2 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
3 * layer above tcp (for rpc's use).
5 * Copyright (c) 2010, Oracle America, Inc.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials
16 * provided with the distribution.
17 * * Neither the name of the "Oracle America, Inc." nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
26 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
28 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 * These routines interface XDRSTREAMS to a tcp/ip connection.
35 * There is a record marking layer between the xdr stream
36 * and the tcp transport level. A record is composed on one or more
37 * record fragments. A record fragment is a thirty-two bit header followed
38 * by n bytes of data, where n is contained in the header. The header
39 * is represented as a htonl(u_long). The high order bit encodes
40 * whether or not the fragment is the last fragment of the record
41 * (1 => fragment is last, 0 => more fragments to follow.
42 * The other 31 bits encode the byte length of the fragment.
52 #include <libio/iolibio.h>
53 #include <shlib-compat.h>
55 static bool_t xdrrec_getlong (XDR *, long *);
56 static bool_t xdrrec_putlong (XDR *, const long *);
57 static bool_t xdrrec_getbytes (XDR *, caddr_t, u_int);
58 static bool_t xdrrec_putbytes (XDR *, const char *, u_int);
59 static u_int xdrrec_getpos (const XDR *);
60 static bool_t xdrrec_setpos (XDR *, u_int);
61 static int32_t *xdrrec_inline (XDR *, u_int);
62 static void xdrrec_destroy (XDR *);
63 static bool_t xdrrec_getint32 (XDR *, int32_t *);
64 static bool_t xdrrec_putint32 (XDR *, const int32_t *);
66 static const struct xdr_ops xdrrec_ops = {
80 * A record is composed of one or more record fragments.
81 * A record fragment is a two-byte header followed by zero to
82 * 2**32-1 bytes. The header is treated as a long unsigned and is
83 * encode/decoded to the network via htonl/ntohl. The low order 31 bits
84 * are a byte count of the fragment. The highest order bit is a boolean:
85 * 1 => this fragment is the last fragment of the record,
86 * 0 => this fragment is followed by more fragment(s).
88 * The fragment/record machinery is not general; it is constructed to
89 * meet the needs of xdr and rpc based on tcp.
92 #define LAST_FRAG (1UL << 31)
94 typedef struct rec_strm
101 int (*writeit) (char *, char *, int);
102 caddr_t out_base; /* output buffer (points to frag header) */
103 caddr_t out_finger; /* next output position */
104 caddr_t out_boundry; /* data cannot up to this address */
105 uint32_t *frag_header; /* beginning of curren fragment */
106 bool_t frag_sent; /* true if buffer sent in middle of record */
110 int (*readit) (char *, char *, int);
111 u_long in_size; /* fixed size of the input buffer */
113 caddr_t in_finger; /* location of next byte to be had */
114 caddr_t in_boundry; /* can read up to this location */
115 long fbtbc; /* fragment bytes to be consumed */
122 static u_int fix_buf_size (u_int) internal_function;
123 static bool_t skip_input_bytes (RECSTREAM *, long) internal_function;
124 static bool_t flush_out (RECSTREAM *, bool_t) internal_function;
125 static bool_t set_input_fragment (RECSTREAM *) internal_function;
126 static bool_t get_input_bytes (RECSTREAM *, caddr_t, int) internal_function;
129 * Create an xdr handle for xdrrec
130 * xdrrec_create fills in xdrs. Sendsize and recvsize are
131 * send and recv buffer sizes (0 => use default).
132 * tcp_handle is an opaque handle that is passed as the first parameter to
133 * the procedures readit and writeit. Readit and writeit are read and
134 * write respectively. They are like the system
135 * calls expect that they take an opaque handle rather than an fd.
