3 * Server side for UDP/IP based RPC. (Does some caching in the hopes of
4 * achieving execute-at-most-once semantics.)
6 * Copyright (C) 2012-2015 Free Software Foundation, Inc.
7 * This file is part of the GNU C Library.
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17 * Lesser General Public License for more details.
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23 * Copyright (c) 2010, Oracle America, Inc.
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57 #include <sys/socket.h>
66 #include <libio/iolibio.h>
68 #define rpc_buffer(xprt) ((xprt)->xp_p1)
70 #define MAX(a, b) ((a > b) ? a : b)
73 static bool_t svcudp_recv (SVCXPRT *, struct rpc_msg *);
74 static bool_t svcudp_reply (SVCXPRT *, struct rpc_msg *);
75 static enum xprt_stat svcudp_stat (SVCXPRT *);
76 static bool_t svcudp_getargs (SVCXPRT *, xdrproc_t, caddr_t);
77 static bool_t svcudp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
78 static void svcudp_destroy (SVCXPRT *);
80 static const struct xp_ops svcudp_op =
90 static int cache_get (SVCXPRT *, struct rpc_msg *, char **replyp,
92 static void cache_set (SVCXPRT *xprt, u_long replylen);
99 u_int su_iosz; /* byte size of send.recv buffer */
100 u_long su_xid; /* transaction id */
101 XDR su_xdrs; /* XDR handle */
102 char su_verfbody[MAX_AUTH_BYTES]; /* verifier body */
103 char *su_cache; /* cached data, NULL if no cache */
105 #define su_data(xprt) ((struct svcudp_data *)(xprt->xp_p2))
109 * xprt = svcudp_create(sock);
111 * If sock<0 then a socket is created, else sock is used.
112 * If the socket, sock is not bound to a port then svcudp_create
113 * binds it to an arbitrary port. In any (successful) case,
114 * xprt->xp_sock is the registered socket number and xprt->xp_port is the
115 * associated port number.
116 * Once *xprt is initialized, it is registered as a transporter;
117 * see (svc.h, xprt_register).
118 * The routines returns NULL if a problem occurred.
121 svcudp_bufcreate (sock, sendsz, recvsz)
123 u_int sendsz, recvsz;
125 bool_t madesock = FALSE;
127 struct svcudp_data *su;
128 struct sockaddr_in addr;
129 socklen_t len = sizeof (struct sockaddr_in);
133 if (sock == RPC_ANYSOCK)
135 if ((sock = __socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
137 perror (_("svcudp_create: socket creation problem"));
138 return (SVCXPRT *) NULL;
142 __bzero ((char *) &addr, sizeof (addr));
143 addr.sin_family = AF_INET;
144 if (bindresvport (sock, &addr))
147 (void) __bind (sock, (struct sockaddr *) &addr, len);
149 if (__getsockname (sock, (struct sockaddr *) &addr, &len) != 0)
151 perror (_("svcudp_create - cannot getsockname"));
153 (void) __close (sock);
154 return (SVCXPRT *) NULL;
156 xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
157 su = (struct svcudp_data *) mem_alloc (sizeof (*su));
158 buf = mem_alloc (((MAX (sendsz, recvsz) + 3) / 4) * 4);
159 if (xprt == NULL || su == NULL || buf == NULL)
161 (void) __fxprintf (NULL, "%s: %s",
162 "svcudp_create", _("out of memory\n"));
163 mem_free (xprt, sizeof (SVCXPRT));
164 mem_free (su, sizeof (*su));
165 mem_free (buf, ((MAX (sendsz, recvsz) + 3) / 4) * 4);
