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

   1 /* -*-c-*-
   2  *
   3  * $Id: identify.c,v 1.8 2003/11/29 20:36:07 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 1.8  2003/11/29 20:36:07  mdw
  33  * Privileged outgoing connections.
  34  *
  35  * Revision 1.7  2002/02/22 23:43:32  mdw
  36  * Call @xfree@ rather than @free@.
  37  *
  38  * Revision 1.6  2001/06/22 19:36:49  mdw
  39  * Enlarge the identity buffer.
  40  *
  41  * Revision 1.5  1999/10/10 16:45:34  mdw
  42  * Modified to use new mLib resolver and ident client.
  43  *
  44  * Revision 1.4  1999/07/27 18:30:53  mdw
  45  * Various minor portability fixes.
  46  *
  47  * Revision 1.3  1999/07/26 23:26:21  mdw
  48  * Minor modifications for new design.
  49  *
  50  * Revision 1.2  1999/07/03 13:56:59  mdw
  51  * Log connections to syslog or stderr as appropriate.
  52  *
  53  * Revision 1.1.1.1  1999/07/01 08:56:23  mdw
  54  * Initial revision.
  55  *
  56  */
  57
  58 /*----- Header files ------------------------------------------------------*/
  59
  60 #include "config.h"
  61
  62 #include <errno.h>
  63 #include <stdio.h>
  64 #include <stdlib.h>
  65 #include <string.h>
  66 #include <time.h>
  67
  68 #include <sys/types.h>
  69 #include <sys/time.h>
  70 #include <unistd.h>
  71 #include <syslog.h>
  72
  73 #include <sys/socket.h>
  74 #include <netinet/in.h>
  75 #include <arpa/inet.h>
  76 #include <netdb.h>
  77
  78 #include <mLib/alloc.h>
  79 #include <mLib/bres.h>
  80 #include <mLib/conn.h>
  81 #include <mLib/dstr.h>
  82 #include <mLib/ident.h>
  83 #include <mLib/report.h>
  84 #include <mLib/sel.h>
  85 #include <mLib/selbuf.h>
  86 #include <mLib/str.h>
  87
  88 #include "fw.h"
  89 #include "identify.h"
  90
  91 /*----- Magic numbers -----------------------------------------------------*/
  92
  93 #define TIMEOUT 15                      /* Seconds to wait for answers */
  94
  95 /*----- Data structures ---------------------------------------------------*/
  96
  97 /* --- Structure to track the progress of an identification --- */
  98
  99 typedef struct id {
 100   id_req q;                             /* Copy of client's request block */
 101   time_t when;                          /* When the connection occurred */
 102   conn c;                               /* Connection selector */
 103   unsigned state;                       /* Current state of the world */
 104   sel_timer t;                          /* Timeout selector */
 105   bres_client r;                        /* Backgd resolver client block */
 106   ident_request i;                      /* Ident client block */
 107   char host[128];                       /* Resolved hostname */
 108   char user[64];                        /* Authenticated client user */
 109 } id;
 110
 111 #define S_HOST 1u                       /* Read the hostname from resolver */
 112 #define S_USER 2u                       /* Read the username from RFC931 */
 113 #define S_TIMER 4u                      /* Timeout has completed */
 114
 115 /*----- Main code ---------------------------------------------------------*/
 116
 117 /* --- @id_done@ --- *
 118  *
 119  * Arguments:   @id *i@ = pointer to identification block
 120  *
 121  * Returns:     ---
 122  *
 123  * Use:         Finishes with an identification block.
