>From feb8c6ff2c42f0d0f556aa1eb1b033cb875d5f2f Mon Sep 17 00:00:00 2001
From: Sergiu Ivanov <unlimitedscol...@gmail.com>
Date: Thu, 11 Jun 2009 17:09:38 +0300
Subject: [PATCH] Add the code for starting up the mountee.
* netfs.c: Update copyright years.
(netfs_S_dir_lookup): Add the code for starting up the mountee
at the first invocation.
(netfs_get_dirents): Likewise.
* unionmount.h: (unionmount_proxy): Declare this variable.
(mountee_port): Likewise.
(mountee_started): Likewise.
(unionmount_start_mountee): Declare this function.
(unionmount_setup): Likewise.
* unionmount.c: (unionmount_proxy): Define this variable.
(mountee_port): Likewise.
(mountee_started): Likewise.
(unionmount_start_mountee): Borrow the code of this function
from node_set_translator in nsmux and adapt its variable names.
(unionmount_setup): Define this function.
---
netfs.c | 38 +++++++++++++-
unionmount.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
unionmount.h | 26 +++++++++
3 files changed, 231 insertions(+), 1 deletions(-)
diff --git a/netfs.c b/netfs.c
index 89d1bf6..fce3366 100644
--- a/netfs.c
+++ b/netfs.c
@@ -1,7 +1,11 @@
/* Hurd unionfs
- Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2005, 2009 Free Software
+ Foundation, Inc.
+
Written by Moritz Schulte <mor...@duesseldorf.ccc.de>.
+ Adapted to unionmount by Sergiu Ivanov <unlimitedscol...@gmail.com>
+
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 of the
@@ -36,6 +40,7 @@
#include "lib.h"
#include "ncache.h"
#include "options.h"
+#include "unionmount.h"
/* Return an argz string describing the current options. Fill *ARGZ
with a pointer to newly malloced storage holding the list and *LEN
@@ -810,6 +815,21 @@ netfs_S_dir_lookup (struct protid *diruser,
goto gotit;
}
+ /*Start the mountee if it's not running yet. */
+ if (!mountee_started)
+ {
+ error = unionmount_setup (diruser);
+ if (error)
+ {
+ /*This is actually the end of initialization, so if something
+ goes bad here we are rightful to die. And, of course,
+ unionmount makes no sense if the mountee is not running. */
+ errno = error;
+ perror ("failed to setup the mountee");
+ exit (EXIT_FAILURE);
+ }
+ }
+
dnp = diruser->po->np;
mutex_lock (&dnp->lock);
@@ -1112,6 +1132,22 @@ netfs_get_dirents (struct iouser *cred, struct node *dir,
return 0;
}
+ /*Start the mountee if it's not running yet. */
+ if (!mountee_started)
+ {
+ err = unionmount_setup
+ (netfs_make_protid (netfs_make_peropen (dir, O_READ, NULL), cred));
+ if (err)
+ {
+ /*This is actually the end of initialization, so if something
+ goes bad here we are rightful to die. And, of course,
+ unionmount makes no sense if the mountee is not running. */
+ errno = err;
+ perror ("failed to setup the mountee");
+ exit (EXIT_FAILURE);
+ }
+ }
+
err = node_entries_get (dir, &dirent_list);
if (! err)
diff --git a/unionmount.c b/unionmount.c
index e4aa043..0e3317d 100644
--- a/unionmount.c
+++ b/unionmount.c
@@ -21,8 +21,176 @@
#define _GNU_SOURCE 1
+#include <hurd/fsys.h>
+#include <fcntl.h>
+
+#include "lib.h"
+#include "ulfs.h"
#include "unionmount.h"
/*The command line for starting the mountee. */
char * mountee_argz;
size_t mountee_argz_len;
+
+/*The node the mountee is sitting on. */
+node_t * unionmount_proxy;
+
+/*The port to the mountee. */
+mach_port_t mountee_port;
+
+/*Shows whether the mountee has been started already. */
+int mountee_started = 0;
+
+/*Starts the mountee (given by `argz` and `argz_len`), sets it on node
+ `np` and opens a port `port` to with `flags`. */
+error_t
+unionmount_start_mountee (struct protid * diruser, node_t * np, char * argz,
+ size_t argz_len, int flags, mach_port_t * port)
+{
+ error_t err;
+ mach_port_t p;
+
+ /*An unauthenticated port to the directory containing `np` */
+ mach_port_t unauth_dir;
+
+ /*The control port for the active translator */
+ mach_port_t active_control;
+
+ /*A copy of the user information, supplied in `user` */
+ struct iouser * user;
+
+ /*A protid for the supplied node */
+ struct protid * newpi;
+
+ /*Identity information about the current process (for fsys_getroot) */
+ uid_t * uids;
+ size_t nuids;
+
+ gid_t * gids;
+ size_t ngids;
+
+ /*The retry information returned by fsys_getroot */
+ string_t retry_name;
+ mach_port_t retry_port;
+
+ /*Try to get the number of effective UIDs */
+ nuids = geteuids (0, 0);
+ if (nuids < 0)
+ return EPERM;
+
+ /*Allocate some memory for the UIDs on the stack */
