blob: 7160c59be2229624bc313b9c8e27549d0845a2d0 [file] [log] [blame]
/*
* nstat.c handy utility to read counters /proc/net/netstat and snmp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/time.h>
#include <fnmatch.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/poll.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <signal.h>
#include <math.h>
#include <getopt.h>
#include <json_writer.h>
#include "version.h"
#include "utils.h"
int dump_zeros;
int reset_history;
int ignore_history;
int no_output;
int json_output;
int no_update;
int scan_interval;
int time_constant;
double W;
char **patterns;
int npatterns;
char info_source[128];
int source_mismatch;
static int generic_proc_open(const char *env, char *name)
{
char store[128];
char *p = getenv(env);
if (!p) {
p = getenv("PROC_ROOT") ? : "/proc";
snprintf(store, sizeof(store)-1, "%s/%s", p, name);
p = store;
}
return open(p, O_RDONLY);
}
static int net_netstat_open(void)
{
return generic_proc_open("PROC_NET_NETSTAT", "net/netstat");
}
static int net_snmp_open(void)
{
return generic_proc_open("PROC_NET_SNMP", "net/snmp");
}
static int net_snmp6_open(void)
{
return generic_proc_open("PROC_NET_SNMP6", "net/snmp6");
}
static int net_sctp_snmp_open(void)
{
return generic_proc_open("PROC_NET_SCTP_SNMP", "net/sctp/snmp");
}
struct nstat_ent {
struct nstat_ent *next;
char *id;
unsigned long long val;
double rate;
};
struct nstat_ent *kern_db;
struct nstat_ent *hist_db;
static const char *useless_numbers[] = {
"IpForwarding", "IpDefaultTTL",
"TcpRtoAlgorithm", "TcpRtoMin", "TcpRtoMax",
"TcpMaxConn", "TcpCurrEstab"
};
static int useless_number(const char *id)
{
int i;
for (i = 0; i < ARRAY_SIZE(useless_numbers); i++)
if (strcmp(id, useless_numbers[i]) == 0)
return 1;
return 0;
}
static int match(const char *id)
{
int i;
if (npatterns == 0)
return 1;
for (i = 0; i < npatterns; i++) {
if (!fnmatch(patterns[i], id, FNM_CASEFOLD))
return 1;
}
return 0;
}
static void load_good_table(FILE *fp)
{
char buf[4096];
struct nstat_ent *db = NULL;
struct nstat_ent *n;
while (fgets(buf, sizeof(buf), fp) != NULL) {
int nr;
unsigned long long val;
double rate;
char idbuf[sizeof(buf)];
if (buf[0] == '#') {
buf[strlen(buf)-1] = 0;
if (info_source[0] && strcmp(info_source, buf+1))
source_mismatch = 1;
strlcpy(info_source, buf + 1, sizeof(info_source));
continue;
}
/* idbuf is as big as buf, so this is safe */
nr = sscanf(buf, "%s%llu%lg", idbuf, &val, &rate);
if (nr < 2) {
fprintf(stderr, "%s:%d: error parsing history file\n",
__FILE__, __LINE__);
exit(-2);
}
if (nr < 3)
rate = 0;
if (useless_number(idbuf))
continue;
if ((n = malloc(sizeof(*n))) == NULL) {
perror("nstat: malloc");
exit(-1);
}
n->id = strdup(idbuf);
n->val = val;
n->rate = rate;
n->next = db;
db = n;
}
while (db) {
n = db;
db = db->next;
n->next = kern_db;
kern_db = n;
}
}
static int count_spaces(const char *line)
{
int count = 0;
char c;
while ((c = *line++) != 0)
count += c == ' ' || c == '\n';
return count;
}
static void load_ugly_table(FILE *fp)
{
char *buf = NULL;
size_t buflen = 0;
ssize_t nread;
struct nstat_ent *db = NULL;
struct nstat_ent *n;
while ((nread = getline(&buf, &buflen, fp)) != -1) {
char idbuf[4096];
int off;
char *p;
int count1, count2, skip = 0;
p = strchr(buf, ':');
if (!p) {
fprintf(stderr, "%s:%d: error parsing history file\n",
__FILE__, __LINE__);
exit(-2);
}
count1 = count_spaces(buf);
*p = 0;
