xref: /freebsd/lib/libc/rpc/svc_dg.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 2009, Sun Microsystems, Inc.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are met:
11  * - Redistributions of source code must retain the above copyright notice,
12  *   this list of conditions and the following disclaimer.
13  * - Redistributions in binary form must reproduce the above copyright notice,
14  *   this list of conditions and the following disclaimer in the documentation
15  *   and/or other materials provided with the distribution.
16  * - Neither the name of Sun Microsystems, Inc. nor the names of its
17  *   contributors may be used to endorse or promote products derived
18  *   from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
39 #endif
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 /*
44  * svc_dg.c, Server side for connectionless RPC.
45  *
46  * Does some caching in the hopes of achieving execute-at-most-once semantics.
47  */
48 
49 #include "namespace.h"
50 #include "reentrant.h"
51 #include <sys/types.h>
52 #include <sys/socket.h>
53 #include <rpc/rpc.h>
54 #include <rpc/svc_dg.h>
55 #include <assert.h>
56 #include <errno.h>
57 #include <unistd.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #ifdef RPC_CACHE_DEBUG
62 #include <netconfig.h>
63 #include <netdir.h>
64 #endif
65 #include <err.h>
66 #include "un-namespace.h"
67 
68 #include "rpc_com.h"
69 #include "mt_misc.h"
70 
71 #define	su_data(xprt)	((struct svc_dg_data *)((xprt)->xp_p2))
72 #define	rpc_buffer(xprt) ((xprt)->xp_p1)
73 
74 #ifndef MAX
75 #define	MAX(a, b)	(((a) > (b)) ? (a) : (b))
76 #endif
77 
78 static void svc_dg_ops(SVCXPRT *);
79 static enum xprt_stat svc_dg_stat(SVCXPRT *);
80 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *);
81 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *);
82 static bool_t svc_dg_getargs(SVCXPRT *, xdrproc_t, void *);
83 static bool_t svc_dg_freeargs(SVCXPRT *, xdrproc_t, void *);
84 static void svc_dg_destroy(SVCXPRT *);
85 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
86 static int cache_get(SVCXPRT *, struct rpc_msg *, char **, size_t *);
87 static void cache_set(SVCXPRT *, size_t);
88 int svc_dg_enablecache(SVCXPRT *, u_int);
89 
90 /*
91  * Usage:
92  *	xprt = svc_dg_create(sock, sendsize, recvsize);
93  * Does other connectionless specific initializations.
94  * Once *xprt is initialized, it is registered.
95  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
96  * system defaults are chosen.
97  * The routines returns NULL if a problem occurred.
98  */
99 static const char svc_dg_str[] = "svc_dg_create: %s";
100 static const char svc_dg_err1[] = "could not get transport information";
101 static const char svc_dg_err2[] = "transport does not support data transfer";
102 static const char svc_dg_err3[] = "getsockname failed";
103 static const char svc_dg_err4[] = "cannot set IP_RECVDSTADDR";
104 static const char __no_mem_str[] = "out of memory";
105 
106 SVCXPRT *
107 svc_dg_create(int fd, u_int sendsize, u_int recvsize)
108 {
109 	SVCXPRT *xprt;
110 	struct svc_dg_data *su = NULL;
111 	struct __rpc_sockinfo si;
112 	struct sockaddr_storage ss;
113 	socklen_t slen;
114 
115 	if (!__rpc_fd2sockinfo(fd, &si)) {
116 		warnx(svc_dg_str, svc_dg_err1);
117 		return (NULL);
118 	}
119 	/*
120 	 * Find the receive and the send size
121 	 */
122 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
123 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
124 	if ((sendsize == 0) || (recvsize == 0)) {
125 		warnx(svc_dg_str, svc_dg_err2);
126 		return (NULL);
127 	}
128 
129 	xprt = svc_xprt_alloc();
130 	if (xprt == NULL)
131 		goto freedata;
132 
133 	su = mem_alloc(sizeof (*su));
134 	if (su == NULL)
