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 (at) 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 pretty; 41 int no_update; 42 int scan_interval; 43 int time_constant; 44 double W; 45 char **patterns; 46 int npatterns; 47 48 char info_source[128]; 49 int source_mismatch; 50 51 static int generic_proc_open(const char *env, char *name) 52 { 53 char store[128]; 54 char *p = getenv(env); 55 56 if (!p) { 57 p = getenv("PROC_ROOT") ? : "/proc"; 58 snprintf(store, sizeof(store)-1, "%s/%s", p, name); 59 p = store; 60 } 61 return open(p, O_RDONLY); 62 } 63 64 static int net_netstat_open(void) 65 { 66 return generic_proc_open("PROC_NET_NETSTAT", "net/netstat"); 67 } 68 69 static int net_snmp_open(void) 70 { 71 return generic_proc_open("PROC_NET_SNMP", "net/snmp"); 72 } 73 74 static int net_snmp6_open(void) 75 { 76 return generic_proc_open("PROC_NET_SNMP6", "net/snmp6"); 77 } 78 79 static int net_sctp_snmp_open(void) 80 { 81 return generic_proc_open("PROC_NET_SCTP_SNMP", "net/sctp/snmp"); 82 } 83 84 struct nstat_ent { 85 struct nstat_ent *next; 86 char *id; 87 unsigned long long val; 88 double rate; 89 }; 90 91 struct nstat_ent *kern_db; 92 struct nstat_ent *hist_db; 93 94 static const char *useless_numbers[] = { 95 "IpForwarding", "IpDefaultTTL", 96 "TcpRtoAlgorithm", "TcpRtoMin", "TcpRtoMax", 97 "TcpMaxConn", "TcpCurrEstab" 98 }; 99 100 static int useless_number(const char *id) 101 { 102 int i; 103 104 for (i = 0; i < ARRAY_SIZE(useless_numbers); i++) 105 if (strcmp(id, useless_numbers[i]) == 0) 106 return 1; 107 return 0; 108 } 109 110 static int match(const char *id) 111 { 112 int i; 113 114 if (npatterns == 0) 115 return 1; 116 117 for (i = 0; i < npatterns; i++) { 118 if (!fnmatch(patterns[i], id, 0)) 119 return 1; 120 } 121 return 0; 122 } 123 124 static void load_good_table(FILE *fp) 125 { 126 char buf[4096]; 127 struct nstat_ent *db = NULL; 128 struct nstat_ent *n; 129 130 while (fgets(buf, sizeof(buf), fp) != NULL) { 131 int nr; 132 unsigned long long val; 133 double rate; 134 char idbuf[sizeof(buf)]; 135 136 if (buf[0] == '#') { 137 buf[strlen(buf)-1] = 0; 138 if (info_source[0] && strcmp(info_source, buf+1)) 139 source_mismatch = 1; 140 info_source[0] = 0; 141 strncat(info_source, buf+1, sizeof(info_source)-1); 142 continue; 143 } 144 /* idbuf is as big as buf, so this is safe */ 145 nr = sscanf(buf, "%s%llu%lg", idbuf, &val, &rate); 146 if (nr < 2) 147 abort(); 148 if (nr < 3) 149 rate = 0; 150 if (useless_number(idbuf)) 151 continue; 152 if ((n = malloc(sizeof(*n))) == NULL) 153 abort(); 154 n->id = strdup(idbuf); 155 n->val = val; 156 n->rate = rate; 157 n->next = db; 158 db = n; 159 } 160 161 while (db) { 162 n = db; 163 db = db->next; 164 n->next = kern_db; 165 kern_db = n; 166 } 167 } 168 169 static int count_spaces(const char *line) 170 { 171 int count = 0; 172 char c; 173 174 while ((c = *line++) != 0) 175 count += c == ' ' || c == '\n'; 176 return count; 177 } 178 179 static void load_ugly_table(FILE *fp) 180 { 181 char buf[4096]; 182 struct nstat_ent *db = NULL; 183 struct nstat_ent *n; 184 185 