xref: /freebsd/sys/rpc/svc_dg.c (revision c1d255d3ffdbe447de3ab875bf4e7d7accc5bfc5)
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  
67  static enum xprt_stat svc_dg_stat(SVCXPRT *);
68  static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *,
69      struct sockaddr **, struct mbuf **);
70  static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *,
71      struct sockaddr *, struct mbuf *, uint32_t *);
72  static void svc_dg_destroy(SVCXPRT *);
73  static bool_t svc_dg_control(SVCXPRT *, const u_int, void *);
74  static int svc_dg_soupcall(struct socket *so, void *arg, int waitflag);
75  
76  static const 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   */
93  static const char svc_dg_str[] = "svc_dg_create: %s";
94  static const char svc_dg_err1[] = "could not get transport information";
95  static const char svc_dg_err2[] = "transport does not support data transfer";
96  static const char __no_mem_str[] = "out of memory";
97  
98  SVCXPRT *
99  svc_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);
145  freedata:
146  	(void) printf(svc_dg_str, __no_mem_str);
147  	svc_xprt_free(xprt);
148  
149  	return (NULL);
150  }
151  
152  /*ARGSUSED*/
153  static enum xprt_stat
154  svc_dg_stat(SVCXPRT *xprt)
155  {
156  
157  	if (soreadable(xprt->xp_socket))
158  		return (XPRT_MOREREQS);
159  
160  	return (XPRT_IDLE);
161  }
162  
163  static bool_t
164  svc_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  
232  static bool_t
233  svc_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  
272  static void
273  svc_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  
289  static bool_t
290  /*ARGSUSED*/
291  svc_dg_control(xprt, rq, in)
292  	SVCXPRT *xprt;
293  	const u_int	rq;
294  	void		*in;
295  {
296  
297  	return (FALSE);
298  }
299  
300  static int
301  svc_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