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);
110 if ((ns->ss_family == AF_INET) &&
111 (ldns_resolver_ip6(r) == LDNS_RESOLV_INET6)) {
117 if ((ns->ss_family == AF_INET6) &&
118 (ldns_resolver_ip6(r) == LDNS_RESOLV_INET)) {
125 all_servers_rtt_inf = false;
127 gettimeofday(&tv_s, NULL);
129 send_status = LDNS_STATUS_ERR;
131 /* reply_bytes implicitly handles our error */
132 if (1 == ldns_resolver_usevc(r)) {
133 for (retries = ldns_resolver_retry(r); retries > 0; retries--) {
135 ldns_tcp_send(&reply_bytes, qb, ns,
136 (socklen_t)ns_len, ldns_resolver_timeout(r),
138 if (send_status == LDNS_STATUS_OK) {
143 for (retries = ldns_resolver_retry(r); retries > 0; retries--) {
144 /* ldns_rdf_print(stdout, ns_array[i]); */
146 ldns_udp_send(&reply_bytes, qb, ns,
147 (socklen_t)ns_len, ldns_resolver_timeout(r),
150 if (send_status == LDNS_STATUS_OK) {
156 if (send_status != LDNS_STATUS_OK) {
157 ldns_resolver_set_nameserver_rtt(r, i, LDNS_RESOLV_RTT_INF);
158 status = send_status;
161 /* obey the fail directive */
163 /* the current nameserver seems to have a problem, blacklist it */
164 if (ldns_resolver_fail(r)) {
166 return LDNS_STATUS_ERR;
173 status = ldns_wire2pkt(&reply, reply_bytes, reply_size);
174 if (status != LDNS_STATUS_OK) {
175 LDNS_FREE(reply_bytes);
181 gettimeofday(&tv_e, NULL);
184 ldns_pkt_set_querytime(reply, (uint32_t)
185 ((tv_e.tv_sec - tv_s.tv_sec) * 1000) +
186 (tv_e.tv_usec - tv_s.tv_usec) / 1000);
187 ldns_pkt_set_answerfrom(reply,
188 ldns_rdf_clone(ns_array[i]));
189 ldns_pkt_set_timestamp(reply, tv_s);
190 ldns_pkt_set_size(reply, reply_size);
193 if (ldns_resolver_fail(r)) {
194 /* if fail is set bail out, after the first
200 /* wait retrans seconds... */
201 sleep((unsigned int) ldns_resolver_retrans(r));
204 if (all_servers_rtt_inf) {
205 LDNS_FREE(reply_bytes);
206 return LDNS_STATUS_RES_NO_NS;
209 if (tsig_mac && reply && reply_bytes) {
210 if (!ldns_pkt_tsig_verify(reply,
213 ldns_resolver_tsig_keyname(r),
214 ldns_resolver_tsig_keydata(r), tsig_mac)) {
215 status = LDNS_STATUS_CRYPTO_TSIG_BOGUS;
220 #endif /* HAVE_SSL */
222 LDNS_FREE(reply_bytes);
230 /** best effort to set nonblocking */
232 ldns_sock_nonblock(int sockfd)
236 if((flag = fcntl(sockfd, F_GETFL)) != -1) {
238 if(fcntl(sockfd, F_SETFL, flag) == -1) {
239 /* ignore error, continue blockingly */
242 #elif defined(HAVE_IOCTLSOCKET)
243 unsigned long on = 1;
244 if(ioctlsocket(sockfd, FIONBIO, &on) != 0) {
245 /* ignore error, continue blockingly */
250 /** best effort to set blocking */
252 ldns_sock_block(int sockfd)
256 if((flag = fcntl(sockfd, F_GETFL)) != -1) {
258 if(fcntl(sockfd, F_SETFL, flag) == -1) {
259 /* ignore error, continue */
262 #elif defined(HAVE_IOCTLSOCKET)
263 unsigned long off = 0;
264 if(ioctlsocket(sockfd, FIONBIO, &off) != 0) {
265 /* ignore error, continue */
270 /** wait for a socket to become ready */
272 ldns_sock_wait(int sockfd, struct timeval timeout, int write)
278 FD_SET(FD_SET_T sockfd, &fds);
280 ret = select(sockfd+1, NULL, &fds, NULL, &timeout);
282 ret = select(sockfd+1, &fds, NULL, NULL, &timeout);
285 /* timeout expired */
294 ldns_udp_send(uint8_t **result, ldns_buffer *qbin, const struct sockaddr_storage *to,
295 socklen_t tolen, struct timeval timeout, size_t *answer_size)
300 sockfd = ldns_udp_bgsend(qbin, to, tolen, timeout);
