source: rtems/cpukit/librpc/src/rpc/svc_udp.c @ 885e1e0

4.104.114.95
Last change on this file since 885e1e0 was 885e1e0, checked in by Ralf Corsepius <ralf.corsepius@…>, on 08/01/08 at 14:14:22

Add missing prototypes.
  • Property mode set to 100644
File size: 12.3 KB
Line 
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(SVCXPRT *xprt, struct rpc_msg *msg);
56static bool_t           svcudp_reply(SVCXPRT *xprt, struct rpc_msg *msg);
57static enum xprt_stat   svcudp_stat(SVCXPRT *xprt);
58static bool_t           svcudp_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr);
59static bool_t           svcudp_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr);
60static void             svcudp_destroy(SVCXPRT *xprt);
61static void             cache_set (SVCXPRT *, u_long);
62static int              cache_get (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(
100        int sock,
101        u_int sendsz,
102        u_int recvsz )
103{
104        bool_t madesock = FALSE;
105        register SVCXPRT *xprt;
106        register struct svcudp_data *su;
107        struct sockaddr_in addr;
108        socklen_t len = sizeof(struct sockaddr_in);
109
110        if (sock == RPC_ANYSOCK) {
111                if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
112                        perror("svcudp_create: socket creation problem");
113                        return ((SVCXPRT *)NULL);
114                }
115                madesock = TRUE;
116        }
117        memset((char *)&addr, 0, sizeof (addr));
118        addr.sin_len = sizeof(struct sockaddr_in);
119        addr.sin_family = AF_INET;
120        if (bindresvport(sock, &addr)) {
121                addr.sin_port = 0;
122                (void)bind(sock, (struct sockaddr *)&addr, len);
123        }
124        if (getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {
125                perror("svcudp_create - cannot getsockname");
126                if (madesock)
127                        (void)_RPC_close(sock);
128                return ((SVCXPRT *)NULL);
129        }
130        xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
131        if (xprt == NULL) {
132                (void)fprintf(stderr, "svcudp_create: out of memory\n");
133                return (NULL);
134        }
135        su = (struct svcudp_data *)mem_alloc(sizeof(*su));
136        if (su == NULL) {
137                (void)fprintf(stderr, "svcudp_create: out of memory\n");
138                return (NULL);
139        }
140        su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
141        if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) {
142                (void)fprintf(stderr, "svcudp_create: out of memory\n");
143                return (NULL);
144        }
145        xdrmem_create(
146            &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);
147        su->su_cache = NULL;
148        xprt->xp_p2 = (caddr_t)su;
149        xprt->xp_verf.oa_base = su->su_verfbody;
150        xprt->xp_ops = &svcudp_op;
151        xprt->xp_port = ntohs(addr.sin_port);
152        xprt->xp_sock = sock;
153        xprt_register(xprt);
154        return (xprt);
155}
156
157SVCXPRT *
158svcudp_create(
159        int sock)
160{
161
162        return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
163}
164
165static enum xprt_stat
166svcudp_stat(
167        SVCXPRT *xprt)
168{
169
170        return (XPRT_IDLE);
171}
172
173static bool_t
174svcudp_recv(
175        SVCXPRT *xprt,
176        struct rpc_msg *msg)
177{
178        register struct svcudp_data *su = su_data(xprt);
179        register XDR *xdrs = &(su->su_xdrs);
180        register int rlen;
181        char *reply;
182        u_long replylen;
183
184    again:
185        xprt->xp_addrlen = sizeof(struct sockaddr_in);
186        rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
187            0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
188        if (rlen == -1 && errno == EINTR)
189                goto again;
190        if (rlen == -1 || rlen < 4*sizeof(u_int32_t))
191                return (FALSE);
192        xdrs->x_op = XDR_DECODE;
193        XDR_SETPOS(xdrs, 0);
194        if (! xdr_callmsg(xdrs, msg))
195                return (FALSE);
196        su->su_xid = msg->rm_xid;
