diff options
Diffstat (limited to 'src/output/dnssim/udp.c')
| -rw-r--r-- | src/output/dnssim/udp.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/output/dnssim/udp.c b/src/output/dnssim/udp.c new file mode 100644 index 0000000..74f8569 --- /dev/null +++ b/src/output/dnssim/udp.c @@ -0,0 +1,156 @@ +/* + * Copyright (c) 2019-2020, CZ.NIC, z.s.p.o. + * All rights reserved. + * + * This file is part of dnsjit. + * + * dnsjit 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. + * + * dnsjit 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 dnsjit. If not, see <http://www.gnu.org/licenses/>. + */ + +#include "config.h" + +#include "output/dnssim.h" +#include "output/dnssim/internal.h" +#include "output/dnssim/ll.h" +#include "core/assert.h" + +static core_log_t _log = LOG_T_INIT("output.dnssim"); + +static int _process_udp_response(uv_udp_t* handle, ssize_t nread, const uv_buf_t* buf) +{ + _output_dnssim_query_udp_t* qry = (_output_dnssim_query_udp_t*)handle->data; + _output_dnssim_request_t* req; + core_object_payload_t payload = CORE_OBJECT_PAYLOAD_INIT(NULL); + core_object_dns_t dns_a = CORE_OBJECT_DNS_INIT(&payload); + mlassert(qry, "qry is nil"); + mlassert(qry->qry.req, "query must be part of a request"); + req = qry->qry.req; + + payload.payload = (uint8_t*)buf->base; + payload.len = nread; + + dns_a.obj_prev = (core_object_t*)&payload; + int ret = core_object_dns_parse_header(&dns_a); + if (ret != 0) { + mldebug("udp response malformed"); + return _ERR_MALFORMED; + } + if (dns_a.id != req->dns_q->id) { + mldebug("udp response msgid mismatch %x(q) != %x(a)", req->dns_q->id, dns_a.id); + return _ERR_MSGID; + } + if (dns_a.tc == 1) { + mldebug("udp response has TC=1"); + return _ERR_TC; + } + ret = _output_dnssim_answers_request(req, &dns_a); + if (ret != 0) { + mlwarning("udp reponse question mismatch"); + return _ERR_QUESTION; + } + + _output_dnssim_request_answered(req, &dns_a); + return 0; +} + +static void _on_udp_query_recv(uv_udp_t* handle, ssize_t nread, const uv_buf_t* buf, const struct sockaddr* addr, unsigned flags) +{ + if (nread > 0) { + mldebug("udp recv: %d", nread); + + // TODO handle TC=1 + _process_udp_response(handle, nread, buf); + } + + if (buf->base != NULL) { + free(buf->base); + } +} + +static void _on_query_udp_closed(uv_handle_t* handle) +{ + _output_dnssim_query_udp_t* qry = (_output_dnssim_query_udp_t*)handle->data; + _output_dnssim_request_t* req; + mlassert(qry, "qry is nil"); + mlassert(qry->qry.req, "query must be part of a request"); + req = qry->qry.req; + + free(qry->handle); + + _ll_remove(req->qry, &qry->qry); + free(qry); + + if (req->qry == NULL) + _output_dnssim_maybe_free_request(req); +} + +void _output_dnssim_close_query_udp(_output_dnssim_query_udp_t* qry) +{ + int ret; + mlassert(qry, "qry is nil"); + + ret = uv_udp_recv_stop(qry->handle); + if (ret < 0) { + mldebug("failed uv_udp_recv_stop(): %s", uv_strerror(ret)); + } + + uv_close((uv_handle_t*)qry->handle, _on_query_udp_closed); +} + +int _output_dnssim_create_query_udp(output_dnssim_t* self, _output_dnssim_request_t* req) +{ + int ret; + _output_dnssim_query_udp_t* qry; + core_object_payload_t* payload; + mlassert_self(); + lassert(req, "req is nil"); + payload = (core_object_payload_t*)req->dns_q->obj_prev; + + lfatal_oom(qry = calloc(1, sizeof(_output_dnssim_query_udp_t))); + lfatal_oom(qry->handle = malloc(sizeof(uv_udp_t))); + + qry->qry.transport = OUTPUT_DNSSIM_TRANSPORT_UDP; + qry->qry.req = req; + qry->buf = uv_buf_init((char*)payload->payload, payload->len); + qry->handle->data = (void*)qry; + ret = uv_udp_init(&_self->loop, qry->handle); + if (ret < 0) { + lwarning("failed to init uv_udp_t"); + goto failure; + } + _ll_append(req->qry, &qry->qry); + + ret = _output_dnssim_bind_before_connect(self, (uv_handle_t*)qry->handle); + if (ret < 0) + return ret; + + ret = uv_udp_try_send(qry->handle, &qry->buf, 1, (struct sockaddr*)&_self->target); + if (ret < 0) { + lwarning("failed to send udp packet: %s", uv_strerror(ret)); + return ret; + } + + // listen for reply + ret = uv_udp_recv_start(qry->handle, _output_dnssim_on_uv_alloc, _on_udp_query_recv); + if (ret < 0) { + lwarning("failed uv_udp_recv_start(): %s", uv_strerror(ret)); + return ret; + } + + return 0; +failure: + free(qry->handle); + free(qry); + return ret; +} |