Imported Upstream version 2.1.10

[platform/upstream/libevent.git] / test / regress_dns.c

/*
 * Copyright (c) 2003-2007 Niels Provos <provos@citi.umich.edu>
 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "../util-internal.h"

#ifdef _WIN32
#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#endif

#include "event2/event-config.h"

#include <sys/types.h>
#include <sys/stat.h>
#ifdef EVENT__HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <sys/queue.h>
#ifndef _WIN32
#include <sys/socket.h>
#include <signal.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#endif
#ifdef EVENT__HAVE_NETINET_IN6_H
#include <netinet/in6.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#ifdef EVENT__HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif

#include "event2/dns.h"
#include "event2/dns_compat.h"
#include "event2/dns_struct.h"
#include "event2/event.h"
#include "event2/event_compat.h"
#include "event2/event_struct.h"
#include "event2/util.h"
#include "event2/listener.h"
#include "event2/bufferevent.h"
#include <event2/thread.h>
#include "log-internal.h"
#include "evthread-internal.h"
#include "regress.h"
#include "regress_testutils.h"
#include "regress_thread.h"

#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))

static int dns_ok = 0;
static int dns_got_cancel = 0;
static int dns_err = 0;


static void
dns_gethostbyname_cb(int result, char type, int count, int ttl,
    void *addresses, void *arg)
{
        dns_ok = dns_err = 0;

        if (result == DNS_ERR_TIMEOUT) {
                printf("[Timed out] ");
                dns_err = result;
                goto out;
        }

        if (result != DNS_ERR_NONE) {
                printf("[Error code %d] ", result);
                goto out;
        }

        TT_BLATHER(("type: %d, count: %d, ttl: %d: ", type, count, ttl));

        switch (type) {
        case DNS_IPv6_AAAA: {
#if defined(EVENT__HAVE_STRUCT_IN6_ADDR) && defined(EVENT__HAVE_INET_NTOP) && defined(INET6_ADDRSTRLEN)
                struct in6_addr *in6_addrs = addresses;
                char buf[INET6_ADDRSTRLEN+1];
                int i;
                /* a resolution that's not valid does not help */
                if (ttl < 0)
                        goto out;
                for (i = 0; i < count; ++i) {
                        const char *b = evutil_inet_ntop(AF_INET6, &in6_addrs[i], buf,sizeof(buf));
                        if (b)
                                TT_BLATHER(("%s ", b));
                        else
                                TT_BLATHER(("%s ", strerror(errno)));
                }
#endif
                break;
        }
        case DNS_IPv4_A: {
                struct in_addr *in_addrs = addresses;
                int i;
                /* a resolution that's not valid does not help */
                if (ttl < 0)
                        goto out;
                for (i = 0; i < count; ++i)
                        TT_BLATHER(("%s ", inet_ntoa(in_addrs[i])));
                break;
        }
        case DNS_PTR:
                /* may get at most one PTR */
                if (count != 1)
                        goto out;

                TT_BLATHER(("%s ", *(char **)addresses));
                break;
        default:
                goto out;
        }

        dns_ok = type;

out:
        if (arg == NULL)
                event_loopexit(NULL);
        else
                event_base_loopexit((struct event_base *)arg, NULL);
}

static void
dns_gethostbyname(void)
{
        dns_ok = 0;
        evdns_resolve_ipv4("www.monkey.org", 0, dns_gethostbyname_cb, NULL);
        event_dispatch();

        tt_int_op(dns_ok, ==, DNS_IPv4_A);
        test_ok = dns_ok;
end:
        ;
}

static void
dns_gethostbyname6(void)
{
        dns_ok = 0;
        evdns_resolve_ipv6("www.ietf.org", 0, dns_gethostbyname_cb, NULL);
        event_dispatch();

        if (!dns_ok && dns_err == DNS_ERR_TIMEOUT) {
                tt_skip();
        }

        tt_int_op(dns_ok, ==, DNS_IPv6_AAAA);
        test_ok = 1;
end:
        ;
}

static void
dns_gethostbyaddr(void)
{
        struct in_addr in;
        in.s_addr = htonl(0x7f000001ul); /* 127.0.0.1 */
        dns_ok = 0;
        evdns_resolve_reverse(&in, 0, dns_gethostbyname_cb, NULL);
        event_dispatch();

        tt_int_op(dns_ok, ==, DNS_PTR);
        test_ok = dns_ok;
end:
        ;
}

static void
dns_resolve_reverse(void *ptr)
{
        struct in_addr in;
        struct event_base *base = event_base_new();
        struct evdns_base *dns = evdns_base_new(base, EVDNS_BASE_INITIALIZE_NAMESERVERS);
        struct evdns_request *req = NULL;

        tt_assert(base);
        tt_assert(dns);
        in.s_addr = htonl(0x7f000001ul); /* 127.0.0.1 */
        dns_ok = 0;

        req = evdns_base_resolve_reverse(
                dns, &in, 0, dns_gethostbyname_cb, base);
        tt_assert(req);

        event_base_dispatch(base);

        tt_int_op(dns_ok, ==, DNS_PTR);

end:
        if (dns)
                evdns_base_free(dns, 0);
        if (base)
                event_base_free(base);
}

static int n_server_responses = 0;

static void
dns_server_request_cb(struct evdns_server_request *req, void *data)
{
        int i, r;
        const char TEST_ARPA[] = "11.11.168.192.in-addr.arpa";
        const char TEST_IN6[] =
            "f.e.f.e." "0.0.0.0." "0.0.0.0." "1.1.1.1."
            "a.a.a.a." "0.0.0.0." "0.0.0.0." "0.f.f.f.ip6.arpa";

        for (i = 0; i < req->nquestions; ++i) {
                const int qtype = req->questions[i]->type;
                const int qclass = req->questions[i]->dns_question_class;
                const char *qname = req->questions[i]->name;

                struct in_addr ans;
                ans.s_addr = htonl(0xc0a80b0bUL); /* 192.168.11.11 */
                if (qtype == EVDNS_TYPE_A &&
                    qclass == EVDNS_CLASS_INET &&
                    !evutil_ascii_strcasecmp(qname, "zz.example.com")) {
                        r = evdns_server_request_add_a_reply(req, qname,
                            1, &ans.s_addr, 12345);
                        if (r<0)
                                dns_ok = 0;
                } else if (qtype == EVDNS_TYPE_AAAA &&
                    qclass == EVDNS_CLASS_INET &&
                    !evutil_ascii_strcasecmp(qname, "zz.example.com")) {
                        char addr6[17] = "abcdefghijklmnop";
                        r = evdns_server_request_add_aaaa_reply(req,
                            qname, 1, addr6, 123);
                        if (r<0)
                                dns_ok = 0;
                } else if (qtype == EVDNS_TYPE_PTR &&
                    qclass == EVDNS_CLASS_INET &&
                    !evutil_ascii_strcasecmp(qname, TEST_ARPA)) {
                        r = evdns_server_request_add_ptr_reply(req, NULL,
                            qname, "ZZ.EXAMPLE.COM", 54321);
                        if (r<0)
                                dns_ok = 0;
                } else if (qtype == EVDNS_TYPE_PTR &&
                    qclass == EVDNS_CLASS_INET &&
                    !evutil_ascii_strcasecmp(qname, TEST_IN6)){
                        r = evdns_server_request_add_ptr_reply(req, NULL,
                            qname,
                            "ZZ-INET6.EXAMPLE.COM", 54322);
                        if (r<0)
                                dns_ok = 0;
                } else if (qtype == EVDNS_TYPE_A &&
                    qclass == EVDNS_CLASS_INET &&
                    !evutil_ascii_strcasecmp(qname, "drop.example.com")) {
                        if (evdns_server_request_drop(req)<0)
                                dns_ok = 0;
                        return;
                } else {
                        printf("Unexpected question %d %d \"%s\" ",
                            qtype, qclass, qname);
                        dns_ok = 0;
                }
        }
        r = evdns_server_request_respond(req, 0);
        if (r<0) {
                printf("Couldn't send reply. ");
                dns_ok = 0;
        }
}

static void
dns_server_gethostbyname_cb(int result, char type, int count, int ttl,
    void *addresses, void *arg)
{
        if (result == DNS_ERR_CANCEL) {
                if (arg != (void*)(char*)90909) {
                        printf("Unexpected cancelation");
                        dns_ok = 0;
                }
                dns_got_cancel = 1;
                goto out;
        }
        if (result != DNS_ERR_NONE) {
                printf("Unexpected result %d. ", result);
                dns_ok = 0;
                goto out;
        }
        if (count != 1) {
                printf("Unexpected answer count %d. ", count);
                dns_ok = 0;
                goto out;
        }
        switch (type) {
        case DNS_IPv4_A: {
                struct in_addr *in_addrs = addresses;
                if (in_addrs[0].s_addr != htonl(0xc0a80b0bUL) || ttl != 12345) {
                        printf("Bad IPv4 response \"%s\" %d. ",
                                        inet_ntoa(in_addrs[0]), ttl);
                        dns_ok = 0;
                        goto out;
                }
                break;
        }
        case DNS_IPv6_AAAA: {
#if defined (EVENT__HAVE_STRUCT_IN6_ADDR) && defined(EVENT__HAVE_INET_NTOP) && defined(INET6_ADDRSTRLEN)
                struct in6_addr *in6_addrs = addresses;
                char buf[INET6_ADDRSTRLEN+1];
                if (memcmp(&in6_addrs[0].s6_addr, "abcdefghijklmnop", 16)
                    || ttl != 123) {
                        const char *b = evutil_inet_ntop(AF_INET6, &in6_addrs[0],buf,sizeof(buf));
                        printf("Bad IPv6 response \"%s\" %d. ", b, ttl);
                        dns_ok = 0;
                        goto out;
                }
#endif
                break;
        }
        case DNS_PTR: {
                char **addrs = addresses;
                if (arg != (void*)6) {
                        if (strcmp(addrs[0], "ZZ.EXAMPLE.COM") ||
                            ttl != 54321) {
                                printf("Bad PTR response \"%s\" %d. ",
                                    addrs[0], ttl);
                                dns_ok = 0;
                                goto out;
                        }
                } else {
                        if (strcmp(addrs[0], "ZZ-INET6.EXAMPLE.COM") ||
                            ttl != 54322) {
                                printf("Bad ipv6 PTR response \"%s\" %d. ",
                                    addrs[0], ttl);
                                dns_ok = 0;
                                goto out;
                        }
                }
                break;
        }
        default:
                printf("Bad response type %d. ", type);
                dns_ok = 0;
        }
 out:
        if (++n_server_responses == 3) {
                event_loopexit(NULL);
        }
}

static void
dns_server(void)
{
        evutil_socket_t sock=-1;
        struct sockaddr_in my_addr;
        struct sockaddr_storage ss;
        ev_socklen_t slen;
        struct evdns_server_port *port=NULL;
        struct in_addr resolve_addr;
        struct in6_addr resolve_addr6;
        struct evdns_base *base=NULL;
        struct evdns_request *req=NULL;

        dns_ok = 1;

        base = evdns_base_new(NULL, 0);

