4 * Network implementation
5 * All network related functions are grouped here
7 * a Net::DNS like library for C
9 * (c) NLnet Labs, 2004-2006
11 * See the file LICENSE for the license
14 #include <ldns/config.h>
16 #include <ldns/ldns.h>
18 #ifdef HAVE_NETINET_IN_H
19 #include <netinet/in.h>
21 #ifdef HAVE_SYS_SOCKET_H
22 #include <sys/socket.h>
27 #ifdef HAVE_ARPA_INET_H
28 #include <arpa/inet.h>
35 ldns_send(ldns_pkt **result_packet, ldns_resolver *r, const ldns_pkt *query_pkt)
39 ldns_rdf *tsig_mac = NULL;
41 qb = ldns_buffer_new(LDNS_MIN_BUFLEN);
43 if (query_pkt && ldns_pkt_tsig(query_pkt)) {
44 tsig_mac = ldns_rr_rdf(ldns_pkt_tsig(query_pkt), 3);
48 ldns_pkt2buffer_wire(qb, query_pkt) != LDNS_STATUS_OK) {
49 result = LDNS_STATUS_ERR;
51 result = ldns_send_buffer(result_packet, r, qb, tsig_mac);
60 ldns_send_buffer(ldns_pkt **result, ldns_resolver *r, ldns_buffer *qb, ldns_rdf *tsig_mac)
64 struct sockaddr_storage *ns;
72 bool all_servers_rtt_inf;
75 uint8_t *reply_bytes = NULL;
76 size_t reply_size = 0;
77 ldns_status status, send_status;
81 status = LDNS_STATUS_OK;
82 rtt = ldns_resolver_rtt(r);
83 ns_array = ldns_resolver_nameservers(r);
87 all_servers_rtt_inf = true;
89 if (ldns_resolver_random(r)) {
90 ldns_resolver_nameservers_randomize(r);
93 /* loop through all defined nameservers */
94 for (i = 0; i < ldns_resolver_nameserver_count(r); i++) {
95 if (rtt[i] == LDNS_RESOLV_RTT_INF) {
96 /* not reachable nameserver! */
100 /* maybe verbosity setting?
101 printf("Sending to ");
102 ldns_rdf_print(stdout, ns_array[i]);
105 ns = ldns_rdf2native_sockaddr_storage(ns_array[i],
106 ldns_resolver_port(r), &ns_len);
108 if ((ns->ss_family == AF_INET) &&
109 (ldns_resolver_ip6(r) == LDNS_RESOLV_INET6)) {
114 if ((ns->ss_family == AF_INET6) &&
115 (ldns_resolver_ip6(r) == LDNS_RESOLV_INET)) {
120 all_servers_rtt_inf = false;
122 gettimeofday(&tv_s, NULL);
124 send_status = LDNS_STATUS_ERR;
126 /* reply_bytes implicitly handles our error */
127 if (1 == ldns_resolver_usevc(r)) {
128 for (retries = ldns_resolver_retry(r); retries > 0; retries--) {
130 ldns_tcp_send(&reply_bytes, qb, ns,
131 (socklen_t)ns_len, ldns_resolver_timeout(r),
133 if (send_status == LDNS_STATUS_OK) {
138 for (retries = ldns_resolver_retry(r); retries > 0; retries--) {
139 /* ldns_rdf_print(stdout, ns_array[i]); */
141 ldns_udp_send(&reply_bytes, qb, ns,
142 (socklen_t)ns_len, ldns_resolver_timeout(r),
145 if (send_status == LDNS_STATUS_OK) {
151 if (send_status != LDNS_STATUS_OK) {
152 ldns_resolver_set_nameserver_rtt(r, i, LDNS_RESOLV_RTT_INF);
153 status = send_status;
156 /* obey the fail directive */
158 /* the current nameserver seems to have a problem, blacklist it */
159 if (ldns_resolver_fail(r)) {
161 return LDNS_STATUS_ERR;
168 status = ldns_wire2pkt(&reply, reply_bytes, reply_size);
169 if (status != LDNS_STATUS_OK) {
170 LDNS_FREE(reply_bytes);
176 gettimeofday(&tv_e, NULL);
179 ldns_pkt_set_querytime(reply, (uint32_t)
