1 /*-
2 * Copyright (c) 2009, Sun Microsystems, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * - Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * - Redistributions in binary form must reproduce the above copyright notice,
10 * this list of conditions and the following disclaimer in the documentation
11 * and/or other materials provided with the distribution.
12 * - Neither the name of Sun Microsystems, Inc. nor the names of its
13 * contributors may be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 *
28 * @(#)svc_dg.c 1.17 94/04/24 SMI
29 * $NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $
30 * $FreeBSD: src/lib/libc/rpc/svc_dg.c,v 1.8 2006/02/27 22:10:59 deischen Exp $
31 */
32
33 /*
34 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
35 */
36
37 /*
38 * svc_dg.c, Server side for connectionless RPC.
39 *
40 * Does some caching in the hopes of achieving execute-at-most-once semantics.
41 */
42
43 #include "namespace.h"
44 #include "reentrant.h"
45 #include <sys/param.h>
46 #include <sys/socket.h>
47 #include <rpc/rpc.h>
48 #include <rpc/svc_dg.h>
49 #include <errno.h>
50 #include <unistd.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #ifdef RPC_CACHE_DEBUG
55 #include <netconfig.h>
56 #include <netdir.h>
57 #endif
58 #include <err.h>
59 #include "un-namespace.h"
60
61 #include "rpc_com.h"
62 #include "mt_misc.h"
63
64 #define su_data(xprt) ((struct svc_dg_data *)(xprt->xp_p2))
65 #define rpc_buffer(xprt) ((xprt)->xp_p1)
66
67 #ifndef MAX
68 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
69 #endif
70
71 static void svc_dg_ops(SVCXPRT *);
72 static enum xprt_stat svc_dg_stat(SVCXPRT *);
73 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *);
74 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *);
75 static bool_t svc_dg_getargs(SVCXPRT *, xdrproc_t, void *);
76 static bool_t svc_dg_freeargs(SVCXPRT *, xdrproc_t, void *);
77 static void svc_dg_destroy(SVCXPRT *);
78 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
79 static int cache_get(SVCXPRT *, struct rpc_msg *, char **, size_t *);
80 static void cache_set(SVCXPRT *, size_t);
81 int svc_dg_enablecache(SVCXPRT *, u_int);
82
83 /*
84 * Usage:
85 * xprt = svc_dg_create(sock, sendsize, recvsize);
86 * Does other connectionless specific initializations.
87 * Once *xprt is initialized, it is registered.
88 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
89 * system defaults are chosen.
90 * The routines returns NULL if a problem occurred.
91 */
92 static const char svc_dg_str[] = "svc_dg_create: %s";
93 static const char svc_dg_err1[] = "could not get transport information";
94 static const char svc_dg_err2[] = " transport does not support data transfer";
95 static const char __no_mem_str[] = "out of memory";
96
97 SVCXPRT *
svc_dg_create(int fd,u_int sendsize,u_int recvsize)98 svc_dg_create(int fd, u_int sendsize, u_int recvsize)
99 {
100 SVCXPRT *xprt;
101 struct svc_dg_data *su = NULL;
102 struct __rpc_sockinfo si;
103 struct sockaddr_storage ss;
104 socklen_t slen;
105
106 if (!__rpc_fd2sockinfo(fd, &si)) {
107 warnx(svc_dg_str, svc_dg_err1);
108 return (NULL);
109 }
110 /*
111 * Find the receive and the send size
112 */
113 sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
114 recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
115 if ((sendsize == 0) || (recvsize == 0)) {
116 warnx(svc_dg_str, svc_dg_err2);
117 return (NULL);
118 }
119
120 xprt = mem_alloc(sizeof (SVCXPRT));
121 if (xprt == NULL)
122 goto freedata;
123 memset(xprt, 0, sizeof (SVCXPRT));
124
