcpRtoAlgorithm", "TcpRtoMin", "TcpRtoMax",
  96         "TcpMaxConn", "TcpCurrEstab"
  97 };
  98
  99 static int useless_number(const char *id)
 100 {
 101         int i;
 102
 103         for (i = 0; i < ARRAY_SIZE(useless_numbers); i++)
 104                 if (strcmp(id, useless_numbers[i]) == 0)
 105                         return 1;
 106         return 0;
 107 }
 108
 109 static int match(const char *id)
 110 {
 111         int i;
 112
 113         if (npatterns == 0)
 114                 return 1;
 115
 116         for (i = 0; i < npatterns; i++) {
 117                 if (!fnmatch(patterns[i], id, 0))
 118                         return 1;
 119         }
 120         return 0;
 121 }
 122
 123 static void load_good_table(FILE *fp)
 124 {
 125         char buf[4096];
 126         struct nstat_ent *db = NULL;
 127         struct nstat_ent *n;
 128
 129         while (fgets(buf, sizeof(buf), fp) != NULL) {
 130                 int nr;
 131                 unsigned long long val;
 132                 double rate;
 133                 char idbuf[sizeof(buf)];
 134
 135                 if (buf[0] == '#') {
 136                         buf[strlen(buf)-1] = 0;
 137                         if (info_source[0] && strcmp(info_source, buf+1))
 138                                 source_mismatch = 1;
 139                         info_source[0] = 0;
 140                         strncat(info_source, buf+1, sizeof(info_source)-1);
 141                         continue;
 142                 }
 143                 /* idbuf is as big as buf, so this is safe */
 144                 nr = sscanf(buf, "%s%llu%lg", idbuf, &val, &rate);
 145                 if (nr < 2)
 146                         abort();
 147                 if (nr < 3)
 148                         rate = 0;
 149                 if (useless_number(idbuf))
 150                         continue;
 151                 if ((n = malloc(sizeof(*n))) == NULL)
 152                         abort();
 153                 n->id = strdup(idbuf);
 154                 n->val = val;
 155                 n->rate = rate;
 156                 n->next = db;
 157                 db = n;
 158         }
 159
 160         while (db) {
 161                 n = db;
 162                 db = db->next;
 163                 n->next = kern_db;
 164                 kern_db = n;
 165         }
 166 }
 167
 168 static int count_spaces(const char *line)
 169 {
 170         int count = 0;
 171         char c;
 172
 173         while ((c = *line++) != 0)
 174                 count += c == ' ' || c == '\n';
 175         return count;
 176 }
 177
 178 static void load_ugly_table(FILE *fp)
 179 {
 180         char buf[2048];
 181         struct nstat_ent *db = NULL;
 182         struct nstat_ent *n;
 183
 184         while (fgets(buf, sizeof(buf), fp) != NULL) {
 185                 char idbuf[4096];
 186                 int  off;
 187                 char *p;
 188                 int count1, count2, skip = 0;
 189
 190                 p = strchr(buf, ':');
 191                 if (!p)
 192                         abort();
 193                 count1 = count_spaces(buf);
 194                 *p = 0;
 195                 idbuf[0] = 0;
 196                 strncat(idbuf, buf, sizeof(idbuf) - 1);
 197                 off = p - buf;
 198                 p += 2;
 199
 200                 while (*p) {
 201                         char *next;
 202
 203                         if ((next = strchr(p, ' ')) != NULL)
 204                                 *next++ = 0;
 205                         else if ((next = strchr(p, '\n')) != NULL)
 206                                 *next++ = 0;
 207                         if (off < sizeof(idbuf)) {
 208                                 idbuf[off] = 0;
 209                                 strncat(idbuf, p, sizeof(idbuf) - off - 1);
 210                         }
 211                         n = malloc(sizeof(*n));
 212                         if (!n)
 213                                 abort();
 214                         n->id = strdup(idbuf);
 215                         n->rate = 0;
 216                         n->next = db;
 217                         db = n;
 218                         p = next;
 219                 }
 220                 n = db;
 221                 if (fgets(buf, sizeof(buf), fp) == NULL)
 222                         abort();
 223                 count2 = count_spaces(buf);
 224                 if (count2 > count1)
 225                         skip = count2 - count1;
 226                 do {
 227                         p = strrchr(buf, ' ');
 228                         if (!p)
 229                                 abort();
 230                         *p = 0;
 231                         if (sscanf(p+1, "%llu", &n->val) != 1)
 232                                 abort();
