DCPluginSyncFilterResult
dcplugin_sync_post_filter(DCPlugin *dcplugin, DCPluginDNSPacket *dcp_packet)
{
Blocking *blocking = dcplugin_get_user_data(dcplugin);
ldns_pkt *packet = NULL;
DCPluginSyncFilterResult result = DCP_SYNC_FILTER_RESULT_OK;
if (blocking->domains == NULL && blocking->ips == NULL) {
return DCP_SYNC_FILTER_RESULT_OK;
}
if (ldns_wire2pkt(&packet, dcplugin_get_wire_data(dcp_packet),
dcplugin_get_wire_data_len(dcp_packet))
!= LDNS_STATUS_OK) {
return DCP_SYNC_FILTER_RESULT_ERROR;
}
if (blocking->domains != NULL &&
(result = apply_block_domains(dcp_packet, blocking, packet)
!= DCP_SYNC_FILTER_RESULT_OK)) {
ldns_pkt_free(packet);
return result;
}
if (blocking->ips != NULL &&
(result = apply_block_ips(dcp_packet, blocking, packet)
!= DCP_SYNC_FILTER_RESULT_OK)) {
ldns_pkt_free(packet);
return result;
}
ldns_pkt_free(packet);
return DCP_SYNC_FILTER_RESULT_OK;
}
ldns_rr *
ldns_axfr_next(ldns_resolver *resolver)
{
ldns_rr *cur_rr;
uint8_t *packet_wire;
size_t packet_wire_size;
ldns_lookup_table *rcode;
ldns_status status;
/* check if start() has been called */
if (!resolver || resolver->_socket == 0) {
return NULL;
}
if (resolver->_cur_axfr_pkt) {
if (resolver->_axfr_i == ldns_pkt_ancount(resolver->_cur_axfr_pkt)) {
ldns_pkt_free(resolver->_cur_axfr_pkt);
resolver->_cur_axfr_pkt = NULL;
return ldns_axfr_next(resolver);
}
cur_rr = ldns_rr_clone(ldns_rr_list_rr(
ldns_pkt_answer(resolver->_cur_axfr_pkt),
resolver->_axfr_i));
resolver->_axfr_i++;
if (ldns_rr_get_type(cur_rr) == LDNS_RR_TYPE_SOA) {
resolver->_axfr_soa_count++;
if (resolver->_axfr_soa_count >= 2) {
close(resolver->_socket);
resolver->_socket = 0;
ldns_pkt_free(resolver->_cur_axfr_pkt);
resolver->_cur_axfr_pkt = NULL;
}
}
return cur_rr;
} else {
packet_wire = ldns_tcp_read_wire(resolver->_socket, &packet_wire_size);
if(!packet_wire)
return NULL;
status = ldns_wire2pkt(&resolver->_cur_axfr_pkt, packet_wire,
packet_wire_size);
free(packet_wire);
resolver->_axfr_i = 0;
if (status != LDNS_STATUS_OK) {
/* TODO: make status return type of this function (...api change) */
fprintf(stderr, "Error parsing rr during AXFR: %s\n", ldns_get_errorstr_by_id(status));
return NULL;
} else if (ldns_pkt_get_rcode(resolver->_cur_axfr_pkt) != 0) {
rcode = ldns_lookup_by_id(ldns_rcodes, (int) ldns_pkt_get_rcode(resolver->_cur_axfr_pkt));
fprintf(stderr, "Error in AXFR: %s\n", rcode->name);
return NULL;
} else {
return ldns_axfr_next(resolver);
}
}
}
ldns_pkt *
ldns_resolver_query(const ldns_resolver *r, const ldns_rdf *name, ldns_rr_type type,
ldns_rr_class c, uint16_t flags)
{
ldns_rdf *newname;
ldns_pkt *pkt;
ldns_status status;
pkt = NULL;
if (!ldns_resolver_defnames(r)) {
status = ldns_resolver_send(&pkt, (ldns_resolver *)r, name, type, c,
flags);
if (status == LDNS_STATUS_OK) {
return pkt;
} else {
if (pkt) {
ldns_pkt_free(pkt);
}
fprintf(stderr, "error: %s\n", ldns_get_errorstr_by_id(status));
return NULL;
}
}
if (!ldns_resolver_domain(r)) {
/* _defnames is set, but the domain is not....?? */
status = ldns_resolver_send(&pkt, (ldns_resolver *)r, name, type, c,
flags);
if (status == LDNS_STATUS_OK) {
return pkt;
} else {
if (pkt) {
ldns_pkt_free(pkt);
}
return NULL;
}
}
newname = ldns_dname_cat_clone((const ldns_rdf*)name, ldns_resolver_domain(r));
if (!newname) {
if (pkt) {
ldns_pkt_free(pkt);
}
return NULL;
}
status = ldns_resolver_send(&pkt, (ldns_resolver *)r, newname, type, c,
flags);
ldns_rdf_free(newname);
return pkt;
}
DCPluginSyncFilterResult
dcplugin_sync_pre_filter(DCPlugin *dcplugin, DCPluginDNSPacket *dcp_packet)
{
uint8_t *new_packet;
ldns_rdf *edns_data;
ldns_pkt *packet;
size_t new_packet_size;
ldns_wire2pkt(&packet, dcplugin_get_wire_data(dcp_packet),
dcplugin_get_wire_data_len(dcp_packet));
edns_data = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_HEX,
dcplugin_get_user_data(dcplugin));
ldns_pkt_set_edns_data(packet, edns_data);
ldns_pkt2wire(&new_packet, packet, &new_packet_size);
if (dcplugin_get_wire_data_max_len(dcp_packet) >= new_packet_size) {
dcplugin_set_wire_data(dcp_packet, new_packet, new_packet_size);
}
free(new_packet);
ldns_pkt_free(packet);
return DCP_SYNC_FILTER_RESULT_OK;
}
/**
* Fill buffer with reply from the entry.
