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[glibc.git] / sunrpc / svc_udp.c
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1 /* @(#)svc_udp.c 2.2 88/07/29 4.0 RPCSRC */
2 /*
3 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4 * unrestricted use provided that this legend is included on all tape
5 * media and as a part of the software program in whole or part. Users
6 * may copy or modify Sun RPC without charge, but are not authorized
7 * to license or distribute it to anyone else except as part of a product or
8 * program developed by the user.
10 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14 * Sun RPC is provided with no support and without any obligation on the
15 * part of Sun Microsystems, Inc. to assist in its use, correction,
16 * modification or enhancement.
18 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20 * OR ANY PART THEREOF.
22 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23 * or profits or other special, indirect and consequential damages, even if
24 * Sun has been advised of the possibility of such damages.
26 * Sun Microsystems, Inc.
27 * 2550 Garcia Avenue
28 * Mountain View, California 94043
30 #if !defined(lint) && defined(SCCSIDS)
31 static char sccsid[] = "@(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";
32 #endif
35 * svc_udp.c,
36 * Server side for UDP/IP based RPC. (Does some caching in the hopes of
37 * achieving execute-at-most-once semantics.)
39 * Copyright (C) 1984, Sun Microsystems, Inc.
42 #include <stdio.h>
43 #include <unistd.h>
44 #include <string.h>
45 #include <rpc/rpc.h>
46 #include <sys/socket.h>
47 #include <errno.h>
49 #ifdef USE_IN_LIBIO
50 # include <libio/iolibio.h>
51 # define fputs(s, f) _IO_fputs (s, f)
52 #endif
54 #define rpc_buffer(xprt) ((xprt)->xp_p1)
55 #ifndef MAX
56 #define MAX(a, b) ((a > b) ? a : b)
57 #endif
59 static bool_t svcudp_recv (SVCXPRT *, struct rpc_msg *);
60 static bool_t svcudp_reply (SVCXPRT *, struct rpc_msg *);
61 static enum xprt_stat svcudp_stat (SVCXPRT *);
62 static bool_t svcudp_getargs (SVCXPRT *, xdrproc_t, caddr_t);
63 static bool_t svcudp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
64 static void svcudp_destroy (SVCXPRT *);
66 static const struct xp_ops svcudp_op =
68 svcudp_recv,
69 svcudp_stat,
70 svcudp_getargs,
71 svcudp_reply,
72 svcudp_freeargs,
73 svcudp_destroy
76 static int cache_get (SVCXPRT *, struct rpc_msg *, char **replyp,
77 u_long *replylenp);
78 static void cache_set (SVCXPRT *xprt, u_long replylen);
81 * kept in xprt->xp_p2
83 struct svcudp_data
85 u_int su_iosz; /* byte size of send.recv buffer */
86 u_long su_xid; /* transaction id */
87 XDR su_xdrs; /* XDR handle */
88 char su_verfbody[MAX_AUTH_BYTES]; /* verifier body */
89 char *su_cache; /* cached data, NULL if no cache */
91 #define su_data(xprt) ((struct svcudp_data *)(xprt->xp_p2))
94 * Usage:
95 * xprt = svcudp_create(sock);
97 * If sock<0 then a socket is created, else sock is used.
98 * If the socket, sock is not bound to a port then svcudp_create
99 * binds it to an arbitrary port. In any (successful) case,
100 * xprt->xp_sock is the registered socket number and xprt->xp_port is the
101 * associated port number.
102 * Once *xprt is initialized, it is registered as a transporter;
103 * see (svc.h, xprt_register).
104 * The routines returns NULL if a problem occurred.
