krpc_subr.c revision 122698 
1/*	$NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $	*/
2
3/*
4 * Copyright (c) 1995 Gordon Ross, Adam Glass
5 * Copyright (c) 1992 Regents of the University of California.
6 * All rights reserved.
7 *
8 * This software was developed by the Computer Systems Engineering group
9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10 * contributed to Berkeley.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 *    must display the following acknowledgement:
22 *	This product includes software developed by the University of
23 *	California, Lawrence Berkeley Laboratory and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 * partially based on:
41 *      libnetboot/rpc.c
42 *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
43 */
44
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD: head/sys/nfsclient/krpc_subr.c 122698 2003-11-14 20:54:10Z alfred $");
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/malloc.h>
51#include <sys/mbuf.h>
52#include <sys/proc.h>
53#include <sys/socket.h>
54#include <sys/socketvar.h>
55#include <sys/uio.h>
56
57#include <net/if.h>
58#include <netinet/in.h>
59
60#include <rpc/rpcclnt.h>
61
62#include <nfs/rpcv2.h>
63#include <nfsclient/krpc.h>
64#include <nfs/xdr_subs.h>
65
66/*
67 * Kernel support for Sun RPC
68 *
69 * Used currently for bootstrapping in nfs diskless configurations.
70 */
71
72/*
73 * Generic RPC headers
74 */
75
76struct auth_info {
77	u_int32_t 	authtype;	/* auth type */
78	u_int32_t	authlen;	/* auth length */
79};
80
81struct auth_unix {
82	int32_t   ua_time;
83	int32_t   ua_hostname;	/* null */
84	int32_t   ua_uid;
85	int32_t   ua_gid;
86	int32_t   ua_gidlist;	/* null */
87};
88
89struct rpc_call {
90	u_int32_t	rp_xid;		/* request transaction id */
91	int32_t 	rp_direction;	/* call direction (0) */
92	u_int32_t	rp_rpcvers;	/* rpc version (2) */
93	u_int32_t	rp_prog;	/* program */
94	u_int32_t	rp_vers;	/* version */
95	u_int32_t	rp_proc;	/* procedure */
96	struct	auth_info rpc_auth;
97	struct	auth_unix rpc_unix;
98	struct	auth_info rpc_verf;
99};
100
101struct rpc_reply {
102	u_int32_t rp_xid;		/* request transaction id */
103	int32_t  rp_direction;		/* call direction (1) */
104	int32_t  rp_astatus;		/* accept status (0: accepted) */
105	union {
106		u_int32_t rpu_errno;
107		struct {
108			struct auth_info rok_auth;
109			u_int32_t	rok_status;
110		} rpu_rok;
111	} rp_u;
112};
113#define rp_errno  rp_u.rpu_errno
114#define rp_auth   rp_u.rpu_rok.rok_auth
115#define rp_status rp_u.rpu_rok.rok_status
116
117#define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
118
119/*
120 * What is the longest we will wait before re-sending a request?
121 * Note this is also the frequency of "RPC timeout" messages.
122 * The re-send loop count sup linearly to this maximum, so the
123 * first complaint will happen after (1+2+3+4+5)=15 seconds.
124 */
125#define	MAX_RESEND_DELAY 5	/* seconds */
126
127/*
128 * Call portmap to lookup a port number for a particular rpc program
129 * Returns non-zero error on failure.
130 */
131int
132krpc_portmap(struct sockaddr_in *sin, u_int prog, u_int vers, u_int16_t *portp,
133    struct thread *td)
134{
135	struct sdata {
136		u_int32_t prog;		/* call program */
137		u_int32_t vers;		/* call version */
138		u_int32_t proto;	/* call protocol */
139		u_int32_t port;		/* call port (unused) */
140	} *sdata;
141	struct rdata {
142		u_int16_t pad;
143		u_int16_t port;
144	} *rdata;
145	struct mbuf *m;
146	int error;
147
148	/* The portmapper port is fixed. */
149	if (prog == PMAPPROG) {
150		*portp = htons(PMAPPORT);
151		return 0;
152	}
153
154	m = m_get(M_TRYWAIT, MT_DATA);
155	if (m == NULL)
156		return ENOBUFS;
157	sdata = mtod(m, struct sdata *);
158	m->m_len = sizeof(*sdata);
159
160	/* Do the RPC to get it. */
161	sdata->prog = txdr_unsigned(prog);
162	sdata->vers = txdr_unsigned(vers);
163	sdata->proto = txdr_unsigned(IPPROTO_UDP);
164	sdata->port = 0;
165
166	sin->sin_port = htons(PMAPPORT);
167	error = krpc_call(sin, PMAPPROG, PMAPVERS,
168					  PMAPPROC_GETPORT, &m, NULL, td);
169	if (error)
170		return error;
171
172	if (m->m_len < sizeof(*rdata)) {
173		m = m_pullup(m, sizeof(*rdata));
174		if (m == NULL)
175			return ENOBUFS;
176	}
177	rdata = mtod(m, struct rdata *);
178	*portp = rdata->port;
179
180	m_freem(m);
181	return 0;
182}
183
184/*
185 * Do a remote procedure call (RPC) and wait for its reply.
