xref: /freebsd/sys/rpc/svc_dg.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
1 /*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 2009, Sun Microsystems, Inc.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are met:
11  * - Redistributions of source code must retain the above copyright notice,
12  *   this list of conditions and the following disclaimer.
13  * - Redistributions in binary form must reproduce the above copyright notice,
14  *   this list of conditions and the following disclaimer in the documentation
15  *   and/or other materials provided with the distribution.
16  * - Neither the name of Sun Microsystems, 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 "AS IS"
21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #endif
39 #include <sys/cdefs.h>
40 /*
41  * svc_dg.c, Server side for connectionless RPC.
42  */
43 
44 #include <sys/param.h>
45 #include <sys/jail.h>
46 #include <sys/lock.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/mutex.h>
51 #include <sys/proc.h>
52 #include <sys/protosw.h>
53 #include <sys/queue.h>
54 #include <sys/socket.h>
55 #include <sys/socketvar.h>
56 #include <sys/sx.h>
57 #include <sys/systm.h>
58 #include <sys/uio.h>
59 
60 #include <net/vnet.h>
61 
62 #include <rpc/rpc.h>
63 
64 #include <rpc/rpc_com.h>
65 
66 static enum xprt_stat svc_dg_stat(SVCXPRT *);
67 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
68     struct sockaddr **, struct mbuf **);
69 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
70     struct sockaddr *, struct mbuf *, uint32_t *);
71 static void svc_dg_destroy(SVCXPRT *);
72 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
73 static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
74 
75 static const struct xp_ops svc_dg_ops = {
76 	.xp_recv =	svc_dg_recv,
77 	.xp_stat =	svc_dg_stat,
78 	.xp_reply =	svc_dg_reply,
79 	.xp_destroy =	svc_dg_destroy,
80 	.xp_control =	svc_dg_control,
81 };
82 
83 /*
84  * Usage:
85  *	xprt = svc_dg_create(sock, sendsize, recvsize);
86  * Does other connectionless specific initializations.
87  * Once *xprt is initialized, it is registered.
88  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
89  * system defaults are chosen.
90  * The routines returns NULL if a problem occurred.
91  */
92 static const char svc_dg_str[] = "svc_dg_create: %s";
93 static const char svc_dg_err1[] = "could not get transport information";
94 static const char svc_dg_err2[] = "transport does not support data transfer";
95 static const char __no_mem_str[] = "out of memory";
96 
97 SVCXPRT *
98 svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
99     size_t recvsize)
100 {
101 	SVCXPRT *xprt;
102 	struct __rpc_sockinfo si;
103 	struct sockaddr* sa;
104 	int error;
105 
106 	if (jailed(curthread->td_ucred))
107 		return (NULL);
108 	if (!__rpc_socket2sockinfo(so, &si)) {
109 		printf(svc_dg_str, svc_dg_err1);
110 		return (NULL);
111 	}
112 	/*
113 	 * Find the receive and the send size
114 	 */
115 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
116 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
117 	if ((sendsize == 0) || (recvsize == 0)) {
118 		printf(svc_dg_str, svc_dg_err2);
119 		return (NULL);
120 	}
121 
122 	xprt = svc_xprt_alloc();
123 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
124 	xprt->xp_pool = pool;
125 	xprt->xp_socket = so;
126 	xprt->xp_p1 = NULL;
127 	xprt->xp_p2 = NULL;
128 	xprt->xp_ops = &svc_dg_ops;
129 
130 	CURVNET_SET(so->so_vnet);
131 	error = so->so_proto->pr_sockaddr(so, &sa);
132 	CURVNET_RESTORE();
133 	if (error)
134 		goto freedata;
135 
136 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
137 	free(sa, M_SONAME);
138 
139 	xprt_register(xprt);
140 
141 	SOCKBUF_LOCK(&so->so_rcv);
142 	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
143 	SOCKBUF_UNLOCK(&so->so_rcv);
144 
145 	return (xprt);
146 freedata:
147 	(void) printf(svc_dg_str, __no_mem_str);
148 	svc_xprt_free(xprt);
149 
150 	return (NULL);
151 }
152 
153 /*ARGSUSED*/
154 static enum xprt_stat
155 svc_dg_stat(SVCXPRT *xprt)
156 {
157 
158 	if (soreadable(xprt->xp_socket))
159 		return (XPRT_MOREREQS);
160 
161 	return (XPRT_IDLE);
162 }
163 
164 static bool_t
165 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
166     struct sockaddr **addrp, struct mbuf **mp)
167 {
168 	struct uio uio;
169 	struct sockaddr *raddr;
170 	struct mbuf *mreq;
171 	XDR xdrs;
172 	int error, rcvflag;
173 
174 	/*
175 	 * Serialise access to the socket.
