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Import NetBSD rcmd, rcp, rsh, rshd

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Change-Id: I83d908bbe17f04826e9b5c3a220a5bb2c3a51c80
This commit is contained in:
David van Moolenbroek
2015-09-19 17:12:39 +00:00
parent ed223591a8
commit 93d36fc9d8
35 changed files with 3375 additions and 2239 deletions
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2
libexec/Makefile
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@@ -6,7 +6,7 @@
SUBDIR= \
fingerd ftpd getty \
ld.elf_so \
\
rshd \

26
libexec/rshd/Makefile Normal file
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@@ -0,0 +1,26 @@
# $NetBSD: Makefile,v 1.19 2011/08/16 10:35:03 christos Exp $
# from: @(#)Makefile 8.1 (Berkeley) 6/4/93
.include <bsd.own.mk>
PROG= rshd
MAN= rshd.8
DPADD+= ${LIBUTIL}
LDADD+= -lutil
CPPFLAGS+=-DLOGIN_CAP
.if (${USE_INET6} != "no")
CPPFLAGS+=-DINET6
.endif
.if (${USE_PAM} != "no")
CPPFLAGS+=-DUSE_PAM
DPADD+= ${LIBPAM} ${PAM_STATIC_DPADD}
LDADD+= -lpam ${PAM_STATIC_LDADD}
.endif
COPTS.rshd.c = -Wno-format-nonliteral
.include <bsd.prog.mk>

235
libexec/rshd/rshd.8 Normal file
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@@ -0,0 +1,235 @@
.\" $NetBSD: rshd.8,v 1.18 2005/03/09 16:42:49 wiz Exp $
.\"
.\" Copyright (c) 1983, 1989, 1991, 1993
.\" The Regents of the University of California. 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.
.\" 3. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
.\"
.\" from: @(#)rshd.8 8.1 (Berkeley) 6/4/93
.\"
.Dd March 9, 2005
.Dt RSHD 8
.Os
.Sh NAME
.Nm rshd
.Nd remote shell server
.Sh SYNOPSIS
.Nm
.Op Fl aLln
.Sh DESCRIPTION
The
.Nm
server is the server for the
.Xr rcmd 3
routine and, consequently, for the
.Xr rsh 1
program.
The server provides remote execution facilities
with authentication based on privileged port numbers from trusted hosts.
.Pp
The
.Nm
server listens for service requests at the port indicated in
the
.Dq cmd
service specification; see
.Xr services 5 .
When a service request is received the following protocol
is initiated:
.Bl -enum
.It
The server checks the client's source port.
If the port is not in the range 512-1023, the server
aborts the connection.
.It
The server reads characters from the socket up
to a null
.Pq Sq \e0
byte.
The resultant string is interpreted as an
.Tn ASCII
number, base 10.
.It
If the number received in step 2 is non-zero,
it is interpreted as the port number of a secondary
stream to be used for the
.Em stderr .
A second connection is then created to the specified
port on the client's machine.
The source port of this
second connection is also in the range 512-1023.
.It
The server checks the client's source address
and requests the corresponding host name (see
.Xr getnameinfo 3 ,
.Xr hosts 5 ,
and
.Xr named 8 ) .
If the hostname cannot be determined,
the dot-notation representation of the host address is used.
If the hostname is in the same domain as the server (according to
the last two components of the domain name), or if the
.Fl a
option is given,
the addresses for the hostname are requested,
verifying that the name and address correspond.
If address verification fails, the connection is aborted
with the message
.Dq Host address mismatch.
.It
A null terminated user name of at most 16 characters
is retrieved on the initial socket.
This user name is interpreted as the user identity on the
.Em client Ns 's
machine.
.It
A null terminated user name of at most 16 characters
is retrieved on the initial socket.
This user name is interpreted as a user identity to use on the
.Sy server Ns 's
machine.
.It
A null terminated command to be passed to a
shell is retrieved on the initial socket.
The length of the command is limited by the upper
bound on the size of the system's argument list.
.It
.Nm
then validates the user using
.Xr ruserok 3 ,
which uses the file
.Pa /etc/hosts.equiv
and the
.Pa .rhosts
file found in the user's home directory.
