Make reincarnation both a tool and a translator

5 files changed, 381 insertions, 32 deletions

diff --git a/Makefile b/Makefile
index b5db788..76cdbc0 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,8 @@ OBJS = $(SRCS:.c=.o) \
        notifyServer.o \
        reincarnationServer.o \
        reincarnationUser.o \
-       start-translator-long.o \
+       fsysServer.o \
+       fsys_proxy.o \
 
 targets = reincarnation persistent-hello
 HURDLIBS = fshelp trivfs ihash shouldbeinlibc
@@ -35,7 +36,8 @@ HURDLIBS = fshelp trivfs ihash shouldbeinlibc
 include ../Makeconf
 
 reincarnation: stubs.o notifyServer.o reincarnationServer.o \
-	start-translator-long.o
+	fsysServer.o fsys_proxy.o \
+	../libfshelp/libfshelp.a
 persistent-hello: reincarnationUser.o ../libtrivfs/libtrivfs.a ../libfshelp/libfshelp.a ../libports/libports.a ../libihash/libihash.a
 
 $(targets): %: %.o lib.o
diff --git a/fsys_proxy.c b/fsys_proxy.c
new file mode 100644
index 0000000..0af04ac
--- /dev/null
+++ b/fsys_proxy.c
@@ -0,0 +1,159 @@
+/* A proxy for fsys messages.
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+
+   Written by Justus Winter <4winter@informatik.uni-hamburg.de>
+
+   This file might one day be a part of the GNU Hurd.
+
+   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, see <http://www.gnu.org/licenses/>.  */
+
+#include "priv.h"
+
+#include <hurd/fsys.h>
+
+error_t
+S_fsys_startup (mach_port_t bootstrap, int flags, mach_port_t control,
+		mach_port_t *real, mach_msg_type_name_t *realtype)
+{
+  error_t err;
+
+  if (failures == 0)
+    {
+      /* This is our first child, do the rendezvous on our bootstrap
+	 port.  */
+      err = fsys_startup (our_bootstrap,
+			  flags,
+			  reincarnation_port,
+			  MACH_MSG_TYPE_COPY_SEND,
+			  real);
+      if (err)
+	return err;
+
+      /* Steal the underlying node.  */
+      node = *real;
+    }
+  else
+    /* Provide the underlying node.  */
+    *real = node;
+
+  /* Always create a copy.  */
+  *realtype = MACH_MSG_TYPE_COPY_SEND;
+
+  /* Update the control port.  */
+  active_control = control;
+
+  if (failures > 0)
+    {
+      /* Reinstall the translator.  */
+      err = install_translator ();
+      if (err)
+	return err;
+    }
+
+  err = register_dead_name_notification ();
+  if (err)
+    return err;
+
+  return err;
+}
+
+error_t
+S_fsys_getroot (mach_port_t fsys_t,
+		mach_port_t dotdotnode,
+		uid_t *uids, size_t nuids,
+		uid_t *gids, size_t ngids,
+		int flags,
+		retry_type *do_retry,
+		char *retry_name,
+		mach_port_t *ret,
+		mach_msg_type_name_t *rettype)
+{
+  *rettype = MACH_MSG_TYPE_MOVE_SEND;
+  return fsys_getroot (active_control,
+		       dotdotnode, MACH_MSG_TYPE_MOVE_SEND,
+		       uids, nuids,
+		       gids, ngids,
+		       flags,
+		       do_retry,
+		       retry_name,
+		       ret);
+}
+
+error_t
+S_fsys_goaway (mach_port_t control, int flags)
+{
+  /* XXX we never get to see those...  */
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_syncfs (mach_port_t control,
+	       int wait,
+	       int recurse)
+{
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_set_options (mach_port_t control,
+		    char *data, mach_msg_type_number_t len,
+		    int do_children)
+{
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_get_options (mach_port_t control,
+		    char **data, mach_msg_type_number_t *len)
+{
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_getfile (mach_port_t control,
+		uid_t *uids, size_t nuids,
+		uid_t *gids, size_t ngids,
+		char *handle, size_t handllen,
+		mach_port_t *pt,
+		mach_msg_type_name_t *pttype)
+{
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_getpriv (mach_port_t control,
+		mach_port_t *host_priv, mach_msg_type_name_t *host_priv_type,
+		mach_port_t *dev_master, mach_msg_type_name_t *dev_master_type,
+		task_t *fs_task, mach_msg_type_name_t *fs_task_type)
+{
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_init (mach_port_t control,
+	   mach_port_t reply,
+	   mach_msg_type_name_t replytype,
+	   mach_port_t proc,
+	   auth_t auth)
+{
+  return EOPNOTSUPP;
+}
+
+error_t
+S_fsys_forward (mach_port_t server, mach_port_t requestor,
+		char *argz, size_t argz_len)
+{
+  return EOPNOTSUPP;
+}
diff --git a/priv.h b/priv.h
new file mode 100644
index 0000000..d3e3dbe
--- /dev/null
+++ b/priv.h
@@ -0,0 +1,50 @@
+/* Reincarnation services for translators.
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+
+   Written by Justus Winter <4winter@informatik.uni-hamburg.de>
+
+   This file might one day be a part of the GNU Hurd.
+
+   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, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef __REINCARNATION_PRIV_H__
+#define __REINCARNATION_PRIV_H__
+
+#include "reincarnation.h"
+
+/* The number of failures.  */
+extern unsigned int failures;
+
+/* XXX currently we handle all messages on this port.  */
+extern mach_port_t reincarnation_port;
+
+/* Our bootstrap port in case we are called as a translator.  */
+extern mach_port_t our_bootstrap;
+
+/* The filesystem node we're putting a translator on.  */
+extern file_t node;
+
+/* The control port for any active translator we start up.  */
+extern fsys_t active_control;
+
+/* XXX */
+error_t
+register_dead_name_notification (void);
+
+/* XXX */
+error_t
+install_translator (void);
+
+#endif  /* __REINCARNATION_PRIV_H__ */
diff --git a/reincarnation.c b/reincarnation.c
index 29b3505..f780b75 100644
--- a/reincarnation.c
+++ b/reincarnation.c
@@ -40,11 +40,21 @@
 
