_public_
uint16_t knot_pkt_type(const knot_pkt_t *pkt)
{
if (pkt == NULL) {
return 0;
}
bool is_query = (knot_wire_get_qr(pkt->wire) == 0);
uint16_t ret = KNOT_QUERY_INVALID;
uint8_t opcode = knot_wire_get_opcode(pkt->wire);
uint8_t query_type = knot_pkt_qtype(pkt);
switch (opcode) {
case KNOT_OPCODE_QUERY:
switch (query_type) {
case 0 /* RESERVED */: /* INVALID */ break;
case KNOT_RRTYPE_AXFR: ret = KNOT_QUERY_AXFR; break;
case KNOT_RRTYPE_IXFR: ret = KNOT_QUERY_IXFR; break;
default: ret = KNOT_QUERY_NORMAL; break;
}
break;
case KNOT_OPCODE_NOTIFY: ret = KNOT_QUERY_NOTIFY; break;
case KNOT_OPCODE_UPDATE: ret = KNOT_QUERY_UPDATE; break;
default: break;
}
if (!is_query) {
ret = ret|KNOT_RESPONSE;
}
return ret;
}
static int update_delegation(struct kr_request *req, struct kr_query *qry, knot_pkt_t *answer, bool has_nsec3)
{
struct kr_zonecut *cut = &qry->zone_cut;
/* RFC4035 3.1.4. authoritative must send either DS or proof of non-existence.
* If it contains neither, the referral is bogus (or an attempted downgrade attack).
*/
unsigned section = KNOT_ANSWER;
if (!knot_wire_get_aa(answer->wire)) { /* Referral */
section = KNOT_AUTHORITY;
} else if (knot_pkt_qtype(answer) == KNOT_RRTYPE_DS) { /* Subrequest */
section = KNOT_ANSWER;
} else { /* N/A */
return kr_ok();
}
int ret = 0;
const knot_dname_t *proved_name = knot_pkt_qname(answer);
/* Aggregate DS records (if using multiple keys) */
knot_rrset_t *new_ds = update_ds(cut, knot_pkt_section(answer, section));
if (!new_ds) {
/* No DS provided, check for proof of non-existence. */
if (!has_nsec3) {
if (!knot_wire_get_aa(answer->wire)) {
/* Referral, check if it is referral to unsigned, rfc4035 5.2 */
ret = kr_nsec_ref_to_unsigned(answer);
} else {
/* No-data answer */
ret = kr_nsec_existence_denial(answer, KNOT_AUTHORITY, proved_name, KNOT_RRTYPE_DS);
}
} else {
if (!knot_wire_get_aa(answer->wire)) {
/* Referral, check if it is referral to unsigned, rfc5155 8.9 */
ret = kr_nsec3_ref_to_unsigned(answer);
} else {
/* No-data answer, QTYPE is DS, rfc5155 8.6 */
ret = kr_nsec3_no_data(answer, KNOT_AUTHORITY, proved_name, KNOT_RRTYPE_DS);
}
if (ret == kr_error(DNSSEC_NOT_FOUND)) {
/* Not bogus, going insecure due to optout */
ret = 0;
}
}
if (ret != 0) {
DEBUG_MSG(qry, "<= bogus proof of DS non-existence\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
} else {
DEBUG_MSG(qry, "<= DS doesn't exist, going insecure\n");
qry->flags &= ~QUERY_DNSSEC_WANT;
qry->flags |= QUERY_DNSSEC_INSECURE;
}
return ret;
}
/* Extend trust anchor */
DEBUG_MSG(qry, "<= DS: OK\n");
cut->trust_anchor = new_ds;
return ret;
}
void print_header_xfr(const knot_pkt_t *packet, const style_t *style)
{
if (style == NULL) {
DBG_NULL;
return;
}
char xfr[16] = "AXFR";
switch (knot_pkt_qtype(packet)) {
case KNOT_RRTYPE_AXFR:
break;
case KNOT_RRTYPE_IXFR:
xfr[0] = 'I';
break;
default:
return;
}
if (style->show_header) {
char *owner = knot_dname_to_str_alloc(knot_pkt_qname(packet));
if (style->style.ascii_to_idn != NULL) {
style->style.ascii_to_idn(&owner);
}
if (owner != NULL) {
printf(";; %s for %s\n", xfr, owner);
free(owner);
}
}
}
