/*
 *
 *	Copyright (C) 1988, 1989 by the Massachusetts Institute of Technology
 *    	Developed by the MIT Student Information Processing Board (SIPB).
 *    	For copying information, see the file mit-copyright.h in this release.
 *
 */
/*
 *
 *  rpcall.c -- Procedures to implement a simple (perhaps brain-asleep) RPC
 *	  	protocol over a TCP connection.
 *		This file handles the caller's side of the connection.
 *
 *	$Source: /afs/sipb.mit.edu/project/discuss/.cvsroot/discuss/source/libds/rpcall.c,v $
 *	$Header: /afs/sipb.mit.edu/project/discuss/.cvsroot/discuss/source/libds/rpcall.c,v 1.18 1995/03/18 07:25:05 srz Exp $
 *	$Locker:  $
 *	$Log: rpcall.c,v $
 * Revision 1.18  1995/03/18  07:25:05  srz
 * Replace bzero(), bcopy() with memset() and memcpy().
 *
 * Revision 1.17  1994/09/24  04:07:42  srz
 * Changed source tree to use configure instead of Imake.  Added WEAK_REALM
 * authentication.  Fixed up includes, etc, for new configure...  still needs
 * more testing.
 *
 * Revision 1.16  1992/06/26  02:18:46  raeburn
 * getting in sync with current source tree
 *
 * Revision 1.15  89/06/03  00:21:41  srz
 * Added standard copyright notice.
 * 
 * Revision 1.14  89/06/03  00:12:42  srz
 * Ken's changes.
 * 
 * Revision 1.13  89/01/04  20:36:24  raeburn
 * Fixed return type of open_rpc and case statement syntax; fixed
 * include paths.
 * 
 * Revision 1.12  88/10/16  14:53:22  raeburn
 * Added function type definitions; handled different errors from
 * gethostbyname; moved static "panic" to top (to avoid implicit
 * declaration).
 * 
 * Revision 1.11  88/10/16  14:03:54  raeburn
 * revised include format
 *
 * Revision 1.10  88/07/28  10:52:12  srz
 * Added better error message when can't exec subprocess.
 *
 * Revision 1.9  87/04/11  00:06:04  srz
 * Added RCS junk
 *
 * Revision 1.8  87/03/18  12:24:35  srz
 * Better handling of unknown rpc's.
 *
 * Revision 1.7  87/03/10  00:07:23  wesommer
 * Added cleanup routines and error exit path for open connection.
 *
 * Revision 1.6  87/03/09  23:52:18  spook
 * Removed some unused variables; added an error check.
 *
 *
 */
#ifndef lint
static char rcsid_rpcall_c[] =
    "$Header: /afs/sipb.mit.edu/project/discuss/.cvsroot/discuss/source/libds/rpcall.c,v 1.18 1995/03/18 07:25:05 srz Exp $";
#endif lint

/* INCLUDES */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */

#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <discuss/tfile.h>
#include "rpc.h"
#include "config.h"

/* DEFINES */

#define min(A, B) ((A) < (B) ? (A) : (B))
#define SUCCESS 1
#define ERROR   -1

/* EXTERNAL ROUTINES */

extern int errno;
extern int auth_type;

int rpc_err;

/* static variables and functions */

/* panic -- just a printf */
static void panic(str)
    char *str;
{
    fprintf(stderr, "panic: %s\n", str);
    perror("discuss");
    exit(1);
}

/* argument list info */
static int procno;				/* procedure number */

/* connections & socket info */
static USPStream *us = NULL;

/*
 *
 * startsend()  -- Get ready for an RPC call.
 *
 */
void startsend(whichproc)
    int whichproc;
{
    procno = whichproc;
    if (us == NULL) {
	rpc_err = RPC_NOT_INIT;
	return;
    }
    USP_begin_block(us,PROC_BASE+procno);
    rpc_err = 0;

    return;
}

/*
 *
 * sendint(i)  -- Send an integer in an RPC call.
 *
 */
void sendint(i)
    int i;
{
    if (USP_put_long_integer(us, i) != SUCCESS) {
	rpc_err = errno;
    }
}
/*
 *
 * sendshort(i)  -- Send a short integer in an RPC call.
 *
 */
void sendshort(i)
    short i;
{
    if (USP_put_integer(us, i) != SUCCESS) {
	rpc_err = errno;
    }
}

