xref: /freebsd/lib/libc/rpc/svc_dg.c (revision 5b9c547c)
1 /*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009, Sun Microsystems, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  * - Redistributions of source code must retain the above copyright notice,
10  *   this list of conditions and the following disclaimer.
11  * - Redistributions in binary form must reproduce the above copyright notice,
12  *   this list of conditions and the following disclaimer in the documentation
13  *   and/or other materials provided with the distribution.
14  * - Neither the name of Sun Microsystems, Inc. nor the names of its
15  *   contributors may be used to endorse or promote products derived
16  *   from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
33  */
34 
35 #if defined(LIBC_SCCS) && !defined(lint)
36 #ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
37 #endif
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 /*
42  * svc_dg.c, Server side for connectionless RPC.
43  *
44  * Does some caching in the hopes of achieving execute-at-most-once semantics.
45  */
46 
47 #include "namespace.h"
48 #include "reentrant.h"
49 #include <sys/types.h>
50 #include <sys/socket.h>
51 #include <rpc/rpc.h>
52 #include <rpc/svc_dg.h>
53 #include <assert.h>
54 #include <errno.h>
55 #include <unistd.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #ifdef RPC_CACHE_DEBUG
60 #include <netconfig.h>
61 #include <netdir.h>
62 #endif
63 #include <err.h>
64 #include "un-namespace.h"
65 
66 #include "rpc_com.h"
67 #include "mt_misc.h"
68 
69 #define	su_data(xprt)	((struct svc_dg_data *)(xprt->xp_p2))
70 #define	rpc_buffer(xprt) ((xprt)->xp_p1)
71 
72 #ifndef MAX
73 #define	MAX(a, b)	(((a) > (b)) ? (a) : (b))
74 #endif
75 
76 static void svc_dg_ops(SVCXPRT *);
77 static enum xprt_stat svc_dg_stat(SVCXPRT *);
78 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *);
79 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *);
80 static bool_t svc_dg_getargs(SVCXPRT *, xdrproc_t, void *);
81 static bool_t svc_dg_freeargs(SVCXPRT *, xdrproc_t, void *);
82 static void svc_dg_destroy(SVCXPRT *);
83 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
84 static int cache_get(SVCXPRT *, struct rpc_msg *, char **, size_t *);
85 static void cache_set(SVCXPRT *, size_t);
86 int svc_dg_enablecache(SVCXPRT *, u_int);
87 
88 /*
89  * Usage:
90  *	xprt = svc_dg_create(sock, sendsize, recvsize);
91  * Does other connectionless specific initializations.
92  * Once *xprt is initialized, it is registered.
93  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
94  * system defaults are chosen.
95  * The routines returns NULL if a problem occurred.
96  */
97 static const char svc_dg_str[] = "svc_dg_create: %s";
98 static const char svc_dg_err1[] = "could not get transport information";
99 static const char svc_dg_err2[] = "transport does not support data transfer";
100 static const char svc_dg_err3[] = "getsockname failed";
101 static const char svc_dg_err4[] = "cannot set IP_RECVDSTADDR";
102 static const char __no_mem_str[] = "out of memory";