while (fgets(buf, sizeof(buf), fp) != NULL) { 186 char idbuf[sizeof(buf)]; 187 int off; 188 char *p; 189 int count1, count2, skip = 0; 190 191 p = strchr(buf, ':'); 192 if (!p) 193 abort(); 194 count1 = count_spaces(buf); 195 *p = 0; 196 idbuf[0] = 0; 197 strncat(idbuf, buf, sizeof(idbuf) - 1); 198 off = p - buf; 199 p += 2; 200 201 while (*p) { 202 char *next; 203 204 if ((next = strchr(p, ' ')) != NULL) 205 *next++ = 0; 206 else if ((next = strchr(p, '\n')) != NULL) 207 *next++ = 0; 208 if (off < sizeof(idbuf)) { 209 idbuf[off] = 0; 210 strncat(idbuf, p, sizeof(idbuf) - off - 1); 211 } 212 n = malloc(sizeof(*n)); 213 if (!n) 214 abort(); 215 n->id = strdup(idbuf); 216 n->rate = 0; 217 n->next = db; 218 db = n; 219 p = next; 220 } 221 n = db; 222 if (fgets(buf, sizeof(buf), fp) == NULL) 223 abort(); 224 count2 = count_spaces(buf); 225 if (count2 > count1) 226 skip = count2 - count1; 227 do { 228 p = strrchr(buf, ' '); 229 if (!p) 230 abort(); 231 *p = 0; 232 if (sscanf(p+1, "%llu", &n->val) != 1) 233 abort(); 234 /* Trick to skip "dummy" trailing ICMP MIB in 2.4 */ 235 if (skip) 236 skip--; 237 else 238 n = n->next; 239 } while (p > buf + off + 2); 240 } 241 242 while (db) { 243 n = db; 244 db = db->next; 245 if (useless_number(n->id)) { 246 free(n->id); 247 free(n); 248 } else { 249 n->next = kern_db; 250 kern_db = n; 251 } 252 } 253 } 254 255 static void load_sctp_snmp(void) 256 { 257 FILE *fp = fdopen(net_sctp_snmp_open(), "r"); 258 259 if (fp) { 260 load_good_table(fp); 261 fclose(fp); 262 } 263 } 264 265 static void load_snmp(void) 266 { 267 FILE *fp = fdopen(net_snmp_open(), "r"); 268 269 if (fp) { 270 load_ugly_table(fp); 271 fclose(fp); 272 } 273 } 274 275 static void load_snmp6(void) 276 { 277 FILE *fp = fdopen(net_snmp6_open(), "r"); 278 279 if (fp) { 280 load_good_table(fp); 281 fclose(fp); 282 } 283 } 284 285 static void load_netstat(void) 286 { 287 FILE *fp = fdopen(net_netstat_open(), "r"); 288 289 if (fp) { 290 load_ugly_table(fp); 291 fclose(fp); 292 } 293 } 294 295 296 static void dump_kern_db(FILE *fp, int to_hist) 297 { 298 json_writer_t *jw = json_output ? jsonw_new(fp) : NULL; 299 struct nstat_ent *n, *h; 300 301 h = hist_db; 302 if (jw) { 303 jsonw_start_object(jw); 304 jsonw_pretty(jw, pretty); 305 jsonw_name(jw, info_source); 306 jsonw_start_object(jw); 307 } else 308 fprintf(fp, "#%s\n", info_source); 309 310 for (n = kern_db; n; n = n->next) { 311 unsigned long long val = n->val; 312 313 if (!dump_zeros && !val && !n->rate) 314 continue; 315 if (!match(n->id)) { 316 struct nstat_ent *h1; 317 318 if (!to_hist) 319 continue; 320 for (h1 = h; h1; h1 = h1->next) { 321 if (strcmp(h1->id, n->id) == 0) { 322 val = h1->val; 323 h = h1->next; 324 break; 325 } 326 } 327 } 328 329 if (jw) 330 jsonw_uint_field(jw, n->id, val); 331 else 332 fprintf(fp, "%-32s%-16llu%6.1f\n", n->id, val, n->rate); 333 } 334 335 if (jw) { 336 jsonw_end_object(jw); 337 338 jsonw_end_object(jw); 339 jsonw_destroy(&jw); 340 } 341 } 342 343 static void dump_incr_db(FILE *fp) 344 { 345 json_writer_t *jw = json_output ? jsonw_new(fp) : NULL; 