xref: /titanic_41/usr/src/ucblib/librpcsoc/svc_udp.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #pragma ident	"%Z%%M%	%I%	%E% SMI"
41 
42 /*
43  * svc_udp.c,
44  * Server side for UDP/IP based RPC.  (Does some caching in the hopes of
45  * achieving execute-at-most-once semantics.)
46  */
47 
48 #include <rpc/rpc.h>
49 #include <rpc/clnt_soc.h>
50 #include <sys/socket.h>
51 #include <errno.h>
52 #include <syslog.h>
53 #include <malloc.h>
54 #include <stdio.h>
55 
56 
57 #define	rpc_buffer(xprt) ((xprt)->xp_p1)
58 
59 static struct xp_ops *svcudp_ops();
60 
61 extern int errno;
62 extern SVCXPRT *svc_xprt_alloc();
63 extern void svc_xprt_free();
64 extern int _socket(int, int, int);
65 extern int _bind(int, const struct sockaddr *, int);
66 extern int _getsockname(int, struct sockaddr *, int *);
67 extern int _listen(int, int);
68 extern int _accept(int, struct sockaddr *, int *);
69 extern int bindresvport(int, struct sockaddr_in *);
70 extern int _recvfrom(int, char *, int, int,
71 		struct sockaddr *, int *);
72 extern int _sendto(int, const char *, int, int,
73 		const struct sockaddr *, int);
74 
75 static int cache_get(SVCXPRT *, struct rpc_msg *,
76 		char **, uint_t *);
77 static void cache_set(SVCXPRT *, uint_t);
78 
79 /*
80  * kept in xprt->xp_p2
81  */
82 struct svcudp_data {
83 	u_int   su_iosz;		/* byte size of send.recv buffer */
84 	uint32_t su_xid;		/* transaction id */
85 	XDR	su_xdrs;		/* XDR handle */
86 	char	su_verfbody[MAX_AUTH_BYTES];	/* verifier body */
87 	char * 	su_cache;	/* cached data, NULL if no cache */
88 };
89 #define	su_data(xprt)	((struct svcudp_data *)(xprt->xp_p2))
90 
91 /*
92  * Usage:
93  *	xprt = svcudp_create(sock);
94  *
95  * If sock<0 then a socket is created, else sock is used.
96  * If the socket, sock is not bound to a port then svcudp_create
97  * binds it to an arbitrary port.  In any (successful) case,
98  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
99  * associated port number.
100  * Once *xprt is initialized, it is registered as a transporter;
101  * see (svc.h, xprt_register).
102  * The routines returns NULL if a problem occurred.
103  */
104 SVCXPRT *
svcudp_bufcreate(sock,sendsz,recvsz)105 svcudp_bufcreate(sock, sendsz, recvsz)
106 	register int sock;
107 	u_int sendsz, recvsz;
108 {
109 	bool_t madesock = FALSE;
110 	register SVCXPRT *xprt;
111 	register struct svcudp_data *su;
112 	struct sockaddr_in addr;
113 	int len = sizeof (struct sockaddr_in);
114 
115 	if (sock == RPC_ANYSOCK) {
116 		if ((sock = _socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
117 			(void) syslog(LOG_ERR, "svcudp_create: socket",
118 				" creation problem: %m");
119 			return ((SVCXPRT *)NULL);
120 		}
121 		madesock = TRUE;
122 	}
123 	memset((char *)&addr, 0, sizeof (addr));
124 	addr.sin_family = AF_INET;
125 	if (bindresvport(sock, &addr)) {
126 		addr.sin_port = 0;
127 		(void) _bind(sock, (struct sockaddr *)&addr, len);
128 	}
129 	if (_getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {
130 		(void) syslog(LOG_ERR, "svcudp_create -",
131 			" cannot getsockname: %m");
132 		if (madesock)
133 			(void) close(sock);
134 		return ((SVCXPRT *)NULL);
135 	}
136 	xprt = svc_xprt_alloc();
137 	if (xprt == NULL) {
138 		(void) syslog(LOG_ERR, "svcudp_create: out of memory");
139 		if (madesock)
140 			(void) close(sock);
141 		return ((SVCXPRT *)NULL);
142 	}
143 	su = (struct svcudp_data *)mem_alloc(sizeof (*su));
144 	if (su == NULL) {
145 		(void) syslog(LOG_ERR, "svcudp_create: out of memory");
146 		svc_xprt_free(xprt);
147 		if (madesock)
148 			(void) close(sock);
149 		return ((SVCXPRT *)NULL);
150 	}
151 	su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
152 	if ((rpc_buffer(xprt) = (char *)mem_alloc(su->su_iosz)) == NULL) {
153 		(void) syslog(LOG_ERR, "svcudp_create: out of memory");
154 		mem_free((char *) su, sizeof (*su));