 233                         /* Trick to skip "dummy" trailing ICMP MIB in 2.4 */
 234                         if (skip)
 235                                 skip--;
 236                         else
 237                                 n = n->next;
 238                 } while (p > buf + off + 2);
 239         }
 240
 241         while (db) {
 242                 n = db;
 243                 db = db->next;
 244                 if (useless_number(n->id)) {
 245                         free(n->id);
 246                         free(n);
 247                 } else {
 248                         n->next = kern_db;
 249                         kern_db = n;
 250                 }
 251         }
 252 }
 253
 254 static void load_sctp_snmp(void)
 255 {
 256         FILE *fp = fdopen(net_sctp_snmp_open(), "r");
 257
 258         if (fp) {
 259                 load_good_table(fp);
 260                 fclose(fp);
 261         }
 262 }
 263
 264 static void load_snmp(void)
 265 {
 266         FILE *fp = fdopen(net_snmp_open(), "r");
 267
 268         if (fp) {
 269                 load_ugly_table(fp);
 270                 fclose(fp);
 271         }
 272 }
 273
 274 static void load_snmp6(void)
 275 {
 276         FILE *fp = fdopen(net_snmp6_open(), "r");
 277
 278         if (fp) {
 279                 load_good_table(fp);
 280                 fclose(fp);
 281         }
 282 }
 283
 284 static void load_netstat(void)
 285 {
 286         FILE *fp = fdopen(net_netstat_open(), "r");
 287
 288         if (fp) {
 289                 load_ugly_table(fp);
 290                 fclose(fp);
 291         }
 292 }
 293
 294
 295 static void dump_kern_db(FILE *fp, int to_hist)
 296 {
 297         json_writer_t *jw = json_output ? jsonw_new(fp) : NULL;
 298         struct nstat_ent *n, *h;
 299
 300         h = hist_db;
 301         if (jw) {
 302                 jsonw_start_object(jw);
 303                 jsonw_pretty(jw, pretty);
 304                 jsonw_name(jw, info_source);
 305                 jsonw_start_object(jw);
 306         } else
 307                 fprintf(fp, "#%s\n", info_source);
 308
 309         for (n = kern_db; n; n = n->next) {
 310                 unsigned long long val = n->val;
 311
 312                 if (!dump_zeros && !val && !n->rate)
 313                         continue;
 314                 if (!match(n->id)) {
 315                         struct nstat_ent *h1;
 316
 317                         if (!to_hist)
 318                                 continue;
 319                         for (h1 = h; h1; h1 = h1->next) {
 320                                 if (strcmp(h1->id, n->id) == 0) {
 321                                         val = h1->val;
 322                                         h = h1->next;
 323                                         break;
 324                                 }
 325                         }
 326                 }
 327
 328                 if (jw)
 329                         jsonw_uint_field(jw, n->id, val);
 330                 else
 331                         fprintf(fp, "%-32s%-16llu%6.1f\n", n->id, val, n->rate);
 332         }
 333
 334         if (jw) {
 335                 jsonw_end_object(jw);
 336
 337                 jsonw_end_object(jw);
 338                 jsonw_destroy(&jw);
 339         }
 340 }
 341
 342 static void dump_incr_db(FILE *fp)
 343 {
 344         json_writer_t *jw = json_output ? jsonw_new(fp) : NULL;
 345         struct nstat_ent *n, *h;
 346
 347         h = hist_db;
 348         if (jw) {
 349                 jsonw_start_object(jw);
 350                 jsonw_pretty(jw, pretty);
 351                 jsonw_name(jw, info_source);
 352                 jsonw_start_object(jw);
 353         } else
 354                 fprintf(fp, "#%s\n", info_source);
 355
 356         for (n = kern_db; n; n = n->next) {
 357                 int ovfl = 0;
 358                 unsigned long long val = n->val;
 359                 struct nstat_ent *h1;
 360
 361                 for (h1 = h; h1; h1 = h1->next) {
 362                         if (strcmp(h1->id, n->id) == 0) {
 363                                 if (val < h1->val) {
 364                                         ovfl = 1;
 365                                         val = h1->val;
 366                                 }
 367                                 val -= h1->val;
 368                                 h = h1->next;
 369                                 break;
 370                         }
 371                 }
 372                 if (!dump_zeros && !val && !n->rate)
 373                         continue;
 374                 if (!match(n->id))
 375                         continue;
 376
 377                 if (jw)
 378                         jsonw_uint_field(jw, n->id, val);
 379                 else
 380                         fprintf(fp, "%-32s%-16llu%6.1f%s\n", n->id, val,
