krpc_subr.c revision 38482 
1/*	$NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $	*/
2/*	$Id: krpc_subr.c,v 1.10 1998/08/18 00:32:48 bde Exp $	*/
3
4/*
5 * Copyright (c) 1995 Gordon Ross, Adam Glass
6 * Copyright (c) 1992 Regents of the University of California.
7 * All rights reserved.
8 *
9 * This software was developed by the Computer Systems Engineering group
10 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
11 * contributed to Berkeley.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 *    must display the following acknowledgement:
23 *	This product includes software developed by the University of
24 *	California, Lawrence Berkeley Laboratory and its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 *    may be used to endorse or promote products derived from this software
27 *    without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 * partially based on:
42 *      libnetboot/rpc.c
43 *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
44 */
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/malloc.h>
49#include <sys/mbuf.h>
50#include <sys/socket.h>
51#include <sys/socketvar.h>
52#include <sys/uio.h>
53
54#include <net/if.h>
55#include <netinet/in.h>
56
57#include <nfs/rpcv2.h>
58#include <nfs/krpc.h>
59#include <nfs/xdr_subs.h>
60
61/*
62 * Kernel support for Sun RPC
63 *
64 * Used currently for bootstrapping in nfs diskless configurations.
65 */
66
67/*
68 * Generic RPC headers
69 */
70
71struct auth_info {
72	u_int32_t 	authtype;	/* auth type */
73	u_int32_t	authlen;	/* auth length */
74};
75
76struct auth_unix {
77	int32_t   ua_time;
78	int32_t   ua_hostname;	/* null */
79	int32_t   ua_uid;
80	int32_t   ua_gid;
81	int32_t   ua_gidlist;	/* null */
82};
83
84struct rpc_call {
85	u_int32_t	rp_xid;		/* request transaction id */
86	int32_t 	rp_direction;	/* call direction (0) */
87	u_int32_t	rp_rpcvers;	/* rpc version (2) */
88	u_int32_t	rp_prog;	/* program */
89	u_int32_t	rp_vers;	/* version */
90	u_int32_t	rp_proc;	/* procedure */
91	struct	auth_info rpc_auth;
92	struct	auth_unix rpc_unix;
93	struct	auth_info rpc_verf;
94};
95
96struct rpc_reply {
97	u_int32_t rp_xid;		/* request transaction id */
98	int32_t  rp_direction;		/* call direction (1) */
99	int32_t  rp_astatus;		/* accept status (0: accepted) */
100	union {
101		u_int32_t rpu_errno;
102		struct {
103			struct auth_info rok_auth;
104			u_int32_t	rok_status;
105		} rpu_rok;
106	} rp_u;
107};
108#define rp_errno  rp_u.rpu_errno
109#define rp_auth   rp_u.rpu_rok.rok_auth
110#define rp_status rp_u.rpu_rok.rok_status
111
112#define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
113
114/*
115 * What is the longest we will wait before re-sending a request?
116 * Note this is also the frequency of "RPC timeout" messages.
117 * The re-send loop count sup linearly to this maximum, so the
118 * first complaint will happen after (1+2+3+4+5)=15 seconds.
119 */
120#define	MAX_RESEND_DELAY 5	/* seconds */
121
122/*
123 * Call portmap to lookup a port number for a particular rpc program
124 * Returns non-zero error on failure.
125 */
126int
127krpc_portmap(sin,  prog, vers, portp, procp)
128	struct sockaddr_in *sin;		/* server address */
129	u_int prog, vers;	/* host order */
130	u_int16_t *portp;	/* network order */
131	struct proc *procp;
132{
133	struct sdata {
134		u_int32_t prog;		/* call program */
135		u_int32_t vers;		/* call version */
136		u_int32_t proto;	/* call protocol */
137		u_int32_t port;		/* call port (unused) */
138	} *sdata;
139	struct rdata {
140		u_int16_t pad;
141		u_int16_t port;
142	} *rdata;
143	struct mbuf *m;
144	int error;
145
146	/* The portmapper port is fixed. */
147	if (prog == PMAPPROG) {
148		*portp = htons(PMAPPORT);
149		return 0;
150	}
151
152	m = m_get(M_WAIT, MT_DATA);
153	if (m == NULL)
154		return ENOBUFS;
155	sdata = mtod(m, struct sdata *);
156	m->m_len = sizeof(*sdata);
157
158	/* Do the RPC to get it. */
159	sdata->prog = txdr_unsigned(prog);
160	sdata->vers = txdr_unsigned(vers);
161	sdata->proto = txdr_unsigned(IPPROTO_UDP);
162	sdata->port = 0;
163
164	sin->sin_port = htons(PMAPPORT);
165	error = krpc_call(sin, PMAPPROG, PMAPVERS,
166					  PMAPPROC_GETPORT, &m, NULL, procp);
167	if (error)
168		return error;
169
170	if (m->m_len < sizeof(*rdata)) {
171		m = m_pullup(m, sizeof(*rdata));
172		if (m == NULL)
173			return ENOBUFS;
174	}
175	rdata = mtod(m, struct rdata *);
176	*portp = rdata->port;
177
178	m_freem(m);
179	return 0;
180}
181
182/*
183 * Do a remote procedure call (RPC) and wait for its reply.