The
.Fl l
option prevents
.Xr ruserok 3
from doing any validation based on the user's
.Dq Pa .rhosts
file, unless the user is the superuser.
.It
If the file
.Pa /etc/nologin
exists and the user is not the superuser,
the connection is closed.
.It
A null byte is returned on the initial socket
and the command line is passed to the normal login
shell of the user.
The shell inherits the network connections established by
.Nm .
.El
.Pp
Transport-level keepalive messages are enabled unless the
.Fl n
option is present.
The use of keepalive messages allows sessions to be timed out
if the client crashes or becomes unreachable.
.Pp
The
.Fl L
option causes all successful accesses to be logged to
.Xr syslogd 8
as
.Li auth.info
messages.
.Sh DIAGNOSTICS
Except for the last one listed below,
all diagnostic messages
are returned on the initial socket,
after which any network connections are closed.
An error is indicated by a leading byte with a value of
1 (0 is returned in step 10 above upon successful completion
of all the steps prior to the execution of the login shell).
.Bl -tag -width indent
.It Sy Locuser too long.
The name of the user on the client's machine is
longer than 16 characters.
.It Sy Ruser too long.
The name of the user on the remote machine is
longer than 16 characters.
.It Sy Command too long .
The command line passed exceeds the size of the argument
list (as configured into the system).
.It Sy Login incorrect.
No password file entry for the user name existed.
.It Sy Remote directory.
The
.Xr chdir 2
to the home directory failed.
.It Sy Permission denied.
The authentication procedure described above failed.
.It Sy Can't make pipe.
The pipe needed for the
.Em stderr ,
wasn't created.
.It Sy Can't fork; try again.
A
.Xr fork 2
by the server failed.
.It Sy \*[Lt]shellname\*[Gt]: ...
The user's login shell could not be started.
This message is returned on the connection associated with the
.Em stderr ,
and is not preceded by a flag byte.
.El
.Sh SEE ALSO
.Xr rsh 1 ,
.Xr ssh 1 ,
.Xr rcmd 3 ,
.Xr ruserok 3 ,
.Xr hosts_access 5 ,
.Xr login.conf 5 ,
.Xr sshd 8
.Sh BUGS
The authentication procedure used here assumes the integrity
of every machine and every network that can reach the rshd/rlogind
ports on the server.
This is insecure, but is useful in an
.Dq open
environment.
.Xr sshd 8
or a Kerberized version of this server are much more secure.
.Pp
A facility to allow all data exchanges to be encrypted should be
present.
.Pp
A more extensible protocol (such as Telnet) should be used.
.Pp
.Nm
intentionally rejects accesses from IPv4 mapped address on top of
.Dv AF_INET6
socket, since IPv4 mapped address complicates
host-address based authentication.
If you would like to accept connections from IPv4 peers, you will
need to run
.Nm
on top of an
.Dv AF_INET
socket, not an
.Dv AF_INET6
socket.

809
libexec/rshd/rshd.c Normal file
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@@ -0,0 +1,809 @@
/* $NetBSD: rshd.c,v 1.50 2012/07/14 15:06:26 darrenr Exp $ */
/*
* Copyright (C) 1998 WIDE Project.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by WIDE Project and
* its contributors.
