1/*	$NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $	*/
2
3/*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2009, Sun Microsystems, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 * - Redistributions of source code must retain the above copyright notice,
12 *   this list of conditions and the following disclaimer.
13 * - Redistributions in binary form must reproduce the above copyright notice,
14 *   this list of conditions and the following disclaimer in the documentation
15 *   and/or other materials provided with the distribution.
16 * - Neither the name of Sun Microsystems, Inc. nor the names of its
17 *   contributors may be used to endorse or promote products derived
18 *   from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33/*
34 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38#ident	"@(#)svc_dg.c	1.17	94/04/24 SMI"
39#endif
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD$");
42
43/*
44 * svc_dg.c, Server side for connectionless RPC.
45 */
46
47#include <sys/param.h>
48#include <sys/lock.h>
49#include <sys/kernel.h>
50#include <sys/malloc.h>
51#include <sys/mbuf.h>
52#include <sys/mutex.h>
53#include <sys/protosw.h>
54#include <sys/queue.h>
55#include <sys/socket.h>
56#include <sys/socketvar.h>
57#include <sys/sx.h>
58#include <sys/systm.h>
59#include <sys/uio.h>
60
61#include <net/vnet.h>
62
63#include <rpc/rpc.h>
64
65#include <rpc/rpc_com.h>
66
67static enum xprt_stat svc_dg_stat(SVCXPRT *);
68static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
69    struct sockaddr **, struct mbuf **);
70static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
71    struct sockaddr *, struct mbuf *, uint32_t *);
72static void svc_dg_destroy(SVCXPRT *);
73static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
74static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
75
76static struct xp_ops svc_dg_ops = {
77	.xp_recv =	svc_dg_recv,
78	.xp_stat =	svc_dg_stat,
79	.xp_reply =	svc_dg_reply,
80	.xp_destroy =	svc_dg_destroy,
81	.xp_control =	svc_dg_control,
82};
83
84/*
85 * Usage:
86 *	xprt = svc_dg_create(sock, sendsize, recvsize);
87 * Does other connectionless specific initializations.
88 * Once *xprt is initialized, it is registered.
89 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
90 * system defaults are chosen.
91 * The routines returns NULL if a problem occurred.
92 */
93static const char svc_dg_str[] = "svc_dg_create: %s";
94static const char svc_dg_err1[] = "could not get transport information";
95static const char svc_dg_err2[] = "transport does not support data transfer";
96static const char __no_mem_str[] = "out of memory";
97
98SVCXPRT *
99svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
100    size_t recvsize)
101{
102	SVCXPRT *xprt;
103	struct __rpc_sockinfo si;
104	struct sockaddr* sa;
105	int error;
106
107	if (!__rpc_socket2sockinfo(so, &si)) {
108		printf(svc_dg_str, svc_dg_err1);
109		return (NULL);
110	}
111	/*
112	 * Find the receive and the send size
113	 */
114	sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
115	recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
116	if ((sendsize == 0) || (recvsize == 0)) {
117		printf(svc_dg_str, svc_dg_err2);
118		return (NULL);
119	}
120
121	xprt = svc_xprt_alloc();
122	sx_init(&xprt->xp_lock, "xprt->xp_lock");
123	xprt->xp_pool = pool;
124	xprt->xp_socket = so;
125	xprt->xp_p1 = NULL;
126	xprt->xp_p2 = NULL;
127	xprt->xp_ops = &svc_dg_ops;
128
129	CURVNET_SET(so->so_vnet);
130	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
131	CURVNET_RESTORE();
132	if (error)
133		goto freedata;
134
135	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
136	free(sa, M_SONAME);
137
138	xprt_register(xprt);
139
140	SOCKBUF_LOCK(&so->so_rcv);
141	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
142	SOCKBUF_UNLOCK(&so->so_rcv);
143
144	return (xprt);
145freedata:
146	(void) printf(svc_dg_str, __no_mem_str);
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		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
201		if (!soreadable(xprt->xp_socket))
202			xprt_inactive_self(xprt);
203		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
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_self(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, uint32_t *seq)
235{
236	XDR xdrs;
237	struct mbuf *mrep;
238	bool_t stat = TRUE;
239	int error;
240
241	mrep = m_gethdr(M_WAITOK, MT_DATA);
242
243	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
244
245	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
246	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
247		if (!xdr_replymsg(&xdrs, msg))
248			stat = FALSE;
249		else
250			xdrmbuf_append(&xdrs, m);
251	} else {
252		stat = xdr_replymsg(&xdrs, msg);
253	}
254
255	if (stat) {
256		m_fixhdr(mrep);
257		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
258		    0, curthread);
259		if (!error) {
260			stat = TRUE;
261		}
262	} else {
263		m_freem(mrep);
264	}
265
266	XDR_DESTROY(&xdrs);
267	xprt->xp_p2 = NULL;
268
269	return (stat);
270}
271
272static void
273svc_dg_destroy(SVCXPRT *xprt)
274{
275
276	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
277	soupcall_clear(xprt->xp_socket, SO_RCV);
278	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
279
280	sx_destroy(&xprt->xp_lock);
281	if (xprt->xp_socket)
282		(void)soclose(xprt->xp_socket);
283
284	if (xprt->xp_netid)
285		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
286	svc_xprt_free(xprt);
287}
288
289static bool_t
290/*ARGSUSED*/
291svc_dg_control(xprt, rq, in)
292	SVCXPRT *xprt;
293	const u_int	rq;
294	void		*in;
295{
296
297	return (FALSE);
298}
299
300static int
301svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
302{
303	SVCXPRT *xprt = (SVCXPRT *) arg;
304
305	xprt_active(xprt);
306	return (SU_OK);
307}
308