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 = NULL;
 181         size_t buflen = 0;
 182         ssize_t nread;
 183         struct nstat_ent *db = NULL;
 184         struct nstat_ent *n;
 185
 186         while ((nread = getline(&buf, &buflen, fp)) != -1) {
 187                 char idbuf[4096];
 188                 int  off;
 189                 char *p;
 190                 int count1, count2, skip = 0;
 191
 192                 p = strchr(buf, ':');
 193                 if (!p)
 194                         abort();
 195                 count1 = count_spaces(buf);
 196                 *p = 0;
 197                 idbuf[0] = 0;
 198                 strncat(idbuf, buf, sizeof(idbuf) - 1);
 199                 off = p - buf;
 200                 p += 2;
 201
 202                 while (*p) {
 203                         char *next;
 204
 205                         if ((next = strchr(p, ' ')) != NULL)
 206                                 *next++ = 0;
 207                         else if ((next = strchr(p, '\n')) != NULL)
 208                                 *next++ = 0;
 209                         if (off < sizeof(idbuf)) {
 210                                 idbuf[off] = 0;
 211                                 strncat(idbuf, p, sizeof(idbuf) - off - 1);
 212                         }
 213                         n = malloc(sizeof(*n));
 214                         if (!n)
 215                                 abort();
 216                         n->id = strdup(idbuf);
 217                         n->rate = 0;
 218                         n->next = db;
 219                         db = n;
 220                         p = next;
 221                 }
 222                 n = db;
 223                 nread = getline(&buf, &buflen, fp);
 224                 if (nread == -1)
 225                         abort();
 226                 count2 = count_spaces(buf);
 227                 if (count2 > count1)
 228                         skip = count2 - count1;
 229                 do {
 230                         p = strrchr(buf, ' ');
 231                         if (!p)
 232                                 abort();
 233                         *p = 0;
 234                         if (sscanf(p+1, "%llu", &n->val) != 1)
 235                                 abort();
 236                         /* Trick to skip "dummy" trailing ICMP MIB in 2.4 */
 237                         if (skip)
 238                                 skip--;
 239                         else
 240                                 n = n->next;
 241                 } while (p > buf + off + 2);
 242         }
 243         free(buf);
 244
 245         while (db) {
 246                 n = db;
 247                 db = db->next;
 248                 if (useless_number(n->id)) {
 249                         free(n->id);
 250                         free(n);
 251                 } else {
 252                         n->next = kern_db;
 253                         kern_db = n;
 254                 }
 255         }
 256 }
 257
 258 static void load_sctp_snmp(void)
 259 {
 260         FILE *fp = fdopen(net_sctp_snmp_open(), "r");
 261
 262         if (fp) {
 263                 load_good_table(fp);
 264                 fclose(fp);
 265         }
 266 }
 267
 268 static void load_snmp(void)
 269 {
 270         FILE *fp = fdopen(net_snmp_open(), "r");
 271
 272         if (fp) {
 273                 load_ugly_table(fp);
 274                 fclose(fp);
 275         }
 276 }
 277
 278 static void load_snmp6(void)
 279 {
 280         FILE *fp = fdopen(net_snmp6_open(), "r");
 281
 282         if (fp) {
 283                 load_good_table(fp);
 284                 fclose(fp);
 285         }
 286 }
 287
 288 static void load_netstat(void)
 289 {
 290         FILE *fp = fdopen(net_netstat_open(), "r");
 291
 292         if (fp) {
 293                 load_ugly_table(fp);
 294                 fclose(fp);
 295         }
 296 }
 297
 298
 299 static void dump_kern_db(FILE *fp, int to_hist)
 300 {
 301         json_writer_t *jw = json_output ? jsonw_new(fp) : NULL;
 302         struct nstat_ent *n, *h;
 303
 304         h = hist_db;
 305         if (jw) {
 306                 jsonw_start_object(jw);
 307                 jsonw_pretty(jw, pretty);
 308                 jsonw_name(jw, info_source);
 309                 jsonw_start_object(jw);
 310         } else
 311                 fprintf(fp, "#%s\n", info_source);
 312
 313         for (n = kern_db; n; n = n->next) {
 314                 unsigned long long val = n->val;
 315
 316                 if (!dump_zeros && !val && !n->rate)
 317                         continue;
 318                 if (!match(n->id)) {
 319                         struct nstat_ent *h1;
 320
 321                         if (!to_hist)
 322                                 continue;
 323                         for (h1 = h; h1; h1 = h1->next) {
 324                                 if (strcmp(h1->id, n->id) == 0) {
 325                                         val = h1->val;
 326                                         h = h1->next;
 327                                         break;
 328                                 }
 329                         }
 330                 }
 331
 332                 if (jw)
 333                         jsonw_uint_field(jw, n->id, val);
 334                 else
 335                         fprintf(fp, "%-32s%-16llu%6.1f\n", n->id, val, n->rate);
