Initial checkin.

9 files changed, 1143 insertions, 0 deletions

diff --git a/hostmux/ChangeLog b/hostmux/ChangeLog
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/hostmux/ChangeLog
diff --git a/hostmux/Makefile b/hostmux/Makefile
new file mode 100644
index 000000000..390277ef2
--- /dev/null
+++ b/hostmux/Makefile
@@ -0,0 +1,31 @@
+# Makefile for hostmux
+# 
+#   Copyright (C) 1997 Free Software Foundation, Inc.
+#
+#   This program 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.
+#
+#   This program 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 this program; if not, write to the Free Software
+#   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+dir := hostmux
+makemode := server
+
+target = hostmux
+
+SRCS = hostmux.c mux.c leaf.c node.c stubs.c
+LCLHDRS = hostmux.h
+
+MIGSTUBS = ioServer.o socketServer.o
+OBJS = $(SRCS:.c=.o)
+HURDLIBS = netfs fshelp iohelp ports threads ihash shouldbeinlibc
+
+include ../Makeconf
diff --git a/hostmux/hostmux-xinl.c b/hostmux/hostmux-xinl.c
new file mode 100644
index 000000000..2f79f96b9
--- /dev/null
+++ b/hostmux/hostmux-xinl.c
@@ -0,0 +1,24 @@
+/* Real definitions for extern inline functions in hostmux.h
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#define HOSTMUX_EI
+#undef __OPTIMIZE__
+#define __OPTIMIZE__
+#include "hostmux.h"
diff --git a/hostmux/hostmux.c b/hostmux/hostmux.c
new file mode 100644
index 000000000..d3127a468
--- /dev/null
+++ b/hostmux/hostmux.c
@@ -0,0 +1,118 @@
+/* Multiplexing filesystems by host
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <unistd.h>
+#include <argp.h>
+#include <argz.h>
+#include <error.h>
+#include <sys/time.h>
+
+#include "hostmux.h"
+
+int netfs_maxsymlinks = 25;
+
+volatile struct mapped_time_value *hostmux_mapped_time;
+
+/* Startup options.  */
+static const struct argp_option options[] =
+{
+  { "host-pattern", 'H', "PAT", OPTION_ARG_OPTIONAL,
+    "The string to replace in the translator specification with the hostname;"
+    " if empty, or doesn't occur, the hostname is appended as additional"
+    " argument instead (default `${host}')" },
+  { 0 }
+};
+static const char args_doc[] = "TRANSLATOR [ARG...]";
+static const char doc[] =
+  "A translator for invoking host-specific translators"
+  "\vThis translator appears like a directory in which hostnames can be"
+  " looked up, and will start TRANSLATOR to service each resulting node.";
+
+/* NFS client main program */
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  struct stat ul_stat;
+  mach_port_t bootstrap;
+  struct hostmux mux = { host_pat: "${host}", next_fileno: 10 };
+  struct netnode root_nn = { mux: &mux };
+
+  error_t parse_opt (int key, char *arg, struct argp_state *state)
+    {
+      switch (key)
+	{
+	case 'H':
+	  mux.host_pat = arg; break;
+	case ARGP_KEY_NO_ARGS:
+	  argp_usage (state);
+	case ARGP_KEY_ARGS:
+	  /* Steal the entire tail of arg vector for our own use.  */
+	  return argz_create (state->argv + state->next,
+			      &mux.trans_template, &mux.trans_template_len);
+	default:
+	  return ARGP_ERR_UNKNOWN;
+	}
+      return 0;
+    }
+  struct argp argp = { options, parse_opt, args_doc, doc };
+
+  /* Parse our command line arguments.  */
+  argp_parse (&argp, argc, argv, 0, 0, 0);
+    
+  task_get_bootstrap_port (mach_task_self (), &bootstrap);
+  netfs_init ();
+
+  /* Create the root node (some attributes initialized below).  */
+  netfs_root_node = netfs_make_node (&root_nn);
+  if (! netfs_root_node)
+    error (5, ENOMEM, "Cannot create root node");
+
+  err = maptime_map (0, 0, &hostmux_mapped_time);
+  if (err)
+    error (6, err, "Cannot map time");
