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 <afsconfig.h>
11 #include <afs/param.h>
25 int cm_deleteReadOnly = 0;
26 int cm_accessPerFileCheck = 0;
28 /* called with scp write-locked, check to see if we have the ACL info we need
29 * and can get it w/o blocking for any locks.
31 * Never drops the scp lock, but may fail if the access control info comes from
32 * the parent directory, and the parent's scache entry can't be found, or it
33 * can't be locked. Thus, this must always be called in a while loop to stabilize
34 * things, since we can always lose the race condition getting to the parent vnode.
36 int cm_HaveAccessRights(struct cm_scache *scp, struct cm_user *userp, afs_uint32 rights,
37 afs_uint32 *outRightsp)
44 int release = 0; /* Used to avoid a call to cm_HoldSCache in the directory case */
47 if (scp->fileType == CM_SCACHETYPE_DIRECTORY || cm_accessPerFileCheck) {
48 aclScp = scp; /* not held, not released */
50 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
51 aclScp = cm_FindSCache(&tfid);
55 if (aclScp->fid.vnode < scp->fid.vnode)
56 lock_ReleaseWrite(&scp->rw);
57 lock_ObtainRead(&aclScp->rw);
58 if (aclScp->fid.vnode < scp->fid.vnode)
59 lock_ObtainWrite(&scp->rw);
61 /* check that we have a callback, too */
62 if (!cm_HaveCallback(aclScp)) {
64 lock_ReleaseRead(&aclScp->rw);
65 cm_ReleaseSCache(aclScp);
73 lock_AssertAny(&aclScp->rw);
75 /* now if rights is a subset of the public rights, we're done.
76 * Otherwise, if we an explicit acl entry, we're also in good shape,
77 * and can definitively answer.
79 #ifdef AFS_FREELANCE_CLIENT
80 if (cm_freelanceEnabled && aclScp == cm_data.rootSCachep)
82 *outRightsp = aclScp->anyAccess;
85 if ((~aclScp->anyAccess & rights) == 0) {
88 /* we have to check the specific rights info */
89 code = cm_FindACLCache(aclScp, userp, &trights);
94 *outRightsp = trights;
97 if (scp->fileType > 0 && scp->fileType != CM_SCACHETYPE_DIRECTORY) {
99 if ((scp->unixModeBits & 0400) == 0) {
100 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing READ scp 0x%p unix 0%o",
101 scp, scp->unixModeBits);
102 *outRightsp &= ~PRSFS_READ;
104 if ((scp->unixModeBits & 0200) == 0 && (rights != (PRSFS_WRITE | PRSFS_LOCK))) {
105 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing WRITE scp 0x%p unix 0%o",
106 scp, scp->unixModeBits);
107 *outRightsp &= ~PRSFS_WRITE;
109 if ((scp->unixModeBits & 0200) == 0 && !cm_deleteReadOnly) {
110 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing DELETE scp 0x%p unix 0%o",
111 scp, scp->unixModeBits);
112 *outRightsp &= ~PRSFS_DELETE;
116 /* if the user can insert, we must assume they can read/write as well
117 * because we do not have the ability to determine if the current user
118 * is the owner of the file. We will have to make the call to the
119 * file server and let the file server tell us if the request should
122 if ((*outRightsp & PRSFS_INSERT) && (scp->creator == userp))
123 *outRightsp |= PRSFS_READ | PRSFS_WRITE;
125 /* if the user can obtain a write-lock, read-locks are implied */
126 if (*outRightsp & PRSFS_WRITE)
127 *outRightsp |= PRSFS_LOCK;
134 lock_ReleaseRead(&aclScp->rw);
136 cm_ReleaseSCache(aclScp);
140 /* called with locked scp; ensures that we have an ACL cache entry for the
141 * user specified by the parameter "userp."
142 * In pathological race conditions, this function may return success without
143 * having loaded the entry properly (due to a racing callback revoke), so this
144 * function must also be called in a while loop to make sure that we eventually
147 long cm_GetAccessRights(struct cm_scache *scp, struct cm_user *userp,
152 cm_scache_t *aclScp = NULL;
155 /* pretty easy: just force a pass through the fetch status code */
157 osi_Log2(afsd_logp, "GetAccessRights scp 0x%p user 0x%p", scp, userp);
159 /* first, start by finding out whether we have a directory or something
160 * else, so we can find what object's ACL we need.
162 if (scp->fileType == CM_SCACHETYPE_DIRECTORY || cm_accessPerFileCheck) {
163 code = cm_SyncOp(scp, NULL, userp, reqp, 0,
164 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
166 cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
168 osi_Log3(afsd_logp, "GetAccessRights syncop failure scp %x user %x code %x", scp, userp, code);
170 /* not a dir, use parent dir's acl */
171 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
172 lock_ReleaseWrite(&scp->rw);
173 code = cm_GetSCache(&tfid, &aclScp, userp, reqp);
175 lock_ObtainWrite(&scp->rw);
179 osi_Log2(afsd_logp, "GetAccessRights parent scp %x user %x", aclScp, userp);
180 lock_ObtainWrite(&aclScp->rw);
181 code = cm_SyncOp(aclScp, NULL, userp, reqp, 0,
182 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
184 cm_SyncOpDone(aclScp, NULL,
185 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
187 osi_Log3(afsd_logp, "GetAccessRights parent syncop failure scp %x user %x code %x", aclScp, userp, code);
188 lock_ReleaseWrite(&aclScp->rw);
189 cm_ReleaseSCache(aclScp);
190 lock_ObtainWrite(&scp->rw);