openrc/src/librc.c

/*
   librc 
   core RC functions
   Copyright 2007 Gentoo Foundation
   Released under the GPLv2
   */

#include <sys/types.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <errno.h>
#ifndef __linux__
/* Although linux should work fine, gcc likes to bitch with our default
   CFLAGS so we just don't include the file and use the GNU one defined
   in string.h */
#include <libgen.h>
#endif
#include <limits.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "einfo.h"
#include "rc.h"
#include "rc-misc.h"
#include "strlist.h"

/* usecs to wait while we poll the fifo */
#define WAIT_INTERVAL	20000

/* max secs to wait until a service comes up */
#define WAIT_MAX	60

#define SOFTLEVEL	RC_SVCDIR "softlevel"

static const char *rc_service_state_names[] = {
  "started",
  "stopped",
  "starting",
  "stopping",
  "inactive",
  "wasinactive",
  "coldplugged",
  "failed",
  NULL
};

bool rc_runlevel_starting (void)
{
  return (rc_is_dir (RC_SVCDIR "softscripts.old"));
}

bool rc_runlevel_stopping (void)
{
  return (rc_is_dir (RC_SVCDIR "softscripts.new"));
}

char **rc_get_runlevels (void)
{
  char **dirs = rc_ls_dir (NULL, RC_RUNLEVELDIR, 0);
  char **runlevels = NULL;
  int i;
  char *dir;

  STRLIST_FOREACH (dirs, dir, i)
    {
      char *path = rc_strcatpaths (RC_RUNLEVELDIR, dir, NULL);
      if (rc_is_dir (path))
	runlevels = rc_strlist_addsort (runlevels, dir);
      free (path);
    }
  rc_strlist_free (dirs);

  return (runlevels);
}

char *rc_get_runlevel (void)
{
  FILE *fp;
  static char buffer [PATH_MAX];

  if (! (fp = fopen (SOFTLEVEL, "r")))
    {
      strcpy (buffer, "sysinit");
      return (buffer);
    }

  if (fgets (buffer, PATH_MAX, fp))
    {
      int i = strlen (buffer) - 1;
      if (buffer[i] == '\n')
	buffer[i] = 0;
      fclose (fp);
      return (buffer);
    }

  fclose (fp);
  strcpy (buffer, "sysinit");
  return (buffer);
}

void rc_set_runlevel (const char *runlevel)
{
  FILE *fp = fopen (SOFTLEVEL, "w");
  if (! fp)
    eerrorx ("failed to open `" SOFTLEVEL "': %s", strerror (errno));
  fprintf (fp, "%s", runlevel);
  fclose (fp);
}

bool rc_runlevel_exists (const char *runlevel)
{
  char *path;
  bool retval;

  if (! runlevel)
    return (false);

  path = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, NULL);
  retval = rc_is_dir (path);
  free (path);
  return (retval);
}

/* Resolve a service name to it's full path */
char *rc_resolve_service (const char *service)
{
  char buffer[PATH_MAX];
  char *file;
  int r = 0;

  if (! service)
    return (NULL);

  if (service[0] == '/')
    return (strdup (service));

  file = rc_strcatpaths (RC_SVCDIR, "started", service, NULL);
  if (! rc_is_link (file))
    {
      free (file);
      file = rc_strcatpaths (RC_SVCDIR, "inactive", service, NULL);
      if (! rc_is_link (file))
	{
	  free (file);
	  file = NULL;
	}
    }

  memset (buffer, 0, sizeof (buffer));
  if (file)
    {
      r = readlink (file, buffer, sizeof (buffer));
      free (file);
      if (r > 0)
	return strdup (buffer);
    }

  snprintf (buffer, sizeof (buffer), RC_INITDIR "%s", service);
  return (strdup (buffer));
}

bool rc_service_exists (const char *service)
{
  char *file;
  bool retval = false;
  int len;

  if (! service)
    return (false);

  len = strlen (service);

  /* .sh files are not init scripts */
  if (len > 2 && service[len - 3] == '.' &&
      service[len - 2] == 's' &&
      service[len - 1] == 'h')
    return (false);

  file = rc_resolve_service (service); 
  if (rc_exists (file))
    retval = rc_is_exec (file);
  free (file);
  return (retval);
}

bool rc_service_in_runlevel (const char *service, const char *runlevel)
{
  char *file;
  bool retval;

  if (! runlevel || ! service)
    return (false);

  if (! rc_service_exists (service))
    return (false);

  file = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, basename (service), NULL);
  retval = rc_exists (file);
  free (file);

  return (retval);
}

bool rc_mark_service (const char *service, const rc_service_state_t state)
{
  char *file;
  int i = 0;
  int skip_state = -1;
  char *base;
  char *init = rc_resolve_service (service);
  bool skip_wasinactive = false;