        /* Now configure a nameserver port. */
        sock = socket(AF_INET, SOCK_DGRAM, 0);
        if (sock<0) {
                tt_abort_perror("socket");
        }

        evutil_make_socket_nonblocking(sock);

        memset(&my_addr, 0, sizeof(my_addr));
        my_addr.sin_family = AF_INET;
        my_addr.sin_port = 0; /* kernel picks */
        my_addr.sin_addr.s_addr = htonl(0x7f000001UL);
        if (bind(sock, (struct sockaddr*)&my_addr, sizeof(my_addr)) < 0) {
                tt_abort_perror("bind");
        }
        slen = sizeof(ss);
        if (getsockname(sock, (struct sockaddr*)&ss, &slen) < 0) {
                tt_abort_perror("getsockname");
        }

        port = evdns_add_server_port(sock, 0, dns_server_request_cb, NULL);

        /* Add ourself as the only nameserver, and make sure we really are
         * the only nameserver. */
        evdns_base_nameserver_sockaddr_add(base, (struct sockaddr*)&ss, slen, 0);
        tt_int_op(evdns_base_count_nameservers(base), ==, 1);
        {
                struct sockaddr_storage ss2;
                int slen2;

                memset(&ss2, 0, sizeof(ss2));

                slen2 = evdns_base_get_nameserver_addr(base, 0, (struct sockaddr *)&ss2, 3);
                tt_int_op(slen2, ==, slen);
                tt_int_op(ss2.ss_family, ==, 0);
                slen2 = evdns_base_get_nameserver_addr(base, 0, (struct sockaddr *)&ss2, sizeof(ss2));
                tt_int_op(slen2, ==, slen);
                tt_mem_op(&ss2, ==, &ss, slen);

                slen2 = evdns_base_get_nameserver_addr(base, 1, (struct sockaddr *)&ss2, sizeof(ss2));
                tt_int_op(-1, ==, slen2);
        }

        /* Send some queries. */
        evdns_base_resolve_ipv4(base, "zz.example.com", DNS_QUERY_NO_SEARCH,
                                           dns_server_gethostbyname_cb, NULL);
        evdns_base_resolve_ipv6(base, "zz.example.com", DNS_QUERY_NO_SEARCH,
                                           dns_server_gethostbyname_cb, NULL);
        resolve_addr.s_addr = htonl(0xc0a80b0bUL); /* 192.168.11.11 */
        evdns_base_resolve_reverse(base, &resolve_addr, 0,
            dns_server_gethostbyname_cb, NULL);
        memcpy(resolve_addr6.s6_addr,
            "\xff\xf0\x00\x00\x00\x00\xaa\xaa"
            "\x11\x11\x00\x00\x00\x00\xef\xef", 16);
        evdns_base_resolve_reverse_ipv6(base, &resolve_addr6, 0,
            dns_server_gethostbyname_cb, (void*)6);

        req = evdns_base_resolve_ipv4(base,
            "drop.example.com", DNS_QUERY_NO_SEARCH,
            dns_server_gethostbyname_cb, (void*)(char*)90909);

        evdns_cancel_request(base, req);

        event_dispatch();

        tt_assert(dns_got_cancel);
        test_ok = dns_ok;

end:
        if (port)
                evdns_close_server_port(port);
        if (sock >= 0)
                evutil_closesocket(sock);
        if (base)
                evdns_base_free(base, 0);
}

static int n_replies_left;
static struct event_base *exit_base;
static struct evdns_server_port *exit_port;

struct generic_dns_callback_result {
        int result;
        char type;
        int count;
        int ttl;
        size_t addrs_len;
        void *addrs;
        char addrs_buf[256];
};

static void
generic_dns_callback(int result, char type, int count, int ttl, void *addresses,
    void *arg)
{
        size_t len;
        struct generic_dns_callback_result *res = arg;
        res->result = result;
        res->type = type;
        res->count = count;
        res->ttl = ttl;

        if (type == DNS_IPv4_A)
                len = count * 4;
        else if (type == DNS_IPv6_AAAA)
                len = count * 16;
        else if (type == DNS_PTR)
                len = strlen(addresses)+1;
        else {
                res->addrs_len = len = 0;
                res->addrs = NULL;
        }
        if (len) {
                res->addrs_len = len;
                if (len > 256)
                        len = 256;
                memcpy(res->addrs_buf, addresses, len);
                res->addrs = res->addrs_buf;
        }

        --n_replies_left;
        if (n_replies_left == 0) {
                if (exit_port) {
                        evdns_close_server_port(exit_port);
                        exit_port = NULL;
                } else
                        event_base_loopexit(exit_base, NULL);
        }
}

static struct regress_dns_server_table search_table[] = {
        { "host.a.example.com", "err", "3", 0, 0 },
        { "host.b.example.com", "err", "3", 0, 0 },
        { "host.c.example.com", "A", "11.22.33.44", 0, 0 },
        { "host2.a.example.com", "err", "3", 0, 0 },
        { "host2.b.example.com", "A", "200.100.0.100", 0, 0 },
        { "host2.c.example.com", "err", "3", 0, 0 },
        { "hostn.a.example.com", "errsoa", "0", 0, 0 },
        { "hostn.b.example.com", "errsoa", "3", 0, 0 },
        { "hostn.c.example.com", "err", "0", 0, 0 },

        { "host", "err", "3", 0, 0 },
        { "host2", "err", "3", 0, 0 },
        { "*", "err", "3", 0, 0 },
        { NULL, NULL, NULL, 0, 0 }
};
static void
dns_search_test_impl(void *arg, int lower)
{
        struct regress_dns_server_table table[ARRAY_SIZE(search_table)];
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;
        ev_uint16_t portnum = 0;
        char buf[64];

        struct generic_dns_callback_result r[8];
        size_t i;

        for (i = 0; i < ARRAY_SIZE(table); ++i) {
                table[i] = search_table[i];
                table[i].lower = lower;
        }

        tt_assert(regress_dnsserver(base, &portnum, table));
        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, 0);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));

        evdns_base_search_add(dns, "a.example.com");
        evdns_base_search_add(dns, "b.example.com");
        evdns_base_search_add(dns, "c.example.com");

        n_replies_left = ARRAY_SIZE(r);
        exit_base = base;

        evdns_base_resolve_ipv4(dns, "host", 0, generic_dns_callback, &r[0]);
        evdns_base_resolve_ipv4(dns, "host2", 0, generic_dns_callback, &r[1]);
        evdns_base_resolve_ipv4(dns, "host", DNS_NO_SEARCH, generic_dns_callback, &r[2]);
        evdns_base_resolve_ipv4(dns, "host2", DNS_NO_SEARCH, generic_dns_callback, &r[3]);
        evdns_base_resolve_ipv4(dns, "host3", 0, generic_dns_callback, &r[4]);
        evdns_base_resolve_ipv4(dns, "hostn.a.example.com", DNS_NO_SEARCH, generic_dns_callback, &r[5]);
        evdns_base_resolve_ipv4(dns, "hostn.b.example.com", DNS_NO_SEARCH, generic_dns_callback, &r[6]);
        evdns_base_resolve_ipv4(dns, "hostn.c.example.com", DNS_NO_SEARCH, generic_dns_callback, &r[7]);

        event_base_dispatch(base);

        tt_int_op(r[0].type, ==, DNS_IPv4_A);
        tt_int_op(r[0].count, ==, 1);
        tt_int_op(((ev_uint32_t*)r[0].addrs)[0], ==, htonl(0x0b16212c));
        tt_int_op(r[1].type, ==, DNS_IPv4_A);
        tt_int_op(r[1].count, ==, 1);
        tt_int_op(((ev_uint32_t*)r[1].addrs)[0], ==, htonl(0xc8640064));
        tt_int_op(r[2].result, ==, DNS_ERR_NOTEXIST);
        tt_int_op(r[3].result, ==, DNS_ERR_NOTEXIST);
        tt_int_op(r[4].result, ==, DNS_ERR_NOTEXIST);
        tt_int_op(r[5].result, ==, DNS_ERR_NODATA);
        tt_int_op(r[5].ttl, ==, 42);
        tt_int_op(r[6].result, ==, DNS_ERR_NOTEXIST);
        tt_int_op(r[6].ttl, ==, 42);
        tt_int_op(r[7].result, ==, DNS_ERR_NODATA);
        tt_int_op(r[7].ttl, ==, 0);

end:
        if (dns)
                evdns_base_free(dns, 0);

        regress_clean_dnsserver();
}
static void
dns_search_empty_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;

        dns = evdns_base_new(base, 0);

        evdns_base_search_add(dns, "whatever.example.com");

        n_replies_left = 1;
        exit_base = base;

        tt_ptr_op(evdns_base_resolve_ipv4(dns, "", 0, generic_dns_callback, NULL), ==, NULL);

end:
        if (dns)
                evdns_base_free(dns, 0);
}
static void dns_search_test(void *arg) { dns_search_test_impl(arg, 0); }
static void dns_search_lower_test(void *arg) { dns_search_test_impl(arg, 1); }

static int request_count = 0;
static struct evdns_request *current_req = NULL;

static void
search_cancel_server_cb(struct evdns_server_request *req, void *data)
{
        const char *question;

        if (req->nquestions != 1)
                TT_DIE(("Only handling one question at a time; got %d",
                        req->nquestions));

        question = req->questions[0]->name;

        TT_BLATHER(("got question, %s", question));

        tt_assert(request_count > 0);
        tt_assert(!evdns_server_request_respond(req, 3));

        if (!--request_count)
                evdns_cancel_request(NULL, current_req);

end:
        ;
}

static void
dns_search_cancel_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;
        struct evdns_server_port *port = NULL;
        ev_uint16_t portnum = 0;
        struct generic_dns_callback_result r1;
        char buf[64];

        port = regress_get_dnsserver(base, &portnum, NULL,
            search_cancel_server_cb, NULL);
        tt_assert(port);
        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, 0);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));

        evdns_base_search_add(dns, "a.example.com");
        evdns_base_search_add(dns, "b.example.com");
        evdns_base_search_add(dns, "c.example.com");
        evdns_base_search_add(dns, "d.example.com");

        exit_base = base;
        request_count = 3;
        n_replies_left = 1;

        current_req = evdns_base_resolve_ipv4(dns, "host", 0,
                                        generic_dns_callback, &r1);
        event_base_dispatch(base);

        tt_int_op(r1.result, ==, DNS_ERR_CANCEL);

end:
        if (port)
                evdns_close_server_port(port);
        if (dns)
                evdns_base_free(dns, 0);
}

static void
fail_server_cb(struct evdns_server_request *req, void *data)
{
        const char *question;
        int *count = data;
        struct in_addr in;