106 SVCXPRT *
107 svcudp_bufcreate (sock, sendsz, recvsz)
108 int sock;
109 u_int sendsz, recvsz;
111 bool_t madesock = FALSE;
112 SVCXPRT *xprt;
113 struct svcudp_data *su;
114 struct sockaddr_in addr;
115 size_t len = sizeof (struct sockaddr_in);
117 if (sock == RPC_ANYSOCK)
119 if ((sock = __socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
121 perror (_("svcudp_create: socket creation problem"));
122 return (SVCXPRT *) NULL;
124 madesock = TRUE;
126 __bzero ((char *) &addr, sizeof (addr));
127 addr.sin_family = AF_INET;
128 if (bindresvport (sock, &addr))
130 addr.sin_port = 0;
131 (void) bind (sock, (struct sockaddr *) &addr, len);
133 if (getsockname (sock, (struct sockaddr *) &addr, &len) != 0)
135 perror (_("svcudp_create - cannot getsockname"));
136 if (madesock)
137 (void) __close (sock);
138 return (SVCXPRT *) NULL;
140 xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
141 if (xprt == NULL)
143 (void) fputs (_("svcudp_create: out of memory\n"), stderr);
144 return NULL;
146 su = (struct svcudp_data *) mem_alloc (sizeof (*su));
147 if (su == NULL)
149 (void) fputs (_("svcudp_create: out of memory\n"), stderr);
150 return NULL;
152 su->su_iosz = ((MAX (sendsz, recvsz) + 3) / 4) * 4;
153 if ((rpc_buffer (xprt) = mem_alloc (su->su_iosz)) == NULL)
155 (void) fputs (_("svcudp_create: out of memory\n"), stderr);
156 return NULL;
158 xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_DECODE);
159 su->su_cache = NULL;
160 xprt->xp_p2 = (caddr_t) su;
161 xprt->xp_verf.oa_base = su->su_verfbody;
162 xprt->xp_ops = &svcudp_op;
163 xprt->xp_port = ntohs (addr.sin_port);
164 xprt->xp_sock = sock;
165 xprt_register (xprt);
166 return xprt;
169 SVCXPRT *
170 svcudp_create (sock)
171 int sock;
174 return svcudp_bufcreate (sock, UDPMSGSIZE, UDPMSGSIZE);
177 static enum xprt_stat
178 svcudp_stat (xprt)
179 SVCXPRT *xprt;
182 return XPRT_IDLE;
185 static bool_t
186 svcudp_recv (xprt, msg)
187 SVCXPRT *xprt;
188 struct rpc_msg *msg;
190 struct svcudp_data *su = su_data (xprt);
191 XDR *xdrs = &(su->su_xdrs);
192 int rlen;
193 char *reply;
194 u_long replylen;
195 size_t len;
197 again:
198 /* FIXME -- should xp_addrlen be a size_t? */
199 len = sizeof(struct sockaddr_in);
200 rlen = recvfrom (xprt->xp_sock, rpc_buffer (xprt), (int) su->su_iosz, 0,
201 (struct sockaddr *) &(xprt->xp_raddr), &len);
202 xprt->xp_addrlen = len;
203 if (rlen == -1 && errno == EINTR)
204 goto again;
205 if (rlen < 16) /* < 4 32-bit ints? */
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)
214 if (cache_get (xprt, msg, &reply, &replylen))
216 (void) sendto (xprt->xp_sock, reply, (int) replylen, 0,
217 (struct sockaddr *) &xprt->xp_raddr, len);
218 return TRUE;
221 return TRUE;
224 static bool_t
225 svcudp_reply (xprt, msg)
226 SVCXPRT *xprt;
227 struct rpc_msg *msg;
229 struct svcudp_data *su = su_data (xprt);
230 XDR *xdrs = &(su->su_xdrs);
231 int slen;
232 bool_t stat = FALSE;
234 xdrs->x_op = XDR_ENCODE;
235 XDR_SETPOS (xdrs, 0);
236 msg->rm_xid = su->su_xid;
237 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)
244 stat = TRUE;
245 if (su->su_cache && slen >= 0)
247 cache_set (xprt, (u_long) slen);
251 return stat;
254 static bool_t
255 svcudp_getargs (xprt, xdr_args, args_ptr)
256 SVCXPRT *xprt;
257 xdrproc_t xdr_args;
258 caddr_t args_ptr;
261 return (*xdr_args) (&(su_data (xprt)->su_xdrs), args_ptr);
264 static bool_t
265 svcudp_freeargs (xprt, xdr_args, args_ptr)
266 SVCXPRT *xprt;
267 xdrproc_t xdr_args;
268 caddr_t args_ptr;
270 XDR *xdrs = &(su_data (xprt)->su_xdrs);
272 xdrs->x_op = XDR_FREE;
273 return (*xdr_args) (xdrs, args_ptr);
276 static void
277 svcudp_destroy (xprt)
278 SVCXPRT *xprt;
280 struct svcudp_data *su = su_data (xprt);
282 xprt_unregister (xprt);
283 (void) __close (xprt->xp_sock);
284 XDR_DESTROY (&(su->su_xdrs));
285 mem_free (rpc_buffer (xprt), su->su_iosz);
286 mem_free ((caddr_t) su, sizeof (struct svcudp_data));
287 mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
291 /***********this could be a separate file*********************/
294 * Fifo cache for udp server
295 * Copies pointers to reply buffers into fifo cache
296 * Buffers are sent again if retransmissions are detected.
