xref: /freebsd/lib/libc/rpc/svc_dg.c (revision 5b31cc94b10d4bb7109c6b27940a0fc76a44a331)
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 #endif
39 /*
40  * svc_dg.c, Server side for connectionless RPC.
41  *
42  * Does some caching in the hopes of achieving execute-at-most-once semantics.
43  */
44 
45 #include "namespace.h"
46 #include "reentrant.h"
47 #include <sys/types.h>
48 #include <sys/socket.h>
49 #include <rpc/rpc.h>
50 #include <rpc/svc_dg.h>
51 #include <assert.h>
52 #include <errno.h>
53 #include <unistd.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #ifdef RPC_CACHE_DEBUG
58 #include <netconfig.h>
59 #include <netdir.h>
60 #endif
61 #include <err.h>
62 #include "un-namespace.h"
63 
64 #include "rpc_com.h"
65 #include "mt_misc.h"
66 
67 #define	su_data(xprt)	((struct svc_dg_data *)((xprt)->xp_p2))
68 #define	rpc_buffer(xprt) ((xprt)->xp_p1)
69 
70 #ifndef MAX
71 #define	MAX(a, b)	(((a) > (b)) ? (a) : (b))
72 #endif
73 
74 static void svc_dg_ops(SVCXPRT *);
75 static enum xprt_stat svc_dg_stat(SVCXPRT *);
76 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *);
77 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *);
78 static bool_t svc_dg_getargs(SVCXPRT *, xdrproc_t, void *);
79 static bool_t svc_dg_freeargs(SVCXPRT *, xdrproc_t, void *);
80 static void svc_dg_destroy(SVCXPRT *);
81 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
82 static int cache_get(SVCXPRT *, struct rpc_msg *, char **, size_t *);
83 static void cache_set(SVCXPRT *, size_t);
84 int svc_dg_enablecache(SVCXPRT *, u_int);
85 
86 /*
87  * Usage:
88  *	xprt = svc_dg_create(sock, sendsize, recvsize);
89  * Does other connectionless specific initializations.
90  * Once *xprt is initialized, it is registered.
91  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
92  * system defaults are chosen.
93  * The routines returns NULL if a problem occurred.
94  */
95 static const char svc_dg_str[] = "svc_dg_create: %s";
96 static const char svc_dg_err1[] = "could not get transport information";
97 static const char svc_dg_err2[] = "transport does not support data transfer";
98 static const char svc_dg_err3[] = "getsockname failed";
99 static const char svc_dg_err4[] = "cannot set IP_RECVDSTADDR";
100 static const char __no_mem_str[] = "out of memory";
101 
102 SVCXPRT *
103 svc_dg_create(int fd, u_int sendsize, u_int recvsize)
104 {
105 	SVCXPRT *xprt;
106 	struct svc_dg_data *su = NULL;
107 	struct __rpc_sockinfo si;
108 	struct sockaddr_storage ss;
109 	socklen_t slen;
110 
111 	if (!__rpc_fd2sockinfo(fd, &si)) {
112 		warnx(svc_dg_str, svc_dg_err1);
113 		return (NULL);
114 	}
115 	/*
116 	 * Find the receive and the send size
117 	 */
118 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
119 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
120 	if ((sendsize == 0) || (recvsize == 0)) {
121 		warnx(svc_dg_str, svc_dg_err2);
122 		return (NULL);
123 	}
124 
125 	xprt = svc_xprt_alloc();
126 	if (xprt == NULL)
127 		goto freedata;
128 
129 	su = mem_alloc(sizeof (*su));
130 	if (su == NULL)
131 		goto freedata;
132 	su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
133 	if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL)
134 		goto freedata;
135 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
136 		XDR_DECODE);
137 	su->su_cache = NULL;
138 	xprt->xp_fd = fd;
139 	xprt->xp_p2 = su;
140 	xprt->xp_verf.oa_base = su->su_verfbody;
141 	svc_dg_ops(xprt);
142 	xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
143 
144 	slen = sizeof ss;
