Running rsh on VxWorks
Mandar A Mathure
I recently built a kernel for a Motorola 68K target with rlogin and
telnet services included. This lets me telnet <target> and also rsh
<target> .
But there is a slight differnce between how rsh is executed on
VxWorks.
% rsh <host> <command/filename> runs the command on a UNIX host
% rsh <target> <command> the connection is refused.
Does anyone know if and how the problem can be rectified?
Thanks in advance
Mandar
Andrew Johnson
>
> I recently built a kernel for a Motorola 68K target with rlogin and
> telnet services included. This lets me telnet <target> and also rsh
> <target> .
You probably don't realize that the command 'rsh <target>' will actually
do a 'rlogin <target>' because you haven't specified any commands for it
to run (go read the manpage for rsh). rlogin and rsh are two different
protocols with different TCP port numbers (513 v 514 IIRC); vxWorks comes
will support for the rlogin and telnet protocols, but not the rsh one. If
you want it, you'll have to write it yourself.
- Andrew
--
The world is such a cheerful place when viewed from upside-down
It makes a rise of every fall, a smile of every frown
Matt Wette
/* rshd.c - rshd for VxWorks
*
* Copyright (C) 1993-2001 Matthew R. Wette -- all rights reserved.
*
* $Id: rshd.c,v 1.2 2001/01/25 21:16:41 mwette Exp $
*
* You may use this program if this copyright notice is kept in tact and
* you don't try to sell it.
*
* To use:
* compile to rshd
* ld < rshd
* rshdInit
*
* This program is subject to a memory leak in the VxWorks shell. Every
* rsh command will eat a little memory. Also, if you're using VxWorks 5.3
* or later, you'll need the SHELL compiled in.
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vxWorks.h>
#include <ioLib.h>
#include <logLib.h>
#include <remLib.h>
#include <shellLib.h>
#include <sockLib.h>
#include <stdioLib.h>
#include <sysLib.h>
#include <taskLib.h>
#include <in.h>
#include <iv.h>
#include <socket.h>
#include <netinet/tcp.h>
static char const rcsid[] = "$Id: rshd.c,v 1.2 2001/01/25 21:16:41 mwette Exp $";
#ifndef RSHD_PORT
#define RSHD_PORT 514
#endif
#ifndef RSHD_PRIO
#define RSHD_PRIO 5
#endif
#define SHELL_CMD 1 /* is a shell command */
#define RESET_CMD 2 /* is a reset command */
#define FEVAL_CMD 3 /* is a function eval command */
int rshdInit(void);
int rshdTask(void);
static int rshd(int sock, struct sockaddr_in*);
static int getstr(int, char*, int, char*);
static int rshdTid = 0;
static int rshdStackSize = 0x8000;
static char rcmd_errmsg[80];
int
rshdInit(void)
{
rshdTid = taskSpawn("tRshd", RSHD_PRIO, VX_STDIO, rshdStackSize, rshdTask,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
if (rshdTid == 0) return ERROR;
return OK;
}
int
rshdTask(void)
{
int status, serv_sock, clnt_sock, clen;
struct sockaddr_in servaddr, clntaddr;
memset(&servaddr, '\0', sizeof(servaddr));
memset(&clntaddr, '\0', sizeof(clntaddr));
/* Open the socket. */
serv_sock = socket(AF_INET, SOCK_STREAM, 0);
if (serv_sock == ERROR) return ERROR;
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(RSHD_PORT);
status = bind(serv_sock, (struct sockaddr *)&servaddr, sizeof(servaddr));
if (status == ERROR) {
close(serv_sock);
logMsg("rshd: bind failed\n", 0, 0, 0, 0, 0, 0);
return ERROR;
}
status = listen(serv_sock, 2);
if (status == ERROR) {
logMsg("rshd: listen failed\n", 0, 0, 0, 0, 0, 0);
close(serv_sock);
return ERROR;
}
while (1) {
clen = sizeof(clntaddr);
clnt_sock = accept(serv_sock, (struct sockaddr*)&clntaddr, &clen);
if (clnt_sock == ERROR) {
logMsg("rshd: accept failed\n", 0, 0, 0, 0, 0, 0);
continue;
}
status = rshd(clnt_sock, &clntaddr);
close(clnt_sock);
}
return OK;
}
static int
rshd(int sock, struct sockaddr_in *addr)
{
int n, status, was_stdout, was_stderr;
int secdport, secdsock, loclport;
char c, *cmd, clntuser[16], servuser[16], bufr[128];
/* Get secondary port request. */
/*alarm(60);*/
secdport = 0;
