4.3BSD/usr/contrib/sunrpc/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
*/
#ifndef lint
static char sccsid[] = "@(#)xdr_rec.c 1.5 85/03/14 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 "types.h"
#include "xdr.h"
#include <sys/time.h>
#include <netinet/in.h>
char *mem_alloc();
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;
/*
* 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;
u_int sendsize;
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) {
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;
}
xdrs->x_ops = &xdrrec_ops;
xdrs->x_private = (caddr_t)rstrm;
rstrm->tcp_handle = tcp_handle;
rstrm->readit = readit;
rstrm->writeit = writeit;
sendsize = fix_buf_size(sendsize);
if ((rstrm->out_base = rstrm->out_finger = rstrm->out_boundry =
mem_alloc(sendsize)) == NULL) {
fprintf(stderr, "xdrrec_create: out of memory\n");
return;
}
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 = fix_buf_size(recvsize);
if ((rstrm->in_base = rstrm->in_boundry=mem_alloc(recvsize)) == NULL) {
fprintf(stderr, "xdrrec_create: out of memory\n");
return;
}
rstrm->in_finger = (rstrm->in_boundry += recvsize);
rstrm->fbtbc = 0;
rstrm->last_frag = TRUE;
rstrm->sendsize = sendsize;
rstrm->recvsize = recvsize;
}
/*
* 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 = ntohl(*buflp);
rstrm->fbtbc -= sizeof(long);
rstrm->in_finger += sizeof(long);
} else {
if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long)))
return (FALSE);
*lp = ntohl(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 = htonl(*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 u_int pos;
pos = lseek((int)rstrm->tcp_handle, 0, 1);
if ((int)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 (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->out_base, rstrm->sendsize);
mem_free(rstrm->in_base, rstrm->recvsize);
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(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 = rstrm->in_base;
register int len = rstrm->in_size;
if (((int)rstrm->in_boundry % 2) != 0) {
/* keep stream odd bytes aligned with memory odd bytes */
where++;
len--;
}
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 = 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;
int 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)
return (3998);
for (; (s % 4) != 2; --s);
return (s);
}