303 return LDNS_STATUS_SOCKET_ERROR;
306 /* wait for an response*/
307 if(!ldns_sock_wait(sockfd, timeout, 0)) {
313 return LDNS_STATUS_NETWORK_ERR;
316 /* set to nonblocking, so if the checksum is bad, it becomes
317 * an EGAIN error and the ldns_udp_send function does not block,
318 * but returns a 'NETWORK_ERROR' much like a timeout. */
319 ldns_sock_nonblock(sockfd);
321 answer = ldns_udp_read_wire(sockfd, answer_size, NULL, NULL);
328 if (*answer_size == 0) {
330 return LDNS_STATUS_NETWORK_ERR;
334 return LDNS_STATUS_OK;
338 ldns_udp_bgsend(ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen,
339 struct timeval timeout)
343 sockfd = ldns_udp_connect(to, timeout);
349 if (ldns_udp_send_query(qbin, sockfd, to, tolen) == 0) {
361 ldns_udp_connect(const struct sockaddr_storage *to, struct timeval ATTR_UNUSED(timeout))
366 if ((sockfd = socket((int)((struct sockaddr*)to)->sa_family, SOCK_DGRAM,
376 ldns_tcp_connect(const struct sockaddr_storage *to, socklen_t tolen,
377 struct timeval timeout)
382 if ((sockfd = socket((int)((struct sockaddr*)to)->sa_family, SOCK_STREAM,
383 IPPROTO_TCP)) == -1) {
388 /* perform nonblocking connect, to be able to wait with select() */
389 ldns_sock_nonblock(sockfd);
390 if (connect(sockfd, (struct sockaddr*)to, tolen) == -1) {
393 if(errno != EINPROGRESS) {
400 #else /* USE_WINSOCK */
401 if(WSAGetLastError() != WSAEINPROGRESS &&
402 WSAGetLastError() != WSAEWOULDBLOCK) {
407 /* error was only telling us that it would block */
410 /* wait(write) until connected or error */
413 socklen_t len = (socklen_t)sizeof(error);
415 if(!ldns_sock_wait(sockfd, timeout, 1)) {
424 /* check if there is a pending error for nonblocking connect */
425 if(getsockopt(sockfd, SOL_SOCKET, SO_ERROR, (void*)&error,
428 error = errno; /* on solaris errno is error */
430 error = WSAGetLastError();
434 #if defined(EINPROGRESS) && defined(EWOULDBLOCK)
435 if(error == EINPROGRESS || error == EWOULDBLOCK)
436 continue; /* try again */
438 else if(error != 0) {
440 /* error in errno for our user */
444 #else /* USE_WINSOCK */
445 if(error == WSAEINPROGRESS)
447 else if(error == WSAEWOULDBLOCK)
449 else if(error != 0) {
454 #endif /* USE_WINSOCK */
459 /* set the socket blocking again */
460 ldns_sock_block(sockfd);
466 ldns_tcp_send_query(ldns_buffer *qbin, int sockfd,
467 const struct sockaddr_storage *to, socklen_t tolen)
472 /* add length of packet */
473 sendbuf = LDNS_XMALLOC(uint8_t, ldns_buffer_position(qbin) + 2);
474 if(!sendbuf) return 0;
475 ldns_write_uint16(sendbuf, ldns_buffer_position(qbin));
476 memcpy(sendbuf + 2, ldns_buffer_begin(qbin), ldns_buffer_position(qbin));
478 bytes = sendto(sockfd, (void*)sendbuf,
479 ldns_buffer_position(qbin) + 2, 0, (struct sockaddr *)to, tolen);
483 if (bytes == -1 || (size_t) bytes != ldns_buffer_position(qbin) + 2 ) {
489 /* don't wait for an answer */
491 ldns_udp_send_query(ldns_buffer *qbin, int sockfd, const struct sockaddr_storage *to,
496 bytes = sendto(sockfd, (void*)ldns_buffer_begin(qbin),
497 ldns_buffer_position(qbin), 0, (struct sockaddr *)to, tolen);
499 if (bytes == -1 || (size_t)bytes != ldns_buffer_position(qbin)) {
502 if ((size_t) bytes != ldns_buffer_position(qbin)) {
509 ldns_udp_read_wire(int sockfd, size_t *size, struct sockaddr_storage *from,