346 struct nstat_ent *n, *h; 347 348 h = hist_db; 349 if (jw) { 350 jsonw_start_object(jw); 351 jsonw_pretty(jw, pretty); 352 jsonw_name(jw, info_source); 353 jsonw_start_object(jw); 354 } else 355 fprintf(fp, "#%s\n", info_source); 356 357 for (n = kern_db; n; n = n->next) { 358 int ovfl = 0; 359 unsigned long long val = n->val; 360 struct nstat_ent *h1; 361 362 for (h1 = h; h1; h1 = h1->next) { 363 if (strcmp(h1->id, n->id) == 0) { 364 if (val < h1->val) { 365 ovfl = 1; 366 val = h1->val; 367 } 368 val -= h1->val; 369 h = h1->next; 370 break; 371 } 372 } 373 if (!dump_zeros && !val && !n->rate) 374 continue; 375 if (!match(n->id)) 376 continue; 377 378 if (jw) 379 jsonw_uint_field(jw, n->id, val); 380 else 381 fprintf(fp, "%-32s%-16llu%6.1f%s\n", n->id, val, 382 n->rate, ovfl?" (overflow)":""); 383 } 384 385 if (jw) { 386 jsonw_end_object(jw); 387 388 jsonw_end_object(jw); 389 jsonw_destroy(&jw); 390 } 391 } 392 393 static int children; 394 395 static void sigchild(int signo) 396 { 397 } 398 399 static void update_db(int interval) 400 { 401 struct nstat_ent *n, *h; 402 403 n = kern_db; 404 kern_db = NULL; 405 406 load_netstat(); 407 load_snmp6(); 408 load_snmp(); 409 load_sctp_snmp(); 410 411 h = kern_db; 412 kern_db = n; 413 414 for (n = kern_db; n; n = n->next) { 415 struct nstat_ent *h1; 416 417 for (h1 = h; h1; h1 = h1->next) { 418 if (strcmp(h1->id, n->id) == 0) { 419 double sample; 420 unsigned long long incr = h1->val - n->val; 421 422 n->val = h1->val; 423 sample = (double)incr * 1000.0 / interval; 424 if (interval >= scan_interval) { 425 n->rate += W*(sample-n->rate); 426 } else if (interval >= 1000) { 427 if (interval >= time_constant) { 428 n->rate = sample; 429 } else { 430 double w = W*(double)interval/scan_interval; 431 432 n->rate += w*(sample-n->rate); 433 } 434 } 435 436 while (h != h1) { 437 struct nstat_ent *tmp = h; 438 439 h = h->next; 440 free(tmp->id); 441 free(tmp); 442 }; 443 h = h1->next; 444 free(h1->id); 445 free(h1); 446 break; 447 } 448 } 449 } 450 } 451 452 #define T_DIFF(a, b) (((a).tv_sec-(b).tv_sec)*1000 + ((a).tv_usec-(b).tv_usec)/1000) 453 454 455 static void server_loop(int fd) 456 { 457 struct timeval snaptime = { 0 }; 458 struct pollfd p; 459 460 p.fd = fd; 461 p.events = p.revents = POLLIN; 462 463 sprintf(info_source, "%d.%lu sampling_interval=%d time_const=%d", 464 getpid(), (unsigned long)random(), scan_interval/1000, time_constant/1000); 465 466 load_netstat(); 467 load_snmp6(); 468 load_snmp(); 469 load_sctp_snmp(); 470 471 for (;;) { 472 int status; 473 time_t tdiff; 474 struct timeval now; 475 476 gettimeofday(&now, NULL); 477 tdiff = T_DIFF(now, snaptime); 478 if (tdiff >= scan_interval) { 479 update_db(tdiff); 480 snaptime = now; 481 tdiff = 0; 482 } 483 if (poll(&p, 1, scan_interval - tdiff) > 0 484 && (p.revents&POLLIN)) { 485 int clnt = accept(fd, NULL, NULL); 486 487 if (clnt >= 0) { 488 pid_t pid; 489 490 if (children >= 5) { 491 close(clnt); 492 } else if ((pid = fork()) != 0) { 493 if (pid > 0) 494 children++; 495 close(clnt); 496 } else { 497 FILE *fp = fdopen(clnt, "w"); 498 499 if (fp) 500 dump_kern_db(fp, 0); 501 exit(0); 502 } 503 } 504 } 505 while (children && waitpid(-1, &status, WNOHANG) > 0) 506 children--; 507 } 508 } 509 510 static int verify_forging(int fd) 511 { 512 struct ucred cred; 513 socklen_t olen = sizeof(cred); 514 515 if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, (void *)&cred, &olen) || 516 olen < sizeof(cred)) 517 return -1; 518 if (cred.uid == getuid() || cred.uid == 0) 519 return 0; 520 return -1; 521 } 522 523 static void usage(void) __attribute__((noreturn)); 524 525 static void usage(void) 526 { 527 fprintf(stderr, 528 "Usage: nstat [OPTION] [ PATTERN [ PATTERN ] ]\n" 529 " -h, --help this message\n" 530 " -a, --ignore ignore history\n" 531 " -d, --scan=SECS sample every statistics every SECS\n" 532 " -j, --json format output in JSON\n" 533 " -n, --nooutput do history only\n" 534 " -p, --pretty pretty print\n" 535 " -r, --reset reset history\n" 536 " -s, --noupdate don't update history\n" 537 " -t, --interval=SECS report average over the last SECS\n" 538 " -V, --version output version information\n" 539 " -z, --zeros show entries with zero activity\n"); 540 exit(-1); 541 } 542 543 static const struct option longopts[] = { 544 { "help", 0, 0, 'h' }, 545 { "ignore", 0, 0, 'a' }, 546 { "scan", 1, 0, 'd'}, 547 { "nooutput", 0, 0, 'n' }, 548 { "json", 0, 0, 'j' }, 549 { "reset", 0, 0, 'r' }, 550 { "noupdate", 0, 0, 's' }, 551 { "pretty", 0, 0, 'p' }, 552 { "interval", 1, 0, 't' }, 553 { "version", 0, 0, 'V' }, 554 { "zeros", 0, 0, 'z' }, 555 { 0 } 556 }; 557 558 int main(int argc, char *argv[]) 559 { 560 char *hist_name; 561 struct sockaddr_un sun; 562 FILE *hist_fp = NULL; 563 int ch; 564 int fd; 565 566 while ((ch = getopt_long(argc, argv, "h?vVzrnasd:t:jp", 567 longopts, NULL)) != EOF) { 568 switch (ch) { 569 case 'z': 570 dump_zeros = 1; 571 break; 572 case 'r': 573 reset_history = 1; 574 break; 575 case 'a': 576 ignore_history = 1; 577 break; 578 case 's': 579 no_update = 1; 580 break; 581 case 'n': 582 no_output = 1; 583 break; 584 case 'd': 585 scan_interval = 1000*atoi(optarg); 586 break; 587 case 't': 588 if (sscanf(optarg, "%d", &time_constant) != 1 || 589 time_constant <= 0) { 590 fprintf(stderr, "nstat: invalid time constant divisor\n"); 591 exit(-1); 592 } 593 break; 594 case 'j': 595 json_output = 1; 596 break; 597 case 'p': 598 pretty = 1; 599 break; 600 case 'v': 601 case 'V': 602 printf("nstat utility, iproute2-ss%s\n", SNAPSHOT); 603 exit(0); 604 case 'h': 605 case '?': 606 default: 607 usage(); 608 } 609 } 610 611 argc -= optind; 612 argv += optind; 613 614 sun.sun_family = AF_UNIX; 615 sun.sun_path[0] = 0; 616 sprintf(sun.sun_path+1, "nstat%d", getuid()); 617 618 if (scan_interval > 0) { 619 if (time_constant == 0) 620 time_constant = 60; 621 time_constant *= 1000; 622 W = 1 - 1/exp(log(10)*(double)scan_interval/time_constant); 623 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) { 624 perror("nstat: socket"); 625 exit(-1); 626 } 627 if (bind(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) < 0) { 628 perror("nstat: