xref: /csrg-svn/sys/nfs/nfs_subs.c (revision 39907)
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	7.16 (Berkeley) 01/15/90
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 "strings.h"
29 #include "param.h"
30 #include "systm.h"
31 #include "user.h"
32 #include "proc.h"
33 #include "mount.h"
34 #include "../ufs/dir.h"
35 #include "time.h"
36 #include "errno.h"
37 #include "kernel.h"
38 #include "malloc.h"
39 #include "mbuf.h"
40 #include "file.h"
41 #include "vnode.h"
42 #include "uio.h"
43 #include "namei.h"
44 #include "ucred.h"
45 #include "map.h"
46 #include "rpcv2.h"
47 #include "nfsv2.h"
48 #include "nfsnode.h"
49 #include "nfs.h"
50 #include "nfsiom.h"
51 #include "xdr_subs.h"
52 #include "nfsm_subs.h"
53 
54 #define TRUE	1
55 #define	FALSE	0
56 
57 /*
58  * Data items converted to xdr at startup, since they are constant
59  * This is kinda hokey, but may save a little time doing byte swaps
60  */
61 u_long nfs_procids[NFS_NPROCS];
62 u_long nfs_xdrneg1;
63 u_long rpc_call, rpc_vers, rpc_reply, rpc_msgdenied,
64 	rpc_mismatch, rpc_auth_unix, rpc_msgaccepted;
65 u_long nfs_vers, nfs_prog, nfs_true, nfs_false;
66 /* And other global data */
67 static u_long *rpc_uidp = (u_long *)0;
68 static u_long nfs_xid = 1;
69 static char *rpc_unixauth;
70 extern long hostid;
71 extern enum vtype v_type[NFLNK+1];
72 extern struct proc *nfs_iodwant[MAX_ASYNCDAEMON];
73 extern struct map nfsmap[NFS_MSIZ];
74 
75 /* Function ret types */
76 static char *nfs_unixauth();
77 
78 /*
79  * Maximum number of groups passed through to NFS server.
80  * For release 3.X systems, the maximum value is 8.
81  * For release 4.X systems, the maximum value is 10.
82  */
83 int numgrps = 8;
84 
85 /*
86  * Create the header for an rpc request packet
87  * The function nfs_unixauth() creates a unix style authorization string
88  * and returns a ptr to it.
89  * The hsiz is the size of the rest of the nfs request header.
90  * (just used to decide if a cluster is a good idea)
91  * nb: Note that the prog, vers and procid args are already in xdr byte order
92  */
93 struct mbuf *nfsm_reqh(prog, vers, procid, cred, hsiz, bpos, mb, retxid)
94 	u_long prog;
95 	u_long vers;
96 	u_long procid;
97 	struct ucred *cred;
98 	int hsiz;
99 	caddr_t *bpos;
100 	struct mbuf **mb;
101 	u_long *retxid;
102 {
103 	register struct mbuf *mreq, *m;
104 	register u_long *p;
105 	struct mbuf *m1;
106 	char *ap;
107 	int asiz, siz;
108 
109 	NFSMGETHDR(mreq);
110 	asiz = (((cred->cr_ngroups > numgrps) ? numgrps : cred->cr_ngroups)<<2);
111 #ifdef FILLINHOST
112 	asiz += nfsm_rndup(hostnamelen)+(9*NFSX_UNSIGNED);
113 #else
114 	asiz += 9*NFSX_UNSIGNED;
115 #endif
116 
117 	/* If we need a lot, alloc a cluster ?? */
118 	if ((asiz+hsiz+RPC_SIZ) > MHLEN)
119 		NFSMCLGET(mreq, M_WAIT);
120 	mreq->m_len = NFSMSIZ(mreq);
121 	siz = mreq->m_len;
122 	m1 = mreq;
123 	/*
124 	 * Alloc enough mbufs
125 	 * We do it now to avoid all sleeps after the call to nfs_unixauth()
126 	 */
127 	while ((asiz+RPC_SIZ) > siz) {
