/* dhcpcd - DHCP client daemon
* Copyright 2006-2008 Roy Marples <roy@marples.name>
* All rights reserved

* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

const char copyright[] = "Copyright (c) 2006-2008 Roy Marples";

#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <paths.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "config.h"
#include "client.h"
#include "dhcpcd.h"
#include "dhcp.h"
#include "interface.h"
#include "logger.h"
#include "socket.h"
#include "version.h"

#include "logwriter.h"

static int doversion = 0;
static int dohelp = 0;
#define EXTRA_OPTS
static const struct option longopts[] =
{
  {"arp",         no_argument,        NULL, 'a'},
  {"script",      required_argument,  NULL, 'c'},
  {"debug",       no_argument,        NULL, 'd'},
  {"hostname",    optional_argument,  NULL, 'h'},
  {"classid",     optional_argument,  NULL, 'i'},
  {"release",     no_argument,        NULL, 'k'},
  {"leasetime",   required_argument,  NULL, 'l'},
  {"metric",      required_argument,  NULL, 'm'},
  {"renew",       no_argument,        NULL, 'n'},
  {"persistent",  no_argument,        NULL, 'p'},
  {"qtsocketaddress",  required_argument,        NULL, 'q'},
  {"inform",      optional_argument,  NULL, 's'},
  {"request",     optional_argument,  NULL, 'r'},
  {"timeout",     required_argument,  NULL, 't'},
  {"userclass",   required_argument,  NULL, 'u'},
  {"exit",        no_argument,        NULL, 'x'},
  {"lastlease",   no_argument,        NULL, 'E'},
  {"fqdn",        required_argument,  NULL, 'F'},
  {"nogateway",   no_argument,        NULL, 'G'},
  {"sethostname", no_argument,        NULL, 'H'},
  {"clientid",    optional_argument,  NULL, 'I'},
  {"noipv4ll",    no_argument,        NULL, 'L'},
  {"nomtu",       no_argument,        NULL, 'M'},
  {"nontp",       no_argument,        NULL, 'N'},
  {"nodns",       no_argument,        NULL, 'R'},
  {"msscr",       no_argument,        NULL, 'S'},
  {"test",        no_argument,        NULL, 'T'},
  {"nonis",       no_argument,        NULL, 'Y'},
  {"help",        no_argument,        &dohelp, 1},
  {"version",     no_argument,        &doversion, 1},
#ifdef THERE_IS_NO_FORK
  {"daemonised",	no_argument,        NULL, 'f'},
  {"skiproutes",  required_argument,  NULL, 'g'},
#endif
  {NULL,          0,                  NULL, 0}
};

#ifdef THERE_IS_NO_FORK
char dhcpcd[PATH_MAX];
char **dhcpcd_argv = NULL;
int dhcpcd_argc = 0;
char *dhcpcd_skiproutes = NULL;
#undef EXTRA_OPTS
#define EXTRA_OPTS "fg:"
#endif

static int atoint (const char *s)
{
  char *t;
  long n;

  errno = 0;
  n = strtol (s, &t, 0);
  if ((errno != 0 && n == 0) || s == t ||
      (errno == ERANGE && (n == LONG_MAX || n == LONG_MIN)))
    {
      logger (LOG_ERR, "`%s' out of range", s);
      return (-1);
    }

  return ((int) n);
}

static pid_t read_pid (const char *pidfile)
{
  FILE *fp;
  pid_t pid = 0;

  if ((fp = fopen (pidfile, "r")) == NULL)
    {
      errno = ENOENT;
      return 0;
    }

  fscanf (fp, "%d", &pid);
  fclose (fp);


  return (pid);
}

static void usage (void)
{
  printf ("usage: "PACKAGE" [-adknpEGHMNRSTY] [-c script] [-h hostname] [-i classID]\n"
          "              [-l leasetime] [-m metric] [-r ipaddress] [-s ipaddress]\n"
          "              [-t timeout] [-u userclass] [-F none | ptr | both]\n"
          "              [-I clientID] [-q qtsocketaddress] <interface>\n");
}


int main (int argc, char **argv)
{
  options_t *options;
  int userclasses = 0;
  int opt;
  int option_index = 0;
  char *prefix;
  pid_t pid;
  int debug = 0;
  int i;
  int pidfd = -1;
  int sig = 0;
  int retval = EXIT_FAILURE;

