xref: /csrg-svn/sys/nfs/nfs_subs.c (revision 42244)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * Redistribution and use in source and binary forms are permitted
9  * provided that the above copyright notice and this paragraph are
10  * duplicated in all such forms and that any documentation,
11  * advertising materials, and other materials related to such
12  * distribution and use acknowledge that the software was developed
13  * by the University of California, Berkeley.  The name of the
14  * University may not be used to endorse or promote products derived
15  * from this software without specific prior written permission.
16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19  *
20  *	@(#)nfs_subs.c	7.25 (Berkeley) 05/18/90
21  */
22 
23 /*
24  * These functions support the macros and help fiddle mbuf chains for
25  * the nfs op functions. They do things like create the rpc header and
26  * copy data between mbuf chains and uio lists.
27  */
28 #include "param.h"
29 #include "user.h"
30 #include "proc.h"
31 #include "systm.h"
32 #include "kernel.h"
33 #include "mount.h"
34 #include "file.h"
35 #include "vnode.h"
36 #include "mbuf.h"
37 #include "errno.h"
38 #include "map.h"
39 #include "rpcv2.h"
40 #include "nfsv2.h"
41 #include "nfsnode.h"
42 #include "nfs.h"
43 #include "nfsiom.h"
44 #include "xdr_subs.h"
45 #include "nfsm_subs.h"
46 
47 #define TRUE	1
48 #define	FALSE	0
49 
50 /*
51  * Data items converted to xdr at startup, since they are constant
52  * This is kinda hokey, but may save a little time doing byte swaps
53  */
54 u_long nfs_procids[NFS_NPROCS];
55 u_long nfs_xdrneg1;
56 u_long rpc_call, rpc_vers, rpc_reply, rpc_msgdenied,
57 	rpc_mismatch, rpc_auth_unix, rpc_msgaccepted;
58 u_long nfs_vers, nfs_prog, nfs_true, nfs_false;
59 /* And other global data */
60 static u_long *rpc_uidp = (u_long *)0;
61 static u_long nfs_xid = 1;
62 static char *rpc_unixauth;
63 extern long hostid;
64 enum vtype ntov_type[7] = { VNON, VREG, VDIR, VBLK, VCHR, VLNK, VNON };
65 extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
66 extern struct map nfsmap[NFS_MSIZ];
67 extern struct nfsreq nfsreqh;
68 
69 /* Function ret types */
70 static char *nfs_unixauth();
71 
72 /*
73  * Maximum number of groups passed through to NFS server.
74  * According to RFC1057 it should be 16.
75  * For release 3.X systems, the maximum value is 8.
76  * For release 4.X systems, the maximum value is 10.
77  */
78 int numgrps = 8;
79 
80 /*
81  * Create the header for an rpc request packet
82  * The function nfs_unixauth() creates a unix style authorization string
83  * and returns a ptr to it.
84  * The hsiz is the size of the rest of the nfs request header.
85  * (just used to decide if a cluster is a good idea)
86  * nb: Note that the prog, vers and procid args are already in xdr byte order
87  */
88 struct mbuf *nfsm_reqh(prog, vers, procid, cred, hsiz, bpos, mb, retxid)
89 	u_long prog;
90 	u_long vers;
91 	u_long procid;
92 	struct ucred *cred;
93 	int hsiz;
94 	caddr_t *bpos;
95 	struct mbuf **mb;
96 	u_long *retxid;
97 {
98 	register struct mbuf *mreq, *m;
99 	register u_long *p;
100 	struct mbuf *m1;
101 	char *ap;
102 	int asiz, siz;
103 
104 	NFSMGETHDR(mreq);
105 	asiz = (((cred->cr_ngroups > numgrps) ? numgrps : cred->cr_ngroups)<<2);
