xref: /titanic_41/usr/src/lib/libnsl/rpc/svc_dg.c (revision 67dbe2be0c0f1e2eb428b89088bb5667e8f0b9f6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
28 /*
29  * Portions of this source code were derived from Berkeley
30  * 4.3 BSD under license from the Regents of the University of
31  * California.
32  */
33 
34 /*
35  * svc_dg.c, Server side for connectionless RPC.
36  *
37  * Does some caching in the hopes of achieving execute-at-most-once semantics.
38  */
39 
40 #include "mt.h"
41 #include "rpc_mt.h"
42 #include <stdio.h>
43 #include <sys/types.h>
44 #include <sys/sysmacros.h>
45 #include <rpc/rpc.h>
46 #include <rpcsvc/svc_dg_priv.h>
47 #include <errno.h>
48 #include <syslog.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <ucred.h>
52 #include <unistd.h>
53 #include <sys/socket.h>
54 #include <netinet/in.h>
55 #include <arpa/inet.h>
56 #ifdef RPC_CACHE_DEBUG
57 #include <netconfig.h>
58 #include <netdir.h>
59 #endif
60 
61 #ifndef MAX
62 #define	MAX(a, b)	(((a) > (b)) ? (a) : (b))
63 #endif
64 
65 static struct xp_ops *svc_dg_ops();
66 static void cache_set();
67 static int cache_get();
68 
69 #define	rpc_buffer(xprt) ((xprt)->xp_p1)
70 
71 /*
72  * Usage:
73  *	xprt = svc_dg_create(sock, sendsize, recvsize);
74  * Does other connectionless specific initializations.
75  * Once *xprt is initialized, it is registered.
76  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
77  * system defaults are chosen.
78  * The routines returns NULL if a problem occurred.
79  */
80 static const char svc_dg_str[] = "svc_dg_create: %s";
81 static const char svc_dg_err1[] = "could not get transport information";
82 static const char svc_dg_err2[] = " transport does not support data transfer";
83 static const char svc_dg_err3[] =
84 		"fd > FD_SETSIZE; Use rpc_control(RPC_SVC_USE_POLLFD,...);";
85 static const char __no_mem_str[] = "out of memory";
86 
87 /* Structure used to initialize SVC_XP_AUTH(xprt).svc_ah_ops. */
88 extern struct svc_auth_ops svc_auth_any_ops;
89 extern int __rpc_get_ltaddr(struct netbuf *, struct netbuf *);
90 
91 void
92 svc_dg_xprtfree(SVCXPRT *xprt)
93 {
94 /* LINTED pointer alignment */
95 	SVCXPRT_EXT		*xt = xprt ? SVCEXT(xprt) : NULL;
96 /* LINTED pointer alignment */
97 	struct svc_dg_data	*su = xprt ? get_svc_dg_data(xprt) : NULL;
98 
99 	if (xprt == NULL)
100 		return;
101 	if (xprt->xp_netid)
102 		free(xprt->xp_netid);
103 	if (xprt->xp_tp)
104 		free(xprt->xp_tp);
105 	if (xt->parent == NULL)
106 		if (xprt->xp_ltaddr.buf)
107 			free(xprt->xp_ltaddr.buf);
108 	if (xprt->xp_rtaddr.buf)
109 		free(xprt->xp_rtaddr.buf);
110 	if (su != NULL) {
111 		XDR_DESTROY(&(su->su_xdrs));
112 		free(su);
113 	}
114 	if (rpc_buffer(xprt))
115 		free(rpc_buffer(xprt));
116 	svc_xprt_free(xprt);
117 }
118 
119 SVCXPRT *
120 svc_dg_create_private(int fd, uint_t sendsize, uint_t recvsize)
121 {
122 	SVCXPRT *xprt;
123 	struct svc_dg_data *su = NULL;
124 	struct t_info tinfo;
125 	size_t ucred_sz = ucred_size();
126 
127 	if (RPC_FD_NOTIN_FDSET(fd)) {
128 		errno = EBADF;
129 		t_errno = TBADF;
130 		syslog(LOG_ERR, svc_dg_str, svc_dg_err3);
131 		return (NULL);
132 	}
133 
134 	if (t_getinfo(fd, &tinfo) == -1) {
