1 /*
2 * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
3 *
4 * Copyright (c) 2010, Oracle America, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 *
10 * * Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials
15 * provided with the distribution.
16 * * Neither the name of the "Oracle America, Inc." nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 * TCP based RPC supports 'batched calls'.
34 * A sequence of calls may be batched-up in a send buffer. The rpc call
35 * return immediately to the client even though the call was not necessarily
36 * sent. The batching occurs if the results' xdr routine is NULL (0) AND
37 * the rpc timeout value is zero (see clnt.h, rpc).
38 *
39 * Clients should NOT casually batch calls that in fact return results; that is,
40 * the server side should be aware that a call is batched and not produce any
41 * return message. Batched calls that produce many result messages can
42 * deadlock (netlock) the client and the server....
43 *
44 * Now go hang yourself.
45 */
46
47 #include <netdb.h>
48 #include <errno.h>
49 #include <stdio.h>
50 #include <unistd.h>
51 #include <libintl.h>
52 #include <rpc/rpc.h>
53 #include <sys/poll.h>
54 #include <sys/socket.h>
55 #include <rpc/pmap_clnt.h>
56 #include <wchar.h>
57 #include <shlib-compat.h>
58
59 extern u_long _create_xid (void);
60
61 #define MCALL_MSG_SIZE 24
62
63 struct ct_data
64 {
65 int ct_sock;
66 bool_t ct_closeit;
67 struct timeval ct_wait;
68 bool_t ct_waitset; /* wait set by clnt_control? */
69 struct sockaddr_in ct_addr;
70 struct rpc_err ct_error;
71 char ct_mcall[MCALL_MSG_SIZE]; /* marshalled callmsg */
72 u_int ct_mpos; /* pos after marshal */
73 XDR ct_xdrs;
74 };
75
76 static int readtcp (char *, char *, int);
77 static int writetcp (char *, char *, int);
78
79 static enum clnt_stat clnttcp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
80 xdrproc_t, caddr_t, struct timeval);
81 static void clnttcp_abort (void);
82 static void clnttcp_geterr (CLIENT *, struct rpc_err *);
83 static bool_t clnttcp_freeres (CLIENT *, xdrproc_t, caddr_t);
84 static bool_t clnttcp_control (CLIENT *, int, char *);
85 static void clnttcp_destroy (CLIENT *);
86
87 static const struct clnt_ops tcp_ops =
88 {
89 clnttcp_call,
90 clnttcp_abort,
91 clnttcp_geterr,
92 clnttcp_freeres,
93 clnttcp_destroy,
94 clnttcp_control
95 };
96
97 /*
98 * Create a client handle for a tcp/ip connection.
99 * If *sockp<0, *sockp is set to a newly created TCP socket and it is
100 * connected to raddr. If *sockp non-negative then
101 * raddr is ignored. The rpc/tcp package does buffering
102 * similar to stdio, so the client must pick send and receive buffer sizes,];
103 * 0 => use the default.
104 * If raddr->sin_port is 0, then a binder on the remote machine is
105 * consulted for the right port number.
106 * NB: *sockp is copied into a private area.
107 * NB: It is the clients responsibility to close *sockp.
108 * NB: The rpch->cl_auth is set null authentication. Caller may wish to set this
109 * something more useful.