125 su = mem_alloc(sizeof (*su));
126 if (su == NULL)
127 goto freedata;
128 su->su_iosz = rounddown(MAX(sendsize, recvsize) + 3, 4);
129 if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL)
130 goto freedata;
131 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
132 XDR_DECODE);
133 su->su_cache = NULL;
134 xprt->xp_fd = fd;
135 xprt->xp_p2 = su;
136 xprt->xp_verf.oa_base = su->su_verfbody;
137 svc_dg_ops(xprt);
138 xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
139
140 slen = sizeof ss;
141 if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0)
142 goto freedata;
143 xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
144 xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
145 xprt->xp_ltaddr.len = slen;
146 memcpy(xprt->xp_ltaddr.buf, &ss, slen);
147
148 xprt_register(xprt);
149 return (xprt);
150 freedata:
151 warnx(svc_dg_str, __no_mem_str);
152 if (xprt) {
153 if (su)
154 mem_free(su, sizeof (*su));
155 mem_free(xprt, sizeof (SVCXPRT));
156 }
157 return (NULL);
158 }
159
160 /*ARGSUSED*/
161 static enum xprt_stat
svc_dg_stat(SVCXPRT * xprt __unused)162 svc_dg_stat(SVCXPRT *xprt __unused)
163 {
164 return (XPRT_IDLE);
165 }
166
167 static bool_t
svc_dg_recv(SVCXPRT * xprt,struct rpc_msg * msg)168 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg)
169 {
170 struct svc_dg_data *su = su_data(xprt);
171 XDR *xdrs = &(su->su_xdrs);
172 char *reply;
173 struct sockaddr_storage ss;
174 socklen_t alen;
175 size_t replylen;
176 ssize_t rlen;
177
178 again:
179 alen = sizeof (struct sockaddr_storage);
180 rlen = _recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz, 0,
181 (struct sockaddr *)(void *)&ss, &alen);
182 if (rlen == -1 && errno == EINTR)
183 goto again;
184 if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
185 return (FALSE);
186 if (xprt->xp_rtaddr.len < alen) {
187 if (xprt->xp_rtaddr.len != 0)
188 mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
189 xprt->xp_rtaddr.buf = mem_alloc(alen);
190 xprt->xp_rtaddr.len = alen;
191 }
192 memcpy(xprt->xp_rtaddr.buf, &ss, alen);
193 #ifdef PORTMAP
194 if (ss.ss_family == AF_INET) {
195 xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
196 xprt->xp_addrlen = sizeof (struct sockaddr_in);
197 }
198 #endif /* PORTMAP */
199 xdrs->x_op = XDR_DECODE;
200 XDR_SETPOS(xdrs, 0);
201 if (! xdr_callmsg(xdrs, msg)) {
202 return (FALSE);
203 }
204 su->su_xid = msg->rm_xid;
205 if (su->su_cache != NULL) {
206 if (cache_get(xprt, msg, &reply, &replylen)) {
207 _sendto(xprt->xp_fd, reply, replylen, 0,
208 (struct sockaddr *)(void *)&ss, alen);
209 return (FALSE);
210 }
211 }
212 return (TRUE);
213 }
214
215 static bool_t
svc_dg_reply(SVCXPRT * xprt,struct rpc_msg * msg)216 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg)
217 {
218 struct svc_dg_data *su = su_data(xprt);
219 XDR *xdrs = &(su->su_xdrs);
220 bool_t stat = FALSE;
221 size_t slen;
222
223 xdrs->x_op = XDR_ENCODE;
224 XDR_SETPOS(xdrs, 0);
225 msg->rm_xid = su->su_xid;
226 if (xdr_replymsg(xdrs, msg)) {
227 slen = XDR_GETPOS(xdrs);
228 if (_sendto(xprt->xp_fd, rpc_buffer(xprt), slen, 0,
229 (struct sockaddr *)xprt->xp_rtaddr.buf,
230 (socklen_t)xprt->xp_rtaddr.len) == (ssize_t) slen) {
231 stat = TRUE;
232 if (su->su_cache)
233 cache_set(xprt, slen);
234 }
235 }
236 return (stat);
237 }
238
239 static bool_t
svc_dg_getargs(SVCXPRT * xprt,xdrproc_t xdr_args,void * args_ptr)240 svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
241 {
242 return (*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr);
243 }
244
245 static bool_t