*/
static void
fill_buffer_with_reply(ldns_buffer* buffer, struct entry* entry, ldns_pkt* q)
{
ldns_status status;
ldns_pkt* answer_pkt = NULL;
log_assert(entry && entry->reply_list);
ldns_buffer_clear(buffer);
if(entry->reply_list->reply_from_hex) {
status = ldns_buffer2pkt_wire(&answer_pkt,
entry->reply_list->reply_from_hex);
if(status != LDNS_STATUS_OK) {
log_err("testbound: hex packet unparsable, used asis.");
ldns_buffer_write(buffer,
ldns_buffer_begin(entry->reply_list->reply_from_hex),
ldns_buffer_limit(entry->reply_list->reply_from_hex));
}
} else {
answer_pkt = ldns_pkt_clone(entry->reply_list->reply);
}
if(answer_pkt) {
if(q) adjust_packet(entry, answer_pkt, q);
status = ldns_pkt2buffer_wire(buffer, answer_pkt);
if(status != LDNS_STATUS_OK)
fatal_exit("ldns: cannot pkt2buffer_wire parsed pkt");
}
ldns_pkt_free(answer_pkt);
ldns_buffer_flip(buffer);
}
ldns_rr_list* mrb_getrr_list(mrb_state *mrb, ldns_resolver *resolver, char *name, uint32_t rrtype,uint32_t rrclass, uint32_t opt, uint32_t rrsection)
{
ldns_pkt *pkt = NULL;
ldns_rr_list *records= NULL;
ldns_rdf *domain = NULL;
domain = ldns_dname_new_frm_str(name);
if(!domain)
{
return NULL;
}
pkt = ldns_resolver_query(resolver,
domain,
rrtype,
rrclass,
opt);
ldns_rdf_deep_free(domain);
if(!pkt)
{
return NULL;
}
records =ldns_pkt_rr_list_by_type(pkt, rrtype, rrsection);
ldns_pkt_free(pkt);
if(!records)
{
return NULL;
}
return records;
}
ldns_rr_list *mrb_getaddress_rr_list(mrb_state *mrb, ldns_resolver *resolver, char *name)
{
ldns_pkt *pkt = NULL;
ldns_rr_list *records= NULL;
ldns_rdf *domain = NULL;
domain = ldns_dname_new_frm_str(name);
if(!domain)
{
return NULL;
}
pkt = ldns_resolver_query(resolver,
domain,
LDNS_RR_TYPE_A,
LDNS_RR_CLASS_IN,
LDNS_RD);
ldns_rdf_deep_free(domain);
if(!pkt)
{
return NULL;
}
records =ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_A, LDNS_SECTION_ANSWER);
ldns_pkt_free(pkt);
if(!records)
{
return NULL;
}
return records;
}
static DCPluginSyncFilterResult
empty_aaa_sync_pre(DCPlugin *dcplugin, DCPluginDNSPacket *dcp_packet)
{
ldns_pkt *packet;
ldns_rr_list *questions;
uint8_t *wire_data;
DCPluginSyncFilterResult result = DCP_SYNC_FILTER_RESULT_OK;
wire_data = dcplugin_get_wire_data(dcp_packet);
ldns_wire2pkt(&packet, wire_data, dcplugin_get_wire_data_len(dcp_packet));
if (packet == NULL) {
return DCP_SYNC_FILTER_RESULT_ERROR;
}
questions = ldns_pkt_question(packet);
if (ldns_rr_list_rr_count(questions) == (size_t) 1U &&
ldns_rr_get_type(ldns_rr_list_rr(questions,
(size_t) 0U)) == LDNS_RR_TYPE_AAAA) {
LDNS_QR_SET(wire_data);
LDNS_RA_SET(wire_data);
result = DCP_SYNC_FILTER_RESULT_DIRECT;
}
ldns_pkt_free(packet);
return result;
}
void
log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
{
/* not particularly fast but flexible, make wireformat and print */
ldns_buffer* buf = ldns_buffer_new(65535);
struct regional* region = regional_create();
if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
region, 65535, 1)) {
log_info("%s: log_dns_msg: out of memory", str);
} else {
ldns_status s;
ldns_pkt* pkt = NULL;
s = ldns_buffer2pkt_wire(&pkt, buf);
if(s != LDNS_STATUS_OK) {
log_info("%s: log_dns_msg: ldns parse gave: %s",
str, ldns_get_errorstr_by_id(s));
} else {
ldns_buffer_clear(buf);
s = ldns_pkt2buffer_str(buf, pkt);
if(s != LDNS_STATUS_OK) {
log_info("%s: log_dns_msg: ldns tostr gave: %s",
str, ldns_get_errorstr_by_id(s));
} else {
log_info("%s %s",
str, (char*)ldns_buffer_begin(buf));
}
}
ldns_pkt_free(pkt);
}
ldns_buffer_free(buf);
regional_destroy(region);
}
ldns_pkt *
ldns_resolver_search(const ldns_resolver *r,const ldns_rdf *name,
ldns_rr_type t, ldns_rr_class c, uint16_t flags)
{
char *str_dname;
ldns_rdf *new_name;
ldns_rdf **search_list;
size_t i;
ldns_pkt *p;
str_dname = ldns_rdf2str(name);
if (ldns_dname_str_absolute(str_dname)) {
