Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 591 insertions, 0 deletions

diff --git a/libcli/dns/dns.c b/libcli/dns/dns.c
new file mode 100644
index 0000000..943b4d5
--- /dev/null
+++ b/libcli/dns/dns.c
@@ -0,0 +1,591 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Small async DNS library for Samba with socketwrapper support
+
+   Copyright (C) 2010 Kai Blin  <kai@samba.org>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/network.h"
+#include <tevent.h>
+#include "lib/tsocket/tsocket.h"
+#include "libcli/dns/libdns.h"
+#include "lib/util/tevent_unix.h"
+#include "lib/util/samba_util.h"
+#include "lib/util/debug.h"
+#include "libcli/util/error.h"
+#include "librpc/ndr/libndr.h"
+#include "librpc/gen_ndr/ndr_dns.h"
+
+struct dns_udp_request_state {
+	struct tevent_context *ev;
+	struct tdgram_context *dgram;
+	size_t query_len;
+	uint8_t *reply;
+	size_t reply_len;
+};
+
+#define DNS_REQUEST_TIMEOUT 10
+
+/* Declare callback functions used below. */
+static void dns_udp_request_get_reply(struct tevent_req *subreq);
+static void dns_udp_request_done(struct tevent_req *subreq);
+
+static struct tevent_req *dns_udp_request_send(TALLOC_CTX *mem_ctx,
+					       struct tevent_context *ev,
+					       const char *server_addr_string,
+					       const uint8_t *query,
+					       size_t query_len)
+{
+	struct tevent_req *req, *subreq;
+	struct dns_udp_request_state *state;
+	struct tsocket_address *local_addr, *server_addr;
+	struct tdgram_context *dgram;
+	int ret;
+
+	req = tevent_req_create(mem_ctx, &state, struct dns_udp_request_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->ev = ev;
+
+	/* Use connected UDP sockets */
+	ret = tsocket_address_inet_from_strings(state, "ip", NULL, 0,
+						&local_addr);
+	if (ret != 0) {
+		tevent_req_error(req, errno);
+		return tevent_req_post(req, ev);
+	}
+
+	ret = tsocket_address_inet_from_hostport_strings(
+	    state, "ip", server_addr_string, DNS_SERVICE_PORT, &server_addr);
+	if (ret != 0) {
+		tevent_req_error(req, errno);
+		return tevent_req_post(req, ev);
+	}
+
+	ret = tdgram_inet_udp_socket(local_addr, server_addr, state, &dgram);
+	if (ret != 0) {
+		tevent_req_error(req, errno);
+		return tevent_req_post(req, ev);
+	}
+
+	state->dgram = dgram;
+	state->query_len = query_len;
+
+	dump_data(10, query, query_len);
+
+	subreq = tdgram_sendto_send(state, ev, dgram, query, query_len, NULL);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+
+	if (!tevent_req_set_endtime(req, ev,
+				timeval_current_ofs(DNS_REQUEST_TIMEOUT, 0))) {
+		return tevent_req_post(req, ev);
+	}
+
+	tevent_req_set_callback(subreq, dns_udp_request_get_reply, req);
+	return req;
+}
+
+static void dns_udp_request_get_reply(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(subreq,
+						struct tevent_req);
+	struct dns_udp_request_state *state = tevent_req_data(req,
+						struct dns_udp_request_state);
+	ssize_t len;
+	int err = 0;
+
+	len = tdgram_sendto_recv(subreq, &err);
+	TALLOC_FREE(subreq);
+
+	if (len == -1 && err != 0) {
+		tevent_req_error(req, err);
+		return;
+	}
+
+	if (len != state->query_len) {
+		tevent_req_error(req, EIO);
+		return;
+	}
+
+	subreq = tdgram_recvfrom_send(state, state->ev, state->dgram);
+	if (tevent_req_nomem(subreq, req)) {
+		return;
+	}
+
+	tevent_req_set_callback(subreq, dns_udp_request_done, req);
+}
+
+static void dns_udp_request_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(subreq,
+						struct tevent_req);
+	struct dns_udp_request_state *state = tevent_req_data(req,
+						struct dns_udp_request_state);
+
+	ssize_t len;
+	int err = 0;
+
+	len = tdgram_recvfrom_recv(subreq, &err, state, &state->reply, NULL);
