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freebsd-nq/lib/libc/net/rcmd.c

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/*
* Copyright (c) 1983, 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.
* 4. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <fcntl.h>
#include <netdb.h>
#include <stdlib.h>
#include <unistd.h>
#include <pwd.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <rpc/rpc.h>
#ifdef YP
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#include <arpa/nameser.h>
#include "un-namespace.h"
extern int innetgr( const char *, const char *, const char *, const char * );
#define max(a, b) ((a > b) ? a : b)
int __ivaliduser(FILE *, u_int32_t, const char *, const char *);
int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int);
int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *,
const char *);
static int __icheckhost(const struct sockaddr *, socklen_t, const char *);
char paddr[NI_MAXHOST];
int
rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
char **ahost;
u_short rport;
const char *locuser, *remuser, *cmd;
int *fd2p;
{
return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
}
int
rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af)
char **ahost;
u_short rport;
const char *locuser, *remuser, *cmd;
int *fd2p;
int af;
{
struct addrinfo hints, *res, *ai;
struct sockaddr_storage from;
fd_set reads;
sigset_t oldmask, newmask;
pid_t pid;
int s, aport, lport, timo, error;
char c, *p;
int refused, nres;
char num[8];
static char canonnamebuf[MAXDNAME]; /* is it proper here? */
/* call rcmdsh() with specified remote shell if appropriate. */
if (!issetugid() && (p = getenv("RSH"))) {
struct servent *sp = getservbyname("shell", "tcp");
if (sp && sp->s_port == rport)
return (rcmdsh(ahost, rport, locuser, remuser,
cmd, p));
}
/* use rsh(1) if non-root and remote port is shell. */
if (geteuid()) {
struct servent *sp = getservbyname("shell", "tcp");
if (sp && sp->s_port == rport)
return (rcmdsh(ahost, rport, locuser, remuser,
cmd, NULL));
}
pid = getpid();
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
hints.ai_family = af;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
(void)snprintf(num, sizeof(num), "%d", ntohs(rport));
error = getaddrinfo(*ahost, num, &hints, &res);
if (error) {
fprintf(stderr, "rcmd: getaddrinfo: %s\n",
gai_strerror(error));
if (error == EAI_SYSTEM)
fprintf(stderr, "rcmd: getaddrinfo: %s\n",
strerror(errno));
return (-1);
}
if (res->ai_canonname
&& strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) {
strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf));
*ahost = canonnamebuf;
}
nres = 0;
for (ai = res; ai; ai = ai->ai_next)
nres++;
ai = res;
refused = 0;
sigemptyset(&newmask);
sigaddset(&newmask, SIGURG);
_sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask);
for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
s = rresvport_af(&lport, ai->ai_family);
if (s < 0) {
if (errno != EAGAIN && ai->ai_next) {
ai = ai->ai_next;
continue;
}
if (errno == EAGAIN)
(void)fprintf(stderr,
"rcmd: socket: All ports in use\n");
else
(void)fprintf(stderr, "rcmd: socket: %s\n",
strerror(errno));
freeaddrinfo(res);
_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
NULL);
return (-1);
}
_fcntl(s, F_SETOWN, pid);
if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
break;
(void)_close(s);
if (errno == EADDRINUSE) {
lport--;
continue;
}
if (errno == ECONNREFUSED)
refused = 1;
if (ai->ai_next == NULL && (!refused || timo > 16)) {
(void)fprintf(stderr, "%s: %s\n",
*ahost, strerror(errno));
freeaddrinfo(res);
_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
NULL);
return (-1);
}
if (nres > 1) {
int oerrno = errno;
getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr,
sizeof(paddr), NULL, 0, NI_NUMERICHOST);
(void)fprintf(stderr, "connect to address %s: ",
paddr);
errno = oerrno;
perror(0);
}
if ((ai = ai->ai_next) == NULL) {
/* refused && timo <= 16 */
struct timespec time_to_sleep, time_remaining;
time_to_sleep.tv_sec = timo;
time_to_sleep.tv_nsec = 0;
(void)_nanosleep(&time_to_sleep, &time_remaining);
timo *= 2;
ai = res;
refused = 0;
}
if (nres > 1) {
getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr,