103 
104 SVCXPRT *
105 svc_dg_create(fd, sendsize, recvsize)
106 	int fd;
107 	u_int sendsize;
108 	u_int recvsize;
109 {
110 	SVCXPRT *xprt;
111 	struct svc_dg_data *su = NULL;
112 	struct __rpc_sockinfo si;
113 	struct sockaddr_storage ss;
114 	socklen_t slen;
115 
116 	if (!__rpc_fd2sockinfo(fd, &si)) {
117 		warnx(svc_dg_str, svc_dg_err1);
118 		return (NULL);
119 	}
120 	/*
121 	 * Find the receive and the send size
122 	 */
123 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
124 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
125 	if ((sendsize == 0) || (recvsize == 0)) {
126 		warnx(svc_dg_str, svc_dg_err2);
127 		return (NULL);
128 	}
129 
130 	xprt = svc_xprt_alloc();
131 	if (xprt == NULL)
132 		goto freedata;
133 
134 	su = mem_alloc(sizeof (*su));
135 	if (su == NULL)
136 		goto freedata;
137 	su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
138 	if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL)
139 		goto freedata;
140 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
141 		XDR_DECODE);
142 	su->su_cache = NULL;
143 	xprt->xp_fd = fd;
144 	xprt->xp_p2 = su;
145 	xprt->xp_verf.oa_base = su->su_verfbody;
146 	svc_dg_ops(xprt);
147 	xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
148 
149 	slen = sizeof ss;
150 	if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0) {
151 		warnx(svc_dg_str, svc_dg_err3);
152 		goto freedata_nowarn;
153 	}
154 	xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
155 	xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
156 	xprt->xp_ltaddr.len = slen;
157 	memcpy(xprt->xp_ltaddr.buf, &ss, slen);
158 
159 	if (ss.ss_family == AF_INET) {
160 		struct sockaddr_in *sin;
161 		static const int true_value = 1;
162 
163 		sin = (struct sockaddr_in *)(void *)&ss;
164 		if (sin->sin_addr.s_addr == INADDR_ANY) {
165 		    su->su_srcaddr.buf = mem_alloc(sizeof (ss));
166 		    su->su_srcaddr.maxlen = sizeof (ss);
167 
168 		    if (_setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR,
169 				    &true_value, sizeof(true_value))) {
170 			    warnx(svc_dg_str,  svc_dg_err4);
171 			    goto freedata_nowarn;
172 		    }
173 		}
174 	}
175 
176 	xprt_register(xprt);
177 	return (xprt);
178 freedata:
179 	(void) warnx(svc_dg_str, __no_mem_str);
180 freedata_nowarn:
181 	if (xprt) {
182 		if (su)
183 			(void) mem_free(su, sizeof (*su));
184 		svc_xprt_free(xprt);
185 	}
186 	return (NULL);
187 }
188 
189 /*ARGSUSED*/
190 static enum xprt_stat
191 svc_dg_stat(xprt)
192 	SVCXPRT *xprt;
193 {
194 	return (XPRT_IDLE);
195 }
196 
197 static int
198 svc_dg_recvfrom(int fd, char *buf, int buflen,
199     struct sockaddr *raddr, socklen_t *raddrlen,
200     struct sockaddr *laddr, socklen_t *laddrlen)
201 {
202 	struct msghdr msg;
203 	struct iovec msg_iov[1];
204 	struct sockaddr_in *lin = (struct sockaddr_in *)laddr;
205 	int rlen;
206 	bool_t have_lin = FALSE;
207 	char tmp[CMSG_LEN(sizeof(*lin))];
208 	struct cmsghdr *cmsg;
209 
210 	memset((char *)&msg, 0, sizeof(msg));
211 	msg_iov[0].iov_base = buf;