110 */
111 CLIENT *
112 clnttcp_create (struct sockaddr_in *raddr, u_long prog, u_long vers,
113 int *sockp, u_int sendsz, u_int recvsz)
114 {
115 CLIENT *h;
116 struct ct_data *ct;
117 struct rpc_msg call_msg;
118
119 h = (CLIENT *) mem_alloc (sizeof (*h));
120 ct = (struct ct_data *) mem_alloc (sizeof (*ct));
121 if (h == NULL || ct == NULL)
122 {
123 struct rpc_createerr *ce = &get_rpc_createerr ();
124 (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
125 ce->cf_stat = RPC_SYSTEMERROR;
126 ce->cf_error.re_errno = ENOMEM;
127 goto fooy;
128 }
129
130 /*
131 * If no port number given ask the pmap for one
132 */
133 if (raddr->sin_port == 0)
134 {
135 u_short port;
136 if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)
137 {
138 mem_free ((caddr_t) ct, sizeof (struct ct_data));
139 mem_free ((caddr_t) h, sizeof (CLIENT));
140 return ((CLIENT *) NULL);
141 }
142 raddr->sin_port = htons (port);
143 }
144
145 /*
146 * If no socket given, open one
147 */
148 if (*sockp < 0)
149 {
150 *sockp = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
151 (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
152 if ((*sockp < 0)
153 || (__connect (*sockp, (struct sockaddr *) raddr,
154 sizeof (*raddr)) < 0))
155 {
156 struct rpc_createerr *ce = &get_rpc_createerr ();
157 ce->cf_stat = RPC_SYSTEMERROR;
158 ce->cf_error.re_errno = errno;
159 if (*sockp >= 0)
160 (void) __close (*sockp);
161 goto fooy;
162 }
163 ct->ct_closeit = TRUE;
164 }
165 else
166 {
167 ct->ct_closeit = FALSE;
168 }
169
170 /*
171 * Set up private data struct
172 */
173 ct->ct_sock = *sockp;
174 ct->ct_wait.tv_usec = 0;
175 ct->ct_waitset = FALSE;
176 ct->ct_addr = *raddr;
177
178 /*
179 * Initialize call message
180 */
181 call_msg.rm_xid = _create_xid ();
182 call_msg.rm_direction = CALL;
183 call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
184 call_msg.rm_call.cb_prog = prog;
185 call_msg.rm_call.cb_vers = vers;
186
187 /*
188 * pre-serialize the static part of the call msg and stash it away
189 */
190 xdrmem_create (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE, XDR_ENCODE);
191 if (!xdr_callhdr (&(ct->ct_xdrs), &call_msg))
192 {
193 if (ct->ct_closeit)
194 {
195 (void) __close (*sockp);
196 }
197 goto fooy;
198 }
199 ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));
200 XDR_DESTROY (&(ct->ct_xdrs));
201
202 /*
203 * Create a client handle which uses xdrrec for serialization
204 * and authnone for authentication.
205 */
206 xdrrec_create (&(ct->ct_xdrs), sendsz, recvsz,
207 (caddr_t) ct, readtcp, writetcp);
208 h->cl_ops = (struct clnt_ops *) &tcp_ops;
209 h->cl_private = (caddr_t) ct;
210 h->cl_auth = authnone_create ();
211 return h;
212
213 fooy:
214 /*
215 * Something goofed, free stuff and barf
216 */
217 mem_free ((caddr_t) ct, sizeof (struct ct_data));
218 mem_free ((caddr_t) h, sizeof (CLIENT));
219 return ((CLIENT *) NULL);
220 }
221 #ifdef EXPORT_RPC_SYMBOLS
222 libc_hidden_def (clnttcp_create)
223 #else
224 libc_hidden_nolink_sunrpc (clnttcp_create, GLIBC_2_0)
225 #endif
226
227 static enum clnt_stat
228 clnttcp_call (CLIENT *h, u_long proc, xdrproc_t xdr_args, caddr_t args_ptr,
229 xdrproc_t xdr_results, caddr_t results_ptr,
230 struct timeval timeout)
231 {
232 struct ct_data *ct = (struct ct_data *) h->cl_private;
233 XDR *xdrs = &(ct->ct_xdrs);
234 struct rpc_msg reply_msg;
235 u_long x_id;
236 uint32_t *msg_x_id = (uint32_t *) (ct->ct_mcall); /* yuk */
237 bool_t shipnow;
238 int refreshes = 2;
239
240 if (!ct->ct_waitset)
241 {
242 ct->ct_wait = timeout;
243 }
244
245 shipnow =
246 (xdr_results == (xdrproc_t) 0 && ct->ct_wait.tv_sec == 0
247 && ct->ct_wait.tv_usec == 0) ? FALSE : TRUE;
248