 #include <version.h>
 
+#include "priv.h"
 #include "reincarnation.h"
 #include "reincarnation_S.h"
 
 const char const *argp_program_version = STANDARD_HURD_VERSION (reincarnation);
 
+/* Our bootstrap port in case we are called as a translator.  */
+mach_port_t our_bootstrap;
+
+/* The number of failures.  */
+unsigned int failures;
+
+/* XXX currently we handle all messages on this port.  */
+mach_port_t reincarnation_port;
+
 /* The filesystem node we're putting a translator on.  */
 char *node_name = NULL;
 file_t node;
@@ -73,6 +83,25 @@ int timeout = DEFAULT_TIMEOUT * 1000; /* ms */
 mach_port_t ports[INIT_PORT_MAX];
 mach_port_t fds[STDERR_FILENO + 1];
 int ints[INIT_INT_MAX];
+
+/* Forward declarations.  */
+int
+translator_mode (void);
+
+error_t
+start_child (void);
+
+error_t
+chainload_translator (char *name, char *argz,
+		      int argz_len, mach_port_t *fds,
+		      mach_msg_type_name_t fds_type, int fds_len,
+		      mach_port_t *ports,
+		      mach_msg_type_name_t ports_type, int ports_len,
+		      int *ints, int ints_len,
+		      uid_t owner_uid,
+		      task_t *task);
+
+/* Command line parsing.  */
 