212 	msg_iov[0].iov_len = buflen;
213 	msg.msg_iov = msg_iov;
214 	msg.msg_iovlen = 1;
215 	msg.msg_namelen = *raddrlen;
216 	msg.msg_name = (char *)raddr;
217 	if (laddr != NULL) {
218 	    msg.msg_control = (caddr_t)tmp;
219 	    msg.msg_controllen = CMSG_LEN(sizeof(*lin));
220 	}
221 	rlen = _recvmsg(fd, &msg, 0);
222 	if (rlen >= 0)
223 		*raddrlen = msg.msg_namelen;
224 
225 	if (rlen == -1 || laddr == NULL ||
226 	    msg.msg_controllen < sizeof(struct cmsghdr) ||
227 	    msg.msg_flags & MSG_CTRUNC)
228 		return rlen;
229 
230 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
231 	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
232 		if (cmsg->cmsg_level == IPPROTO_IP &&
233 		    cmsg->cmsg_type == IP_RECVDSTADDR) {
234 			have_lin = TRUE;
235 			memcpy(&lin->sin_addr,
236 			    (struct in_addr *)CMSG_DATA(cmsg),
237 			    sizeof(struct in_addr));
238 			break;
239 		}
240 	}
241 
242 	lin->sin_family = AF_INET;
243 	lin->sin_port = 0;
244 	*laddrlen = sizeof(struct sockaddr_in);
245 
246 	if (!have_lin)
247 		lin->sin_addr.s_addr = INADDR_ANY;
248 
249 	return rlen;
250 }
251 
252 static bool_t
253 svc_dg_recv(xprt, msg)
254 	SVCXPRT *xprt;
255 	struct rpc_msg *msg;
256 {
257 	struct svc_dg_data *su = su_data(xprt);
258 	XDR *xdrs = &(su->su_xdrs);
259 	char *reply;
260 	struct sockaddr_storage ss;
261 	socklen_t alen;
262 	size_t replylen;
263 	ssize_t rlen;
264 
265 again:
266 	alen = sizeof (struct sockaddr_storage);
267 	rlen = svc_dg_recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz,
268 	    (struct sockaddr *)(void *)&ss, &alen,
269 	    (struct sockaddr *)su->su_srcaddr.buf, &su->su_srcaddr.len);
270 	if (rlen == -1 && errno == EINTR)
271 		goto again;
272 	if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
273 		return (FALSE);
274 	if (xprt->xp_rtaddr.len < alen) {
275 		if (xprt->xp_rtaddr.len != 0)
276 			mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
277 		xprt->xp_rtaddr.buf = mem_alloc(alen);
278 		xprt->xp_rtaddr.len = alen;
279 	}
280 	memcpy(xprt->xp_rtaddr.buf, &ss, alen);
281 #ifdef PORTMAP
282 	if (ss.ss_family == AF_INET) {
283 		xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
284 		xprt->xp_addrlen = sizeof (struct sockaddr_in);
285 	}
286 #endif				/* PORTMAP */
287 	xdrs->x_op = XDR_DECODE;
288 	XDR_SETPOS(xdrs, 0);
289 	if (! xdr_callmsg(xdrs, msg)) {
290 		return (FALSE);
291 	}
292 	su->su_xid = msg->rm_xid;
293 	if (su->su_cache != NULL) {
294 		if (cache_get(xprt, msg, &reply, &replylen)) {
295 			(void)_sendto(xprt->xp_fd, reply, replylen, 0,
296 			    (struct sockaddr *)(void *)&ss, alen);
297 			return (FALSE);
298 		}
299 	}
300 	return (TRUE);
301 }
302 
303 static int
304 svc_dg_sendto(int fd, char *buf, int buflen,
305     const struct sockaddr *raddr, socklen_t raddrlen,
306     const struct sockaddr *laddr, socklen_t laddrlen)
307 {
308 	struct msghdr msg;
309 	struct iovec msg_iov[1];
310 	struct sockaddr_in *laddr_in = (struct sockaddr_in *)laddr;
311 	struct in_addr *lin = &laddr_in->sin_addr;