184 * If from_p is non-null, then we are doing broadcast, and
185 * the address from whence the response came is saved there.
186 */
187int
188krpc_call(sa, prog, vers, func, data, from_p, procp)
189	struct sockaddr_in *sa;
190	u_int prog, vers, func;
191	struct mbuf **data;	/* input/output */
192	struct sockaddr **from_p;	/* output */
193	struct proc *procp;
194{
195	struct socket *so;
196	struct sockaddr_in *sin, ssin;
197	struct sockaddr *from;
198	struct mbuf *m, *nam, *mhead;
199	struct rpc_call *call;
200	struct rpc_reply *reply;
201	struct sockopt sopt;
202	struct timeval tv;
203	struct uio auio;
204	int error, rcvflg, timo, secs, len;
205	static u_int32_t xid = ~0xFF;
206	u_int16_t tport;
207
208	/*
209	 * Validate address family.
210	 * Sorry, this is INET specific...
211	 */
212	if (sa->sin_family != AF_INET)
213		return (EAFNOSUPPORT);
214
215	/* Free at end if not null. */
216	nam = mhead = NULL;
217	from = NULL;
218
219	/*
220	 * Create socket and set its recieve timeout.
221	 */
222	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, procp)))
223		goto out;
224
225	tv.tv_sec = 1;
226	tv.tv_usec = 0;
227	bzero(&sopt, sizeof sopt);
228	sopt.sopt_level = SOL_SOCKET;
229	sopt.sopt_name = SO_RCVTIMEO;
230	sopt.sopt_val = &tv;
231	sopt.sopt_valsize = sizeof tv;
232
233	if (error = sosetopt(so, &sopt))
234		goto out;
235
236	/*
237	 * Enable broadcast if necessary.
238	 */
239	if (from_p) {
240		int on = 1;
241		sopt.sopt_name = SO_BROADCAST;
242		sopt.sopt_val = &on;
243		sopt.sopt_valsize = sizeof on;
244		if (error = sosetopt(so, &sopt))
245			goto out;
246	}
247
248	/*
249	 * Bind the local endpoint to a reserved port,
250	 * because some NFS servers refuse requests from
251	 * non-reserved (non-privileged) ports.
252	 */
253	sin = &ssin;
254	bzero(sin, sizeof *sin);
255	sin->sin_len = sizeof(*sin);
256	sin->sin_family = AF_INET;
257	sin->sin_addr.s_addr = INADDR_ANY;
258	tport = IPPORT_RESERVED;
259	do {
260		tport--;
261		sin->sin_port = htons(tport);
262		error = sobind(so, (struct sockaddr *)sin, procp);
263	} while (error == EADDRINUSE &&
264			 tport > IPPORT_RESERVED / 2);
265	if (error) {
266		printf("bind failed\n");
267		goto out;
268	}
269
270	/*
271	 * Setup socket address for the server.
272	 */
273
274	/*
275	 * Prepend RPC message header.
276	 */
277	mhead = m_gethdr(M_WAIT, MT_DATA);
278	mhead->m_next = *data;
279	call = mtod(mhead, struct rpc_call *);
280	mhead->m_len = sizeof(*call);
281	bzero((caddr_t)call, sizeof(*call));
282	/* rpc_call part */
283	xid++;
284	call->rp_xid = txdr_unsigned(xid);
285	/* call->rp_direction = 0; */
286	call->rp_rpcvers = txdr_unsigned(2);
287	call->rp_prog = txdr_unsigned(prog);
288	call->rp_vers = txdr_unsigned(vers);
289	call->rp_proc = txdr_unsigned(func);
290	/* rpc_auth part (auth_unix as root) */
291	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
292	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
293	/* rpc_verf part (auth_null) */
294	call->rpc_verf.authtype = 0;
295	call->rpc_verf.authlen  = 0;
296
297	/*
298	 * Setup packet header
299	 */
300	len = 0;
301	m = mhead;
302	while (m) {
303		len += m->m_len;
304		m = m->m_next;
305	}
306	mhead->m_pkthdr.len = len;
307	mhead->m_pkthdr.rcvif = NULL;
308
309	/*
310	 * Send it, repeatedly, until a reply is received,
311	 * but delay each re-send by an increasing amount.