+	TALLOC_FREE(subreq);
+
+	if (len == -1 && err != 0) {
+		tevent_req_error(req, err);
+		return;
+	}
+
+	state->reply_len = len;
+	dump_data(10, state->reply, state->reply_len);
+	tevent_req_done(req);
+}
+
+static int dns_udp_request_recv(struct tevent_req *req,
+				TALLOC_CTX *mem_ctx,
+				uint8_t **reply,
+				size_t *reply_len)
+{
+	struct dns_udp_request_state *state = tevent_req_data(req,
+			struct dns_udp_request_state);
+	int err;
+
+	if (tevent_req_is_unix_error(req, &err)) {
+		tevent_req_received(req);
+		return err;
+	}
+
+	*reply = talloc_move(mem_ctx, &state->reply);
+	*reply_len = state->reply_len;
+	tevent_req_received(req);
+
+	return 0;
+}
+
+struct dns_tcp_request_state {
+	struct tevent_context *ev;
+	struct tstream_context *stream;
+	const uint8_t *query;
+	size_t query_len;
+
+	uint8_t dns_msglen_hdr[2];
+	struct iovec iov[2];
+
+	size_t nread;
+	uint8_t *reply;
+};
+
+static void dns_tcp_request_connected(struct tevent_req *subreq);
+static void dns_tcp_request_sent(struct tevent_req *subreq);
+static int dns_tcp_request_next_vector(struct tstream_context *stream,
+				       void *private_data,
+				       TALLOC_CTX *mem_ctx,
+				       struct iovec **_vector,
+				       size_t *_count);
+static void dns_tcp_request_received(struct tevent_req *subreq);
+
+static struct tevent_req *dns_tcp_request_send(TALLOC_CTX *mem_ctx,
+					       struct tevent_context *ev,
+					       const char *server_addr_string,
+					       const uint8_t *query,
+					       size_t query_len)
+{
+	struct tevent_req *req, *subreq;
+	struct dns_tcp_request_state *state;
+	struct tsocket_address *local, *remote;
+	int ret;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct dns_tcp_request_state);
+	if (req == NULL) {
+		return NULL;
+	}
+	state->ev = ev;
+	state->query = query;
+	state->query_len = query_len;
+
+	if (query_len > UINT16_MAX) {
+		tevent_req_error(req, EMSGSIZE);
+		return tevent_req_post(req, ev);
+	}
+
+	ret = tsocket_address_inet_from_strings(state, "ip", NULL, 0, &local);
+	if (ret != 0) {
+		tevent_req_error(req, errno);
+		return tevent_req_post(req, ev);
+	}
+
+	ret = tsocket_address_inet_from_hostport_strings(
+	    state, "ip", server_addr_string, DNS_SERVICE_PORT, &remote);
+	if (ret != 0) {
+		tevent_req_error(req, errno);
+		return tevent_req_post(req, ev);
+	}
+
+	subreq = tstream_inet_tcp_connect_send(state, state->ev,
+					       local, remote);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, dns_tcp_request_connected, req);
+
+	return req;
+}
+
+static void dns_tcp_request_connected(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct dns_tcp_request_state *state = tevent_req_data(
+		req, struct dns_tcp_request_state);
+	int ret, err;
+
+	ret = tstream_inet_tcp_connect_recv(subreq, &err, state,
+					    &state->stream, NULL);
+	TALLOC_FREE(subreq);
+	if (ret == -1) {
+		tevent_req_error(req, err);
+		return;
+	}
+
+	RSSVAL(state->dns_msglen_hdr, 0, state->query_len);
+	state->iov[0] = (struct iovec) {
+		.iov_base = state->dns_msglen_hdr,
+		.iov_len = sizeof(state->dns_msglen_hdr)
+	};
+	state->iov[1] = (struct iovec) {
+		.iov_base = discard_const_p(void, state->query),
+		.iov_len = state->query_len
+	};
+
+	subreq = tstream_writev_send(state, state->ev, state->stream,
+				     state->iov, ARRAY_SIZE(state->iov));
+	if (tevent_req_nomem(subreq, req)) {
+		return;
+	}
+	tevent_req_set_callback(subreq, dns_tcp_request_sent, req);
+}
+
+static void dns_tcp_request_sent(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct dns_tcp_request_state *state = tevent_req_data(
+		req, struct dns_tcp_request_state);
+	int ret, err;
+
