xref: /freebsd/sys/rpc/svc_dg.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
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 #ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
39 #endif
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 /*
44  * svc_dg.c, Server side for connectionless RPC.
45  */
46 
47 #include <sys/param.h>
48 #include <sys/jail.h>
49 #include <sys/lock.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/mbuf.h>
53 #include <sys/mutex.h>
54 #include <sys/proc.h>
55 #include <sys/protosw.h>
56 #include <sys/queue.h>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/sx.h>
60 #include <sys/systm.h>
61 #include <sys/uio.h>
62 
63 #include <net/vnet.h>
64 
65 #include <rpc/rpc.h>
66 
67 #include <rpc/rpc_com.h>
68 
69 static enum xprt_stat svc_dg_stat(SVCXPRT *);
70 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
71     struct sockaddr **, struct mbuf **);
72 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
73     struct sockaddr *, struct mbuf *, uint32_t *);
74 static void svc_dg_destroy(SVCXPRT *);
75 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
76 static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
77 
78 static const struct xp_ops svc_dg_ops = {
79 	.xp_recv =	svc_dg_recv,
80 	.xp_stat =	svc_dg_stat,
81 	.xp_reply =	svc_dg_reply,
82 	.xp_destroy =	svc_dg_destroy,
83 	.xp_control =	svc_dg_control,
84 };
85 
86 /*
87  * Usage:
88  *	xprt = svc_dg_create(sock, sendsize, recvsize);
89  * Does other connectionless specific initializations.
90  * Once *xprt is initialized, it is registered.
91  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
92  * system defaults are chosen.
93  * The routines returns NULL if a problem occurred.
94  */
95 static const char svc_dg_str[] = "svc_dg_create: %s";
96 static const char svc_dg_err1[] = "could not get transport information";
97 static const char svc_dg_err2[] = "transport does not support data transfer";
98 static const char __no_mem_str[] = "out of memory";
99 
100 SVCXPRT *
101 svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
102     size_t recvsize)
103 {
104 	SVCXPRT *xprt;
105 	struct __rpc_sockinfo si;
106 	struct sockaddr* sa;
107 	int error;
108 
109 	if (jailed(curthread->td_ucred))
110 		return (NULL);
111 	if (!__rpc_socket2sockinfo(so, &si)) {
112 		printf(svc_dg_str, svc_dg_err1);
113 		return (NULL);
114 	}
115 	/*
116 	 * Find the receive and the send size
117 	 */
118 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
119 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
120 	if ((sendsize == 0) || (recvsize == 0)) {
121 		printf(svc_dg_str, svc_dg_err2);
122 		return (NULL);
123 	}
124 
125 	xprt = svc_xprt_alloc();
126 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
127 	xprt->xp_pool = pool;
128 	xprt->xp_socket = so;
129 	xprt->xp_p1 = NULL;
130 	xprt->xp_p2 = NULL;
131 	xprt->xp_ops = &svc_dg_ops;
132 
133 	CURVNET_SET(so->so_vnet);
134 	error = so->so_proto->pr_sockaddr(so, &sa);
135 	CURVNET_RESTORE();
136 	if (error)
137 		goto freedata;
138 
139 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
140 	free(sa, M_SONAME);
141 
142 	xprt_register(xprt);
143 
144 	SOCKBUF_LOCK(&so->so_rcv);
145 	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
146 	SOCKBUF_UNLOCK(&so->so_rcv);
147 
148 	return (xprt);
149 freedata:
150 	(void) printf(svc_dg_str, __no_mem_str);
151 	svc_xprt_free(xprt);
152 
153 	return (NULL);
154 }
155 
156 /*ARGSUSED*/
157 static enum xprt_stat
158 svc_dg_stat(SVCXPRT *xprt)
159 {
160 
161 	if (soreadable(xprt->xp_socket))
162 		return (XPRT_MOREREQS);
163 
164 	return (XPRT_IDLE);
165 }
166 
167 static bool_t
168 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
169     struct sockaddr **addrp, struct mbuf **mp)
170 {
171 	struct uio uio;
172 	struct sockaddr *raddr;
173 	struct mbuf *mreq;
174 	XDR xdrs;
175 	int error, rcvflag;
176 
177 	/*
178 	 * Serialise access to the socket.