168 su->su_iosz = ((MAX (sendsz, recvsz) + 3) / 4) * 4;
169 rpc_buffer (xprt) = buf;
170 xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_DECODE);
172 xprt->xp_p2 = (caddr_t) su;
173 xprt->xp_verf.oa_base = su->su_verfbody;
174 xprt->xp_ops = &svcudp_op;
175 xprt->xp_port = ntohs (addr.sin_port);
176 xprt->xp_sock = sock;
179 if ((sizeof (struct iovec) + sizeof (struct msghdr)
180 + sizeof(struct cmsghdr) + sizeof (struct in_pktinfo))
181 > sizeof (xprt->xp_pad))
183 (void) __fxprintf (NULL,"%s", _("\
184 svcudp_create: xp_pad is too small for IP_PKTINFO\n"));
188 if (__setsockopt (sock, SOL_IP, IP_PKTINFO, (void *) &pad,
190 /* Set the padding to all 1s. */
194 /* Clear the padding. */
196 memset (&xprt->xp_pad [0], pad, sizeof (xprt->xp_pad));
198 xprt_register (xprt);
201 #ifdef EXPORT_RPC_SYMBOLS
202 libc_hidden_def (svcudp_bufcreate)
204 libc_hidden_nolink_sunrpc (svcudp_bufcreate, GLIBC_2_0)
208 svcudp_create (int sock)
210 return svcudp_bufcreate (sock, UDPMSGSIZE, UDPMSGSIZE);
212 #ifdef EXPORT_RPC_SYMBOLS
213 libc_hidden_def (svcudp_create)
215 libc_hidden_nolink_sunrpc (svcudp_create, GLIBC_2_0)
218 static enum xprt_stat
219 svcudp_stat (SVCXPRT *xprt)
226 svcudp_recv (SVCXPRT *xprt, struct rpc_msg *msg)
228 struct svcudp_data *su = su_data (xprt);
229 XDR *xdrs = &(su->su_xdrs);
235 /* It is very tricky when you have IP aliases. We want to make sure
236 that we are sending the packet from the IP address where the
237 incoming packet is addressed to. H.J. */
240 struct msghdr *mesgp;
244 /* FIXME -- should xp_addrlen be a size_t? */
245 len = (socklen_t) sizeof(struct sockaddr_in);
247 iovp = (struct iovec *) &xprt->xp_pad [0];
248 mesgp = (struct msghdr *) &xprt->xp_pad [sizeof (struct iovec)];
249 if (mesgp->msg_iovlen)
251 iovp->iov_base = rpc_buffer (xprt);
252 iovp->iov_len = su->su_iosz;
253 mesgp->msg_iov = iovp;
254 mesgp->msg_iovlen = 1;
255 mesgp->msg_name = &(xprt->xp_raddr);
256 mesgp->msg_namelen = len;
257 mesgp->msg_control = &xprt->xp_pad [sizeof (struct iovec)
258 + sizeof (struct msghdr)];
259 mesgp->msg_controllen = sizeof(xprt->xp_pad)
260 - sizeof (struct iovec) - sizeof (struct msghdr);
261 rlen = __recvmsg (xprt->xp_sock, mesgp, 0);
264 struct cmsghdr *cmsg;
265 len = mesgp->msg_namelen;
266 cmsg = CMSG_FIRSTHDR (mesgp);
268 || CMSG_NXTHDR (mesgp, cmsg) != NULL
269 || cmsg->cmsg_level != SOL_IP
270 || cmsg->cmsg_type != IP_PKTINFO
271 || cmsg->cmsg_len < (sizeof (struct cmsghdr)
272 + sizeof (struct in_pktinfo)))
274 /* Not a simple IP_PKTINFO, ignore it. */
275 mesgp->msg_control = NULL;
276 mesgp->msg_controllen = 0;
280 /* It was a simple IP_PKTIFO as we expected, discard the
282 struct in_pktinfo *pkti = (struct in_pktinfo *) CMSG_DATA (cmsg);
283 pkti->ipi_ifindex = 0;
289 rlen = __recvfrom (xprt->xp_sock, rpc_buffer (xprt),
290 (int) su->su_iosz, 0,
291 (struct sockaddr *) &(xprt->xp_raddr), &len);
292 xprt->xp_addrlen = len;
297 __svc_accept_failed ();
299 if (rlen < 16) /* < 4 32-bit ints? */
301 xdrs->x_op = XDR_DECODE;
302 XDR_SETPOS (xdrs, 0);
303 if (!xdr_callmsg (xdrs, msg))
305 su->su_xid = msg->rm_xid;
306 if (su->su_cache != NULL)
