core: Add generic "commit filter" API, use it to implement statoverride

The builder wants the ability to mark a given file as e.g. setuid.  To
implement this, the repo now has a callback-based API when importing a
directory to modify or remove items.

The commit tool accepts a "statoverride" file as input which looks like:

+mode /path/to/file

src/libostree/ostree-repo.c

@@ -1465,21 +1465,58 @@ create_modified_file_info (GFileInfo               *info,
 
   ret = g_file_info_dup (info);
   
-  if (modifier->uid >= 0)
-    g_file_info_set_attribute_uint32 (ret, "unix::uid", modifier->uid);
-  if (modifier->gid >= 0)
-    g_file_info_set_attribute_uint32 (ret, "unix::gid", modifier->gid);
-
   return ret;
 }
 
-gboolean
+static OstreeRepoCommitFilterResult
-ostree_repo_stage_directory_to_mtree (OstreeRepo           *self,
+apply_commit_filter (OstreeRepo            *self,
-                                      GFile                *dir,
+                     OstreeRepoCommitModifier *modifier,
-                                      OstreeMutableTree    *mtree,
+                     GPtrArray                *path,
-                                      OstreeRepoCommitModifier *modifier,
+                     GFileInfo                *file_info,
-                                      GCancellable         *cancellable,
+                     GFileInfo               **out_modified_info)
-                                      GError              **error)
+{
+  GString *path_buf;
+  guint i;
+  OstreeRepoCommitFilterResult result;
+  GFileInfo *modified_info;
+  
+  if (modifier == NULL || modifier->filter == NULL)
+    {
+      *out_modified_info = g_object_ref (file_info);
+      return OSTREE_REPO_COMMIT_FILTER_ALLOW;
+    }
+
+  path_buf = g_string_new ("");
+
+  if (path->len == 0)
+    g_string_append_c (path_buf, '/');
+  else
+    {
+      for (i = 0; i < path->len; i++)
+        {
+          const char *elt = path->pdata[i];
+          
+          g_string_append_c (path_buf, '/');
+          g_string_append (path_buf, elt);
+        }
+    }
+
+  modified_info = g_file_info_dup (file_info);
+  result = modifier->filter (self, path_buf->str, modified_info, modifier->user_data);
+  *out_modified_info = modified_info;
+
+  g_string_free (path_buf, TRUE);
+  return result;
+}
+
+static gboolean
+stage_directory_to_mtree_internal (OstreeRepo           *self,
+                                   GFile                *dir,
+                                   OstreeMutableTree    *mtree,
+                                   OstreeRepoCommitModifier *modifier,
+                                   GPtrArray             *path,
+                                   GCancellable         *cancellable,
+                                   GError              **error)
 {
   gboolean ret = FALSE;
   OstreeRepoFile *repo_dir = NULL;
@@ -1493,6 +1530,7 @@ ostree_repo_stage_directory_to_mtree (OstreeRepo           *self,
   GVariant *xattrs = NULL;
   GInputStream *file_input = NULL;
   gboolean repo_dir_was_empty = FALSE;
+  OstreeRepoCommitFilterResult filter_result;
 
   /* We can only reuse checksums directly if there's no modifier */
   if (OSTREE_IS_REPO_FILE (dir) && modifier == NULL)
@@ -1507,6 +1545,8 @@ ostree_repo_stage_directory_to_mtree (OstreeRepo           *self,
       repo_dir_was_empty = 
         g_hash_table_size (ostree_mutable_tree_get_files (mtree)) == 0
         && g_hash_table_size (ostree_mutable_tree_get_subdirs (mtree)) == 0;
+
+      filter_result = OSTREE_REPO_COMMIT_FILTER_ALLOW;
     }
   else
     {
@@ -1516,96 +1556,108 @@ ostree_repo_stage_directory_to_mtree (OstreeRepo           *self,
       if (!child_info)
         goto out;
       
