1 /*
2 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
3 * layer above tcp (for rpc's use).
4 *
5 * Copyright (c) 2010, Oracle America, Inc.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met:
10 *
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.
20 *
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.
33 *
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.
43 */
44
45 #include <stdio.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <stdint.h>
49 #include <rpc/rpc.h>
50 #include <libintl.h>
51 #include <wchar.h>
52 #include <libio/iolibio.h>
53 #include <shlib-compat.h>
54
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 *);
65
66 static const struct xdr_ops xdrrec_ops = {
67 xdrrec_getlong,
68 xdrrec_putlong,
69 xdrrec_getbytes,
70 xdrrec_putbytes,
71 xdrrec_getpos,
72 xdrrec_setpos,
73 xdrrec_inline,
74 xdrrec_destroy,
75 xdrrec_getint32,
76 xdrrec_putint32
77 };
78
79 /*
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).
87 *
88 * The fragment/record machinery is not general; it is constructed to
89 * meet the needs of xdr and rpc based on tcp.
90 */
91
92 #define LAST_FRAG (1UL << 31)
93
94 typedef struct rec_strm
95 {
96 caddr_t tcp_handle;
97 caddr_t the_buffer;
98 /*
99 * out-going bits
100 */
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 current fragment */
106 bool_t frag_sent; /* true if buffer sent in middle of record */
107 /*
108 * in-coming bits
109 */
110 int (*readit) (char *, char *, int);
111 u_long in_size; /* fixed size of the input buffer */
112 caddr_t in_base;
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 */
116 bool_t last_frag;
117 u_int sendsize;
118 u_int recvsize;
119 }
120 RECSTREAM;
121
122 static u_int fix_buf_size (u_int);
123 static bool_t skip_input_bytes (RECSTREAM *, long);
124 static bool_t flush_out (RECSTREAM *, bool_t);
125 static bool_t set_input_fragment (RECSTREAM *);
126 static bool_t get_input_bytes (RECSTREAM *, caddr_t, int);
127
128 /*
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.
136 */
137 void
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))
142 {
143 RECSTREAM *rstrm = (RECSTREAM *) mem_alloc (sizeof (RECSTREAM));
144 caddr_t tmp;
145 char *buf;
146
147 sendsize = fix_buf_size (sendsize);
148 recvsize = fix_buf_size (recvsize);
149 buf = mem_alloc (sendsize + recvsize + BYTES_PER_XDR_UNIT);
150
151 if (rstrm == NULL || buf == NULL)
152 {
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);
156 /*
157 * This is bad. Should rework xdrrec_create to
158 * return a handle, and in this case return NULL
159 */
160 return;
161 }
162 /*
163 * adjust sizes and allocate buffer quad byte aligned
164 */
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;
173 /*
174 * now the rest ...
175 */
176 /* We have to add the cast since the `struct xdr_ops' in `struct XDR'
177 is not `const'. */
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);
191 rstrm->fbtbc = 0;
192 rstrm->last_frag = TRUE;
193 }
194 libc_hidden_nolink_sunrpc (xdrrec_create, GLIBC_2_0)
195
196
197 /*
198 * The routines defined below are the xdr ops which will go into the
199 * xdr handle filled in by xdrrec_create.