* 4. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
*/
/*-
* Copyright (c) 1988, 1989, 1992, 1993, 1994
* The Regents of the University of California. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1992, 1993, 1994\
The Regents of the University of California. All rights reserved.");
#if 0
static char sccsid[] = "@(#)rshd.c 8.2 (Berkeley) 4/6/94";
#else
__RCSID("$NetBSD: rshd.c,v 1.50 2012/07/14 15:06:26 darrenr Exp $");
#endif
#endif /* not lint */
/*
* remote shell server:
* [port]\0
* remuser\0
* locuser\0
* command\0
* data
*/
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <poll.h>
#ifdef LOGIN_CAP
#include <login_cap.h>
#endif
#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/openpam.h>
#include <sys/wait.h>
static struct pam_conv pamc = { openpam_nullconv, NULL };
static pam_handle_t *pamh;
static int pam_err;
#define PAM_END do { \
if ((pam_err = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \
syslog(LOG_ERR|LOG_AUTH, "pam_setcred(): %s", \
pam_strerror(pamh, pam_err)); \
if ((pam_err = pam_close_session(pamh,0)) != PAM_SUCCESS) \
syslog(LOG_ERR|LOG_AUTH, "pam_close_session(): %s", \
pam_strerror(pamh, pam_err)); \
if ((pam_err = pam_end(pamh, pam_err)) != PAM_SUCCESS) \
syslog(LOG_ERR|LOG_AUTH, "pam_end(): %s", \
pam_strerror(pamh, pam_err)); \
} while (/*CONSTCOND*/0)
#else
#define PAM_END
#endif
static int keepalive = 1;
static int check_all;
static int log_success; /* If TRUE, log all successful accesses */
static int sent_null;
__dead static void doit(struct sockaddr *, struct sockaddr *);
__dead static void rshd_errx(int, const char *, ...) __printflike(2, 3);
static void getstr(char *, int, const char *);
static int local_domain(char *);
static char *topdomain(char *);
__dead static void usage(void);
#define OPTIONS "aLln"
extern int __check_rhosts_file;
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
#ifdef USE_PAM
static const char incorrect[] = "Login incorrect.";
#endif
int
main(int argc, char *argv[])
{
struct linger linger;
int ch, on = 1;
socklen_t fromlen;
socklen_t locallen;
struct sockaddr_storage from;
struct sockaddr_storage local;
struct protoent *proto;
openlog("rshd", LOG_PID, LOG_DAEMON);
opterr = 0;
while ((ch = getopt(argc, argv, OPTIONS)) != -1)
switch (ch) {
case 'a':
check_all = 1;
break;
case 'l':
__check_rhosts_file = 0;
break;
case 'n':
keepalive = 0;
break;
case 'L':
log_success = 1;
break;
case '?':
default:
usage();
break;
}
argc -= optind;
argv += optind;
fromlen = sizeof(from); /* xxx */
locallen = sizeof(local); /* xxx */
if (getpeername(STDIN_FILENO, (struct sockaddr *)&from, &fromlen) < 0) {
syslog(LOG_ERR, "getpeername: %m");
return EXIT_FAILURE;
}
if (getsockname(STDIN_FILENO, (struct sockaddr *)&local,
&locallen) < 0) {
syslog(LOG_ERR, "getsockname: %m");
return EXIT_FAILURE;
}
#if 0
if (((struct sockaddr *)&from)->sa_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&from)->sin6_addr) &&
sizeof(struct sockaddr_in) <= sizeof(from)) {
struct sockaddr_in sin;
struct sockaddr_in6 *sin6;
const int off = sizeof(struct sockaddr_in6) -
sizeof(struct sockaddr_in);
sin6 = (struct sockaddr_in6 *)&from;
(void)memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
(void)memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[off],
sizeof(sin.sin_addr));
(void)memcpy(&from, &sin, sizeof(sin));
fromlen = sin.sin_len;
}
#else
if (((struct sockaddr *)&from)->sa_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&from)->sin6_addr)) {
char hbuf[NI_MAXHOST];
if (getnameinfo((struct sockaddr *)&from, fromlen, hbuf,
sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0) {
strlcpy(hbuf, "invalid", sizeof(hbuf));
}
syslog(LOG_ERR, "malformed \"from\" address (v4 mapped, %s)",
hbuf);
return EXIT_FAILURE;
}
#endif
if (keepalive &&
setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, (char *)&on,
sizeof(on)) < 0)
syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
linger.l_onoff = 1;
linger.l_linger = 60; /* XXX */
if (setsockopt(STDIN_FILENO, SOL_SOCKET, SO_LINGER, (char *)&linger,
sizeof (linger)) < 0)
syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m");
proto = getprotobyname("tcp");
(void)setsockopt(STDIN_FILENO, proto->p_proto, TCP_NODELAY, &on,
sizeof(on));
doit((struct sockaddr *)&from, (struct sockaddr *)&local);
}
extern char **environ;
static void
doit(struct sockaddr *fromp, struct sockaddr *localp)
{
struct passwd *pwd, pwres;
in_port_t port;
struct pollfd set[2];
int cc, pv[2], pid, s = -1; /* XXX gcc */
int one = 1;
char *hostname, *errorhost = NULL; /* XXX gcc */
const char *cp;
char sig, buf[BUFSIZ];
char cmdbuf[NCARGS+1], locuser[16], remuser[16];
char remotehost[2 * MAXHOSTNAMELEN + 1];
char hostnamebuf[2 * MAXHOSTNAMELEN + 1];
#ifdef LOGIN_CAP
login_cap_t *lc;
#endif
char naddr[NI_MAXHOST];
char saddr[NI_MAXHOST];
char raddr[NI_MAXHOST];
char pbuf[NI_MAXSERV];
int af = fromp->sa_family;
u_int16_t *portp;
struct addrinfo hints, *res, *res0;
int gaierror;
const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
const char *errormsg = NULL, *errorstr = NULL;
char pwbuf[1024];
(void)signal(SIGINT, SIG_DFL);
(void)signal(SIGQUIT, SIG_DFL);
(void)signal(SIGTERM, SIG_DFL);
#ifdef DEBUG
{
int t = open(_PATH_TTY, O_RDWR);
if (t >= 0) {
ioctl(t, TIOCNOTTY, NULL);
(void)close(t);
}
}
#endif
switch (af) {
case AF_INET:
portp = &((struct sockaddr_in *)fromp)->sin_port;
break;
#ifdef INET6
case AF_INET6:
portp = &((struct sockaddr_in6 *)fromp)->sin6_port;
break;
#endif
default:
syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
exit(EXIT_FAILURE);
}
if (getnameinfo(fromp, fromp->sa_len, naddr, sizeof(naddr),
pbuf, sizeof(pbuf), niflags) != 0) {
syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
exit(EXIT_FAILURE);
}
#ifdef IP_OPTIONS
if (af == AF_INET) {
u_char optbuf[BUFSIZ/3];
socklen_t optsize = sizeof(optbuf);
int ipproto;
unsigned int i;
struct protoent *ip;
if ((ip = getprotobyname("ip")) != NULL)
ipproto = ip->p_proto;
else
ipproto = IPPROTO_IP;
if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) &&
optsize != 0) {
for (i = 0; i < optsize;) {
u_char c = optbuf[i];
if (c == IPOPT_LSRR || c == IPOPT_SSRR) {
syslog(LOG_NOTICE,
"Connection refused from %s "
"with IP option %s",
inet_ntoa((
(struct sockaddr_in *)fromp)->sin_addr),
c == IPOPT_LSRR ? "LSRR" : "SSRR");
exit(EXIT_FAILURE);
}
if (c == IPOPT_EOL)
break;
i += (c == IPOPT_NOP) ? 1 : optbuf[i + 1];
}
}
}
#endif
if (ntohs(*portp) >= IPPORT_RESERVED
|| ntohs(*portp) < IPPORT_RESERVED / 2) {
syslog(LOG_NOTICE|LOG_AUTH,
"Connection from %s on illegal port %u",
naddr, ntohs(*portp));
exit(EXIT_FAILURE);
}
(void) alarm(60);
port = 0;
for (;;) {
char c;
if ((cc = read(STDIN_FILENO, &c, 1)) != 1) {
if (cc < 0)
syslog(LOG_ERR, "read: %m");
(void)shutdown(0, SHUT_RDWR);
exit(EXIT_FAILURE);
}
if (c == 0)
break;
port = port * 10 + c - '0';
}
(void) alarm(0);
if (port != 0) {
int lport = IPPORT_RESERVED - 1;
s = rresvport_af_addr(&lport, af, localp);
if (s < 0) {
syslog(LOG_ERR, "can't get stderr port: %m");
exit(EXIT_FAILURE);
}
if (port >= IPPORT_RESERVED) {
syslog(LOG_ERR, "2nd port not reserved");
exit(EXIT_FAILURE);
}
*portp = htons(port);
if (connect(s, fromp, fromp->sa_len) < 0) {
syslog(LOG_ERR, "connect second port %d: %m", port);
exit(EXIT_FAILURE);
}
}
#ifdef notdef
/* from inetd, socket is already on 0, 1, 2 */
(void)dup2(f, STDIN_FILENO);
(void)dup2(f, STDOUT_FILENO);
(void)dup2(f, STDERR_FILENO);
#endif
if (getnameinfo(fromp, fromp->sa_len, saddr, sizeof(saddr),
NULL, 0, NI_NAMEREQD) == 0) {
/*
* If name returned by getnameinfo is in our domain,
* attempt to verify that we haven't been fooled by someone
* in a remote net; look up the name and check that this
* address corresponds to the name.