249 call_again:
250 xdrs->x_op = XDR_ENCODE;
251 ct->ct_error.re_status = RPC_SUCCESS;
252 x_id = ntohl (--(*msg_x_id));
253 if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||
254 (!XDR_PUTLONG (xdrs, (long *) &proc)) ||
255 (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||
256 (!(*xdr_args) (xdrs, args_ptr)))
257 {
258 if (ct->ct_error.re_status == RPC_SUCCESS)
259 ct->ct_error.re_status = RPC_CANTENCODEARGS;
260 (void) xdrrec_endofrecord (xdrs, TRUE);
261 return (ct->ct_error.re_status);
262 }
263 if (!xdrrec_endofrecord (xdrs, shipnow))
264 return ct->ct_error.re_status = RPC_CANTSEND;
265 if (!shipnow)
266 return RPC_SUCCESS;
267 /*
268 * Hack to provide rpc-based message passing
269 */
270 if (ct->ct_wait.tv_sec == 0 && ct->ct_wait.tv_usec == 0)
271 {
272 return ct->ct_error.re_status = RPC_TIMEDOUT;
273 }
274
275
276 /*
277 * Keep receiving until we get a valid transaction id
278 */
279 xdrs->x_op = XDR_DECODE;
280 while (TRUE)
281 {
282 reply_msg.acpted_rply.ar_verf = _null_auth;
283 reply_msg.acpted_rply.ar_results.where = NULL;
284 reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
285 if (!xdrrec_skiprecord (xdrs))
286 return (ct->ct_error.re_status);
287 /* now decode and validate the response header */
288 if (!xdr_replymsg (xdrs, &reply_msg))
289 {
290 if (ct->ct_error.re_status == RPC_SUCCESS)
291 continue;
292 return ct->ct_error.re_status;
293 }
294 if ((uint32_t) reply_msg.rm_xid == (uint32_t) x_id)
295 break;
296 }
297
298 /*
299 * process header
300 */
301 _seterr_reply (&reply_msg, &(ct->ct_error));
302 if (ct->ct_error.re_status == RPC_SUCCESS)
303 {
304 if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))
305 {
306 ct->ct_error.re_status = RPC_AUTHERROR;
307 ct->ct_error.re_why = AUTH_INVALIDRESP;
308 }
309 else if (!(*xdr_results) (xdrs, results_ptr))
310 {
311 if (ct->ct_error.re_status == RPC_SUCCESS)
312 ct->ct_error.re_status = RPC_CANTDECODERES;
313 }
314 /* free verifier ... */
315 if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
316 {
317 xdrs->x_op = XDR_FREE;
318 (void) xdr_opaque_auth (xdrs, &(reply_msg.acpted_rply.ar_verf));
319 }
320 } /* end successful completion */
321 else
322 {
323 /* maybe our credentials need to be refreshed ... */
324 if (refreshes-- && AUTH_REFRESH (h->cl_auth))
325 goto call_again;
326 } /* end of unsuccessful completion */
327 return ct->ct_error.re_status;
328 }
329
330 static void
331 clnttcp_geterr (CLIENT *h, struct rpc_err *errp)
332 {
333 struct ct_data *ct =
334 (struct ct_data *) h->cl_private;
335
336 *errp = ct->ct_error;
337 }
338
339 static bool_t
340 clnttcp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
341 {
342 struct ct_data *ct = (struct ct_data *) cl->cl_private;
343 XDR *xdrs = &(ct->ct_xdrs);
344
345 xdrs->x_op = XDR_FREE;
346 return (*xdr_res) (xdrs, res_ptr);
347 }
348
349 static void
350 clnttcp_abort (void)
351 {
352 }
353
354 static bool_t
355 clnttcp_control (CLIENT *cl, int request, char *info)
356 {
357 struct ct_data *ct = (struct ct_data *) cl->cl_private;
358 u_long ul;
359 uint32_t ui32;
360
361
362 switch (request)
363 {
364 case CLSET_FD_CLOSE:
365 ct->ct_closeit = TRUE;
366 break;
367 case CLSET_FD_NCLOSE:
368 ct->ct_closeit = FALSE;
369 break;
370 case CLSET_TIMEOUT:
371 ct->ct_wait = *(struct timeval *) info;
372 ct->ct_waitset = TRUE;
373 break;
374 case CLGET_TIMEOUT:
375 *(struct timeval *) info = ct->ct_wait;
376 break;
377 case CLGET_SERVER_ADDR:
378 *(struct sockaddr_in *) info = ct->ct_addr;
379 break;
380 case CLGET_FD:
381 *(int *)info = ct->ct_sock;
382 break;
383 case CLGET_XID:
384 /*
385 * use the knowledge that xid is the
386 * first element in the call structure *.
