krpc_subr.c revision 1.2 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/nfs/krpc_subr.c 248207 2013-03-12 13:42:47Z glebius "); */
47 __RCSID("$NetBSD: krpc_subr.c,v 1.2 2015/02/07 04:06:52 christos Exp $");
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/jail.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/proc.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/uio.h>
58
59 #include <net/if.h>
60 #include <net/vnet.h>
61
62 #include <netinet/in.h>
63
64 #include <rpc/types.h>
65 #include <rpc/auth.h>
66 #include <rpc/rpc_msg.h>
67 #include <nfs/krpc.h>
68 #include <nfs/xdr_subs.h>
69
70 /*
71 * Kernel support for Sun RPC
72 *
73 * Used currently for bootstrapping in nfs diskless configurations.
74 */
75
76 /*
77 * Generic RPC headers
78 */
79
80 struct auth_info {
81 u_int32_t authtype; /* auth type */
82 u_int32_t authlen; /* auth length */
83 };
84
85 struct auth_unix {
86 int32_t ua_time;
87 int32_t ua_hostname; /* null */
88 int32_t ua_uid;
89 int32_t ua_gid;
90 int32_t ua_gidlist; /* null */
91 };
92
93 struct krpc_call {
94 u_int32_t rp_xid; /* request transaction id */
95 int32_t rp_direction; /* call direction (0) */
96 u_int32_t rp_rpcvers; /* rpc version (2) */
97 u_int32_t rp_prog; /* program */
98 u_int32_t rp_vers; /* version */
99 u_int32_t rp_proc; /* procedure */
100 struct auth_info rpc_auth;
101 struct auth_unix rpc_unix;
102 struct auth_info rpc_verf;
103 };
104
105 struct krpc_reply {
106 u_int32_t rp_xid; /* request transaction id */
107 int32_t rp_direction; /* call direction (1) */
108 int32_t rp_astatus; /* accept status (0: accepted) */
109 union {
110 u_int32_t rpu_errno;
111 struct {
112 struct auth_info rok_auth;
113 u_int32_t rok_status;
114 } rpu_rok;
115 } rp_u;
116 };
117 #define rp_errno rp_u.rpu_errno
118 #define rp_auth rp_u.rpu_rok.rok_auth
119 #define rp_status rp_u.rpu_rok.rok_status
120
121 #define MIN_REPLY_HDR 16 /* xid, dir, astat, errno */
122
123 /*
124 * What is the longest we will wait before re-sending a request?
125 * Note this is also the frequency of "RPC timeout" messages.
126 * The re-send loop count sup linearly to this maximum, so the
127 * first complaint will happen after (1+2+3+4+5)=15 seconds.
128 */
129 #define MAX_RESEND_DELAY 5 /* seconds */
130
131 /*
132 * Call portmap to lookup a port number for a particular rpc program
133 * Returns non-zero error on failure.
134 */
135 int
136 krpc_portmap(struct sockaddr_in *sin, u_int prog, u_int vers, u_int16_t *portp,
137 struct thread *td)
138 {
139 struct sdata {
140 u_int32_t prog; /* call program */
141 u_int32_t vers; /* call version */
142 u_int32_t proto; /* call protocol */
143 u_int32_t port; /* call port (unused) */
144 } *sdata;
145 struct rdata {
146 u_int16_t pad;
147 u_int16_t port;
148 } *rdata;
149 struct mbuf *m;
150 int error;
151
152 /* The portmapper port is fixed. */
153 if (prog == PMAPPROG) {
154 *portp = htons(PMAPPORT);
155 return 0;
156 }
157
158 m = m_get(M_WAITOK, MT_DATA);
159 sdata = mtod(m, struct sdata *);
160 m->m_len = sizeof(*sdata);
161
162 /* Do the RPC to get it. */
163 sdata->prog = txdr_unsigned(prog);
164 sdata->vers = txdr_unsigned(vers);
165 sdata->proto = txdr_unsigned(IPPROTO_UDP);
166 sdata->port = 0;
167
168 sin->sin_port = htons(PMAPPORT);
169 error = krpc_call(sin, PMAPPROG, PMAPVERS,
170 PMAPPROC_GETPORT, &m, NULL, td);
171 if (error)
172 goto out;
173
174 if (m->m_len < sizeof(*rdata)) {
175 m = m_pullup(m, sizeof(*rdata));
176 if (m == NULL)
177 return ENOBUFS;
178 }
179 rdata = mtod(m, struct rdata *);
180 *portp = rdata->port;
181
182 out:
183 m_freem(m);
184 return error;
185 }
186
187 /*
188 * Do a remote procedure call (RPC) and wait for its reply.
