[unix-history] / lib / librpc / rpc / xdr_rec.c

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 * 
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 * 
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 * 
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 * 
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 * 
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */
#if defined(LIBC_SCCS) && !defined(lint) 
/*static char *sccsid = "from: @(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";*/
/*static char *sccsid = "from: @(#)xdr_rec.c	2.2 88/08/01 4.0 RPCSRC";*/
static char *rcsid = "$Id: xdr_rec.c,v 1.4 1993/08/26 00:53:51 jtc Exp $";
#endif

/*
 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
 * layer above tcp (for rpc's use).
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * These routines interface XDRSTREAMS to a tcp/ip connection.
 * There is a record marking layer between the xdr stream
 * and the tcp transport level.  A record is composed on one or more
 * record fragments.  A record fragment is a thirty-two bit header followed
 * by n bytes of data, where n is contained in the header.  The header
 * is represented as a htonl(u_long).  Thegh order bit encodes
 * whether or not the fragment is the last fragment of the record
 * (1 => fragment is last, 0 => more fragments to follow. 
 * The other 31 bits encode the byte length of the fragment.
 */

#include <stdio.h>
#include <stdlib.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <netinet/in.h>

extern long	lseek();

static u_int	fix_buf_size();
static bool_t	flush_out();
static bool_t	get_input_bytes();
static bool_t	set_input_fragment();
static bool_t	skip_input_bytes();

static bool_t	xdrrec_getlong();
static bool_t	xdrrec_putlong();
static bool_t	xdrrec_getbytes();
static bool_t	xdrrec_putbytes();
static u_int	xdrrec_getpos();
static bool_t	xdrrec_setpos();
static long *	xdrrec_inline();
static void	xdrrec_destroy();

static struct  xdr_ops xdrrec_ops = {
	xdrrec_getlong,
	xdrrec_putlong,
	xdrrec_getbytes,
	xdrrec_putbytes,
	xdrrec_getpos,
	xdrrec_setpos,
	xdrrec_inline,
	xdrrec_destroy
};

/*
 * A record is composed of one or more record fragments.
 * A record fragment is a two-byte header followed by zero to
 * 2**32-1 bytes.  The header is treated as a long unsigned and is
 * encode/decoded to the network via htonl/ntohl.  The low order 31 bits
 * are a byte count of the fragment.  The highest order bit is a boolean:
 * 1 => this fragment is the last fragment of the record,
 * 0 => this fragment is followed by more fragment(s).
 *
 * The fragment/record machinery is not general;  it is constructed to
 * meet the needs of xdr and rpc based on tcp.
 */

#define LAST_FRAG ((u_long)(1 << 31))

typedef struct rec_strm {
	caddr_t tcp_handle;
	caddr_t the_buffer;
	/*
	 * out-goung bits
	 */
	int (*writeit)();
	caddr_t out_base;	/* output buffer (points to frag header) */
	caddr_t out_finger;	/* next output position */
	caddr_t out_boundry;	/* data cannot up to this address */
	u_long *frag_header;	/* beginning of curren fragment */
	bool_t frag_sent;	/* true if buffer sent in middle of record */
	/*
	 * in-coming bits
	 */
	int (*readit)();
	u_long in_size;	/* fixed size of the input buffer */
	caddr_t in_base;
	caddr_t in_finger;	/* location of next byte to be had */
	caddr_t in_boundry;	/* can read up to this location */
	long fbtbc;		/* fragment bytes to be consumed */
	bool_t last_frag;
	u_int sendsize;
	u_int recvsize;
} RECSTREAM;


/*
 * Create an xdr handle for xdrrec
 * xdrrec_create fills in xdrs.  Sendsize and recvsize are
 * send and recv buffer sizes (0 => use default).
 * tcp_handle is an opaque handle that is passed as the first parameter to
 * the procedures readit and writeit.  Readit and writeit are read and
 * write respectively.   They are like the system
 * calls expect that they take an opaque handle rather than an fd.
 */
void
xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit)
	register XDR *xdrs;
	register u_int sendsize;
	register u_int recvsize;
	caddr_t tcp_handle;
	int (*readit)();  /* like read, but pass it a tcp_handle, not sock */
	int (*writeit)();  /* like write, but pass it a tcp_handle, not sock */
{
	register RECSTREAM *rstrm =
		(RECSTREAM *)mem_alloc(sizeof(RECSTREAM));