 381                                 n->rate, ovfl?" (overflow)":"");
 382         }
 383
 384         if (jw) {
 385                 jsonw_end_object(jw);
 386
 387                 jsonw_end_object(jw);
 388                 jsonw_destroy(&jw);
 389         }
 390 }
 391
 392 static int children;
 393
 394 static void sigchild(int signo)
 395 {
 396 }
 397
 398 static void update_db(int interval)
 399 {
 400         struct nstat_ent *n, *h;
 401
 402         n = kern_db;
 403         kern_db = NULL;
 404
 405         load_netstat();
 406         load_snmp6();
 407         load_snmp();
 408         load_sctp_snmp();
 409
 410         h = kern_db;
 411         kern_db = n;
 412
 413         for (n = kern_db; n; n = n->next) {
 414                 struct nstat_ent *h1;
 415
 416                 for (h1 = h; h1; h1 = h1->next) {
 417                         if (strcmp(h1->id, n->id) == 0) {
 418                                 double sample;
 419                                 unsigned long long incr = h1->val - n->val;
 420
 421                                 n->val = h1->val;
 422                                 sample = (double)incr * 1000.0 / interval;
 423                                 if (interval >= scan_interval) {
 424                                         n->rate += W*(sample-n->rate);
 425                                 } else if (interval >= 1000) {
 426                                         if (interval >= time_constant) {
 427                                                 n->rate = sample;
 428                                         } else {
 429                                                 double w = W*(double)interval/scan_interval;
 430
 431                                                 n->rate += w*(sample-n->rate);
 432                                         }
 433                                 }
 434
 435                                 while (h != h1) {
 436                                         struct nstat_ent *tmp = h;
 437
 438                                         h = h->next;
 439                                         free(tmp->id);
 440                                         free(tmp);
 441                                 };
 442                                 h = h1->next;
 443                                 free(h1->id);
 444                                 free(h1);
 445                                 break;
 446                         }
 447                 }
 448         }
 449 }
 450
 451 #define T_DIFF(a, b) (((a).tv_sec-(b).tv_sec)*1000 + ((a).tv_usec-(b).tv_usec)/1000)
 452
 453
 454 static void server_loop(int fd)
 455 {
 456         struct timeval snaptime = { 0 };
 457         struct pollfd p;
 458
 459         p.fd = fd;
 460         p.events = p.revents = POLLIN;
 461
 462         sprintf(info_source, "%d.%lu sampling_interval=%d time_const=%d",
 463                 getpid(), (unsigned long)random(), scan_interval/1000, time_constant/1000);
 464
 465         load_netstat();
 466         load_snmp6();
 467         load_snmp();
 468         load_sctp_snmp();
 469
 470         for (;;) {
 471                 int status;
 472                 time_t tdiff;
 473                 struct timeval now;
 474
 475                 gettimeofday(&now, NULL);
 476                 tdiff = T_DIFF(now, snaptime);
 477                 if (tdiff >= scan_interval) {
 478                         update_db(tdiff);
 479                         snaptime = now;
 480                         tdiff = 0;
 481                 }
 482                 if (poll(&p, 1, scan_interval - tdiff) > 0
 483                     && (p.revents&POLLIN)) {
 484                         int clnt = accept(fd, NULL, NULL);
 485
 486                         if (clnt >= 0) {
 487                                 pid_t pid;
 488
 489                                 if (children >= 5) {
 490                                         close(clnt);
 491                                 } else if ((pid = fork()) != 0) {
 492                                         if (pid > 0)
 493                                                 children++;
 494                                         close(clnt);
 495                                 } else {
 496                                         FILE *fp = fdopen(clnt, "w");
 497
 498                                         if (fp)
 499                                                 dump_kern_db(fp, 0);
 500                                         exit(0);
 501                                 }
 502                         }
 503                 }
 504                 while (children && waitpid(-1, &status, WNOHANG) > 0)
 505                         children--;
 506         }
 507 }
 508
 509 static int verify_forging(int fd)
 510 {
 511         struct ucred cred;
 512         socklen_t olen = sizeof(cred);
