From 42f978a143b3bf2b2f8696ef70ccf712ed147350 Mon Sep 17 00:00:00 2001
From: deva <deva>
Date: Tue, 18 Mar 2008 09:11:45 +0000
Subject: A lot of changes to the daemon code.

---
 server/src/daemon.cc | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)
 create mode 100644 server/src/daemon.cc

(limited to 'server/src/daemon.cc')

diff --git a/server/src/daemon.cc b/server/src/daemon.cc
new file mode 100644
index 0000000..a88fa39
--- /dev/null
+++ b/server/src/daemon.cc
@@ -0,0 +1,158 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            daemon.cc
+ *
+ *  Thu Jun  9 10:27:59 CEST 2005
+ *  Copyright  2005 Bent Bisballe
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  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; either version 2 of the License, or
+ *  (at your option) any later version.
+ *  
+ *  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
+ */
+
+#include "daemon.h"
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+// For getgrent and getgrent
+#include <sys/types.h>
+#include <grp.h>
+#include <pwd.h>
+
+// For strcmp
+#include <string.h>
+
+/* Resolve a group's name or id into a numeric gid */
+static gid_t get_gid(const char *grp)
+{
+  char *eptr;
+  gid_t xid = strtoul(grp, &eptr, 10);
+  struct group *gr;
+  errno = 0;      /* Per getgrnam(3) and getgrgid(3) manual page */
+  if(!*eptr)
+    gr = getgrgid(xid);
+  else
+    gr = getgrnam(grp);
+  return !gr ? 0 : gr->gr_gid;
+}
+
+/* Resolve a user's name or id into a numeric uid with associated gid */
+static uid_t get_uid(const char *usr, gid_t *gid)
+{
+  char *eptr;
+  uid_t xid = strtoul(usr, &eptr, 10);
+  struct passwd *pw;
+  errno = 0;      /* Per getpwnam(3) and getpwuid(3) manual page */
+  if(!*eptr)
+    pw = getpwuid(xid);
+  else
+    pw = getpwnam(usr);
+  if(!pw)
+    return 0;
+  if(!gid)
+    *gid = pw->pw_gid;
+  return pw->pw_uid;
+}
+
+Daemon::Daemon()
+{}
+
+Daemon::~Daemon()
+{}
+
+int Daemon::run(const char *user, const char* group, bool detach)
+{
+  int f;
+  int fd;
+
+  // Fetch user and group IDs
+  gid_t gid = 0;
+  uid_t uid = 0;
+  if(user && *user) {
+    uid = get_uid(user, &gid);
+    if(errno) {
+      fprintf(stderr, "Could resolve user \"%s\"", user);
+      perror("");
+    }
+  }
+
+  if(group && *group) {
+    gid = get_gid(group);
+    if(errno) {
+      fprintf(stderr, "Could not resolve group \"%s\"", group);
+      perror("");
+    }
+  }
+
+  chdir("/");
+  umask(0);
+
+  if(detach) {
+    switch(fork()) {
+    case -1: // Fork error
+      perror("Fork in daemon.cc");
+      return 1;
+      
+    case 0:  // Forked child
+      break; // Break out of switch
+      
+    default: // Parent
+      // exit(0);
+      return 0;
+    }
+  }
+
+  if(gid) {
+    // Switch to given group
+    if(setgid(gid) != 0) {
+      fprintf(stderr, "Failed to change to group \"%s\" (gid: %d), quitting.\n", group, gid);
+      perror("");
+      fprintf(stderr, "Runnning daemon as current group\n");
+    }
+  }
+    
+  if(uid) {
+    // Switch to given user
+    if(setuid(uid) != 0) {
+      fprintf(stderr, "Failed to change to user \"%s\" (uid: %d), quitting.\n", user, uid);
+      perror("");
+      fprintf(stderr, "Runnning daemon as current user\n");
+    }
+  }
+  
+  // Redirect stdin, stdout and stderr to /dev/null
+  fd = open("/dev/null", O_NOCTTY | O_RDWR, 0666);
+  
+  dup2(0, fd);
+  dup2(1, fd);
+  dup2(2, fd);
+    
+  close(fd);
+
+  setsid();
+
+  signal (SIGTERM, SIG_IGN);
+  signal (SIGHUP, SIG_IGN);
+  if(detach) signal (SIGINT, SIG_IGN); // Don't disable Ctrl+c when running in foreground.
+
+  return daemon_main();
+}
-- 
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