backup/lib/myrcmd.c

/*
 * 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 1999 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <myrcmd.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <pwd.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/file.h>
#include <signal.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <netdb.h>
#include <fcntl.h>
#include <libintl.h>

#include <memutils.h>

#define index(s, c)     strchr(s, c)
char    *strchr();

char    *inet_ntoa();

char myrcmd_stderr[1024];

int
myrcmd(char **ahost, unsigned short rport, char *locuser, char *remuser,
    char *cmd)
{
    uint_t loclen, remlen, cmdlen;
    int s, timo, retval;
    int tries = 0;
    pid_t pid;
    struct sockaddr_in sin;
    char c;
    int lport;
    int saverr;
    struct hostent *hp;
    sigset_t oldmask;
    sigset_t newmask;
    struct sigaction oldaction;
    struct sigaction newaction;
    static struct hostent numhp;
    static char numhostname[32];    /* big enough for "255.255.255.255" */
    struct in_addr numaddr;
    struct in_addr *numaddrlist[2];

    myrcmd_stderr[0] = '\0';    /* empty error string */
    pid = getpid();
    hp = gethostbyname(*ahost);
    if (hp == 0) {
        char *straddr;

        bzero((char *)numaddrlist, sizeof (numaddrlist));
        if ((numaddr.s_addr = inet_addr(*ahost)) == (in_addr_t)-1) {
            (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
                gettext("%s: unknown host\n"), *ahost);
            return (MYRCMD_NOHOST);
        } else {
            bzero((char *)&numhp, sizeof (numhp));
            bzero(numhostname, sizeof (numhostname));

            if ((straddr = inet_ntoa(numaddr)) == (char *)0) {
                (void) snprintf(myrcmd_stderr,
                    sizeof (myrcmd_stderr),
                    gettext("%s: unknown host\n"), *ahost);
                return (MYRCMD_NOHOST);
            }
            (void) strncpy(numhostname, straddr,
                sizeof (numhostname));
            numhostname[sizeof (numhostname) - 1] = '\0';
            numhp.h_name = numhostname;
            numhp.h_addrtype = AF_INET;
            numhp.h_length = sizeof (numaddr);
            numaddrlist[0] = &numaddr;
            numaddrlist[1] = NULL;
            numhp.h_addr_list = (char **)numaddrlist;
            hp = &numhp;
        }
    }
    *ahost = hp->h_name;

    /* This provides a bounds-test for the bcopy()s below. */
    if ((unsigned)(hp->h_length) > sizeof (sin.sin_addr)) {
        (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
            gettext("rcmd: address size: %d larger than limit %d\n"),
            hp->h_length, sizeof (sin.sin_addr));
        return (MYRCMD_EBAD);
    }

    /* ignore SIGPIPE */
    bzero((char *)&newaction, sizeof (newaction));
    newaction.sa_handler = SIG_IGN;
    newaction.sa_flags = SA_ONSTACK;
    (void) sigaction(SIGPIPE, &newaction, &oldaction);

    /* block SIGURG */
    bzero((char *)&newmask, sizeof (newmask));
    (void) sigaddset(&newmask, SIGURG);
    (void) sigprocmask(SIG_BLOCK, &newmask, &oldmask);
again:
    timo = 1;
    /*
     * Use 0 as lport means that rresvport() will bind to a port in
     * the anonymous priviledged port range.
     */
    lport = 0;
    for (;;) {
        s = rresvport(&lport);
        if (s < 0) {
            int err;

            if (errno == EAGAIN) {
                (void) snprintf(myrcmd_stderr,
                    sizeof (myrcmd_stderr),
                    gettext("socket: All ports in use\n"));
                err = MYRCMD_ENOPORT;
            } else {
                saverr = errno;
                (void) snprintf(myrcmd_stderr,
                    sizeof (myrcmd_stderr),
                    gettext("rcmd: socket: %s\n"),
                    strerror(saverr));
                err = MYRCMD_ENOSOCK;
            }
            /* restore original SIGPIPE handler */
            (void) sigaction(SIGPIPE, &oldaction,
                (struct sigaction *)0);