        /* Drop the first N requests that we get. */
        if (*count > 0) {
                --*count;
                tt_want(! evdns_server_request_drop(req));
                return;
        }

        if (req->nquestions != 1)
                TT_DIE(("Only handling one question at a time; got %d",
                        req->nquestions));

        question = req->questions[0]->name;

        if (!evutil_ascii_strcasecmp(question, "google.com")) {
                /* Detect a probe, and get out of the loop. */
                event_base_loopexit(exit_base, NULL);
        }

        tt_assert(evutil_inet_pton(AF_INET, "16.32.64.128", &in));
        evdns_server_request_add_a_reply(req, question, 1, &in.s_addr,
            100);
        tt_assert(! evdns_server_request_respond(req, 0))
        return;
end:
        tt_want(! evdns_server_request_drop(req));
}

static void
dns_retry_test_impl(void *arg, int flags)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_server_port *port = NULL;
        struct evdns_base *dns = NULL;
        int drop_count = 2;
        ev_uint16_t portnum = 0;
        char buf[64];

        struct generic_dns_callback_result r1;

        port = regress_get_dnsserver(base, &portnum, NULL,
            fail_server_cb, &drop_count);
        tt_assert(port);
        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, flags);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));
        tt_assert(! evdns_base_set_option(dns, "timeout", "0.2"));
        tt_assert(! evdns_base_set_option(dns, "max-timeouts:", "10"));
        tt_assert(! evdns_base_set_option(dns, "initial-probe-timeout", "0.1"));

        evdns_base_resolve_ipv4(dns, "host.example.com", 0,
            generic_dns_callback, &r1);

        n_replies_left = 1;
        exit_base = base;

        event_base_dispatch(base);

        tt_int_op(drop_count, ==, 0);

        tt_int_op(r1.type, ==, DNS_IPv4_A);
        tt_int_op(r1.count, ==, 1);
        tt_int_op(((ev_uint32_t*)r1.addrs)[0], ==, htonl(0x10204080));

        /* Now try again, but this time have the server get treated as
         * failed, so we can send it a test probe. */
        drop_count = 4;
        tt_assert(! evdns_base_set_option(dns, "max-timeouts:", "2"));
        tt_assert(! evdns_base_set_option(dns, "attempts:", "3"));
        memset(&r1, 0, sizeof(r1));

        evdns_base_resolve_ipv4(dns, "host.example.com", 0,
            generic_dns_callback, &r1);

        n_replies_left = 2;

        /* This will run until it answers the "google.com" probe request. */
        event_base_dispatch(base);

        /* We'll treat the server as failed here. */
        tt_int_op(r1.result, ==, DNS_ERR_TIMEOUT);

        /* It should work this time. */
        tt_int_op(drop_count, ==, 0);
        evdns_base_resolve_ipv4(dns, "host.example.com", 0,
            generic_dns_callback, &r1);

        event_base_dispatch(base);
        tt_int_op(r1.result, ==, DNS_ERR_NONE);
        tt_int_op(r1.type, ==, DNS_IPv4_A);
        tt_int_op(r1.count, ==, 1);
        tt_int_op(((ev_uint32_t*)r1.addrs)[0], ==, htonl(0x10204080));

end:
        if (dns)
                evdns_base_free(dns, 0);
        if (port)
                evdns_close_server_port(port);
}
static void
dns_retry_test(void *arg)
{
        dns_retry_test_impl(arg, 0);
}
static void
dns_retry_disable_when_inactive_test(void *arg)
{
        dns_retry_test_impl(arg, EVDNS_BASE_DISABLE_WHEN_INACTIVE);
}

static struct regress_dns_server_table internal_error_table[] = {
        /* Error 4 (NOTIMPL) makes us reissue the request to another server
           if we can.

           XXXX we should reissue under a much wider set of circumstances!
         */
        { "foof.example.com", "err", "4", 0, 0 },
        { NULL, NULL, NULL, 0, 0 }
};

static struct regress_dns_server_table reissue_table[] = {
        { "foof.example.com", "A", "240.15.240.15", 0, 0 },
        { NULL, NULL, NULL, 0, 0 }
};

static void
dns_reissue_test_impl(void *arg, int flags)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_server_port *port1 = NULL, *port2 = NULL;
        struct evdns_base *dns = NULL;
        struct generic_dns_callback_result r1;
        ev_uint16_t portnum1 = 0, portnum2=0;
        char buf1[64], buf2[64];

        port1 = regress_get_dnsserver(base, &portnum1, NULL,
            regress_dns_server_cb, internal_error_table);
        tt_assert(port1);
        port2 = regress_get_dnsserver(base, &portnum2, NULL,
            regress_dns_server_cb, reissue_table);
        tt_assert(port2);
        evutil_snprintf(buf1, sizeof(buf1), "127.0.0.1:%d", (int)portnum1);
        evutil_snprintf(buf2, sizeof(buf2), "127.0.0.1:%d", (int)portnum2);

        dns = evdns_base_new(base, flags);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf1));
        tt_assert(! evdns_base_set_option(dns, "timeout:", "0.3"));
        tt_assert(! evdns_base_set_option(dns, "max-timeouts:", "2"));
        tt_assert(! evdns_base_set_option(dns, "attempts:", "5"));

        memset(&r1, 0, sizeof(r1));
        evdns_base_resolve_ipv4(dns, "foof.example.com", 0,
            generic_dns_callback, &r1);

        /* Add this after, so that we are sure to get a reissue. */
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf2));

        n_replies_left = 1;
        exit_base = base;

        event_base_dispatch(base);
        tt_int_op(r1.result, ==, DNS_ERR_NONE);
        tt_int_op(r1.type, ==, DNS_IPv4_A);
        tt_int_op(r1.count, ==, 1);
        tt_int_op(((ev_uint32_t*)r1.addrs)[0], ==, htonl(0xf00ff00f));

        /* Make sure we dropped at least once. */
        tt_int_op(internal_error_table[0].seen, >, 0);

end:
        if (dns)
                evdns_base_free(dns, 0);
        if (port1)
                evdns_close_server_port(port1);
        if (port2)
                evdns_close_server_port(port2);
}
static void
dns_reissue_test(void *arg)
{
        dns_reissue_test_impl(arg, 0);
}
static void
dns_reissue_disable_when_inactive_test(void *arg)
{
        dns_reissue_test_impl(arg, EVDNS_BASE_DISABLE_WHEN_INACTIVE);
}

#if 0
static void
dumb_bytes_fn(char *p, size_t n)
{
        unsigned i;
        /* This gets us 6 bits of entropy per transaction ID, which means we
         * will have probably have collisions and need to pick again. */
        for (i=0;i<n;++i)
                p[i] = (char)(rand() & 7);
}
#endif

static void
dns_inflight_test_impl(void *arg, int flags)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;
        struct evdns_server_port *dns_port = NULL;
        ev_uint16_t portnum = 0;
        char buf[64];
        int disable_when_inactive = flags & EVDNS_BASE_DISABLE_WHEN_INACTIVE;

        struct generic_dns_callback_result r[20];
        int i;

        dns_port = regress_get_dnsserver(base, &portnum, NULL,
                regress_dns_server_cb, reissue_table);
        tt_assert(dns_port);
        if (disable_when_inactive) {
                exit_port = dns_port;
        }

        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, flags);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));
        tt_assert(! evdns_base_set_option(dns, "max-inflight:", "3"));
        tt_assert(! evdns_base_set_option(dns, "randomize-case:", "0"));

        for (i=0;i<20;++i)
                evdns_base_resolve_ipv4(dns, "foof.example.com", 0, generic_dns_callback, &r[i]);

        n_replies_left = 20;
        exit_base = base;

        event_base_dispatch(base);

        for (i=0;i<20;++i) {
                tt_int_op(r[i].type, ==, DNS_IPv4_A);
                tt_int_op(r[i].count, ==, 1);
                tt_int_op(((ev_uint32_t*)r[i].addrs)[0], ==, htonl(0xf00ff00f));
        }

end:
        if (dns)
                evdns_base_free(dns, 0);
        if (exit_port) {
                evdns_close_server_port(exit_port);
                exit_port = NULL;
        } else if (! disable_when_inactive) {
                evdns_close_server_port(dns_port);
        }
}

static void
dns_inflight_test(void *arg)
{
        dns_inflight_test_impl(arg, 0);
}

static void
dns_disable_when_inactive_test(void *arg)
{
        dns_inflight_test_impl(arg, EVDNS_BASE_DISABLE_WHEN_INACTIVE);
}

static void
dns_disable_when_inactive_no_ns_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base, *inactive_base;
        struct evdns_base *dns = NULL;
        ev_uint16_t portnum = 0;
        char buf[64];
        struct generic_dns_callback_result r;

        inactive_base = event_base_new();
        tt_assert(inactive_base);

        /** Create dns server with inactive base, to avoid replying to clients */
        tt_assert(regress_dnsserver(inactive_base, &portnum, search_table));
        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, EVDNS_BASE_DISABLE_WHEN_INACTIVE);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));
        tt_assert(! evdns_base_set_option(dns, "timeout:", "0.1"));

        evdns_base_resolve_ipv4(dns, "foof.example.com", 0, generic_dns_callback, &r);
        n_replies_left = 1;
        exit_base = base;

        event_base_dispatch(base);

        tt_int_op(n_replies_left, ==, 0);

        tt_int_op(r.result, ==, DNS_ERR_TIMEOUT);
        tt_int_op(r.count, ==, 0);
        tt_ptr_op(r.addrs, ==, NULL);

end:
        if (dns)
                evdns_base_free(dns, 0);
        regress_clean_dnsserver();
        if (inactive_base)
                event_base_free(inactive_base);
}

static void
dns_initialize_nameservers_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;

        dns = evdns_base_new(base, 0);
        tt_assert(dns);
        tt_int_op(evdns_base_get_nameserver_addr(dns, 0, NULL, 0), ==, -1);
        evdns_base_free(dns, 0);

        dns = evdns_base_new(base, EVDNS_BASE_INITIALIZE_NAMESERVERS);
        tt_assert(dns);
        tt_int_op(evdns_base_get_nameserver_addr(dns, 0, NULL, 0), ==, sizeof(struct sockaddr));

end:
        if (dns)
                evdns_base_free(dns, 0);
}
#ifndef _WIN32
#define RESOLV_FILE "empty-resolv.conf"
static void
dns_nameservers_no_default_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;
        int ok = access(RESOLV_FILE, R_OK);

        tt_assert(ok);

        dns = evdns_base_new(base, 0);
        tt_assert(dns);
        tt_int_op(evdns_base_get_nameserver_addr(dns, 0, NULL, 0), ==, -1);