static void print_error_host(const uint16_t code,
const knot_pkt_t *packet,
const style_t *style)
{
const char *rcode_str = "Unknown";
char type[32] = "Unknown";
char *owner;
lookup_table_t *rcode;
owner = knot_dname_to_str_alloc(knot_pkt_qname(packet));
if (style->style.ascii_to_idn != NULL) {
style->style.ascii_to_idn(&owner);
}
rcode = lookup_by_id(knot_rcode_names, code);
if (rcode != NULL) {
rcode_str = rcode->name;
}
knot_rrtype_to_string(knot_pkt_qtype(packet), type, sizeof(type));
if (code == KNOT_RCODE_NOERROR) {
printf("Host %s has no %s record\n", owner, type);
} else {
printf("Host %s type %s error: %s\n", owner, type, rcode_str);
}
free(owner);
}
/*! \brief Check if query fits the template requirements. */
static int template_match(int state, synth_template_t *tpl, knot_pkt_t *pkt, struct query_data *qdata)
{
/* Parse address from query name. */
char addr_str[SOCKADDR_STRLEN] = { '\0' };
int ret = addr_parse(qdata, tpl, addr_str);
if (ret != KNOT_EOK) {
return state; /* Can't identify addr in QNAME, not applicable. */
}
/* Match against template netblock. */
struct sockaddr_storage query_addr = { '\0' };
int provided_af = tpl->subnet.ss.ss_family;
ret = sockaddr_set(&query_addr, provided_af, addr_str, 0);
if (ret == KNOT_EOK) {
ret = netblock_match(&tpl->subnet, &query_addr);
}
if (ret != 0) {
return state; /* Out of our netblock, not applicable. */
}
/* Check if the request is for an available query type. */
uint16_t qtype = knot_pkt_qtype(qdata->query);
switch (tpl->type) {
case SYNTH_FORWARD:
if (!query_satisfied_by_family(qtype, provided_af)) {
qdata->rcode = KNOT_RCODE_NOERROR;
return NODATA;
}
break;
case SYNTH_REVERSE:
if (qtype != KNOT_RRTYPE_PTR && qtype != KNOT_RRTYPE_ANY) {
qdata->rcode = KNOT_RCODE_NOERROR;
return NODATA;
}
break;
default:
break;
}
/* Synthetise record from template. */
knot_rrset_t *rr = synth_rr(addr_str, tpl, pkt, qdata);
if (rr == NULL) {
qdata->rcode = KNOT_RCODE_SERVFAIL;
return ERROR;
}
/* Insert synthetic response into packet. */
if (knot_pkt_put(pkt, 0, rr, KNOT_PF_FREE) != KNOT_EOK) {
return ERROR;
}
/* Authoritative response. */
knot_wire_set_aa(pkt->wire);
return HIT;
}
static int rosedb_synth(knot_pkt_t *pkt, const knot_dname_t *key, struct iter *it,
struct query_data *qdata)
{
struct entry entry;
int ret = KNOT_EOK;
uint16_t qtype = knot_pkt_qtype(qdata->query);
/* Answer section. */
while (ret == KNOT_EOK) {
if (cache_iter_val(it, &entry) == 0) {
ret = rosedb_synth_rr(pkt, &entry, qtype);
}
if (cache_iter_next(it) != 0) {
break;
}
}
/* Authority section. */
knot_pkt_begin(pkt, KNOT_AUTHORITY);
/* Not found (zone cut if records exist). */
ret = cache_iter_begin(it, key);
while (ret == KNOT_EOK) {
if (cache_iter_val(it, &entry) == 0) {
ret = rosedb_synth_rr(pkt, &entry, KNOT_RRTYPE_NS);
ret = rosedb_synth_rr(pkt, &entry, KNOT_RRTYPE_SOA);
}
if (cache_iter_next(it) != 0) {
break;
}
}
/* Our response is authoritative. */
if (knot_wire_get_nscount(pkt->wire) > 0) {
knot_wire_set_aa(pkt->wire);
if (knot_wire_get_ancount(pkt->wire) == 0) {
qdata->rcode = KNOT_RCODE_NXDOMAIN;
}
}
/* Send message to syslog. */
struct sockaddr_storage syslog_addr;