387 * This will get the xid of the PREVIOUS call
388 */
389 memcpy (&ui32, ct->ct_mcall, sizeof (ui32));
390 ul = ntohl (ui32);
391 memcpy (info, &ul, sizeof (ul));
392 break;
393 case CLSET_XID:
394 /* This will set the xid of the NEXT call */
395 memcpy (&ul, info, sizeof (ul));
396 ui32 = htonl (ul - 1);
397 memcpy (ct->ct_mcall, &ui32, sizeof (ui32));
398 /* decrement by 1 as clnttcp_call() increments once */
399 break;
400 case CLGET_VERS:
401 /*
402 * This RELIES on the information that, in the call body,
403 * the version number field is the fifth field from the
404 * beginning of the RPC header. MUST be changed if the
405 * call_struct is changed
406 */
407 memcpy (&ui32, ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT, sizeof (ui32));
408 ul = ntohl (ui32);
409 memcpy (info, &ul, sizeof (ul));
410 break;
411 case CLSET_VERS:
412 memcpy (&ul, info, sizeof (ul));
413 ui32 = htonl (ul);
414 memcpy (ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));
415 break;
416 case CLGET_PROG:
417 /*
418 * This RELIES on the information that, in the call body,
419 * the program number field is the field from the
420 * beginning of the RPC header. MUST be changed if the
421 * call_struct is changed
422 */
423 memcpy (&ui32, ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT, sizeof (ui32));
424 ul = ntohl (ui32);
425 memcpy (info, &ul, sizeof (ul));
426 break;
427 case CLSET_PROG:
428 memcpy (&ul, info, sizeof (ul));
429 ui32 = htonl (ul);
430 memcpy (ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));
431 break;
432 /* The following are only possible with TI-RPC */
433 case CLGET_RETRY_TIMEOUT:
434 case CLSET_RETRY_TIMEOUT:
435 case CLGET_SVC_ADDR:
436 case CLSET_SVC_ADDR:
437 case CLSET_PUSH_TIMOD:
438 case CLSET_POP_TIMOD:
439 default:
440 return FALSE;
441 }
442 return TRUE;
443 }
444
445
446 static void
447 clnttcp_destroy (CLIENT *h)
448 {
449 struct ct_data *ct =
450 (struct ct_data *) h->cl_private;
451
452 if (ct->ct_closeit)
453 {
454 (void) __close (ct->ct_sock);
455 }
456 XDR_DESTROY (&(ct->ct_xdrs));
457 mem_free ((caddr_t) ct, sizeof (struct ct_data));
458 mem_free ((caddr_t) h, sizeof (CLIENT));
459 }
460
461 /*
462 * Interface between xdr serializer and tcp connection.
463 * Behaves like the system calls, read & write, but keeps some error state
464 * around for the rpc level.
465 */
466 static int
467 readtcp (char *ctptr, char *buf, int len)
468 {
469 struct ct_data *ct = (struct ct_data *)ctptr;
470 struct pollfd fd;
471 int milliseconds = (ct->ct_wait.tv_sec * 1000) +
472 (ct->ct_wait.tv_usec / 1000);
473
474 if (len == 0)
475 return 0;
476
477 fd.fd = ct->ct_sock;
478 fd.events = POLLIN;
479 while (TRUE)
480 {
481 switch (__poll(&fd, 1, milliseconds))
482 {
483 case 0:
484 ct->ct_error.re_status = RPC_TIMEDOUT;
485 return -1;
486
487 case -1:
488 if (errno == EINTR)
489 continue;
490 ct->ct_error.re_status = RPC_CANTRECV;
491 ct->ct_error.re_errno = errno;
492 return -1;
493 }
494 break;
495 }
496 switch (len = __read (ct->ct_sock, buf, len))
497 {
498
499 case 0:
500 /* premature eof */
501 ct->ct_error.re_errno = ECONNRESET;
502 ct->ct_error.re_status = RPC_CANTRECV;
503 len = -1; /* it's really an error */
504 break;
505
506 case -1:
507 ct->ct_error.re_errno = errno;
508 ct->ct_error.re_status = RPC_CANTRECV;
509 break;
510 }
511 return len;
512 }
513
514 static int
515 writetcp (char *ctptr, char *buf, int len)
516 {
517 int i, cnt;
518 struct ct_data *ct = (struct ct_data*)ctptr;
519
520 for (cnt = len; cnt > 0; cnt -= i, buf += i)
521 {
522 if ((i = __write (ct->ct_sock, buf, cnt)) == -1)
523 {
524 ct->ct_error.re_errno = errno;
525 ct->ct_error.re_status = RPC_CANTSEND;
526 return -1;
527 }
528 }
529 return len;
530 }