sizeof(paddr), NULL, 0, NI_NUMERICHOST);
fprintf(stderr, "Trying %s...\n", paddr);
}
}
lport--;
if (fd2p == 0) {
_write(s, "", 1);
lport = 0;
} else {
int s2 = rresvport_af(&lport, ai->ai_family), s3;
socklen_t len = ai->ai_addrlen;
int nfds;
if (s2 < 0)
goto bad;
_listen(s2, 1);
(void)snprintf(num, sizeof(num), "%d", lport);
if (_write(s, num, strlen(num)+1) != strlen(num)+1) {
(void)fprintf(stderr,
"rcmd: write (setting up stderr): %s\n",
strerror(errno));
(void)_close(s2);
goto bad;
}
nfds = max(s, s2)+1;
if(nfds > FD_SETSIZE) {
fprintf(stderr, "rcmd: too many files\n");
(void)_close(s2);
goto bad;
}
again:
FD_ZERO(&reads);
FD_SET(s, &reads);
FD_SET(s2, &reads);
errno = 0;
if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){
if (errno != 0)
(void)fprintf(stderr,
"rcmd: select (setting up stderr): %s\n",
strerror(errno));
else
(void)fprintf(stderr,
"select: protocol failure in circuit setup\n");
(void)_close(s2);
goto bad;
}
s3 = _accept(s2, (struct sockaddr *)&from, &len);
switch (from.ss_family) {
case AF_INET:
aport = ntohs(((struct sockaddr_in *)&from)->sin_port);
break;
#ifdef INET6
case AF_INET6:
aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
break;
#endif
default:
aport = 0; /* error */
break;
}
/*
* XXX careful for ftp bounce attacks. If discovered, shut them
* down and check for the real auxiliary channel to connect.
*/
if (aport == 20) {
_close(s3);
goto again;
}
(void)_close(s2);
if (s3 < 0) {
(void)fprintf(stderr,
"rcmd: accept: %s\n", strerror(errno));
lport = 0;
goto bad;
}
*fd2p = s3;
if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) {
(void)fprintf(stderr,
"socket: protocol failure in circuit setup.\n");
goto bad2;
}
}
(void)_write(s, locuser, strlen(locuser)+1);
(void)_write(s, remuser, strlen(remuser)+1);
(void)_write(s, cmd, strlen(cmd)+1);
if (_read(s, &c, 1) != 1) {
(void)fprintf(stderr,
"rcmd: %s: %s\n", *ahost, strerror(errno));
goto bad2;
}
if (c != 0) {
while (_read(s, &c, 1) == 1) {
(void)_write(STDERR_FILENO, &c, 1);
if (c == '\n')
break;
}
goto bad2;
}
_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
freeaddrinfo(res);
return (s);
bad2:
if (lport)
(void)_close(*fd2p);
bad:
(void)_close(s);
_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
freeaddrinfo(res);
return (-1);
}
int
rresvport(port)
int *port;
{
return rresvport_af(port, AF_INET);
}
int
rresvport_af(alport, family)
int *alport, family;
{
int s;
struct sockaddr_storage ss;
u_short *sport;
memset(&ss, 0, sizeof(ss));
ss.ss_family = family;
switch (family) {
case AF_INET:
((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in);
sport = &((struct sockaddr_in *)&ss)->sin_port;
((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY;
break;
#ifdef INET6
case AF_INET6:
((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6);
sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any;
break;
#endif
default:
errno = EAFNOSUPPORT;
return -1;
}
s = _socket(ss.ss_family, SOCK_STREAM, 0);
if (s < 0)
return (-1);
#if 0 /* compat_exact_traditional_rresvport_semantics */
sin.sin_port = htons((u_short)*alport);
if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
return (s);
if (errno != EADDRINUSE) {
(void)_close(s);
return (-1);
}
#endif
*sport = 0;
if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) {
(void)_close(s);
return (-1);
}
*alport = (int)ntohs(*sport);
return (s);
}
int __check_rhosts_file = 1;
char *__rcmd_errstr;
int
ruserok(rhost, superuser, ruser, luser)
const char *rhost, *ruser, *luser;
int superuser;
{
struct addrinfo hints, *res, *r;
int error;
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM; /*dummy*/
error = getaddrinfo(rhost, "0", &hints, &res);
if (error)
return (-1);
for (r = res; r; r = r->ai_next) {
if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
luser) == 0) {
freeaddrinfo(res);
return (0);
}
}
freeaddrinfo(res);
return (-1);
}
/*
* New .rhosts strategy: We are passed an ip address. We spin through
* hosts.equiv and .rhosts looking for a match. When the .rhosts only
* has ip addresses, we don't have to trust a nameserver. When it
* contains hostnames, we spin through the list of addresses the nameserver
* gives us and look for a match.