312	 * If the delay hits the maximum, start complaining.
313	 */
314	timo = 0;
315	for (;;) {
316		/* Send RPC request (or re-send). */
317		m = m_copym(mhead, 0, M_COPYALL, M_WAIT);
318		if (m == NULL) {
319			error = ENOBUFS;
320			goto out;
321		}
322		error = sosend(so, (struct sockaddr *)sa, NULL, m,
323			       NULL, 0, 0);
324		if (error) {
325			printf("krpc_call: sosend: %d\n", error);
326			goto out;
327		}
328		m = NULL;
329
330		/* Determine new timeout. */
331		if (timo < MAX_RESEND_DELAY)
332			timo++;
333		else
334			printf("RPC timeout for server 0x%lx\n",
335			       (u_long)ntohl(sa->sin_addr.s_addr));
336
337		/*
338		 * Wait for up to timo seconds for a reply.
339		 * The socket receive timeout was set to 1 second.
340		 */
341		secs = timo;
342		while (secs > 0) {
343			if (from) {
344				FREE(from, M_SONAME);
345				from = NULL;
346			}
347			if (m) {
348				m_freem(m);
349				m = NULL;
350			}
351			bzero(&auio,sizeof(auio));
352			auio.uio_resid = len = 1<<16;
353			rcvflg = 0;
354			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
355			if (error == EWOULDBLOCK) {
356				secs--;
357				continue;
358			}
359			if (error)
360				goto out;
361			len -= auio.uio_resid;
362
363			/* Does the reply contain at least a header? */
364			if (len < MIN_REPLY_HDR)
365				continue;
366			if (m->m_len < MIN_REPLY_HDR)
367				continue;
368			reply = mtod(m, struct rpc_reply *);
369
370			/* Is it the right reply? */
371			if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
372				continue;
373
374			if (reply->rp_xid != txdr_unsigned(xid))
375				continue;
376
377			/* Was RPC accepted? (authorization OK) */
378			if (reply->rp_astatus != 0) {
379				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
380				printf("rpc denied, error=%d\n", error);
381				continue;
382			}
383
384			/* Did the call succeed? */
385			if (reply->rp_status != 0) {
386				error = fxdr_unsigned(u_int32_t, reply->rp_status);
387				if (error == RPC_PROGMISMATCH) {
388				  error = EBADRPC;
389				  goto out;
390				}
391				printf("rpc denied, status=%d\n", error);
392				continue;
393			}
394
395			goto gotreply;	/* break two levels */
396
397		} /* while secs */
398	} /* forever send/receive */
399
400	error = ETIMEDOUT;
401	goto out;
402
403 gotreply:
404
405	/*
406	 * Get RPC reply header into first mbuf,
407	 * get its length, then strip it off.
408	 */
409	len = sizeof(*reply);
410	if (m->m_len < len) {
411		m = m_pullup(m, len);
412		if (m == NULL) {
413			error = ENOBUFS;
414			goto out;
415		}
416	}
417	reply = mtod(m, struct rpc_reply *);
418	if (reply->rp_auth.authtype != 0) {
419		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
420		len = (len + 3) & ~3; /* XXX? */
421	}
422	m_adj(m, len);
423
424	/* result */
425	*data = m;
426	if (from_p) {
427		*from_p = from;
428		from = NULL;
429	}
430
431 out:
432	if (mhead) m_freem(mhead);
433	if (from) free(from, M_SONAME);
434	soclose(so);
435	return error;
436}
437
438/*
439 * eXternal Data Representation routines.
440 * (but with non-standard args...)
441 */
442
443/*
444 * String representation for RPC.
445 */
446struct xdr_string {
447	u_int32_t len;		/* length without null or padding */
448	char data[4];	/* data (longer, of course) */
449    /* data is padded to a long-word boundary */
450};
451
452struct mbuf *
453xdr_string_encode(str, len)
454	char *str;
455	int len;
456{
457	struct mbuf *m;
458	struct xdr_string *xs;
459	int dlen;	/* padded string length */
460	int mlen;	/* message length */
461
462	dlen = (len + 3) & ~3;
463	mlen = dlen + 4;
464
465	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
466		return (NULL);
467
468	m = m_get(M_WAIT, MT_DATA);
469	if (mlen > MLEN) {
470		MCLGET(m, M_WAIT);
471		if ((m->m_flags & M_EXT) == 0) {
472			(void) m_free(m);	/* There can be only one. */
473			return (NULL);
474		}
475	}
476	xs = mtod(m, struct xdr_string *);
477	m->m_len = mlen;
478	xs->len = txdr_unsigned(len);
479	bcopy(str, xs->data, len);
480	return (m);
481}
482