312 	char tmp[CMSG_SPACE(sizeof(*lin))];
313 	struct cmsghdr *cmsg;
314 
315 	memset((char *)&msg, 0, sizeof(msg));
316 	msg_iov[0].iov_base = buf;
317 	msg_iov[0].iov_len = buflen;
318 	msg.msg_iov = msg_iov;
319 	msg.msg_iovlen = 1;
320 	msg.msg_namelen = raddrlen;
321 	msg.msg_name = (char *)raddr;
322 
323 	if (laddr != NULL && laddr->sa_family == AF_INET &&
324 	    lin->s_addr != INADDR_ANY) {
325 		msg.msg_control = (caddr_t)tmp;
326 		msg.msg_controllen = CMSG_LEN(sizeof(*lin));
327 		cmsg = CMSG_FIRSTHDR(&msg);
328 		cmsg->cmsg_len = CMSG_LEN(sizeof(*lin));
329 		cmsg->cmsg_level = IPPROTO_IP;
330 		cmsg->cmsg_type = IP_SENDSRCADDR;
331 		memcpy(CMSG_DATA(cmsg), lin, sizeof(*lin));
332 	}
333 
334 	return _sendmsg(fd, &msg, 0);
335 }
336 
337 static bool_t
338 svc_dg_reply(xprt, msg)
339 	SVCXPRT *xprt;
340 	struct rpc_msg *msg;
341 {
342 	struct svc_dg_data *su = su_data(xprt);
343 	XDR *xdrs = &(su->su_xdrs);
344 	bool_t stat = TRUE;
345 	size_t slen;
346 	xdrproc_t xdr_proc;
347 	caddr_t xdr_where;
348 
349 	xdrs->x_op = XDR_ENCODE;
350 	XDR_SETPOS(xdrs, 0);
351 	msg->rm_xid = su->su_xid;
352 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
353 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
354 		xdr_proc = msg->acpted_rply.ar_results.proc;
355 		xdr_where = msg->acpted_rply.ar_results.where;
356 		msg->acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;
357 		msg->acpted_rply.ar_results.where = NULL;
358 
359 		if (!xdr_replymsg(xdrs, msg) ||
360 		    !SVCAUTH_WRAP(&SVC_AUTH(xprt), xdrs, xdr_proc, xdr_where))
361 			stat = FALSE;
362 	} else {
363 		stat = xdr_replymsg(xdrs, msg);
364 	}
365 	if (stat) {
366 		slen = XDR_GETPOS(xdrs);
367 		if (svc_dg_sendto(xprt->xp_fd, rpc_buffer(xprt), slen,
368 		    (struct sockaddr *)xprt->xp_rtaddr.buf,
369 		    (socklen_t)xprt->xp_rtaddr.len,
370 		    (struct sockaddr *)su->su_srcaddr.buf,
371 		    (socklen_t)su->su_srcaddr.len) == (ssize_t) slen) {
372 			stat = TRUE;
373 			if (su->su_cache)
374 				cache_set(xprt, slen);
375 		}
376 	}
377 	return (stat);
378 }
379 
380 static bool_t
381 svc_dg_getargs(xprt, xdr_args, args_ptr)
382 	SVCXPRT *xprt;
383 	xdrproc_t xdr_args;
384 	void *args_ptr;
385 {
386 	struct svc_dg_data *su;
387 
388 	assert(xprt != NULL);
389 	su = su_data(xprt);
390 	return (SVCAUTH_UNWRAP(&SVC_AUTH(xprt),
391 		&su->su_xdrs, xdr_args, args_ptr));
392 }
393 
394 static bool_t
395 svc_dg_freeargs(xprt, xdr_args, args_ptr)
396 	SVCXPRT *xprt;
397 	xdrproc_t xdr_args;
398 	void *args_ptr;
399 {
400 	XDR *xdrs = &(su_data(xprt)->su_xdrs);
401 
402 	xdrs->x_op = XDR_FREE;
403 	return (*xdr_args)(xdrs, args_ptr);
404 }
405 
406 static void
407 svc_dg_destroy(xprt)
408 	SVCXPRT *xprt;
409 {
410 	struct svc_dg_data *su = su_data(xprt);
411 
412 	xprt_unregister(xprt);
413 	if (xprt->xp_fd != -1)
414 		(void)_close(xprt->xp_fd);
415 	XDR_DESTROY(&(su->su_xdrs));
416 	(void) mem_free(rpc_buffer(xprt), su->su_iosz);
417 	if (su->su_srcaddr.buf)
418 		(void) mem_free(su->su_srcaddr.buf, su->su_srcaddr.maxlen);
