lib/samples/sample-async.c

/*
 * Copyright (C) 2009, 2013-2016  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/.
 */

/* $Id: sample-async.c,v 1.5 2009/09/29 15:06:07 fdupont Exp $ */

#include <config.h>

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

#include <netinet/in.h>

#include <arpa/inet.h>

#include <unistd.h>
#endif

#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;
    isc_boolean_t 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, ISC_FALSE, ISC_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 == ISC_TRUE);
    REQUIRE(outstanding_queries > 0);

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

    if (rev->result != ISC_R_SUCCESS)
        printf("  failed: %d(%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 = ISC_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 (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 == ISC_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);
    dns_fixedname_init(&trans->fixedname);
    trans->qname = dns_fixedname_name(&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 = ISC_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 = ISC_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: %d\n", result);
        exit(1);
    }

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

    isc_app_ctxstart(query_actx);

    result = dns_client_createx(mctx, query_actx, taskmgr, socketmgr,
                    timermgr, 0, &client);
    if (result != ISC_R_SUCCESS) {
        fprintf(stderr, "dns_client_createx failed: %d\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: %d\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: %d\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 == ISC_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);
}