+
+  /* Handshake with the party trying to start the translator.  */
+  mux.underlying = netfs_startup (bootstrap, 0);
+
+  /* We inherit various attributes from the node underlying this translator. */
+  err = io_stat (mux.underlying, &ul_stat);
+  if (err)
+    error (7, err, "Cannot stat underlying node");
+
+  /* MUX.stat_template contains some fields that are inherited by all nodes
+     we create.  */
+  mux.stat_template.st_uid = ul_stat.st_uid;
+  mux.stat_template.st_gid = ul_stat.st_gid;
+  mux.stat_template.st_author = ul_stat.st_author;
+  mux.stat_template.st_fsid = getpid ();
+  mux.stat_template.st_nlink = 1;
+  mux.stat_template.st_fstype = FSTYPE_MISC;
+
+  /* Initialize the root node's stat information.  */
+  netfs_root_node->nn_stat = mux.stat_template;
+  netfs_root_node->nn_stat.st_ino = 2;
+  netfs_root_node->nn_stat.st_mode =
+    S_IFDIR | (ul_stat.st_mode & ~S_IFMT & ~S_ITRANS);
+  touch (netfs_root_node, TOUCH_ATIME|TOUCH_MTIME|TOUCH_CTIME);
+  
+  for (;;)			/* ?? */
+    netfs_server_loop ();
+}
diff --git a/hostmux/hostmux.h b/hostmux/hostmux.h
new file mode 100644
index 000000000..54c11738a
--- /dev/null
+++ b/hostmux/hostmux.h
@@ -0,0 +1,122 @@
+/* Multiplexing filesystems by host
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#ifndef __HOSTMUX_H__
+#define __HOSTMUX_H__
+
+#include <hurd/netfs.h>
+#include <rwlock.h>
+#include <maptime.h>
+
+/* Handy source of time.  */
+volatile struct mapped_time_value *hostmux_mapped_time;
+
+/* The state associated with a host multiplexer translator.  */
+struct hostmux
+{
+  /* The host hodes in this mux.  */
+  struct hostmux_name *names;
+  struct rwlock names_lock;
+
+  /* The next inode number we'll use; protected by NAMES_LOCK.  */
+  ino_t next_fileno;
+
+  /* A template argz, which is used to start each host-specific translator
+     with the host name appropriately added.  */
+  char *trans_template;
+  size_t trans_template_len;
+
+  /* What string to replace in TRANS_TEMPLATE with the name of the host; if
+     0, or it doesn't occur, the host name is appended as an additional
+     argument.  */
+  char *host_pat;
+
+  /* Constant fields for host stat entries.  */
+  struct stat stat_template;
+
+  /* The file that this translator is sitting on top of; we inherit various
+     characteristics from it.  */
+  file_t underlying;
+};
+
+/* The name of a recently looked up host entry.  */
+struct hostmux_name
+{
+  const char *name;		/* Looked up name (may be a number).  */
+  const char *canon;		/* The canonical (fq) host name.  */
+
+  /* A filesystem node associated with NAME.  If NAME = CANON, then this will
+     refer to a node with a translator for that host, otherwise, the node
+     will be a symbolic link to the canonical name.  */
+  struct node *node;
+
+  ino_t fileno;			/* The inode number for this entry.  */
+
+  struct hostmux_name *next;
+};
+
+/* The fs specific storage that libnetfs associates with each filesystem
+   node.  */
+struct netnode
+{
+  /* The mux this node belongs to (the node can either be the mux root, or
+     one of the hosts served by it).  */
+  struct hostmux *mux;
+
+  /* For mux nodes, 0, and for leaf nodes, the name under which the node was
+     looked up. */
+  struct hostmux_name *name;
+};
+
+/* Timestamps to change.  */
+#define TOUCH_ATIME 0x1
+#define TOUCH_MTIME 0x2
+#define TOUCH_CTIME 0x4
+
+#ifndef HOSTMUX_EI
+# define HOSTMUX_EI extern inline
+#endif
+
+/* Change the stat times of NODE as indicated by WHAT (from the set TOUCH_*)
+   to the current time.  */
+HOSTMUX_EI void touch (struct node *node, unsigned what)
+{
+  struct timeval tv;
