624 lines
15 KiB
C
624 lines
15 KiB
C
/*
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* Copyright (c) 1983, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/param.h>
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#include <sys/poll.h>
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#include <sys/socket.h>
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#include <sys/stat.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <alloca.h>
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#include <signal.h>
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#include <fcntl.h>
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#include <netdb.h>
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#include <unistd.h>
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#include <pwd.h>
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#include <errno.h>
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#include <stdio.h>
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#include <ctype.h>
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#include <string.h>
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#include <libintl.h>
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int __ivaliduser __P ((FILE *, u_int32_t, const char *, const char *));
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static int __ivaliduser2 __P ((FILE *, u_int32_t, const char *, const char *,
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const char *));
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int
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rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
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char **ahost;
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u_short rport;
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const char *locuser, *remuser, *cmd;
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int *fd2p;
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{
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struct hostent hostbuf, *hp;
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size_t hstbuflen;
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char *tmphstbuf;
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struct sockaddr_in sin, from;
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struct pollfd pfd[2];
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int32_t oldmask;
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pid_t pid;
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int s, lport, timo;
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char c;
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int herr;
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pid = __getpid();
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hstbuflen = 1024;
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tmphstbuf = __alloca (hstbuflen);
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while (__gethostbyname_r (*ahost, &hostbuf, tmphstbuf, hstbuflen,
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&hp, &herr) < 0)
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if (herr != NETDB_INTERNAL || errno != ERANGE)
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{
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__set_h_errno (herr);
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herror(*ahost);
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return -1;
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}
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else
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{
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/* Enlarge the buffer. */
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hstbuflen *= 2;
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tmphstbuf = __alloca (hstbuflen);
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}
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pfd[0].events = POLLIN;
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pfd[1].events = POLLIN;
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*ahost = hp->h_name;
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oldmask = __sigblock(sigmask(SIGURG));
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for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
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s = rresvport(&lport);
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if (s < 0) {
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if (errno == EAGAIN)
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(void)fprintf(stderr,
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_("rcmd: socket: All ports in use\n"));
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else
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(void)fprintf(stderr, "rcmd: socket: %m\n");
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__sigsetmask(oldmask);
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return -1;
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}
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__fcntl(s, F_SETOWN, pid);
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sin.sin_family = hp->h_addrtype;
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bcopy(hp->h_addr_list[0], &sin.sin_addr,
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MIN (sizeof (sin.sin_addr), hp->h_length));
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sin.sin_port = rport;
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if (__connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
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break;
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(void)__close(s);
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if (errno == EADDRINUSE) {
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lport--;
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continue;
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}
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if (errno == ECONNREFUSED && timo <= 16) {
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(void)__sleep(timo);
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timo *= 2;
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continue;
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}
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if (hp->h_addr_list[1] != NULL) {
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int oerrno = errno;
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(void)fprintf(stderr, _("connect to address %s: "),
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inet_ntoa(sin.sin_addr));
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__set_errno (oerrno);
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perror(0);
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hp->h_addr_list++;
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bcopy(hp->h_addr_list[0], &sin.sin_addr,
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MIN (sizeof (sin.sin_addr), hp->h_length));
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(void)fprintf(stderr, _("Trying %s...\n"),
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inet_ntoa(sin.sin_addr));
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continue;
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}
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(void)fprintf(stderr, "%s: %m\n", hp->h_name);
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__sigsetmask(oldmask);
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return -1;
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}
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lport--;
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if (fd2p == 0) {
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__write(s, "", 1);
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lport = 0;
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} else {
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char num[8];
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int s2 = rresvport(&lport), s3;
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size_t len = sizeof(from);
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if (s2 < 0)
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goto bad;
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listen(s2, 1);
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(void)__snprintf(num, sizeof(num), "%d", lport);
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if (__write(s, num, strlen(num)+1) != strlen(num)+1) {
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(void)fprintf(stderr,
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_("rcmd: write (setting up stderr): %m\n"));
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(void)__close(s2);
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goto bad;
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}
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pfd[0].fd = s;
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pfd[1].fd = s2;
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__set_errno (0);
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if (__poll (pfd, 2, -1) < 1 || (pfd[1].revents & POLLIN) == 0){
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if (errno != 0)
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(void)fprintf(stderr,
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_("rcmd: poll (setting up stderr): %m\n"));
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else
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(void)fprintf(stderr,
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_("poll: protocol failure in circuit setup\n"));
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(void)__close(s2);
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goto bad;
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}
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s3 = accept(s2, (struct sockaddr *)&from, &len);
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(void)__close(s2);
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if (s3 < 0) {
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(void)fprintf(stderr,
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"rcmd: accept: %m\n");
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lport = 0;
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goto bad;