106 #ifdef FILLINHOST
107 	asiz += nfsm_rndup(hostnamelen)+(9*NFSX_UNSIGNED);
108 #else
109 	asiz += 9*NFSX_UNSIGNED;
110 #endif
111 
112 	/* If we need a lot, alloc a cluster ?? */
113 	if ((asiz+hsiz+RPC_SIZ) > MHLEN)
114 		MCLGET(mreq, M_WAIT);
115 	mreq->m_len = NFSMSIZ(mreq);
116 	siz = mreq->m_len;
117 	m1 = mreq;
118 	/*
119 	 * Alloc enough mbufs
120 	 * We do it now to avoid all sleeps after the call to nfs_unixauth()
121 	 */
122 	while ((asiz+RPC_SIZ) > siz) {
123 		MGET(m, M_WAIT, MT_DATA);
124 		m1->m_next = m;
125 		m->m_len = MLEN;
126 		siz += MLEN;
127 		m1 = m;
128 	}
129 	p = mtod(mreq, u_long *);
130 	*p++ = *retxid = txdr_unsigned(++nfs_xid);
131 	*p++ = rpc_call;
132 	*p++ = rpc_vers;
133 	*p++ = prog;
134 	*p++ = vers;
135 	*p++ = procid;
136 
137 	/* Now we can call nfs_unixauth() and copy it in */
138 	ap = nfs_unixauth(cred);
139 	m = mreq;
140 	siz = m->m_len-RPC_SIZ;
141 	if (asiz <= siz) {
142 		bcopy(ap, (caddr_t)p, asiz);
143 		m->m_len = asiz+RPC_SIZ;
144 	} else {
145 		bcopy(ap, (caddr_t)p, siz);
146 		ap += siz;
147 		asiz -= siz;
148 		while (asiz > 0) {
149 			siz = (asiz > MLEN) ? MLEN : asiz;
150 			m = m->m_next;
151 			bcopy(ap, mtod(m, caddr_t), siz);
152 			m->m_len = siz;
153 			asiz -= siz;
154 			ap += siz;
155 		}
156 	}
157 
158 	/* Finally, return values */
159 	*mb = m;
160 	*bpos = mtod(m, caddr_t)+m->m_len;
161 	return (mreq);
162 }
163 
164 /*
165  * copies mbuf chain to the uio scatter/gather list
166  */
167 nfsm_mbuftouio(mrep, uiop, siz, dpos)
168 	struct mbuf **mrep;
169 	struct uio *uiop;
170 	int siz;
171 	caddr_t *dpos;
172 {
173 	register int xfer, left, len;
174 	register struct mbuf *mp;
175 	register char *mbufcp, *uiocp;
176 	long uiosiz, rem;
177 	int error = 0;
178 
179 	mp = *mrep;
180 	mbufcp = *dpos;
181 	len = mtod(mp, caddr_t)+mp->m_len-mbufcp;
182 	rem = nfsm_rndup(siz)-siz;
183 	while (siz > 0) {
184 		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
185 			return (EFBIG);
186 		left = uiop->uio_iov->iov_len;
187 		uiocp = uiop->uio_iov->iov_base;
188 		if (left > siz)
189 			left = siz;
190 		uiosiz = left;
191 		while (left > 0) {
192 			while (len == 0) {
193 				mp = mp->m_next;
194 				if (mp == NULL)
195 					return (EBADRPC);
196 				mbufcp = mtod(mp, caddr_t);
197 				len = mp->m_len;
198 			}
199 			xfer = (left > len) ? len : left;
200 #ifdef notdef
201 			/* Not Yet.. */
202 			if (uiop->uio_iov->iov_op != NULL)
203 				(*(uiop->uio_iov->iov_op))
204 				(mbufcp, uiocp, xfer);
205 			else
206 #endif
207 			if (uiop->uio_segflg == UIO_SYSSPACE)
208 				bcopy(mbufcp, uiocp, xfer);
209 			else
210 				copyout(mbufcp, uiocp, xfer);
211 			left -= xfer;
212 			len -= xfer;
213 			mbufcp += xfer;
214 			uiocp += xfer;
215 			uiop->uio_offset += xfer;
216 			uiop->uio_resid -= xfer;
217 		}
218 		if (uiop->uio_iov->iov_len <= siz) {
219 			uiop->uio_iovcnt--;
220 			uiop->uio_iov++;
221 		} else {
222 			uiop->uio_iov->iov_base += uiosiz;
223 			uiop->uio_iov->iov_len -= uiosiz;
224 		}
225 		siz -= uiosiz;
226 	}
227 	*dpos = mbufcp;
228 	*mrep = mp;
229 	if (rem > 0) {
230 		if (len < rem)
231 			error = nfs_adv(mrep, dpos, rem, len);
232 		else
233 			*dpos += rem;
234 	}
235 	return (error);
236 }
237 
238 /*
239  * copies a uio scatter/gather list to an mbuf chain...
