xref: /netbsd-src/sys/nfs/krpc_subr.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1994 Gordon Ross, Adam Glass
3  * Copyright (c) 1992 Regents of the University of California.
4  * All rights reserved.
5  *
6  * This software was developed by the Computer Systems Engineering group
7  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
8  * contributed to Berkeley.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Lawrence Berkeley Laboratory and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  * partially based on:
39  *      libnetboot/rpc.c
40  *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
41  *   $Id: krpc_subr.c,v 1.2 1994/06/13 15:28:55 gwr Exp $
42  */
43 
44 #include <sys/param.h>
45 #include <sys/conf.h>
46 #include <sys/ioctl.h>
47 #include <sys/proc.h>
48 #include <sys/mount.h>
49 #include <sys/mbuf.h>
50 #include <sys/socket.h>
51 #include <sys/systm.h>
52 #include <sys/reboot.h>
53 
54 #include <net/if.h>
55 #include <netinet/in.h>
56 
57 #include <nfs/rpcv2.h>
58 
59 /*
60  * Kernel support for Sun RPC
61  *
62  * Used currently for bootstrapping in nfs diskless configurations.
63  *
64  * Note: will not work on variable-sized rpc args/results.
65  *       implicit size-limit of an mbuf.
66  */
67 
68 #define	PMAPPORT		111
69 #define	PMAPPROG		100000
70 #define	PMAPVERS		2
71 #define	PMAPPROC_GETPORT	3
72 
73 /*
74  * Generic RPC headers
75  */
76 
77 struct auth_info {
78 	int	rp_atype;		/* auth type */
79 	u_long	rp_alen;		/* auth length */
80 };
81 
82 struct rpc_call {
83 	u_long	rp_xid;			/* request transaction id */
84 	int 	rp_direction;	        /* call direction (0) */
85 	u_long	rp_rpcvers;		/* rpc version (2) */
86 	u_long	rp_prog;		/* program */
87 	u_long	rp_vers;		/* version */
88 	u_long	rp_proc;		/* procedure */
89 	struct	auth_info rp_auth;
90 	struct	auth_info rp_verf;
91 };
92 
93 struct rpc_reply {
94 	u_long	rp_xid;			/* request transaction id */
95 	int	rp_direction;		/* call direction (1) */
96 	int	rp_astatus;		/* accept status (0: accepted) */
97 	union {
98 		u_long	rpu_errno;
99 		struct {
100 			struct auth_info rp_auth;
101 			u_long	rp_rstatus;		/* reply status */
102 		} rpu_ok;
103 	} rp_u;
104 };
105 
106 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
107 
108 /*
109  * What is the longest we will wait before re-sending a request?
110  * Note this is also the frequency of "RPC timeout" messages.
111  * The re-send loop count sup linearly to this maximum, so the
112  * first complaint will happen after (1+2+3+4+5)=15 seconds.
113  */
114 #define	MAX_RESEND_DELAY 5	/* seconds */
115 
116 /*
117  * Call portmap to lookup a port number for a particular rpc program
118  * Returns non-zero error on failure.
119  */
120 int
121 krpc_portmap(sa,  prog, vers, portp)
122 	struct sockaddr *sa;		/* server address */
123 	u_long prog, vers;	/* host order */
124 	u_short *portp;		/* network order */
125 {
126 	struct sdata {
127 		u_long	prog;		/* call program */
128 		u_long	vers;		/* call version */
129 		u_long	proto;		/* call protocol */
130 		u_long	port;		/* call port (unused) */
131 	} *sdata;
132 	struct rdata {
133 		u_short pad;
134 		u_short port;
135 	} *rdata;
136 	struct mbuf *m;
137 	int error;
138 
139 	/* The portmapper port is fixed. */
140 	if (prog == PMAPPROG) {
141 		*portp = htons(PMAPPORT);
142 		return 0;
143 	}
144 
145 	m = m_gethdr(M_WAIT, MT_DATA);
146 	if (m == NULL)
147 		return ENOBUFS;
148 	m->m_len = sizeof(*sdata);
149 	m->m_pkthdr.len = m->m_len;
150 	sdata = mtod(m, struct sdata *);
151 
152 	/* Do the RPC to get it. */
153 	sdata->prog = htonl(prog);
154 	sdata->vers = htonl(vers);
155 	sdata->proto = htonl(IPPROTO_UDP);
156 	sdata->port = 0;
157 
158 	error = krpc_call(sa, PMAPPROG, PMAPVERS,
159 					  PMAPPROC_GETPORT, &m);
160 	if (error)
161 		return error;
162 
163 	rdata = mtod(m, struct rdata *);
164 	*portp = rdata->port;
165 
166 	m_freem(m);
167 	return 0;
168 }
169 
170 /*
171  * Do a remote procedure call (RPC) and wait for its reply.
