1 files changed, 792 insertions, 0 deletions

diff --git a/src/xdr_rec.c b/src/xdr_rec.c
new file mode 100644
index 0000000..676cc82
--- /dev/null
+++ b/src/xdr_rec.c
@@ -0,0 +1,792 @@
+
+/*
+ * Copyright (c) 2009, Sun Microsystems, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - 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.
+ * - Neither the name of Sun Microsystems, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
+ */
+
+
+/*
+ * 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 <sys/types.h>
+
+#include <netinet/in.h>
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <rpc/types.h>
+#include <rpc/xdr.h>
+#include <rpc/auth.h>
+#include <rpc/svc_auth.h>
+#include <rpc/svc.h>
+#include <rpc/clnt.h>
+#include <stddef.h>
+#include <errno.h>
+#include "rpc_com.h"
+static bool_t	xdrrec_getlong(XDR *, long *);
+static bool_t	xdrrec_putlong(XDR *, const long *);
+static bool_t	xdrrec_getbytes(XDR *, char *, u_int);
+
+static bool_t	xdrrec_putbytes(XDR *, const char *, u_int);
+static u_int	xdrrec_getpos(XDR *);
+static bool_t	xdrrec_setpos(XDR *, u_int);
+static int32_t *xdrrec_inline(XDR *, u_int);
+static void	xdrrec_destroy(XDR *);
+
+static const 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 four-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_int32_t)(1 << 31))
+
+typedef struct rec_strm {
+	char *tcp_handle;
+	/*
+	 * out-goung bits
+	 */
+	int (*writeit)(void *, void *, int);
+	char *out_base;	/* output buffer (points to frag header) */
+	char *out_finger;	/* next output position */
+	char *out_boundry;	/* data cannot up to this address */
+	u_int32_t *frag_header;	/* beginning of curren fragment */
+	bool_t frag_sent;	/* true if buffer sent in middle of record */
+	/*
+	 * in-coming bits
+	 */
+	int (*readit)(void *, void *, int);
+	u_long in_size;	/* fixed size of the input buffer */
+	char *in_base;
+	char *in_finger;	/* location of next byte to be had */
+	char *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;
+
+	bool_t nonblock;
+	bool_t in_haveheader;
+	u_int32_t in_header;
+	char *in_hdrp;
+	int in_hdrlen;
+	int in_reclen;
+	int in_received;
+	int in_maxrec;
+} RECSTREAM;
+
+static u_int	fix_buf_size(u_int);
+static bool_t	flush_out(RECSTREAM *, bool_t);
+static bool_t	fill_input_buf(RECSTREAM *);
+static bool_t	get_input_bytes(RECSTREAM *, char *, int);
+static bool_t	set_input_fragment(RECSTREAM *);
+static bool_t	skip_input_bytes(RECSTREAM *, long);
+static bool_t	realloc_stream(RECSTREAM *, int);
+
+
+/*
+ * 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)
+	XDR *xdrs;
+	u_int sendsize;
+	u_int recvsize;
+	void *tcp_handle;
+	/* like read, but pass it a tcp_handle, not sock */
+	int (*readit)(void *, void *, int);
+	/* like write, but pass it a tcp_handle, not sock */
+	int (*writeit)(void *, void *, int);
+{
+	RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM));
+
+	if (rstrm == NULL) {
+		warnx("xdrrec_create: out of memory");
+		/* 
+		 *  This is bad.  Should rework xdrrec_create to 
+		 *  return a handle, and in this case return NULL
+		 */
+		return;
+	}
+	rstrm->sendsize = sendsize = fix_buf_size(sendsize);
+	rstrm->out_base = mem_alloc(rstrm->sendsize);
+	if (rstrm->out_base == NULL) {
+		warnx("xdrrec_create: out of memory");
+		mem_free(rstrm, sizeof(RECSTREAM));
+		return;
+	}
+	rstrm->recvsize = recvsize = fix_buf_size(recvsize);
+	rstrm->in_base = mem_alloc(recvsize);
+	if (rstrm->in_base == NULL) {
+		warnx("xdrrec_create: out of memory");
+		mem_free(rstrm->out_base, sendsize);
+		mem_free(rstrm, sizeof(RECSTREAM));
+		return;
+	}
+	/*
+	 * now the rest ...