135 		goto freedata;
136 	su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
137 	if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL)
138 		goto freedata;
139 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
140 		XDR_DECODE);
141 	su->su_cache = NULL;
142 	xprt->xp_fd = fd;
143 	xprt->xp_p2 = su;
144 	xprt->xp_verf.oa_base = su->su_verfbody;
145 	svc_dg_ops(xprt);
146 	xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
147 
148 	slen = sizeof ss;
149 	if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0) {
150 		warnx(svc_dg_str, svc_dg_err3);
151 		goto freedata_nowarn;
152 	}
153 	xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
154 	xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
155 	xprt->xp_ltaddr.len = slen;
156 	memcpy(xprt->xp_ltaddr.buf, &ss, slen);
157 
158 	if (ss.ss_family == AF_INET) {
159 		struct sockaddr_in *sin;
160 		static const int true_value = 1;
161 
162 		sin = (struct sockaddr_in *)(void *)&ss;
163 		if (sin->sin_addr.s_addr == INADDR_ANY) {
164 		    su->su_srcaddr.buf = mem_alloc(sizeof (ss));
165 		    su->su_srcaddr.maxlen = sizeof (ss);
166 
167 		    if (_setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR,
168 				    &true_value, sizeof(true_value))) {
169 			    warnx(svc_dg_str,  svc_dg_err4);
170 			    goto freedata_nowarn;
171 		    }
172 		}
173 	}
174 
175 	xprt_register(xprt);
176 	return (xprt);
177 freedata:
178 	(void) warnx(svc_dg_str, __no_mem_str);
179 freedata_nowarn:
180 	if (xprt) {
181 		if (su)
182 			(void) mem_free(su, sizeof (*su));
183 		svc_xprt_free(xprt);
184 	}
185 	return (NULL);
186 }
187 
188 /*ARGSUSED*/
189 static enum xprt_stat
190 svc_dg_stat(SVCXPRT *xprt)
191 {
192 	return (XPRT_IDLE);
193 }
194 
195 static int
196 svc_dg_recvfrom(int fd, char *buf, int buflen,
197     struct sockaddr *raddr, socklen_t *raddrlen,
198     struct sockaddr *laddr, socklen_t *laddrlen)
199 {
200 	struct msghdr msg;
201 	struct iovec msg_iov[1];
202 	struct sockaddr_in *lin = (struct sockaddr_in *)laddr;
203 	int rlen;
204 	bool_t have_lin = FALSE;
205 	char tmp[CMSG_LEN(sizeof(*lin))];
206 	struct cmsghdr *cmsg;
207 
208 	memset((char *)&msg, 0, sizeof(msg));
209 	msg_iov[0].iov_base = buf;
210 	msg_iov[0].iov_len = buflen;
211 	msg.msg_iov = msg_iov;
212 	msg.msg_iovlen = 1;
213 	msg.msg_namelen = *raddrlen;
214 	msg.msg_name = (char *)raddr;
215 	if (laddr != NULL) {
216 	    msg.msg_control = (caddr_t)tmp;
217 	    msg.msg_controllen = CMSG_LEN(sizeof(*lin));
218 	}
219 	rlen = _recvmsg(fd, &msg, 0);
220 	if (rlen >= 0)
221 		*raddrlen = msg.msg_namelen;
222 
223 	if (rlen == -1 || laddr == NULL ||
224 	    msg.msg_controllen < sizeof(struct cmsghdr) ||
225 	    msg.msg_flags & MSG_CTRUNC)
226 		return rlen;
227 
228 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
229 	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
230 		if (cmsg->cmsg_level == IPPROTO_IP &&
231 		    cmsg->cmsg_type == IP_RECVDSTADDR) {
232 			have_lin = TRUE;
233 			memcpy(&lin->sin_addr,
234 			    (struct in_addr *)CMSG_DATA(cmsg),
235 			    sizeof(struct in_addr));
236 			break;
237 		}
238 	}
239 
240 	lin->sin_family = AF_INET;
241 	lin->sin_port = 0;
242 	*laddrlen = sizeof(struct sockaddr_in);
243 
244 	if (!have_lin)
245 		lin->sin_addr.s_addr = INADDR_ANY;
246 
247 	return rlen;
248 }
249 
250 static bool_t
251 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg)
252 {
253 	struct svc_dg_data *su = su_data(xprt);
254 	XDR *xdrs = &(su->su_xdrs);
255 	char *reply;
256 	struct sockaddr_storage ss;
257 	socklen_t alen;
258 	size_t replylen;
259 	ssize_t rlen;
260 
261 again:
262 	alen = sizeof (struct sockaddr_storage);