180 ((tv_e.tv_sec - tv_s.tv_sec) * 1000) +
181 (tv_e.tv_usec - tv_s.tv_usec) / 1000);
182 ldns_pkt_set_answerfrom(reply, ns_array[i]);
183 ldns_pkt_set_timestamp(reply, tv_s);
184 ldns_pkt_set_size(reply, reply_size);
187 if (ldns_resolver_fail(r)) {
188 /* if fail is set bail out, after the first
194 /* wait retrans seconds... */
195 sleep((unsigned int) ldns_resolver_retrans(r));
198 if (all_servers_rtt_inf) {
199 LDNS_FREE(reply_bytes);
200 return LDNS_STATUS_RES_NO_NS;
203 if (tsig_mac && reply_bytes) {
204 if (!ldns_pkt_tsig_verify(reply,
207 ldns_resolver_tsig_keyname(r),
208 ldns_resolver_tsig_keydata(r), tsig_mac)) {
209 status = LDNS_STATUS_CRYPTO_TSIG_BOGUS;
214 #endif /* HAVE_SSL */
216 LDNS_FREE(reply_bytes);
224 /** best effort to set nonblocking */
226 ldns_sock_nonblock(int sockfd)
230 if((flag = fcntl(sockfd, F_GETFL)) != -1) {
232 if(fcntl(sockfd, F_SETFL, flag) == -1) {
233 /* ignore error, continue blockingly */
236 #elif defined(HAVE_IOCTLSOCKET)
237 unsigned long on = 1;
238 if(ioctlsocket(sockfd, FIONBIO, &on) != 0) {
239 /* ignore error, continue blockingly */
244 /** best effort to set blocking */
246 ldns_sock_block(int sockfd)
250 if((flag = fcntl(sockfd, F_GETFL)) != -1) {
252 if(fcntl(sockfd, F_SETFL, flag) == -1) {
253 /* ignore error, continue */
256 #elif defined(HAVE_IOCTLSOCKET)
257 unsigned long off = 0;
258 if(ioctlsocket(sockfd, FIONBIO, &off) != 0) {
259 /* ignore error, continue */
264 /** wait for a socket to become ready */
266 ldns_sock_wait(int sockfd, struct timeval timeout, int write)
272 FD_SET(FD_SET_T sockfd, &fds);
275 ret = select(sockfd+1, NULL, &fds, NULL, &timeout);
277 ret = select(sockfd+1, &fds, NULL, NULL, &timeout);
279 /* timeout expired */
288 ldns_udp_send(uint8_t **result, ldns_buffer *qbin, const struct sockaddr_storage *to,
289 socklen_t tolen, struct timeval timeout, size_t *answer_size)
294 sockfd = ldns_udp_bgsend(qbin, to, tolen, timeout);
297 return LDNS_STATUS_SOCKET_ERROR;
300 /* wait for an response*/
301 if(!ldns_sock_wait(sockfd, timeout, 0)) {
307 return LDNS_STATUS_NETWORK_ERR;
310 /* set to nonblocking, so if the checksum is bad, it becomes
311 * an EGAIN error and the ldns_udp_send function does not block,
312 * but returns a 'NETWORK_ERROR' much like a timeout. */
313 ldns_sock_nonblock(sockfd);
315 answer = ldns_udp_read_wire(sockfd, answer_size, NULL, NULL);
322 if (*answer_size == 0) {
324 return LDNS_STATUS_NETWORK_ERR;
328 return LDNS_STATUS_OK;
332 ldns_udp_bgsend(ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen,
333 struct timeval timeout)
337 sockfd = ldns_udp_connect(to, timeout);
343 if (ldns_udp_send_query(qbin, sockfd, to, tolen) == 0) {
350 ldns_udp_connect(const struct sockaddr_storage *to, struct timeval ATTR_UNUSED(timeout))
354 if ((sockfd = socket((int)((struct sockaddr*)to)->sa_family, SOCK_DGRAM,
363 ldns_tcp_connect(const struct sockaddr_storage *to, socklen_t tolen,
364 struct timeval timeout)
