OpenBSD-4.6/usr.sbin/portmap/portmap.c
/* $OpenBSD: portmap.c,v 1.37 2009/05/20 20:37:43 thib Exp $ */
/*-
* Copyright (c) 1996, 1997 Theo de Raadt (OpenBSD). All rights reserved.
* Copyright (c) 1990 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.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1990 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)portmap.c 5.4 (Berkeley) 4/19/91";
#else
static char rcsid[] = "$OpenBSD: portmap.c,v 1.37 2009/05/20 20:37:43 thib Exp $";
#endif
#endif /* not lint */
/*
@(#)portmap.c 2.3 88/08/11 4.0 RPCSRC
static char sccsid[] = "@(#)portmap.c 1.32 87/08/06 Copyr 1984 Sun Micro";
*/
/*
* portmap.c, Implements the program,version to port number mapping for
* rpc.
*/
/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/resource.h>
#include <rpcsvc/nfs_prot.h>
#include <arpa/inet.h>
#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <netdb.h>
#include <pwd.h>
#include <errno.h>
void reg_service(struct svc_req *, SVCXPRT *);
void reap(int);
void callit(struct svc_req *, SVCXPRT *);
int check_callit(struct sockaddr_in *, u_long, u_long);
struct pmaplist *find_service(u_long, u_long, u_long);
struct pmaplist *pmaplist;
int debugging = 0;
SVCXPRT *ludpxprt, *ltcpxprt;
int
main(int argc, char *argv[])
{
int sock, lsock, c, on = 1, len = sizeof(struct sockaddr_in);
struct sockaddr_in addr, laddr;
struct pmaplist *pml;
struct passwd *pw;
SVCXPRT *xprt;
while ((c = getopt(argc, argv, "d")) != -1) {
switch (c) {
case 'd':
debugging = 1;
break;
default:
(void) fprintf(stderr, "usage: %s [-d]\n", argv[0]);
exit(1);
}
}
if (!debugging && daemon(0, 0)) {
(void) fprintf(stderr, "portmap: fork: %s", strerror(errno));
exit(1);
}
openlog("portmap", LOG_NDELAY | (debugging ? LOG_PID | LOG_PERROR : LOG_PID),
LOG_DAEMON);
bzero((char *)&addr, sizeof addr);
addr.sin_addr.s_addr = 0;
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(PMAPPORT);
bzero((char *)&laddr, sizeof laddr);
laddr.sin_addr.s_addr = 0;
laddr.sin_family = AF_INET;
laddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
laddr.sin_port = htons(PMAPPORT);
if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
syslog(LOG_ERR, "cannot create udp socket: %m");
exit(1);
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
syslog(LOG_ERR, "cannot bind udp: %m");
exit(1);
}
if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
syslog(LOG_ERR, "couldn't do udp_create");
exit(1);
}
if ((lsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
syslog(LOG_ERR, "cannot create udp socket: %m");
exit(1);
}
setsockopt(lsock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
if (bind(lsock, (struct sockaddr *)&laddr, len) != 0) {
syslog(LOG_ERR, "cannot bind local udp: %m");
exit(1);
}
if ((ludpxprt = svcudp_create(lsock)) == (SVCXPRT *)NULL) {
syslog(LOG_ERR, "couldn't do udp_create");
exit(1);
}
/* make an entry for ourself */
pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
if (pml == NULL) {
syslog(LOG_ERR, "out of memory");
exit(1);
}
pml->pml_next = 0;
pml->pml_map.pm_prog = PMAPPROG;
pml->pml_map.pm_vers = PMAPVERS;
pml->pml_map.pm_prot = IPPROTO_UDP;
pml->pml_map.pm_port = PMAPPORT;
pmaplist = pml;
if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
syslog(LOG_ERR, "cannot create tcp socket: %m");
exit(1);
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
syslog(LOG_ERR, "cannot bind tcp: %m");
exit(1);
}
if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
== (SVCXPRT *)NULL) {
syslog(LOG_ERR, "couldn't do tcp_create");
exit(1);
}
if ((lsock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
syslog(LOG_ERR, "cannot create tcp socket: %m");
exit(1);
}
setsockopt(lsock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
