source: rtems/cpukit/librpc/src/rpc/svc_udp.c @ 3239698

4.104.114.84.95
Last change on this file since 3239698 was 3239698, checked in by Ralf Corsepius <ralf.corsepius@…>, on 04/15/04 at 13:26:21

Remove stray white spaces.
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File size: 12.3 KB
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1/*
2 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3 * unrestricted use provided that this legend is included on all tape
4 * media and as a part of the software program in whole or part.  Users
5 * may copy or modify Sun RPC without charge, but are not authorized
6 * to license or distribute it to anyone else except as part of a product or
7 * program developed by the user.
8 *
9 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12 *
13 * Sun RPC is provided with no support and without any obligation on the
14 * part of Sun Microsystems, Inc. to assist in its use, correction,
15 * modification or enhancement.
16 *
17 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19 * OR ANY PART THEREOF.
20 *
21 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22 * or profits or other special, indirect and consequential damages, even if
23 * Sun has been advised of the possibility of such damages.
24 *
25 * Sun Microsystems, Inc.
26 * 2550 Garcia Avenue
27 * Mountain View, California  94043
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31/*static char *sccsid = "from: @(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";*/
32/*static char *sccsid = "from: @(#)svc_udp.c    2.2 88/07/29 4.0 RPCSRC";*/
33static char *rcsid = "$FreeBSD: src/lib/libc/rpc/svc_udp.c,v 1.13 2000/01/27 23:06:41 jasone Exp $";
34#endif
35
36/*
37 * svc_udp.c,
38 * Server side for UDP/IP based RPC.  (Does some caching in the hopes of
39 * achieving execute-at-most-once semantics.)
40 *
41 * Copyright (C) 1984, Sun Microsystems, Inc.
42 */
43
44#include <stdio.h>
45#include <stdlib.h>
46#include <unistd.h>
47#include <string.h>
48#include <rpc/rpc.h>
49#include <sys/socket.h>
50#include <errno.h>
51
52#define rpc_buffer(xprt) ((xprt)->xp_p1)
53#define MAX(a, b)     ((a > b) ? a : b)
54
55static bool_t           svcudp_recv();
56static bool_t           svcudp_reply();
57static enum xprt_stat   svcudp_stat();
58static bool_t           svcudp_getargs();
59static bool_t           svcudp_freeargs();
60static void             svcudp_destroy();
61static void             cache_set __P((SVCXPRT *, u_long));
62static int              cache_get __P((SVCXPRT *, struct rpc_msg *, char **, u_long *));
63
64static struct xp_ops svcudp_op = {
65        svcudp_recv,
66        svcudp_stat,
67        svcudp_getargs,
68        svcudp_reply,
69        svcudp_freeargs,
70        svcudp_destroy
71};
72
73/*
74 * kept in xprt->xp_p2
75 */
76struct svcudp_data {
77        u_int   su_iosz;        /* byte size of send.recv buffer */
78        u_long  su_xid;         /* transaction id */
79        XDR     su_xdrs;        /* XDR handle */
80        char    su_verfbody[MAX_AUTH_BYTES];    /* verifier body */
81        char *  su_cache;       /* cached data, NULL if no cache */
82};
83#define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))
84
85/*
86 * Usage:
87 *      xprt = svcudp_create(sock);
88 *
89 * If sock<0 then a socket is created, else sock is used.
90 * If the socket, sock is not bound to a port then svcudp_create
91 * binds it to an arbitrary port.  In any (successful) case,
92 * xprt->xp_sock is the registered socket number and xprt->xp_port is the
93 * associated port number.
94 * Once *xprt is initialized, it is registered as a transporter;
95 * see (svc.h, xprt_register).
96 * The routines returns NULL if a problem occurred.
