Implement emergency shell.

* src/pies.c (main): Move init-specific command line
handling to sysvinit_parse_argv.
* src/pies.h (dfl_level): Remove extern.
(sysvinit_parse_argv): New proto.
* src/sysvinit.c (sysvinit_parse_argv): New function.
(sysvinit_begin): Start emergency shell, if requested.

4 files changed, 95 insertions, 25 deletions

diff --git a/src/pies.c b/src/pies.c
index 3734b47..653a865 100644
--- a/src/pies.c
+++ b/src/pies.c
@@ -1927,7 +1927,6 @@ char **pies_master_argv;
 int
 main (int argc, char **argv)
 {
-  int index;
   pid_t pid;
   extern char **environ;
   struct grecs_list_entry *ep;
@@ -2001,18 +2000,24 @@ main (int argc, char **argv)
       config_file_add_type (CONF_INITTAB, "/etc/inittab");
       config_file_add_type (CONF_PIES, "/etc/pies.init");
 #endif
-      for (index = 1; index < argc; index++)
+      sysvinit_parse_argv (argc, argv);
+    }
+  else
+    {
+      int index;
+
+      parse_options (argc, argv, &index);
+      argc -= index;
+      argv += index;
+      
+      if (argc && !(command == COM_RESTART_COMPONENT
+                    || command == COM_TRACE_DEPEND
+                    || command == COM_TRACE_PREREQ))
         {
-          if (!strcmp (argv[index], "single") || !strcmp (argv[index], "-s"))
-            dfl_level = 'S';
-          else if (strchr("0123456789sS", argv[index][0]) && !argv[index][1])
-            {
-              dfl_level = toupper (argv[index][0]);
-            }     
+          logmsg (LOG_ERR, "extra command line arguments");
+          exit (EX_USAGE);
         }
     }
-  else
-    parse_options (argc, argv, &index);
   
   if (!instance)
     {
@@ -2059,15 +2064,6 @@ main (int argc, char **argv)
   /* Re-setup logging: it might have been reset in the config file */
   diag_setup (log_to_stderr_only ? DIAG_TO_STDERR : 0);
   
-  if (argc != index
-      && !(command == COM_RESTART_COMPONENT
-           || command == COM_TRACE_DEPEND
-           || command == COM_TRACE_PREREQ))
-    {
-      logmsg (LOG_ERR, "extra command line arguments");
-      exit (EX_CONFIG);
-    }
-
   if (!control.url)
     {
       char const *str = default_control_url[init_process];
@@ -2086,7 +2082,7 @@ main (int argc, char **argv)
       pies_priv_setup (&pies_privs);
       if (pies_umask)
         umask (pies_umask);
-      exit (request_restart_components (argc - index, argv + index));
+      exit (request_restart_components (argc, argv));
       
     case COM_RELOAD:
       exit (request_reload ());
@@ -2102,11 +2098,11 @@ main (int argc, char **argv)
       exit (0);
 
     case COM_TRACE_DEPEND:
-      components_trace (argv + index, depmap_row);
+      components_trace (argv, depmap_row);
       exit (0);
       
     case COM_TRACE_PREREQ: 
-      components_trace (argv + index, depmap_col);
+      components_trace (argv, depmap_col);
       exit (0);
       
     default:
diff --git a/src/pies.h b/src/pies.h
index bcce32a..4a6160f 100644
--- a/src/pies.h
+++ b/src/pies.h
@@ -291,7 +291,6 @@ extern char *qotdfile;
 extern int init_process;
 extern char *console_device;
 extern int initdefault;
-extern int dfl_level;
 
 extern size_t pies_master_argc;
 extern char **pies_master_argv;
@@ -523,6 +522,7 @@ void sysvinit_power (void);
 
 void sysvinit_report (struct json_value *obj);
 int sysvinit_set_runlevel (int newlevel);
+void sysvinit_parse_argv (int argc, char **argv);
 
 extern char *sysvinit_environ_hint[];
 extern char *init_fifo;
diff --git a/src/progman.c b/src/progman.c
index 8a5187c..1be7d27 100644
--- a/src/progman.c
+++ b/src/progman.c
@@ -1205,7 +1205,7 @@ prog_start (struct prog *prog)
       close_fds (&fdset);
 
       prog_execute (prog);
-
+      
       
     case -1:
       logmsg (LOG_CRIT,
@@ -1546,6 +1546,9 @@ progman_wake_sleeping (int onalrm)
     {
       if (IS_ACTIVE_COMPONENT (prog) && prog->v.p.wait)
         {
+          /* The following works on the assumption that prog->v.p.wait is
+             set when enabling the component and gets cleared right after
+             it has finished. */
           if (prog->v.p.status != status_running)
             prog_start (prog);
           return;
@@ -2411,4 +2414,5 @@ progman_stop_tag (const char *name)
   struct prog *prog = progman_locate (name);
   progman_stop_component (&prog);
 }
+
 /* EOF */
diff --git a/src/sysvinit.c b/src/sysvinit.c
index 2d0671c..0370fcc 100644
--- a/src/sysvinit.c
+++ b/src/sysvinit.c
@@ -16,6 +16,7 @@
 
 #include "pies.h"
 #include "prog.h"
+#include <sys/ioctl.h>
 #include <termios.h>
 
 enum boot_state
@@ -59,12 +60,13 @@ int prevlevel = 'N';
 
 int initdefault;               /* Default runlevel */
 int dfl_level;
+int emergency_shell;
 
 int
 console_open (int mode)
 {
   int i, fd;
-  
+
   for (i = 0; i < 5; i++)
     {
       fd = open (console_device, mode | O_NONBLOCK);
@@ -646,6 +648,56 @@ unintr_sleep (unsigned n)
     ;
 }
 
+static void
+start_shell (const char *shell)
+{
+  pid_t pid, rc;
+  int st;
+  struct sigaction act, old;
+
+  act.sa_flags = SA_RESTART;
+  act.sa_handler = SIG_DFL;
+  sigemptyset (&act.sa_mask);
+  sigaction (SIGCHLD, &act, &old);
+
+  pid = fork ();
+  if (pid == -1)
+    {
+      logmsg (LOG_CRIT, "cannot run `%s': fork failed: %s",
+              shell, strerror (errno));
+      exit (1);
+    }
+
+  if (pid == 0)
+    {
+      int fd;
+
+      signal_setup (SIG_DFL);
+      setsid ();
+      
+      fd = console_open (O_RDWR|O_NOCTTY);
+      if (fd < 0) 
+        {
+          logmsg (LOG_CRIT, "open(%s): %s",
+                  console_device, strerror (errno));
+          exit (1);
+        }
+      ioctl (fd, TIOCSCTTY, 1);
+      dup (fd);
+      dup (fd);
+
+      execl (shell, shell, NULL);
+      _exit (127);
+    }
+  
+  while ((rc = wait (&st)) != pid)
+    if (rc == (pid_t) -1 && errno == ECHILD)
+      break;
+  
+  logmsg (LOG_CRIT, "shell finished");
+  sigaction (SIGCHLD, &old, NULL);
+}
+
 /* Memory allocation functions for INIT.  They may not fail, therefore
    they just retry allocation until it eventually succeeds.
 */
@@ -698,6 +750,8 @@ sysvinit_begin ()
   sysvinit_runlevel_setup (PIES_COMP_DEFAULT);
   add_extra_sigv (sigv, ARRAY_SIZE (sigv));