Fuse the proclist into the root node

* dircat.c, dircat.h: New files, merge directories.
* Makefile: Add the dircat module.
* main.c: Use dircat to merge the proclist into the root
  directory, instead of having it as a stand-alone one.
* procfs.h, procfs.c: Add a "refresh hack" to have the
  contents of the root directory recreated on each request.
* proclist.c (proclist_make_node): Enable the hack in question.

1 files changed, 99 insertions, 0 deletions

diff --git a/dircat.c b/dircat.c
new file mode 100644
index 0000000..857ba72
--- /dev/null
+++ b/dircat.c
@@ -0,0 +1,99 @@
+#include <stdlib.h>
+#include <string.h>
+#include "procfs.h"
+
+struct dircat_node
+{
+  struct node **dirs;
+};
+
+static error_t
+dircat_get_contents (void *hook, void **contents, size_t *contents_len)
+{
+  struct dircat_node *dcn = hook;
+  int i, sz, pos;
+  error_t err;
+
+  pos = 0;
+  *contents = malloc (sz = 512);
+
+  for (i=0; dcn->dirs[i]; i++)
+    {
+      void *subcon;
+      size_t sublen;
+
+      err = procfs_get_contents (dcn->dirs[i], &subcon, &sublen);
+      if (err)
+        {
+	  free (*contents);
+	  *contents = NULL;
+	  return err;
+	}
+
+      while (pos + sublen > sz)
+	*contents = realloc (*contents, sz *= 2);
+
+      memcpy (*contents + pos, subcon, sublen);
+      pos += sublen;
+    }
+
+  *contents_len = pos;
+  return 0;
+}
+
+static error_t
+dircat_lookup (void *hook, const char *name, struct node **np)
+{
+  struct dircat_node *dcn = hook;
+  error_t err;
+  int i;
+
+  err = ENOENT;
+  for (i=0; err && dcn->dirs[i]; i++)
+    err = procfs_lookup (dcn->dirs[i], name, np);
+
+  return err;
+}
+
+static void
+dircat_release_dirs (struct node **dirs)
+{
+  int i;
+
+  for (i=0; dirs[i]; i++)
+    netfs_nrele (dirs[i]);
+}
+
+static void
+dircat_cleanup (void *hook)
+{
+  struct dircat_node *dcn = hook;
+
+  dircat_release_dirs (dcn->dirs);
+  free (dcn);
+}
+
+struct node *
+dircat_make_node (struct node **dirs)
+{
+  static struct procfs_node_ops ops = {
+    .get_contents = dircat_get_contents,
+    .cleanup_contents = procfs_cleanup_contents_with_free,
+    .lookup = dircat_lookup,
+    .cleanup = dircat_cleanup,
+    /* necessary so that it propagates to proclist */
+    .enable_refresh_hack_and_break_readdir = 1,
+  };
+  struct dircat_node *dcn;
+
+  dcn = malloc (sizeof *dcn);
+  if (! dcn)
+    {
+      dircat_release_dirs (dirs);
+      return NULL;
+    }
+
+  dcn->dirs = dirs;
+  return procfs_make_node (&ops, dcn);
+}
+