1/*	$NetBSD: rpc.c,v 1.18 1998/01/23 19:27:45 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 1992 Regents of the University of California.
5 * All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD$");
40
41/*
42 * RPC functions used by NFS and bootparams.
43 * Note that bootparams requires the ability to find out the
44 * address of the server from which its response has come.
45 * This is supported by keeping the IP/UDP headers in the
46 * buffer space provided by the caller.  (See rpc_fromaddr)
47 */
48
49#include <sys/param.h>
50#include <sys/socket.h>
51
52#include <netinet/in.h>
53#include <netinet/in_systm.h>
54
55#include <string.h>
56
57#include "rpcv2.h"
58
59#include "stand.h"
60#include "net.h"
61#include "netif.h"
62#include "rpc.h"
63
64struct auth_info {
65	int32_t 	authtype;	/* auth type */
66	u_int32_t	authlen;	/* auth length */
67};
68
69struct auth_unix {
70	int32_t   ua_time;
71	int32_t   ua_hostname;	/* null */
72	int32_t   ua_uid;
73	int32_t   ua_gid;
74	int32_t   ua_gidlist;	/* null */
75};
76
77struct rpc_call {
78	u_int32_t	rp_xid;		/* request transaction id */
79	int32_t 	rp_direction;	/* call direction (0) */
80	u_int32_t	rp_rpcvers;	/* rpc version (2) */
81	u_int32_t	rp_prog;	/* program */
82	u_int32_t	rp_vers;	/* version */
83	u_int32_t	rp_proc;	/* procedure */
84};
85
86struct rpc_reply {
87	u_int32_t	rp_xid;		/* request transaction id */
88	int32_t 	rp_direction;	/* call direction (1) */
89	int32_t 	rp_astatus;	/* accept status (0: accepted) */
90	union {
91		u_int32_t	rpu_errno;
92		struct {
93			struct auth_info rok_auth;
94			u_int32_t	rok_status;
95		} rpu_rok;
96	} rp_u;
97};
98
99/* Local forwards */
100static	ssize_t recvrpc(struct iodesc *, void *, size_t, time_t);
101static	int rpc_getport(struct iodesc *, n_long, n_long);
102
103int rpc_xid;
104int rpc_port = 0x400;	/* predecrement */
105
106/*
107 * Make a rpc call; return length of answer
108 * Note: Caller must leave room for headers.
109 */
110ssize_t
111rpc_call(struct iodesc *d, n_long prog, n_long vers, n_long proc,
112	void *sdata, size_t slen, void *rdata, size_t rlen)
113{
114	ssize_t cc;
115	struct auth_info *auth;
116	struct rpc_call *call;
117	struct rpc_reply *reply;
118	char *send_head, *send_tail;
119	char *recv_head, *recv_tail;
120	n_long x;
121	int port;	/* host order */
122
123#ifdef RPC_DEBUG
124	if (debug)
125		printf("rpc_call: prog=0x%x vers=%d proc=%d\n",
126		    prog, vers, proc);
127#endif
128
129	port = rpc_getport(d, prog, vers);
130	if (port == -1)
131		return (-1);
132
133	d->destport = htons(port);
134
135	/*
136	 * Prepend authorization stuff and headers.
137	 * Note, must prepend things in reverse order.