 336         }
 337
 338         if (jw) {
 339                 jsonw_end_object(jw);
 340
 341                 jsonw_end_object(jw);
 342                 jsonw_destroy(&jw);
 343         }
 344 }
 345
 346 static void dump_incr_db(FILE *fp)
 347 {
 348         json_writer_t *jw = json_output ? jsonw_new(fp) : NULL;
 349         struct nstat_ent *n, *h;
 350
 351         h = hist_db;
 352         if (jw) {
 353                 jsonw_start_object(jw);
 354                 jsonw_pretty(jw, pretty);
 355                 jsonw_name(jw, info_source);
 356                 jsonw_start_object(jw);
 357         } else
 358                 fprintf(fp, "#%s\n", info_source);
 359
 360         for (n = kern_db; n; n = n->next) {
 361                 int ovfl = 0;
 362                 unsigned long long val = n->val;
 363                 struct nstat_ent *h1;
 364
 365                 for (h1 = h; h1; h1 = h1->next) {
 366                         if (strcmp(h1->id, n->id) == 0) {
 367                                 if (val < h1->val) {
 368                                         ovfl = 1;
 369                                         val = h1->val;
 370                                 }
 371                                 val -= h1->val;
 372                                 h = h1->next;
 373                                 break;
 374                         }
 375                 }
 376                 if (!dump_zeros && !val && !n->rate)
 377                         continue;
 378                 if (!match(n->id))
 379                         continue;
 380
 381                 if (jw)
 382                         jsonw_uint_field(jw, n->id, val);
 383                 else
 384                         fprintf(fp, "%-32s%-16llu%6.1f%s\n", n->id, val,
 385                                 n->rate, ovfl?" (overflow)":"");
 386         }
 387
 388         if (jw) {
 389                 jsonw_end_object(jw);
 390
 391                 jsonw_end_object(jw);
 392                 jsonw_destroy(&jw);
 393         }
 394 }
 395
 396 static int children;
 397
 398 static void sigchild(int signo)
 399 {
 400 }
 401
 402 static void update_db(int interval)
 403 {
 404         struct nstat_ent *n, *h;
 405
 406         n = kern_db;
 407         kern_db = NULL;
 408
 409         load_netstat();
 410         load_snmp6();
 411         load_snmp();
 412         load_sctp_snmp();
 413
 414         h = kern_db;
 415         kern_db = n;
 416
 417         for (n = kern_db; n; n = n->next) {
 418                 struct nstat_ent *h1;
 419
 420                 for (h1 = h; h1; h1 = h1->next) {
 421                         if (strcmp(h1->id, n->id) == 0) {
 422                                 double sample;
 423                                 unsigned long long incr = h1->val - n->val;
 424
 425                                 n->val = h1->val;
 426                                 sample = (double)incr * 1000.0 / interval;
 427                                 if (interval >= scan_interval) {
 428                                         n->rate += W*(sample-n->rate);
 429                                 } else if (interval >= 1000) {
 430                                         if (interval >= time_constant) {
 431                                                 n->rate = sample;
 432                                         } else {
 433                                                 double w = W*(double)interval/scan_interval;
 434
 435                                                 n->rate += w*(sample-n->rate);
 436                                         }
 437                                 }
 438
 439                                 while (h != h1) {
 440                                         struct nstat_ent *tmp = h;
 441
 442                                         h = h->next;
 443                                         free(tmp->id);
 444                                         free(tmp);
 445                                 };
 446                                 h = h1->next;
 447                                 free(h1->id);
 448                                 free(h1);
 449                                 break;
 450                         }
 451                 }
 452         }
 453 }
 454
 455 #define T_DIFF(a, b) (((a).tv_sec-(b).tv_sec)*1000 + ((a).tv_usec-(b).tv_usec)/1000)
 456
 457
 458 static void server_loop(int fd)
 459 {
 460         struct timeval snaptime = { 0 };
 461         struct pollfd p;
 462
 463         p.fd = fd;
 464         p.events = p.revents = POLLIN;
 465
 466         sprintf(info_source, "%d.%lu sampling_interval=%d time_const=%d",
 467                 getpid(), (unsigned long)random(), scan_interval/1000, time_constant/1000);
 468
 469         load_netstat();
 470         load_snmp6();
 471         load_snmp();
 472         load_sctp_snmp();
 473
 474         for (;;) {
 475                 int status;
 476                 time_t tdiff;
 477                 struct timeval now;
 478
 479                 gettimeofday(&now, NULL);
 480                 tdiff = T_DIFF(now, snaptime);
 481                 if (tdiff >= scan_interval) {
 482                         update_db(tdiff);
 483                         snaptime = now;
 484                         tdiff = 0;
 485                 }
 486                 if (poll(&p, 1, scan_interval - tdiff) > 0
 487                     && (p.revents&POLLIN)) {