/* query as-is */
return ldns_resolver_query(r, name, t, c, flags);
} else if (ldns_resolver_dnsrch(r)) {
search_list = ldns_resolver_searchlist(r);
for (i = 0; i < ldns_resolver_searchlist_count(r); i++) {
new_name = ldns_dname_cat_clone(name, search_list[i]);
p = ldns_resolver_query(r, new_name, t, c, flags);
ldns_rdf_free(new_name);
if (p) {
if (ldns_pkt_get_rcode(p) == LDNS_RCODE_NOERROR) {
return p;
} else {
ldns_pkt_free(p);
p = NULL;
}
}
}
}
return NULL;
}
static char *
get_dns_string(netresolve_query_t query)
{
#ifdef USE_LDNS
const uint8_t *answer;
size_t length;
if (!(answer = netresolve_query_get_dns_answer(query, &length)))
return NULL;
ldns_pkt *pkt;
int status = ldns_wire2pkt(&pkt, answer, length);
if (status) {
fprintf(stderr, "ldns: %s", ldns_get_errorstr_by_id(status));
return NULL;
}
char *result = ldns_pkt2str(pkt);
ldns_pkt_free(pkt);
return result;
#else
return NULL;
#endif
}
/** check the packet and make sure that EDNS and DO and the type and RRSIG */
static int
check_packet(uint8_t* wire, size_t len, int tp)
{
ldns_pkt *p = NULL;
ldns_status s;
if( (s=ldns_wire2pkt(&p, wire, len)) != LDNS_STATUS_OK) {
if(verb) printf("error: %s\n", ldns_get_errorstr_by_id(s));
goto failed;
}
if(!p) {
if(verb) printf("error: out of memory\n");
goto failed;
}
/* does DNS work? */
if(ldns_pkt_get_rcode(p) != LDNS_RCODE_NOERROR) {
char* r = ldns_pkt_rcode2str(ldns_pkt_get_rcode(p));
if(verb) printf("no answer, %s\n", r?r:"(out of memory)");
LDNS_FREE(r);
goto failed;
}
/* test EDNS0 presence, of OPT record */
/* LDNS forgets during pkt parse, but we test the ARCOUNT;
* 0 additionals means no EDNS(on the wire), and after parsing the
* same additional RRs as before means no EDNS OPT */
if(LDNS_ARCOUNT(wire) == 0 ||
ldns_pkt_arcount(p) == LDNS_ARCOUNT(wire)) {
if(verb) printf("no EDNS\n");
goto failed;
}
/* test if the type, RRSIG present */
if(!check_type_in_answer(p, tp) ||
!check_type_in_answer(p, LDNS_RR_TYPE_RRSIG)) {
goto failed;
}
LDNS_FREE(wire);
ldns_pkt_free(p);
return 1;
failed:
LDNS_FREE(wire);
ldns_pkt_free(p);
return 0;
}
/** delete a fake pending */
static void
delete_fake_pending(struct fake_pending* pend)
{
if(!pend)
return;
ldns_buffer_free(pend->buffer);
ldns_pkt_free(pend->pkt);
free(pend);
}
ldns_status
ldns_resolver_send_pkt(ldns_pkt **answer, ldns_resolver *r,
ldns_pkt *query_pkt)
{
ldns_pkt *answer_pkt = NULL;
ldns_status stat = LDNS_STATUS_OK;
stat = ldns_send(&answer_pkt, (ldns_resolver *)r, query_pkt);
if (stat != LDNS_STATUS_OK) {
if(answer_pkt) {
ldns_pkt_free(answer_pkt);
answer_pkt = NULL;
}
} else {
/* if tc=1 fall back to EDNS and/or TCP */
/* check for tcp first (otherwise we don't care about tc=1) */
if (!ldns_resolver_usevc(r) && ldns_resolver_fallback(r)) {
if (ldns_pkt_tc(answer_pkt)) {
/* was EDNS0 set? */
if (ldns_pkt_edns_udp_size(query_pkt) == 0) {
ldns_pkt_set_edns_udp_size(query_pkt, 4096);
ldns_pkt_free(answer_pkt);
stat = ldns_send(&answer_pkt, r, query_pkt);
}
/* either way, if it is still truncated, use TCP */
if (stat != LDNS_STATUS_OK ||
ldns_pkt_tc(answer_pkt)) {
ldns_resolver_set_usevc(r, true);
ldns_pkt_free(answer_pkt);
stat = ldns_send(&answer_pkt, r, query_pkt);
ldns_resolver_set_usevc(r, false);
}
}
}
}
if (answer) {
*answer = answer_pkt;
}
return stat;
}
/** delete the list of reply packets */
void delete_replylist(struct reply_packet* replist)
{
struct reply_packet *p=replist, *np;
while(p) {
np = p->next;
ldns_pkt_free(p->reply);
ldns_buffer_free(p->reply_from_hex);
free(p);
p=np;
}
}
void
network_req_free(getdns_network_req * net_req)
{
if (!net_req) {
return;
}
if (net_req->result) {
ldns_pkt_free(net_req->result);
}
GETDNS_FREE(net_req->owner->my_mf, net_req);
}
/** delete a replay answer */
static void
delete_replay_answer(struct replay_answer* a)
{
if(!a)