145 	if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0) {
146 		warnx(svc_dg_str, svc_dg_err3);
147 		goto freedata_nowarn;
148 	}
149 	xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
150 	xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
151 	xprt->xp_ltaddr.len = slen;
152 	memcpy(xprt->xp_ltaddr.buf, &ss, slen);
153 
154 	if (ss.ss_family == AF_INET) {
155 		struct sockaddr_in *sin;
156 		static const int true_value = 1;
157 
158 		sin = (struct sockaddr_in *)(void *)&ss;
159 		if (sin->sin_addr.s_addr == INADDR_ANY) {
160 		    su->su_srcaddr.buf = mem_alloc(sizeof (ss));
161 		    su->su_srcaddr.maxlen = sizeof (ss);
162 
163 		    if (_setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR,
164 				    &true_value, sizeof(true_value))) {
165 			    warnx(svc_dg_str,  svc_dg_err4);
166 			    goto freedata_nowarn;
167 		    }
168 		}
169 	}
170 
171 	xprt_register(xprt);
172 	return (xprt);
173 freedata:
174 	(void) warnx(svc_dg_str, __no_mem_str);
175 freedata_nowarn:
176 	if (xprt) {
177 		if (su)
178 			(void) mem_free(su, sizeof (*su));
179 		svc_xprt_free(xprt);
180 	}
181 	return (NULL);
182 }
183 
184 /*ARGSUSED*/
185 static enum xprt_stat
186 svc_dg_stat(SVCXPRT *xprt)
187 {
188 	return (XPRT_IDLE);
189 }
190 
191 static int
192 svc_dg_recvfrom(int fd, char *buf, int buflen,
193     struct sockaddr *raddr, socklen_t *raddrlen,
194     struct sockaddr *laddr, socklen_t *laddrlen)
195 {
196 	struct msghdr msg;
197 	struct iovec msg_iov[1];
198 	struct sockaddr_in *lin = (struct sockaddr_in *)laddr;
199 	int rlen;
200 	bool_t have_lin = FALSE;
201 	char tmp[CMSG_LEN(sizeof(*lin))];
202 	struct cmsghdr *cmsg;
203 
204 	memset((char *)&msg, 0, sizeof(msg));
205 	msg_iov[0].iov_base = buf;
206 	msg_iov[0].iov_len = buflen;
207 	msg.msg_iov = msg_iov;
208 	msg.msg_iovlen = 1;
209 	msg.msg_namelen = *raddrlen;
210 	msg.msg_name = (char *)raddr;
211 	if (laddr != NULL) {
212 	    msg.msg_control = (caddr_t)tmp;
213 	    msg.msg_controllen = CMSG_LEN(sizeof(*lin));
214 	}
215 	rlen = _recvmsg(fd, &msg, 0);
216 	if (rlen >= 0)
217 		*raddrlen = msg.msg_namelen;
218 
219 	if (rlen == -1 || laddr == NULL ||
220 	    msg.msg_controllen < sizeof(struct cmsghdr) ||
221 	    msg.msg_flags & MSG_CTRUNC)
222 		return rlen;
223 
224 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
225 	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
226 		if (cmsg->cmsg_level == IPPROTO_IP &&
227 		    cmsg->cmsg_type == IP_RECVDSTADDR) {
228 			have_lin = TRUE;
229 			memcpy(&lin->sin_addr,
230 			    (struct in_addr *)CMSG_DATA(cmsg),
231 			    sizeof(struct in_addr));
232 			break;
233 		}
234 	}
235 
236 	lin->sin_family = AF_INET;
237 	lin->sin_port = 0;
238 	*laddrlen = sizeof(struct sockaddr_in);
239 
240 	if (!have_lin)
241 		lin->sin_addr.s_addr = INADDR_ANY;
242 
243 	return rlen;
244 }
245 
246 static bool_t
247 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg)
248 {
249 	struct svc_dg_data *su = su_data(xprt);
250 	XDR *xdrs = &(su->su_xdrs);
251 	char *reply;
252 	struct sockaddr_storage ss;
253 	socklen_t alen;
254 	size_t replylen;
255 	ssize_t rlen;
256 
257 again:
258 	alen = sizeof (struct sockaddr_storage);
259 	rlen = svc_dg_recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz,
260 	    (struct sockaddr *)(void *)&ss, &alen,
261 	    (struct sockaddr *)su->su_srcaddr.buf, &su->su_srcaddr.len);
262 	if (rlen == -1 && errno == EINTR)
263 		goto again;
264 	if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
265 		return (FALSE);
266 	if (xprt->xp_rtaddr.len < alen) {
