Initial checkin.

1 files changed, 401 insertions, 0 deletions

diff --git a/hostmux/mux.c b/hostmux/mux.c
new file mode 100644
index 00000000..cba29126
--- /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;
+    }
+}