419 	(void) mem_free(su, sizeof (*su));
420 	if (xprt->xp_rtaddr.buf)
421 		(void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
422 	if (xprt->xp_ltaddr.buf)
423 		(void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
424 	if (xprt->xp_tp)
425 		(void) free(xprt->xp_tp);
426 	svc_xprt_free(xprt);
427 }
428 
429 static bool_t
430 /*ARGSUSED*/
431 svc_dg_control(xprt, rq, in)
432 	SVCXPRT *xprt;
433 	const u_int	rq;
434 	void		*in;
435 {
436 	return (FALSE);
437 }
438 
439 static void
440 svc_dg_ops(xprt)
441 	SVCXPRT *xprt;
442 {
443 	static struct xp_ops ops;
444 	static struct xp_ops2 ops2;
445 
446 /* VARIABLES PROTECTED BY ops_lock: ops */
447 
448 	mutex_lock(&ops_lock);
449 	if (ops.xp_recv == NULL) {
450 		ops.xp_recv = svc_dg_recv;
451 		ops.xp_stat = svc_dg_stat;
452 		ops.xp_getargs = svc_dg_getargs;
453 		ops.xp_reply = svc_dg_reply;
454 		ops.xp_freeargs = svc_dg_freeargs;
455 		ops.xp_destroy = svc_dg_destroy;
456 		ops2.xp_control = svc_dg_control;
457 	}
458 	xprt->xp_ops = &ops;
459 	xprt->xp_ops2 = &ops2;
460 	mutex_unlock(&ops_lock);
461 }
462 
463 /*  The CACHING COMPONENT */
464 
465 /*
466  * Could have been a separate file, but some part of it depends upon the
467  * private structure of the client handle.
468  *
469  * Fifo cache for cl server
470  * Copies pointers to reply buffers into fifo cache
471  * Buffers are sent again if retransmissions are detected.
472  */
473 
474 #define	SPARSENESS 4	/* 75% sparse */
475 
476 #define	ALLOC(type, size)	\
477 	(type *) mem_alloc((sizeof (type) * (size)))
478 
479 #define	MEMZERO(addr, type, size)	 \
480 	(void) memset((void *) (addr), 0, sizeof (type) * (int) (size))
481 
482 #define	FREE(addr, type, size)	\
483 	mem_free((addr), (sizeof (type) * (size)))
484 
485 /*
486  * An entry in the cache
487  */
488 typedef struct cache_node *cache_ptr;
489 struct cache_node {
490 	/*
491 	 * Index into cache is xid, proc, vers, prog and address
492 	 */
493 	u_int32_t cache_xid;
494 	rpcproc_t cache_proc;
495 	rpcvers_t cache_vers;
496 	rpcprog_t cache_prog;
497 	struct netbuf cache_addr;
498 	/*
499 	 * The cached reply and length
500 	 */
501 	char *cache_reply;
502 	size_t cache_replylen;
503 	/*
504 	 * Next node on the list, if there is a collision
505 	 */
506 	cache_ptr cache_next;
507 };
508 
509 /*
510  * The entire cache
511  */
512 struct cl_cache {
513 	u_int uc_size;		/* size of cache */
514 	cache_ptr *uc_entries;	/* hash table of entries in cache */
515 	cache_ptr *uc_fifo;	/* fifo list of entries in cache */
516 	u_int uc_nextvictim;	/* points to next victim in fifo list */
517 	rpcprog_t uc_prog;	/* saved program number */
518 	rpcvers_t uc_vers;	/* saved version number */
519 	rpcproc_t uc_proc;	/* saved procedure number */
520 };
521 
522 
523 /*
524  * the hashing function
525  */
526 #define	CACHE_LOC(transp, xid)	\
527 	(xid % (SPARSENESS * ((struct cl_cache *) \
528 		su_data(transp)->su_cache)->uc_size))
529 
530 /*
531  * Enable use of the cache. Returns 1 on success, 0 on failure.
532  * Note: there is no disable.
