/*      $NetBSD: resolv.c,v 1.6 2004/05/23 16:59:11 christos Exp $      */

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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 <sys/cdefs.h>
__RCSID("$NetBSD: resolv.c,v 1.6 2004/05/23 16:59:11 christos Exp $");

#include <sys/types.h>
#include <sys/socket.h>
#include <assert.h>
#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <stdatomic.h>
#include <netdb.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stringlist.h>

#include <atf-c.h>

#define NTHREADS        10
#define NHOSTS          100
#define WS              " \t\n\r"

enum method {
        METHOD_GETADDRINFO,
        METHOD_GETHOSTBY,
        METHOD_GETIPNODEBY
};

static StringList *hosts = NULL;
static _Atomic(int) *ask = NULL;
static _Atomic(int) *got = NULL;
static bool debug_output = 0;

static void load(const char *);
static void resolvone(long, int, enum method);
static void *resolvloop(void *);
static pthread_t run(int, enum method, long);

#define DBG(...) do {                                   \
        if (debug_output)                               \
                dprintf(STDOUT_FILENO, __VA_ARGS__);    \
        } while (0)

static void
load(const char *fname)
{
        FILE *fp;
        size_t linecap;
        char *line;

        fp = fopen(fname, "r");
        ATF_REQUIRE(fp != NULL);
        line = NULL;
        linecap = 0;
        while (getline(&line, &linecap, fp) >= 0) {
                char *ptr;

                for (ptr = strtok(line, WS); ptr; ptr = strtok(NULL, WS)) {
                        if (ptr[0] == '#')
                                break;
                        sl_add(hosts, strdup(ptr));
                }
        }
        free(line);

        (void)fclose(fp);
}

static int
resolv_getaddrinfo(long threadnum, char *host, int port, const char **errstr)
{
        char portstr[6], hbuf[NI_MAXHOST], pbuf[NI_MAXSERV];
        struct addrinfo hints, *res;
        int error;

        snprintf(portstr, sizeof(portstr), "%d", port);
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_UNSPEC;
        hints.ai_flags = AI_PASSIVE;
        hints.ai_socktype = SOCK_STREAM;
        error = getaddrinfo(host, portstr, &hints, &res);
        if (error == 0) {
                DBG("T%ld: host %s ok\n", threadnum, host);
                memset(hbuf, 0, sizeof(hbuf));
                memset(pbuf, 0, sizeof(pbuf));
                getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof(hbuf),
                    pbuf, sizeof(pbuf), 0);
                DBG("T%ld: reverse %s %s\n", threadnum, hbuf, pbuf);
                freeaddrinfo(res);
        } else {
                *errstr = gai_strerror(error);
                DBG("T%ld: host %s not found: %s\n", threadnum, host, *errstr);
        }
        return error;
}

static int
resolv_gethostby(long threadnum, char *host, const char **errstr)
{
        char buf[1024];
        struct hostent *hp, *hp2;

        hp = gethostbyname(host);
        if (hp) {
                DBG("T%ld: host %s ok\n", threadnum, host);
                memcpy(buf, hp->h_addr, hp->h_length);
                hp2 = gethostbyaddr(buf, hp->h_length, hp->h_addrtype);
                if (hp2) {
                        DBG("T%ld: reverse %s\n", threadnum, hp2->h_name);
                }
        } else {
                *errstr = hstrerror(h_errno);
                DBG("T%ld: host %s not found: %s\n", threadnum, host, *errstr);
        }
        return hp ? 0 : h_errno;
}

static int
resolv_getipnodeby(long threadnum, char *host, const char **errstr)
{
        char buf[1024];
        struct hostent *hp, *hp2;
        int error = 0;

        hp = getipnodebyname(host, AF_INET, 0, &error);
        if (hp) {
                DBG("T%ld: host %s ok\n", threadnum, host);
                memcpy(buf, hp->h_addr, hp->h_length);
                hp2 = getipnodebyaddr(buf, hp->h_length, hp->h_addrtype,
                    &error);
                if (hp2) {
                        DBG("T%ld: reverse %s\n", threadnum, hp2->h_name);
                        freehostent(hp2);
                }
                freehostent(hp);
        } else {
                *errstr = hstrerror(error);
                DBG("T%ld: host %s not found: %s\n", threadnum, host, *errstr);
        }
        return hp ? 0 : error;
}

static void
resolvone(long threadnum, int n, enum method method)
{
        const char* errstr = NULL;
        size_t i = (random() & 0x0fffffff) % hosts->sl_cur;
        char *host = hosts->sl_str[i];
        int error;