128 		MGET(m, M_WAIT, MT_DATA);
129 		m1->m_next = m;
130 		m->m_len = MLEN;
131 		siz += MLEN;
132 		m1 = m;
133 	}
134 	p = mtod(mreq, u_long *);
135 	*p++ = *retxid = txdr_unsigned(++nfs_xid);
136 	*p++ = rpc_call;
137 	*p++ = rpc_vers;
138 	*p++ = prog;
139 	*p++ = vers;
140 	*p++ = procid;
141 
142 	/* Now we can call nfs_unixauth() and copy it in */
143 	ap = nfs_unixauth(cred);
144 	m = mreq;
145 	siz = m->m_len-RPC_SIZ;
146 	if (asiz <= siz) {
147 		bcopy(ap, (caddr_t)p, asiz);
148 		m->m_len = asiz+RPC_SIZ;
149 	} else {
150 		bcopy(ap, (caddr_t)p, siz);
151 		ap += siz;
152 		asiz -= siz;
153 		while (asiz > 0) {
154 			siz = (asiz > MLEN) ? MLEN : asiz;
155 			m = m->m_next;
156 			bcopy(ap, mtod(m, caddr_t), siz);
157 			m->m_len = siz;
158 			asiz -= siz;
159 			ap += siz;
160 		}
161 	}
162 
163 	/* Finally, return values */
164 	*mb = m;
165 	*bpos = mtod(m, caddr_t)+m->m_len;
166 	return (mreq);
167 }
168 
169 /*
170  * copies mbuf chain to the uio scatter/gather list
171  */
172 nfsm_mbuftouio(mrep, uiop, siz, dpos)
173 	struct mbuf **mrep;
174 	struct uio *uiop;
175 	int siz;
176 	caddr_t *dpos;
177 {
178 	register int xfer, left, len;
179 	register struct mbuf *mp;
180 	register char *mbufcp, *uiocp;
181 	long uiosiz, rem;
182 
183 	mp = *mrep;
184 	mbufcp = *dpos;
185 	len = mtod(mp, caddr_t)+mp->m_len-mbufcp;
186 	rem = nfsm_rndup(siz)-siz;
187 	while (siz > 0) {
188 		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
189 			return(EFBIG);
190 		left = uiop->uio_iov->iov_len;
191 		uiocp = uiop->uio_iov->iov_base;
192 		if (left > siz)
193 			left = siz;
194 		uiosiz = left;
195 		while (left > 0) {
196 			while (len == 0) {
197 				mp = mp->m_next;
198 				if (mp == NULL)
199 					return (EBADRPC);
200 				mbufcp = mtod(mp, caddr_t);
201 				len = mp->m_len;
202 			}
203 			xfer = (left > len) ? len : left;
204 #ifdef notdef
205 			/* Not Yet.. */
206 			if (uiop->uio_iov->iov_op != NULL)
207 				(*(uiop->uio_iov->iov_op))
208 				(mbufcp, uiocp, xfer);
209 			else
210 #endif
211 			if (uiop->uio_segflg == UIO_SYSSPACE)
212 				bcopy(mbufcp, uiocp, xfer);
213 			else
214 				copyout(mbufcp, uiocp, xfer);
215 			left -= xfer;
216 			len -= xfer;
217 			mbufcp += xfer;
218 			uiocp += xfer;
219 			uiop->uio_offset += xfer;
220 			uiop->uio_resid -= xfer;
221 		}
222 		if (uiop->uio_iov->iov_len <= siz) {
223 			uiop->uio_iovcnt--;
224 			uiop->uio_iov++;
225 		} else {
226 			uiop->uio_iov->iov_base += uiosiz;
227 			uiop->uio_iov->iov_len -= uiosiz;
228 		}
229 		siz -= uiosiz;
230 	}
231 	if (rem > 0)
232 		mbufcp += rem;
233 	*dpos = mbufcp;
234 	*mrep = mp;
235 	return(0);
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 				NFSMCLGET(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 		return(0);
351 	} else if (mp->m_next == NULL) {
352 		return(EBADRPC);
353 	} else if (siz > MCLBYTES) {
354 		panic("nfs S too big");
355 	} else {
356 		/* Iff update, you can overwrite, else must alloc new mbuf */
357 		if (updateflg) {