	if (rstrm == NULL) {
		(void)fprintf(stderr, "xdrrec_create: out of memory\n");
		/* 
		 *  This is bad.  Should rework xdrrec_create to 
		 *  return a handle, and in this case return NULL
		 */
		return;
	}
	/*
	 * adjust sizes and allocate buffer quad byte aligned
	 */
	rstrm->sendsize = sendsize = fix_buf_size(sendsize);
	rstrm->recvsize = recvsize = fix_buf_size(recvsize);
	rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT);
	if (rstrm->the_buffer == NULL) {
		(void)fprintf(stderr, "xdrrec_create: out of memory\n");
		return;
	}
	for (rstrm->out_base = rstrm->the_buffer;
		(u_int)rstrm->out_base % BYTES_PER_XDR_UNIT != 0;
		rstrm->out_base++);
	rstrm->in_base = rstrm->out_base + sendsize;
	/*
	 * now the rest ...
	 */
	xdrs->x_ops = &xdrrec_ops;
	xdrs->x_private = (caddr_t)rstrm;
	rstrm->tcp_handle = tcp_handle;
	rstrm->readit = readit;
	rstrm->writeit = writeit;
	rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
	rstrm->frag_header = (u_long *)rstrm->out_base;
	rstrm->out_finger += sizeof(u_long);
	rstrm->out_boundry += sendsize;
	rstrm->frag_sent = FALSE;
	rstrm->in_size = recvsize;
	rstrm->in_boundry = rstrm->in_base;
	rstrm->in_finger = (rstrm->in_boundry += recvsize);
	rstrm->fbtbc = 0;
	rstrm->last_frag = TRUE;
}


/*
 * The reoutines defined below are the xdr ops which will go into the
 * xdr handle filled in by xdrrec_create.
 */

static bool_t
xdrrec_getlong(xdrs, lp)
	XDR *xdrs;
	long *lp;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
	register long *buflp = (long *)(rstrm->in_finger);
	long mylong;

	/* first try the inline, fast case */
	if ((rstrm->fbtbc >= sizeof(long)) &&
		(((int)rstrm->in_boundry - (int)buflp) >= sizeof(long))) {
		*lp = (long)ntohl((u_long)(*buflp));
		rstrm->fbtbc -= sizeof(long);
		rstrm->in_finger += sizeof(long);
	} else {
		if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long)))
			return (FALSE);
		*lp = (long)ntohl((u_long)mylong);
	}
	return (TRUE);
}

static bool_t
xdrrec_putlong(xdrs, lp)
	XDR *xdrs;
	long *lp;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
	register long *dest_lp = ((long *)(rstrm->out_finger));

	if ((rstrm->out_finger += sizeof(long)) > rstrm->out_boundry) {
		/*
		 * this case should almost never happen so the code is
		 * inefficient
		 */
		rstrm->out_finger -= sizeof(long);
		rstrm->frag_sent = TRUE;
		if (! flush_out(rstrm, FALSE))
			return (FALSE);
		dest_lp = ((long *)(rstrm->out_finger));
		rstrm->out_finger += sizeof(long);
	}
	*dest_lp = (long)htonl((u_long)(*lp));
	return (TRUE);
}

static bool_t  /* must manage buffers, fragments, and records */
xdrrec_getbytes(xdrs, addr, len)
	XDR *xdrs;
	register caddr_t addr;
	register u_int len;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
	register int current;

	while (len > 0) {
		current = rstrm->fbtbc;
		if (current == 0) {
			if (rstrm->last_frag)
				return (FALSE);
			if (! set_input_fragment(rstrm))
				return (FALSE);
			continue;
		}
		current = (len < current) ? len : current;
		if (! get_input_bytes(rstrm, addr, current))
			return (FALSE);
		addr += current; 
		rstrm->fbtbc -= current;
		len -= current;
	}
	return (TRUE);
}

static bool_t
xdrrec_putbytes(xdrs, addr, len)
	XDR *xdrs;
	register caddr_t addr;
	register u_int len;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
	register int current;

	while (len > 0) {
		current = (u_int)rstrm->out_boundry - (u_int)rstrm->out_finger;
		current = (len < current) ? len : current;
		bcopy(addr, rstrm->out_finger, current);
		rstrm->out_finger += current;
		addr += current;
		len -= current;
		if (rstrm->out_finger == rstrm->out_boundry) {
			rstrm->frag_sent = TRUE;
			if (! flush_out(rstrm, FALSE))
				return (FALSE);
		}
	}
	return (TRUE);
}