        DBG("T%ld: %d resolving %s %zd\n", threadnum, n, host, i);
        switch (method) {
        case METHOD_GETADDRINFO:
                error = resolv_getaddrinfo(threadnum, host, i, &errstr);
                break;
        case METHOD_GETHOSTBY:
                error = resolv_gethostby(threadnum, host, &errstr);
                break;
        case METHOD_GETIPNODEBY:
                error = resolv_getipnodeby(threadnum, host, &errstr);
                break;
        default:
                /* UNREACHABLE */
                /* XXX Needs an __assert_unreachable() for userland. */
                assert(0 && "Unreachable segment reached");
                abort();
                break;
        }
        atomic_fetch_add_explicit(&ask[i], 1, memory_order_relaxed);
        if (error == 0)
                atomic_fetch_add_explicit(&got[i], 1, memory_order_relaxed);
        else if (got[i] != 0)
                fprintf(stderr,
                    "T%ld ERROR after previous success for %s: %d (%s)\n",
                    threadnum, hosts->sl_str[i], error, errstr);
}

struct resolvloop_args {
        int nhosts;
        enum method method;
        long threadnum;
};

static void *
resolvloop(void *p)
{
        struct resolvloop_args *args = p;
        int nhosts = args->nhosts;

        if (nhosts == 0) {
                free(args);
                return NULL;
        }

        do {
                resolvone(args->threadnum, nhosts, args->method);
        } while (--nhosts);
        free(args);
        return (void *)(uintptr_t)nhosts;
}

static pthread_t
run(int nhosts, enum method method, long i)
{
        pthread_t t;
        int rc;
        struct resolvloop_args *args;

        /* Created thread is responsible for free(). */
        args = malloc(sizeof(*args));
        ATF_REQUIRE(args != NULL);

        args->nhosts = nhosts;
        args->method = method;
        args->threadnum = i + 1;
        rc = pthread_create(&t, NULL, resolvloop, args);
        ATF_REQUIRE_MSG(rc == 0, "pthread_create failed: %s", strerror(rc));
        return t;
}

static int
run_tests(const char *hostlist_file, enum method method)
{
        size_t nthreads = NTHREADS;
        pthread_t *threads;
        size_t nhosts = NHOSTS;
        size_t i;
        int c;
        hosts = sl_init();

        srandom(1234);
        debug_output = getenv("DEBUG_OUTPUT") != NULL;

        load(hostlist_file);

        ATF_REQUIRE_MSG(0 < hosts->sl_cur, "0 hosts in %s", hostlist_file);

        ask = calloc(hosts->sl_cur, sizeof(int));
        ATF_REQUIRE(ask != NULL);

        got = calloc(hosts->sl_cur, sizeof(int));
        ATF_REQUIRE(got != NULL);

        threads = calloc(nthreads, sizeof(pthread_t));
        ATF_REQUIRE(threads != NULL);

        for (i = 0; i < nthreads; i++) {
                threads[i] = run(nhosts, method, i);
        }
        /* Wait for all threads to join and check that they checked all hosts */
        for (i = 0; i < nthreads; i++) {
                size_t remaining;

                remaining = (uintptr_t)pthread_join(threads[i], NULL);
                ATF_CHECK_EQ_MSG(0, remaining,
                    "Thread %zd still had %zd hosts to check!", i, remaining);
        }

        c = 0;
        for (i = 0; i < hosts->sl_cur; i++) {
                if (got[i] != 0) {
                        ATF_CHECK_EQ_MSG(ask[i], got[i],
                            "Error: host %s ask %d got %d", hosts->sl_str[i],
                            ask[i], got[i]);
                        c += ask[i] != got[i];
                }
        }
        free(threads);
        free(ask);
        free(got);
        sl_free(hosts, 1);
        return c;
}

#define HOSTLIST_FILE   "mach"

#define RUN_TESTS(tc, method) \
do {                                                                    \
        char *_hostlist_file;                                           \
        ATF_REQUIRE(0 < asprintf(&_hostlist_file, "%s/%s",              \
            atf_tc_get_config_var(tc, "srcdir"), HOSTLIST_FILE));       \
        ATF_REQUIRE(run_tests(_hostlist_file, method) == 0);            \
} while(0)

ATF_TC(getaddrinfo_test);
ATF_TC_HEAD(getaddrinfo_test, tc) {
        atf_tc_set_md_var(tc, "timeout", "1200");
}
ATF_TC_BODY(getaddrinfo_test, tc)
{

        RUN_TESTS(tc, METHOD_GETADDRINFO);
}

ATF_TC(gethostby_test);
ATF_TC_HEAD(gethostby_test, tc) {
        atf_tc_set_md_var(tc, "timeout", "1200");
}
ATF_TC_BODY(gethostby_test, tc)
{

        RUN_TESTS(tc, METHOD_GETHOSTBY);
}

ATF_TC(getipnodeby_test);
ATF_TC_HEAD(getipnodeby_test, tc) {

        atf_tc_set_md_var(tc, "timeout", "1200");
}
ATF_TC_BODY(getipnodeby_test, tc)
{

        RUN_TESTS(tc, METHOD_GETIPNODEBY);
}

ATF_TP_ADD_TCS(tp)
{

        ATF_TP_ADD_TC(tp, getaddrinfo_test);
        ATF_TP_ADD_TC(tp, gethostby_test);
        ATF_TP_ADD_TC(tp, getipnodeby_test);

        return (atf_no_error());
}