186 * If from_p is non-null, then we are doing broadcast, and
187 * the address from whence the response came is saved there.
188 */
189int
190krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
191    struct mbuf **data, struct sockaddr **from_p, struct thread *td)
192{
193	struct socket *so;
194	struct sockaddr_in *sin, ssin;
195	struct sockaddr *from;
196	struct mbuf *m, *nam, *mhead;
197	struct rpc_call *call;
198	struct rpc_reply *reply;
199	struct sockopt sopt;
200	struct timeval tv;
201	struct uio auio;
202	int error, rcvflg, timo, secs, len;
203	static u_int32_t xid = ~0xFF;
204	u_int16_t tport;
205	u_int32_t saddr;
206
207	/*
208	 * Validate address family.
209	 * Sorry, this is INET specific...
210	 */
211	if (sa->sin_family != AF_INET)
212		return (EAFNOSUPPORT);
213
214	/* Free at end if not null. */
215	nam = mhead = NULL;
216	from = NULL;
217
218	GIANT_REQUIRED;		/* XXX until socket locking done */
219
220	/*
221	 * Create socket and set its recieve timeout.
222	 */
223	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td->td_ucred, td)))
224		goto out;
225
226	tv.tv_sec = 1;
227	tv.tv_usec = 0;
228	bzero(&sopt, sizeof sopt);
229	sopt.sopt_dir = SOPT_SET;
230	sopt.sopt_level = SOL_SOCKET;
231	sopt.sopt_name = SO_RCVTIMEO;
232	sopt.sopt_val = &tv;
233	sopt.sopt_valsize = sizeof tv;
234
235	if ((error = sosetopt(so, &sopt)) != 0)
236		goto out;
237
238	/*
239	 * Enable broadcast if necessary.
240	 */
241	if (from_p) {
242		int on = 1;
243		sopt.sopt_name = SO_BROADCAST;
244		sopt.sopt_val = &on;
245		sopt.sopt_valsize = sizeof on;
246		if ((error = sosetopt(so, &sopt)) != 0)
247			goto out;
248	}
249
250	/*
251	 * Bind the local endpoint to a reserved port,
252	 * because some NFS servers refuse requests from
253	 * non-reserved (non-privileged) ports.
254	 */
255	sin = &ssin;
256	bzero(sin, sizeof *sin);
257	sin->sin_len = sizeof(*sin);
258	sin->sin_family = AF_INET;
259	sin->sin_addr.s_addr = INADDR_ANY;
260	tport = IPPORT_RESERVED;
261	do {
262		tport--;
263		sin->sin_port = htons(tport);
264		error = sobind(so, (struct sockaddr *)sin, td);
265	} while (error == EADDRINUSE &&
266			 tport > IPPORT_RESERVED / 2);
267	if (error) {
268		printf("bind failed\n");
269		goto out;
270	}
271
272	/*
273	 * Setup socket address for the server.
274	 */
275
276	/*
277	 * Prepend RPC message header.
278	 */
279	mhead = m_gethdr(M_TRYWAIT, MT_DATA);
280	mhead->m_next = *data;
281	call = mtod(mhead, struct rpc_call *);
282	mhead->m_len = sizeof(*call);
283	bzero((caddr_t)call, sizeof(*call));
284	/* rpc_call part */
285	xid++;
286	call->rp_xid = txdr_unsigned(xid);
287	/* call->rp_direction = 0; */
288	call->rp_rpcvers = txdr_unsigned(2);
289	call->rp_prog = txdr_unsigned(prog);
290	call->rp_vers = txdr_unsigned(vers);
291	call->rp_proc = txdr_unsigned(func);
292	/* rpc_auth part (auth_unix as root) */
293	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
294	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
295	/* rpc_verf part (auth_null) */
296	call->rpc_verf.authtype = 0;
297	call->rpc_verf.authlen  = 0;
298
299	/*
300	 * Setup packet header
301	 */
302	len = 0;
303	m = mhead;
304	while (m) {
305		len += m->m_len;
306		m = m->m_next;
307	}
308	mhead->m_pkthdr.len = len;
309	mhead->m_pkthdr.rcvif = NULL;
310
311	/*
312	 * Send it, repeatedly, until a reply is received,
313	 * but delay each re-send by an increasing amount.
314	 * If the delay hits the maximum, start complaining.
