Basic infrastructure

* procfs.h: New file; basic interfaces for procfs nodes.
* procfs.c: New file; implement the basic infrastructure.
* netfs.c: New file; bridge libnetfs and the procfs interfaces.
* main.c: New file; mostly a "Hello, World!" for now.
* Makefile: New file; standalone for now.

1 files changed, 90 insertions, 0 deletions

diff --git a/procfs.c b/procfs.c
new file mode 100644
index 00000000..304befba
--- /dev/null
+++ b/procfs.c
@@ -0,0 +1,90 @@
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <hurd/netfs.h>
+#include <hurd/fshelp.h>
+#include "procfs.h"
+
+struct netnode
+{
+  const struct procfs_node_ops *ops;
+  void *hook;
+
+  /* (cached) contents of the node */
+  void *contents;
+  size_t contents_len;
+};
+
+struct node *procfs_make_node (const struct procfs_node_ops *ops, void *hook)
+{
+  struct netnode *nn;
+  struct node *np;
+ 
+  nn = malloc (sizeof *nn);
+  if (! nn)
+    return NULL;
+
+  memset (nn, 0, sizeof *nn);
+  nn->ops = ops;
+  nn->hook = hook;
+
+  np = netfs_make_node (nn);
+  if (! np)
+    {
+      free (nn);
+      return NULL;
+    }
+
+  np->nn = nn;
+  memset (&np->nn_stat, 0, sizeof np->nn_stat);
+  np->nn_translated = 0;
+
+  if (np->nn->ops->lookup)
+    np->nn_stat.st_mode = S_IFDIR | 0555;
+  else
+    np->nn_stat.st_mode = S_IFREG | 0444;
+
+  return np;
+}
+
+error_t procfs_get_contents (struct node *np, void **data, size_t *data_len)
+{
+  if (! np->nn->contents && np->nn->ops->get_contents)
+    {
+      void *contents;
+      size_t contents_len;
+      error_t err;
+
+      err = np->nn->ops->get_contents (np->nn->hook, &contents, &contents_len);
+      if (err)
+	return err;
+
+      np->nn->contents = contents;
+      np->nn->contents_len = contents_len;
+    }
+
+  *data = np->nn->contents;
+  *data_len = np->nn->contents_len;
+  return 0;
+}
+
+error_t procfs_lookup (struct node *np, const char *name, struct node **npp)
+{
+  error_t err = ENOENT;
+
+  if (np->nn->ops->lookup)
+    err = np->nn->ops->lookup (np->nn->hook, name, npp);
+
+  return err;
+}
+
+void procfs_cleanup (struct node *np)
+{
+  if (np->nn->contents && np->nn->ops->cleanup_contents)
+    np->nn->ops->cleanup_contents (np->nn->contents);
+
+  if (np->nn->ops->cleanup)
+    np->nn->ops->cleanup (np->nn->hook);
+
+  free (np->nn);
+}