xref: /freebsd/lib/libc/rpc/svc_dg.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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 /*
41  * svc_dg.c, Server side for connectionless RPC.
42  *
43  * Does some caching in the hopes of achieving execute-at-most-once semantics.
44  */
45 
46 #include "namespace.h"
47 #include "reentrant.h"
48 #include <sys/types.h>
49 #include <sys/socket.h>
50 #include <rpc/rpc.h>
51 #include <rpc/svc_dg.h>
52 #include <assert.h>
53 #include <errno.h>
54 #include <unistd.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #ifdef RPC_CACHE_DEBUG
59 #include <netconfig.h>
60 #include <netdir.h>
61 #endif
62 #include <err.h>
63 #include "un-namespace.h"
64 
65 #include "rpc_com.h"
66 #include "mt_misc.h"
67 
68 #define	su_data(xprt)	((struct svc_dg_data *)((xprt)->xp_p2))
69 #define	rpc_buffer(xprt) ((xprt)->xp_p1)
70 
71 #ifndef MAX
72 #define	MAX(a, b)	(((a) > (b)) ? (a) : (b))
73 #endif
74 
75 static void svc_dg_ops(SVCXPRT *);
76 static enum xprt_stat svc_dg_stat(SVCXPRT *);
77 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *);
78 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *);
79 static bool_t svc_dg_getargs(SVCXPRT *, xdrproc_t, void *);
80 static bool_t svc_dg_freeargs(SVCXPRT *, xdrproc_t, void *);
81 static void svc_dg_destroy(SVCXPRT *);
82 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
83 static int cache_get(SVCXPRT *, struct rpc_msg *, char **, size_t *);
84 static void cache_set(SVCXPRT *, size_t);
85 int svc_dg_enablecache(SVCXPRT *, u_int);
86 
87 /*
88  * Usage:
89  *	xprt = svc_dg_create(sock, sendsize, recvsize);
90  * Does other connectionless specific initializations.
91  * Once *xprt is initialized, it is registered.
92  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
93  * system defaults are chosen.
94  * The routines returns NULL if a problem occurred.
95  */
96 static const char svc_dg_str[] = "svc_dg_create: %s";
97 static const char svc_dg_err1[] = "could not get transport information";
98 static const char svc_dg_err2[] = "transport does not support data transfer";
99 static const char svc_dg_err3[] = "getsockname failed";
100 static const char svc_dg_err4[] = "cannot set IP_RECVDSTADDR";
101 static const char __no_mem_str[] = "out of memory";
102 
103 SVCXPRT *
104 svc_dg_create(int fd, u_int sendsize, u_int recvsize)
105 {
106 	SVCXPRT *xprt;
107 	struct svc_dg_data *su = NULL;
108 	struct __rpc_sockinfo si;
109 	struct sockaddr_storage ss;
110 	socklen_t slen;
111 
112 	if (!__rpc_fd2sockinfo(fd, &si)) {
113 		warnx(svc_dg_str, svc_dg_err1);
114 		return (NULL);
115 	}
116 	/*
117 	 * Find the receive and the send size
118 	 */
119 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
120 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
121 	if ((sendsize == 0) || (recvsize == 0)) {
122 		warnx(svc_dg_str, svc_dg_err2);
123 		return (NULL);
124 	}
125 
126 	xprt = svc_xprt_alloc();
127 	if (xprt == NULL)
128 		goto freedata;
129 
130 	su = mem_alloc(sizeof (*su));
131 	if (su == NULL)
132 		goto freedata;
133 	su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
134 	if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL)
135 		goto freedata;
136 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
137 		XDR_DECODE);
138 	su->su_cache = NULL;
139 	xprt->xp_fd = fd;
140 	xprt->xp_p2 = su;
141 	xprt->xp_verf.oa_base = su->su_verfbody;
142 	svc_dg_ops(xprt);
143 	xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
144 
145 	slen = sizeof ss;