240  */
241 nfsm_uiotombuf(uiop, mq, siz, bpos)
242 	register struct uio *uiop;
243 	struct mbuf **mq;
244 	int siz;
245 	caddr_t *bpos;
246 {
247 	register struct mbuf *mp;
248 	struct mbuf *mp2;
249 	long xfer, left, uiosiz;
250 	int clflg;
251 	int rem, len;
252 	char *cp, *uiocp;
253 
254 	if (siz > MLEN)		/* or should it >= MCLBYTES ?? */
255 		clflg = 1;
256 	else
257 		clflg = 0;
258 	rem = nfsm_rndup(siz)-siz;
259 	mp2 = *mq;
260 	while (siz > 0) {
261 		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
262 			return (EINVAL);
263 		left = uiop->uio_iov->iov_len;
264 		uiocp = uiop->uio_iov->iov_base;
265 		if (left > siz)
266 			left = siz;
267 		uiosiz = left;
268 		while (left > 0) {
269 			MGET(mp, M_WAIT, MT_DATA);
270 			if (clflg)
271 				MCLGET(mp, M_WAIT);
272 			mp->m_len = NFSMSIZ(mp);
273 			mp2->m_next = mp;
274 			mp2 = mp;
275 			xfer = (left > mp->m_len) ? mp->m_len : left;
276 #ifdef notdef
277 			/* Not Yet.. */
278 			if (uiop->uio_iov->iov_op != NULL)
279 				(*(uiop->uio_iov->iov_op))
280 				(uiocp, mtod(mp, caddr_t), xfer);
281 			else
282 #endif
283 			if (uiop->uio_segflg == UIO_SYSSPACE)
284 				bcopy(uiocp, mtod(mp, caddr_t), xfer);
285 			else
286 				copyin(uiocp, mtod(mp, caddr_t), xfer);
287 			len = mp->m_len;
288 			mp->m_len = xfer;
289 			left -= xfer;
290 			uiocp += xfer;
291 			uiop->uio_offset += xfer;
292 			uiop->uio_resid -= xfer;
293 		}
294 		if (uiop->uio_iov->iov_len <= siz) {
295 			uiop->uio_iovcnt--;
296 			uiop->uio_iov++;
297 		} else {
298 			uiop->uio_iov->iov_base += uiosiz;
299 			uiop->uio_iov->iov_len -= uiosiz;
300 		}
301 		siz -= uiosiz;
302 	}
303 	if (rem > 0) {
304 		if (rem > (len-mp->m_len)) {
305 			MGET(mp, M_WAIT, MT_DATA);
306 			mp->m_len = 0;
307 			mp2->m_next = mp;
308 		}
309 		cp = mtod(mp, caddr_t)+mp->m_len;
310 		for (left = 0; left < rem; left++)
311 			*cp++ = '\0';
312 		mp->m_len += rem;
313 		*bpos = cp;
314 	} else
315 		*bpos = mtod(mp, caddr_t)+mp->m_len;
316 	*mq = mp;
317 	return (0);
318 }
319 
320 /*
321  * Help break down an mbuf chain by setting the first siz bytes contiguous
322  * pointed to by returned val.