+
+  maptime_read (hostmux_mapped_time, &tv);
+
+  if (what & TOUCH_ATIME)
+    {
+      netfs_root_node->nn_stat.st_atime = tv.tv_sec;
+      netfs_root_node->nn_stat.st_atime_usec = tv.tv_usec;
+    }
+  if (what & TOUCH_CTIME)
+    {
+      netfs_root_node->nn_stat.st_ctime = tv.tv_sec;
+      netfs_root_node->nn_stat.st_ctime_usec = tv.tv_usec;
+    }
+  if (what & TOUCH_MTIME)
+    {
+      netfs_root_node->nn_stat.st_mtime = tv.tv_sec;
+      netfs_root_node->nn_stat.st_mtime_usec = tv.tv_usec;
+    }
+}
+
+#endif /* __HOSTMUX_H__ */
diff --git a/hostmux/leaf.c b/hostmux/leaf.c
new file mode 100644
index 000000000..d17a4bce6
--- /dev/null
+++ b/hostmux/leaf.c
@@ -0,0 +1,187 @@
+/* Hostmux leaf node functions
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <string.h>
+#include <argz.h>
+
+#include "hostmux.h"
+
+/* Read the contents of NODE (a symlink), for USER, into BUF. */
+error_t
+netfs_attempt_readlink (struct iouser *user, struct node *node, char *buf)
+{
+  assert (node->nn->name);
+  memcpy (buf, node->nn->name->canon, node->nn_stat.st_size);
+  touch (node, TOUCH_ATIME);
+  return 0;
+}
+
+/* Append BUF, of length BUF_LEN to *TO, of length *TO_LEN, reallocating and
+   updating *TO & *TO_LEN appropriately.  If an allocation error occurs,
+   *TO's old value is freed, and *TO is set to 0.  */
+static void
+str_append (char **to, size_t *to_len, const char *buf, const size_t buf_len)
+{
+  size_t new_len = *to_len + buf_len;
+  char *new_to = realloc (*to, new_len + 1);
+
+  if (new_to)
+    {
+      memcpy (new_to + *to_len, buf, buf_len);
+      new_to[new_len] = '\0';
+      *to = new_to;
+      *to_len = new_len;
+    }
+  else
+    {
+      free (*to);
+      *to = 0;
+    }
+}
+
+/* For locked node NODE with S_IPTRANS set in its mode, look up the name of
+   its translator.  Store the name into newly malloced storage, and return it
+   in *ARGZ; set *ARGZ_LEN to the total length.
+
+   For hostmux, this creates a new translator string by instantiating the
+   global translator template.  */
+error_t
+netfs_get_translator (struct node *node, char **argz, size_t *argz_len)
+{
+  if (! node->nn->name)
+    return EINVAL;
+  else
+    {
+      error_t err = 0;
+      char *arg = 0;
+      int did_replace = 0;
+      struct hostmux *mux = node->nn->mux;
+      char *template = mux->trans_template;
+      size_t template_len = mux->trans_template_len;
+      char *host_pat = mux->host_pat;
+      const char *host = node->nn->name->canon;
+      size_t host_len = strlen (host);
+
+      *argz = 0;			/* Initialize return value.  */
+      *argz_len = 0;
+
+      if (host_pat)
+	{
+	  size_t host_pat_len = strlen (host_pat);
+
+	  while (!err && (arg = argz_next (template, template_len, arg)))
+	    {
+	      char *match = strstr (arg, host_pat);
+	      if (match)
+		{
+		  char *from = match + host_pat_len;
+		  size_t to_len = match - arg;
+		  char *to = strndup (arg, to_len);
+
+		  while (to && from)
+		    {
+		      str_append (&to, &to_len, host, host_len);
+		      if (to)
+			{
+			  match = strstr (from, host_pat);
+			  if (match)
+			    {
+			      str_append (&to, &to_len, from, match - from);
+			      from = match + host_pat_len;
+			    }
+			  else
+			    {
+			      str_append (&to, &to_len, from, strlen (from));
+			      from = 0;
+			    }
+			}
+		    }
+
+		  if (to)
+		    {
+		      err = argz_add (argz, argz_len, to);
+		      free (to);
+		    }
+		  else
+		    err = ENOMEM;
+
+		  did_replace = 1;
+		}
+	      else
+		err = argz_add (argz, argz_len, arg);
+	    }
+	}
+      else
+	err = argz_append (argz, argz_len, template, template_len);