533  */
534 static const char cache_enable_str[] = "svc_enablecache: %s %s";
535 static const char alloc_err[] = "could not allocate cache ";
536 static const char enable_err[] = "cache already enabled";
537 
538 int
539 svc_dg_enablecache(transp, size)
540 	SVCXPRT *transp;
541 	u_int size;
542 {
543 	struct svc_dg_data *su = su_data(transp);
544 	struct cl_cache *uc;
545 
546 	mutex_lock(&dupreq_lock);
547 	if (su->su_cache != NULL) {
548 		(void) warnx(cache_enable_str, enable_err, " ");
549 		mutex_unlock(&dupreq_lock);
550 		return (0);
551 	}
552 	uc = ALLOC(struct cl_cache, 1);
553 	if (uc == NULL) {
554 		warnx(cache_enable_str, alloc_err, " ");
555 		mutex_unlock(&dupreq_lock);
556 		return (0);
557 	}
558 	uc->uc_size = size;
559 	uc->uc_nextvictim = 0;
560 	uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
561 	if (uc->uc_entries == NULL) {
562 		warnx(cache_enable_str, alloc_err, "data");
563 		FREE(uc, struct cl_cache, 1);
564 		mutex_unlock(&dupreq_lock);
565 		return (0);
566 	}
567 	MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
568 	uc->uc_fifo = ALLOC(cache_ptr, size);
569 	if (uc->uc_fifo == NULL) {
570 		warnx(cache_enable_str, alloc_err, "fifo");
571 		FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
572 		FREE(uc, struct cl_cache, 1);
573 		mutex_unlock(&dupreq_lock);
574 		return (0);
575 	}
576 	MEMZERO(uc->uc_fifo, cache_ptr, size);
577 	su->su_cache = (char *)(void *)uc;
578 	mutex_unlock(&dupreq_lock);
579 	return (1);
580 }
581 
582 /*
583  * Set an entry in the cache.  It assumes that the uc entry is set from
584  * the earlier call to cache_get() for the same procedure.  This will always
585  * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
586  * by svc_dg_reply().  All this hoopla because the right RPC parameters are
587  * not available at svc_dg_reply time.
588  */
589 
590 static const char cache_set_str[] = "cache_set: %s";
591 static const char cache_set_err1[] = "victim not found";
592 static const char cache_set_err2[] = "victim alloc failed";
593 static const char cache_set_err3[] = "could not allocate new rpc buffer";
594 
595 static void
596 cache_set(xprt, replylen)
597 	SVCXPRT *xprt;
598 	size_t replylen;
599 {
600 	cache_ptr victim;
601 	cache_ptr *vicp;
602 	struct svc_dg_data *su = su_data(xprt);
603 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
604 	u_int loc;
605 	char *newbuf;
606 #ifdef RPC_CACHE_DEBUG
607 	struct netconfig *nconf;
608 	char *uaddr;
609 #endif
610 
611 	mutex_lock(&dupreq_lock);
612 	/*
613 	 * Find space for the new entry, either by
614 	 * reusing an old entry, or by mallocing a new one
615 	 */
616 	victim = uc->uc_fifo[uc->uc_nextvictim];
617 	if (victim != NULL) {
618 		loc = CACHE_LOC(xprt, victim->cache_xid);
619 		for (vicp = &uc->uc_entries[loc];
620 			*vicp != NULL && *vicp != victim;
621 			vicp = &(*vicp)->cache_next)
622 			;
623 		if (*vicp == NULL) {
624 			warnx(cache_set_str, cache_set_err1);
625 			mutex_unlock(&dupreq_lock);
626 			return;
627 		}
628 		*vicp = victim->cache_next;	/* remove from cache */
629 		newbuf = victim->cache_reply;
630 	} else {
631 		victim = ALLOC(struct cache_node, 1);
632 		if (victim == NULL) {
633 			warnx(cache_set_str, cache_set_err2);
634 			mutex_unlock(&dupreq_lock);
635 			return;
