static int
dns_parse_a(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
void **result, unsigned dsize) {
struct dns_rr_a *ret;
struct dns_parse p;
struct dns_rr rr;
int r;
/* first, validate and count number of addresses */
dns_initparse(&p, qdn, pkt, cur, end);
while((r = dns_nextrr(&p, &rr)) > 0)
if (rr.dnsrr_dsz != dsize)
return DNS_E_PROTOCOL;
if (r < 0)
return DNS_E_PROTOCOL;
else if (!p.dnsp_nrr)
return DNS_E_NODATA;
ret = malloc(sizeof(*ret) + dsize * p.dnsp_nrr + dns_stdrr_size(&p));
if (!ret)
return DNS_E_NOMEM;
ret->dnsa_nrr = p.dnsp_nrr;
ret->dnsa_addr = (unsigned char*)(ret+1);
/* copy the RRs */
for (dns_rewind(&p, qdn), r = 0; dns_nextrr(&p, &rr); ++r)
memcpy(ret->dnsa_addr + dsize * r, rr.dnsrr_dptr, dsize);
dns_stdrr_finish((struct dns_rr_null *)ret,
(char *)(ret->dnsa_addr + dsize * p.dnsp_nrr), &p);
*result = ret;
return 0;
}
static void dnscb(struct dns_ctx *ctx, void *result, void *data) {
int r = dns_status(ctx);
struct query *q = data;
struct dns_parse p;
struct dns_rr rr;
unsigned nrr;
unsigned char dn[DNS_MAXDN];
const unsigned char *pkt, *cur, *end;
if (!result) {
return;
}
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 = p.dnsp_qtyp = 0;
nrr = 0;
while((r = dns_nextrr(&p, &rr)) > 0) {
if (!dns_dnequal(dn, rr.dnsrr_dn)) continue;
if ((qcls == DNS_C_ANY || qcls == rr.dnsrr_cls) &&
(q->qtyp == DNS_T_ANY || q->qtyp == 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) {
r = DNS_E_PROTOCOL;
break;
}
else {
dns_dntodn(p.dnsp_dnbuf, dn, sizeof(dn));
}
}
}
if (!r && !nrr)
r = DNS_E_NODATA;
if (r < 0) {
free(result);
return;
}
dns_rewind(&p, NULL);
p.dnsp_qtyp = q->qtyp == DNS_T_ANY ? 0 : q->qtyp;
p.dnsp_qcls = qcls == DNS_C_ANY ? 0 : qcls;
while(dns_nextrr(&p, &rr)) {
const unsigned char *dptr = rr.dnsrr_dptr;
if (rr.dnsrr_dsz == 4) {
char *ip = xmalloc(sizeof(char) * 16);
sprintf(ip, "%d.%d.%d.%d", dptr[0], dptr[1], dptr[2], dptr[3]);
q->callback(ip, q->data, q->g_ape);
break;
}
}
free(result);
query_free(q);
}
int
dns_parse_srv(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
void **result) {
struct dns_rr_srv *ret;
struct dns_parse p;
struct dns_rr rr;
int r, l;
char *sp;
dnsc_t srv[DNS_MAXDN];
assert(dns_get16(cur+2) == DNS_C_IN && dns_get16(cur+0) == DNS_T_SRV);
/* first, validate the answer and count size of the result */
l = 0;
dns_initparse(&p, qdn, pkt, cur, end);
while((r = dns_nextrr(&p, &rr)) > 0) {
cur = rr.dnsrr_dptr + 6;
r = dns_getdn(pkt, &cur, end, srv, sizeof(srv));
if (r <= 0 || cur != rr.dnsrr_dend)
return DNS_E_PROTOCOL;
l += dns_dntop_size(srv);
}
if (r < 0)
return DNS_E_PROTOCOL;
if (!p.dnsp_nrr)
return DNS_E_NODATA;
/* next, allocate and set up result */
l += dns_stdrr_size(&p);
ret = malloc(sizeof(*ret) + sizeof(struct dns_srv) * p.dnsp_nrr + l);
if (!ret)
return DNS_E_NOMEM;
ret->dnssrv_nrr = p.dnsp_nrr;
ret->dnssrv_srv = (struct dns_srv *)(ret+1);
/* and 3rd, fill in result, finally */
sp = (char*)(ret->dnssrv_srv + p.dnsp_nrr);
for (dns_rewind(&p, qdn), r = 0; dns_nextrr(&p, &rr); ++r) {
ret->dnssrv_srv[r].name = sp;
cur = rr.dnsrr_dptr;
ret->dnssrv_srv[r].priority = dns_get16(cur);
ret->dnssrv_srv[r].weight = dns_get16(cur+2);
ret->dnssrv_srv[r].port = dns_get16(cur+4);
cur += 6;
dns_getdn(pkt, &cur, end, srv, sizeof(srv));
sp += dns_dntop(srv, sp, DNS_MAXNAME);
}
dns_stdrr_finish((struct dns_rr_null *)ret, sp, &p);
*result = ret;
return 0;
}
static void dns_cache_resolve(struct dns_ctx *ctx, void *result, void *data,
enum dns_type rtype) {
int i, ttl, acnt, r = dns_status(ctx);
dns_cache_node *n = data;