static u_int
xdrrec_getpos(xdrs)
	register XDR *xdrs;
{
	register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
	register long pos;

	pos = lseek((int)rstrm->tcp_handle, (long) 0, 1);
	if (pos != -1)
		switch (xdrs->x_op) {

		case XDR_ENCODE:
			pos += rstrm->out_finger - rstrm->out_base;
			break;

		case XDR_DECODE:
			pos -= rstrm->in_boundry - rstrm->in_finger;
			break;

		default:
			pos = (u_int) -1;
			break;
		}
	return ((u_int) pos);
}

static bool_t
xdrrec_setpos(xdrs, pos)
	register XDR *xdrs;
	u_int pos;
{
	register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
	u_int currpos = xdrrec_getpos(xdrs);
	int delta = currpos - pos;
	caddr_t newpos;

	if ((int)currpos != -1)
		switch (xdrs->x_op) {

		case XDR_ENCODE:
			newpos = rstrm->out_finger - delta;
			if ((newpos > (caddr_t)(rstrm->frag_header)) &&
				(newpos < rstrm->out_boundry)) {
				rstrm->out_finger = newpos;
				return (TRUE);
			}
			break;

		case XDR_DECODE:
			newpos = rstrm->in_finger - delta;
			if ((delta < (int)(rstrm->fbtbc)) &&
				(newpos <= rstrm->in_boundry) &&
				(newpos >= rstrm->in_base)) {
				rstrm->in_finger = newpos;
				rstrm->fbtbc -= delta;
				return (TRUE);
			}
			break;
		}
	return (FALSE);
}

static long *
xdrrec_inline(xdrs, len)
	register XDR *xdrs;
	int len;
{
	register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
	long * buf = NULL;

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
			buf = (long *) rstrm->out_finger;
			rstrm->out_finger += len;
		}
		break;

	case XDR_DECODE:
		if ((len <= rstrm->fbtbc) &&
			((rstrm->in_finger + len) <= rstrm->in_boundry)) {
			buf = (long *) rstrm->in_finger;
			rstrm->fbtbc -= len;
			rstrm->in_finger += len;
		}
		break;
	}
	return (buf);
}

static void
xdrrec_destroy(xdrs)
	register XDR *xdrs;
{
	register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;

	mem_free(rstrm->the_buffer,
		rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT);
	mem_free((caddr_t)rstrm, sizeof(RECSTREAM));
}


/*
 * Exported routines to manage xdr records
 */

/*
 * Before reading (deserializing from the stream, one should always call
 * this procedure to guarantee proper record alignment.
 */
bool_t
xdrrec_skiprecord(xdrs)
	XDR *xdrs;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);

	while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
		if (! skip_input_bytes(rstrm, rstrm->fbtbc))
			return (FALSE);
		rstrm->fbtbc = 0;
		if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
			return (FALSE);
	}
	rstrm->last_frag = FALSE;
	return (TRUE);
}

/*
 * Look ahead fuction.
 * Returns TRUE iff there is no more input in the buffer 
 * after consuming the rest of the current record.
 */
bool_t
xdrrec_eof(xdrs)
	XDR *xdrs;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);

	while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
		if (! skip_input_bytes(rstrm, rstrm->fbtbc))
			return (TRUE);
		rstrm->fbtbc = 0;
		if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
			return (TRUE);
	}
	if (rstrm->in_finger == rstrm->in_boundry)
		return (TRUE);
	return (FALSE);
}

/*
 * The client must tell the package when an end-of-record has occurred.
 * The second paraemters tells whether the record should be flushed to the
 * (output) tcp stream.  (This let's the package support batched or
 * pipelined procedure calls.)  TRUE => immmediate flush to tcp connection.
 */
bool_t
xdrrec_endofrecord(xdrs, sendnow)
	XDR *xdrs;
	bool_t sendnow;
{
	register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
	register u_long len;  /* fragment length */

	if (sendnow || rstrm->frag_sent ||
		((u_long)rstrm->out_finger + sizeof(u_long) >=
		(u_long)rstrm->out_boundry)) {
		rstrm->frag_sent = FALSE;
		return (flush_out(rstrm, TRUE));
	}
	len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
	   sizeof(u_long);
	*(rstrm->frag_header) = htonl((u_long)len | LAST_FRAG);
	rstrm->frag_header = (u_long *)rstrm->out_finger;
	rstrm->out_finger += sizeof(u_long);
	return (TRUE);
}