  /* Close any un-needed fd's */
  for (i = getdtablesize() - 1; i >= 3; --i)
    close (i);

  openlog (PACKAGE, LOG_PID, LOG_LOCAL0);

  options = xzalloc (sizeof (*options));
  options->script = (char *) DEFAULT_SCRIPT;
  snprintf (options->classid, CLASS_ID_MAX_LEN, "%s %s",
            PACKAGE, VERSION);

  options->doarp = true;
  options->dodns = true;
  options->domtu = true;
  options->donis = true;
  options->dontp = true;
  options->dogateway = true;
  options->daemonise = true;
  options->doinform = false;
  options->doipv4ll = true;
  options->doduid = true;
  options->timeout = DEFAULT_TIMEOUT;
  /* added by Niklas Goby, additional field, storing the socket address path for
   * communicating with Qt "server"
   * defined in dhcpcd.h */
  strcpy(options->qtsocketaddress, DEFAULT_QTSOCKETADDRESS);

  gethostname (options->hostname, sizeof (options->hostname));
  if (strcmp (options->hostname, "(none)") == 0 ||
      strcmp (options->hostname, "localhost") == 0)
    memset (options->hostname, 0, sizeof (options->hostname));


  /* Don't set any optional arguments here so we retain POSIX
  	 * compatibility with getopt */
  while ((opt = getopt_long(argc, argv, EXTRA_OPTS
                            "c:dh:i:kl:m:npq:r:s:t:u:xAEF:GHI:LMNRSTY",
                            longopts, &option_index)) != -1)
    {
      switch (opt)
        {
        case 0:
          if (longopts[option_index].flag)
            break;
          logger (LOG_ERR,
                  "option `%s' should set a flag",
                  longopts[option_index].name);
          goto abort;
        case 'c':
          options->script = optarg;
          break;
        case 'd':
          debug++;
          switch (debug)
            {
            case 1:
              setloglevel (LOG_DEBUG);
              break;
            case 2:
              options->daemonise = false;
              break;
            }
          break;
#ifdef THERE_IS_NO_FORK
        case 'f':
          options->daemonised = true;
          close_fds ();
          break;
        case 'g':
          dhcpcd_skiproutes = xstrdup (optarg);
          break;
#endif
        case 'h':
          if (! optarg)
            *options->hostname = '\0';
          else if (strlen (optarg) > MAXHOSTNAMELEN)
            {
              logger (LOG_ERR,
                      "`%s' too long for HostName string, max is %d",
                      optarg, MAXHOSTNAMELEN);
              goto abort;
            }
          else
            strlcpy (options->hostname, optarg,
                     sizeof (options->hostname));
          break;
        case 'i':
          if (! optarg)
            {
              *options->classid = '\0';
            }
          else if (strlen (optarg) > CLASS_ID_MAX_LEN)
            {
              logger (LOG_ERR,
                      "`%s' too long for ClassID string, max is %d",
                      optarg, CLASS_ID_MAX_LEN);
              goto abort;
            }
          else
            strlcpy (options->classid, optarg,
                     sizeof (options->classid));
          break;
        case 'k':
          sig = SIGHUP;
          break;
        case 'l':
          if (*optarg == '-')
            {
              logger (LOG_ERR,
                      "leasetime must be a positive value");
              goto abort;
            }
          errno = 0;
          options->leasetime = (uint32_t) strtol (optarg, NULL, 0);
          if (errno == EINVAL || errno == ERANGE)
            {
              logger (LOG_ERR, "`%s' out of range", optarg);
              goto abort;
            }
          break;
        case 'm':
          options->metric = atoint (optarg);
          if (options->metric < 0)
            {
              logger (LOG_ERR,
                      "metric must be a positive value");
              goto abort;
            }
          break;
        case 'n':
          sig = SIGALRM;
          break;
        case 'p':
          options->persistent = true;
          break;
