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

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