/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

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

#include <netinet/in.h>

#include <stdio.h>
#include <netdb.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <libintl.h>

#ifdef SYSV
#define bcopy(a, b, c)  (void) memcpy((b), (a), (c))
#endif

#define MAX_SHORTSTRLEN 6

void _ruserpass(const char *host, char **aname, char **apass);

int rexec(char **ahost, unsigned short rport, const char *name,
    const char *pass, const char *cmd, int *fd2p)
{
                return (rexec_af(ahost, rport, name, pass, cmd, fd2p, AF_INET));
}

int rexec_af(char **ahost, unsigned short rport, const char *name,
    const char *pass, const char *cmd, int *fd2p, int af)
{
        int s, timo = 1, s3;
        char c;
        ushort_t port;
        static char hostname[MAXHOSTNAMELEN];
        int rc;
        struct addrinfo *res;
        struct addrinfo hints;
        char aport[MAX_SHORTSTRLEN];

        if (!(af == AF_INET || af == AF_INET6 || af == AF_UNSPEC)) {
                (void) fprintf(stderr,
                    dgettext(TEXT_DOMAIN, "%d: Address family not "
                    "supported\n"), af);
                errno = EAFNOSUPPORT;
                return (-1);
        }
        memset(&hints, 0, sizeof (hints));
        (void) snprintf(aport, MAX_SHORTSTRLEN, "%u", ntohs(rport));
        hints.ai_flags = AI_CANONNAME|AI_ADDRCONFIG|AI_V4MAPPED;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_family = af;
        rc = getaddrinfo(*ahost, aport, &hints, &res);

        if (rc != 0) {
                (void) fprintf(stderr,
                    dgettext(TEXT_DOMAIN, "%s: unknown host\n"),
                    *ahost);
                return (-1);
        }
        (void) strlcpy(hostname, res->ai_canonname, MAXHOSTNAMELEN);
        *ahost = hostname;
        _ruserpass(res->ai_canonname, (char **)&name, (char **)&pass);
retry:
        s = socket(res->ai_addr->sa_family, res->ai_socktype, res->ai_protocol);
        if (s < 0) {
                perror("rexec: socket");
                freeaddrinfo(res);
                return (-1);
        }
        if (connect(s, res->ai_addr, res->ai_addrlen) != 0) {
                if (errno == ECONNREFUSED && timo <= 16) {
                        (void) close(s);
                        (void) sleep(timo);
                        timo *= 2;
                        goto retry;
                }
                perror(*ahost);
                (void) close(s);
                freeaddrinfo(res);
                return (-1);
        }
        if (fd2p == 0) {
                (void) write(s, "", 1);
                port = 0;
        } else {
                int s2;
                socklen_t sin2len;
                struct sockaddr_storage sin2, from;

                s2 = socket(res->ai_family, SOCK_STREAM, 0);
                if (s2 < 0) {
                        (void) close(s);
                        freeaddrinfo(res);
                        return (-1);
                }
                (void) listen(s2, 1);
                sin2len = (socklen_t)sizeof (sin2);
                if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0) {
                        perror("getsockname");
                        (void) close(s2);
                        goto bad;
                }
                if (res->ai_family == AF_INET6) {
                        port = ntohs(((struct sockaddr_in6 *)&sin2)->sin6_port);
                } else {
                        port = ntohs(((struct sockaddr_in *)&sin2)->sin_port);
                }
                (void) snprintf(aport, MAX_SHORTSTRLEN, "%u", port);
                (void) write(s, aport, strlen(aport)+1);
                {
                        socklen_t len = (socklen_t)sizeof (from);
                        s3 = accept(s2, (struct sockaddr *)&from, &len);
                        (void) close(s2);
                        if (s3 < 0) {
                                perror("accept");
                                port = 0;
                                goto bad;
                        }
                }
                *fd2p = s3;
        }
        (void) write(s, name, strlen(name) + 1);
        /* should public key encypt the password here */
        (void) write(s, pass, strlen(pass) + 1);
        (void) write(s, cmd, strlen(cmd) + 1);
        if (read(s, &c, 1) != 1) {
                perror(*ahost);
                goto bad;
        }
        if (c != 0) {
                while (read(s, &c, 1) == 1) {
                        (void) write(2, &c, 1);
                        if (c == '\n')
                                break;
                }
                goto bad;
        }
        freeaddrinfo(res);
        return (s);
bad:
        if (port)
                (void) close(*fd2p);
        (void) close(s);
        freeaddrinfo(res);
        return (-1);
}