            /* restore original signal mask */
            (void) sigprocmask(SIG_SETMASK, &oldmask,
                (sigset_t *)0);
            return (err);
        }
        /* Can't fail, according to fcntl(2) */
        (void) fcntl(s, F_SETOWN, pid);
        sin.sin_family = hp->h_addrtype;
        bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
        sin.sin_port = rport;
        if (connect(s, (struct sockaddr *)&sin, sizeof (sin)) >= 0)
            break;
        saverr = errno;
        (void) close(s);
        if (saverr == EADDRINUSE) {
            continue;
        }
        if (saverr == ECONNREFUSED && timo <= 16) {
            sleep(timo);
            timo *= 2;
            continue;
        }
        if (hp->h_addr_list[1] != NULL) {
            saverr = errno;

            fprintf(stderr,
                gettext("connect to address %s: "),
                inet_ntoa(sin.sin_addr));
            errno = saverr;
            perror(0);
            hp->h_addr_list++;
            bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr,
                hp->h_length);
            fprintf(stderr, gettext("Trying %s...\n"),
                inet_ntoa(sin.sin_addr));
            continue;
        }
        (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
            "%s: %s\n", hp->h_name, strerror(saverr));
        /* restore original SIGPIPE handler */
        (void) sigaction(SIGPIPE, &oldaction,
            (struct sigaction *)0);

        /* restore original signal mask */
        (void) sigprocmask(SIG_SETMASK, &oldmask, (sigset_t *)0);
        return (MYRCMD_ENOCONNECT);
    }
    if (write(s, "", 1) < 0) {
        (void) close(s);
        return (MYRCMD_ENOCONNECT);
    }

    loclen = strlen(locuser) + 1;
    remlen = strlen(remuser) + 1;
    cmdlen = strlen(cmd) + 1;

    if (((retval = write(s, locuser, loclen)) != loclen) ||
        ((retval = write(s, remuser, remlen)) != remlen) ||
        ((retval = write(s, cmd, cmdlen)) != cmdlen)) {
        if (retval == -1)
            (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
                "write: %s\n", strerror(errno));
        else
            (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
                gettext("write unexpectedly truncated\n"));
        goto bad;
    }
    retval = read(s, &c, 1);
    if (retval != 1) {
        if (retval == 0) {
            /*
             * Solaris 2.0 bug alert.  Sometimes, if the
             * tapehost is a Solaris 2.0 system, the connection
             * will be dropped at this point.  Let's try again,
             * three times, before we throw in the towel.
             */
            if (++tries < 3) {
                (void) close(s);
                goto again;
            }
            (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
                gettext("Protocol error, %s closed connection\n"),
                *ahost);
        } else if (retval < 0) {
            (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
                "%s: %s\n", *ahost, strerror(errno));
        } else {
            (void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
                gettext("Protocol error, %s sent %d bytes\n"),
                *ahost, retval);
        }
        goto bad;
    }
    if (c != 0) {
        char *cp = myrcmd_stderr;
        char *ecp = &myrcmd_stderr[sizeof (myrcmd_stderr) - 1];

        while (read(s, &c, 1) == 1) {
            *cp++ = c;
            if (c == '\n' || cp >= ecp)
                break;
        }
        *cp = '\0';
        goto bad;
    }
    /* restore original SIGPIPE handler */
    (void) sigaction(SIGPIPE, &oldaction, (struct sigaction *)0);

    /* restore original signal mask */
    (void) sigprocmask(SIG_SETMASK, &oldmask, (sigset_t *)0);
    return (s);
bad:
    (void) close(s);
    /* restore original SIGPIPE handler */
    (void) sigaction(SIGPIPE, &oldaction, (struct sigaction *)0);

    /* restore original signal mask */
    (void) sigprocmask(SIG_SETMASK, &oldmask, (sigset_t *)0);
    return (MYRCMD_EBAD);
}