/*
 * Internal useful routines
 */
static bool_t
flush_out(rstrm, eor)
	register RECSTREAM *rstrm;
	bool_t eor;
{
	register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
	register u_long len = (u_long)(rstrm->out_finger) - 
		(u_long)(rstrm->frag_header) - sizeof(u_long);

	*(rstrm->frag_header) = htonl(len | eormask);
	len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base);
	if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
		!= (int)len)
		return (FALSE);
	rstrm->frag_header = (u_long *)rstrm->out_base;
	rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_long);
	return (TRUE);
}

static bool_t  /* knows nothing about records!  Only about input buffers */
fill_input_buf(rstrm)
	register RECSTREAM *rstrm;
{
	register caddr_t where;
	u_int i;
	register int len;

	where = rstrm->in_base;
	i = (u_int)rstrm->in_boundry % BYTES_PER_XDR_UNIT;
	where += i;
	len = rstrm->in_size - i;
	if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
		return (FALSE);
	rstrm->in_finger = where;
	where += len;
	rstrm->in_boundry = where;
	return (TRUE);
}

static bool_t  /* knows nothing about records!  Only about input buffers */
get_input_bytes(rstrm, addr, len)
	register RECSTREAM *rstrm;
	register caddr_t addr;
	register int len;
{
	register int current;

	while (len > 0) {
		current = (int)rstrm->in_boundry - (int)rstrm->in_finger;
		if (current == 0) {
			if (! fill_input_buf(rstrm))
				return (FALSE);
			continue;
		}
		current = (len < current) ? len : current;
		bcopy(rstrm->in_finger, addr, current);
		rstrm->in_finger += current;
		addr += current;
		len -= current;
	}
	return (TRUE);
}

static bool_t  /* next two bytes of the input stream are treated as a header */
set_input_fragment(rstrm)
	register RECSTREAM *rstrm;
{
	u_long header;

	if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header)))
		return (FALSE);
	header = (long)ntohl(header);
	rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
	rstrm->fbtbc = header & (~LAST_FRAG);
	return (TRUE);
}

static bool_t  /* consumes input bytes; knows nothing about records! */
skip_input_bytes(rstrm, cnt)
	register RECSTREAM *rstrm;
	long cnt;
{
	register int current;

	while (cnt > 0) {
		current = (int)rstrm->in_boundry - (int)rstrm->in_finger;
		if (current == 0) {
			if (! fill_input_buf(rstrm))
				return (FALSE);
			continue;
		}
		current = (cnt < current) ? cnt : current;
		rstrm->in_finger += current;
		cnt -= current;
	}
	return (TRUE);
}