 #define _STRINGIFY(arg) #arg
 #define STRINGIFY(arg) _STRINGIFY (arg)
@@ -114,7 +143,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
     case 't': timeout = atof (arg) * 1000.0; break;
 
     case ARGP_KEY_ARG:
-      if (state->arg_num == 0)
+      if (state->arg_num == 0 && ! translator_mode ())
 	node_name = arg;
       else			/* command */
 	{
@@ -136,19 +165,17 @@ parse_opt (int key, char *arg, struct argp_state *state)
 }
 struct argp argp = {options, parse_opt, args_doc, doc};
 
-mach_port_t reincarnation_port;
-error_t
-start_child (void);
-
 static int
 demuxer (mach_msg_header_t *inp,
 	 mach_msg_header_t *outp)
 {
   extern int notify_server ();
   extern int reincarnation_server ();
+  extern int fsys_server ();
 
   return (notify_server (inp, outp) ||
-	  reincarnation_server (inp, outp));
+	  reincarnation_server (inp, outp) ||
+	  fsys_server (inp, outp));
 }
 
 error_t
@@ -171,10 +198,23 @@ prepare_child (void)
 }
 
 int
+translator_mode (void)
+{
+  return our_bootstrap != MACH_PORT_NULL;
+}
+
+int
 main (int argc, char **argv)
 {
   error_t err;
 
+  /* See if we are used as translator.  */
+  task_get_bootstrap_port (mach_task_self (), &our_bootstrap);
+  if (translator_mode ())
+    {
+      active_flags |= FS_TRANS_ORPHAN;
+    }
+
   argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, 0);
 
   err = mach_port_allocate (mach_task_self (), MACH_PORT_RIGHT_RECEIVE,
@@ -197,7 +237,7 @@ main (int argc, char **argv)
 
   err = start_child ();
   if (err)
-    error (5, err, "starting child");
+    error (5, err, "starting initial child");
 
   while (1)
     {
@@ -249,40 +289,135 @@ start_child (void)
     return 0;
   }
 
-  err = fshelp_start_translator_long (open_node, NULL,
-				      argz, argz, argz_len,
-				      fds, MACH_MSG_TYPE_COPY_SEND,
-				      STDERR_FILENO + 1,
-				      ports, MACH_MSG_TYPE_COPY_SEND,
-				      INIT_PORT_MAX,
-				      ints, INIT_INT_MAX,
-				      geteuid (),
-				      timeout, &active_control);
-  if (err)
-    return err;
+  if (translator_mode ())
+    {
+      ports[INIT_PORT_BOOTSTRAP] = reincarnation_port; /* XXX */
+      err = chainload_translator (argz, argz, argz_len,
+				  fds, MACH_MSG_TYPE_COPY_SEND,
+				  STDERR_FILENO + 1,
+				  ports, MACH_MSG_TYPE_COPY_SEND,
+				  INIT_PORT_MAX,
+				  ints, INIT_INT_MAX,
+				  geteuid (),
+				  &child_task);
+    }
+  else
+    {
+      err = fshelp_start_translator_long (open_node, NULL,
+					  argz, argz, argz_len,
+					  fds, MACH_MSG_TYPE_COPY_SEND,
+					  STDERR_FILENO + 1,
+					  ports, MACH_MSG_TYPE_COPY_SEND,
+					  INIT_PORT_MAX,
+					  ints, INIT_INT_MAX,
+					  geteuid (),
+					  timeout, &active_control);
+      if (err)
+	return err;
+
+      err = install_translator ();
+      if (err)
+	return err;
+
+      err = register_dead_name_notification ();
+    }
+
+  return err;
+}
+
+error_t
+register_dead_name_notification (void)
+{
+  error_t err;
 
