libuafs: return error on symlink to self

[openafs.git] / src / afs / UKERNEL / afs_usrops.c

diff --git a/src/afs/UKERNEL/afs_usrops.c b/src/afs/UKERNEL/afs_usrops.c
index b44e54b..f6195b9 100644 (file)
--- a/src/afs/UKERNEL/afs_usrops.c
+++ b/src/afs/UKERNEL/afs_usrops.c
@@ -412,11 +412,12 @@ get_user_struct(void)
 {
     struct usr_user *uptr;
     int st;
-    st = usr_getspecific(afs_global_u_key, (void **)&uptr);
+
+    st = usr_getspecific(afs_global_u_key, &uptr);
     usr_assert(st == 0);
     if (uptr == NULL) {
        uafs_InitThread();
-       st = usr_getspecific(afs_global_u_key, (void **)&uptr);
+       st = usr_getspecific(afs_global_u_key, &uptr);
        usr_assert(st == 0);
        usr_assert(uptr != NULL);
     }
@@ -1653,6 +1654,77 @@ uafs_RPCStatsClearPeer(void)
 }
 
 /*
+ * Lookup the target of a symbolic link
+ * Call VN_HOLD on the output vnode if successful.
+ * Returns zero on success, error code on failure.
+ * If provided, use a path for confirming we are not linked to ourself.
+ *
+ * Note: Caller must hold the AFS global lock.
+ */
+static int
+uafs_LookupLinkPath(struct usr_vnode *vp, struct usr_vnode *parentVp,
+                   char *ppathP, struct usr_vnode **vpp)
+{
+    int code;
+    int len;
+    char *pathP;
+    struct usr_vnode *linkVp;
+    struct usr_uio uio;
+    struct iovec iov[1];
+
+    AFS_ASSERT_GLOCK();
+
+    pathP = afs_osi_Alloc(MAX_OSI_PATH + 1);
+    usr_assert(pathP != NULL);
+
+    /*
+     * set up the uio buffer
+     */
+    iov[0].iov_base = pathP;
+    iov[0].iov_len = MAX_OSI_PATH + 1;
+    uio.uio_iov = &iov[0];
+    uio.uio_iovcnt = 1;
+    uio.uio_offset = 0;
+    uio.uio_segflg = 0;
+    uio.uio_fmode = FREAD;
+    uio.uio_resid = MAX_OSI_PATH + 1;
+
+    /*
+     * Read the link data
+     */
+    code = afs_readlink(VTOAFS(vp), &uio, get_user_struct()->u_cred);
+    if (code) {
+       afs_osi_Free(pathP, MAX_OSI_PATH + 1);
+       return code;
+    }
+    len = MAX_OSI_PATH + 1 - uio.uio_resid;
+    pathP[len] = '\0';
+
+    /* are we linked to ourname or ./ourname? ELOOP */
+    if (ppathP) {
+       if ((strcmp(pathP, ppathP) == 0) ||
+           ((pathP[0] == '.') &&
+            (pathP[1] == '/') &&
+            (strcmp(&(pathP[2]), ppathP) == 0))) {
+           return ELOOP;
+       }
+    }
+
+    /*
+     * Find the target of the symbolic link
+     */
+    code = uafs_LookupName(pathP, parentVp, &linkVp, 1, 0);
+    if (code) {
+       afs_osi_Free(pathP, MAX_OSI_PATH + 1);
+       return code;
+    }
+
+    afs_osi_Free(pathP, MAX_OSI_PATH + 1);
+    *vpp = linkVp;
+    return 0;
+}
+
+/*
  * Lookup a file or directory given its path.
  * Call VN_HOLD on the output vnode if successful.
  * Returns zero on success, error code on failure.
@@ -1768,7 +1840,7 @@ uafs_LookupName(char *path, struct usr_vnode *parentVp,
                    afs_osi_Free(tmpPath, strlen(path) + 1);
                    return code;
                }
-               code = uafs_LookupLink(nextVp, vp, &linkVp);
+               code = uafs_LookupLinkPath(nextVp, vp, NULL, &linkVp);
                if (code) {
                    VN_RELE(vp);
                    VN_RELE(nextVp);
@@ -1799,64 +1871,11 @@ uafs_LookupName(char *path, struct usr_vnode *parentVp,
     return 0;
 }
 
