1 /* $NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $ */
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21 * OR ANY PART THEREOF.
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29 * Mountain View, California 94043
33 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #ident "@(#)svc_dg.c 1.17 94/04/24 SMI"
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
43 * svc_dg.c, Server side for connectionless RPC.
45 * Does some caching in the hopes of achieving execute-at-most-once semantics.
48 #include "namespace.h"
49 #include "reentrant.h"
50 #include <sys/types.h>
51 #include <sys/socket.h>
53 #include <rpc/svc_dg.h>
59 #ifdef RPC_CACHE_DEBUG
60 #include <netconfig.h>
64 #include "un-namespace.h"
69 #define su_data(xprt) ((struct svc_dg_data *)(xprt->xp_p2))
70 #define rpc_buffer(xprt) ((xprt)->xp_p1)
73 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
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);
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.
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 __no_mem_str[] = "out of memory";
103 svc_dg_create(fd, sendsize, recvsize)
109 struct svc_dg_data *su = NULL;
110 struct __rpc_sockinfo si;
111 struct sockaddr_storage ss;
114 if (!__rpc_fd2sockinfo(fd, &si)) {
115 warnx(svc_dg_str, svc_dg_err1);
119 * Find the receive and the send size
121 sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
122 recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
123 if ((sendsize == 0) || (recvsize == 0)) {
124 warnx(svc_dg_str, svc_dg_err2);
128 xprt = mem_alloc(sizeof (SVCXPRT));
131 memset(xprt, 0, sizeof (SVCXPRT));
133 su = mem_alloc(sizeof (*su));
136 su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
137 if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL)
139 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
144 xprt->xp_verf.oa_base = su->su_verfbody;
146 xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
149 if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0)
151 xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
152 xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
153 xprt->xp_ltaddr.len = slen;
154 memcpy(xprt->xp_ltaddr.buf, &ss, slen);
159 (void) warnx(svc_dg_str, __no_mem_str);
162 (void) mem_free(su, sizeof (*su));
163 (void) mem_free(xprt, sizeof (SVCXPRT));
169 static enum xprt_stat
177 svc_dg_recv(xprt, msg)
181 struct svc_dg_data *su = su_data(xprt);
182 XDR *xdrs = &(su->su_xdrs);
184 struct sockaddr_storage ss;
190 alen = sizeof (struct sockaddr_storage);
191 rlen = _recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz, 0,
192 (struct sockaddr *)(void *)&ss, &alen);
193 if (rlen == -1 && errno == EINTR)
195 if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
197 if (xprt->xp_rtaddr.len < alen) {
198 if (xprt->xp_rtaddr.len != 0)
199 mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
200 xprt->xp_rtaddr.buf = mem_alloc(alen);
201 xprt->xp_rtaddr.len = alen;
203 memcpy(xprt->xp_rtaddr.buf, &ss, alen);
205 if (ss.ss_family == AF_INET) {
206 xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
207 xprt->xp_addrlen = sizeof (struct sockaddr_in);
210 xdrs->x_op = XDR_DECODE;
212 if (! xdr_callmsg(xdrs, msg)) {
215 su->su_xid = msg->rm_xid;
216 if (su->su_cache != NULL) {
217 if (cache_get(xprt, msg, &reply, &replylen)) {
218 (void)_sendto(xprt->xp_fd, reply, replylen, 0,
219 (struct sockaddr *)(void *)&ss, alen);
227 svc_dg_reply(xprt, msg)
231 struct svc_dg_data *su = su_data(xprt);
232 XDR *xdrs = &(su->su_xdrs);
236 xdrs->x_op = XDR_ENCODE;
238 msg->rm_xid = su->su_xid;
239 if (xdr_replymsg(xdrs, msg)) {
240 slen = XDR_GETPOS(xdrs);
241 if (_sendto(xprt->xp_fd, rpc_buffer(xprt), slen, 0,
242 (struct sockaddr *)xprt->xp_rtaddr.buf,
243 (socklen_t)xprt->xp_rtaddr.len) == (ssize_t) slen) {
246 cache_set(xprt, slen);
253 svc_dg_getargs(xprt, xdr_args, args_ptr)
258 return (*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr);
262 svc_dg_freeargs(xprt, xdr_args, args_ptr)
267 XDR *xdrs = &(su_data(xprt)->su_xdrs);
269 xdrs->x_op = XDR_FREE;
270 return (*xdr_args)(xdrs, args_ptr);
277 struct svc_dg_data *su = su_data(xprt);
279 xprt_unregister(xprt);
280 if (xprt->xp_fd != -1)
281 (void)_close(xprt->xp_fd);
282 XDR_DESTROY(&(su->su_xdrs));
283 (void) mem_free(rpc_buffer(xprt), su->su_iosz);
284 (void) mem_free(su, sizeof (*su));
285 if (xprt->xp_rtaddr.buf)
286 (void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
287 if (xprt->xp_ltaddr.buf)
288 (void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
290 (void) free(xprt->xp_tp);
291 (void) mem_free(xprt, sizeof (SVCXPRT));
296 svc_dg_control(xprt, rq, in)
308 static struct xp_ops ops;
309 static struct xp_ops2 ops2;
311 /* VARIABLES PROTECTED BY ops_lock: ops */
313 mutex_lock(&ops_lock);
314 if (ops.xp_recv == NULL) {
315 ops.xp_recv = svc_dg_recv;
316 ops.xp_stat = svc_dg_stat;
317 ops.xp_getargs = svc_dg_getargs;
318 ops.xp_reply = svc_dg_reply;
319 ops.xp_freeargs = svc_dg_freeargs;
320 ops.xp_destroy = svc_dg_destroy;
321 ops2.xp_control = svc_dg_control;
324 xprt->xp_ops2 = &ops2;
325 mutex_unlock(&ops_lock);
328 /* The CACHING COMPONENT */
331 * Could have been a separate file, but some part of it depends upon the
332 * private structure of the client handle.
