/*-
 * Copyright (c) 2007 Bruce M. Simpson
 * 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.
 */

/*
 * Test utility for IPv4 broadcast sockets.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <pwd.h>
#include <unistd.h>
#include <netdb.h>
#include <libgen.h>

#ifndef IP_SENDIF
#define IP_SENDIF       24              /* XXX */
#endif

#ifndef IPPROTO_ZEROHOP
#define IPPROTO_ZEROHOP 114             /* any 0-hop protocol */
#endif

#define DEFAULT_PORT            6698
#define DEFAULT_PAYLOAD_SIZE    24
#define DEFAULT_TTL             1

#define MY_CMSG_SIZE                            \
        CMSG_SPACE(sizeof(struct in_addr)) +    \
        CMSG_SPACE(sizeof(struct sockaddr_dl))

static char *progname = NULL;

static void
usage(void)
{

        fprintf(stderr, "IPv4 broadcast test program. Sends a %d byte UDP "
                "datagram to <dest>:<port>.\n\n", DEFAULT_PAYLOAD_SIZE);
        fprintf(stderr,
"usage: %s [-1] [-A laddr] [-b] [-B] [-d] [-i iface] [-l len]\n"
"                   [-p port] [-R] [-s srcaddr] [-t ttl] <dest>\n",
            progname);
        fprintf(stderr, "-1: Set IP_ONESBCAST\n");
        fprintf(stderr, "-A: specify laddr (default: INADDR_ANY)\n");
        fprintf(stderr, "-b: bind socket to <laddr>:<lport>\n");
        fprintf(stderr, "-B: Set SO_BROADCAST\n");
        fprintf(stderr, "-d: Set SO_DONTROUTE\n");
        fprintf(stderr, "-i: Set IP_SENDIF <iface> (if supported)\n");
        fprintf(stderr, "-l: Set payload size to <len>\n");
        fprintf(stderr, "-p: Set local and remote port (default: %d)\n",
            DEFAULT_PORT);
        fprintf(stderr, "-R: Use raw IP (protocol %d)\n", IPPROTO_ZEROHOP);
        fprintf(stderr, "-s: Set IP_SENDSRCADDR to <srcaddr>\n");
        fprintf(stderr, "-t: Set IP_TTL to <ttl>\n");

        exit(EXIT_FAILURE);
}

int
main(int argc, char *argv[])
{
        char                    *buf;
        char                     cmsgbuf[MY_CMSG_SIZE];
        struct iovec             iov[1];
        struct msghdr            msg;
        struct sockaddr_in       dsin;
        struct sockaddr_in       laddr;
        struct cmsghdr          *cmsgp;
        struct in_addr           dstaddr;
        char                    *ifname;
        char                    *laddr_s;
        char                    *srcaddr_s;
        int                      ch;
        int                      dobind;
        int                      dobroadcast;
        int                      dontroute;
        int                      doonesbcast;
        int                      dorawip;
        size_t                   buflen;
        ssize_t                  nbytes;
        int                      portno;
        int                      ret;
        int                      s;
        socklen_t                soptlen;
        int                      soptval;
        int                      ttl;

        dobind = 0;
        dobroadcast = 0;
        dontroute = 0;
        doonesbcast = 0;
        dorawip = 0;

        ifname = NULL;
        dstaddr.s_addr = INADDR_ANY;
        laddr_s = NULL;
        srcaddr_s = NULL;
        portno = DEFAULT_PORT;
        ttl = DEFAULT_TTL;

        buf = NULL;
        buflen = DEFAULT_PAYLOAD_SIZE;

        progname = basename(argv[0]);
        while ((ch = getopt(argc, argv, "1A:bBdi:l:p:Rs:t:")) != -1) {
                switch (ch) {
                case '1':
                        doonesbcast = 1;
                        break;
                case 'A':
                        laddr_s = optarg;
                        break;
                case 'b':
                        dobind = 1;
                        break;
                case 'B':
                        dobroadcast = 1;
                        break;
                case 'd':
                        dontroute = 1;
                        break;
                case 'i':
                        ifname = optarg;
                        break;
                case 'l':
                        buflen = atoi(optarg);
                        break;
                case 'p':
                        portno = atoi(optarg);
                        break;
                case 'R':
                        dorawip = 1;
                        break;
                case 's':
                        srcaddr_s = optarg;
                        break;
                case 't':
                        ttl = atoi(optarg);
                        break;
                default:
                        usage();
                        break;
                }
        }
        argc -= optind;
        argv += optind;

        if (argc != 1)
                usage();
        if (argv[0] == NULL || inet_aton(argv[0], &dstaddr) == 0)
                usage();
        /* IP_SENDSRCADDR and IP_SENDIF are mutually exclusive just now. */
        if (srcaddr_s != NULL && ifname != NULL)
                usage();
        if (dorawip) {
                if (geteuid() != 0)
                        fprintf(stderr, "WARNING: not running as root.\n");
                s = socket(PF_INET, SOCK_RAW, IPPROTO_ZEROHOP);
        } else {
                s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
        }
        if (s == -1) {
                perror("socket");
                exit(EXIT_FAILURE);
        }