idbuf[0] = 0;
strncat(idbuf, buf, sizeof(idbuf) - 1);
off = p - buf;
p += 2;
while (*p) {
char *next;
if ((next = strchr(p, ' ')) != NULL)
*next++ = 0;
else if ((next = strchr(p, '\n')) != NULL)
*next++ = 0;
if (off < sizeof(idbuf)) {
idbuf[off] = 0;
strncat(idbuf, p, sizeof(idbuf) - off - 1);
}
n = malloc(sizeof(*n));
if (!n) {
perror("nstat: malloc");
exit(-1);
}
n->id = strdup(idbuf);
n->rate = 0;
n->next = db;
db = n;
p = next;
}
n = db;
nread = getline(&buf, &buflen, fp);
if (nread == -1) {
fprintf(stderr, "%s:%d: error parsing history file\n",
__FILE__, __LINE__);
exit(-2);
}
count2 = count_spaces(buf);
if (count2 > count1)
skip = count2 - count1;
do {
p = strrchr(buf, ' ');
if (!p) {
fprintf(stderr, "%s:%d: error parsing history file\n",
__FILE__, __LINE__);
exit(-2);
}
*p = 0;
if (sscanf(p+1, "%llu", &n->val) != 1) {
fprintf(stderr, "%s:%d: error parsing history file\n",
__FILE__, __LINE__);
exit(-2);
}
/* Trick to skip "dummy" trailing ICMP MIB in 2.4 */
if (skip)
skip--;
else
n = n->next;
} while (p > buf + off + 2);
}
free(buf);
while (db) {
n = db;
db = db->next;
if (useless_number(n->id)) {
free(n->id);
free(n);
} else {
n->next = kern_db;
kern_db = n;
}
}
}
static void load_sctp_snmp(void)
{
FILE *fp = fdopen(net_sctp_snmp_open(), "r");
if (fp) {
load_good_table(fp);
fclose(fp);
}
}
static void load_snmp(void)
{
FILE *fp = fdopen(net_snmp_open(), "r");
if (fp) {
load_ugly_table(fp);
fclose(fp);
}
}
static void load_snmp6(void)
{
FILE *fp = fdopen(net_snmp6_open(), "r");
if (fp) {
load_good_table(fp);
fclose(fp);
}
}
static void load_netstat(void)
{
FILE *fp = fdopen(net_netstat_open(), "r");
if (fp) {
load_ugly_table(fp);
fclose(fp);
}
}
static void dump_kern_db(FILE *fp, int to_hist)
{
json_writer_t *jw = json_output ? jsonw_new(fp) : NULL;
struct nstat_ent *n, *h;
h = hist_db;
if (jw) {
jsonw_start_object(jw);
jsonw_pretty(jw, pretty);
jsonw_name(jw, info_source);
jsonw_start_object(jw);
} else
fprintf(fp, "#%s\n", info_source);
for (n = kern_db; n; n = n->next) {
unsigned long long val = n->val;
if (!dump_zeros && !val && !n->rate)
continue;
if (!match(n->id)) {
struct nstat_ent *h1;
if (!to_hist)
continue;
for (h1 = h; h1; h1 = h1->next) {
if (strcmp(h1->id, n->id) == 0) {
val = h1->val;
h = h1->next;
break;
}
}
}
if (jw)
jsonw_uint_field(jw, n->id, val);
else
fprintf(fp, "%-32s%-16llu%6.1f\n", n->id, val, n->rate);
}
if (jw) {
jsonw_end_object(jw);
jsonw_end_object(jw);
jsonw_destroy(&jw);
}
}
static void dump_incr_db(FILE *fp)
{
json_writer_t *jw = json_output ? jsonw_new(fp) : NULL;
struct nstat_ent *n, *h;
h = hist_db;
if (jw) {
jsonw_start_object(jw);
jsonw_pretty(jw, pretty);
jsonw_name(jw, info_source);
jsonw_start_object(jw);
} else
fprintf(fp, "#%s\n", info_source);
for (n = kern_db; n; n = n->next) {
int ovfl = 0;
unsigned long long val = n->val;
struct nstat_ent *h1;
for (h1 = h; h1; h1 = h1->next) {
if (strcmp(h1->id, n->id) == 0) {
if (val < h1->val) {
ovfl = 1;
val = h1->val;
}
val -= h1->val;
h = h1->next;
break;
}
}
if (!dump_zeros && !val && !n->rate)
continue;
if (!match(n->id))
continue;
if (jw)
jsonw_uint_field(jw, n->id, val);
else
fprintf(fp, "%-32s%-16llu%6.1f%s\n", n->id, val,
n->rate, ovfl?" (overflow)":"");
}
if (jw) {
jsonw_end_object(jw);
jsonw_end_object(jw);
jsonw_destroy(&jw);
}
}
static int children;
static void sigchild(int signo)
{
}
static void update_db(int interval)