368 if ((sockfd = socket((int)((struct sockaddr*)to)->sa_family, SOCK_STREAM,
369 IPPROTO_TCP)) == -1) {
373 /* perform nonblocking connect, to be able to wait with select() */
374 ldns_sock_nonblock(sockfd);
375 if (connect(sockfd, (struct sockaddr*)to, tolen) == -1) {
378 if(errno != EINPROGRESS) {
385 #else /* USE_WINSOCK */
386 if(WSAGetLastError() != WSAEINPROGRESS &&
387 WSAGetLastError() != WSAEWOULDBLOCK) {
392 /* error was only telling us that it would block */
395 /* wait(write) until connected or error */
398 socklen_t len = (socklen_t)sizeof(error);
400 if(!ldns_sock_wait(sockfd, timeout, 1)) {
409 /* check if there is a pending error for nonblocking connect */
410 if(getsockopt(sockfd, SOL_SOCKET, SO_ERROR, (void*)&error,
413 error = errno; /* on solaris errno is error */
415 error = WSAGetLastError();
419 #if defined(EINPROGRESS) && defined(EWOULDBLOCK)
420 if(error == EINPROGRESS || error == EWOULDBLOCK)
421 continue; /* try again */
423 else if(error != 0) {
425 /* error in errno for our user */
429 #else /* USE_WINSOCK */
430 if(error == WSAEINPROGRESS)
432 else if(error == WSAEWOULDBLOCK)
434 else if(error != 0) {
439 #endif /* USE_WINSOCK */
444 /* set the socket blocking again */
445 ldns_sock_block(sockfd);
451 ldns_tcp_send_query(ldns_buffer *qbin, int sockfd,
452 const struct sockaddr_storage *to, socklen_t tolen)
457 /* add length of packet */
458 sendbuf = LDNS_XMALLOC(uint8_t, ldns_buffer_position(qbin) + 2);
459 if(!sendbuf) return 0;
460 ldns_write_uint16(sendbuf, ldns_buffer_position(qbin));
461 memcpy(sendbuf + 2, ldns_buffer_export(qbin), ldns_buffer_position(qbin));
463 bytes = sendto(sockfd, (void*)sendbuf,
464 ldns_buffer_position(qbin) + 2, 0, (struct sockaddr *)to, tolen);
468 if (bytes == -1 || (size_t) bytes != ldns_buffer_position(qbin) + 2 ) {
474 /* don't wait for an answer */
476 ldns_udp_send_query(ldns_buffer *qbin, int sockfd, const struct sockaddr_storage *to,
481 bytes = sendto(sockfd, (void*)ldns_buffer_begin(qbin),
482 ldns_buffer_position(qbin), 0, (struct sockaddr *)to, tolen);
484 if (bytes == -1 || (size_t)bytes != ldns_buffer_position(qbin)) {
487 if ((size_t) bytes != ldns_buffer_position(qbin)) {
494 ldns_udp_read_wire(int sockfd, size_t *size, struct sockaddr_storage *from,
497 uint8_t *wire, *wireout;
500 wire = LDNS_XMALLOC(uint8_t, LDNS_MAX_PACKETLEN);
506 wire_size = recvfrom(sockfd, (void*)wire, LDNS_MAX_PACKETLEN, 0,
507 (struct sockaddr *)from, fromlen);
509 /* recvfrom can also return 0 */
510 if (wire_size == -1 || wire_size == 0) {
516 *size = (size_t)wire_size;
517 wireout = LDNS_XREALLOC(wire, uint8_t, (size_t)wire_size);
518 if(!wireout) LDNS_FREE(wire);
524 ldns_tcp_read_wire_timeout(int sockfd, size_t *size, struct timeval timeout)
528 ssize_t bytes = 0, rc = 0;
530 wire = LDNS_XMALLOC(uint8_t, 2);
537 if(!ldns_sock_wait(sockfd, timeout, 0)) {
542 rc = recv(sockfd, (void*) (wire + bytes),
543 (size_t) (2 - bytes), 0);
544 if (rc == -1 || rc == 0) {