if (sockaddr_set(&syslog_addr, AF_INET, entry.syslog_ip, DEFAULT_PORT) == KNOT_EOK) {
int sock = net_unbound_socket(AF_INET, &syslog_addr);
if (sock > 0) {
rosedb_send_log(sock, (struct sockaddr *)&syslog_addr, pkt,
entry.threat_code, qdata);
close(sock);
}
}
return ret;
}
static uint8_t rrl_clsid(rrl_req_t *p)
{
/* Check error code */
int ret = CLS_NULL;
switch (knot_wire_get_rcode(p->w)) {
case KNOT_RCODE_NOERROR:
ret = CLS_NORMAL;
break;
case KNOT_RCODE_NXDOMAIN:
return CLS_NXDOMAIN;
break;
default:
return CLS_ERROR;
break;
}
/* Check if answered from a qname */
if (ret == CLS_NORMAL && p->flags & RRL_WILDCARD) {
return CLS_WILDCARD;
}
/* Check query type for spec. classes. */
if (p->query) {
switch(knot_pkt_qtype(p->query)) {
case KNOT_RRTYPE_ANY: /* ANY spec. class */
return CLS_ANY;
break;
case KNOT_RRTYPE_DNSKEY:
case KNOT_RRTYPE_RRSIG:
case KNOT_RRTYPE_DS: /* DNSSEC-related RR class. */
return CLS_DNSSEC;
break;
default:
break;
}
}
/* Check packet size for threshold. */
if (p->len >= RRL_PSIZE_LARGE) {
return CLS_LARGE;
}
/* Check ancount */
if (knot_wire_get_ancount(p->w) == 0) {
return CLS_EMPTY;
}
return ret;
}
static int validate(knot_layer_t *ctx, knot_pkt_t *pkt)
{
int ret = 0;
struct kr_request *req = ctx->data;
struct kr_query *qry = req->current_query;
/* Ignore faulty or unprocessed responses. */
if (ctx->state & (KNOT_STATE_FAIL|KNOT_STATE_CONSUME)) {
return ctx->state;
}
/* Pass-through if user doesn't want secure answer or stub. */
/* @todo: Validating stub resolver mode. */
if (!(qry->flags & QUERY_DNSSEC_WANT) || (qry->flags & QUERY_STUB)) {
return ctx->state;
}
/* Answer for RRSIG may not set DO=1, but all records MUST still validate. */
bool use_signatures = (knot_pkt_qtype(pkt) != KNOT_RRTYPE_RRSIG);
if (!(qry->flags & QUERY_CACHED) && !knot_pkt_has_dnssec(pkt) && !use_signatures) {
DEBUG_MSG(qry, "<= got insecure response\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
/* Track difference between current TA and signer name.
* This indicates that the NS is auth for both parent-child, and we must update DS/DNSKEY to validate it.
*/
const bool track_pc_change = (!(qry->flags & QUERY_CACHED) && (qry->flags & QUERY_DNSSEC_WANT));
const knot_dname_t *ta_name = qry->zone_cut.trust_anchor ? qry->zone_cut.trust_anchor->owner : NULL;
const knot_dname_t *signer = signature_authority(pkt);
if (track_pc_change && ta_name && (!signer || !knot_dname_is_equal(ta_name, signer))) {
if (ctx->state == KNOT_STATE_YIELD) { /* Already yielded for revalidation. */
return KNOT_STATE_FAIL;
}
DEBUG_MSG(qry, ">< cut changed, needs revalidation\n");
if (!signer) {
/* Not a DNSSEC-signed response, ask parent for DS to prove transition to INSECURE. */
} else if (knot_dname_is_sub(signer, qry->zone_cut.name)) {
/* Key signer is below current cut, advance and refetch keys. */
qry->zone_cut.name = knot_dname_copy(signer, &req->pool);
} else if (!knot_dname_is_equal(signer, qry->zone_cut.name)) {
/* Key signer is above the current cut, so we can't validate it. This happens when
a server is authoritative for both grandparent, parent and child zone.