135 		syslog(LOG_ERR, svc_dg_str, svc_dg_err1);
136 		return (NULL);
137 	}
138 	/*
139 	 * Find the receive and the send size
140 	 */
141 	sendsize = __rpc_get_t_size((int)sendsize, tinfo.tsdu);
142 	recvsize = __rpc_get_t_size((int)recvsize, tinfo.tsdu);
143 	if ((sendsize == 0) || (recvsize == 0)) {
144 		syslog(LOG_ERR, svc_dg_str, svc_dg_err2);
145 		return (NULL);
146 	}
147 
148 	if ((xprt = svc_xprt_alloc()) == NULL)
149 		goto freedata;
150 /* LINTED pointer alignment */
151 	svc_flags(xprt) |= SVC_DGRAM;
152 
153 	su = malloc(sizeof (*su) + ucred_sz);
154 	if (su == NULL)
155 		goto freedata;
156 	su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
157 	if ((rpc_buffer(xprt) = malloc(su->su_iosz)) == NULL)
158 		goto freedata;
159 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
160 	    XDR_DECODE);
161 	su->su_cache = NULL;
162 	xprt->xp_fd = fd;
163 	xprt->xp_p2 = (caddr_t)su;
164 	xprt->xp_verf.oa_base = su->su_verfbody;
165 	xprt->xp_ops = svc_dg_ops();
166 
167 	su->su_tudata.addr.maxlen =  0; /* Fill in later */
168 
169 	su->su_tudata.udata.buf = (char *)rpc_buffer(xprt);
170 	su->su_tudata.opt.buf = (char *)su->opts;
171 	su->su_tudata.udata.maxlen = su->su_iosz;
172 	su->su_tudata.opt.maxlen = MAX_OPT_WORDS * sizeof (int) + ucred_sz;
173 /* LINTED pointer alignment */
174 	SVC_XP_AUTH(xprt).svc_ah_ops = svc_auth_any_ops;
175 /* LINTED pointer alignment */
176 	SVC_XP_AUTH(xprt).svc_ah_private = NULL;
177 	return (xprt);
178 freedata:
179 	(void) syslog(LOG_ERR, svc_dg_str, __no_mem_str);
180 	if (xprt)
181 		svc_dg_xprtfree(xprt);
182 	return (NULL);
183 }
184 
185 SVCXPRT *
186 svc_dg_create(const int fd, const uint_t sendsize, const uint_t recvsize)
187 {
188 	SVCXPRT *xprt;
189 
190 	if ((xprt = svc_dg_create_private(fd, sendsize, recvsize)) != NULL)
191 		xprt_register(xprt);
192 	return (xprt);
193 }
194 
195 SVCXPRT *
196 svc_dg_xprtcopy(SVCXPRT *parent)
197 {
198 	SVCXPRT			*xprt;
199 	struct svc_dg_data	*su;
200 	size_t			ucred_sz = ucred_size();
201 
202 	if ((xprt = svc_xprt_alloc()) == NULL)
203 		return (NULL);
204 
205 /* LINTED pointer alignment */
206 	SVCEXT(xprt)->parent = parent;
207 /* LINTED pointer alignment */
208 	SVCEXT(xprt)->flags = SVCEXT(parent)->flags;
209 
210 	xprt->xp_fd = parent->xp_fd;
211 	xprt->xp_port = parent->xp_port;
212 	xprt->xp_ops = svc_dg_ops();
213 	if (parent->xp_tp) {
214 		xprt->xp_tp = (char *)strdup(parent->xp_tp);
215 		if (xprt->xp_tp == NULL) {
216 			syslog(LOG_ERR, "svc_dg_xprtcopy: strdup failed");
217 			svc_dg_xprtfree(xprt);
218 			return (NULL);
219 		}
220 	}
221 	if (parent->xp_netid) {
222 		xprt->xp_netid = (char *)strdup(parent->xp_netid);
223 		if (xprt->xp_netid == NULL) {
224 			syslog(LOG_ERR, "svc_dg_xprtcopy: strdup failed");
225 			if (parent->xp_tp)
226 				free(parent->xp_tp);
227 			svc_dg_xprtfree(xprt);
228 			return (NULL);
229 		}
230 	}
231 	xprt->xp_ltaddr = parent->xp_ltaddr;	/* shared with parent */
232 
233 	xprt->xp_rtaddr = parent->xp_rtaddr;
234 	xprt->xp_rtaddr.buf = malloc(xprt->xp_rtaddr.maxlen);
235 	if (xprt->xp_rtaddr.buf == NULL) {
236 		svc_dg_xprtfree(xprt);
237 		return (NULL);
238 	}