if (bind(lsock, (struct sockaddr *)&laddr, len) != 0) {
syslog(LOG_ERR, "cannot bind tcp: %m");
exit(1);
}
if ((ltcpxprt = svctcp_create(lsock, RPCSMALLMSGSIZE,
RPCSMALLMSGSIZE)) == (SVCXPRT *)NULL) {
syslog(LOG_ERR, "couldn't do tcp_create");
exit(1);
}
/* make an entry for ourself */
pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
if (pml == NULL) {
syslog(LOG_ERR, "out of memory");
exit(1);
}
pml->pml_map.pm_prog = PMAPPROG;
pml->pml_map.pm_vers = PMAPVERS;
pml->pml_map.pm_prot = IPPROTO_TCP;
pml->pml_map.pm_port = PMAPPORT;
pml->pml_next = pmaplist;
pmaplist = pml;
if ((pw = getpwnam("_portmap")) == NULL) {
syslog(LOG_ERR, "no such user _portmap");
exit(1);
}
if (chroot("/var/empty") == -1) {
syslog(LOG_ERR, "cannot chdir to /var/empty.");
exit(1);
}
chdir("/");
if (pw) {
if (setgroups(1, &pw->pw_gid) == -1 ||
setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1 ||
setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) {
syslog(LOG_ERR, "revoke privs: %s", strerror(errno));
exit(1);
}
}
endpwent();
if (svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE) == 0) {
syslog(LOG_ERR, "svc_register failed.");
exit(1);
}
(void)signal(SIGCHLD, reap);
svc_run();
syslog(LOG_ERR, "svc_run returned unexpectedly");
abort();
}
#ifndef lint
/* need to override perror calls in rpc library */
void
perror(const char *what)
{
syslog(LOG_ERR, "%s: %m", what);
}
#endif
struct pmaplist *
find_service(u_long prog, u_long vers, u_long prot)
{
struct pmaplist *hit = NULL;
struct pmaplist *pml;
for (pml = pmaplist; pml != NULL; pml = pml->pml_next) {
if ((pml->pml_map.pm_prog != prog) ||
(pml->pml_map.pm_prot != prot))
continue;
hit = pml;
if (pml->pml_map.pm_vers == vers)
break;
}
return (hit);
}
/*
* 1 OK, 0 not
*/
void
reg_service(struct svc_req *rqstp, SVCXPRT *xprt)
{
struct pmap reg;
struct pmaplist *pml, *prevpml, *fnd;
struct sockaddr_in *fromsin;
long ans = 0, port;
caddr_t t;
fromsin = svc_getcaller(xprt);
if (debugging)
(void) fprintf(stderr, "server: about to do a switch\n");
switch (rqstp->rq_proc) {
case PMAPPROC_NULL:
/*
* Null proc call
*/
if (!svc_sendreply(xprt, xdr_void, (caddr_t)0) && debugging) {
abort();
}
break;
case PMAPPROC_SET:
/*
* Set a program,version to port mapping
*/
if (xprt != ltcpxprt && xprt != ludpxprt) {
syslog(LOG_WARNING,
"non-local set attempt (might be from %s)",
inet_ntoa(fromsin->sin_addr));
svcerr_noproc(xprt);
return;
}
if (!svc_getargs(xprt, xdr_pmap, (caddr_t)®)) {
svcerr_decode(xprt);
break;
}
/*
* check to see if already used
* find_service returns a hit even if
* the versions don't match, so check for it
*/
fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
if (fnd && fnd->pml_map.pm_vers == reg.pm_vers) {
if (fnd->pml_map.pm_port == reg.pm_port)
ans = 1;
goto done;
}
if (debugging)
printf("set: prog %lu vers %lu port %lu\n",
reg.pm_prog, reg.pm_vers, reg.pm_port);
if (reg.pm_port & ~0xffff)
goto done;
/*
* only permit localhost root to create
* mappings pointing at sensitive ports
*/
if ((reg.pm_port < IPPORT_RESERVED ||
reg.pm_port == NFS_PORT) &&
htons(fromsin->sin_port) >= IPPORT_RESERVED) {
syslog(LOG_WARNING,
"resvport set attempt by non-root");
goto done;
}
/*
* add to END of list
*/
pml = (struct pmaplist *)malloc(sizeof(struct pmaplist));
if (pml == NULL) {
syslog(LOG_ERR, "out of memory");
svcerr_systemerr(xprt);
return;
}
pml->pml_map = reg;
pml->pml_next = 0;
if (pmaplist == 0) {
pmaplist = pml;
} else {
for (fnd = pmaplist; fnd->pml_next != 0;
fnd = fnd->pml_next);
fnd->pml_next = pml;
}
ans = 1;
done:
if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
debugging) {
(void) fprintf(stderr, "svc_sendreply\n");
abort();
}
break;
case PMAPPROC_UNSET:
/*
* Remove a program,version to port mapping.