while ((n = read(sock, &c, 1)) == 1) {
if (c == '\0') break;
secdport = 10*secdport + c - '0';
}
if (secdport != 0) {
loclport = IPPORT_RESERVED - 1;
secdsock = rresvport(&loclport);
addr->sin_port = htons((unsigned short)secdport);
status = connect(secdsock, (struct sockaddr*)addr, sizeof(*addr));
if (status == ERROR) {
logMsg("rshd: connect() on second port %d failed\n", secdport, 0, 0, 0,
0, 0);
close(sock);
return status;
}
}
/* get the command strings */
getstr(sock, clntuser, sizeof(clntuser), "clntuser");
getstr(sock, servuser, sizeof(servuser), "servuser");
getstr(sock, bufr, sizeof(bufr), "command");
# ifdef DEBUG
logMsg("rshd: command=[%s]\n", bufr, 0, 0, 0, 0, 0);
# endif
cmd = bufr;
while (*cmd == ' ' || *cmd == '\t') cmd++; /* strip leading whitespace */
if (*cmd++ != '-') {
/* -- lock shell -- */
status = shellLock(TRUE);
if (status == FALSE) {
logMsg("rshd: failed to lock shell\n", 0, 0, 0, 0, 0, 0);
write(sock, "!", 1);
remCurIdGet(servuser, 0);
sprintf(rcmd_errmsg, "rshd: shell locked by user \"%s\"\n", servuser);
if (strlen(rcmd_errmsg) > 80) rcmd_errmsg[79] = '\n';
write(sock, rcmd_errmsg, strlen(rcmd_errmsg));
goto exit1;
}
status = remCurIdSet(clntuser, 0);
/* -- set I/O -- */
was_stdout = ioGlobalStdGet(1);
ioGlobalStdSet(1, sock);
if (secdport) {
was_stderr = ioGlobalStdGet(2);
ioGlobalStdSet(2, secdsock);
}
/* -- let the client know we're alive -- */
if (write(sock, "", 1) != 1) {
logMsg("rshd: null write to client failed\n", 0, 0, 0, 0, 0, 0);
goto exit3;
}
/* -- execute -- */
status = execute(bufr);
if (status == ERROR) {
logMsg("rshd: execute() failed\n", 0, 0, 0, 0, 0, 0);
goto exit3;
}
break;
} else {
/* insert hooks here */
logMsg("rshd: bad command\n", 0, 0, 0, 0, 0, 0);
goto exit2;
}
exit3:
/* Reestablish I/O */
ioGlobalStdSet(STD_OUT, was_stdout);
if (secdport) ioGlobalStdSet(STD_ERR, was_stderr);
exit2:
/* unlock shell */
status = shellLock(FALSE);
exit1:
/* close sockets */
close(sock);
if (secdport) close(secdsock);
if (qCmdPending) qCmdExec();
return status;
}
static int
getstr(int sock, char *bufr, int cnt, char* errmsg)
{
int i, n;
char c;
bufr[i=0] = '\0';
while ((n = read(sock, &c, 1)) == 1) {
bufr[i++] = c;
if (i == cnt) return ERROR;
if (c == '\0') return OK;
}
if (n == -1) return ERROR;
return OK;
}
/*
SYNOPSIS
int rshdInit(void) - starts rshdTask
int rshdTask(void) - server task
int rshd() - service a request
on Unix host:
rsh <host> <command>
DESCRIPTION
This is an implementation of the remote shell daemon for VxWorks hosts.
It allows users on Unix hosts to run shell commands via the rsh.
ERRORS
If an error occurs rsh will prints a single line error message.
BUGS
Surely some exist.
SEE ALSO: rsh(1), rcmd(1), rshd(8), in.rshd(8)
AUTHOR
Matt Wette <mwe...@alumni.caltech.edu>, Jet Propulsion Laboratory
*/
/* --- last line of rshd.c --- */
--
Matthew.R.Wette at jpl.nasa.gov -- I speak for myself, not for JPL.
Steve Christensen
>Mandar A Mathure wrote:
>>
>> I recently built a kernel for a Motorola 68K target with rlogin and
>> telnet services included. This lets me telnet <target> and also rsh
>> <target> .
>
>You probably don't realize that the command 'rsh <target>' will actually
>do a 'rlogin <target>' because you haven't specified any commands for it
>to run (go read the manpage for rsh). rlogin and rsh are two different
>protocols with different TCP port numbers (513 v 514 IIRC); vxWorks comes
>will support for the rlogin and telnet protocols, but not the rsh one. If
>you want it, you'll have to write it yourself.
>
Rather than have more code running on the target system, you could also
script a telnet session using python/perl/tcl.
For example, in python:
import telnetlib
target = "targetName"
tn = telnetlib.Telnet(target)
print tn.read_until("->")
tn.write("i\n")
print tn.read_until("->")
tn.close()
-Steve
--
Steve Christensen | "It's like getting a scalp massage from Lucifer"
stnc...@xmission.com | -- Space Ghost, SGCC