334 * Fifo cache for cl server
335 * Copies pointers to reply buffers into fifo cache
336 * Buffers are sent again if retransmissions are detected.
339 #define SPARSENESS 4 /* 75% sparse */
341 #define ALLOC(type, size) \
342 (type *) mem_alloc((sizeof (type) * (size)))
344 #define MEMZERO(addr, type, size) \
345 (void) memset((void *) (addr), 0, sizeof (type) * (int) (size))
347 #define FREE(addr, type, size) \
348 mem_free((addr), (sizeof (type) * (size)))
351 * An entry in the cache
353 typedef struct cache_node *cache_ptr;
356 * Index into cache is xid, proc, vers, prog and address
359 rpcproc_t cache_proc;
360 rpcvers_t cache_vers;
361 rpcprog_t cache_prog;
362 struct netbuf cache_addr;
364 * The cached reply and length
367 size_t cache_replylen;
369 * Next node on the list, if there is a collision
371 cache_ptr cache_next;
378 u_int uc_size; /* size of cache */
379 cache_ptr *uc_entries; /* hash table of entries in cache */
380 cache_ptr *uc_fifo; /* fifo list of entries in cache */
381 u_int uc_nextvictim; /* points to next victim in fifo list */
382 rpcprog_t uc_prog; /* saved program number */
383 rpcvers_t uc_vers; /* saved version number */
384 rpcproc_t uc_proc; /* saved procedure number */
389 * the hashing function
391 #define CACHE_LOC(transp, xid) \
392 (xid % (SPARSENESS * ((struct cl_cache *) \
393 su_data(transp)->su_cache)->uc_size))
396 * Enable use of the cache. Returns 1 on success, 0 on failure.
397 * Note: there is no disable.
399 static const char cache_enable_str[] = "svc_enablecache: %s %s";
400 static const char alloc_err[] = "could not allocate cache ";
401 static const char enable_err[] = "cache already enabled";
404 svc_dg_enablecache(transp, size)
408 struct svc_dg_data *su = su_data(transp);
411 mutex_lock(&dupreq_lock);
412 if (su->su_cache != NULL) {
413 (void) warnx(cache_enable_str, enable_err, " ");
414 mutex_unlock(&dupreq_lock);
417 uc = ALLOC(struct cl_cache, 1);
419 warnx(cache_enable_str, alloc_err, " ");
420 mutex_unlock(&dupreq_lock);
424 uc->uc_nextvictim = 0;
425 uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
426 if (uc->uc_entries == NULL) {
427 warnx(cache_enable_str, alloc_err, "data");
428 FREE(uc, struct cl_cache, 1);
429 mutex_unlock(&dupreq_lock);
432 MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
433 uc->uc_fifo = ALLOC(cache_ptr, size);
434 if (uc->uc_fifo == NULL) {
435 warnx(cache_enable_str, alloc_err, "fifo");
436 FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
437 FREE(uc, struct cl_cache, 1);
438 mutex_unlock(&dupreq_lock);
441 MEMZERO(uc->uc_fifo, cache_ptr, size);
442 su->su_cache = (char *)(void *)uc;
443 mutex_unlock(&dupreq_lock);
448 * Set an entry in the cache. It assumes that the uc entry is set from
449 * the earlier call to cache_get() for the same procedure. This will always
450 * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
451 * by svc_dg_reply(). All this hoopla because the right RPC parameters are
452 * not available at svc_dg_reply time.
