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/*----------------------------------------------------------------------------*/
/* Xymon monitor library. */
/* */
/* This is a library module for Xymon, implementing IP-address based access */
/* controls. */
/* */
/* Copyright (C) 2004-2011 Henrik Storner <henrik@hswn.dk> */
/* */
/* This program is released under the GNU General Public License (GPL), */
/* version 2. See the file "COPYING" for details. */
/* */
/*----------------------------------------------------------------------------*/
static char rcsid[] = "$Id: ipaccess.c 7476 2014-09-28 09:46:30Z storner $";
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include "libxymon.h"
sender_t *getsenderlist(char *iplist)
{
char *ips, *p, *tok;
sender_t *result;
int count;
dbgprintf("-> getsenderlist\n");
ips = strdup(iplist);
count = 0; p = ips; do { count++; p = strchr(p, ','); if (p) p++; } while (p);
result = (sender_t *) calloc(1, sizeof(sender_t) * (count+1));
tok = strtok(ips, ","); count = 0;
while (tok) {
int bits = 32;
p = strchr(tok, '/');
if (p) *p = '\0';
result[count].ipval = ntohl(inet_addr(tok));
if (p) { *p = '/'; p++; bits = atoi(p); }
if (bits < 32)
result[count].ipmask = (0xFFFFFFFF << (32 - atoi(p)));
else
result[count].ipmask = 0xFFFFFFFF;
tok = strtok(NULL, ",");
count++;
}
xfree(ips);
dbgprintf("<- getsenderlist\n");
return result;
}
int oksender(sender_t *oklist, char *targetip, struct in_addr sender, char *msgbuf)
{
int i;
unsigned long int tg_ip;
char *eoln = NULL;
dbgprintf("-> oksender\n");
/* If oklist is empty, we're not doing any access checks - so return OK */
if (oklist == NULL) {
dbgprintf("<- oksender(1-a)\n");
return 1;
}
/* If we know the target, it would be ok for the host to report on itself. */
if (targetip) {
if (strcmp(targetip, "0.0.0.0") == 0) return 1; /* DHCP hosts can report from any address */
tg_ip = ntohl(inet_addr(targetip));
if (ntohl(sender.s_addr) == tg_ip) {
dbgprintf("<- oksender(1-b)\n");
return 1;
}
}
/* If sender is 0.0.0.0 (i.e. it arrived via backfeed channel), then OK */
if (sender.s_addr == INADDR_ANY) {
dbgprintf("<- oksender(1-c)\n");
return 1;
}
/* It's someone else reporting about the host. Check the access list */
i = 0;
do {
if ((oklist[i].ipval & oklist[i].ipmask) == (ntohl(sender.s_addr) & oklist[i].ipmask)) {
dbgprintf("<- oksender(1-c)\n");
return 1;
}
i++;
} while (oklist[i].ipval != 0);
/* Refuse and log the message */
if (msgbuf) { eoln = strchr(msgbuf, '\n'); if (eoln) *eoln = '\0'; }
errprintf("Refused message from %s: %s\n", inet_ntoa(sender), (msgbuf ? msgbuf : ""));
if (msgbuf && eoln) *eoln = '\n';
dbgprintf("<- oksender(0)\n");
return 0;
}
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