308 if (cache_get (xprt, msg, &reply, &replylen))
311 if (mesgp->msg_iovlen)
313 iovp->iov_base = reply;
314 iovp->iov_len = replylen;
315 (void) __sendmsg (xprt->xp_sock, mesgp, 0);
319 (void) __sendto (xprt->xp_sock, reply, (int) replylen, 0,
320 (struct sockaddr *) &xprt->xp_raddr, len);
328 svcudp_reply (SVCXPRT *xprt, struct rpc_msg *msg)
330 struct svcudp_data *su = su_data (xprt);
331 XDR *xdrs = &(su->su_xdrs);
336 struct msghdr *mesgp;
339 xdrs->x_op = XDR_ENCODE;
340 XDR_SETPOS (xdrs, 0);
341 msg->rm_xid = su->su_xid;
342 if (xdr_replymsg (xdrs, msg))
344 slen = (int) XDR_GETPOS (xdrs);
346 mesgp = (struct msghdr *) &xprt->xp_pad [sizeof (struct iovec)];
347 if (mesgp->msg_iovlen)
349 iovp = (struct iovec *) &xprt->xp_pad [0];
350 iovp->iov_base = rpc_buffer (xprt);
351 iovp->iov_len = slen;
352 sent = __sendmsg (xprt->xp_sock, mesgp, 0);
356 sent = __sendto (xprt->xp_sock, rpc_buffer (xprt), slen, 0,
357 (struct sockaddr *) &(xprt->xp_raddr),
362 if (su->su_cache && slen >= 0)
364 cache_set (xprt, (u_long) slen);
372 svcudp_getargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
375 return (*xdr_args) (&(su_data (xprt)->su_xdrs), args_ptr);
379 svcudp_freeargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
381 XDR *xdrs = &(su_data (xprt)->su_xdrs);
383 xdrs->x_op = XDR_FREE;
384 return (*xdr_args) (xdrs, args_ptr);
388 svcudp_destroy (SVCXPRT *xprt)
390 struct svcudp_data *su = su_data (xprt);
392 xprt_unregister (xprt);
393 (void) __close (xprt->xp_sock);
394 XDR_DESTROY (&(su->su_xdrs));
395 mem_free (rpc_buffer (xprt), su->su_iosz);
396 mem_free ((caddr_t) su, sizeof (struct svcudp_data));
397 mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
401 /***********this could be a separate file*********************/
404 * Fifo cache for udp server
405 * Copies pointers to reply buffers into fifo cache
406 * Buffers are sent again if retransmissions are detected.
409 #define SPARSENESS 4 /* 75% sparse */
411 #define CACHE_PERROR(msg) \
412 (void) __fxprintf(NULL, "%s\n", msg)
414 #define ALLOC(type, size) \
415 (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
417 #define CALLOC(type, size) \
418 (type *) calloc (sizeof (type), size)
421 * An entry in the cache
423 typedef struct cache_node *cache_ptr;
427 * Index into cache is xid, proc, vers, prog and address
433 struct sockaddr_in cache_addr;
435 * The cached reply and length
438 u_long cache_replylen;
440 * Next node on the list, if there is a collision
442 cache_ptr cache_next;
452 u_long uc_size; /* size of cache */
453 cache_ptr *uc_entries; /* hash table of entries in cache */
454 cache_ptr *uc_fifo; /* fifo list of entries in cache */
455 u_long uc_nextvictim; /* points to next victim in fifo list */
456 u_long uc_prog; /* saved program number */
457 u_long uc_vers; /* saved version number */
458 u_long uc_proc; /* saved procedure number */
459 struct sockaddr_in uc_addr; /* saved caller's address */
464 * the hashing function
466 #define CACHE_LOC(transp, xid) \
467 (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
471 * Enable use of the cache.
472 * Note: there is no disable.