97 */
98SVCXPRT *
99svcudp_bufcreate(sock, sendsz, recvsz)
100        register int sock;
101        u_int sendsz, recvsz;
102{
103        bool_t madesock = FALSE;
104        register SVCXPRT *xprt;
105        register struct svcudp_data *su;
106        struct sockaddr_in addr;
107        int len = sizeof(struct sockaddr_in);
108
109        if (sock == RPC_ANYSOCK) {
110                if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
111                        perror("svcudp_create: socket creation problem");
112                        return ((SVCXPRT *)NULL);
113                }
114                madesock = TRUE;
115        }
116        memset((char *)&addr, 0, sizeof (addr));
117        addr.sin_len = sizeof(struct sockaddr_in);
118        addr.sin_family = AF_INET;
119        if (bindresvport(sock, &addr)) {
120                addr.sin_port = 0;
121                (void)bind(sock, (struct sockaddr *)&addr, len);
122        }
123        if (getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {
124                perror("svcudp_create - cannot getsockname");
125                if (madesock)
126                        (void)_RPC_close(sock);
127                return ((SVCXPRT *)NULL);
128        }
129        xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
130        if (xprt == NULL) {
131                (void)fprintf(stderr, "svcudp_create: out of memory\n");
132                return (NULL);
133        }
134        su = (struct svcudp_data *)mem_alloc(sizeof(*su));
135        if (su == NULL) {
136                (void)fprintf(stderr, "svcudp_create: out of memory\n");
137                return (NULL);
138        }
139        su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
140        if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) {
141                (void)fprintf(stderr, "svcudp_create: out of memory\n");
142                return (NULL);
143        }
144        xdrmem_create(
145            &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);
146        su->su_cache = NULL;
147        xprt->xp_p2 = (caddr_t)su;
148        xprt->xp_verf.oa_base = su->su_verfbody;
149        xprt->xp_ops = &svcudp_op;
150        xprt->xp_port = ntohs(addr.sin_port);
151        xprt->xp_sock = sock;
152        xprt_register(xprt);
153        return (xprt);
154}
155
156SVCXPRT *
157svcudp_create(sock)
158        int sock;
159{
160
161        return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
162}
163
164static enum xprt_stat
165svcudp_stat(xprt)
166        SVCXPRT *xprt;
167{
168
169        return (XPRT_IDLE);
170}
171
172static bool_t
173svcudp_recv(xprt, msg)
174        register SVCXPRT *xprt;
175        struct rpc_msg *msg;
176{
177        register struct svcudp_data *su = su_data(xprt);
178        register XDR *xdrs = &(su->su_xdrs);
179        register int rlen;
180        char *reply;
181        u_long replylen;
182
183    again:
184        xprt->xp_addrlen = sizeof(struct sockaddr_in);
185        rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
186            0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
187        if (rlen == -1 && errno == EINTR)
188                goto again;
189        if (rlen == -1 || rlen < 4*sizeof(u_int32_t))
190                return (FALSE);
191        xdrs->x_op = XDR_DECODE;
192        XDR_SETPOS(xdrs, 0);
193        if (! xdr_callmsg(xdrs, msg))
194                return (FALSE);
195        su->su_xid = msg->rm_xid;
196        if (su->su_cache != NULL) {
197                if (cache_get(xprt, msg, &reply, &replylen)) {
198                        (void) sendto(xprt->xp_sock, reply, (int) replylen, 0,
199                          (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);
200                        return (TRUE);
201                }
202        }
203        return (TRUE);
204}
205
206static bool_t
207svcudp_reply(xprt, msg)
208        register SVCXPRT *xprt;
