// $Id: main.c 1939 2005-03-19 02:07:40Z ensc $    --*- c -*--

// Copyright (C) 2004 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
//  
// 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; version 2 of the License.
//  
// 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, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "vserver-start.h"
#include "vshelper.h"
#include "pathconfig.h"
#include "interface.h"
#include "configuration.h"
#include "mount.h"
#include "undo.h"

#include "lib_internal/util.h"
#include "lib_internal/errinfo.h"
#include "lib_internal/sys_clone.h"
#include "lib/vserver.h"
#include "lib/internal.h"

#include <sys/file.h>
#include <sched.h>
#include <signal.h>
#include <unistd.h>
#include <sys/socket.h>

#define ENSC_WRAPPERS_VSERVER	1
#define ENSC_WRAPPERS_SOCKET	1
#define ENSC_WRAPPERS_UNISTD	1
#define ENSC_WRAPPERS_FCNTL	1
#define ENSC_WRAPPERS_STDLIB	1
#include <ensc_wrappers/wrappers.h>

struct Options			opts;
struct Configuration		cfg;
int				wrapper_exit_code;

static void
env2Str(char const **var, char const *env, bool req)
{
  char const *		tmp = getenv(env);
  if (req && tmp==0) {
    WRITE_MSG(2, "vserver.start: required environment variable $");
    WRITE_STR(2, env);
    WRITE_STR(2, " not set; aborting...\n");
    exit(1);
  }

  *var = tmp;
  unsetenv(env);
}

static void
env2Bool(bool *var, char const *env, bool req)
{
  char const *	tmp;
  env2Str(&tmp, env, req);
  *var = !(tmp==0 || atoi(tmp)==0);
}

static void
initGlobals()
{
  env2Str (&opts.VSERVER_DIR,       "VSERVER_DIR",       true);
  env2Str (&opts.VSERVER_NAME,      "VSERVER_NAME",      true);
  env2Bool(&opts.OPTION_DEBUG,      "OPTION_DEBUG",      false);
  env2Bool(&opts.OPTION_DEFAULTTTY, "OPTION_DEFAULTTTY", false);  
}

static void
initLock()
{
  size_t			l   = strlen(opts.VSERVER_DIR);
  char 				tmp[sizeof(LOCKDIR "/vserver..startup") + l];
  char *			ptr = tmp;
  struct ErrorInformation	err = { .app = 0 };
  int				fd;

  ptr  = Xmemcpy(ptr, LOCKDIR "/vserver.", sizeof(LOCKDIR "/vserver.")-1);
  ((char *)(Xmemcpy(ptr, opts.VSERVER_DIR, l)))[0] = '\0';
  ptr += canonifyVserverName(ptr);
  ptr  = Xmemcpy(ptr, ".startup",  sizeof(".startup"));
  *ptr = '\0';

  if (!lockfile(&fd, tmp, LOCK_EX, 30, &err)) {
    WRITE_MSG(2, "vserver.start: failed to lock '");
    WRITE_STR(2, tmp);
    WRITE_MSG(2, "': ");
    ErrInfo_writeErrno(&err);
    exit(1);
  }
}

static void
checkConstraints()
{
  xid_t			xid;
  bool			is_running;
  struct vc_vx_info	info;

  xid = vc_getVserverCtx(opts.VSERVER_DIR, vcCFG_RECENT_FULL,
			 true, &is_running);

  if (xid!=VC_NOCTX && vc_get_vx_info(xid, &info)!=-1) {
    WRITE_MSG(2, "vserver.start: vserver '");
    WRITE_STR(2, opts.VSERVER_NAME);
    WRITE_MSG(2, "' already running; aborting...\n");
    exit(1);
  }

  Vshelper_doSanityCheck();
}

static void
setCFlag(xid_t xid, uint_least64_t value)
{
  struct vc_ctx_flags	flags = {
    .flagword = value,
    .mask     = value
  };

  Evc_set_cflags(xid, &flags);
}

int main(int UNUSED argc, char UNUSED *argv[])
{
  Cfg_init(&cfg);
  
  initGlobals();
  initLock();
  checkConstraints();

  int		sync_fd[2];
  char		c;
  xid_t		xid;
  char		buf[sizeof(xid)*3 + 2];
  PathInfo	cfgdir = { .d = opts.VSERVER_DIR, .l = strlen(opts.VSERVER_DIR) };

  Esocketpair(AF_UNIX, SOCK_STREAM, 0, sync_fd);
  Efcntl(sync_fd[0], F_SETFD, FD_CLOEXEC);
  Efcntl(sync_fd[1], F_SETFD, FD_CLOEXEC);
  
  getConfiguration(&cfg, &cfgdir);
  pid_t		pid    = sys_clone(CLONE_NEWNS|SIGCHLD, 0);
  FatalErrnoError(pid==-1, "sys_clone()");
  
  switch (pid) {
    case 0	:
      Undo_init();
      execScriptlets(&cfgdir, opts.VSERVER_NAME, "prepre-start");
      activateInterfaces(&cfg.interfaces);
      
      xid = Evc_ctx_create(cfg.xid);
      setCFlag(xid, VC_VXF_INFO_NAMESPACE);
      
      mountVserver(&cfg);
	//      prepareInit(&cfg, &cfgdir);

      Esend(sync_fd[0], &xid, sizeof xid, MSG_NOSIGNAL);
	// 'pre-start.parent' will be executed now in the parent-context
      Erecv(sync_fd[0], &c, 1, 0);
      execScriptlets(&cfgdir, opts.VSERVER_NAME, "pre-start");

      if (cfg.nice)
	Enice(atoi(cfg.nice));
      if (opts.OPTION_DEFAULTTTY)
	setDefaultTTY(&cfgdir, 0);

      

      Undo_detach();
      break;

    default	:
      Erecv(sync_fd[1], &xid, sizeof xid, 0);
      utilvserver_fmt_uint(buf, xid);
      Esetenv("CHILD_XID", buf, 1);
      
      execScriptlets(&cfgdir, opts.VSERVER_NAME, "pre-start.parent");
      Esend(sync_fd[1], ".", 1, MSG_NOSIGNAL);
      
      break;
  }
}