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authorKai Blin <kai@samba.org>2012-03-11 10:13:51 +0100
committerKai Blin <kai@samba.org>2012-03-27 16:03:07 +0200
commit7566e6a5347b9d6b2b0b8b27f9211599febd8da1 (patch)
tree04b9e927b8b53a39d81895d5132be50242fdbb96 /libcli
parent95ebb111ba7e5fbc1e8ca6c560c473d24c5d6c2d (diff)
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s4 dns: Add a simple async client library
Diffstat (limited to 'libcli')
-rw-r--r--libcli/dns/dns.c172
-rw-r--r--libcli/dns/libdns.h53
-rw-r--r--libcli/dns/wscript_build5
3 files changed, 230 insertions, 0 deletions
diff --git a/libcli/dns/dns.c b/libcli/dns/dns.c
new file mode 100644
index 0000000000..ac0c9e4995
--- /dev/null
+++ b/libcli/dns/dns.c
@@ -0,0 +1,172 @@
+/*
+ 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/util/werror.h"
+#include "libcli/dns/libdns.h"
+#include "lib/util/tevent_werror.h"
+#include "lib/util/samba_util.h"
+#include "libcli/util/error.h"
+#include "librpc/gen_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;
+};
+
+/* Declare callback functions used below. */
+static void dns_request_get_reply(struct tevent_req *subreq);
+static void dns_request_done(struct tevent_req *subreq);
+
+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_werror(req, unix_to_werror(ret));
+ return tevent_req_post(req, ev);
+ }
+
+ ret = tsocket_address_inet_from_strings(state, "ip", server_addr_string,
+ DNS_SERVICE_PORT, &server_addr);
+ if (ret != 0) {
+ tevent_req_werror(req, unix_to_werror(ret));
+ return tevent_req_post(req, ev);
+ }
+
+ ret = tdgram_inet_udp_socket(local_addr, server_addr, state, &dgram);
+ if (ret != 0) {
+ tevent_req_werror(req, unix_to_werror(ret));
+ 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);
+ }
+
+ tevent_req_set_callback(subreq, dns_request_get_reply, req);
+ return req;
+}
+
+static void dns_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_werror(req, unix_to_werror(err));
+ return;
+ }
+
+ if (len != state->query_len) {
+ tevent_req_werror(req, WERR_NET_WRITE_FAULT);
+ return;
+ }
+
+ subreq = tdgram_recvfrom_send(state, state->ev, state->dgram);
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+
+ tevent_req_set_callback(subreq, dns_request_done, req);
+ return;
+}
+
+static void dns_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_werror(req, unix_to_werror(err));
+ return;
+ }
+
+ state->reply_len = len;
+ dump_data(10, state->reply, state->reply_len);
+ tevent_req_done(req);
+}
+
+WERROR 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);
+ WERROR w_error;
+
+ if (tevent_req_is_werror(req, &w_error)) {
+ tevent_req_received(req);
+ return w_error;
+ }
+
+ *reply = talloc_move(mem_ctx, &state->reply);
+ *reply_len = state->reply_len;
+ tevent_req_received(req);
+
+ return WERR_OK;
+}
diff --git a/libcli/dns/libdns.h b/libcli/dns/libdns.h
new file mode 100644
index 0000000000..31474ebc53
--- /dev/null
+++ b/libcli/dns/libdns.h
@@ -0,0 +1,53 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ Small async DNS library for Samba with socketwrapper support
+
+ Copyright (C) 2012 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/>.
+*/
+
+#ifndef __LIBDNS_H__
+#define __LIBDNS_H__
+
+/** Send an dns request to a dns server using UDP
+ *
+ *@param mem_ctx talloc memory context to use
+ *@param ev tevent context to use
+ *@param server_address address of the server as a string
+ *@param query dns query to send
+ *@param query_len length of the query
+ *@return tevent_req with the active request or NULL on out-of-memory
+ */
+struct tevent_req *dns_udp_request_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ const char *server_address,
+ const uint8_t *query,
+ size_t query_len);
+
+/** Get the dns response from a dns server via UDP
+ *
+ *@param req tevent_req struct returned from dns_request_send
+ *@param mem_ctx talloc memory context to use for the reply string
+ *@param reply buffer that will be allocated and filled with the dns reply
+ *@param reply_len length of the reply buffer
+ *@return WERROR code depending on the async request result
+ */
+WERROR dns_udp_request_recv(struct tevent_req *req,
+ TALLOC_CTX *mem_ctx,
+ uint8_t **reply,
+ size_t *reply_len);
+
+#endif /*__LIBDNS_H__*/
diff --git a/libcli/dns/wscript_build b/libcli/dns/wscript_build
new file mode 100644
index 0000000000..2e445da141
--- /dev/null
+++ b/libcli/dns/wscript_build
@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+
+bld.SAMBA_SUBSYSTEM('LIBCLI_DNS',
+ source='dns.c',
+ deps='LIBTSOCKET tevent-util')