323  * If Updateflg == True we can overwrite the first part of the mbuf data
324  * This is used by the macros nfsm_disect and nfsm_disecton for tough
325  * cases. (The macros use the vars. dpos and dpos2)
326  */
327 nfsm_disct(mdp, dposp, siz, left, updateflg, cp2)
328 	struct mbuf **mdp;
329 	caddr_t *dposp;
330 	int siz;
331 	int left;
332 	int updateflg;
333 	caddr_t *cp2;
334 {
335 	register struct mbuf *mp, *mp2;
336 	register int siz2, xfer;
337 	register caddr_t p;
338 
339 	mp = *mdp;
340 	while (left == 0) {
341 		*mdp = mp = mp->m_next;
342 		if (mp == NULL)
343 			return (EBADRPC);
344 		left = mp->m_len;
345 		*dposp = mtod(mp, caddr_t);
346 	}
347 	if (left >= siz) {
348 		*cp2 = *dposp;
349 		*dposp += siz;
350 	} else if (mp->m_next == NULL) {
351 		return (EBADRPC);
352 	} else if (siz > MHLEN) {
353 		panic("nfs S too big");
354 	} else {
355 		/* Iff update, you can overwrite, else must alloc new mbuf */
356 		if (updateflg) {
357 			NFSMINOFF(mp);
358 		} else {
359 			MGET(mp2, M_WAIT, MT_DATA);
360 			mp2->m_next = mp->m_next;
361 			mp->m_next = mp2;
362 			mp->m_len -= left;
363 			mp = mp2;
364 		}
365 		*cp2 = p = mtod(mp, caddr_t);
366 		bcopy(*dposp, p, left);		/* Copy what was left */
367 		siz2 = siz-left;
368 		p += left;
369 		mp2 = mp->m_next;
370 		/* Loop around copying up the siz2 bytes */
371 		while (siz2 > 0) {
372 			if (mp2 == NULL)
373 				return (EBADRPC);
374 			xfer = (siz2 > mp2->m_len) ? mp2->m_len : siz2;
375 			if (xfer > 0) {
376 				bcopy(mtod(mp2, caddr_t), p, xfer);
377 				NFSMADV(mp2, xfer);
378 				mp2->m_len -= xfer;
379 				p += xfer;
380 				siz2 -= xfer;
381 			}
382 			if (siz2 > 0)
383 				mp2 = mp2->m_next;
384 		}
385 		mp->m_len = siz;
386 		*mdp = mp2;
387 		*dposp = mtod(mp2, caddr_t);
388 	}
389 	return (0);
390 }
391 
392 /*
393  * Advance the position in the mbuf chain.
394  */
395 nfs_adv(mdp, dposp, offs, left)
396 	struct mbuf **mdp;
397 	caddr_t *dposp;
398 	int offs;
399 	int left;
400 {
401 	register struct mbuf *m;
402 	register int s;
403 
404 	m = *mdp;
405 	s = left;
406 	while (s < offs) {
407 		offs -= s;
408 		m = m->m_next;
409 		if (m == NULL)
410 			return (EBADRPC);
411 		s = m->m_len;
412 	}
413 	*mdp = m;
414 	*dposp = mtod(m, caddr_t)+offs;
415 	return (0);
416 }
417 
418 /*
419  * Copy a string into mbufs for the hard cases...
420  */
421 nfsm_strtmbuf(mb, bpos, cp, siz)
422 	struct mbuf **mb;
423 	char **bpos;
424 	char *cp;
425 	long siz;
426 {
427 	register struct mbuf *m1, *m2;
428 	long left, xfer, len, tlen;
429 	u_long *p;
430 	int putsize;
431 
432 	putsize = 1;
433 	m2 = *mb;
434 	left = NFSMSIZ(m2)-m2->m_len;
435 	if (left > 0) {
436 		p = ((u_long *)(*bpos));
437 		*p++ = txdr_unsigned(siz);
438 		putsize = 0;
439 		left -= NFSX_UNSIGNED;
440 		m2->m_len += NFSX_UNSIGNED;
441 		if (left > 0) {
442 			bcopy(cp, (caddr_t) p, left);
443 			siz -= left;
444 			cp += left;
445 			m2->m_len += left;
446 			left = 0;
447 		}
448 	}
449 	/* Loop arround adding mbufs */
450 	while (siz > 0) {
451 		MGET(m1, M_WAIT, MT_DATA);
452 		if (siz > MLEN)
453 			MCLGET(m1, M_WAIT);
454 		m1->m_len = NFSMSIZ(m1);
455 		m2->m_next = m1;
456 		m2 = m1;
457 		p = mtod(m1, u_long *);
458 		tlen = 0;
459 		if (putsize) {
460 			*p++ = txdr_unsigned(siz);
461 			m1->m_len -= NFSX_UNSIGNED;
462 			tlen = NFSX_UNSIGNED;
463 			putsize = 0;
464 		}
465 		if (siz < m1->m_len) {
466 			len = nfsm_rndup(siz);
467 			xfer = siz;
468 			if (xfer < len)
469 				*(p+(xfer>>2)) = 0;
470 		} else {
471 			xfer = len = m1->m_len;
472 		}
473 		bcopy(cp, (caddr_t) p, xfer);
474 		m1->m_len = len+tlen;
475 		siz -= xfer;
476 		cp += xfer;
477 	}
478 	*mb = m1;
479 	*bpos = mtod(m1, caddr_t)+m1->m_len;
480 	return (0);
481 }
482 
483 /*
484  * Called once to initialize data structures...
