xref: /freebsd/sys/rpc/svc_dg.c (revision 5748b897da441d1f10e1fe0c39155ea33d6d383a)
1 /*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009, Sun Microsystems, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  * - Redistributions of source code must retain the above copyright notice,
10  *   this list of conditions and the following disclaimer.
11  * - Redistributions in binary form must reproduce the above copyright notice,
12  *   this list of conditions and the following disclaimer in the documentation
13  *   and/or other materials provided with the distribution.
14  * - Neither the name of Sun Microsystems, Inc. nor the names of its
15  *   contributors may be used to endorse or promote products derived
16  *   from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
33  */
34 
35 #if defined(LIBC_SCCS) && !defined(lint)
36 #ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
37 #endif
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 /*
42  * svc_dg.c, Server side for connectionless RPC.
43  */
44 
45 #include <sys/param.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/protosw.h>
52 #include <sys/queue.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/sx.h>
56 #include <sys/systm.h>
57 #include <sys/uio.h>
58 
59 #include <net/vnet.h>
60 
61 #include <rpc/rpc.h>
62 
63 #include <rpc/rpc_com.h>
64 
65 static enum xprt_stat svc_dg_stat(SVCXPRT *);
66 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
67     struct sockaddr **, struct mbuf **);
68 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
69     struct sockaddr *, struct mbuf *, uint32_t *);
70 static void svc_dg_destroy(SVCXPRT *);
71 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
72 static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
73 
74 static struct xp_ops svc_dg_ops = {
75 	.xp_recv =	svc_dg_recv,
76 	.xp_stat =	svc_dg_stat,
77 	.xp_reply =	svc_dg_reply,
78 	.xp_destroy =	svc_dg_destroy,
79 	.xp_control =	svc_dg_control,
80 };
81 
82 /*
83  * Usage:
84  *	xprt = svc_dg_create(sock, sendsize, recvsize);
85  * Does other connectionless specific initializations.
86  * Once *xprt is initialized, it is registered.
87  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
88  * system defaults are chosen.
89  * The routines returns NULL if a problem occurred.
90  */
91 static const char svc_dg_str[] = "svc_dg_create: %s";
92 static const char svc_dg_err1[] = "could not get transport information";
93 static const char svc_dg_err2[] = "transport does not support data transfer";
94 static const char __no_mem_str[] = "out of memory";
95 
96 SVCXPRT *
97 svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
98     size_t recvsize)
99 {
100 	SVCXPRT *xprt;
101 	struct __rpc_sockinfo si;
102 	struct sockaddr* sa;
103 	int error;
104 
105 	if (!__rpc_socket2sockinfo(so, &si)) {
106 		printf(svc_dg_str, svc_dg_err1);
107 		return (NULL);
108 	}
109 	/*
110 	 * Find the receive and the send size
111 	 */
112 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
113 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
114 	if ((sendsize == 0) || (recvsize == 0)) {
115 		printf(svc_dg_str, svc_dg_err2);
116 		return (NULL);
117 	}
118 
119 	xprt = svc_xprt_alloc();
120 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
121 	xprt->xp_pool = pool;
122 	xprt->xp_socket = so;
123 	xprt->xp_p1 = NULL;
124 	xprt->xp_p2 = NULL;
125 	xprt->xp_ops = &svc_dg_ops;
126 
127 	CURVNET_SET(so->so_vnet);
128 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
129 	CURVNET_RESTORE();
130 	if (error)
131 		goto freedata;
132 
133 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
134 	free(sa, M_SONAME);
135 
136 	xprt_register(xprt);
137 
138 	SOCKBUF_LOCK(&so->so_rcv);
139 	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
140 	SOCKBUF_UNLOCK(&so->so_rcv);
141 
142 	return (xprt);
143 freedata:
144 	(void) printf(svc_dg_str, __no_mem_str);
145 	if (xprt) {
146 		svc_xprt_free(xprt);
147 	}
148 	return (NULL);
149 }
150 
151 /*ARGSUSED*/
152 static enum xprt_stat
153 svc_dg_stat(SVCXPRT *xprt)
154 {
155 
156 	if (soreadable(xprt->xp_socket))
157 		return (XPRT_MOREREQS);
158 
159 	return (XPRT_IDLE);
160 }
161 
162 static bool_t
163 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
164     struct sockaddr **addrp, struct mbuf **mp)
165 {
166 	struct uio uio;
167 	struct sockaddr *raddr;
168 	struct mbuf *mreq;
169 	XDR xdrs;
170 	int error, rcvflag;
171 
172 	/*
173 	 * Serialise access to the socket.
