/*      $NetBSD: regress_dns.c,v 1.6 2021/04/07 03:36:48 christos Exp $ */

/*
* Copyright (c) 2003-2007 Niels Provos <[email protected]>
* 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/cdefs.h>
__RCSID("$NetBSD: regress_dns.c,v 1.6 2021/04/07 03:36:48 christos Exp $");

#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");
       unsigned i;
       int ret;

       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, ==, !emfile ? BEV_EVENT_CONNECTED : BEV_EVENT_ERROR);
       tt_int_op(be_outcome[1].dnserr, ==, 0);
       tt_int_op(be_outcome[2].what, ==, !emfile ? BEV_EVENT_CONNECTED : BEV_EVENT_ERROR);
       tt_int_op(be_outcome[2].dnserr, ==, 0);
       tt_int_op(be_outcome[3].what, ==, !emfile ? BEV_EVENT_CONNECTED : BEV_EVENT_ERROR);
       if (!emfile) {
               tt_int_op(be_outcome[3].dnserr, ==, 0);
       } else {
               tt_int_op(be_outcome[3].dnserr, !=, 0);
       }
       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 gaic_pending = 0;
static int gaic_freed = 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 (res)
       {
               TT_BLATHER(("evutil_freeaddrinfo(%p)", res));
               evutil_freeaddrinfo(res);
               ++gaic_freed;
       }
       if (--gaic_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);
       ++gaic_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);

       // at least some was canceled via external event
       tt_int_op(gaic_freed, !=, 1000);

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;
       int limit_inflight = data->setup_data && !strcmp(data->setup_data, "limit-inflight");
       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));

       if (limit_inflight)
               tt_assert(!evdns_base_set_option(dns, "max-inflight:", "11"));

       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;
       struct timeval tv;

       (void)arg;

       thread = calloc(n_threads, sizeof(*thread));
       tt_assert(thread);

       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);
       free(thread);
}
#endif

static void
test_set_so_rcvbuf_so_sndbuf(void *arg)
{
       struct basic_test_data *data = arg;
       struct evdns_base *dns_base;

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

       tt_assert(!evdns_base_set_option(dns_base, "so-rcvbuf", "10240"));
       tt_assert(!evdns_base_set_option(dns_base, "so-sndbuf", "10240"));

       /* actually check SO_RCVBUF/SO_SNDBUF not fails */
       tt_assert(!evdns_base_nameserver_ip_add(dns_base, "127.0.0.1"));

end:
       if (dns_base)
               evdns_base_free(dns_base, 0);
}

static void
test_set_option(void *arg)
{
#define SUCCESS 0
#define FAIL -1
       struct basic_test_data *data = arg;
       struct evdns_base *dns_base;
       size_t i;
       /* Option names are allowed to have ':' at the end.
        * So all test option names come in pairs.
        */
       const char *int_options[] = {
               "ndots", "ndots:",
               "max-timeouts", "max-timeouts:",
               "max-inflight", "max-inflight:",
               "attempts", "attempts:",
               "randomize-case", "randomize-case:",
               "so-rcvbuf", "so-rcvbuf:",
               "so-sndbuf", "so-sndbuf:",
       };
       const char *timeval_options[] = {
               "timeout", "timeout:",
               "getaddrinfo-allow-skew", "getaddrinfo-allow-skew:",
               "initial-probe-timeout", "initial-probe-timeout:",
       };
       const char *addr_port_options[] = {
               "bind-to", "bind-to:",
       };

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

       for (i = 0; i < ARRAY_SIZE(int_options); ++i) {
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, int_options[i], "0"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, int_options[i], "1"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, int_options[i], "10000"));
               tt_assert(FAIL == evdns_base_set_option(dns_base, int_options[i], "foo"));
               tt_assert(FAIL == evdns_base_set_option(dns_base, int_options[i], "3.14"));
       }

       for (i = 0; i < ARRAY_SIZE(timeval_options); ++i) {
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, timeval_options[i], "1"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, timeval_options[i], "0.001"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, timeval_options[i], "3.14"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, timeval_options[i], "10000"));
               tt_assert(FAIL == evdns_base_set_option(dns_base, timeval_options[i], "0"));
               tt_assert(FAIL == evdns_base_set_option(dns_base, timeval_options[i], "foo"));
       }

       for (i = 0; i < ARRAY_SIZE(addr_port_options); ++i) {
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, addr_port_options[i], "8.8.8.8:80"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, addr_port_options[i], "1.2.3.4"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, addr_port_options[i], "::1:82"));
               tt_assert(SUCCESS == evdns_base_set_option(dns_base, addr_port_options[i], "3::4"));
               tt_assert(FAIL == evdns_base_set_option(dns_base, addr_port_options[i], "3.14"));
               tt_assert(FAIL == evdns_base_set_option(dns_base, addr_port_options[i], "foo"));
       }

#undef SUCCESS
#undef FAIL
end:
       if (dns_base)
               evdns_base_free(dns_base, 0);
}

#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, __UNCONST("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, __UNCONST("") },
       { "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_waiting_requests", dns_client_fail_requests_test,
         TT_FORK|TT_NEED_BASE|TT_NO_LOGS, &basic_setup, __UNCONST("limit-inflight") },
       { "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

       { "set_SO_RCVBUF_SO_SNDBUF", test_set_so_rcvbuf_so_sndbuf,
         TT_FORK|TT_NEED_BASE, &basic_setup, NULL },
       { "set_options", test_set_option,
         TT_FORK|TT_NEED_BASE, &basic_setup, NULL },

       END_OF_TESTCASES
};