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;
23 int cm_accessPerFileCheck = 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->fileType == CM_SCACHETYPE_DIRECTORY || cm_accessPerFileCheck) {
45 aclScp = scp; /* not held, not released */
47 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
48 aclScp = cm_FindSCache(&tfid);
52 if (aclScp->fid.vnode < scp->fid.vnode)
53 lock_ReleaseWrite(&scp->rw);
54 lock_ObtainRead(&aclScp->rw);
55 if (aclScp->fid.vnode < scp->fid.vnode)
56 lock_ObtainWrite(&scp->rw);
58 /* check that we have a callback, too */
59 if (!cm_HaveCallback(aclScp)) {
61 lock_ReleaseRead(&aclScp->rw);
62 cm_ReleaseSCache(aclScp);
70 lock_AssertAny(&aclScp->rw);
72 /* now if rights is a subset of the public rights, we're done.
73 * Otherwise, if we an explicit acl entry, we're also in good shape,
74 * and can definitively answer.
76 #ifdef AFS_FREELANCE_CLIENT
77 if (cm_freelanceEnabled && aclScp == cm_data.rootSCachep)
79 *outRightsp = aclScp->anyAccess;
82 if ((~aclScp->anyAccess & rights) == 0) {
85 /* we have to check the specific rights info */
86 code = cm_FindACLCache(aclScp, userp, &trights);
91 *outRightsp = trights;
94 if (scp->fileType > 0 && scp->fileType != CM_SCACHETYPE_DIRECTORY) {
96 if ((scp->unixModeBits & 0400) == 0) {
97 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing READ scp 0x%p unix 0x%x",
98 scp, scp->unixModeBits);
99 *outRightsp &= ~PRSFS_READ;
101 if ((scp->unixModeBits & 0200) == 0 && (rights != (PRSFS_WRITE | PRSFS_LOCK))) {
102 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing WRITE scp 0x%p unix 0%o",
103 scp, scp->unixModeBits);
104 *outRightsp &= ~PRSFS_WRITE;
106 if ((scp->unixModeBits & 0200) == 0 && !cm_deleteReadOnly) {
107 osi_Log2(afsd_logp,"cm_HaveAccessRights UnixMode removing DELETE scp 0x%p unix 0%o",
108 scp, scp->unixModeBits);
109 *outRightsp &= ~PRSFS_DELETE;
113 /* if the user can insert, we must assume they can read/write as well
114 * because we do not have the ability to determine if the current user
115 * is the owner of the file. We will have to make the call to the
116 * file server and let the file server tell us if the request should
119 if ((*outRightsp & PRSFS_INSERT) && (scp->creator == userp))
120 *outRightsp |= PRSFS_READ | PRSFS_WRITE;
122 /* if the user can obtain a write-lock, read-locks are implied */
123 if (*outRightsp & PRSFS_WRITE)
124 *outRightsp |= PRSFS_LOCK;
131 lock_ReleaseRead(&aclScp->rw);
133 cm_ReleaseSCache(aclScp);
137 /* called with locked scp; ensures that we have an ACL cache entry for the
138 * user specified by the parameter "userp."
139 * In pathological race conditions, this function may return success without
140 * having loaded the entry properly (due to a racing callback revoke), so this
141 * function must also be called in a while loop to make sure that we eventually
144 long cm_GetAccessRights(struct cm_scache *scp, struct cm_user *userp,
149 cm_scache_t *aclScp = NULL;
152 /* pretty easy: just force a pass through the fetch status code */
154 osi_Log2(afsd_logp, "GetAccessRights scp 0x%p user 0x%p", scp, userp);
156 /* first, start by finding out whether we have a directory or something
157 * else, so we can find what object's ACL we need.
159 if (scp->fileType == CM_SCACHETYPE_DIRECTORY || cm_accessPerFileCheck) {
160 code = cm_SyncOp(scp, NULL, userp, reqp, 0,
161 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
163 cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
165 osi_Log3(afsd_logp, "GetAccessRights syncop failure scp %x user %x code %x", scp, userp, code);
167 /* not a dir, use parent dir's acl */
168 cm_SetFid(&tfid, scp->fid.cell, scp->fid.volume, scp->parentVnode, scp->parentUnique);
169 lock_ReleaseWrite(&scp->rw);
170 code = cm_GetSCache(&tfid, &aclScp, userp, reqp);
172 lock_ObtainWrite(&scp->rw);
176 osi_Log2(afsd_logp, "GetAccessRights parent scp %x user %x", aclScp, userp);
177 lock_ObtainWrite(&aclScp->rw);
178 code = cm_SyncOp(aclScp, NULL, userp, reqp, 0,
179 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS | CM_SCACHESYNC_FORCECB);
181 cm_SyncOpDone(aclScp, NULL,
182 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS);
184 osi_Log3(afsd_logp, "GetAccessRights parent syncop failure scp %x user %x code %x", aclScp, userp, code);
185 lock_ReleaseWrite(&aclScp->rw);
186 cm_ReleaseSCache(aclScp);
187 lock_ObtainWrite(&scp->rw);