        /* We cannot test
         * EVDNS_BASE_INITIALIZE_NAMESERVERS|EVDNS_BASE_NAMESERVERS_NO_DEFAULT
         * because we cannot mock "/etc/resolv.conf" (yet). */

        evdns_base_resolv_conf_parse(dns,
                DNS_OPTIONS_ALL|DNS_OPTION_NAMESERVERS_NO_DEFAULT, RESOLV_FILE);
        tt_int_op(evdns_base_get_nameserver_addr(dns, 0, NULL, 0), ==, -1);

        evdns_base_resolv_conf_parse(dns, DNS_OPTIONS_ALL, RESOLV_FILE);
        tt_int_op(evdns_base_get_nameserver_addr(dns, 0, NULL, 0), ==, sizeof(struct sockaddr));

end:
        if (dns)
                evdns_base_free(dns, 0);
}
#endif

/* === Test for bufferevent_socket_connect_hostname */

static int total_connected_or_failed = 0;
static int total_n_accepted = 0;
static struct event_base *be_connect_hostname_base = NULL;

/* Implements a DNS server for the connect_hostname test and the
 * getaddrinfo_async test */
static void
be_getaddrinfo_server_cb(struct evdns_server_request *req, void *data)
{
        int i;
        int *n_got_p=data;
        int added_any=0;
        ++*n_got_p;

        for (i = 0; i < req->nquestions; ++i) {
                const int qtype = req->questions[i]->type;
                const int qclass = req->questions[i]->dns_question_class;
                const char *qname = req->questions[i]->name;
                struct in_addr ans;
                struct in6_addr ans6;
                memset(&ans6, 0, sizeof(ans6));

                TT_BLATHER(("Got question about %s, type=%d", qname, qtype));

                if (qtype == EVDNS_TYPE_A &&
                    qclass == EVDNS_CLASS_INET &&
                    !evutil_ascii_strcasecmp(qname, "nobodaddy.example.com")) {
                        ans.s_addr = htonl(0x7f000001);
                        evdns_server_request_add_a_reply(req, qname,
                            1, &ans.s_addr, 2000);
                        added_any = 1;
                } else if (!evutil_ascii_strcasecmp(qname,
                        "nosuchplace.example.com")) {
                        /* ok, just say notfound. */
                } else if (!evutil_ascii_strcasecmp(qname,
                        "both.example.com")) {
                        if (qtype == EVDNS_TYPE_A) {
                                ans.s_addr = htonl(0x50502020);
                                evdns_server_request_add_a_reply(req, qname,
                                    1, &ans.s_addr, 2000);
                                added_any = 1;
                        } else if (qtype == EVDNS_TYPE_AAAA) {
                                ans6.s6_addr[0] = 0x80;
                                ans6.s6_addr[1] = 0xff;
                                ans6.s6_addr[14] = 0xbb;
                                ans6.s6_addr[15] = 0xbb;
                                evdns_server_request_add_aaaa_reply(req, qname,
                                    1, &ans6.s6_addr, 2000);
                                added_any = 1;
                        }
                        evdns_server_request_add_cname_reply(req, qname,
                            "both-canonical.example.com", 1000);
                } else if (!evutil_ascii_strcasecmp(qname,
                        "v4only.example.com") ||
                    !evutil_ascii_strcasecmp(qname, "v4assert.example.com")) {
                        if (qtype == EVDNS_TYPE_A) {
                                ans.s_addr = htonl(0x12345678);
                                evdns_server_request_add_a_reply(req, qname,
                                    1, &ans.s_addr, 2000);
                                added_any = 1;
                        } else if (!evutil_ascii_strcasecmp(qname,
                                "v4assert.example.com")) {
                                TT_FAIL(("Got an AAAA request for v4assert"));
                        }
                } else if (!evutil_ascii_strcasecmp(qname,
                        "v6only.example.com") ||
                    !evutil_ascii_strcasecmp(qname, "v6assert.example.com")) {
                        if (qtype == EVDNS_TYPE_AAAA) {
                                ans6.s6_addr[0] = 0x0b;
                                ans6.s6_addr[1] = 0x0b;
                                ans6.s6_addr[14] = 0xf0;
                                ans6.s6_addr[15] = 0x0d;
                                evdns_server_request_add_aaaa_reply(req, qname,
                                    1, &ans6.s6_addr, 2000);
                                added_any = 1;
                        }  else if (!evutil_ascii_strcasecmp(qname,
                                "v6assert.example.com")) {
                                TT_FAIL(("Got a A request for v6assert"));
                        }
                } else if (!evutil_ascii_strcasecmp(qname,
                        "v6timeout.example.com")) {
                        if (qtype == EVDNS_TYPE_A) {
                                ans.s_addr = htonl(0xabcdef01);
                                evdns_server_request_add_a_reply(req, qname,
                                    1, &ans.s_addr, 2000);
                                added_any = 1;
                        } else if (qtype == EVDNS_TYPE_AAAA) {
                                /* Let the v6 request time out.*/
                                evdns_server_request_drop(req);
                                return;
                        }
                } else if (!evutil_ascii_strcasecmp(qname,
                        "v4timeout.example.com")) {
                        if (qtype == EVDNS_TYPE_AAAA) {
                                ans6.s6_addr[0] = 0x0a;
                                ans6.s6_addr[1] = 0x0a;
                                ans6.s6_addr[14] = 0xff;
                                ans6.s6_addr[15] = 0x01;
                                evdns_server_request_add_aaaa_reply(req, qname,
                                    1, &ans6.s6_addr, 2000);
                                added_any = 1;
                        } else if (qtype == EVDNS_TYPE_A) {
                                /* Let the v4 request time out.*/
                                evdns_server_request_drop(req);
                                return;
                        }
                } else if (!evutil_ascii_strcasecmp(qname,
                        "v6timeout-nonexist.example.com")) {
                        if (qtype == EVDNS_TYPE_A) {
                                /* Fall through, give an nexist. */
                        } else if (qtype == EVDNS_TYPE_AAAA) {
                                /* Let the v6 request time out.*/
                                evdns_server_request_drop(req);
                                return;
                        }
                } else if (!evutil_ascii_strcasecmp(qname,
                        "all-timeout.example.com")) {
                        /* drop all requests */
                        evdns_server_request_drop(req);
                        return;
                } else {
                        TT_GRIPE(("Got weird request for %s",qname));
                }
        }
        if (added_any) {
                TT_BLATHER(("answering"));
                evdns_server_request_respond(req, 0);
        } else {
                TT_BLATHER(("saying nexist."));
                evdns_server_request_respond(req, 3);
        }
}

/* Implements a listener for connect_hostname test. */
static void
nil_accept_cb(struct evconnlistener *l, evutil_socket_t fd, struct sockaddr *s,
    int socklen, void *arg)
{
        int *p = arg;
        (*p)++;
        ++total_n_accepted;
        /* don't do anything with the socket; let it close when we exit() */
        if (total_n_accepted >= 3 && total_connected_or_failed >= 5)
                event_base_loopexit(be_connect_hostname_base,
                    NULL);
}

struct be_conn_hostname_result {
        int dnserr;
        int what;
};

/* Bufferevent event callback for the connect_hostname test: remembers what
 * event we got. */
static void
be_connect_hostname_event_cb(struct bufferevent *bev, short what, void *ctx)
{
        struct be_conn_hostname_result *got = ctx;

        if (got->what) {
                TT_FAIL(("Two events on one bufferevent. %d,%d",
                        got->what, (int)what));
        }

        TT_BLATHER(("Got a bufferevent event %d", what));
        got->what = what;

        if ((what & BEV_EVENT_CONNECTED) || (what & BEV_EVENT_ERROR)) {
                int expected = 3;
                int r = bufferevent_socket_get_dns_error(bev);

                if (r) {
                        got->dnserr = r;
                        TT_BLATHER(("DNS error %d: %s", r,
                                   evutil_gai_strerror(r)));
                }
                ++total_connected_or_failed;
                TT_BLATHER(("Got %d connections or errors.", total_connected_or_failed));

                /** emfile test */
                if (errno == EMFILE) {
                        expected = 0;
                }

                if (total_n_accepted >= expected && total_connected_or_failed >= 5)
                        event_base_loopexit(be_connect_hostname_base,
                            NULL);
        }
}

static void
test_bufferevent_connect_hostname(void *arg)
{
        struct basic_test_data *data = arg;
        struct evconnlistener *listener = NULL;
        struct bufferevent *be[5];
        struct be_conn_hostname_result be_outcome[ARRAY_SIZE(be)];
        int expect_err;
        struct evdns_base *dns=NULL;
        struct evdns_server_port *port=NULL;
        struct sockaddr_in sin;
        int listener_port=-1;
        ev_uint16_t dns_port=0;
        int n_accept=0, n_dns=0;
        char buf[128];
        int emfile = data->setup_data && !strcmp(data->setup_data, "emfile");
        int success = BEV_EVENT_CONNECTED;
        int default_error = 0;
        unsigned i;
        int ret;

        if (emfile) {
                success = BEV_EVENT_ERROR;
#if defined(__linux__)
                /* on linux glibc/musl reports EAI_SYSTEM, when getaddrinfo() cannot
                 * open file for resolving service. */
                default_error = EVUTIL_EAI_SYSTEM;
#elif defined(__sun__)
                /* on solaris it returns EAI_FAIL */
                default_error = EVUTIL_EAI_FAIL;
                /** the DP_POLL can also fail with EINVAL under EMFILE */
#else
                /* on osx/freebsd it returns EAI_NONAME */
                default_error = EVUTIL_EAI_NONAME;
#endif
        }

        be_connect_hostname_base = data->base;

        /* Bind an address and figure out what port it's on. */
        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = htonl(0x7f000001); /* 127.0.0.1 */
        sin.sin_port = 0;
        listener = evconnlistener_new_bind(data->base, nil_accept_cb,
            &n_accept,
            LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_EXEC,
            -1, (struct sockaddr *)&sin, sizeof(sin));
        tt_assert(listener);
        listener_port = regress_get_socket_port(
                evconnlistener_get_fd(listener));

        port = regress_get_dnsserver(data->base, &dns_port, NULL,
            be_getaddrinfo_server_cb, &n_dns);
        tt_assert(port);
        tt_int_op(dns_port, >=, 0);

        /* Start an evdns_base that uses the server as its resolver. */
        dns = evdns_base_new(data->base, 0);
        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)dns_port);
        evdns_base_nameserver_ip_add(dns, buf);

