1/*	$NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $	*/
2
3/*-
4 * SPDX-License-Identifier: BSD-4-Clause
5 *
6 * Copyright (c) 1995 Gordon Ross, Adam Glass
7 * Copyright (c) 1992 Regents of the University of California.
8 * All rights reserved.
9 *
10 * This software was developed by the Computer Systems Engineering group
11 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
12 * contributed to Berkeley.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 * 3. All advertising materials mentioning features or use of this software
23 *    must display the following acknowledgement:
24 *	This product includes software developed by the University of
25 *	California, Lawrence Berkeley Laboratory and its contributors.
26 * 4. Neither the name of the University nor the names of its contributors
27 *    may be used to endorse or promote products derived from this software
28 *    without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
41 *
42 * partially based on:
43 *      libnetboot/rpc.c
44 */
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/jail.h>
49#include <sys/malloc.h>
50#include <sys/mbuf.h>
51#include <sys/proc.h>
52#include <sys/socket.h>
53#include <sys/socketvar.h>
54#include <sys/uio.h>
55
56#include <net/if.h>
57#include <net/vnet.h>
58
59#include <netinet/in.h>
60
61#include <rpc/types.h>
62#include <rpc/auth.h>
63#include <rpc/rpc_msg.h>
64#include <nfs/krpc.h>
65#include <nfs/xdr_subs.h>
66
67/*
68 * Kernel support for Sun RPC
69 *
70 * Used currently for bootstrapping in nfs diskless configurations.
71 */
72
73/*
74 * Generic RPC headers
75 */
76
77struct auth_info {
78	u_int32_t 	authtype;	/* auth type */
79	u_int32_t	authlen;	/* auth length */
80};
81
82struct auth_unix {
83	int32_t   ua_time;
84	int32_t   ua_hostname;	/* null */
85	int32_t   ua_uid;
86	int32_t   ua_gid;
87	int32_t   ua_gidlist;	/* null */
88};
89
90struct krpc_call {
91	u_int32_t	rp_xid;		/* request transaction id */
92	int32_t 	rp_direction;	/* call direction (0) */
93	u_int32_t	rp_rpcvers;	/* rpc version (2) */
94	u_int32_t	rp_prog;	/* program */
95	u_int32_t	rp_vers;	/* version */
96	u_int32_t	rp_proc;	/* procedure */
97	struct	auth_info rpc_auth;
98	struct	auth_unix rpc_unix;
99	struct	auth_info rpc_verf;
100};
101
102struct krpc_reply {
103	u_int32_t rp_xid;		/* request transaction id */
104	int32_t  rp_direction;		/* call direction (1) */
105	int32_t  rp_astatus;		/* accept status (0: accepted) */
106	union {
107		u_int32_t rpu_errno;
108		struct {
109			struct auth_info rok_auth;
110			u_int32_t	rok_status;
111		} rpu_rok;
112	} rp_u;
113};
114#define rp_errno  rp_u.rpu_errno
115#define rp_auth   rp_u.rpu_rok.rok_auth
116#define rp_status rp_u.rpu_rok.rok_status
117
118#define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
119
120/*
121 * What is the longest we will wait before re-sending a request?
122 * Note this is also the frequency of "RPC timeout" messages.
123 * The re-send loop count sup linearly to this maximum, so the
124 * first complaint will happen after (1+2+3+4+5)=15 seconds.
125 */
126#define	MAX_RESEND_DELAY 5	/* seconds */
127
128/*
129 * Call portmap to lookup a port number for a particular rpc program
130 * Returns non-zero error on failure.
131 */
132int
133krpc_portmap(struct sockaddr_in *sin, u_int prog, u_int vers, u_int16_t *portp,
134    struct thread *td)
135{
136	struct sdata {
137		u_int32_t prog;		/* call program */
138		u_int32_t vers;		/* call version */
139		u_int32_t proto;	/* call protocol */
140		u_int32_t port;		/* call port (unused) */
141	} *sdata;
142	struct rdata {
143		u_int16_t pad;
144		u_int16_t port;
145	} *rdata;
146	struct mbuf *m;
147	int error;
148
149	/* The portmapper port is fixed. */
150	if (prog == PMAPPROG) {
151		*portp = htons(PMAPPORT);
152		return 0;
153	}
154
155	m = m_get(M_WAITOK, MT_DATA);
156	sdata = mtod(m, struct sdata *);
157	m->m_len = sizeof(*sdata);
158
159	/* Do the RPC to get it. */
160	sdata->prog = txdr_unsigned(prog);
161	sdata->vers = txdr_unsigned(vers);
162	sdata->proto = txdr_unsigned(IPPROTO_UDP);
163	sdata->port = 0;
164
165	sin->sin_port = htons(PMAPPORT);
166	error = krpc_call(sin, PMAPPROG, PMAPVERS,
167					  PMAPPROC_GETPORT, &m, NULL, td);
168	if (error)
169		return error;
170
171	if (m->m_len < sizeof(*rdata)) {
172		m = m_pullup(m, sizeof(*rdata));
173		if (m == NULL)
174			return ENOBUFS;
175	}
176	rdata = mtod(m, struct rdata *);
177	*portp = rdata->port;
178
179	m_freem(m);
180	return 0;
181}
182
183/*
184 * Do a remote procedure call (RPC) and wait for its reply.