315	 */
316	timo = 0;
317	for (;;) {
318		/* Send RPC request (or re-send). */
319		m = m_copym(mhead, 0, M_COPYALL, M_TRYWAIT);
320		if (m == NULL) {
321			error = ENOBUFS;
322			goto out;
323		}
324		error = sosend(so, (struct sockaddr *)sa, NULL, m,
325			       NULL, 0, td);
326		if (error) {
327			printf("krpc_call: sosend: %d\n", error);
328			goto out;
329		}
330		m = NULL;
331
332		/* Determine new timeout. */
333		if (timo < MAX_RESEND_DELAY)
334			timo++;
335		else {
336			saddr = ntohl(sa->sin_addr.s_addr);
337			printf("RPC timeout for server %d.%d.%d.%d\n",
338			       (saddr >> 24) & 255,
339			       (saddr >> 16) & 255,
340			       (saddr >> 8) & 255,
341			       saddr & 255);
342		}
343
344		/*
345		 * Wait for up to timo seconds for a reply.
346		 * The socket receive timeout was set to 1 second.
347		 */
348		secs = timo;
349		while (secs > 0) {
350			if (from) {
351				FREE(from, M_SONAME);
352				from = NULL;
353			}
354			if (m) {
355				m_freem(m);
356				m = NULL;
357			}
358			bzero(&auio, sizeof(auio));
359			auio.uio_resid = len = 1<<16;
360			rcvflg = 0;
361			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
362			if (error == EWOULDBLOCK) {
363				secs--;
364				continue;
365			}
366			if (error)
367				goto out;
368			len -= auio.uio_resid;
369
370			/* Does the reply contain at least a header? */
371			if (len < MIN_REPLY_HDR)
372				continue;
373			if (m->m_len < MIN_REPLY_HDR)
374				continue;
375			reply = mtod(m, struct rpc_reply *);
376
377			/* Is it the right reply? */
378			if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
379				continue;
380
381			if (reply->rp_xid != txdr_unsigned(xid))
382				continue;
383
384			/* Was RPC accepted? (authorization OK) */
385			if (reply->rp_astatus != 0) {
386				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
387				printf("rpc denied, error=%d\n", error);
388				continue;
389			}
390
391			/* Did the call succeed? */
392			if (reply->rp_status != 0) {
393				error = fxdr_unsigned(u_int32_t, reply->rp_status);
394				if (error == RPC_PROGMISMATCH) {
395				  error = EBADRPC;
396				  goto out;
397				}
398				printf("rpc denied, status=%d\n", error);
399				continue;
400			}
401
402			goto gotreply;	/* break two levels */
403
404		} /* while secs */
405	} /* forever send/receive */
406
407	error = ETIMEDOUT;
408	goto out;
409
410 gotreply:
411
412	/*
413	 * Get RPC reply header into first mbuf,
414	 * get its length, then strip it off.
415	 */
416	len = sizeof(*reply);
417	if (m->m_len < len) {
418		m = m_pullup(m, len);
419		if (m == NULL) {
420			error = ENOBUFS;
421			goto out;
422		}
423	}
424	reply = mtod(m, struct rpc_reply *);
425	if (reply->rp_auth.authtype != 0) {
426		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
427		len = (len + 3) & ~3; /* XXX? */
428	}
429	m_adj(m, len);
430
431	/* result */
432	*data = m;
433	if (from_p) {
434		*from_p = from;
435		from = NULL;
436	}
437
438 out:
439	if (mhead) m_freem(mhead);
440	if (from) free(from, M_SONAME);
441	soclose(so);
442	return error;
443}
444
445/*
446 * eXternal Data Representation routines.
447 * (but with non-standard args...)
448 */
449
450/*
451 * String representation for RPC.
452 */
453struct xdr_string {
454	u_int32_t len;		/* length without null or padding */
455	char data[4];	/* data (longer, of course) */
456    /* data is padded to a long-word boundary */
457};
458
459struct mbuf *
460xdr_string_encode(char *str, int len)
461{
462	struct mbuf *m;
463	struct xdr_string *xs;
464	int dlen;	/* padded string length */
465	int mlen;	/* message length */
466
467	dlen = (len + 3) & ~3;
468	mlen = dlen + 4;
469
470	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
471		return (NULL);
472
473	m = m_get(M_TRYWAIT, MT_DATA);
474	if (mlen > MLEN) {
475		MCLGET(m, M_TRYWAIT);
476		if ((m->m_flags & M_EXT) == 0) {
477			(void) m_free(m);	/* There can be only one. */
478			return (NULL);
479		}
480	}
481	xs = mtod(m, struct xdr_string *);
482	m->m_len = mlen;
483	xs->len = txdr_unsigned(len);
484	bcopy(str, xs->data, len);
485	return (m);
486}
487