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>
22 int cm_deleteReadOnly = 0;
24 /* called with scp write-locked, check to see if we have the ACL info we need
25 * and can get it w/o blocking for any locks.
27 * Never drops the scp lock, but may fail if the access control info comes from
28 * the parent directory, and the parent's scache entry can't be found, or it
29 * can't be locked. Thus, this must always be called in a while loop to stabilize
30 * things, since we can always lose the race condition getting to the parent vnode.
32 int cm_HaveAccessRights(struct cm_scache *scp, struct cm_user *userp, afs_uint32 rights,
33 afs_uint32 *outRightsp)
40 int release = 0; /* Used to avoid a call to cm_HoldSCache in the directory case */
43 if (scp->fileType == CM_SCACHETYPE_DIRECTORY) {
44 aclScp = scp; /* not held, not released */
46 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
47 aclScp = cm_FindSCache(&tfid);
51 if (aclScp->fid.vnode < scp->fid.vnode)
52 lock_ReleaseWrite(&scp->rw);
53 lock_ObtainRead(&aclScp->rw);
54 if (aclScp->fid.vnode < scp->fid.vnode)
55 lock_ObtainWrite(&scp->rw);
57 /* check that we have a callback, too */
58 if (!cm_HaveCallback(aclScp)) {
60 lock_ReleaseRead(&aclScp->rw);
61 cm_ReleaseSCache(aclScp);
69 lock_AssertAny(&aclScp->rw);
71 /* now if rights is a subset of the public rights, we're done.
72 * Otherwise, if we an explicit acl entry, we're also in good shape,
73 * and can definitively answer.
75 #ifdef AFS_FREELANCE_CLIENT
76 if (cm_freelanceEnabled && aclScp == cm_data.rootSCachep)
78 *outRightsp = aclScp->anyAccess;
81 if ((~aclScp->anyAccess & rights) == 0) {
84 /* we have to check the specific rights info */
85 code = cm_FindACLCache(aclScp, userp, &trights);
90 *outRightsp = trights;
93 if (scp->fileType > 0 && scp->fileType != CM_SCACHETYPE_DIRECTORY) {
95 if ((scp->unixModeBits & 0400) == 0) {
96 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing READ scp 0x%p unix 0x%x",
97 scp, scp->unixModeBits);
98 *outRightsp &= ~PRSFS_READ;
100 if ((scp->unixModeBits & 0200) == 0 && (rights != (PRSFS_WRITE | PRSFS_LOCK))) {
101 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing WRITE scp 0x%p unix 0%o",
102 scp, scp->unixModeBits);
103 *outRightsp &= ~PRSFS_WRITE;
105 if ((scp->unixModeBits & 0200) == 0 && !cm_deleteReadOnly) {
106 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing DELETE scp 0x%p unix 0%o",
107 scp, scp->unixModeBits);
108 *outRightsp &= ~PRSFS_DELETE;
112 /* if the user can insert, we must assume they can read/write as well
113 * because we do not have the ability to determine if the current user
114 * is the owner of the file. We will have to make the call to the
115 * file server and let the file server tell us if the request should
118 if ((*outRightsp & PRSFS_INSERT) && (scp->creator == userp))
119 *outRightsp |= PRSFS_READ | PRSFS_WRITE;
121 /* if the user can obtain a write-lock, read-locks are implied */
122 if (*outRightsp & PRSFS_WRITE)
123 *outRightsp |= PRSFS_LOCK;
130 lock_ReleaseRead(&aclScp->rw);
132 cm_ReleaseSCache(aclScp);
136 /* called with locked scp; ensures that we have an ACL cache entry for the
137 * user specified by the parameter "userp."
138 * In pathological race conditions, this function may return success without
139 * having loaded the entry properly (due to a racing callback revoke), so this
140 * function must also be called in a while loop to make sure that we eventually
143 long cm_GetAccessRights(struct cm_scache *scp, struct cm_user *userp,
148 cm_scache_t *aclScp = NULL;
151 /* pretty easy: just force a pass through the fetch status code */
153 osi_Log2(afsd_logp, "GetAccessRights scp 0x%p user 0x%p", scp, userp);
155 /* first, start by finding out whether we have a directory or something
156 * else, so we can find what object's ACL we need.
158 if (scp->fileType == CM_SCACHETYPE_DIRECTORY ) {
159 code = cm_SyncOp(scp, NULL, userp, reqp, 0,
160 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
162 cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
164 osi_Log3(afsd_logp, "GetAccessRights syncop failure scp %x user %x code %x", scp, userp, code);
166 /* not a dir, use parent dir's acl */
167 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
168 lock_ReleaseWrite(&scp->rw);
169 code = cm_GetSCache(&tfid, &aclScp, userp, reqp);
171 lock_ObtainWrite(&scp->rw);
175 osi_Log2(afsd_logp, "GetAccessRights parent scp %x user %x", aclScp, userp);
176 lock_ObtainWrite(&aclScp->rw);
177 code = cm_SyncOp(aclScp, NULL, userp, reqp, 0,
178 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
180 cm_SyncOpDone(aclScp, NULL,
181 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
183 osi_Log3(afsd_logp, "GetAccessRights parent syncop failure scp %x user %x code %x", aclScp, userp, code);
184 lock_ReleaseWrite(&aclScp->rw);
185 cm_ReleaseSCache(aclScp);
186 lock_ObtainWrite(&scp->rw);