263 	rlen = svc_dg_recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz,
264 	    (struct sockaddr *)(void *)&ss, &alen,
265 	    (struct sockaddr *)su->su_srcaddr.buf, &su->su_srcaddr.len);
266 	if (rlen == -1 && errno == EINTR)
267 		goto again;
268 	if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
269 		return (FALSE);
270 	if (xprt->xp_rtaddr.len < alen) {
271 		if (xprt->xp_rtaddr.len != 0)
272 			mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
273 		xprt->xp_rtaddr.buf = mem_alloc(alen);
274 		xprt->xp_rtaddr.len = alen;
275 	}
276 	memcpy(xprt->xp_rtaddr.buf, &ss, alen);
277 #ifdef PORTMAP
278 	if (ss.ss_family == AF_INET) {
279 		xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
280 		xprt->xp_addrlen = sizeof (struct sockaddr_in);
281 	}
282 #endif				/* PORTMAP */
283 	xdrs->x_op = XDR_DECODE;
284 	XDR_SETPOS(xdrs, 0);
285 	if (! xdr_callmsg(xdrs, msg)) {
286 		return (FALSE);
287 	}
288 	su->su_xid = msg->rm_xid;
289 	if (su->su_cache != NULL) {
290 		if (cache_get(xprt, msg, &reply, &replylen)) {
291 			(void)_sendto(xprt->xp_fd, reply, replylen, 0,
292 			    (struct sockaddr *)(void *)&ss, alen);
293 			return (FALSE);
294 		}
295 	}
296 	return (TRUE);
297 }
298 
299 static int
300 svc_dg_sendto(int fd, char *buf, int buflen,
301     const struct sockaddr *raddr, socklen_t raddrlen,
302     const struct sockaddr *laddr, socklen_t laddrlen)
303 {
304 	struct msghdr msg;
305 	struct iovec msg_iov[1];
306 	struct sockaddr_in *laddr_in = (struct sockaddr_in *)laddr;
307 	struct in_addr *lin = &laddr_in->sin_addr;
308 	char tmp[CMSG_SPACE(sizeof(*lin))];
309 	struct cmsghdr *cmsg;
310 
311 	memset((char *)&msg, 0, sizeof(msg));
312 	msg_iov[0].iov_base = buf;
313 	msg_iov[0].iov_len = buflen;
314 	msg.msg_iov = msg_iov;
315 	msg.msg_iovlen = 1;
316 	msg.msg_namelen = raddrlen;
317 	msg.msg_name = (char *)raddr;
318 
319 	if (laddr != NULL && laddr->sa_family == AF_INET &&
320 	    lin->s_addr != INADDR_ANY) {
321 		msg.msg_control = (caddr_t)tmp;
322 		msg.msg_controllen = CMSG_LEN(sizeof(*lin));
323 		cmsg = CMSG_FIRSTHDR(&msg);
324 		cmsg->cmsg_len = CMSG_LEN(sizeof(*lin));
325 		cmsg->cmsg_level = IPPROTO_IP;
326 		cmsg->cmsg_type = IP_SENDSRCADDR;
327 		memcpy(CMSG_DATA(cmsg), lin, sizeof(*lin));
328 	}
329 
330 	return _sendmsg(fd, &msg, 0);
331 }
332 
333 static bool_t
334 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg)
335 {
336 	struct svc_dg_data *su = su_data(xprt);
337 	XDR *xdrs = &(su->su_xdrs);
338 	bool_t stat = TRUE;
339 	size_t slen;
340 	xdrproc_t xdr_proc;
341 	caddr_t xdr_where;
342 
343 	xdrs->x_op = XDR_ENCODE;
344 	XDR_SETPOS(xdrs, 0);
345 	msg->rm_xid = su->su_xid;
346 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
347 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
348 		xdr_proc = msg->acpted_rply.ar_results.proc;
349 		xdr_where = msg->acpted_rply.ar_results.where;
350 		msg->acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;
351 		msg->acpted_rply.ar_results.where = NULL;
352 
353 		if (!xdr_replymsg(xdrs, msg) ||
354 		    !SVCAUTH_WRAP(&SVC_AUTH(xprt), xdrs, xdr_proc, xdr_where))
355 			stat = FALSE;
356 	} else {
357 		stat = xdr_replymsg(xdrs, msg);
358 	}
359 	if (stat) {
360 		slen = XDR_GETPOS(xdrs);
361 		if (svc_dg_sendto(xprt->xp_fd, rpc_buffer(xprt), slen,
362 		    (struct sockaddr *)xprt->xp_rtaddr.buf,
363 		    (socklen_t)xprt->xp_rtaddr.len,
364 		    (struct sockaddr *)su->su_srcaddr.buf,
365 		    (socklen_t)su->su_srcaddr.len) == (ssize_t) slen) {
366 			stat = TRUE;
367 			if (su->su_cache)
368 				cache_set(xprt, slen);
369 		}
370 	}
371 	return (stat);
372 }
373 
374 static bool_t
375 svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
376 {
377 	struct svc_dg_data *su;