unsigned char idn[DNS_MAXDN], dn[DNS_MAXDN];
struct dns_parse p;
struct dns_rr rr;
unsigned nrr;
char **answers;
const unsigned char *pkt, *cur, *end;
if(!result) goto blank;
dns_dntodn(n->dn, idn, sizeof(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) {
if (!dns_dnequal(idn, rr.dnsrr_dn)) 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));
}
}
}
if(!r && !nrr) goto blank;
dns_rewind(&p, NULL);
p.dnsp_qcls = DNS_C_IN;
p.dnsp_qtyp = rtype;
answers = calloc(nrr, sizeof(*answers));
acnt = 0;
while(dns_nextrr(&p, &rr) && nrr < MAX_RR) {
char buff[INET6_ADDRSTRLEN];
if (!dns_dnequal(idn, rr.dnsrr_dn)) 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;
inet_ntop(AF_INET, rr.dnsrr_dptr, buff, sizeof(buff));
answers[acnt++] = strdup(buff);
break;
case DNS_T_AAAA:
if(rr.dnsrr_dsz != 16) continue;
inet_ntop(AF_INET6, rr.dnsrr_dptr, buff, sizeof(buff));
answers[acnt++] = strdup(buff);
break;
default:
break;
}
}
}
n->ttl = ttl;
if(rtype == DNS_T_A) {
for(i=0;i<n->ip4_cnt;i++) if(n->ip4[i]) free(n->ip4[i]);
if(n->ip4) free(n->ip4);
n->ip4_cnt = acnt;
n->ip4 = answers;
n->lookup_inflight_v4 = noit_false;
}
else if(rtype == DNS_T_AAAA) {
for(i=0;i<n->ip6_cnt;i++) if(n->ip6[i]) free(n->ip6[i]);
if(n->ip6) free(n->ip6);
n->ip6_cnt = acnt;
n->ip6 = answers;
n->lookup_inflight_v6 = noit_false;
}
noit_skiplist_remove(&nc_dns_cache, n->target, NULL);
n->last_updated = time(NULL);
noit_skiplist_insert(&nc_dns_cache, n);
noitL(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:
if(rtype == DNS_T_A) blank_update_v4(n);
if(rtype == DNS_T_AAAA) blank_update_v6(n);
noitL(noit_debug, "Resolved %s/%s -> blank\n", n->target,
(rtype == DNS_T_AAAA ? "IPv6" : (rtype == DNS_T_A ? "IPv4" : "???")));
if(result) free(result);
return;
}
static void dns_cb(struct dns_ctx *ctx, void *result, void *data) {
int r = dns_status(ctx);
int len, i;
struct dns_check_info *ci = data;
struct dns_parse p;
struct dns_rr rr;
unsigned nrr;
unsigned char dn[DNS_MAXDN];
const unsigned char *pkt, *cur, *end;
char *result_str[MAX_RR] = { NULL };
char *result_combined = NULL;
/* If out ci isn't active, we must have timed out already */
if(!__isactive_ci(ci)) {
if(result) free(result);
return;
}
ci->timed_out = 0;
/* If we don't have a result, explode */
if (!result) {
ci->error = strdup(dns_strerror(r));
goto cleanup;
}
/* Process the packet */
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;
while((r = dns_nextrr(&p, &rr)) > 0) {
if (!dns_dnequal(dn, rr.dnsrr_dn)) continue;
if ((ci->query_ctype == DNS_C_ANY || ci->query_ctype == rr.dnsrr_cls) &&
(ci->query_rtype == DNS_T_ANY || ci->query_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) {
ci->error = strdup("protocol error");
break;
}
else {
int32_t on = 1;
/* This actually updates what we're looking for */
dns_dntodn(p.dnsp_dnbuf, ci->dn, sizeof(dn));
noit_stats_set_metric(ci->check, &ci->current, "cname", METRIC_INT32, &on);
/* Now follow the leader */
noitL(nldeb, "%s. CNAME %s.\n", dns_dntosp(dn),
dns_dntosp(p.dnsp_dnbuf));
dns_dntodn(p.dnsp_dnbuf, dn, sizeof(dn));
noitL(nldeb, " ---> '%s'\n", dns_dntosp(dn));
}
}
}
if (!r && !nrr) {
ci->error = strdup("no data");
}
dns_rewind(&p, NULL);
p.dnsp_qtyp = ci->query_rtype == DNS_T_ANY ? 0 : ci->query_rtype;
p.dnsp_qcls = ci->query_ctype == DNS_C_ANY ? 0 : ci->query_ctype;
while(dns_nextrr(&p, &rr) && ci->nrr < MAX_RR)
decode_rr(ci, &p, &rr, &result_str[ci->nrr]);
if(ci->sort)
qsort(result_str, ci->nrr, sizeof(*result_str), cstring_cmp);
/* calculate the length and allocate on the stack */
len = 0;