static u_int
fix_buf_size(s)
	register u_int s;
{

	if (s < 100)
		s = 4000;
	return (RNDUP(s));
}
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
	3	* unrestricted use provided that this legend is included on all tape
	4	* media and as a part of the software program in whole or part. Users
	5	* may copy or modify Sun RPC without charge, but are not authorized
	6	* to license or distribute it to anyone else except as part of a product or
	7	* program developed by the user.
	8	*
	9	* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
	10	* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
	11	* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
	12	*
	13	* Sun RPC is provided with no support and without any obligation on the
	14	* part of Sun Microsystems, Inc. to assist in its use, correction,
	15	* modification or enhancement.
	16	*
	17	* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
	18	* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
	19	* OR ANY PART THEREOF.
	20	*
	21	* In no event will Sun Microsystems, Inc. be liable for any lost revenue
	22	* or profits or other special, indirect and consequential damages, even if
	23	* Sun has been advised of the possibility of such damages.
	24	*
	25	* Sun Microsystems, Inc.
	26	* 2550 Garcia Avenue
	27	* Mountain View, California 94043
	28	*/
78ed81a3	29	#if defined(LIBC_SCCS) && !defined(lint)
	30	/static char sccsid = "from: @(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";*/
	31	/static char sccsid = "from: @(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";*/
	32	static char *rcsid = "$Id: xdr_rec.c,v 1.4 1993/08/26 00:53:51 jtc Exp $";
15637ed4 RG	33	#endif
	34
	35	/*
	36	* xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
	37	* layer above tcp (for rpc's use).
	38	*
	39	* Copyright (C) 1984, Sun Microsystems, Inc.
	40	*
	41	* These routines interface XDRSTREAMS to a tcp/ip connection.
	42	* There is a record marking layer between the xdr stream
	43	* and the tcp transport level. A record is composed on one or more
	44	* record fragments. A record fragment is a thirty-two bit header followed
	45	* by n bytes of data, where n is contained in the header. The header
	46	* is represented as a htonl(u_long). Thegh order bit encodes
	47	* whether or not the fragment is the last fragment of the record
	48	* (1 => fragment is last, 0 => more fragments to follow.
	49	* The other 31 bits encode the byte length of the fragment.
	50	*/
	51
	52	#include <stdio.h>
78ed81a3	53	#include <stdlib.h>
15637ed4 RG	54	#include <rpc/types.h>
	55	#include <rpc/xdr.h>
	56	#include <netinet/in.h>
	57
	58	extern long lseek();
	59
	60	static u_int fix_buf_size();
	61	static bool_t flush_out();
	62	static bool_t get_input_bytes();
	63	static bool_t set_input_fragment();
	64	static bool_t skip_input_bytes();
	65
	66	static bool_t xdrrec_getlong();
	67	static bool_t xdrrec_putlong();
	68	static bool_t xdrrec_getbytes();
	69	static bool_t xdrrec_putbytes();
	70	static u_int xdrrec_getpos();
	71	static bool_t xdrrec_setpos();
	72	static long * xdrrec_inline();
	73	static void xdrrec_destroy();
	74
	75	static struct xdr_ops xdrrec_ops = {
	76	xdrrec_getlong,
	77	xdrrec_putlong,
	78	xdrrec_getbytes,
	79	xdrrec_putbytes,
	80	xdrrec_getpos,
	81	xdrrec_setpos,
	82	xdrrec_inline,
	83	xdrrec_destroy
	84	};
	85
	86	/*
	87	* A record is composed of one or more record fragments.
	88	* A record fragment is a two-byte header followed by zero to
	89	* 2**32-1 bytes. The header is treated as a long unsigned and is
	90	* encode/decoded to the network via htonl/ntohl. The low order 31 bits
	91	* are a byte count of the fragment. The highest order bit is a boolean:
	92	* 1 => this fragment is the last fragment of the record,
	93	* 0 => this fragment is followed by more fragment(s).
	94	*
	95	* The fragment/record machinery is not general; it is constructed to
	96	* meet the needs of xdr and rpc based on tcp.
	97	*/
	98
	99	#define LAST_FRAG ((u_long)(1 << 31))
	100
	101	typedef struct rec_strm {
	102	caddr_t tcp_handle;
	103	caddr_t the_buffer;
	104	/*
	105	* out-goung bits
	106	*/
	107	int (*writeit)();
	108	caddr_t out_base; /* output buffer (points to frag header) */
	109	caddr_t out_finger; /* next output position */
	110	caddr_t out_boundry; /* data cannot up to this address */