+
+      if (!err && !did_replace)
+	err = argz_add (argz, argz_len, host);
+
+      if (err && *argz_len > 0)
+	free (*argz);
+
+      return err;
+    }
+}
+
+/* Create a new leaf node in MUX, with a name NAME, and return the new node
+   with a single reference in NODE.  */
+error_t
+create_host_node (struct hostmux *mux, struct hostmux_name *name,
+		  struct node **node)
+{
+  struct node *new;
+  struct netnode *nn = malloc (sizeof (struct netnode));
+
+  if (! nn)
+    return ENOMEM;
+
+  nn->mux = mux;
+  nn->name = name;
+
+  new = netfs_make_node (nn);
+  if (! new)
+    {
+      free (nn);
+      return ENOMEM;
+    }
+
+  new->nn_stat = mux->stat_template;
+  new->nn_stat.st_ino = name->fileno;
+
+  if (strcmp (name->name, name->canon) == 0)
+    /* The real name of the host, make a real node.  */
+    {
+      new->nn_stat.st_mode = (S_IFREG | S_IPTRANS | 0666);
+      new->nn_stat.st_size = 0;
+    }
+  else
+    /* An alias for this host, make a symlink instead.  */
+    {
+      new->nn_stat.st_mode = (S_IFLNK | 0666);
+      new->nn_stat.st_size = strlen (name->canon);
+    }
+
+  name->node = new;
+
+  *node = new;
+
+  return 0;
+}
diff --git a/hostmux/mux.c b/hostmux/mux.c
new file mode 100644
index 000000000..cba291261
--- /dev/null
+++ b/hostmux/mux.c
@@ -0,0 +1,401 @@
+/* Root hostmux node
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <stddef.h>
+#include <string.h>
+#include <dirent.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+
+#include "hostmux.h"
+
+error_t create_host_node (struct hostmux *mux, struct hostmux_name *name,
+			  struct node **node);
+
+/* Returned directory entries are aligned to blocks this many bytes long.
+   Must be a power of two.  */
+#define DIRENT_ALIGN 4
+#define DIRENT_NAME_OFFS offsetof (struct dirent, d_name)
+
+/* Length is structure before the name + the name + '\0', all
+   padded to a four-byte alignment.  */
+#define DIRENT_LEN(name_len)						      \
+  ((DIRENT_NAME_OFFS + (name_len) + 1 + (DIRENT_ALIGN - 1))		      \
+   & ~(DIRENT_ALIGN - 1))
+
+static error_t lookup_host (struct hostmux *mux, const char *host,
+			    struct node **node); /* fwd decl */
+
+/* [root] Directory operations.  */
+
+/* Lookup NAME in DIR for USER; set *NODE to the found name upon return.  If
+   the name was not found, then return ENOENT.  On any error, clear *NODE.
+   (*NODE, if found, should be locked, this call should unlock DIR no matter
+   what.) */
+error_t
+netfs_attempt_lookup (struct iouser *user, struct node *dir, 
+		      char *name, struct node **node)
+{
+  error_t err;
+
+  if (dir->nn->name)
+    err = ENOTDIR;
+  else
+    err = lookup_host (dir->nn->mux, name, node);
+
+  touch (dir, TOUCH_ATIME);
+
+  mutex_unlock (&dir->lock);
+
+  if (! err)
+    mutex_lock (&(*node)->lock);
+
+  return err;
+}
+
+/* Implement the netfs_get_directs callback as described in
+   <hurd/netfs.h>. */
+error_t
+netfs_get_dirents (struct iouser *cred, struct node *dir,
+		   int first_entry, int num_entries, char **data,
+		   mach_msg_type_number_t *data_len,
+		   vm_size_t max_data_len, int *data_entries)
+{
+  error_t err;
+  int count;
+  size_t size = 0;		/* Total size of our return block.  */
+  struct hostmux_name *first_name, *nm;
+
+  if (dir->nn->name)
+    return ENOTDIR;
+
+  rwlock_reader_lock (&dir->nn->mux->names_lock);
+
+  /* Find the first entry.  */
+  for (first_name = dir->nn->mux->names;
+       first_name && first_entry > 0;
+       first_name = first_name->next)
+    if (first_name->node)
+      first_entry--;
+
+  /* See how much space we need for the result.  */
+  for (nm = first_name, count = 0;
