Minix2.0/src/lib/ip/rcmd.c
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement: ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rcmd.c 5.22 (Berkeley) 6/1/90";
#endif /* LIBC_SCCS and not lint */
#if _MINIX
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <net/gen/netdb.h>
#include <net/gen/in.h>
#include <net/gen/tcp.h>
#include <net/gen/tcp_io.h>
#include <net/hton.h>
#include <net/netlib.h>
#define MAXHOSTNAMELEN 256
#define MAXPATHLEN PATH_MAX
#else
#include <stdio.h>
#include <ctype.h>
#include <pwd.h>
#include <sys/param.h>
#include <sys/file.h>
#include <sys/signal.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#endif
#ifdef __STDC__
#define CONST const
#else
#define CONST
#endif
extern errno;
#if _MINIX
int _validuser _ARGS(( FILE *hostf, const char *rhost, const char *luser,
const char *ruser, int baselen ));
static int _checkhost _ARGS(( const char *rhost, const char *lhost, int len ));
#else
char *index();
#endif
#if _MINIX
int rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
char **ahost;
int rport;
CONST char *locuser, *remuser, *cmd;
int *fd2p;
{
int fd, fd2, result;
struct hostent *hp;
tcpport_t lport;
nwio_tcpconf_t tcpconf;
nwio_tcpcl_t tcpconnopt;
pid_t pid;
char num[8];
char c;
char *tcp_device;
fd= -1;
fd2= -1;
tcp_device= getenv("TCP_DEVICE");
if (tcp_device == NULL)
tcp_device= TCP_DEVICE;
hp= gethostbyname(*ahost);
if (!hp)
{
fprintf(stderr, "%s: unknown host\n", *ahost);
return -1;
}
*ahost= hp->h_name;
for (lport= TCPPORT_RESERVED-1; lport >= TCPPORT_RESERVED/2; lport--)
{
fd= open (tcp_device, O_RDWR);
if (fd<0)
{
fprintf(stderr, "unable to open %s: %s\n",
tcp_device, strerror(errno));
goto bad;
}
tcpconf.nwtc_flags= NWTC_LP_SET | NWTC_SET_RA | NWTC_SET_RP |
NWTC_EXCL;
tcpconf.nwtc_locport= htons(lport);
tcpconf.nwtc_remport= rport;
tcpconf.nwtc_remaddr= *(ipaddr_t *)hp->h_addr;
result= ioctl(fd, NWIOSTCPCONF, &tcpconf);
if (result<0)
{
if (errno == EADDRINUSE)
{
close(fd);
continue;
}
fprintf(stderr, "unable to ioctl(NWIOSTCPCONF): %s\n",
strerror(errno));
goto bad;
}
tcpconf.nwtc_flags= NWTC_SHARED;
result= ioctl(fd, NWIOSTCPCONF, &tcpconf);
if (result<0)
{
fprintf(stderr, "unable to ioctl(NWIOSTCPCONF): %s\n",
strerror(errno));
goto bad;
}
tcpconnopt.nwtcl_flags= 0;
do
{
result= ioctl (fd, NWIOTCPCONN, &tcpconnopt);
if (result<0 && errno == EAGAIN)
{
sleep(2);
}
} while (result<0 && errno == EAGAIN);
if (result<0 && errno != EADDRINUSE)
{
fprintf(stderr,
"unable to ioctl(NWIOTCPCONN): %s\n",
strerror(errno));
goto bad;
}
if (result>=0)
break;
}
if (lport<TCPPORT_RESERVED/2)
{
fprintf(stderr, "can't get port\n");
return -1;
}
if (!fd2p)
{
if (write(fd, "", 1) != 1)
{
fprintf(stderr, "unable to write: %s", strerror(errno));
goto bad;
}
}
else
{
fd2= open (tcp_device, O_RDWR);
if (fd2<0)
{
fprintf(stderr, "unable to open %s: %s\n",
tcp_device, strerror(errno));
goto bad;
}
tcpconf.nwtc_flags= NWTC_LP_SET | NWTC_UNSET_RA |
NWTC_UNSET_RP | NWTC_SHARED;
tcpconf.nwtc_locport= htons(lport);
result= ioctl(fd2, NWIOSTCPCONF, &tcpconf);
if (result<0)
{
fprintf(stderr,
"unable to ioctl(NWIOSTCPCONF): %s\n",
strerror(errno));
goto bad;
}
pid= fork();
if (pid<0)
{
fprintf(stderr, "unable to fork: %s\n",
strerror(errno));
goto bad;
}
if (!pid)
{
alarm(0);
signal(SIGALRM, SIG_DFL);
alarm(30); /* give up after half a minute */
tcpconnopt.nwtcl_flags= 0;
do
{
result= ioctl (fd2, NWIOTCPLISTEN,
&tcpconnopt);
if (result<0 && errno == EAGAIN)
{
sleep(2);
}
} while (result<0 && errno == EAGAIN);
if (result<0 && errno != EADDRINUSE)
{
fprintf(stderr,
"unable to ioctl(NWIOTCPLISTEN): %s\n",
strerror(errno));
exit(1);
}
if (result>=0)
exit(0);
else
exit(1);
}
/*
* This sleep is a HACK. The command that we are starting
* will try to connect to the fd2 port. It seems that for
* this to succeed the child process must have already made
* the call to ioctl above (the NWIOTCPLISTEN) call.