#ifdef EVENT__HAVE_SETRLIMIT
        if (emfile) {
                int fd = socket(AF_INET, SOCK_STREAM, 0);
                struct rlimit file = { fd, fd };

                tt_int_op(fd, >=, 0);
                tt_assert(!close(fd));

                tt_assert(!setrlimit(RLIMIT_NOFILE, &file));
        }
#endif

        /* Now, finally, at long last, launch the bufferevents.  One should do
         * a failing lookup IP, one should do a successful lookup by IP,
         * and one should do a successful lookup by hostname. */
        for (i = 0; i < ARRAY_SIZE(be); ++i) {
                memset(&be_outcome[i], 0, sizeof(be_outcome[i]));
                be[i] = bufferevent_socket_new(data->base, -1, BEV_OPT_CLOSE_ON_FREE);
                bufferevent_setcb(be[i], NULL, NULL, be_connect_hostname_event_cb,
                        &be_outcome[i]);
        }

        /* Use the blocking resolver.  This one will fail if your resolver
         * can't resolve localhost to 127.0.0.1 */
        tt_assert(!bufferevent_socket_connect_hostname(be[3], NULL, AF_INET,
                "localhost", listener_port));
        /* Use the blocking resolver with a nonexistent hostname. */
        tt_assert(!bufferevent_socket_connect_hostname(be[4], NULL, AF_INET,
                "nonesuch.nowhere.example.com", 80));
        {
                /* The blocking resolver will use the system nameserver, which
                 * might tell us anything.  (Yes, some twits even pretend that
                 * example.com is real.) Let's see what answer to expect. */
                struct evutil_addrinfo hints, *ai = NULL;
                memset(&hints, 0, sizeof(hints));
                hints.ai_family = AF_INET;
                hints.ai_socktype = SOCK_STREAM;
                hints.ai_protocol = IPPROTO_TCP;
                expect_err = evutil_getaddrinfo(
                        "nonesuch.nowhere.example.com", "80", &hints, &ai);
        }
        /* Launch an async resolve that will fail. */
        tt_assert(!bufferevent_socket_connect_hostname(be[0], dns, AF_INET,
                "nosuchplace.example.com", listener_port));
        /* Connect to the IP without resolving. */
        tt_assert(!bufferevent_socket_connect_hostname(be[1], dns, AF_INET,
                "127.0.0.1", listener_port));
        /* Launch an async resolve that will succeed. */
        tt_assert(!bufferevent_socket_connect_hostname(be[2], dns, AF_INET,
                "nobodaddy.example.com", listener_port));

        ret = event_base_dispatch(data->base);
#ifdef __sun__
        if (emfile && !strcmp(event_base_get_method(data->base), "devpoll")) {
                tt_int_op(ret, ==, -1);
                /** DP_POLL failed */
                tt_skip();
        } else
#endif
        {
                tt_int_op(ret, ==, 0);
        }

        tt_int_op(be_outcome[0].what, ==, BEV_EVENT_ERROR);
        tt_int_op(be_outcome[0].dnserr, ==, EVUTIL_EAI_NONAME);
        tt_int_op(be_outcome[1].what, ==, success);
        tt_int_op(be_outcome[1].dnserr, ==, 0);
        tt_int_op(be_outcome[2].what, ==, success);
        tt_int_op(be_outcome[2].dnserr, ==, 0);
        tt_int_op(be_outcome[3].what, ==, success);
        tt_int_op(be_outcome[3].dnserr, ==, default_error);
        if (expect_err) {
                tt_int_op(be_outcome[4].what, ==, BEV_EVENT_ERROR);
                tt_int_op(be_outcome[4].dnserr, ==, expect_err);
        }

        if (emfile) {
                tt_int_op(n_accept, ==, 0);
        } else {
                tt_int_op(n_accept, ==, 3);
        }
        tt_int_op(n_dns, ==, 2);

end:
        if (listener)
                evconnlistener_free(listener);
        if (port)
                evdns_close_server_port(port);
        if (dns)
                evdns_base_free(dns, 0);
        for (i = 0; i < ARRAY_SIZE(be); ++i) {
                if (be[i])
                        bufferevent_free(be[i]);
        }
}


struct gai_outcome {
        int err;
        struct evutil_addrinfo *ai;
};

static int n_gai_results_pending = 0;
static struct event_base *exit_base_on_no_pending_results = NULL;

static void
gai_cb(int err, struct evutil_addrinfo *res, void *ptr)
{
        struct gai_outcome *go = ptr;
        go->err = err;
        go->ai = res;
        if (--n_gai_results_pending <= 0 && exit_base_on_no_pending_results)
                event_base_loopexit(exit_base_on_no_pending_results, NULL);
        if (n_gai_results_pending < 900)
                TT_BLATHER(("Got an answer; expecting %d more.",
                        n_gai_results_pending));
}

static void
cancel_gai_cb(evutil_socket_t fd, short what, void *ptr)
{
        struct evdns_getaddrinfo_request *r = ptr;
        evdns_getaddrinfo_cancel(r);
}

static void
test_getaddrinfo_async(void *arg)
{
        struct basic_test_data *data = arg;
        struct evutil_addrinfo hints, *a;
        struct gai_outcome local_outcome;
        struct gai_outcome a_out[12];
        unsigned i;
        struct evdns_getaddrinfo_request *r;
        char buf[128];
        struct evdns_server_port *port = NULL;
        ev_uint16_t dns_port = 0;
        int n_dns_questions = 0;
        struct evdns_base *dns_base;

        memset(a_out, 0, sizeof(a_out));
        memset(&local_outcome, 0, sizeof(local_outcome));

        dns_base = evdns_base_new(data->base, 0);
        tt_assert(dns_base);

        /* for localhost */
        evdns_base_load_hosts(dns_base, NULL);

        tt_assert(! evdns_base_set_option(dns_base, "timeout", "0.3"));
        tt_assert(! evdns_base_set_option(dns_base, "getaddrinfo-allow-skew", "0.2"));

        n_gai_results_pending = 10000; /* don't think about exiting yet. */

        /* 1. Try some cases that will never hit the asynchronous resolver. */
        /* 1a. Simple case with a symbolic service name */
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = PF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
        memset(&local_outcome, 0, sizeof(local_outcome));
        r = evdns_getaddrinfo(dns_base, "1.2.3.4", "http",
            &hints, gai_cb, &local_outcome);
        tt_assert(! r);
        if (!local_outcome.err) {
                tt_ptr_op(local_outcome.ai,!=,NULL);
                test_ai_eq(local_outcome.ai, "1.2.3.4:80", SOCK_STREAM, IPPROTO_TCP);
                evutil_freeaddrinfo(local_outcome.ai);
                local_outcome.ai = NULL;
        } else {
                TT_BLATHER(("Apparently we have no getservbyname."));
        }

        /* 1b. EVUTIL_AI_NUMERICHOST is set */
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = PF_UNSPEC;
        hints.ai_flags = EVUTIL_AI_NUMERICHOST;
        memset(&local_outcome, 0, sizeof(local_outcome));
        r = evdns_getaddrinfo(dns_base, "www.google.com", "80",
            &hints, gai_cb, &local_outcome);
        tt_ptr_op(r,==,NULL);
        tt_int_op(local_outcome.err,==,EVUTIL_EAI_NONAME);
        tt_ptr_op(local_outcome.ai,==,NULL);

        /* 1c. We give a numeric address (ipv6) */
        memset(&hints, 0, sizeof(hints));
        memset(&local_outcome, 0, sizeof(local_outcome));
        hints.ai_family = PF_UNSPEC;
        hints.ai_protocol = IPPROTO_TCP;
        r = evdns_getaddrinfo(dns_base, "f::f", "8008",
            &hints, gai_cb, &local_outcome);
        tt_assert(!r);
        tt_int_op(local_outcome.err,==,0);
        tt_assert(local_outcome.ai);
        tt_ptr_op(local_outcome.ai->ai_next,==,NULL);
        test_ai_eq(local_outcome.ai, "[f::f]:8008", SOCK_STREAM, IPPROTO_TCP);
        evutil_freeaddrinfo(local_outcome.ai);
        local_outcome.ai = NULL;

        /* 1d. We give a numeric address (ipv4) */
        memset(&hints, 0, sizeof(hints));
        memset(&local_outcome, 0, sizeof(local_outcome));
        hints.ai_family = PF_UNSPEC;
        r = evdns_getaddrinfo(dns_base, "5.6.7.8", NULL,
            &hints, gai_cb, &local_outcome);
        tt_assert(!r);
        tt_int_op(local_outcome.err,==,0);
        tt_assert(local_outcome.ai);
        a = ai_find_by_protocol(local_outcome.ai, IPPROTO_TCP);
        tt_assert(a);
        test_ai_eq(a, "5.6.7.8", SOCK_STREAM, IPPROTO_TCP);
        a = ai_find_by_protocol(local_outcome.ai, IPPROTO_UDP);
        tt_assert(a);
        test_ai_eq(a, "5.6.7.8", SOCK_DGRAM, IPPROTO_UDP);
        evutil_freeaddrinfo(local_outcome.ai);
        local_outcome.ai = NULL;

        /* 1e. nodename is NULL (bind) */
        memset(&hints, 0, sizeof(hints));
        memset(&local_outcome, 0, sizeof(local_outcome));
        hints.ai_family = PF_UNSPEC;
        hints.ai_socktype = SOCK_DGRAM;
        hints.ai_flags = EVUTIL_AI_PASSIVE;
        r = evdns_getaddrinfo(dns_base, NULL, "9090",
            &hints, gai_cb, &local_outcome);
        tt_assert(!r);
        tt_int_op(local_outcome.err,==,0);
        tt_assert(local_outcome.ai);
        /* we should get a v4 address of 0.0.0.0... */
        a = ai_find_by_family(local_outcome.ai, PF_INET);
        tt_assert(a);
        test_ai_eq(a, "0.0.0.0:9090", SOCK_DGRAM, IPPROTO_UDP);
        /* ... and a v6 address of ::0 */
        a = ai_find_by_family(local_outcome.ai, PF_INET6);
        tt_assert(a);
        test_ai_eq(a, "[::]:9090", SOCK_DGRAM, IPPROTO_UDP);
        evutil_freeaddrinfo(local_outcome.ai);
        local_outcome.ai = NULL;

        /* 1f. nodename is NULL (connect) */
        memset(&hints, 0, sizeof(hints));
        memset(&local_outcome, 0, sizeof(local_outcome));
        hints.ai_family = PF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
        r = evdns_getaddrinfo(dns_base, NULL, "2",
            &hints, gai_cb, &local_outcome);
        tt_assert(!r);
        tt_int_op(local_outcome.err,==,0);
        tt_assert(local_outcome.ai);
        /* we should get a v4 address of 127.0.0.1 .... */
        a = ai_find_by_family(local_outcome.ai, PF_INET);
        tt_assert(a);
        test_ai_eq(a, "127.0.0.1:2", SOCK_STREAM, IPPROTO_TCP);
        /* ... and a v6 address of ::1 */
        a = ai_find_by_family(local_outcome.ai, PF_INET6);
        tt_assert(a);
        test_ai_eq(a, "[::1]:2", SOCK_STREAM, IPPROTO_TCP);
        evutil_freeaddrinfo(local_outcome.ai);
        local_outcome.ai = NULL;

