1/*
2 * svc_tcp.c, Server side for TCP/IP based RPC.
3 *
4 * Copyright (C) 2012-2020 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 */
72static bool_t svctcp_recv (SVCXPRT *, struct rpc_msg *);
73static enum xprt_stat svctcp_stat (SVCXPRT *);
74static bool_t svctcp_getargs (SVCXPRT *, xdrproc_t, caddr_t);
75static bool_t svctcp_reply (SVCXPRT *, struct rpc_msg *);
76static bool_t svctcp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
77static void svctcp_destroy (SVCXPRT *);
78
79static 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 */
92static bool_t rendezvous_request (SVCXPRT *, struct rpc_msg *);
93static enum xprt_stat rendezvous_stat (SVCXPRT *);
94static 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. */
98static void
99svctcp_rendezvous_abort (void)
100{
101 abort ();
102};
103
104static 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
114static int readtcp (char*, char *, int);
115static int writetcp (char *, char *, int);
116static SVCXPRT *makefd_xprt (int, u_int, u_int);
117
118struct tcp_rendezvous
119 { /* kept in xprt->xp_p1 */
120 u_int sendsize;
121 u_int recvsize;
122 };
123
124struct 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 */
152SVCXPRT *
153svctcp_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
206libc_hidden_def (svctcp_create)
207#else
208libc_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 */
215SVCXPRT *
216svcfd_create (int fd, u_int sendsize, u_int recvsize)
217{
218 return makefd_xprt (fd, sendsize, recvsize);
219}
220libc_hidden_nolink_sunrpc (svcfd_create, GLIBC_2_0)
221
222static SVCXPRT *
223makefd_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
252static bool_t
253rendezvous_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;
261again:
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 memcpy (&xprt->xp_raddr, &addr, sizeof (addr));
275 xprt->xp_addrlen = len;
276 return FALSE; /* there is never an rpc msg to be processed */
277}
278
279static enum xprt_stat
280rendezvous_stat (SVCXPRT *xprt)
281{
282 return XPRT_IDLE;
283}
284
285static void
286svctcp_destroy (SVCXPRT *xprt)
287{
288 struct tcp_conn *cd = (struct tcp_conn *) xprt->xp_p1;
289
290 xprt_unregister (xprt);
291 (void) __close (xprt->xp_sock);
292 if (xprt->xp_port != 0)
293 {
294 /* a rendezvouser socket */
295 xprt->xp_port = 0;
296 }
297 else
298 {
299 /* an actual connection socket */
300 XDR_DESTROY (&(cd->xdrs));
301 }
302 mem_free ((caddr_t) cd, sizeof (struct tcp_conn));
303 mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
304}
305
306
307/*
308 * reads data from the tcp connection.
309 * any error is fatal and the connection is closed.
310 * (And a read of zero bytes is a half closed stream => error.)
311 */
312static int
313readtcp (char *xprtptr, char *buf, int len)
314{
315 SVCXPRT *xprt = (SVCXPRT *)xprtptr;
316 int sock = xprt->xp_sock;
317 int milliseconds = 35 * 1000;
318 struct pollfd pollfd;
319
320 do
321 {
322 pollfd.fd = sock;
323 pollfd.events = POLLIN;
324 switch (__poll (&pollfd, 1, milliseconds))
325 {
326 case -1:
327 if (errno == EINTR)
328 continue;
329 /*FALLTHROUGH*/
330 case 0:
331 goto fatal_err;
332 default:
333 if ((pollfd.revents & POLLERR) || (pollfd.revents & POLLHUP)
334 || (pollfd.revents & POLLNVAL))
335 goto fatal_err;
336 break;
337 }
338 }
339 while ((pollfd.revents & POLLIN) == 0);
340
341 if ((len = __read (sock, buf, len)) > 0)
342 return len;
343
344 fatal_err:
345 ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
346 return -1;
347}
348
349/*
350 * writes data to the tcp connection.
351 * Any error is fatal and the connection is closed.
352 */
353static int
354writetcp (char *xprtptr, char * buf, int len)
355{
356 SVCXPRT *xprt = (SVCXPRT *)xprtptr;
357 int i, cnt;
358
359 for (cnt = len; cnt > 0; cnt -= i, buf += i)
360 {
361 if ((i = __write (xprt->xp_sock, buf, cnt)) < 0)
362 {
363 ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
364 return -1;
365 }
366 }
367 return len;
368}
369
370static enum xprt_stat
371svctcp_stat (SVCXPRT *xprt)
372{
373 struct tcp_conn *cd =
374 (struct tcp_conn *) (xprt->xp_p1);
375
376 if (cd->strm_stat == XPRT_DIED)
377 return XPRT_DIED;
378 if (!xdrrec_eof (&(cd->xdrs)))
379 return XPRT_MOREREQS;
380 return XPRT_IDLE;
381}
382
383static bool_t
384svctcp_recv (SVCXPRT *xprt, struct rpc_msg *msg)
385{
386 struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
387 XDR *xdrs = &(cd->xdrs);
388
389 xdrs->x_op = XDR_DECODE;
390 (void) xdrrec_skiprecord (xdrs);
391 if (xdr_callmsg (xdrs, msg))
392 {
393 cd->x_id = msg->rm_xid;
394 return TRUE;
395 }
396 cd->strm_stat = XPRT_DIED; /* XXXX */
397 return FALSE;
398}
399
400static bool_t
401svctcp_getargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
402{
403 return ((*xdr_args) (&(((struct tcp_conn *)
404 (xprt->xp_p1))->xdrs), args_ptr));
405}
406
407static bool_t
408svctcp_freeargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
409{
410 XDR *xdrs = &(((struct tcp_conn *) (xprt->xp_p1))->xdrs);
411
412 xdrs->x_op = XDR_FREE;
413 return ((*xdr_args) (xdrs, args_ptr));
414}
415
416static bool_t
417svctcp_reply (SVCXPRT *xprt, struct rpc_msg *msg)
418{
419 struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
420 XDR *xdrs = &(cd->xdrs);
421 bool_t stat;
422
423 xdrs->x_op = XDR_ENCODE;
424 msg->rm_xid = cd->x_id;
425 stat = xdr_replymsg (xdrs, msg);
426 (void) xdrrec_endofrecord (xdrs, TRUE);
427 return stat;
428}
429