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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /* $NetBSD: umap_subr.c,v 1.4 1994/09/20 06:43:02 cgd Exp $ */
23:
24: /*
25: * Copyright (c) 1992, 1993
26: * The Regents of the University of California. All rights reserved.
27: *
28: * This code is derived from software donated to Berkeley by
29: * Jan-Simon Pendry.
30: *
31: * Redistribution and use in source and binary forms, with or without
32: * modification, are permitted provided that the following conditions
33: * are met:
34: * 1. Redistributions of source code must retain the above copyright
35: * notice, this list of conditions and the following disclaimer.
36: * 2. Redistributions in binary form must reproduce the above copyright
37: * notice, this list of conditions and the following disclaimer in the
38: * documentation and/or other materials provided with the distribution.
39: * 3. All advertising materials mentioning features or use of this software
40: * must display the following acknowledgement:
41: * This product includes software developed by the University of
42: * California, Berkeley and its contributors.
43: * 4. Neither the name of the University nor the names of its contributors
44: * may be used to endorse or promote products derived from this software
45: * without specific prior written permission.
46: *
47: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
48: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
51: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57: * SUCH DAMAGE.
58: *
59: * from: Id: lofs_subr.c, v 1.11 1992/05/30 10:05:43 jsp Exp
60: * @(#)umap_subr.c 8.6 (Berkeley) 1/26/94
61: */
62:
63: #include <sys/param.h>
64: #include <sys/systm.h>
65: #include <sys/time.h>
66: #include <sys/types.h>
67: #include <sys/vnode.h>
68: #include <sys/mount.h>
69: #include <sys/namei.h>
70: #include <sys/malloc.h>
71: #include <miscfs/specfs/specdev.h>
72: #include <miscfs/umapfs/umap.h>
73:
74: #define LOG2_SIZEVNODE 7 /* log2(sizeof struct vnode) */
75: #define NUMAPNODECACHE 16
76:
77: /*
78: * Null layer cache:
79: * Each cache entry holds a reference to the target vnode
80: * along with a pointer to the alias vnode. When an
81: * entry is added the target vnode is VREF'd. When the
82: * alias is removed the target vnode is vrele'd.
83: */
84:
85: #define UMAP_NHASH(vp) \
86: (&umap_node_hashtbl[(((u_long)vp)>>LOG2_SIZEVNODE) & umap_node_hash])
87: LIST_HEAD(umap_node_hashhead, umap_node) *umap_node_hashtbl;
88: u_long umap_node_hash;
89:
90: /*
91: * Initialise cache headers
92: */
93: umapfs_init()
94: {
95:
96: #ifdef UMAPFS_DIAGNOSTIC
97: printf("umapfs_init\n"); /* printed during system boot */
98: #endif
99: umap_node_hashtbl = hashinit(NUMAPNODECACHE, M_CACHE, &umap_node_hash);
100: }
101:
102: /*
103: * umap_findid is called by various routines in umap_vnodeops.c to
104: * find a user or group id in a map.
105: */
106: static u_long
107: umap_findid(id, map, nentries)
108: u_long id;
109: u_long map[][2];
110: int nentries;
111: {
112: int i;
113:
114: /* Find uid entry in map */
115: i = 0;
116: while ((i<nentries) && ((map[i][0]) != id))
117: i++;
118:
119: if (i < nentries)
120: return (map[i][1]);
121: else
122: return (-1);
123:
124: }
125:
126: /*
127: * umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
128: * find a user or group id in a map, in reverse.
129: */
130: u_long
131: umap_reverse_findid(id, map, nentries)
132: u_long id;
133: u_long map[][2];
134: int nentries;
135: {
136: int i;
137:
138: /* Find uid entry in map */
139: i = 0;
140: while ((i<nentries) && ((map[i][1]) != id))
141: i++;
142:
143: if (i < nentries)
144: return (map[i][0]);
145: else
146: return (-1);
147:
148: }
149:
150: /*
151: * Return alias for target vnode if already exists, else 0.
152: */
153: static struct vnode *
154: umap_node_find(mp, targetvp)
155: struct mount *mp;
156: struct vnode *targetvp;
157: {
158: struct umap_node_hashhead *hd;
159: struct umap_node *a;
160: struct vnode *vp;
161:
162: #ifdef UMAPFS_DIAGNOSTIC
163: printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp);
164: #endif
165:
166: /*
167: * Find hash base, and then search the (two-way) linked
168: * list looking for a umap_node structure which is referencing
169: * the target vnode. If found, the increment the umap_node
170: * reference count (but NOT the target vnode's VREF counter).
171: */
172: hd = UMAP_NHASH(targetvp);
173: loop:
174: for (a = hd->lh_first; a != 0; a = a->umap_hash.le_next) {
175: if (a->umap_lowervp == targetvp &&
176: a->umap_vnode->v_mount == mp) {
177: vp = UMAPTOV(a);
178: /*
179: * We need vget for the VXLOCK
180: * stuff, but we don't want to lock
181: * the lower node.
