svc_dg.c revision 218757 
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: head/sys/rpc/svc_dg.c 218757 2011-02-16 21:29:13Z bz $");
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
66static enum xprt_stat svc_dg_stat(SVCXPRT *);
67static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
68    struct sockaddr **, struct mbuf **);
69static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
70    struct sockaddr *, struct mbuf *);
71static void svc_dg_destroy(SVCXPRT *);
72static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
73static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
74
75static 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 */
92static const char svc_dg_str[] = "svc_dg_create: %s";
93static const char svc_dg_err1[] = "could not get transport information";
94static const char svc_dg_err2[] = "transport does not support data transfer";
95static const char __no_mem_str[] = "out of memory";
96
97SVCXPRT *
98svc_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	if (!__rpc_socket2sockinfo(so, &si)) {
107		printf(svc_dg_str, svc_dg_err1);
108		return (NULL);
109	}
110	/*
111	 * Find the receive and the send size
112	 */
113	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
114	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
115	if ((sendsize == 0) || (recvsize == 0)) {
116		printf(svc_dg_str, svc_dg_err2);
117		return (NULL);
118	}
119
120	xprt = svc_xprt_alloc();
121	sx_init(&xprt->xp_lock, "xprt->xp_lock");
122	xprt->xp_pool = pool;
123	xprt->xp_socket = so;
124	xprt->xp_p1 = NULL;
125	xprt->xp_p2 = NULL;
126	xprt->xp_ops = &svc_dg_ops;
127
128	CURVNET_SET(so->so_vnet);
129	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
130	CURVNET_RESTORE();
131	if (error)
132		goto freedata;
133
134	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
135	free(sa, M_SONAME);
136
137	xprt_register(xprt);
138
139	SOCKBUF_LOCK(&so->so_rcv);
140	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
141	SOCKBUF_UNLOCK(&so->so_rcv);
142
143	return (xprt);
144freedata:
145	(void) printf(svc_dg_str, __no_mem_str);
146	if (xprt) {
147		svc_xprt_free(xprt);
148	}
149	return (NULL);
150}
151
152/*ARGSUSED*/
153static enum xprt_stat
154svc_dg_stat(SVCXPRT *xprt)
155{
156
157	if (soreadable(xprt->xp_socket))
158		return (XPRT_MOREREQS);
159
160	return (XPRT_IDLE);
161}
162
163static bool_t
164svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
165    struct sockaddr **addrp, struct mbuf **mp)
166{
167	struct uio uio;
168	struct sockaddr *raddr;
169	struct mbuf *mreq;
170	XDR xdrs;
171	int error, rcvflag;
172
173	/*
174	 * Serialise access to the socket.
175	 */
176	sx_xlock(&xprt->xp_lock);
177
178	/*
179	 * The socket upcall calls xprt_active() which will eventually
180	 * cause the server to call us here. We attempt to read a
181	 * packet from the socket and process it. If the read fails,
182	 * we have drained all pending requests so we call
183	 * xprt_inactive().
184	 */
185	uio.uio_resid = 1000000000;
186	uio.uio_td = curthread;
187	mreq = NULL;
188	rcvflag = MSG_DONTWAIT;
189	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
190
191	if (error == EWOULDBLOCK) {
192		/*
193		 * We must re-test for readability after taking the
194		 * lock to protect us in the case where a new packet
195		 * arrives on the socket after our call to soreceive
196		 * fails with EWOULDBLOCK. The pool lock protects us
197		 * from racing the upcall after our soreadable() call
198		 * returns false.
199		 */
200		mtx_lock(&xprt->xp_pool->sp_lock);
201		if (!soreadable(xprt->xp_socket))
202			xprt_inactive_locked(xprt);
203		mtx_unlock(&xprt->xp_pool->sp_lock);
204		sx_xunlock(&xprt->xp_lock);
205		return (FALSE);
206	}
207
208	if (error) {
209		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
210		soupcall_clear(xprt->xp_socket, SO_RCV);
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
232static bool_t
233svc_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
273static void
274svc_dg_destroy(SVCXPRT *xprt)
275{
276
277	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
278	soupcall_clear(xprt->xp_socket, SO_RCV);
279	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
280
281	sx_destroy(&xprt->xp_lock);
282	if (xprt->xp_socket)
283		(void)soclose(xprt->xp_socket);
284
285	if (xprt->xp_netid)
286		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
287	svc_xprt_free(xprt);
288}
289
290static bool_t
291/*ARGSUSED*/
292svc_dg_control(xprt, rq, in)
293	SVCXPRT *xprt;
294	const u_int	rq;
295	void		*in;
296{
297
298	return (FALSE);
299}
300
301static int
302svc_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