unsigned
dns_dntodn(dnscc_t *sdn, dnsc_t *ddn, unsigned ddnsiz) {
unsigned sdnlen = dns_dnlen(sdn);
if (ddnsiz < sdnlen)
return 0;
memcpy(ddn, sdn, sdnlen);
return sdnlen;
}
int dns_a6todn(const struct in6_addr *addr, dnscc_t *tdn,
dnsc_t *dn, unsigned dnsiz) {
dnsc_t *dne = dn + (dnsiz > DNS_MAXDN ? DNS_MAXDN : dnsiz);
dnsc_t *p;
unsigned l;
p = dns_a6todn_(addr, dn, dne);
if (!p) return 0;
if (!tdn)
tdn = dns_ip6_arpa_dn;
l = dns_dnlen(tdn);
if (p + l > dne) return dnsiz >= DNS_MAXDN ? -1 : 0;
memcpy(p, tdn, l);
return (p + l) - dn;
}
static struct query *query_new(const char *name, const unsigned char *dn, enum dns_type qtyp) {
struct query *q = xmalloc(sizeof(*q));
unsigned l = dns_dnlen(dn);
unsigned char *cdn = xmalloc(l);
memcpy(cdn, dn, l);
q->name = xstrdup(name);
q->dn = cdn;
q->qtyp = qtyp;
return q;
}
int main(int argc, char **argv) {
int i;
int sz;
dnsc_t dn[DNS_MAXDN+10];
dnsc_t *dl, *dp;
int isabs;
sz = (argc > 1) ? atoi(argv[1]) : 0;
for(i = 2; i < argc; ++i) {
int r = dns_ptodn(argv[i], 0, dn, sz, &isabs);
printf("%s: ", argv[i]);
if (r < 0) printf("error\n");
else if (!r) printf("buffer too small\n");
else {
printf("len=%d dnlen=%d size=%d name:",
r, dns_dnlen(dn), dns_dntop_size(dn));
dl = dn;
while(*dl) {
printf(" %d=", *dl);
dp = dl + 1;
dl = dp + *dl;
while(dp < dl) {
if (*dp <= ' ' || *dp >= 0x7f)
printf("\\%03d", *dp);
else if (*dp == '.' || *dp == '\\')
printf("\\%c", *dp);
else
putchar(*dp);
++dp;
}
}
if (isabs) putchar('.');
putchar('\n');
}
}
return 0;
}
static void dns_cache_resolve(struct dns_ctx *ctx, void *result, void *data,
enum dns_type rtype) {
int ttl, acnt, r = dns_status(ctx), idnlen;
dns_cache_node *n = data;
unsigned char idn[DNS_MAXDN], dn[DNS_MAXDN];
struct dns_parse p;
struct dns_rr rr;
unsigned nrr;
struct in_addr *answers4;
struct in6_addr *answers6;
const unsigned char *pkt, *cur, *end;
if(!result) goto blank;
dns_dntodn(n->dn, idn, sizeof(idn));
idnlen = dns_dnlen(idn);
pkt = result; end = pkt + r; cur = dns_payload(pkt);
dns_getdn(pkt, &cur, end, dn, sizeof(dn));
dns_initparse(&p, NULL, pkt, cur, end);
p.dnsp_qcls = 0;
p.dnsp_qtyp = 0;
nrr = 0;
ttl = 0;
while((r = dns_nextrr(&p, &rr)) > 0) {
int dnlen = dns_dnlen(rr.dnsrr_dn);
/* if we aren't searching and the don't match...
* or if we are searching and the prefixes don't match...
*/
if ((dns_search_flag && !dns_dnequal(idn, rr.dnsrr_dn)) ||
(dns_search_flag == 0 &&
(idnlen > dnlen || memcmp(idn, rr.dnsrr_dn, idnlen-1)))) continue;
if (DNS_C_IN == rr.dnsrr_cls && rtype == rr.dnsrr_typ) ++nrr;
else if (rr.dnsrr_typ == DNS_T_CNAME && !nrr) {
if (dns_getdn(pkt, &rr.dnsrr_dptr, end,
p.dnsp_dnbuf, sizeof(p.dnsp_dnbuf)) <= 0 ||
rr.dnsrr_dptr != rr.dnsrr_dend) {
break;
}
else {
if(rr.dnsrr_ttl > 0 && (ttl == 0 || rr.dnsrr_ttl < ttl))
ttl = rr.dnsrr_ttl;
dns_dntodn(p.dnsp_dnbuf, idn, sizeof(idn));
idnlen = dns_dnlen(idn);
}
}
}
if(!r && !nrr) goto blank;
dns_rewind(&p, NULL);
p.dnsp_qcls = DNS_C_IN;
p.dnsp_qtyp = rtype;
if(rtype == DNS_T_A)
answers4 = calloc(nrr, sizeof(*answers4));
else if(rtype == DNS_T_AAAA)
answers6 = calloc(nrr, sizeof(*answers6));
acnt = 0;
while(dns_nextrr(&p, &rr) && nrr < MAX_RR) {
int dnlen = dns_dnlen(rr.dnsrr_dn);
if ((dns_search_flag && !dns_dnequal(idn, rr.dnsrr_dn)) ||
(dns_search_flag == 0 &&
(idnlen > dnlen || memcmp(idn, rr.dnsrr_dn, idnlen-1)))) continue;
if (p.dnsp_rrl && !rr.dnsrr_dn[0] && rr.dnsrr_typ == DNS_T_OPT) continue;
if (rtype == rr.dnsrr_typ) {
if(rr.dnsrr_ttl > 0 && (ttl == 0 || rr.dnsrr_ttl < ttl))
ttl = rr.dnsrr_ttl;
switch(rr.dnsrr_typ) {
case DNS_T_A:
if(rr.dnsrr_dsz != 4) continue;
memcpy(&answers4[acnt++], rr.dnsrr_dptr, rr.dnsrr_dsz);
break;
case DNS_T_AAAA:
if(rr.dnsrr_dsz != 16) continue;
memcpy(&answers6[acnt++], rr.dnsrr_dptr, rr.dnsrr_dsz);
break;
default:
break;
}
}
}
n->ttl = ttl;
if(rtype == DNS_T_A) {
if(n->ip4) free(n->ip4);
n->ip4_cnt = acnt;
n->ip4 = answers4;
n->lookup_inflight_v4 = mtev_false;
}
else if(rtype == DNS_T_AAAA) {
if(n->ip6) free(n->ip6);
n->ip6_cnt = acnt;
n->ip6 = answers6;
n->lookup_inflight_v6 = mtev_false;
}
else {
if(result) free(result);
return;
}
DCLOCK();
mtev_skiplist_remove(&nc_dns_cache, n->target, NULL);
n->last_updated = time(NULL);
mtev_skiplist_insert(&nc_dns_cache, n);
DCUNLOCK();
mtevL(noit_debug, "Resolved %s/%s -> %d records\n", n->target,
(rtype == DNS_T_AAAA ? "IPv6" : (rtype == DNS_T_A ? "IPv4" : "???")),
acnt);
if(result) free(result);
return;
blank:
DCLOCK();
if(rtype == DNS_T_A) blank_update_v4(n);
if(rtype == DNS_T_AAAA) blank_update_v6(n);
DCUNLOCK();
mtevL(noit_debug, "Resolved %s/%s -> blank\n", n->target,
(rtype == DNS_T_AAAA ? "IPv6" : (rtype == DNS_T_A ? "IPv4" : "???")));
if(result) free(result);
return;
}