svc_dg_freeargs(SVCXPRT * xprt,xdrproc_t xdr_args,void * args_ptr)246 svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
247 {
248 XDR *xdrs = &(su_data(xprt)->su_xdrs);
249
250 xdrs->x_op = XDR_FREE;
251 return (*xdr_args)(xdrs, args_ptr);
252 }
253
254 static void
svc_dg_destroy(SVCXPRT * xprt)255 svc_dg_destroy(SVCXPRT *xprt)
256 {
257 struct svc_dg_data *su = su_data(xprt);
258
259 xprt_unregister(xprt);
260 if (xprt->xp_fd != -1)
261 _close(xprt->xp_fd);
262 XDR_DESTROY(&(su->su_xdrs));
263 mem_free(rpc_buffer(xprt), su->su_iosz);
264 mem_free(su, sizeof (*su));
265 if (xprt->xp_rtaddr.buf)
266 mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
267 if (xprt->xp_ltaddr.buf)
268 mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
269 if (xprt->xp_tp)
270 free(xprt->xp_tp);
271 mem_free(xprt, sizeof (SVCXPRT));
272 }
273
274 static bool_t
275 /*ARGSUSED*/
svc_dg_control(SVCXPRT * xprt __unused,const u_int rq __unused,void * in __unused)276 svc_dg_control(SVCXPRT *xprt __unused, const u_int rq __unused,
277 void *in __unused)
278 {
279 return (FALSE);
280 }
281
282 static void
svc_dg_ops(SVCXPRT * xprt)283 svc_dg_ops(SVCXPRT *xprt)
284 {
285 static struct xp_ops ops;
286 static struct xp_ops2 ops2;
287
288 /* VARIABLES PROTECTED BY ops_lock: ops */
289
290 mutex_lock(&ops_lock);
291 if (ops.xp_recv == NULL) {
292 ops.xp_recv = svc_dg_recv;
293 ops.xp_stat = svc_dg_stat;
294 ops.xp_getargs = svc_dg_getargs;
295 ops.xp_reply = svc_dg_reply;
296 ops.xp_freeargs = svc_dg_freeargs;
297 ops.xp_destroy = svc_dg_destroy;
298 ops2.xp_control = svc_dg_control;
299 }
300 xprt->xp_ops = &ops;
301 xprt->xp_ops2 = &ops2;
302 mutex_unlock(&ops_lock);
303 }
304
305 /* The CACHING COMPONENT */
306
307 /*
308 * Could have been a separate file, but some part of it depends upon the
309 * private structure of the client handle.
310 *
311 * Fifo cache for cl server
312 * Copies pointers to reply buffers into fifo cache
313 * Buffers are sent again if retransmissions are detected.
314 */
315
316 #define SPARSENESS 4 /* 75% sparse */
317
318 #define ALLOC(type, size) \
319 (type *) mem_alloc((sizeof (type) * (size)))
320
321 #define MEMZERO(addr, type, size) \
322 memset((void *) (addr), 0, sizeof (type) * (int) (size))
323
324 #define FREE(addr, type, size) \
325 mem_free((addr), (sizeof (type) * (size)))
326
327 /*
328 * An entry in the cache
329 */
330 typedef struct cache_node *cache_ptr;
331 struct cache_node {
332 /*
333 * Index into cache is xid, proc, vers, prog and address
334 */
335 u_int32_t cache_xid;
336 rpcproc_t cache_proc;
337 rpcvers_t cache_vers;
338 rpcprog_t cache_prog;
339 struct netbuf cache_addr;
340 /*
341 * The cached reply and length
342 */
343 char *cache_reply;
344 size_t cache_replylen;
345 /*
346 * Next node on the list, if there is a collision
347 */
348 cache_ptr cache_next;
349 };
350
351 /*
352 * The entire cache
353 */
354 struct cl_cache {
355 u_int uc_size; /* size of cache */
356 cache_ptr *uc_entries; /* hash table of entries in cache */
357 cache_ptr *uc_fifo; /* fifo list of entries in cache */
358 u_int uc_nextvictim; /* points to next victim in fifo list */
359 rpcprog_t uc_prog; /* saved program number */
360 rpcvers_t uc_vers; /* saved version number */
361 rpcproc_t uc_proc; /* saved procedure number */
362 };
363
364
365 /*
366 * the hashing function
367 */
368 #define CACHE_LOC(transp, xid) \
369 (xid % (SPARSENESS * ((struct cl_cache *) \
370 su_data(transp)->su_cache)->uc_size))
371
372 /*
373 * Enable use of the cache. Returns 1 on success, 0 on failure.