200 */
201
202 static bool_t
203 xdrrec_getlong (XDR *xdrs, long *lp)
204 {
205 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
206 int32_t *buflp = (int32_t *) rstrm->in_finger;
207 int32_t mylong;
208
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)
212 {
213 *lp = (int32_t) ntohl (*buflp);
214 rstrm->fbtbc -= BYTES_PER_XDR_UNIT;
215 rstrm->in_finger += BYTES_PER_XDR_UNIT;
216 }
217 else
218 {
219 if (!xdrrec_getbytes (xdrs, (caddr_t) & mylong,
220 BYTES_PER_XDR_UNIT))
221 return FALSE;
222 *lp = (int32_t) ntohl (mylong);
223 }
224 return TRUE;
225 }
226
227 static bool_t
228 xdrrec_putlong (XDR *xdrs, const long *lp)
229 {
230 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
231 int32_t *dest_lp = (int32_t *) rstrm->out_finger;
232
233 if ((rstrm->out_finger += BYTES_PER_XDR_UNIT) > rstrm->out_boundry)
234 {
235 /*
236 * this case should almost never happen so the code is
237 * inefficient
238 */
239 rstrm->out_finger -= BYTES_PER_XDR_UNIT;
240 rstrm->frag_sent = TRUE;
241 if (!flush_out (rstrm, FALSE))
242 return FALSE;
243 dest_lp = (int32_t *) rstrm->out_finger;
244 rstrm->out_finger += BYTES_PER_XDR_UNIT;
245 }
246 *dest_lp = htonl (*lp);
247 return TRUE;
248 }
249
250 static bool_t /* must manage buffers, fragments, and records */
251 xdrrec_getbytes (XDR *xdrs, caddr_t addr, u_int len)
252 {
253 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
254 u_int current;
255
256 while (len > 0)
257 {
258 current = rstrm->fbtbc;
259 if (current == 0)
260 {
261 if (rstrm->last_frag)
262 return FALSE;
263 if (!set_input_fragment (rstrm))
264 return FALSE;
265 continue;
266 }
267 current = (len < current) ? len : current;
268 if (!get_input_bytes (rstrm, addr, current))
269 return FALSE;
270 addr += current;
271 rstrm->fbtbc -= current;
272 len -= current;
273 }
274 return TRUE;
275 }
276
277 static bool_t
278 xdrrec_putbytes (XDR *xdrs, const char *addr, u_int len)
279 {
280 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
281 u_int current;
282
283 while (len > 0)
284 {
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;
289 addr += current;
290 len -= current;
291 if (rstrm->out_finger == rstrm->out_boundry && len > 0)
292 {
293 rstrm->frag_sent = TRUE;
294 if (!flush_out (rstrm, FALSE))
295 return FALSE;
296 }
297 }
298 return TRUE;
299 }
300
301 static u_int
302 xdrrec_getpos (const XDR *xdrs)
303 {
304 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
305 long pos;
306
307 pos = __lseek ((int) (long) rstrm->tcp_handle, (long) 0, 1);
308 if (pos != -1)
309 switch (xdrs->x_op)
310 {
311
312 case XDR_ENCODE:
313 pos += rstrm->out_finger - rstrm->out_base;
314 break;
315
316 case XDR_DECODE:
317 pos -= rstrm->in_boundry - rstrm->in_finger;
318 break;
319
320 default:
321 pos = (u_int) - 1;
322 break;
323 }
324 return (u_int) pos;
325 }
326
327 static bool_t
328 xdrrec_setpos (XDR *xdrs, u_int pos)
329 {
330 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
331 u_int currpos = xdrrec_getpos (xdrs);
332 int delta = currpos - pos;
333 caddr_t newpos;
334
335 if ((int) currpos != -1)
336 switch (xdrs->x_op)
337 {
338
339 case XDR_ENCODE:
340 newpos = rstrm->out_finger - delta;
341 if (newpos > (caddr_t) rstrm->frag_header &&
342 newpos < rstrm->out_boundry)
343 {
344 rstrm->out_finger = newpos;
345 return TRUE;
346 }
347 break;
348
349 case XDR_DECODE:
350 newpos = rstrm->in_finger - delta;
351 if ((delta < (int) (rstrm->fbtbc)) &&
352 (newpos <= rstrm->in_boundry) &&
353 (newpos >= rstrm->in_base))
354 {
355 rstrm->in_finger = newpos;
356 rstrm->fbtbc -= delta;
