/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * chargen inetd service - both stream and dgram based.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <stdio.h>
#include <strings.h>
#include <netinet/in.h>
#include <sys/sysmacros.h>
#include <ctype.h>
#include <inetsvc.h>


#define LINESIZE                72
#define RINGSIZE                128


static  char    ring[RINGSIZE];
static  char    *endring;


static void
initring(void)
{
        unsigned char ch;

        endring = ring;

        for (ch = 0; ch <= RINGSIZE; ++ch) {
                if (isprint(ch))
                        *endring++ = ch;
        }
}

static void
chargen_stream(int s, char *argv[])
{
        char    text[LINESIZE+2];
        int     i;
        char    *rp;
        char    *dp;
        char    *rs = ring;

        setproctitle("chargen", s, argv);

        for (;;) {
                if (rs >= endring)
                        rs = ring;
                rp = rs++;
                dp = text;
                i = MIN(LINESIZE, endring - rp);
                (void) memmove(dp, rp, i);
                dp += i;
                if ((rp += i) >= endring)
                        rp = ring;
                if (i < LINESIZE) {
                        i = LINESIZE - i;
                        (void) memmove(dp, rp, i);
                        dp += i;
                        if ((rp += i) >= endring)
                                rp = ring;
                }

                *dp++ = '\r';
                *dp++ = '\n';

                if (safe_write(s, text, dp - text) != 0)
                        break;
        }
}

/* ARGSUSED3 */
static void
chargen_dg(int s, const struct sockaddr *sap, int sa_size, const void *buf,
    size_t sz)
{
        char            text[LINESIZE+2];
        int             i;
        char            *rp;
        static char     *rs = ring;

        rp = rs;
        if (rs++ >= endring)
                rs = ring;
        i = MIN(LINESIZE, endring - rp);
        (void) memmove(text, rp, i);
        if ((rp += i) >= endring)
                rp = ring;
        if (i < LINESIZE) {
                (void) memmove(text, rp, i);
                if ((rp += i) >= endring)
                        rp = ring;
        }

        text[LINESIZE - 2] = '\r';
        text[LINESIZE - 1] = '\n';

        (void) safe_sendto(s, text, sizeof (text), 0, sap, sa_size);
}

int
main(int argc, char *argv[])
{
        opterr = 0;     /* disable getopt error msgs */

        initring();

        switch (getopt(argc, argv, "ds")) {
        case 'd':
                dg_template(chargen_dg, STDIN_FILENO, NULL, 0);
                break;
        case 's':
                chargen_stream(STDIN_FILENO, argv);
                break;
        default:
                return (1);
        }

        return (0);
}