512 uint8_t *wire, *wireout;
515 wire = LDNS_XMALLOC(uint8_t, LDNS_MAX_PACKETLEN);
521 wire_size = recvfrom(sockfd, (void*)wire, LDNS_MAX_PACKETLEN, 0,
522 (struct sockaddr *)from, fromlen);
524 /* recvfrom can also return 0 */
525 if (wire_size == -1 || wire_size == 0) {
531 *size = (size_t)wire_size;
532 wireout = LDNS_XREALLOC(wire, uint8_t, (size_t)wire_size);
533 if(!wireout) LDNS_FREE(wire);
539 ldns_tcp_read_wire_timeout(int sockfd, size_t *size, struct timeval timeout)
543 ssize_t bytes = 0, rc = 0;
545 wire = LDNS_XMALLOC(uint8_t, 2);
552 if(!ldns_sock_wait(sockfd, timeout, 0)) {
557 rc = recv(sockfd, (void*) (wire + bytes),
558 (size_t) (2 - bytes), 0);
559 if (rc == -1 || rc == 0) {
567 wire_size = ldns_read_uint16(wire);
570 wire = LDNS_XMALLOC(uint8_t, wire_size);
577 while (bytes < (ssize_t) wire_size) {
578 if(!ldns_sock_wait(sockfd, timeout, 0)) {
583 rc = recv(sockfd, (void*) (wire + bytes),
584 (size_t) (wire_size - bytes), 0);
585 if (rc == -1 || rc == 0) {
593 *size = (size_t) bytes;
598 ldns_tcp_read_wire(int sockfd, size_t *size)
602 ssize_t bytes = 0, rc = 0;
604 wire = LDNS_XMALLOC(uint8_t, 2);
611 rc = recv(sockfd, (void*) (wire + bytes),
612 (size_t) (2 - bytes), 0);
613 if (rc == -1 || rc == 0) {
621 wire_size = ldns_read_uint16(wire);
624 wire = LDNS_XMALLOC(uint8_t, wire_size);
631 while (bytes < (ssize_t) wire_size) {
632 rc = recv(sockfd, (void*) (wire + bytes),
633 (size_t) (wire_size - bytes), 0);
634 if (rc == -1 || rc == 0) {
642 *size = (size_t) bytes;
646 /* keep in mind that in DNS tcp messages the first 2 bytes signal the
647 * amount data to expect
650 ldns_tcp_send(uint8_t **result, ldns_buffer *qbin, const struct sockaddr_storage *to,
651 socklen_t tolen, struct timeval timeout, size_t *answer_size)
656 sockfd = ldns_tcp_bgsend(qbin, to, tolen, timeout);
659 return LDNS_STATUS_ERR;
662 answer = ldns_tcp_read_wire_timeout(sockfd, answer_size, timeout);
669 if (*answer_size == 0) {
671 return LDNS_STATUS_NETWORK_ERR;
674 /* resize accordingly */
675 *result = LDNS_XREALLOC(answer, uint8_t, (size_t)*answer_size);
678 return LDNS_STATUS_MEM_ERR;
680 return LDNS_STATUS_OK;
684 ldns_tcp_bgsend(ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen,
685 struct timeval timeout)
689 sockfd = ldns_tcp_connect(to, tolen, timeout);
695 if (ldns_tcp_send_query(qbin, sockfd, to, tolen) == 0) {
707 /* code from rdata.c */
708 struct sockaddr_storage *
709 ldns_rdf2native_sockaddr_storage(const ldns_rdf *rd, uint16_t port, size_t *size)
711 struct sockaddr_storage *data;
712 struct sockaddr_in *data_in;
713 struct sockaddr_in6 *data_in6;
715 data = LDNS_MALLOC(struct sockaddr_storage);
719 /* zero the structure for portability */
720 memset(data, 0, sizeof(struct sockaddr_storage));
725 switch(ldns_rdf_get_type(rd)) {
726 case LDNS_RDF_TYPE_A:
728 data->ss_family = AF_INET;
730 data_in = (struct sockaddr_in*) data;
731 data_in->sin_port = (in_port_t)htons(port);
732 memcpy(&(data_in->sin_addr), ldns_rdf_data(rd), ldns_rdf_size(rd));
733 *size = sizeof(struct sockaddr_in);
735 case LDNS_RDF_TYPE_AAAA:
737 data->ss_family = AF_INET6;
739 data_in6 = (struct sockaddr_in6*) data;
740 data_in6->sin6_port = (in_port_t)htons(port);
741 memcpy(&data_in6->sin6_addr, ldns_rdf_data(rd), ldns_rdf_size(rd));
742 *size = sizeof(struct sockaddr_in6);