197        if (su->su_cache != NULL) {
198                if (cache_get(xprt, msg, &reply, &replylen)) {
199                        (void) sendto(xprt->xp_sock, reply, (int) replylen, 0,
200                          (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);
201                        return (TRUE);
202                }
203        }
204        return (TRUE);
205}
206
207static bool_t
208svcudp_reply(
209        SVCXPRT *xprt,
210        struct rpc_msg *msg)
211{
212        register struct svcudp_data *su = su_data(xprt);
213        register XDR *xdrs = &(su->su_xdrs);
214        register int slen;
215        register bool_t stat = FALSE;
216
217        xdrs->x_op = XDR_ENCODE;
218        XDR_SETPOS(xdrs, 0);
219        msg->rm_xid = su->su_xid;
220        if (xdr_replymsg(xdrs, msg)) {
221                slen = (int)XDR_GETPOS(xdrs);
222                if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
223                    (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
224                    == slen) {
225                        stat = TRUE;
226                        if (su->su_cache && slen >= 0) {
227                                cache_set(xprt, (u_long) slen);
228                        }
229                }
230        }
231        return (stat);
232}
233
234static bool_t
235svcudp_getargs(
236        SVCXPRT *xprt,
237        xdrproc_t xdr_args,
238        caddr_t args_ptr)
239{
240
241        return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
242}
243
244static bool_t
245svcudp_freeargs(
246        SVCXPRT *xprt,
247        xdrproc_t xdr_args,
248        caddr_t args_ptr)
249{
250        register XDR *xdrs = &(su_data(xprt)->su_xdrs);
251
252        xdrs->x_op = XDR_FREE;
253        return ((*xdr_args)(xdrs, args_ptr));
254}
255
256static void
257svcudp_destroy(
258        SVCXPRT *xprt)
259{
260        register struct svcudp_data *su = su_data(xprt);
261
262        xprt_unregister(xprt);
263        (void)_RPC_close(xprt->xp_sock);
264        XDR_DESTROY(&(su->su_xdrs));
265        mem_free(rpc_buffer(xprt), su->su_iosz);
266        mem_free((caddr_t)su, sizeof(struct svcudp_data));
267        mem_free((caddr_t)xprt, sizeof(SVCXPRT));
268}
269
270
271/***********this could be a separate file*********************/
272
273/*
274 * Fifo cache for udp server
275 * Copies pointers to reply buffers into fifo cache
276 * Buffers are sent again if retransmissions are detected.
277 */
278
279#define SPARSENESS 4    /* 75% sparse */
280
281#define CACHE_PERROR(msg)       \
282        (void) fprintf(stderr,"%s\n", msg)
283
284#define ALLOC(type, size)       \
285        (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
286
287#define BZERO(addr, type, size)  \
288        memset((char *) addr, 0, sizeof(type) * (int) (size))
289
290/*
291 * An entry in the cache
292 */
293typedef struct cache_node *cache_ptr;
294struct cache_node {
295        /*
296         * Index into cache is xid, proc, vers, prog and address
297         */
298        u_long cache_xid;
299        u_long cache_proc;
300        u_long cache_vers;
301        u_long cache_prog;
302        struct sockaddr_in cache_addr;
303        /*
304         * The cached reply and length
305         */
306        char * cache_reply;
307        u_long cache_replylen;
308        /*
309         * Next node on the list, if there is a collision
310         */
311        cache_ptr cache_next;
312};
313
314
315
316/*
317 * The entire cache
318 */
319struct udp_cache {
320        u_long uc_size;         /* size of cache */
321        cache_ptr *uc_entries;  /* hash table of entries in cache */
322        cache_ptr *uc_fifo;     /* fifo list of entries in cache */
323        u_long uc_nextvictim;   /* points to next victim in fifo list */
324        u_long uc_prog;         /* saved program number */
325        u_long uc_vers;         /* saved version number */
326        u_long uc_proc;         /* saved procedure number */
327        struct sockaddr_in uc_addr; /* saved caller's address */
328};
329
330
331/*
332 * the hashing function
333 */
334#define CACHE_LOC(transp, xid)  \
335 (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
336
337
338/*
339 * Enable use of the cache.
340 * Note: there is no disable.
