src/daemon.hpp

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