138	 */
139	send_head = sdata;
140	send_tail = (char *)sdata + slen;
141
142	/* Auth verifier is always auth_null */
143	send_head -= sizeof(*auth);
144	auth = (struct auth_info *)send_head;
145	auth->authtype = htonl(RPCAUTH_NULL);
146	auth->authlen = 0;
147
148#if 1
149	/* Auth credentials: always auth unix (as root) */
150	send_head -= sizeof(struct auth_unix);
151	bzero(send_head, sizeof(struct auth_unix));
152	send_head -= sizeof(*auth);
153	auth = (struct auth_info *)send_head;
154	auth->authtype = htonl(RPCAUTH_UNIX);
155	auth->authlen = htonl(sizeof(struct auth_unix));
156#else
157	/* Auth credentials: always auth_null (XXX OK?) */
158	send_head -= sizeof(*auth);
159	auth = send_head;
160	auth->authtype = htonl(RPCAUTH_NULL);
161	auth->authlen = 0;
162#endif
163
164	/* RPC call structure. */
165	send_head -= sizeof(*call);
166	call = (struct rpc_call *)send_head;
167	rpc_xid++;
168	call->rp_xid       = htonl(rpc_xid);
169	call->rp_direction = htonl(RPC_CALL);
170	call->rp_rpcvers   = htonl(RPC_VER2);
171	call->rp_prog = htonl(prog);
172	call->rp_vers = htonl(vers);
173	call->rp_proc = htonl(proc);
174
175	/* Make room for the rpc_reply header. */
176	recv_head = rdata;
177	recv_tail = (char *)rdata + rlen;
178	recv_head -= sizeof(*reply);
179
180	cc = sendrecv(d,
181	    sendudp, send_head, send_tail - send_head,
182	    recvrpc, recv_head, recv_tail - recv_head);
183
184#ifdef RPC_DEBUG
185	if (debug)
186		printf("callrpc: cc=%ld rlen=%lu\n", (long)cc, (u_long)rlen);
187#endif
188	if (cc == -1)
189		return (-1);
190
191	if (cc <= sizeof(*reply)) {
192		errno = EBADRPC;
193		return (-1);
194	}
195
196	recv_tail = recv_head + cc;
197
198	/*
199	 * Check the RPC reply status.
200	 * The xid, dir, astatus were already checked.
201	 */
202	reply = (struct rpc_reply *)recv_head;
203	auth = &reply->rp_u.rpu_rok.rok_auth;
204	x = ntohl(auth->authlen);
205	if (x != 0) {
206#ifdef RPC_DEBUG
207		if (debug)
208			printf("callrpc: reply auth != NULL\n");
209#endif
210		errno = EBADRPC;
211		return(-1);
212	}
213	x = ntohl(reply->rp_u.rpu_rok.rok_status);
214	if (x != 0) {
215		printf("callrpc: error = %ld\n", (long)x);
216		errno = EBADRPC;
217		return(-1);
218	}
219	recv_head += sizeof(*reply);
220
221	return (ssize_t)(recv_tail - recv_head);
222}
223
224/*
225 * Returns true if packet is the one we're waiting for.
226 * This just checks the XID, direction, acceptance.
227 * Remaining checks are done by callrpc
228 */
229static ssize_t
230recvrpc(struct iodesc *d, void *pkt, size_t len, time_t tleft)
231{
232	struct rpc_reply *reply;
233	ssize_t	n;
234	int	x;
235
236	errno = 0;
237#ifdef RPC_DEBUG
238	if (debug)
239		printf("recvrpc: called len=%lu\n", (u_long)len);
240#endif
241
242	n = readudp(d, pkt, len, tleft);
243	if (n <= (4 * 4))
244		return -1;
245
246	reply = (struct rpc_reply *)pkt;
247
248	x = ntohl(reply->rp_xid);
249	if (x != rpc_xid) {
250#ifdef RPC_DEBUG
251		if (debug)
252			printf("recvrpc: rp_xid %d != xid %d\n", x, rpc_xid);
253#endif
254		return -1;
255	}
256
257	x = ntohl(reply->rp_direction);
258	if (x != RPC_REPLY) {
259#ifdef RPC_DEBUG
260		if (debug)
261			printf("recvrpc: rp_direction %d != REPLY\n", x);
262#endif
263		return -1;
264	}
265
266	x = ntohl(reply->rp_astatus);
267	if (x != RPC_MSGACCEPTED) {
268		errno = ntohl(reply->rp_u.rpu_errno);
269		printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno);
270		return -1;
271	}
272
273	/* Return data count (thus indicating success) */
274	return (n);
275}
276
277/*
278 * Given a pointer to a reply just received,
279 * dig out the IP address/port from the headers.
