bind9/lib/samples/sample-async.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 http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

#ifndef WIN32
#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <unistd.h>
#endif /* ifndef WIN32 */

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <isc/app.h>
#include <isc/buffer.h>
#include <isc/commandline.h>
#include <isc/lib.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/socket.h>
#include <isc/sockaddr.h>
#include <isc/task.h>
#include <isc/timer.h>
#include <isc/util.h>

#include <dns/client.h>
#include <dns/fixedname.h>
#include <dns/lib.h>
#include <dns/name.h>
#include <dns/rdataset.h>
#include <dns/rdatatype.h>
#include <dns/result.h>

#define MAX_SERVERS 10
#define MAX_QUERIES 100

static dns_client_t*client = NULL;
static isc_task_t*query_task = NULL;
static isc_appctx_t*query_actx = NULL;
static unsigned int outstanding_queries = 0;
static const char*def_server = "127.0.0.1";
static FILE*fp;

struct query_trans {
	int			    id;
	bool			    inuse;
	dns_rdatatype_t		    type;
	dns_fixedname_t		    fixedname;
	dns_name_t*		    qname;
	dns_namelist_t		    answerlist;
	dns_clientrestrans_t*	    xid;
};

static struct query_trans query_array[MAX_QUERIES];

static isc_result_t dispatch_query(struct query_trans*trans);

static void
ctxs_destroy(isc_mem_t**mctxp,
	     isc_appctx_t**actxp,
	     isc_taskmgr_t**taskmgrp,
	     isc_socketmgr_t**socketmgrp,
	     isc_timermgr_t**timermgrp)
{
	if (*taskmgrp != NULL) {
		isc_taskmgr_destroy(taskmgrp);
	}

	if (*timermgrp != NULL) {
		isc_timermgr_destroy(timermgrp);
	}

	if (*socketmgrp != NULL) {
		isc_socketmgr_destroy(socketmgrp);
	}

	if (*actxp != NULL) {
		isc_appctx_destroy(actxp);
	}

	if (*mctxp != NULL) {
		isc_mem_destroy(mctxp);
	}
}

static isc_result_t
ctxs_init(isc_mem_t**mctxp,
	  isc_appctx_t**actxp,
	  isc_taskmgr_t**taskmgrp,
	  isc_socketmgr_t**socketmgrp,
	  isc_timermgr_t**timermgrp)
{
	isc_result_t result;

	result = isc_mem_create(0,0,mctxp);
	if (result != ISC_R_SUCCESS) {
		goto fail;
	}

	result = isc_appctx_create(*mctxp,actxp);
	if (result != ISC_R_SUCCESS) {
		goto fail;
	}

	result = isc_taskmgr_createinctx(*mctxp,*actxp,1,0,taskmgrp);
	if (result != ISC_R_SUCCESS) {
		goto fail;
	}

	result = isc_socketmgr_createinctx(*mctxp,*actxp,socketmgrp);
	if (result != ISC_R_SUCCESS) {
		goto fail;
	}

	result = isc_timermgr_createinctx(*mctxp,*actxp,timermgrp);
	if (result != ISC_R_SUCCESS) {
		goto fail;
	}

	return (ISC_R_SUCCESS);

 fail:
	ctxs_destroy(mctxp,actxp,taskmgrp,socketmgrp,timermgrp);

	return (result);
}

static isc_result_t
printdata(dns_rdataset_t*rdataset,dns_name_t*owner) {
	isc_buffer_t target;
	isc_result_t result;
	isc_region_t r;
	char t[4096];

	isc_buffer_init(&target,t,sizeof(t));

	if (!dns_rdataset_isassociated(rdataset)) {
		return (ISC_R_SUCCESS);
	}
	result = dns_rdataset_totext(rdataset,owner,false,false,
				     &target);
	if (result != ISC_R_SUCCESS) {
		return (result);
	}
	isc_buffer_usedregion(&target,&r);
	printf("  %.*s",(int)r.length,(char*)r.base);

	return (ISC_R_SUCCESS);
}

static void
process_answer(isc_task_t*task,isc_event_t*event) {
	struct query_trans*trans = event->ev_arg;
	dns_clientresevent_t*rev = (dns_clientresevent_t*)event;
	dns_name_t*name;
	dns_rdataset_t*rdataset;
	isc_result_t result;

	REQUIRE(task == query_task);
	REQUIRE(trans->inuse == true);
	REQUIRE(outstanding_queries > 0);

	printf("answer[%2d]\n",trans->id);

	if (rev->result != ISC_R_SUCCESS) {
		printf("  failed: %u(%s)\n",rev->result,
		       dns_result_totext(rev->result));
	}

	for (name = ISC_LIST_HEAD(rev->answerlist); name != NULL;
	     name = ISC_LIST_NEXT(name,link))
	{
		for (rdataset = ISC_LIST_HEAD(name->list);
		     rdataset != NULL;
		     rdataset = ISC_LIST_NEXT(rdataset,link))
		{
			(void)printdata(rdataset,name);
		}
	}

	dns_client_freeresanswer(client,&rev->answerlist);
	dns_client_destroyrestrans(&trans->xid);

	isc_event_free(&event);

	trans->inuse = false;
	dns_fixedname_invalidate(&trans->fixedname);
	trans->qname = NULL;
	outstanding_queries--;

	result = dispatch_query(trans);
#if 0                           /* for cancel test */
	if (result == ISC_R_SUCCESS) {
		static int count = 0;

		if ((++count) % 10 == 0) {
			dns_client_cancelresolve(trans->xid);
		}
	}
#endif /* if 0 */
	if (result == ISC_R_NOMORE && outstanding_queries == 0) {
		isc_app_ctxshutdown(query_actx);
	}
}

static isc_result_t
dispatch_query(struct query_trans*trans) {
	isc_result_t result;
	unsigned int namelen;
	isc_buffer_t b;
	char buf[4096]; /* XXX ad hoc constant, but should be enough */
	char*cp;