378 
379 	assert(xprt != NULL);
380 	su = su_data(xprt);
381 	return (SVCAUTH_UNWRAP(&SVC_AUTH(xprt),
382 		&su->su_xdrs, xdr_args, args_ptr));
383 }
384 
385 static bool_t
386 svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
387 {
388 	XDR *xdrs = &(su_data(xprt)->su_xdrs);
389 
390 	xdrs->x_op = XDR_FREE;
391 	return (*xdr_args)(xdrs, args_ptr);
392 }
393 
394 static void
395 svc_dg_destroy(SVCXPRT *xprt)
396 {
397 	struct svc_dg_data *su = su_data(xprt);
398 
399 	xprt_unregister(xprt);
400 	if (xprt->xp_fd != -1)
401 		(void)_close(xprt->xp_fd);
402 	XDR_DESTROY(&(su->su_xdrs));
403 	(void) mem_free(rpc_buffer(xprt), su->su_iosz);
404 	if (su->su_srcaddr.buf)
405 		(void) mem_free(su->su_srcaddr.buf, su->su_srcaddr.maxlen);
406 	(void) mem_free(su, sizeof (*su));
407 	if (xprt->xp_rtaddr.buf)
408 		(void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
409 	if (xprt->xp_ltaddr.buf)
410 		(void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
411 	free(xprt->xp_tp);
412 	svc_xprt_free(xprt);
413 }
414 
415 static bool_t
416 /*ARGSUSED*/
417 svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in)
418 {
419 	return (FALSE);
420 }
421 
422 static void
423 svc_dg_ops(SVCXPRT *xprt)
424 {
425 	static struct xp_ops ops;
426 	static struct xp_ops2 ops2;
427 
428 /* VARIABLES PROTECTED BY ops_lock: ops */
429 
430 	mutex_lock(&ops_lock);
431 	if (ops.xp_recv == NULL) {
432 		ops.xp_recv = svc_dg_recv;
433 		ops.xp_stat = svc_dg_stat;
434 		ops.xp_getargs = svc_dg_getargs;
435 		ops.xp_reply = svc_dg_reply;
436 		ops.xp_freeargs = svc_dg_freeargs;
437 		ops.xp_destroy = svc_dg_destroy;
438 		ops2.xp_control = svc_dg_control;
439 	}
440 	xprt->xp_ops = &ops;
441 	xprt->xp_ops2 = &ops2;
442 	mutex_unlock(&ops_lock);
443 }
444 
445 /*  The CACHING COMPONENT */
446 
447 /*
448  * Could have been a separate file, but some part of it depends upon the
449  * private structure of the client handle.
450  *
451  * Fifo cache for cl server
452  * Copies pointers to reply buffers into fifo cache
453  * Buffers are sent again if retransmissions are detected.
454  */
455 
456 #define	SPARSENESS 4	/* 75% sparse */
457 
458 #define	ALLOC(type, size)	\
459 	(type *) mem_alloc((sizeof (type) * (size)))
460 
461 #define	MEMZERO(addr, type, size)	 \
462 	(void) memset((void *) (addr), 0, sizeof (type) * (int) (size))
463 
464 #define	FREE(addr, type, size)	\
465 	mem_free((addr), (sizeof (type) * (size)))
466 
467 /*
468  * An entry in the cache
469  */
470 typedef struct cache_node *cache_ptr;
471 struct cache_node {
472 	/*
473 	 * Index into cache is xid, proc, vers, prog and address
474 	 */
475 	u_int32_t cache_xid;
476 	rpcproc_t cache_proc;
477 	rpcvers_t cache_vers;
478 	rpcprog_t cache_prog;
479 	struct netbuf cache_addr;
480 	/*
481 	 * The cached reply and length
482 	 */
483 	char *cache_reply;
484 	size_t cache_replylen;
485 	/*
486 	 * Next node on the list, if there is a collision
487 	 */
488 	cache_ptr cache_next;
489 };
490 
491 /*
492  * The entire cache
493  */
494 struct cl_cache {
495 	u_int uc_size;		/* size of cache */
496 	cache_ptr *uc_entries;	/* hash table of entries in cache */
497 	cache_ptr *uc_fifo;	/* fifo list of entries in cache */
498 	u_int uc_nextvictim;	/* points to next victim in fifo list */
499 	rpcprog_t uc_prog;	/* saved program number */
500 	rpcvers_t uc_vers;	/* saved version number */
501 	rpcproc_t uc_proc;	/* saved procedure number */
502 };
503 
504 
505 /*
506  * the hashing function
507  */
508 #define	CACHE_LOC(transp, xid)	\
509 	(xid % (SPARSENESS * ((struct cl_cache *) \
510 		su_data(transp)->su_cache)->uc_size))
511 
512 /*
513  * Enable use of the cache. Returns 1 on success, 0 on failure.