+	 */
+	xdrs->x_ops = &xdrrec_ops;
+	xdrs->x_private = 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_int32_t *)(void *)rstrm->out_base;
+	rstrm->out_finger += sizeof(u_int32_t);
+	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;
+	rstrm->in_haveheader = FALSE;
+	rstrm->in_hdrlen = 0;
+	rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
+	rstrm->nonblock = FALSE;
+	rstrm->in_reclen = 0;
+	rstrm->in_received = 0;
+}
+
+
+/*
+ * 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;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger);
+	int32_t mylong;
+
+	/* first try the inline, fast case */
+	if ((rstrm->fbtbc >= sizeof(int32_t)) &&
+		(((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) {
+		*lp = (long)ntohl((u_int32_t)(*buflp));
+		rstrm->fbtbc -= sizeof(int32_t);
+		rstrm->in_finger += sizeof(int32_t);
+	} else {
+		if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong,
+		    sizeof(int32_t)))
+			return (FALSE);
+		*lp = (long)ntohl((u_int32_t)mylong);
+	}
+	return (TRUE);
+}
+
+static bool_t
+xdrrec_putlong(xdrs, lp)
+	XDR *xdrs;
+	const long *lp;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
+
+	if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) {
+		/*
+		 * this case should almost never happen so the code is
+		 * inefficient
+		 */
+		rstrm->out_finger -= sizeof(int32_t);
+		rstrm->frag_sent = TRUE;
+		if (! flush_out(rstrm, FALSE))
+			return (FALSE);
+		dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
+		rstrm->out_finger += sizeof(int32_t);
+	}
+	*dest_lp = (int32_t)htonl((u_int32_t)(*lp));
+	return (TRUE);
+}
+
+static bool_t  /* must manage buffers, fragments, and records */
+xdrrec_getbytes(xdrs, addr, len)
+	XDR *xdrs;
+	char *addr;
+	u_int len;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	int current;
+
+	while (len > 0) {
+		current = (int)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;
+	const char *addr;
+	u_int len;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	size_t current;
+
+	while (len > 0) {
+		current = (size_t)((u_long)rstrm->out_boundry -
+		    (u_long)rstrm->out_finger);
+		current = (len < current) ? len : current;
+		memmove(rstrm->out_finger, addr, 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)
+	XDR *xdrs;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
+	off_t pos;
+
+	switch (xdrs->x_op) {
+
+	case XDR_ENCODE:
+		pos = rstrm->out_finger - rstrm->out_base
+			- BYTES_PER_XDR_UNIT;
+		break;
+
+	case XDR_DECODE:
+		pos = rstrm->in_boundry - rstrm->in_finger
+			- BYTES_PER_XDR_UNIT;
+		break;
+
+	default:
+		pos = (off_t) -1;
+		break;
+	}
+	return ((u_int) pos);
+}
+
+static bool_t
+xdrrec_setpos(xdrs, pos)
+	XDR *xdrs;
+	u_int pos;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
+	u_int currpos = xdrrec_getpos(xdrs);
+	int delta = currpos - pos;
+	char *newpos;
+
+	if ((int)currpos != -1)
+		switch (xdrs->x_op) {
+
+		case XDR_ENCODE:
+			newpos = rstrm->out_finger - delta;
+			if ((newpos > (char *)(void *)(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;
+
+		case XDR_FREE:
+			break;
+		}
+	return (FALSE);
+}
+
+static int32_t *
+xdrrec_inline(xdrs, len)
+	XDR *xdrs;
+	u_int len;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
+	int32_t *buf = NULL;
+
+	switch (xdrs->x_op) {
+
+	case XDR_ENCODE:
+		if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
+			buf = (int32_t *)(void *)rstrm->out_finger;
+			rstrm->out_finger += len;
+		}
+		break;
+
+	case XDR_DECODE:
+		if ((len <= rstrm->fbtbc) &&
+			((rstrm->in_finger + len) <= rstrm->in_boundry)) {
+			buf = (int32_t *)(void *)rstrm->in_finger;
+			rstrm->fbtbc -= len;
+			rstrm->in_finger += len;
+		}
+		break;
+
+	case XDR_FREE:
+		break;
+	}
+	return (buf);
+}
+
+static void
+xdrrec_destroy(xdrs)
+	XDR *xdrs;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
+
+	mem_free(rstrm->out_base, rstrm->sendsize);
+	mem_free(rstrm->in_base, rstrm->recvsize);
+	mem_free(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;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	enum xprt_stat xstat;
+
+	if (rstrm->nonblock) {
+		if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
+			rstrm->fbtbc = 0;
+			return TRUE;
+		}
+		if (rstrm->in_finger == rstrm->in_boundry &&
+		    xstat == XPRT_MOREREQS) {
+			rstrm->fbtbc = 0;
+			return TRUE;
+		}
+		return FALSE;
+	}
+
+	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 function.