146 	if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0) {
147 		warnx(svc_dg_str, svc_dg_err3);
148 		goto freedata_nowarn;
149 	}
150 	xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
151 	xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
152 	xprt->xp_ltaddr.len = slen;
153 	memcpy(xprt->xp_ltaddr.buf, &ss, slen);
154 
155 	if (ss.ss_family == AF_INET) {
156 		struct sockaddr_in *sin;
157 		static const int true_value = 1;
158 
159 		sin = (struct sockaddr_in *)(void *)&ss;
160 		if (sin->sin_addr.s_addr == INADDR_ANY) {
161 		    su->su_srcaddr.buf = mem_alloc(sizeof (ss));
162 		    su->su_srcaddr.maxlen = sizeof (ss);
163 
164 		    if (_setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR,
165 				    &true_value, sizeof(true_value))) {
166 			    warnx(svc_dg_str,  svc_dg_err4);
167 			    goto freedata_nowarn;
168 		    }
169 		}
170 	}
171 
172 	xprt_register(xprt);
173 	return (xprt);
174 freedata:
175 	(void) warnx(svc_dg_str, __no_mem_str);
176 freedata_nowarn:
177 	if (xprt) {
178 		if (su)
179 			(void) mem_free(su, sizeof (*su));
180 		svc_xprt_free(xprt);
181 	}
182 	return (NULL);
183 }
184 
185 /*ARGSUSED*/
186 static enum xprt_stat
187 svc_dg_stat(SVCXPRT *xprt)
188 {
189 	return (XPRT_IDLE);
190 }
191 
192 static int
193 svc_dg_recvfrom(int fd, char *buf, int buflen,
194     struct sockaddr *raddr, socklen_t *raddrlen,
195     struct sockaddr *laddr, socklen_t *laddrlen)
196 {
197 	struct msghdr msg;
198 	struct iovec msg_iov[1];
199 	struct sockaddr_in *lin = (struct sockaddr_in *)laddr;
200 	int rlen;
201 	bool_t have_lin = FALSE;
202 	char tmp[CMSG_LEN(sizeof(*lin))];
203 	struct cmsghdr *cmsg;
204 
205 	memset((char *)&msg, 0, sizeof(msg));
206 	msg_iov[0].iov_base = buf;
207 	msg_iov[0].iov_len = buflen;
208 	msg.msg_iov = msg_iov;
209 	msg.msg_iovlen = 1;
210 	msg.msg_namelen = *raddrlen;
211 	msg.msg_name = (char *)raddr;
212 	if (laddr != NULL) {
213 	    msg.msg_control = (caddr_t)tmp;
214 	    msg.msg_controllen = CMSG_LEN(sizeof(*lin));
215 	}
216 	rlen = _recvmsg(fd, &msg, 0);
217 	if (rlen >= 0)
218 		*raddrlen = msg.msg_namelen;
219 
220 	if (rlen == -1 || laddr == NULL ||
221 	    msg.msg_controllen < sizeof(struct cmsghdr) ||
222 	    msg.msg_flags & MSG_CTRUNC)
223 		return rlen;
224 
225 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
226 	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
227 		if (cmsg->cmsg_level == IPPROTO_IP &&
228 		    cmsg->cmsg_type == IP_RECVDSTADDR) {
229 			have_lin = TRUE;
230 			memcpy(&lin->sin_addr,
231 			    (struct in_addr *)CMSG_DATA(cmsg),
232 			    sizeof(struct in_addr));
233 			break;
234 		}
235 	}
236 
237 	lin->sin_family = AF_INET;
238 	lin->sin_port = 0;
239 	*laddrlen = sizeof(struct sockaddr_in);
240 
241 	if (!have_lin)
242 		lin->sin_addr.s_addr = INADDR_ANY;
243 
244 	return rlen;
245 }
246 
247 static bool_t
248 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg)
249 {
250 	struct svc_dg_data *su = su_data(xprt);
251 	XDR *xdrs = &(su->su_xdrs);
252 	char *reply;
253 	struct sockaddr_storage ss;
254 	socklen_t alen;
255 	size_t replylen;
256 	ssize_t rlen;
257 
258 again:
259 	alen = sizeof (struct sockaddr_storage);
260 	rlen = svc_dg_recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz,
261 	    (struct sockaddr *)(void *)&ss, &alen,
262 	    (struct sockaddr *)su->su_srcaddr.buf, &su->su_srcaddr.len);
263 	if (rlen == -1 && errno == EINTR)
264 		goto again;
265 	if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
266 		return (FALSE);
267 	if (xprt->xp_rtaddr.len < alen) {
