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/*
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;
};
#define DNS_REQUEST_TIMEOUT 2
/* 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);
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);
}
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_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_udp_request_done, req);
return;
}
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_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;
}
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