155 		svc_xprt_free(xprt);
156 		if (madesock)
157 			(void) close(sock);
158 		return ((SVCXPRT *)NULL);
159 	}
160 	xdrmem_create(
161 	    &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);
162 	su->su_cache = NULL;
163 	xprt->xp_p2 = (caddr_t)su;
164 	xprt->xp_netid = NULL;
165 	xprt->xp_verf.oa_base = su->su_verfbody;
166 	xprt->xp_ops = svcudp_ops();
167 	xprt->xp_port = ntohs(addr.sin_port);
168 	xprt->xp_sock = sock;
169 	xprt->xp_rtaddr.buf = &xprt->xp_raddr[0];
170 	xprt_register(xprt);
171 	return (xprt);
172 }
173 
174 SVCXPRT *
svcudp_create(sock)175 svcudp_create(sock)
176 	int sock;
177 {
178 
179 	return (svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
180 }
181 
182 static enum xprt_stat
svcudp_stat(xprt)183 svcudp_stat(xprt)
184 	SVCXPRT *xprt;
185 {
186 
187 	return (XPRT_IDLE);
188 }
189 
190 static bool_t
svcudp_recv(xprt,msg)191 svcudp_recv(xprt, msg)
192 	register SVCXPRT *xprt;
193 	struct rpc_msg *msg;
194 {
195 	register struct svcudp_data *su = su_data(xprt);
196 	register XDR *xdrs = &(su->su_xdrs);
197 	register int rlen;
198 	char *reply;
199 	uint_t replylen;
200 
201 	again:
202 	xprt->xp_addrlen = sizeof (struct sockaddr_in);
203 	rlen = _recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
204 	    0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
205 	if (rlen == -1 && errno == EINTR)
206 		goto again;
207 	if (rlen < 4*sizeof (uint32_t))
208 		return (FALSE);
209 	xdrs->x_op = XDR_DECODE;
210 	XDR_SETPOS(xdrs, 0);
211 	if (! xdr_callmsg(xdrs, msg))
212 		return (FALSE);
213 	su->su_xid = msg->rm_xid;
214 	if (su->su_cache != NULL) {
215 		if (cache_get(xprt, msg, &reply, &replylen)) {
216 			(void) _sendto(xprt->xp_sock, reply, (int) replylen, 0,
217 				(struct sockaddr *) &xprt->xp_raddr,
218 				xprt->xp_addrlen);
219 			return (TRUE);
220 		}
221 	}
222 	return (TRUE);
223 }
224 
225 static bool_t
svcudp_reply(xprt,msg)226 svcudp_reply(xprt, msg)
227 	register SVCXPRT *xprt;
228 	struct rpc_msg *msg;
229 {
230 	register struct svcudp_data *su = su_data(xprt);
231 	register XDR *xdrs = &(su->su_xdrs);
232 	register int slen;
233 	register bool_t stat = FALSE;
234 
235 	xdrs->x_op = XDR_ENCODE;
236 	XDR_SETPOS(xdrs, 0);
237 	msg->rm_xid = su->su_xid;
238 	if (xdr_replymsg(xdrs, msg)) {
239 		slen = (int)XDR_GETPOS(xdrs);
240 		if (_sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
241 		    (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
242 		    == slen) {
243 			stat = TRUE;
244 			if (su->su_cache && slen >= 0) {
245 				(void) cache_set(xprt, (uint_t) slen);
246 			}
247 		}
248 	}
249 	return (stat);
250 }
251 
252 static bool_t
svcudp_getargs(xprt,xdr_args,args_ptr)253 svcudp_getargs(xprt, xdr_args, args_ptr)
254 	SVCXPRT *xprt;
255 	xdrproc_t xdr_args;
256 	caddr_t args_ptr;
257 {
258 
259 	return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
260 }
261 
262 static bool_t
svcudp_freeargs(xprt,xdr_args,args_ptr)263 svcudp_freeargs(xprt, xdr_args, args_ptr)
264 	SVCXPRT *xprt;
265 	xdrproc_t xdr_args;
266 	caddr_t args_ptr;
267 {
268 	register XDR *xdrs = &(su_data(xprt)->su_xdrs);
269 
270 	xdrs->x_op = XDR_FREE;
271 	return ((*xdr_args)(xdrs, args_ptr));
272 }
273 
274 static void
svcudp_destroy(xprt)275 svcudp_destroy(xprt)
276 	register SVCXPRT *xprt;
277 {
278 	register struct svcudp_data *su = su_data(xprt);
279 
280 	xprt_unregister(xprt);
281 	(void) close(xprt->xp_sock);
282 	XDR_DESTROY(&(su->su_xdrs));
283 	mem_free(rpc_buffer(xprt), su->su_iosz);
284 	mem_free((caddr_t)su, sizeof (struct svcudp_data));
285 	svc_xprt_free(xprt);
286 }
287 
288 
289 /* **********this could be a separate file********************* */
290 
291 /*
292  * Fifo cache for udp server
293  * Copies pointers to reply buffers into fifo cache
294  * Buffers are sent again if retransmissions are detected.