        if (dontroute) {
                soptval = 1;
                soptlen = sizeof(soptval);
                ret = setsockopt(s, SOL_SOCKET, SO_DONTROUTE, &soptval,
                    soptlen);
                if (ret == -1) {
                        perror("setsockopt SO_DONTROUTE");
                        close(s);
                        exit(EXIT_FAILURE);
                }
        }

        if (dobroadcast) {
                soptval = 1;
                soptlen = sizeof(soptval);
                ret = setsockopt(s, SOL_SOCKET, SO_BROADCAST, &soptval,
                    soptlen);
                if (ret == -1) {
                        perror("setsockopt SO_BROADCAST");
                        close(s);
                        exit(EXIT_FAILURE);
                }
        }

        soptval = ttl;
        soptlen = sizeof(soptval);
        ret = setsockopt(s, IPPROTO_IP, IP_TTL, &soptval, soptlen);
        if (ret == -1) {
                perror("setsockopt IPPROTO_IP IP_TTL");
                close(s);
                exit(EXIT_FAILURE);
        }

        if (doonesbcast) {
                soptval = 1;
                soptlen = sizeof(soptval);
                ret = setsockopt(s, IPPROTO_IP, IP_ONESBCAST, &soptval,
                    soptlen);
                if (ret == -1) {
                        perror("setsockopt IP_ONESBCAST");
                        close(s);
                        exit(EXIT_FAILURE);
                }
        }

        if (dobind) {
                memset(&laddr, 0, sizeof(struct sockaddr_in));
                laddr.sin_family = AF_INET;
                laddr.sin_len = sizeof(struct sockaddr_in);
                if (laddr_s != NULL) {
                        laddr.sin_addr.s_addr = inet_addr(laddr_s);
                } else
                        laddr.sin_addr.s_addr = INADDR_ANY;
                laddr.sin_port = htons(portno);
                ret = bind(s, (struct sockaddr *)&laddr, sizeof(laddr));
                if (ret == -1) {
                        perror("bind");
                        close(s);
                        exit(EXIT_FAILURE);
                }
        }

        memset(&dsin, 0, sizeof(struct sockaddr_in));
        dsin.sin_family = AF_INET;
        dsin.sin_len = sizeof(struct sockaddr_in);
        dsin.sin_addr.s_addr = dstaddr.s_addr;
        dsin.sin_port = htons(portno);

        buf = malloc(buflen);
        if (buf == NULL) {
                perror("malloc");
                close(s);
                exit(EXIT_FAILURE);
        }
        memset(iov, 0, sizeof(iov));
        iov[0].iov_base = buf;
        iov[0].iov_len = buflen;

        memset(&msg, 0, sizeof(struct msghdr));
        msg.msg_name = &dsin;
        msg.msg_namelen = sizeof(dsin);
        msg.msg_iov = iov;
        msg.msg_iovlen = 1;

        /* Assume we fill out a control msg; macros need to see buf ptr */
        msg.msg_control = cmsgbuf;
        msg.msg_controllen = 0;
        memset(cmsgbuf, 0, MY_CMSG_SIZE);

        /* IP_SENDSRCADDR and IP_SENDIF are mutually exclusive just now. */
        if (srcaddr_s != NULL) {
                msg.msg_controllen += CMSG_SPACE(sizeof(struct in_addr));
                cmsgp = CMSG_FIRSTHDR(&msg);
                cmsgp->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
                cmsgp->cmsg_level = IPPROTO_IP;
                cmsgp->cmsg_type = IP_SENDSRCADDR;
                memcpy(CMSG_DATA(cmsgp),
                    &(struct in_addr){ inet_addr(srcaddr_s) },
                    sizeof(struct in_addr));
        }

        if (ifname != NULL) {
#ifdef IP_SENDIF
                msg.msg_controllen += CMSG_SPACE(sizeof(struct sockaddr_dl));
                cmsgp = CMSG_FIRSTHDR(&msg);
                cmsgp->cmsg_len = CMSG_LEN(sizeof(struct sockaddr_dl));
                cmsgp->cmsg_level = IPPROTO_IP;
                cmsgp->cmsg_type = IP_SENDIF;

#ifdef DIAGNOSTIC
                fprintf(stderr, "DEBUG: cmsgp->cmsg_len is %d\n",
                    cmsgp->cmsg_len);
#endif
                memcpy(CMSG_DATA(cmsgp), &(struct sockaddr_dl){
                    .sdl_family = AF_LINK,
                    .sdl_len = sizeof(struct sockaddr_dl),
                    .sdl_index = if_nametoindex(ifname) },
                    sizeof(struct sockaddr_dl));
#ifdef DIAGNOSTIC
                fprintf(stderr, "DEBUG: sdl->sdl_family is %d\n",
                    sdl->sdl_family);
                fprintf(stderr, "DEBUG: sdl->sdl_len is %d\n",
                    sdl->sdl_len);
                fprintf(stderr, "DEBUG: sdl->sdl_index is %d\n",
                    sdl->sdl_index);
#endif
#else
                fprintf(stderr, "WARNING: IP_SENDIF not supported, ignored.\n");
#endif
        }

        if (msg.msg_controllen == 0)
                msg.msg_control = NULL;

        nbytes = sendmsg(s, &msg, (dontroute ? MSG_DONTROUTE : 0));
        if (nbytes == -1) {
                perror("sendmsg");
                close(s);
                exit(EXIT_FAILURE);
        }

        close(s);

        exit(EXIT_SUCCESS);
}