 513
 514         if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, (void *)&cred, &olen) ||
 515             olen < sizeof(cred))
 516                 return -1;
 517         if (cred.uid == getuid() || cred.uid == 0)
 518                 return 0;
 519         return -1;
 520 }
 521
 522 static void usage(void) __attribute__((noreturn));
 523
 524 static void usage(void)
 525 {
 526         fprintf(stderr,
 527 "Usage: nstat [OPTION] [ PATTERN [ PATTERN ] ]\n"
 528 "   -h, --help           this message\n"
 529 "   -a, --ignore         ignore history\n"
 530 "   -d, --scan=SECS      sample every statistics every SECS\n"
 531 "   -j, --json           format output in JSON\n"
 532 "   -n, --nooutput       do history only\n"
 533 "   -p, --pretty         pretty print\n"
 534 "   -r, --reset          reset history\n"
 535 "   -s, --noupdate       don't update history\n"
 536 "   -t, --interval=SECS  report average over the last SECS\n"
 537 "   -V, --version        output version information\n"
 538 "   -z, --zeros          show entries with zero activity\n");
 539         exit(-1);
 540 }
 541
 542 static const struct option longopts[] = {
 543         { "help", 0, 0, 'h' },
 544         { "ignore",  0,  0, 'a' },
 545         { "scan", 1, 0, 'd'},
 546         { "nooutput", 0, 0, 'n' },
 547         { "json", 0, 0, 'j' },
 548         { "reset", 0, 0, 'r' },
 549         { "noupdate", 0, 0, 's' },
 550         { "pretty", 0, 0, 'p' },
 551         { "interval", 1, 0, 't' },
 552         { "version", 0, 0, 'V' },
 553         { "zeros", 0, 0, 'z' },
 554         { 0 }
 555 };
 556
 557 int main(int argc, char *argv[])
 558 {
 559         char *hist_name;
 560         struct sockaddr_un sun;
 561         FILE *hist_fp = NULL;
 562         int ch;
 563         int fd;
 564
 565         while ((ch = getopt_long(argc, argv, "h?vVzrnasd:t:jp",
 566                                  longopts, NULL)) != EOF) {
 567                 switch (ch) {
 568                 case 'z':
 569                         dump_zeros = 1;
 570                         break;
 571                 case 'r':
 572                         reset_history = 1;
 573                         break;
 574                 case 'a':
 575                         ignore_history = 1;
 576                         break;
 577                 case 's':
 578                         no_update = 1;
 579                         break;
 580                 case 'n':
 581                         no_output = 1;
 582                         break;
 583                 case 'd':
 584                         scan_interval = 1000*atoi(optarg);
 585                         break;
 586                 case 't':
 587                         if (sscanf(optarg, "%d", &time_constant) != 1 ||
 588                             time_constant <= 0) {
 589                                 fprintf(stderr, "nstat: invalid time constant divisor\n");
 590                                 exit(-1);
 591                         }
 592                         break;
 593                 case 'j':
 594                         json_output = 1;
 595                         break;
 596                 case 'p':
 597                         pretty = 1;
 598                         break;
 599                 case 'v':
 600                 case 'V':
 601                         printf("nstat utility, iproute2-ss%s\n", SNAPSHOT);
 602                         exit(0);
 603                 case 'h':
 604                 case '?':
 605                 default:
 606                         usage();
 607                 }
 608         }
 609
 610         argc -= optind;
 611         argv += optind;
 612
 613         sun.sun_family = AF_UNIX;
 614         sun.sun_path[0] = 0;
 615         sprintf(sun.sun_path+1, "nstat%d", getuid());
 616
 617         if (scan_interval > 0) {
 618                 if (time_constant == 0)
 619                         time_constant = 60;
 620                 time_constant *= 1000;
 621                 W = 1 - 1/exp(log(10)*(double)scan_interval/time_constant);
 622                 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
 623                         perror("nstat: socket");
 624                         exit(-1);
 625                 }
 626                 if (bind(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) < 0) {
 627                         perror("nstat: bind");
 628                         exit(-1);
 629                 }
 630                 if (listen(fd, 5) < 0) {
 631                         perror("nstat: listen");
 632                         exit(-1);
 633                 }
 634                 if (daemon(0, 0)) {
 635                         perror("nstat: daemon");
 636                         exit(-1);
 637                 }
 638                 signal(SIGPIPE, SIG_IGN);