	111	u_long frag_header; / beginning of curren fragment */
	112	bool_t frag_sent; /* true if buffer sent in middle of record */
	113	/*
	114	* in-coming bits
	115	*/
	116	int (*readit)();
	117	u_long in_size; /* fixed size of the input buffer */
118	caddr_t in_base;
119	caddr_t in_finger; /* location of next byte to be had */
120	caddr_t in_boundry; /* can read up to this location */
121	long fbtbc; /* fragment bytes to be consumed */
122	bool_t last_frag;
123	u_int sendsize;
124	u_int recvsize;
125	} RECSTREAM;
126
127
128	/*
129	* Create an xdr handle for xdrrec
130	* xdrrec_create fills in xdrs. Sendsize and recvsize are
131	* send and recv buffer sizes (0 => use default).
132	* tcp_handle is an opaque handle that is passed as the first parameter to
133	* the procedures readit and writeit. Readit and writeit are read and
134	* write respectively. They are like the system
135	* calls expect that they take an opaque handle rather than an fd.
136	*/
137	void
138	xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit)
139	register XDR *xdrs;
140	register u_int sendsize;
141	register u_int recvsize;
142	caddr_t tcp_handle;
143	int (readit)(); / like read, but pass it a tcp_handle, not sock */
144	int (writeit)(); / like write, but pass it a tcp_handle, not sock */
145	{
146	register RECSTREAM *rstrm =
147	(RECSTREAM *)mem_alloc(sizeof(RECSTREAM));
148
149	if (rstrm == NULL) {
150	(void)fprintf(stderr, "xdrrec_create: out of memory\n");
151	/*
152	* This is bad. Should rework xdrrec_create to
153	* return a handle, and in this case return NULL
154	*/
155	return;
156	}
157	/*
158	* adjust sizes and allocate buffer quad byte aligned
159	*/
160	rstrm->sendsize = sendsize = fix_buf_size(sendsize);
161	rstrm->recvsize = recvsize = fix_buf_size(recvsize);
162	rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT);
163	if (rstrm->the_buffer == NULL) {
164	(void)fprintf(stderr, "xdrrec_create: out of memory\n");
165	return;
166	}
167	for (rstrm->out_base = rstrm->the_buffer;
168	(u_int)rstrm->out_base % BYTES_PER_XDR_UNIT != 0;
169	rstrm->out_base++);
170	rstrm->in_base = rstrm->out_base + sendsize;
171	/*
172	* now the rest ...
173	*/
174	xdrs->x_ops = &xdrrec_ops;
175	xdrs->x_private = (caddr_t)rstrm;
176	rstrm->tcp_handle = tcp_handle;
177	rstrm->readit = readit;
178	rstrm->writeit = writeit;
179	rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
180	rstrm->frag_header = (u_long *)rstrm->out_base;
181	rstrm->out_finger += sizeof(u_long);
182	rstrm->out_boundry += sendsize;
183	rstrm->frag_sent = FALSE;
184	rstrm->in_size = recvsize;
185	rstrm->in_boundry = rstrm->in_base;
186	rstrm->in_finger = (rstrm->in_boundry += recvsize);
187	rstrm->fbtbc = 0;
188	rstrm->last_frag = TRUE;
189	}
190
191
192	/*
193	* The reoutines defined below are the xdr ops which will go into the
194	* xdr handle filled in by xdrrec_create.
195	*/
196
197	static bool_t
198	xdrrec_getlong(xdrs, lp)
199	XDR *xdrs;
200	long *lp;
201	{
202	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
203	register long buflp = (long )(rstrm->in_finger);
204	long mylong;
205
206	/* first try the inline, fast case */
207	if ((rstrm->fbtbc >= sizeof(long)) &&
208	(((int)rstrm->in_boundry - (int)buflp) >= sizeof(long))) {
209	lp = (long)ntohl((u_long)(buflp));
210	rstrm->fbtbc -= sizeof(long);
211	rstrm->in_finger += sizeof(long);
212	} else {
213	if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long)))
214	return (FALSE);
215	*lp = (long)ntohl((u_long)mylong);
216	}
217	return (TRUE);
218	}
219
220	static bool_t
221	xdrrec_putlong(xdrs, lp)
222	XDR *xdrs;
223	long *lp;
224	{
225	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
226	register long dest_lp = ((long )(rstrm->out_finger));
227
228	if ((rstrm->out_finger += sizeof(long)) > rstrm->out_boundry) {
229	/*
230	* this case should almost never happen so the code is
231	* inefficient
232	*/
233	rstrm->out_finger -= sizeof(long);
234	rstrm->frag_sent = TRUE;
235	if (! flush_out(rstrm, FALSE))
236	return (FALSE);
237	dest_lp = ((long *)(rstrm->out_finger));
238	rstrm->out_finger += sizeof(long);
239	}
240	dest_lp = (long)htonl((u_long)(lp));
241	return (TRUE);
242	}
243
244	static bool_t /* must manage buffers, fragments, and records */
245	xdrrec_getbytes(xdrs, addr, len)