267 		if (xprt->xp_rtaddr.len != 0)
268 			mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
269 		xprt->xp_rtaddr.buf = mem_alloc(alen);
270 		xprt->xp_rtaddr.len = alen;
271 	}
272 	memcpy(xprt->xp_rtaddr.buf, &ss, alen);
273 #ifdef PORTMAP
274 	if (ss.ss_family == AF_INET) {
275 		xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
276 		xprt->xp_addrlen = sizeof (struct sockaddr_in);
277 	}
278 #endif				/* PORTMAP */
279 	xdrs->x_op = XDR_DECODE;
280 	XDR_SETPOS(xdrs, 0);
281 	if (! xdr_callmsg(xdrs, msg)) {
282 		return (FALSE);
283 	}
284 	su->su_xid = msg->rm_xid;
285 	if (su->su_cache != NULL) {
286 		if (cache_get(xprt, msg, &reply, &replylen)) {
287 			(void)_sendto(xprt->xp_fd, reply, replylen, 0,
288 			    (struct sockaddr *)(void *)&ss, alen);
289 			return (FALSE);
290 		}
291 	}
292 	return (TRUE);
293 }
294 
295 static int
296 svc_dg_sendto(int fd, char *buf, int buflen,
297     const struct sockaddr *raddr, socklen_t raddrlen,
298     const struct sockaddr *laddr, socklen_t laddrlen)
299 {
300 	struct msghdr msg;
301 	struct iovec msg_iov[1];
302 	struct sockaddr_in *laddr_in = (struct sockaddr_in *)laddr;
303 	struct in_addr *lin = &laddr_in->sin_addr;
304 	char tmp[CMSG_SPACE(sizeof(*lin))];
305 	struct cmsghdr *cmsg;
306 
307 	memset((char *)&msg, 0, sizeof(msg));
308 	msg_iov[0].iov_base = buf;
309 	msg_iov[0].iov_len = buflen;
310 	msg.msg_iov = msg_iov;
311 	msg.msg_iovlen = 1;
312 	msg.msg_namelen = raddrlen;
313 	msg.msg_name = (char *)raddr;
314 
315 	if (laddr != NULL && laddr->sa_family == AF_INET &&
316 	    lin->s_addr != INADDR_ANY) {
317 		msg.msg_control = (caddr_t)tmp;
318 		msg.msg_controllen = CMSG_LEN(sizeof(*lin));
319 		cmsg = CMSG_FIRSTHDR(&msg);
320 		cmsg->cmsg_len = CMSG_LEN(sizeof(*lin));
321 		cmsg->cmsg_level = IPPROTO_IP;
322 		cmsg->cmsg_type = IP_SENDSRCADDR;
323 		memcpy(CMSG_DATA(cmsg), lin, sizeof(*lin));
324 	}
325 
326 	return _sendmsg(fd, &msg, 0);
327 }
328 
329 static bool_t
330 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg)
331 {
332 	struct svc_dg_data *su = su_data(xprt);
333 	XDR *xdrs = &(su->su_xdrs);
334 	bool_t stat = TRUE;
335 	size_t slen;
336 	xdrproc_t xdr_proc;
337 	caddr_t xdr_where;
338 
339 	xdrs->x_op = XDR_ENCODE;
340 	XDR_SETPOS(xdrs, 0);
341 	msg->rm_xid = su->su_xid;
342 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
343 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
344 		xdr_proc = msg->acpted_rply.ar_results.proc;
345 		xdr_where = msg->acpted_rply.ar_results.where;
346 		msg->acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;
347 		msg->acpted_rply.ar_results.where = NULL;
348 
349 		if (!xdr_replymsg(xdrs, msg) ||
350 		    !SVCAUTH_WRAP(&SVC_AUTH(xprt), xdrs, xdr_proc, xdr_where))
351 			stat = FALSE;
352 	} else {
353 		stat = xdr_replymsg(xdrs, msg);
354 	}
355 	if (stat) {
356 		slen = XDR_GETPOS(xdrs);
357 		if (svc_dg_sendto(xprt->xp_fd, rpc_buffer(xprt), slen,
358 		    (struct sockaddr *)xprt->xp_rtaddr.buf,
359 		    (socklen_t)xprt->xp_rtaddr.len,
360 		    (struct sockaddr *)su->su_srcaddr.buf,
361 		    (socklen_t)su->su_srcaddr.len) == (ssize_t) slen) {
362 			stat = TRUE;
363 			if (su->su_cache)
364 				cache_set(xprt, slen);
365 		}
366 	}
367 	return (stat);
368 }
369 
370 static bool_t
371 svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
372 {
373 	struct svc_dg_data *su;
374 
375 	assert(xprt != NULL);
376 	su = su_data(xprt);
377 	return (SVCAUTH_UNWRAP(&SVC_AUTH(xprt),
378 		&su->su_xdrs, xdr_args, args_ptr));
379 }
380 
