/*-
 * Copyright (c) 2000-2015 Mark R V Murray
 * 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
 *    in this position and unchanged.
 * 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 ``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.
 */

/*
 Build this by going:

cc -g -O0 -pthread -DRANDOM_<alg> -I../.. -lstdthreads -Wall \
        unit_test.c \
        fortuna.c \
        hash.c \
        ../../crypto/rijndael/rijndael-api-fst.c \
        ../../crypto/rijndael/rijndael-alg-fst.c \
        ../../crypto/sha2/sha256c.c \
        -lz \
        -o unit_test
./unit_test

Where <alg> is FORTUNA. The parameterisation is a leftover from
when Yarrow was an option, and remains to enable the testing of
possible future algorithms.
*/

#include <sys/types.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <threads.h>
#include <unistd.h>
#include <zlib.h>

#include "randomdev.h"
#include "unit_test.h"

#define NUM_THREADS       3
#define DEBUG

static volatile int stopseeding = 0;

static __inline void
check_err(int err, const char *func)
{
        if (err != Z_OK) {
                fprintf(stderr, "Compress error in %s: %d\n", func, err);
                exit(0);
        }
}

void *
myalloc(void *q, unsigned n, unsigned m)
{
        q = Z_NULL;
        return (calloc(n, m));
}

void myfree(void *q, void *p)
{
        q = Z_NULL;
        free(p);
}

size_t
block_deflate(uint8_t *uncompr, uint8_t *compr, const size_t len)
{
        z_stream c_stream;
        int err;

        if (len == 0)
                return (0);

        c_stream.zalloc = myalloc;
        c_stream.zfree = myfree;
        c_stream.opaque = NULL;

        err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
        check_err(err, "deflateInit");

        c_stream.next_in  = uncompr;
        c_stream.next_out = compr;
        c_stream.avail_in = len;
        c_stream.avail_out = len*2u +512u;

        while (c_stream.total_in != len && c_stream.total_out < (len*2u + 512u)) {
                err = deflate(&c_stream, Z_NO_FLUSH);
#ifdef DEBUG
                printf("deflate progress: len = %zd  total_in = %lu  total_out = %lu\n", len, c_stream.total_in, c_stream.total_out);
#endif
                check_err(err, "deflate(..., Z_NO_FLUSH)");
        }

        for (;;) {
                err = deflate(&c_stream, Z_FINISH);
#ifdef DEBUG
                printf("deflate    final: len = %zd  total_in = %lu  total_out = %lu\n", len, c_stream.total_in, c_stream.total_out);
#endif
                if (err == Z_STREAM_END) break;
                check_err(err, "deflate(..., Z_STREAM_END)");
        }

        err = deflateEnd(&c_stream);
        check_err(err, "deflateEnd");

        return ((size_t)c_stream.total_out);
}

void
randomdev_unblock(void)
{

#if 0
        if (mtx_trylock(&random_reseed_mtx) == thrd_busy)
                printf("Mutex held. Good.\n");
        else {
                printf("Mutex not held. PANIC!!\n");
                thrd_exit(0);
        }
#endif
        printf("random: unblocking device.\n");
}

static int
RunHarvester(void *arg __unused)
{
        int i, r;
        struct harvest_event e;

        for (i = 0; ; i++) {
                if (stopseeding)
                        break;
                if (i % 1000 == 0)
                        printf("Harvest: %d\n", i);
                r = random()%10;
                e.he_somecounter = i;
                *((uint64_t *)e.he_entropy) = random();
                e.he_size = 8;
                e.he_destination = i;
                e.he_source = (i + 3)%7;
                e.he_next = NULL;
                random_alg_context.ra_event_processor(&e);
                usleep(r);
        }

        printf("Thread #0 ends\n");

        thrd_exit(0);

        return (0);
}

static int
ReadCSPRNG(void *threadid)
{
        size_t tid, zsize;
        u_int buffersize;
        uint8_t *buf, *zbuf;
        int i;
#ifdef DEBUG
        int j;
#endif

        tid = (size_t)threadid;
        printf("Thread #%zd starts\n", tid);

        while (!random_alg_context.ra_seeded())
        {
                random_alg_context.ra_pre_read();
                usleep(100);
        }

        for (i = 0; i < 100000; i++) {
                buffersize = i + RANDOM_BLOCKSIZE;
                buffersize -= buffersize%RANDOM_BLOCKSIZE;
                buf = malloc(buffersize);
                zbuf = malloc(2*i + 1024);
                if (i % 1000 == 0)
                        printf("Thread read %zd - %d\n", tid, i);
                if (buf != NULL && zbuf != NULL) {
                        random_alg_context.ra_pre_read();
                        random_alg_context.ra_read(buf, buffersize);
                        zsize = block_deflate(buf, zbuf, i);
                        if (zsize < i)
                                printf("ERROR!! Compressible RNG output!\n");
#ifdef DEBUG
                        printf("RNG output:\n");
                        for (j = 0; j < i; j++) {
                                printf(" %02X", buf[j]);
                                if (j % 32 == 31 || j == i - 1)
                                        printf("\n");
                        }
                        printf("Compressed output:\n");
                        for (j = 0; j < zsize; j++) {
                                printf(" %02X", zbuf[j]);
                                if (j % 32 == 31 || j == zsize - 1)
                                        printf("\n");
                        }
#endif
                        free(zbuf);
                        free(buf);
                }
                usleep(100);
        }

        printf("Thread #%zd ends\n", tid);

        thrd_exit(0);

        return (0);
}

int
main(int argc, char *argv[])
{
        thrd_t threads[NUM_THREADS];
        int rc;
        long t;

        random_alg_context.ra_init_alg(NULL);

        for (t = 0; t < NUM_THREADS; t++) {
                printf("In main: creating thread %ld\n", t);
                rc = thrd_create(&threads[t], (t == 0 ? RunHarvester : ReadCSPRNG), NULL);
                if (rc != thrd_success) {
                        printf("ERROR; return code from thrd_create() is %d\n", rc);
                        exit(-1);
                }
        }

        for (t = 2; t < NUM_THREADS; t++)
                thrd_join(threads[t], &rc);

        stopseeding = 1;

        thrd_join(threads[1], &rc);
        thrd_join(threads[0], &rc);

        random_alg_context.ra_deinit_alg(NULL);

        /* Last thing that main() should do */
        thrd_exit(0);

        return (0);
}