*/
if (xprt != ltcpxprt && xprt != ludpxprt) {
syslog(LOG_WARNING,
"non-local unset attempt (might be from %s)",
inet_ntoa(fromsin->sin_addr));
svcerr_noproc(xprt);
return;
}
if (!svc_getargs(xprt, xdr_pmap, (caddr_t)®)) {
svcerr_decode(xprt);
break;
}
for (prevpml = NULL, pml = pmaplist; pml != NULL; ) {
if ((pml->pml_map.pm_prog != reg.pm_prog) ||
(pml->pml_map.pm_vers != reg.pm_vers)) {
/* both pml & prevpml move forwards */
prevpml = pml;
pml = pml->pml_next;
continue;
}
if ((pml->pml_map.pm_port < IPPORT_RESERVED ||
pml->pml_map.pm_port == NFS_PORT) &&
htons(fromsin->sin_port) >= IPPORT_RESERVED) {
syslog(LOG_WARNING,
"resvport unset attempt by non-root");
break;
}
/* found it; pml moves forward, prevpml stays */
ans = 1;
t = (caddr_t)pml;
pml = pml->pml_next;
if (prevpml == NULL)
pmaplist = pml;
else
prevpml->pml_next = pml;
free(t);
}
if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
debugging) {
fprintf(stderr, "svc_sendreply\n");
abort();
}
break;
case PMAPPROC_GETPORT:
/*
* Lookup the mapping for a program,version and return its port
*/
if (!svc_getargs(xprt, xdr_pmap, (caddr_t)®)) {
svcerr_decode(xprt);
break;
}
fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
if (fnd)
port = fnd->pml_map.pm_port;
else
port = 0;
if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&port)) &&
debugging) {
fprintf(stderr, "svc_sendreply\n");
abort();
}
break;
case PMAPPROC_DUMP:
/*
* Return the current set of mapped program,version
*/
if (!svc_getargs(xprt, xdr_void, NULL)) {
svcerr_decode(xprt);
break;
}
if (!svc_sendreply(xprt, xdr_pmaplist, (caddr_t)&pmaplist) &&
debugging) {
fprintf(stderr, "svc_sendreply\n");
abort();
}
break;
case PMAPPROC_CALLIT:
/*
* Calls a procedure on the local machine. If the requested
* procedure is not registered this procedure does not return
* error information!!
* This procedure is only supported on rpc/udp and calls via
* rpc/udp. It passes null authentication parameters.
*/
callit(rqstp, xprt);
break;
default:
svcerr_noproc(xprt);
break;
}
}
/*
* Stuff for the rmtcall service
*/
#define ARGSIZE 9000
struct encap_parms {
u_int arglen;
char *args;
};
static bool_t
xdr_encap_parms(XDR *xdrs, struct encap_parms *epp)
{
return (xdr_bytes(xdrs, &(epp->args), &(epp->arglen), ARGSIZE));
}
struct rmtcallargs {
u_long rmt_prog;
u_long rmt_vers;
u_long rmt_port;
u_long rmt_proc;
struct encap_parms rmt_args;
};
static bool_t
xdr_rmtcall_args(XDR *xdrs, struct rmtcallargs *cap)
{
/* does not get a port number */
if (xdr_u_long(xdrs, &(cap->rmt_prog)) &&
xdr_u_long(xdrs, &(cap->rmt_vers)) &&
xdr_u_long(xdrs, &(cap->rmt_proc))) {
return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
}
return (FALSE);
}
static bool_t
xdr_rmtcall_result(XDR *xdrs, struct rmtcallargs *cap)
{
if (xdr_u_long(xdrs, &(cap->rmt_port)))
return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
return (FALSE);
}
/*
* only worries about the struct encap_parms part of struct rmtcallargs.
* The arglen must already be set!!
*/
static bool_t
xdr_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
{
return (xdr_opaque(xdrs, cap->rmt_args.args, cap->rmt_args.arglen));
}
/*
* This routine finds and sets the length of incoming opaque paraters
* and then calls xdr_opaque_parms.