239 	(void) memcpy(xprt->xp_rtaddr.buf, parent->xp_rtaddr.buf,
240 	    xprt->xp_rtaddr.maxlen);
241 	xprt->xp_type = parent->xp_type;
242 
243 	if ((su = malloc(sizeof (struct svc_dg_data) + ucred_sz)) == NULL) {
244 		svc_dg_xprtfree(xprt);
245 		return (NULL);
246 	}
247 /* LINTED pointer alignment */
248 	su->su_iosz = get_svc_dg_data(parent)->su_iosz;
249 	if ((rpc_buffer(xprt) = malloc(su->su_iosz)) == NULL) {
250 		svc_dg_xprtfree(xprt);
251 		free(su);
252 		return (NULL);
253 	}
254 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
255 	    XDR_DECODE);
256 	su->su_cache = NULL;
257 	su->su_tudata.addr.maxlen =  0; /* Fill in later */
258 	su->su_tudata.udata.buf = (char *)rpc_buffer(xprt);
259 	su->su_tudata.opt.buf = (char *)su->opts;
260 	su->su_tudata.udata.maxlen = su->su_iosz;
261 	su->su_tudata.opt.maxlen = MAX_OPT_WORDS * sizeof (int) + ucred_sz;
262 	xprt->xp_p2 = (caddr_t)su;	/* get_svc_dg_data(xprt) = su */
263 	xprt->xp_verf.oa_base = su->su_verfbody;
264 
265 	return (xprt);
266 }
267 
268 /*ARGSUSED*/
269 static enum xprt_stat
270 svc_dg_stat(SVCXPRT *xprt)
271 {
272 	return (XPRT_IDLE);
273 }
274 
275 /*
276  * Find the SCM_UCRED in src and place a pointer to that option alone in dest.
277  * Note that these two 'netbuf' structures might be the same one, so the code
278  * has to be careful about referring to src after changing dest.
279  */
280 static void
281 extract_cred(const struct netbuf *src, struct netbuf *dest)
282 {
283 	char *cp = src->buf;
284 	unsigned int len = src->len;
285 	const struct T_opthdr *opt;
286 	unsigned int olen;
287 
288 	while (len >= sizeof (*opt)) {
289 		/* LINTED: pointer alignment */
290 		opt = (const struct T_opthdr *)cp;
291 		olen = opt->len;
292 		if (olen > len || olen < sizeof (*opt) ||
293 		    !IS_P2ALIGNED(olen, sizeof (t_uscalar_t)))
294 			break;
295 		if (opt->level == SOL_SOCKET && opt->name == SCM_UCRED) {
296 			dest->buf = cp;
297 			dest->len = olen;
298 			return;
299 		}
300 		cp += olen;
301 		len -= olen;
302 	}
303 	dest->len = 0;
304 }
305 
306 /*
307  * This routine extracts the destination IP address of the inbound RPC packet
308  * and sets that as source IP address for the outbound response.
309  */
310 static void
311 set_src_addr(SVCXPRT *xprt, struct netbuf *opt)
312 {
313 	struct netbuf *nbufp, *ltaddr;
314 	struct T_opthdr *opthdr;
315 	in_pktinfo_t *pktinfo;
316 	struct sockaddr_in *sock = (struct sockaddr_in *)NULL;
317 
318 	/* extract dest IP of inbound packet */
319 	/* LINTED pointer alignment */
320 	nbufp = (struct netbuf *)xprt->xp_p2;
321 	ltaddr = &xprt->xp_ltaddr;
322 	if (__rpc_get_ltaddr(nbufp, ltaddr) != 0)
323 		return;
324 
325 	/* do nothing for non-IPv4 packet */
326 	/* LINTED pointer alignment */
327 	sock = (struct sockaddr_in *)ltaddr->buf;
328 	if (sock->sin_family != AF_INET)
329 		return;
330 
331 	/* set desired option header */
332 	opthdr = (struct T_opthdr *)memalign(sizeof (int),
333 	    sizeof (struct T_opthdr) + sizeof (in_pktinfo_t));
334 	if (opthdr == NULL)
335 		return;
336 	opthdr->len = sizeof (struct T_opthdr) + sizeof (in_pktinfo_t);
337 	opthdr->level = IPPROTO_IP;
338 	opthdr->name = IP_PKTINFO;
339 
340 	/*