*/
hostname = saddr;
res0 = NULL;
if (check_all || local_domain(saddr)) {
(void)strlcpy(remotehost, saddr, sizeof(remotehost));
errorhost = remotehost;
(void)memset(&hints, 0, sizeof(hints));
hints.ai_family = fromp->sa_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_CANONNAME;
gaierror = getaddrinfo(remotehost, pbuf, &hints, &res0);
if (gaierror) {
syslog(LOG_NOTICE,
"Couldn't look up address for %s: %s",
remotehost, gai_strerror(gaierror));
errorstr =
"Couldn't look up address for your host (%s)\n";
hostname = naddr;
} else {
for (res = res0; res; res = res->ai_next) {
if (res->ai_family != fromp->sa_family)
continue;
if (res->ai_addrlen != fromp->sa_len)
continue;
if (getnameinfo(res->ai_addr,
res->ai_addrlen,
raddr, sizeof(raddr), NULL, 0,
niflags) == 0
&& strcmp(naddr, raddr) == 0) {
hostname = res->ai_canonname
? res->ai_canonname
: saddr;
break;
}
}
if (res == NULL) {
syslog(LOG_NOTICE,
"Host addr %s not listed for host %s",
naddr, res0->ai_canonname
? res0->ai_canonname
: saddr);
errorstr =
"Host address mismatch for %s\n";
hostname = naddr;
}
}
}
(void)strlcpy(hostnamebuf, hostname, sizeof(hostnamebuf));
hostname = hostnamebuf;
if (res0)
freeaddrinfo(res0);
} else {
(void)strlcpy(hostnamebuf, naddr, sizeof(hostnamebuf));
errorhost = hostname = hostnamebuf;
}
(void)alarm(60);
getstr(remuser, sizeof(remuser), "remuser");
getstr(locuser, sizeof(locuser), "locuser");
getstr(cmdbuf, sizeof(cmdbuf), "command");
(void)alarm(0);
#ifdef USE_PAM
pam_err = pam_start("rsh", locuser, &pamc, &pamh);
if (pam_err != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_start(): %s",
pam_strerror(pamh, pam_err));
rshd_errx(EXIT_FAILURE, incorrect);
}
if ((pam_err = pam_set_item(pamh, PAM_RUSER, remuser)) != PAM_SUCCESS ||
(pam_err = pam_set_item(pamh, PAM_RHOST, hostname)) != PAM_SUCCESS){
syslog(LOG_ERR|LOG_AUTH, "pam_set_item(): %s",
pam_strerror(pamh, pam_err));
rshd_errx(EXIT_FAILURE, incorrect);
}
pam_err = pam_authenticate(pamh, 0);
if (pam_err == PAM_SUCCESS) {
if ((pam_err = pam_get_user(pamh, &cp, NULL)) == PAM_SUCCESS) {
(void)strlcpy(locuser, cp, sizeof(locuser));
/* XXX truncation! */
}
pam_err = pam_acct_mgmt(pamh, 0);
}
if (pam_err != PAM_SUCCESS) {
errorstr = incorrect;
errormsg = pam_strerror(pamh, pam_err);
goto badlogin;
}
#endif /* USE_PAM */
setpwent();
if (getpwnam_r(locuser, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
pwd == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown login. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Permission denied.";
rshd_errx(EXIT_FAILURE, errorstr, errorhost);
}
#ifdef LOGIN_CAP
lc = login_getclass(pwd ? pwd->pw_class : NULL);
#endif
if (chdir(pwd->pw_dir) < 0) {
if (chdir("/") < 0
#ifdef LOGIN_CAP
|| login_getcapbool(lc, "requirehome", pwd->pw_uid ? 1 : 0)
#endif
) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: no home directory. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
rshd_errx(EXIT_SUCCESS, "No remote home directory.");
}
}
#ifndef USE_PAM
if (errorstr ||
(pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
iruserok_sa(fromp, fromp->sa_len, pwd->pw_uid == 0, remuser,
locuser) < 0)) {
errormsg = __rcmd_errstr ? __rcmd_errstr : "unknown error";
if (errorstr == NULL)
errorstr = "Permission denied.";
goto badlogin;
}
if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK))
rshd_errx(EXIT_FAILURE, "Logins currently disabled.");
#endif
#ifdef LOGIN_CAP
/*
* PAM modules might add supplementary groups in
* pam_setcred(), so initialize them first.