179 	 */
180 	sx_xlock(&xprt->xp_lock);
181 
182 	/*
183 	 * The socket upcall calls xprt_active() which will eventually
184 	 * cause the server to call us here. We attempt to read a
185 	 * packet from the socket and process it. If the read fails,
186 	 * we have drained all pending requests so we call
187 	 * xprt_inactive().
188 	 */
189 	uio.uio_resid = 1000000000;
190 	uio.uio_td = curthread;
191 	mreq = NULL;
192 	rcvflag = MSG_DONTWAIT;
193 	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
194 
195 	if (error == EWOULDBLOCK) {
196 		/*
197 		 * We must re-test for readability after taking the
198 		 * lock to protect us in the case where a new packet
199 		 * arrives on the socket after our call to soreceive
200 		 * fails with EWOULDBLOCK. The pool lock protects us
201 		 * from racing the upcall after our soreadable() call
202 		 * returns false.
203 		 */
204 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
205 		if (!soreadable(xprt->xp_socket))
206 			xprt_inactive_self(xprt);
207 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
208 		sx_xunlock(&xprt->xp_lock);
209 		return (FALSE);
210 	}
211 
212 	if (error) {
213 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
214 		soupcall_clear(xprt->xp_socket, SO_RCV);
215 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
216 		xprt_inactive_self(xprt);
217 		sx_xunlock(&xprt->xp_lock);
218 		return (FALSE);
219 	}
220 
221 	sx_xunlock(&xprt->xp_lock);
222 
223 	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
224 	if (! xdr_callmsg(&xdrs, msg)) {
225 		XDR_DESTROY(&xdrs);
226 		return (FALSE);
227 	}
228 
229 	*addrp = raddr;
230 	*mp = xdrmbuf_getall(&xdrs);
231 	XDR_DESTROY(&xdrs);
232 
233 	return (TRUE);
234 }
235 
236 static bool_t
237 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
238     struct sockaddr *addr, struct mbuf *m, uint32_t *seq)
239 {
240 	XDR xdrs;
241 	struct mbuf *mrep;
242 	bool_t stat = TRUE;
243 	int error;
244 
245 	mrep = m_gethdr(M_WAITOK, MT_DATA);
246 
247 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
248 
249 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
250 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
251 		if (!xdr_replymsg(&xdrs, msg))
252 			stat = FALSE;
253 		else
254 			xdrmbuf_append(&xdrs, m);
255 	} else {
256 		stat = xdr_replymsg(&xdrs, msg);
257 	}
258 
259 	if (stat) {
260 		m_fixhdr(mrep);
261 		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
262 		    0, curthread);
263 		if (!error) {
264 			stat = TRUE;
265 		}
266 	} else {
267 		m_freem(mrep);
268 	}
269 
270 	XDR_DESTROY(&xdrs);
271 	xprt->xp_p2 = NULL;
272 
273 	return (stat);
274 }
275 
276 static void
277 svc_dg_destroy(SVCXPRT *xprt)
278 {
279 
280 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
281 	soupcall_clear(xprt->xp_socket, SO_RCV);
282 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
283 
284 	sx_destroy(&xprt->xp_lock);
285 	if (xprt->xp_socket)
286 		(void)soclose(xprt->xp_socket);
287 
288 	if (xprt->xp_netid)
289 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
290 	svc_xprt_free(xprt);
291 }
292 
293 static bool_t
294 /*ARGSUSED*/
295 svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in)
296 {
297 
298 	return (FALSE);
299 }
300 
301 static int
302 svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
303 {
304 	SVCXPRT *xprt = (SVCXPRT *) arg;
305 
306 	xprt_active(xprt);
307 	return (SU_OK);
308 }
309