358 			NFSMINOFF(mp);
359 		} else {
360 			MGET(mp2, M_WAIT, MT_DATA);
361 			mp2->m_next = mp->m_next;
362 			mp->m_next = mp2;
363 			mp->m_len -= left;
364 			mp = mp2;
365 		}
366 		/* Alloc cluster iff we need it */
367 		if (!M_HASCL(mp) && siz > NFSMSIZ(mp)) {
368 			NFSMCLGET(mp, M_WAIT);
369 			if (!M_HASCL(mp))
370 				return(ENOBUFS);
371 		}
372 		*cp2 = p = mtod(mp, caddr_t);
373 		bcopy(*dposp, p, left);		/* Copy what was left */
374 		siz2 = siz-left;
375 		p += left;
376 		mp2 = mp->m_next;
377 		/* Loop arround copying up the siz2 bytes */
378 		while (siz2 > 0) {
379 			if (mp2 == NULL)
380 				return (EBADRPC);
381 			xfer = (siz2 > mp2->m_len) ? mp2->m_len : siz2;
382 			bcopy(mtod(mp2, caddr_t), p, xfer);
383 			NFSMADV(mp2, xfer);
384 			mp2->m_len -= xfer;
385 			siz2 -= xfer;
386 			if (siz2 > 0)
387 				mp2 = mp2->m_next;
388 		}
389 		mp->m_len = siz;
390 		*mdp = mp2;
391 		*dposp = mtod(mp2, caddr_t);
392 	}
393 	return (0);
394 }
395 
396 /*
397  * Advance the position in the mbuf chain with/without freeing mbufs
398  */
399 nfs_adv(mdp, dposp, offs, left)
400 	struct mbuf **mdp;
401 	caddr_t *dposp;
402 	int offs;
403 	int left;
404 {
405 	register struct mbuf *m;
406 	register int s;
407 
408 	m = *mdp;
409 	s = left;
410 	while (s < offs) {
411 		offs -= s;
412 		m = m->m_next;
413 		if (m == NULL)
414 			return(EBADRPC);
415 		s = m->m_len;
416 	}
417 	*mdp = m;
418 	*dposp = mtod(m, caddr_t)+offs;
419 	return(0);
420 }
421 
422 /*
423  * Copy a string into mbufs for the hard cases...
424  */
425 nfsm_strtmbuf(mb, bpos, cp, siz)
426 	struct mbuf **mb;
427 	char **bpos;
428 	char *cp;
429 	long siz;
430 {
431 	register struct mbuf *m1, *m2;
432 	long left, xfer, len, tlen;
433 	u_long *p;
434 	int putsize;
435 
436 	putsize = 1;
437 	m2 = *mb;
438 	left = NFSMSIZ(m2)-m2->m_len;
439 	if (left > 0) {
440 		p = ((u_long *)(*bpos));
441 		*p++ = txdr_unsigned(siz);
442 		putsize = 0;
443 		left -= NFSX_UNSIGNED;
444 		m2->m_len += NFSX_UNSIGNED;
445 		if (left > 0) {
446 			bcopy(cp, (caddr_t) p, left);
447 			siz -= left;
448 			cp += left;
449 			m2->m_len += left;
450 			left = 0;
451 		}
452 	}
453 	/* Loop arround adding mbufs */
454 	while (siz > 0) {
455 		MGET(m1, M_WAIT, MT_DATA);
456 		if (siz > MLEN)
457 			NFSMCLGET(m1, M_WAIT);
458 		m1->m_len = NFSMSIZ(m1);
459 		m2->m_next = m1;
460 		m2 = m1;
461 		p = mtod(m1, u_long *);
462 		tlen = 0;
463 		if (putsize) {
464 			*p++ = txdr_unsigned(siz);
465 			m1->m_len -= NFSX_UNSIGNED;
466 			tlen = NFSX_UNSIGNED;
467 			putsize = 0;
468 		}
469 		if (siz < m1->m_len) {
470 			len = nfsm_rndup(siz);
471 			xfer = siz;
472 			if (xfer < len)
473 				*(p+(xfer>>2)) = 0;
474 		} else {
475 			xfer = len = m1->m_len;
476 		}
477 		bcopy(cp, (caddr_t) p, xfer);
478 		m1->m_len = len+tlen;
479 		siz -= xfer;
480 		cp += xfer;
481 	}
482 	*mb = m1;
483 	*bpos = mtod(m1, caddr_t)+m1->m_len;
484 	return(0);
485 }
486 
487 /*
488  * Called once to initialize data structures...
