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/*
* Copyright (c) 2013 RIPE NCC <atlas@ripe.net>
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#define LINEL (INET6_ADDRSTRLEN * 2)
#include "libbb.h"
#include "resolv.h"
#include "eperd.h"
#include <math.h>
static void nameserver_ip_add (char *nsentry, char *ip_as_string)
{
strncpy (nsentry, ip_as_string, LINEL);
// printf("AA added nameserver %s\n", ip_as_string);
// printf("AA added nameserver to ns %s\n", nsentry);
return;
}
static int resolv_conf_parse_line (char *nsentry, char *line)
{
#define NEXT_TOKEN strtok_r(NULL, delims, &strtok_state)
char *strtok_state;
static const char *const delims = " \t";
char *const first_token = strtok_r(line, delims, &strtok_state);
if (!first_token) return 0;
if (!strcmp(first_token, "nameserver")) {
char *const nameserver = NEXT_TOKEN;
if (nameserver) {
if(nameserver[(strlen(nameserver) - 1)] == '\n')
nameserver[(strlen(nameserver) - 1)] = NULL;
nameserver_ip_add(nsentry, nameserver);
//printf("AA added nameserver %s\n", nsentry);
return 1;
}
}
return 0;
}
void get_local_resolvers(char nslist[MAXNS][INET6_ADDRSTRLEN * 2],
int *resolv_max)
{
#ifndef RESOLV_CONF
#define RESOLV_CONF "/etc/resolv.conf"
#endif
char buf[LINEL];
char *buf_start;
int i = 0;
time_t now;
int r;
struct stat sb;
static resolv_last_check = -1;
static time_t last_time= -1;
now = time(NULL);
if(*resolv_max){
if ( pow (resolv_last_check - now, 2) > 3) {
crondlog(LVL5 "check the %s", RESOLV_CONF);
}
else {
return;
}
}
r = stat(RESOLV_CONF, &sb);
if (r == -1)
{
crondlog(LVL8 "error accessing resolv.conf: %s",
strerror(errno));
return;
}
resolv_last_check = now;
if (last_time == sb.st_mtime)
{
/* nothing changed */
crondlog(LVL5 "re-read %s. not reading this time", RESOLV_CONF);
return;
}
else {
crondlog(LVL5 "re-read %s . it has changed", RESOLV_CONF);
}
FILE *R = fopen (RESOLV_CONF, "r");
if (R != NULL) {
while ( (fgets (buf, LINEL, R)) && (i < MAXNS)) {
buf_start = buf;
if(resolv_conf_parse_line(nslist[i], buf) ) {
crondlog(LVL5 "parsed file %s , line %s i=%d", RESOLV_CONF, buf_start, i);
i++;
}
else
crondlog(LVL5 "ERROR failed to parse from %s i=%d, line %s", RESOLV_CONF, i, buf_start);
}
fclose (R);
}
last_time = sb.st_mtime;
*resolv_max = i;
return;
}
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