* The sleep gives the child a chance to make the call
* before the parent sends the port number to the
* command being started.
*/
sleep(1);
sprintf(num, "%d", lport);
if (write(fd, num, strlen(num)+1) != strlen(num)+1)
{
fprintf(stderr, "unable to write: %s\n",
strerror(errno));
goto bad;
}
}
write (fd, locuser, strlen(locuser)+1);
write (fd, remuser, strlen(remuser)+1);
write (fd, cmd, strlen(cmd)+1);
if (read(fd, &c, 1) != 1)
{
fprintf(stderr, "unable to read: %s\n", strerror(errno) );
goto bad;
}
if (c != 0)
{
while (read(fd, &c, 1) == 1)
{
write(2, &c, 1);
if (c == '\n')
break;
}
goto bad;
}
if (fd2p)
{
*fd2p= fd2;
result= ioctl(fd2, NWIOGTCPCONF, &tcpconf);
if (result<0)
{
fprintf(stderr, "unable to ioctl(NWIOGTCPCONF): %s\n",
strerror(errno) );
goto bad;
}
if (ntohs(tcpconf.nwtc_remport) >= TCPPORT_RESERVED)
{
fprintf(stderr, "unable to setup 2nd channel\n");
goto bad;
}
}
return fd;
bad:
if (fd>=0)
close(fd);
if (fd2>=0)
close(fd2);
return -1;
}
#else /* _MINIX */
rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
char **ahost;
u_short rport;
char *locuser, *remuser, *cmd;
int *fd2p;
{
int s, timo = 1, pid;
long oldmask;
struct sockaddr_in sin, sin2, from;
char c;
int lport = IPPORT_RESERVED - 1;
struct hostent *hp;
fd_set reads;
pid = getpid();
hp = gethostbyname(*ahost);
if (hp == 0) {
herror(*ahost);
return (-1);
}
*ahost = hp->h_name;
oldmask = sigblock(sigmask(SIGURG));
for (;;) {
s = rresvport(&lport);
if (s < 0) {
if (errno == EAGAIN)
fprintf(stderr, "socket: All ports in use\n");
else
perror("rcmd: socket");
sigsetmask(oldmask);
return (-1);
}
fcntl(s, F_SETOWN, pid);
sin.sin_family = hp->h_addrtype;
bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
sin.sin_port = rport;
if (connect(s, (caddr_t)&sin, sizeof (sin), 0) >= 0)
break;
(void) close(s);
if (errno == EADDRINUSE) {
lport--;
continue;
}
if (errno == ECONNREFUSED && timo <= 16) {
sleep(timo);
timo *= 2;
continue;
}
if (hp->h_addr_list[1] != NULL) {
int oerrno = errno;
fprintf(stderr,
"connect to address %s: ", inet_ntoa(sin.sin_addr));
errno = oerrno;
perror(0);
hp->h_addr_list++;
bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr,
hp->h_length);
fprintf(stderr, "Trying %s...\n",
inet_ntoa(sin.sin_addr));
continue;
}
perror(hp->h_name);
sigsetmask(oldmask);
return (-1);
}
lport--;
if (fd2p == 0) {
write(s, "", 1);
lport = 0;
} else {
char num[8];
int s2 = rresvport(&lport), s3;
int len = sizeof (from);
if (s2 < 0)
goto bad;
listen(s2, 1);
(void) sprintf(num, "%d", lport);
if (write(s, num, strlen(num)+1) != strlen(num)+1) {
perror("write: setting up stderr");
(void) close(s2);
goto bad;
}
FD_ZERO(&reads);
FD_SET(s, &reads);
FD_SET(s2, &reads);
errno = 0;
if (select(32, &reads, 0, 0, 0) < 1 ||
!FD_ISSET(s2, &reads)) {
if (errno != 0)
perror("select: setting up stderr");
else
fprintf(stderr,
"select: protocol failure in circuit setup.\n");
(void) close(s2);
goto bad;
}
s3 = accept(s2, &from, &len, 0);
(void) close(s2);
if (s3 < 0) {
perror("accept");
lport = 0;
goto bad;
}
*fd2p = s3;
from.sin_port = ntohs((u_short)from.sin_port);
if (from.sin_family != AF_INET ||
from.sin_port >= IPPORT_RESERVED ||
from.sin_port < IPPORT_RESERVED / 2) {