552 wire_size = ldns_read_uint16(wire);
555 wire = LDNS_XMALLOC(uint8_t, wire_size);
562 while (bytes < (ssize_t) wire_size) {
563 if(!ldns_sock_wait(sockfd, timeout, 0)) {
568 rc = recv(sockfd, (void*) (wire + bytes),
569 (size_t) (wire_size - bytes), 0);
570 if (rc == -1 || rc == 0) {
578 *size = (size_t) bytes;
583 ldns_tcp_read_wire(int sockfd, size_t *size)
587 ssize_t bytes = 0, rc = 0;
589 wire = LDNS_XMALLOC(uint8_t, 2);
596 rc = recv(sockfd, (void*) (wire + bytes),
597 (size_t) (2 - bytes), 0);
598 if (rc == -1 || rc == 0) {
606 wire_size = ldns_read_uint16(wire);
609 wire = LDNS_XMALLOC(uint8_t, wire_size);
616 while (bytes < (ssize_t) wire_size) {
617 rc = recv(sockfd, (void*) (wire + bytes),
618 (size_t) (wire_size - bytes), 0);
619 if (rc == -1 || rc == 0) {
627 *size = (size_t) bytes;
631 /* keep in mind that in DNS tcp messages the first 2 bytes signal the
632 * amount data to expect
635 ldns_tcp_send(uint8_t **result, ldns_buffer *qbin, const struct sockaddr_storage *to,
636 socklen_t tolen, struct timeval timeout, size_t *answer_size)
641 sockfd = ldns_tcp_bgsend(qbin, to, tolen, timeout);
644 return LDNS_STATUS_ERR;
647 answer = ldns_tcp_read_wire_timeout(sockfd, answer_size, timeout);
654 if (*answer_size == 0) {
656 return LDNS_STATUS_NETWORK_ERR;
659 /* resize accordingly */
660 *result = (uint8_t*)LDNS_XREALLOC(answer, uint8_t *, (size_t)*answer_size);
663 return LDNS_STATUS_MEM_ERR;
665 return LDNS_STATUS_OK;
669 ldns_tcp_bgsend(ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen,
670 struct timeval timeout)
674 sockfd = ldns_tcp_connect(to, tolen, timeout);
680 if (ldns_tcp_send_query(qbin, sockfd, to, tolen) == 0) {
687 /* code from rdata.c */
688 struct sockaddr_storage *
689 ldns_rdf2native_sockaddr_storage(const ldns_rdf *rd, uint16_t port, size_t *size)
691 struct sockaddr_storage *data;
692 struct sockaddr_in *data_in;
693 struct sockaddr_in6 *data_in6;
695 data = LDNS_MALLOC(struct sockaddr_storage);
699 /* zero the structure for portability */
700 memset(data, 0, sizeof(struct sockaddr_storage));
705 switch(ldns_rdf_get_type(rd)) {
706 case LDNS_RDF_TYPE_A:
707 data->ss_family = AF_INET;
708 data_in = (struct sockaddr_in*) data;
709 data_in->sin_port = (in_port_t)htons(port);
710 memcpy(&(data_in->sin_addr), ldns_rdf_data(rd), ldns_rdf_size(rd));
711 *size = sizeof(struct sockaddr_in);
713 case LDNS_RDF_TYPE_AAAA:
714 data->ss_family = AF_INET6;
715 data_in6 = (struct sockaddr_in6*) data;
716 data_in6->sin6_port = (in_port_t)htons(port);
717 memcpy(&data_in6->sin6_addr, ldns_rdf_data(rd), ldns_rdf_size(rd));
718 *size = sizeof(struct sockaddr_in6);
727 ldns_sockaddr_storage2rdf(struct sockaddr_storage *sock, uint16_t *port)
730 struct sockaddr_in *data_in;
731 struct sockaddr_in6 *data_in6;
733 switch(sock->ss_family) {
735 data_in = (struct sockaddr_in*)sock;
737 *port = ntohs((uint16_t)data_in->sin_port);
739 addr = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_A,