268 		if (xprt->xp_rtaddr.len != 0)
269 			mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
270 		xprt->xp_rtaddr.buf = mem_alloc(alen);
271 		xprt->xp_rtaddr.len = alen;
272 	}
273 	memcpy(xprt->xp_rtaddr.buf, &ss, alen);
274 #ifdef PORTMAP
275 	if (ss.ss_family == AF_INET) {
276 		xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
277 		xprt->xp_addrlen = sizeof (struct sockaddr_in);
278 	}
279 #endif				/* PORTMAP */
280 	xdrs->x_op = XDR_DECODE;
281 	XDR_SETPOS(xdrs, 0);
282 	if (! xdr_callmsg(xdrs, msg)) {
283 		return (FALSE);
284 	}
285 	su->su_xid = msg->rm_xid;
286 	if (su->su_cache != NULL) {
287 		if (cache_get(xprt, msg, &reply, &replylen)) {
288 			(void)_sendto(xprt->xp_fd, reply, replylen, 0,
289 			    (struct sockaddr *)(void *)&ss, alen);
290 			return (FALSE);
291 		}
292 	}
293 	return (TRUE);
294 }
295 
296 static int
297 svc_dg_sendto(int fd, char *buf, int buflen,
298     const struct sockaddr *raddr, socklen_t raddrlen,
299     const struct sockaddr *laddr, socklen_t laddrlen)
300 {
301 	struct msghdr msg;
302 	struct iovec msg_iov[1];
303 	struct sockaddr_in *laddr_in = (struct sockaddr_in *)laddr;
304 	struct in_addr *lin = &laddr_in->sin_addr;
305 	char tmp[CMSG_SPACE(sizeof(*lin))];
306 	struct cmsghdr *cmsg;
307 
308 	memset((char *)&msg, 0, sizeof(msg));
309 	msg_iov[0].iov_base = buf;
310 	msg_iov[0].iov_len = buflen;
311 	msg.msg_iov = msg_iov;
312 	msg.msg_iovlen = 1;
313 	msg.msg_namelen = raddrlen;
314 	msg.msg_name = (char *)raddr;
315 
316 	if (laddr != NULL && laddr->sa_family == AF_INET &&
317 	    lin->s_addr != INADDR_ANY) {
318 		msg.msg_control = (caddr_t)tmp;
319 		msg.msg_controllen = CMSG_LEN(sizeof(*lin));
320 		cmsg = CMSG_FIRSTHDR(&msg);
321 		cmsg->cmsg_len = CMSG_LEN(sizeof(*lin));
322 		cmsg->cmsg_level = IPPROTO_IP;
323 		cmsg->cmsg_type = IP_SENDSRCADDR;
324 		memcpy(CMSG_DATA(cmsg), lin, sizeof(*lin));
325 	}
326 
327 	return _sendmsg(fd, &msg, 0);
328 }
329 
330 static bool_t
331 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg)
332 {
333 	struct svc_dg_data *su = su_data(xprt);
334 	XDR *xdrs = &(su->su_xdrs);
335 	bool_t stat = TRUE;
336 	size_t slen;
337 	xdrproc_t xdr_proc;
338 	caddr_t xdr_where;
339 
340 	xdrs->x_op = XDR_ENCODE;
341 	XDR_SETPOS(xdrs, 0);
342 	msg->rm_xid = su->su_xid;
343 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
344 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
345 		xdr_proc = msg->acpted_rply.ar_results.proc;
346 		xdr_where = msg->acpted_rply.ar_results.where;
347 		msg->acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;
348 		msg->acpted_rply.ar_results.where = NULL;
349 
350 		if (!xdr_replymsg(xdrs, msg) ||
351 		    !SVCAUTH_WRAP(&SVC_AUTH(xprt), xdrs, xdr_proc, xdr_where))
352 			stat = FALSE;
353 	} else {
354 		stat = xdr_replymsg(xdrs, msg);
355 	}
356 	if (stat) {
357 		slen = XDR_GETPOS(xdrs);
358 		if (svc_dg_sendto(xprt->xp_fd, rpc_buffer(xprt), slen,
359 		    (struct sockaddr *)xprt->xp_rtaddr.buf,
360 		    (socklen_t)xprt->xp_rtaddr.len,
361 		    (struct sockaddr *)su->su_srcaddr.buf,
362 		    (socklen_t)su->su_srcaddr.len) == (ssize_t) slen) {
363 			stat = TRUE;
364 			if (su->su_cache)
365 				cache_set(xprt, slen);
366 		}
367 	}
368 	return (stat);
369 }
370 
371 static bool_t
372 svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
373 {
374 	struct svc_dg_data *su;
375 
376 	assert(xprt != NULL);
377 	su = su_data(xprt);
378 	return (SVCAUTH_UNWRAP(&SVC_AUTH(xprt),
379 		&su->su_xdrs, xdr_args, args_ptr));
380 }
381 
382 static bool_t
