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NetBSD/lib/libc/rpc/xdr_rec.c

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/* $NetBSD: xdr_rec.c,v 1.16 1999/03/04 05:26:48 lukem Exp $ */
/*
* 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
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char *sccsid = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";
#else
__RCSID("$NetBSD: xdr_rec.c,v 1.16 1999/03/04 05:26:48 lukem Exp $");
#endif
#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 "namespace.h"
#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>
#ifdef __weak_alias
__weak_alias(xdrrec_create,_xdrrec_create);
__weak_alias(xdrrec_endofrecord,_xdrrec_endofrecord);
__weak_alias(xdrrec_eof,_xdrrec_eof);
__weak_alias(xdrrec_skiprecord,_xdrrec_skiprecord);
#endif
static bool_t xdrrec_getlong __P((XDR *, long *));
static bool_t xdrrec_putlong __P((XDR *, const long *));
static bool_t xdrrec_getbytes __P((XDR *, char *, u_int));
static bool_t xdrrec_putbytes __P((XDR *, const char *, u_int));
static u_int xdrrec_getpos __P((XDR *));
static bool_t xdrrec_setpos __P((XDR *, u_int));
static int32_t *xdrrec_inline __P((XDR *, u_int));
static void xdrrec_destroy __P((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 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_int32_t)(1 << 31))
typedef struct rec_strm {
char *tcp_handle;
char *the_buffer;
/*
* out-goung bits
*/
int (*writeit) __P((char *, char *, 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) __P((char *, char *, 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;
} RECSTREAM;
static u_int fix_buf_size __P((u_int));
static bool_t flush_out __P((RECSTREAM *, bool_t));
static bool_t fill_input_buf __P((RECSTREAM *));
static bool_t get_input_bytes __P((RECSTREAM *, char *, int));
static bool_t set_input_fragment __P((RECSTREAM *));
static bool_t skip_input_bytes __P((RECSTREAM *, long));
/*
* 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;
char *tcp_handle;
/* like read, but pass it a tcp_handle, not sock */
int (*readit) __P((char *, char *, int));
/* like write, but pass it a tcp_handle, not sock */
int (*writeit) __P((char *, char *, int));
{
RECSTREAM *rstrm =
(RECSTREAM *)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;
}
/*
* 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) {
warnx("xdrrec_create: out of memory");
return;
}
for (rstrm->out_base = rstrm->the_buffer;
(u_long)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 = 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;
}
/*
* 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;
pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)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 = (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->the_buffer,
rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT);
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);
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;
{
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);
}
/*
* 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;
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;
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 (! 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 & (~LAST_FRAG)) == 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));
}
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