-      modified_info = create_modified_file_info (child_info, modifier);
+      filter_result = apply_commit_filter (self, modifier, path, child_info, &modified_info);
-      
+
-      if (!(modifier && modifier->skip_xattrs))
+      if (filter_result == OSTREE_REPO_COMMIT_FILTER_ALLOW)
         {
-          xattrs = ostree_get_xattrs_for_file (dir, error);
-          if (!xattrs)
-            goto out;
-        }
-      
-      if (!stage_directory_meta (self, modified_info, xattrs, &child_file_checksum,
-                                 cancellable, error))
-        goto out;
-      
-      ostree_mutable_tree_set_metadata_checksum (mtree, g_checksum_get_string (child_file_checksum));
-
-      g_clear_object (&child_info);
-      g_clear_object (&modified_info);
-    }
-
-  dir_enum = g_file_enumerate_children ((GFile*)dir, OSTREE_GIO_FAST_QUERYINFO, 
-                                        G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
-                                        cancellable, 
-                                        error);
-  if (!dir_enum)
-    goto out;
-
-  while ((child_info = g_file_enumerator_next_file (dir_enum, cancellable, &temp_error)) != NULL)
-    {
-      const char *name = g_file_info_get_name (child_info);
-
-      g_clear_object (&modified_info);
-      modified_info = create_modified_file_info (child_info, modifier);
-
-      g_clear_object (&child);
-      child = g_file_get_child (dir, name);
-
-      if (g_file_info_get_file_type (child_info) == G_FILE_TYPE_DIRECTORY)
-        {
-          g_clear_object (&child_mtree);
-          if (!ostree_mutable_tree_ensure_dir (mtree, name, &child_mtree, error))
-            goto out;
-
-          if (!ostree_repo_stage_directory_to_mtree (self, child, child_mtree,
-                                                     modifier, cancellable, error))
-            goto out;
-        }
-      else if (repo_dir)
-        {
-          if (!ostree_mutable_tree_replace_file (mtree, name, 
-                                                 ostree_repo_file_get_checksum ((OstreeRepoFile*) child),
-                                                 error))
-            goto out;
-        }
-      else
-        {
-          ot_clear_checksum (&child_file_checksum);
-          ot_clear_gvariant (&xattrs);
-          g_clear_object (&file_input);
-
-          if (g_file_info_get_file_type (modified_info) == G_FILE_TYPE_REGULAR)
-            {
-              file_input = (GInputStream*)g_file_read (child, cancellable, error);
-              if (!file_input)
-                goto out;
-            }
-
           if (!(modifier && modifier->skip_xattrs))
             {
-              xattrs = ostree_get_xattrs_for_file (child, error);
+              xattrs = ostree_get_xattrs_for_file (dir, error);
               if (!xattrs)
                 goto out;
             }
-
+          
-          if (!stage_object_impl (self, OSTREE_OBJECT_TYPE_RAW_FILE,
+          if (!stage_directory_meta (self, modified_info, xattrs, &child_file_checksum,
-                                  modified_info, xattrs, file_input, NULL,
+                                     cancellable, error))
-                                  &child_file_checksum, cancellable, error))
-            goto out;
-
-          if (!ostree_mutable_tree_replace_file (mtree, name, 
-                                                 g_checksum_get_string (child_file_checksum),
-                                                 error))
             goto out;
+          
+          ostree_mutable_tree_set_metadata_checksum (mtree, g_checksum_get_string (child_file_checksum));
+          
+          g_clear_object (&child_info);
+          g_clear_object (&modified_info);
         }
-
-      g_clear_object (&child_info);
     }
-  if (temp_error != NULL)
+
+  if (filter_result == OSTREE_REPO_COMMIT_FILTER_ALLOW)
     {
-      g_propagate_error (error, temp_error);
+      dir_enum = g_file_enumerate_children ((GFile*)dir, OSTREE_GIO_FAST_QUERYINFO, 
-      goto out;
+                                            G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                            cancellable, 
+                                            error);
+      if (!dir_enum)
+        goto out;
+
+      while ((child_info = g_file_enumerator_next_file (dir_enum, cancellable, &temp_error)) != NULL)
+        {
+          const char *name = g_file_info_get_name (child_info);
+
+          g_clear_object (&modified_info);
+          g_ptr_array_add (path, (char*)name);
+          filter_result = apply_commit_filter (self, modifier, path, child_info, &modified_info);
+
+          if (filter_result == OSTREE_REPO_COMMIT_FILTER_ALLOW)
+            {
+              g_clear_object (&child);
+              child = g_file_get_child (dir, name);
+
+              if (g_file_info_get_file_type (child_info) == G_FILE_TYPE_DIRECTORY)
+                {
+                  g_clear_object (&child_mtree);
+                  if (!ostree_mutable_tree_ensure_dir (mtree, name, &child_mtree, error))
+                    goto out;
+
+                  if (!stage_directory_to_mtree_internal (self, child, child_mtree,
+                                                          modifier, path, cancellable, error))
+                    goto out;
+                }
+              else if (repo_dir)
+                {
+                  if (!ostree_mutable_tree_replace_file (mtree, name, 
+                                                         ostree_repo_file_get_checksum ((OstreeRepoFile*) child),
+                                                         error))
+                    goto out;
+                }
+              else
+                {
+                  ot_clear_checksum (&child_file_checksum);
+                  ot_clear_gvariant (&xattrs);
+                  g_clear_object (&file_input);
+
+                  if (g_file_info_get_file_type (modified_info) == G_FILE_TYPE_REGULAR)
+                    {
+                      file_input = (GInputStream*)g_file_read (child, cancellable, error);
+                      if (!file_input)
+                        goto out;
+                    }
+
+                  if (!(modifier && modifier->skip_xattrs))
+                    {
+                      xattrs = ostree_get_xattrs_for_file (child, error);
+                      if (!xattrs)
+                        goto out;
+                    }
+
+                  if (!stage_object_impl (self, OSTREE_OBJECT_TYPE_RAW_FILE,
+                                          modified_info, xattrs, file_input, NULL,
+                                          &child_file_checksum, cancellable, error))
+                    goto out;
+
+                  if (!ostree_mutable_tree_replace_file (mtree, name, 
+                                                         g_checksum_get_string (child_file_checksum),
+                                                         error))
+                    goto out;
+                }
+
+              g_ptr_array_remove_index (path, path->len - 1);
+            }
+
+          g_clear_object (&child_info);
+        }
+      if (temp_error != NULL)
+        {
+          g_propagate_error (error, temp_error);
+          goto out;
+        }
     }
 