514  * Note: there is no disable.
515  */
516 static const char cache_enable_str[] = "svc_enablecache: %s %s";
517 static const char alloc_err[] = "could not allocate cache ";
518 static const char enable_err[] = "cache already enabled";
519 
520 int
521 svc_dg_enablecache(SVCXPRT *transp, u_int size)
522 {
523 	struct svc_dg_data *su = su_data(transp);
524 	struct cl_cache *uc;
525 
526 	mutex_lock(&dupreq_lock);
527 	if (su->su_cache != NULL) {
528 		(void) warnx(cache_enable_str, enable_err, " ");
529 		mutex_unlock(&dupreq_lock);
530 		return (0);
531 	}
532 	uc = ALLOC(struct cl_cache, 1);
533 	if (uc == NULL) {
534 		warnx(cache_enable_str, alloc_err, " ");
535 		mutex_unlock(&dupreq_lock);
536 		return (0);
537 	}
538 	uc->uc_size = size;
539 	uc->uc_nextvictim = 0;
540 	uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
541 	if (uc->uc_entries == NULL) {
542 		warnx(cache_enable_str, alloc_err, "data");
543 		FREE(uc, struct cl_cache, 1);
544 		mutex_unlock(&dupreq_lock);
545 		return (0);
546 	}
547 	MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
548 	uc->uc_fifo = ALLOC(cache_ptr, size);
549 	if (uc->uc_fifo == NULL) {
550 		warnx(cache_enable_str, alloc_err, "fifo");
551 		FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
552 		FREE(uc, struct cl_cache, 1);
553 		mutex_unlock(&dupreq_lock);
554 		return (0);
555 	}
556 	MEMZERO(uc->uc_fifo, cache_ptr, size);
557 	su->su_cache = (char *)(void *)uc;
558 	mutex_unlock(&dupreq_lock);
559 	return (1);
560 }
561 
562 /*
563  * Set an entry in the cache.  It assumes that the uc entry is set from
564  * the earlier call to cache_get() for the same procedure.  This will always
565  * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
566  * by svc_dg_reply().  All this hoopla because the right RPC parameters are
567  * not available at svc_dg_reply time.