295  */
296 
297 #define	SPARSENESS 4	/* 75% sparse */
298 
299 #define	ALLOC(type, size)	\
300 	(type *) mem_alloc((unsigned) (sizeof (type) * (size)))
301 
302 #define	BZERO(addr, type, size)	 \
303 	memset((char *) (addr), 0, sizeof (type) * (int) (size))
304 
305 #define	FREE(addr, type, size)	\
306 	(void) mem_free((char *) (addr), (sizeof (type) * (size)))
307 
308 /*
309  * An entry in the cache
310  */
311 typedef struct cache_node *cache_ptr;
312 struct cache_node {
313 	/*
314 	 * Index into cache is xid, proc, vers, prog and address
315 	 */
316 	uint32_t cache_xid;
317 	uint32_t cache_proc;
318 	uint32_t cache_vers;
319 	uint32_t cache_prog;
320 	struct sockaddr_in cache_addr;
321 	/*
322 	 * The cached reply and length
323 	 */
324 	char * cache_reply;
325 	uint32_t cache_replylen;
326 	/*
327 	 * Next node on the list, if there is a collision
328 	 */
329 	cache_ptr cache_next;
330 };
331 
332 
333 
334 /*
335  * The entire cache
336  */
337 struct udp_cache {
338 	uint32_t uc_size;		/* size of cache */
339 	cache_ptr *uc_entries;	/* hash table of entries in cache */
340 	cache_ptr *uc_fifo;	/* fifo list of entries in cache */
341 	uint32_t uc_nextvictim;	/* points to next victim in fifo list */
342 	uint32_t uc_prog;		/* saved program number */
343 	uint32_t uc_vers;		/* saved version number */
344 	uint32_t uc_proc;		/* saved procedure number */
345 	struct sockaddr_in uc_addr; /* saved caller's address */
346 };
347 
348 
349 /*
350  * the hashing function
351  */
352 #define	CACHE_LOC(transp, xid)	\
353 	(xid % (SPARSENESS*((struct udp_cache *) \
354 	su_data(transp)->su_cache)->uc_size))
355 
356 
357 /*
358  * Enable use of the cache.
359  * Note: there is no disable.
360  */
361 int
svcudp_enablecache(transp,size)362 svcudp_enablecache(transp, size)
363 	SVCXPRT *transp;
364 	uint_t size;
365 {
366 	struct svcudp_data *su = su_data(transp);
367 	struct udp_cache *uc;
368 
369 	if (su->su_cache != NULL) {
370 		(void) syslog(LOG_ERR, "enablecache: cache already enabled");
371 		return (0);
372 	}
373 	uc = ALLOC(struct udp_cache, 1);
374 	if (uc == NULL) {
375 		(void) syslog(LOG_ERR, "enablecache: could not allocate cache");
376 		return (0);
377 	}
378 	uc->uc_size = size;
379 	uc->uc_nextvictim = 0;
380 	uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
381 	if (uc->uc_entries == NULL) {
382 		(void) syslog(LOG_ERR, "enablecache: could not",
383 			" allocate cache data");
384 		FREE(uc, struct udp_cache, 1);
385 		return (0);
386 	}
387 	BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
388 	uc->uc_fifo = ALLOC(cache_ptr, size);
389 	if (uc->uc_fifo == NULL) {
390 		(void) syslog(LOG_ERR, "enablecache: could not",
391 			" allocate cache fifo");
392 		FREE((char *)uc->uc_entries, cache_ptr, size * SPARSENESS);
393 		FREE((char *)uc, struct udp_cache, 1);
394 		return (0);
395 	}
396 	BZERO(uc->uc_fifo, cache_ptr, size);
397 	su->su_cache = (char *) uc;
398 	return (1);
399 }
400 
401 
402 /*
403  * Set an entry in the cache
404  */
405 static void
cache_set(xprt,replylen)406 cache_set(xprt, replylen)
407 	SVCXPRT *xprt;
408 	uint_t replylen;
409 {
410 	register cache_ptr victim;
411 	register cache_ptr *vicp;
412 	register struct svcudp_data *su = su_data(xprt);
413 	struct udp_cache *uc = (struct udp_cache *) su->su_cache;
414 	u_int loc;
415 	char *newbuf;
416 
417 	/*
