1 /*
2 * svc_tcp.c, Server side for TCP/IP based RPC.
3 *
4 * Copyright (C) 2012-2023 Free Software Foundation, Inc.
5 * This file is part of the GNU C Library.
6 *
7 * The GNU C Library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * The GNU C Library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with the GNU C Library; if not, see
19 * <https://www.gnu.org/licenses/>.
20 *
21 * Copyright (c) 2010, Oracle America, Inc.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions are
25 * met:
26 *
27 * * Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the following disclaimer.
29 * * Redistributions in binary form must reproduce the above
30 * copyright notice, this list of conditions and the following
31 * disclaimer in the documentation and/or other materials
32 * provided with the distribution.
33 * * Neither the name of the "Oracle America, Inc." nor the names of its
34 * contributors may be used to endorse or promote products derived
35 * from this software without specific prior written permission.
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
38 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
39 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
40 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
41 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
42 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
43 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
44 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
45 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
46 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
47 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
48 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
49 *
50 * Actually implements two flavors of transporter -
51 * a tcp rendezvouser (a listener and connection establisher)
52 * and a record/tcp stream.
53 */
54
55 #include <stdio.h>
56 #include <unistd.h>
57 #include <string.h>
58 #include <libintl.h>
59 #include <rpc/rpc.h>
60 #include <sys/socket.h>
61 #include <sys/poll.h>
62 #include <errno.h>
63 #include <stdlib.h>
64
65 #include <wchar.h>
66 #include <libio/iolibio.h>
67 #include <shlib-compat.h>
68
69 /*
70 * Ops vector for TCP/IP based rpc service handle
71 */
72 static bool_t svctcp_recv (SVCXPRT *, struct rpc_msg *);
73 static enum xprt_stat svctcp_stat (SVCXPRT *);
74 static bool_t svctcp_getargs (SVCXPRT *, xdrproc_t, caddr_t);
75 static bool_t svctcp_reply (SVCXPRT *, struct rpc_msg *);
76 static bool_t svctcp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
77 static void svctcp_destroy (SVCXPRT *);
78
79 static const struct xp_ops svctcp_op =
80 {
81 svctcp_recv,
82 svctcp_stat,
83 svctcp_getargs,
84 svctcp_reply,
85 svctcp_freeargs,
86 svctcp_destroy
87 };
88
89 /*
90 * Ops vector for TCP/IP rendezvous handler
91 */
92 static bool_t rendezvous_request (SVCXPRT *, struct rpc_msg *);
93 static enum xprt_stat rendezvous_stat (SVCXPRT *);
94 static void svctcp_rendezvous_abort (void) __attribute__ ((__noreturn__));
95
96 /* This function makes sure abort() relocation goes through PLT
97 and thus can be lazy bound. */
98 static void
99 svctcp_rendezvous_abort (void)
100 {
101 abort ();
102 };
103
104 static const struct xp_ops svctcp_rendezvous_op =
105 {
106 rendezvous_request,
107 rendezvous_stat,
108 (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
109 (bool_t (*) (SVCXPRT *, struct rpc_msg *)) svctcp_rendezvous_abort,
110 (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
111 svctcp_destroy
112 };
113
114 static int readtcp (char*, char *, int);
115 static int writetcp (char *, char *, int);
116 static SVCXPRT *makefd_xprt (int, u_int, u_int);
117
118 struct tcp_rendezvous
119 { /* kept in xprt->xp_p1 */
120 u_int sendsize;
121 u_int recvsize;
122 };
123
124 struct tcp_conn
125 { /* kept in xprt->xp_p1 */
126 enum xprt_stat strm_stat;
127 u_long x_id;
128 XDR xdrs;
129 char verf_body[MAX_AUTH_BYTES];
130 };
131
132 /*
133 * Usage:
134 * xprt = svctcp_create(sock, send_buf_size, recv_buf_size);
135 *
136 * Creates, registers, and returns a (rpc) tcp based transporter.
137 * Once *xprt is initialized, it is registered as a transporter
138 * see (svc.h, xprt_register). This routine returns
139 * a NULL if a problem occurred.
140 *
141 * If sock<0 then a socket is created, else sock is used.
142 * If the socket, sock is not bound to a port then svctcp_create
143 * binds it to an arbitrary port. The routine then starts a tcp
144 * listener on the socket's associated port. In any (successful) case,
145 * xprt->xp_sock is the registered socket number and xprt->xp_port is the
146 * associated port number.
147 *
148 * Since tcp streams do buffered io similar to stdio, the caller can specify
149 * how big the send and receive buffers are via the second and third parms;
150 * 0 => use the system default.