+       nm && (num_entries == -1 || count < num_entries);
+       nm = nm->next)
+    if (nm->node)
+      {
+	size_t new_size = size + DIRENT_LEN (strlen (nm->name));
+	if (new_size > max_data_len)
+	  break;
+	size = new_size;
+	count++;
+      }
+
+  /* Allocate it.  */
+  err = vm_allocate (mach_task_self (), (vm_address_t *) data, size, 1);
+  if (! err)
+    /* Copy out the result.  */
+    {
+      char *p = *data;
+
+      *data_len = size;
+      *data_entries = count;
+
+      /* See how much space we need for the result.  */
+      for (nm = first_name, count = 0;
+	   nm && (num_entries == -1 || count < num_entries);
+	   nm = nm->next)
+	if (nm->node)
+	  {
+	    struct dirent hdr;
+	    size_t name_len = strlen (nm->name);
+	    size_t sz = DIRENT_LEN (name_len);
+
+	    if (sz > size)
+	      break;
+	    else
+	      size -= sz;
+
+	    hdr.d_fileno = nm->fileno;
+	    hdr.d_reclen = sz;
+	    hdr.d_type =
+	      (strcmp (nm->canon, nm->name) == 0 ? DT_REG : DT_LNK);
+	    hdr.d_namlen = name_len;
+
+	    memcpy (p, &hdr, DIRENT_NAME_OFFS);
+	    strcpy (p + DIRENT_NAME_OFFS, nm->name);
+	    p += sz;
+
+	    count++;
+	  }
+
+    }
+
+  rwlock_reader_unlock (&dir->nn->mux->names_lock);
+
+  touch (dir, TOUCH_ATIME);
+
+  return err;
+}
+
+/* Host lookup.  */
+
+/* Free storage allocated consumed by the host mux name NM, but not the node
+   it points to.  */
+static void
+free_name (struct hostmux_name *nm)
+{
+  free ((char *)nm->name);
+  if (nm->name != nm->canon)
+    free ((char *)nm->canon);
+  free (nm);
+}
+
+/* See if there's an existing entry for the name HOST, and if so, return its
+   node in NODE with an additional references.  True is returned iff the
+   lookup succeeds.  If PURGE is true, then any nodes with a null node are
+   removed.  */
+static int
+lookup_cached (struct hostmux *mux, const char *host, int purge,
+	       struct node **node)
+{
+  struct hostmux_name *nm = mux->names, **prevl = &mux->names;
+
+  while (nm)
+    {
+      struct hostmux_name *next = nm->next;
+
+      if (strcasecmp (host, nm->name) == 0)
+	{
+	  spin_lock (&netfs_node_refcnt_lock);
+	  if (nm->node)
+	    nm->node->references++;
+	  spin_unlock (&netfs_node_refcnt_lock);
+
+	  if (nm->node)
+	    {
+	      *node = nm->node;
+	      return 1;
+	    }
+	}
+
+      if (purge && !nm->node)
+	{
+	  *prevl = nm->next;
+	  free_name (nm);
+	}
+      else
+	prevl = &nm->next;
+
+      nm = next;
+    }
+
+  return 0;
+}
+
+/* See if there's an existing entry for the name HOST, and if so, return its
+   node in NODE, with an additional reference, otherwise, create a new node
+   for the host HE as referred to by HOST, and return that instead, with a
+   single reference.  The type of node created is either a translator node,
+   if HOST refers to the official name of the host, or a symlink node to the
+   official name, if it doesn't.  */
+static error_t
+lookup_hostent (struct hostmux *mux, const char *host, struct hostent *he,
+		struct node **node)
+{
+  error_t err;
+  struct hostmux_name *nm = malloc (sizeof (struct hostmux_name));
+
+  if (! nm)
+    return ENOMEM;
+
+  nm->name = strdup (host);
+  if (strcmp (host, he->h_name) == 0)
+    nm->canon = nm->name;
+  else
+    nm->canon = strdup (he->h_name);
+
+  err = create_host_node (mux, nm, node);
+  if (err)
+    {
+      free_name (nm);
+      return err;
+    }
+
+  rwlock_writer_lock (&mux->names_lock);
+  if (lookup_cached (mux, host, 1, node))
+    /* An entry for HOST has already been created between the time we last
+       looked and now (which is possible because we didn't lock MUX).