341 	 * 1. set source IP of outbound packet
342 	 * 2. value '0' for index means IP layer uses this as source address
343 	 */
344 	pktinfo = (in_pktinfo_t *)(opthdr + 1);
345 	(void) memset(pktinfo, 0, sizeof (in_pktinfo_t));
346 	pktinfo->ipi_spec_dst.s_addr = sock->sin_addr.s_addr;
347 	pktinfo->ipi_ifindex = 0;
348 
349 	/* copy data into ancillary buffer */
350 	if (opthdr->len + opt->len <= opt->maxlen) {
351 		(void) memcpy((void *)(opt->buf+opt->len), (const void *)opthdr,
352 		    opthdr->len);
353 		opt->len += opthdr->len;
354 	}
355 	free(opthdr);
356 }
357 
358 static bool_t
359 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg)
360 {
361 /* LINTED pointer alignment */
362 	struct svc_dg_data *su = get_svc_dg_data(xprt);
363 	XDR *xdrs = &(su->su_xdrs);
364 	struct t_unitdata *tu_data = &(su->su_tudata);
365 	int moreflag;
366 	struct netbuf *nbufp;
367 	struct netconfig *nconf;
368 
369 	/* XXX: tudata should have been made a part of the server handle */
370 	if (tu_data->addr.maxlen == 0)
371 		tu_data->addr = xprt->xp_rtaddr;
372 again:
373 	tu_data->addr.len = 0;
374 	tu_data->opt.len  = 0;
375 	tu_data->udata.len  = 0;
376 
377 	moreflag = 0;
378 	if (t_rcvudata(xprt->xp_fd, tu_data, &moreflag) == -1) {
379 #ifdef RPC_DEBUG
380 		syslog(LOG_ERR, "svc_dg_recv: t_rcvudata t_errno=%d errno=%d\n",
381 		    t_errno, errno);
382 #endif
383 		if (t_errno == TLOOK) {
384 			int lookres;
385 
386 			lookres = t_look(xprt->xp_fd);
387 			if ((lookres & T_UDERR) &&
388 			    (t_rcvuderr(xprt->xp_fd,
389 				    (struct t_uderr *)0) < 0)) {
390 				/*EMPTY*/
391 #ifdef RPC_DEBUG
392 				syslog(LOG_ERR,
393 				"svc_dg_recv: t_rcvuderr t_errno = %d\n",
394 					t_errno);
395 #endif
396 			}
397 			if (lookres & T_DATA)
398 				goto again;
399 		} else if ((errno == EINTR) && (t_errno == TSYSERR))
400 			goto again;
401 		else {
402 			return (FALSE);
403 		}
404 	}
405 
406 	if ((moreflag) ||
407 	    (tu_data->udata.len < 4 * (uint_t)sizeof (uint32_t))) {
408 		/*
409 		 * If moreflag is set, drop that data packet. Something wrong
410 		 */
411 		return (FALSE);
412 	}
413 	su->optbuf = tu_data->opt;
414 	xprt->xp_rtaddr.len = tu_data->addr.len;
415 	xdrs->x_op = XDR_DECODE;
416 	XDR_SETPOS(xdrs, 0);
417 	if (!xdr_callmsg(xdrs, msg))
418 		return (FALSE);
419 	su->su_xid = msg->rm_xid;
420 	if (su->su_cache != NULL) {
421 		char *reply;
422 		uint32_t replylen;
423 
424 		if (cache_get(xprt, msg, &reply, &replylen)) {
425 			/* tu_data.addr is already set */
426 			tu_data->udata.buf = reply;
427 			tu_data->udata.len = (uint_t)replylen;
428 			extract_cred(&tu_data->opt, &tu_data->opt);
429 			set_src_addr(xprt, &tu_data->opt);
430 			(void) t_sndudata(xprt->xp_fd, tu_data);
431 			tu_data->udata.buf = (char *)rpc_buffer(xprt);
432 			tu_data->opt.buf = (char *)su->opts;
433 			return (FALSE);
434 		}
435 	}
436 
437 	/*
438 	 * get local ip address
439 	 */
440 
441 	if ((nconf = getnetconfigent(xprt->xp_netid)) != NULL) {
442 		if (strcmp(nconf->nc_protofmly, NC_INET) == 0 ||
443 		    strcmp(nconf->nc_protofmly, NC_INET6) == 0) {
444 			if (nconf->nc_semantics == NC_TPI_CLTS) {
445 				/* LINTED pointer cast */
