/*
* xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
* layer above tcp (for rpc's use).
*
* Copyright (c) 2010, Oracle America, Inc.
*
* 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 the "Oracle America, 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.
*
* 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). The high 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 <string.h>
#include <unistd.h>
#include <stdint.h>
#include <rpc/rpc.h>
#include <libintl.h>
#include <wchar.h>
#include <libio/iolibio.h>
#include <shlib-compat.h>
static bool_t xdrrec_getlong (XDR *, long *);
static bool_t xdrrec_putlong (XDR *, const long *);
static bool_t xdrrec_getbytes (XDR *, caddr_t, u_int);
static bool_t xdrrec_putbytes (XDR *, const char *, u_int);
static u_int xdrrec_getpos (const XDR *);
static bool_t xdrrec_setpos (XDR *, u_int);
static int32_t *xdrrec_inline (XDR *, u_int);
static void xdrrec_destroy (XDR *);
static bool_t xdrrec_getint32 (XDR *, int32_t *);
static bool_t xdrrec_putint32 (XDR *, const int32_t *);
static const struct xdr_ops xdrrec_ops = {
xdrrec_getlong,
xdrrec_putlong,
xdrrec_getbytes,
xdrrec_putbytes,
xdrrec_getpos,
xdrrec_setpos,
xdrrec_inline,
xdrrec_destroy,
xdrrec_getint32,
xdrrec_putint32
};
/*
* 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 (1UL << 31)
typedef struct rec_strm
{
caddr_t tcp_handle;
caddr_t the_buffer;
/*
* out-going bits
*/
int (*writeit) (char *, char *, int);
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 */
uint32_t *frag_header; /* beginning of curren fragment */
bool_t frag_sent; /* true if buffer sent in middle of record */
/*
* in-coming bits
*/
int (*readit) (char *, char *, int);
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;
static u_int fix_buf_size (u_int);
static bool_t skip_input_bytes (RECSTREAM *, long);
static bool_t flush_out (RECSTREAM *, bool_t);
static bool_t set_input_fragment (RECSTREAM *);
static bool_t get_input_bytes (RECSTREAM *, caddr_t, 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 (XDR *xdrs, u_int sendsize,
u_int recvsize, caddr_t tcp_handle,
int (*readit) (char *, char *, int),
int (*writeit) (char *, char *, int))
{
RECSTREAM *rstrm = (RECSTREAM *) mem_alloc (sizeof (RECSTREAM));
caddr_t tmp;
char *buf;
sendsize = fix_buf_size (sendsize);
recvsize = fix_buf_size (recvsize);
buf = mem_alloc (sendsize + recvsize + BYTES_PER_XDR_UNIT);
if (rstrm == NULL || buf == NULL)
{
(void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
mem_free (rstrm, sizeof (RECSTREAM));
mem_free (buf, sendsize + recvsize + BYTES_PER_XDR_UNIT);
/*
* 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;
rstrm->recvsize = recvsize;
rstrm->the_buffer = buf;
tmp = rstrm->the_buffer;
if ((size_t)tmp % BYTES_PER_XDR_UNIT)
tmp += BYTES_PER_XDR_UNIT - (size_t)tmp % BYTES_PER_XDR_UNIT;
rstrm->out_base = tmp;
rstrm->in_base = tmp + sendsize;
/*
* now the rest ...
*/
/* We have to add the cast since the `struct xdr_ops' in `struct XDR'
is not `const'. */
xdrs->x_ops = (struct xdr_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 = (uint32_t *) rstrm->out_base;
rstrm->out_finger += 4;
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;
}
libc_hidden_nolink_sunrpc (xdrrec_create, GLIBC_2_0)
/*
* The routines defined below are the xdr ops which will go into the
* xdr handle filled in by xdrrec_create.
*/
static bool_t
xdrrec_getlong (XDR *xdrs, long *lp)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
int32_t *buflp = (int32_t *) rstrm->in_finger;
int32_t mylong;
/* first try the inline, fast case */
if (rstrm->fbtbc >= BYTES_PER_XDR_UNIT &&
rstrm->in_boundry - (char *) buflp >= BYTES_PER_XDR_UNIT)
{
*lp = (int32_t) ntohl (*buflp);
rstrm->fbtbc -= BYTES_PER_XDR_UNIT;
rstrm->in_finger += BYTES_PER_XDR_UNIT;
}
else
{
if (!xdrrec_getbytes (xdrs, (caddr_t) & mylong,
BYTES_PER_XDR_UNIT))
return FALSE;
*lp = (int32_t) ntohl (mylong);
}
return TRUE;
}
static bool_t
xdrrec_putlong (XDR *xdrs, const long *lp)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
int32_t *dest_lp = (int32_t *) rstrm->out_finger;
if ((rstrm->out_finger += BYTES_PER_XDR_UNIT) > rstrm->out_boundry)
{
/*
* this case should almost never happen so the code is
* inefficient
*/
rstrm->out_finger -= BYTES_PER_XDR_UNIT;
rstrm->frag_sent = TRUE;
if (!flush_out (rstrm, FALSE))
return FALSE;
dest_lp = (int32_t *) rstrm->out_finger;
rstrm->out_finger += BYTES_PER_XDR_UNIT;
}
*dest_lp = htonl (*lp);
return TRUE;
}
static bool_t /* must manage buffers, fragments, and records */
xdrrec_getbytes (XDR *xdrs, caddr_t addr, u_int len)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
u_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 (XDR *xdrs, const char *addr, u_int len)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
u_int current;
while (len > 0)
{
current = rstrm->out_boundry - rstrm->out_finger;
current = (len < current) ? len : current;
memcpy (rstrm->out_finger, addr, current);
rstrm->out_finger += current;
addr += current;
len -= current;
if (rstrm->out_finger == rstrm->out_boundry && len > 0)
{
rstrm->frag_sent = TRUE;
