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