/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright (c) 2018, Joyent, Inc.
 */

/*
 * Send a raw Ethernet frame once a second to a specified MAC address.
 */

#include <stdio.h>
#include <errno.h>
#include <strings.h>
#include <unistd.h>
#include <stdarg.h>
#include <libgen.h>
#include <limits.h>
#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#include <libdlpi.h>
#include <stddef.h>
#include <stdint.h>
#include <endian.h>
#include <err.h>

#include "dlsend.h"

static uint_t dlsend_sap = DLSEND_SAP;
static const char *dlsend_msg = DLSEND_MSG;
static const char *dlsend_prog;

static void
dlsend_usage(const char *fmt, ...)
{
        if (fmt != NULL) {
                va_list ap;

                (void) fprintf(stderr, "%s: ", dlsend_prog);
                va_start(ap, fmt);
                (void) vfprintf(stderr, fmt, ap);
                va_end(ap);
        }

        (void) fprintf(stderr, "Usage: %s [-s sap] device target-mac\n"
            "\t-s sap\tspecify SAP to send on\n",
            dlsend_prog);
}

int
main(int argc, char *argv[])
{
        int c, maclen, ret;
        unsigned long sap;
        char *eptr;
        uchar_t *mac;
        char host[MAXHOSTNAMELEN];
        uint_t bind_sap;
        dlpi_handle_t dh;
        uint64_t count;

        dlsend_prog = basename(argv[0]);

        while ((c = getopt(argc, argv, ":s:")) != -1) {
                switch (c) {
                case 's':
                        errno = 0;
                        sap = strtoul(optarg, &eptr, 10);
                        if (errno != 0 || sap == 0 || sap >= UINT16_MAX ||
                            *eptr != '\0') {
                                dlsend_usage("Invalid value for sap (-s): %s\n",
                                    optarg);
                                return (2);
                        }
                        dlsend_sap = sap;
                        break;
                case ':':
                        dlsend_usage("Option -%c requires an operand\n",
                            optopt);
                        return (2);
                case '?':
                        dlsend_usage("Unknown option: -%c\n", optopt);
                        return (2);
                }
        }

        argc -= optind;
        argv += optind;

        if (argc != 2) {
                dlsend_usage("missing required operands\n");
                return (2);
        }

        if ((mac = _link_aton(argv[1], &maclen)) == NULL) {
                warnx("failed to convert target address %s\n", argv[1]);
                return (1);
        }

        if (gethostname(host, sizeof (host)) != 0) {
                warnx("failed to obtain the system hostname: %s\n",
                    strerror(errno));
                (void) strlcpy(host, "<unknown host>", sizeof (host));
        }

        if ((ret = dlpi_open(argv[0], &dh, 0)) != DLPI_SUCCESS) {
                warnx("failed to open %s: %s\n", argv[0],
                    dlpi_strerror(ret));
                exit(1);
        }

        if ((ret = dlpi_bind(dh, dlsend_sap, &bind_sap)) != DLPI_SUCCESS) {
                warnx("failed to bind to sap 0x%x: %s\n", dlsend_sap,
                    dlpi_strerror(ret));
                exit(1);
        }

        if (bind_sap != dlsend_sap) {
                warnx("failed to bind to requested sap 0x%x, bound to "
                    "0x%x\n", dlsend_sap, bind_sap);
                exit(1);
        }

        count = 0;
        for (;;) {
                dlsend_msg_t msg;

                count++;
                bzero(&msg, sizeof (msg));
                msg.dm_count = htobe64(count);
                (void) strlcpy(msg.dm_host, host, sizeof (msg.dm_host));
                (void) strlcpy(msg.dm_mesg, dlsend_msg, sizeof (msg.dm_mesg));
                ret = dlpi_send(dh, mac, maclen, &msg, sizeof (msg), NULL);
                if (ret != DLPI_SUCCESS) {
                        warnx("failed to send message: %s\n",
                            dlpi_strerror(ret));
                        exit(1);
                }

                (void) sleep(1);
        }

        /* LINTED: E_STMT_NOT_REACHED */
        return (0);
}