383 svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
384 {
385 	XDR *xdrs = &(su_data(xprt)->su_xdrs);
386 
387 	xdrs->x_op = XDR_FREE;
388 	return (*xdr_args)(xdrs, args_ptr);
389 }
390 
391 static void
392 svc_dg_destroy(SVCXPRT *xprt)
393 {
394 	struct svc_dg_data *su = su_data(xprt);
395 
396 	xprt_unregister(xprt);
397 	if (xprt->xp_fd != -1)
398 		(void)_close(xprt->xp_fd);
399 	XDR_DESTROY(&(su->su_xdrs));
400 	(void) mem_free(rpc_buffer(xprt), su->su_iosz);
401 	if (su->su_srcaddr.buf)
402 		(void) mem_free(su->su_srcaddr.buf, su->su_srcaddr.maxlen);
403 	(void) mem_free(su, sizeof (*su));
404 	if (xprt->xp_rtaddr.buf)
405 		(void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
406 	if (xprt->xp_ltaddr.buf)
407 		(void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
408 	free(xprt->xp_tp);
409 	svc_xprt_free(xprt);
410 }
411 
412 static bool_t
413 /*ARGSUSED*/
414 svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in)
415 {
416 	return (FALSE);
417 }
418 
419 static void
420 svc_dg_ops(SVCXPRT *xprt)
421 {
422 	static struct xp_ops ops;
423 	static struct xp_ops2 ops2;
424 
425 /* VARIABLES PROTECTED BY ops_lock: ops */
426 
427 	mutex_lock(&ops_lock);
428 	if (ops.xp_recv == NULL) {
429 		ops.xp_recv = svc_dg_recv;
430 		ops.xp_stat = svc_dg_stat;
431 		ops.xp_getargs = svc_dg_getargs;
432 		ops.xp_reply = svc_dg_reply;
433 		ops.xp_freeargs = svc_dg_freeargs;
434 		ops.xp_destroy = svc_dg_destroy;
435 		ops2.xp_control = svc_dg_control;
436 	}
437 	xprt->xp_ops = &ops;
438 	xprt->xp_ops2 = &ops2;
439 	mutex_unlock(&ops_lock);
440 }
441 
442 /*  The CACHING COMPONENT */
443 
444 /*
445  * Could have been a separate file, but some part of it depends upon the
446  * private structure of the client handle.
447  *
448  * Fifo cache for cl server
449  * Copies pointers to reply buffers into fifo cache
450  * Buffers are sent again if retransmissions are detected.
451  */
452 
453 #define	SPARSENESS 4	/* 75% sparse */
454 
455 #define	ALLOC(type, size)	\
456 	(type *) mem_alloc((sizeof (type) * (size)))
457 
458 #define	MEMZERO(addr, type, size)	 \
459 	(void) memset((void *) (addr), 0, sizeof (type) * (int) (size))
460 
461 #define	FREE(addr, type, size)	\
462 	mem_free((addr), (sizeof (type) * (size)))
463 
464 /*
465  * An entry in the cache
466  */
467 typedef struct cache_node *cache_ptr;
468 struct cache_node {
469 	/*
470 	 * Index into cache is xid, proc, vers, prog and address
471 	 */
472 	u_int32_t cache_xid;
473 	rpcproc_t cache_proc;
474 	rpcvers_t cache_vers;
475 	rpcprog_t cache_prog;
476 	struct netbuf cache_addr;
477 	/*
478 	 * The cached reply and length
479 	 */
480 	char *cache_reply;
481 	size_t cache_replylen;
482 	/*
483 	 * Next node on the list, if there is a collision
484 	 */
485 	cache_ptr cache_next;
486 };
487 
488 /*
489  * The entire cache
490  */
491 struct cl_cache {
492 	u_int uc_size;		/* size of cache */
493 	cache_ptr *uc_entries;	/* hash table of entries in cache */
494 	cache_ptr *uc_fifo;	/* fifo list of entries in cache */
495 	u_int uc_nextvictim;	/* points to next victim in fifo list */
496 	rpcprog_t uc_prog;	/* saved program number */
497 	rpcvers_t uc_vers;	/* saved version number */
498 	rpcproc_t uc_proc;	/* saved procedure number */
499 };
500 
501 
502 /*
503  * the hashing function
504  */
505 #define	CACHE_LOC(transp, xid)	\
506 	(xid % (SPARSENESS * ((struct cl_cache *) \
507 		su_data(transp)->su_cache)->uc_size))
508 
509 /*
510  * Enable use of the cache. Returns 1 on success, 0 on failure.