374 * Note: there is no disable.
375 */
376 static const char cache_enable_str[] = "svc_enablecache: %s %s";
377 static const char alloc_err[] = "could not allocate cache ";
378 static const char enable_err[] = "cache already enabled";
379
380 int
svc_dg_enablecache(SVCXPRT * transp,u_int size)381 svc_dg_enablecache(SVCXPRT *transp, u_int size)
382 {
383 struct svc_dg_data *su = su_data(transp);
384 struct cl_cache *uc;
385
386 mutex_lock(&dupreq_lock);
387 if (su->su_cache != NULL) {
388 warnx(cache_enable_str, enable_err, " ");
389 mutex_unlock(&dupreq_lock);
390 return (0);
391 }
392 uc = ALLOC(struct cl_cache, 1);
393 if (uc == NULL) {
394 warnx(cache_enable_str, alloc_err, " ");
395 mutex_unlock(&dupreq_lock);
396 return (0);
397 }
398 uc->uc_size = size;
399 uc->uc_nextvictim = 0;
400 uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
401 if (uc->uc_entries == NULL) {
402 warnx(cache_enable_str, alloc_err, "data");
403 FREE(uc, struct cl_cache, 1);
404 mutex_unlock(&dupreq_lock);
405 return (0);
406 }
407 MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
408 uc->uc_fifo = ALLOC(cache_ptr, size);
409 if (uc->uc_fifo == NULL) {
410 warnx(cache_enable_str, alloc_err, "fifo");
411 FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
412 FREE(uc, struct cl_cache, 1);
413 mutex_unlock(&dupreq_lock);
414 return (0);
415 }
416 MEMZERO(uc->uc_fifo, cache_ptr, size);
417 su->su_cache = (char *)(void *)uc;
418 mutex_unlock(&dupreq_lock);
419 return (1);
420 }
421
422 /*
423 * Set an entry in the cache. It assumes that the uc entry is set from
424 * the earlier call to cache_get() for the same procedure. This will always
425 * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
426 * by svc_dg_reply(). All this hoopla because the right RPC parameters are
427 * not available at svc_dg_reply time.
428 */
429
430 static const char cache_set_str[] = "cache_set: %s";
431 static const char cache_set_err1[] = "victim not found";
432 static const char cache_set_err2[] = "victim alloc failed";
433 static const char cache_set_err3[] = "could not allocate new rpc buffer";
434
435 static void
cache_set(SVCXPRT * xprt,size_t replylen)436 cache_set(SVCXPRT *xprt, size_t replylen)
437 {
438 cache_ptr victim;
439 cache_ptr *vicp;
440 struct svc_dg_data *su = su_data(xprt);
441 struct cl_cache *uc = (struct cl_cache *) su->su_cache;
442 u_int loc;
443 char *newbuf;
444 #ifdef RPC_CACHE_DEBUG
445 struct netconfig *nconf;
446 char *uaddr;
447 #endif
448
449 mutex_lock(&dupreq_lock);
450 /*
451 * Find space for the new entry, either by
452 * reusing an old entry, or by mallocing a new one
453 */
454 victim = uc->uc_fifo[uc->uc_nextvictim];
455 if (victim != NULL) {
456 loc = CACHE_LOC(xprt, victim->cache_xid);
457 for (vicp = &uc->uc_entries[loc];
458 *vicp != NULL && *vicp != victim;
459 vicp = &(*vicp)->cache_next)
460 ;
461 if (*vicp == NULL) {
462 warnx(cache_set_str, cache_set_err1);
463 mutex_unlock(&dupreq_lock);
464 return;
465 }
466 *vicp = victim->cache_next; /* remove from cache */
467 newbuf = victim->cache_reply;
468 } else {
469 victim = ALLOC(struct cache_node, 1);
470 if (victim == NULL) {
471 warnx(cache_set_str, cache_set_err2);
