vfs_shadow_copy2: implement SMB_VFS_OPENAT()

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/modules/vfs_shadow_copy2.c b/source3/modules/vfs_shadow_copy2.c
index 51c1a5ebc066f4f65751e0e2ff76b7ddca1c30c1..119c8458e55b4bfe14accac205bb75bcd35ff892 100644 (file)
--- a/source3/modules/vfs_shadow_copy2.c
+++ b/source3/modules/vfs_shadow_copy2.c
@@ -1381,6 +1381,93 @@ static int shadow_copy2_open(vfs_handle_struct *handle,
        return ret;
 }
 
+static int shadow_copy2_openat(vfs_handle_struct *handle,
+                              const struct files_struct *dirfsp,
+                              const struct smb_filename *smb_fname_in,
+                              struct files_struct *fsp,
+                              int flags,
+                              mode_t mode)
+{
+       struct smb_filename *smb_fname = NULL;
+       time_t timestamp = 0;
+       char *stripped = NULL;
+       bool is_converted = false;
+       int saved_errno = 0;
+       int ret;
+       bool ok;
+
+       ok = shadow_copy2_strip_snapshot_converted(talloc_tos(),
+                                                  handle,
+                                                  smb_fname_in,
+                                                  &timestamp,
+                                                  &stripped,
+                                                  &is_converted);
+       if (!ok) {
+               return -1;
+       }
+       if (timestamp == 0) {
+               if (is_converted) {
+                       /*
+                        * Just pave over the user requested mode and use
+                        * O_RDONLY. Later attempts by the client to write on
+                        * the handle will fail in the pwrite() syscall with
+                        * EINVAL which we carefully map to EROFS. In sum, this
+                        * matches Windows behaviour.
+                        */
+                       flags = O_RDONLY;
+               }
+               return SMB_VFS_NEXT_OPENAT(handle,
+                                          dirfsp,
+                                          smb_fname_in,
+                                          fsp,
+                                          flags,
+                                          mode);
+       }
+
+       smb_fname = cp_smb_filename(talloc_tos(), smb_fname_in);
+       if (smb_fname == NULL) {
+               TALLOC_FREE(stripped);
+               errno = ENOMEM;
+               return -1;
+       }
+
+       smb_fname->base_name = shadow_copy2_convert(smb_fname,
+                                              handle,
+                                              stripped,
+                                              timestamp);
+       TALLOC_FREE(stripped);
+       if (smb_fname->base_name == NULL) {
+               TALLOC_FREE(smb_fname);
+               errno = ENOMEM;
+               return -1;
+       }
+
+       /*
+        * Just pave over the user requested mode and use O_RDONLY. Later
+        * attempts by the client to write on the handle will fail in the
+        * pwrite() syscall with EINVAL which we carefully map to EROFS. In sum,
+        * this matches Windows behaviour.
+        */
+       flags = O_RDONLY;
+
+       ret = SMB_VFS_NEXT_OPENAT(handle,
+                                 dirfsp,
+                                 smb_fname,
+                                 fsp,
+                                 flags,
+                                 mode);
+       if (ret == -1) {
+               saved_errno = errno;
+       }
+
+       TALLOC_FREE(smb_fname);
+
+       if (saved_errno != 0) {
+               errno = saved_errno;
+       }
+       return ret;
+}
+
 static int shadow_copy2_unlinkat(vfs_handle_struct *handle,
                        struct files_struct *dirfsp,
                        const struct smb_filename *smb_fname,
@@ -3160,6 +3247,7 @@ static struct vfs_fn_pointers vfs_shadow_copy2_fns = {
        .lstat_fn = shadow_copy2_lstat,
        .fstat_fn = shadow_copy2_fstat,
        .open_fn = shadow_copy2_open,
+       .openat_fn = shadow_copy2_openat,
        .unlinkat_fn = shadow_copy2_unlinkat,
        .chmod_fn = shadow_copy2_chmod,
        .chdir_fn = shadow_copy2_chdir,