        /* 1g. We find localhost immediately. (pf_unspec) */
        memset(&hints, 0, sizeof(hints));
        memset(&local_outcome, 0, sizeof(local_outcome));
        hints.ai_family = PF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
        r = evdns_getaddrinfo(dns_base, "LOCALHOST", "80",
            &hints, gai_cb, &local_outcome);
        tt_assert(!r);
        tt_int_op(local_outcome.err,==,0);
        tt_assert(local_outcome.ai);
        /* we should get a v4 address of 127.0.0.1 .... */
        a = ai_find_by_family(local_outcome.ai, PF_INET);
        tt_assert(a);
        test_ai_eq(a, "127.0.0.1:80", SOCK_STREAM, IPPROTO_TCP);
        /* ... and a v6 address of ::1 */
        a = ai_find_by_family(local_outcome.ai, PF_INET6);
        tt_assert(a);
        test_ai_eq(a, "[::1]:80", SOCK_STREAM, IPPROTO_TCP);
        evutil_freeaddrinfo(local_outcome.ai);
        local_outcome.ai = NULL;

        /* 1g. We find localhost immediately. (pf_inet6) */
        memset(&hints, 0, sizeof(hints));
        memset(&local_outcome, 0, sizeof(local_outcome));
        hints.ai_family = PF_INET6;
        hints.ai_socktype = SOCK_STREAM;
        r = evdns_getaddrinfo(dns_base, "LOCALHOST", "9999",
            &hints, gai_cb, &local_outcome);
        tt_assert(! r);
        tt_int_op(local_outcome.err,==,0);
        tt_assert(local_outcome.ai);
        a = local_outcome.ai;
        test_ai_eq(a, "[::1]:9999", SOCK_STREAM, IPPROTO_TCP);
        tt_ptr_op(a->ai_next, ==, NULL);
        evutil_freeaddrinfo(local_outcome.ai);
        local_outcome.ai = NULL;

        /* 2. Okay, now we can actually test the asynchronous resolver. */
        /* Start a dummy local dns server... */
        port = regress_get_dnsserver(data->base, &dns_port, NULL,
            be_getaddrinfo_server_cb, &n_dns_questions);
        tt_assert(port);
        tt_int_op(dns_port, >=, 0);
        /* ... and tell the evdns_base about it. */
        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", dns_port);
        evdns_base_nameserver_ip_add(dns_base, buf);

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = PF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_flags = EVUTIL_AI_CANONNAME;
        /* 0: Request for both.example.com should return both addresses. */
        r = evdns_getaddrinfo(dns_base, "both.example.com", "8000",
            &hints, gai_cb, &a_out[0]);
        tt_assert(r);

        /* 1: Request for v4only.example.com should return one address. */
        r = evdns_getaddrinfo(dns_base, "v4only.example.com", "8001",
            &hints, gai_cb, &a_out[1]);
        tt_assert(r);

        /* 2: Request for v6only.example.com should return one address. */
        hints.ai_flags = 0;
        r = evdns_getaddrinfo(dns_base, "v6only.example.com", "8002",
            &hints, gai_cb, &a_out[2]);
        tt_assert(r);

        /* 3: PF_INET request for v4assert.example.com should not generate a
         * v6 request.  The server will fail the test if it does. */
        hints.ai_family = PF_INET;
        r = evdns_getaddrinfo(dns_base, "v4assert.example.com", "8003",
            &hints, gai_cb, &a_out[3]);
        tt_assert(r);

        /* 4: PF_INET6 request for v6assert.example.com should not generate a
         * v4 request.  The server will fail the test if it does. */
        hints.ai_family = PF_INET6;
        r = evdns_getaddrinfo(dns_base, "v6assert.example.com", "8004",
            &hints, gai_cb, &a_out[4]);
        tt_assert(r);

        /* 5: PF_INET request for nosuchplace.example.com should give NEXIST. */
        hints.ai_family = PF_INET;
        r = evdns_getaddrinfo(dns_base, "nosuchplace.example.com", "8005",
            &hints, gai_cb, &a_out[5]);
        tt_assert(r);

        /* 6: PF_UNSPEC request for nosuchplace.example.com should give NEXIST.
         */
        hints.ai_family = PF_UNSPEC;
        r = evdns_getaddrinfo(dns_base, "nosuchplace.example.com", "8006",
            &hints, gai_cb, &a_out[6]);
        tt_assert(r);

        /* 7: PF_UNSPEC request for v6timeout.example.com should give an ipv4
         * address only. */
        hints.ai_family = PF_UNSPEC;
        r = evdns_getaddrinfo(dns_base, "v6timeout.example.com", "8007",
            &hints, gai_cb, &a_out[7]);
        tt_assert(r);

        /* 8: PF_UNSPEC request for v6timeout-nonexist.example.com should give
         * a NEXIST */
        hints.ai_family = PF_UNSPEC;
        r = evdns_getaddrinfo(dns_base, "v6timeout-nonexist.example.com",
            "8008", &hints, gai_cb, &a_out[8]);
        tt_assert(r);

        /* 9: AI_ADDRCONFIG should at least not crash.  Can't test it more
         * without knowing what kind of internet we have. */
        hints.ai_flags |= EVUTIL_AI_ADDRCONFIG;
        r = evdns_getaddrinfo(dns_base, "both.example.com",
            "8009", &hints, gai_cb, &a_out[9]);
        tt_assert(r);

        /* 10: PF_UNSPEC for v4timeout.example.com should give an ipv6 address
         * only. */
        hints.ai_family = PF_UNSPEC;
        hints.ai_flags = 0;
        r = evdns_getaddrinfo(dns_base, "v4timeout.example.com", "8010",
            &hints, gai_cb, &a_out[10]);
        tt_assert(r);

        /* 11: timeout.example.com: cancel it after 100 msec. */
        r = evdns_getaddrinfo(dns_base, "all-timeout.example.com", "8011",
            &hints, gai_cb, &a_out[11]);
        tt_assert(r);
        {
                struct timeval tv;
                tv.tv_sec = 0;
                tv.tv_usec = 100*1000; /* 100 msec */
                event_base_once(data->base, -1, EV_TIMEOUT, cancel_gai_cb,
                    r, &tv);
        }

        /* XXXXX There are more tests we could do, including:

           - A test to elicit NODATA.

         */

        n_gai_results_pending = 12;
        exit_base_on_no_pending_results = data->base;

        event_base_dispatch(data->base);

        /* 0: both.example.com */
        tt_int_op(a_out[0].err, ==, 0);
        tt_assert(a_out[0].ai);
        tt_assert(a_out[0].ai->ai_next);
        tt_assert(!a_out[0].ai->ai_next->ai_next);
        a = ai_find_by_family(a_out[0].ai, PF_INET);
        tt_assert(a);
        test_ai_eq(a, "80.80.32.32:8000", SOCK_STREAM, IPPROTO_TCP);
        a = ai_find_by_family(a_out[0].ai, PF_INET6);
        tt_assert(a);
        test_ai_eq(a, "[80ff::bbbb]:8000", SOCK_STREAM, IPPROTO_TCP);
        tt_assert(a_out[0].ai->ai_canonname);
        tt_str_op(a_out[0].ai->ai_canonname, ==, "both-canonical.example.com");

        /* 1: v4only.example.com */
        tt_int_op(a_out[1].err, ==, 0);
        tt_assert(a_out[1].ai);
        tt_assert(! a_out[1].ai->ai_next);
        test_ai_eq(a_out[1].ai, "18.52.86.120:8001", SOCK_STREAM, IPPROTO_TCP);
        tt_assert(a_out[1].ai->ai_canonname == NULL);


        /* 2: v6only.example.com */
        tt_int_op(a_out[2].err, ==, 0);
        tt_assert(a_out[2].ai);
        tt_assert(! a_out[2].ai->ai_next);
        test_ai_eq(a_out[2].ai, "[b0b::f00d]:8002", SOCK_STREAM, IPPROTO_TCP);

        /* 3: v4assert.example.com */
        tt_int_op(a_out[3].err, ==, 0);
        tt_assert(a_out[3].ai);
        tt_assert(! a_out[3].ai->ai_next);
        test_ai_eq(a_out[3].ai, "18.52.86.120:8003", SOCK_STREAM, IPPROTO_TCP);

        /* 4: v6assert.example.com */
        tt_int_op(a_out[4].err, ==, 0);
        tt_assert(a_out[4].ai);
        tt_assert(! a_out[4].ai->ai_next);
        test_ai_eq(a_out[4].ai, "[b0b::f00d]:8004", SOCK_STREAM, IPPROTO_TCP);

        /* 5: nosuchplace.example.com (inet) */
        tt_int_op(a_out[5].err, ==, EVUTIL_EAI_NONAME);
        tt_assert(! a_out[5].ai);

        /* 6: nosuchplace.example.com (unspec) */
        tt_int_op(a_out[6].err, ==, EVUTIL_EAI_NONAME);
        tt_assert(! a_out[6].ai);

        /* 7: v6timeout.example.com */
        tt_int_op(a_out[7].err, ==, 0);
        tt_assert(a_out[7].ai);
        tt_assert(! a_out[7].ai->ai_next);
        test_ai_eq(a_out[7].ai, "171.205.239.1:8007", SOCK_STREAM, IPPROTO_TCP);

        /* 8: v6timeout-nonexist.example.com */
        tt_int_op(a_out[8].err, ==, EVUTIL_EAI_NONAME);
        tt_assert(! a_out[8].ai);

        /* 9: both (ADDRCONFIG) */
        tt_int_op(a_out[9].err, ==, 0);
        tt_assert(a_out[9].ai);
        a = ai_find_by_family(a_out[9].ai, PF_INET);
        if (a)
                test_ai_eq(a, "80.80.32.32:8009", SOCK_STREAM, IPPROTO_TCP);
        else
                tt_assert(ai_find_by_family(a_out[9].ai, PF_INET6));
        a = ai_find_by_family(a_out[9].ai, PF_INET6);
        if (a)
                test_ai_eq(a, "[80ff::bbbb]:8009", SOCK_STREAM, IPPROTO_TCP);
        else
                tt_assert(ai_find_by_family(a_out[9].ai, PF_INET));