455 static const char cache_set_str[] = "cache_set: %s";
456 static const char cache_set_err1[] = "victim not found";
457 static const char cache_set_err2[] = "victim alloc failed";
458 static const char cache_set_err3[] = "could not allocate new rpc buffer";
461 cache_set(xprt, replylen)
467 struct svc_dg_data *su = su_data(xprt);
468 struct cl_cache *uc = (struct cl_cache *) su->su_cache;
471 #ifdef RPC_CACHE_DEBUG
472 struct netconfig *nconf;
476 mutex_lock(&dupreq_lock);
478 * Find space for the new entry, either by
479 * reusing an old entry, or by mallocing a new one
481 victim = uc->uc_fifo[uc->uc_nextvictim];
482 if (victim != NULL) {
483 loc = CACHE_LOC(xprt, victim->cache_xid);
484 for (vicp = &uc->uc_entries[loc];
485 *vicp != NULL && *vicp != victim;
486 vicp = &(*vicp)->cache_next)
489 warnx(cache_set_str, cache_set_err1);
490 mutex_unlock(&dupreq_lock);
493 *vicp = victim->cache_next; /* remove from cache */
494 newbuf = victim->cache_reply;
496 victim = ALLOC(struct cache_node, 1);
497 if (victim == NULL) {
498 warnx(cache_set_str, cache_set_err2);
499 mutex_unlock(&dupreq_lock);
502 newbuf = mem_alloc(su->su_iosz);
503 if (newbuf == NULL) {
504 warnx(cache_set_str, cache_set_err3);
505 FREE(victim, struct cache_node, 1);
506 mutex_unlock(&dupreq_lock);
514 #ifdef RPC_CACHE_DEBUG
515 if (nconf = getnetconfigent(xprt->xp_netid)) {
516 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
517 freenetconfigent(nconf);
519 "cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
520 su->su_xid, uc->uc_prog, uc->uc_vers,
525 victim->cache_replylen = replylen;
526 victim->cache_reply = rpc_buffer(xprt);
527 rpc_buffer(xprt) = newbuf;
528 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt),
529 su->su_iosz, XDR_ENCODE);
530 victim->cache_xid = su->su_xid;
531 victim->cache_proc = uc->uc_proc;
532 victim->cache_vers = uc->uc_vers;
533 victim->cache_prog = uc->uc_prog;
534 victim->cache_addr = xprt->xp_rtaddr;
535 victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
536 (void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
537 (size_t)xprt->xp_rtaddr.len);
538 loc = CACHE_LOC(xprt, victim->cache_xid);
539 victim->cache_next = uc->uc_entries[loc];
540 uc->uc_entries[loc] = victim;
541 uc->uc_fifo[uc->uc_nextvictim++] = victim;
542 uc->uc_nextvictim %= uc->uc_size;
543 mutex_unlock(&dupreq_lock);
547 * Try to get an entry from the cache
548 * return 1 if found, 0 if not found and set the stage for cache_set()
551 cache_get(xprt, msg, replyp, replylenp)
559 struct svc_dg_data *su = su_data(xprt);
560 struct cl_cache *uc = (struct cl_cache *) su->su_cache;
561 #ifdef RPC_CACHE_DEBUG
562 struct netconfig *nconf;
566 mutex_lock(&dupreq_lock);
567 loc = CACHE_LOC(xprt, su->su_xid);
568 for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
569 if (ent->cache_xid == su->su_xid &&
570 ent->cache_proc == msg->rm_call.cb_proc &&
571 ent->cache_vers == msg->rm_call.cb_vers &&
572 ent->cache_prog == msg->rm_call.cb_prog &&
573 ent->cache_addr.len == xprt->xp_rtaddr.len &&
574 (memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
575 xprt->xp_rtaddr.len) == 0)) {
576 #ifdef RPC_CACHE_DEBUG
577 if (nconf = getnetconfigent(xprt->xp_netid)) {
578 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
579 freenetconfigent(nconf);
581 "cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
582 su->su_xid, msg->rm_call.cb_prog,
583 msg->rm_call.cb_vers,
584 msg->rm_call.cb_proc, uaddr);
588 *replyp = ent->cache_reply;
589 *replylenp = ent->cache_replylen;
590 mutex_unlock(&dupreq_lock);
595 * Failed to find entry
596 * Remember a few things so we can do a set later
598 uc->uc_proc = msg->rm_call.cb_proc;
599 uc->uc_vers = msg->rm_call.cb_vers;
600 uc->uc_prog = msg->rm_call.cb_prog;
601 mutex_unlock(&dupreq_lock);