*/
static bool_t
xdr_len_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
{
u_int beginpos, lowpos, highpos, currpos, pos;
beginpos = lowpos = pos = xdr_getpos(xdrs);
highpos = lowpos + ARGSIZE;
while ((int)(highpos - lowpos) >= 0) {
currpos = (lowpos + highpos) / 2;
if (xdr_setpos(xdrs, currpos)) {
pos = currpos;
lowpos = currpos + 1;
} else {
highpos = currpos - 1;
}
}
xdr_setpos(xdrs, beginpos);
cap->rmt_args.arglen = pos - beginpos;
return (xdr_opaque_parms(xdrs, cap));
}
/*
* Call a remote procedure service
* This procedure is very quiet when things go wrong.
* The proc is written to support broadcast rpc. In the broadcast case,
* a machine should shut-up instead of complain, less the requestor be
* overrun with complaints at the expense of not hearing a valid reply ...
*
* This now forks so that the program & process that it calls can call
* back to the portmapper.
*/
void
callit(struct svc_req *rqstp, SVCXPRT *xprt)
{
struct rmtcallargs a;
struct pmaplist *pml;
u_short port;
struct sockaddr_in me;
pid_t pid;
int so = -1, dontblock = 1;
CLIENT *client;
struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
struct timeval timeout;
char buf[ARGSIZE];
timeout.tv_sec = 5;
timeout.tv_usec = 0;
a.rmt_args.args = buf;
if (!svc_getargs(xprt, xdr_rmtcall_args, (caddr_t)&a))
return;
if (!check_callit(svc_getcaller(xprt), a.rmt_prog, a.rmt_proc))
return;
if ((pml = find_service(a.rmt_prog, a.rmt_vers,
(u_long)IPPROTO_UDP)) == NULL)
return;
/*
* fork a child to do the work. Parent immediately returns.
* Child exits upon completion.
*/
if ((pid = fork()) != 0) {
if (pid == -1)
syslog(LOG_ERR, "CALLIT (prog %lu): fork: %m",
a.rmt_prog);
return;
}
port = pml->pml_map.pm_port;
get_myaddress(&me);
me.sin_port = htons(port);
/* Avoid implicit binding to reserved port by clntudp_create() */
so = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (so == -1)
exit(1);
if (ioctl(so, FIONBIO, &dontblock) == -1)
exit(1);
client = clntudp_create(&me, a.rmt_prog, a.rmt_vers, timeout, &so);
if (client != (CLIENT *)NULL) {
if (rqstp->rq_cred.oa_flavor == AUTH_UNIX)
client->cl_auth = authunix_create(au->aup_machname,
au->aup_uid, au->aup_gid, au->aup_len, au->aup_gids);
a.rmt_port = (u_long)port;
if (clnt_call(client, a.rmt_proc, xdr_opaque_parms, &a,
xdr_len_opaque_parms, &a, timeout) == RPC_SUCCESS)
svc_sendreply(xprt, xdr_rmtcall_result, (caddr_t)&a);
AUTH_DESTROY(client->cl_auth);
clnt_destroy(client);
}
(void)close(so);
exit(0);
}
/* ARGSUSED */
void
reap(int signo)
{
int save_errno = errno;
while (wait3(NULL, WNOHANG, NULL) > 0)
;
errno = save_errno;
}
#define NFSPROG ((u_long) 100003)
#define MOUNTPROG ((u_long) 100005)
#define YPXPROG ((u_long) 100069)
#define YPPROG ((u_long) 100004)
#define YPPROC_DOMAIN_NONACK ((u_long) 2)
#define MOUNTPROC_MNT ((u_long) 1)
#define XXXPROC_NOP ((u_long) 0)
int
check_callit(struct sockaddr_in *addr, u_long prog, u_long aproc)
{
if ((prog == PMAPPROG && aproc != XXXPROC_NOP) ||
(prog == NFSPROG && aproc != XXXPROC_NOP) ||
(prog == YPXPROG && aproc != XXXPROC_NOP) ||
(prog == MOUNTPROG && aproc == MOUNTPROC_MNT) ||
(prog == YPPROG && aproc != YPPROC_DOMAIN_NONACK)) {
syslog(LOG_WARNING,
"callit prog %d aproc %d (might be from %s)",
(int)prog, (int)aproc, inet_ntoa(addr->sin_addr));
return (FALSE);
}
return (TRUE);
}