mdw@git.distorted.org.uk Git - fwd/blob - identify.c

   1 /* -*-c-*-
   2  *
   3  * $Id: identify.c,v 1.11 2004/04/08 01:36:25 mdw Exp $
   4  *
   5  * Identifies and logs the client of a connection
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Header files ------------------------------------------------------*/
  30
  31 #include "config.h"
  32
  33 #include <errno.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <time.h>
  38
  39 #include <sys/types.h>
  40 #include <sys/time.h>
  41 #include <unistd.h>
  42 #include <syslog.h>
  43
  44 #include <sys/socket.h>
  45 #include <netinet/in.h>
  46 #include <arpa/inet.h>
  47 #include <netdb.h>
  48
  49 #include <mLib/alloc.h>
  50 #include <mLib/bres.h>
  51 #include <mLib/conn.h>
  52 #include <mLib/dstr.h>
  53 #include <mLib/ident.h>
  54 #include <mLib/report.h>
  55 #include <mLib/sel.h>
  56 #include <mLib/selbuf.h>
  57 #include <mLib/str.h>
  58
  59 #include "fw.h"
  60 #include "identify.h"
  61
  62 /*----- Magic numbers -----------------------------------------------------*/
  63
  64 #define TIMEOUT 15                      /* Seconds to wait for answers */
  65
  66 /*----- Data structures ---------------------------------------------------*/
  67
  68 /* --- Structure to track the progress of an identification --- */
  69
  70 typedef struct id {
  71   id_req q;                             /* Copy of client's request block */
  72   time_t when;                          /* When the connection occurred */
  73   conn c;                               /* Connection selector */
  74   unsigned state;                       /* Current state of the world */
  75   sel_timer t;                          /* Timeout selector */
  76   bres_client r;                        /* Backgd resolver client block */
  77   ident_request i;                      /* Ident client block */
  78   char host[128];                       /* Resolved hostname */
  79   char user[64];                        /* Authenticated client user */
  80 } id;
  81
  82 #define S_HOST 1u                       /* Read the hostname from resolver */
  83 #define S_USER 2u                       /* Read the username from RFC931 */
  84 #define S_TIMER 4u                      /* Timeout has completed */
  85
  86 /*----- Main code ---------------------------------------------------------*/
  87
  88 /* --- @id_done@ --- *
  89  *
  90  * Arguments:   @id *i@ = pointer to identification block
  91  *
  92  * Returns:     ---
  93  *
  94  * Use:         Finishes with an identification block.
  95  */
  96
  97 static void id_done(id *i)
  98 {
  99   /* --- Close down the various dependent bits --- */
 100
 101   if (!(i->state & S_HOST))
 102     bres_abort(&i->r);
 103   if (!(i->state & S_USER))
 104     ident_abort(&i->i);
 105   if (!(i->state & S_TIMER))
 106     sel_rmtimer(&i->t);
 107
 108   /* --- Report the final result --- */
 109
 110   fw_log(i->when, "[%s] %s from %s@%s [%s:%u]",
 111          i->q.desc, i->q.act,
 112          i->user, i->host,
 113          inet_ntoa(i->q.rsin.sin_addr), (unsigned)ntohs(i->q.rsin.sin_port));
 114
 115   /* --- Dispose of the block --- */
 116
 117   REFFD_DEC(i->q.r);
 118   xfree(i);
 119 }
 120
 121 /* --- @id_res@ --- *
 122  *
 123  * Arguments:   @struct hostent *h@ = name of the resolved host
 124  *              @void *vp@ = pointer to identification block
 125  *
 126  * Returns:     ---
 127  *
 128  * Use:         Responds to a completed reverse name resolution.
 129  */
 130
 131 static void id_res(struct hostent *h, void *vp)
 132 {
 133   id *i = vp;
 134   if (h)
 135     str_sanitize(i->host, h->h_name, sizeof(i->host));
 136   i->state |= S_HOST;
 137   if (i->state & S_USER)
 138     id_done(i);
 139 }
 140
 141 /* --- @id_ident@ --- *
 142  *
 143  * Arguments:   @ident_reply *i@ = pointer to string read from server
 144  *              @void *vp@ = pointer to identification block
 145  *
 146  * Returns:     ---
 147  *
 148  * Use:         Responds to a line read from the remote RFC931 server.
 149  */
 150
 151 static void id_ident(ident_reply *ir, void *vp)
 152 {
 153   id *i = vp;
 154
 155   /* --- Read the information from the client --- */
 156
 157   if (ir && ir->type == IDENT_USERID)
 158     str_sanitize(i->user, ir->u.userid.user, sizeof(i->user));
 159
 160   /* --- Maybe finish off this identification --- */
 161
 162   i->state |= S_USER;
 163   if (i->state & S_HOST)
 164     id_done(i);
 165 }
 166
 167 /* --- @id_timer@ --- *
 168  *
 169  * Arguments:   @struct timeval *tv@ = pointer to the current time
 170  *              @void *vp@ = pointer to identification block
 171  *
 172  * Returns:     ---
 173  *
 174  * Use:         Times an identification job out.
 175  */
 176
 177 static void id_timer(struct timeval *tv, void *vp)
 178 {
 179   id *i = vp;
 180   i->state |= S_TIMER;
 181   id_done(i);
 182 }
 183
 184 /* --- @identify@ --- *
 185  *
 186  * Arguments:   @const id_req *q@ = pointer to request block
 187  *
 188  * Returns:     ---
 189  *
 190  * Use:         Starts a background ident lookup and reverse-resolve job
 191  *              which will, eventually, report a message to the system log.
 192  */
 193
 194 void identify(const id_req *q)
 195 {
 196   id *i;
 197
 198   /* --- Initialize the block with stuff --- */
 199
 200   i = xmalloc(sizeof(*i));
 201   i->q = *q;
 202   REFFD_INC(i->q.r);
 203
 204   str_sanitize(i->host, inet_ntoa(q->rsin.sin_addr), sizeof(i->host));
 205   strcpy(i->user, "<ANONYMOUS>");
 206   i->state = 0;
 207   i->when = time(0);
 208
 209   /* --- Set up the connection to the identity server --- */
 210
 211   ident(&i->i, sel, &q->lsin, &q->rsin, id_ident, i);
 212
 213   /* --- Set up the name resolver --- */
 214
 215   bres_byaddr(&i->r, q->rsin.sin_addr, id_res, i);
 216
 217   /* --- Set up the time limiter --- */
 218
 219   {
 220     struct timeval tv;
 221     gettimeofday(&tv, 0);
 222     tv.tv_sec += TIMEOUT;
 223     sel_addtimer(sel, &i->t, &tv, id_timer, i);
 224   }
 225 }
 226
 227 /*----- That's all, folks -------------------------------------------------*/