 124  */
 125
 126 static void id_done(id *i)
 127 {
 128   /* --- Close down the various dependent bits --- */
 129
 130   if (!(i->state & S_HOST))
 131     bres_abort(&i->r);
 132   if (!(i->state & S_USER))
 133     ident_abort(&i->i);
 134   if (!(i->state & S_TIMER))
 135     sel_rmtimer(&i->t);
 136
 137   /* --- Report the final result --- */
 138
 139   fw_log(i->when, "[%s] %s from %s@%s [%s:%u]",
 140          i->q.desc, i->q.act,
 141          i->user, i->host,
 142          inet_ntoa(i->q.rsin.sin_addr), (unsigned)ntohs(i->q.rsin.sin_port));
 143
 144   /* --- Dispose of the block --- */
 145
 146   REFFD_DEC(i->q.r);
 147   xfree(i);
 148 }
 149
 150 /* --- @id_res@ --- *
 151  *
 152  * Arguments:   @struct hostent *h@ = name of the resolved host
 153  *              @void *vp@ = pointer to identification block
 154  *
 155  * Returns:     ---
 156  *
 157  * Use:         Responds to a completed reverse name resolution.
 158  */
 159
 160 static void id_res(struct hostent *h, void *vp)
 161 {
 162   id *i = vp;
 163   if (h)
 164     str_sanitize(i->host, h->h_name, sizeof(i->host));
 165   i->state |= S_HOST;
 166   if (i->state & S_USER)
 167     id_done(i);
 168 }
 169
 170 /* --- @id_ident@ --- *
 171  *
 172  * Arguments:   @ident_reply *i@ = pointer to string read from server
 173  *              @void *vp@ = pointer to identification block
 174  *
 175  * Returns:     ---
 176  *
 177  * Use:         Responds to a line read from the remote RFC931 server.
 178  */
 179
 180 static void id_ident(ident_reply *ir, void *vp)
 181 {
 182   id *i = vp;
 183
 184   /* --- Read the information from the client --- */
 185
 186   if (ir && ir->type == IDENT_USERID)
 187     str_sanitize(i->user, ir->u.userid.user, sizeof(i->user));
 188
 189   /* --- Maybe finish off this identification --- */
 190
 191   i->state |= S_USER;
 192   if (i->state & S_HOST)
 193     id_done(i);
 194 }
 195
 196 /* --- @id_timer@ --- *
 197  *
 198  * Arguments:   @struct timeval *tv@ = pointer to the current time
 199  *              @void *vp@ = pointer to identification block
 200  *
 201  * Returns:     ---
 202  *
 203  * Use:         Times an identification job out.
 204  */
 205
 206 static void id_timer(struct timeval *tv, void *vp)
 207 {
 208   id *i = vp;
 209   id_done(i);
 210 }
 211
 212 /* --- @identify@ --- *
 213  *
 214  * Arguments:   @const id_req *q@ = pointer to request block
 215  *
 216  * Returns:     ---
 217  *
 218  * Use:         Starts a background ident lookup and reverse-resolve job
 219  *              which will, eventually, report a message to the system log.
 220  */
 221
 222 void identify(const id_req *q)
 223 {
 224   id *i;
 225
 226   /* --- Initialize the block with stuff --- */
 227
 228   i = xmalloc(sizeof(*i));
 229   i->q = *q;
 230   REFFD_INC(i->q.r);
 231
 232   str_sanitize(i->host, inet_ntoa(q->rsin.sin_addr), sizeof(i->host));
 233   strcpy(i->user, "<ANONYMOUS>");
 234   i->state = 0;
 235   i->when = time(0);
 236
 237   /* --- Set up the connection to the identity server --- */
 238
 239   ident(&i->i, sel, &q->lsin, &q->rsin, id_ident, i);
 240
 241   /* --- Set up the name resolver --- */
 242
 243   bres_byaddr(&i->r, q->rsin.sin_addr, id_res, i);
 244
 245   /* --- Set up the time limiter --- */
 246
 247   {
 248     struct timeval tv;
 249     gettimeofday(&tv, 0);
 250     tv.tv_sec += TIMEOUT;
 251     sel_addtimer(sel, &i->t, &tv, id_timer, i);
 252   }
 253 }
 254
 255 /*----- That's all, folks -------------------------------------------------*/