138 xdrrec_create (XDR *xdrs, u_int sendsize,
139 u_int recvsize, caddr_t tcp_handle,
140 int (*readit) (char *, char *, int),
141 int (*writeit) (char *, char *, int))
143 RECSTREAM *rstrm = (RECSTREAM *) mem_alloc (sizeof (RECSTREAM));
147 sendsize = fix_buf_size (sendsize);
148 recvsize = fix_buf_size (recvsize);
149 buf = mem_alloc (sendsize + recvsize + BYTES_PER_XDR_UNIT);
151 if (rstrm == NULL || buf == NULL)
153 (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
154 mem_free (rstrm, sizeof (RECSTREAM));
155 mem_free (buf, sendsize + recvsize + BYTES_PER_XDR_UNIT);
157 * This is bad. Should rework xdrrec_create to
158 * return a handle, and in this case return NULL
163 * adjust sizes and allocate buffer quad byte aligned
165 rstrm->sendsize = sendsize;
166 rstrm->recvsize = recvsize;
167 rstrm->the_buffer = buf;
168 tmp = rstrm->the_buffer;
169 if ((size_t)tmp % BYTES_PER_XDR_UNIT)
170 tmp += BYTES_PER_XDR_UNIT - (size_t)tmp % BYTES_PER_XDR_UNIT;
171 rstrm->out_base = tmp;
172 rstrm->in_base = tmp + sendsize;
176 /* We have to add the cast since the `struct xdr_ops' in `struct XDR'
178 xdrs->x_ops = (struct xdr_ops *) &xdrrec_ops;
179 xdrs->x_private = (caddr_t) rstrm;
180 rstrm->tcp_handle = tcp_handle;
181 rstrm->readit = readit;
182 rstrm->writeit = writeit;
183 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
184 rstrm->frag_header = (uint32_t *) rstrm->out_base;
185 rstrm->out_finger += 4;
186 rstrm->out_boundry += sendsize;
187 rstrm->frag_sent = FALSE;
188 rstrm->in_size = recvsize;
189 rstrm->in_boundry = rstrm->in_base;
190 rstrm->in_finger = (rstrm->in_boundry += recvsize);
192 rstrm->last_frag = TRUE;
194 libc_hidden_nolink_sunrpc (xdrrec_create, GLIBC_2_0)
198 * The routines defined below are the xdr ops which will go into the
199 * xdr handle filled in by xdrrec_create.
203 xdrrec_getlong (XDR *xdrs, long *lp)
205 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
206 int32_t *buflp = (int32_t *) rstrm->in_finger;
209 /* first try the inline, fast case */
210 if (rstrm->fbtbc >= BYTES_PER_XDR_UNIT &&
211 rstrm->in_boundry - (char *) buflp >= BYTES_PER_XDR_UNIT)
213 *lp = (int32_t) ntohl (*buflp);
214 rstrm->fbtbc -= BYTES_PER_XDR_UNIT;
215 rstrm->in_finger += BYTES_PER_XDR_UNIT;
219 if (!xdrrec_getbytes (xdrs, (caddr_t) & mylong,
222 *lp = (int32_t) ntohl (mylong);
228 xdrrec_putlong (XDR *xdrs, const long *lp)
230 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
231 int32_t *dest_lp = (int32_t *) rstrm->out_finger;
233 if ((rstrm->out_finger += BYTES_PER_XDR_UNIT) > rstrm->out_boundry)
236 * this case should almost never happen so the code is
239 rstrm->out_finger -= BYTES_PER_XDR_UNIT;
240 rstrm->frag_sent = TRUE;
241 if (!flush_out (rstrm, FALSE))
243 dest_lp = (int32_t *) rstrm->out_finger;
244 rstrm->out_finger += BYTES_PER_XDR_UNIT;
246 *dest_lp = htonl (*lp);
250 static bool_t /* must manage buffers, fragments, and records */
251 xdrrec_getbytes (XDR *xdrs, caddr_t addr, u_int len)
253 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
258 current = rstrm->fbtbc;
261 if (rstrm->last_frag)
263 if (!set_input_fragment (rstrm))
267 current = (len < current) ? len : current;
268 if (!get_input_bytes (rstrm, addr, current))
271 rstrm->fbtbc -= current;
278 xdrrec_putbytes (XDR *xdrs, const char *addr, u_int len)
280 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