176 	 */
177 	sx_xlock(&xprt->xp_lock);
178 
179 	/*
180 	 * The socket upcall calls xprt_active() which will eventually
181 	 * cause the server to call us here. We attempt to read a
182 	 * packet from the socket and process it. If the read fails,
183 	 * we have drained all pending requests so we call
184 	 * xprt_inactive().
185 	 */
186 	uio.uio_resid = 1000000000;
187 	uio.uio_td = curthread;
188 	mreq = NULL;
189 	rcvflag = MSG_DONTWAIT;
190 	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
191 
192 	if (error == EWOULDBLOCK) {
193 		/*
194 		 * We must re-test for readability after taking the
195 		 * lock to protect us in the case where a new packet
196 		 * arrives on the socket after our call to soreceive
197 		 * fails with EWOULDBLOCK. The pool lock protects us
198 		 * from racing the upcall after our soreadable() call
199 		 * returns false.
200 		 */
201 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
202 		if (!soreadable(xprt->xp_socket))
203 			xprt_inactive_self(xprt);
204 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
205 		sx_xunlock(&xprt->xp_lock);
206 		return (FALSE);
207 	}
208 
209 	if (error) {
210 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
211 		soupcall_clear(xprt->xp_socket, SO_RCV);
212 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
213 		xprt_inactive_self(xprt);
214 		sx_xunlock(&xprt->xp_lock);
215 		return (FALSE);
216 	}
217 
218 	sx_xunlock(&xprt->xp_lock);
219 
220 	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
221 	if (! xdr_callmsg(&xdrs, msg)) {
222 		XDR_DESTROY(&xdrs);
223 		return (FALSE);
224 	}
225 
226 	*addrp = raddr;
227 	*mp = xdrmbuf_getall(&xdrs);
228 	XDR_DESTROY(&xdrs);
229 
230 	return (TRUE);
231 }
232 
233 static bool_t
234 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
235     struct sockaddr *addr, struct mbuf *m, uint32_t *seq)
236 {
237 	XDR xdrs;
238 	struct mbuf *mrep;
239 	bool_t stat = TRUE;
240 	int error;
241 
242 	mrep = m_gethdr(M_WAITOK, MT_DATA);
243 
244 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
245 
246 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
247 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
248 		if (!xdr_replymsg(&xdrs, msg))
249 			stat = FALSE;
250 		else
251 			xdrmbuf_append(&xdrs, m);
252 	} else {
253 		stat = xdr_replymsg(&xdrs, msg);
254 	}
255 
256 	if (stat) {
257 		m_fixhdr(mrep);
258 		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
259 		    0, curthread);
260 		if (!error) {
261 			stat = TRUE;
262 		}
263 	} else {
264 		m_freem(mrep);
265 	}
266 
267 	XDR_DESTROY(&xdrs);
268 	xprt->xp_p2 = NULL;
269 
270 	return (stat);
271 }
272 
273 static void
274 svc_dg_destroy(SVCXPRT *xprt)
275 {
276 
277 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
278 	soupcall_clear(xprt->xp_socket, SO_RCV);
279 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
280 
281 	sx_destroy(&xprt->xp_lock);
282 	if (xprt->xp_socket)
283 		(void)soclose(xprt->xp_socket);
284 
285 	if (xprt->xp_netid)
286 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
287 	svc_xprt_free(xprt);
288 }
289 
290 static bool_t
291 /*ARGSUSED*/
292 svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in)
293 {
294 
295 	return (FALSE);
296 }
297 
298 static int
299 svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
300 {
301 	SVCXPRT *xprt = (SVCXPRT *) arg;
302 
303 	xprt_active(xprt);
304 	return (SU_OK);
305 }
306