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/*
38 * svc_dg.c, Server side for connectionless RPC.
39 */
40
41#include <sys/param.h>
42#include <sys/jail.h>
43#include <sys/lock.h>
44#include <sys/kernel.h>
45#include <sys/malloc.h>
46#include <sys/mbuf.h>
47#include <sys/mutex.h>
48#include <sys/proc.h>
49#include <sys/protosw.h>
50#include <sys/queue.h>
51#include <sys/socket.h>
52#include <sys/socketvar.h>
53#include <sys/sx.h>
54#include <sys/systm.h>
55#include <sys/uio.h>
56
57#include <net/vnet.h>
58
59#include <rpc/rpc.h>
60
61#include <rpc/rpc_com.h>
62
63static enum xprt_stat svc_dg_stat(SVCXPRT *);
64static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
65    struct sockaddr **, struct mbuf **);
66static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
67    struct sockaddr *, struct mbuf *, uint32_t *);
68static void svc_dg_destroy(SVCXPRT *);
69static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
70static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
71
72static const struct xp_ops svc_dg_ops = {
73	.xp_recv =	svc_dg_recv,
74	.xp_stat =	svc_dg_stat,
75	.xp_reply =	svc_dg_reply,
76	.xp_destroy =	svc_dg_destroy,
77	.xp_control =	svc_dg_control,
78};
79
80/*
81 * Usage:
82 *	xprt = svc_dg_create(sock, sendsize, recvsize);
83 * Does other connectionless specific initializations.
84 * Once *xprt is initialized, it is registered.
85 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
86 * system defaults are chosen.
87 * The routines returns NULL if a problem occurred.
88 */
89static const char svc_dg_str[] = "svc_dg_create: %s";
90static const char svc_dg_err1[] = "could not get transport information";
91static const char svc_dg_err2[] = "transport does not support data transfer";
92static const char __no_mem_str[] = "out of memory";
93
94SVCXPRT *
95svc_dg_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
96    size_t recvsize)
97{
98	SVCXPRT *xprt;
99	struct __rpc_sockinfo si;
100	int error;
101
102	if (jailed(curthread->td_ucred))
103		return (NULL);
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	xprt->xp_ltaddr.ss_len = sizeof(xprt->xp_ltaddr);
127	error = sosockaddr(so, (struct sockaddr *)&xprt->xp_ltaddr);
128	if (error)
129		goto freedata;
130
131	xprt_register(xprt);
132
133	SOCK_RECVBUF_LOCK(so);
134	soupcall_set(so, SO_RCV, svc_dg_soupcall, xprt);
135	SOCK_RECVBUF_UNLOCK(so);
136
137	return (xprt);
138freedata:
139	(void) printf(svc_dg_str, __no_mem_str);
140	svc_xprt_free(xprt);
141
142	return (NULL);
143}
144
145/*ARGSUSED*/
146static enum xprt_stat
147svc_dg_stat(SVCXPRT *xprt)
148{
149
150	if (soreadable(xprt->xp_socket))
151		return (XPRT_MOREREQS);
152
153	return (XPRT_IDLE);
154}
155
156static bool_t
157svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg,
158    struct sockaddr **addrp, struct mbuf **mp)
159{
160	struct uio uio;
161	struct sockaddr *raddr;
162	struct mbuf *mreq;
163	XDR xdrs;
164	int error, rcvflag;
165
166	/*
167	 * Serialise access to the socket.
168	 */
169	sx_xlock(&xprt->xp_lock);
170
171	/*
172	 * The socket upcall calls xprt_active() which will eventually
173	 * cause the server to call us here. We attempt to read a
174	 * packet from the socket and process it. If the read fails,
175	 * we have drained all pending requests so we call
176	 * xprt_inactive().
177	 */
178	uio.uio_resid = 1000000000;
179	uio.uio_td = curthread;
180	mreq = NULL;
181	rcvflag = MSG_DONTWAIT;
182	error = soreceive(xprt->xp_socket, &raddr, &uio, &mreq, NULL, &rcvflag);
183
184	if (error == EWOULDBLOCK) {
185		/*
186		 * We must re-test for readability after taking the
187		 * lock to protect us in the case where a new packet
188		 * arrives on the socket after our call to soreceive
189		 * fails with EWOULDBLOCK. The pool lock protects us
190		 * from racing the upcall after our soreadable() call
191		 * returns false.
192		 */
193		SOCK_RECVBUF_LOCK(xprt->xp_socket);
194		if (!soreadable(xprt->xp_socket))
195			xprt_inactive_self(xprt);
196		SOCK_RECVBUF_UNLOCK(xprt->xp_socket);
197		sx_xunlock(&xprt->xp_lock);
198		return (FALSE);
199	}
200
201	if (error) {
202		SOCK_RECVBUF_LOCK(xprt->xp_socket);
203		soupcall_clear(xprt->xp_socket, SO_RCV);
204		SOCK_RECVBUF_UNLOCK(xprt->xp_socket);
205		xprt_inactive_self(xprt);
206		sx_xunlock(&xprt->xp_lock);
207		return (FALSE);
208	}
209
210	sx_xunlock(&xprt->xp_lock);
211
212	xdrmbuf_create(&xdrs, mreq, XDR_DECODE);
213	if (! xdr_callmsg(&xdrs, msg)) {
214		XDR_DESTROY(&xdrs);
215		return (FALSE);
216	}
217
218	*addrp = raddr;
219	*mp = xdrmbuf_getall(&xdrs);
220	XDR_DESTROY(&xdrs);
221
222	return (TRUE);
223}
224
225static bool_t
226svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg,
227    struct sockaddr *addr, struct mbuf *m, uint32_t *seq)
228{
229	XDR xdrs;
230	struct mbuf *mrep;
231	bool_t stat = TRUE;
232	int error;
233
234	mrep = m_gethdr(M_WAITOK, MT_DATA);
235
236	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
237
238	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
239	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
240		if (!xdr_replymsg(&xdrs, msg))
241			stat = FALSE;
242		else
243			xdrmbuf_append(&xdrs, m);
244	} else {
245		stat = xdr_replymsg(&xdrs, msg);
246	}
247
248	if (stat) {
249		m_fixhdr(mrep);
250		error = sosend(xprt->xp_socket, addr, NULL, mrep, NULL,
251		    0, curthread);
252		if (!error) {
253			stat = TRUE;
254		}
255	} else {
256		m_freem(mrep);
257	}
258
259	XDR_DESTROY(&xdrs);
260	xprt->xp_p2 = NULL;
261
262	return (stat);
263}
264
265static void
266svc_dg_destroy(SVCXPRT *xprt)
267{
268
269	SOCK_RECVBUF_LOCK(xprt->xp_socket);
270	soupcall_clear(xprt->xp_socket, SO_RCV);
271	SOCK_RECVBUF_UNLOCK(xprt->xp_socket);
272
273	sx_destroy(&xprt->xp_lock);
274	if (xprt->xp_socket)
275		(void)soclose(xprt->xp_socket);
276
277	if (xprt->xp_netid)
278		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
279	svc_xprt_free(xprt);
280}
281
282static bool_t
283/*ARGSUSED*/
284svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in)
285{
286
287	return (FALSE);
288}
289
290static int
291svc_dg_soupcall(struct socket *so, void *arg, int waitflag)
292{
293	SVCXPRT *xprt = (SVCXPRT *) arg;
294
295	xprt_active(xprt);
296	return (SU_OK);
297}
298