2 * nstat.c handy utility to read counters /proc/net/netstat and snmp
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.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
22 #include <sys/socket.h>
33 int reset_history = 0;
34 int ignore_history = 0;
37 int scan_interval = 0;
38 int time_constant = 0;
43 char info_source[128];
46 int generic_proc_open(char *env, char *name)
49 char *p = getenv(env);
51 p = getenv("PROC_ROOT") ? : "/proc";
52 snprintf(store, sizeof(store)-1, "%s/%s", p, name);
55 return open(store, O_RDONLY);
58 int net_netstat_open(void)
60 return generic_proc_open("PROC_NET_NETSTAT", "net/netstat");
63 int net_snmp_open(void)
65 return generic_proc_open("PROC_NET_SNMP", "net/snmp");
68 int net_snmp6_open(void)
70 return generic_proc_open("PROC_NET_SNMP6", "net/snmp6");
75 struct nstat_ent *next;
77 unsigned long long val;
82 struct nstat_ent *kern_db;
83 struct nstat_ent *hist_db;
85 char *useless_numbers[] = {
86 "IpForwarding", "IpDefaultTTL",
87 "TcpRtoAlgorithm", "TcpRtoMin", "TcpRtoMax",
88 "TcpMaxConn", "TcpCurrEstab"
91 int useless_number(char *id)
94 for (i=0; i<sizeof(useless_numbers)/sizeof(*useless_numbers); i++)
95 if (strcmp(id, useless_numbers[i]) == 0)
107 for (i=0; i<npatterns; i++) {
108 if (!fnmatch(patterns[i], id, 0))
114 void load_good_table(FILE *fp)
117 struct nstat_ent *db = NULL;
120 while (fgets(buf, sizeof(buf), fp) != NULL) {
122 unsigned long long val;
124 char idbuf[sizeof(buf)];
126 buf[strlen(buf)-1] = 0;
127 if (info_source[0] && strcmp(info_source, buf+1))
130 strncat(info_source, buf+1, sizeof(info_source)-1);
133 /* idbuf is as big as buf, so this is safe */
134 nr = sscanf(buf, "%s%llu%lg", idbuf, &val, &rate);
139 if (useless_number(idbuf))
141 if ((n = malloc(sizeof(*n))) == NULL)
143 n->id = strdup(idbuf);
144 n->ival = (unsigned long)val;
160 void load_ugly_table(FILE *fp)
163 struct nstat_ent *db = NULL;
166 while (fgets(buf, sizeof(buf), fp) != NULL) {
167 char idbuf[sizeof(buf)];
171 p = strchr(buf, ':');
176 strncat(idbuf, buf, sizeof(idbuf) - 1);
182 if ((next = strchr(p, ' ')) != NULL)
184 else if ((next = strchr(p, '\n')) != NULL)
186 if (off < sizeof(idbuf)) {
188 strncat(idbuf, p, sizeof(idbuf) - off - 1);
190 n = malloc(sizeof(*n));
193 n->id = strdup(idbuf);
200 if (fgets(buf, sizeof(buf), fp) == NULL)
203 p = strrchr(buf, ' ');
207 if (sscanf(p+1, "%lu", &n->ival) != 1)
210 /* Trick to skip "dummy" trailing ICMP MIB in 2.4 */
211 if (strcmp(idbuf, "IcmpOutAddrMaskReps") == 0)
215 } while (p > buf + off + 2);
221 if (useless_number(n->id)) {
233 FILE *fp = fdopen(net_snmp_open(), "r");
240 void load_snmp6(void)
242 FILE *fp = fdopen(net_snmp6_open(), "r");
249 void load_netstat(void)
251 FILE *fp = fdopen(net_netstat_open(), "r");
258 void dump_kern_db(FILE *fp, int to_hist)
260 struct nstat_ent *n, *h;
262 fprintf(fp, "#%s\n", info_source);
263 for (n=kern_db; n; n=n->next) {
264 unsigned long long val = n->val;
265 if (!dump_zeros && !val && !n->rate)
268 struct nstat_ent *h1;
271 for (h1 = h; h1; h1 = h1->next) {
272 if (strcmp(h1->id, n->id) == 0) {
279 fprintf(fp, "%-32s%-16llu%6.1f\n", n->id, val, n->rate);
283 void dump_incr_db(FILE *fp)
285 struct nstat_ent *n, *h;
287 fprintf(fp, "#%s\n", info_source);
288 for (n=kern_db; n; n=n->next) {
290 unsigned long long val = n->val;
291 struct nstat_ent *h1;
292 for (h1 = h; h1; h1 = h1->next) {
293 if (strcmp(h1->id, n->id) == 0) {
303 if (!dump_zeros && !val && !n->rate)
307 fprintf(fp, "%-32s%-16llu%6.1f%s\n", n->id, val,
308 n->rate, ovfl?" (overflow)":"");
314 void sigchild(int signo)
318 void update_db(int interval)
320 struct nstat_ent *n, *h;
332 for (n = kern_db; n; n = n->next) {
333 struct nstat_ent *h1;
334 for (h1 = h; h1; h1 = h1->next) {
335 if (strcmp(h1->id, n->id) == 0) {
337 unsigned long incr = h1->ival - n->ival;
340 sample = (double)(incr*1000)/interval;
341 if (interval >= scan_interval) {
342 n->rate += W*(sample-n->rate);
343 } else if (interval >= 1000) {
