xref: /freebsd/sys/rpc/svc_dg.c (revision d5fc25e5d6c52b306312784663ccad85923a9c76)
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 int 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 	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
137 	SOCKBUF_UNLOCK(&so->so_rcv);
138 
139 	return (xprt);
140 freedata:
141 	(void) printf(svc_dg_str, __no_mem_str);
142 	if (xprt) {
143 		svc_xprt_free(xprt);
144 	}
145 	return (NULL);
146 }
147 
148 /*ARGSUSED*/
149 static enum xprt_stat
150 svc_dg_stat(SVCXPRT *xprt)
151 {
152 
153 	if (soreadable(xprt->xp_socket))
154 		return (XPRT_MOREREQS);
155 
156 	return (XPRT_IDLE);
157 }
158 
159 static bool_t
160 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
161     struct sockaddr **addrp, struct mbuf **mp)
162 {
163 	struct uio uio;
164 	struct sockaddr *raddr;
165 	struct mbuf *mreq;
166 	XDR xdrs;
167 	int error, rcvflag;
168 
169 	/*
170 	 * Serialise access to the socket.
171 	 */
172 	sx_xlock(&xprt->xp_lock);
173 
174 	/*
175 	 * The socket upcall calls xprt_active() which will eventually
176 	 * cause the server to call us here. We attempt to read a
177 	 * packet from the socket and process it. If the read fails,
178 	 * we have drained all pending requests so we call
179 	 * xprt_inactive().
180 	 */
181 	uio.uio_resid = 1000000000;
182 	uio.uio_td = curthread;
183 	mreq = NULL;
184 	rcvflag = MSG_DONTWAIT;
185 	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
186 
187 	if (error == EWOULDBLOCK) {
188 		/*
189 		 * We must re-test for readability after taking the
190 		 * lock to protect us in the case where a new packet
191 		 * arrives on the socket after our call to soreceive
192 		 * fails with EWOULDBLOCK. The pool lock protects us
193 		 * from racing the upcall after our soreadable() call
194 		 * returns false.
195 		 */
196 		mtx_lock(&xprt->xp_pool->sp_lock);
197 		if (!soreadable(xprt->xp_socket))
198 			xprt_inactive_locked(xprt);
199 		mtx_unlock(&xprt->xp_pool->sp_lock);
200 		sx_xunlock(&xprt->xp_lock);
201 		return (FALSE);
202 	}
203 
204 	if (error) {
205 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
206 		soupcall_clear(xprt->xp_socket, SO_RCV);
207 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
208 		xprt_inactive(xprt);
209 		sx_xunlock(&xprt->xp_lock);
210 		return (FALSE);
211 	}
212 
213 	sx_xunlock(&xprt->xp_lock);
214 
215 	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
216 	if (! xdr_callmsg(&xdrs, msg)) {
217 		XDR_DESTROY(&xdrs);
218 		return (FALSE);
219 	}
220 
221 	*addrp = raddr;
222 	*mp = xdrmbuf_getall(&xdrs);
223 	XDR_DESTROY(&xdrs);
224 
225 	return (TRUE);
226 }
227 
228 static bool_t
229 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
230     struct sockaddr *addr, struct mbuf *m)
231 {
232 	XDR xdrs;
233 	struct mbuf *mrep;
234 	bool_t stat = TRUE;
235 	int error;
236 
237 	MGETHDR(mrep, M_WAIT, MT_DATA);
238 	mrep->m_len = 0;
239 
240 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
241 
242 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
243 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
244 		if (!xdr_replymsg(&xdrs, msg))
245 			stat = FALSE;
246 		else
247 			xdrmbuf_append(&xdrs, m);
248 	} else {
249 		stat = xdr_replymsg(&xdrs, msg);
250 	}
251 
252 	if (stat) {
253 		m_fixhdr(mrep);
254 		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
255 		    0, curthread);
256 		if (!error) {
257 			stat = TRUE;
258 		}
259 	} else {
260 		m_freem(mrep);
261 	}
262 
263 	XDR_DESTROY(&xdrs);
264 	xprt->xp_p2 = NULL;
265 
266 	return (stat);
267 }
268 
269 static void
270 svc_dg_destroy(SVCXPRT *xprt)
271 {
272 
273 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
274 	soupcall_clear(xprt->xp_socket, SO_RCV);
275 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
276 
277 	sx_destroy(&xprt->xp_lock);
278 	if (xprt->xp_socket)
279 		(void)soclose(xprt->xp_socket);
280 
281 	if (xprt->xp_netid)
282 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
283 	svc_xprt_free(xprt);
284 }
285 
286 static bool_t
287 /*ARGSUSED*/
288 svc_dg_control(xprt, rq, in)
289 	SVCXPRT *xprt;
290 	const u_int	rq;
291 	void		*in;
292 {
293 
294 	return (FALSE);
295 }
296 
297 static int
298 svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
299 {
300 	SVCXPRT *xprt = (SVCXPRT *) arg;
301 
302 	xprt_active(xprt);
303 	return (SU_OK);
304 }
305