*
* Returns 0 if ok, -1 if not ok.
*/
int
iruserok(raddr, superuser, ruser, luser)
unsigned long raddr;
int superuser;
const char *ruser, *luser;
{
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser,
ruser, luser);
}
/*
* AF independent extension of iruserok.
*
* Returns 0 if ok, -1 if not ok.
*/
int
iruserok_sa(ra, rlen, superuser, ruser, luser)
const void *ra;
int rlen;
int superuser;
const char *ruser, *luser;
{
char *cp;
struct stat sbuf;
struct passwd *pwd;
FILE *hostf;
uid_t uid;
int first;
char pbuf[MAXPATHLEN];
const struct sockaddr *raddr;
struct sockaddr_storage ss;
/* avoid alignment issue */
if (rlen > sizeof(ss))
return(-1);
memcpy(&ss, ra, rlen);
raddr = (struct sockaddr *)&ss;
first = 1;
hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "re");
again:
if (hostf) {
if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) {
(void)fclose(hostf);
return (0);
}
(void)fclose(hostf);
}
if (first == 1 && (__check_rhosts_file || superuser)) {
first = 0;
if ((pwd = getpwnam(luser)) == NULL)
return (-1);
(void)strcpy(pbuf, pwd->pw_dir);
(void)strcat(pbuf, "/.rhosts");
/*
* Change effective uid while opening .rhosts. If root and
* reading an NFS mounted file system, can't read files that
* are protected read/write owner only.
*/
uid = geteuid();
(void)seteuid(pwd->pw_uid);
hostf = fopen(pbuf, "re");
(void)seteuid(uid);
if (hostf == NULL)
return (-1);
/*
* If not a regular file, or is owned by someone other than
* user or root or if writeable by anyone but the owner, quit.
*/
cp = NULL;
if (lstat(pbuf, &sbuf) < 0)
cp = ".rhosts lstat failed";
else if (!S_ISREG(sbuf.st_mode))
cp = ".rhosts not regular file";
else if (_fstat(fileno(hostf), &sbuf) < 0)
cp = ".rhosts fstat failed";
else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
cp = "bad .rhosts owner";
else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
cp = ".rhosts writeable by other than owner";
/* If there were any problems, quit. */
if (cp) {
__rcmd_errstr = cp;
(void)fclose(hostf);
return (-1);
}
goto again;
}
return (-1);
}
/*
* XXX
* Don't make static, used by lpd(8).
*
* Returns 0 if ok, -1 if not ok.
*/
int
__ivaliduser(hostf, raddr, luser, ruser)
FILE *hostf;
u_int32_t raddr;
const char *luser, *ruser;
{
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len,
luser, ruser);
}
/*
* Returns 0 if ok, -1 if not ok.
*
* XXX obsolete API.
*/
int
__ivaliduser_af(hostf, raddr, luser, ruser, af, len)
FILE *hostf;
const void *raddr;
const char *luser, *ruser;
int af, len;
{
struct sockaddr *sa = NULL;
struct sockaddr_in *sin = NULL;
#ifdef INET6
struct sockaddr_in6 *sin6 = NULL;
#endif
struct sockaddr_storage ss;
memset(&ss, 0, sizeof(ss));
switch (af) {
case AF_INET:
if (len != sizeof(sin->sin_addr))
return -1;
sin = (struct sockaddr_in *)&ss;
sin->sin_family = AF_INET;
sin->sin_len = sizeof(struct sockaddr_in);
memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr));
break;
#ifdef INET6
case AF_INET6:
if (len != sizeof(sin6->sin6_addr))
return -1;
/* you will lose scope info */
sin6 = (struct sockaddr_in6 *)&ss;
sin6->sin6_family = AF_INET6;
sin6->sin6_len = sizeof(struct sockaddr_in6);
memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr));
break;
#endif
default:
return -1;
}
sa = (struct sockaddr *)&ss;
return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser);
}
int
__ivaliduser_sa(hostf, raddr, salen, luser, ruser)
FILE *hostf;
const struct sockaddr *raddr;
socklen_t salen;
const char *luser, *ruser;
{
char *user, *p;
int ch;
char buf[MAXHOSTNAMELEN + 128]; /* host + login */