151 */
152 SVCXPRT *
153 svctcp_create (int sock, u_int sendsize, u_int recvsize)
154 {
155 bool_t madesock = FALSE;
156 SVCXPRT *xprt;
157 struct tcp_rendezvous *r;
158 struct sockaddr_in addr;
159 socklen_t len = sizeof (struct sockaddr_in);
160
161 if (sock == RPC_ANYSOCK)
162 {
163 if ((sock = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
164 {
165 perror (_("svc_tcp.c - tcp socket creation problem"));
166 return (SVCXPRT *) NULL;
167 }
168 madesock = TRUE;
169 }
170 memset ((char *) &addr, 0, sizeof (addr));
171 addr.sin_family = AF_INET;
172 if (bindresvport (sock, &addr))
173 {
174 addr.sin_port = 0;
175 (void) __bind (sock, (struct sockaddr *) &addr, len);
176 }
177 if ((__getsockname (sock, (struct sockaddr *) &addr, &len) != 0) ||
178 (__listen (sock, SOMAXCONN) != 0))
179 {
180 perror (_("svc_tcp.c - cannot getsockname or listen"));
181 if (madesock)
182 (void) __close (sock);
183 return (SVCXPRT *) NULL;
184 }
185 r = (struct tcp_rendezvous *) mem_alloc (sizeof (*r));
186 xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
187 if (r == NULL || xprt == NULL)
188 {
189 (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
190 mem_free (r, sizeof (*r));
191 mem_free (xprt, sizeof (SVCXPRT));
192 return NULL;
193 }
194 r->sendsize = sendsize;
195 r->recvsize = recvsize;
196 xprt->xp_p2 = NULL;
197 xprt->xp_p1 = (caddr_t) r;
198 xprt->xp_verf = _null_auth;
199 xprt->xp_ops = &svctcp_rendezvous_op;
200 xprt->xp_port = ntohs (addr.sin_port);
201 xprt->xp_sock = sock;
202 xprt_register (xprt);
203 return xprt;
204 }
205 #ifdef EXPORT_RPC_SYMBOLS
206 libc_hidden_def (svctcp_create)
207 #else
208 libc_hidden_nolink_sunrpc (svctcp_create, GLIBC_2_0)
209 #endif
210
211 /*
212 * Like svtcp_create(), except the routine takes any *open* UNIX file
213 * descriptor as its first input.
214 */
215 SVCXPRT *
216 svcfd_create (int fd, u_int sendsize, u_int recvsize)
217 {
218 return makefd_xprt (fd, sendsize, recvsize);
219 }
220 libc_hidden_nolink_sunrpc (svcfd_create, GLIBC_2_0)
221
222 static SVCXPRT *
223 makefd_xprt (int fd, u_int sendsize, u_int recvsize)
224 {
225 SVCXPRT *xprt;
226 struct tcp_conn *cd;
227
228 xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
229 cd = (struct tcp_conn *) mem_alloc (sizeof (struct tcp_conn));
230 if (xprt == (SVCXPRT *) NULL || cd == NULL)
231 {
232 (void) __fxprintf (NULL, "%s: %s", "svc_tcp: makefd_xprt",
233 _("out of memory\n"));
234 mem_free (xprt, sizeof (SVCXPRT));
235 mem_free (cd, sizeof (struct tcp_conn));
236 return NULL;
237 }
238 cd->strm_stat = XPRT_IDLE;
239 xdrrec_create (&(cd->xdrs), sendsize, recvsize,
240 (caddr_t) xprt, readtcp, writetcp);
241 xprt->xp_p2 = NULL;
242 xprt->xp_p1 = (caddr_t) cd;
243 xprt->xp_verf.oa_base = cd->verf_body;
244 xprt->xp_addrlen = 0;
245 xprt->xp_ops = &svctcp_op; /* truly deals with calls */
246 xprt->xp_port = 0; /* this is a connection, not a rendezvouser */
247 xprt->xp_sock = fd;
248 xprt_register (xprt);
249 return xprt;
250 }
251
252 static bool_t
253 rendezvous_request (SVCXPRT *xprt, struct rpc_msg *errmsg)
254 {
255 int sock;
256 struct tcp_rendezvous *r;
257 struct sockaddr_in addr;
258 socklen_t len;
259
260 r = (struct tcp_rendezvous *) xprt->xp_p1;
261 again:
262 len = sizeof (struct sockaddr_in);
263 if ((sock = accept (xprt->xp_sock, (struct sockaddr *) &addr, &len)) < 0)
264 {
265 if (errno == EINTR)
266 goto again;
267 __svc_accept_failed ();
268 return FALSE;
269 }
270 /*
271 * make a new transporter (re-uses xprt)
272 */
273 xprt = makefd_xprt (sock, r->sendsize, r->recvsize);
274
275 /* If we are out of memory, makefd_xprt has already dumped an error. */
276 if (xprt == NULL)
277 {
278 __svc_wait_on_error ();
279 return FALSE;
280 }
281
282 memcpy (&xprt->xp_raddr, &addr, sizeof (addr));
283 xprt->xp_addrlen = len;
284 return FALSE; /* there is never an rpc msg to be processed */
285 }
286
287 static enum xprt_stat
288 rendezvous_stat (SVCXPRT *xprt)
289 {
290 return XPRT_IDLE;
291 }
292
293 static void
294 svctcp_destroy (SVCXPRT *xprt)
295 {
296 struct tcp_conn *cd = (struct tcp_conn *) xprt->xp_p1;
297
298 xprt_unregister (xprt);
299 (void) __close (xprt->xp_sock);
300 if (xprt->xp_port != 0)
301 {
302 /* a rendezvouser socket */
303 xprt->xp_port = 0;
304 }
305 else
306 {
307 /* an actual connection socket */
308 XDR_DESTROY (&(cd->xdrs));
309 }
310 mem_free ((caddr_t) cd, sizeof (struct tcp_conn));
311 mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
312 }
313
314
315 /*
316 * reads data from the tcp connection.