446 				nbufp = (struct netbuf *)(xprt->xp_p2);
447 				if (__rpc_get_ltaddr(nbufp,
448 				    &xprt->xp_ltaddr) < 0) {
449 					if (strcmp(nconf->nc_protofmly,
450 					    NC_INET) == 0) {
451 						syslog(LOG_ERR,
452 						    "svc_dg_recv: ip(udp), "
453 						    "t_errno=%d, errno=%d",
454 						    t_errno, errno);
455 					}
456 					if (strcmp(nconf->nc_protofmly,
457 					    NC_INET6) == 0) {
458 						syslog(LOG_ERR,
459 						    "svc_dg_recv: ip (udp6), "
460 						    "t_errno=%d, errno=%d",
461 						    t_errno, errno);
462 					}
463 					freenetconfigent(nconf);
464 					return (FALSE);
465 				}
466 			}
467 		}
468 		freenetconfigent(nconf);
469 	}
470 	return (TRUE);
471 }
472 
473 static bool_t
474 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg)
475 {
476 /* LINTED pointer alignment */
477 	struct svc_dg_data *su = get_svc_dg_data(xprt);
478 	XDR *xdrs = &(su->su_xdrs);
479 	bool_t stat = FALSE;
480 	xdrproc_t xdr_results;
481 	caddr_t xdr_location;
482 	bool_t has_args;
483 
484 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
485 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
486 		has_args = TRUE;
487 		xdr_results = msg->acpted_rply.ar_results.proc;
488 		xdr_location = msg->acpted_rply.ar_results.where;
489 		msg->acpted_rply.ar_results.proc = xdr_void;
490 		msg->acpted_rply.ar_results.where = NULL;
491 	} else
492 		has_args = FALSE;
493 
494 	xdrs->x_op = XDR_ENCODE;
495 	XDR_SETPOS(xdrs, 0);
496 	msg->rm_xid = su->su_xid;
497 	if (xdr_replymsg(xdrs, msg) && (!has_args ||
498 /* LINTED pointer alignment */
499 	    SVCAUTH_WRAP(&SVC_XP_AUTH(xprt), xdrs, xdr_results,
500 	    xdr_location))) {
501 		int slen;
502 		struct t_unitdata *tu_data = &(su->su_tudata);
503 
504 		slen = (int)XDR_GETPOS(xdrs);
505 		tu_data->udata.len = slen;
506 		extract_cred(&su->optbuf, &tu_data->opt);
507 		set_src_addr(xprt, &tu_data->opt);
508 try_again:
509 		if (t_sndudata(xprt->xp_fd, tu_data) == 0) {
510 			stat = TRUE;
511 			if (su->su_cache && slen >= 0) {
512 				cache_set(xprt, (uint32_t)slen);
513 			}
514 		} else {
515 			if (errno == EINTR)
516 				goto try_again;
517 
518 			syslog(LOG_ERR,
519 			    "svc_dg_reply: t_sndudata error t_errno=%d ",
520 			    "errno=%d\n", t_errno, errno);
521 		}
522 		tu_data->opt.buf = (char *)su->opts;
523 	}
524 	return (stat);
525 }
526 
527 static bool_t
528 svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
529 {
530 	if (svc_mt_mode != RPC_SVC_MT_NONE)
531 		svc_args_done(xprt);
532 /* LINTED pointer alignment */
533 	return (SVCAUTH_UNWRAP(&SVC_XP_AUTH(xprt),
534 	    &(get_svc_dg_data(xprt)->su_xdrs), xdr_args, args_ptr));
535 }
536 
537 static bool_t
538 svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
539 {
540 /* LINTED pointer alignment */
541 	XDR *xdrs = &(get_svc_dg_data(xprt)->su_xdrs);
542 
543 	xdrs->x_op = XDR_FREE;
544 	return ((*xdr_args)(xdrs, args_ptr));
545 }
546 
547 static void
548 svc_dg_destroy(SVCXPRT *xprt)
549 {
550 	(void) mutex_lock(&svc_mutex);
551 	_svc_dg_destroy_private(xprt);
552 	(void) mutex_unlock(&svc_mutex);
553 }
554 
555 void
556 _svc_dg_destroy_private(SVCXPRT *xprt)
557 {
558 	if (svc_mt_mode != RPC_SVC_MT_NONE) {