 488                         int clnt = accept(fd, NULL, NULL);
 489
 490                         if (clnt >= 0) {
 491                                 pid_t pid;
 492
 493                                 if (children >= 5) {
 494                                         close(clnt);
 495                                 } else if ((pid = fork()) != 0) {
 496                                         if (pid > 0)
 497                                                 children++;
 498                                         close(clnt);
 499                                 } else {
 500                                         FILE *fp = fdopen(clnt, "w");
 501
 502                                         if (fp)
 503                                                 dump_kern_db(fp, 0);
 504                                         exit(0);
 505                                 }
 506                         }
 507                 }
 508                 while (children && waitpid(-1, &status, WNOHANG) > 0)
 509                         children--;
 510         }
 511 }
 512
 513 static int verify_forging(int fd)
 514 {
 515         struct ucred cred;
 516         socklen_t olen = sizeof(cred);
 517
 518         if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, (void *)&cred, &olen) ||
 519             olen < sizeof(cred))
 520                 return -1;
 521         if (cred.uid == getuid() || cred.uid == 0)
 522                 return 0;
 523         return -1;
 524 }
 525
 526 static void usage(void) __attribute__((noreturn));
 527
 528 static void usage(void)
 529 {
 530         fprintf(stderr,
 531 "Usage: nstat [OPTION] [ PATTERN [ PATTERN ] ]\n"
 532 "   -h, --help           this message\n"
 533 "   -a, --ignore         ignore history\n"
 534 "   -d, --scan=SECS      sample every statistics every SECS\n"
 535 "   -j, --json           format output in JSON\n"
 536 "   -n, --nooutput       do history only\n"
 537 "   -p, --pretty         pretty print\n"
 538 "   -r, --reset          reset history\n"
 539 "   -s, --noupdate       don't update history\n"
 540 "   -t, --interval=SECS  report average over the last SECS\n"
 541 "   -V, --version        output version information\n"
 542 "   -z, --zeros          show entries with zero activity\n");
 543         exit(-1);
 544 }
 545
 546 static const struct option longopts[] = {
 547         { "help", 0, 0, 'h' },
 548         { "ignore",  0,  0, 'a' },
 549         { "scan", 1, 0, 'd'},
 550         { "nooutput", 0, 0, 'n' },
 551         { "json", 0, 0, 'j' },
 552         { "reset", 0, 0, 'r' },
 553         { "noupdate", 0, 0, 's' },
 554         { "pretty", 0, 0, 'p' },
 555         { "interval", 1, 0, 't' },
 556         { "version", 0, 0, 'V' },
 557         { "zeros", 0, 0, 'z' },
 558         { 0 }
 559 };
 560
 561 int main(int argc, char *argv[])
 562 {
 563         char *hist_name;
 564         struct sockaddr_un sun;
 565         FILE *hist_fp = NULL;
 566         int ch;
 567         int fd;
 568
 569         while ((ch = getopt_long(argc, argv, "h?vVzrnasd:t:jp",
 570                                  longopts, NULL)) != EOF) {
 571                 switch (ch) {
 572                 case 'z':
 573                         dump_zeros = 1;
 574                         break;
 575                 case 'r':
 576                         reset_history = 1;
 577                         break;
 578                 case 'a':
 579                         ignore_history = 1;
 580                         break;
 581                 case 's':
 582                         no_update = 1;
 583                         break;
 584                 case 'n':
 585                         no_output = 1;
 586                         break;
 587                 case 'd':
 588                         scan_interval = 1000*atoi(optarg);
 589                         break;
 590                 case 't':
 591                         if (sscanf(optarg, "%d", &time_constant) != 1 ||
 592                             time_constant <= 0) {
 593                                 fprintf(stderr, "nstat: invalid time constant divisor\n");
 594                                 exit(-1);
 595                         }
 596                         break;
 597                 case 'j':
 598                         json_output = 1;
 599                         break;
 600                 case 'p':
 601                         pretty = 1;
 602                         break;
 603                 case 'v':
 604                 case 'V':
 605                         printf("nstat utility, iproute2-ss%s\n", SNAPSHOT);
 606                         exit(0);
 607                 case 'h':
 608                 case '?':
 609                 default:
 610                         usage();
 611                 }
 612         }
 613
 614         argc -= optind;
 615         argv += optind;
 616
 617         sun.sun_family = AF_UNIX;
 618         sun.sun_path[0] = 0;
 619         sprintf(sun.sun_path+1, "nstat%d", getuid());
 620
 621         if (scan_interval > 0) {
 622                 if (time_constant == 0)
 623                         time_constant = 60;
 624                 time_constant *= 1000;
 625                 W = 1 - 1/exp(log(10)*(double)scan_interval/time_constant);
 626                 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
 627                         perror("nstat: socket");
 628                         exit(-1);