485  */
486 nfs_init()
487 {
488 	register int i;
489 
490 	rpc_vers = txdr_unsigned(RPC_VER2);
491 	rpc_call = txdr_unsigned(RPC_CALL);
492 	rpc_reply = txdr_unsigned(RPC_REPLY);
493 	rpc_msgdenied = txdr_unsigned(RPC_MSGDENIED);
494 	rpc_msgaccepted = txdr_unsigned(RPC_MSGACCEPTED);
495 	rpc_mismatch = txdr_unsigned(RPC_MISMATCH);
496 	rpc_auth_unix = txdr_unsigned(RPCAUTH_UNIX);
497 	nfs_vers = txdr_unsigned(NFS_VER2);
498 	nfs_prog = txdr_unsigned(NFS_PROG);
499 	nfs_true = txdr_unsigned(TRUE);
500 	nfs_false = txdr_unsigned(FALSE);
501 	/* Loop thru nfs procids */
502 	for (i = 0; i < NFS_NPROCS; i++)
503 		nfs_procids[i] = txdr_unsigned(i);
504 	/* Ensure async daemons disabled */
505 	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
506 		nfs_iodwant[i] = (struct proc *)0;
507 	nfs_xdrneg1 = txdr_unsigned(-1);
508 	nfs_nhinit();			/* Init the nfsnode table */
509 	nfsrv_initcache();		/* Init the server request cache */
510 	rminit(nfsmap, (long)NFS_MAPREG, (long)1, "nfs mapreg", NFS_MSIZ);
511 
512 	/*
513 	 * Initialize reply list and start timer
514 	 */
515 	nfsreqh.r_prev = nfsreqh.r_next = &nfsreqh;
516 	nfs_timer();
517 }
518 
519 /*
520  * Fill in the rest of the rpc_unixauth and return it
521  */
522 static char *nfs_unixauth(cr)
523 	register struct ucred *cr;
524 {
525 	register u_long *p;
526 	register int i;
527 	int ngr;
528 
529 	/* Maybe someday there should be a cache of AUTH_SHORT's */
530 	if ((p = rpc_uidp) == NULL) {
531 #ifdef FILLINHOST
532 		i = nfsm_rndup(hostnamelen)+(19*NFSX_UNSIGNED);
533 #else
534 		i = 19*NFSX_UNSIGNED;
535 #endif
536 		MALLOC(p, u_long *, i, M_TEMP, M_WAITOK);
537 		bzero((caddr_t)p, i);
538 		rpc_unixauth = (caddr_t)p;
539 		*p++ = txdr_unsigned(RPCAUTH_UNIX);
540 		p++;	/* Fill in size later */
541 		*p++ = hostid;
542 #ifdef FILLINHOST
543 		*p++ = txdr_unsigned(hostnamelen);
544 		i = nfsm_rndup(hostnamelen);
545 		bcopy(hostname, (caddr_t)p, hostnamelen);
546 		p += (i>>2);
547 #else
548 		*p++ = 0;
549 #endif
550 		rpc_uidp = p;
551 	}
552 	*p++ = txdr_unsigned(cr->cr_uid);
553 	*p++ = txdr_unsigned(cr->cr_groups[0]);
554 	ngr = (cr->cr_ngroups > numgrps) ? numgrps : cr->cr_ngroups;
555 	*p++ = txdr_unsigned(ngr);
556 	for (i = 0; i < ngr; i++)
557 		*p++ = txdr_unsigned(cr->cr_groups[i]);
558 	/* And add the AUTH_NULL */
559 	*p++ = 0;
560 	*p = 0;
561 	i = (((caddr_t)p)-rpc_unixauth)-12;
562 	p = (u_long *)(rpc_unixauth+4);
563 	*p = txdr_unsigned(i);
564 	return (rpc_unixauth);
565 }
566 
567 /*
568  * Attribute cache routines.