489  */
490 nfs_init()
491 {
492 	register int i;
493 
494 	rpc_vers = txdr_unsigned(RPC_VER2);
495 	rpc_call = txdr_unsigned(RPC_CALL);
496 	rpc_reply = txdr_unsigned(RPC_REPLY);
497 	rpc_msgdenied = txdr_unsigned(RPC_MSGDENIED);
498 	rpc_msgaccepted = txdr_unsigned(RPC_MSGACCEPTED);
499 	rpc_mismatch = txdr_unsigned(RPC_MISMATCH);
500 	rpc_auth_unix = txdr_unsigned(RPCAUTH_UNIX);
501 	nfs_vers = txdr_unsigned(NFS_VER2);
502 	nfs_prog = txdr_unsigned(NFS_PROG);
503 	nfs_true = txdr_unsigned(TRUE);
504 	nfs_false = txdr_unsigned(FALSE);
505 	/* Loop thru nfs procids */
506 	for (i = 0; i < NFS_NPROCS; i++)
507 		nfs_procids[i] = txdr_unsigned(i);
508 	/* Ensure async daemons disabled */
509 	for (i = 0; i < MAX_ASYNCDAEMON; i++)
510 		nfs_iodwant[i] = (struct proc *)0;
511 	v_type[0] = VNON;
512 	v_type[1] = VREG;
513 	v_type[2] = VDIR;
514 	v_type[3] = VBLK;
515 	v_type[4] = VCHR;
516 	v_type[5] = VLNK;
517 	nfs_xdrneg1 = txdr_unsigned(-1);
518 	nfs_nhinit();			/* Init the nfsnode table */
519 	nfsrv_initcache();		/* Init the server request cache */
520 	rminit(nfsmap, (long)NFS_MAPREG, (long)1, "nfs mapreg", NFS_MSIZ);
521 	/* And start timer */
522 	nfs_timer();
523 }
524 
525 /*
526  * Fill in the rest of the rpc_unixauth and return it
527  */
528 static char *nfs_unixauth(cr)
529 	register struct ucred *cr;
530 {
531 	register u_long *p;
532 	register int i;
533 	int ngr;
534 
535 	/* Maybe someday there should be a cache of AUTH_SHORT's */
536 	if ((p = rpc_uidp) == NULL) {
537 #ifdef FILLINHOST
538 		i = nfsm_rndup(hostnamelen)+(19*NFSX_UNSIGNED);
539 #else
540 		i = 19*NFSX_UNSIGNED;
541 #endif
542 		MALLOC(p, u_long *, i, M_TEMP, M_WAITOK);
543 		bzero((caddr_t)p, i);
544 		rpc_unixauth = (caddr_t)p;
545 		*p++ = txdr_unsigned(RPCAUTH_UNIX);
546 		p++;	/* Fill in size later */
547 		*p++ = hostid;
548 #ifdef FILLINHOST
549 		*p++ = txdr_unsigned(hostnamelen);
550 		i = nfsm_rndup(hostnamelen);
551 		bcopy(hostname, (caddr_t)p, hostnamelen);
552 		p += (i>>2);
553 #else
554 		*p++ = 0;
555 #endif
556 		rpc_uidp = p;
557 	}
558 	*p++ = txdr_unsigned(cr->cr_uid);
559 	*p++ = txdr_unsigned(cr->cr_groups[0]);
560 	ngr = (cr->cr_ngroups > numgrps) ? numgrps : cr->cr_ngroups;
561 	*p++ = txdr_unsigned(ngr);
562 	for (i = 0; i < ngr; i++)
563 		*p++ = txdr_unsigned(cr->cr_groups[i]);
564 	/* And add the AUTH_NULL */
565 	*p++ = 0;
566 	*p = 0;
567 	i = (((caddr_t)p)-rpc_unixauth)-12;
568 	p = (u_long *)(rpc_unixauth+4);
569 	*p = txdr_unsigned(i);
570 	return(rpc_unixauth);
571 }
572 
573 /*
574  * Attribute cache routines.