+       Just throw away our version and return the one already in the cache.  */
+    {
+      rwlock_writer_unlock (&mux->names_lock);
+      nm->node->nn->name = 0;	/* Avoid touching the mux name list.  */
+      netfs_nrele (nm->node);	/* Free the tentative new node.  */
+      free_name (nm);		/* And the name it was under.  */
+    }
+  else
+    /* Enter NM into MUX's list of names, and return the new node.  */
+    {
+      nm->fileno = mux->next_fileno++; /* Now that we hold the lock...  */
+      nm->next = mux->names;
+      mux->names = nm;
+      rwlock_writer_unlock (&mux->names_lock);
+    }
+
+  return 0;
+}  
+
+/* Lookup the host HOST in MUX, and return the resulting node in NODE, with
+   an additional reference, or an error.  */
+static error_t
+lookup_host (struct hostmux *mux, const char *host, struct node **node)
+{
+  int was_cached;
+  int h_err;
+  struct hostent _he, *he;
+  struct in_addr inet_addr;
+  char hostent_data[2048];	/* XXX what size should this be???? */
+
+  rwlock_reader_lock (&mux->names_lock);
+  was_cached = lookup_cached (mux, host, 0, node);
+  rwlock_reader_unlock (&mux->names_lock);
+
+  if (was_cached)
+    return 0;
+  else if (inet_aton (host, &inet_addr))
+    {
+      if (gethostbyaddr_r ((char *)&inet_addr, sizeof inet_addr, AF_INET,
+			   &_he, hostent_data, sizeof hostent_data,
+			   &he, &h_err) == 0)
+	return lookup_hostent (mux, host, he, node);
+      else
+	return ENOENT;
+    }
+  else if (gethostbyname_r (host, &_he, hostent_data, sizeof hostent_data,
+			    &he, &h_err) == 0)
+    return lookup_hostent (mux, host, he, node);
+  else
+    return ENOENT;
+}
+
+/* This should sync the entire remote filesystem.  If WAIT is set, return
+   only after sync is completely finished.  */
+error_t
+netfs_attempt_syncfs (struct iouser *cred, int wait)
+{
+  return 0;
+}
+
+/* This should attempt a chmod call for the user specified by CRED on node
+   NODE, to change the owner to UID and the group to GID. */
+error_t
+netfs_attempt_chown (struct iouser *cred, struct node *node, uid_t uid, uid_t gid)
+{
+  if (node->nn->name)
+    return EOPNOTSUPP;
+  else
+    {
+      struct hostmux *mux = node->nn->mux;
+      error_t err = file_chown (mux->underlying, uid, gid);
+
+      if (! err)
+	{
+	  struct hostmux_name *nm;
+
+	  /* Change NODE's owner.  */
+	  mux->stat_template.st_uid = uid;
+	  mux->stat_template.st_gid = gid;
+	  node->nn_stat.st_uid = uid;
+	  node->nn_stat.st_gid = gid;
+
+	  /* Change the owner of each leaf node.  */
+	  rwlock_reader_lock (&mux->names_lock);
+	  for (nm = mux->names; nm; nm = nm->next)
+	    if (nm->node)
+	      {
+		nm->node->nn_stat.st_uid = uid;
+		nm->node->nn_stat.st_gid = gid;
+	      }
+	  rwlock_reader_unlock (&mux->names_lock);
+
+	  touch (node, TOUCH_CTIME);
+	}
+
+      return err;
+    }
+}
+
+/* This should attempt a chauthor call for the user specified by CRED on node
+   NODE, to change the author to AUTHOR. */
+error_t
+netfs_attempt_chauthor (struct iouser *cred, struct node *node, uid_t author)
+{
+  if (node->nn->name)
+    return EOPNOTSUPP;
+  else
+    {
+      struct hostmux *mux = node->nn->mux;
+      error_t err = file_chauthor (mux->underlying, author);
+
+      if (! err)
+	{
+	  struct hostmux_name *nm;
+
+	  /* Change NODE's owner.  */
+	  mux->stat_template.st_author = author;
+	  node->nn_stat.st_author = author;
+
+	  /* Change the owner of each leaf node.  */
+	  rwlock_reader_lock (&mux->names_lock);
+	  for (nm = mux->names; nm; nm = nm->next)
+	    if (nm->node)
+	      nm->node->nn_stat.st_author = author;
+	  rwlock_reader_unlock (&mux->names_lock);
+
+	  touch (node, TOUCH_CTIME);
+	}
+
+      return err;
+    }
+}
+
+/* This should attempt a chmod call for the user specified by CRED on node
+   NODE, to change the mode to MODE.  Unlike the normal Unix and Hurd meaning