475 svcudp_enablecache (SVCXPRT *transp, u_long size)
477 struct svcudp_data *su = su_data (transp);
478 struct udp_cache *uc;
480 if (su->su_cache != NULL)
482 CACHE_PERROR (_("enablecache: cache already enabled"));
485 uc = ALLOC (struct udp_cache, 1);
488 CACHE_PERROR (_("enablecache: could not allocate cache"));
492 uc->uc_nextvictim = 0;
493 uc->uc_entries = CALLOC (cache_ptr, size * SPARSENESS);
494 if (uc->uc_entries == NULL)
496 mem_free (uc, sizeof (struct udp_cache));
497 CACHE_PERROR (_("enablecache: could not allocate cache data"));
500 uc->uc_fifo = CALLOC (cache_ptr, size);
501 if (uc->uc_fifo == NULL)
503 mem_free (uc->uc_entries, size * SPARSENESS);
504 mem_free (uc, sizeof (struct udp_cache));
505 CACHE_PERROR (_("enablecache: could not allocate cache fifo"));
508 su->su_cache = (char *) uc;
511 libc_hidden_nolink_sunrpc (svcudp_enablecache, GLIBC_2_0)
515 * Set an entry in the cache
518 cache_set (SVCXPRT *xprt, u_long replylen)
522 struct svcudp_data *su = su_data (xprt);
523 struct udp_cache *uc = (struct udp_cache *) su->su_cache;
528 * Find space for the new entry, either by
529 * reusing an old entry, or by mallocing a new one
531 victim = uc->uc_fifo[uc->uc_nextvictim];
534 loc = CACHE_LOC (xprt, victim->cache_xid);
535 for (vicp = &uc->uc_entries[loc];
536 *vicp != NULL && *vicp != victim;
537 vicp = &(*vicp)->cache_next)
541 CACHE_PERROR (_("cache_set: victim not found"));
544 *vicp = victim->cache_next; /* remote from cache */
545 newbuf = victim->cache_reply;
549 victim = ALLOC (struct cache_node, 1);
552 CACHE_PERROR (_("cache_set: victim alloc failed"));
555 newbuf = mem_alloc (su->su_iosz);
558 mem_free (victim, sizeof (struct cache_node));
559 CACHE_PERROR (_("cache_set: could not allocate new rpc_buffer"));
567 victim->cache_replylen = replylen;
568 victim->cache_reply = rpc_buffer (xprt);
569 rpc_buffer (xprt) = newbuf;
570 xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_ENCODE);
571 victim->cache_xid = su->su_xid;
572 victim->cache_proc = uc->uc_proc;
573 victim->cache_vers = uc->uc_vers;
574 victim->cache_prog = uc->uc_prog;
575 victim->cache_addr = uc->uc_addr;
576 loc = CACHE_LOC (xprt, victim->cache_xid);
577 victim->cache_next = uc->uc_entries[loc];
578 uc->uc_entries[loc] = victim;
579 uc->uc_fifo[uc->uc_nextvictim++] = victim;
580 uc->uc_nextvictim %= uc->uc_size;
584 * Try to get an entry from the cache
585 * return 1 if found, 0 if not found
588 cache_get (xprt, msg, replyp, replylenp)
596 struct svcudp_data *su = su_data (xprt);
597 struct udp_cache *uc = (struct udp_cache *) su->su_cache;
599 #define EQADDR(a1, a2) (memcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
601 loc = CACHE_LOC (xprt, su->su_xid);
602 for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next)
604 if (ent->cache_xid == su->su_xid &&
605 ent->cache_proc == uc->uc_proc &&
606 ent->cache_vers == uc->uc_vers &&
607 ent->cache_prog == uc->uc_prog &&
608 EQADDR (ent->cache_addr, uc->uc_addr))
610 *replyp = ent->cache_reply;
611 *replylenp = ent->cache_replylen;
616 * Failed to find entry
617 * Remember a few things so we can do a set later
619 uc->uc_proc = msg->rm_call.cb_proc;
620 uc->uc_vers = msg->rm_call.cb_vers;
621 uc->uc_prog = msg->rm_call.cb_prog;
622 memcpy (&uc->uc_addr, &xprt->xp_raddr, sizeof (uc->uc_addr));