568  */
569 
570 static const char cache_set_str[] = "cache_set: %s";
571 static const char cache_set_err1[] = "victim not found";
572 static const char cache_set_err2[] = "victim alloc failed";
573 static const char cache_set_err3[] = "could not allocate new rpc buffer";
574 
575 static void
576 cache_set(SVCXPRT *xprt, size_t replylen)
577 {
578 	cache_ptr victim;
579 	cache_ptr *vicp;
580 	struct svc_dg_data *su = su_data(xprt);
581 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
582 	u_int loc;
583 	char *newbuf;
584 #ifdef RPC_CACHE_DEBUG
585 	struct netconfig *nconf;
586 	char *uaddr;
587 #endif
588 
589 	mutex_lock(&dupreq_lock);
590 	/*
591 	 * Find space for the new entry, either by
592 	 * reusing an old entry, or by mallocing a new one
593 	 */
594 	victim = uc->uc_fifo[uc->uc_nextvictim];
595 	if (victim != NULL) {
596 		loc = CACHE_LOC(xprt, victim->cache_xid);
597 		for (vicp = &uc->uc_entries[loc];
598 			*vicp != NULL && *vicp != victim;
599 			vicp = &(*vicp)->cache_next)
600 			;
601 		if (*vicp == NULL) {
602 			warnx(cache_set_str, cache_set_err1);
603 			mutex_unlock(&dupreq_lock);
604 			return;
605 		}
606 		*vicp = victim->cache_next;	/* remove from cache */
607 		newbuf = victim->cache_reply;
608 	} else {
609 		victim = ALLOC(struct cache_node, 1);
610 		if (victim == NULL) {
611 			warnx(cache_set_str, cache_set_err2);
612 			mutex_unlock(&dupreq_lock);
613 			return;
614 		}
615 		newbuf = mem_alloc(su->su_iosz);
616 		if (newbuf == NULL) {
617 			warnx(cache_set_str, cache_set_err3);
618 			FREE(victim, struct cache_node, 1);
619 			mutex_unlock(&dupreq_lock);
620 			return;
621 		}
622 	}
623 
624 	/*
625 	 * Store it away
626 	 */
627 #ifdef RPC_CACHE_DEBUG
628 	if (nconf = getnetconfigent(xprt->xp_netid)) {
629 		uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
630 		freenetconfigent(nconf);
631 		printf(
632 	"cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
633 			su->su_xid, uc->uc_prog, uc->uc_vers,
634 			uc->uc_proc, uaddr);
635 		free(uaddr);
636 	}
637 #endif
638 	victim->cache_replylen = replylen;
639 	victim->cache_reply = rpc_buffer(xprt);
640 	rpc_buffer(xprt) = newbuf;
641 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
642 			su->su_iosz, XDR_ENCODE);
643 	victim->cache_xid = su->su_xid;
644 	victim->cache_proc = uc->uc_proc;
645 	victim->cache_vers = uc->uc_vers;
646 	victim->cache_prog = uc->uc_prog;
647 	victim->cache_addr = xprt->xp_rtaddr;
648 	victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
649 	(void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
650 	    (size_t)xprt->xp_rtaddr.len);
651 	loc = CACHE_LOC(xprt, victim->cache_xid);
652 	victim->cache_next = uc->uc_entries[loc];
653 	uc->uc_entries[loc] = victim;
654 	uc->uc_fifo[uc->uc_nextvictim++] = victim;
655 	uc->uc_nextvictim %= uc->uc_size;
656 	mutex_unlock(&dupreq_lock);
657 }
658 
659 /*
660  * Try to get an entry from the cache
661  * return 1 if found, 0 if not found and set the stage for cache_set()
662  */
663 static int
664 cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp, size_t *replylenp)
665 {
666 	u_int loc;
667 	cache_ptr ent;
668 	struct svc_dg_data *su = su_data(xprt);
669 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
670 #ifdef RPC_CACHE_DEBUG
671 	struct netconfig *nconf;
672 	char *uaddr;
673 #endif
674 
675 	mutex_lock(&dupreq_lock);
676 	loc = CACHE_LOC(xprt, su->su_xid);
677 	for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
678 		if (ent->cache_xid == su->su_xid &&
679 			ent->cache_proc == msg->rm_call.cb_proc &&
680 			ent->cache_vers == msg->rm_call.cb_vers &&
681 			ent->cache_prog == msg->rm_call.cb_prog &&
682 			ent->cache_addr.len == xprt->xp_rtaddr.len &&
683 			(memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
684 				xprt->xp_rtaddr.len) == 0)) {
685 #ifdef RPC_CACHE_DEBUG
686 			if (nconf = getnetconfigent(xprt->xp_netid)) {
687 				uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
688 				freenetconfigent(nconf);
689 				printf(
690 	"cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
691 					su->su_xid, msg->rm_call.cb_prog,
692 					msg->rm_call.cb_vers,
693 					msg->rm_call.cb_proc, uaddr);
694 				free(uaddr);
695 			}
696 #endif
697 			*replyp = ent->cache_reply;
698 			*replylenp = ent->cache_replylen;
699 			mutex_unlock(&dupreq_lock);
700 			return (1);
701 		}
702 	}
703 	/*
704 	 * Failed to find entry
705 	 * Remember a few things so we can do a set later
706 	 */
707 	uc->uc_proc = msg->rm_call.cb_proc;
708 	uc->uc_vers = msg->rm_call.cb_vers;
709 	uc->uc_prog = msg->rm_call.cb_prog;
710 	mutex_unlock(&dupreq_lock);
711 	return (0);
712 }
713