172  */
173 int
174 krpc_call(sa, prog, vers, func, data)
175 	struct sockaddr *sa;
176 	u_long prog, vers, func;
177 	struct mbuf **data;	/* input/output */
178 {
179 	struct socket *so;
180 	struct sockaddr_in *sin;
181 	struct timeval *tv;
182 	struct mbuf *m, *nam, *mhead;
183 	struct rpc_call *call;
184 	struct rpc_reply *reply;
185 	struct uio auio;
186 	int error, rcvflg, timo, secs, len;
187 	static u_long xid = ~0xFF;
188 
189 	/*
190 	 * Validate address family.
191 	 * Sorry, this is INET specific...
192 	 */
193 	if (sa->sa_family != AF_INET)
194 		return (EAFNOSUPPORT);
195 
196 	/* Free at end if not null. */
197 	nam = mhead = NULL;
198 
199 	/*
200 	 * Create socket and set its recieve timeout.
201 	 */
202 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)))
203 		goto out;
204 
205 	m = m_get(M_WAIT, MT_SOOPTS);
206 	if (m == NULL) {
207 		error = ENOBUFS;
208 		goto out;
209 	}
210 	tv = mtod(m, struct timeval *);
211 	m->m_len = sizeof(*tv);
212 	tv->tv_sec = 1;
213 	tv->tv_usec = 0;
214 	if ((error = sosetopt(so, SOL_SOCKET, SO_RCVTIMEO, m)))
215 		goto out;
216 
217 	/*
218 	 * Setup socket address for the server.
219 	 */
220 	nam = m_get(M_WAIT, MT_SONAME);
221 	if (nam == NULL) {
222 		error = ENOBUFS;
223 		goto out;
224 	}
225 	sin = mtod(nam, struct sockaddr_in *);
226 	bcopy((caddr_t)sa, (caddr_t)sin, (nam->m_len = sa->sa_len));
227 
228 	/*
229 	 * Set the port number that the request will use.
230 	 */
231 	if ((error = krpc_portmap(sa, prog, vers, &sin->sin_port)))
232 		goto out;
233 
234 	/*
235 	 * Prepend RPC message header.
236 	 */
237 	m = *data;
238 	*data = NULL;
239 #ifdef	DIAGNOSTIC
240 	if ((m->m_flags & M_PKTHDR) == 0)
241 		panic("krpc_call: send data w/o pkthdr");
242 	if (m->m_pkthdr.len < m->m_len)
243 		panic("krpc_call: pkthdr.len not set");
244 #endif
245 	mhead = m_prepend(m, sizeof(*call), M_WAIT);
246 	if (mhead == NULL) {
247 		error = ENOBUFS;
248 		goto out;
249 	}
250 	mhead->m_pkthdr.len += sizeof(*call);
251 	mhead->m_pkthdr.rcvif = NULL;
252 
253 	/*
254 	 * Fill in the RPC header
255 	 */
256 	call = mtod(mhead, struct rpc_call *);
257 	bzero((caddr_t)call, sizeof(*call));
258 	call->rp_xid = ++xid;	/* no need to put in network order */
259 	/* call->rp_direction = 0; */
260 	call->rp_rpcvers = htonl(2);
261 	call->rp_prog = htonl(prog);
262 	call->rp_vers = htonl(vers);
263 	call->rp_proc = htonl(func);
264 	/* call->rp_auth = 0; */
265 	/* call->rp_verf = 0; */
266 
267 	/*
268 	 * Send it, repeatedly, until a reply is received,
269 	 * but delay each re-send by an increasing amount.