+ * 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;
+{
+	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;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	u_long len;  /* fragment length */
+
+	if (sendnow || rstrm->frag_sent ||
+		((u_long)rstrm->out_finger + sizeof(u_int32_t) >=
+		(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_int32_t);
+	*(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG);
+	rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger;
+	rstrm->out_finger += sizeof(u_int32_t);
+	return (TRUE);
+}
+
+/*
+ * Fill the stream buffer with a record for a non-blocking connection.
+ * Return true if a record is available in the buffer, false if not.
+ */
+bool_t
+__xdrrec_getrec(xdrs, statp, expectdata)
+	XDR *xdrs;
+	enum xprt_stat *statp;
+	bool_t expectdata;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+	ssize_t n;
+	int fraglen;
+
+	if (!rstrm->in_haveheader) {
+		n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
+		    (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
+		if (n == 0) {
+			/* EAGAIN or EWOULDBLOCK means a zero length
+			 * read not an EOF.
+			 */
+			if (errno == EAGAIN || errno == EWOULDBLOCK)
+				*statp = XPRT_IDLE;
+			else
+				*statp = expectdata ? XPRT_DIED : XPRT_IDLE;
+			return FALSE;
+		}
+		if (n < 0) {
+			*statp = XPRT_DIED;
+			return FALSE;
+		}
+		rstrm->in_hdrp += n;
+		rstrm->in_hdrlen += n;
+		if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) {
+			*statp = XPRT_MOREREQS;
+			return FALSE;
+		}
+		rstrm->in_header = ntohl(rstrm->in_header);
+		fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
+		if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
+		    (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
+			*statp = XPRT_DIED;
+			return FALSE;
+		}
+		rstrm->in_reclen += fraglen;
+		if (rstrm->in_reclen > rstrm->recvsize)
+			realloc_stream(rstrm, rstrm->in_reclen);
+		if (rstrm->in_header & LAST_FRAG) {
+			rstrm->in_header &= ~LAST_FRAG;
+			rstrm->last_frag = TRUE;
+		}
+		rstrm->in_haveheader = 1;
+	}
+
+	n =  rstrm->readit(rstrm->tcp_handle,
+	    rstrm->in_base + rstrm->in_received,
+	    (rstrm->in_reclen - rstrm->in_received));
+
+	if (n < 0) {
+		*statp = XPRT_DIED;
+		return FALSE;
+	}
+
+	if (n == 0) {
+		/* EAGAIN or EWOULDBLOCK means a zero length
+		 * read not an EOF.