185 * If from_p is non-null, then we are doing broadcast, and
186 * the address from whence the response came is saved there.
187 */
188int
189krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
190    struct mbuf **data, struct sockaddr **from_p, struct thread *td)
191{
192	struct socket *so;
193	struct sockaddr_in *sin, ssin;
194	struct sockaddr *from;
195	struct mbuf *m, *mhead;
196	struct krpc_call *call;
197	struct krpc_reply *reply;
198	struct sockopt sopt;
199	struct timeval tv;
200	struct uio auio;
201	int error, rcvflg, timo, secs, len;
202	static u_int32_t xid = ~0xFF;
203	u_int16_t tport;
204	u_int32_t saddr;
205
206	/*
207	 * Validate address family.
208	 * Sorry, this is INET specific...
209	 */
210	if (sa->sin_family != AF_INET)
211		return (EAFNOSUPPORT);
212
213	/* Free at end if not null. */
214	mhead = NULL;
215	from = NULL;
216
217	/*
218	 * Create socket and set its receive timeout.
219	 */
220	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td->td_ucred, td)))
221		return error;
222
223	tv.tv_sec = 1;
224	tv.tv_usec = 0;
225	bzero(&sopt, sizeof sopt);
226	sopt.sopt_dir = SOPT_SET;
227	sopt.sopt_level = SOL_SOCKET;
228	sopt.sopt_name = SO_RCVTIMEO;
229	sopt.sopt_val = &tv;
230	sopt.sopt_valsize = sizeof tv;
231
232	if ((error = sosetopt(so, &sopt)) != 0)
233		goto out;
234
235	/*
236	 * Enable broadcast if necessary.
237	 */
238	if (from_p) {
239		int on = 1;
240		sopt.sopt_name = SO_BROADCAST;
241		sopt.sopt_val = &on;
242		sopt.sopt_valsize = sizeof on;
243		if ((error = sosetopt(so, &sopt)) != 0)
244			goto out;
245	}
246
247	/*
248	 * Bind the local endpoint to a reserved port,
249	 * because some NFS servers refuse requests from
250	 * non-reserved (non-privileged) ports.
251	 */
252	sin = &ssin;
253	bzero(sin, sizeof *sin);
254	sin->sin_len = sizeof(*sin);
255	sin->sin_family = AF_INET;
256	sin->sin_addr.s_addr = INADDR_ANY;
257	tport = IPPORT_RESERVED;
258	do {
259		tport--;
260		sin->sin_port = htons(tport);
261		error = sobind(so, (struct sockaddr *)sin, td);
262	} while (error == EADDRINUSE &&
263			 tport > IPPORT_RESERVED / 2);
264	if (error) {
265		printf("bind failed\n");
266		goto out;
267	}
268
269	/*
270	 * Setup socket address for the server.
271	 */
272
273	/*
274	 * Prepend RPC message header.
275	 */
276	mhead = m_gethdr(M_WAITOK, MT_DATA);
277	mhead->m_next = *data;
278	call = mtod(mhead, struct krpc_call *);
279	mhead->m_len = sizeof(*call);
280	bzero((caddr_t)call, sizeof(*call));
281	/* rpc_call part */
282	xid++;
283	call->rp_xid = txdr_unsigned(xid);
284	/* call->rp_direction = 0; */
285	call->rp_rpcvers = txdr_unsigned(2);
286	call->rp_prog = txdr_unsigned(prog);
287	call->rp_vers = txdr_unsigned(vers);
288	call->rp_proc = txdr_unsigned(func);
289	/* rpc_auth part (auth_unix as root) */
290	call->rpc_auth.authtype = txdr_unsigned(AUTH_UNIX);
291	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
292	/* rpc_verf part (auth_null) */
293	call->rpc_verf.authtype = 0;
294	call->rpc_verf.authlen  = 0;
295
296	/*
297	 * Setup packet header
298	 */
299	m_fixhdr(mhead);
300	mhead->m_pkthdr.rcvif = NULL;
301
302	/*
303	 * Send it, repeatedly, until a reply is received,
304	 * but delay each re-send by an increasing amount.
