bind9/lib/samples/sample-request.c
Ondřej Surý f0989bdf03 The dns_message_create() cannot fail, change the return to void
The dns_message_create() function cannot soft fail (as all memory
allocations either succeed or cause abort), so we change the function to
return void and cleanup the calls.

(cherry picked from commit 33eefe9f85)
2020-09-30 14:26:26 +02:00

248 lines
5.9 KiB
C

/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#ifndef WIN32
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#endif /* ifndef WIN32 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <isc/base64.h>
#include <isc/buffer.h>
#include <isc/commandline.h>
#include <isc/lib.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/sockaddr.h>
#include <isc/util.h>
#include <dns/client.h>
#include <dns/fixedname.h>
#include <dns/keyvalues.h>
#include <dns/lib.h>
#include <dns/masterdump.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/secalg.h>
#include <dst/dst.h>
static isc_mem_t *mctx;
static dns_fixedname_t fixedqname;
ISC_PLATFORM_NORETURN_PRE static void
usage(void) ISC_PLATFORM_NORETURN_POST;
static void
usage(void) {
fprintf(stderr, "sample-request [-t RRtype] server_address hostname\n");
exit(1);
}
static isc_result_t
make_querymessage(dns_message_t *message, const char *namestr,
dns_rdatatype_t rdtype) {
dns_name_t *qname = NULL, *qname0;
dns_rdataset_t *qrdataset = NULL;
isc_result_t result;
isc_buffer_t b;
unsigned int namelen;
REQUIRE(message != NULL);
REQUIRE(namestr != NULL);
/* Construct qname */
namelen = strlen(namestr);
isc_buffer_constinit(&b, namestr, namelen);
isc_buffer_add(&b, namelen);
qname0 = dns_fixedname_initname(&fixedqname);
result = dns_name_fromtext(qname0, &b, dns_rootname, 0, NULL);
if (result != ISC_R_SUCCESS) {
fprintf(stderr, "failed to convert qname: %u\n", result);
return (result);
}
/* Construct query message */
message->opcode = dns_opcode_query;
message->rdclass = dns_rdataclass_in;
result = dns_message_gettempname(message, &qname);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
result = dns_message_gettemprdataset(message, &qrdataset);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
dns_name_init(qname, NULL);
dns_name_clone(qname0, qname);
dns_rdataset_makequestion(qrdataset, message->rdclass, rdtype);
ISC_LIST_APPEND(qname->list, qrdataset, link);
dns_message_addname(message, qname, DNS_SECTION_QUESTION);
return (ISC_R_SUCCESS);
cleanup:
if (qname != NULL) {
dns_message_puttempname(message, &qname);
}
if (qrdataset != NULL) {
dns_message_puttemprdataset(message, &qrdataset);
}
dns_message_detach(&message);
return (result);
}
static void
print_section(dns_message_t *message, int section, isc_buffer_t *buf) {
isc_result_t result;
isc_region_t r;
result = dns_message_sectiontotext(message, section,
&dns_master_style_full, 0, buf);
if (result != ISC_R_SUCCESS) {
goto fail;
}
isc_buffer_usedregion(buf, &r);
printf("%.*s", (int)r.length, (char *)r.base);
return;
fail:
fprintf(stderr, "failed to convert a section\n");
}
int
main(int argc, char *argv[]) {
int ch, i, gaierror;
struct addrinfo hints, *res;
isc_textregion_t tr;
dns_client_t *client = NULL;
isc_result_t result;
isc_sockaddr_t sa;
dns_message_t *qmessage, *rmessage;
dns_rdatatype_t type = dns_rdatatype_a;
isc_buffer_t *outputbuf;
while ((ch = isc_commandline_parse(argc, argv, "t:")) != -1) {
switch (ch) {
case 't':
tr.base = isc_commandline_argument;
tr.length = strlen(isc_commandline_argument);
result = dns_rdatatype_fromtext(&type, &tr);
if (result != ISC_R_SUCCESS) {
fprintf(stderr, "invalid RRtype: %s\n",
isc_commandline_argument);
exit(1);
}
break;
default:
usage();
}
}
argc -= isc_commandline_index;
argv += isc_commandline_index;
if (argc < 2) {
usage();
}
isc_lib_register();
result = dns_lib_init();
if (result != ISC_R_SUCCESS) {
fprintf(stderr, "dns_lib_init failed: %u\n", result);
exit(1);
}
result = dns_client_create(&client, 0);
if (result != ISC_R_SUCCESS) {
fprintf(stderr, "dns_client_create failed: %u\n", result);
exit(1);
}
/* Prepare message structures */
mctx = NULL;
qmessage = NULL;
rmessage = NULL;
isc_mem_create(&mctx);
dns_message_create(mctx, DNS_MESSAGE_INTENTRENDER, &qmessage);
dns_message_create(mctx, DNS_MESSAGE_INTENTPARSE, &rmessage);
/* Initialize the nameserver address */
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
#ifdef AI_NUMERICHOST
hints.ai_flags = AI_NUMERICHOST;
#endif /* ifdef AI_NUMERICHOST */
gaierror = getaddrinfo(argv[0], "53", &hints, &res);
if (gaierror != 0) {
fprintf(stderr, "getaddrinfo failed: %s\n",
gai_strerror(gaierror));
exit(1);
}
INSIST(res->ai_addrlen <= sizeof(sa.type));
memmove(&sa.type, res->ai_addr, res->ai_addrlen);
freeaddrinfo(res);
sa.length = (unsigned int)res->ai_addrlen;
ISC_LINK_INIT(&sa, link);
/* Construct qname */
result = make_querymessage(qmessage, argv[1], type);
if (result != ISC_R_SUCCESS) {
fprintf(stderr, "failed to create a query\n");
exit(1);
}
/* Send request and wait for a response */
result = dns_client_request(client, qmessage, rmessage, &sa, 0, 0, NULL,
60, 0, 3);
if (result != ISC_R_SUCCESS) {
fprintf(stderr, "failed to get a response: %s\n",
dns_result_totext(result));
}
/* Dump the response */
outputbuf = NULL;
isc_buffer_allocate(mctx, &outputbuf, 65535);
for (i = 0; i < DNS_SECTION_MAX; i++) {
print_section(rmessage, i, outputbuf);
isc_buffer_clear(outputbuf);
}
isc_buffer_free(&outputbuf);
/* Cleanup */
dns_message_detach(&qmessage);
dns_message_detach(&rmessage);
isc_mem_destroy(&mctx);
dns_client_destroy(&client);
dns_lib_shutdown();
return (0);
}