ACPI tables translator

Exposes x86 ACPI tables as a netfs on a mount point

* acpi: New directory.
* Makefile (prog-subdirs): Add acpi.
* hurd/hurd_types.h (FSTYPE_ACPI): New macro.

1 files changed, 265 insertions, 0 deletions

diff --git a/acpi/acpifs.c b/acpi/acpifs.c
new file mode 100644
index 00000000..e779e0f9
--- /dev/null
+++ b/acpi/acpifs.c
@@ -0,0 +1,265 @@
+/*
+   Copyright (C) 2018 Free Software Foundation, Inc.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd.  If not, see <<a rel="nofollow" href="http://www.gnu.org/licenses/">http://www.gnu.org/licenses/</a>>.
+*/
+
+/* ACPI Filesystem implementation */
+
+#include <acpifs.h>
+
+#include <error.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <hurd/netfs.h>
+
+#include <ncache.h>
+#include <func_files.h>
+
+static error_t
+create_dir_entry (char *name, struct acpi_table *t,
+                 struct acpifs_dirent *parent, io_statbuf_t stat,
+                 struct node *node, struct acpifs_dirent *entry)
+{
+  uint16_t parent_num_entries;
+
+  strncpy (entry->name, name, NAME_SIZE);
+  entry->acpitable = t;
+  entry->parent = parent;
+  entry->stat = stat;
+  entry->dir = 0;
+  entry->node = node;
+
+  /* Update parent's child list */
+  if (entry->parent)
+    {
+      if (!entry->parent->dir)
+       {
+         /* First child */
+         entry->parent->dir = calloc (1, sizeof (struct acpifs_dir));
+         if (!entry->parent->dir)
+           return ENOMEM;
+       }
+
+      parent_num_entries = entry->parent->dir->num_entries++;
+      entry->parent->dir->entries = realloc (entry->parent->dir->entries,
+                                            entry->parent->dir->num_entries *
+                                            sizeof (struct acpifs_dirent *));
+      if (!entry->parent->dir->entries)
+       return ENOMEM;
+      entry->parent->dir->entries[parent_num_entries] = entry;
+    }
+
+  return 0;
+}
+
+error_t
+alloc_file_system (struct acpifs **fs)
+{
+  *fs = calloc (1, sizeof (struct acpifs));
+  if (!*fs)
+    return ENOMEM;
+
+  return 0;
+}
+
+error_t
+init_file_system (file_t underlying_node, struct acpifs *fs)
+{
+  error_t err;
+  struct node *np;
+  io_statbuf_t underlying_node_stat;
+
+  /* Initialize status from underlying node.  */
+  err = io_stat (underlying_node, &underlying_node_stat);
+  if (err)
+    return err;
+
+  np = netfs_make_node_alloc (sizeof (struct netnode));
+  if (!np)
+    return ENOMEM;
+  np->nn_stat = underlying_node_stat;
+  np->nn_stat.st_fsid = getpid ();
+  np->nn_stat.st_mode =
+    S_IFDIR | S_IROOT | S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH |
+    S_IXOTH;
+  np->nn_translated = np->nn_stat.st_mode;
+
+  /* Set times to now */
+  fshelp_touch (&np->nn_stat, TOUCH_ATIME | TOUCH_MTIME | TOUCH_CTIME,
+               acpifs_maptime);
+
+  fs->entries = calloc (1, sizeof (struct acpifs_dirent));
+  if (!fs->entries)
+    {
+      free (fs->entries);
+      return ENOMEM;
+    }
+
+  /* Create the root entry */
+  err = create_dir_entry ("", 0, 0, np->nn_stat, np, fs->entries);
+
+  fs->num_entries = 1;
+  fs->root = netfs_root_node = np;
+  fs->root->nn->ln = fs->entries;
+  pthread_mutex_init (&fs->node_cache_lock, 0);
+
+  return 0;
+}
+
+error_t
+create_fs_tree (struct acpifs *fs)
+{
+  error_t err = 0;
+  int i;