182: */
183: if (vget(vp, 0)) {
184: #ifdef UMAPFS_DIAGNOSTIC
185: printf ("umap_node_find: vget failed.\n");
186: #endif
187: goto loop;
188: }
189: return (vp);
190: }
191: }
192:
193: #ifdef UMAPFS_DIAGNOSTIC
194: printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp);
195: #endif
196:
197: return (0);
198: }
199:
200: /*
201: * Make a new umap_node node.
202: * Vp is the alias vnode, lowervp is the target vnode.
203: * Maintain a reference to lowervp.
204: */
205: static int
206: umap_node_alloc(mp, lowervp, vpp)
207: struct mount *mp;
208: struct vnode *lowervp;
209: struct vnode **vpp;
210: {
211: struct umap_node_hashhead *hd;
212: struct umap_node *xp;
213: struct vnode *vp, *nvp;
214: int error;
215: extern int (**dead_vnodeop_p)();
216: struct specinfo *sp = (struct specinfo *)0;
217:
218: if (lowervp->v_type == VBLK || lowervp->v_type == VCHR)
219: MALLOC_ZONE(sp, struct specinfo *, sizeof(struct specinfo),
220: M_VNODE, M_WAITOK);
221:
222: MALLOC(xp, struct umap_node *, sizeof(struct umap_node), M_TEMP,
223: M_WAITOK);
224: if (error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, &vp)) {
225: FREE(xp, M_TEMP);
226: if (sp)
227: FREE_ZONE(sp, sizeof (struct specinfo), M_VNODE);
228: return (error);
229: }
230: vp->v_type = lowervp->v_type;
231:
232: if (vp->v_type == VBLK || vp->v_type == VCHR) {
233: vp->v_specinfo = sp;
234: vp->v_rdev = lowervp->v_rdev;
235: }
236:
237: vp->v_data = xp;
238: xp->umap_vnode = vp;
239: xp->umap_lowervp = lowervp;
240: /*
241: * Before we insert our new node onto the hash chains,
242: * check to see if someone else has beaten us to it.
243: */
244: if (nvp = umap_node_find(lowervp)) {
245: *vpp = nvp;
246:
247: /* free the substructures we've allocated. */
248: FREE(xp, M_TEMP);
249: if (sp) {
250: vp->v_specinfo = (struct specinfo *)0;
251: FREE_ZONE(sp, sizeof (struct specinfo), M_VNODE);
252: }
253:
254: vp->v_type = VBAD; /* node is discarded */
255: vp->v_op = dead_vnodeop_p; /* so ops will still work */
256: vrele(vp); /* get rid of it. */
257: return (0);
258: }
259:
260: /*
261: * XXX if it's a device node, it needs to be checkalias()ed.
262: * however, for locking reasons, that's just not possible.
263: * so we have to do most of the dirty work inline. Note that
264: * this is a limited case; we know that there's going to be
265: * an alias, and we know that that alias will be a "real"
266: * device node, i.e. not tagged VT_NON.
267: */
268: if (vp->v_type == VBLK || vp->v_type == VCHR) {
269: struct vnode *cvp, **cvpp;
270:
271: cvpp = &speclisth[SPECHASH(vp->v_rdev)];
272: loop:
273: for (cvp = *cvpp; cvp; cvp = cvp->v_specnext) {
274: if (vp->v_rdev != cvp->v_rdev ||
275: vp->v_type != cvp->v_type)
276: continue;
277:
278: /*
279: * Alias, but not in use, so flush it out.
280: */
281: if (cvp->v_usecount == 0) {
282: vgone(cvp);
283: goto loop;
284: }
285: if (vget(cvp, 0)) /* can't lock; will die! */
286: goto loop;
287: break;
288: }
289:
290: vp->v_hashchain = cvpp;
291: vp->v_specnext = *cvpp;
292: vp->v_specflags = 0;
293: *cvpp = vp;
294: #if DIAGNOSTIC
295: if (cvp == NULLVP)
296: panic("umap_node_alloc: no alias for device");
297: #endif
298: vp->v_flag |= VALIASED;
299: cvp->v_flag |= VALIASED;
300: vrele(cvp);
301: }
302: /* XXX end of transmogrified checkalias() */
303:
304: *vpp = vp;
305: VREF(lowervp); /* Extra VREF will be vrele'd in umap_node_create */
306: hd = UMAP_NHASH(lowervp);
307: LIST_INSERT_HEAD(hd, xp, umap_hash);
308: return (0);
309: }
310:
311:
312: /*
313: * Try to find an existing umap_node vnode refering
314: * to it, otherwise make a new umap_node vnode which
315: * contains a reference to the target vnode.