  if (! service)
    return (false);

  base = basename (service);

  if (state != rc_service_stopped)
    {
      if (! rc_is_file(init))
	{
	  free (init);
	  return (false);
	}

      file = rc_strcatpaths (RC_SVCDIR, rc_service_state_names[state], base, NULL);
      if (rc_exists (file))
	unlink (file);
      i = symlink (init, file);
      if (i != 0)
	{
	  free (file);
	  free (init);
	  einfo ("%d %s %s", state, rc_service_state_names[state], base);
	  eerror ("symlink `%s' to `%s': %s", init, file, strerror (errno));
	  return (false);
	}

      free (file);
      skip_state = state;
    }

  if (state == rc_service_coldplugged)
    {
      free (init);
      return (true);
    }

  /* Remove any old states now */
  i = 0;
  while (rc_service_state_names[i])
    {
      if ((i != skip_state &&
	   i != rc_service_stopped &&
	   i != rc_service_coldplugged &&
	   i != rc_service_crashed) &&
	 (! skip_wasinactive || i != rc_service_wasinactive))
	{
	  file = rc_strcatpaths (RC_SVCDIR, rc_service_state_names[i], base, NULL);
	  if (rc_exists (file))
	    {
	      if ((state == rc_service_starting ||
		   state == rc_service_stopping) &&
		  i == rc_service_inactive)
		{
		  char *wasfile = rc_strcatpaths (RC_SVCDIR,
						  rc_service_state_names[rc_service_wasinactive],
						  base, NULL);

		  if (symlink (init, wasfile) != 0)
		    eerror ("symlink `%s' to `%s': %s", init, wasfile,
			    strerror (errno));

		  skip_wasinactive = true;
		  free (wasfile);
		}

	      errno = 0;
	      if (unlink (file) != 0 && errno != ENOENT)
		eerror ("failed to delete `%s': %s", file,
			strerror (errno));
	    }
	  free (file);
	}
      i++;
    }

  /* Remove the exclusive state if we're inactive */
  if (state == rc_service_started ||
      state == rc_service_stopped ||
      state == rc_service_inactive)
    {
      file = rc_strcatpaths (RC_SVCDIR, "exclusive", base, NULL);
      if (rc_exists (file))
	if (unlink (file) != 0)
	  eerror ("unlink `%s': %s", file, strerror (errno));
      free (file);
    }

  /* Remove any options and daemons the service may have stored */
  if (state == rc_service_stopped)
    {
      char *dir = rc_strcatpaths (RC_SVCDIR, "options", base, NULL);

      if (rc_is_dir (dir))
	rc_rm_dir (dir, true);
      free (dir);

      dir = rc_strcatpaths (RC_SVCDIR, "daemons", base, NULL);
      if (rc_is_dir (dir))
	rc_rm_dir (dir, true);
      free (dir);
      
      rc_schedule_clear (service);
    }

  /* These are final states, so remove us from scheduled */
  if (state == rc_service_started || state == rc_service_stopped)
    {
      char *sdir = rc_strcatpaths (RC_SVCDIR, "scheduled", NULL);
      char **dirs = rc_ls_dir (NULL, sdir, 0);
      char *dir;
      int serrno;

      STRLIST_FOREACH (dirs, dir, i)
	{
	  char *bdir = rc_strcatpaths (sdir, dir, NULL);
	  file = rc_strcatpaths (bdir, base, NULL);
	  if (rc_exists (file))
	    if (unlink (file) != 0)
	      eerror ("unlink `%s': %s", file, strerror (errno));
	  free (file);

	  /* Try and remove the dir - we don't care about errors */
	  serrno = errno;
	  rmdir (bdir);
	  errno = serrno;
	  free (bdir);
	}
      rc_strlist_free (dirs);
      free (sdir);
    }

  free (init);
  return (true);
}

bool rc_service_state (const char *service, const rc_service_state_t state)
{
  char *file;
  bool retval;

  /* If the init script does not exist then we are stopped */
  if (! rc_service_exists (service))
    return (state == rc_service_stopped ? true : false);

  /* We check stopped state by not being in any of the others */
  if (state == rc_service_stopped)
    return ( ! (rc_service_state (service, rc_service_started) ||
		rc_service_state (service, rc_service_starting) ||
		rc_service_state (service, rc_service_stopping) ||
		rc_service_state (service, rc_service_inactive)));

  /* The crashed state and scheduled states are virtual */
  if (state == rc_service_crashed)
    return (rc_service_daemons_crashed (service));
  else if (state == rc_service_scheduled)
    {
      char **services = rc_services_scheduled_by (service);
      retval = (services);
      if (services)
	free (services);
      return (retval);
    }