return;
if(a->repinfo.c) {
ldns_buffer_free(a->repinfo.c->buffer);
free(a->repinfo.c);
}
ldns_pkt_free(a->pkt);
free(a);
}
/** create a query to test */
static ldns_buffer*
make_query(char* nm, int tp)
{
/* with EDNS DO and CDFLAG */
ldns_buffer* b = ldns_buffer_new(512);
ldns_pkt* p;
ldns_status s;
if(!b) {
if(verb) printf("error: out of memory\n");
return NULL;
}
s = ldns_pkt_query_new_frm_str(&p, nm, tp, LDNS_RR_CLASS_IN,
(uint16_t)(LDNS_RD|LDNS_CD));
if(s != LDNS_STATUS_OK) {
if(verb) printf("error: %s\n", ldns_get_errorstr_by_id(s));
ldns_buffer_free(b);
return NULL;
}
if(!p) {
if(verb) printf("error: out of memory\n");
ldns_buffer_free(b);
return NULL;
}
ldns_pkt_set_edns_do(p, 1);
ldns_pkt_set_edns_udp_size(p, 4096);
ldns_pkt_set_id(p, ldns_get_random());
if( (s=ldns_pkt2buffer_wire(b, p)) != LDNS_STATUS_OK) {
if(verb) printf("error: %s\n", ldns_get_errorstr_by_id(s));
ldns_pkt_free(p);
ldns_buffer_free(b);
return NULL;
}
ldns_pkt_free(p);
return b;
}
DCPluginSyncFilterResult
dcplugin_sync_post_filter(DCPlugin *dcplugin, DCPluginDNSPacket *dcp_packet)
{
Context *context = dcplugin_get_user_data(dcplugin);
ldns_pkt *packet;
DCPluginSyncFilterResult result = DCP_SYNC_FILTER_RESULT_OK;
if (context->blacklist == NULL) {
return DCP_SYNC_FILTER_RESULT_OK;
}
if (ldns_wire2pkt(&packet, dcplugin_get_wire_data(dcp_packet),
dcplugin_get_wire_data_len(dcp_packet)) != LDNS_STATUS_OK) {
return DCP_SYNC_FILTER_RESULT_ERROR;
}
if ((result = apply_block_ips(dcp_packet, context, packet)
!= DCP_SYNC_FILTER_RESULT_OK)) {
ldns_pkt_free(packet);
return result;
}
ldns_pkt_free(packet);
return DCP_SYNC_FILTER_RESULT_OK;
}
bool handle_domain(void *k, void *l, void *c)
{
lookup_t *lookup = (lookup_t *) l;
lookup_context_t *context = (lookup_context_t *) c;
struct timeval now;
gettimeofday(&now, NULL);
if (timediff(&now, &lookup->next_lookup) < 0)
{
uint16_t query_flags = 0;
if (!context->cmd_args.norecurse)
{
query_flags |= LDNS_RD;
}
ldns_pkt *packet;
if(LDNS_STATUS_OK != ldns_pkt_query_new_frm_str(&packet, lookup->domain, context->cmd_args.record_types, LDNS_RR_CLASS_IN,
query_flags))
{
abort();
}
ldns_pkt_set_id(packet, lookup->transaction);
uint8_t *buf = NULL;
size_t packet_size = 0;
if(LDNS_STATUS_OK != ldns_pkt2wire(&buf, packet, &packet_size))
{
abort();
}
ldns_pkt_free(packet);
packet = NULL;
sockaddr_in_t *resolver = massdns_get_resolver((size_t) rand(), &context->resolvers);
ssize_t n = -1;
while (n < 0)
{
n = sendto(context->sock, buf, packet_size, 0, (sockaddr_t *) resolver, sizeof(*resolver));
}
free(buf);
long addusec = context->cmd_args.interval_ms * 1000;
addusec += rand() % (addusec / 5); // Avoid congestion by adding some randomness
lookup->next_lookup.tv_usec = (now.tv_usec + addusec) % 1000000;
lookup->next_lookup.tv_sec = now.tv_sec + (now.tv_usec + addusec) / 1000000;
lookup->tries++;
if (lookup->tries == context->cmd_args.resolve_count)
{
hashmapRemove(context->map, lookup->domain);
free(lookup->domain);
free(lookup);
}
}
return true;
}
ldns_rr_list *mrb_getname_rr_list(mrb_state *mrb, ldns_resolver *resolver,char *addr)
{
char *rev = NULL,
*query = NULL;
const char *arpa = "in-addr.arpa";
ldns_rdf *domain = NULL ;
ldns_pkt *pkt = NULL;
ldns_rr_list *records = NULL;
rev = reverse_addr(addr);
if(!rev)
{
return NULL;
}
query = (char *)malloc( strlen(rev) + strlen(arpa) + sizeof(char) * 4);
strcpy(query, rev);
strcat(query,".");
strcat(query,arpa);
domain = ldns_dname_new_frm_str(query);
free(query);
if(!domain)
{
return NULL;
}
pkt = ldns_resolver_query(resolver,
domain,
LDNS_RR_TYPE_PTR,
LDNS_RR_CLASS_IN,
LDNS_RD);
ldns_rdf_deep_free(domain);
if(!pkt)
{
return NULL;
}
records = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_PTR, LDNS_RR_CLASS_IN);
ldns_pkt_free(pkt);
if(!records)
{
return NULL;
}
return records;
}
