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