+	ret = tstream_writev_recv(subreq, &err);
+	TALLOC_FREE(subreq);
+	if (ret == -1) {
+		tevent_req_error(req, err);
+		return;
+	}
+
+	subreq = tstream_readv_pdu_send(state, state->ev, state->stream,
+					dns_tcp_request_next_vector, state);
+	if (tevent_req_nomem(subreq, req)) {
+		return;
+	}
+	tevent_req_set_callback(subreq, dns_tcp_request_received, req);
+}
+
+static int dns_tcp_request_next_vector(struct tstream_context *stream,
+				       void *private_data,
+				       TALLOC_CTX *mem_ctx,
+				       struct iovec **_vector,
+				       size_t *_count)
+{
+	struct dns_tcp_request_state *state = talloc_get_type_abort(
+		private_data, struct dns_tcp_request_state);
+	struct iovec *vector;
+	uint16_t msglen;
+
+	if (state->nread == 0) {
+		vector = talloc_array(mem_ctx, struct iovec, 1);
+		if (vector == NULL) {
+			return -1;
+		}
+		vector[0] = (struct iovec) {
+			.iov_base = state->dns_msglen_hdr,
+			.iov_len = sizeof(state->dns_msglen_hdr)
+		};
+		state->nread = sizeof(state->dns_msglen_hdr);
+
+		*_vector = vector;
+		*_count = 1;
+		return 0;
+	}
+
+	if (state->nread == sizeof(state->dns_msglen_hdr)) {
+		msglen = RSVAL(state->dns_msglen_hdr, 0);
+
+		state->reply = talloc_array(state, uint8_t, msglen);
+		if (state->reply == NULL) {
+			return -1;
+		}
+
+		vector = talloc_array(mem_ctx, struct iovec, 1);
+		if (vector == NULL) {
+			return -1;
+		}
+		vector[0] = (struct iovec) {
+			.iov_base = state->reply,
+			.iov_len = msglen
+		};
+		state->nread += msglen;
+
+		*_vector = vector;
+		*_count = 1;
+		return 0;
+	}
+
+	*_vector = NULL;
+	*_count = 0;
+	return 0;
+}
+
+static void dns_tcp_request_received(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	int ret, err;
+
+	ret = tstream_readv_pdu_recv(subreq, &err);
+	TALLOC_FREE(subreq);
+	if (ret == -1) {
+		tevent_req_error(req, err);
+		return;
+	}
+
+	tevent_req_done(req);
+}
+
+static int dns_tcp_request_recv(struct tevent_req *req,
+				TALLOC_CTX *mem_ctx,
+				uint8_t **reply,
+				size_t *reply_len)
+{
+	struct dns_tcp_request_state *state = tevent_req_data(
+		req, struct dns_tcp_request_state);
+	int err;
+
+	if (tevent_req_is_unix_error(req, &err)) {
+		tevent_req_received(req);
+		return err;
+	}
+
+	*reply_len = talloc_array_length(state->reply);
+	*reply = talloc_move(mem_ctx, &state->reply);
+	tevent_req_received(req);
+
+	return 0;
+}
+
+struct dns_cli_request_state {
+	struct tevent_context *ev;
+	const char *nameserver;
+
+	uint16_t req_id;
+
+	DATA_BLOB query;
+
+	struct dns_name_packet *reply;
+};
+
+static void dns_cli_request_udp_done(struct tevent_req *subreq);
+static void dns_cli_request_tcp_done(struct tevent_req *subreq);
+
+struct tevent_req *dns_cli_request_send(TALLOC_CTX *mem_ctx,
+					struct tevent_context *ev,
+					const char *nameserver,
+					const char *name,
+					enum dns_qclass qclass,
+					enum dns_qtype qtype)
+{
+	struct tevent_req *req, *subreq;
+	struct dns_cli_request_state *state;
+	struct dns_name_question question;
+	struct dns_name_packet out_packet;
+	enum ndr_err_code ndr_err;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct dns_cli_request_state);
+	if (req == NULL) {
+		return NULL;
+	}
+	state->ev = ev;
+	state->nameserver = nameserver;
+
+	DBG_DEBUG("Asking %s for %s/%d/%d via UDP\n", nameserver,
+		  name, (int)qclass, (int)qtype);
+
+	generate_random_buffer((uint8_t *)&state->req_id,
+			       sizeof(state->req_id));
+
+	question = (struct dns_name_question) {
+		.name = discard_const_p(char, name),
+		.question_type = qtype, .question_class = qclass
+	};
+
+	out_packet = (struct dns_name_packet) {
+		.id = state->req_id,
+		.operation = DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED,