        /* 10: v4timeout.example.com */
        tt_int_op(a_out[10].err, ==, 0);
        tt_assert(a_out[10].ai);
        tt_assert(! a_out[10].ai->ai_next);
        test_ai_eq(a_out[10].ai, "[a0a::ff01]:8010", SOCK_STREAM, IPPROTO_TCP);

        /* 11: cancelled request. */
        tt_int_op(a_out[11].err, ==, EVUTIL_EAI_CANCEL);
        tt_assert(a_out[11].ai == NULL);

end:
        if (local_outcome.ai)
                evutil_freeaddrinfo(local_outcome.ai);
        for (i = 0; i < ARRAY_SIZE(a_out); ++i) {
                if (a_out[i].ai)
                        evutil_freeaddrinfo(a_out[i].ai);
        }
        if (port)
                evdns_close_server_port(port);
        if (dns_base)
                evdns_base_free(dns_base, 0);
}

struct gaic_request_status {
        int magic;
        struct event_base *base;
        struct evdns_base *dns_base;
        struct evdns_getaddrinfo_request *request;
        struct event cancel_event;
        int canceled;
};

#define GAIC_MAGIC 0x1234abcd

static int pending = 0;

static void
gaic_cancel_request_cb(evutil_socket_t fd, short what, void *arg)
{
        struct gaic_request_status *status = arg;

        tt_assert(status->magic == GAIC_MAGIC);
        status->canceled = 1;
        evdns_getaddrinfo_cancel(status->request);
        return;
end:
        event_base_loopexit(status->base, NULL);
}

static void
gaic_server_cb(struct evdns_server_request *req, void *arg)
{
        ev_uint32_t answer = 0x7f000001;
        tt_assert(req->nquestions);
        evdns_server_request_add_a_reply(req, req->questions[0]->name, 1,
            &answer, 100);
        evdns_server_request_respond(req, 0);
        return;
end:
        evdns_server_request_respond(req, DNS_ERR_REFUSED);
}


static void
gaic_getaddrinfo_cb(int result, struct evutil_addrinfo *res, void *arg)
{
        struct gaic_request_status *status = arg;
        struct event_base *base = status->base;
        tt_assert(status->magic == GAIC_MAGIC);

        if (result == EVUTIL_EAI_CANCEL) {
                tt_assert(status->canceled);
        }
        event_del(&status->cancel_event);

        memset(status, 0xf0, sizeof(*status));
        free(status);

end:
        if (--pending <= 0)
                event_base_loopexit(base, NULL);
}

static void
gaic_launch(struct event_base *base, struct evdns_base *dns_base)
{
        struct gaic_request_status *status = calloc(1,sizeof(*status));
        struct timeval tv = { 0, 10000 };
        status->magic = GAIC_MAGIC;
        status->base = base;
        status->dns_base = dns_base;
        event_assign(&status->cancel_event, base, -1, 0, gaic_cancel_request_cb,
            status);
        status->request = evdns_getaddrinfo(dns_base,
            "foobar.bazquux.example.com", "80", NULL, gaic_getaddrinfo_cb,
            status);
        event_add(&status->cancel_event, &tv);
        ++pending;
}

#ifdef EVENT_SET_MEM_FUNCTIONS_IMPLEMENTED
/* FIXME: We should move this to regress_main.c if anything else needs it.*/

/* Trivial replacements for malloc/free/realloc to check for memory leaks.
 * Not threadsafe. */
static int allocated_chunks = 0;

static void *
cnt_malloc(size_t sz)
{
        allocated_chunks += 1;
        return malloc(sz);
}

static void *
cnt_realloc(void *old, size_t sz)
{
        if (!old)
                allocated_chunks += 1;
        if (!sz)
                allocated_chunks -= 1;
        return realloc(old, sz);
}

static void
cnt_free(void *ptr)
{
        allocated_chunks -= 1;
        free(ptr);
}

struct testleak_env_t {
        struct event_base *base;
        struct evdns_base *dns_base;
        struct evdns_request *req;
        struct generic_dns_callback_result r;
};

static void *
testleak_setup(const struct testcase_t *testcase)
{
        struct testleak_env_t *env;

        allocated_chunks = 0;

        /* Reset allocation counter, to start allocations from the very beginning.
         * (this will avoid false-positive negative numbers for allocated_chunks)
         */
        libevent_global_shutdown();

        event_set_mem_functions(cnt_malloc, cnt_realloc, cnt_free);

        event_enable_debug_mode();

        /* not mm_calloc: we don't want to mess with the count. */
        env = calloc(1, sizeof(struct testleak_env_t));
        env->base = event_base_new();
        env->dns_base = evdns_base_new(env->base, 0);
        env->req = evdns_base_resolve_ipv4(
                env->dns_base, "example.com", DNS_QUERY_NO_SEARCH,
                generic_dns_callback, &env->r);
        return env;
}

static int
testleak_cleanup(const struct testcase_t *testcase, void *env_)
{
        int ok = 0;
        struct testleak_env_t *env = env_;
        tt_assert(env);
#ifdef EVENT__DISABLE_DEBUG_MODE
        tt_int_op(allocated_chunks, ==, 0);
#else
        libevent_global_shutdown();
        tt_int_op(allocated_chunks, ==, 0);
#endif
        ok = 1;
end:
        if (env) {
                if (env->dns_base)
                        evdns_base_free(env->dns_base, 0);
                if (env->base)
                        event_base_free(env->base);
                free(env);
        }
        return ok;
}

static struct testcase_setup_t testleak_funcs = {
        testleak_setup, testleak_cleanup
};

static void
test_dbg_leak_cancel(void *env_)
{
        /* cancel, loop, free/dns, free/base */
        struct testleak_env_t *env = env_;
        int send_err_shutdown = 1;
        evdns_cancel_request(env->dns_base, env->req);
        env->req = 0;

        /* `req` is freed in callback, that's why one loop is required. */
        event_base_loop(env->base, EVLOOP_NONBLOCK);

        /* send_err_shutdown means nothing as soon as our request is
         * already canceled */
        evdns_base_free(env->dns_base, send_err_shutdown);
        env->dns_base = 0;
        event_base_free(env->base);
        env->base = 0;
}

static void
dbg_leak_resume(void *env_, int cancel, int send_err_shutdown)
{
        /* cancel, loop, free/dns, free/base */
        struct testleak_env_t *env = env_;
        if (cancel) {
                evdns_cancel_request(env->dns_base, env->req);
                tt_assert(!evdns_base_resume(env->dns_base));
        } else {
                /* TODO: No nameservers, request can't be processed, must be errored */
                tt_assert(!evdns_base_resume(env->dns_base));
        }

        event_base_loop(env->base, EVLOOP_NONBLOCK);
        /**
         * Because we don't cancel request, and want our callback to recieve
         * DNS_ERR_SHUTDOWN, we use deferred callback, and there was:
         * - one extra malloc(),
         *   @see reply_schedule_callback()
         * - and one missing free
         *   @see request_finished() (req->handle->pending_cb = 1)
         * than we don't need to count in testleak_cleanup(), but we can clean them
         * if we will run loop once again, but *after* evdns base freed.
         */
        evdns_base_free(env->dns_base, send_err_shutdown);
        env->dns_base = 0;
        event_base_loop(env->base, EVLOOP_NONBLOCK);

end:
        event_base_free(env->base);
        env->base = 0;
}

#define IMPL_DBG_LEAK_RESUME(name, cancel, send_err_shutdown)      \
        static void                                                    \
        test_dbg_leak_##name##_(void *env_)                            \
        {                                                              \
                dbg_leak_resume(env_, cancel, send_err_shutdown);          \
        }
IMPL_DBG_LEAK_RESUME(resume, 0, 0)
IMPL_DBG_LEAK_RESUME(cancel_and_resume, 1, 0)
IMPL_DBG_LEAK_RESUME(resume_send_err, 0, 1)
IMPL_DBG_LEAK_RESUME(cancel_and_resume_send_err, 1, 1)

static void
test_dbg_leak_shutdown(void *env_)
{
        /* free/dns, loop, free/base */
        struct testleak_env_t *env = env_;
        int send_err_shutdown = 1;

        /* `req` is freed both with `send_err_shutdown` and without it,
         * the only difference is `evdns_callback` call */
        env->req = 0;

        evdns_base_free(env->dns_base, send_err_shutdown);
        env->dns_base = 0;

        /* `req` is freed in callback, that's why one loop is required */
        event_base_loop(env->base, EVLOOP_NONBLOCK);
        event_base_free(env->base);
        env->base = 0;
}
#endif

static void
test_getaddrinfo_async_cancel_stress(void *ptr)
{
        struct event_base *base;
        struct evdns_base *dns_base = NULL;
        struct evdns_server_port *server = NULL;
        evutil_socket_t fd = -1;
        struct sockaddr_in sin;
        struct sockaddr_storage ss;
        ev_socklen_t slen;
        unsigned i;

        base = event_base_new();
        dns_base = evdns_base_new(base, 0);

        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_port = 0;
        sin.sin_addr.s_addr = htonl(0x7f000001);
        if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
                tt_abort_perror("socket");
        }
        evutil_make_socket_nonblocking(fd);
        if (bind(fd, (struct sockaddr*)&sin, sizeof(sin))<0) {
                tt_abort_perror("bind");
        }
        server = evdns_add_server_port_with_base(base, fd, 0, gaic_server_cb,
            base);

        memset(&ss, 0, sizeof(ss));
        slen = sizeof(ss);
        if (getsockname(fd, (struct sockaddr*)&ss, &slen)<0) {
                tt_abort_perror("getsockname");
        }
        evdns_base_nameserver_sockaddr_add(dns_base,
            (struct sockaddr*)&ss, slen, 0);

        for (i = 0; i < 1000; ++i) {
                gaic_launch(base, dns_base);
        }

        event_base_dispatch(base);

end:
        if (dns_base)
                evdns_base_free(dns_base, 1);
        if (server)
                evdns_close_server_port(server);
        if (base)
                event_base_free(base);
        if (fd >= 0)
                evutil_closesocket(fd);
}

static void
dns_client_fail_requests_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;
        struct evdns_server_port *dns_port = NULL;
        ev_uint16_t portnum = 0;
        char buf[64];

        struct generic_dns_callback_result r[20];
        unsigned i;

        dns_port = regress_get_dnsserver(base, &portnum, NULL,
                regress_dns_server_cb, reissue_table);
        tt_assert(dns_port);