Ascend to parent cut, and refetch authority for signer. */
if (qry->zone_cut.parent) {
memcpy(&qry->zone_cut, qry->zone_cut.parent, sizeof(qry->zone_cut));
} else {
qry->flags |= QUERY_AWAIT_CUT;
}
qry->zone_cut.name = knot_dname_copy(signer, &req->pool);
} /* else zone cut matches, but DS/DNSKEY doesn't => refetch. */
return KNOT_STATE_YIELD;
}
/* Check if this is a DNSKEY answer, check trust chain and store. */
uint8_t pkt_rcode = knot_wire_get_rcode(pkt->wire);
uint16_t qtype = knot_pkt_qtype(pkt);
bool has_nsec3 = pkt_has_type(pkt, KNOT_RRTYPE_NSEC3);
if (knot_wire_get_aa(pkt->wire) && qtype == KNOT_RRTYPE_DNSKEY) {
ret = validate_keyset(qry, pkt, has_nsec3);
if (ret != 0) {
DEBUG_MSG(qry, "<= bad keys, broken trust chain\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
/* Validate non-existence proof if not positive answer. */
if (!(qry->flags & QUERY_CACHED) && pkt_rcode == KNOT_RCODE_NXDOMAIN) {
/* @todo If knot_pkt_qname(pkt) is used instead of qry->sname then the tests crash. */
if (!has_nsec3) {
ret = kr_nsec_name_error_response_check(pkt, KNOT_AUTHORITY, qry->sname);
} else {
ret = kr_nsec3_name_error_response_check(pkt, KNOT_AUTHORITY, qry->sname);
}
if (ret != 0) {
DEBUG_MSG(qry, "<= bad NXDOMAIN proof\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
/* @todo WTH, this needs API that just tries to find a proof and the caller
* doesn't have to worry about NSEC/NSEC3
* @todo rework this */
if (!(qry->flags & QUERY_CACHED)) {
const knot_pktsection_t *an = knot_pkt_section(pkt, KNOT_ANSWER);
if (pkt_rcode == KNOT_RCODE_NOERROR && an->count == 0 && knot_wire_get_aa(pkt->wire)) {
/* @todo
* ? quick mechanism to determine which check to preform first
* ? merge the functionality together to share code/resources
*/
if (!has_nsec3) {
ret = kr_nsec_existence_denial(pkt, KNOT_AUTHORITY, knot_pkt_qname(pkt), knot_pkt_qtype(pkt));
} else {
ret = kr_nsec3_no_data(pkt, KNOT_AUTHORITY, knot_pkt_qname(pkt), knot_pkt_qtype(pkt));
}
if (ret != 0) {
if (has_nsec3 && (ret == kr_error(DNSSEC_NOT_FOUND))) {
DEBUG_MSG(qry, "<= can't prove NODATA due to optout, going insecure\n");
qry->flags &= ~QUERY_DNSSEC_WANT;
qry->flags |= QUERY_DNSSEC_INSECURE;
} else {
DEBUG_MSG(qry, "<= bad NODATA proof\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
}
}
/* Validate all records, fail as bogus if it doesn't match.
* Do not revalidate data from cache, as it's already trusted. */
if (!(qry->flags & QUERY_CACHED)) {
ret = validate_records(qry, pkt, req->rplan.pool, has_nsec3);
if (ret != 0) {
DEBUG_MSG(qry, "<= couldn't validate RRSIGs\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
/* Check if wildcard expansion detected for final query.