for(i=0; i<ci->nrr; i++) len += strlen(result_str[i]) + 2;
result_combined = alloca(len);
result_combined[0] = '\0';
/* string it together */
len = 0;
for(i=0; i<ci->nrr; i++) {
int slen;
if(i) { memcpy(result_combined + len, ", ", 2); len += 2; }
slen = strlen(result_str[i]);
memcpy(result_combined + len, result_str[i], slen);
len += slen;
result_combined[len] = '\0';
free(result_str[i]); /* free as we go */
}
noit_stats_set_metric(ci->check, &ci->current, "answer", METRIC_STRING, result_combined);
cleanup:
if(result) free(result);
if(ci->timeout_event) {
eventer_t e = eventer_remove(ci->timeout_event);
ci->timeout_event = NULL;
if(e) eventer_free(e);
}
ci->check->flags &= ~NP_RUNNING;
dns_check_log_results(ci);
__deactivate_ci(ci);
}
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;
}
static void dns_cb(struct dns_ctx *ctx, void *result, void *data) {
int r = dns_status(ctx);
dns_lookup_ctx_t *dlc = data;
struct dns_parse p;
struct dns_rr rr;
unsigned nrr = 0;
unsigned char dn[DNS_MAXDN];
const unsigned char *pkt, *cur, *end;
lua_State *L;
if(!dlc->active) goto cleanup;
if(!result) goto cleanup;
L = dlc->ci->coro_state;
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;
while(dns_nextrr(&p, &rr) > 0) {
const char *fieldname = NULL;
char buff[DNS_MAXDN], *txt_str, *c;
int totalsize;
const unsigned char *pkt = p.dnsp_pkt;
const unsigned char *end = p.dnsp_end;
const unsigned char *dptr = rr.dnsrr_dptr;
const unsigned char *dend = rr.dnsrr_dend;
unsigned char *dn = rr.dnsrr_dn;
const unsigned char *tmp;
if (!dns_dnequal(dn, rr.dnsrr_dn)) continue;
if ((dlc->query_ctype == DNS_C_ANY || dlc->query_ctype == rr.dnsrr_cls) &&
(dlc->query_rtype == DNS_T_ANY || dlc->query_rtype == rr.dnsrr_typ)) {
lua_newtable(L);
lua_pushinteger(L, rr.dnsrr_ttl);
lua_setfield(L, -2, "ttl");
switch(rr.dnsrr_typ) {
case DNS_T_A:
if(rr.dnsrr_dsz == 4) {
snprintf(buff, sizeof(buff), "%d.%d.%d.%d",
dptr[0], dptr[1], dptr[2], dptr[3]);
lua_pushstring(L, buff);
lua_setfield(L, -2, "a");
}
break;
case DNS_T_AAAA:
if(rr.dnsrr_dsz == 16) {
inet_ntop(AF_INET6, dptr, buff, 16);
lua_pushstring(L, buff);
lua_setfield(L, -2, "aaaa");
}
break;
case DNS_T_TXT:
totalsize = 0;
for(tmp = dptr; tmp < dend; totalsize += *tmp, tmp += *tmp + 1)
if(tmp + *tmp + 1 > dend) break;
/* worst case: every character escaped + '\0' */
txt_str = alloca(totalsize * 3 + 1);
if(!txt_str) break;
c = txt_str;
for(tmp = dptr; tmp < dend; tmp += *tmp + 1)
c = encode_txt(c, tmp+1, *tmp);
lua_pushstring(L, txt_str);
lua_setfield(L, -2, "txt");
break;
case DNS_T_MX:
lua_pushinteger(L, dns_get16(dptr));
lua_setfield(L, -2, "preference");
tmp = dptr + 2;
if(dns_getdn(pkt, &tmp, end, dn, DNS_MAXDN) <= 0 || tmp != dend)
break;
dns_dntop(dn, buff + strlen(buff), sizeof(buff) - strlen(buff));
lua_pushstring(L, buff);
lua_setfield(L, -2, "mx");
break;
case DNS_T_CNAME: if(!fieldname) fieldname = "cname";
case DNS_T_PTR: if(!fieldname) fieldname = "ptr";
case DNS_T_NS: if(!fieldname) fieldname = "ns";
case DNS_T_MB: if(!fieldname) fieldname = "mb";
case DNS_T_MD: if(!fieldname) fieldname = "md";
case DNS_T_MF: if(!fieldname) fieldname = "mf";
case DNS_T_MG: if(!fieldname) fieldname = "mg";
case DNS_T_MR: if(!fieldname) fieldname = "mr";
if(dns_getdn(pkt, &dptr, end, dn, DNS_MAXDN) <= 0) break;
dns_dntop(dn, buff, sizeof(buff));
lua_pushstring(L, buff);
lua_setfield(L, -2, fieldname);
break;
default:
break;
}
++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;
}
}
}
cleanup:
if(result) free(result);
if(dlc->active) noit_lua_resume(dlc->ci, nrr);
lookup_ctx_release(dlc);
}