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