559 /* LINTED pointer alignment */
560 		if (SVCEXT(xprt)->parent)
561 /* LINTED pointer alignment */
562 			xprt = SVCEXT(xprt)->parent;
563 /* LINTED pointer alignment */
564 		svc_flags(xprt) |= SVC_DEFUNCT;
565 /* LINTED pointer alignment */
566 		if (SVCEXT(xprt)->refcnt > 0)
567 			return;
568 	}
569 
570 	xprt_unregister(xprt);
571 	(void) t_close(xprt->xp_fd);
572 
573 	if (svc_mt_mode != RPC_SVC_MT_NONE)
574 		svc_xprt_destroy(xprt);
575 	else
576 		svc_dg_xprtfree(xprt);
577 }
578 
579 /*ARGSUSED*/
580 static bool_t
581 svc_dg_control(SVCXPRT *xprt, const uint_t rq, void *in)
582 {
583 	switch (rq) {
584 	case SVCGET_XID:
585 		if (xprt->xp_p2 == NULL)
586 			return (FALSE);
587 		/* LINTED pointer alignment */
588 		*(uint32_t *)in = ((struct svc_dg_data *)(xprt->xp_p2))->su_xid;
589 		return (TRUE);
590 	default:
591 		return (FALSE);
592 	}
593 }
594 
595 static struct xp_ops *
596 svc_dg_ops(void)
597 {
598 	static struct xp_ops ops;
599 	extern mutex_t ops_lock;
600 
601 /* VARIABLES PROTECTED BY ops_lock: ops */
602 
603 	(void) mutex_lock(&ops_lock);
604 	if (ops.xp_recv == NULL) {
605 		ops.xp_recv = svc_dg_recv;
606 		ops.xp_stat = svc_dg_stat;
607 		ops.xp_getargs = svc_dg_getargs;
608 		ops.xp_reply = svc_dg_reply;
609 		ops.xp_freeargs = svc_dg_freeargs;
610 		ops.xp_destroy = svc_dg_destroy;
611 		ops.xp_control = svc_dg_control;
612 	}
613 	(void) mutex_unlock(&ops_lock);
614 	return (&ops);
615 }
616 
617 /*  The CACHING COMPONENT */
618 
619 /*
620  * Could have been a separate file, but some part of it depends upon the
621  * private structure of the client handle.
622  *
623  * Fifo cache for cl server
624  * Copies pointers to reply buffers into fifo cache
625  * Buffers are sent again if retransmissions are detected.
626  */
627 
628 #define	SPARSENESS 4	/* 75% sparse */
629 
630 /*
631  * An entry in the cache
632  */
633 typedef struct cache_node *cache_ptr;
634 struct cache_node {
635 	/*
636 	 * Index into cache is xid, proc, vers, prog and address
637 	 */
638 	uint32_t cache_xid;
639 	rpcproc_t cache_proc;
640 	rpcvers_t cache_vers;
641 	rpcprog_t cache_prog;
642 	struct netbuf cache_addr;
643 	/*
644 	 * The cached reply and length
645 	 */
646 	char *cache_reply;
647 	uint32_t cache_replylen;
648 	/*
649 	 * Next node on the list, if there is a collision
650 	 */
651 	cache_ptr cache_next;
652 };
653 
654 /*
655  * The entire cache
656  */
657 struct cl_cache {
658 	uint32_t uc_size;		/* size of cache */
659 	cache_ptr *uc_entries;	/* hash table of entries in cache */
660 	cache_ptr *uc_fifo;	/* fifo list of entries in cache */
661 	uint32_t uc_nextvictim;	/* points to next victim in fifo list */
662 	rpcprog_t uc_prog;	/* saved program number */
663 	rpcvers_t uc_vers;	/* saved version number */
664 	rpcproc_t uc_proc;	/* saved procedure number */
665 };
666 
667 
668 /*
669  * the hashing function
670  */
671 #define	CACHE_LOC(transp, xid)	\
672 	(xid % (SPARSENESS * ((struct cl_cache *) \
673 		get_svc_dg_data(transp)->su_cache)->uc_size))
674 
675 extern mutex_t	dupreq_lock;
676 
677 /*
678  * Enable use of the cache. Returns 1 on success, 0 on failure.
679  * Note: there is no disable.
