diff options
Diffstat (limited to 'libcli/dns/dns.c')
| -rw-r--r-- | libcli/dns/dns.c | 172 |
1 files changed, 172 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; +} |