189 * If from_p is non-null, then we are doing broadcast, and
190 * the address from whence the response came is saved there.
191 */
192 int
193 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
194 struct mbuf **data, struct sockaddr **from_p, struct thread *td)
195 {
196 struct socket *so;
197 struct sockaddr_in *sin, ssin;
198 struct sockaddr *from;
199 struct mbuf *m, *nam, *mhead;
200 struct krpc_call *call;
201 struct krpc_reply *reply;
202 struct sockopt sopt;
203 struct timeval tv;
204 struct uio auio;
205 int error, rcvflg, timo, secs, len;
206 static u_int32_t xid = ~0xFF;
207 u_int16_t tport;
208 u_int32_t saddr;
209
210 /*
211 * Validate address family.
212 * Sorry, this is INET specific...
213 */
214 if (sa->sin_family != AF_INET)
215 return (EAFNOSUPPORT);
216
217 /* Free at end if not null. */
218 nam = mhead = NULL;
219 from = NULL;
220
221 /*
222 * Create socket and set its recieve timeout.
223 */
224 if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td->td_ucred, td)))
225 goto out;
226
227 tv.tv_sec = 1;
228 tv.tv_usec = 0;
229 bzero(&sopt, sizeof sopt);
230 sopt.sopt_dir = SOPT_SET;
231 sopt.sopt_level = SOL_SOCKET;
232 sopt.sopt_name = SO_RCVTIMEO;
233 sopt.sopt_val = &tv;
234 sopt.sopt_valsize = sizeof tv;
235
236 if ((error = sosetopt(so, &sopt)) != 0)
237 goto out;
238
239 /*
240 * Enable broadcast if necessary.
241 */
242 if (from_p) {
243 int on = 1;
244 sopt.sopt_name = SO_BROADCAST;
245 sopt.sopt_val = &on;
246 sopt.sopt_valsize = sizeof on;
247 if ((error = sosetopt(so, &sopt)) != 0)
248 goto out;
249 }
250
251 /*
252 * Bind the local endpoint to a reserved port,
253 * because some NFS servers refuse requests from
254 * non-reserved (non-privileged) ports.
255 */
256 sin = &ssin;
257 bzero(sin, sizeof *sin);
258 sin->sin_len = sizeof(*sin);
259 sin->sin_family = AF_INET;
260 sin->sin_addr.s_addr = INADDR_ANY;
261 tport = IPPORT_RESERVED;
262 do {
263 tport--;
264 sin->sin_port = htons(tport);
265 error = sobind(so, (struct sockaddr *)sin, td);
266 } while (error == EADDRINUSE &&
267 tport > IPPORT_RESERVED / 2);
268 if (error) {
269 printf("bind failed\n");
270 goto out;
271 }
272
273 /*
274 * Setup socket address for the server.
275 */
276
277 /*
278 * Prepend RPC message header.
279 */
280 mhead = m_gethdr(M_WAITOK, MT_DATA);
281 mhead->m_next = *data;
282 call = mtod(mhead, struct krpc_call *);
283 mhead->m_len = sizeof(*call);
284 bzero((caddr_t)call, sizeof(*call));
285 /* rpc_call part */
286 xid++;
287 call->rp_xid = txdr_unsigned(xid);
288 /* call->rp_direction = 0; */
289 call->rp_rpcvers = txdr_unsigned(2);
290 call->rp_prog = txdr_unsigned(prog);
291 call->rp_vers = txdr_unsigned(vers);
292 call->rp_proc = txdr_unsigned(func);
293 /* rpc_auth part (auth_unix as root) */
294 call->rpc_auth.authtype = txdr_unsigned(AUTH_UNIX);
295 call->rpc_auth.authlen = txdr_unsigned(sizeof(struct auth_unix));
296 /* rpc_verf part (auth_null) */
297 call->rpc_verf.authtype = 0;
298 call->rpc_verf.authlen = 0;
299
300 /*
301 * Setup packet header
302 */
303 m_fixhdr(mhead);
304 mhead->m_pkthdr.rcvif = NULL;
305
306 /*
307 * Send it, repeatedly, until a reply is received,
308 * but delay each re-send by an increasing amount.
309 * If the delay hits the maximum, start complaining.