575  * nfs_loadattrcache() - loads or updates the cache contents from attributes
576  *	that are on the mbuf list
577  * nfs_getattrcache() - returns valid attributes if found in cache, returns
578  *	error otherwise
579  */
580 
581 /*
582  * Load the attribute cache (that lives in the nfsnode entry) with
583  * the values on the mbuf list and
584  * Iff vap not NULL
585  *    copy the attributes to *vaper
586  */
587 nfs_loadattrcache(vpp, mdp, dposp, vaper)
588 	struct vnode **vpp;
589 	struct mbuf **mdp;
590 	caddr_t *dposp;
591 	struct vattr *vaper;
592 {
593 	register struct vnode *vp = *vpp;
594 	register struct vattr *vap;
595 	register struct nfsv2_fattr *fp;
596 	extern struct vnodeops spec_nfsv2nodeops;
597 	register struct nfsnode *np;
598 	register long t1;
599 	caddr_t dpos, cp2;
600 	int error = 0;
601 	struct mbuf *md;
602 	enum vtype type;
603 	dev_t rdev;
604 	struct timeval mtime;
605 	struct vnode *nvp;
606 
607 	md = *mdp;
608 	dpos = *dposp;
609 	t1 = (mtod(md, caddr_t)+md->m_len)-dpos;
610 	if (error = nfsm_disct(&md, &dpos, NFSX_FATTR, t1, TRUE, &cp2))
611 		return (error);
612 	fp = (struct nfsv2_fattr *)cp2;
613 	type = nfstov_type(fp->fa_type);
614 	rdev = fxdr_unsigned(dev_t, fp->fa_rdev);
615 	fxdr_time(&fp->fa_mtime, &mtime);
616 	/*
617 	 * If v_type == VNON it is a new node, so fill in the v_type,
618 	 * n_mtime fields. Check to see if it represents a special
619 	 * device, and if so, check for a possible alias. Once the
620 	 * correct vnode has been obtained, fill in the rest of the
621 	 * information.
622 	 */
623 	np = VTONFS(vp);
624 	if (vp->v_type == VNON) {
625 		vp->v_type = type;
626 		if (vp->v_type == VCHR || vp->v_type == VBLK) {
627 			vp->v_op = &spec_nfsv2nodeops;
628 			if (nvp = checkalias(vp, rdev, vp->v_mount)) {
629 				/*
630 				 * Reinitialize aliased node.