511  * Note: there is no disable.
512  */
513 static const char cache_enable_str[] = "svc_enablecache: %s %s";
514 static const char alloc_err[] = "could not allocate cache ";
515 static const char enable_err[] = "cache already enabled";
516 
517 int
518 svc_dg_enablecache(SVCXPRT *transp, u_int size)
519 {
520 	struct svc_dg_data *su = su_data(transp);
521 	struct cl_cache *uc;
522 
523 	mutex_lock(&dupreq_lock);
524 	if (su->su_cache != NULL) {
525 		(void) warnx(cache_enable_str, enable_err, " ");
526 		mutex_unlock(&dupreq_lock);
527 		return (0);
528 	}
529 	uc = ALLOC(struct cl_cache, 1);
530 	if (uc == NULL) {
531 		warnx(cache_enable_str, alloc_err, " ");
532 		mutex_unlock(&dupreq_lock);
533 		return (0);
534 	}
535 	uc->uc_size = size;
536 	uc->uc_nextvictim = 0;
537 	uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
538 	if (uc->uc_entries == NULL) {
539 		warnx(cache_enable_str, alloc_err, "data");
540 		FREE(uc, struct cl_cache, 1);
541 		mutex_unlock(&dupreq_lock);
542 		return (0);
543 	}
544 	MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
545 	uc->uc_fifo = ALLOC(cache_ptr, size);
546 	if (uc->uc_fifo == NULL) {
547 		warnx(cache_enable_str, alloc_err, "fifo");
548 		FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
549 		FREE(uc, struct cl_cache, 1);
550 		mutex_unlock(&dupreq_lock);
551 		return (0);
552 	}
553 	MEMZERO(uc->uc_fifo, cache_ptr, size);
554 	su->su_cache = (char *)(void *)uc;
555 	mutex_unlock(&dupreq_lock);
556 	return (1);
557 }
558 
559 /*
560  * Set an entry in the cache.  It assumes that the uc entry is set from
561  * the earlier call to cache_get() for the same procedure.  This will always
562  * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
563  * by svc_dg_reply().  All this hoopla because the right RPC parameters are
564  * not available at svc_dg_reply time.
565  */
566 
567 static const char cache_set_str[] = "cache_set: %s";
568 static const char cache_set_err1[] = "victim not found";
569 static const char cache_set_err2[] = "victim alloc failed";
570 static const char cache_set_err3[] = "could not allocate new rpc buffer";
571 
572 static void
573 cache_set(SVCXPRT *xprt, size_t replylen)
574 {
575 	cache_ptr victim;
576 	cache_ptr *vicp;
577 	struct svc_dg_data *su = su_data(xprt);
578 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
579 	u_int loc;
580 	char *newbuf;
581 #ifdef RPC_CACHE_DEBUG
582 	struct netconfig *nconf;
583 	char *uaddr;
584 #endif
585 
586 	mutex_lock(&dupreq_lock);
587 	/*
588 	 * Find space for the new entry, either by
589 	 * reusing an old entry, or by mallocing a new one
590 	 */
591 	victim = uc->uc_fifo[uc->uc_nextvictim];
592 	if (victim != NULL) {
593 		loc = CACHE_LOC(xprt, victim->cache_xid);
594 		for (vicp = &uc->uc_entries[loc];
595 			*vicp != NULL && *vicp != victim;
596 			vicp = &(*vicp)->cache_next)
597 			;
598 		if (*vicp == NULL) {
599 			warnx(cache_set_str, cache_set_err1);
600 			mutex_unlock(&dupreq_lock);
601 			return;
602 		}
603 		*vicp = victim->cache_next;	/* remove from cache */
604 		newbuf = victim->cache_reply;
605 	} else {
606 		victim = ALLOC(struct cache_node, 1);
607 		if (victim == NULL) {
608 			warnx(cache_set_str, cache_set_err2);
609 			mutex_unlock(&dupreq_lock);