char hname[MAXHOSTNAMELEN];
/* Presumed guilty until proven innocent. */
int userok = 0, hostok = 0;
#ifdef YP
char *ypdomain;
if (yp_get_default_domain(&ypdomain))
ypdomain = NULL;
#else
#define ypdomain NULL
#endif
/* We need to get the damn hostname back for netgroup matching. */
if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0,
NI_NAMEREQD) != 0)
hname[0] = '\0';
while (fgets(buf, sizeof(buf), hostf)) {
p = buf;
/* Skip lines that are too long. */
if (strchr(p, '\n') == NULL) {
while ((ch = getc(hostf)) != '\n' && ch != EOF);
continue;
}
if (*p == '\n' || *p == '#') {
/* comment... */
continue;
}
while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
*p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p;
p++;
}
if (*p == ' ' || *p == '\t') {
*p++ = '\0';
while (*p == ' ' || *p == '\t')
p++;
user = p;
while (*p != '\n' && *p != ' ' &&
*p != '\t' && *p != '\0')
p++;
} else
user = p;
*p = '\0';
/*
* Do +/- and +@/-@ checking. This looks really nasty,
* but it matches SunOS's behavior so far as I can tell.
*/
switch(buf[0]) {
case '+':
if (!buf[1]) { /* '+' matches all hosts */
hostok = 1;
break;
}
if (buf[1] == '@') /* match a host by netgroup */
hostok = hname[0] != '\0' &&
innetgr(&buf[2], hname, NULL, ypdomain);
else /* match a host by addr */
hostok = __icheckhost(raddr, salen,
(char *)&buf[1]);
break;
case '-': /* reject '-' hosts and all their users */
if (buf[1] == '@') {
if (hname[0] == '\0' ||
innetgr(&buf[2], hname, NULL, ypdomain))
return(-1);
} else {
if (__icheckhost(raddr, salen,
(char *)&buf[1]))
return(-1);
}
break;
default: /* if no '+' or '-', do a simple match */
hostok = __icheckhost(raddr, salen, buf);
break;
}
switch(*user) {
case '+':
if (!*(user+1)) { /* '+' matches all users */
userok = 1;
break;
}
if (*(user+1) == '@') /* match a user by netgroup */
userok = innetgr(user+2, NULL, ruser, ypdomain);
else /* match a user by direct specification */
userok = !(strcmp(ruser, user+1));
break;
case '-': /* if we matched a hostname, */
if (hostok) { /* check for user field rejections */
if (!*(user+1))
return(-1);
if (*(user+1) == '@') {
if (innetgr(user+2, NULL,
ruser, ypdomain))
return(-1);
} else {
if (!strcmp(ruser, user+1))
return(-1);
}
}
break;
default: /* no rejections: try to match the user */
if (hostok)
userok = !(strcmp(ruser,*user ? user : luser));
break;
}
if (hostok && userok)
return(0);
}
return (-1);
}
/*
* Returns "true" if match, 0 if no match.
*/
static int
__icheckhost(raddr, salen, lhost)
const struct sockaddr *raddr;
socklen_t salen;
const char *lhost;
{
struct sockaddr_in sin;
struct sockaddr_in6 *sin6;
struct addrinfo hints, *res, *r;
int error;
char h1[NI_MAXHOST], h2[NI_MAXHOST];
if (raddr->sa_family == AF_INET6) {
sin6 = (struct sockaddr_in6 *)raddr;
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
sizeof(sin.sin_addr));
raddr = (struct sockaddr *)&sin;
salen = sin.sin_len;
}
}
h1[0] = '\0';
if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0,
NI_NUMERICHOST) != 0)
return (0);
/* Resolve laddr into sockaddr */
memset(&hints, 0, sizeof(hints));
hints.ai_family = raddr->sa_family;
hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/
res = NULL;
error = getaddrinfo(lhost, "0", &hints, &res);
if (error)
return (0);
for (r = res; r ; r = r->ai_next) {
h2[0] = '\0';
if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
NULL, 0, NI_NUMERICHOST) != 0)
continue;
if (strcmp(h1, h2) == 0) {
freeaddrinfo(res);
return (1);
}
}
/* No match. */
freeaddrinfo(res);
return (0);
}
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