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) {
perror(*ahost);
goto bad2;
}
if (c != 0) {
while (read(s, &c, 1) == 1) {
(void) write(2, &c, 1);
if (c == '\n')
break;
}
goto bad2;
}
sigsetmask(oldmask);
return (s);
bad2:
if (lport)
(void) close(*fd2p);
bad:
(void) close(s);
sigsetmask(oldmask);
return (-1);
}
rresvport(alport)
int *alport;
{
struct sockaddr_in sin;
int s;
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = INADDR_ANY;
s = socket(AF_INET, SOCK_STREAM, 0);
if (s < 0)
return (-1);
for (;;) {
sin.sin_port = htons((u_short)*alport);
if (bind(s, (caddr_t)&sin, sizeof (sin)) >= 0)
return (s);
if (errno != EADDRINUSE) {
(void) close(s);
return (-1);
}
(*alport)--;
if (*alport == IPPORT_RESERVED/2) {
(void) close(s);
errno = EAGAIN; /* close */
return (-1);
}
}
}
#endif /* _MINIX */
int _check_rhosts_file = 1;
ruserok(rhost, superuser, ruser, luser)
CONST char *rhost;
int superuser;
CONST char *ruser, *luser;
{
FILE *hostf;
char fhost[MAXHOSTNAMELEN];
int first = 1;
register CONST char *sp;
register char *p;
int baselen = -1;
sp = rhost;
p = fhost;
while (*sp) {
if (*sp == '.') {
if (baselen == -1)
baselen = sp - rhost;
*p++ = *sp++;
} else {
*p++ = isupper(*sp) ? tolower(*sp++) : *sp++;
}
}
*p = '\0';
hostf = superuser ? (FILE *)0 : fopen(_PATH_HEQUIV, "r");
again:
if (hostf) {
if (!_validuser(hostf, fhost, luser, ruser, baselen)) {
(void) fclose(hostf);
return(0);
}
(void) fclose(hostf);
}
if (first == 1 && (_check_rhosts_file || superuser)) {
struct stat sbuf;
struct passwd *pwd;
char pbuf[MAXPATHLEN];
first = 0;
if ((pwd = getpwnam(luser)) == NULL)
return(-1);
(void)strcpy(pbuf, pwd->pw_dir);
(void)strcat(pbuf, "/.rhosts");
if ((hostf = fopen(pbuf, "r")) == NULL)
return(-1);
/*
* if owned by someone other than user or root or if
* writeable by anyone but the owner, quit
*/
if (fstat(fileno(hostf), &sbuf) ||
sbuf.st_uid && sbuf.st_uid != pwd->pw_uid ||
sbuf.st_mode&022) {
fclose(hostf);
return(-1);
}
goto again;
}
return (-1);
}
/* don't make static, used by lpd(8) */
int _validuser(hostf, rhost, luser, ruser, baselen)
FILE *hostf;
CONST char *rhost, *luser, *ruser;
int baselen;
{
char *user;
char ahost[MAXHOSTNAMELEN];
register char *p;
while (fgets(ahost, sizeof (ahost), hostf)) {
p = ahost;
while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
*p = isupper(*p) ? tolower(*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';
if (_checkhost(rhost, ahost, baselen) &&
!strcmp(ruser, *user ? user : luser)) {
return (0);
}
}
return (-1);
}
static int
_checkhost(rhost, lhost, len)
CONST char *rhost, *lhost;
int len;
{
static char ldomain[MAXHOSTNAMELEN + 1];
static char *domainp = NULL;
static int nodomain = 0;
register char *cp;
if (len == -1)
return(!strcmp(rhost, lhost));
if (strncmp(rhost, lhost, len))
return(0);
if (!strcmp(rhost, lhost))
return(1);
if (*(lhost + len) != '\0')
return(0);
if (nodomain)
return(0);
if (!domainp) {
if (gethostname(ldomain, sizeof(ldomain)) == -1) {
nodomain = 1;
return(0);
}
ldomain[MAXHOSTNAMELEN] = 0;
if ((domainp = index(ldomain, '.')) == (char *)NULL) {
nodomain = 1;
return(0);
}
for (cp = ++domainp; *cp; ++cp)
if (isupper(*cp))
*cp = tolower(*cp);
}
return(!strcmp(domainp, rhost + len +1));
}