xref: /freebsd/sys/rpc/svc_dg.c (revision 66e576525d35c68fcb86f142ebaa5a448555c0c7)
1 /*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 /*
33  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
38 #endif
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 /*
43  * svc_dg.c, Server side for connectionless RPC.
44  */
45 
46 #include <sys/param.h>
47 #include <sys/lock.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/mutex.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 *);
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 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 	CURVNET_SET(so->so_vnet);
107 	if (!__rpc_socket2sockinfo(so, &si)) {
108 		printf(svc_dg_str, svc_dg_err1);
109 		CURVNET_RESTORE();
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 		CURVNET_RESTORE();
120 		return (NULL);
121 	}
122 
123 	xprt = svc_xprt_alloc();
124 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
125 	xprt->xp_pool = pool;
126 	xprt->xp_socket = so;
127 	xprt->xp_p1 = NULL;
128 	xprt->xp_p2 = NULL;
129 	xprt->xp_ops = &svc_dg_ops;
130 
131 	error = so->so_proto->pr_usrreqs->pru_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 	if (xprt) {
149 		svc_xprt_free(xprt);
150 	}
151 	return (NULL);
152 }
153 
154 /*ARGSUSED*/
155 static enum xprt_stat
156 svc_dg_stat(SVCXPRT *xprt)
157 {
158 
159 	if (soreadable(xprt->xp_socket))
160 		return (XPRT_MOREREQS);
161 
162 	return (XPRT_IDLE);
163 }
164 
165 static bool_t
166 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
167     struct sockaddr **addrp, struct mbuf **mp)
168 {
169 	struct uio uio;
170 	struct sockaddr *raddr;
171 	struct mbuf *mreq;
172 	XDR xdrs;
173 	int error, rcvflag;
174 
175 	/*
176 	 * Serialise access to the socket.
177 	 */
178 	sx_xlock(&xprt->xp_lock);
179 
180 	/*
181 	 * The socket upcall calls xprt_active() which will eventually
182 	 * cause the server to call us here. We attempt to read a
183 	 * packet from the socket and process it. If the read fails,
184 	 * we have drained all pending requests so we call
185 	 * xprt_inactive().
186 	 */
187 	uio.uio_resid = 1000000000;
188 	uio.uio_td = curthread;
189 	mreq = NULL;
190 	rcvflag = MSG_DONTWAIT;
191 	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
192 
193 	if (error == EWOULDBLOCK) {
194 		/*
195 		 * We must re-test for readability after taking the
196 		 * lock to protect us in the case where a new packet
197 		 * arrives on the socket after our call to soreceive
198 		 * fails with EWOULDBLOCK. The pool lock protects us
199 		 * from racing the upcall after our soreadable() call
200 		 * returns false.
201 		 */
202 		mtx_lock(&xprt->xp_pool->sp_lock);
203 		if (!soreadable(xprt->xp_socket))
204 			xprt_inactive_locked(xprt);
205 		mtx_unlock(&xprt->xp_pool->sp_lock);
206 		sx_xunlock(&xprt->xp_lock);
207 		return (FALSE);
208 	}
209 
210 	if (error) {
211 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
212 		soupcall_clear(xprt->xp_socket, SO_RCV);
213 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
214 		xprt_inactive(xprt);
215 		sx_xunlock(&xprt->xp_lock);
216 		return (FALSE);
217 	}
218 
219 	sx_xunlock(&xprt->xp_lock);
220 
221 	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
222 	if (! xdr_callmsg(&xdrs, msg)) {
223 		XDR_DESTROY(&xdrs);
224 		return (FALSE);
225 	}
226 
227 	*addrp = raddr;
228 	*mp = xdrmbuf_getall(&xdrs);
229 	XDR_DESTROY(&xdrs);
230 
231 	return (TRUE);
232 }
233 
234 static bool_t
235 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
236     struct sockaddr *addr, struct mbuf *m)
237 {
238 	XDR xdrs;
239 	struct mbuf *mrep;
240 	bool_t stat = TRUE;
241 	int error;
242 
243 	MGETHDR(mrep, M_WAIT, MT_DATA);
244 	mrep->m_len = 0;
245 
246 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
247 
248 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
249 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
250 		if (!xdr_replymsg(&xdrs, msg))
251 			stat = FALSE;
252 		else
253 			xdrmbuf_append(&xdrs, m);
254 	} else {
255 		stat = xdr_replymsg(&xdrs, msg);
256 	}
257 
258 	if (stat) {
259 		m_fixhdr(mrep);
260 		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
261 		    0, curthread);
262 		if (!error) {
263 			stat = TRUE;
264 		}
265 	} else {
266 		m_freem(mrep);
267 	}
268 
269 	XDR_DESTROY(&xdrs);
270 	xprt->xp_p2 = NULL;
271 
272 	return (stat);
273 }
274 
275 static void
276 svc_dg_destroy(SVCXPRT *xprt)
277 {
278 
279 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
280 	soupcall_clear(xprt->xp_socket, SO_RCV);
281 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
282 
283 	sx_destroy(&xprt->xp_lock);
284 	if (xprt->xp_socket)
285 		(void)soclose(xprt->xp_socket);
286 
287 	if (xprt->xp_netid)
288 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
289 	svc_xprt_free(xprt);
290 }
291 
292 static bool_t
293 /*ARGSUSED*/
294 svc_dg_control(xprt, rq, in)
295 	SVCXPRT *xprt;
296 	const u_int	rq;
297 	void		*in;
298 {
299 
300 	return (FALSE);
301 }
302 
303 static int
304 svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
305 {
306 	SVCXPRT *xprt = (SVCXPRT *) arg;
307 
308 	xprt_active(xprt);
309 	return (SU_OK);
310 }
311