+   of chmod, this function is also used to attempt to change files into other
+   types.  If such a transition is attempted which is impossible, then return
+   EOPNOTSUPP.  */
+error_t
+netfs_attempt_chmod (struct iouser *cred, struct node *node, mode_t mode)
+{
+  mode &= ~S_ITRANS;
+  if (node->nn->name || ((mode & S_IFMT) != (node->nn_stat.st_mode & S_IFMT)))
+    return EOPNOTSUPP;
+  else
+    {
+      error_t err = file_chmod (node->nn->mux->underlying, mode & ~S_IFMT);
+      if (! err)
+	{
+	  node->nn_stat.st_mode = mode;
+	  touch (node, TOUCH_CTIME);
+	}
+      return err;
+    }
+}
diff --git a/hostmux/node.c b/hostmux/node.c
new file mode 100644
index 000000000..3d808afed
--- /dev/null
+++ b/hostmux/node.c
@@ -0,0 +1,117 @@
+/* General fs node functions
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <fcntl.h>
+
+#include "hostmux.h"
+
+/* Node maintenance.  */
+
+/* Node NP is all done; free all its associated storage. */
+void
+netfs_node_norefs (struct node *node)
+{
+  if (node->nn->name)
+    /* Remove our name's pointer to us; the name itself will eventually be
+       freed by another party.  */
+    node->nn->name->node = 0;
+  free (node->nn);
+  free (node);
+}
+
+/* Attempt to create a file named NAME in DIR for USER with MODE.  Set *NODE
+   to the new node upon return.  On any error, clear *NODE.  *NODE should be
+   locked on success; no matter what, unlock DIR before returning.  */
+error_t
+netfs_attempt_create_file (struct iouser *user, struct node *dir,
+			   char *name, mode_t mode, struct node **node)
+{
+  *node = 0;
+  mutex_unlock (&dir->lock);
+  return EOPNOTSUPP;
+}
+
+/* Node NODE is being opened by USER, with FLAGS.  NEWNODE is nonzero if we
+   just created this node.  Return an error if we should not permit the open
+   to complete because of a permission restriction. */
+error_t
+netfs_check_open_permissions (struct iouser *user, struct node *node,
+			      int flags, int newnode)
+{
+  error_t err = 0;
+  if (flags & O_READ)
+    err = fshelp_access (&node->nn_stat, S_IREAD, user);
+  if (!err && (flags & O_WRITE))
+    err = fshelp_access (&node->nn_stat, S_IWRITE, user);
+  if (!err && (flags & O_EXEC))
+    err = fshelp_access (&node->nn_stat, S_IEXEC, user);
+  return err;
+}
+
+/* This should attempt a utimes call for the user specified by CRED on node
+   NODE, to change the atime to ATIME and the mtime to MTIME. */
+error_t
+netfs_attempt_utimes (struct iouser *cred, struct node *node,
+		      struct timespec *atime, struct timespec *mtime)
+{
+  error_t err = fshelp_isowner (&node->nn_stat, cred);
+  if (! err)
+    {
+      node->nn_stat.st_mtime = mtime->tv_sec;
+      node->nn_stat.st_mtime_usec = mtime->tv_nsec / 1000;
+      node->nn_stat.st_atime = atime->tv_sec;
+      node->nn_stat.st_atime_usec = atime->tv_nsec / 1000;
+      touch (node, TOUCH_CTIME);
+    }
+  return err;
+}
+
+/* Return the valid access types (bitwise OR of O_READ, O_WRITE, and O_EXEC)
+   in *TYPES for file NODE and user CRED.  */
+error_t
+netfs_report_access (struct iouser *cred, struct node *node, int *types)
+{
+  *types = 0;
+  if (fshelp_access (&node->nn_stat, S_IREAD, cred) == 0)
+    *types |= O_READ;
+  if (fshelp_access (&node->nn_stat, S_IWRITE, cred) == 0)
+    *types |= O_WRITE;
+  if (fshelp_access (&node->nn_stat, S_IEXEC, cred) == 0)
+    *types |= O_EXEC;
+  return 0;
+}
+
+/* Trivial definitions.  */
+
+/* Make sure that NP->nn_stat is filled with current information.  CRED
+   identifies the user responsible for the operation.  */
+error_t
+netfs_validate_stat (struct node *node, struct iouser *cred)
+{
+  return 0;
+}
+
+/* This should sync the file NODE completely to disk, for the user CRED.  If
+   WAIT is set, return only after sync is completely finished.  */