 639                 signal(SIGCHLD, sigchild);
 640                 server_loop(fd);
 641                 exit(0);
 642         }
 643
 644         patterns = argv;
 645         npatterns = argc;
 646
 647         if ((hist_name = getenv("NSTAT_HISTORY")) == NULL) {
 648                 hist_name = malloc(128);
 649                 sprintf(hist_name, "/tmp/.nstat.u%d", getuid());
 650         }
 651
 652         if (reset_history)
 653                 unlink(hist_name);
 654
 655         if (!ignore_history || !no_update) {
 656                 struct stat stb;
 657
 658                 fd = open(hist_name, O_RDWR|O_CREAT|O_NOFOLLOW, 0600);
 659                 if (fd < 0) {
 660                         perror("nstat: open history file");
 661                         exit(-1);
 662                 }
 663                 if ((hist_fp = fdopen(fd, "r+")) == NULL) {
 664                         perror("nstat: fdopen history file");
 665                         exit(-1);
 666                 }
 667                 if (flock(fileno(hist_fp), LOCK_EX)) {
 668                         perror("nstat: flock history file");
 669                         exit(-1);
 670                 }
 671                 if (fstat(fileno(hist_fp), &stb) != 0) {
 672                         perror("nstat: fstat history file");
 673                         exit(-1);
 674                 }
 675                 if (stb.st_nlink != 1 || stb.st_uid != getuid()) {
 676                         fprintf(stderr, "nstat: something is so wrong with history file, that I prefer not to proceed.\n");
 677                         exit(-1);
 678                 }
 679                 if (!ignore_history) {
 680                         FILE *tfp;
 681                         long uptime = -1;
 682
 683                         if ((tfp = fopen("/proc/uptime", "r")) != NULL) {
 684                                 if (fscanf(tfp, "%ld", &uptime) != 1)
 685                                         uptime = -1;
 686                                 fclose(tfp);
 687                         }
 688                         if (uptime >= 0 && time(NULL) >= stb.st_mtime+uptime) {
 689                                 fprintf(stderr, "nstat: history is aged out, resetting\n");
 690                                 if (ftruncate(fileno(hist_fp), 0) < 0)
 691                                         perror("nstat: ftruncate");
 692                         }
 693                 }
 694
 695                 load_good_table(hist_fp);
 696
 697                 hist_db = kern_db;
 698                 kern_db = NULL;
 699         }
 700
 701         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0 &&
 702             (connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0
 703              || (strcpy(sun.sun_path+1, "nstat0"),
 704                  connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0))
 705             && verify_forging(fd) == 0) {
 706                 FILE *sfp = fdopen(fd, "r");
 707
 708                 if (!sfp) {
 709                         fprintf(stderr, "nstat: fdopen failed: %s\n",
 710                                 strerror(errno));
 711                         close(fd);
 712                 } else {
 713                         load_good_table(sfp);
 714                         if (hist_db && source_mismatch) {
 715                                 fprintf(stderr, "nstat: history is stale, ignoring it.\n");
 716                                 hist_db = NULL;
 717                         }
 718                         fclose(sfp);
 719                 }
 720         } else {
 721                 if (fd >= 0)
 722                         close(fd);
 723                 if (hist_db && info_source[0] && strcmp(info_source, "kernel")) {
 724                         fprintf(stderr, "nstat: history is stale, ignoring it.\n");
 725                         hist_db = NULL;
 726                         info_source[0] = 0;
 727                 }
 728                 load_netstat();
 729                 load_snmp6();
 730                 load_snmp();
 731                 load_sctp_snmp();
 732                 if (info_source[0] == 0)
 733                         strcpy(info_source, "kernel");
 734         }
 735
 736         if (!no_output) {
 737                 if (ignore_history || hist_db == NULL)
 738                         dump_kern_db(stdout, 0);
 739                 else
 740                         dump_incr_db(stdout);
 741         }
 742         if (!no_update) {
 743                 if (ftruncate(fileno(hist_fp), 0) < 0)
 744                         perror("nstat: ftruncate");
 745                 rewind(hist_fp);
 746
 747                 json_output = 0;
 748                 dump_kern_db(hist_fp, 1);
 749                 fclose(hist_fp);
 750         }
 751         exit(0);
 752 }