1 /* $NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $ */
2 /* $FreeBSD: src/sys/nfs/krpc_subr.c,v 1.13.2.1 2000/11/20 21:17:14 tegge 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 #include <sys/fcntl.h>
54
55 #include <net/if.h>
56 #include <netinet/in.h>
57
58 #include "rpcv2.h"
59 #include "krpc.h"
60 #include "xdr_subs.h"
61
62 /*
63 * Kernel support for Sun RPC
64 *
65 * Used currently for bootstrapping in nfs diskless configurations.
66 */
67
68 /*
69 * Generic RPC headers
70 */
71
72 struct auth_info {
73 u_int32_t authtype; /* auth type */
74 u_int32_t authlen; /* auth length */
75 };
76
77 struct auth_unix {
78 int32_t ua_time;
79 int32_t ua_hostname; /* null */
80 int32_t ua_uid;
81 int32_t ua_gid;
82 int32_t ua_gidlist; /* null */
83 };
84
85 struct rpc_call {
86 u_int32_t rp_xid; /* request transaction id */
87 int32_t rp_direction; /* call direction (0) */
88 u_int32_t rp_rpcvers; /* rpc version (2) */
89 u_int32_t rp_prog; /* program */
90 u_int32_t rp_vers; /* version */
91 u_int32_t rp_proc; /* procedure */
92 struct auth_info rpc_auth;
93 struct auth_unix rpc_unix;
94 struct auth_info rpc_verf;
95 };
96
97 struct rpc_reply {
98 u_int32_t rp_xid; /* request transaction id */
99 int32_t rp_direction; /* call direction (1) */
100 int32_t rp_astatus; /* accept status (0: accepted) */
101 union {
102 u_int32_t rpu_errno;
103 struct {
104 struct auth_info rok_auth;
105 u_int32_t rok_status;
106 } rpu_rok;
107 } rp_u;
108 };
109 #define rp_errno rp_u.rpu_errno
110 #define rp_auth rp_u.rpu_rok.rok_auth
111 #define rp_status rp_u.rpu_rok.rok_status
112
113 #define MIN_REPLY_HDR 16 /* xid, dir, astat, errno */
114
115 /*
116 * What is the longest we will wait before re-sending a request?
117 * Note this is also the frequency of "RPC timeout" messages.
118 * The re-send loop count sup linearly to this maximum, so the
119 * first complaint will happen after (1+2+3+4+5)=15 seconds.
120 */
121 #define MAX_RESEND_DELAY 5 /* seconds */
122
123 /*
124 * Call portmap to lookup a port number for a particular rpc program
125 * Returns non-zero error on failure.
126 */
127 int
krpc_portmap(struct sockaddr_in * sin,u_int prog,u_int vers,u_int16_t * portp,struct thread * td)128 krpc_portmap(struct sockaddr_in *sin, /* server address */
129 u_int prog, u_int vers, /* host order */
130 u_int16_t *portp, /* network order */
131 struct thread *td)
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_WAITOK, MT_DATA);
153 sdata = mtod(m, struct sdata *);
154 m->m_len = sizeof(*sdata);
155
156 /* Do the RPC to get it. */
157 sdata->prog = txdr_unsigned(prog);
158 sdata->vers = txdr_unsigned(vers);
159 sdata->proto = txdr_unsigned(IPPROTO_UDP);
160 sdata->port = 0;
161
162 sin->sin_port = htons(PMAPPORT);
163 error = krpc_call(sin, PMAPPROG, PMAPVERS,
164 PMAPPROC_GETPORT, &m, NULL, td);
165 if (error)
166 return error;
167
168 if (m->m_len < sizeof(*rdata)) {
169 m = m_pullup(m, sizeof(*rdata));
170 if (m == NULL)
171 return ENOBUFS;
172 }
173 rdata = mtod(m, struct rdata *);
174 *portp = rdata->port;
175
176 m_freem(m);
177 return 0;
178 }
179
180 /*
181 * Do a remote procedure call (RPC) and wait for its reply.
182 * If from_p is non-null, then we are doing broadcast, and
183 * the address from whence the response came is saved there.
184 */
185 int
krpc_call(struct sockaddr_in * sa,u_int prog,u_int vers,u_int func,struct mbuf ** data,struct sockaddr ** from_p,struct thread * td)186 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
187 struct mbuf **data, /* input/output */
188 struct sockaddr **from_p, /* output */
189 struct thread *td)
190 {
191 struct socket *so;
192 struct sockaddr_in *sin, ssin;
193 struct sockaddr *from;
194 struct mbuf *m, *mhead;
195 struct rpc_call *call;
196 struct rpc_reply *reply;
197 struct sockopt sopt;
198 struct timeval tv;
199 struct sockbuf sio;
200 int error, rcvflg, timo, secs, len;
201 static u_int32_t static_xid = ~0xFF;
202 u_int32_t xid;
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 recieve timeout.
219 */
220 if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td)))
221 goto out;
222
223 tv.tv_sec = 1;
224 tv.tv_usec = 0;
225 bzero(&sopt, sizeof sopt);
226 sopt.sopt_level = SOL_SOCKET;
227 sopt.sopt_name = SO_RCVTIMEO;
228 sopt.sopt_val = &tv;
229 sopt.sopt_valsize = sizeof tv;
230
231 if ((error = sosetopt(so, &sopt)) != 0)
232 goto out;
233
234 /*
235 * Enable broadcast if necessary.
236 */
237 if (from_p) {
238 int on = 1;
239 sopt.sopt_name = SO_BROADCAST;
240 sopt.sopt_val = &on;
241 sopt.sopt_valsize = sizeof on;
242 if ((error = sosetopt(so, &sopt)) != 0)
243 goto out;
244 }
245
246 /*
247 * Bind the local endpoint to a reserved port,
248 * because some NFS servers refuse requests from
249 * non-reserved (non-privileged) ports.