bind"); 629 exit(-1); 630 } 631 if (listen(fd, 5) < 0) { 632 perror("nstat: listen"); 633 exit(-1); 634 } 635 if (daemon(0, 0)) { 636 perror("nstat: daemon"); 637 exit(-1); 638 } 639 signal(SIGPIPE, SIG_IGN); 640 signal(SIGCHLD, sigchild); 641 server_loop(fd); 642 exit(0); 643 } 644 645 patterns = argv; 646 npatterns = argc; 647 648 if ((hist_name = getenv("NSTAT_HISTORY")) == NULL) { 649 hist_name = malloc(128); 650 sprintf(hist_name, "/tmp/.nstat.u%d", getuid()); 651 } 652 653 if (reset_history) 654 unlink(hist_name); 655 656 if (!ignore_history || !no_update) { 657 struct stat stb; 658 659 fd = open(hist_name, O_RDWR|O_CREAT|O_NOFOLLOW, 0600); 660 if (fd < 0) { 661 perror("nstat: open history file"); 662 exit(-1); 663 } 664 if ((hist_fp = fdopen(fd, "r+")) == NULL) { 665 perror("nstat: fdopen history file"); 666 exit(-1); 667 } 668 if (flock(fileno(hist_fp), LOCK_EX)) { 669 perror("nstat: flock history file"); 670 exit(-1); 671 } 672 if (fstat(fileno(hist_fp), &stb) != 0) { 673 perror("nstat: fstat history file"); 674 exit(-1); 675 } 676 if (stb.st_nlink != 1 || stb.st_uid != getuid()) { 677 fprintf(stderr, "nstat: something is so wrong with history file, that I prefer not to proceed.\n"); 678 exit(-1); 679 } 680 if (!ignore_history) { 681 FILE *tfp; 682 long uptime = -1; 683 684 if ((tfp = fopen("/proc/uptime", "r")) != NULL) { 685 if (fscanf(tfp, "%ld", &uptime) != 1) 686 uptime = -1; 687 fclose(tfp); 688 } 689 if (uptime >= 0 && time(NULL) >= stb.st_mtime+uptime) { 690 fprintf(stderr, "nstat: history is aged out, resetting\n"); 691 if (ftruncate(fileno(hist_fp), 0) < 0) 692 perror("nstat: ftruncate"); 693 } 694 } 695 696 load_good_table(hist_fp); 697 698 hist_db = kern_db; 699 kern_db = NULL; 700 } 701 702 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0 && 703 (connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0 704 || (strcpy(sun.sun_path+1, "nstat0"), 705 connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0)) 706 && verify_forging(fd) == 0) { 707 FILE *sfp = fdopen(fd, "r"); 708 709 if (!sfp) { 710 fprintf(stderr, "nstat: fdopen failed: %s\n", 711 strerror(errno)); 712 close(fd); 713 } else { 714 load_good_table(sfp); 715 if (hist_db && source_mismatch) { 716 fprintf(stderr, "nstat: history is stale, ignoring it.\n"); 717 hist_db = NULL; 718 } 719 fclose(sfp); 720 } 721 } else { 722 if (fd >= 0) 723 close(fd); 724 if (hist_db && info_source[0] && strcmp(info_source, "kernel")) { 725 fprintf(stderr, "nstat: history is stale, ignoring it.\n"); 726 hist_db = NULL; 727 info_source[0] = 0; 728 } 729 load_netstat(); 730 load_snmp6(); 731 load_snmp(); 732 load_sctp_snmp(); 733 if (info_source[0] == 0) 734 strcpy(info_source, "kernel"); 735 } 736 737 if (!no_output) { 738 if (ignore_history || hist_db == NULL) 739 dump_kern_db(stdout, 0); 740 else 741 dump_incr_db(stdout); 742 } 743 if (!no_update) { 744 if (ftruncate(fileno(hist_fp), 0) < 0) 745 perror("nstat: ftruncate"); 746 rewind(hist_fp); 747 748 json_output = 0; 749 dump_kern_db(hist_fp, 1); 750 fclose(hist_fp); 751 } 752 exit(0); 753 } 754