752 ldns_sockaddr_storage2rdf(struct sockaddr_storage *sock, uint16_t *port)
755 struct sockaddr_in *data_in;
756 struct sockaddr_in6 *data_in6;
758 switch(sock->ss_family) {
760 data_in = (struct sockaddr_in*)sock;
762 *port = ntohs((uint16_t)data_in->sin_port);
764 addr = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_A,
765 LDNS_IP4ADDRLEN, &data_in->sin_addr);
768 data_in6 = (struct sockaddr_in6*)sock;
770 *port = ntohs((uint16_t)data_in6->sin6_port);
772 addr = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_AAAA,
773 LDNS_IP6ADDRLEN, &data_in6->sin6_addr);
785 /* code from resolver.c */
787 ldns_axfr_start(ldns_resolver *resolver, ldns_rdf *domain, ldns_rr_class class)
790 ldns_buffer *query_wire;
792 struct sockaddr_storage *ns = NULL;
797 if (!resolver || ldns_resolver_nameserver_count(resolver) < 1) {
798 return LDNS_STATUS_ERR;
801 query = ldns_pkt_query_new(ldns_rdf_clone(domain), LDNS_RR_TYPE_AXFR, class, 0);
804 return LDNS_STATUS_ADDRESS_ERR;
806 /* For AXFR, we have to make the connection ourselves */
807 /* try all nameservers (which usually would mean v4 fallback if
808 * @hostname is used */
810 ns_i < ldns_resolver_nameserver_count(resolver) &&
811 resolver->_socket == 0;
816 ns = ldns_rdf2native_sockaddr_storage(
817 resolver->_nameservers[ns_i],
818 ldns_resolver_port(resolver), &ns_len);
820 resolver->_socket = ldns_tcp_connect(ns, (socklen_t)ns_len,
821 ldns_resolver_timeout(resolver));
824 if (resolver->_socket == 0) {
825 ldns_pkt_free(query);
827 return LDNS_STATUS_NETWORK_ERR;
831 if (ldns_resolver_tsig_keyname(resolver) && ldns_resolver_tsig_keydata(resolver)) {
832 status = ldns_pkt_tsig_sign(query,
833 ldns_resolver_tsig_keyname(resolver),
834 ldns_resolver_tsig_keydata(resolver),
835 300, ldns_resolver_tsig_algorithm(resolver), NULL);
836 if (status != LDNS_STATUS_OK) {
837 /* RoRi: to prevent problems on subsequent calls to ldns_axfr_start
838 we have to close the socket here! */
840 close(resolver->_socket);
842 closesocket(resolver->_socket);
844 resolver->_socket = 0;
846 ldns_pkt_free(query);
849 return LDNS_STATUS_CRYPTO_TSIG_ERR;
852 #endif /* HAVE_SSL */
854 /* Convert the query to a buffer
857 query_wire = ldns_buffer_new(LDNS_MAX_PACKETLEN);
859 ldns_pkt_free(query);
862 close(resolver->_socket);
864 closesocket(resolver->_socket);
866 resolver->_socket = 0;
868 return LDNS_STATUS_MEM_ERR;
870 status = ldns_pkt2buffer_wire(query_wire, query);
871 if (status != LDNS_STATUS_OK) {
872 ldns_pkt_free(query);
873 ldns_buffer_free(query_wire);
876 /* RoRi: to prevent problems on subsequent calls to ldns_axfr_start
877 we have to close the socket here! */
879 close(resolver->_socket);
881 closesocket(resolver->_socket);
883 resolver->_socket = 0;
888 if (ldns_tcp_send_query(query_wire, resolver->_socket, ns,
889 (socklen_t)ns_len) == 0) {
890 ldns_pkt_free(query);
891 ldns_buffer_free(query_wire);
894 /* RoRi: to prevent problems on subsequent calls to ldns_axfr_start
895 we have to close the socket here! */
898 close(resolver->_socket);
900 closesocket(resolver->_socket);
902 resolver->_socket = 0;
904 return LDNS_STATUS_NETWORK_ERR;
907 ldns_pkt_free(query);
908 ldns_buffer_free(query_wire);
912 * The AXFR is done once the second SOA record is sent
914 resolver->_axfr_soa_count = 0;
915 return LDNS_STATUS_OK;