317 * any error is fatal and the connection is closed.
318 * (And a read of zero bytes is a half closed stream => error.)
319 */
320 static int
321 readtcp (char *xprtptr, char *buf, int len)
322 {
323 SVCXPRT *xprt = (SVCXPRT *)xprtptr;
324 int sock = xprt->xp_sock;
325 int milliseconds = 35 * 1000;
326 struct pollfd pollfd;
327
328 do
329 {
330 pollfd.fd = sock;
331 pollfd.events = POLLIN;
332 switch (__poll (&pollfd, 1, milliseconds))
333 {
334 case -1:
335 if (errno == EINTR)
336 continue;
337 /*FALLTHROUGH*/
338 case 0:
339 goto fatal_err;
340 default:
341 if ((pollfd.revents & POLLERR) || (pollfd.revents & POLLHUP)
342 || (pollfd.revents & POLLNVAL))
343 goto fatal_err;
344 break;
345 }
346 }
347 while ((pollfd.revents & POLLIN) == 0);
348
349 if ((len = __read (sock, buf, len)) > 0)
350 return len;
351
352 fatal_err:
353 ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
354 return -1;
355 }
356
357 /*
358 * writes data to the tcp connection.
359 * Any error is fatal and the connection is closed.
360 */
361 static int
362 writetcp (char *xprtptr, char * buf, int len)
363 {
364 SVCXPRT *xprt = (SVCXPRT *)xprtptr;
365 int i, cnt;
366
367 for (cnt = len; cnt > 0; cnt -= i, buf += i)
368 {
369 if ((i = __write (xprt->xp_sock, buf, cnt)) < 0)
370 {
371 ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
372 return -1;
373 }
374 }
375 return len;
376 }
377
378 static enum xprt_stat
379 svctcp_stat (SVCXPRT *xprt)
380 {
381 struct tcp_conn *cd =
382 (struct tcp_conn *) (xprt->xp_p1);
383
384 if (cd->strm_stat == XPRT_DIED)
385 return XPRT_DIED;
386 if (!xdrrec_eof (&(cd->xdrs)))
387 return XPRT_MOREREQS;
388 return XPRT_IDLE;
389 }
390
391 static bool_t
392 svctcp_recv (SVCXPRT *xprt, struct rpc_msg *msg)
393 {
394 struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
395 XDR *xdrs = &(cd->xdrs);
396
397 xdrs->x_op = XDR_DECODE;
398 (void) xdrrec_skiprecord (xdrs);
399 if (xdr_callmsg (xdrs, msg))
400 {
401 cd->x_id = msg->rm_xid;
402 return TRUE;
403 }
404 cd->strm_stat = XPRT_DIED; /* XXXX */
405 return FALSE;
406 }
407
408 static bool_t
409 svctcp_getargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
410 {
411 return ((*xdr_args) (&(((struct tcp_conn *)
412 (xprt->xp_p1))->xdrs), args_ptr));
413 }
414
415 static bool_t
416 svctcp_freeargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
417 {
418 XDR *xdrs = &(((struct tcp_conn *) (xprt->xp_p1))->xdrs);
419
420 xdrs->x_op = XDR_FREE;
421 return ((*xdr_args) (xdrs, args_ptr));
422 }
423
424 static bool_t
425 svctcp_reply (SVCXPRT *xprt, struct rpc_msg *msg)
426 {
427 struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
428 XDR *xdrs = &(cd->xdrs);
429 bool_t stat;
430
431 xdrs->x_op = XDR_ENCODE;
432 msg->rm_xid = cd->x_id;
433 stat = xdr_replymsg (xdrs, msg);
434 (void) xdrrec_endofrecord (xdrs, TRUE);
435 return stat;
436 }