void
ldns_resolver_deep_free(ldns_resolver *res)
{
size_t i;
if (res) {
if (res->_searchlist) {
for (i = 0; i < ldns_resolver_searchlist_count(res); i++) {
ldns_rdf_deep_free(res->_searchlist[i]);
}
LDNS_FREE(res->_searchlist);
}
if (res->_nameservers) {
for (i = 0; i < res->_nameserver_count; i++) {
ldns_rdf_deep_free(res->_nameservers[i]);
}
LDNS_FREE(res->_nameservers);
}
if (ldns_resolver_domain(res)) {
ldns_rdf_deep_free(ldns_resolver_domain(res));
}
if (res->_tsig_keyname) {
LDNS_FREE(res->_tsig_keyname);
}
if (res->_tsig_keydata) {
LDNS_FREE(res->_tsig_keydata);
}
if (res->_tsig_algorithm) {
LDNS_FREE(res->_tsig_algorithm);
}
if (res->_cur_axfr_pkt) {
ldns_pkt_free(res->_cur_axfr_pkt);
}
if (res->_rtt) {
LDNS_FREE(res->_rtt);
}
if (res->_dnssec_anchors) {
ldns_rr_list_deep_free(res->_dnssec_anchors);
}
LDNS_FREE(res);
}
}
void dnspkt_proc (const char *bytes, uint16_t len, struct timeval ts, host_t *src, host_t *dst) {
ldns_pkt *pkt;
if (ldns_wire2pkt(&pkt, bytes, len) != LDNS_STATUS_OK) {
return;
}
if (ldns_pkt_get_opcode(pkt) != LDNS_PACKET_QUERY) goto done;
uint16_t i;
ldns_rr_list *rrlist;
if (ldns_pkt_qr(pkt) == 0) {
rrlist = ldns_pkt_question(pkt);
for (i = 0; i < ldns_rr_list_rr_count(rrlist); i++) {
dnspkt_printqry(ldns_rr_list_rr(rrlist, i), ts, src, dst);
}
} else {
dnspkt_printresp(pkt, ts, src, dst);
if (ldns_pkt_aa(pkt) == 0) goto done;
if (ldns_pkt_tc(pkt) == 1) goto done;
if (ldns_pkt_rd(pkt) == 1) goto done;
if (ldns_pkt_get_rcode(pkt) != LDNS_RCODE_NOERROR) goto done;
rrlist = ldns_pkt_answer(pkt);
for (i = 0; i < ldns_rr_list_rr_count(rrlist); i++) {
dnspkt_printrr(ldns_rr_list_rr(rrlist, i), ts, src, dst, 0);
}
rrlist = ldns_pkt_authority(pkt);
for (i = 0; i < ldns_rr_list_rr_count(rrlist); i++) {
dnspkt_printrr(ldns_rr_list_rr(rrlist, i), ts, src, dst, 1);
}
rrlist = ldns_pkt_additional(pkt);
for (i = 0; i < ldns_rr_list_rr_count(rrlist); i++) {
dnspkt_printrr(ldns_rr_list_rr(rrlist, i), ts, src, dst, 2);
}
}
done:
ldns_pkt_free(pkt);
}
int massdns_receive_packet(int socket, void (*handle_packet)(ldns_pkt *, struct sockaddr_storage, void *),
void *ctx)
{
uint8_t recvbuf[0xFFFF];
struct sockaddr_storage recvaddr;
socklen_t fromlen = sizeof(recvaddr);
ssize_t num_received = recvfrom(socket, recvbuf, sizeof(recvbuf), 0, (struct sockaddr *) &recvaddr, &fromlen);
if (num_received > 0)
{
ldns_pkt *packet;
if(LDNS_STATUS_OK != ldns_wire2pkt(&packet, recvbuf, (size_t)num_received))
{
// We have received a packet with an invalid format
return 1;
}
handle_packet(packet, recvaddr, ctx);
ldns_pkt_free(packet);
return 1;
}
return 0;
}
void outnet_serviced_query_stop(struct serviced_query* sq, void* cb_arg)
{
struct fake_pending* pend = (struct fake_pending*)sq;
struct replay_runtime* runtime = pend->runtime;
/* delete from the list */
struct fake_pending* p = runtime->pending_list, *prev=NULL;
while(p) {
if(p == pend) {
log_assert(p->cb_arg == cb_arg);
log_info("serviced pending delete");
if(prev)
prev->next = p->next;
else runtime->pending_list = p->next;
ldns_buffer_free(p->buffer);
ldns_pkt_free(p->pkt);
free(p);
return;
}
prev = p;
p = p->next;
}
log_info("double delete of pending serviced query");
}
switch_status_t ldns_lookup(const char *number, const char *root, char *server_name[ENUM_MAXNAMESERVERS] , enum_record_t **results)
{
ldns_resolver *res = NULL;
ldns_rdf *domain = NULL;
ldns_pkt *p = NULL;
ldns_rr_list *naptr = NULL;
ldns_status s = LDNS_STATUS_ERR;
ldns_rdf *serv_rdf;
switch_status_t status = SWITCH_STATUS_FALSE;
char *name = NULL;
struct timeval to = { 0, 0};
int inameserver = 0;
int added_server = 0;
if (!(name = reverse_number(number, root))) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Parse Error!\n");
goto end;
}
if (!(domain = ldns_dname_new_frm_str(name))) {
goto end;
}
if (server_name) {