 629                 }
 630                 if (bind(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) < 0) {
 631                         perror("nstat: bind");
 632                         exit(-1);
 633                 }
 634                 if (listen(fd, 5) < 0) {
 635                         perror("nstat: listen");
 636                         exit(-1);
 637                 }
 638                 if (daemon(0, 0)) {
 639                         perror("nstat: daemon");
 640                         exit(-1);
 641                 }
 642                 signal(SIGPIPE, SIG_IGN);
 643                 signal(SIGCHLD, sigchild);
 644                 server_loop(fd);
 645                 exit(0);
 646         }
 647
 648         patterns = argv;
 649         npatterns = argc;
 650
 651         if ((hist_name = getenv("NSTAT_HISTORY")) == NULL) {
 652                 hist_name = malloc(128);
 653                 sprintf(hist_name, "/tmp/.nstat.u%d", getuid());
 654         }
 655
 656         if (reset_history)
 657                 unlink(hist_name);
 658
 659         if (!ignore_history || !no_update) {
 660                 struct stat stb;
 661
 662                 fd = open(hist_name, O_RDWR|O_CREAT|O_NOFOLLOW, 0600);
 663                 if (fd < 0) {
 664                         perror("nstat: open history file");
 665                         exit(-1);
 666                 }
 667                 if ((hist_fp = fdopen(fd, "r+")) == NULL) {
 668                         perror("nstat: fdopen history file");
 669                         exit(-1);
 670                 }
 671                 if (flock(fileno(hist_fp), LOCK_EX)) {
 672                         perror("nstat: flock history file");
 673                         exit(-1);
 674                 }
 675                 if (fstat(fileno(hist_fp), &stb) != 0) {
 676                         perror("nstat: fstat history file");
 677                         exit(-1);
 678                 }
 679                 if (stb.st_nlink != 1 || stb.st_uid != getuid()) {
 680                         fprintf(stderr, "nstat: something is so wrong with history file, that I prefer not to proceed.\n");
 681                         exit(-1);
 682                 }
 683                 if (!ignore_history) {
 684                         FILE *tfp;
 685                         long uptime = -1;
 686
 687                         if ((tfp = fopen("/proc/uptime", "r")) != NULL) {
 688                                 if (fscanf(tfp, "%ld", &uptime) != 1)
 689                                         uptime = -1;
 690                                 fclose(tfp);
 691                         }
 692                         if (uptime >= 0 && time(NULL) >= stb.st_mtime+uptime) {
 693                                 fprintf(stderr, "nstat: history is aged out, resetting\n");
 694                                 if (ftruncate(fileno(hist_fp), 0) < 0)
 695                                         perror("nstat: ftruncate");
 696                         }
 697                 }
 698
 699                 load_good_table(hist_fp);
 700
 701                 hist_db = kern_db;
 702                 kern_db = NULL;
 703         }
 704
 705         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0 &&
 706             (connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0
 707              || (strcpy(sun.sun_path+1, "nstat0"),
 708                  connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0))
 709             && verify_forging(fd) == 0) {
 710                 FILE *sfp = fdopen(fd, "r");
 711
 712                 if (!sfp) {
 713                         fprintf(stderr, "nstat: fdopen failed: %s\n",
 714                                 strerror(errno));
 715                         close(fd);
 716                 } else {
 717                         load_good_table(sfp);
 718                         if (hist_db && source_mismatch) {
 719                                 fprintf(stderr, "nstat: history is stale, ignoring it.\n");
 720                                 hist_db = NULL;
 721                         }
 722                         fclose(sfp);
 723                 }
 724         } else {
 725                 if (fd >= 0)
 726                         close(fd);
 727                 if (hist_db && info_source[0] && strcmp(info_source, "kernel")) {
 728                         fprintf(stderr, "nstat: history is stale, ignoring it.\n");
 729                         hist_db = NULL;
 730                         info_source[0] = 0;
 731                 }
 732                 load_netstat();
 733                 load_snmp6();
 734                 load_snmp();
 735                 load_sctp_snmp();
 736                 if (info_source[0] == 0)
 737                         strcpy(info_source, "kernel");
 738         }
 739
 740         if (!no_output) {
 741                 if (ignore_history || hist_db == NULL)
 742                         dump_kern_db(stdout, 0);
 743                 else
 744                         dump_incr_db(stdout);
 745         }
 746         if (!no_update) {
 747                 if (ftruncate(fileno(hist_fp), 0) < 0)
 748                         perror("nstat: ftruncate");
 749                 rewind(hist_fp);
 750
 751                 json_output = 0;
 752                 dump_kern_db(hist_fp, 1);
 753                 fclose(hist_fp);
 754         }
 755         exit(0);
 756 }