280 */
281void
282rpc_fromaddr(void *pkt, struct in_addr *addr, u_short *port)
283{
284	struct hackhdr {
285		/* Tail of IP header: just IP addresses */
286		n_long ip_src;
287		n_long ip_dst;
288		/* UDP header: */
289		u_int16_t uh_sport;		/* source port */
290		u_int16_t uh_dport;		/* destination port */
291		int16_t	  uh_ulen;		/* udp length */
292		u_int16_t uh_sum;		/* udp checksum */
293		/* RPC reply header: */
294		struct rpc_reply rpc;
295	} *hhdr;
296
297	hhdr = ((struct hackhdr *)pkt) - 1;
298	addr->s_addr = hhdr->ip_src;
299	*port = hhdr->uh_sport;
300}
301
302/*
303 * RPC Portmapper cache
304 */
305#define PMAP_NUM 8			/* need at most 5 pmap entries */
306
307int rpc_pmap_num;
308struct pmap_list {
309	struct in_addr	addr;	/* server, net order */
310	u_int	prog;		/* host order */
311	u_int	vers;		/* host order */
312	int 	port;		/* host order */
313} rpc_pmap_list[PMAP_NUM];
314
315/*
316 * return port number in host order, or -1.
317 * arguments are:
318 *  addr .. server, net order.
319 *  prog .. host order.
320 *  vers .. host order.
321 */
322int
323rpc_pmap_getcache(struct in_addr addr, u_int prog, u_int vers)
324{
325	struct pmap_list *pl;
326
327	for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) {
328		if (pl->addr.s_addr == addr.s_addr &&
329			pl->prog == prog && pl->vers == vers )
330		{
331			return (pl->port);
332		}
333	}
334	return (-1);
335}
336
337/*
338 * arguments are:
339 *  addr .. server, net order.
340 *  prog .. host order.
341 *  vers .. host order.
342 *  port .. host order.
343 */
344void
345rpc_pmap_putcache(struct in_addr addr, u_int prog, u_int vers, int port)
346{
347	struct pmap_list *pl;
348
349	/* Don't overflow cache... */
350	if (rpc_pmap_num >= PMAP_NUM) {
351		/* ... just re-use the last entry. */
352		rpc_pmap_num = PMAP_NUM - 1;
353#ifdef	RPC_DEBUG
354		printf("rpc_pmap_putcache: cache overflow\n");
355#endif
356	}
357
358	pl = &rpc_pmap_list[rpc_pmap_num];
359	rpc_pmap_num++;
360
361	/* Cache answer */
362	pl->addr = addr;
363	pl->prog = prog;
364	pl->vers = vers;
365	pl->port = port;
366}
367
368
369/*
370 * Request a port number from the port mapper.
371 * Returns the port in host order.
372 * prog and vers are host order.
373 */
374int
375rpc_getport(struct iodesc *d, n_long prog, n_long vers)
376{
377	struct args {
378		n_long	prog;		/* call program */
379		n_long	vers;		/* call version */
380		n_long	proto;		/* call protocol */
381		n_long	port;		/* call port (unused) */
382	} *args;
383	struct res {
384		n_long port;
385	} *res;
386	struct {
387		n_long	h[RPC_HEADER_WORDS];
388		struct args d;
389	} sdata;
390	struct {
391		n_long	h[RPC_HEADER_WORDS];
392		struct res d;
393		n_long  pad;
394	} rdata;
395	ssize_t cc;
396	int port;
397
398#ifdef RPC_DEBUG
399	if (debug)
400		printf("%s: prog=0x%x vers=%d\n", __func__, prog, vers);
401#endif
402
403	/* This one is fixed forever. */
404	if (prog == PMAPPROG) {
405		port = PMAPPORT;
406		goto out;
407	}
408
409	/* Try for cached answer first */
410	port = rpc_pmap_getcache(d->destip, prog, vers);
411	if (port != -1)
412		goto out;
413
414	args = &sdata.d;
415	args->prog = htonl(prog);
416	args->vers = htonl(vers);
417	args->proto = htonl(IPPROTO_UDP);
418	args->port = 0;
419	res = &rdata.d;
420
421	cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT,
422		args, sizeof(*args), res, sizeof(*res));
423	if (cc < sizeof(*res)) {
424		printf("getport: %s", strerror(errno));
425		errno = EBADRPC;
426		return (-1);
427	}
428	port = (int)ntohl(res->port);
429
430	rpc_pmap_putcache(d->destip, prog, vers, port);
431
432out:
433#ifdef RPC_DEBUG
434	if (debug)
435		printf("%s: port=%u\n", __func__, port);
436#endif
437	return (port);
438}
439