   /* Ask to be told if TASK dies.  */
   mach_port_t prev_notify;
   err =
-    mach_port_request_notification(mach_task_self(),
-				   active_control, MACH_NOTIFY_DEAD_NAME, 0,
-				   reincarnation_port,
-				   MACH_MSG_TYPE_MAKE_SEND_ONCE,
-				   &prev_notify);
+    mach_port_request_notification (mach_task_self (),
+				    active_control,
+				    MACH_NOTIFY_DEAD_NAME, 0,
+				    reincarnation_port,
+				    MACH_MSG_TYPE_MAKE_SEND_ONCE,
+				    &prev_notify);
   if (err)
     return err;
 
   if (prev_notify != MACH_PORT_NULL)
     mach_port_deallocate (mach_task_self (), prev_notify);
 
-  err = file_set_translator (node,
-			     passive_flags, active_flags, goaway_flags,
-			     argz, argz_len,
-			     active_control, MACH_MSG_TYPE_COPY_SEND);
+  return err;
+}
+
+error_t
+install_translator (void)
+{
+  error_t err = file_set_translator (node,
+				     passive_flags, active_flags, goaway_flags,
+				     argz, argz_len,
+				     active_control, MACH_MSG_TYPE_COPY_SEND);
+  return err;
+}
+
+error_t
+chainload_translator (char *name, char *argz,
+		      int argz_len, mach_port_t *fds,
+		      mach_msg_type_name_t fds_type, int fds_len,
+		      mach_port_t *ports,
+		      mach_msg_type_name_t ports_type, int ports_len,
+		      int *ints, int ints_len,
+		      uid_t owner_uid,
+		      task_t *task)
+{
+  error_t err;
+
+  /* Find the translator itself.  */
+  file_t executable = file_name_lookup (name, O_EXEC, 0);
+  if (executable == MACH_PORT_NULL)
+    return errno;
+
+  /* Create the task for the translator.  */
+  err = task_create (mach_task_self (),
+#ifdef KERN_INVALID_LEDGER
+		     NULL, 0,	/* OSF Mach */
+#endif
+		     0, task);
   if (err)
-    return err;
+    goto lose;
 
-  return 0;
+  /* XXX 25 is BASEPRI_USER, which isn't exported by the kernel.  Ideally,
+     nice values should be used, perhaps with a simple wrapper to convert
+     them to Mach priorities.  */
+  err = task_priority (*task, 25, FALSE);
+  if (err)
+    goto lose;
+
+  /* Designate TASK as our child and set it's owner accordingly. */
+  mach_port_t proc = getproc ();
+  proc_child (proc, *task);
+  mach_port_t childproc;
+  err = proc_task2proc (proc, *task, &childproc);
+  mach_port_deallocate (mach_task_self (), proc);
+  if (err)
+    goto lose;
+  err = proc_setowner (childproc, owner_uid, owner_uid == (uid_t) -1);
+  mach_port_deallocate (mach_task_self (), childproc);
+  if (err)
+    goto lose;
+
+  /* Try and exec the translator in TASK...  */
+  err = file_exec (executable, *task, EXEC_DEFAULTS,
+		   argz, argz_len, 0, 0,
+		   fds, fds_type, fds_len,
+		   ports, ports_type, ports_len,
+		   ints, ints_len, 0, 0, 0, 0);
+  if (err)
+    {
+      task_terminate (*task);
+      goto lose;
+    }
+
+ lose:
+  return err;
 }
 
 kern_return_t
@@ -295,7 +430,8 @@ do_mach_notify_dead_name (mach_port_t notify,
   if (name != active_control)
     return EPERM;
 
-  error (0, 0, "child died");
+  failures += 1;
+  error (0, 0, "Child died (%u failure%s)", failures, failures > 1? "s": "");
 
   err = start_child ();
   if (err)
diff --git a/reincarnation.h b/reincarnation.h
index 7e1b16e..8432e42 100644
--- a/reincarnation.h
+++ b/reincarnation.h
@@ -22,7 +22,9 @@
 #ifndef __REINCARNATION_H__
 #define __REINCARNATION_H__
 
+#include <error.h>
 #include <hurd.h>
+#include <mach.h>
 
 #define TASK_PORT_REGISTER_REINCARNATION	0