569  * nfs_loadattrcache() - loads or updates the cache contents from attributes
570  *	that are on the mbuf list
571  * nfs_getattrcache() - returns valid attributes if found in cache, returns
572  *	error otherwise
573  */
574 
575 /*
576  * Load the attribute cache (that lives in the nfsnode entry) with
577  * the values on the mbuf list and
578  * Iff vap not NULL
579  *    copy the attributes to *vaper
580  */
581 nfs_loadattrcache(vpp, mdp, dposp, vaper)
582 	struct vnode **vpp;
583 	struct mbuf **mdp;
584 	caddr_t *dposp;
585 	struct vattr *vaper;
586 {
587 	register struct vnode *vp = *vpp;
588 	register struct vattr *vap;
589 	register struct nfsv2_fattr *fp;
590 	extern struct vnodeops spec_nfsv2nodeops;
591 	register struct nfsnode *np;
592 	register long t1;
593 	caddr_t dpos, cp2;
594 	int error = 0;
595 	struct mbuf *md;
596 	enum vtype type;
597 	long rdev;
598 	struct timeval mtime;
599 	struct vnode *nvp;
600 
601 	md = *mdp;
602 	dpos = *dposp;
603 	t1 = (mtod(md, caddr_t)+md->m_len)-dpos;
604 	if (error = nfsm_disct(&md, &dpos, NFSX_FATTR, t1, TRUE, &cp2))
605 		return (error);
606 	fp = (struct nfsv2_fattr *)cp2;
607 	type = nfstov_type(fp->fa_type);
608 	rdev = fxdr_unsigned(long, fp->fa_rdev);
609 	fxdr_time(&fp->fa_mtime, &mtime);
610 	/*
611 	 * If v_type == VNON it is a new node, so fill in the v_type,
612 	 * n_mtime fields. Check to see if it represents a special
613 	 * device, and if so, check for a possible alias. Once the
614 	 * correct vnode has been obtained, fill in the rest of the
615 	 * information.
616 	 */
617 	np = VTONFS(vp);
618 	if (vp->v_type == VNON) {
619 		if (type == VCHR && rdev == 0xffffffff)
620 			vp->v_type = type = VFIFO;
621 		else
622 			vp->v_type = type;
623 		if (vp->v_type == VFIFO) {
624 #ifdef FIFO
625 			extern struct vnodeops fifo_nfsv2nodeops;
626 			vp->v_op = &fifo_nfsv2nodeops;
627 #else
628 			return (EOPNOTSUPP);
629 #endif /* FIFO */
630 		}
631 		if (vp->v_type == VCHR || vp->v_type == VBLK) {
632 			vp->v_op = &spec_nfsv2nodeops;
633 			if (nvp = checkalias(vp, (dev_t)rdev, vp->v_mount)) {
634 				/*
635 				 * Reinitialize aliased node.
636 				 */
637 				np = VTONFS(nvp);
638 				np->n_vnode = nvp;
639 				np->n_flag = 0;
640 				nfs_lock(nvp);
641 				bcopy((caddr_t)&VTONFS(vp)->n_fh,
642 					(caddr_t)&np->n_fh, NFSX_FH);
643 				insque(np, nfs_hash(&np->n_fh));
644 				np->n_attrstamp = 0;
645 				np->n_sillyrename = (struct sillyrename *)0;
646 				/*
647 				 * Discard unneeded vnode and update actual one
648 				 */
649 				vput(vp);
650 				*vpp = nvp;
651 			}
652 		}
653 		np->n_mtime = mtime.tv_sec;
654 	}
655 	vap = &np->n_vattr;
656 	vap->va_type = type;
