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/*
* anytun
*
* The secure anycast tunneling protocol (satp) defines a protocol used
* for communication between any combination of unicast and anycast
* tunnel endpoints. It has less protocol overhead than IPSec in Tunnel
* mode and allows tunneling of every ETHER TYPE protocol (e.g.
* ethernet, ip, arp ...). satp directly includes cryptography and
* message authentication based on the methodes used by SRTP. It is
* intended to deliver a generic, scaleable and secure solution for
* tunneling and relaying of packets of any protocol.
*
*
* Copyright (C) 2007-2008 Othmar Gsenger, Erwin Nindl,
* Christian Pointner <satp@wirdorange.org>
*
* This file is part of Anytun.
*
* Anytun is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* Anytun 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 anytun. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _DAEMON_HPP
#define _DAEMON_HPP
#ifndef NO_DAEMON
#include <sstream>
#include <poll.h>
#include <fcntl.h>
#include <pwd.h>
#include <grp.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <unistd.h>
#include "log.h"
#ifndef NO_PRIVDROP
class PrivInfo
{
public:
PrivInfo(std::string const& username, std::string const& groupname)
{
pw_ = NULL;
gr_ = NULL;
if(username == "")
return;
pw_ = getpwnam(username.c_str());
if(!pw_)
throw std::runtime_error("unkown user " + username);
if(groupname != "")
gr_ = getgrnam(groupname.c_str());
else
gr_ = getgrgid(pw_->pw_gid);
if(!gr_)
throw std::runtime_error("unkown group " + groupname);
}
void drop()
{
if(!pw_ || !gr_)
return;
if(setgid(gr_->gr_gid)) {
std::stringstream msg;
msg << "setgid('" << gr_->gr_name << "') failed: " << LogErrno(errno);
throw std::runtime_error(msg.str());
}
gid_t gr_list[1];
gr_list[0] = gr_->gr_gid;
if(setgroups (1, gr_list)) {
std::stringstream msg;
msg << "setgroups(['" << gr_->gr_name << "']) failed: " << LogErrno(errno);
throw std::runtime_error(msg.str());
}
if(setuid(pw_->pw_uid)) {
std::stringstream msg;
msg << "setuid('" << pw_->pw_name << "') failed: " << LogErrno(errno);
throw std::runtime_error(msg.str());
}
cLog.msg(Log::PRIO_NOTICE) << "dropped privileges to " << pw_->pw_name << ":" << gr_->gr_name;
}
private:
struct passwd* pw_;
struct group* gr_;
};
#endif
void do_chroot(std::string const& chrootdir)
{
if (getuid() != 0)
throw std::runtime_error("this programm has to be run as root in order to run in a chroot");
if(chroot(chrootdir.c_str()))
throw std::runtime_error("can't chroot to " + chrootdir);
cLog.msg(Log::PRIO_NOTICE) << "we are in chroot jail (" << chrootdir << ") now" << std::endl;
if(chdir("/"))
throw std::runtime_error("can't change to /");
}
void daemonize()
{
pid_t pid;
pid = fork();
if(pid < 0) {
std::stringstream msg;
msg << "daemonizing failed at fork(): " << LogErrno(errno) << ", exitting";
throw std::runtime_error(msg.str());
}
if(pid) exit(0);
umask(0);
if(setsid() < 0) {
std::stringstream msg;
msg << "daemonizing failed at setsid(): " << LogErrno(errno) << ", exitting";
throw std::runtime_error(msg.str());
}
pid = fork();
if(pid < 0) {
std::stringstream msg;
msg << "daemonizing failed at fork(): " << LogErrno(errno) << ", exitting";
throw std::runtime_error(msg.str());
}
if(pid) exit(0);
if ((chdir("/")) < 0) {
std::stringstream msg;
msg << "daemonizing failed at chdir(): " << LogErrno(errno) << ", exitting";
throw std::runtime_error(msg.str());
}
// std::cout << "running in background now..." << std::endl;
int fd;
// for (fd=getdtablesize();fd>=0;--fd) // close all file descriptors
for (fd=0;fd<=2;fd++) // close all file descriptors
close(fd);
fd = open("/dev/null",O_RDWR); // stdin
if(fd == -1)
cLog.msg(Log::PRIO_WARNING) << "can't open stdin (chroot and no link to /dev/null?)";
else {
if(dup(fd) == -1) // stdout
cLog.msg(Log::PRIO_WARNING) << "can't open stdout";
if(dup(fd) == -1) // stderr
cLog.msg(Log::PRIO_WARNING) << "can't open stderr";
}
umask(027);
}
#endif
#endif
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