285 current = rstrm->out_boundry - rstrm->out_finger;
286 current = (len < current) ? len : current;
287 memcpy (rstrm->out_finger, addr, current);
288 rstrm->out_finger += current;
291 if (rstrm->out_finger == rstrm->out_boundry && len > 0)
293 rstrm->frag_sent = TRUE;
294 if (!flush_out (rstrm, FALSE))
302 xdrrec_getpos (const XDR *xdrs)
304 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
307 pos = __lseek ((int) (long) rstrm->tcp_handle, (long) 0, 1);
313 pos += rstrm->out_finger - rstrm->out_base;
317 pos -= rstrm->in_boundry - rstrm->in_finger;
328 xdrrec_setpos (XDR *xdrs, u_int pos)
330 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
331 u_int currpos = xdrrec_getpos (xdrs);
332 int delta = currpos - pos;
335 if ((int) currpos != -1)
340 newpos = rstrm->out_finger - delta;
341 if (newpos > (caddr_t) rstrm->frag_header &&
342 newpos < rstrm->out_boundry)
344 rstrm->out_finger = newpos;
350 newpos = rstrm->in_finger - delta;
351 if ((delta < (int) (rstrm->fbtbc)) &&
352 (newpos <= rstrm->in_boundry) &&
353 (newpos >= rstrm->in_base))
355 rstrm->in_finger = newpos;
356 rstrm->fbtbc -= delta;
368 xdrrec_inline (XDR *xdrs, u_int len)
370 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
377 if ((rstrm->out_finger + len) <= rstrm->out_boundry)
379 buf = (int32_t *) rstrm->out_finger;
380 rstrm->out_finger += len;
385 if ((len <= rstrm->fbtbc) &&
386 ((rstrm->in_finger + len) <= rstrm->in_boundry))
388 buf = (int32_t *) rstrm->in_finger;
390 rstrm->in_finger += len;
401 xdrrec_destroy (XDR *xdrs)
403 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
405 mem_free (rstrm->the_buffer,
406 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT);
407 mem_free ((caddr_t) rstrm, sizeof (RECSTREAM));
411 xdrrec_getint32 (XDR *xdrs, int32_t *ip)
413 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
414 int32_t *bufip = (int32_t *) rstrm->in_finger;
417 /* first try the inline, fast case */
418 if (rstrm->fbtbc >= BYTES_PER_XDR_UNIT &&
419 rstrm->in_boundry - (char *) bufip >= BYTES_PER_XDR_UNIT)
421 *ip = ntohl (*bufip);
422 rstrm->fbtbc -= BYTES_PER_XDR_UNIT;
423 rstrm->in_finger += BYTES_PER_XDR_UNIT;
427 if (!xdrrec_getbytes (xdrs, (caddr_t) &mylong,
430 *ip = ntohl (mylong);
436 xdrrec_putint32 (XDR *xdrs, const int32_t *ip)
438 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
439 int32_t *dest_ip = (int32_t *) rstrm->out_finger;
441 if ((rstrm->out_finger += BYTES_PER_XDR_UNIT) > rstrm->out_boundry)
444 * this case should almost never happen so the code is
447 rstrm->out_finger -= BYTES_PER_XDR_UNIT;
448 rstrm->frag_sent = TRUE;
449 if (!flush_out (rstrm, FALSE))
451 dest_ip = (int32_t *) rstrm->out_finger;
452 rstrm->out_finger += BYTES_PER_XDR_UNIT;
454 *dest_ip = htonl (*ip);
459 * Exported routines to manage xdr records
463 * Before reading (deserializing from the stream, one should always call
464 * this procedure to guarantee proper record alignment.
467 xdrrec_skiprecord (XDR *xdrs)
469 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
471 while (rstrm->fbtbc > 0 || (!rstrm->last_frag))
473 if (!skip_input_bytes (rstrm, rstrm->fbtbc))
476 if ((!rstrm->last_frag) && (!set_input_fragment (rstrm)))
479 rstrm->last_frag = FALSE;
482 libc_hidden_nolink_sunrpc (xdrrec_skiprecord, GLIBC_2_0)
485 * Lookahead function.
486 * Returns TRUE iff there is no more input in the buffer
487 * after consuming the rest of the current record.