631 				 */
632 				np = VTONFS(nvp);
633 				np->n_vnode = nvp;
634 				np->n_flag = 0;
635 				nfs_lock(nvp);
636 				bcopy((caddr_t)&VTONFS(vp)->n_fh,
637 					(caddr_t)&np->n_fh, NFSX_FH);
638 				insque(np, nfs_hash(&np->n_fh));
639 				np->n_attrstamp = 0;
640 				np->n_sillyrename = (struct sillyrename *)0;
641 				/*
642 				 * Discard unneeded vnode and update actual one
643 				 */
644 				vput(vp);
645 				*vpp = nvp;
646 			}
647 		}
648 		np->n_mtime = mtime.tv_sec;
649 	}
650 	vap = &np->n_vattr;
651 	vap->va_type = type;
652 	vap->va_mode = nfstov_mode(fp->fa_mode);
653 	vap->va_nlink = fxdr_unsigned(u_short, fp->fa_nlink);
654 	vap->va_uid = fxdr_unsigned(uid_t, fp->fa_uid);
655 	vap->va_gid = fxdr_unsigned(gid_t, fp->fa_gid);
656 	vap->va_size = fxdr_unsigned(u_long, fp->fa_size);
657 	if ((np->n_flag & NMODIFIED) == 0 || vap->va_size > np->n_size)
658 		np->n_size = vap->va_size;
659 	vap->va_size1 = 0;		/* OR -1 ?? */
660 	vap->va_blocksize = fxdr_unsigned(long, fp->fa_blocksize);
661 	vap->va_rdev = rdev;
662 	vap->va_bytes = fxdr_unsigned(long, fp->fa_blocks) * vap->va_blocksize;
663 	vap->va_bytes1 = 0;
664 	vap->va_fsid = vp->v_mount->m_fsid.val[0];
665 	vap->va_fileid = fxdr_unsigned(long, fp->fa_fileid);
666 	vap->va_atime.tv_sec = fxdr_unsigned(long, fp->fa_atime.tv_sec);
667 	vap->va_atime.tv_usec = 0;
668 	vap->va_flags = fxdr_unsigned(u_long, fp->fa_atime.tv_usec);
669 	vap->va_mtime = mtime;
670 	vap->va_ctime.tv_sec = fxdr_unsigned(long, fp->fa_ctime.tv_sec);
671 	vap->va_ctime.tv_usec = 0;
672 	vap->va_gen = fxdr_unsigned(u_long, fp->fa_ctime.tv_usec);
673 	np->n_attrstamp = time.tv_sec;
674 	*dposp = dpos;
675 	*mdp = md;
676 	if (vaper != NULL) {
677 		bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(*vap));
678 		if ((np->n_flag & NMODIFIED) && (np->n_size > vap->va_size))
679 			vaper->va_size = np->n_size;
680 	}
681 	return (0);
682 }
683 
684 /*
685  * Check the time stamp
686  * If the cache is valid, copy contents to *vap and return 0
687  * otherwise return an error
688  */
689 nfs_getattrcache(vp, vap)
690 	register struct vnode *vp;
691 	struct vattr *vap;
692 {
693 	register struct nfsnode *np;
694 
695 	np = VTONFS(vp);
696 	if ((time.tv_sec-np->n_attrstamp) < NFS_ATTRTIMEO) {
697 		nfsstats.attrcache_hits++;
698 		bcopy((caddr_t)&np->n_vattr,(caddr_t)vap,sizeof(struct vattr));
699 		if ((np->n_flag & NMODIFIED) == 0)
700 			np->n_size = vap->va_size;
701 		else if (np->n_size > vap->va_size)
702 			vap->va_size = np->n_size;
703 		return (0);
704 	} else {
705 		nfsstats.attrcache_misses++;
706 		return (ENOENT);
707 	}
708 }
709 
710 /*
711  * nfs_namei - a liitle like namei(), but for one element only
712  *	essentially look up file handle, fill in ndp and call VOP_LOOKUP()
713  */
714 nfs_namei(ndp, fhp, len, mdp, dposp)
715 	register struct nameidata *ndp;
716 	fhandle_t *fhp;
717 	int len;
718 	struct mbuf **mdp;
719 	caddr_t *dposp;
720 {
721 	register int i, rem;
722 	register struct mbuf *md;
723 	register char *cp;
724 	struct vnode *dp = (struct vnode *)0;
725 	int flag;
726 	int docache;
727 	int wantparent;
728 	int lockparent;
729 	int error = 0;
730 