+		 */
+		if (errno == EAGAIN || errno == EWOULDBLOCK)
+			*statp = XPRT_IDLE;
+		else
+			*statp = expectdata ? XPRT_DIED : XPRT_IDLE;
+		return FALSE;
+	}
+
+	rstrm->in_received += n;
+
+	if (rstrm->in_received == rstrm->in_reclen) {
+		rstrm->in_haveheader = FALSE;
+		rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
+		rstrm->in_hdrlen = 0;
+		if (rstrm->last_frag) {
+			rstrm->fbtbc = rstrm->in_reclen;
+			rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
+			rstrm->in_finger = rstrm->in_base;
+			rstrm->in_reclen = rstrm->in_received = 0;
+			*statp = XPRT_MOREREQS;
+			return TRUE;
+		}
+	}
+
+	*statp = XPRT_MOREREQS;
+	return FALSE;
+}
+
+bool_t
+__xdrrec_setnonblock(xdrs, maxrec)
+	XDR *xdrs;
+	int maxrec;
+{
+	RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
+
+	rstrm->nonblock = TRUE;
+	if (maxrec == 0)
+		maxrec = rstrm->recvsize;
+	rstrm->in_maxrec = maxrec;
+	return TRUE;
+}
+
+/*
+ * Internal useful routines
+ */
+static bool_t
+flush_out(rstrm, eor)
+	RECSTREAM *rstrm;
+	bool_t eor;
+{
+	u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
+	u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) - 
+		(u_long)(rstrm->frag_header) - sizeof(u_int32_t));
+
+	*(rstrm->frag_header) = htonl(len | eormask);
+	len = (u_int32_t)((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_int32_t *)(void *)rstrm->out_base;
+	rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t);
+	return (TRUE);
+}
+
+static bool_t  /* knows nothing about records!  Only about input buffers */
+fill_input_buf(rstrm)
+	RECSTREAM *rstrm;
+{
+	char *where;
+	u_int32_t i;
+	int len;
+
+	if (rstrm->nonblock)
+		return FALSE;
+
+	where = rstrm->in_base;
+	i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT);
+	where += i;
+	len = (u_int32_t)(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)
+	RECSTREAM *rstrm;
+	char *addr;
+	int len;
+{
+	size_t current;
+
+	if (rstrm->nonblock) {
+		if (len > (int)(rstrm->in_boundry - rstrm->in_finger))
+			return FALSE;
+		memcpy(addr, rstrm->in_finger, (size_t)len);
+		rstrm->in_finger += len;
+		return TRUE;
+	}
+
+	while (len > 0) {
+		current = (size_t)((long)rstrm->in_boundry -
+		    (long)rstrm->in_finger);
+		if (current == 0) {
+			if (! fill_input_buf(rstrm))
+				return (FALSE);
+			continue;
+		}
+		current = (len < current) ? len : current;
+		memmove(addr, rstrm->in_finger, 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)
+	RECSTREAM *rstrm;
+{
+	u_int32_t header;
+
+	if (rstrm->nonblock)
+		return FALSE;
+	if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header)))
+		return (FALSE);
+	header = ntohl(header);
+	rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
+	/*
+	 * Sanity check. Try not to accept wildly incorrect
+	 * record sizes. Unfortunately, the only record size
+	 * we can positively identify as being 'wildly incorrect'
+	 * is zero. Ridiculously large record sizes may look wrong,
+	 * but we don't have any way to be certain that they aren't
+	 * what the client actually intended to send us.
+	 */
+	if (header == 0)
+		return(FALSE);
+	rstrm->fbtbc = header & (~LAST_FRAG);
+	return (TRUE);
+}
+
+static bool_t  /* consumes input bytes; knows nothing about records! */
+skip_input_bytes(rstrm, cnt)
+	RECSTREAM *rstrm;
+	long cnt;
+{
+	u_int32_t current;
+
+	while (cnt > 0) {
+		current = (size_t)((long)rstrm->in_boundry - 
+		    (long)rstrm->in_finger);
+		if (current == 0) {
+			if (! fill_input_buf(rstrm))
+				return (FALSE);
+			continue;
+		}
+		current = (u_int32_t)((cnt < current) ? cnt : current);
+		rstrm->in_finger += current;
+		cnt -= current;
+	}
+	return (TRUE);
+}
+
+static u_int
+fix_buf_size(s)
+	u_int s;
+{
+
+	if (s < 100)
+		s = 4000;
+	return (RNDUP(s));
+}
+
+/*
+ * Reallocate the input buffer for a non-block stream.
+ */
+static bool_t
+realloc_stream(rstrm, size)
+	RECSTREAM *rstrm;
+	int size;
+{
+	ptrdiff_t diff;
+	char *buf;
+
+	if (size > rstrm->recvsize) {
+		buf = realloc(rstrm->in_base, (size_t)size);
+		if (buf == NULL)
+			return FALSE;
+		diff = buf - rstrm->in_base;
+		rstrm->in_finger += diff;
+		rstrm->in_base = buf;
+		rstrm->in_boundry = buf + size;
+		rstrm->recvsize = size;
+		rstrm->in_size = size;
+	}
+
+	return TRUE;
+}