381 static bool_t
382 svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
383 {
384 	XDR *xdrs = &(su_data(xprt)->su_xdrs);
385 
386 	xdrs->x_op = XDR_FREE;
387 	return (*xdr_args)(xdrs, args_ptr);
388 }
389 
390 static void
391 svc_dg_destroy(SVCXPRT *xprt)
392 {
393 	struct svc_dg_data *su = su_data(xprt);
394 
395 	xprt_unregister(xprt);
396 	if (xprt->xp_fd != -1)
397 		(void)_close(xprt->xp_fd);
398 	XDR_DESTROY(&(su->su_xdrs));
399 	(void) mem_free(rpc_buffer(xprt), su->su_iosz);
400 	if (su->su_srcaddr.buf)
401 		(void) mem_free(su->su_srcaddr.buf, su->su_srcaddr.maxlen);
402 	(void) mem_free(su, sizeof (*su));
403 	if (xprt->xp_rtaddr.buf)
404 		(void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
405 	if (xprt->xp_ltaddr.buf)
406 		(void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
407 	free(xprt->xp_tp);
408 	svc_xprt_free(xprt);
409 }
410 
411 static bool_t
412 /*ARGSUSED*/
413 svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in)
414 {
415 	return (FALSE);
416 }
417 
418 static void
419 svc_dg_ops(SVCXPRT *xprt)
420 {
421 	static struct xp_ops ops;
422 	static struct xp_ops2 ops2;
423 
424 /* VARIABLES PROTECTED BY ops_lock: ops */
425 
426 	mutex_lock(&ops_lock);
427 	if (ops.xp_recv == NULL) {
428 		ops.xp_recv = svc_dg_recv;
429 		ops.xp_stat = svc_dg_stat;
430 		ops.xp_getargs = svc_dg_getargs;
431 		ops.xp_reply = svc_dg_reply;
432 		ops.xp_freeargs = svc_dg_freeargs;
433 		ops.xp_destroy = svc_dg_destroy;
434 		ops2.xp_control = svc_dg_control;
435 	}
436 	xprt->xp_ops = &ops;
437 	xprt->xp_ops2 = &ops2;
438 	mutex_unlock(&ops_lock);
439 }
440 
441 /*  The CACHING COMPONENT */
442 
443 /*
444  * Could have been a separate file, but some part of it depends upon the
445  * private structure of the client handle.
446  *
447  * Fifo cache for cl server
448  * Copies pointers to reply buffers into fifo cache
449  * Buffers are sent again if retransmissions are detected.
450  */
451 
452 #define	SPARSENESS 4	/* 75% sparse */
453 
454 #define	ALLOC(type, size)	\
455 	(type *) mem_alloc((sizeof (type) * (size)))
456 
457 #define	MEMZERO(addr, type, size)	 \
458 	(void) memset((void *) (addr), 0, sizeof (type) * (int) (size))
459 
460 #define	FREE(addr, type, size)	\
461 	mem_free((addr), (sizeof (type) * (size)))
462 
463 /*
464  * An entry in the cache
465  */
466 typedef struct cache_node *cache_ptr;
467 struct cache_node {
468 	/*
469 	 * Index into cache is xid, proc, vers, prog and address
470 	 */
471 	u_int32_t cache_xid;
472 	rpcproc_t cache_proc;
473 	rpcvers_t cache_vers;
474 	rpcprog_t cache_prog;
475 	struct netbuf cache_addr;
476 	/*
477 	 * The cached reply and length
478 	 */
479 	char *cache_reply;
480 	size_t cache_replylen;
481 	/*
482 	 * Next node on the list, if there is a collision
483 	 */
484 	cache_ptr cache_next;
485 };
486 
487 /*
488  * The entire cache
489  */
490 struct cl_cache {
491 	u_int uc_size;		/* size of cache */
492 	cache_ptr *uc_entries;	/* hash table of entries in cache */
493 	cache_ptr *uc_fifo;	/* fifo list of entries in cache */
494 	u_int uc_nextvictim;	/* points to next victim in fifo list */
495 	rpcprog_t uc_prog;	/* saved program number */
496 	rpcvers_t uc_vers;	/* saved version number */
497 	rpcproc_t uc_proc;	/* saved procedure number */
498 };
499 
500 
501 /*
502  * the hashing function
503  */
504 #define	CACHE_LOC(transp, xid)	\
505 	(xid % (SPARSENESS * ((struct cl_cache *) \
506 		su_data(transp)->su_cache)->uc_size))
507 
508 /*
509  * Enable use of the cache. Returns 1 on success, 0 on failure.