418 	 * Find space for the new entry, either by
419 	 * reusing an old entry, or by mallocing a new one
420 	 */
421 	victim = uc->uc_fifo[uc->uc_nextvictim];
422 	if (victim != NULL) {
423 		loc = CACHE_LOC(xprt, victim->cache_xid);
424 		for (vicp = &uc->uc_entries[loc];
425 			*vicp != NULL && *vicp != victim;
426 			vicp = &(*vicp)->cache_next)
427 				;
428 		if (*vicp == NULL) {
429 			(void) syslog(LOG_ERR, "cache_set: victim not found");
430 			return;
431 		}
432 		*vicp = victim->cache_next;	/* remote from cache */
433 		newbuf = victim->cache_reply;
434 	} else {
435 		victim = ALLOC(struct cache_node, 1);
436 		if (victim == NULL) {
437 			(void) syslog(LOG_ERR, "cache_set: victim alloc",
438 				" failed");
439 			return;
440 		}
441 		newbuf = (char *)mem_alloc(su->su_iosz);
442 		if (newbuf == NULL) {
443 			(void) syslog(LOG_ERR, "cache_set: could not",
444 				" allocate new rpc_buffer");
445 			FREE(victim, struct cache_node, 1);
446 			return;
447 		}
448 	}
449 
450 	/*
451 	 * Store it away
452 	 */
453 	victim->cache_replylen = replylen;
454 	victim->cache_reply = rpc_buffer(xprt);
455 	rpc_buffer(xprt) = newbuf;
456 	xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
457 		su->su_iosz, XDR_ENCODE);
458 	victim->cache_xid = su->su_xid;
459 	victim->cache_proc = uc->uc_proc;
460 	victim->cache_vers = uc->uc_vers;
461 	victim->cache_prog = uc->uc_prog;
462 	victim->cache_addr = uc->uc_addr;
463 	loc = CACHE_LOC(xprt, victim->cache_xid);
464 	victim->cache_next = uc->uc_entries[loc];
465 	uc->uc_entries[loc] = victim;
466 	uc->uc_fifo[uc->uc_nextvictim++] = victim;
467 	uc->uc_nextvictim %= uc->uc_size;
468 }
469 
470 /*
471  * Try to get an entry from the cache
472  * return 1 if found, 0 if not found
473  */
474 static int
cache_get(xprt,msg,replyp,replylenp)475 cache_get(xprt, msg, replyp, replylenp)
476 	SVCXPRT *xprt;
477 	struct rpc_msg *msg;
478 	char **replyp;
479 	uint_t *replylenp;
480 {
481 	u_int loc;
482 	register cache_ptr ent;
483 	register struct svcudp_data *su = su_data(xprt);
484 	register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
485 
486 #define	EQADDR(a1, a2) \
487 	(memcmp((char *)&a1, (char *)&a2, sizeof (a1)) == 0)
488 
489 	loc = CACHE_LOC(xprt, su->su_xid);
490 	for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
491 		if (ent->cache_xid == su->su_xid &&
492 			ent->cache_proc == uc->uc_proc &&
493 			ent->cache_vers == uc->uc_vers &&
494 			ent->cache_prog == uc->uc_prog &&
495 			EQADDR(ent->cache_addr, uc->uc_addr)) {
496 			*replyp = ent->cache_reply;
497 			*replylenp = ent->cache_replylen;
498 			return (1);
499 		}
500 	}
501 	/*
502 	 * Failed to find entry
503 	 * Remember a few things so we can do a set later
504 	 */
505 	uc->uc_proc = msg->rm_call.cb_proc;
506 	uc->uc_vers = msg->rm_call.cb_vers;
507 	uc->uc_prog = msg->rm_call.cb_prog;
508 	memcpy((char *)&uc->uc_addr, (char *)&xprt->xp_raddr,
509 		sizeof (struct sockaddr_in));
510 	return (0);
511 }
512 
513 static struct xp_ops *
svcudp_ops()514 svcudp_ops()
515 {
516 	static struct xp_ops ops;
517 
518 	if (ops.xp_recv == NULL) {
519 		ops.xp_recv = svcudp_recv;
520 		ops.xp_stat = svcudp_stat;
521 		ops.xp_getargs = svcudp_getargs;
522 		ops.xp_reply = svcudp_reply;
523 		ops.xp_freeargs = svcudp_freeargs;
524 		ops.xp_destroy = svcudp_destroy;
525 	}
526 	return (&ops);
527 }
528