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}
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*fd2p = s3;
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from.sin_port = ntohs((u_short)from.sin_port);
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if (from.sin_family != AF_INET ||
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from.sin_port >= IPPORT_RESERVED ||
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from.sin_port < IPPORT_RESERVED / 2) {
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(void)fprintf(stderr,
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_("socket: protocol failure in circuit setup\n"));
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goto bad2;
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}
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}
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(void)__write(s, locuser, strlen(locuser)+1);
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(void)__write(s, remuser, strlen(remuser)+1);
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(void)__write(s, cmd, strlen(cmd)+1);
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if (__read(s, &c, 1) != 1) {
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(void)fprintf(stderr,
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"rcmd: %s: %m\n", *ahost);
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goto bad2;
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}
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if (c != 0) {
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while (__read(s, &c, 1) == 1) {
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(void)__write(STDERR_FILENO, &c, 1);
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if (c == '\n')
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break;
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}
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goto bad2;
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}
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__sigsetmask(oldmask);
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return s;
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bad2:
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if (lport)
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(void)__close(*fd2p);
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bad:
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(void)__close(s);
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__sigsetmask(oldmask);
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return -1;
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}
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int
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rresvport(alport)
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int *alport;
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{
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struct sockaddr_in sin;
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int s;
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sin.sin_family = AF_INET;
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sin.sin_addr.s_addr = INADDR_ANY;
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s = __socket(AF_INET, SOCK_STREAM, 0);
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if (s < 0)
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return -1;
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for (;;) {
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sin.sin_port = htons((u_short)*alport);
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if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
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return s;
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if (errno != EADDRINUSE) {
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(void)__close(s);
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return -1;
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}
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(*alport)--;
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if (*alport == IPPORT_RESERVED/2) {
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(void)__close(s);
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__set_errno (EAGAIN); /* close */
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return -1;
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}
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}
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}
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int __check_rhosts_file = 1;
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char *__rcmd_errstr;
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int
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ruserok(rhost, superuser, ruser, luser)
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const char *rhost, *ruser, *luser;
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int superuser;
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{
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struct hostent hostbuf, *hp;
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size_t buflen;
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char *buffer;
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u_int32_t addr;
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char **ap;
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int herr;
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buflen = 1024;
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buffer = __alloca (buflen);
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while (__gethostbyname_r (rhost, &hostbuf, buffer, buflen, &hp, &herr)
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< 0)
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if (herr != NETDB_INTERNAL || errno != ERANGE)
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return -1;
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else
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{
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/* Enlarge the buffer. */
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buflen *= 2;
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buffer = __alloca (buflen);
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}
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for (ap = hp->h_addr_list; *ap; ++ap) {
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bcopy(*ap, &addr, sizeof(addr));
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if (iruserok(addr, superuser, ruser, luser, rhost) == 0)
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return 0;
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}
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return -1;
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}
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/* Extremely paranoid file open function. */
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static FILE *
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iruserfopen (char *file, uid_t okuser)
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{
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struct stat st;
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char *cp = NULL;
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FILE *res = NULL;
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/* If not a regular file, if owned by someone other than user or
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root, if writeable by anyone but the owner, or if hardlinked
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anywhere, quit. */
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cp = NULL;
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if (__lxstat (_STAT_VER, file, &st))
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cp = _("lstat failed");
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else if (!S_ISREG (st.st_mode))
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cp = _("not regular file");
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else
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{
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res = fopen (file, "r");
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if (!res)
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cp = _("cannot open");
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else if (__fxstat (_STAT_VER, fileno (res), &st) < 0)
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cp = _("fstat failed");
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else if (st.st_uid && st.st_uid != okuser)
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cp = _("bad owner");
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else if (st.st_mode & (S_IWGRP|S_IWOTH))
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cp = _("writeable by other than owner");
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else if (st.st_nlink > 1)
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cp = _("hard linked somewhere");
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}
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/* If there were any problems, quit. */
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if (cp != NULL)
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{
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__rcmd_errstr = cp;
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if (res)
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fclose (res);
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return NULL;
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}
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return res;
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}
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/*
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* New .rhosts strategy: We are passed an ip address. We spin through
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* hosts.equiv and .rhosts looking for a match. When the .rhosts only
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* has ip addresses, we don't have to trust a nameserver. When it
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* contains hostnames, we spin through the list of addresses the nameserver
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* gives us and look for a match.