+		.qdcount = 1,
+		.questions = &question
+	};
+
+	ndr_err = ndr_push_struct_blob(
+		&state->query, state, &out_packet,
+		(ndr_push_flags_fn_t)ndr_push_dns_name_packet);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		tevent_req_error(req, ndr_map_error2errno(ndr_err));
+		return tevent_req_post(req, ev);
+	}
+
+	subreq = dns_udp_request_send(state, state->ev, state->nameserver,
+				      state->query.data, state->query.length);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, dns_cli_request_udp_done, req);
+	return req;
+}
+
+static void dns_cli_request_udp_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct dns_cli_request_state *state = tevent_req_data(
+		req, struct dns_cli_request_state);
+	DATA_BLOB reply;
+	enum ndr_err_code ndr_err;
+	uint16_t reply_id, operation;
+	int ret;
+
+	ret = dns_udp_request_recv(subreq, state, &reply.data, &reply.length);
+	TALLOC_FREE(subreq);
+	if (tevent_req_error(req, ret)) {
+		return;
+	}
+
+	if (reply.length < 4) {
+		DBG_DEBUG("Short DNS packet: length=%zu\n", reply.length);
+		tevent_req_error(req, EINVAL);
+		return;
+	}
+
+	reply_id = PULL_BE_U16(reply.data, 0);
+	if (reply_id != state->req_id) {
+		DBG_DEBUG("Got id %"PRIu16", expected %"PRIu16"\n",
+			  state->reply->id, state->req_id);
+		tevent_req_error(req, ENOMSG);
+		return;
+	}
+
+	operation = PULL_BE_U16(reply.data, 2);
+	if ((operation & DNS_FLAG_TRUNCATION) != 0) {
+		DBG_DEBUG("Reply was truncated, retrying TCP\n");
+		subreq = dns_tcp_request_send(
+			state,
+			state->ev,
+			state->nameserver,
+			state->query.data,
+			state->query.length);
+		if (tevent_req_nomem(subreq, req)) {
+			return;
+		}
+		tevent_req_set_callback(subreq, dns_cli_request_tcp_done, req);
+		return;
+	}
+
+	state->reply = talloc(state, struct dns_name_packet);
+	if (tevent_req_nomem(state->reply, req)) {
+		return;
+	}
+
+	ndr_err = ndr_pull_struct_blob(
+		&reply, state->reply, state->reply,
+		(ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		tevent_req_error(req, ndr_map_error2errno(ndr_err));
+		return;
+	}
+	TALLOC_FREE(reply.data);
+
+	tevent_req_done(req);
+}
+
+static void dns_cli_request_tcp_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct dns_cli_request_state *state = tevent_req_data(
+		req, struct dns_cli_request_state);
+	DATA_BLOB reply;
+	enum ndr_err_code ndr_err;
+	int ret;
+
+	ret = dns_tcp_request_recv(subreq, state, &reply.data, &reply.length);
+	TALLOC_FREE(subreq);
+	if (tevent_req_error(req, ret)) {
+		return;
+	}
+
+	state->reply = talloc(state, struct dns_name_packet);
+	if (tevent_req_nomem(state->reply, req)) {
+		return;
+	}
+
+	ndr_err = ndr_pull_struct_blob(
+		&reply, state->reply, state->reply,
+		(ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		tevent_req_error(req, ndr_map_error2errno(ndr_err));
+		return;
+	}
+	TALLOC_FREE(reply.data);
+
+	if (state->reply->id != state->req_id) {
+		DBG_DEBUG("Got id %"PRIu16", expected %"PRIu16"\n",
+			  state->reply->id, state->req_id);
+		tevent_req_error(req, ENOMSG);
+		return;
+	}
+
+	DBG_DEBUG("Got op=%x %"PRIu16"/%"PRIu16"/%"PRIu16"/%"PRIu16
+		  " recs\n", (int)state->reply->operation,
+		  state->reply->qdcount, state->reply->ancount,
+		  state->reply->nscount, state->reply->nscount);
+
+	tevent_req_done(req);
+}
+
+int dns_cli_request_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+			 struct dns_name_packet **reply)
+{
+	struct dns_cli_request_state *state = tevent_req_data(
+		req, struct dns_cli_request_state);
+	int err;
+
+	if (tevent_req_is_unix_error(req, &err)) {
+		return err;
+	}
+	*reply = talloc_move(mem_ctx, &state->reply);
+	return 0;
+}