680  */
681 static const char cache_enable_str[] = "svc_enablecache: %s %s";
682 static const char alloc_err[] = "could not allocate cache ";
683 static const char enable_err[] = "cache already enabled";
684 
685 int
686 svc_dg_enablecache(SVCXPRT *xprt, const uint_t size)
687 {
688 	SVCXPRT *transp;
689 	struct svc_dg_data *su;
690 	struct cl_cache *uc;
691 
692 /* LINTED pointer alignment */
693 	if (svc_mt_mode != RPC_SVC_MT_NONE && SVCEXT(xprt)->parent != NULL)
694 /* LINTED pointer alignment */
695 		transp = SVCEXT(xprt)->parent;
696 	else
697 		transp = xprt;
698 /* LINTED pointer alignment */
699 	su = get_svc_dg_data(transp);
700 
701 	(void) mutex_lock(&dupreq_lock);
702 	if (su->su_cache != NULL) {
703 		(void) syslog(LOG_ERR, cache_enable_str,
704 		    enable_err, " ");
705 		(void) mutex_unlock(&dupreq_lock);
706 		return (0);
707 	}
708 	uc = malloc(sizeof (struct cl_cache));
709 	if (uc == NULL) {
710 		(void) syslog(LOG_ERR, cache_enable_str,
711 		    alloc_err, " ");
712 		(void) mutex_unlock(&dupreq_lock);
713 		return (0);
714 	}
715 	uc->uc_size = size;
716 	uc->uc_nextvictim = 0;
717 	uc->uc_entries = calloc(size * SPARSENESS, sizeof (cache_ptr));
718 	if (uc->uc_entries == NULL) {
719 		(void) syslog(LOG_ERR, cache_enable_str, alloc_err, "data");
720 		free(uc);
721 		(void) mutex_unlock(&dupreq_lock);
722 		return (0);
723 	}
724 	uc->uc_fifo = calloc(size, sizeof (cache_ptr));
725 	if (uc->uc_fifo == NULL) {
726 		(void) syslog(LOG_ERR, cache_enable_str, alloc_err, "fifo");
727 		free(uc->uc_entries);
728 		free(uc);
729 		(void) mutex_unlock(&dupreq_lock);
730 		return (0);
731 	}
732 	su->su_cache = (char *)uc;
733 	(void) mutex_unlock(&dupreq_lock);
734 	return (1);
735 }
736 
737 /*
738  * Set an entry in the cache.  It assumes that the uc entry is set from
739  * the earlier call to cache_get() for the same procedure.  This will always
740  * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
741  * by svc_dg_reply().  All this hoopla because the right RPC parameters are
742  * not available at svc_dg_reply time.
743  */
744 
745 static const char cache_set_str[] = "cache_set: %s";
746 static const char cache_set_err1[] = "victim not found";
747 static const char cache_set_err2[] = "victim alloc failed";
748 static const char cache_set_err3[] = "could not allocate new rpc buffer";
749 
750 static void
751 cache_set(SVCXPRT *xprt, uint32_t replylen)
752 {
753 	SVCXPRT *parent;
754 	cache_ptr victim;
755 	cache_ptr *vicp;
756 	struct svc_dg_data *su;
757 	struct cl_cache *uc;
758 	uint_t loc;
759 	char *newbuf, *newbuf2;
760 	int my_mallocs = 0;
761 #ifdef RPC_CACHE_DEBUG
762 	struct netconfig *nconf;
763 	char *uaddr;
764 #endif
765 
766 /* LINTED pointer alignment */
767 	if (svc_mt_mode != RPC_SVC_MT_NONE && SVCEXT(xprt)->parent != NULL)
768 /* LINTED pointer alignment */
769 		parent = SVCEXT(xprt)->parent;
770 	else
771 		parent = xprt;
772 /* LINTED pointer alignment */
773 	su = get_svc_dg_data(xprt);
774 /* LINTED pointer alignment */
775 	uc = (struct cl_cache *)get_svc_dg_data(parent)->su_cache;
776 
777 	(void) mutex_lock(&dupreq_lock);
778 	/*
779 	 * Find space for the new entry, either by
780 	 * reusing an old entry, or by mallocing a new one
781 	 */
782 	victim = uc->uc_fifo[uc->uc_nextvictim];
783 	if (victim != NULL) {
784 /* LINTED pointer alignment */
785 		loc = CACHE_LOC(parent, victim->cache_xid);
786 		for (vicp = &uc->uc_entries[loc];
787 		    *vicp != NULL && *vicp != victim;
788 		    vicp = &(*vicp)->cache_next)
789 			;
790 		if (*vicp == NULL) {
791 			(void) syslog(LOG_ERR, cache_set_str, cache_set_err1);
792 			(void) mutex_unlock(&dupreq_lock);
793 			return;
794 		}
795 		*vicp = victim->cache_next;	/* remove from cache */
796 		newbuf = victim->cache_reply;
797 	} else {
798 		victim = malloc(sizeof (struct cache_node));
799 		if (victim == NULL) {
800 			(void) syslog(LOG_ERR, cache_set_str, cache_set_err2);
801 			(void) mutex_unlock(&dupreq_lock);
802 			return;
803 		}
