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

   1 /* -*-c-*-
   2  *
   3  * $Id: identify.c,v 1.7 2002/02/22 23:43:32 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 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: identify.c,v $
  32  * Revision 1.7  2002/02/22 23:43:32  mdw
  33  * Call @xfree@ rather than @free@.
  34  *
  35  * Revision 1.6  2001/06/22 19:36:49  mdw
  36  * Enlarge the identity buffer.
  37  *
  38  * Revision 1.5  1999/10/10 16:45:34  mdw
  39  * Modified to use new mLib resolver and ident client.
  40  *
  41  * Revision 1.4  1999/07/27 18:30:53  mdw
  42  * Various minor portability fixes.
  43  *
  44  * Revision 1.3  1999/07/26 23:26:21  mdw
  45  * Minor modifications for new design.
  46  *
  47  * Revision 1.2  1999/07/03 13:56:59  mdw
  48  * Log connections to syslog or stderr as appropriate.
  49  *
  50  * Revision 1.1.1.1  1999/07/01 08:56:23  mdw
  51  * Initial revision.
  52  *
  53  */
  54
  55 /*----- Header files ------------------------------------------------------*/
  56
  57 #include "config.h"
  58
  59 #include <errno.h>
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <string.h>
  63 #include <time.h>
  64
  65 #include <sys/types.h>
  66 #include <sys/time.h>
  67 #include <unistd.h>
  68 #include <syslog.h>
  69
  70 #include <sys/socket.h>
  71 #include <netinet/in.h>
  72 #include <arpa/inet.h>
  73 #include <netdb.h>
  74
  75 #include <mLib/alloc.h>
  76 #include <mLib/bres.h>
  77 #include <mLib/conn.h>
  78 #include <mLib/dstr.h>
  79 #include <mLib/ident.h>
  80 #include <mLib/report.h>
  81 #include <mLib/sel.h>
  82 #include <mLib/selbuf.h>
  83 #include <mLib/str.h>
  84
  85 #include "fw.h"
  86 #include "identify.h"
  87
  88 /*----- Magic numbers -----------------------------------------------------*/
  89
  90 #define TIMEOUT 15                      /* Seconds to wait for answers */
  91
  92 /*----- Data structures ---------------------------------------------------*/
  93
  94 /* --- Structure to track the progress of an identification --- */
  95
  96 typedef struct id {
  97   id_req q;                             /* Copy of client's request block */
  98   time_t when;                          /* When the connection occurred */
  99   conn c;                               /* Connection selector */
 100   unsigned state;                       /* Current state of the world */
 101   sel_timer t;                          /* Timeout selector */
 102   bres_client r;                        /* Backgd resolver client block */
 103   ident_request i;                      /* Ident client block */
 104   char host[128];                       /* Resolved hostname */
 105   char user[64];                        /* Authenticated client user */
 106 } id;
 107
 108 #define S_HOST 1u                       /* Read the hostname from resolver */
 109 #define S_USER 2u                       /* Read the username from RFC931 */
 110 #define S_TIMER 4u                      /* Timeout has completed */
 111
 112 /*----- Main code ---------------------------------------------------------*/
 113
 114 /* --- @id_done@ --- *
 115  *
 116  * Arguments:   @id *i@ = pointer to identification block
 117  *
 118  * Returns:     ---
 119  *
 120  * Use:         Finishes with an identification block.
 121  */
 122
 123 static void id_done(id *i)
 124 {
 125   /* --- Close down the various dependent bits --- */
 126
 127   if (!(i->state & S_HOST))
 128     bres_abort(&i->r);
 129   if (!(i->state & S_USER))
 130     ident_abort(&i->i);
 131   if (!(i->state & S_TIMER))
 132     sel_rmtimer(&i->t);
 133
 134   /* --- Report the final result --- */
 135
 136   fw_log(i->when, "[%s] %s from %s@%s [%s]",
 137          i->q.desc, i->q.act,
 138          i->user, i->host, inet_ntoa(i->q.rsin.sin_addr));
 139
 140   /* --- Dispose of the block --- */
 141
 142   REFFD_DEC(i->q.r);
 143   xfree(i);
 144 }
 145
 146 /* --- @id_res@ --- *
 147  *
 148  * Arguments:   @struct hostent *h@ = name of the resolved host
 149  *              @void *vp@ = pointer to identification block
 150  *
 151  * Returns:     ---
 152  *
 153  * Use:         Responds to a completed reverse name resolution.
 154  */
 155
 156 static void id_res(struct hostent *h, void *vp)
 157 {
 158   id *i = vp;
 159   if (h)
 160     str_sanitize(i->host, h->h_name, sizeof(i->host));
 161   i->state |= S_HOST;
 162   if (i->state & S_USER)
 163     id_done(i);
 164 }
 165
 166 /* --- @id_ident@ --- *
 167  *
 168  * Arguments:   @ident_reply *i@ = pointer to string read from server
 169  *              @void *vp@ = pointer to identification block
 170  *
 171  * Returns:     ---
 172  *
 173  * Use:         Responds to a line read from the remote RFC931 server.
 174  */
 175
 176 static void id_ident(ident_reply *ir, void *vp)
 177 {
 178   id *i = vp;
 179
 180   /* --- Read the information from the client --- */
 181
 182   if (ir && ir->type == IDENT_USERID)
 183     str_sanitize(i->user, ir->u.userid.user, sizeof(i->user));
 184
 185   /* --- Maybe finish off this identification --- */
 186
 187   i->state |= S_USER;
 188   if (i->state & S_HOST)
 189     id_done(i);
 190 }
 191
 192 /* --- @id_timer@ --- *
 193  *
 194  * Arguments:   @struct timeval *tv@ = pointer to the current time
 195  *              @void *vp@ = pointer to identification block
 196  *
 197  * Returns:     ---
 198  *
 199  * Use:         Times an identification job out.
 200  */
 201
 202 static void id_timer(struct timeval *tv, void *vp)
 203 {
 204   id *i = vp;
 205   id_done(i);
 206 }
 207
 208 /* --- @identify@ --- *
 209  *
 210  * Arguments:   @const id_req *q@ = pointer to request block
 211  *
 212  * Returns:     ---
 213  *
 214  * Use:         Starts a background ident lookup and reverse-resolve job
 215  *              which will, eventually, report a message to the system log.
 216  */
 217
 218 void identify(const id_req *q)
 219 {
 220   id *i;
 221
 222   /* --- Initialize the block with stuff --- */
 223
 224   i = xmalloc(sizeof(*i));
 225   i->q = *q;
 226   REFFD_INC(i->q.r);
 227
 228   str_sanitize(i->host, inet_ntoa(q->rsin.sin_addr), sizeof(i->host));
 229   strcpy(i->user, "<ANONYMOUS>");
 230   i->state = 0;
 231   i->when = time(0);
 232
 233   /* --- Set up the connection to the identity server --- */
 234
 235   ident(&i->i, sel, &q->lsin, &q->rsin, id_ident, i);
 236
 237   /* --- Set up the name resolver --- */
 238
 239   bres_byaddr(&i->r, q->rsin.sin_addr, id_res, i);
 240
 241   /* --- Set up the time limiter --- */
 242
 243   {
 244     struct timeval tv;
 245     gettimeofday(&tv, 0);
 246     tv.tv_sec += TIMEOUT;
 247     sel_addtimer(sel, &i->t, &tv, id_timer, i);
 248   }
 249 }
 250
 251 /*----- That's all, folks -------------------------------------------------*/