490 xdrrec_eof (XDR *xdrs)
492 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
494 while (rstrm->fbtbc > 0 || (!rstrm->last_frag))
496 if (!skip_input_bytes (rstrm, rstrm->fbtbc))
499 if ((!rstrm->last_frag) && (!set_input_fragment (rstrm)))
502 if (rstrm->in_finger == rstrm->in_boundry)
506 libc_hidden_nolink_sunrpc (xdrrec_eof, GLIBC_2_0)
509 * The client must tell the package when an end-of-record has occurred.
510 * The second parameter tells whether the record should be flushed to the
511 * (output) tcp stream. (This lets the package support batched or
512 * pipelined procedure calls.) TRUE => immediate flush to tcp connection.
515 xdrrec_endofrecord (XDR *xdrs, bool_t sendnow)
517 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
518 u_long len; /* fragment length */
520 if (sendnow || rstrm->frag_sent
521 || rstrm->out_finger + BYTES_PER_XDR_UNIT >= rstrm->out_boundry)
523 rstrm->frag_sent = FALSE;
524 return flush_out (rstrm, TRUE);
526 len = (rstrm->out_finger - (char *) rstrm->frag_header
527 - BYTES_PER_XDR_UNIT);
528 *rstrm->frag_header = htonl ((u_long) len | LAST_FRAG);
529 rstrm->frag_header = (uint32_t *) rstrm->out_finger;
530 rstrm->out_finger += BYTES_PER_XDR_UNIT;
533 libc_hidden_nolink_sunrpc (xdrrec_endofrecord, GLIBC_2_0)
537 * Internal useful routines
541 flush_out (RECSTREAM *rstrm, bool_t eor)
543 u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
544 u_long len = (rstrm->out_finger - (char *) rstrm->frag_header
545 - BYTES_PER_XDR_UNIT);
547 *rstrm->frag_header = htonl (len | eormask);
548 len = rstrm->out_finger - rstrm->out_base;
549 if ((*(rstrm->writeit)) (rstrm->tcp_handle, rstrm->out_base, (int) len)
552 rstrm->frag_header = (uint32_t *) rstrm->out_base;
553 rstrm->out_finger = (caddr_t) rstrm->out_base + BYTES_PER_XDR_UNIT;
557 static bool_t /* knows nothing about records! Only about input buffers */
558 fill_input_buf (RECSTREAM *rstrm)
564 where = rstrm->in_base;
565 i = (size_t) rstrm->in_boundry % BYTES_PER_XDR_UNIT;
567 len = rstrm->in_size - i;
568 if ((len = (*(rstrm->readit)) (rstrm->tcp_handle, where, len)) == -1)
570 rstrm->in_finger = where;
572 rstrm->in_boundry = where;
576 static bool_t /* knows nothing about records! Only about input buffers */
578 get_input_bytes (RECSTREAM *rstrm, caddr_t addr, int len)
584 current = rstrm->in_boundry - rstrm->in_finger;
587 if (!fill_input_buf (rstrm))
591 current = (len < current) ? len : current;
592 memcpy (addr, rstrm->in_finger, current);
593 rstrm->in_finger += current;
600 static bool_t /* next two bytes of the input stream are treated as a header */
602 set_input_fragment (RECSTREAM *rstrm)
606 if (! get_input_bytes (rstrm, (caddr_t)&header, BYTES_PER_XDR_UNIT))
608 header = ntohl (header);
609 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
611 * Sanity check. Try not to accept wildly incorrect fragment
612 * sizes. Unfortunately, only a size of zero can be identified as
613 * 'wildely incorrect', and this only, if it is not the last
614 * fragment of a message. Ridiculously large fragment sizes may look
615 * wrong, but we don't have any way to be certain that they aren't
616 * what the client actually intended to send us. Many existing RPC
617 * implementations may sent a fragment of size zero as the last
618 * fragment of a message.
622 rstrm->fbtbc = header & ~LAST_FRAG;
626 static bool_t /* consumes input bytes; knows nothing about records! */
628 skip_input_bytes (RECSTREAM *rstrm, long cnt)
634 current = rstrm->in_boundry - rstrm->in_finger;
637 if (!fill_input_buf (rstrm))
641 current = (cnt < current) ? cnt : current;
642 rstrm->in_finger += current;
650 fix_buf_size (u_int s)