316: */
317: int
318: umap_node_create(mp, targetvp, newvpp)
319: struct mount *mp;
320: struct vnode *targetvp;
321: struct vnode **newvpp;
322: {
323: struct vnode *aliasvp;
324:
325: if (aliasvp = umap_node_find(mp, targetvp)) {
326: /*
327: * Take another reference to the alias vnode
328: */
329: #ifdef UMAPFS_DIAGNOSTIC
330: vprint("umap_node_create: exists", ap->umap_vnode);
331: #endif
332: /* VREF(aliasvp); */
333: } else {
334: int error;
335:
336: /*
337: * Get new vnode.
338: */
339: #ifdef UMAPFS_DIAGNOSTIC
340: printf("umap_node_create: create new alias vnode\n");
341: #endif
342: /*
343: * Make new vnode reference the umap_node.
344: */
345: if (error = umap_node_alloc(mp, targetvp, &aliasvp))
346: return (error);
347:
348: /*
349: * aliasvp is already VREF'd by getnewvnode()
350: */
351: }
352:
353: vrele(targetvp);
354:
355: #ifdef UMAPFS_DIAGNOSTIC
356: vprint("umap_node_create: alias", aliasvp);
357: vprint("umap_node_create: target", targetvp);
358: #endif
359:
360: *newvpp = aliasvp;
361: return (0);
362: }
363:
364: #ifdef UMAPFS_DIAGNOSTIC
365: int umap_checkvp_barrier = 1;
366: struct vnode *
367: umap_checkvp(vp, fil, lno)
368: struct vnode *vp;
369: char *fil;
370: int lno;
371: {
372: struct umap_node *a = VTOUMAP(vp);
373: #if 0
374: /*
375: * Can't do this check because vop_reclaim runs
376: * with funny vop vector.
377: */
378: if (vp->v_op != umap_vnodeop_p) {
379: printf ("umap_checkvp: on non-umap-node\n");
380: while (umap_checkvp_barrier) /*WAIT*/ ;
381: panic("umap_checkvp");
382: }
383: #endif
384: if (a->umap_lowervp == NULL) {
385: /* Should never happen */
386: int i; u_long *p;
387: printf("vp = %x, ZERO ptr\n", vp);
388: for (p = (u_long *) a, i = 0; i < 8; i++)
389: printf(" %x", p[i]);
390: printf("\n");
391: /* wait for debugger */
392: while (umap_checkvp_barrier) /*WAIT*/ ;
393: panic("umap_checkvp");
394: }
395: if (a->umap_lowervp->v_usecount < 1) {
396: int i; u_long *p;
397: printf("vp = %x, unref'ed lowervp\n", vp);
398: for (p = (u_long *) a, i = 0; i < 8; i++)
399: printf(" %x", p[i]);
400: printf("\n");
401: /* wait for debugger */
402: while (umap_checkvp_barrier) /*WAIT*/ ;
403: panic ("umap with unref'ed lowervp");
404: }
405: #if 0
406: printf("umap %x/%d -> %x/%d [%s, %d]\n",
407: a->umap_vnode, a->umap_vnode->v_usecount,
408: a->umap_lowervp, a->umap_lowervp->v_usecount,
409: fil, lno);
410: #endif
411: return (a->umap_lowervp);
412: }
413: #endif
414:
415: /* umap_mapids maps all of the ids in a credential, both user and group. */
416:
417: void
418: umap_mapids(v_mount, credp)
419: struct mount *v_mount;
420: struct ucred *credp;
421: {
422: int i, unentries, gnentries;
423: uid_t uid, *usermap;
424: gid_t gid, *groupmap;
425:
426: unentries = MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
427: usermap = &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]);
428: gnentries = MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
429: groupmap = &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]);
430:
431: /* Find uid entry in map */
432:
433: uid = (uid_t) umap_findid(credp->cr_uid, usermap, unentries);
434:
435: if (uid != -1)
436: credp->cr_uid = uid;
437: else
438: credp->cr_uid = (uid_t) NOBODY;
439:
440: #ifdef notdef
441: /* cr_gid is the same as cr_groups[0] in 4BSD */
442:
443: /* Find gid entry in map */
444:
445: gid = (gid_t) umap_findid(credp->cr_gid, groupmap, gnentries);
446:
447: if (gid != -1)
448: credp->cr_gid = gid;
449: else
450: credp->cr_gid = NULLGROUP;
451: #endif
452:
453: /* Now we must map each of the set of groups in the cr_groups
454: structure. */
455:
456: i = 0;
457: while (credp->cr_groups[i] != 0) {
458: gid = (gid_t) umap_findid(credp->cr_groups[i],
459: groupmap, gnentries);
460:
461: if (gid != -1)
462: credp->cr_groups[i++] = gid;
463: else
464: credp->cr_groups[i++] = NULLGROUP;
465: }
466: }
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