510  * Note: there is no disable.
511  */
512 static const char cache_enable_str[] = "svc_enablecache: %s %s";
513 static const char alloc_err[] = "could not allocate cache ";
514 static const char enable_err[] = "cache already enabled";
515 
516 int
517 svc_dg_enablecache(SVCXPRT *transp, u_int size)
518 {
519 	struct svc_dg_data *su = su_data(transp);
520 	struct cl_cache *uc;
521 
522 	mutex_lock(&dupreq_lock);
523 	if (su->su_cache != NULL) {
524 		(void) warnx(cache_enable_str, enable_err, " ");
525 		mutex_unlock(&dupreq_lock);
526 		return (0);
527 	}
528 	uc = ALLOC(struct cl_cache, 1);
529 	if (uc == NULL) {
530 		warnx(cache_enable_str, alloc_err, " ");
531 		mutex_unlock(&dupreq_lock);
532 		return (0);
533 	}
534 	uc->uc_size = size;
535 	uc->uc_nextvictim = 0;
536 	uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
537 	if (uc->uc_entries == NULL) {
538 		warnx(cache_enable_str, alloc_err, "data");
539 		FREE(uc, struct cl_cache, 1);
540 		mutex_unlock(&dupreq_lock);
541 		return (0);
542 	}
543 	MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
544 	uc->uc_fifo = ALLOC(cache_ptr, size);
545 	if (uc->uc_fifo == NULL) {
546 		warnx(cache_enable_str, alloc_err, "fifo");
547 		FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
548 		FREE(uc, struct cl_cache, 1);
549 		mutex_unlock(&dupreq_lock);
550 		return (0);
551 	}
552 	MEMZERO(uc->uc_fifo, cache_ptr, size);
553 	su->su_cache = (char *)(void *)uc;
554 	mutex_unlock(&dupreq_lock);
555 	return (1);
556 }
557 
558 /*
559  * Set an entry in the cache.  It assumes that the uc entry is set from
560  * the earlier call to cache_get() for the same procedure.  This will always
561  * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
562  * by svc_dg_reply().  All this hoopla because the right RPC parameters are
563  * not available at svc_dg_reply time.
564  */
565 
566 static const char cache_set_str[] = "cache_set: %s";
567 static const char cache_set_err1[] = "victim not found";
568 static const char cache_set_err2[] = "victim alloc failed";
569 static const char cache_set_err3[] = "could not allocate new rpc buffer";
570 
571 static void
572 cache_set(SVCXPRT *xprt, size_t replylen)
573 {
574 	cache_ptr victim;
575 	cache_ptr *vicp;
576 	struct svc_dg_data *su = su_data(xprt);
577 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
578 	u_int loc;
579 	char *newbuf;
580 #ifdef RPC_CACHE_DEBUG
581 	struct netconfig *nconf;
582 	char *uaddr;
583 #endif
584 
585 	mutex_lock(&dupreq_lock);
586 	/*
587 	 * Find space for the new entry, either by
588 	 * reusing an old entry, or by mallocing a new one
589 	 */
590 	victim = uc->uc_fifo[uc->uc_nextvictim];
591 	if (victim != NULL) {
592 		loc = CACHE_LOC(xprt, victim->cache_xid);
593 		for (vicp = &uc->uc_entries[loc];
594 			*vicp != NULL && *vicp != victim;
595 			vicp = &(*vicp)->cache_next)
596 			;
597 		if (*vicp == NULL) {
598 			warnx(cache_set_str, cache_set_err1);
599 			mutex_unlock(&dupreq_lock);
600 			return;
601 		}
602 		*vicp = victim->cache_next;	/* remove from cache */
603 		newbuf = victim->cache_reply;
604 	} else {
605 		victim = ALLOC(struct cache_node, 1);
606 		if (victim == NULL) {
607 			warnx(cache_set_str, cache_set_err2);
608 			mutex_unlock(&dupreq_lock);
