Implement simple directories

* procfs_dir.h: New file; declare the procfs_dir_make_node
  function, based on the procfs_dir_entry structure.
* procfs_dir.c: New file; implement simple directories.
* Makefile: Add the procfs_dir module.
* main.c: Use it.

4 files changed, 103 insertions, 22 deletions

diff --git a/Makefile b/Makefile
index e7282ce..ab6e406 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 TARGET = procfs
-OBJS = procfs.o netfs.o procfs_file.o main.o
+OBJS = procfs.o netfs.o procfs_file.o procfs_dir.o main.o
 LIBS = -lnetfs
 
 CC = gcc
diff --git a/main.c b/main.c
index 457cf6a..62e440d 100644
--- a/main.c
+++ b/main.c
@@ -4,32 +4,19 @@
 #include <hurd/netfs.h>
 #include "procfs.h"
 #include "procfs_file.h"
+#include "procfs_dir.h"
 
-static error_t get_entries (void *hook, void **contents, size_t *contents_len)
+static struct node *make_file (void *dir_hook, void *ent_hook)
 {
-  static const char entries[] = "hello";
-  *contents = (void *) entries;
-  *contents_len = sizeof entries;
-  return 0;
-}
-
-static error_t lookup (void *hook, const char *name, struct node **np)
-{
-  if (strcmp (name, "hello"))
-    return ENOENT;
-
-  *np = procfs_file_make_node ("Hello, World!\n", -1, NULL);
-  if (! *np)
-    return ENOMEM;
-
-  return 0;
+  return procfs_file_make_node (ent_hook, -1, NULL);
 }
 
 int main (int argc, char **argv)
 {
-  static const struct procfs_node_ops ops = {
-    .get_contents = get_entries,
-    .lookup = lookup,
+  static const struct procfs_dir_entry entries[] = {
+    { "hello",		make_file,	"Hello, World!\n" },
+    { "goodbye",	make_file,	"Goodbye, cruel World!\n" },
+    { }
   };
   mach_port_t bootstrap;
 
@@ -40,7 +27,7 @@ int main (int argc, char **argv)
     error (1, 0, "Must be started as a translator");
 
   netfs_init ();
-  netfs_root_node = procfs_make_node (&ops, NULL);
+  netfs_root_node = procfs_dir_make_node (entries, NULL);
 
   netfs_startup (bootstrap, 0);
   for (;;)
diff --git a/procfs_dir.c b/procfs_dir.c
new file mode 100644
index 0000000..4d4faa2
--- /dev/null
+++ b/procfs_dir.c
@@ -0,0 +1,79 @@
+#include <stdlib.h>
+#include <string.h>
+#include "procfs.h"
+#include "procfs_dir.h"
+
+struct procfs_dir_node
+{
+  const struct procfs_dir_entry *entries;
+  void *hook;
+};
+
+static error_t
+procfs_dir_get_contents (void *hook, void **contents, size_t *contents_len)
+{
+  struct procfs_dir_node *dn = hook;
+  const struct procfs_dir_entry *ent;
+  char *pos;
+
+  *contents_len = 0;
+  for (ent = dn->entries; ent->name; ent++)
+    *contents_len += strlen (ent->name) + 1;
+
+  *contents = malloc (*contents_len);
+  if (! *contents)
+    return ENOMEM;
+
+  pos = *contents;
+  for (ent = dn->entries; ent->name; ent++)
+    {
+      strcpy (pos, ent->name);
+      pos += strlen (ent->name) + 1;
+    }
+
+  return 0;
+}
+
+static error_t
+procfs_dir_lookup (void *hook, const char *name, struct node **np)
+{
+  struct procfs_dir_node *dn = hook;
+  const struct procfs_dir_entry *ent;
+
+  for (ent = dn->entries; ent->name && strcmp (name, ent->name); ent++);
+  if (! ent->name)
+    return ENOENT;
+
+  *np = ent->make_node (dn->hook, ent->hook);
+  if (! *np)
+    return ENOMEM;
+
+  return 0;
+}
+
+struct node *
+procfs_dir_make_node (const struct procfs_dir_entry *entries, void *dir_hook)
+{
+  static const struct procfs_node_ops ops = {
+    .get_contents = procfs_dir_get_contents,
+    .lookup = procfs_dir_lookup,
+    .cleanup_contents = free,
+    .cleanup = free,
+  };
+  struct procfs_dir_node *dn;
+  struct node *np;
+
+  dn = malloc (sizeof *dn);
+  if (! dn)
+    return NULL;
+
+  dn->entries = entries;
+  dn->hook = dir_hook;
+
+  np = procfs_make_node (&ops, dn);
+  if (! np)
+    free (dn);
+
+  return np;
+}
+
diff --git a/procfs_dir.h b/procfs_dir.h
new file mode 100644
index 0000000..1ba45ad
--- /dev/null
+++ b/procfs_dir.h
@@ -0,0 +1,15 @@
+
+/* Each entry associates a name with a callback function for creating new
+   nodes corresponding to that entry.  */
+struct procfs_dir_entry
+{
+  const char *name;
+  struct node *(*make_node)(void *dir_hook, void *entry_hook);
+  void *hook;
+};
+
+/* A simple directory is built from a table of entries.  The table is
+   terminated by a null NAME pointer.  */
+struct node *
+procfs_dir_make_node (const struct procfs_dir_entry *entries, void *dir_hook);
+