   if (repo_dir && repo_dir_was_empty)
@@ -1624,6 +1676,28 @@ ostree_repo_stage_directory_to_mtree (OstreeRepo           *self,
   return ret;
 }
 
+gboolean
+ostree_repo_stage_directory_to_mtree (OstreeRepo           *self,
+                                      GFile                *dir,
+                                      OstreeMutableTree    *mtree,
+                                      OstreeRepoCommitModifier *modifier,
+                                      GCancellable         *cancellable,
+                                      GError              **error)
+{
+  gboolean ret = FALSE;
+  GPtrArray *path = NULL;
+
+  path = g_ptr_array_new ();
+  if (!stage_directory_to_mtree_internal (self, dir, mtree, modifier, path, cancellable, error))
+    goto out;
+  
+  ret = TRUE;
+ out:
+  if (path)
+    g_ptr_array_free (path, TRUE);
+  return ret;
+}
+
 gboolean
 ostree_repo_stage_mtree (OstreeRepo           *self,
                          OstreeMutableTree    *mtree,
@@ -2020,8 +2094,6 @@ OstreeRepoCommitModifier *
 ostree_repo_commit_modifier_new (void)
 {
   OstreeRepoCommitModifier *modifier = g_new0 (OstreeRepoCommitModifier, 1);
-  modifier->uid = -1;
-  modifier->gid = -1;
 
   modifier->refcount = 1;
 

src/libostree/ostree-repo.h

@@ -135,15 +135,25 @@ gboolean      ostree_repo_load_variant (OstreeRepo  *self,
                                         GVariant     **out_variant,
                                         GError       **error);
 
