/*-
 * Copyright (c) 2004 Brian Fundakowski Feldman
 * All rights reserved.
 *
 * 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 AUTHOR 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 AUTHOR 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/types.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>

#include <err.h>
#include <netdb.h>
#include <pthread.h>
#include <resolv.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/* Per-thread struct containing all important data. */
struct worker {
        pthread_t w_thread;                          /* self */
        uintmax_t w_lookup_success, w_lookup_failure;   /* getaddrinfo stats */
        struct timespec w_max_lookup_time;
};

static volatile int workers_stop = 0;
static double max_random_sleep = 1.0;
static char **randwords;
static size_t nrandwords;
static const struct addrinfo *hints, hintipv4only = { .ai_family = AF_INET };

/*
 * We don't have good random(3)-type functions that are thread-safe,
 * unfortunately.
 */
static u_int32_t
my_arc4random_r(void)
{
        static pthread_mutex_t mymutex = PTHREAD_MUTEX_INITIALIZER;
        u_int32_t ret;

        (void)pthread_mutex_lock(&mymutex);
        ret = arc4random();
        (void)pthread_mutex_unlock(&mymutex);
        return (ret);
}

static void
randomsleep(double max_sleep_sec)
{
        struct timespec slptime = { 0, 0 };
        double rndsleep;

        rndsleep = (double)my_arc4random_r() / 4294967296.0 * max_sleep_sec;
        while (rndsleep >= 1.0) {
                slptime.tv_sec++;
                rndsleep -= 1.0;
        }
        slptime.tv_nsec = rndsleep * 1e9;
        (void)nanosleep(&slptime, NULL);
}

/*
 * Start looking up arbitrary hostnames and record the successes/failures.
 * Between lookups, sleep a random amount of time to make sure threads
 * stay well out of synchronization.
 *
 * Host name:   part            probability
 *              ----            -----------
 *              www.            1/2
 *              random word     always, equal
 *              random word     1/3, equal
 *              .(net|com|org)  equal
 */
static void *
work(void *arg)
{
        struct worker *w = arg;

        /* Turn off domain name list searching as much as possible. */
        if (_res.options & RES_INIT || res_init() == 0)
                _res.options &= ~RES_DNSRCH;
        do {
                const char *suffixes[] = { "net", "com", "org" };
                const size_t nsuffixes = sizeof(suffixes) / sizeof(suffixes[0]);
                struct timespec ts_begintime, ts_total;
                struct addrinfo *res;
                char *hostname;
                int error;

                randomsleep(max_random_sleep);
                if (asprintf(&hostname, "%s%s%s.%s",
                    (my_arc4random_r() % 2) == 0 ? "www." : "",
                    randwords[my_arc4random_r() % nrandwords],
                    (my_arc4random_r() % 3) == 0 ?
                    randwords[my_arc4random_r() % nrandwords] : "",
                    suffixes[my_arc4random_r() % nsuffixes]) == -1)
                        continue;
                (void)clock_gettime(CLOCK_REALTIME, &ts_begintime);
                error = getaddrinfo(hostname, NULL, hints, &res);
                (void)clock_gettime(CLOCK_REALTIME, &ts_total);
                ts_total.tv_sec -= ts_begintime.tv_sec;
                ts_total.tv_nsec -= ts_begintime.tv_nsec;
                if (ts_total.tv_nsec < 0) {
                        ts_total.tv_sec--;
                        ts_total.tv_nsec += 1000000000;
                }
                if (ts_total.tv_sec > w->w_max_lookup_time.tv_sec ||
                    (ts_total.tv_sec == w->w_max_lookup_time.tv_sec &&
                    ts_total.tv_nsec > w->w_max_lookup_time.tv_sec))
                        w->w_max_lookup_time = ts_total;
                free(hostname);
                if (error == 0) {
                        w->w_lookup_success++;
                        freeaddrinfo(res);
                } else {
                        w->w_lookup_failure++;
                }
        } while (!workers_stop);

        pthread_exit(NULL);
}

int
dowordfile(const char *fname)
{
        FILE *fp;
        char newword[64];
        size_t n;

