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; }