Make reincarnation both a tool and a translator

1 files changed, 166 insertions, 30 deletions

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)