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

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