246	XDR *xdrs;
247	register caddr_t addr;
248	register u_int len;
249	{
250	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
251	register int current;
252
253	while (len > 0) {
254	current = rstrm->fbtbc;
255	if (current == 0) {
256	if (rstrm->last_frag)
257	return (FALSE);
258	if (! set_input_fragment(rstrm))
259	return (FALSE);
260	continue;
261	}
262	current = (len < current) ? len : current;
263	if (! get_input_bytes(rstrm, addr, current))
264	return (FALSE);
265	addr += current;
266	rstrm->fbtbc -= current;
267	len -= current;
268	}
269	return (TRUE);
270	}
271
272	static bool_t
273	xdrrec_putbytes(xdrs, addr, len)
274	XDR *xdrs;
275	register caddr_t addr;
276	register u_int len;
277	{
278	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
279	register int current;
280
281	while (len > 0) {
282	current = (u_int)rstrm->out_boundry - (u_int)rstrm->out_finger;
283	current = (len < current) ? len : current;
284	bcopy(addr, rstrm->out_finger, current);
285	rstrm->out_finger += current;
286	addr += current;
287	len -= current;
288	if (rstrm->out_finger == rstrm->out_boundry) {
289	rstrm->frag_sent = TRUE;
290	if (! flush_out(rstrm, FALSE))
291	return (FALSE);
292	}
293	}
294	return (TRUE);
295	}
296
297	static u_int
298	xdrrec_getpos(xdrs)
299	register XDR *xdrs;
300	{
301	register RECSTREAM rstrm = (RECSTREAM )xdrs->x_private;
302	register long pos;
303
304	pos = lseek((int)rstrm->tcp_handle, (long) 0, 1);
305	if (pos != -1)
306	switch (xdrs->x_op) {
307
308	case XDR_ENCODE:
309	pos += rstrm->out_finger - rstrm->out_base;
310	break;
311
312	case XDR_DECODE:
313	pos -= rstrm->in_boundry - rstrm->in_finger;
314	break;
315
316	default:
317	pos = (u_int) -1;
318	break;
319	}
320	return ((u_int) pos);
321	}
322
323	static bool_t
324	xdrrec_setpos(xdrs, pos)
325	register XDR *xdrs;
326	u_int pos;
327	{
328	register RECSTREAM rstrm = (RECSTREAM )xdrs->x_private;
329	u_int currpos = xdrrec_getpos(xdrs);
330	int delta = currpos - pos;
331	caddr_t newpos;
332
333	if ((int)currpos != -1)
334	switch (xdrs->x_op) {
335
336	case XDR_ENCODE:
337	newpos = rstrm->out_finger - delta;
338	if ((newpos > (caddr_t)(rstrm->frag_header)) &&
339	(newpos < rstrm->out_boundry)) {
340	rstrm->out_finger = newpos;
341	return (TRUE);
342	}
343	break;
344
345	case XDR_DECODE:
346	newpos = rstrm->in_finger - delta;
347	if ((delta < (int)(rstrm->fbtbc)) &&
348	(newpos <= rstrm->in_boundry) &&
349	(newpos >= rstrm->in_base)) {
350	rstrm->in_finger = newpos;
351	rstrm->fbtbc -= delta;
352	return (TRUE);
353	}
354	break;
355	}
356	return (FALSE);
357	}
358
359	static long *
360	xdrrec_inline(xdrs, len)
361	register XDR *xdrs;
362	int len;
363	{
364	register RECSTREAM rstrm = (RECSTREAM )xdrs->x_private;
365	long * buf = NULL;
366
367	switch (xdrs->x_op) {
368
369	case XDR_ENCODE:
370	if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
371	buf = (long *) rstrm->out_finger;
372	rstrm->out_finger += len;
373	}
374	break;
375
376	case XDR_DECODE:
377	if ((len <= rstrm->fbtbc) &&
378	((rstrm->in_finger + len) <= rstrm->in_boundry)) {
379	buf = (long *) rstrm->in_finger;
380	rstrm->fbtbc -= len;
381	rstrm->in_finger += len;
382	}
383	break;
384	}
385	return (buf);
386	}
387
388	static void
389	xdrrec_destroy(xdrs)
390	register XDR *xdrs;
391	{
392	register RECSTREAM rstrm = (RECSTREAM )xdrs->x_private;
393
394	mem_free(rstrm->the_buffer,
395	rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT);
396	mem_free((caddr_t)rstrm, sizeof(RECSTREAM));
397	}
398
399
400	/*
401	* Exported routines to manage xdr records
402	*/
403
404	/*
405	* Before reading (deserializing from the stream, one should always call
406	* this procedure to guarantee proper record alignment.
407	*/
408	bool_t
409	xdrrec_skiprecord(xdrs)
410	XDR *xdrs;
411	{
412	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
413
414	while (rstrm->fbtbc > 0 \|\| (! rstrm->last_frag)) {
415	if (! skip_input_bytes(rstrm, rstrm->fbtbc))
416	return (FALSE);
417	rstrm->fbtbc = 0;
418	if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
419	return (FALSE);
420	}
421	rstrm->last_frag = FALSE;
422	return (TRUE);
423	}
424
425	/*
426	* Look ahead fuction.
427	* Returns TRUE iff there is no more input in the buffer
428	* after consuming the rest of the current record.
429	*/
430	bool_t
