pkg-monitoring-plugins/contrib/check_logins.c
2006-01-20 18:48:40 +00:00

352 lines
9.9 KiB
C

/*=================================
* check_logins - Nagios plugin
* Copyright (C) 2003 Dag Robøle
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Authors email: drobole@broadpark.no
*/
//=================================
#include <sys/types.h>
#include <signal.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "config.h"
#include "common.h"
#include "utils.h"
#include "popen.h"
//=================================
#define REVISION "$Revision: 1.1 $"
#define COPYRIGHT "2003"
#define AUTHOR "Dag Robole"
#define EMAIL "drobole@broadpark.no"
#define SUMMARY "Check for multiple user logins"
#define check(func, errmsg) { if((func) == -1) die(STATE_UNKNOWN, errmsg); }
#define checkz(func, errmsg) { if(!(func)) die(STATE_UNKNOWN, errmsg); }
//=================================
typedef struct USERNODE_TYP {
char *name;
char *host;
struct USERNODE_TYP* next;
} USERNODE;
//=================================
char *progname = NULL;
USERNODE *userlist = NULL, *adminlist = NULL;
int warning_limit = 0, critical_limit = 0;
void print_usage();
void print_help();
void process_arguments(int argc, char* *argv);
void parse_wholine(const char *line, char *name, char *host);
void node_create(USERNODE* *node, const char *name, const char *host);
void node_free(USERNODE* *node);
USERNODE* list_insert_sort_uniq(USERNODE* *list, USERNODE* *node);
void list_free(USERNODE* *list);
void cleanup();
//=================================
int main(int argc, char* *argv)
{
FILE *who;
USERNODE *newnode, *nptra, *nptrb;
char buffer[BUFSIZ], username[BUFSIZ], hostname[BUFSIZ], *cptra, *cptrb;
char max_login_name[BUFSIZ], currname[BUFSIZ];
int max_login_count = 0, counter = 0, skip;
void (*old_sig_alrm)();
progname = argv[0];
if(atexit(cleanup))
die(STATE_UNKNOWN, "atexit failed\n");
if((old_sig_alrm = signal((int)SIGALRM, timeout_alarm_handler)) == SIG_ERR)
die(STATE_UNKNOWN, "signal failed\n");
alarm(timeout_interval);
process_arguments(argc, argv);
checkz(who = spopen(PATH_TO_WHO), "spopen failed\n");
while(fgets(buffer, sizeof(buffer), who) != NULL) {
parse_wholine(buffer, username, hostname);
skip = 0;
nptra = adminlist;
while(nptra != NULL) {
if(!strcmp(nptra->name, username)) {
skip = 1;
break;
}
nptra = nptra->next;
}
if(!skip) {
node_create(&newnode, username, hostname);
if(!list_insert_sort_uniq(&userlist, &newnode))
node_free(&newnode);
}
}
check(spclose(who), "spclose failed\n");
if(userlist != NULL) {
nptra = userlist;
strcpy(currname, nptra->name);
strcpy(max_login_name, nptra->name);
max_login_count = 1;
while(nptra != NULL) {
if(!strcmp(currname, nptra->name))
++counter;
else {
if(counter > max_login_count) {
max_login_count = counter;
strcpy(max_login_name, currname);
}
strcpy(currname, nptra->name);
counter = 1;
}
nptra = nptra->next;
}
if(counter > max_login_count) {
max_login_count = counter;
strcpy(max_login_name, currname);
}
}
if(signal((int)SIGALRM, old_sig_alrm) == SIG_ERR)
die(STATE_UNKNOWN, "signal failed\n");
if(max_login_count) {
if(critical_limit && max_login_count >= critical_limit) {
printf("CRITICAL - User %s has logged in from %d different hosts\n", max_login_name, max_login_count);
return STATE_CRITICAL;
}
else if(warning_limit && max_login_count >= warning_limit) {
printf("WARNING - User %s has logged in from %d different hosts\n", max_login_name, max_login_count);
return STATE_WARNING;
}
}
printf("OK - No users has exceeded the login limits\n");
return STATE_OK;
}
//=================================
void print_usage()
{
fprintf(stderr, "Usage: %s [ -hV ] [ -w limit ] [ -c limit ] [ -u username1, ... ,usernameN ]\n", progname);
}
//=================================
void print_help()
{
print_revision(progname, REVISION);
printf("Copyright (c) %s %s <%s>\n\n%s\n\n", COPYRIGHT, AUTHOR, EMAIL, SUMMARY);
print_usage();
printf("\nDescription:\n"
"\tThis plugin supports the w (warning) and c (critical) options indicating the upper limits\n"
"\tof logins allowed before a warning is given.\n"
"\tThe output from %s is the username and number of login sessions for the user\n"
"\twho has the most login sessions (from different hosts) running at a given point in time.\n"
"\tThe u (users) option takes a comma separated list of usernames that will be ignored\n"
"\twhile scannig users.\n"
"\nOptions:\n"
"\t-h | --help\n\t\tShow this help message and exit\n"