* If yes, copy authority. */
if ((qry->parent == NULL) && (qry->flags & QUERY_DNSSEC_WEXPAND)) {
const knot_pktsection_t *auth = knot_pkt_section(pkt, KNOT_AUTHORITY);
for (unsigned i = 0; i < auth->count; ++i) {
const knot_rrset_t *rr = knot_pkt_rr(auth, i);
kr_rrarray_add(&req->authority, rr, &req->answer->mm);
}
}
/* Check and update current delegation point security status. */
ret = update_delegation(req, qry, pkt, has_nsec3);
if (ret != 0) {
return KNOT_STATE_FAIL;
}
/* Update parent query zone cut */
if (qry->parent) {
if (update_parent_keys(qry, qtype) != 0) {
return KNOT_STATE_FAIL;
}
}
DEBUG_MSG(qry, "<= answer valid, OK\n");
return KNOT_STATE_DONE;
}
static int rosedb_log_message(char *stream, size_t *maxlen, knot_pkt_t *pkt,
const char *threat_code, struct query_data *qdata)
{
char dname_buf[KNOT_DNAME_MAXLEN] = {'\0'};
struct sockaddr_storage addr;
socklen_t addr_len = sizeof(addr);
time_t now = time(NULL);
struct tm tm;
gmtime_r(&now, &tm);
/* Field 1 Timestamp (UTC). */
STREAM_WRITE(stream, maxlen, strftime, "%Y-%m-%d %H:%M:%S\t", &tm);
/* Field 2/3 Remote, local address. */
const struct sockaddr *remote = (const struct sockaddr *)qdata->param->remote;
memcpy(&addr, remote, sockaddr_len(remote));
int client_port = sockaddr_port(&addr);
sockaddr_port_set(&addr, 0);
STREAM_WRITE(stream, maxlen, sockaddr_tostr, &addr);
STREAM_WRITE(stream, maxlen, snprintf, "\t");
getsockname(qdata->param->socket, (struct sockaddr *)&addr, &addr_len);
int server_port = sockaddr_port(&addr);
sockaddr_port_set(&addr, 0);
STREAM_WRITE(stream, maxlen, sockaddr_tostr, &addr);
STREAM_WRITE(stream, maxlen, snprintf, "\t");
/* Field 4/5 Local, remote port. */
STREAM_WRITE(stream, maxlen, snprintf, "%d\t%d\t", client_port, server_port);
/* Field 6 Threat ID. */
STREAM_WRITE(stream, maxlen, snprintf, "%s\t", threat_code);
/* Field 7 - 13 NULL */
STREAM_WRITE(stream, maxlen, snprintf, "\t\t\t\t\t\t\t");
/* Field 14 QNAME */
knot_dname_to_str(dname_buf, knot_pkt_qname(qdata->query), sizeof(dname_buf));
STREAM_WRITE(stream, maxlen, snprintf, "%s\t", dname_buf);
/* Field 15 Resolution (0 = local, 1 = lookup)*/
STREAM_WRITE(stream, maxlen, snprintf, "0\t");
/* Field 16 RDATA.
* - Return randomly RDATA in the answer section (probabilistic rotation).
* - Empty if no answer.
*/
const knot_pktsection_t *ans = knot_pkt_section(pkt, KNOT_ANSWER);
if (ans->count > 0) {
const knot_rrset_t *rr = &ans->rr[knot_random_uint16_t() % ans->count];
int ret = knot_rrset_txt_dump_data(rr, 0, stream, *maxlen, &KNOT_DUMP_STYLE_DEFAULT);
if (ret < 0) {
return ret;
}
stream_skip(&stream, maxlen, ret);
}
STREAM_WRITE(stream, maxlen, snprintf, "\t");
/* Field 17 Connection type. */
STREAM_WRITE(stream, maxlen, snprintf, "%s\t",
net_is_connected(qdata->param->socket) ? "TCP" : "UDP");
/* Field 18 Query type. */
char type_str[16] = { '\0' };
knot_rrtype_to_string(knot_pkt_qtype(qdata->query), type_str, sizeof(type_str));
STREAM_WRITE(stream, maxlen, snprintf, "%s\t", type_str);
/* Field 19 First authority. */
const knot_pktsection_t *ns = knot_pkt_section(pkt, KNOT_AUTHORITY);
if (ns->count > 0 && ns->rr[0].type == KNOT_RRTYPE_NS) {
const knot_dname_t *label = knot_ns_name(&ns->rr[0].rrs, 0);
memset(dname_buf, 0, sizeof(dname_buf));
memcpy(dname_buf, label + 1, *label);
STREAM_WRITE(stream, maxlen, snprintf, "%s", dname_buf);
}
return KNOT_EOK;
}
void print_packet(const knot_pkt_t *packet,
const net_t *net,
const size_t size,
const float elapsed,
const time_t exec_time,
const bool incoming,
const style_t *style)
{
if (packet == NULL || style == NULL) {
DBG_NULL;
return;
}
const knot_pktsection_t *answers = knot_pkt_section(packet,
KNOT_ANSWER);
const knot_pktsection_t *authority = knot_pkt_section(packet,
KNOT_AUTHORITY);
const knot_pktsection_t *additional = knot_pkt_section(packet,
KNOT_ADDITIONAL);
uint16_t qdcount = knot_wire_get_qdcount(packet->wire);
uint16_t ancount = knot_wire_get_ancount(packet->wire);
uint16_t nscount = knot_wire_get_nscount(packet->wire);
uint16_t arcount = knot_wire_get_arcount(packet->wire);
// Get Extended RCODE from the packet.