740 LDNS_IP4ADDRLEN, &data_in->sin_addr);
743 data_in6 = (struct sockaddr_in6*)sock;
745 *port = ntohs((uint16_t)data_in6->sin6_port);
747 addr = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_AAAA,
748 LDNS_IP6ADDRLEN, &data_in6->sin6_addr);
759 /* code from resolver.c */
761 ldns_axfr_start(ldns_resolver *resolver, ldns_rdf *domain, ldns_rr_class class)
764 ldns_buffer *query_wire;
766 struct sockaddr_storage *ns = NULL;
771 if (!resolver || ldns_resolver_nameserver_count(resolver) < 1) {
772 return LDNS_STATUS_ERR;
775 query = ldns_pkt_query_new(ldns_rdf_clone(domain), LDNS_RR_TYPE_AXFR, class, 0);
778 return LDNS_STATUS_ADDRESS_ERR;
780 /* For AXFR, we have to make the connection ourselves */
781 /* try all nameservers (which usually would mean v4 fallback if
782 * @hostname is used */
784 ns_i < ldns_resolver_nameserver_count(resolver) &&
785 resolver->_socket == 0;
787 ns = ldns_rdf2native_sockaddr_storage(
788 resolver->_nameservers[ns_i],
789 ldns_resolver_port(resolver), &ns_len);
791 resolver->_socket = ldns_tcp_connect(ns, (socklen_t)ns_len,
792 ldns_resolver_timeout(resolver));
795 if (resolver->_socket == 0) {
796 ldns_pkt_free(query);
798 return LDNS_STATUS_NETWORK_ERR;
802 if (ldns_resolver_tsig_keyname(resolver) && ldns_resolver_tsig_keydata(resolver)) {
803 status = ldns_pkt_tsig_sign(query,
804 ldns_resolver_tsig_keyname(resolver),
805 ldns_resolver_tsig_keydata(resolver),
806 300, ldns_resolver_tsig_algorithm(resolver), NULL);
807 if (status != LDNS_STATUS_OK) {
808 /* RoRi: to prevent problems on subsequent calls to ldns_axfr_start
809 we have to close the socket here! */
811 close(resolver->_socket);
813 closesocket(resolver->_socket);
815 resolver->_socket = 0;
817 return LDNS_STATUS_CRYPTO_TSIG_ERR;
820 #endif /* HAVE_SSL */
822 /* Convert the query to a buffer
825 query_wire = ldns_buffer_new(LDNS_MAX_PACKETLEN);
827 ldns_pkt_free(query);
830 close(resolver->_socket);
832 closesocket(resolver->_socket);
834 resolver->_socket = 0;
836 return LDNS_STATUS_MEM_ERR;
838 status = ldns_pkt2buffer_wire(query_wire, query);
839 if (status != LDNS_STATUS_OK) {
840 ldns_pkt_free(query);
841 ldns_buffer_free(query_wire);
844 /* RoRi: to prevent problems on subsequent calls to ldns_axfr_start
845 we have to close the socket here! */
847 close(resolver->_socket);
849 closesocket(resolver->_socket);
851 resolver->_socket = 0;
856 if (ldns_tcp_send_query(query_wire, resolver->_socket, ns,
857 (socklen_t)ns_len) == 0) {
858 ldns_pkt_free(query);
859 ldns_buffer_free(query_wire);
862 /* RoRi: to prevent problems on subsequent calls to ldns_axfr_start
863 we have to close the socket here! */
866 close(resolver->_socket);
868 closesocket(resolver->_socket);
870 resolver->_socket = 0;
872 return LDNS_STATUS_NETWORK_ERR;
875 ldns_pkt_free(query);
876 ldns_buffer_free(query_wire);
880 * The AXFR is done once the second SOA record is sent
882 resolver->_axfr_soa_count = 0;
883 return LDNS_STATUS_OK;