* But we need to open the session as root.
*/
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
syslog(LOG_ERR, "setusercontext: %m");
exit(EXIT_FAILURE);
}
#else
initgroups(pwd->pw_name, pwd->pw_gid);
#endif
#ifdef USE_PAM
if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_open_session: %s",
pam_strerror(pamh, pam_err));
} else if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED))
!= PAM_SUCCESS) {
syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, pam_err));
}
#endif
(void)write(STDERR_FILENO, "\0", 1);
sent_null = 1;
if (port) {
if (pipe(pv) < 0)
rshd_errx(EXIT_FAILURE, "Can't make pipe. (%s)",
strerror(errno));
pid = fork();
if (pid == -1)
rshd_errx(EXIT_FAILURE, "Can't fork. (%s)",
strerror(errno));
if (pid) {
(void)close(STDIN_FILENO);
(void)close(STDOUT_FILENO);
(void)close(STDERR_FILENO);
(void)close(pv[1]);
set[0].fd = s;
set[0].events = POLLIN;
set[1].fd = pv[0];
set[1].events = POLLIN;
ioctl(pv[0], FIONBIO, (char *)&one);
/* should set s nbio! */
do {
#ifdef __minix
if (set[0].events == 0 && set[1].events == 0)
break;
#endif /* __minix */
if (poll(set, 2, INFTIM) < 0)
break;
if (set[0].revents & POLLIN) {
int ret;
ret = read(s, &sig, 1);
if (ret <= 0)
set[0].events = 0;
else
killpg(pid, sig);
}
if (set[1].revents & POLLIN) {
errno = 0;
cc = read(pv[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(s, SHUT_RDWR);
set[1].events = 0;
} else {
(void)write(s, buf, cc);
}
}
} while ((set[0].revents | set[1].revents) & POLLIN);
PAM_END;
exit(EXIT_SUCCESS);
}
(void)close(s);
(void)close(pv[0]);
(void)dup2(pv[1], STDERR_FILENO);
close(pv[1]);
}
#ifdef USE_PAM
else {
pid = fork();
if (pid == -1)
rshd_errx(EXIT_FAILURE, "Can't fork. (%s)",
strerror(errno));
if (pid) {
pid_t xpid;
int status;
if ((xpid = waitpid(pid, &status, 0)) != pid) {
pam_err = pam_close_session(pamh, 0);
if (pam_err != PAM_SUCCESS) {
syslog(LOG_ERR,
"pam_close_session: %s",
pam_strerror(pamh, pam_err));
}
PAM_END;
if (xpid != -1)
syslog(LOG_WARNING,
"wrong PID: %d != %d", pid, xpid);
else
syslog(LOG_WARNING,
"wait pid=%d failed %m", pid);
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
}
}
#endif
#ifdef F_CLOSEM
(void)fcntl(STDERR_FILENO + 1, F_CLOSEM, 0);
#else
for (fd = getdtablesize(); fd > STDERR_FILENO; fd--)
(void)close(fd);
#endif
if (setsid() == -1)
syslog(LOG_ERR, "setsid() failed: %m");
#ifdef USE_PAM
if (setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failed: %m");
if (*pwd->pw_shell == '\0')
pwd->pw_shell = __UNCONST(_PATH_BSHELL);
(void)pam_setenv(pamh, "HOME", pwd->pw_dir, 1);
(void)pam_setenv(pamh, "SHELL", pwd->pw_shell, 1);
(void)pam_setenv(pamh, "USER", pwd->pw_name, 1);
(void)pam_setenv(pamh, "PATH", _PATH_DEFPATH, 1);
environ = pam_getenvlist(pamh);
(void)pam_end(pamh, pam_err);
#else
