1 files changed, 384 insertions, 0 deletions
diff --git a/login/programs/utmpd.c b/login/programs/utmpd.c
new file mode 100644
index 0000000000..e11218151c
--- /dev/null
+++ b/login/programs/utmpd.c
@@ -0,0 +1,384 @@
+/* Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <libintl.h>
+#include <pwd.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <syslog.h>
+#include <unistd.h>
+
+#include "utmpd.h"
+#include "utmpd-private.h"
+
+/* Get libc version number.  */
+#include "../../version.h"
+
+#define PACKAGE "libc"
+
+/* Long options.  */
+static const struct option long_options[] =
+{
+  { "debug", no_argument, NULL, 'd' },
+  { "help", no_argument, NULL, 'h' },
+  { "version", no_argument, NULL, 'V' },
+  { NULL, 0, NULL, 0}
+};
+
+/* The UTMP database.  */
+utmp_database *utmp_db;
+
+/* The socket for read only requests.  */
+int ro_sock = -1;
+
+/* The socket for read/write requests.  */
+int rw_sock = -1;
+
+
+/* Prototypes for the local functions.  */
+static void usage (int status) __attribute__ ((noreturn));
+static void drop_priviliges (void);
+static int make_socket (const char *name);
+static void handle_requests (void) __attribute__ ((noreturn));
+static void termination_handler (int signum);
+static int check_pid (const char *file);
+static int write_pid (const char *file);
+
+
+int
+main (int argc, char *argv[])
+{
+  mode_t mask;
+  int debug;
+  int do_help;
+  int do_version;
+  int opt;
+
+  /* Initialize local variables.  */
+  debug = 0;
+  do_help = 0;
+  do_version = 0;
+  
+  while ((opt = getopt_long (argc, argv, "dhV", long_options, NULL)) != -1)
+    switch (opt)
+      {
+      case '\0':		/* Long option.  */
+	break;
+      case 'h':
+	do_help = 1;
+	break;
+      case 'd':
+	debug = 1;
+	break;
+      case 'V':
+	do_version = 1;
+	break;
+      default:
+	usage (EXIT_FAILURE);
+      }
+
+  /* Version information is reequested.  */
+  if (do_version)
+    {
+      printf ("utmpd (GNU %s) %s\n", PACKAGE, VERSION);
+      printf (gettext ("\
+Copyright (C) %s Free Software Foundation, Inc.\n\
+This is free software; see the source for copying conditions.  There is NO\n\
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
+"), "1997");
+      printf (gettext ("Written by %s.\n"), "Mark Kettenis");
+
+      exit (EXIT_SUCCESS);
+    }
+
+  /* Help is requested.  */
+  if (do_help)
+    usage (EXIT_SUCCESS);
+
+  signal (SIGINT, termination_handler);
+  signal (SIGTERM, termination_handler);
+
+  /* Check if we are already running.  */
+  if (check_pid (_PATH_UTMPDPID))
+    error (EXIT_FAILURE, 0, "already running");
+
+  /* Open UTMP database.  */
+  utmp_db = open_database (_PATH_UTMP "x", _PATH_UTMP);
+  if (utmp_db == NULL)
+    error (EXIT_FAILURE, errno, "%s", _PATH_UTMP);
+
+  /* Create sockets, with the right permissions.  */
+  mask = umask (S_IXUSR | S_IXGRP | S_IXOTH);
+  ro_sock = make_socket (_PATH_UTMPD_RO);
+  umask (S_IXUSR | S_IRWXG | S_IRWXO);
+  rw_sock = make_socket (_PATH_UTMPD_RW);
+  umask (mask);
+
+  /* Set the sockets up to accept connections.  */
+  if (listen (ro_sock, MAX_CONNECTIONS) < 0
+      || listen (rw_sock, MAX_CONNECTIONS) < 0)
+    error (EXIT_FAILURE, errno, "cannot enable socket to accept connections");
+
+  /* Behave like a daemon.  */
+  if (!debug)
+    {
+      openlog ("utmpd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
+      
+      if (daemon (0, 0) < 0)
+	error (EXIT_FAILURE, errno, "cannot auto-background");
+      forked = 1;
+
+      if (write_pid (_PATH_UTMPDPID) < 0)
+	warning (errno, "%s", _PATH_UTMPDPID);
+    }
+
+  /* Drop priviliges.  */
+  drop_priviliges ();
+  
+  /* Handle incoming requests.  */
+  handle_requests ();
+}
+
+
+/* Display usage information and exit.  */
+static void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    fprintf (stderr, gettext ("Try `%s --help' for more information.\n"),
+	     program_invocation_name);
+  else
+    {
+      printf (gettext ("\
+Usage: %s [OPTION]...\n\
+  -d, --debug           do not fork and display messages on the current tty\n\
+  -h, --help	        display this help and exit\n\
+  -V, --version         output version information and exit\n"),
+	      program_invocation_name);
+      fputs (gettext ("\
+Report bugs to <kettenis@phys.uva.nl>.\n"),
+	     stdout);
+    }
+  
+  exit (status);