657 	vap->va_mode = nfstov_mode(fp->fa_mode);
658 	vap->va_nlink = fxdr_unsigned(u_short, fp->fa_nlink);
659 	vap->va_uid = fxdr_unsigned(uid_t, fp->fa_uid);
660 	vap->va_gid = fxdr_unsigned(gid_t, fp->fa_gid);
661 	vap->va_size = fxdr_unsigned(u_long, fp->fa_size);
662 	if ((np->n_flag & NMODIFIED) == 0 || vap->va_size > np->n_size)
663 		np->n_size = vap->va_size;
664 	vap->va_size_rsv = 0;
665 	vap->va_blocksize = fxdr_unsigned(long, fp->fa_blocksize);
666 	vap->va_rdev = (dev_t)rdev;
667 	vap->va_bytes = fxdr_unsigned(long, fp->fa_blocks) * NFS_FABLKSIZE;
668 	vap->va_bytes_rsv = 0;
669 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0] | 0x8000;
670 	vap->va_fileid = fxdr_unsigned(long, fp->fa_fileid);
671 	vap->va_atime.tv_sec = fxdr_unsigned(long, fp->fa_atime.tv_sec);
672 	vap->va_atime.tv_usec = 0;
673 	vap->va_flags = fxdr_unsigned(u_long, fp->fa_atime.tv_usec);
674 	vap->va_mtime = mtime;
675 	vap->va_ctime.tv_sec = fxdr_unsigned(long, fp->fa_ctime.tv_sec);
676 	vap->va_ctime.tv_usec = 0;
677 	vap->va_gen = fxdr_unsigned(u_long, fp->fa_ctime.tv_usec);
678 	np->n_attrstamp = time.tv_sec;
679 	*dposp = dpos;
680 	*mdp = md;
681 	if (vaper != NULL) {
682 		bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(*vap));
683 		if ((np->n_flag & NMODIFIED) && (np->n_size > vap->va_size))
684 			vaper->va_size = np->n_size;
685 	}
686 	return (0);
687 }
688 
689 /*
690  * Check the time stamp
691  * If the cache is valid, copy contents to *vap and return 0
692  * otherwise return an error
693  */
694 nfs_getattrcache(vp, vap)
695 	register struct vnode *vp;
696 	struct vattr *vap;
697 {
698 	register struct nfsnode *np;
699 
700 	np = VTONFS(vp);
701 	if ((time.tv_sec-np->n_attrstamp) < NFS_ATTRTIMEO) {
702 		nfsstats.attrcache_hits++;
703 		bcopy((caddr_t)&np->n_vattr,(caddr_t)vap,sizeof(struct vattr));
704 		if ((np->n_flag & NMODIFIED) == 0)
705 			np->n_size = vap->va_size;
706 		else if (np->n_size > vap->va_size)
707 			vap->va_size = np->n_size;
708 		return (0);
709 	} else {
710 		nfsstats.attrcache_misses++;
711 		return (ENOENT);
712 	}
713 }
714 
715 /*
716  * Set up nameidata for a namei() call and do it
717  */
718 nfs_namei(ndp, fhp, len, mdp, dposp)
719 	register struct nameidata *ndp;
720 	fhandle_t *fhp;
721 	int len;
722 	struct mbuf **mdp;
723 	caddr_t *dposp;
724 {
725 	register int i, rem;
726 	register struct mbuf *md;
727 	register char *cp;
728 	struct vnode *dp;
729 	int flag;
730 	int error;
731 
732 	if ((ndp->ni_nameiop & HASBUF) == 0) {
733 		flag = ndp->ni_nameiop & OPFLAG;
734 		/*
735 		 * Copy the name from the mbuf list to the d_name field of ndp
736 		 * and set the various ndp fields appropriately.