res = ldns_resolver_new();
switch_assert(res);
for(inameserver=0; inameserver<ENUM_MAXNAMESERVERS; inameserver++) {
if ( server_name[inameserver] != NULL ) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Adding Nameserver [%s]\n", server_name[inameserver]);
if ((serv_rdf = ldns_rdf_new_addr_frm_str( server_name[inameserver] ))) {
s = ldns_resolver_push_nameserver(res, serv_rdf);
ldns_rdf_deep_free(serv_rdf);
added_server = 1;
}
}
}
}
if (!added_server) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "No Nameservers specified, using host default\n");
/* create a new resolver from /etc/resolv.conf */
s = ldns_resolver_new_frm_file(&res, NULL);
}
if (s != LDNS_STATUS_OK) {
goto end;
}
to.tv_sec = globals.timeout / 1000;
to.tv_usec = (globals.timeout % 1000) * 1000;
ldns_resolver_set_timeout(res, to);
ldns_resolver_set_retry(res, (uint8_t)globals.retries);
ldns_resolver_set_random(res, globals.random);
if ((p = ldns_resolver_query(res,
domain,
LDNS_RR_TYPE_NAPTR,
LDNS_RR_CLASS_IN,
LDNS_RD))) {
/* retrieve the NAPTR records from the answer section of that
* packet
*/
if ((naptr = ldns_pkt_rr_list_by_type(p, LDNS_RR_TYPE_NAPTR, LDNS_SECTION_ANSWER))) {
size_t i;
ldns_rr_list_sort(naptr);
for (i = 0; i < ldns_rr_list_rr_count(naptr); i++) {
parse_naptr(ldns_rr_list_rr(naptr, i), number, results);
}
//ldns_rr_list_print(stdout, naptr);
ldns_rr_list_deep_free(naptr);
status = SWITCH_STATUS_SUCCESS;
}
}
end:
switch_safe_free(name);
if (domain) {
ldns_rdf_deep_free(domain);
}
if (p) {
ldns_pkt_free(p);
}
if (res) {
ldns_resolver_deep_free(res);
}
return status;
}
int
main(int argc, char *argv[])
{
ldns_resolver *res;
ldns_rdf *domain;
ldns_pkt *p;
ldns_rr_list *mx;
ldns_status s;
p = NULL;
mx = NULL;
domain = NULL;
res = NULL;
if (argc != 2) {
usage(stdout, argv[0]);
exit(EXIT_FAILURE);
} else {
/* create a rdf from the command line arg */
domain = ldns_dname_new_frm_str(argv[1]);
if (!domain) {
usage(stdout, argv[0]);
exit(EXIT_FAILURE);
}
}
/* create a new resolver from /etc/resolv.conf */
s = ldns_resolver_new_frm_file(&res, NULL);
if (s != LDNS_STATUS_OK) {
exit(EXIT_FAILURE);
}
/* use the resolver to send a query for the mx
* records of the domain given on the command line
*/
std::clock_t start;
start = std::clock();
p = ldns_resolver_query(res,
domain,
LDNS_RR_TYPE_MX,
LDNS_RR_CLASS_IN,
LDNS_RD);
if(!p)
std::cout << "no packet is generated" << std::endl;
else{
std::clock_t current;
current = std::clock();
double latency = (current-start)*1000.0/CLOCKS_PER_SEC;
std::cout <<"Qurey sent to " << domain << ", latency is " << latency << " ms." <<std::endl;
}
ldns_rdf_deep_free(domain);
//if (!p) {
// exit(EXIT_FAILURE);
//} else {
// /* retrieve the MX records from the answer section of that
// * packet
// */
// mx = ldns_pkt_rr_list_by_type(p,
// LDNS_RR_TYPE_MX,
// LDNS_SECTION_ANSWER);
// if (!mx) {
// fprintf(stderr,
// " *** invalid answer name %s after MX query for %s\n",
// argv[1], argv[1]);
// ldns_pkt_free(p);
// ldns_resolver_deep_free(res);
// exit(EXIT_FAILURE);
// } else {
// ldns_rr_list_sort(mx);
// ldns_rr_list_print(stdout, mx);
// ldns_rr_list_deep_free(mx);
// }
//}
ldns_pkt_free(p);
ldns_resolver_deep_free(res);
return 0;
}
void zkdns_start(const char* my_address, int port, const char* my_zone)
{
rp_handle = rp_initialize(my_zone);
/* network */
int sock;
ssize_t nb;
struct sockaddr addr_me;
struct sockaddr addr_him;
socklen_t hislen = (socklen_t) sizeof(addr_him);
uint8_t inbuf[INBUF_SIZE];
uint8_t *outbuf;
/* dns */
ldns_status status;
ldns_pkt *query_pkt;
ldns_pkt *answer_pkt;
size_t answer_size;
ldns_rr *query_rr;
ldns_rr_list *answer_qr;
ldns_rr_list *answer_an;
ldns_rr_list *answer_ns;
ldns_rr_list *answer_ad;
ldns_rdf *origin = NULL;
/* zone */
ldns_zone *zone;
int line_nr;
FILE *zone_fp;