609 			return;
610 		}
611 		newbuf = mem_alloc(su->su_iosz);
612 		if (newbuf == NULL) {
613 			warnx(cache_set_str, cache_set_err3);
614 			FREE(victim, struct cache_node, 1);
615 			mutex_unlock(&dupreq_lock);
616 			return;
617 		}
618 	}
619 
620 	/*
621 	 * Store it away
622 	 */
623 #ifdef RPC_CACHE_DEBUG
624 	if (nconf = getnetconfigent(xprt->xp_netid)) {
625 		uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
626 		freenetconfigent(nconf);
627 		printf(
628 	"cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
629 			su->su_xid, uc->uc_prog, uc->uc_vers,
630 			uc->uc_proc, uaddr);
631 		free(uaddr);
632 	}
633 #endif
634 	victim->cache_replylen = replylen;
635 	victim->cache_reply = rpc_buffer(xprt);
636 	rpc_buffer(xprt) = newbuf;
637 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
638 			su->su_iosz, XDR_ENCODE);
639 	victim->cache_xid = su->su_xid;
640 	victim->cache_proc = uc->uc_proc;
641 	victim->cache_vers = uc->uc_vers;
642 	victim->cache_prog = uc->uc_prog;
643 	victim->cache_addr = xprt->xp_rtaddr;
644 	victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
645 	(void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
646 	    (size_t)xprt->xp_rtaddr.len);
647 	loc = CACHE_LOC(xprt, victim->cache_xid);
648 	victim->cache_next = uc->uc_entries[loc];
649 	uc->uc_entries[loc] = victim;
650 	uc->uc_fifo[uc->uc_nextvictim++] = victim;
651 	uc->uc_nextvictim %= uc->uc_size;
652 	mutex_unlock(&dupreq_lock);
653 }
654 
655 /*
656  * Try to get an entry from the cache
657  * return 1 if found, 0 if not found and set the stage for cache_set()
658  */
659 static int
660 cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp, size_t *replylenp)
661 {
662 	u_int loc;
663 	cache_ptr ent;
664 	struct svc_dg_data *su = su_data(xprt);
665 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
666 #ifdef RPC_CACHE_DEBUG
667 	struct netconfig *nconf;
668 	char *uaddr;
669 #endif
670 
671 	mutex_lock(&dupreq_lock);
672 	loc = CACHE_LOC(xprt, su->su_xid);
673 	for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
674 		if (ent->cache_xid == su->su_xid &&
675 			ent->cache_proc == msg->rm_call.cb_proc &&
676 			ent->cache_vers == msg->rm_call.cb_vers &&
677 			ent->cache_prog == msg->rm_call.cb_prog &&
678 			ent->cache_addr.len == xprt->xp_rtaddr.len &&
679 			(memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
680 				xprt->xp_rtaddr.len) == 0)) {
681 #ifdef RPC_CACHE_DEBUG
682 			if (nconf = getnetconfigent(xprt->xp_netid)) {
683 				uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
684 				freenetconfigent(nconf);
685 				printf(
686 	"cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
687 					su->su_xid, msg->rm_call.cb_prog,
688 					msg->rm_call.cb_vers,
689 					msg->rm_call.cb_proc, uaddr);
690 				free(uaddr);
691 			}
692 #endif
693 			*replyp = ent->cache_reply;
694 			*replylenp = ent->cache_replylen;
695 			mutex_unlock(&dupreq_lock);
696 			return (1);
697 		}
698 	}
699 	/*
700 	 * Failed to find entry
701 	 * Remember a few things so we can do a set later
702 	 */
703 	uc->uc_proc = msg->rm_call.cb_proc;
704 	uc->uc_vers = msg->rm_call.cb_vers;
705 	uc->uc_prog = msg->rm_call.cb_prog;
706 	mutex_unlock(&dupreq_lock);
707 	return (0);
708 }
709