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#include "taia.h"
#include "openreadclose.h"
#include "byte.h"
#include "ip4.h"
#include "env.h"
#include "dns.h"
static stralloc data = {0};
static int init(char ip[64])
{
int i;
int j;
int iplen = 0;
char *x;
x = env_get("DNSCACHEIP");
if (x)
while (iplen <= 60) {
if (*x == '.')
++x;
else {
i = ip4_scan(x,ip + iplen);
if (!i) break;
x += i;
iplen += 4;
}
}
if (!iplen) {
i = openreadclose("/etc/resolv.conf",&data,64);
if (i == -1) return -1;
if (i) {
if (!stralloc_append(&data,"\n")) return -1;
i = 0;
for (j = 0;j < data.len;++j)
if (data.s[j] == '\n') {
if (byte_equal("nameserver ",11,data.s + i) || byte_equal("nameserver\t",11,data.s + i)) {
i += 10;
while ((data.s[i] == ' ') || (data.s[i] == '\t'))
++i;
if (iplen <= 60)
if (ip4_scan(data.s + i,ip + iplen)) {
if (byte_equal(ip + iplen,4,"\0\0\0\0"))
byte_copy(ip + iplen,4,"\177\0\0\1");
iplen += 4;
}
}
i = j + 1;
}
}
}
if (!iplen) {
byte_copy(ip,4,"\177\0\0\1");
iplen = 4;
}
byte_zero(ip + iplen,64 - iplen);
return 0;
}
static int ok = 0;
static unsigned int uses;
static struct taia deadline;
static char ip[64]; /* defined if ok */
int dns_resolvconfip(char s[64])
{
struct taia now;
taia_now(&now);
if (taia_less(&deadline,&now)) ok = 0;
if (!uses) ok = 0;
if (!ok) {
if (init(ip) == -1) return -1;
taia_uint(&deadline,600);
taia_add(&deadline,&now,&deadline);
uses = 10000;
ok = 1;
}
--uses;
byte_copy(s,64,ip);
return 0;
}