svc_dg.c revision 196503 
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 196503 2009-08-24 10:09:30Z zec $");
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	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);
146freedata:
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*/
155static enum xprt_stat
156svc_dg_stat(SVCXPRT *xprt)
157{
158
159	if (soreadable(xprt->xp_socket))
160		return (XPRT_MOREREQS);
161
162	return (XPRT_IDLE);
163}
164
165static bool_t
166svc_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
234static bool_t
235svc_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
275static void
276svc_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
292static bool_t
293/*ARGSUSED*/
294svc_dg_control(xprt, rq, in)
295	SVCXPRT *xprt;
296	const u_int	rq;
297	void		*in;
298{
299
300	return (FALSE);
301}
302
303static int
304svc_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