        case 'q':
          if (strlen(optarg) > QTSOCKETADDRESSLENGTH)
            {
              logger(LOG_ERR, "`%s' too long for an socket address path (max=%d)",
                     optarg, QTSOCKETADDRESSLENGTH);
              goto abort;
            }
          strlcpy(options->qtsocketaddress, optarg, sizeof(options->qtsocketaddress));
          break;
        case 's':
          options->doinform = true;
          options->doarp = false;
          if (! optarg || strlen (optarg) == 0)
            {
              options->request_address.s_addr = 0;
              break;
            }
          else
            {
              char *slash = strchr (optarg, '/');
              if (slash)
                {
                  int cidr;
                  /* nullify the slash, so the -r option can read the
                   * address */
                  *slash++ = '\0';
                  if (sscanf (slash, "%d", &cidr) != 1 ||
                      inet_cidrtoaddr (cidr, &options->request_netmask) != 0)
                    {
                      logger (LOG_ERR, "`%s' is not a valid CIDR", slash);
                      goto abort;
                    }
                }
            }
          /* FALLTHROUGH */
        case 'r':
          if (! options->doinform)
            options->dorequest = true;
          if (strlen (optarg) > 0 &&
              ! inet_aton (optarg, &options->request_address))
            {
              logger (LOG_ERR, "`%s' is not a valid IP address", optarg);
              goto abort;
            }
          break;
        case 't':
          options->timeout = atoint (optarg);
          if (options->timeout < 0)
            {
              logger (LOG_ERR, "timeout must be a positive value");
              goto abort;
            }
          break;
        case 'u':
        {
          int offset = 0;
          for (i = 0; i < userclasses; i++)
            offset += (int) options->userclass[offset] + 1;
          if (offset + 1 + strlen (optarg) > USERCLASS_MAX_LEN)
            {
              logger (LOG_ERR, "userclass overrun, max is %d",
                      USERCLASS_MAX_LEN);
              goto abort;
            }
          userclasses++;
          memcpy (options->userclass + offset + 1 , optarg, strlen (optarg));
          options->userclass[offset] = strlen (optarg);
          options->userclass_len += (strlen (optarg)) + 1;
        }
        break;
        case 'x':
          sig = SIGTERM;
          break;
        case 'A':
#ifndef ENABLE_ARP
          logger (LOG_ERR,
                  "arp not compiled into dhcpcd");
          goto abort;
#endif
          options->doarp = false;
          break;
        case 'E':
#ifndef ENABLE_INFO
          logger (LOG_ERR,
                  "info not compiled into dhcpcd");
          goto abort;
#endif
          options->dolastlease = true;
          break;
        case 'F':
          if (strncmp (optarg, "none", strlen (optarg)) == 0)
            options->fqdn = FQDN_NONE;
          else if (strncmp (optarg, "ptr", strlen (optarg)) == 0)
            options->fqdn = FQDN_PTR;
          else if (strncmp (optarg, "both", strlen (optarg)) == 0)
            options->fqdn = FQDN_BOTH;
          else
            {
              logger (LOG_ERR, "invalid value `%s' for FQDN", optarg);
              goto abort;
            }
          break;
        case 'G':
          options->dogateway = false;
          break;
        case 'H':
          options->dohostname++;
          break;
        case 'I':
          if (optarg)
            {
              if (strlen (optarg) > CLIENT_ID_MAX_LEN)
                {
                  logger (LOG_ERR, "`%s' is too long for ClientID, max is %d",
                          optarg, CLIENT_ID_MAX_LEN);
                  goto abort;
                }
              if (strlcpy (options->clientid, optarg,
                           sizeof (options->clientid)) == 0)
                /* empty string disabled duid */
                options->doduid = false;

