/* fingerd.c -- Simple daemon body. */

/* Copyright (C) 1996-1997  Janos Farkas

   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, 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 "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <string.h>

#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <netinet/in.h>

#ifdef HAVE_TCPD_H
#include <tcpd.h>
#endif

#include "util.h"
#include "finger.h"
#include "broken.h"
   
/* Tweaking room, feel free to change these flags */

struct fng_info deffi =
{
  /* Show [login name/real name/home dir/shell] respectively. */
  1, 1, 1, 1,
  /* Show [room number/work phone/home phone/other field] respectively. */
  1, 1, 1, 1,
  /* Show [new mail date/mail last read date] */
  1, 1,
  /* Show [last login/if online/origin] */
  1, 1, 1,
  /* Show [plan/project/pgpkey/nofinger] files */
  1, 1, 1, 1
};

struct fng_config deffg =
{
  /* True if this is a `local' finger.  Not used yet. */
  0,

  /* True if you want to `match' fingered names against the GECOS
     field. */
  1,

  /* The names of the plan, project, pgpkey and nofinger files,
     respectively.  If NULL, the appropriate field is not used. */
  ".plan",
  ".project",
  ".pgpkey",
  ".nofinger",

  /* The program you want to run when someone does not specify a
     user in finger.  In an open environment, I would
     prefer to run `w', but that's too much in general... :) */
  "/usr/bin/finger",

  /* The uniform message to be returned when no user found. */
  "sorry, no such user.",

  /* The message which will be returned when libwrap tells us
     they are refused.  This is my preferred text.. :) */
  "Sorry, you either don't run identd, or don't have a host name\n"
  "for your IP address.  Both problem can be fixed quite easily,\n"
  "so complain to your system/network administrator.\n"
  "Please try again only if you have fixed this problem.\n"
};

#ifdef HAVE_LIBWRAP
int allow_severity = LOG_INFO;
int deny_severity = LOG_WARNING;
#endif

char *basename (const char *);

static void
logentry (const char *name, const char *client, int refused)
{
  char *buf = xmalloc ((name ? strlen (name) : 0) + 16);

  if (name != 0 && *name != '\0') {
    sprintf (buf, "%singer `%s'", refused ? "f" : "F", name);
  } else {
    sprintf (buf, "%sserlist", refused ? "u" : "U");
  }
  syslog (LOG_WARNING, "%s%s from %s", refused ? "Refused " : "", buf, client);
  free (buf);
}

int
main (int argc, char *argv[])
{
  char *client, *info, *ip;
  char *progname, *buf;
  struct fng_info *fi = &deffi;
  struct fng_config *fg = &deffg;
  
  struct sockaddr_in snam;
  int count, refused;
#ifdef HAVE_LIBWRAP
  struct request_info req;
#endif

  /* I happen to like to reuse variables sometimes... sorry.. :) */
  refused = sizeof(snam);

  progname = basename (argv[0]);
  if (getpeername (0, (struct sockaddr *)&snam, &refused)) {
    fprintf (stderr, "%s: stdin is not socket\n", progname);
    exit (1);
  }

  openlog (progname, LOG_PID, LOG_AUTHPRIV);

  /* Are we run from tcpserver?  Then it's easier to look these up,
   * and faster too */
  refused = 0;
  client = getenv("TCPREMOTEHOST");
  ip = getenv("TCPREMOTEIP");
  info = getenv("TCPREMOTEINFO");
  buf = xmalloc(1024);
  if (client || info || ip) {
    if (ip && !info)
      info = ip, ip = 0;
    snprintf(buf, 1024, "%s%s%s%s%s%s",
	info?info:"",
	info?"@":"",
	client?client:"",
	ip?" [":"",
	ip?ip:"",
	ip?"]":"");
    client = buf;
  } else {
#ifdef HAVE_LIBWRAP
    request_init (&req, RQ_DAEMON, argv[0], RQ_FILE, 0, NULL);
    fromhost(&req);
    refused = !hosts_access (&req);
    client = xstrdup (eval_client (&req));
#else
    /* no overflow, IP addresses must fit there */
    client = strcpy(buf,(char *)inet_ntoa(snam.sin_addr)), buf;
#endif
  }

  buf = xmalloc (1024);
  if (!fgets(buf, 1024-1, stdin)) {
    syslog (LOG_WARNING, "Empty finger from %s", client);
    /* XXX: print something? */
    exit (0);
  }

  buf[1024-1] = 0;
  count = strlen (buf);
  if (count > 0 && buf[count-1] == '\n')
    buf[--count] = 0;
  if (count > 0 && buf[count-1] == '\r')
    buf[--count] = 0;

  /* This is just an arbitrary limit...  Who has longer usernames? */
  if (count > 80) {
    syslog (LOG_WARNING, "Long finger from %s", client);
    printf ("finger: %s\n", fg->nouser);
    exit (0);
  }

  /* Compatibility with finger -l, why punt them? */
  if (strncmp (buf, "/W ", 3) == 0) {
    buf += 3;
  } else if (strncmp (buf, "-l ", 3) == 0) {
    buf += 3;
  }

  /* Log the access, then prepare the reply. */
  logentry (buf, client, refused);
  if (refused) {
    if (fg->refused)
      printf(fg->refused);
  } else {
    finger_name (fi, fg, buf);
  }

  exit (0);
}