system.c

早期freebsd实现

/*-
 * Copyright (c) 1988, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 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.
 */

#ifndef lint
static char sccsid[] = "@(#)system.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#include <sys/types.h>

#if     defined(pyr)
#define fd_set fdset_t
#endif  /* defined(pyr) */

/*
 * Wouldn't it be nice if these REALLY were in <sys/inode.h>?  Or,
 * equivalently, if <sys/inode.h> REALLY existed?
 */
#define	IREAD	00400
#define	IWRITE	00200

#include <sys/file.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/wait.h>

#include <errno.h>
extern int errno;

#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <pwd.h>

#include "../general/general.h"
#include "../ctlr/api.h"
#include "../api/api_exch.h"

#include "../general/globals.h"

#ifndef	FD_SETSIZE
/*
 * The following is defined just in case someone should want to run
 * this telnet on a 4.2 system.
 *
 */

#define	FD_SET(n, p)	((p)->fds_bits[0] |= (1<<(n)))
#define	FD_CLR(n, p)	((p)->fds_bits[0] &= ~(1<<(n)))
#define	FD_ISSET(n, p)	((p)->fds_bits[0] & (1<<(n)))
#define FD_ZERO(p)	((p)->fds_bits[0] = 0)

#endif

static int shell_pid = 0;
static char key[50];			/* Actual key */
static char *keyname;			/* Name of file with key in it */

static char *ourENVlist[200];		/* Lots of room */

static int
    sock = -1,				/* Connected socket */
    serversock;				/* Server (listening) socket */

static enum { DEAD, UNCONNECTED, CONNECTED } state;

static long
    storage_location;		/* Address we have */
static short
    storage_length = 0;		/* Length we have */
static int
    storage_must_send = 0,	/* Storage belongs on other side of wire */
    storage_accessed = 0;	/* The storage is accessed (so leave alone)! */

static long storage[1000];

static union REGS inputRegs;
static struct SREGS inputSregs;

extern int apitrace;

static void
kill_connection()
{
    state = UNCONNECTED;
    if (sock != -1) {
	(void) close(sock);
	sock = -1;
    }
}


static int
nextstore()
{
    struct storage_descriptor sd;

    if (api_exch_intype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd) == -1) {
	storage_length = 0;
	return -1;
    }
    storage_length = sd.length;
    storage_location = sd.location;
    if (storage_length > sizeof storage) {
	fprintf(stderr, "API client tried to send too much storage (%d).\n",
		storage_length);
	storage_length = 0;
	return -1;
    }
    if (api_exch_intype(EXCH_TYPE_BYTES, storage_length, (char *)storage)
							== -1) {
	storage_length = 0;
	return -1;
    }
    return 0;
}


static int
doreject(message)
char	*message;
{
    struct storage_descriptor sd;
    int length = strlen(message);

    if (api_exch_outcommand(EXCH_CMD_REJECTED) == -1) {
	return -1;
    }
    sd.length = length;
    if (api_exch_outtype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd) == -1) {
	return -1;
    }
    if (api_exch_outtype(EXCH_TYPE_BYTES, length, message) == -1) {
	return -1;
    }
    return 0;
}


/*
 * doassociate()
 *
 * Negotiate with the other side and try to do something.
 *
 * Returns:
 *
 *	-1:	Error in processing
 *	 0:	Invalid password entered
 *	 1:	Association OK
 */

static int
doassociate()
{
    struct passwd *pwent;
    char
	promptbuf[100],
	buffer[200];
    struct storage_descriptor sd;
    extern char *crypt();

    if (api_exch_intype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd) == -1) {
	return -1;
    }
    sd.length = sd.length;
    if (sd.length > sizeof buffer) {
	doreject("(internal error) Authentication key too long");
	return -1;
    }
    if (api_exch_intype(EXCH_TYPE_BYTES, sd.length, buffer) == -1) {
	return -1;
    }
    buffer[sd.length] = 0;

    if (strcmp(buffer, key) != 0) {
#if	(!defined(sun)) || defined(BSD) && (BSD >= 43)
	extern uid_t geteuid();
#endif	/* (!defined(sun)) || defined(BSD) && (BSD >= 43) */