            }
          else
            {
              memset (options->clientid, 0, sizeof (options->clientid));
              options->doduid = false;
            }
          break;
        case 'L':
          options->doipv4ll = false;
          break;
        case 'M':
          options->domtu = false;
          break;
        case 'N':
          options->dontp = false;
          break;
        case 'R':
          options->dodns = false;
          break;
        case 'S':
          options->domscsr++;
          break;
        case 'T':
#ifndef ENABLE_INFO
          logger (LOG_ERR, "info support not compiled into dhcpcd");
          goto abort;
#endif
          options->test = true;
          options->persistent = true;
          break;
        case 'Y':
          options->donis = false;
          break;
        case '?':
          usage ();
          goto abort;
        default:
          usage ();
          goto abort;
        }
    }
  if (doversion)
    {
      printf (""PACKAGE" "VERSION"\n");
      printf ("Compile time options:"
#ifdef ENABLE_ARP
              " ARP"
#endif
#ifdef ENABLE_DUID
              " DUID"
#endif
#ifdef ENABLE_INFO
              " INFO"
#endif
#ifdef ENABLE_INFO_COMPAT
              " INFO_COMPAT"
#endif
#ifdef ENABLE_IPV4LL
              " IPV4LL"
#endif
#ifdef ENABLE_NIS
              " NIS"
#endif
#ifdef ENABLE_NTP
              " NTP"
#endif
#ifdef SERVICE
              " " SERVICE
#endif
#ifdef ENABLE_RESOLVCONF
              " RESOLVCONF"
#endif
#ifdef THERE_IS_NO_FORK
              " THERE_IS_NO_FORK"
#endif
              "\n");
    }

  if (dohelp)
    usage ();


#ifdef THERE_IS_NO_FORK
  dhcpcd_argv = argv;
  dhcpcd_argc = argc;
  if (! realpath (argv[0], dhcpcd))
    {
      logger (LOG_ERR, "unable to resolve the path `%s': %s",
              argv[0], strerror (errno));
      goto abort;
    }
#endif

  /* initializations for the ipc connection to qt*/
  setSocketName(options->qtsocketaddress);
  if (initQtLoggerSocket() < 0)
    {
      logger(LOG_ERR, "initialization Qt Logger failed: %s ", strerror (errno));
      goto abort;
    }


  if (optind < argc)
    {
      if (strlen(argv[optind]) > IF_NAMESIZE)
        {
          logger(LOG_ERR, "`%s' too long for an interface name (max=%d)",
                 argv[optind], IF_NAMESIZE);
          goto abort;
        }
      strlcpy(options->interface, argv[optind], sizeof(options->interface));
      setInterfaceName(options->interface);
    }
  else
    {
      /* If only version was requested then exit now */
      if (doversion || dohelp)
        {
          retval = 0;
          goto abort;
        }

      logger(LOG_ERR, "no interface specified");
      setInterfaceName("no_if");
      goto abort;
    }

  if (strchr(options->hostname, '.'))
    {
      if (options->fqdn == FQDN_DISABLE)
        options->fqdn = FQDN_BOTH;
    }
  else
    options->fqdn = FQDN_DISABLE;

  if (options->request_address.s_addr == 0 && options->doinform)
    {
      if ((options->request_address.s_addr = get_address(options->interface))
          != 0)
        options->keep_address = true;
    }

  if (IN_LINKLOCAL (ntohl (options->request_address.s_addr)))
    {
      logger (LOG_ERR,
              "you are not allowed to request a link local address");
      logToQt(LOG_ERR, -1, "you are not allowed to request a link local address");
      goto abort;
    }

  if (geteuid ())
    {
      logger (LOG_WARNING, PACKAGE " will not work correctly unless"
              " run as root");
    }

  prefix = xmalloc (sizeof (char) * (IF_NAMESIZE + 3));
  snprintf (prefix, IF_NAMESIZE, "%s: ", options->interface);
  setlogprefix (prefix);
  snprintf (options->pidfile, sizeof (options->pidfile), PIDFILE,
            options->interface);
  free (prefix);