+typedef enum {
+  OSTREE_REPO_COMMIT_FILTER_ALLOW,
+  OSTREE_REPO_COMMIT_FILTER_SKIP
+} OstreeRepoCommitFilterResult;
+
+typedef OstreeRepoCommitFilterResult (*OstreeRepoCommitFilter) (OstreeRepo    *repo,
+                                                                const char    *path,
+                                                                GFileInfo     *file_info,
+                                                                gpointer       user_data);
+
 typedef struct {
   volatile gint refcount;
 
-  gint uid;
-  gint gid;
-
   guint reserved_flags : 31;
   guint skip_xattrs : 1;
 
+  OstreeRepoCommitFilter filter;
+  gpointer user_data;
+
   gpointer reserved[3];
 } OstreeRepoCommitModifier;
 

src/ostree/ot-builtin-commit.c

@@ -36,6 +36,7 @@ static char *body;
 static char *parent;
 static char *branch;
 static char **metadata_strings;
+static char *statoverride_file;
 static gboolean skip_if_unchanged;
 static gboolean tar_autocreate_parents;
 static gboolean no_xattrs;
@@ -57,9 +58,93 @@ static GOptionEntry options[] = {
   { "no-xattrs", 0, 0, G_OPTION_ARG_NONE, &no_xattrs, "Do not import extended attributes", NULL },
   { "tar-autocreate-parents", 0, 0, G_OPTION_ARG_NONE, &tar_autocreate_parents, "When loading tar archives, automatically create parent directories as needed", NULL },
   { "skip-if-unchanged", 0, 0, G_OPTION_ARG_NONE, &skip_if_unchanged, "If the contents are unchanged from previous commit, do nothing", NULL },
+  { "statoverride", 0, 0, G_OPTION_ARG_FILENAME, &statoverride_file, "File containing list of modifications to make to permissions", "path" },
   { NULL }
 };
 
+static gboolean
+parse_statoverride_file (GHashTable   **out_mode_add,
+                         GCancellable  *cancellable,
+                         GError        **error)
+{
+  gboolean ret = FALSE;
+  GFile *path = NULL;
+  char *contents = NULL;
+  gsize len;
+  GHashTable *ret_hash = NULL;
+  char **lines = NULL;
+  char **iter = NULL;
+
+  path = ot_gfile_new_for_path (statoverride_file);
+
+  if (!g_file_load_contents (path, cancellable, &contents, &len, NULL,
+                             error))
+    goto out;
+  
+  ret_hash = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
+  lines = g_strsplit (contents, "\n", -1);
+
+  for (iter = lines; iter && *iter; iter++)
+    {
+      const char *line = *iter;
+
+      if (*line == '+')
+        {
+          const char *spc;
+          guint mode_add;
+
+          spc = strchr (line + 1, ' ');
+          if (!spc)
+            {
+              g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                           "Malformed statoverride file");
+              goto out;
+            }
+          
+          mode_add = (guint32)(gint32)g_ascii_strtod (line + 1, NULL);
+          g_hash_table_insert (ret_hash,
+                               g_strdup (spc + 1),
+                               GUINT_TO_POINTER((gint32)mode_add));
+        }
+    }
+
+  ret = TRUE;
+  ot_transfer_out_value (out_mode_add, &ret_hash);
+ out:
+  if (ret_hash)
+    g_hash_table_unref (ret_hash);
+  g_free (contents);
+  g_strfreev (lines);
+  g_clear_object (&path);
+  return ret;
+}
+
+static OstreeRepoCommitFilterResult
+commit_filter (OstreeRepo         *self,
+               const char         *path,
+               GFileInfo          *file_info,
+               gpointer            user_data)
+{
+  GHashTable *mode_adds = user_data;
+  gpointer value;
+
+  if (owner_uid >= 0)
+    g_file_info_set_attribute_uint32 (file_info, "unix::uid", owner_uid);
+  if (owner_gid >= 0)
+    g_file_info_set_attribute_uint32 (file_info, "unix::gid", owner_gid);
+
+  if (mode_adds && g_hash_table_lookup_extended (mode_adds, path, NULL, &value))
+    {
+      guint current_mode = g_file_info_get_attribute_uint32 (file_info, "unix::mode");
+      guint mode_add = GPOINTER_TO_UINT (value);
+      g_file_info_set_attribute_uint32 (file_info, "unix::mode",
+                                        current_mode | mode_add);
+      g_hash_table_remove (mode_adds, path);
+    }
+  
+  return OSTREE_REPO_COMMIT_FILTER_ALLOW;
+}
+
 gboolean
 ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error)
 {
@@ -82,6 +167,7 @@ ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error)
   gboolean metadata_builder_initialized = FALSE;
   gboolean skip_commit = FALSE;
   gboolean in_transaction = FALSE;
+  GHashTable *mode_adds = NULL;
 