341 */
342int svcudp_enablecache(
343        SVCXPRT *transp,
344        u_long size)
345{
346        struct svcudp_data *su = su_data(transp);
347        struct udp_cache *uc;
348
349        if (su->su_cache != NULL) {
350                CACHE_PERROR("enablecache: cache already enabled");
351                return(0);
352        }
353        uc = ALLOC(struct udp_cache, 1);
354        if (uc == NULL) {
355                CACHE_PERROR("enablecache: could not allocate cache");
356                return(0);
357        }
358        uc->uc_size = size;
359        uc->uc_nextvictim = 0;
360        uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
361        if (uc->uc_entries == NULL) {
362                CACHE_PERROR("enablecache: could not allocate cache data");
363                return(0);
364        }
365        BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
366        uc->uc_fifo = ALLOC(cache_ptr, size);
367        if (uc->uc_fifo == NULL) {
368                CACHE_PERROR("enablecache: could not allocate cache fifo");
369                return(0);
370        }
371        BZERO(uc->uc_fifo, cache_ptr, size);
372        su->su_cache = (char *) uc;
373        return(1);
374}
375
376
377/*
378 * Set an entry in the cache
379 */
380static void
381cache_set(
382        SVCXPRT *xprt,
383        u_long replylen)
384{
385        register cache_ptr victim;
386        register cache_ptr *vicp;
387        register struct svcudp_data *su = su_data(xprt);
388        struct udp_cache *uc = (struct udp_cache *) su->su_cache;
389        u_int loc;
390        char *newbuf;
391
392        /*
393         * Find space for the new entry, either by
394         * reusing an old entry, or by mallocing a new one
395         */
396        victim = uc->uc_fifo[uc->uc_nextvictim];
397        if (victim != NULL) {
398                loc = CACHE_LOC(xprt, victim->cache_xid);
399                for (vicp = &uc->uc_entries[loc];
400                  *vicp != NULL && *vicp != victim;
401                  vicp = &(*vicp)->cache_next)
402                                ;
403                if (*vicp == NULL) {
404                        CACHE_PERROR("cache_set: victim not found");
405                        return;
406                }
407                *vicp = victim->cache_next;     /* remote from cache */
408                newbuf = victim->cache_reply;
409        } else {
410                victim = ALLOC(struct cache_node, 1);
411                if (victim == NULL) {
412                        CACHE_PERROR("cache_set: victim alloc failed");
413                        return;
414                }
415                newbuf = mem_alloc(su->su_iosz);
416                if (newbuf == NULL) {
417                        CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
418                        return;
419                }
420        }
421
422        /*
423         * Store it away
424         */
425        victim->cache_replylen = replylen;
426        victim->cache_reply = rpc_buffer(xprt);
427        rpc_buffer(xprt) = newbuf;
428        xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);
429        victim->cache_xid = su->su_xid;
430        victim->cache_proc = uc->uc_proc;
431        victim->cache_vers = uc->uc_vers;
432        victim->cache_prog = uc->uc_prog;
433        victim->cache_addr = uc->uc_addr;
434        loc = CACHE_LOC(xprt, victim->cache_xid);
435        victim->cache_next = uc->uc_entries[loc];
436        uc->uc_entries[loc] = victim;
437        uc->uc_fifo[uc->uc_nextvictim++] = victim;
438        uc->uc_nextvictim %= uc->uc_size;
439}
440
441/*
442 * Try to get an entry from the cache
443 * return 1 if found, 0 if not found
444 */
445static int
446cache_get(
447        SVCXPRT *xprt,
448        struct rpc_msg *msg,
449        char **replyp,
450        u_long *replylenp)
451{
452        u_int loc;
453        register cache_ptr ent;
454        register struct svcudp_data *su = su_data(xprt);
455        register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
456
457#       define EQADDR(a1, a2)   (memcmp(&a1, &a2, sizeof(a1)) == 0)
458
459        loc = CACHE_LOC(xprt, su->su_xid);
460        for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
461                if (ent->cache_xid == su->su_xid &&
462                  ent->cache_proc == uc->uc_proc &&
463                  ent->cache_vers == uc->uc_vers &&
464                  ent->cache_prog == uc->uc_prog &&
465                  EQADDR(ent->cache_addr, uc->uc_addr)) {
466                        *replyp = ent->cache_reply;
467                        *replylenp = ent->cache_replylen;
468                        return(1);
469                }
470        }
471        /*
472         * Failed to find entry
473         * Remember a few things so we can do a set later
474         */
475        uc->uc_proc = msg->rm_call.cb_proc;
476        uc->uc_vers = msg->rm_call.cb_vers;
477        uc->uc_prog = msg->rm_call.cb_prog;
478        uc->uc_addr = xprt->xp_raddr;
479        return(0);
480}
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