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 `fwd' port forwarder.
  11  *
  12  * `fwd' 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  * `fwd' 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 `fwd'; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 #include "fwd.h"
  28
  29 /*----- Magic numbers -----------------------------------------------------*/
  30
  31 #define TIMEOUT 15                      /* Seconds to wait for answers */
  32
  33 /*----- Data structures ---------------------------------------------------*/
  34
  35 /* --- Structure to track the progress of an identification --- */
  36
  37 typedef struct id {
  38   id_req q;                             /* Copy of client's request block */
  39   time_t when;                          /* When the connection occurred */
  40   conn c;                               /* Connection selector */
  41   unsigned state;                       /* Current state of the world */
  42   sel_timer t;                          /* Timeout selector */
  43   bres_client r;                        /* Backgd resolver client block */
  44   ident_request i;                      /* Ident client block */
  45   char host[128];                       /* Resolved hostname */
  46   char user[64];                        /* Authenticated client user */
  47 } id;
  48
  49 #define S_HOST 1u                       /* Read the hostname from resolver */
  50 #define S_USER 2u                       /* Read the username from RFC931 */
  51 #define S_TIMER 4u                      /* Timeout has completed */
  52
  53 /*----- Main code ---------------------------------------------------------*/
  54
  55 /* --- @id_done@ --- *
  56  *
  57  * Arguments:   @id *i@ = pointer to identification block
  58  *
  59  * Returns:     ---
  60  *
  61  * Use:         Finishes with an identification block.
  62  */
  63
  64 static void id_done(id *i)
  65 {
  66   /* --- Close down the various dependent bits --- */
  67
  68   if (!(i->state & S_HOST))
  69     bres_abort(&i->r);
  70   if (!(i->state & S_USER))
  71     ident_abort(&i->i);
  72   if (!(i->state & S_TIMER))
  73     sel_rmtimer(&i->t);
  74
  75   /* --- Report the final result --- */
  76
  77   fw_log(i->when, "[%s] %s from %s@%s [%s:%u]",
  78          i->q.desc, i->q.act,
  79          i->user, i->host,
  80          inet_ntoa(i->q.rsin.sin_addr), (unsigned)ntohs(i->q.rsin.sin_port));
  81
  82   /* --- Dispose of the block --- */
  83
  84   REFFD_DEC(i->q.r);
  85   xfree((/*unconst*/ char *)i->q.desc);
  86   xfree(i);
  87 }
  88
  89 /* --- @id_res@ --- *
  90  *
  91  * Arguments:   @struct hostent *h@ = name of the resolved host
  92  *              @void *vp@ = pointer to identification block
  93  *
  94  * Returns:     ---
  95  *
  96  * Use:         Responds to a completed reverse name resolution.
  97  */
  98
  99 static void id_res(struct hostent *h, void *vp)
 100 {
 101   id *i = vp;
 102   if (h)
 103     str_sanitize(i->host, h->h_name, sizeof(i->host));
 104   i->state |= S_HOST;
 105   if (i->state & S_USER)
 106     id_done(i);
 107 }
 108
 109 /* --- @id_ident@ --- *
 110  *
 111  * Arguments:   @ident_reply *i@ = pointer to string read from server
 112  *              @void *vp@ = pointer to identification block
 113  *
 114  * Returns:     ---
 115  *
 116  * Use:         Responds to a line read from the remote RFC931 server.
 117  */
 118
 119 static void id_ident(ident_reply *ir, void *vp)
 120 {
 121   id *i = vp;
 122
 123   /* --- Read the information from the client --- */
 124
 125   if (ir && ir->type == IDENT_USERID)
 126     str_sanitize(i->user, ir->u.userid.user, sizeof(i->user));
 127
 128   /* --- Maybe finish off this identification --- */
 129
 130   i->state |= S_USER;
 131   if (i->state & S_HOST)
 132     id_done(i);
 133 }
 134
 135 /* --- @id_timer@ --- *
 136  *
 137  * Arguments:   @struct timeval *tv@ = pointer to the current time
 138  *              @void *vp@ = pointer to identification block
 139  *
 140  * Returns:     ---
 141  *
 142  * Use:         Times an identification job out.
 143  */
 144
 145 static void id_timer(struct timeval *tv, void *vp)
 146 {
 147   id *i = vp;
 148   i->state |= S_TIMER;
 149   id_done(i);
 150 }
 151
 152 /* --- @identify@ --- *
 153  *
 154  * Arguments:   @const id_req *q@ = pointer to request block
 155  *
 156  * Returns:     ---
 157  *
 158  * Use:         Starts a background ident lookup and reverse-resolve job
 159  *              which will, eventually, report a message to the system log.
 160  */
 161
 162 void identify(const id_req *q)
 163 {
 164   id *i;
 165
 166   /* --- Initialize the block with stuff --- */
 167
 168   i = xmalloc(sizeof(*i));
 169   i->q = *q;
 170   i->q.desc = xstrdup(q->desc);
 171   REFFD_INC(i->q.r);
 172
 173   str_sanitize(i->host, inet_ntoa(q->rsin.sin_addr), sizeof(i->host));
 174   strcpy(i->user, "<ANONYMOUS>");
 175   i->state = 0;
 176   i->when = time(0);
 177
 178   /* --- Set up the connection to the identity server --- */
 179
 180   ident(&i->i, sel, &q->lsin, &q->rsin, id_ident, i);
 181
 182   /* --- Set up the name resolver --- */
 183
 184   bres_byaddr(&i->r, q->rsin.sin_addr, id_res, i);
 185
 186   /* --- Set up the time limiter --- */
 187
 188   {
 189     struct timeval tv;
 190     gettimeofday(&tv, 0);
 191     tv.tv_sec += TIMEOUT;
 192     sel_addtimer(sel, &i->t, &tv, id_timer, i);
 193   }
 194 }
 195
 196 /*----- That's all, folks -------------------------------------------------*/