+}
+
+
+/* Drop priviliges.  */
+static void
+drop_priviliges (void)
+{
+  struct passwd *pw;
+
+  pw = getpwnam ("daemon");
+  if (pw)
+    {
+      seteuid (pw->pw_uid);
+      setegid (pw->pw_gid);
+    }
+}
+
+
+/* Make a socket in the file namespace using the filename NAME as the
+   socket's address.  */
+static int
+make_socket (const char *name)
+{
+  struct sockaddr_un addr;
+  size_t size;
+  int sock;
+
+  /* Create the socket.  */
+  sock = socket (PF_UNIX, SOCK_STREAM, 0);
+  if (sock < 0)
+    error (EXIT_FAILURE, errno, "cannot create socket");
+
+  /* Bind a name to the socket.  */
+  addr.sun_family = AF_UNIX;
+  strcpy (addr.sun_path, name);
+
+  /* The size of the address is the offset of the start
+     of the filename, plus its length, plus one for the
+     terminating null byte. */
+  size = (offsetof (struct sockaddr_un, sun_path)
+	  + strlen (addr.sun_path));
+     
+  if (bind (sock, (struct sockaddr *) &addr, size) < 0)
+    error (EXIT_FAILURE, errno, "%s", name);
+     
+  return sock;
+}
+
+
+/* Hanlde incoming requests.  */
+static
+void handle_requests (void)
+{
+  client_connection *connection;
+  fd_set active_read_fd_set;
+  fd_set active_write_fd_set;
+  fd_set read_fd_set;
+  fd_set write_fd_set;
+  int fd;
+  
+  /* Initialize the set of active sockets.  */
+  FD_ZERO (&active_read_fd_set);
+  FD_ZERO (&active_write_fd_set);
+  FD_SET (rw_sock, &active_read_fd_set);
+  FD_SET (ro_sock, &active_read_fd_set);
+
+  while (1)
+    {
+      /* Block until input arrives on one or more active sockets.  */
+      read_fd_set = active_read_fd_set;
+      write_fd_set = active_write_fd_set;
+      if (select (FD_SETSIZE, &read_fd_set, &write_fd_set, NULL, NULL) < 0)
+	error (EXIT_FAILURE, errno, "cannot get input on sockets");
+
+      /* Service all the sockets with input pending.  */
+      for (fd = 0; fd < FD_SETSIZE; fd++)
+	{
+	  if (FD_ISSET (fd, &read_fd_set))
+	    {
+	      if (fd == ro_sock || fd == rw_sock)
+		{
+		  int access = ((fd == rw_sock) ? (R_OK | W_OK) : R_OK);
+
+		  connection = accept_connection (fd, access);
+		  if (connection == NULL)
+		    error (0, errno, "cannot accept connection");
+
+		  FD_SET (connection->sock, &active_read_fd_set);
+		}
+	      else
+		{
+		  connection = find_connection (fd);
+		  if (connection == NULL)
+		    error (EXIT_FAILURE, 0, "cannot find connection");
+
+		  if (read_data (connection) < 0)
+		    {
+		      close_connection (connection);
+		      FD_CLR (fd, &active_read_fd_set);
+		      FD_CLR (fd, &active_write_fd_set);
+		    }
+
+		  if (connection->write_ptr > connection->write_base)
+		      FD_SET (fd, &active_write_fd_set);
+		}
+	    }
+	  if (FD_ISSET (fd, &write_fd_set) &&
+	      fd != rw_sock && fd != ro_sock)
+	    {
+	      connection = find_connection (fd);
+	      if (connection == NULL)
+		error (EXIT_FAILURE, 0, "cannot find connection");
+
+	      if (write_data (connection) < 0)
+		{
+		  close_connection (connection);
+		  FD_CLR (fd, &active_read_fd_set);
+		  FD_CLR (fd, &active_write_fd_set);
+		}
+
+	      if (connection->write_ptr == connection->write_base)
+		FD_CLR (fd, &active_write_fd_set);
+	    }
+	}	
+    }
+}
+
+
+/* Cleanup.  */
+static void
+termination_handler (int signum)
+{
+  /* Close sockets.  */
+  close (ro_sock);
+  close (rw_sock);
+
+  /* Restore user id.  */
+  seteuid (getuid ());
+  
+  /* Clean up the files created by `bind'.  */
+  unlink (_PATH_UTMPD_RO);
+  unlink (_PATH_UTMPD_RW);
+
+  if (utmp_db)
+    close_database (utmp_db);
+
+  /* Clean up pid file.  */
+  unlink (_PATH_UTMPDPID);
+  
+  exit (EXIT_SUCCESS);
+}
+
+
+/* Returns 1 if the process in pid file FILE is running, 0 if not.  */
+static int
+check_pid (const char *file)
+{
+  FILE *fp;
+  
+  fp = fopen (_PATH_UTMPDPID, "r");
+  if (fp)
+    {
+      pid_t pid;
+      
+      fscanf (fp, "%d", &pid);
+      fclose (fp);
+
+      if (kill (pid, 0) == 0)
+	return 1;
+    }
+
+  return 0;
+}
+
+/* Write the current process id to the file FILE.  Returns 0 if
+   successful, -1 if not.  */
+static int
+write_pid (const char *file)
+{
+  FILE *fp;
+  
+  fp = fopen (_PATH_UTMPDPID, "w");
+  if (fp == NULL)
+    return -1;
+  
+  fprintf (fp, "%d\n", getpid ());
+  if (ferror (fp))
+    return -1;
+  
+  fclose (fp);
+
+  return 0;
+}
+