	if ((pwent = getpwuid((int)geteuid())) == 0) {
	    return -1;
	}
	sprintf(promptbuf, "Enter password for user %s:", pwent->pw_name);
	if (api_exch_outcommand(EXCH_CMD_SEND_AUTH) == -1) {
	    return -1;
	}
	sd.length = strlen(promptbuf);
	if (api_exch_outtype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd)
									== -1) {
	    return -1;
	}
	if (api_exch_outtype(EXCH_TYPE_BYTES, strlen(promptbuf), promptbuf)
									== -1) {
	    return -1;
	}
	sd.length = strlen(pwent->pw_name);
	if (api_exch_outtype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd)
									== -1) {
	    return -1;
	}
	if (api_exch_outtype(EXCH_TYPE_BYTES,
			    strlen(pwent->pw_name), pwent->pw_name) == -1) {
	    return -1;
	}
	if (api_exch_incommand(EXCH_CMD_AUTH) == -1) {
	    return -1;
	}
	if (api_exch_intype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd)
									== -1) {
	    return -1;
	}
	sd.length = sd.length;
	if (sd.length > sizeof buffer) {
	    doreject("Password entered was too long");
	    return -1;
	}
	if (api_exch_intype(EXCH_TYPE_BYTES, sd.length, buffer) == -1) {
	    return -1;
	}
	buffer[sd.length] = 0;

	/* Is this the correct password? */
	if (strlen(pwent->pw_name)) {
	    char *ptr;
	    int i;

	    ptr = pwent->pw_name;
	    i = 0;
	    while (i < sd.length) {
		buffer[i++] ^= *ptr++;
		if (*ptr == 0) {
		    ptr = pwent->pw_name;
		}
	    }
	}
	if (strcmp(crypt(buffer, pwent->pw_passwd), pwent->pw_passwd) != 0) {
	    doreject("Invalid password");
	    sleep(10);		/* Don't let us do too many of these */
	    return 0;
	}
    }
    if (api_exch_outcommand(EXCH_CMD_ASSOCIATED) == -1) {
	return -1;
    } else {
	return 1;
    }
}


void
freestorage()
{
    struct storage_descriptor sd;

    if (storage_accessed) {
	fprintf(stderr, "Internal error - attempt to free accessed storage.\n");
	fprintf(stderr, "(Encountered in file %s at line %d.)\n",
			__FILE__, __LINE__);
	quit();
    }
    if (storage_must_send == 0) {
	return;
    }
    storage_must_send = 0;
    if (api_exch_outcommand(EXCH_CMD_HEREIS) == -1) {
	kill_connection();
	return;
    }
    sd.length = storage_length;
    sd.location = storage_location;
    if (api_exch_outtype(EXCH_TYPE_STORE_DESC, sizeof sd, (char *)&sd) == -1) {
	kill_connection();
	return;
    }
    if (api_exch_outtype(EXCH_TYPE_BYTES, storage_length, (char *)storage)
							    == -1) {
	kill_connection();
	return;
    }
}


static int
getstorage(address, length, copyin)
long
    address;
int
    length,
    copyin;
{
    struct storage_descriptor sd;

    freestorage();
    if (storage_accessed) {
	fprintf(stderr,
		"Internal error - attempt to get while storage accessed.\n");
	fprintf(stderr, "(Encountered in file %s at line %d.)\n",
			__FILE__, __LINE__);
	quit();
    }
    storage_must_send = 0;
    if (api_exch_outcommand(EXCH_CMD_GIMME) == -1) {
	kill_connection();
	return -1;
    }
    storage_location = address;
    storage_length = length;
    if (copyin) {
	sd.location = (long)storage_location;
	sd.length = storage_length;
	if (api_exch_outtype(EXCH_TYPE_STORE_DESC,
					sizeof sd, (char *)&sd) == -1) {
	    kill_connection();
	    return -1;
	}
	if (api_exch_incommand(EXCH_CMD_HEREIS) == -1) {
	    fprintf(stderr, "Bad data from other side.\n");
	    fprintf(stderr, "(Encountered at %s, %d.)\n", __FILE__, __LINE__);
	    return -1;
	}
	if (nextstore() == -1) {
	    kill_connection();
	    return -1;
	}
    }
    return 0;
}

/*ARGSUSED*/
void
movetous(local, es, di, length)
char
    *local;
unsigned int
    es,
    di;
int
    length;
{
    long where = SEG_OFF_BACK(es, di);

    if (length > sizeof storage) {
	fprintf(stderr, "Internal API error - movetous() length too long.\n");
	fprintf(stderr, "(detected in file %s, line %d)\n", __FILE__, __LINE__);
	quit();
    } else if (length == 0) {