636 		}
637 		newbuf = mem_alloc(su->su_iosz);
638 		if (newbuf == NULL) {
639 			warnx(cache_set_str, cache_set_err3);
640 			FREE(victim, struct cache_node, 1);
641 			mutex_unlock(&dupreq_lock);
642 			return;
643 		}
644 	}
645 
646 	/*
647 	 * Store it away
648 	 */
649 #ifdef RPC_CACHE_DEBUG
650 	if (nconf = getnetconfigent(xprt->xp_netid)) {
651 		uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
652 		freenetconfigent(nconf);
653 		printf(
654 	"cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
655 			su->su_xid, uc->uc_prog, uc->uc_vers,
656 			uc->uc_proc, uaddr);
657 		free(uaddr);
658 	}
659 #endif
660 	victim->cache_replylen = replylen;
661 	victim->cache_reply = rpc_buffer(xprt);
662 	rpc_buffer(xprt) = newbuf;
663 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
664 			su->su_iosz, XDR_ENCODE);
665 	victim->cache_xid = su->su_xid;
666 	victim->cache_proc = uc->uc_proc;
667 	victim->cache_vers = uc->uc_vers;
668 	victim->cache_prog = uc->uc_prog;
669 	victim->cache_addr = xprt->xp_rtaddr;
670 	victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
671 	(void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
672 	    (size_t)xprt->xp_rtaddr.len);
673 	loc = CACHE_LOC(xprt, victim->cache_xid);
674 	victim->cache_next = uc->uc_entries[loc];
675 	uc->uc_entries[loc] = victim;
676 	uc->uc_fifo[uc->uc_nextvictim++] = victim;
677 	uc->uc_nextvictim %= uc->uc_size;
678 	mutex_unlock(&dupreq_lock);
679 }
680 
681 /*
682  * Try to get an entry from the cache
683  * return 1 if found, 0 if not found and set the stage for cache_set()
684  */
685 static int
686 cache_get(xprt, msg, replyp, replylenp)
687 	SVCXPRT *xprt;
688 	struct rpc_msg *msg;
689 	char **replyp;
690 	size_t *replylenp;
691 {
692 	u_int loc;
693 	cache_ptr ent;
694 	struct svc_dg_data *su = su_data(xprt);
695 	struct cl_cache *uc = (struct cl_cache *) su->su_cache;
696 #ifdef RPC_CACHE_DEBUG
697 	struct netconfig *nconf;
698 	char *uaddr;
699 #endif
700 
701 	mutex_lock(&dupreq_lock);
702 	loc = CACHE_LOC(xprt, su->su_xid);
703 	for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
704 		if (ent->cache_xid == su->su_xid &&
705 			ent->cache_proc == msg->rm_call.cb_proc &&
706 			ent->cache_vers == msg->rm_call.cb_vers &&
707 			ent->cache_prog == msg->rm_call.cb_prog &&
708 			ent->cache_addr.len == xprt->xp_rtaddr.len &&
709 			(memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
710 				xprt->xp_rtaddr.len) == 0)) {
711 #ifdef RPC_CACHE_DEBUG
712 			if (nconf = getnetconfigent(xprt->xp_netid)) {
713 				uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
714 				freenetconfigent(nconf);
715 				printf(
716 	"cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
717 					su->su_xid, msg->rm_call.cb_prog,
718 					msg->rm_call.cb_vers,
719 					msg->rm_call.cb_proc, uaddr);
720 				free(uaddr);
721 			}
722 #endif
723 			*replyp = ent->cache_reply;
724 			*replylenp = ent->cache_replylen;
725 			mutex_unlock(&dupreq_lock);
726 			return (1);
727 		}
728 	}
729 	/*
730 	 * Failed to find entry
731 	 * Remember a few things so we can do a set later
732 	 */
733 	uc->uc_proc = msg->rm_call.cb_proc;
734 	uc->uc_vers = msg->rm_call.cb_vers;
735 	uc->uc_prog = msg->rm_call.cb_prog;
736 	mutex_unlock(&dupreq_lock);
737 	return (0);
738 }
739