        fp = fopen(fname, "r");
        if (fp == NULL)
                return (-1);
        nrandwords = 0;
        while (fgets(newword, sizeof(newword), fp) != NULL)
                nrandwords++;
        if (ferror(fp) || fseek(fp, 0, SEEK_SET) != 0)
                goto fail;
        randwords = calloc(nrandwords, sizeof(char *));
        if (randwords == NULL)
                goto fail;
        n = nrandwords;
        nrandwords = 0;
        while (fgets(newword, sizeof(newword), fp) != NULL) {
                newword[strcspn(newword, "\r\n")] = '\0';
                randwords[nrandwords] = strdup(newword);
                if (randwords[nrandwords] == NULL)
                        err(1, "reading words file");
                if (++nrandwords == n)
                        break;
        }
        nrandwords = n;
        fclose(fp);
        return (0);
fail:
        fclose(fp);
        return (-1);
}

int
main(int argc, char **argv) {
        unsigned long nworkers = 1;
        struct worker *workers;
        size_t i;
        char waiting[3], *send, *wordfile = "/usr/share/dict/words";
        int ch;

        if (getprogname() == NULL)
                setprogname(argv[0]);
        printf("%s: threaded stress-tester for getaddrinfo(3)\n",
            getprogname());
        printf("(c) 2004 Brian Feldman <green@FreeBSD.org>\n");
        while ((ch = getopt(argc, argv, "4s:t:w:")) != -1) {
                switch (ch) {
                case '4':
                        hints = &hintipv4only;
                        break;
                case 's':
                        max_random_sleep = strtod(optarg, &send);
                        if (*send != '\0')
                                goto usage;
                        break;
                case 't':
                        nworkers = strtoul(optarg, &send, 0);
                        if (*send != '\0')
                                goto usage;
                        break;
                case 'w':
                        wordfile = optarg;
                        break;
                default:
usage:
                        fprintf(stderr, "usage: %s [-4] [-s sleep] "
                            "[-t threads] [-w wordfile]\n", getprogname());
                        exit(2);
                }
        }
        argc -= optind;
        argv += optind;

        if (nworkers < 1 || nworkers != (size_t)nworkers)
                goto usage;
        if (dowordfile(wordfile) == -1)
                err(1, "reading word file %s", wordfile);
        if (nrandwords < 1)
                errx(1, "word file %s did not have >0 words", wordfile);
        printf("Read %zu random words from %s.\n", nrandwords, wordfile);
        workers = calloc(nworkers, sizeof(*workers));
        if (workers == NULL)
                err(1, "allocating workers");
        printf("Intra-query delay time is from 0 to %g seconds (random).\n",
            max_random_sleep);

        printf("Starting %lu worker%.*s: ", nworkers, nworkers > 1, "s");
        fflush(stdout);
        for (i = 0; i < nworkers; i++) {
                if (pthread_create(&workers[i].w_thread, NULL, work,
                    &workers[i]) != 0)
                        err(1, "creating worker %zu", i);
                printf("%zu%s", i, i == nworkers - 1 ? ".\n" : ", ");
                fflush(stdout);
        }

        printf("<Press enter key to end test.>\n");
        (void)fgets(waiting, sizeof(waiting), stdin);
        workers_stop = 1;

        printf("Stopping %lu worker%.*s: ", nworkers, nworkers > 1, "s");
        fflush(stdout);
        for (i = 0; i < nworkers; i++) {
                pthread_join(workers[i].w_thread, NULL);
                printf("%zu%s", i, i == nworkers - 1 ? ".\n" : ", ");
                fflush(stdout);
        }

        printf("%-10s%-20s%-20s%-29s\n", "Worker", "Successful GAI",
            "Failed GAI", "Max resolution time (M:SS*)");
        printf("%-10s%-20s%-20s%-29s\n", "------", "--------------",
            "----------", "---------------------------");
        for (i = 0; i < nworkers; i++) {
                printf("%-10zu%-20ju%-20ju%ld:%s%.2f\n", i,
                    workers[i].w_lookup_success, workers[i].w_lookup_failure,
                    workers[i].w_max_lookup_time.tv_sec / 60,
                    workers[i].w_max_lookup_time.tv_sec % 60 < 10 ? "0" : "",
                    (double)(workers[i].w_max_lookup_time.tv_sec % 60) +
                    (double)workers[i].w_max_lookup_time.tv_nsec / 1e9);
        }

        exit(0);
}