if (!flush_out (rstrm, FALSE))
return FALSE;
}
}
return TRUE;
}
static u_int
xdrrec_getpos (const XDR *xdrs)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
long pos;
pos = __lseek ((int) (long) 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 (XDR *xdrs, u_int pos)
{
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;
default:
break;
}
return FALSE;
}
static int32_t *
xdrrec_inline (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 *) 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 *) rstrm->in_finger;
rstrm->fbtbc -= len;
rstrm->in_finger += len;
}
break;
default:
break;
}
return buf;
}
static void
xdrrec_destroy (XDR *xdrs)
{
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));
}
static bool_t
xdrrec_getint32 (XDR *xdrs, int32_t *ip)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
int32_t *bufip = (int32_t *) rstrm->in_finger;
int32_t mylong;
/* first try the inline, fast case */
if (rstrm->fbtbc >= BYTES_PER_XDR_UNIT &&
rstrm->in_boundry - (char *) bufip >= BYTES_PER_XDR_UNIT)
{
*ip = ntohl (*bufip);
rstrm->fbtbc -= BYTES_PER_XDR_UNIT;
rstrm->in_finger += BYTES_PER_XDR_UNIT;
}
else
{
if (!xdrrec_getbytes (xdrs, (caddr_t) &mylong,
BYTES_PER_XDR_UNIT))
return FALSE;
*ip = ntohl (mylong);
}
return TRUE;
}
static bool_t
xdrrec_putint32 (XDR *xdrs, const int32_t *ip)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
int32_t *dest_ip = (int32_t *) rstrm->out_finger;
if ((rstrm->out_finger += BYTES_PER_XDR_UNIT) > rstrm->out_boundry)
{
/*
* this case should almost never happen so the code is
* inefficient
*/
rstrm->out_finger -= BYTES_PER_XDR_UNIT;
rstrm->frag_sent = TRUE;
if (!flush_out (rstrm, FALSE))
return FALSE;
dest_ip = (int32_t *) rstrm->out_finger;
rstrm->out_finger += BYTES_PER_XDR_UNIT;
}
*dest_ip = htonl (*ip);
return TRUE;
}
/*
* 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 (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;
}
libc_hidden_nolink_sunrpc (xdrrec_skiprecord, GLIBC_2_0)
/*
* Lookahead function.
* Returns TRUE iff there is no more input in the buffer
* after consuming the rest of the current record.
*/
bool_t
xdrrec_eof (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;
}
libc_hidden_nolink_sunrpc (xdrrec_eof, GLIBC_2_0)
/*
* The client must tell the package when an end-of-record has occurred.
* The second parameter tells whether the record should be flushed to the
* (output) tcp stream. (This lets the package support batched or
* pipelined procedure calls.) TRUE => immediate flush to tcp connection.
*/
bool_t
xdrrec_endofrecord (XDR *xdrs, bool_t sendnow)
{
RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
u_long len; /* fragment length */
if (sendnow || rstrm->frag_sent
|| rstrm->out_finger + BYTES_PER_XDR_UNIT >= rstrm->out_boundry)
{
rstrm->frag_sent = FALSE;
return flush_out (rstrm, TRUE);
}
len = (rstrm->out_finger - (char *) rstrm->frag_header
- BYTES_PER_XDR_UNIT);
*rstrm->frag_header = htonl ((u_long) len | LAST_FRAG);
rstrm->frag_header = (uint32_t *) rstrm->out_finger;
rstrm->out_finger += BYTES_PER_XDR_UNIT;
return TRUE;
}
libc_hidden_nolink_sunrpc (xdrrec_endofrecord, GLIBC_2_0)
/*
* Internal useful routines
*/
static bool_t
flush_out (RECSTREAM *rstrm, bool_t eor)
{
u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
u_long len = (rstrm->out_finger - (char *) rstrm->frag_header
- BYTES_PER_XDR_UNIT);
*rstrm->frag_header = htonl (len | eormask);
len = rstrm->out_finger - rstrm->out_base;
if ((*(rstrm->writeit)) (rstrm->tcp_handle, rstrm->out_base, (int) len)
!= (int) len)
return FALSE;
rstrm->frag_header = (uint32_t *) rstrm->out_base;
rstrm->out_finger = (caddr_t) rstrm->out_base + BYTES_PER_XDR_UNIT;
return TRUE;
}
static bool_t /* knows nothing about records! Only about input buffers */
fill_input_buf (RECSTREAM *rstrm)
{
caddr_t where;
size_t i;
int len;
where = rstrm->in_base;
i = (size_t) 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 (RECSTREAM *rstrm, caddr_t addr, int len)
{
int current;
while (len > 0)
{
current = rstrm->in_boundry - rstrm->in_finger;
if (current == 0)
{
if (!fill_input_buf (rstrm))
return FALSE;
continue;
}
current = (len < current) ? len : current;
memcpy (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 (RECSTREAM *rstrm)
{
uint32_t header;
if (! get_input_bytes (rstrm, (caddr_t)&header, BYTES_PER_XDR_UNIT))
return FALSE;
header = ntohl (header);
rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
/*
* Sanity check. Try not to accept wildly incorrect fragment
* sizes. Unfortunately, only a size of zero can be identified as
* 'wildely incorrect', and this only, if it is not the last
* fragment of a message. Ridiculously large fragment 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. Many existing RPC
* implementations may sent a fragment of size zero as the last
* fragment of a message.
*/
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 (RECSTREAM *rstrm, long cnt)
{
int current;
while (cnt > 0)
{
current = rstrm->in_boundry - 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 (u_int s)
{
if (s < 100)
s = 4000;
return RNDUP (s);
}