  chdir ("/");
  umask (022);

  if (mkdir (INFODIR, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP
             | S_IROTH | S_IXOTH) && errno != EEXIST)
    {
      logger (LOG_ERR,
              "mkdir(\"%s\",0): %s\n", INFODIR, strerror (errno));
      goto abort;
    }

  if (mkdir (ETCDIR, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP
             | S_IROTH | S_IXOTH) && errno != EEXIST)
    {
      logger (LOG_ERR,
              "mkdir(\"%s\",0): %s\n", ETCDIR, strerror (errno));
      goto abort;
    }

  if (options->test)
    {
      if (options->dorequest || options->doinform)
        {
          logger (LOG_ERR,
                  "cannot test with --inform or --request");
          goto abort;
        }

      if (options->dolastlease)
        {
          logger (LOG_ERR, "cannot test with --lastlease");
          goto abort;
        }

      if (sig != 0)
        {
          logger (LOG_ERR,
                  "cannot test with --release or --renew");
          goto abort;
        }
    }

  if (sig != 0)
    {
      int killed = -1;
      pid = read_pid (options->pidfile);
      if (pid != 0)
        logger (LOG_INFO, "sending signal %d to pid %d",
                sig, pid);

      if (! pid || (killed = kill (pid, sig)))
        logger (sig == SIGALRM ? LOG_INFO : LOG_ERR,
                ""PACKAGE" not running");

      if (pid != 0 && (sig != SIGALRM || killed != 0))
        unlink (options->pidfile);

      if (killed == 0)
        {
          retval = EXIT_SUCCESS;
          goto abort;
        }

      if (sig != SIGALRM)
        goto abort;
    }

  if (! options->test && ! options->daemonised)
    {
      if ((pid = read_pid (options->pidfile)) > 0 &&
          kill (pid, 0) == 0)
        {
          logger (LOG_ERR, ""PACKAGE
                  " already running on pid %d (%s)",
                  pid, options->pidfile);
          goto abort;
        }

      pidfd = open (options->pidfile,
                    O_WRONLY | O_CREAT | O_NONBLOCK, 0664);
      if (pidfd == -1)
        {
          logger (LOG_ERR, "open `%s': %s",
                  options->pidfile, strerror (errno));
          goto abort;
        }

      /* Lock the file so that only one instance of dhcpcd runs
       * on an interface */
      if (flock (pidfd, LOCK_EX | LOCK_NB) == -1)
        {
          logger (LOG_ERR, "flock `%s': %s",
                  options->pidfile, strerror (errno));
          goto abort;
        }

      /* dhcpcd.sh should not interhit this fd */
      if ((i = fcntl (pidfd, F_GETFD, 0)) == -1 ||
          fcntl (pidfd, F_SETFD, i | FD_CLOEXEC) == -1)
        logger (LOG_ERR, "fcntl: %s", strerror (errno));

      writepid (pidfd, getpid ());
      logger (LOG_INFO, PACKAGE " " VERSION " starting");
    }

  /* Seed random */
  srandomdev ();

  /* Massage our filters per platform */
  setup_packet_filters ();

  /* dhcp_run : defined in client.c */
  if (dhcp_run (options, &pidfd) == 0)
    retval = EXIT_SUCCESS;

abort:
  /* If we didn't daemonise then we need to punt the pidfile now */
  if (pidfd > -1)
    {
      close (pidfd);
      unlink (options->pidfile);
    }

  free (options);

#ifdef THERE_IS_NO_FORK
  /* There may have been an error before the dhcp_run function
   * clears this, so just do it here to be safe */
  free (dhcpcd_skiproutes);
#endif

  logger (LOG_INFO, "exiting");
  logToQt(LOG_INFO, DHCPCD_EXIT, "exiting due abort");
  closeQtLoggerSocket();
  exit (retval);
  /* NOTREACHED */
}