731 	ndp->ni_vp = ndp->ni_dvp = (struct vnode *)0;
732 	flag = ndp->ni_nameiop & OPFLAG;
733 	wantparent = ndp->ni_nameiop & (LOCKPARENT | WANTPARENT);
734 	lockparent = ndp->ni_nameiop & LOCKPARENT;
735 	docache = (ndp->ni_nameiop & NOCACHE) ^ NOCACHE;
736 	if (flag == DELETE || wantparent)
737 		docache = 0;
738 
739 	/* Fill in the nameidata and call lookup */
740 	cp = *dposp;
741 	md = *mdp;
742 	rem = mtod(md, caddr_t)+md->m_len-cp;
743 	ndp->ni_hash = 0;
744 	for (i = 0; i < len;) {
745 		if (rem == 0) {
746 			md = md->m_next;
747 			if (md == NULL)
748 				return (EBADRPC);
749 			cp = mtod(md, caddr_t);
750 			rem = md->m_len;
751 		}
752 		if (*cp == '\0' || *cp == '/')
753 			return (EINVAL);
754 		if (*cp & 0200)
755 			if ((*cp&0377) == ('/'|0200) || flag != DELETE)
756 				return (EINVAL);
757 		ndp->ni_dent.d_name[i++] = *cp;
758 		ndp->ni_hash += (unsigned char)*cp * i;
759 		cp++;
760 		rem--;
761 	}
762 	*mdp = md;
763 	len = nfsm_rndup(len)-len;
764 	if (len > 0)
765 		*dposp = cp+len;
766 	else
767 		*dposp = cp;
768 	ndp->ni_namelen = i;
769 	ndp->ni_dent.d_namlen = i;
770 	ndp->ni_dent.d_name[i] = '\0';
771 	ndp->ni_pathlen = 1;
772 	ndp->ni_dirp = ndp->ni_ptr = &ndp->ni_dent.d_name[0];
773 	ndp->ni_next = &ndp->ni_dent.d_name[i];
774 	ndp->ni_loopcnt = 0;	/* Not actually used for now */
775 	ndp->ni_endoff = 0;
776 	if (docache)
777 		ndp->ni_makeentry = 1;
778 	else
779 		ndp->ni_makeentry = 0;
780 	ndp->ni_isdotdot = (i == 2 &&
781 		ndp->ni_dent.d_name[1] == '.' && ndp->ni_dent.d_name[0] == '.');
782 
783 	if (error = nfsrv_fhtovp(fhp, TRUE, &dp, ndp->ni_cred))
784 		return (error);
785 	if (dp->v_type != VDIR) {
786 		vput(dp);
787 		return (ENOTDIR);
788 	}
789 	/*
790 	 * Must set current directory here to avoid confusion in namei()
791 	 * called from rename()
792 	 */
793 	ndp->ni_cdir = dp;
794 	ndp->ni_rdir = (struct vnode *)0;
795 
796 	/*
797 	 * Handle "..":
798 	 * If this vnode is the root of the mounted
799 	 *    file system, then ignore it so can't get out
800 	 */
801 	if (ndp->ni_isdotdot && (dp->v_flag & VROOT)) {
802 		ndp->ni_dvp = dp;
803 		ndp->ni_vp = dp;
804 		VREF(dp);
805 		goto nextname;
806 	}
807 
808 	/*
809 	 * We now have a segment name to search for, and a directory to search.
810 	 */
811 	if (error = VOP_LOOKUP(dp, ndp)) {
812 		if (ndp->ni_vp != NULL)
813 			panic("leaf should be empty");
814 		/*
815 		 * If creating and at end of pathname, then can consider
816 		 * allowing file to be created.
817 		 */
818 		if (ndp->ni_dvp->v_mount->m_flag & (M_RDONLY | M_EXRDONLY))
819 			error = EROFS;
820 		if (flag == LOOKUP || flag == DELETE || error != ENOENT)
821 			goto bad;
822 		/*
823 		 * We return with ni_vp NULL to indicate that the entry
824 		 * doesn't currently exist, leaving a pointer to the
825 		 * (possibly locked) directory inode in ndp->ni_dvp.
826 		 */
827 		return (0);	/* should this be ENOENT? */
828 	}
829 
830 	dp = ndp->ni_vp;
831 
832 nextname:
833 	ndp->ni_ptr = ndp->ni_next;
834 	/*
835 	 * Check for read-only file systems
836 	 */
837 	if (flag == DELETE || flag == RENAME) {
838 		/*
839 		 * Disallow directory write attempts on read-only
840 		 * file systems.