/*
 *
 * sendstr(i)  -- Send a string in an RPC call.
 *
 */
void sendstr(str)
    char *str;
{
    if (us == NULL) {
	rpc_err = RPC_NOT_INIT;
	return;
    }
    if (USP_put_string(us, str) != SUCCESS) {
	rpc_err = errno;
    }
}

/*
 *
 * sendbool(b)  -- Send a boolean in an RPC call.
 *
 */
void sendbool(b)
    unsigned short b;
{
    if (USP_put_boolean(us, b) != SUCCESS) {
	rpc_err = errno;
    }
}


/*
 *
 * sendfile(tf)  -- Send a file in an RPC call.
 *
 */
void sendfile(tf)
    tfile tf;
{
    int tfs;

    tfs = tfsize (tf);
    if (USP_put_long_integer(us, tfs) != SUCCESS) {
	rpc_err = errno;
    }
}

/*
 *
 * sendit () -- Make the final call.
 *
 */
void sendit(dest)
    char *dest;
{
    if (USP_end_block(us) != SUCCESS) {
	rpc_err = errno;
    }
    return;
}

/*
 *
 * init_rpc () -- Initialize the RPC mechanism
 *
 */
void init_rpc ()
{
    init_rpc_err_tbl();
    init_usp_err_tbl();
}

/*
 *
 * term_rpc -- Shutdown the rpc mechanism
 *
 */
void term_rpc()
{
    flush_convs ();
    return;
}

/*
 *
 * close_rpc () -- Close down a specific rpc conversation
 *
 */
void close_rpc(rc)
    rpc_conversation rc;
{
    USP_close_connection(rc);
    us = NULL;
    return;
}

/*
 *
 * set_rpc ()  -- Sets the current rpc conversation
 *
 */
void set_rpc(rc)
    rpc_conversation rc;
{
    us = rc;
}

/*
 *
 * open_rpc ()  -- Open the connection to the server
 *		   Returns an rpc conversation id.
 *
 */
rpc_conversation open_rpc (host, port_num, service_id, code)
    char *host;			/* hostname to connect to */
    int port_num;		/* port number to use */
    char *service_id;		/* authenticator service id */
    register int *code;		/* return code */
{
    int parent,sv[2];
    rpc_conversation conv;
    struct hostent *hp;
    int authl,auth_blk_type;
    register int i, s = -1;

    char *server_name,*authp;
    struct sockaddr_in address;

    *code = 0;

    if (service_id [0] == '/') { /* authenticate using sub-process */
	if (socketpair(AF_UNIX,SOCK_STREAM,0,sv) < 0)
	    panic ("can't do socket pair");

	parent = fork ();
	if (parent < 0)
	    panic ("Can't fork");
	if (!parent) {		/* child's play */
	    dup2(sv[1],0);	/* child takes second one */

	    for (i = 3; i < 20; i++)
		(void) close (i);

	    server_name = strrchr (service_id, '/');
	    if (server_name == NULL)
		server_name = service_id;
	    else
		server_name++;
	    execl(service_id, server_name, 0);
	    {
		char buf[100];
		sprintf(buf, "Can't exec %s", service_id);
		panic (buf);
	    }
	} else {
	    (void) close (sv[1]);
	    (void) fcntl (sv[0], F_SETFD, 1);
	    us = USP_associate (sv[0]);
	    return(us);
	}
    }

    hp = gethostbyname(host);
    if (hp == NULL) {
	extern int h_errno;
	int h = h_errno;
	switch (h) {
	case HOST_NOT_FOUND:
	    *code = RPC_HOST_UNKNOWN;
	    break;
	case TRY_AGAIN:
	    *code = RPC_NS_TIMEOUT;
	    break;
	case NO_RECOVERY:
	    *code = RPC_NS_ERROR;
	    break;
	case NO_ADDRESS:
	    *code = RPC_NO_ADDR;
	    break;
	default:
	    *code = RPC_NS_ERROR;
	    break;
	}
	return(NULL);
    }