        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, EVDNS_BASE_DISABLE_WHEN_INACTIVE);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));

        for (i = 0; i < 20; ++i)
                evdns_base_resolve_ipv4(dns, "foof.example.com", 0, generic_dns_callback, &r[i]);

        n_replies_left = 20;
        exit_base = base;

        evdns_base_free(dns, 1 /** fail requests */);
        /** run defered callbacks, to trigger UAF */
        event_base_dispatch(base);

        tt_int_op(n_replies_left, ==, 0);
        for (i = 0; i < 20; ++i)
                tt_int_op(r[i].result, ==, DNS_ERR_SHUTDOWN);

end:
        evdns_close_server_port(dns_port);
}

static void
getaddrinfo_cb(int err, struct evutil_addrinfo *res, void *ptr)
{
        generic_dns_callback(err, 0, 0, 0, NULL, ptr);
}
static void
dns_client_fail_requests_getaddrinfo_test(void *arg)
{
        struct basic_test_data *data = arg;
        struct event_base *base = data->base;
        struct evdns_base *dns = NULL;
        struct evdns_server_port *dns_port = NULL;
        ev_uint16_t portnum = 0;
        char buf[64];

        struct generic_dns_callback_result r[20];
        int i;

        dns_port = regress_get_dnsserver(base, &portnum, NULL,
                regress_dns_server_cb, reissue_table);
        tt_assert(dns_port);

        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        dns = evdns_base_new(base, EVDNS_BASE_DISABLE_WHEN_INACTIVE);
        tt_assert(!evdns_base_nameserver_ip_add(dns, buf));

        for (i = 0; i < 20; ++i)
                tt_assert(evdns_getaddrinfo(dns, "foof.example.com", "80", NULL, getaddrinfo_cb, &r[i]));

        n_replies_left = 20;
        exit_base = base;

        evdns_base_free(dns, 1 /** fail requests */);
        /** run defered callbacks, to trigger UAF */
        event_base_dispatch(base);

        tt_int_op(n_replies_left, ==, 0);
        for (i = 0; i < 20; ++i)
                tt_int_op(r[i].result, ==, EVUTIL_EAI_FAIL);

end:
        evdns_close_server_port(dns_port);
}

#ifdef EVTHREAD_USE_PTHREADS_IMPLEMENTED
struct race_param
{
        void *lock;
        void *reqs_cmpl_cond;
        int bw_threads;
        void *bw_threads_exited_cond;
        volatile int stopping;
        void *base;
        void *dns;

        int locked;
};
static void *
race_base_run(void *arg)
{
        struct race_param *rp = (struct race_param *)arg;
        event_base_loop(rp->base, EVLOOP_NO_EXIT_ON_EMPTY);
        THREAD_RETURN();
}
static void *
race_busywait_run(void *arg)
{
        struct race_param *rp = (struct race_param *)arg;
        struct sockaddr_storage ss;
        while (!rp->stopping)
                evdns_base_get_nameserver_addr(rp->dns, 0, (struct sockaddr *)&ss, sizeof(ss));
        EVLOCK_LOCK(rp->lock, 0);
        if (--rp->bw_threads == 0)
                EVTHREAD_COND_SIGNAL(rp->bw_threads_exited_cond);
        EVLOCK_UNLOCK(rp->lock, 0);
        THREAD_RETURN();
}
static void
race_gai_cb(int result, struct evutil_addrinfo *res, void *arg)
{
        struct race_param *rp = arg;
        (void)result;
        (void)res;

        --n_replies_left;
        if (n_replies_left == 0) {
                EVLOCK_LOCK(rp->lock, 0);
                EVTHREAD_COND_SIGNAL(rp->reqs_cmpl_cond);
                EVLOCK_UNLOCK(rp->lock, 0);
        }
}
static void
getaddrinfo_race_gotresolve_test(void *arg)
{
        struct race_param rp;
        struct evdns_server_port *dns_port = NULL;
        ev_uint16_t portnum = 0;
        char buf[64];
        int i;

        // Some stress is needed to yield inside getaddrinfo between resolve_ipv4 and resolve_ipv6
        int n_reqs = 16384;
#ifdef _SC_NPROCESSORS_ONLN
        int n_threads = sysconf(_SC_NPROCESSORS_ONLN) + 1;
#else
        int n_threads = 17;
#endif
        THREAD_T thread[n_threads];
        struct timeval tv;

        (void)arg;

        evthread_use_pthreads();

        rp.base = event_base_new();
        tt_assert(rp.base);
        if (evthread_make_base_notifiable(rp.base) < 0)
                tt_abort_msg("Couldn't make base notifiable!");

        dns_port = regress_get_dnsserver(rp.base, &portnum, NULL,
                                                                         regress_dns_server_cb, reissue_table);
        tt_assert(dns_port);

        evutil_snprintf(buf, sizeof(buf), "127.0.0.1:%d", (int)portnum);

        rp.dns = evdns_base_new(rp.base, 0);
        tt_assert(!evdns_base_nameserver_ip_add(rp.dns, buf));

        n_replies_left = n_reqs;

        EVTHREAD_ALLOC_LOCK(rp.lock, 0);
        EVTHREAD_ALLOC_COND(rp.reqs_cmpl_cond);
        EVTHREAD_ALLOC_COND(rp.bw_threads_exited_cond);
        tt_assert(rp.lock);
        tt_assert(rp.reqs_cmpl_cond);
        tt_assert(rp.bw_threads_exited_cond);
        rp.bw_threads = 0;
        rp.stopping = 0;

        // Run resolver thread
        THREAD_START(thread[0], race_base_run, &rp);
        // Run busy-wait threads used to force yield this thread
        for (i = 1; i < n_threads; i++) {
                rp.bw_threads++;
                THREAD_START(thread[i], race_busywait_run, &rp);
        }

        EVLOCK_LOCK(rp.lock, 0);
        rp.locked = 1;

        for (i = 0; i < n_reqs; ++i) {
                tt_assert(evdns_getaddrinfo(rp.dns, "foof.example.com", "80", NULL, race_gai_cb, &rp));
                // This magic along with busy-wait threads make this thread yield frequently
                if (i % 100 == 0) {
                        tv.tv_sec = 0;
                        tv.tv_usec = 10000;
                        evutil_usleep_(&tv);
                }
        }

        exit_base = rp.base;

        // Wait for some time
        tv.tv_sec = 5;
        tv.tv_usec = 0;
        EVTHREAD_COND_WAIT_TIMED(rp.reqs_cmpl_cond, rp.lock, &tv);

        // Stop busy-wait threads
        tv.tv_sec = 1;
        tv.tv_usec = 0;
        rp.stopping = 1;
        tt_assert(EVTHREAD_COND_WAIT_TIMED(rp.bw_threads_exited_cond, rp.lock, &tv) == 0);

        EVLOCK_UNLOCK(rp.lock, 0);
        rp.locked = 0;

        evdns_base_free(rp.dns, 1 /** fail requests */);

        tt_int_op(n_replies_left, ==, 0);

end:
        if (rp.locked)
                EVLOCK_UNLOCK(rp.lock, 0);
        EVTHREAD_FREE_LOCK(rp.lock, 0);
        EVTHREAD_FREE_COND(rp.reqs_cmpl_cond);
        EVTHREAD_FREE_COND(rp.bw_threads_exited_cond);
        evdns_close_server_port(dns_port);
        event_base_loopbreak(rp.base);
        event_base_free(rp.base);
}
#endif

#define DNS_LEGACY(name, flags)                                        \
        { #name, run_legacy_test_fn, flags|TT_LEGACY, &legacy_setup,   \
                    dns_##name }

struct testcase_t dns_testcases[] = {
        DNS_LEGACY(server, TT_FORK|TT_NEED_BASE),
        DNS_LEGACY(gethostbyname, TT_FORK|TT_NEED_BASE|TT_NEED_DNS|TT_OFF_BY_DEFAULT),
        DNS_LEGACY(gethostbyname6, TT_FORK|TT_NEED_BASE|TT_NEED_DNS|TT_OFF_BY_DEFAULT),
        DNS_LEGACY(gethostbyaddr, TT_FORK|TT_NEED_BASE|TT_NEED_DNS|TT_OFF_BY_DEFAULT),
        { "resolve_reverse", dns_resolve_reverse, TT_FORK|TT_OFF_BY_DEFAULT, NULL, NULL },
        { "search_empty", dns_search_empty_test, TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
        { "search", dns_search_test, TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
        { "search_lower", dns_search_lower_test, TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
        { "search_cancel", dns_search_cancel_test,
          TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
        { "retry", dns_retry_test, TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },
        { "retry_disable_when_inactive", dns_retry_disable_when_inactive_test,
          TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },
        { "reissue", dns_reissue_test, TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },
        { "reissue_disable_when_inactive", dns_reissue_disable_when_inactive_test,
          TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },
        { "inflight", dns_inflight_test, TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
        { "bufferevent_connect_hostname", test_bufferevent_connect_hostname,
          TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
#ifdef EVENT__HAVE_SETRLIMIT
        { "bufferevent_connect_hostname_emfile", test_bufferevent_connect_hostname,
          TT_FORK|TT_NEED_BASE, &basic_setup, (char*)"emfile" },
#endif
        { "disable_when_inactive", dns_disable_when_inactive_test,
          TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
        { "disable_when_inactive_no_ns", dns_disable_when_inactive_no_ns_test,
          TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },

        { "initialize_nameservers", dns_initialize_nameservers_test,
          TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
#ifndef _WIN32
        { "nameservers_no_default", dns_nameservers_no_default_test,
          TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
#endif

        { "getaddrinfo_async", test_getaddrinfo_async,
          TT_FORK|TT_NEED_BASE, &basic_setup, (char*)"" },
        { "getaddrinfo_cancel_stress", test_getaddrinfo_async_cancel_stress,
          TT_FORK, NULL, NULL },

#ifdef EVENT_SET_MEM_FUNCTIONS_IMPLEMENTED
        { "leak_shutdown", test_dbg_leak_shutdown, TT_FORK, &testleak_funcs, NULL },
        { "leak_cancel", test_dbg_leak_cancel, TT_FORK, &testleak_funcs, NULL },

        { "leak_resume", test_dbg_leak_resume_, TT_FORK, &testleak_funcs, NULL },
        { "leak_cancel_and_resume", test_dbg_leak_cancel_and_resume_,
          TT_FORK, &testleak_funcs, NULL },
        { "leak_resume_send_err", test_dbg_leak_resume_send_err_,
          TT_FORK, &testleak_funcs, NULL },
        { "leak_cancel_and_resume_send_err", test_dbg_leak_cancel_and_resume_send_err_,
          TT_FORK, &testleak_funcs, NULL },
#endif

        { "client_fail_requests", dns_client_fail_requests_test,
          TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },
        { "client_fail_requests_getaddrinfo",
          dns_client_fail_requests_getaddrinfo_test,
          TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, NULL },
#ifdef EVTHREAD_USE_PTHREADS_IMPLEMENTED
        { "getaddrinfo_race_gotresolve",
          getaddrinfo_race_gotresolve_test,
          TT_FORK|TT_OFF_BY_DEFAULT, NULL, NULL },
#endif

        END_OF_TESTCASES
};