"\t-V | --version\n\t\tShow version description\n"
"\t-w | --warning=INTEGER\n\t\tSet warning limit for logins (minimum value is 2)\n"
"\t-c | --critical=INTEGER\n\t\tSet critical limit for logins (minimum value is 2)\n"
"\t-u | --users=STRING\n\t\tSet usernames to be ignored\n"
"\nExamples:\n\t%s -w 3 -c 5\n"
"\t%s -w 3 -c 5 -u root,guest,jcarmack\n\n", progname, progname, progname);
}
//=================================
void process_arguments(int argc, char* *argv)
{
USERNODE *newnode;
int optch;
char buffer[BUFSIZ], *cptra;
static struct option long_opts[] = {
{"help", no_argument, 0, 'h'},
{"version", no_argument, 0, 'V'},
{"warning", required_argument, 0, 'w'},
{"critical", required_argument, 0, 'c'},
{"users", required_argument, 0, 'u'},
{0, 0, 0, 0},
};
while((optch = getopt_long(argc, argv, "hVw:c:u:", long_opts, NULL)) != -1) {
switch(optch) {
case 'h':
print_help();
exit(STATE_OK);
break;
case 'V':
print_revision(progname, REVISION);
exit(STATE_OK);
break;
case 'w':
if(!is_numeric(optarg)) {
print_usage();
die(STATE_UNKNOWN, "invalid options\n");
}
warning_limit = atoi(optarg) > 2 ? atoi(optarg) : 2;
break;
case 'c':
if(!is_numeric(optarg)) {
print_usage();
die(STATE_UNKNOWN, "invalid options\n");
}
critical_limit = atoi(optarg) > 2 ? atoi(optarg) : 2;
break;
case 'u':
strcpy(buffer, optarg);
cptra = strtok(buffer, ",");
while(cptra != NULL) {
node_create(&newnode, cptra, "(adminhost)");
list_insert_sort_uniq(&adminlist, &newnode);
cptra = strtok(NULL, ",");
}
break;
default:
print_usage();
exit(STATE_UNKNOWN);
break;
}
}
if(argc > optind) {
print_usage();
die(STATE_UNKNOWN, "invalid options\n");
}
if(!warning_limit && !critical_limit) {
print_usage();
die(STATE_UNKNOWN, "you must provide a limit for this plugin\n");
}
if(critical_limit && warning_limit > critical_limit) {
print_usage();
die(STATE_UNKNOWN, "warning limit must be less or equal critical limit\n");
}
}
//=================================
void parse_wholine(const char *line, char *name, char *host)
{
char buffer[BUFSIZ], *cptra, *cptrb, *display;
strcpy(buffer, line);
cptra = buffer;
checkz(cptrb = (char*)strchr(buffer, ' '), "strchr failed\n");
strncpy(name, cptra, cptrb-cptra);
name[cptrb-cptra] = '\0';
if((cptra = strchr(buffer, '(')) != NULL) // hostname found in source arg...
{
if(cptra[1] == ':') // local host
strcpy(host, "(localhost)");
else // extern host
{
checkz(cptrb = strchr(cptra, ')'), "strchr failed\n");
cptrb++;
strncpy(host, cptra, cptrb-cptra);
host[cptrb-cptra] = '\0';
}
}
else // no hostname in source arg, look in line arg...
{
checkz(cptra = strtok(buffer, " \t\r\n"), "strtok failed\n");
checkz(cptra = strtok(NULL, " \t\r\n"), "strtok failed\n");
if(cptra[0] == ':') // local host
strcpy(host, "(localhost)");
else // extern host
sprintf(host, "(%s)", cptra);
}
if((cptra = strchr(host, ':')) != NULL) // remove display if any...
strcpy(cptra, ")");
}
//=================================
void node_create(USERNODE* *node, const char *name, const char *host)
{
checkz(*node = (USERNODE*)malloc(sizeof(USERNODE)), "malloc failed\n");
checkz((*node)->name = (char*)malloc(strlen(name)+1), "malloc failed\n");
checkz((*node)->host = (char*)malloc(strlen(host)+1), "malloc failed\n");
(*node)->next = NULL;
strcpy((*node)->name, name);
strcpy((*node)->host, host);
}
//=================================
void node_free(USERNODE* *node)
{
free((*node)->name);
free((*node)->host);
free(*node);
*node = NULL;
}
//=================================
USERNODE* list_insert_sort_uniq(USERNODE* *list, USERNODE* *node)
{
char n1[BUFSIZ], n2[BUFSIZ];
USERNODE *last_nptr = NULL, *nptr = *list;
if(*list == NULL)
return(*list = *node);
else {
sprintf(n1, "%s %s", (*node)->name, (*node)->host);
while(nptr != NULL) {
sprintf(n2, "%s %s", nptr->name, nptr->host);
if(!strcmp(n1, n2))
return NULL;
else if(strcmp(n1, n2) < 0) {
if(last_nptr) {
last_nptr->next = *node;
(*node)->next = nptr;
}
else {
(*node)->next = *list;
*list = *node;
}
break;
}
else {
last_nptr = nptr;
nptr = nptr->next;
}
}
if(nptr == NULL)
last_nptr->next = *node;
}
return *node;
}
//=================================
void list_free(USERNODE* *list)
{
USERNODE *doe, *nptr = *list;
while(nptr != NULL) {
doe = nptr;
nptr = nptr->next;
node_free(&doe);
}
*list = NULL;
}
//=================================
void cleanup()
{
list_free(&userlist);
list_free(&adminlist);
}
//=================================