+error_t
+netfs_attempt_sync (struct iouser *cred, struct node *node, int wait)
+{
+  return 0;
+}
diff --git a/hostmux/stubs.c b/hostmux/stubs.c
new file mode 100644
index 000000000..d94028776
--- /dev/null
+++ b/hostmux/stubs.c
@@ -0,0 +1,143 @@
+/* Stub routines for hostmux
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <hurd/netfs.h>
+
+/* Attempt to turn NODE (user CRED) into a symlink with target NAME. */
+error_t
+netfs_attempt_mksymlink (struct iouser *cred, struct node *node, char *name)
+{
+  return EOPNOTSUPP;
+}
+
+/* Attempt to turn NODE (user CRED) into a device.  TYPE is either S_IFBLK or
+   S_IFCHR. */
+error_t
+netfs_attempt_mkdev (struct iouser *cred, struct node *node,
+		     mode_t type, dev_t indexes)
+{
+  return EOPNOTSUPP;
+}
+
+/* Attempt to set the passive translator record for FILE to ARGZ (of length
+   ARGZLEN) for user CRED. */
+error_t
+netfs_set_translator (struct iouser *cred, struct node *node,
+		      char *argz, size_t argzlen)
+{
+  return EOPNOTSUPP;
+}
+
+/* This should attempt a chflags call for the user specified by CRED on node
+   NODE, to change the flags to FLAGS. */
+error_t
+netfs_attempt_chflags (struct iouser *cred, struct node *node, int flags)
+{
+  return EOPNOTSUPP;
+}
+
+/* This should attempt to set the size of the file NODE (for user CRED) to
+   SIZE bytes long. */
+error_t
+netfs_attempt_set_size (struct iouser *cred, struct node *node, off_t size)
+{
+  return EOPNOTSUPP;
+}
+
+/* This should attempt to fetch filesystem status information for the remote
+   filesystem, for the user CRED. */
+error_t
+netfs_attempt_statfs (struct iouser *cred, struct node *node,
+		      struct statfs *st)
+{
+  return EOPNOTSUPP;
+}
+
+/* Delete NAME in DIR for USER. */
+error_t
+netfs_attempt_unlink (struct iouser *user, struct node *dir, char *name)
+{
+  return EOPNOTSUPP;
+}
+
+/* Note that in this one call, neither of the specific nodes are locked. */
+error_t
+netfs_attempt_rename (struct iouser *user, struct node *fromdir,
+		      char *fromname, struct node *todir, 
+		      char *toname, int excl)
+{
+  return EOPNOTSUPP;
+}
+
+/* Attempt to create a new directory named NAME in DIR for USER with mode
+   MODE.  */
+error_t
+netfs_attempt_mkdir (struct iouser *user, struct node *dir,
+		     char *name, mode_t mode)
+{
+  return EOPNOTSUPP;
+}
+
+/* Attempt to remove directory named NAME in DIR for USER. */
+error_t
+netfs_attempt_rmdir (struct iouser *user, 
+		     struct node *dir, char *name)
+{
+  return EOPNOTSUPP;
+}
+
+/* Create a link in DIR with name NAME to FILE for USER.  Note that neither
+   DIR nor FILE are locked.  If EXCL is set, do not delete the target, but
+   return EEXIST if NAME is already found in DIR.  */
+error_t
+netfs_attempt_link (struct iouser *user, struct node *dir,
+		    struct node *file, char *name, int excl)
+{
+  return EOPNOTSUPP;
+}
+
+/* Attempt to create an anonymous file related to DIR for USER with MODE.
+   Set *NODE to the returned file upon success.  No matter what, unlock DIR. */
+error_t
+netfs_attempt_mkfile (struct iouser *user, struct node *dir,
+		      mode_t mode, struct node **node)
+{
+  return EOPNOTSUPP;
+}
+
+/* Read from the file NODE for user CRED starting at OFFSET and continuing for
+   up to *LEN bytes.  Put the data at DATA.  Set *LEN to the amount
+   successfully read upon return.  */
+error_t
+netfs_attempt_read (struct iouser *cred, struct node *node,
+		    off_t offset, size_t *len, void *data)
+{
+  return EOPNOTSUPP;
+}
+
+/* Write to the file NODE for user CRED starting at OFSET and continuing for up
+   to *LEN bytes from DATA.  Set *LEN to the amount seccessfully written upon
+   return. */
+error_t
+netfs_attempt_write (struct iouser *cred, struct node *node,
+		     off_t offset, size_t *len, void *data)
+{
+  return EOPNOTSUPP;
+}