174 	 */
175 	sx_xlock(&xprt->xp_lock);
176 
177 	/*
178 	 * The socket upcall calls xprt_active() which will eventually
179 	 * cause the server to call us here. We attempt to read a
180 	 * packet from the socket and process it. If the read fails,
181 	 * we have drained all pending requests so we call
182 	 * xprt_inactive().
183 	 */
184 	uio.uio_resid = 1000000000;
185 	uio.uio_td = curthread;
186 	mreq = NULL;
187 	rcvflag = MSG_DONTWAIT;
188 	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
189 
190 	if (error == EWOULDBLOCK) {
191 		/*
192 		 * We must re-test for readability after taking the
193 		 * lock to protect us in the case where a new packet
194 		 * arrives on the socket after our call to soreceive
195 		 * fails with EWOULDBLOCK. The pool lock protects us
196 		 * from racing the upcall after our soreadable() call
197 		 * returns false.
198 		 */
199 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
200 		if (!soreadable(xprt->xp_socket))
201 			xprt_inactive_self(xprt);
202 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
203 		sx_xunlock(&xprt->xp_lock);
204 		return (FALSE);
205 	}
206 
207 	if (error) {
208 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
209 		soupcall_clear(xprt->xp_socket, SO_RCV);
210 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
211 		xprt_inactive_self(xprt);
212 		sx_xunlock(&xprt->xp_lock);
213 		return (FALSE);
214 	}
215 
216 	sx_xunlock(&xprt->xp_lock);
217 
218 	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
219 	if (! xdr_callmsg(&xdrs, msg)) {
220 		XDR_DESTROY(&xdrs);
221 		return (FALSE);
222 	}
223 
224 	*addrp = raddr;
225 	*mp = xdrmbuf_getall(&xdrs);
226 	XDR_DESTROY(&xdrs);
227 
228 	return (TRUE);
229 }
230 
231 static bool_t
232 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
233     struct sockaddr *addr, struct mbuf *m, uint32_t *seq)
234 {
235 	XDR xdrs;
236 	struct mbuf *mrep;
237 	bool_t stat = TRUE;
238 	int error;
239 
240 	mrep = m_gethdr(M_WAITOK, MT_DATA);
241 
242 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
243 
244 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
245 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
246 		if (!xdr_replymsg(&xdrs, msg))
247 			stat = FALSE;
248 		else
249 			xdrmbuf_append(&xdrs, m);
250 	} else {
251 		stat = xdr_replymsg(&xdrs, msg);
252 	}
253 
254 	if (stat) {
255 		m_fixhdr(mrep);
256 		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
257 		    0, curthread);
258 		if (!error) {
259 			stat = TRUE;
260 		}
261 	} else {
262 		m_freem(mrep);
263 	}
264 
265 	XDR_DESTROY(&xdrs);
266 	xprt->xp_p2 = NULL;
267 
268 	return (stat);
269 }
270 
271 static void
272 svc_dg_destroy(SVCXPRT *xprt)
273 {
274 
275 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
276 	soupcall_clear(xprt->xp_socket, SO_RCV);
277 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
278 
279 	sx_destroy(&xprt->xp_lock);
280 	if (xprt->xp_socket)
281 		(void)soclose(xprt->xp_socket);
282 
283 	if (xprt->xp_netid)
284 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
285 	svc_xprt_free(xprt);
286 }
287 
288 static bool_t
289 /*ARGSUSED*/
290 svc_dg_control(xprt, rq, in)
291 	SVCXPRT *xprt;
292 	const u_int	rq;
293 	void		*in;
294 {
295 
296 	return (FALSE);
297 }
298 
299 static int
300 svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
301 {
302 	SVCXPRT *xprt = (SVCXPRT *) arg;
303 
304 	xprt_active(xprt);
305 	return (SU_OK);
306 }
307