  /* Now we just check if a file by the service name rc_exists
     in the state dir */
  file = rc_strcatpaths (RC_SVCDIR, rc_service_state_names[state],
		      basename (service), NULL);
  retval = rc_exists (file);
  free (file);
  return (retval);
}

bool rc_get_service_option (const char *service, const char *option,
			    char *value)
{
  FILE *fp;
  char buffer[1024];
  char *file = rc_strcatpaths (RC_SVCDIR, "options", service, option, NULL);
  bool retval = false;

  if (rc_exists (file))
    {
      if ((fp = fopen (file, "r")) == NULL)
	eerror ("fopen `%s': %s", file, strerror (errno));
      else
	{
	  memset (buffer, 0, sizeof (buffer));
	  while (fgets (buffer, RC_LINEBUFFER, fp))
	    {
	      memcpy (value, buffer, strlen (buffer));
	      value += strlen (buffer);
	    }
	  fclose (fp);
	  retval = true;
	}
    }

  free (file);
  return (retval);
}

bool rc_set_service_option (const char *service, const char *option,
			    const char *value)
{
  FILE *fp;
  char *path = rc_strcatpaths (RC_SVCDIR, "options", service, NULL);
  char *file = rc_strcatpaths (path, option, NULL);
  bool retval = false;

  if (! rc_is_dir (path))
    {
      if (mkdir (path, 0755) != 0)
	{
	  eerror ("mkdir `%s': %s", path, strerror (errno));
	  free (path);
	  free (file);
	  return (false);
	}
    }

  if ((fp = fopen (file, "w")) == NULL)
    eerror ("fopen `%s': %s", file, strerror (errno));
  else
    {
      if (value)
	fprintf (fp, "%s", value);
      fclose (fp);
      retval = true;
    }

  free (path);
  free (file);
  return (retval);
}

static pid_t _exec_service (const char *service, const char *arg)
{
  char *file;
  char *fifo;
  pid_t pid = -1;
  pid_t savedpid;
  int status;

  file = rc_resolve_service (service);
  if (! rc_is_file (file))
    {
      rc_mark_service (service, rc_service_stopped);
      free (file);
      return (0);
    }

  /* We create a fifo so that other services can wait until we complete */
  fifo = rc_strcatpaths (RC_SVCDIR, "exclusive", basename (service), NULL);

  if (mkfifo (fifo, 0600) != 0 && errno != EEXIST)
    {
      eerror ("unable to create fifo `%s': %s", fifo, strerror (errno));
      free (fifo);
      free (file);
      return (-1);
    }

  if ((pid = fork ()) == 0)
    {
      char *myarg = strdup (arg);
      int e = 0;
      execl (file, file, myarg, NULL);
      e = errno;
      free (myarg);
      unlink (fifo);
      free (fifo);
      eerrorx ("unable to exec `%s': %s", file, strerror (errno));
    }

  free (fifo);
  free (file);

  if (pid == -1)
    {
      eerror ("unable to fork: %s", strerror (errno));
      return (pid);
    }

  if (rc_is_env ("RC_PARALLEL_STARTUP", "yes"))
    return (pid);

  savedpid = pid;
  errno = 0;
  do
    {
      pid = waitpid (savedpid, &status, 0);
      if (pid < 0)
	{
	  if (errno != ECHILD)
	    eerror ("waitpid %d: %s", savedpid, strerror (errno));
	  return (-1);
	}
    } while (! WIFEXITED (status) && ! WIFSIGNALED (status)); 

  return (0);
}

pid_t rc_stop_service (const char *service)
{
  if (rc_service_state (service, rc_service_stopped))
    return (0);

  return (_exec_service (service, "stop"));
}


pid_t rc_start_service (const char *service)
{
  if (! rc_service_state (service, rc_service_stopped))
    return (0);

  return (_exec_service (service, "start"));
}

void rc_schedule_start_service (const char *service,
				const char *service_to_start)
{
  char *dir;
  char *init;
  char *file;

  if (! rc_service_exists (service) || ! rc_service_exists (service_to_start))
    return;

  dir = rc_strcatpaths (RC_SVCDIR, "scheduled", basename (service), NULL);
  if (! rc_is_dir (dir))
    if (mkdir (dir, 0755) != 0)
      {
	eerror ("mkdir `%s': %s", dir, strerror (errno));
	free (dir);
	return;
      }

  init = rc_resolve_service (service_to_start);
  file = rc_strcatpaths (dir, basename (service_to_start), NULL);
  if (! rc_exists (file) && symlink (init, file) != 0)
    eerror ("symlink `%s' to `%s': %s", init, file, strerror (errno));

  free (init);
  free (file);
  free (dir);
}

void rc_schedule_clear (const char *service)
{
  char *dir = rc_strcatpaths (RC_SVCDIR, "scheduled", basename (service), NULL);

