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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sunrpc/xdr_rec.c
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initial import
Diffstat (limited to 'sunrpc/xdr_rec.c')
-rw-r--r--sunrpc/xdr_rec.c580
1 files changed, 580 insertions, 0 deletions
diff --git a/sunrpc/xdr_rec.c b/sunrpc/xdr_rec.c
new file mode 100644
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+++ b/sunrpc/xdr_rec.c
@@ -0,0 +1,580 @@
+/* @(#)xdr_rec.c	2.2 88/08/01 4.0 RPCSRC */
+/*
+ * 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(lint) && defined(SCCSIDS)
+static char sccsid[] = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";
+#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 <rpc/types.h>
+#include <rpc/xdr.h>
+#include <netinet/in.h>
+
+extern long	lseek();
+
+static u_int	fix_buf_size();
+
+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));
+}