610 			return;
611 		}
612 		newbuf = mem_alloc(su->su_iosz);
613 		if (newbuf == NULL) {
614 			warnx(cache_set_str, cache_set_err3);
615 			FREE(victim, struct cache_node, 1);
616 			mutex_unlock(&dupreq_lock);
617 			return;
618 		}
619 	}
620 
621 	/*
622 	 * Store it away
623 	 */
624 #ifdef RPC_CACHE_DEBUG
625 	if (nconf = getnetconfigent(xprt->xp_netid)) {
626 		uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
627 		freenetconfigent(nconf);
628 		printf(
629 	"cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
630 			su->su_xid, uc->uc_prog, uc->uc_vers,
631 			uc->uc_proc, uaddr);
632 		free(uaddr);
633 	}
634 #endif
635 	victim->cache_replylen = replylen;
636 	victim->cache_reply = rpc_buffer(xprt);
637 	rpc_buffer(xprt) = newbuf;
638 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
639 			su->su_iosz, XDR_ENCODE);
640 	victim->cache_xid = su->su_xid;
641 	victim->cache_proc = uc->uc_proc;
642 	victim->cache_vers = uc->uc_vers;
643 	victim->cache_prog = uc->uc_prog;
644 	victim->cache_addr = xprt->xp_rtaddr;
645 	victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
646 	(void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
647 	    (size_t)xprt->xp_rtaddr.len);
648 	loc = CACHE_LOC(xprt, victim->cache_xid);
649 	victim->cache_next = uc->uc_entries[loc];
650 	uc->uc_entries[loc] = victim;
651 	uc->uc_fifo[uc->uc_nextvictim++] = victim;
652 	uc->uc_nextvictim %= uc->uc_size;
653 	mutex_unlock(&dupreq_lock);
654 }
655 
656 /*
657  * Try to get an entry from the cache
658  * return 1 if found, 0 if not found and set the stage for cache_set()
659  */
660 static int
661 cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp, size_t *replylenp)
662 {
663 	u_int loc;
664 	cache_ptr ent;
665 	struct svc_dg_data *su = su_data(xprt);
666 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
667 #ifdef RPC_CACHE_DEBUG
668 	struct netconfig *nconf;
669 	char *uaddr;
670 #endif
671 
672 	mutex_lock(&dupreq_lock);
673 	loc = CACHE_LOC(xprt, su->su_xid);
674 	for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
675 		if (ent->cache_xid == su->su_xid &&
676 			ent->cache_proc == msg->rm_call.cb_proc &&
677 			ent->cache_vers == msg->rm_call.cb_vers &&
678 			ent->cache_prog == msg->rm_call.cb_prog &&
679 			ent->cache_addr.len == xprt->xp_rtaddr.len &&
680 			(memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
681 				xprt->xp_rtaddr.len) == 0)) {
682 #ifdef RPC_CACHE_DEBUG
683 			if (nconf = getnetconfigent(xprt->xp_netid)) {
684 				uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
685 				freenetconfigent(nconf);
686 				printf(
687 	"cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
688 					su->su_xid, msg->rm_call.cb_prog,
689 					msg->rm_call.cb_vers,
690 					msg->rm_call.cb_proc, uaddr);
691 				free(uaddr);
692 			}
693 #endif
694 			*replyp = ent->cache_reply;
695 			*replylenp = ent->cache_replylen;
696 			mutex_unlock(&dupreq_lock);
697 			return (1);
698 		}
699 	}
700 	/*
701 	 * Failed to find entry
702 	 * Remember a few things so we can do a set later
703 	 */
704 	uc->uc_proc = msg->rm_call.cb_proc;
705 	uc->uc_vers = msg->rm_call.cb_vers;
706 	uc->uc_prog = msg->rm_call.cb_prog;
707 	mutex_unlock(&dupreq_lock);
708 	return (0);
709 }
710