xref: /freebsd/sys/rpc/svc_dg.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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 <rpc/rpc.h>
61 
62 #include <rpc/rpc_com.h>
63 
64 static enum xprt_stat svc_dg_stat(SVCXPRT *);
65 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
66     struct sockaddr **, struct mbuf **);
67 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
68     struct sockaddr *, struct mbuf *);
69 static void svc_dg_destroy(SVCXPRT *);
70 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
71 static void svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
72 
73 static struct xp_ops svc_dg_ops = {
74 	.xp_recv =	svc_dg_recv,
75 	.xp_stat =	svc_dg_stat,
76 	.xp_reply =	svc_dg_reply,
77 	.xp_destroy =	svc_dg_destroy,
78 	.xp_control =	svc_dg_control,
79 };
80 
81 /*
82  * Usage:
83  *	xprt = svc_dg_create(sock, sendsize, recvsize);
84  * Does other connectionless specific initializations.
85  * Once *xprt is initialized, it is registered.
86  * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
87  * system defaults are chosen.
88  * The routines returns NULL if a problem occurred.
89  */
90 static const char svc_dg_str[] = "svc_dg_create: %s";
91 static const char svc_dg_err1[] = "could not get transport information";
92 static const char svc_dg_err2[] = "transport does not support data transfer";
93 static const char __no_mem_str[] = "out of memory";
94 
95 SVCXPRT *
96 svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
97     size_t recvsize)
98 {
99 	SVCXPRT *xprt;
100 	struct __rpc_sockinfo si;
101 	struct sockaddr* sa;
102 	int error;
103 
104 	if (!__rpc_socket2sockinfo(so, &si)) {
105 		printf(svc_dg_str, svc_dg_err1);
106 		return (NULL);
107 	}
108 	/*
109 	 * Find the receive and the send size
110 	 */
111 	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
112 	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
113 	if ((sendsize == 0) || (recvsize == 0)) {
114 		printf(svc_dg_str, svc_dg_err2);
115 		return (NULL);
116 	}
117 
118 	xprt = svc_xprt_alloc();
119 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
120 	xprt->xp_pool = pool;
121 	xprt->xp_socket = so;
122 	xprt->xp_p1 = NULL;
123 	xprt->xp_p2 = NULL;
124 	xprt->xp_ops = &svc_dg_ops;
125 
126 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
127 	if (error)
128 		goto freedata;
129 
130 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
131 	free(sa, M_SONAME);
132 
133 	xprt_register(xprt);
134 
135 	SOCKBUF_LOCK(&so->so_rcv);
136 	so->so_upcallarg = xprt;
137 	so->so_upcall = svc_dg_soupcall;
138 	so->so_rcv.sb_flags |= SB_UPCALL;
139 	SOCKBUF_UNLOCK(&so->so_rcv);
140 
141 	return (xprt);
142 freedata:
143 	(void) printf(svc_dg_str, __no_mem_str);
144 	if (xprt) {
145 		svc_xprt_free(xprt);
146 	}
147 	return (NULL);
148 }
149 
150 /*ARGSUSED*/
151 static enum xprt_stat
152 svc_dg_stat(SVCXPRT *xprt)
153 {
154 
155 	if (soreadable(xprt->xp_socket))
156 		return (XPRT_MOREREQS);
157 
158 	return (XPRT_IDLE);
159 }
160 
161 static bool_t
162 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
163     struct sockaddr **addrp, struct mbuf **mp)
164 {
165 	struct uio uio;
166 	struct sockaddr *raddr;
167 	struct mbuf *mreq;
168 	XDR xdrs;
169 	int error, rcvflag;
170 
171 	/*
172 	 * Serialise access to the socket.
173 	 */
174 	sx_xlock(&xprt->xp_lock);
175 
176 	/*
177 	 * The socket upcall calls xprt_active() which will eventually
178 	 * cause the server to call us here. We attempt to read a
179 	 * packet from the socket and process it. If the read fails,
180 	 * we have drained all pending requests so we call
181 	 * xprt_inactive().
182 	 */
183 	uio.uio_resid = 1000000000;
184 	uio.uio_td = curthread;
185 	mreq = NULL;
186 	rcvflag = MSG_DONTWAIT;
187 	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
188 
189 	if (error == EWOULDBLOCK) {
190 		/*
191 		 * We must re-test for readability after taking the
192 		 * lock to protect us in the case where a new packet
193 		 * arrives on the socket after our call to soreceive
194 		 * fails with EWOULDBLOCK. The pool lock protects us
195 		 * from racing the upcall after our soreadable() call
196 		 * returns false.
197 		 */
198 		mtx_lock(&xprt->xp_pool->sp_lock);
199 		if (!soreadable(xprt->xp_socket))
200 			xprt_inactive_locked(xprt);
201 		mtx_unlock(&xprt->xp_pool->sp_lock);
202 		sx_xunlock(&xprt->xp_lock);
203 		return (FALSE);
204 	}
205 
206 	if (error) {
207 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
208 		xprt->xp_socket->so_upcallarg = NULL;
209 		xprt->xp_socket->so_upcall = NULL;
210 		xprt->xp_socket->so_rcv.sb_flags &= ~SB_UPCALL;
211 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
212 		xprt_inactive(xprt);
213 		sx_xunlock(&xprt->xp_lock);
214 		return (FALSE);
215 	}
216 
217 	sx_xunlock(&xprt->xp_lock);
218 
219 	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
220 	if (! xdr_callmsg(&xdrs, msg)) {
221 		XDR_DESTROY(&xdrs);
222 		return (FALSE);
223 	}
224 
225 	*addrp = raddr;
226 	*mp = xdrmbuf_getall(&xdrs);
227 	XDR_DESTROY(&xdrs);
228 
229 	return (TRUE);
230 }
231 
232 static bool_t
233 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
234     struct sockaddr *addr, struct mbuf *m)
235 {
236 	XDR xdrs;
237 	struct mbuf *mrep;
238 	bool_t stat = TRUE;
239 	int error;
240 
241 	MGETHDR(mrep, M_WAIT, MT_DATA);
242 	mrep->m_len = 0;
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 	xprt->xp_socket->so_upcallarg = NULL;
279 	xprt->xp_socket->so_upcall = NULL;
280 	xprt->xp_socket->so_rcv.sb_flags &= ~SB_UPCALL;
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 void
304 svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
305 {
306 	SVCXPRT *xprt = (SVCXPRT *) arg;
307 
308 	xprt_active(xprt);
309 }
310