/*
 * 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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * mconnect.c - A program to test out SMTP connections.
 * Usage: mconnect [host]
 *  ... SMTP dialog
 *  ^C or ^D or QUIT
 */

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <ctype.h>
#include <string.h>
#include <strings.h>
#include <sgtty.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <errno.h>

union bigsockaddr
{
        struct sockaddr         sa;     /* general version */
        struct sockaddr_in      sin;    /* INET family */
        struct sockaddr_in6     sin6;   /* INET/IPv6 */
};

static struct sgttyb TtyBuf;
static int raw = 0;

/* ARGSUSED */
static void
finis(sig)
        int sig;
{
        if (raw)
                (void) ioctl(0, TIOCSETP, &TtyBuf);
        exit(0);
}

int
main(argc, argv)
        int argc;
        char **argv;
{
        union bigsockaddr SendmailAddress;
        register int s;
        char *host = NULL;
        int pid;
        int on = 1;
        struct servent *sp;
        char buf[1000];
        register FILE *f;
        register struct hostent *hp;
        in_port_t port = 0;
        int err;
        char buf6[INET6_ADDRSTRLEN];
        int addr_num = 0;
        int addrlen;

        (void) ioctl(0, TIOCGETP, &TtyBuf);
        (void) signal(SIGINT, finis);

        while (--argc > 0)
        {
                register char *p;

                p = *++argv;
                if (*p == '-')
                {
                        switch (*++p)
                        {
                            case 'h':           /* host */
                                break;

                            case 'p':           /* port */
                                port = htons(atoi(*++argv));
                                argc--;
                                break;

                            case 'r':           /* raw connection */
                                raw = 1;
                                break;
                        }
                } else if (host == NULL)
                        host = p;
        }
        if (host == NULL)
                host = "localhost";

        bzero(&SendmailAddress, sizeof (SendmailAddress));
        hp = getipnodebyname(host, AF_INET6, AI_DEFAULT|AI_ALL, &err);
        if (hp == NULL)
        {
                (void) fprintf(stderr, "mconnect: unknown host %s\r\n", host);
                exit(0);
        }

        if (port == 0) {
                sp = getservbyname("smtp", "tcp");
                if (sp != NULL)
                        port = sp->s_port;
        }

        for (;;) {
                bcopy(hp->h_addr_list[addr_num],
                    &SendmailAddress.sin6.sin6_addr, IN6ADDRSZ);
                if (IN6_IS_ADDR_V4MAPPED(&SendmailAddress.sin6.sin6_addr)) {
                        SendmailAddress.sa.sa_family = AF_INET;
                        SendmailAddress.sin.sin_port = port;
                        bcopy(&hp->h_addr_list[addr_num][IN6ADDRSZ - INADDRSZ],
                                &SendmailAddress.sin.sin_addr, INADDRSZ);
                        addrlen = sizeof (struct sockaddr_in);
                } else {
                        SendmailAddress.sa.sa_family = AF_INET6;
                        SendmailAddress.sin6.sin6_port = port;
                        addrlen = sizeof (struct sockaddr_in6);
                }

                s = socket(SendmailAddress.sa.sa_family, SOCK_STREAM, 0);
                if (s < 0)
                {
                        perror("socket");
                        exit(-1);
                }
                (void) setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (char *)&on,
                    sizeof (on));
                if (SendmailAddress.sa.sa_family == AF_INET)
                        (void) printf("connecting to host %s (%s), port %d\r\n",
                                host, inet_ntoa(SendmailAddress.sin.sin_addr),
                                ntohs(SendmailAddress.sin.sin_port));
                else
                        (void) printf("connecting to host %s (%s), port %d\r\n",
                                host, inet_ntop(AF_INET6,
                                        SendmailAddress.sin6.sin6_addr.s6_addr,
                                        buf6, sizeof (buf6)),
                                ntohs(SendmailAddress.sin6.sin6_port));
                if (connect(s, (struct sockaddr *)&SendmailAddress,
                                addrlen) >= 0)
                        break;
                if (hp->h_addr_list[++addr_num] != NULL) {
                        (void) printf("connect failed (%s), next address ...\n",
                                strerror(errno));
                        bcopy(hp->h_addr_list[addr_num],
                                &SendmailAddress.sin6.sin6_addr, IN6ADDRSZ);
                        if (IN6_IS_ADDR_V4MAPPED(
                            &SendmailAddress.sin6.sin6_addr)) {
                                SendmailAddress.sa.sa_family = AF_INET;
                                bcopy(&hp->h_addr_list[addr_num]
                                    [IN6ADDRSZ - INADDRSZ],
                                        &SendmailAddress.sin.sin_addr,
                                        INADDRSZ);
                                addrlen = sizeof (struct sockaddr_in);
                        } else {
                                SendmailAddress.sa.sa_family = AF_INET6;
                                addrlen = sizeof (struct sockaddr_in6);
                        }
                        continue;
                }
                perror("connect");
                exit(-1);
        }

        if (raw) {
                TtyBuf.sg_flags &= ~CRMOD;
                (void) ioctl(0, TIOCSETP, &TtyBuf);
                TtyBuf.sg_flags |= CRMOD;
        }

        /* good connection, fork both sides */
        (void) printf("connection open\n");
        pid = fork();
        if (pid < 0)
        {
                perror("fork");
                exit(-1);
        }
        if (pid == 0)
        {
                /* child -- standard input to sendmail */
                int c;

                f = fdopen(s, "w");
                while ((c = fgetc(stdin)) >= 0)
                {
                        if (!raw && c == '\n')
                                (void) fputc('\r', f);
                        (void) fputc(c, f);
                        if (c == '\n')
                                (void) fflush(f);
                }
                (void) shutdown(s, 1);
                (void) sleep(10);
        }
        else
        {
                /* parent -- sendmail to standard output */
                f = fdopen(s, "r");
                while (fgets(buf, sizeof (buf), f) != NULL)
                {
                        (void) fputs(buf, stdout);
                        (void) fflush(stdout);
                }
                (void) kill(pid, SIGTERM);
        }
        if (raw)
                (void) ioctl(0, TIOCSETP, &TtyBuf);
        return (0);
}