299 #define SPARSENESS 4 /* 75% sparse */
301 #define CACHE_PERROR(msg) \
302 (void) fprintf(stderr,"%s\n", msg)
304 #define ALLOC(type, size) \
305 (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
307 #define BZERO(addr, type, size) \
308 __bzero((char *) addr, sizeof(type) * (int) (size))
311 * An entry in the cache
313 typedef struct cache_node *cache_ptr;
314 struct cache_node
317 * Index into cache is xid, proc, vers, prog and address
319 u_long cache_xid;
320 u_long cache_proc;
321 u_long cache_vers;
322 u_long cache_prog;
323 struct sockaddr_in cache_addr;
325 * The cached reply and length
327 char *cache_reply;
328 u_long cache_replylen;
330 * Next node on the list, if there is a collision
332 cache_ptr cache_next;
338 * The entire cache
340 struct udp_cache
342 u_long uc_size; /* size of cache */
343 cache_ptr *uc_entries; /* hash table of entries in cache */
344 cache_ptr *uc_fifo; /* fifo list of entries in cache */
345 u_long uc_nextvictim; /* points to next victim in fifo list */
346 u_long uc_prog; /* saved program number */
347 u_long uc_vers; /* saved version number */
348 u_long uc_proc; /* saved procedure number */
349 struct sockaddr_in uc_addr; /* saved caller's address */
354 * the hashing function
356 #define CACHE_LOC(transp, xid) \
357 (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
361 * Enable use of the cache.
362 * Note: there is no disable.
365 svcudp_enablecache (SVCXPRT *transp, u_long size)
367 struct svcudp_data *su = su_data (transp);
368 struct udp_cache *uc;
370 if (su->su_cache != NULL)
372 CACHE_PERROR (_("enablecache: cache already enabled"));
373 return 0;
375 uc = ALLOC (struct udp_cache, 1);
376 if (uc == NULL)
378 CACHE_PERROR (_("enablecache: could not allocate cache"));
379 return 0;
381 uc->uc_size = size;
382 uc->uc_nextvictim = 0;
383 uc->uc_entries = ALLOC (cache_ptr, size * SPARSENESS);
384 if (uc->uc_entries == NULL)
386 CACHE_PERROR (_("enablecache: could not allocate cache data"));
387 return 0;
389 BZERO (uc->uc_entries, cache_ptr, size * SPARSENESS);
390 uc->uc_fifo = ALLOC (cache_ptr, size);
391 if (uc->uc_fifo == NULL)
393 CACHE_PERROR (_("enablecache: could not allocate cache fifo"));
394 return 0;
396 BZERO (uc->uc_fifo, cache_ptr, size);
397 su->su_cache = (char *) uc;
398 return 1;
403 * Set an entry in the cache
405 static void
406 cache_set (SVCXPRT *xprt, u_long replylen)
408 cache_ptr victim;
409 cache_ptr *vicp;
410 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;
416 * Find space for the new entry, either by
417 * reusing an old entry, or by mallocing a new one
419 victim = uc->uc_fifo[uc->uc_nextvictim];
420 if (victim != NULL)
422 loc = CACHE_LOC (xprt, victim->cache_xid);
423 for (vicp = &uc->uc_entries[loc];
424 *vicp != NULL && *vicp != victim;
425 vicp = &(*vicp)->cache_next)
427 if (*vicp == NULL)
429 CACHE_PERROR (_("cache_set: victim not found"));
430 return;
432 *vicp = victim->cache_next; /* remote from cache */
433 newbuf = victim->cache_reply;
435 else
437 victim = ALLOC (struct cache_node, 1);
438 if (victim == NULL)
440 CACHE_PERROR (_("cache_set: victim alloc failed"));
441 return;
443 newbuf = mem_alloc (su->su_iosz);
444 if (newbuf == NULL)
446 CACHE_PERROR (_("cache_set: could not allocate new rpc_buffer"));
447 return;
452 * Store it away
454 victim->cache_replylen = replylen;
455 victim->cache_reply = rpc_buffer (xprt);
456 rpc_buffer (xprt) = newbuf;
457 xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), 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;
471 * Try to get an entry from the cache
472 * return 1 if found, 0 if not found
474 static int
475 cache_get (xprt, msg, replyp, replylenp)
476 SVCXPRT *xprt;
477 struct rpc_msg *msg;
478 char **replyp;
479 u_long *replylenp;
481 u_int loc;
482 cache_ptr ent;
483 struct svcudp_data *su = su_data (xprt);
484 struct udp_cache *uc = (struct udp_cache *) su->su_cache;
486 #define EQADDR(a1, a2) (memcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
488 loc = CACHE_LOC (xprt, su->su_xid);
489 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))
497 *replyp = ent->cache_reply;
498 *replylenp = ent->cache_replylen;
499 return 1;
503 * Failed to find entry
504 * Remember a few things so we can do a set later
506 uc->uc_proc = msg->rm_call.cb_proc;
507 uc->uc_vers = msg->rm_call.cb_vers;
508 uc->uc_prog = msg->rm_call.cb_prog;
509 uc->uc_addr = xprt->xp_raddr;
510 return 0;