  if (rc_is_dir (dir))
    rc_rm_dir (dir, true);
  free (dir);
}

bool rc_wait_service (const char *service)
{
  char *fifo = rc_strcatpaths (RC_SVCDIR, "exclusive", basename (service), NULL);
  struct timeval tv;
  struct timeval stopat;
  struct timeval now;
  bool retval = false;

  if (gettimeofday (&stopat, NULL) != 0)
    {
      eerror ("gettimeofday: %s", strerror (errno));
      return (false);
    }
  stopat.tv_sec += WAIT_MAX;

  while (true)
    {
      if (! rc_exists (fifo))
	{
	  retval = true;
	  break;
	}

      tv.tv_sec = 0;
      tv.tv_usec = WAIT_INTERVAL;
      if (select (0, 0, 0, 0, &tv) < 0)
	{
	  if (errno != EINTR)
	    eerror ("select: %s",strerror (errno));
	  break;
	}

      /* Don't hang around forever */
      if (gettimeofday (&now, NULL) != 0)
	{
	  eerror ("gettimeofday: %s", strerror (errno));
	  break;
	}
      if (timercmp (&now, &stopat, >))
	break;
    }

  free (fifo);
  return (retval);
}

char **rc_services_in_runlevel (const char *runlevel)
{
  char *dir;
  char **list = NULL;

  if (! runlevel)
    return (rc_ls_dir (NULL, RC_INITDIR, RC_LS_INITD));

  /* These special levels never contain any services */
  if (strcmp (runlevel, RC_LEVEL_SYSINIT) == 0 ||
      strcmp (runlevel, RC_LEVEL_SINGLE) == 0)
    return (NULL);

  dir = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, NULL);
  if (! rc_is_dir (dir))
      eerror ("runlevel `%s' does not exist", runlevel);
  else
    list = rc_ls_dir (list, dir, RC_LS_INITD);

  free (dir);
  return (list);
}

char **rc_services_in_state (rc_service_state_t state)
{
  char *dir = rc_strcatpaths (RC_SVCDIR, rc_service_state_names[state], NULL);
  char **list = NULL;

  if (rc_is_dir (dir))
    list = rc_ls_dir (list, dir, RC_LS_INITD);

  free (dir);
  return (list);
}

bool rc_service_add (const char *runlevel, const char *service)
{
  bool retval;
  char *init;
  char *file;

  if (! rc_runlevel_exists (runlevel))
    {
      errno = ENOENT;
      return (false);
    }
  
  if (rc_service_in_runlevel (service, runlevel))
    {
      errno = EEXIST;
      return (false);
    }

  init = rc_resolve_service (service);
  file = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, basename (service), NULL);
  retval = (symlink (init, file) == 0);
  free (init);
  free (file);
  return (retval);
}

bool rc_service_delete (const char *runlevel, const char *service)
{
  char *file;
  bool retval = false;

  if (! runlevel || ! service)
    return (false);
   
  file = rc_strcatpaths (RC_RUNLEVELDIR, runlevel, basename (service), NULL);
  if (unlink (file) == 0)
    retval = true;
    
  free (file);
  return (retval);
}

char **rc_services_scheduled_by (const char *service)
{
  char **dirs = rc_ls_dir (NULL, RC_SVCDIR "scheduled", 0);
  char **list = NULL;
  char *dir;
  int i;

  STRLIST_FOREACH (dirs, dir, i)
    {
      char *file = rc_strcatpaths (RC_SVCDIR "scheduled", dir, service, NULL);
      if (rc_exists (file))
	list = rc_strlist_add (list, file);
      free (file);
    }
  rc_strlist_free (dirs);
  
  return (list);
}

char **rc_services_scheduled (const char *service)
{
  char *dir = rc_strcatpaths (RC_SVCDIR, "scheduled", basename (service), NULL);
  char **list = NULL;

  if (rc_is_dir (dir))
    list = rc_ls_dir (list, dir, RC_LS_INITD);

  free (dir);
  return (list);
}

bool rc_allow_plug (char *service)
{
  char *list;
  char *p;
  char *star;
  char *token;
  bool allow = true;
  char *match = getenv ("RC_PLUG_SERVICES");
  if (! match)
    return true;

  list = strdup (match);
  p = list;
  while ((token = strsep (&p, " ")))
    {
      bool truefalse = true;
      if (token[0] == '!')
	{
	  truefalse = false;
	  token++;
	}

      star = strchr (token, '*');
      if (star)
	{
	  if (strncmp (service, token, star - token) == 0)
	    {
	      allow = truefalse;
	      break;
	    }
	}
      else
	{
	  if (strcmp (service, token) == 0)
	    {
	      allow = truefalse;
	      break;
	    }
	}
    }

  free (list);
  return (allow);
}