#ifdef LOGIN_CAP
{
char *sh;
if ((sh = login_getcapstr(lc, "shell", NULL, NULL))) {
if(!(sh = strdup(sh))) {
syslog(LOG_ERR, "Cannot alloc mem");
exit(EXIT_FAILURE);
}
pwd->pw_shell = sh;
}
}
#endif
{
static char *envinit[] = { NULL };
environ = envinit;
}
setenv("PATH", _PATH_DEFPATH, 1);
setenv("HOME", pwd->pw_dir, 1);
setenv("SHELL", pwd->pw_shell, 1);
setenv("USER", pwd->pw_name, 1);
#endif
cp = strrchr(pwd->pw_shell, '/');
if (cp)
cp++;
else
cp = pwd->pw_shell;
#ifdef LOGIN_CAP
if (setusercontext(lc, pwd, pwd->pw_uid,
LOGIN_SETALL & ~LOGIN_SETGROUP) < 0) {
syslog(LOG_ERR, "setusercontext(): %m");
exit(EXIT_FAILURE);
}
login_close(lc);
#else
(void)setgid((gid_t)pwd->pw_gid);
(void)setuid((uid_t)pwd->pw_uid);
#endif
endpwent();
if (log_success || pwd->pw_uid == 0) {
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
}
(void)execl(pwd->pw_shell, cp, "-c", cmdbuf, NULL);
rshd_errx(EXIT_FAILURE, "%s: %s", pwd->pw_shell, strerror(errno));
badlogin:
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
remuser, hostname, locuser, errormsg, cmdbuf);
rshd_errx(EXIT_FAILURE, errorstr, errorhost);
}
/*
* Report error to client. Note: can't be used until second socket has
* connected to client, or older clients will hang waiting for that
* connection first.
*/
#include <stdarg.h>
static void
rshd_errx(int error, const char *fmt, ...)
{
va_list ap;
int len, rv;
char *bp, buf[BUFSIZ];
va_start(ap, fmt);
bp = buf;
if (sent_null == 0) {
*bp++ = 1;
len = 1;
} else
len = 0;
rv = vsnprintf(bp, sizeof(buf) - 2, fmt, ap);
bp[rv++] = '\n';
(void)write(STDERR_FILENO, buf, len + rv);
va_end(ap);
exit(error);
}
static void
getstr(char *buf, int cnt, const char *err)
{
char c;
do {
if (read(STDIN_FILENO, &c, 1) != 1)
exit(EXIT_FAILURE);
*buf++ = c;
if (--cnt == 0)
rshd_errx(EXIT_FAILURE, "%s too long", err);
} while (c != 0);
}
/*
* Check whether host h is in our local domain,
* defined as sharing the last two components of the domain part,
* or the entire domain part if the local domain has only one component.
* If either name is unqualified (contains no '.'),
* assume that the host is local, as it will be
* interpreted as such.
*/
static int
local_domain(char *h)
{
char localhost[MAXHOSTNAMELEN + 1];
char *p1, *p2;
localhost[0] = 0;
(void)gethostname(localhost, sizeof(localhost));
localhost[sizeof(localhost) - 1] = '\0';
p1 = topdomain(localhost);
p2 = topdomain(h);
if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2))
return (1);
return (0);
}
static char *
topdomain(char *h)
{
char *p, *maybe = NULL;
int dots = 0;
for (p = h + strlen(h); p >= h; p--) {
if (*p == '.') {
if (++dots == 2)
return (p);
maybe = p;
}
}
return (maybe);
}
static void
usage(void)
{
syslog(LOG_ERR, "Usage: %s [-%s]", getprogname(), OPTIONS);
exit(EXIT_FAILURE);
}