svc_dg.c revision 303692
1/*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 *   this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 *   this list of conditions and the following disclaimer in the documentation
13 *   and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 *   contributors may be used to endorse or promote products derived
16 *   from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31/*
32 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
33 */
34
35#if defined(LIBC_SCCS) && !defined(lint)
36#ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
37#endif
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: stable/10/sys/rpc/svc_dg.c 303692 2016-08-03 01:19:10Z ngie $");
40
41/*
42 * svc_dg.c, Server side for connectionless RPC.
43 */
44
45#include <sys/param.h>
46#include <sys/lock.h>
47#include <sys/kernel.h>
48#include <sys/malloc.h>
49#include <sys/mbuf.h>
50#include <sys/mutex.h>
51#include <sys/protosw.h>
52#include <sys/queue.h>
53#include <sys/socket.h>
54#include <sys/socketvar.h>
55#include <sys/sx.h>
56#include <sys/systm.h>
57#include <sys/uio.h>
58
59#include <net/vnet.h>
60
61#include <rpc/rpc.h>
62
63#include <rpc/rpc_com.h>
64
65static enum xprt_stat svc_dg_stat(SVCXPRT *);
66static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
67    struct sockaddr **, struct mbuf **);
68static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
69    struct sockaddr *, struct mbuf *, uint32_t *);
70static void svc_dg_destroy(SVCXPRT *);
71static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
72static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
73
74static struct xp_ops svc_dg_ops = {
75	.xp_recv =	svc_dg_recv,
76	.xp_stat =	svc_dg_stat,
77	.xp_reply =	svc_dg_reply,
78	.xp_destroy =	svc_dg_destroy,
79	.xp_control =	svc_dg_control,
80};
81
82/*
83 * Usage:
84 *	xprt = svc_dg_create(sock, sendsize, recvsize);
85 * Does other connectionless specific initializations.
86 * Once *xprt is initialized, it is registered.
87 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
88 * system defaults are chosen.
89 * The routines returns NULL if a problem occurred.
90 */
91static const char svc_dg_str[] = "svc_dg_create: %s";
92static const char svc_dg_err1[] = "could not get transport information";
93static const char svc_dg_err2[] = "transport does not support data transfer";
94static const char __no_mem_str[] = "out of memory";
95
96SVCXPRT *
97svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
98    size_t recvsize)
99{
100	SVCXPRT *xprt;
101	struct __rpc_sockinfo si;
102	struct sockaddr* sa;
103	int error;
104
105	if (!__rpc_socket2sockinfo(so, &si)) {
106		printf(svc_dg_str, svc_dg_err1);
107		return (NULL);
108	}
109	/*
110	 * Find the receive and the send size
111	 */
112	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
113	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
114	if ((sendsize == 0) || (recvsize == 0)) {
115		printf(svc_dg_str, svc_dg_err2);
116		return (NULL);
117	}
118
119	xprt = svc_xprt_alloc();
120	sx_init(&xprt->xp_lock, "xprt->xp_lock");
121	xprt->xp_pool = pool;
122	xprt->xp_socket = so;
123	xprt->xp_p1 = NULL;
124	xprt->xp_p2 = NULL;
125	xprt->xp_ops = &svc_dg_ops;
126
127	CURVNET_SET(so->so_vnet);
128	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
129	CURVNET_RESTORE();
130	if (error)
131		goto freedata;
132
133	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
134	free(sa, M_SONAME);
135
136	xprt_register(xprt);
137
138	SOCKBUF_LOCK(&so->so_rcv);
139	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
140	SOCKBUF_UNLOCK(&so->so_rcv);
141
142	return (xprt);
143freedata:
144	(void) printf(svc_dg_str, __no_mem_str);
145	svc_xprt_free(xprt);
146
147	return (NULL);
148}
149
150/*ARGSUSED*/
151static enum xprt_stat
152svc_dg_stat(SVCXPRT *xprt)
153{
154
155	if (soreadable(xprt->xp_socket))
156		return (XPRT_MOREREQS);
157
158	return (XPRT_IDLE);
159}
160
161static bool_t
162svc_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		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
199		if (!soreadable(xprt->xp_socket))
200			xprt_inactive_self(xprt);
201		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
202		sx_xunlock(&xprt->xp_lock);
203		return (FALSE);
204	}
205
206	if (error) {
207		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
208		soupcall_clear(xprt->xp_socket, SO_RCV);
209		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
210		xprt_inactive_self(xprt);
211		sx_xunlock(&xprt->xp_lock);
212		return (FALSE);
213	}
214
215	sx_xunlock(&xprt->xp_lock);
216
217	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
218	if (! xdr_callmsg(&xdrs, msg)) {
219		XDR_DESTROY(&xdrs);
220		return (FALSE);
221	}
222
223	*addrp = raddr;
224	*mp = xdrmbuf_getall(&xdrs);
225	XDR_DESTROY(&xdrs);
226
227	return (TRUE);
228}
229
230static bool_t
231svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
232    struct sockaddr *addr, struct mbuf *m, uint32_t *seq)
233{
234	XDR xdrs;
235	struct mbuf *mrep;
236	bool_t stat = TRUE;
237	int error;
238
239	mrep = m_gethdr(M_WAITOK, MT_DATA);
240
241	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
242
243	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
244	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
245		if (!xdr_replymsg(&xdrs, msg))
246			stat = FALSE;
247		else
248			xdrmbuf_append(&xdrs, m);
249	} else {
250		stat = xdr_replymsg(&xdrs, msg);
251	}
252
253	if (stat) {
254		m_fixhdr(mrep);
255		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
256		    0, curthread);
257		if (!error) {
258			stat = TRUE;
259		}
260	} else {
261		m_freem(mrep);
262	}
263
264	XDR_DESTROY(&xdrs);
265	xprt->xp_p2 = NULL;
266
267	return (stat);
268}
269
270static void
271svc_dg_destroy(SVCXPRT *xprt)
272{
273
274	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
275	soupcall_clear(xprt->xp_socket, SO_RCV);
276	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
277
278	sx_destroy(&xprt->xp_lock);
279	if (xprt->xp_socket)
280		(void)soclose(xprt->xp_socket);
281
282	if (xprt->xp_netid)
283		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
284	svc_xprt_free(xprt);
285}
286
287static bool_t
288/*ARGSUSED*/
289svc_dg_control(xprt, rq, in)
290	SVCXPRT *xprt;
291	const u_int	rq;
292	void		*in;
293{
294
295	return (FALSE);
296}
297
298static int
299svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
300{
301	SVCXPRT *xprt = (SVCXPRT *) arg;
302
303	xprt_active(xprt);
304	return (SU_OK);
305}
306