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*
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* Returns 0 if ok, -1 if not ok.
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*/
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static int
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iruserok2 (raddr, superuser, ruser, luser, rhost)
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u_int32_t raddr;
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int superuser;
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const char *ruser, *luser, *rhost;
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{
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FILE *hostf = NULL;
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int isbad;
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if (!superuser)
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hostf = iruserfopen (_PATH_HEQUIV, 0);
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if (hostf)
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{
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isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
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fclose (hostf);
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if (!isbad)
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return 0;
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}
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if (__check_rhosts_file || superuser)
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{
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char *pbuf;
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struct passwd pwdbuf, *pwd;
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size_t dirlen;
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size_t buflen = __sysconf (_SC_GETPW_R_SIZE_MAX);
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char *buffer = __alloca (buflen);
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uid_t uid;
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if (__getpwnam_r (luser, &pwdbuf, buffer, buflen, &pwd))
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return -1;
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dirlen = strlen (pwd->pw_dir);
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pbuf = alloca (dirlen + sizeof "/.rhosts");
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__mempcpy (__mempcpy (pbuf, pwd->pw_dir, dirlen),
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"/.rhosts", sizeof "/.rhosts");
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/* Change effective uid while reading .rhosts. If root and
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reading an NFS mounted file system, can't read files that
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are protected read/write owner only. */
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uid = __geteuid ();
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seteuid (pwd->pw_uid);
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hostf = iruserfopen (pbuf, pwd->pw_uid);
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if (hostf != NULL)
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{
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isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
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fclose (hostf);
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}
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seteuid (uid);
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return isbad;
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}
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return -1;
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}
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/* This is the exported version. */
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int
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iruserok (raddr, superuser, ruser, luser)
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u_int32_t raddr;
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int superuser;
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const char *ruser, *luser;
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{
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return iruserok2 (raddr, superuser, ruser, luser, "-");
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}
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/*
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* XXX
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* Don't make static, used by lpd(8).
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*
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* This function is not used anymore. It is only present because lpd(8)
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* calls it (!?!). We simply call __invaliduser2() with an illegal rhost
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* argument. This means that netgroups won't work in .rhost/hosts.equiv
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* files. If you want lpd to work with netgroups, fix lpd to use ruserok()
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* or PAM.
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* Returns 0 if ok, -1 if not ok.
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*/
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int
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__ivaliduser(hostf, raddr, luser, ruser)
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FILE *hostf;
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u_int32_t raddr;
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const char *luser, *ruser;
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{
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return __ivaliduser2(hostf, raddr, luser, ruser, "-");
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}
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/* Returns 1 on positive match, 0 on no match, -1 on negative match. */
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static int
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internal_function
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__icheckhost (raddr, lhost, rhost)
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u_int32_t raddr;
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char *lhost;
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const char *rhost;
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{
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struct hostent hostbuf, *hp;
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size_t buflen;
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char *buffer;
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int herr;
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int save_errno;
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u_int32_t laddr;
