From e2f6f861375aea953866477f5736de5a4150d360 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@anytun.org>
Date: Sat, 27 Dec 2008 01:37:51 +0000
Subject: initial checkin damonizing chroot signal handling syslog

---
 src/daemon.h | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 src/daemon.h

(limited to 'src/daemon.h')

diff --git a/src/daemon.h b/src/daemon.h
new file mode 100644
index 0000000..085f563
--- /dev/null
+++ b/src/daemon.h
@@ -0,0 +1,107 @@
+/*
+ *  ľAnytun
+ *
+ *  ľAnytun is a tiny implementation of SATP. Unlike Anytun which is a full
+ *  featured implementation ľAnytun has no support for multiple connections
+ *  or synchronisation. It is a small single threaded implementation intended
+ *  to act as a client on small platforms.
+ *  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 Christian Pointner <equinox@anytun.org>
+ *
+ *  This file is part of ľAnytun.
+ *
+ *  ľAnytun 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.
+ *
+ *  ľAnytun 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 ľAnytun. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _DAEMON_H_
+#define _DAEMON_H_
+
+#include <poll.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <grp.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+void chrootAndDrop(const char* chrootdir, const char* username)
+{
+  if (getuid() != 0)
+  {
+    fprintf(stderr, "this programm has to be run as root in order to run in a chroot\n");
+    exit(-1);
+  }
+
+  struct passwd *pw = getpwnam(username);
+  if(pw) {
+    if(chroot(chrootdir))
+    {
+      fprintf(stderr, "can't chroot to %s\n", chrootdir);
+      exit(-1);
+    }
+    log_printf(NOTICE, "we are in chroot jail (%s) now\n", chrootdir);
+    if(chdir("/"))
+    {
+      fprintf(stderr, "can't change to /\n");
+      exit(-1);
+    }
+    if (initgroups(pw->pw_name, pw->pw_gid) || setgid(pw->pw_gid) || setuid(pw->pw_uid))
+    {
+      fprintf(stderr, "can't drop to user %s %d:%d\n", username, pw->pw_uid, pw->pw_gid);
+      exit(-1);
+    }
+    log_printf(NOTICE, "dropped user to %s %d:%d\n", username, pw->pw_uid, pw->pw_gid);
+  }
+  else
+  {
+    fprintf(stderr, "unknown user %s\n", username);
+    exit(-1);
+  }
+}
+
+void daemonize()
+{
+  pid_t pid;
+
+  pid = fork();
+  if(pid) exit(0);
+  setsid();
+  pid = fork();
+  if(pid) exit(0);
+
+  int fd;
+  for (fd=0;fd<=2;fd++) // close all file descriptors
+    close(fd);
+  fd = open("/dev/null",O_RDWR);        // stdin
+  if(fd == -1)
+    log_printf(WARNING, "can't open stdin (chroot and no link to /dev/null?)");
+  else {
+    if(dup(fd) == -1)   // stdout
+      log_printf(WARNING, "can't open stdout");
+    if(dup(fd) == -1)   // stderr
+      log_printf(WARNING, "can't open stderr");
+  }
+  umask(027);
+}
+
+#endif
+
-- 
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