{
struct nstat_ent *n, *h;
n = kern_db;
kern_db = NULL;
load_netstat();
load_snmp6();
load_snmp();
load_sctp_snmp();
h = kern_db;
kern_db = n;
for (n = kern_db; n; n = n->next) {
struct nstat_ent *h1;
for (h1 = h; h1; h1 = h1->next) {
if (strcmp(h1->id, n->id) == 0) {
double sample;
unsigned long long incr = h1->val - n->val;
n->val = h1->val;
sample = (double)incr * 1000.0 / interval;
if (interval >= scan_interval) {
n->rate += W*(sample-n->rate);
} else if (interval >= 1000) {
if (interval >= time_constant) {
n->rate = sample;
} else {
double w = W*(double)interval/scan_interval;
n->rate += w*(sample-n->rate);
}
}
while (h != h1) {
struct nstat_ent *tmp = h;
h = h->next;
free(tmp->id);
free(tmp);
};
h = h1->next;
free(h1->id);
free(h1);
break;
}
}
}
}
#define T_DIFF(a, b) (((a).tv_sec-(b).tv_sec)*1000 + ((a).tv_usec-(b).tv_usec)/1000)
static void server_loop(int fd)
{
struct timeval snaptime = { 0 };
struct pollfd p;
p.fd = fd;
p.events = p.revents = POLLIN;
sprintf(info_source, "%d.%lu sampling_interval=%d time_const=%d",
getpid(), (unsigned long)random(), scan_interval/1000, time_constant/1000);
load_netstat();
load_snmp6();
load_snmp();
load_sctp_snmp();
for (;;) {
int status;
time_t tdiff;
struct timeval now;
gettimeofday(&now, NULL);
tdiff = T_DIFF(now, snaptime);
if (tdiff >= scan_interval) {
update_db(tdiff);
snaptime = now;
tdiff = 0;
}
if (poll(&p, 1, scan_interval - tdiff) > 0
&& (p.revents&POLLIN)) {
int clnt = accept(fd, NULL, NULL);
if (clnt >= 0) {
pid_t pid;
if (children >= 5) {
close(clnt);
} else if ((pid = fork()) != 0) {
if (pid > 0)
children++;
close(clnt);
} else {
FILE *fp = fdopen(clnt, "w");
if (fp)
dump_kern_db(fp, 0);
exit(0);
}
}
}
while (children && waitpid(-1, &status, WNOHANG) > 0)
children--;
}
}
static int verify_forging(int fd)
{
struct ucred cred;
socklen_t olen = sizeof(cred);
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, (void *)&cred, &olen) ||
olen < sizeof(cred))
return -1;
if (cred.uid == getuid() || cred.uid == 0)
return 0;
return -1;
}
static void usage(void) __attribute__((noreturn));
static void usage(void)
{
fprintf(stderr,
"Usage: nstat [OPTION] [ PATTERN [ PATTERN ] ]\n"
" -h, --help this message\n"
" -a, --ignore ignore history\n"
" -d, --scan=SECS sample every statistics every SECS\n"
" -j, --json format output in JSON\n"
" -n, --nooutput do history only\n"
" -p, --pretty pretty print\n"
" -r, --reset reset history\n"
" -s, --noupdate don't update history\n"
" -t, --interval=SECS report average over the last SECS\n"
" -V, --version output version information\n"
" -z, --zeros show entries with zero activity\n");
exit(-1);
}
static const struct option longopts[] = {
{ "help", 0, 0, 'h' },
{ "ignore", 0, 0, 'a' },
{ "scan", 1, 0, 'd'},
{ "nooutput", 0, 0, 'n' },
{ "json", 0, 0, 'j' },
{ "reset", 0, 0, 'r' },
{ "noupdate", 0, 0, 's' },
{ "pretty", 0, 0, 'p' },
{ "interval", 1, 0, 't' },
{ "version", 0, 0, 'V' },
{ "zeros", 0, 0, 'z' },
{ 0 }
};
int main(int argc, char *argv[])
{
char *hist_name;
struct sockaddr_un sun;
FILE *hist_fp = NULL;
int ch;
int fd;
while ((ch = getopt_long(argc, argv, "h?vVzrnasd:t:jp",
longopts, NULL)) != EOF) {
switch (ch) {
case 'z':
dump_zeros = 1;
break;
case 'r':
reset_history = 1;
break;
case 'a':
ignore_history = 1;
break;
case 's':
no_update = 1;
break;
case 'n':
no_output = 1;
break;
case 'd':
scan_interval = 1000*atoi(optarg);