-/*
- * Lookup the target of a symbolic link
- * Call VN_HOLD on the output vnode if successful.
- * Returns zero on success, error code on failure.
- *
- * Note: Caller must hold the AFS global lock.
- */
 int
 uafs_LookupLink(struct usr_vnode *vp, struct usr_vnode *parentVp,
                struct usr_vnode **vpp)
 {
-    int code;
-    int len;
-    char *pathP;
-    struct usr_vnode *linkVp;
-    struct usr_uio uio;
-    struct iovec iov[1];
-
-    AFS_ASSERT_GLOCK();
-
-    pathP = afs_osi_Alloc(MAX_OSI_PATH + 1);
-    usr_assert(pathP != NULL);
-
-    /*
-     * set up the uio buffer
-     */
-    iov[0].iov_base = pathP;
-    iov[0].iov_len = MAX_OSI_PATH + 1;
-    uio.uio_iov = &iov[0];
-    uio.uio_iovcnt = 1;
-    uio.uio_offset = 0;
-    uio.uio_segflg = 0;
-    uio.uio_fmode = FREAD;
-    uio.uio_resid = MAX_OSI_PATH + 1;
-
-    /*
-     * Read the link data
-     */
-    code = afs_readlink(VTOAFS(vp), &uio, get_user_struct()->u_cred);
-    if (code) {
-       afs_osi_Free(pathP, MAX_OSI_PATH + 1);
-       return code;
-    }
-    len = MAX_OSI_PATH + 1 - uio.uio_resid;
-    pathP[len] = '\0';
-
-    /*
-     * Find the target of the symbolic link
-     */
-    code = uafs_LookupName(pathP, parentVp, &linkVp, 1, 0);
-    if (code) {
-       afs_osi_Free(pathP, MAX_OSI_PATH + 1);
-       return code;
-    }
-
-    afs_osi_Free(pathP, MAX_OSI_PATH + 1);
-    *vpp = linkVp;
-    return 0;
+    return uafs_LookupLinkPath(vp, parentVp, NULL, vpp);
 }
 
 /*
@@ -3590,34 +3609,6 @@ uafs_closedir_r(usr_DIR * dirp)
 }
 
 /*
- * Do AFS authentication
- */
-int
-uafs_klog(char *user, char *cell, char *passwd, char **reason)
-{
-    int code;
-    afs_int32 password_expires = -1;
-
-    usr_mutex_lock(&osi_authenticate_lock);
-    code =
-       ka_UserAuthenticateGeneral(KA_USERAUTH_VERSION +
-                                  KA_USERAUTH_DOSETPAG2, user, NULL, cell,
-                                  passwd, 0, &password_expires, 0, reason);
-    usr_mutex_unlock(&osi_authenticate_lock);
-    return code;
-}
-
-int
-uafs_klog_r(char *user, char *cell, char *passwd, char **reason)
-{
-    int retval;
-    AFS_GUNLOCK();
-    retval = uafs_klog(user, cell, passwd, reason);
-    AFS_GLOCK();
-    return retval;
-}
-
-/*
  * Destroy AFS credentials from the kernel cache
  */
 int
@@ -3681,25 +3672,6 @@ uafs_afsPathName(char *path)
 }
 
 /*
- * uafs_klog_nopag
- * klog but don't allocate a new pag
- */
-int
-uafs_klog_nopag(char *user, char *cell, char *passwd, char **reason)
-{
-    int code;
-    afs_int32 password_expires = -1;
-
-    usr_mutex_lock(&osi_authenticate_lock);
-    code = ka_UserAuthenticateGeneral(KA_USERAUTH_VERSION
-                                     /*+KA_USERAUTH_DOSETPAG2 */ , user,
-                                     NULL, cell, passwd, 0,
-                                     &password_expires, 0, reason);
-    usr_mutex_unlock(&osi_authenticate_lock);
-    return code;
-}
-
-/*
  * uafs_getcellstatus
  * get the cell status
  */