	REQUIRE(trans != NULL);
	REQUIRE(trans->inuse == false);
	REQUIRE(ISC_LIST_EMPTY(trans->answerlist));
	REQUIRE(outstanding_queries < MAX_QUERIES);

	/* Construct qname */
	cp = fgets(buf,sizeof(buf),fp);
	if (cp == NULL) {
		return (ISC_R_NOMORE);
	}
	/* zap NL if any */
	if ((cp = strchr(buf,'\n')) != NULL) {
		*cp = '\0';
	}
	namelen = strlen(buf);
	isc_buffer_init(&b,buf,namelen);
	isc_buffer_add(&b,namelen);
	trans->qname = dns_fixedname_initname(&trans->fixedname);
	result = dns_name_fromtext(trans->qname,&b,dns_rootname,0,NULL);
	if (result != ISC_R_SUCCESS) {
		goto cleanup;
	}

	/* Start resolution */
	result = dns_client_startresolve(client,trans->qname,
					 dns_rdataclass_in,trans->type,0,
					 query_task,process_answer,trans,
					 &trans->xid);
	if (result != ISC_R_SUCCESS) {
		goto cleanup;
	}

	trans->inuse = true;
	outstanding_queries++;

	return (ISC_R_SUCCESS);

 cleanup:
	dns_fixedname_invalidate(&trans->fixedname);

	return (result);
}

ISC_PLATFORM_NORETURN_PRE static void
usage(void) ISC_PLATFORM_NORETURN_POST;

static void
usage(void) {
	fprintf(stderr,"usage: sample-async [-s server_address] [-t RR type] "
		"input_file\n");

	exit(1);
}

int
main(int argc,char*argv[]) {
	int ch;
	isc_textregion_t tr;
	isc_mem_t*mctx = NULL;
	isc_taskmgr_t*taskmgr = NULL;
	isc_socketmgr_t*socketmgr = NULL;
	isc_timermgr_t*timermgr = NULL;
	int nservers = 0;
	const char*serveraddr[MAX_SERVERS];
	isc_sockaddr_t sa[MAX_SERVERS];
	isc_sockaddrlist_t servers;
	dns_rdatatype_t type = dns_rdatatype_a;
	struct in_addr inaddr;
	isc_result_t result;
	int i;

	while ((ch = isc_commandline_parse(argc,argv,"s: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;
		case 's':
			if (nservers == MAX_SERVERS) {
				fprintf(stderr,
					"too many servers (up to %d)\n",
					MAX_SERVERS);
				exit(1);
			}
			serveraddr[nservers++] =
				(const char*)isc_commandline_argument;
			break;
		default:
			usage();
		}
	}

	argc -= isc_commandline_index;
	argv += isc_commandline_index;
	if (argc < 1) {
		usage();
	}

	if (nservers == 0) {
		nservers = 1;
		serveraddr[0] = def_server;
	}

	for (i = 0; i < MAX_QUERIES; i++) {
		query_array[i].id = i;
		query_array[i].inuse = false;
		query_array[i].type = type;
		dns_fixedname_init(&query_array[i].fixedname);
		query_array[i].qname = NULL;
		ISC_LIST_INIT(query_array[i].answerlist);
		query_array[i].xid = NULL;
	}

	isc_lib_register();
	result = dns_lib_init();
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr,"dns_lib_init failed: %u\n",result);
		exit(1);
	}

	result = ctxs_init(&mctx,&query_actx,&taskmgr,&socketmgr,
			   &timermgr);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr,"ctx create failed: %u\n",result);
		exit(1);
	}

	isc_app_ctxstart(query_actx);

	result = dns_client_createx(mctx,query_actx,taskmgr,socketmgr,
				    timermgr,0,&client,NULL,NULL);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr,"dns_client_createx failed: %u\n",result);
		exit(1);
	}

	/* Set nameservers */
	ISC_LIST_INIT(servers);
	for (i = 0; i < nservers; i++) {
		if (inet_pton(AF_INET,serveraddr[i],&inaddr) != 1) {
			fprintf(stderr,"failed to parse IPv4 address %s\n",
				serveraddr[i]);
			exit(1);
		}
		isc_sockaddr_fromin(&sa[i],&inaddr,53);
		ISC_LIST_APPEND(servers,&sa[i],link);
	}
	result = dns_client_setservers(client,dns_rdataclass_in,NULL,
				       &servers);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr,"set server failed: %u\n",result);
		exit(1);
	}

	/* Create the main task */
	query_task = NULL;
	result = isc_task_create(taskmgr,0,&query_task);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr,"failed to create task: %u\n",result);
		exit(1);
	}

	/* Open input file */
	fp = fopen(argv[0],"r");
	if (fp == NULL) {
		fprintf(stderr,"failed to open input file: %s\n",argv[1]);
		exit(1);
	}

	/* Dispatch initial queries */
	for (i = 0; i < MAX_QUERIES; i++) {
		result = dispatch_query(&query_array[i]);
		if (result == ISC_R_NOMORE) {
			break;
		}
	}

	/* Start event loop */
	isc_app_ctxrun(query_actx);

	/* Sanity check */
	for (i = 0; i < MAX_QUERIES; i++)
		INSIST(query_array[i].inuse == false);

	/* Cleanup */
	isc_task_detach(&query_task);
	dns_client_destroy(&client);
	dns_lib_shutdown();
	isc_app_ctxfinish(query_actx);
	ctxs_destroy(&mctx,&query_actx,&taskmgr,&socketmgr,&timermgr);

	return (0);
}