/*-
 * Copyright (c) 2004 Robert N. M. Watson
 * 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.
 */

/*
 * tcpstream sets up a simple TCP client and server, and then streams a
 * predictable pseudo-random byte sequence through it using variable block
 * sizes.  The intent is to detect corruption of data in the TCP stream.
 */

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define MAX_LOOPS       10240
#define MAX_LONGS       1024

static void
usage(void)
{

        fprintf(stderr, "tcpstream client [ip] [port] [seed]\n");
        fprintf(stderr, "tcpstream server [port] [seed]\n");
        exit(-1);
}

static void
fill_buffer(long *buffer, int len)
{
        int i;

        for (i = 0; i < len; i++)
                buffer[i] = htonl(random());
}

static int
check_buffer(long *buffer, int len)
{
        int i;

        for (i = 0; i < len; i++) {
                if (buffer[i] != htonl(random()))
                        return (0);
        }
        return (1);
}

static void
tcpstream_client(struct sockaddr_in sin, long seed)
{
        long buffer[MAX_LONGS];
        ssize_t len;
        int i, j, sock;

        srandom(seed);

        sock = socket(PF_INET, SOCK_STREAM, 0);
        if (sock == -1)
                errx(-1, "socket: %s", strerror(errno));

        if (connect(sock, (struct sockaddr *) &sin, sizeof(sin)) == -1)
                errx(-1, "connect: %s", strerror(errno));

        for (j = 0; j < MAX_LOOPS; j++) {
                for (i = 0; i < MAX_LONGS; i++) {
                        fill_buffer(buffer, i);
                        len = send(sock, buffer, i * sizeof(long), 0);
                        if (len == -1) {
                                printf("%d bytes written of %d expected\n",
                                    len, i * sizeof(long));
                                fflush(stdout);
                                perror("send");
                                goto done;
                        }
                }
        }

done:
        close(sock);
}

static void
tcpstream_server(struct sockaddr_in sin, long seed)
{
        int i, j, listen_sock, accept_sock;
        struct sockaddr_in other_sin;
        long buffer[MAX_LONGS];
        socklen_t addrlen;
        ssize_t len;

        int input_byte_counter;

        listen_sock = socket(PF_INET, SOCK_STREAM, 0);
        if (listen_sock == -1)
                errx(-1, "socket: %s", strerror(errno));

        if (bind(listen_sock, (struct sockaddr *)&sin, sizeof(sin)) == -1)
                errx(-1, "bind: %s", strerror(errno));

        if (listen(listen_sock, -1) == -1)
                errx(-1, "listen: %s", strerror(errno));

        while (1) {
                bzero(&other_sin, sizeof(other_sin));
                addrlen = sizeof(other_sin);

                accept_sock = accept(listen_sock, (struct sockaddr *)
                    &other_sin, &addrlen);
                if (accept_sock == -1) {
                        perror("accept");
                        continue;
                }
                printf("connection opened from %s:%d\n",
                    inet_ntoa(other_sin.sin_addr), ntohs(other_sin.sin_port));
                input_byte_counter = 0;

                srandom(seed);

                for (j = 0; j < MAX_LOOPS; j++) {
                        for (i = 0; i < MAX_LONGS; i++) {
                                len = recv(accept_sock, buffer,
                                    i * sizeof(long), MSG_WAITALL);
                                if (len != i * sizeof(long)) {
                                        perror("recv");
                                        goto done;
                                }
                                if (check_buffer(buffer, i) == 0) {
                                        fprintf(stderr,
    "Corruption in block beginning %d and ending %d\n", input_byte_counter,
    input_byte_counter + len);
                                        fprintf(stderr,
    "Block size %d\n", i * sizeof(long));
                                        goto done;
                                }
                                input_byte_counter += len;
                        }
                }
done:
                printf("connection closed\n");
                close(accept_sock);
        }
}

int
main(int argc, char *argv[])
{
        struct sockaddr_in sin;
        long port, seed;
        char *dummy;

        if (argc < 2)
                usage();
        if (strcmp(argv[1], "client") == 0) {
                if (argc != 5)
                        usage();

                bzero(&sin, sizeof(sin));
                sin.sin_len = sizeof(sin);
                sin.sin_family = AF_INET;

                if (inet_aton(argv[2], &sin.sin_addr) != 1)
                        errx(-1, "%s: %s", argv[2], strerror(EINVAL));

                port = strtoul(argv[3], &dummy, 10);
                if (port < 1 || port > 65535 || *dummy != '\0')
                        usage();
                sin.sin_port = htons(port);

                seed = strtoul(argv[4], &dummy, 10);
                if (*dummy != '\0')
                        usage();

                tcpstream_client(sin, seed);

        } else if (strcmp(argv[1], "server") == 0) {
                if (argc != 4)
                        usage();

                bzero(&sin, sizeof(sin));
                sin.sin_len = sizeof(sin);
                sin.sin_family = AF_INET;
                sin.sin_addr.s_addr = INADDR_ANY;

                port = strtoul(argv[2], &dummy, 10);
                if (port < 1 || port > 65535 || *dummy != '\0')
                        usage();
                sin.sin_port = htons(port);

                seed = strtoul(argv[3], &dummy, 10);
                if (*dummy != '\0')
                        usage();

                tcpstream_server(sin, seed);
        } else
                usage();

        return (0);
}