357 return TRUE;
358 }
359 break;
360
361 default:
362 break;
363 }
364 return FALSE;
365 }
366
367 static int32_t *
368 xdrrec_inline (XDR *xdrs, u_int len)
369 {
370 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
371 int32_t *buf = NULL;
372
373 switch (xdrs->x_op)
374 {
375
376 case XDR_ENCODE:
377 if ((rstrm->out_finger + len) <= rstrm->out_boundry)
378 {
379 buf = (int32_t *) rstrm->out_finger;
380 rstrm->out_finger += len;
381 }
382 break;
383
384 case XDR_DECODE:
385 if ((len <= rstrm->fbtbc) &&
386 ((rstrm->in_finger + len) <= rstrm->in_boundry))
387 {
388 buf = (int32_t *) rstrm->in_finger;
389 rstrm->fbtbc -= len;
390 rstrm->in_finger += len;
391 }
392 break;
393
394 default:
395 break;
396 }
397 return buf;
398 }
399
400 static void
401 xdrrec_destroy (XDR *xdrs)
402 {
403 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
404
405 mem_free (rstrm->the_buffer,
406 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT);
407 mem_free ((caddr_t) rstrm, sizeof (RECSTREAM));
408 }
409
410 static bool_t
411 xdrrec_getint32 (XDR *xdrs, int32_t *ip)
412 {
413 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
414 int32_t *bufip = (int32_t *) rstrm->in_finger;
415 int32_t mylong;
416
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)
420 {
421 *ip = ntohl (*bufip);
422 rstrm->fbtbc -= BYTES_PER_XDR_UNIT;
423 rstrm->in_finger += BYTES_PER_XDR_UNIT;
424 }
425 else
426 {
427 if (!xdrrec_getbytes (xdrs, (caddr_t) &mylong,
428 BYTES_PER_XDR_UNIT))
429 return FALSE;
430 *ip = ntohl (mylong);
431 }
432 return TRUE;
433 }
434
435 static bool_t
436 xdrrec_putint32 (XDR *xdrs, const int32_t *ip)
437 {
438 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
439 int32_t *dest_ip = (int32_t *) rstrm->out_finger;
440
441 if ((rstrm->out_finger += BYTES_PER_XDR_UNIT) > rstrm->out_boundry)
442 {
443 /*
444 * this case should almost never happen so the code is
445 * inefficient
446 */
447 rstrm->out_finger -= BYTES_PER_XDR_UNIT;
448 rstrm->frag_sent = TRUE;
449 if (!flush_out (rstrm, FALSE))
450 return FALSE;
451 dest_ip = (int32_t *) rstrm->out_finger;
452 rstrm->out_finger += BYTES_PER_XDR_UNIT;
453 }
454 *dest_ip = htonl (*ip);
455 return TRUE;
456 }
457
458 /*
459 * Exported routines to manage xdr records
460 */
461
462 /*
463 * Before reading (deserializing from the stream, one should always call
464 * this procedure to guarantee proper record alignment.
465 */
466 bool_t
467 xdrrec_skiprecord (XDR *xdrs)
468 {
469 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
470
471 while (rstrm->fbtbc > 0 || (!rstrm->last_frag))
472 {
473 if (!skip_input_bytes (rstrm, rstrm->fbtbc))
474 return FALSE;
475 rstrm->fbtbc = 0;
476 if ((!rstrm->last_frag) && (!set_input_fragment (rstrm)))
477 return FALSE;
478 }
479 rstrm->last_frag = FALSE;
480 return TRUE;
481 }
482 libc_hidden_nolink_sunrpc (xdrrec_skiprecord, GLIBC_2_0)
483
484 /*
485 * Lookahead function.
486 * Returns TRUE iff there is no more input in the buffer
487 * after consuming the rest of the current record.
488 */
489 bool_t
490 xdrrec_eof (XDR *xdrs)
491 {
492 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
493
494 while (rstrm->fbtbc > 0 || (!rstrm->last_frag))
495 {
496 if (!skip_input_bytes (rstrm, rstrm->fbtbc))
497 return TRUE;
498 rstrm->fbtbc = 0;
499 if ((!rstrm->last_frag) && (!set_input_fragment (rstrm)))
500 return TRUE;
501 }
502 if (rstrm->in_finger == rstrm->in_boundry)
503 return TRUE;
504 return FALSE;
505 }
506 libc_hidden_nolink_sunrpc (xdrrec_eof, GLIBC_2_0)
507
508 /*
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.