305	 * If the delay hits the maximum, start complaining.
306	 */
307	timo = 0;
308	for (;;) {
309		/* Send RPC request (or re-send). */
310		m = m_copym(mhead, 0, M_COPYALL, M_WAITOK);
311		error = sosend(so, (struct sockaddr *)sa, NULL, m,
312			       NULL, 0, td);
313		if (error) {
314			printf("krpc_call: sosend: %d\n", error);
315			goto out;
316		}
317		m = NULL;
318
319		/* Determine new timeout. */
320		if (timo < MAX_RESEND_DELAY)
321			timo++;
322		else {
323			saddr = ntohl(sa->sin_addr.s_addr);
324			printf("RPC timeout for server %d.%d.%d.%d\n",
325			       (saddr >> 24) & 255,
326			       (saddr >> 16) & 255,
327			       (saddr >> 8) & 255,
328			       saddr & 255);
329		}
330
331		/*
332		 * Wait for up to timo seconds for a reply.
333		 * The socket receive timeout was set to 1 second.
334		 */
335		secs = timo;
336		while (secs > 0) {
337			if (from) {
338				free(from, M_SONAME);
339				from = NULL;
340			}
341			if (m) {
342				m_freem(m);
343				m = NULL;
344			}
345			bzero(&auio, sizeof(auio));
346			auio.uio_resid = len = 1<<16;
347			rcvflg = 0;
348			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
349			if (error == EWOULDBLOCK) {
350				secs--;
351				continue;
352			}
353			if (error)
354				goto out;
355			len -= auio.uio_resid;
356
357			/* Does the reply contain at least a header? */
358			if (len < MIN_REPLY_HDR)
359				continue;
360			if (m->m_len < MIN_REPLY_HDR)
361				continue;
362			reply = mtod(m, struct krpc_reply *);
363
364			/* Is it the right reply? */
365			if (reply->rp_direction != txdr_unsigned(REPLY))
366				continue;
367
368			if (reply->rp_xid != txdr_unsigned(xid))
369				continue;
370
371			/* Was RPC accepted? (authorization OK) */
372			if (reply->rp_astatus != 0) {
373				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
374				printf("rpc denied, error=%d\n", error);
375				continue;
376			}
377
378			/* Did the call succeed? */
379			if (reply->rp_status != 0) {
380				error = fxdr_unsigned(u_int32_t, reply->rp_status);
381				if (error == PROG_MISMATCH) {
382				  error = EBADRPC;
383				  goto out;
384				}
385				printf("rpc denied, status=%d\n", error);
386				continue;
387			}
388
389			goto gotreply;	/* break two levels */
390
391		} /* while secs */
392	} /* forever send/receive */
393
394	error = ETIMEDOUT;
395	goto out;
396
397 gotreply:
398
399	/*
400	 * Get RPC reply header into first mbuf,
401	 * get its length, then strip it off.
402	 */
403	len = sizeof(*reply);
404	if (m->m_len < len) {
405		m = m_pullup(m, len);
406		if (m == NULL) {
407			error = ENOBUFS;
408			goto out;
409		}
410	}
411	reply = mtod(m, struct krpc_reply *);
412	if (reply->rp_auth.authtype != 0) {
413		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
414		len = (len + 3) & ~3; /* XXX? */
415	}
416	m_adj(m, len);
417
418	/* result */
419	*data = m;
420	if (from_p) {
421		*from_p = from;
422		from = NULL;
423	}
424
425 out:
426	if (mhead) m_freem(mhead);
427	if (from) free(from, M_SONAME);
428	soclose(so);
429	return error;
430}
431
432/*
433 * eXternal Data Representation routines.
434 * (but with non-standard args...)
435 */
436
437/*
438 * String representation for RPC.
439 */
440struct xdr_string {
441	u_int32_t len;		/* length without null or padding */
442	char data[4];	/* data (longer, of course) */
443    /* data is padded to a long-word boundary */
444};
445
446struct mbuf *
447xdr_string_encode(char *str, int len)
448{
449	struct mbuf *m;
450	struct xdr_string *xs;
451	int dlen;	/* padded string length */
452	int mlen;	/* message length */
453
454	dlen = (len + 3) & ~3;
455	mlen = dlen + 4;
456
457	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
458		return (NULL);
459
460	m = m_get2(mlen, M_WAITOK, MT_DATA, 0);
461	xs = mtod(m, struct xdr_string *);
462	m->m_len = mlen;
463	xs->len = txdr_unsigned(len);
464	bcopy(str, xs->data, len);
465	return (m);
466}
467