break;
case 't':
if (sscanf(optarg, "%d", &time_constant) != 1 ||
time_constant <= 0) {
fprintf(stderr, "nstat: invalid time constant divisor\n");
exit(-1);
}
break;
case 'j':
json_output = 1;
break;
case 'p':
pretty = 1;
break;
case 'v':
case 'V':
printf("nstat utility, iproute2-%s\n", version);
exit(0);
case 'h':
case '?':
default:
usage();
}
}
argc -= optind;
argv += optind;
sun.sun_family = AF_UNIX;
sun.sun_path[0] = 0;
sprintf(sun.sun_path+1, "nstat%d", getuid());
if (scan_interval > 0) {
if (time_constant == 0)
time_constant = 60;
time_constant *= 1000;
W = 1 - 1/exp(log(10)*(double)scan_interval/time_constant);
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
perror("nstat: socket");
exit(-1);
}
if (bind(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) < 0) {
perror("nstat: bind");
exit(-1);
}
if (listen(fd, 5) < 0) {
perror("nstat: listen");
exit(-1);
}
if (daemon(0, 0)) {
perror("nstat: daemon");
exit(-1);
}
signal(SIGPIPE, SIG_IGN);
signal(SIGCHLD, sigchild);
server_loop(fd);
exit(0);
}
patterns = argv;
npatterns = argc;
if ((hist_name = getenv("NSTAT_HISTORY")) == NULL) {
hist_name = malloc(128);
sprintf(hist_name, "/tmp/.nstat.u%d", getuid());
}
if (reset_history)
unlink(hist_name);
if (!ignore_history || !no_update) {
struct stat stb;
fd = open(hist_name, O_RDWR|O_CREAT|O_NOFOLLOW, 0600);
if (fd < 0) {
perror("nstat: open history file");
exit(-1);
}
if ((hist_fp = fdopen(fd, "r+")) == NULL) {
perror("nstat: fdopen history file");
exit(-1);
}
if (flock(fileno(hist_fp), LOCK_EX)) {
perror("nstat: flock history file");
exit(-1);
}
if (fstat(fileno(hist_fp), &stb) != 0) {
perror("nstat: fstat history file");
exit(-1);
}
if (stb.st_nlink != 1 || stb.st_uid != getuid()) {
fprintf(stderr, "nstat: something is so wrong with history file, that I prefer not to proceed.\n");
exit(-1);
}
if (!ignore_history) {
FILE *tfp;
long uptime = -1;
if ((tfp = fopen("/proc/uptime", "r")) != NULL) {
if (fscanf(tfp, "%ld", &uptime) != 1)
uptime = -1;
fclose(tfp);
}
if (uptime >= 0 && time(NULL) >= stb.st_mtime+uptime) {
fprintf(stderr, "nstat: history is aged out, resetting\n");
if (ftruncate(fileno(hist_fp), 0) < 0)
perror("nstat: ftruncate");
}
}
load_good_table(hist_fp);
hist_db = kern_db;
kern_db = NULL;
}
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0 &&
(connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0
|| (strcpy(sun.sun_path+1, "nstat0"),
connect(fd, (struct sockaddr *)&sun, 2+1+strlen(sun.sun_path+1)) == 0))
&& verify_forging(fd) == 0) {
FILE *sfp = fdopen(fd, "r");
if (!sfp) {
fprintf(stderr, "nstat: fdopen failed: %s\n",
strerror(errno));
close(fd);
} else {
load_good_table(sfp);
if (hist_db && source_mismatch) {
fprintf(stderr, "nstat: history is stale, ignoring it.\n");
hist_db = NULL;
}
fclose(sfp);
}
} else {
if (fd >= 0)
close(fd);
if (hist_db && info_source[0] && strcmp(info_source, "kernel")) {
fprintf(stderr, "nstat: history is stale, ignoring it.\n");
hist_db = NULL;
info_source[0] = 0;
}
load_netstat();
load_snmp6();
load_snmp();
load_sctp_snmp();
if (info_source[0] == 0)
strcpy(info_source, "kernel");
}
if (!no_output) {
if (ignore_history || hist_db == NULL)
dump_kern_db(stdout, 0);
else
dump_incr_db(stdout);
}
if (!no_update) {
if (ftruncate(fileno(hist_fp), 0) < 0)
perror("nstat: ftruncate");
rewind(hist_fp);
json_output = 0;
dump_kern_db(hist_fp, 1);
fclose(hist_fp);
}
exit(0);
}