513 */
514 bool_t
515 xdrrec_endofrecord (XDR *xdrs, bool_t sendnow)
516 {
517 RECSTREAM *rstrm = (RECSTREAM *) xdrs->x_private;
518 u_long len; /* fragment length */
519
520 if (sendnow || rstrm->frag_sent
521 || rstrm->out_finger + BYTES_PER_XDR_UNIT >= rstrm->out_boundry)
522 {
523 rstrm->frag_sent = FALSE;
524 return flush_out (rstrm, TRUE);
525 }
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;
531 return TRUE;
532 }
533 libc_hidden_nolink_sunrpc (xdrrec_endofrecord, GLIBC_2_0)
534
535
536 /*
537 * Internal useful routines
538 */
539 static bool_t
540 flush_out (RECSTREAM *rstrm, bool_t eor)
541 {
542 u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
543 u_long len = (rstrm->out_finger - (char *) rstrm->frag_header
544 - BYTES_PER_XDR_UNIT);
545
546 *rstrm->frag_header = htonl (len | eormask);
547 len = rstrm->out_finger - rstrm->out_base;
548 if ((*(rstrm->writeit)) (rstrm->tcp_handle, rstrm->out_base, (int) len)
549 != (int) len)
550 return FALSE;
551 rstrm->frag_header = (uint32_t *) rstrm->out_base;
552 rstrm->out_finger = (caddr_t) rstrm->out_base + BYTES_PER_XDR_UNIT;
553 return TRUE;
554 }
555
556 static bool_t /* knows nothing about records! Only about input buffers */
557 fill_input_buf (RECSTREAM *rstrm)
558 {
559 caddr_t where;
560 size_t i;
561 int len;
562
563 where = rstrm->in_base;
564 i = (size_t) rstrm->in_boundry % BYTES_PER_XDR_UNIT;
565 where += i;
566 len = rstrm->in_size - i;
567 if ((len = (*(rstrm->readit)) (rstrm->tcp_handle, where, len)) == -1)
568 return FALSE;
569 rstrm->in_finger = where;
570 where += len;
571 rstrm->in_boundry = where;
572 return TRUE;
573 }
574
575 static bool_t /* knows nothing about records! Only about input buffers */
576 get_input_bytes (RECSTREAM *rstrm, caddr_t addr, int len)
577 {
578 int current;
579
580 while (len > 0)
581 {
582 current = rstrm->in_boundry - rstrm->in_finger;
583 if (current == 0)
584 {
585 if (!fill_input_buf (rstrm))
586 return FALSE;
587 continue;
588 }
589 current = (len < current) ? len : current;
590 memcpy (addr, rstrm->in_finger, current);
591 rstrm->in_finger += current;
592 addr += current;
593 len -= current;
594 }
595 return TRUE;
596 }
597
598 static bool_t /* next two bytes of the input stream are treated as a header */
599 set_input_fragment (RECSTREAM *rstrm)
600 {
601 uint32_t header;
602
603 if (! get_input_bytes (rstrm, (caddr_t)&header, BYTES_PER_XDR_UNIT))
604 return FALSE;
605 header = ntohl (header);
606 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
607 /*
608 * Sanity check. Try not to accept wildly incorrect fragment
609 * sizes. Unfortunately, only a size of zero can be identified as
610 * 'wildely incorrect', and this only, if it is not the last
611 * fragment of a message. Ridiculously large fragment sizes may look
612 * wrong, but we don't have any way to be certain that they aren't
613 * what the client actually intended to send us. Many existing RPC
614 * implementations may sent a fragment of size zero as the last
615 * fragment of a message.
616 */
617 if (header == 0)
618 return FALSE;
619 rstrm->fbtbc = header & ~LAST_FRAG;
620 return TRUE;
621 }
622
623 static bool_t /* consumes input bytes; knows nothing about records! */
624 skip_input_bytes (RECSTREAM *rstrm, long cnt)
625 {
626 int current;
627
628 while (cnt > 0)
629 {
630 current = rstrm->in_boundry - rstrm->in_finger;
631 if (current == 0)
632 {
633 if (!fill_input_buf (rstrm))
634 return FALSE;
635 continue;
636 }
637 current = (cnt < current) ? cnt : current;
638 rstrm->in_finger += current;
639 cnt -= current;
640 }
641 return TRUE;
642 }
643
644 static u_int
645 fix_buf_size (u_int s)
646 {
647 if (s < 100)
648 s = 4000;
649 return RNDUP (s);
650 }