250 */
251 sin = &ssin;
252 bzero(sin, sizeof *sin);
253 sin->sin_len = sizeof(*sin);
254 sin->sin_family = AF_INET;
255 sin->sin_addr.s_addr = INADDR_ANY;
256 tport = IPPORT_RESERVED;
257 do {
258 tport--;
259 sin->sin_port = htons(tport);
260 error = sobind(so, (struct sockaddr *)sin, td);
261 } while (error == EADDRINUSE &&
262 tport > IPPORT_RESERVED / 2);
263 if (error) {
264 kprintf("bind failed\n");
265 goto out;
266 }
267
268 /*
269 * Setup socket address for the server.
270 */
271
272 /*
273 * Prepend RPC message header.
274 */
275 mhead = m_gethdr(M_WAITOK, MT_DATA);
276 mhead->m_next = *data;
277 call = mtod(mhead, struct rpc_call *);
278 mhead->m_len = sizeof(*call);
279 bzero((caddr_t)call, sizeof(*call));
280 /* rpc_call part */
281 do {
282 xid = atomic_fetchadd_int(&static_xid, 1);
283 } while (xid == 0);
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_WAITOK);
318 if (m == NULL) {
319 error = ENOBUFS;
320 goto out;
321 }
322 error = sosend(so, (struct sockaddr *)sa, NULL, m,
323 NULL, 0, td);
324 if (error) {
325 kprintf("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 saddr = ntohl(sa->sin_addr.s_addr);
335 kprintf("RPC timeout for server %d.%d.%d.%d\n",
336 (saddr >> 24) & 255,
337 (saddr >> 16) & 255,
338 (saddr >> 8) & 255,
339 saddr & 255);
340 }
341
342 /*
343 * Wait for up to timo seconds for a reply.
344 * The socket receive timeout was set to 1 second.
345 */
346 secs = timo;
347 while (secs > 0) {
348 if (from) {
349 kfree(from, M_SONAME);
350 from = NULL;
351 }
352 if (m) {
353 m_freem(m);
354 m = NULL;
355 }
356 len = 1 << 16;
357 sbinit(&sio, len);
358 rcvflg = 0;
359 error = soreceive(so, &from, NULL, &sio, NULL, &rcvflg);
360 if (error == EWOULDBLOCK) {
361 secs--;
362 continue;
363 }
364 if (error)
365 goto out;
366 len -= sio.sb_cc;
367 m = sio.sb_mb;
368
369 /* Does the reply contain at least a header? */
370 if (len < MIN_REPLY_HDR)
371 continue;
372 if (m->m_len < MIN_REPLY_HDR)
373 continue;
374 reply = mtod(m, struct rpc_reply *);
375
376 /* Is it the right reply? */
377 if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
378 continue;
379
380 if (reply->rp_xid != txdr_unsigned(xid))
381 continue;
382
383 /* Was RPC accepted? (authorization OK) */
384 if (reply->rp_astatus != 0) {
385 error = fxdr_unsigned(u_int32_t, reply->rp_errno);
386 kprintf("rpc denied, error=%d\n", error);
387 continue;
388 }
389
390 /* Did the call succeed? */
391 if (reply->rp_status != 0) {
392 error = fxdr_unsigned(u_int32_t, reply->rp_status);
393 if (error == RPC_PROGMISMATCH) {
394 error = EBADRPC;
395 goto out;
396 }
397 kprintf("rpc denied, status=%d\n", error);
398 continue;
399 }
400
401 goto gotreply; /* break two levels */
402
403 } /* while secs */
404 } /* forever send/receive */
405
406 error = ETIMEDOUT;
407 goto out;
408
409 gotreply:
410
411 /*
412 * Get RPC reply header into first mbuf,
413 * get its length, then strip it off.
414 */
415 len = sizeof(*reply);
416 if (m->m_len < len) {
417 m = m_pullup(m, len);
418 if (m == NULL) {
419 error = ENOBUFS;
420 goto out;
421 }
422 }
423 reply = mtod(m, struct rpc_reply *);
424 if (reply->rp_auth.authtype != 0) {
425 len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
426 len = (len + 3) & ~3; /* XXX? */
427 }
428 m_adj(m, len);
429
430 /* result */
431 *data = m;
432 if (from_p) {
433 *from_p = from;
434 from = NULL;
435 }
436
437 out:
438 if (mhead) m_freem(mhead);
439 if (from) kfree(from, M_SONAME);
440 soclose(so, FNONBLOCK);
441 return error;
442 }
443
444 /*
445 * eXternal Data Representation routines.
446 * (but with non-standard args...)
447 */
448
449 /*
450 * String representation for RPC.
451 */
452 struct xdr_string {
453 u_int32_t len; /* length without null or padding */
454 char data[4]; /* data (longer, of course) */
455 /* data is padded to a long-word boundary */
456 };
457
458 struct mbuf *
xdr_string_encode(char * str,int len)459 xdr_string_encode(char *str, int len)
460 {
461 struct mbuf *m;
462 struct xdr_string *xs;
463 int dlen; /* padded string length */
464 int mlen; /* message length */
465
466 dlen = (len + 3) & ~3;
467 mlen = dlen + 4;
468
469 if (mlen > MCLBYTES) /* If too big, we just can't do it. */
470 return (NULL);
471
472 m = m_getl(mlen, M_WAITOK, MT_DATA, 0, NULL);
473 xs = mtod(m, struct xdr_string *);
474 m->m_len = mlen;
475 xs->len = txdr_unsigned(len);
476 bcopy(str, xs->data, len);
477 return (m);
478 }
479