472 mutex_unlock(&dupreq_lock);
473 return;
474 }
475 newbuf = mem_alloc(su->su_iosz);
476 if (newbuf == NULL) {
477 warnx(cache_set_str, cache_set_err3);
478 FREE(victim, struct cache_node, 1);
479 mutex_unlock(&dupreq_lock);
480 return;
481 }
482 }
483
484 /*
485 * Store it away
486 */
487 #ifdef RPC_CACHE_DEBUG
488 if (nconf = getnetconfigent(xprt->xp_netid)) {
489 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
490 freenetconfigent(nconf);
491 printf(
492 "cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
493 su->su_xid, uc->uc_prog, uc->uc_vers,
494 uc->uc_proc, uaddr);
495 free(uaddr);
496 }
497 #endif
498 victim->cache_replylen = replylen;
499 victim->cache_reply = rpc_buffer(xprt);
500 rpc_buffer(xprt) = newbuf;
501 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
502 su->su_iosz, XDR_ENCODE);
503 victim->cache_xid = su->su_xid;
504 victim->cache_proc = uc->uc_proc;
505 victim->cache_vers = uc->uc_vers;
506 victim->cache_prog = uc->uc_prog;
507 victim->cache_addr = xprt->xp_rtaddr;
508 victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
509 memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
510 (size_t)xprt->xp_rtaddr.len);
511 loc = CACHE_LOC(xprt, victim->cache_xid);
512 victim->cache_next = uc->uc_entries[loc];
513 uc->uc_entries[loc] = victim;
514 uc->uc_fifo[uc->uc_nextvictim++] = victim;
515 uc->uc_nextvictim %= uc->uc_size;
516 mutex_unlock(&dupreq_lock);
517 }
518
519 /*
520 * Try to get an entry from the cache
521 * return 1 if found, 0 if not found and set the stage for cache_set()
522 */
523 static int
cache_get(SVCXPRT * xprt,struct rpc_msg * msg,char ** replyp,size_t * replylenp)524 cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp, size_t *replylenp)
525 {
526 u_int loc;
527 cache_ptr ent;
528 struct svc_dg_data *su = su_data(xprt);
529 struct cl_cache *uc = (struct cl_cache *) su->su_cache;
530 #ifdef RPC_CACHE_DEBUG
531 struct netconfig *nconf;
532 char *uaddr;
533 #endif
534
535 mutex_lock(&dupreq_lock);
536 loc = CACHE_LOC(xprt, su->su_xid);
537 for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
538 if (ent->cache_xid == su->su_xid &&
539 ent->cache_proc == msg->rm_call.cb_proc &&
540 ent->cache_vers == msg->rm_call.cb_vers &&
541 ent->cache_prog == msg->rm_call.cb_prog &&
542 ent->cache_addr.len == xprt->xp_rtaddr.len &&
543 (memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
544 xprt->xp_rtaddr.len) == 0)) {
545 #ifdef RPC_CACHE_DEBUG
546 if (nconf = getnetconfigent(xprt->xp_netid)) {
547 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
548 freenetconfigent(nconf);
549 printf(
550 "cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
551 su->su_xid, msg->rm_call.cb_prog,
552 msg->rm_call.cb_vers,
553 msg->rm_call.cb_proc, uaddr);
554 free(uaddr);
555 }
556 #endif
557 *replyp = ent->cache_reply;
558 *replylenp = ent->cache_replylen;
559 mutex_unlock(&dupreq_lock);
560 return (1);
561 }
562 }
563 /*
564 * Failed to find entry
565 * Remember a few things so we can do a set later
566 */
567 uc->uc_proc = msg->rm_call.cb_proc;
568 uc->uc_vers = msg->rm_call.cb_vers;
569 uc->uc_prog = msg->rm_call.cb_prog;
570 mutex_unlock(&dupreq_lock);
571 return (0);
572 }
573