2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 #include <afs/param.h>
23 int cm_deleteReadOnly = 0;
25 /* called with scp write-locked, check to see if we have the ACL info we need
26 * and can get it w/o blocking for any locks.
28 * Never drops the scp lock, but may fail if the access control info comes from
29 * the parent directory, and the parent's scache entry can't be found, or it
30 * can't be locked. Thus, this must always be called in a while loop to stabilize
31 * things, since we can always lose the race condition getting to the parent vnode.
33 int cm_HaveAccessRights(struct cm_scache *scp, struct cm_user *userp, afs_uint32 rights,
34 afs_uint32 *outRightsp)
41 int release = 0; /* Used to avoid a call to cm_HoldSCache in the directory case */
44 if (scp->flags & CM_SCACHEFLAG_EACCESS) {
50 if (scp->fileType == CM_SCACHETYPE_DIRECTORY) {
51 aclScp = scp; /* not held, not released */
53 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
54 aclScp = cm_FindSCache(&tfid);
58 code = lock_TryRead(&aclScp->rw);
60 /* can't get lock safely and easily */
61 cm_ReleaseSCache(aclScp);
65 /* check that we have a callback, too */
66 if (!cm_HaveCallback(aclScp)) {
68 lock_ReleaseRead(&aclScp->rw);
69 cm_ReleaseSCache(aclScp);
77 lock_AssertAny(&aclScp->rw);
79 /* now if rights is a subset of the public rights, we're done.
80 * Otherwise, if we an explicit acl entry, we're also in good shape,
81 * and can definitively answer.
83 #ifdef AFS_FREELANCE_CLIENT
84 if (cm_freelanceEnabled && aclScp == cm_data.rootSCachep)
86 *outRightsp = aclScp->anyAccess;
89 if ((~aclScp->anyAccess & rights) == 0) {
92 /* we have to check the specific rights info */
93 code = cm_FindACLCache(aclScp, userp, &trights);
98 *outRightsp = trights;
101 if (scp->fileType > 0 && scp->fileType != CM_SCACHETYPE_DIRECTORY) {
102 /* check mode bits */
103 if ((scp->unixModeBits & 0400) == 0) {
104 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing READ scp 0x%p unix 0x%x",
105 scp, scp->unixModeBits);
106 *outRightsp &= ~PRSFS_READ;
108 if ((scp->unixModeBits & 0200) == 0 && (rights != (PRSFS_WRITE | PRSFS_LOCK))) {
109 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing WRITE scp 0x%p unix 0%o",
110 scp, scp->unixModeBits);
111 *outRightsp &= ~PRSFS_WRITE;
113 if ((scp->unixModeBits & 0200) == 0 && !cm_deleteReadOnly) {
114 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing DELETE scp 0x%p unix 0%o",
115 scp, scp->unixModeBits);
116 *outRightsp &= ~PRSFS_DELETE;
120 /* if the user can insert, we must assume they can read/write as well
121 * because we do not have the ability to determine if the current user
122 * is the owner of the file. We will have to make the call to the
123 * file server and let the file server tell us if the request should
126 if ((*outRightsp & PRSFS_INSERT) && (scp->creator == userp))
127 *outRightsp |= PRSFS_READ | PRSFS_WRITE;
129 /* if the user can obtain a write-lock, read-locks are implied */
130 if (*outRightsp & PRSFS_WRITE)
131 *outRightsp |= PRSFS_LOCK;
138 lock_ReleaseRead(&aclScp->rw);
140 cm_ReleaseSCache(aclScp);
144 /* called with locked scp; ensures that we have an ACL cache entry for the
145 * user specified by the parameter "userp."
146 * In pathological race conditions, this function may return success without
147 * having loaded the entry properly (due to a racing callback revoke), so this
148 * function must also be called in a while loop to make sure that we eventually
151 long cm_GetAccessRights(struct cm_scache *scp, struct cm_user *userp,
156 cm_scache_t *aclScp = NULL;
159 /* pretty easy: just force a pass through the fetch status code */
161 osi_Log2(afsd_logp, "GetAccess scp 0x%p user 0x%p", scp, userp);
163 /* first, start by finding out whether we have a directory or something
164 * else, so we can find what object's ACL we need.
166 if (scp->fileType == CM_SCACHETYPE_DIRECTORY ) {
167 code = cm_SyncOp(scp, NULL, userp, reqp, 0,
168 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
170 cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
172 /* not a dir, use parent dir's acl */
173 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
174 lock_ReleaseWrite(&scp->rw);
175 code = cm_GetSCache(&tfid, &aclScp, userp, reqp);
177 lock_ObtainWrite(&scp->rw);
181 osi_Log2(afsd_logp, "GetAccess parent scp %x user %x", aclScp, userp);
182 lock_ObtainWrite(&aclScp->rw);
183 code = cm_SyncOp(aclScp, NULL, userp, reqp, 0,
184 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
186 cm_SyncOpDone(aclScp, NULL,
187 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
188 lock_ReleaseWrite(&aclScp->rw);
189 cm_ReleaseSCache(aclScp);
190 lock_ObtainWrite(&scp->rw);