    /* since we already have our port number, the following code was
       stolen from USP to manually set up the connection.  Note that
       one benefit from using the primitive USP routine (USP_associate)
       is that we eliminate an extra host lookup, and we don't have
       to rely on USP's primitive error mechanism.  Yeah! */

    memset((char *) &address, 0, sizeof(address));
    memcpy((char *) &address.sin_addr, hp->h_addr, hp->h_length);
    address.sin_family = hp->h_addrtype;
    address.sin_port = port_num;
    if((s = socket(hp->h_addrtype, SOCK_STREAM, 0)) < 0)
	goto punt;

    if(connect(s, (char *) &address, sizeof(address)) < 0)
	goto punt;

    (void) fcntl (s, F_SETFD, 1);
    conv = USP_associate (s);
    us = conv;
    if (!us)
	goto punt;

    get_authenticator(service_id, 0, &authp, &authl, code);
    switch (auth_type) {
    case AUTH_WEAK:
	 auth_blk_type = WEAK_TICKET;
	 break;

    case AUTH_KRB:
    case AUTH_STD:
    default:
	 auth_blk_type = KRB_TICKET;
	 break;
    }
    if (! *code) {
	 USP_begin_block(us,auth_blk_type);
	 sendshort(authl);
	 for (i = 0; i < authl; i++) {
	      sendshort(*authp++);
	 }
	 USP_end_block(us);
    } else {
	 USP_begin_block(us,auth_blk_type);	/* send blank ticket */
	 sendshort(0);
	 USP_end_block(us);
    }
    return(conv);
punt:
    if (s >= 0) close(s);
    *code = errno;
    return(NULL);
}

/*
 *
 * recvreply ()  -- Routine to accept an RPC return.
 *
 */
void recvreply ()
{
    USPCardinal bt;

    if (USP_rcv_blk(us, &bt) != SUCCESS) {
	rpc_err = errno;
	return;
    }

    if (bt != REPLY_TYPE) {
	if (bt == UNKNOWN_CALL)
	    rpc_err = RPC_UNIMPL_CALL;
	else
	    rpc_err = RPC_PROTOCOL;
	USP_flush_block(us);
    }
    return;

}

int recvint ()
{
    USPLong_integer li;

    if (USP_get_long_integer(us, &li) != SUCCESS) {
	rpc_err = errno;
	return(0);
    }

    return (li);
}

/*
 *
 * recvstr ()  -- Receive a string from an RPC call
 *
 */

char *recvstr ()
{
    USPString str;

    if (USP_get_string(us, &str) != SUCCESS) {
	rpc_err = errno;
	return("");
    }

    return (str);
}
unsigned short recvbool()
{
    USPBoolean flag;

    if (USP_get_boolean(us, &flag) != SUCCESS) {
	rpc_err = errno;
	return(0);
    }

    return (flag);
}

/*
 *
 * senddata () -- Routine to send the contents of a transaction file
 * 		  across the net.
 *
 */
void senddata(tf)
    tfile tf;
{
    int tfs,tocopy;
    char buffer[508];
    int result;

    topen (tf, "r", &result);
    USP_begin_block (us, TFILE_BLK);
    tfs = tfsize(tf);
    while (tfs > 0) {
	tocopy = min (tfs, 508);
	tread (tf, buffer, tocopy, &result);
	if (result)
	    break;
	USP_put_byte_block(us, buffer, tocopy);
	tfs -= tocopy;
    }
    USP_end_block(us);
    tclose (tf, &result);
}

/*
 *
 * recvdata () -- Routine to receive a USP file.
 *
 */
void recvdata(tf)
    tfile tf;
{
    char buffer[508];
    USPCardinal bt;
    unsigned actual;
    int result;

    if (USP_rcv_blk(us, &bt) != SUCCESS) {
	rpc_err = errno;
	return;
    }

    if (bt != TFILE_BLK) {
	rpc_err = RPC_PROTOCOL;
	return;
    }

    topen (tf, "w", &result);
    if (result) goto done;
    for (;;) {
	if (USP_get_byte_block(us, buffer, 508, &actual) != SUCCESS) {
	    rpc_err = errno;
	    break;
	}
	if (actual == 0)
	    break;
	twrite(tf, buffer, actual, &result);
	if (result) break;
    }

    tclose (tf, &result);

done:
    USP_flush_block(us);
}