209        struct rpc_msg *msg;
210{
211        register struct svcudp_data *su = su_data(xprt);
212        register XDR *xdrs = &(su->su_xdrs);
213        register int slen;
214        register bool_t stat = FALSE;
215
216        xdrs->x_op = XDR_ENCODE;
217        XDR_SETPOS(xdrs, 0);
218        msg->rm_xid = su->su_xid;
219        if (xdr_replymsg(xdrs, msg)) {
220                slen = (int)XDR_GETPOS(xdrs);
221                if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
222                    (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
223                    == slen) {
224                        stat = TRUE;
225                        if (su->su_cache && slen >= 0) {
226                                cache_set(xprt, (u_long) slen);
227                        }
228                }
229        }
230        return (stat);
231}
232
233static bool_t
234svcudp_getargs(xprt, xdr_args, args_ptr)
235        SVCXPRT *xprt;
236        xdrproc_t xdr_args;
237        caddr_t args_ptr;
238{
239
240        return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
241}
242
243static bool_t
244svcudp_freeargs(xprt, xdr_args, args_ptr)
245        SVCXPRT *xprt;
246        xdrproc_t xdr_args;
247        caddr_t args_ptr;
248{
249        register XDR *xdrs = &(su_data(xprt)->su_xdrs);
250
251        xdrs->x_op = XDR_FREE;
252        return ((*xdr_args)(xdrs, args_ptr));
253}
254
255static void
256svcudp_destroy(xprt)
257        register SVCXPRT *xprt;
258{
259        register struct svcudp_data *su = su_data(xprt);
260
261        xprt_unregister(xprt);
262        (void)_RPC_close(xprt->xp_sock);
263        XDR_DESTROY(&(su->su_xdrs));
264        mem_free(rpc_buffer(xprt), su->su_iosz);
265        mem_free((caddr_t)su, sizeof(struct svcudp_data));
266        mem_free((caddr_t)xprt, sizeof(SVCXPRT));
267}
268
269
270/***********this could be a separate file*********************/
271
272/*
273 * Fifo cache for udp server
274 * Copies pointers to reply buffers into fifo cache
275 * Buffers are sent again if retransmissions are detected.
276 */
277
278#define SPARSENESS 4    /* 75% sparse */
279
280#define CACHE_PERROR(msg)       \
281        (void) fprintf(stderr,"%s\n", msg)
282
283#define ALLOC(type, size)       \
284        (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
285
286#define BZERO(addr, type, size)  \
287        memset((char *) addr, 0, sizeof(type) * (int) (size))
288
289/*
290 * An entry in the cache
291 */
292typedef struct cache_node *cache_ptr;
293struct cache_node {
294        /*
295         * Index into cache is xid, proc, vers, prog and address
296         */
297        u_long cache_xid;
298        u_long cache_proc;
299        u_long cache_vers;
300        u_long cache_prog;
301        struct sockaddr_in cache_addr;
302        /*
303         * The cached reply and length
304         */
305        char * cache_reply;
306        u_long cache_replylen;
307        /*
308         * Next node on the list, if there is a collision
309         */
310        cache_ptr cache_next;
311};
312
313
314
315/*
316 * The entire cache
317 */
318struct udp_cache {
319        u_long uc_size;         /* size of cache */
320        cache_ptr *uc_entries;  /* hash table of entries in cache */
321        cache_ptr *uc_fifo;     /* fifo list of entries in cache */
322        u_long uc_nextvictim;   /* points to next victim in fifo list */
323        u_long uc_prog;         /* saved program number */
324        u_long uc_vers;         /* saved version number */
325        u_long uc_proc;         /* saved procedure number */
326        struct sockaddr_in uc_addr; /* saved caller's address */
327};
328
329
330/*
331 * the hashing function
332 */
333#define CACHE_LOC(transp, xid)  \
334 (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
335
336
337/*
338 * Enable use of the cache.
339 * Note: there is no disable.