431	xdrrec_eof(xdrs)
432	XDR *xdrs;
433	{
434	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
435
436	while (rstrm->fbtbc > 0 \|\| (! rstrm->last_frag)) {
437	if (! skip_input_bytes(rstrm, rstrm->fbtbc))
438	return (TRUE);
439	rstrm->fbtbc = 0;
440	if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
441	return (TRUE);
442	}
443	if (rstrm->in_finger == rstrm->in_boundry)
444	return (TRUE);
445	return (FALSE);
446	}
447
448	/*
449	* The client must tell the package when an end-of-record has occurred.
450	* The second paraemters tells whether the record should be flushed to the
451	* (output) tcp stream. (This let's the package support batched or
452	* pipelined procedure calls.) TRUE => immmediate flush to tcp connection.
453	*/
454	bool_t
455	xdrrec_endofrecord(xdrs, sendnow)
456	XDR *xdrs;
457	bool_t sendnow;
458	{
459	register RECSTREAM rstrm = (RECSTREAM )(xdrs->x_private);
460	register u_long len; /* fragment length */
461
462	if (sendnow \|\| rstrm->frag_sent \|\|
463	((u_long)rstrm->out_finger + sizeof(u_long) >=
464	(u_long)rstrm->out_boundry)) {
465	rstrm->frag_sent = FALSE;
466	return (flush_out(rstrm, TRUE));
467	}
468	len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
469	sizeof(u_long);
470	*(rstrm->frag_header) = htonl((u_long)len \| LAST_FRAG);
471	rstrm->frag_header = (u_long *)rstrm->out_finger;
472	rstrm->out_finger += sizeof(u_long);
473	return (TRUE);
474	}
475
476
477	/*
478	* Internal useful routines
479	*/
480	static bool_t
481	flush_out(rstrm, eor)
482	register RECSTREAM *rstrm;
483	bool_t eor;
484	{
485	register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
486	register u_long len = (u_long)(rstrm->out_finger) -
487	(u_long)(rstrm->frag_header) - sizeof(u_long);
488
489	*(rstrm->frag_header) = htonl(len \| eormask);
490	len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base);
491	if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
492	!= (int)len)
493	return (FALSE);
494	rstrm->frag_header = (u_long *)rstrm->out_base;
495	rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_long);
496	return (TRUE);
497	}
498
499	static bool_t /* knows nothing about records! Only about input buffers */
500	fill_input_buf(rstrm)
501	register RECSTREAM *rstrm;
502	{
503	register caddr_t where;
504	u_int i;
505	register int len;
506
507	where = rstrm->in_base;
508	i = (u_int)rstrm->in_boundry % BYTES_PER_XDR_UNIT;
509	where += i;
510	len = rstrm->in_size - i;
511	if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
512	return (FALSE);
513	rstrm->in_finger = where;
514	where += len;
515	rstrm->in_boundry = where;
516	return (TRUE);
517	}
518
519	static bool_t /* knows nothing about records! Only about input buffers */
520	get_input_bytes(rstrm, addr, len)
521	register RECSTREAM *rstrm;
522	register caddr_t addr;
523	register int len;
524	{
525	register int current;
526
527	while (len > 0) {
528	current = (int)rstrm->in_boundry - (int)rstrm->in_finger;
529	if (current == 0) {
530	if (! fill_input_buf(rstrm))
531	return (FALSE);
532	continue;
533	}
534	current = (len < current) ? len : current;
535	bcopy(rstrm->in_finger, addr, current);
536	rstrm->in_finger += current;
537	addr += current;
538	len -= current;
539	}
540	return (TRUE);
541	}
542
543	static bool_t /* next two bytes of the input stream are treated as a header */
544	set_input_fragment(rstrm)
545	register RECSTREAM *rstrm;
546	{
547	u_long header;
548
549	if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header)))
550	return (FALSE);
551	header = (long)ntohl(header);
552	rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
553	rstrm->fbtbc = header & (~LAST_FRAG);
554	return (TRUE);
555	}
556
557	static bool_t /* consumes input bytes; knows nothing about records! */
558	skip_input_bytes(rstrm, cnt)
559	register RECSTREAM *rstrm;
560	long cnt;
561	{
562	register int current;
563
564	while (cnt > 0) {
565	current = (int)rstrm->in_boundry - (int)rstrm->in_finger;
566	if (current == 0) {
567	if (! fill_input_buf(rstrm))
568	return (FALSE);
569	continue;
570	}
571	current = (cnt < current) ? cnt : current;
572	rstrm->in_finger += current;
573	cnt -= current;
574	}
575	return (TRUE);
576	}
577
578	static u_int
579	fix_buf_size(s)
580	register u_int s;
581	{
582
583	if (s < 100)
584	s = 4000;
585	return (RNDUP(s));
586	}