841 		 */
842 		if ((dp->v_mount->m_flag & (M_RDONLY|M_EXRDONLY)) ||
843 		    (wantparent && (ndp->ni_dvp->v_mount->m_flag & (M_RDONLY|M_EXRDONLY)))) {
844 			error = EROFS;
845 			goto bad2;
846 		}
847 	}
848 
849 	if (!wantparent)
850 		vrele(ndp->ni_dvp);
851 
852 	if ((ndp->ni_nameiop & LOCKLEAF) == 0)
853 		VOP_UNLOCK(dp);
854 	return (0);
855 
856 bad2:
857 	if (lockparent)
858 		VOP_UNLOCK(ndp->ni_dvp);
859 	vrele(ndp->ni_dvp);
860 bad:
861 	vput(dp);
862 	ndp->ni_vp = NULL;
863 	return (error);
864 }
865 
866 /*
867  * A fiddled version of m_adj() that ensures null fill to a long
868  * boundary and only trims off the back end
869  */
870 nfsm_adj(mp, len, nul)
871 	struct mbuf *mp;
872 	register int len;
873 	int nul;
874 {
875 	register struct mbuf *m;
876 	register int count, i;
877 	register char *cp;
878 
879 	/*
880 	 * Trim from tail.  Scan the mbuf chain,
881 	 * calculating its length and finding the last mbuf.
882 	 * If the adjustment only affects this mbuf, then just
883 	 * adjust and return.  Otherwise, rescan and truncate
884 	 * after the remaining size.
885 	 */
886 	count = 0;
887 	m = mp;
888 	for (;;) {
889 		count += m->m_len;
890 		if (m->m_next == (struct mbuf *)0)
891 			break;
892 		m = m->m_next;
893 	}
894 	if (m->m_len > len) {
895 		m->m_len -= len;
896 		if (nul > 0) {
897 			cp = mtod(m, caddr_t)+m->m_len-nul;
898 			for (i = 0; i < nul; i++)
899 				*cp++ = '\0';
900 		}
901 		return;
902 	}
903 	count -= len;
904 	if (count < 0)
905 		count = 0;
906 	/*
907 	 * Correct length for chain is "count".
908 	 * Find the mbuf with last data, adjust its length,
909 	 * and toss data from remaining mbufs on chain.
910 	 */
911 	for (m = mp; m; m = m->m_next) {
912 		if (m->m_len >= count) {
913 			m->m_len = count;
914 			if (nul > 0) {
915 				cp = mtod(m, caddr_t)+m->m_len-nul;
916 				for (i = 0; i < nul; i++)
917 					*cp++ = '\0';
918 			}
919 			break;
920 		}
921 		count -= m->m_len;
922 	}
923 	while (m = m->m_next)
924 		m->m_len = 0;
925 }
926 
927 /*
928  * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
929  * 	- look up fsid in mount list (if not found ret error)
930  *	- check that it is exported
931  *	- get vp by calling VFS_FHTOVP() macro
932  *	- if not lockflag unlock it with VOP_UNLOCK()
933  *	- if cred->cr_uid == 0 set it to m_exroot
934  */
935 nfsrv_fhtovp(fhp, lockflag, vpp, cred)
936 	fhandle_t *fhp;
937 	int lockflag;
938 	struct vnode **vpp;
939 	struct ucred *cred;
940 {
941 	register struct mount *mp;
942 
943 	if ((mp = getvfs(&fhp->fh_fsid)) == NULL)
944 		return (ESTALE);
945 	if ((mp->m_flag & M_EXPORTED) == 0)
946 		return (EACCES);
947 	if (VFS_FHTOVP(mp, &fhp->fh_fid, vpp))
948 		return (ESTALE);
949 	if (cred->cr_uid == 0)
950 		cred->cr_uid = mp->m_exroot;
951 	if (!lockflag)
952 		VOP_UNLOCK(*vpp);
953 	return (0);
954 }
955