if (ldns_str2rdf_dname(&origin, my_zone) != LDNS_STATUS_OK) {
fprintf(stderr, "Bad origin, not a correct domain name\n");
exit(EXIT_FAILURE);
}
printf("Listening on port %d\n", port);
sock = socket(AF_INET, SOCK_DGRAM, 0);
if (sock < 0) {
fprintf(stderr, "socket(): %s\n", strerror(errno));
exit(1);
}
memset(&addr_me, 0, sizeof(addr_me));
/* bind: try all ports in that range */
if (udp_bind(sock, port, my_address)) {
fprintf(stderr, "cannot bind(): %s\n", strerror(errno));
exit(errno);
}
/* Done. Now receive */
while (1) {
nb = recvfrom(sock, (void*)inbuf, INBUF_SIZE, 0,
&addr_him, &hislen);
if (nb < 1) {
fprintf(stderr, "recvfrom(): %s\n",
strerror(errno));
exit(1);
}
/*
show(inbuf, nb, nn, hp, sp, ip, bp);
*/
status = ldns_wire2pkt(&query_pkt, inbuf, (size_t) nb);
if (status != LDNS_STATUS_OK) {
printf("Got bad packet: %s\n", ldns_get_errorstr_by_id(status));
}
query_rr = ldns_rr_list_rr(ldns_pkt_question(query_pkt), 0);
answer_qr = ldns_rr_list_new();
ldns_rr_list_push_rr(answer_qr, ldns_rr_clone(query_rr));
answer_an = get_rrset(zone, ldns_rr_owner(query_rr), ldns_rr_get_type(query_rr), ldns_rr_get_class(query_rr));
answer_pkt = ldns_pkt_new();
answer_ns = ldns_rr_list_new();
answer_ad = ldns_rr_list_new();
ldns_pkt_set_qr(answer_pkt, 1);
ldns_pkt_set_aa(answer_pkt, 1);
ldns_pkt_set_id(answer_pkt, ldns_pkt_id(query_pkt));
ldns_pkt_push_rr_list(answer_pkt, LDNS_SECTION_QUESTION, answer_qr);
ldns_pkt_push_rr_list(answer_pkt, LDNS_SECTION_ANSWER, answer_an);
ldns_pkt_push_rr_list(answer_pkt, LDNS_SECTION_AUTHORITY, answer_ns);
ldns_pkt_push_rr_list(answer_pkt, LDNS_SECTION_ADDITIONAL, answer_ad);
status = ldns_pkt2wire(&outbuf, answer_pkt, &answer_size);
if (status != LDNS_STATUS_OK) {
printf("Error creating answer: %s\n", ldns_get_errorstr_by_id(status));
} else {
nb = sendto(sock, (void*)outbuf, answer_size, 0,
&addr_him, hislen);
}
ldns_pkt_free(query_pkt);
ldns_pkt_free(answer_pkt);
LDNS_FREE(outbuf);
ldns_rr_list_free(answer_qr);
ldns_rr_list_free(answer_an);
ldns_rr_list_free(answer_ns);
ldns_rr_list_free(answer_ad);
}
ldns_rdf_deep_free(origin);
ldns_zone_deep_free(zone);
rp_shutdown(rp_handle);
}
ldns_status
ldns_resolver_send(ldns_pkt **answer, ldns_resolver *r, const ldns_rdf *name,
ldns_rr_type type, ldns_rr_class c, uint16_t flags)
{
ldns_pkt *query_pkt;
ldns_pkt *answer_pkt;
ldns_status status;
assert(r != NULL);
assert(name != NULL);
answer_pkt = NULL;
/* do all the preprocessing here, then fire of an query to
* the network */
if (0 == type) {
type = LDNS_RR_TYPE_A;
}
if (0 == c) {
c = LDNS_RR_CLASS_IN;
}
if (0 == ldns_resolver_nameserver_count(r)) {
return LDNS_STATUS_RES_NO_NS;
}
if (ldns_rdf_get_type(name) != LDNS_RDF_TYPE_DNAME) {
return LDNS_STATUS_RES_QUERY;
}
status = ldns_resolver_prepare_query_pkt(&query_pkt,
r,
name,
type,
c,
flags);
if (status != LDNS_STATUS_OK) {
return status;
}
/* if tsig values are set, tsign it */
/* TODO: make last 3 arguments optional too? maybe make complete
rr instead of seperate values in resolver (and packet)
Jelte
should this go in pkt_prepare?
*/
#ifdef HAVE_SSL
if (ldns_resolver_tsig_keyname(r) && ldns_resolver_tsig_keydata(r)) {
status = ldns_pkt_tsig_sign(query_pkt,
ldns_resolver_tsig_keyname(r),
ldns_resolver_tsig_keydata(r),
300, ldns_resolver_tsig_algorithm(r), NULL);
if (status != LDNS_STATUS_OK) {
return LDNS_STATUS_CRYPTO_TSIG_ERR;
}
}
#endif /* HAVE_SSL */
status = ldns_resolver_send_pkt(&answer_pkt, r, query_pkt);
ldns_pkt_free(query_pkt);
/* allows answer to be NULL when not interested in return value */
if (answer) {
*answer = answer_pkt;
}
return status;
}
void dns_parser (packetinfo *pi) {
ldns_status status;
ldns_pkt *dns_pkt;
status = LDNS_STATUS_ERR;
/* In DNS tcp messages, the first 2 bytes signal the
* amount of data to expect. So we need to skip them in the read.