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int negate=1; /* Multiply return with this to get -1 instead of 1 */
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char **pp, *user;
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/* Check nis netgroup. */
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if (strncmp ("+@", lhost, 2) == 0)
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return innetgr (&lhost[2], rhost, NULL, NULL);
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if (strncmp ("-@", lhost, 2) == 0)
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return -innetgr (&lhost[2], rhost, NULL, NULL);
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/* -host */
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if (strncmp ("-", lhost,1) == 0) {
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negate = -1;
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lhost++;
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} else if (strcmp ("+",lhost) == 0) {
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return 1; /* asking for trouble, but ok.. */
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}
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/* Try for raw ip address first. */
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if (isdigit (*lhost) && (long) (laddr = inet_addr (lhost)) != -1)
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return negate * (! (raddr ^ laddr));
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/* Better be a hostname. */
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buflen = 1024;
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buffer = __alloca (buflen);
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save_errno = errno;
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while (__gethostbyname_r (lhost, &hostbuf, buffer, buflen, &hp, &herr)
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< 0)
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if (herr != NETDB_INTERNAL || errno != ERANGE)
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return (0);
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else {
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/* Enlarge the buffer. */
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buflen *= 2;
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buffer = __alloca (buflen);
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__set_errno (0);
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}
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__set_errno (save_errno);
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if (hp == NULL)
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return 0;
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/* Spin through ip addresses. */
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for (pp = hp->h_addr_list; *pp; ++pp)
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if (!memcmp (&raddr, *pp, sizeof (u_int32_t)))
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return negate;
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/* No match. */
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return (0);
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}
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/* Returns 1 on positive match, 0 on no match, -1 on negative match. */
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static int
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internal_function
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__icheckuser (luser, ruser)
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const char *luser, *ruser;
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{
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/*
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luser is user entry from .rhosts/hosts.equiv file
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ruser is user id on remote host
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*/
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char *user;
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/* [-+]@netgroup */
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if (strncmp ("+@", luser, 2) == 0)
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return innetgr (&luser[2], NULL, ruser, NULL);
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if (strncmp ("-@", luser,2) == 0)
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return -innetgr (&luser[2], NULL, ruser, NULL);
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/* -user */
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if (strncmp ("-", luser, 1) == 0)
|
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return -(strcmp (&luser[1], ruser) == 0);
|
|
|
|
/* + */
|
|
if (strcmp ("+", luser) == 0)
|
|
return 1;
|
|
|
|
/* simple string match */
|
|
return strcmp (ruser, luser) == 0;
|
|
}
|
|
|
|
/*
|
|
* Returns 1 for blank lines (or only comment lines) and 0 otherwise
|
|
*/
|
|
static int
|
|
__isempty(p)
|
|
char *p;
|
|
{
|
|
while (*p && isspace (*p)) {
|
|
++p;
|
|
}
|
|
|
|
return (*p == '\0' || *p == '#') ? 1 : 0 ;
|
|
}
|
|
|
|
/*
|
|
* Returns 0 if positive match, -1 if _not_ ok.
|
|
*/
|
|
static int
|
|
__ivaliduser2(hostf, raddr, luser, ruser, rhost)
|
|
FILE *hostf;
|
|
u_int32_t raddr;
|
|
const char *luser, *ruser, *rhost;
|
|
{
|
|
register const char *user;
|
|
register char *p;
|
|
int hcheck, ucheck;
|
|
char *buf = NULL;
|
|
size_t bufsize = 0;
|
|
int retval = -1;
|
|
|
|
while (__getline (&buf, &bufsize, hostf) > 0) {
|
|
buf[bufsize - 1] = '\0'; /* Make sure it's terminated. */
|
|
p = buf;
|
|
|
|
/* Skip empty or comment lines */
|
|
if (__isempty (p)) {
|
|
continue;
|
|
}
|
|
|
|
/* Skip lines that are too long. */
|
|
if (strchr (p, '\n') == NULL) {
|
|
int ch = getc (hostf);
|
|
|
|
while (ch != '\n' && ch != EOF)
|
|
ch = getc (hostf);
|
|
continue;
|
|
}
|
|
|
|
for (;*p && !isspace(*p); ++p) {
|
|
*p = _tolower (*p);
|
|
}
|
|
|
|
/* Next we want to find the permitted name for the remote user. */
|
|
if (*p == ' ' || *p == '\t') {
|
|
/* <nul> terminate hostname and skip spaces */
|
|
for (*p++='\0'; *p && isspace (*p); ++p);
|
|
|
|
user = p; /* this is the user's name */
|
|
while (*p && !isspace (*p))
|
|
++p; /* find end of user's name */
|
|
} else
|
|
user = p;
|
|
|
|
*p = '\0'; /* <nul> terminate username (+host?) */
|
|
|
|
/* buf -> host(?) ; user -> username(?) */
|
|
|
|
/* First check host part */
|
|
hcheck = __icheckhost (raddr, buf, rhost);
|
|
|
|
if (hcheck < 0)
|
|
break;
|
|
|
|
if (hcheck) {
|
|
/* Then check user part */
|
|
if (! (*user))
|
|
user = luser;
|
|
|
|
ucheck = __icheckuser (user, ruser);
|
|
|
|
/* Positive 'host user' match? */
|
|
if (ucheck > 0) {
|
|
retval = 0;
|
|
break;
|
|
}
|
|
|
|
/* Negative 'host -user' match? */
|
|
if (ucheck < 0)
|
|
break;
|
|
|
|
/* Neither, go on looking for match */
|
|
}
|
|
}
|
|
|
|
if (buf != NULL)
|
|
free (buf);
|
|
|
|
return retval;
|
|
}
|