804 		newbuf = malloc(su->su_iosz);
805 		if (newbuf == NULL) {
806 			(void) syslog(LOG_ERR, cache_set_str, cache_set_err3);
807 			free(victim);
808 			(void) mutex_unlock(&dupreq_lock);
809 			return;
810 		}
811 		my_mallocs = 1;
812 	}
813 
814 	/*
815 	 * Store it away
816 	 */
817 #ifdef RPC_CACHE_DEBUG
818 	if (nconf = getnetconfigent(xprt->xp_netid)) {
819 		uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
820 		freenetconfigent(nconf);
821 		printf(
822 	"cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
823 		    su->su_xid, uc->uc_prog, uc->uc_vers, uc->uc_proc, uaddr);
824 		free(uaddr);
825 	}
826 #endif
827 	newbuf2 = malloc(sizeof (char) * xprt->xp_rtaddr.len);
828 	if (newbuf2 == NULL) {
829 		syslog(LOG_ERR, "cache_set : out of memory");
830 		if (my_mallocs) {
831 			free(victim);
832 			free(newbuf);
833 		}
834 		(void) mutex_unlock(&dupreq_lock);
835 		return;
836 	}
837 	victim->cache_replylen = replylen;
838 	victim->cache_reply = rpc_buffer(xprt);
839 	rpc_buffer(xprt) = newbuf;
840 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
841 	    XDR_ENCODE);
842 	su->su_tudata.udata.buf = (char *)rpc_buffer(xprt);
843 	victim->cache_xid = su->su_xid;
844 	victim->cache_proc = uc->uc_proc;
845 	victim->cache_vers = uc->uc_vers;
846 	victim->cache_prog = uc->uc_prog;
847 	victim->cache_addr = xprt->xp_rtaddr;
848 	victim->cache_addr.buf = newbuf2;
849 	(void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
850 	    (int)xprt->xp_rtaddr.len);
851 /* LINTED pointer alignment */
852 	loc = CACHE_LOC(parent, victim->cache_xid);
853 	victim->cache_next = uc->uc_entries[loc];
854 	uc->uc_entries[loc] = victim;
855 	uc->uc_fifo[uc->uc_nextvictim++] = victim;
856 	uc->uc_nextvictim %= uc->uc_size;
857 	(void) mutex_unlock(&dupreq_lock);
858 }
859 
860 /*
861  * Try to get an entry from the cache
862  * return 1 if found, 0 if not found and set the stage for cache_set()
863  */
864 static int
865 cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp,
866 							uint32_t *replylenp)
867 {
868 	SVCXPRT *parent;
869 	uint_t loc;
870 	cache_ptr ent;
871 	struct svc_dg_data *su;
872 	struct cl_cache *uc;
873 #ifdef RPC_CACHE_DEBUG
874 	struct netconfig *nconf;
875 	char *uaddr;
876 #endif
877 
878 /* LINTED pointer alignment */
879 	if (svc_mt_mode != RPC_SVC_MT_NONE && SVCEXT(xprt)->parent != NULL)
880 /* LINTED pointer alignment */
881 		parent = SVCEXT(xprt)->parent;
882 	else
883 		parent = xprt;
884 /* LINTED pointer alignment */
885 	su = get_svc_dg_data(xprt);
886 /* LINTED pointer alignment */
887 	uc = (struct cl_cache *)get_svc_dg_data(parent)->su_cache;
888 
889 	(void) mutex_lock(&dupreq_lock);
890 /* LINTED pointer alignment */
891 	loc = CACHE_LOC(parent, su->su_xid);
892 	for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
893 		if (ent->cache_xid == su->su_xid &&
894 		    ent->cache_proc == msg->rm_call.cb_proc &&
895 		    ent->cache_vers == msg->rm_call.cb_vers &&
896 		    ent->cache_prog == msg->rm_call.cb_prog &&
897 		    ent->cache_addr.len == xprt->xp_rtaddr.len &&
898 		    (memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
899 		    xprt->xp_rtaddr.len) == 0)) {
900 #ifdef RPC_CACHE_DEBUG
901 			if (nconf = getnetconfigent(xprt->xp_netid)) {
902 				uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
903 				freenetconfigent(nconf);
904 				printf(
905 	"cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
906 				    su->su_xid, msg->rm_call.cb_prog,
907 				    msg->rm_call.cb_vers,
908 				    msg->rm_call.cb_proc, uaddr);
909 				free(uaddr);
910 			}
911 #endif
912 			*replyp = ent->cache_reply;
913 			*replylenp = ent->cache_replylen;
914 			(void) mutex_unlock(&dupreq_lock);
915 			return (1);
916 		}
917 	}
918 	/*
919 	 * Failed to find entry
920 	 * Remember a few things so we can do a set later
921 	 */
922 	uc->uc_proc = msg->rm_call.cb_proc;
923 	uc->uc_vers = msg->rm_call.cb_vers;
924 	uc->uc_prog = msg->rm_call.cb_prog;
925 	(void) mutex_unlock(&dupreq_lock);
926 	return (0);
927 }
928