270 	 * If the delay hits the maximum, start complaining.
271 	 */
272 	timo = 0;
273 	for (;;) {
274 		/* Send RPC request (or re-send). */
275 		m = m_copym(mhead, 0, M_COPYALL, M_WAIT);
276 		if (m == NULL) {
277 			error = ENOBUFS;
278 			goto out;
279 		}
280 		error = sosend(so, nam, NULL, m, NULL, 0);
281 		if (error) {
282 			printf("krpc_call: sosend: %d\n", error);
283 			goto out;
284 		}
285 		m = NULL;
286 
287 		/* Determine new timeout. */
288 		if (timo < MAX_RESEND_DELAY)
289 			timo++;
290 		else
291 			printf("RPC timeout for server 0x%x\n",
292 			       ntohl(sin->sin_addr.s_addr));
293 
294 		/*
295 		 * Wait for up to timo seconds for a reply.
296 		 * The socket receive timeout was set to 1 second.
297 		 */
298 		secs = timo;
299 		while (secs > 0) {
300 			auio.uio_resid = len = 1<<16;
301 			rcvflg = 0;
302 			error = soreceive(so, NULL, &auio, &m, NULL, &rcvflg);
303 			if (error == EWOULDBLOCK) {
304 				secs--;
305 				continue;
306 			}
307 			if (error)
308 				goto out;
309 			len -= auio.uio_resid;
310 
311 			/* Is the reply complete and the right one? */
312 			if (len < MIN_REPLY_HDR) {
313 				m_freem(m);
314 				continue;
315 			}
316 			if (m->m_len < MIN_REPLY_HDR) {
317 				m = m_pullup(m, MIN_REPLY_HDR);
318 				if (!m)
319 					continue;
320 			}
321 			reply = mtod(m, struct rpc_reply *);
322 			if ((reply->rp_direction == htonl(RPC_REPLY)) &&
323 				(reply->rp_xid == xid))
324 				goto gotreply;	/* break two levels */
325 		} /* while secs */
326 	} /* forever send/receive */
327  gotreply:
328 
329 	/*
330 	 * Make result buffer contiguous.
331 	 */
332 #ifdef	DIAGNOSTIC
333 	if ((m->m_flags & M_PKTHDR) == 0)
334 		panic("krpc_call: received pkt w/o header?");
335 #endif
336 	len = m->m_pkthdr.len;
337 	if (m->m_len < len) {
338 		m = m_pullup(m, len);
339 		if (m == NULL) {
340 			error = ENOBUFS;
341 			goto out;
342 		}
343 	}
344 	reply = mtod(m, struct rpc_reply *);
345 
346 	/*
347 	 * Check RPC acceptance and status.
348 	 */
349 	if (reply->rp_astatus != 0) {
350 		error = reply->rp_u.rpu_errno;
351 		printf("rpc denied, error=%d\n", error);
352 		m_freem(m);
353 		goto out;
354 	}
355 	if ((error = reply->rp_u.rpu_ok.rp_rstatus) != 0) {
356 		printf("rpc status=%d\n", error);
357 		m_freem(m);
358 		goto out;
359 	}
360 
361 	/*
362 	 * Strip RPC header
363 	 */
364 	len = sizeof(*reply);
365 	if (reply->rp_u.rpu_ok.rp_auth.rp_atype != 0) {
366 		len += ntohl(reply->rp_u.rpu_ok.rp_auth.rp_alen);
367 		len = (len + 3) & ~3; /* XXX? */
368 	}
369 	m_adj(m, len);
370 
371 	/* result */
372 	*data = m;
373 
374  out:
375 	if (nam) m_freem(nam);
376 	if (mhead) m_freem(mhead);
377 	soclose(so);
378 	return error;
379 }
380