   context = g_option_context_new ("[ARG] - Commit a new revision");
   g_option_context_add_main_entries (context, options, NULL);
@@ -143,6 +229,12 @@ ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error)
       metadata_builder_initialized = FALSE;
     }
 
+  if (statoverride_file)
+    {
+      if (!parse_statoverride_file (&mode_adds, cancellable, error))
+        goto out;
+    }
+
   repo = ostree_repo_new (repo_path);
   if (!ostree_repo_check (repo, error))
     goto out;
@@ -161,11 +253,13 @@ ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error)
       goto out;
     }
 
-  if (owner_uid >= 0 || owner_gid >= 0)
+  if (owner_uid >= 0 || owner_gid >= 0 || statoverride_file != NULL
+      || no_xattrs)
     {
       modifier = ostree_repo_commit_modifier_new ();
-      modifier->uid = owner_uid;
+      modifier->skip_xattrs = no_xattrs;
-      modifier->gid = owner_gid;
+      modifier->filter = commit_filter;
+      modifier->user_data = mode_adds;
     }
 
   if (!ostree_repo_resolve_rev (repo, branch, TRUE, &parent, error))
@@ -249,6 +343,22 @@ ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error)
             }
         }
     }
+
+  if (mode_adds && g_hash_table_size (mode_adds) > 0)
+    {
+      GHashTableIter hash_iter;
+      gpointer key, value;
+
+      g_hash_table_iter_init (&hash_iter, mode_adds);
+
+      while (g_hash_table_iter_next (&hash_iter, &key, &value))
+        {
+          g_printerr ("Unmatched statoverride path: %s\n", (char*)key);
+        }
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "Unmatched statoverride paths");
+      goto out;
+    }
           
   if (!ostree_repo_stage_mtree (repo, mtree, &contents_checksum, cancellable, error))
     goto out;
@@ -316,6 +426,8 @@ ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error)
   g_free (contents_checksum);
   g_free (parent);
   ot_clear_gvariant(&parent_commit);
+  if (mode_adds)
+    g_hash_table_unref (mode_adds);
   g_free (tree_type);
   if (metadata_mappedf)
     g_mapped_file_unref (metadata_mappedf);

tests/t0000-basic.sh

@@ -19,7 +19,7 @@
 
 set -e
 
-echo "1..23"
+echo "1..24"
 
 . libtest.sh
 
@@ -173,3 +173,11 @@ echo "ok metadata commit with strings"
 cd ${test_tmpdir}/checkout-test2-4
 $OSTREE commit -b test2 -s "no xattrs" --no-xattrs
 echo "ok commit with no xattrs"
+
+cd ${test_tmpdir}
+cat > test-statoverride.txt <<EOF
++2048 /a/nested/3
+EOF
+cd ${test_tmpdir}/checkout-test2-4
+$OSTREE commit -b test2 -s "with statoverride" --statoverride=../test-statoverride.txt
+echo "ok commit statoverridde"