src/daemon.hpp

   1 #ifndef _DAEMON_HPP
   2 #define _DAEMON_HPP
   3 #ifndef NODAEMON
   4
   5 void chrootAndDrop(std::string const& chrootdir, std::string const& username)
   6 {
   7   if (getuid() != 0)
   8   {
   9     std::cerr << "this programm has to be run as root in order to run in a chroot" << std::endl;
  10     exit(-1);
  11   }
  12
  13   struct passwd *pw = getpwnam(username.c_str());
  14   if(pw) {
  15     if(chroot(chrootdir.c_str()))
  16     {
  17       std::cerr << "can't chroot to " << chrootdir << std::endl;
  18       exit(-1);
  19     }
  20     cLog.msg(Log::PRIO_NOTICE) << "we are in chroot jail (" << chrootdir << ") now" << std::endl;
  21     chdir("/");
  22     if (initgroups(pw->pw_name, pw->pw_gid) || setgid(pw->pw_gid) || setuid(pw->pw_uid))
  23     {
  24       std::cerr << "can't drop to user " << username << " " << pw->pw_uid << ":" << pw->pw_gid << std::endl;
  25       exit(-1);
  26     }
  27     cLog.msg(Log::PRIO_NOTICE) << "dropped user to " << username << " " << pw->pw_uid << ":" << pw->pw_gid << std::endl;
  28   }
  29   else
  30   {
  31     std::cerr << "unknown user " << username << std::endl;
  32     exit(-1);
  33   }
  34 }
  35
  36 void daemonize()
  37 {
  38   pid_t pid;
  39
  40   pid = fork();
  41   if(pid) exit(0);
  42   setsid();
  43   pid = fork();
  44   if(pid) exit(0);
  45
  46 //  std::cout << "running in background now..." << std::endl;
  47
  48   int fd;
  49 //  for (fd=getdtablesize();fd>=0;--fd) // close all file descriptors
  50   for (fd=0;fd<=2;fd++) // close all file descriptors
  51     close(fd);
  52   fd=open("/dev/null",O_RDWR);        // stdin
  53   dup(fd);                            // stdout
  54   dup(fd);                            // stderr
  55   umask(027);
  56 }
  57 #endif
  58 #endif
  59