uint16_t rcode = knot_pkt_get_ext_rcode(packet);
// Disable additionals printing if there are no other records.
// OPT record may be placed anywhere within additionals!
if (knot_pkt_has_edns(packet) && arcount == 1) {
arcount = 0;
}
// Print packet information header.
if (style->show_header) {
print_header(packet, style, rcode);
}
// Print EDNS section.
if (style->show_edns && knot_pkt_has_edns(packet)) {
printf("\n;; EDNS PSEUDOSECTION:\n;; ");
print_section_opt(packet->opt_rr,
knot_wire_get_rcode(packet->wire));
}
// Print DNS sections.
switch (style->format) {
case FORMAT_DIG:
if (ancount > 0) {
print_section_dig(knot_pkt_rr(answers, 0), ancount, style);
}
break;
case FORMAT_HOST:
if (ancount > 0) {
print_section_host(knot_pkt_rr(answers, 0), ancount, style);
} else {
print_error_host(rcode, packet, style);
}
break;
case FORMAT_NSUPDATE:
if (style->show_question && qdcount > 0) {
printf("\n;; ZONE SECTION:\n;; ");
print_section_question(knot_pkt_qname(packet),
knot_pkt_qclass(packet),
knot_pkt_qtype(packet),
style);
}
if (style->show_answer && ancount > 0) {
printf("\n;; PREREQUISITE SECTION:\n");
print_section_full(knot_pkt_rr(answers, 0), ancount, style, true);
}
if (style->show_authority && nscount > 0) {
printf("\n;; UPDATE SECTION:\n");
print_section_full(knot_pkt_rr(authority, 0), nscount, style, true);
}
if (style->show_additional && arcount > 0) {
printf("\n;; ADDITIONAL DATA:\n");
print_section_full(knot_pkt_rr(additional, 0), arcount, style, true);
}
break;
case FORMAT_FULL:
if (style->show_question && qdcount > 0) {
printf("\n;; QUESTION SECTION:\n;; ");
print_section_question(knot_pkt_qname(packet),
knot_pkt_qclass(packet),
knot_pkt_qtype(packet),
style);
}
if (style->show_answer && ancount > 0) {
printf("\n;; ANSWER SECTION:\n");
print_section_full(knot_pkt_rr(answers, 0), ancount, style, true);
}
if (style->show_authority && nscount > 0) {
printf("\n;; AUTHORITY SECTION:\n");
print_section_full(knot_pkt_rr(authority, 0), nscount, style, true);
}
if (style->show_additional && arcount > 0) {
printf("\n;; ADDITIONAL SECTION:\n");
print_section_full(knot_pkt_rr(additional, 0), arcount, style, true);
}
break;
default:
break;
}
// Print TSIG section.
if (style->show_tsig && knot_pkt_has_tsig(packet)) {
printf("\n;; TSIG PSEUDOSECTION:\n");
print_section_full(packet->tsig_rr, 1, style, false);
}
// Print packet statistics.
if (style->show_footer) {
printf("\n");
print_footer(size, 0, 0, net, elapsed, exec_time, incoming);
}
}