310 */
311 timo = 0;
312 for (;;) {
313 /* Send RPC request (or re-send). */
314 m = m_copym(mhead, 0, M_COPYALL, M_WAITOK);
315 error = sosend(so, (struct sockaddr *)sa, NULL, m,
316 NULL, 0, td);
317 if (error) {
318 printf("krpc_call: sosend: %d\n", error);
319 goto out;
320 }
321 m = NULL;
322
323 /* Determine new timeout. */
324 if (timo < MAX_RESEND_DELAY)
325 timo++;
326 else {
327 saddr = ntohl(sa->sin_addr.s_addr);
328 printf("RPC timeout for server %d.%d.%d.%d\n",
329 (saddr >> 24) & 255,
330 (saddr >> 16) & 255,
331 (saddr >> 8) & 255,
332 saddr & 255);
333 }
334
335 /*
336 * Wait for up to timo seconds for a reply.
337 * The socket receive timeout was set to 1 second.
338 */
339 secs = timo;
340 while (secs > 0) {
341 if (from) {
342 free(from, M_SONAME);
343 from = NULL;
344 }
345 if (m) {
346 m_freem(m);
347 m = NULL;
348 }
349 bzero(&auio, sizeof(auio));
350 auio.uio_resid = len = 1<<16;
351 rcvflg = 0;
352 error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
353 if (error == EWOULDBLOCK) {
354 secs--;
355 continue;
356 }
357 if (error)
358 goto out;
359 len -= auio.uio_resid;
360
361 /* Does the reply contain at least a header? */
362 if (len < MIN_REPLY_HDR)
363 continue;
364 if (m->m_len < MIN_REPLY_HDR)
365 continue;
366 reply = mtod(m, struct krpc_reply *);
367
368 /* Is it the right reply? */
369 if (reply->rp_direction != txdr_unsigned(REPLY))
370 continue;
371
372 if (reply->rp_xid != txdr_unsigned(xid))
373 continue;
374
375 /* Was RPC accepted? (authorization OK) */
376 if (reply->rp_astatus != 0) {
377 error = fxdr_unsigned(u_int32_t, reply->rp_errno);
378 printf("rpc denied, error=%d\n", error);
379 continue;
380 }
381
382 /* Did the call succeed? */
383 if (reply->rp_status != 0) {
384 error = fxdr_unsigned(u_int32_t, reply->rp_status);
385 if (error == PROG_MISMATCH) {
386 error = EBADRPC;
387 goto out;
388 }
389 printf("rpc denied, status=%d\n", error);
390 continue;
391 }
392
393 goto gotreply; /* break two levels */
394
395 } /* while secs */
396 } /* forever send/receive */
397
398 error = ETIMEDOUT;
399 goto out;
400
401 gotreply:
402
403 /*
404 * Get RPC reply header into first mbuf,
405 * get its length, then strip it off.
406 */
407 len = sizeof(*reply);
408 if (m->m_len < len) {
409 m = m_pullup(m, len);
410 if (m == NULL) {
411 error = ENOBUFS;
412 goto out;
413 }
414 }
415 reply = mtod(m, struct krpc_reply *);
416 if (reply->rp_auth.authtype != 0) {
417 len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
418 len = (len + 3) & ~3; /* XXX? */
419 }
420 m_adj(m, len);
421
422 /* result */
423 *data = m;
424 if (from_p) {
425 *from_p = from;
426 from = NULL;
427 }
428
429 out:
430 if (mhead) m_freem(mhead);
431 if (from) free(from, M_SONAME);
432 soclose(so);
433 return error;
434 }
435
436 /*
437 * eXternal Data Representation routines.
438 * (but with non-standard args...)
439 */
440
441 /*
442 * String representation for RPC.
443 */
444 struct xdr_string {
445 u_int32_t len; /* length without null or padding */
446 char data[4]; /* data (longer, of course) */
447 /* data is padded to a long-word boundary */
448 };
449
450 struct mbuf *
451 xdr_string_encode(char *str, int len)
452 {
453 struct mbuf *m;
454 struct xdr_string *xs;
455 int dlen; /* padded string length */
456 int mlen; /* message length */
457
458 dlen = (len + 3) & ~3;
459 mlen = dlen + 4;
460
461 if (mlen > MCLBYTES) /* If too big, we just can't do it. */
462 return (NULL);
463
464 m = m_get2(mlen, M_WAITOK, MT_DATA, 0);
465 xs = mtod(m, struct xdr_string *);
466 m->m_len = mlen;
467 xs->len = txdr_unsigned(len);
468 bcopy(str, xs->data, len);
469 return (m);
470 }
471