+ uids = alloca (nuids * sizeof (uid_t));
+
+ /*Fetch the UIDs themselves */
+ nuids = geteuids (nuids, uids);
+ if (nuids < 0)
+ return EPERM;
+
+ /*Try to get the number of effective GIDs */
+ ngids = getgroups (0, 0);
+ if (ngids < 0)
+ return EPERM;
+
+ /*Allocate some memory for the GIDs on the stack */
+ gids = alloca (ngids * sizeof (gid_t));
+
+ /*Fetch the GIDs themselves */
+ ngids = getgroups (ngids, gids);
+ if (ngids < 0)
+ return EPERM;
+
+ /*Opens the port on which to set the new translator */
+ error_t
+ open_port
+ (int flags, mach_port_t * underlying,
+ mach_msg_type_name_t * underlying_type, task_t task, void *cookie)
+ {
+ err = 0;
+
+ /*Duplicate the supplied user */
+ err = iohelp_dup_iouser (&user, diruser->user);
+ if (err)
+ return err;
+
+ /*Create a protid for this node */
+ newpi = netfs_make_protid
+ (netfs_make_peropen (np, flags, diruser->po), user);
+ if (!newpi)
+ {
+ iohelp_free_iouser (user);
+ return errno;
+ }
+
+ /*Obtain the resulting port right and set its type appropriately */
+ *underlying = p = ports_get_send_right (newpi);
+ *underlying_type = MACH_MSG_TYPE_COPY_SEND;
+
+ /*Drop our reference to the port */
+ ports_port_deref (newpi);
+
+ /*Return the result of operations (everything should be okay here) */
+ return err;
+ } /*open_port */
+
+ /*Obtain the unauthenticated port to the directory */
+ err = io_restrict_auth
+ (diruser->po->np->nn->ulfs[0].port, &unauth_dir, 0, 0, 0, 0);
+ if (err)
+ return err;
+
+ /*Start the translator */
+ /*The value 60000 for the timeout is the one found in settrans */
+ err = fshelp_start_translator
+ (open_port, NULL, argz, argz, argz_len, 60000, &active_control);
+ if (err)
+ return err;
+
+ /*Attempt to set a translator on the port opened by the previous call */
+ err = file_set_translator
+ (p, 0, FS_TRANS_SET, 0, argz, argz_len,
+ active_control, MACH_MSG_TYPE_COPY_SEND);
+ port_dealloc (p);
+ if (err)
+ return err;
+
+ /*Obtain the port to the top of the newly-set translator */
+ err = fsys_getroot
+ (active_control, unauth_dir, MACH_MSG_TYPE_COPY_SEND,
+ uids, nuids, gids, ngids, flags, &retry_port, retry_name, &p);
+ if (err)
+ return err;
+
+ /*Return the port */
+ *port = p;
+
+ /*Everything is OK here */
+ return 0;
+} /* unionmount_start_trans */
+
+/*Sets up a proxy node, sets the translator on it, and registers the
+ filesystem published by the translator in the list of merged
+ filesystems. */
+/*Diruser is required for some additional information. */
+error_t
+unionmount_setup (struct protid * diruser)
+{
+ error_t err = 0;
+
+ /*Create a clone of the root node of the translator. */
+ unionmount_proxy = netfs_make_node (netfs_root_node->nn);
+ if (!unionmount_proxy)
+ return ENOMEM;
+
+ /*Set the mountee on the proxy node. */
+ /*Note that the flags parameter does not actually limit access to
+ the translator's filesystem, because unionmount gives off ports to
+ libnetfs nodes only when it looks up directories. The end client
+ communicates to the translator when operating on regular files. */
+ unionmount_start_mountee (diruser, unionmount_proxy, mountee_argz,
+ mountee_argz_len, O_READ, &mountee_port);
+
+ mountee_started = 1;
+
+ return err;
+} /* unionmount_setup */
+
diff --git a/unionmount.h b/unionmount.h
index a3f7588..fabb2f5 100644
--- a/unionmount.h
+++ b/unionmount.h
@@ -22,10 +22,36 @@
#ifndef INCLUDED_UNIONMOUNT_H
#define INCLUDED_UNIONMOUNT_H
+#include <error.h>
#include <unistd.h>
+#include <hurd/hurd_types.h>
+
+#include "node.h"
/*The command line for starting the mountee. */
extern char * mountee_argz;
extern size_t mountee_argz_len;
+/*The node the mountee is sitting on. */
+extern node_t * unionmount_proxy;
+
+/*The port to the mountee. */
+extern mach_port_t mountee_port;
+
+/*Shows whether the mountee has been started already. */
+extern int mountee_started;
+
+/*Starts the mountee (given by `argz` and `argz_len`), sets it on node
+ `np` and opens a port `port` to with `flags`. */
+error_t
+unionmount_start_mountee (struct protid * diruser, node_t * np, char * argz,
+ size_t argz_len, int flags, mach_port_t * port);
+
+/*Sets up a proxy node, sets the translator on it, and registers the
+ filesystem published by the translator in the list of merged
+ filesystems. */
+/*Diruser is required for additional information. */
+error_t
+unionmount_setup (struct protid * diruser);
+
#endif /*INCLUDED_UNIONMOUNT_H*/
--
1.5.2.4