344 if (interval >= time_constant) {
347 double w = W*(double)interval/scan_interval;
348 n->rate += w*(sample-n->rate);
353 struct nstat_ent *tmp = h;
367 #define T_DIFF(a,b) (((a).tv_sec-(b).tv_sec)*1000 + ((a).tv_usec-(b).tv_usec)/1000)
370 void server_loop(int fd)
372 struct timeval snaptime = { 0 };
375 p.events = p.revents = POLLIN;
377 sprintf(info_source, "%d.%lu sampling_interval=%d time_const=%d",
378 getpid(), (unsigned long)random(), scan_interval/1000, time_constant/1000);
388 gettimeofday(&now, NULL);
389 tdiff = T_DIFF(now, snaptime);
390 if (tdiff >= scan_interval) {
395 if (poll(&p, 1, tdiff + scan_interval) > 0
396 && (p.revents&POLLIN)) {
397 int clnt = accept(fd, NULL, NULL);
402 } else if ((pid = fork()) != 0) {
407 FILE *fp = fdopen(clnt, "w");
417 while (children && waitpid(-1, &status, WNOHANG) > 0)
422 int verify_forging(int fd)
425 socklen_t olen = sizeof(cred);
427 if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, (void*)&cred, &olen) ||
430 if (cred.uid == getuid() || cred.uid == 0)
435 static void usage(void) __attribute__((noreturn));
437 static void usage(void)
440 "Usage: nstat [ -h?vVzrnasd:t: ] [ PATTERN [ PATTERN ] ]\n"
446 int main(int argc, char *argv[])
449 struct sockaddr_un sun;
450 FILE *hist_fp = NULL;
454 while ((ch = getopt(argc, argv, "h?vVzrnasd:t:")) != EOF) {
472 scan_interval = 1000*atoi(optarg);
475 if (sscanf(optarg, "%d", &time_constant) != 1 ||
476 time_constant <= 0) {
477 fprintf(stderr, "nstat: invalid time constant divisor\n");
483 printf("nstat utility, iproute2-ss%s\n", SNAPSHOT);
495 sun.sun_family = AF_UNIX;
497 sprintf(sun.sun_path+1, "nstat%d", getuid());
499 if (scan_interval > 0) {
500 if (time_constant == 0)
502 time_constant *= 1000;
503 W = 1 - 1/exp(log(10)*(double)scan_interval/time_constant);
504 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
505 perror("nstat: socket");
508 if (bind(fd, (struct sockaddr*)&sun, 2+1+strlen(sun.sun_path+1)) < 0) {
509 perror("nstat: bind");
512 if (listen(fd, 5) < 0) {
513 perror("nstat: listen");
519 close(0); close(1); close(2); setsid();
520 signal(SIGPIPE, SIG_IGN);
521 signal(SIGCHLD, sigchild);
529 if (getenv("NSTAT_HISTORY"))
530 snprintf(hist_name, sizeof(hist_name), getenv("NSTAT_HISTORY"));
532 sprintf(hist_name, "/tmp/.nstat.u%d", getuid());
537 if (!ignore_history || !no_update) {
540 fd = open(hist_name, O_RDWR|O_CREAT|O_NOFOLLOW, 0600);
542 perror("nstat: open history file");
545 if ((hist_fp = fdopen(fd, "r+")) == NULL) {
546 perror("nstat: fdopen history file");
549 if (flock(fileno(hist_fp), LOCK_EX)) {
550 perror("nstat: flock history file");
553 if (fstat(fileno(hist_fp), &stb) != 0) {
554 perror("nstat: fstat history file");
557 if (stb.st_nlink != 1 || stb.st_uid != getuid()) {
558 fprintf(stderr, "nstat: something is so wrong with history file, that I prefer not to proceed.\n");
561 if (!ignore_history) {
564 if ((tfp = fopen("/proc/uptime", "r")) != NULL) {
565 if (fscanf(tfp, "%ld", &uptime) != 1)
569 if (uptime >= 0 && time(NULL) >= stb.st_mtime+uptime) {
570 fprintf(stderr, "nstat: history is aged out, resetting\n");
571 ftruncate(fileno(hist_fp), 0);
575 load_good_table(hist_fp);
581 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0 &&
582 (connect(fd, (struct sockaddr*)&sun, 2+1+strlen(sun.sun_path+1)) == 0
583 || (strcpy(sun.sun_path+1, "nstat0"),
584 connect(fd, (struct sockaddr*)&sun, 2+1+strlen(sun.sun_path+1)) == 0))
585 && verify_forging(fd) == 0) {
586 FILE *sfp = fdopen(fd, "r");
587 load_good_table(sfp);
588 if (hist_db && source_mismatch) {
589 fprintf(stderr, "nstat: history is stale, ignoring it.\n");
596 if (hist_db && info_source[0] && strcmp(info_source, "kernel")) {
597 fprintf(stderr, "nstat: history is stale, ignoring it.\n");
604 if (info_source[0] == 0)
605 strcpy(info_source, "kernel");
609 if (ignore_history || hist_db == NULL)
610 dump_kern_db(stdout, 0);
612 dump_incr_db(stdout);
615 ftruncate(fileno(hist_fp), 0);
617 dump_kern_db(hist_fp, 1);