737 		 */
738 		cp = *dposp;
739 		md = *mdp;
740 		rem = mtod(md, caddr_t)+md->m_len-cp;
741 		ndp->ni_hash = 0;
742 		for (i = 0; i < len;) {
743 			while (rem == 0) {
744 				md = md->m_next;
745 				if (md == NULL)
746 					return (EBADRPC);
747 				cp = mtod(md, caddr_t);
748 				rem = md->m_len;
749 			}
750 			if (*cp == '\0' || *cp == '/')
751 				return (EINVAL);
752 			if (*cp & 0200)
753 				if ((*cp&0377) == ('/'|0200) || flag != DELETE)
754 					return (EINVAL);
755 			ndp->ni_dent.d_name[i++] = *cp;
756 			ndp->ni_hash += (unsigned char)*cp * i;
757 			cp++;
758 			rem--;
759 		}
760 		*mdp = md;
761 		*dposp = cp;
762 		len = nfsm_rndup(len)-len;
763 		if (len > 0) {
764 			if (rem < len) {
765 				if (error = nfs_adv(mdp, dposp, len, rem))
766 					return (error);
767 			} else
768 				*dposp += len;
769 		}
770 	} else
771 		i = len;
772 	ndp->ni_namelen = i;
773 	ndp->ni_dent.d_namlen = i;
774 	ndp->ni_dent.d_name[i] = '\0';
775 	ndp->ni_segflg = UIO_SYSSPACE;
776 	ndp->ni_pathlen = 1;
777 	ndp->ni_pnbuf = ndp->ni_dirp = ndp->ni_ptr = &ndp->ni_dent.d_name[0];
778 	ndp->ni_next = &ndp->ni_dent.d_name[i];
779 	ndp->ni_nameiop |= (NOCROSSMOUNT | REMOTE | HASBUF);
780 
781 	if (error = nfsrv_fhtovp(fhp, FALSE, &dp, ndp->ni_cred))
782 		return (error);
783 	if (dp->v_type != VDIR) {
784 		vrele(dp);
785 		return (ENOTDIR);
786 	}
787 	/*
788 	 * Must set current directory here to avoid confusion in namei()
789 	 * called from rename()
790 	 */
791 	ndp->ni_cdir = dp;
792 	ndp->ni_rdir = NULLVP;
793 
794 	/*
795 	 * And call namei() to do the real work
796 	 */
797 	error = namei(ndp);
798 	vrele(dp);
799 	return (error);
800 }
801 
802 /*
803  * A fiddled version of m_adj() that ensures null fill to a long
804  * boundary and only trims off the back end
805  */
806 nfsm_adj(mp, len, nul)
807 	struct mbuf *mp;
808 	register int len;
809 	int nul;
810 {
811 	register struct mbuf *m;
812 	register int count, i;
813 	register char *cp;
814 
815 	/*
816 	 * Trim from tail.  Scan the mbuf chain,
817 	 * calculating its length and finding the last mbuf.
818 	 * If the adjustment only affects this mbuf, then just
819 	 * adjust and return.  Otherwise, rescan and truncate
820 	 * after the remaining size.
821 	 */
822 	count = 0;
823 	m = mp;
824 	for (;;) {
825 		count += m->m_len;
826 		if (m->m_next == (struct mbuf *)0)
827 			break;
828 		m = m->m_next;
829 	}
830 	if (m->m_len > len) {
831 		m->m_len -= len;
832 		if (nul > 0) {
833 			cp = mtod(m, caddr_t)+m->m_len-nul;
834 			for (i = 0; i < nul; i++)
835 				*cp++ = '\0';
836 		}
837 		return;
838 	}
839 	count -= len;
840 	if (count < 0)
841 		count = 0;
842 	/*
843 	 * Correct length for chain is "count".
844 	 * Find the mbuf with last data, adjust its length,
845 	 * and toss data from remaining mbufs on chain.
846 	 */
847 	for (m = mp; m; m = m->m_next) {
848 		if (m->m_len >= count) {
849 			m->m_len = count;
850 			if (nul > 0) {
851 				cp = mtod(m, caddr_t)+m->m_len-nul;
852 				for (i = 0; i < nul; i++)
853 					*cp++ = '\0';
854 			}
855 			break;
856 		}
857 		count -= m->m_len;
858 	}
859 	while (m = m->m_next)
860 		m->m_len = 0;
861 }
862 
863 /*
864  * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
865  * 	- look up fsid in mount list (if not found ret error)
866  *	- check that it is exported
867  *	- get vp by calling VFS_FHTOVP() macro
868  *	- if not lockflag unlock it with VOP_UNLOCK()
869  *	- if cred->cr_uid == 0 set it to m_exroot
870  */
871 nfsrv_fhtovp(fhp, lockflag, vpp, cred)
872 	fhandle_t *fhp;
873 	int lockflag;
874 	struct vnode **vpp;
875 	struct ucred *cred;
876 {
877 	register struct mount *mp;
878 
879 	if ((mp = getvfs(&fhp->fh_fsid)) == NULL)
880 		return (ESTALE);
881 	if ((mp->mnt_flag & MNT_EXPORTED) == 0)
882 		return (EACCES);
883 	if (VFS_FHTOVP(mp, &fhp->fh_fid, vpp))
884 		return (ESTALE);
885 	if (cred->cr_uid == 0)
886 		cred->cr_uid = mp->mnt_exroot;
887 	if (!lockflag)
888 		VOP_UNLOCK(*vpp);
889 	return (0);
890 }
891