340 */
341int svcudp_enablecache(transp, size)
342        SVCXPRT *transp;
343        u_long size;
344{
345        struct svcudp_data *su = su_data(transp);
346        struct udp_cache *uc;
347
348        if (su->su_cache != NULL) {
349                CACHE_PERROR("enablecache: cache already enabled");
350                return(0);
351        }
352        uc = ALLOC(struct udp_cache, 1);
353        if (uc == NULL) {
354                CACHE_PERROR("enablecache: could not allocate cache");
355                return(0);
356        }
357        uc->uc_size = size;
358        uc->uc_nextvictim = 0;
359        uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
360        if (uc->uc_entries == NULL) {
361                CACHE_PERROR("enablecache: could not allocate cache data");
362                return(0);
363        }
364        BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
365        uc->uc_fifo = ALLOC(cache_ptr, size);
366        if (uc->uc_fifo == NULL) {
367                CACHE_PERROR("enablecache: could not allocate cache fifo");
368                return(0);
369        }
370        BZERO(uc->uc_fifo, cache_ptr, size);
371        su->su_cache = (char *) uc;
372        return(1);
373}
374
375
376/*
377 * Set an entry in the cache
378 */
379static void
380cache_set(xprt, replylen)
381        SVCXPRT *xprt;
382        u_long replylen;
383{
384        register cache_ptr victim;
385        register cache_ptr *vicp;
386        register struct svcudp_data *su = su_data(xprt);
387        struct udp_cache *uc = (struct udp_cache *) su->su_cache;
388        u_int loc;
389        char *newbuf;
390
391        /*
392         * Find space for the new entry, either by
393         * reusing an old entry, or by mallocing a new one
394         */
395        victim = uc->uc_fifo[uc->uc_nextvictim];
396        if (victim != NULL) {
397                loc = CACHE_LOC(xprt, victim->cache_xid);
398                for (vicp = &uc->uc_entries[loc];
399                  *vicp != NULL && *vicp != victim;
400                  vicp = &(*vicp)->cache_next)
401                                ;
402                if (*vicp == NULL) {
403                        CACHE_PERROR("cache_set: victim not found");
404                        return;
405                }
406                *vicp = victim->cache_next;     /* remote from cache */
407                newbuf = victim->cache_reply;
408        } else {
409                victim = ALLOC(struct cache_node, 1);
410                if (victim == NULL) {
411                        CACHE_PERROR("cache_set: victim alloc failed");
412                        return;
413                }
414                newbuf = mem_alloc(su->su_iosz);
415                if (newbuf == NULL) {
416                        CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
417                        return;
418                }
419        }
420
421        /*
422         * Store it away
423         */
424        victim->cache_replylen = replylen;
425        victim->cache_reply = rpc_buffer(xprt);
426        rpc_buffer(xprt) = newbuf;
427        xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);
428        victim->cache_xid = su->su_xid;
429        victim->cache_proc = uc->uc_proc;
430        victim->cache_vers = uc->uc_vers;
431        victim->cache_prog = uc->uc_prog;
432        victim->cache_addr = uc->uc_addr;
433        loc = CACHE_LOC(xprt, victim->cache_xid);
434        victim->cache_next = uc->uc_entries[loc];
435        uc->uc_entries[loc] = victim;
436        uc->uc_fifo[uc->uc_nextvictim++] = victim;
437        uc->uc_nextvictim %= uc->uc_size;
438}
439
440/*
441 * Try to get an entry from the cache
442 * return 1 if found, 0 if not found
443 */
444static int
445cache_get(xprt, msg, replyp, replylenp)
446        SVCXPRT *xprt;
447        struct rpc_msg *msg;
448        char **replyp;
449        u_long *replylenp;
450{
451        u_int loc;
452        register cache_ptr ent;
453        register struct svcudp_data *su = su_data(xprt);
454        register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
455
456#       define EQADDR(a1, a2)   (memcmp(&a1, &a2, sizeof(a1)) == 0)
457
458        loc = CACHE_LOC(xprt, su->su_xid);
459        for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
460                if (ent->cache_xid == su->su_xid &&
461                  ent->cache_proc == uc->uc_proc &&
462                  ent->cache_vers == uc->uc_vers &&
463                  ent->cache_prog == uc->uc_prog &&
464                  EQADDR(ent->cache_addr, uc->uc_addr)) {
465                        *replyp = ent->cache_reply;
466                        *replylenp = ent->cache_replylen;
467                        return(1);
468                }
469        }
470        /*
471         * Failed to find entry
472         * Remember a few things so we can do a set later
473         */
474        uc->uc_proc = msg->rm_call.cb_proc;
475        uc->uc_vers = msg->rm_call.cb_vers;
476        uc->uc_prog = msg->rm_call.cb_prog;
477        uc->uc_addr = xprt->xp_raddr;
478        return(0);
479}
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