source/libsmb/unexpected.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    handle unexpected packets
   5    Copyright (C) Andrew Tridgell 2000
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 */
  22
  23 #include "includes.h"
  24
  25 static TDB_CONTEXT *tdbd = NULL;
  26
  27 /* the key type used in the unexpeceted packet database */
  28 struct unexpected_key {
  29         enum packet_type packet_type;
  30         time_t timestamp;
  31         int count;
  32 };
  33
  34
  35
  36 /****************************************************************************
  37  all unexpected packets are passed in here, to be stored in a unexpected
  38  packet database. This allows nmblookup and other tools to receive packets
  39  erroneoously sent to the wrong port by broken MS systems
  40   **************************************************************************/
  41 void unexpected_packet(struct packet_struct *p)
  42 {
  43         static int count;
  44         TDB_DATA kbuf, dbuf;
  45         struct unexpected_key key;
  46         char buf[1024];
  47         int len=0;
  48
  49         if (!tdbd) {
  50                 tdbd = tdb_open_log(lock_path("unexpected.tdb"), 0,
  51                                TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
  52                                O_RDWR | O_CREAT, 0644);
  53                 if (!tdbd) {
  54                         DEBUG(0,("Failed to open unexpected.tdb\n"));
  55                         return;
  56                 }
  57         }
  58
  59         memset(buf,'\0',sizeof(buf));
  60
  61         len = build_packet(buf, p);
  62
  63         key.packet_type = p->packet_type;
  64         key.timestamp = p->timestamp;
  65         key.count = count++;
  66
  67         kbuf.dptr = (char *)&key;
  68         kbuf.dsize = sizeof(key);
  69         dbuf.dptr = buf;
  70         dbuf.dsize = len;
  71
  72         tdb_store(tdbd, kbuf, dbuf, TDB_REPLACE);
  73 }
  74
  75
  76 static time_t lastt;
  77
  78 /****************************************************************************
  79 delete the record if it is too old
  80   **************************************************************************/
  81 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
  82 {
  83         struct unexpected_key key;
  84
  85         memcpy(&key, kbuf.dptr, sizeof(key));
  86
  87         if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
  88                 tdb_delete(ttdb, kbuf);
  89         }
  90
  91         return 0;
  92 }
  93
  94
  95 /****************************************************************************
  96 delete all old unexpected packets
  97   **************************************************************************/
  98 void clear_unexpected(time_t t)
  99 {
 100         if (!tdbd) return;
 101
 102         if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
 103                 return;
 104
 105         lastt = t;
 106
 107         tdb_traverse(tdbd, traverse_fn, NULL);
 108 }
 109
 110
 111 static struct packet_struct *matched_packet;
 112 static int match_id;
 113 static enum packet_type match_type;
 114 static char *match_name;
 115
 116 /****************************************************************************
 117 tdb traversal fn to find a matching 137 packet
 118   **************************************************************************/
 119 static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 120 {
 121         struct unexpected_key key;
 122         struct packet_struct *p;
 123
 124         memcpy(&key, kbuf.dptr, sizeof(key));
 125
 126         if (key.packet_type != match_type) return 0;
 127
 128         p = parse_packet(dbuf.dptr, dbuf.dsize, match_type);
 129
 130         if ((match_type == NMB_PACKET &&
 131              p->packet.nmb.header.name_trn_id == match_id) ||
 132             (match_type == DGRAM_PACKET &&
 133              match_mailslot_name(p, match_name))) {
 134                 matched_packet = p;
 135                 return -1;
 136         }
 137
 138         free_packet(p);
 139
 140         return 0;
 141 }
 142
 143
 144 /****************************************************************************
 145 check for a particular packet in the unexpected packet queue
 146   **************************************************************************/
 147 struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
 148                                          char *mailslot_name)
 149 {
 150         TDB_CONTEXT *tdb2 = NULL;
 151
 152         tdb2 = tdb_open_log(lock_path("unexpected.tdb"), 0, 0, O_RDONLY, 0);
 153         if (!tdb2) return NULL;
 154
 155         matched_packet = NULL;
 156         match_id = id;
 157         match_type = packet_type;
 158         match_name = mailslot_name;
 159
 160         tdb_traverse(tdb2, traverse_match, NULL);
 161
 162         tdb_close(tdb2);
 163
 164         return matched_packet;
 165 }