+  size_t nentries, ntables = 0;
+  struct acpifs_dirent *e, *list, *parent;
+  struct stat e_stat;
+  char entry_name[NAME_SIZE];
+  struct acpi_table *iter = NULL;
+
+  /* Copy the root stat */
+  e_stat = fs->entries->stat;
+
+  err = acpi_get_num_tables(&ntables);
+  if (err)
+    return err;
+
+  /* Allocate enough for / + "tables"/ + each table */
+  nentries = ntables + 2;
+
+  list = realloc (fs->entries, nentries * sizeof (struct acpifs_dirent));
+  if (!list) {
+    if (fs->entries)
+      free(fs->entries);
+    return ENOMEM;
+  }
+
+  e = list + 1;
+  parent = list;
+  e_stat.st_mode &= ~S_IROOT;   /* Remove the root mode */
+  memset (entry_name, 0, NAME_SIZE);
+  strncpy (entry_name, DIR_TABLES_NAME, NAME_SIZE);
+
+  err = create_dir_entry (entry_name, 0, parent, e_stat, 0, e);
+  if (err)
+    return err;
+
+  parent = e;
+
+  /* Remove all permissions to others */
+  e_stat.st_mode &= ~(S_IROTH | S_IWOTH | S_IXOTH);
+
+  /* Change mode to a regular read-only file */
+  e_stat.st_mode &= ~(S_IFDIR | S_IXUSR | S_IXGRP | S_IWUSR | S_IWGRP);
+  e_stat.st_mode |= S_IFREG;
+
+  /* Get all ACPI tables */
+  err = acpi_get_tables(&iter);
+  if (err)
+    return err;
+
+  for (i = 0; i < ntables; i++, iter++)
+    {
+      e_stat.st_size = iter->datalen;
+
+      // Create ACPI table entry
+      memset (entry_name, 0, NAME_SIZE);
+
+      snprintf (entry_name, NAME_SIZE, "%c%c%c%c",
+                iter->h.signature[0],
+                iter->h.signature[1],
+                iter->h.signature[2],
+                iter->h.signature[3]);
+      e++;
+      err = create_dir_entry (entry_name, iter, parent, e_stat, 0, e);
+      if (err)
+       return err;
+    }
+
+  /* The root node points to the first element of the entry list */
+  fs->entries = list;
+  fs->num_entries = nentries;
+  fs->root->nn->ln = fs->entries;
+
+  return err;
+}
+
+error_t
+entry_check_perms (struct iouser *user, struct acpifs_dirent *e, int flags)
+{
+  error_t err = 0;
+
+  if (!err && (flags & O_READ))
+    err = fshelp_access (&e->stat, S_IREAD, user);
+  if (!err && (flags & O_WRITE))
+    err = fshelp_access (&e->stat, S_IWRITE, user);
+  if (!err && (flags & O_EXEC))
+    err = fshelp_access (&e->stat, S_IEXEC, user);
+
+  return err;
+}
+
+/* Set default permissions to the given entry */
+static void
+entry_default_perms (struct acpifs *fs, struct acpifs_dirent *e)
+{
+  /* Set default owner and group */
+  UPDATE_OWNER (e, fs->root->nn->ln->stat.st_uid);
+  UPDATE_GROUP (e, fs->root->nn->ln->stat.st_gid);
+
+  /* Update ctime */
+  UPDATE_TIMES (e, TOUCH_CTIME);
+
+  return;
+}
+
+static void
+entry_set_perms (struct acpifs *fs, struct acpifs_dirent *e)
+{
+  struct acpifs_perm *perm = &fs->perm;
+  if (perm->uid >= 0)
+    UPDATE_OWNER (e, perm->uid);
+  if (perm->gid >= 0)
+    UPDATE_GROUP (e, perm->gid);
+
+  /* Update ctime */
+  UPDATE_TIMES (e, TOUCH_CTIME);
+
+  return;
+}
+
+/* Update all entries' permissions */
+error_t
+fs_set_permissions (struct acpifs *fs)
+{
+  int i;
+  struct acpifs_dirent *e;
+
+  for (i = 0, e = fs->entries; i < fs->num_entries; i++, e++)
+    {
+      /* Restore default perms, as this may be called from fsysopts */
+      entry_default_perms (fs, e);
+
+      /* Set new permissions, if any */
+      entry_set_perms (fs, e);
+    }
+
+  return 0;
+}