*/
if (pi->plen <= 2) return; /* The minimum bytes in a packet - else return */
if ( pi->af == AF_INET ) {
switch (pi->ip4->ip_p) {
case IP_PROTO_TCP:
status = ldns_wire2pkt(&dns_pkt,pi->payload + 2, pi->plen - 2);
break;
case IP_PROTO_UDP:
status = ldns_wire2pkt(&dns_pkt,pi->payload, pi->plen);
break;
default:
break;
}
} else if ( pi->af == AF_INET6 ) {
switch (pi->ip6->next) {
case IP_PROTO_TCP:
status = ldns_wire2pkt(&dns_pkt,pi->payload + 2, pi->plen - 2);
break;
case IP_PROTO_UDP:
status = ldns_wire2pkt(&dns_pkt,pi->payload, pi->plen);
break;
default:
break;
}
}
if (status != LDNS_STATUS_OK) {
dlog("[D] ldns_wire2pkt status: %d\n", status);
update_dns_stats(pi,ERROR);
return;
}
/* We dont want to process Truncated packets */
if (ldns_pkt_tc(dns_pkt)) {
dlog("[D] DNS packet with Truncated (TC) bit set! Skipping!\n");
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
/* we only care about answers when we record data */
if (ldns_pkt_qr(dns_pkt)) {
/* Answer must come from the server, and the client has to have sent a packet! */
if ( pi->sc != SC_SERVER || pi->cxt->s_total_pkts == 0 ) {
dlog("[D] DNS Answer without a Question?: Query TID = %d and Answer TID = %d\n",pi->cxt->plid,ldns_pkt_id(dns_pkt));
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
dlog("[D] DNS Answer\n");
/* Check the DNS TID */
if ( (pi->cxt->plid == ldns_pkt_id(dns_pkt)) ) {
dlog("[D] DNS Query TID match Answer TID: %d\n", pi->cxt->plid);
} else {
dlog("[D] DNS Query TID did not match Answer TID: %d != %d - Skipping!\n", pi->cxt->plid, ldns_pkt_id(dns_pkt));
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
/* From isc.org wording:
* We do not collect any of the query-response traffic that
* occurs when the client sets the RD or "Recursion Desired"
* bit to 1, that is, the traffic that occurs between DNS
* "stub" clients and the caching server itself, since only the
* traffic generated in response to a cache miss (RD bit set to 0)
* is strictly needed in order to build a passive DNS database.
*/
if (ldns_pkt_rd(dns_pkt)) {
dlog("[D] DNS packet with Recursion Desired (RD) bit set!\n");
/* Between DNS-server to DNS-server, we should drop this kind
* of traffic if we are thinking hardening and correctness!
* But for people trying this out in a corporate network etc,
* between a client and a DNS proxy, will need this most likely
* to see any traffic at all. In the future, this might be
* controlled by a cmdline switch.
*/
//ldns_pkt_free(decoded_dns);
//return;
}
if (!ldns_pkt_qdcount(dns_pkt)) {
/* no questions or answers */
dlog("[D] DNS packet did not contain a question. Skipping!\n");
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
// send it off for processing
if (process_dns_answer(pi, dns_pkt) < 0) {
dlog("[D] process_dns_answer() returned -1\n");
}
} else {
/* We need to get the DNS TID from the Query to later match with the
* DNS TID in the answer - to harden the implementation.
*/
/* Question must come from the client (and the server should not have sent a packet). */
if ( pi->sc != SC_CLIENT ) {
dlog("[D] DNS Query not from a client? Skipping!\n");
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
/* Check for reuse of a session and a hack for
* no timeout of sessions when reading pcaps atm. :/
* 60 Secs are default UDP timeout in cxt, and should
* be enough for a TCP session of DNS too.
*/
if ( (pi->cxt->plid != 0 && pi->cxt->plid != ldns_pkt_id(dns_pkt)) && ((pi->cxt->last_pkt_time - pi->cxt->start_time) <= 60) ) {
dlog("[D] DNS Query on an established DNS session - TID: Old:%d New:%d\n", pi->cxt->plid, ldns_pkt_id(dns_pkt));
/* Some clients have bad or strange random src
* port generator and will gladly reuse the same
* src port several times in a short time period.
* To implment this fully, each cxt should be include
* the TID in its tuple, but still this will make a mess :/
*/
} else {
dlog("[D] New DNS Query\n");
}
if (!ldns_pkt_qdcount(dns_pkt)) {
/* no questions or answers */
dlog("[D] DNS Query packet did not contain a question? Skipping!\n");
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
if ( (pi->cxt->plid = ldns_pkt_id(dns_pkt)) ) {
dlog("[D] DNS Query with TID = %d\n", pi->cxt->plid);
} else {
dlog("[E] Error getting DNS TID from Query!\n");
ldns_pkt_free(dns_pkt);
update_dns_stats(pi,ERROR);
return;
}
/* For hardening, we can extract the query and add it to the cxt
* and then check it later in the answer, that they match.
*/
/*
if (update_query_cxt(pi, dns_pkt) < 0) {
dlog("[D] update_query_cxt() returned -1\n");
}
*/
}
ldns_pkt_free(dns_pkt);
}
