s3: VFS: ceph: Add vfswrap_ceph_read_dfs_pathat().

Not yet used.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14282

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
(cherry picked from commit e52e2135dd9b8bd2e65261c210e7b8d36a727396)

diff --git a/source3/modules/vfs_ceph.c b/source3/modules/vfs_ceph.c
index 3526cbe0f6db0fae198f4a5cd9bb19444cab244a..76393a84152e60035606934bd47c5ea6bf2284c2 100644 (file)
--- a/source3/modules/vfs_ceph.c
+++ b/source3/modules/vfs_ceph.c
@@ -1331,6 +1331,105 @@ static NTSTATUS cephwrap_create_dfs_pathat(struct vfs_handle_struct *handle,
        return status;
 }
 
+/*
+ * Read and return the contents of a DFS redirect given a
+ * pathname. A caller can pass in NULL for ppreflist and
+ * preferral_count but still determine if this was a
+ * DFS redirect point by getting NT_STATUS_OK back
+ * without incurring the overhead of reading and parsing
+ * the referral contents.
+ */
+
+static NTSTATUS cephwrap_read_dfs_pathat(struct vfs_handle_struct *handle,
+                               TALLOC_CTX *mem_ctx,
+                               struct files_struct *dirfsp,
+                               const struct smb_filename *smb_fname,
+                               struct referral **ppreflist,
+                               size_t *preferral_count)
+{
+       NTSTATUS status = NT_STATUS_NO_MEMORY;
+       size_t bufsize;
+       char *link_target = NULL;
+       int referral_len;
+       bool ok;
+#if defined(HAVE_BROKEN_READLINK)
+       char link_target_buf[PATH_MAX];
+#else
+       char link_target_buf[7];
+#endif
+
+       SMB_ASSERT(dirfsp == dirfsp->conn->cwd_fsp);
+
+       if (ppreflist == NULL && preferral_count == NULL) {
+               /*
+                * We're only checking if this is a DFS
+                * redirect. We don't need to return data.
+                */
+               bufsize = sizeof(link_target_buf);
+               link_target = link_target_buf;
+       } else {
+               bufsize = PATH_MAX;
+               link_target = talloc_array(mem_ctx, char, bufsize);
+               if (!link_target) {
+                       goto err;
+               }
+       }
+
+        referral_len = ceph_readlink(handle->data,
+                                smb_fname->base_name,
+                                link_target,
+                                bufsize - 1);
+        if (referral_len < 0) {
+               /* ceph errors are -errno. */
+               if (-referral_len == EINVAL) {
+                       DBG_INFO("%s is not a link.\n",
+                               smb_fname->base_name);
+                       status = NT_STATUS_OBJECT_TYPE_MISMATCH;
+               } else {
+                       status = map_nt_error_from_unix(-referral_len);
+                       DBG_ERR("Error reading "
+                               "msdfs link %s: %s\n",
+                               smb_fname->base_name,
+                       strerror(errno));
+               }
+                goto err;
+        }
+        link_target[referral_len] = '\0';
+
+        DBG_INFO("%s -> %s\n",
+                        smb_fname->base_name,
+                        link_target);
+
+        if (!strnequal(link_target, "msdfs:", 6)) {
+                status = NT_STATUS_OBJECT_TYPE_MISMATCH;
+                goto err;
+        }
+
+        if (ppreflist == NULL && preferral_count == NULL) {
+                /* Early return for checking if this is a DFS link. */
+                return NT_STATUS_OK;
+        }
+
+        ok = parse_msdfs_symlink(mem_ctx,
+                        lp_msdfs_shuffle_referrals(SNUM(handle->conn)),
+                        link_target,
+                        ppreflist,
+                        preferral_count);
+
+        if (ok) {
+                status = NT_STATUS_OK;
+        } else {
+                status = NT_STATUS_NO_MEMORY;
+        }
+
+  err:
+
+        if (link_target != link_target_buf) {
+                TALLOC_FREE(link_target);
+        }
+        return status;
+}
+
 static struct vfs_fn_pointers ceph_fns = {
        /* Disk operations */
 
@@ -1356,6 +1455,7 @@ static struct vfs_fn_pointers ceph_fns = {
        /* File operations */
 
        .create_dfs_pathat_fn = cephwrap_create_dfs_pathat,
+       .read_dfs_pathat_fn = cephwrap_read_dfs_pathat,
        .open_fn = cephwrap_open,
        .close_fn = cephwrap_close,
        .pread_fn = cephwrap_pread,